A microfluidic approach to water-rock interactions using thin rock sections: Pb and U sorption onto thin shale and granite sections.

PubMed

Oh, Youn Soo; Jo, Ho Young; Ryu, Ji-Hun; Kim, Geon-Young

2017-02-15

The feasibility of using microfluidic tests to investigate water-rock (mineral) interactions in fractures regarding sorption onto thin rock sections (i.e., shale and granite) of lead (Pb) and uranium (U) was evaluated using a synthetic PbCl 2 solution and uranium-containing natural groundwater as fluids. Effluent composition and element distribution on the thin rock sections before and after microfluidic testing were analyzed. Most Pb removal (9.8mg/cm 2 ) occurred within 3.5h (140 PVF), which was 74% of the total Pb removal (13.2mg/cm 2 ) at the end of testing (14.5h, 560 PVF). Element composition on the thin shale sections determined by μ-XRF analysis indicated that Pb removal was related primarily to Fe-containing minerals (e.g., pyrite). Two thin granite sections (biotite rich, Bt-R and biotite poor, Bt-P) exhibited no marked difference in uranium removal capacity, but a slightly higher amount of uranium was removed onto the thin Bt-R section (266μg/cm 2 ) than the thin Bt-P section (240μg/cm 2 ) within 120h (4800 PVF). However, uranium could not be detected by micro X-ray fluorescence (μ-XRF) analysis, likely due to the detection limit. These results suggest that microfluidic testing on thin rock sections enables quantitative evaluation of rock (mineral)-water interactions at the micro-fracture or pore scale. Copyright © 2016 Elsevier B.V. All rights reserved.

Scanning electron microscope cathodoluminescence imaging of subgrain boundaries, twins and planar deformation features in quartz

NASA Astrophysics Data System (ADS)

Hamers, M. F.; Pennock, G. M.; Drury, M. R.

2017-04-01

The study of deformation features has been of great importance to determine deformation mechanisms in quartz. Relevant microstructures in both growth and deformation processes include dislocations, subgrains, subgrain boundaries, Brazil and Dauphiné twins and planar deformation features (PDFs). Dislocations and twin boundaries are most commonly imaged using a transmission electron microscope (TEM), because these cannot directly be observed using light microscopy, in contrast to PDFs. Here, we show that red-filtered cathodoluminescence imaging in a scanning electron microscope (SEM) is a useful method to visualise subgrain boundaries, Brazil and Dauphiné twin boundaries. Because standard petrographic thin sections can be studied in the SEM, the observed structures can be directly and easily correlated to light microscopy studies. In contrast to TEM preparation methods, SEM techniques are non-destructive to the area of interest on a petrographic thin section.

Carbonaceous Chondrite Thin Section Preparation

NASA Technical Reports Server (NTRS)

Harrington, R.; Righter, K.

2017-01-01

Carbonaceous chondrite meteorites have long posed a challenge for thin section makers. The variability in sample hardness among the different types, and sometimes within individual sections, creates the need for an adaptable approach at each step of the thin section making process. This poster will share some of the procedural adjustments that have proven to be successful at the NASA JSC Meteorite Thin Section Laboratory. These adjustments are modifications of preparation methods that have been in use for decades and therefore do not require investment in new technology or materials.

Synchrotron X-Ray Diffraction Analysis of Meteorites in Thin Section: Preliminary Results

NASA Technical Reports Server (NTRS)

Treiman, A. H.; Lanzirotti, A.; Xirouchakis, D.

2004-01-01

X-ray diffraction is the pre-eminent technique for mineral identification and structure determination, but is difficult to apply to grains in thin section, the standard meteorite preparation. Bright focused X-ray beams from synchrotrons have been used extensively in mineralogy and have been applied to extraterrestrial particles. The intensity and small spot size achievable in synchrotron X-ray beams makes them useful for study of materials in thin sections. Here, we describe Synchrotron X-ray Diffraction (SXRD) in thin section as done at the National Synchrotron Light Source, and cite examples of its value for studies of meteorites in thin section.

Space Shuttle Stiffener Ring Foam Failure, a Non-Conventional Approach

NASA Technical Reports Server (NTRS)

Howard, Philip M.

2007-01-01

The Space Shuttle makes use of the excellent properties of rigid polyurethane foam for cryogenic tank insulation and as structural protection on the solid rocket boosters. When foam applications debond, classical methods of analysis do not always provide root cause of the failure of the foam. Realizing that foam is the ideal media to document and preserve its own mode of failure, thin sectioning was seen as a logical approach for foam failure analysis. Thin sectioning in two directions, both horizontal and vertical to the application, was chosen to observe the three dimensional morphology of the foam cells. The cell foam morphology provided a much greater understanding of the failure modes than previously achieved.

Quantitation of repaglinide and metabolites in mouse whole-body thin tissue sections using droplet-based liquid microjunction surface sampling-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry.

PubMed

Chen, Weiqi; Wang, Lifei; Van Berkel, Gary J; Kertesz, Vilmos; Gan, Jinping

2016-03-25

Herein, quantitation aspects of a fully automated autosampler/HPLC-MS/MS system applied for unattended droplet-based surface sampling of repaglinide dosed thin tissue sections with subsequent HPLC separation and mass spectrometric analysis of parent drug and various drug metabolites were studied. Major organs (brain, lung, liver, kidney and muscle) from whole-body thin tissue sections and corresponding organ homogenates prepared from repaglinide dosed mice were sampled by surface sampling and by bulk extraction, respectively, and analyzed by HPLC-MS/MS. A semi-quantitative agreement between data obtained by surface sampling and that by employing organ homogenate extraction was observed. Drug concentrations obtained by the two methods followed the same patterns for post-dose time points (0.25, 0.5, 1 and 2 h). Drug amounts determined in the specific tissues was typically higher when analyzing extracts from the organ homogenates. In addition, relative comparison of the levels of individual metabolites between the two analytical methods also revealed good semi-quantitative agreement. Copyright © 2015 Elsevier B.V. All rights reserved.

Quantitation of repaglinide and metabolites in mouse whole-body thin tissue sections using droplet-based liquid microjunction surface sampling-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

DOE PAGES

Chen, Weiqi; Wang, Lifei; Van Berkel, Gary J.; ...

2015-11-03

Herein, quantitation aspects of a fully automated autosampler/HPLC-MS/MS system applied for unattended droplet-based surface sampling of repaglinide dosed thin tissue sections with subsequent HPLC separation and mass spectrometric analysis of parent drug and various drug metabolites was studied. Major organs (brain, lung, liver, kidney, muscle) from whole-body thin tissue sections and corresponding organ homogenates prepared from repaglinide dosed mice were sampled by surface sampling and by bulk extraction, respectively, and analyzed by HPLC-MS/MS. A semi-quantitative agreement between data obtained by surface sampling and that by employing organ homogenate extraction was observed. Drug concentrations obtained by the two methods followed themore » same patterns for post-dose time points (0.25, 0.5, 1 and 2 h). Drug amounts determined in the specific tissues was typically higher when analyzing extracts from the organ homogenates. Furthermore, relative comparison of the levels of individual metabolites between the two analytical methods also revealed good semi-quantitative agreement.« less

Quantitation of repaglinide and metabolites in mouse whole-body thin tissue sections using droplet-based liquid microjunction surface sampling-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

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

Chen, Weiqi; Wang, Lifei; Van Berkel, Gary J.

Herein, quantitation aspects of a fully automated autosampler/HPLC-MS/MS system applied for unattended droplet-based surface sampling of repaglinide dosed thin tissue sections with subsequent HPLC separation and mass spectrometric analysis of parent drug and various drug metabolites was studied. Major organs (brain, lung, liver, kidney, muscle) from whole-body thin tissue sections and corresponding organ homogenates prepared from repaglinide dosed mice were sampled by surface sampling and by bulk extraction, respectively, and analyzed by HPLC-MS/MS. A semi-quantitative agreement between data obtained by surface sampling and that by employing organ homogenate extraction was observed. Drug concentrations obtained by the two methods followed themore » same patterns for post-dose time points (0.25, 0.5, 1 and 2 h). Drug amounts determined in the specific tissues was typically higher when analyzing extracts from the organ homogenates. Furthermore, relative comparison of the levels of individual metabolites between the two analytical methods also revealed good semi-quantitative agreement.« less

Towards crack-free ablation cutting of thin glass sheets with picosecond pulsed lasers

NASA Astrophysics Data System (ADS)

Sun, Mingying; Eppelt, Urs; Hartmann, Claudia; Schulz, Wolfgang; Zhu, Jianqiang; Lin, Zunqi

2017-08-01

We investigated the morphology and mechanism of laser-induced damage in the ablation cutting of thin glass sheets with picosecond laser. Two kinds of damage morphologies observed on the cross-section of the cut channel, are caused by high-density free-electrons and the temperature accumulation, respectively. Notches and micro-cracks can be observed on the top surface of the sample near the cut edge. The surface micro-cracks were related to high energy free-electrons and also the heat-affected zone. Heat-affected-zone and visible-cracks free conditions of glass cutting were achieved by controlling the repetition rate and spatial overlap of laser pulses.

Benefit of computer-aided detection analysis for the detection of subsolid and solid lung nodules on thin- and thick-section CT.

PubMed

Godoy, Myrna C B; Kim, Tae Jung; White, Charles S; Bogoni, Luca; de Groot, Patricia; Florin, Charles; Obuchowski, Nancy; Babb, James S; Salganicoff, Marcos; Naidich, David P; Anand, Vikram; Park, Sangmin; Vlahos, Ioannis; Ko, Jane P

2013-01-01

The objective of our study was to evaluate the impact of computer-aided detection (CAD) on the identification of subsolid and solid lung nodules on thin- and thick-section CT. For 46 chest CT examinations with ground-glass opacity (GGO) nodules, CAD marks computed using thin data were evaluated in two phases. First, four chest radiologists reviewed thin sections (reader(thin)) for nodules and subsequently CAD marks (reader(thin) + CAD(thin)). After 4 months, the same cases were reviewed on thick sections (reader(thick)) and subsequently with CAD marks (reader(thick) + CAD(thick)). Sensitivities were evaluated. Additionally, reader(thick) sensitivity with assessment of CAD marks on thin sections was estimated (reader(thick) + CAD(thin)). For 155 nodules (mean, 5.5 mm; range, 4.0-27.5 mm)-74 solid nodules, 22 part-solid (part-solid nodules), and 59 GGO nodules-CAD stand-alone sensitivity was 80%, 95%, and 71%, respectively, with three false-positives on average (0-12) per CT study. Reader(thin) + CAD(thin) sensitivities were higher than reader(thin) for solid nodules (82% vs 57%, p < 0.001), part-solid nodules (97% vs 81%, p = 0.0027), and GGO nodules (82% vs 69%, p < 0.001) for all readers (p < 0.001). Respective sensitivities for reader(thick), reader(thick) + CAD(thick), reader(thick) + CAD(thin) were 40%, 58% (p < 0.001), and 77% (p < 0.001) for solid nodules; 72%, 73% (p = 0.322), and 94% (p < 0.001) for part-solid nodules; and 53%, 58% (p = 0.008), and 79% (p < 0.001) for GGO nodules. For reader(thin), false-positives increased from 0.64 per case to 0.90 with CAD(thin) (p < 0.001) but not for reader(thick); false-positive rates were 1.17, 1.19, and 1.26 per case for reader(thick), reader(thick) + CAD(thick), and reader(thick) + CAD(thin), respectively. Detection of GGO nodules and solid nodules is significantly improved with CAD. When interpretation is performed on thick sections, the benefit is greater when CAD marks are reviewed on thin rather than thick sections.

Insights into the Timing, Origin, and Deformation of the Highland Mountains Gneiss Dome in Southwestern Montana, USA

NASA Astrophysics Data System (ADS)

Boyer, Lane Markes

The Highland Mountains of southwestern Montana offer a unique view of the Archean igneous and metamorphic rocks within the Great Falls tectonic zone (GFTZ). A Paleoproterozoic structural gneiss dome has been interpreted in the southern extent of the Highland Mountains. The ˜ 130km2 of exhumed metamorphic rocks and gneiss dome exposed in the Highland Mountains are the primary focus of this research. The formation of the Highland Mountains gneiss dome is proposed to be directly related to a northwest-side down detachment (the Steels Pass shear zone) that formed during terrane collision along the GFTZ. The field investigation determined foliation and lineation orientation measurements taken at 65 stations. Twenty-two field oriented samples were obtained from a variety of rock types distributed across the ˜ 24 km2 field area. Three field-based domains were established from the lithology, foliation, and lineation observations. Full-section X-ray maps of three sample thin-sections were collected via EPMA to identify all monazite grains. Twenty-eight grains were mapped at high-spatial resolution (0.3--6.0 mum). Thin section micro-structures observed show effects of a multistage deformation history with both dynamic and static recrystallization processes. Monazite geochronology of one thin section revealed two distinct populations of monazite grains; Archean (˜ 2.5 Ga) and Mesoproterozoic (˜ 1.5 Ga). The older population represents the crystallization age of either, or both the Medicine Hat block and the Wyoming province terranes. The younger population is hypothesized to have grown during deformation/alteration associated with the formation of the Belt-Purcell Rift Basin.

Micromorphological investigations of the Late Quaternary loess-paleosol sequences of the Kashmir Valley, India

NASA Astrophysics Data System (ADS)

Dar, Reyaz Ahmad; Chandra, Rakesh; Romshoo, Shakil Ahmad; Kowser, Nazia

2015-11-01

The loess-paleosol sequences of the Karewa Group preserve a valuable repository of the Late Quaternary climatic changes and the landscape evolution history of the Karewa Basin of Kashmir Valley in their lithological and pedogenic records. Three representative loess-paleosol sections at Shankerpora (SP), Khan Sahib (KS) and Pattan (PT) localities were chosen for detailed lithostratigraphic fieldwork and micromorphological observations of thin sections. Lithostratigraphic analysis revealed lateral and vertical variation in thickness and number of paleosol profiles from south-west to north-west of the Karewa Basin suggesting the availability of land-surface for periodic loess deposition. The SP section is marked by 6 (SP-S6, S7, S8, S9, S10, S12), KS section by 3 (KS-S2, S4, S5) and PT section by 2 (PT-S1, S3) thick mature paleosol profiles. Theses paleosols have well developed 'Ah' and 'Btk' horizons representing prolonged land-surface stability when pedogenic processes outpace loess deposition. On the other hand comparatively thin to thick paleosol profiles represent weak to moderate pedogenic maturity indicating short stratigraphic breaks with rapid loess deposition. Micromorphological observations of thin sections suggested that clay illuviation and CaCO3 accumulation have operated within the paleosol profiles. CaCO3 features are often associated with clay coatings suggesting decalcification of carbonates followed by clay illuviation. Pedogenic CaCO3 probably resulted from the precipitation of the soil solution near the average depth of wetting front. The pedogenic CaCO3, illuvial clay, mottles, iron manganese features, pedal microstructure and blocky aggregates reveal variation in the pedogenic maturity among and within the loess-paleosol sections. The morphological (both micro- and macro-morphological) attributes of loess-paleosols suggest variation of climatic conditions during the Late Quaternary period in the Karewa Basin of Kashmir Valley, India.

Liquid microjunction surface sampling coupled with high-pressure liquid chromatography-electrospray ionization-mass spectrometry for analysis of drugs and metabolites in whole-body thin tissue sections.

PubMed

Kertesz, Vilmos; Van Berkel, Gary J

2010-07-15

In this work, a commercially available autosampler was adapted to perform direct liquid microjunction (LMJ) surface sampling followed by a high-pressure liquid chromatography (HPLC) separation of the extract components and detection with electrospray ionization mass spectrometry (ESI-MS). To illustrate the utility of coupling a separation with this direct liquid extraction based surface sampling approach, four different organs (brain, lung, kidney, and liver) from whole-body thin tissue sections of propranolol dosed and control mice were examined. The parent drug was observed in the chromatograms of the surface sampling extracts from all the organs of the dosed mouse examined. In addition, two isomeric phase II metabolites of propranolol (an aliphatic and an aromatic hydroxypropranolol glucuronide) were observed in the chromatograms of the extracts from lung, kidney, and liver. Confirming the presence of one or the other or both of these glucuronides in the extract from the various organs was not possible without the separation. These drug and metabolite data obtained using the LMJ surface sampling/HPLC-MS method and the results achieved by analyzing similar samples by conventional extraction of the tissues and subsequent HPLC-MS analysis were consistent. The ability to directly and efficiently sample from thin tissue sections via a liquid extraction and then perform a subsequent liquid phase separation increases the utility of this liquid extraction surface sampling approach.

Student Use of Thin Sections in Introductory Geology

ERIC Educational Resources Information Center

O'Brien, Lawrence

1978-01-01

Thin-section photomicrographs are used to introduce the introductory geology laboratory classes to many of the optical properties of minerals. Evaluation by questionnaire suggests that the study of thin sections has a positive effect on the enjoyment and understanding of rock identification and classification by introductory students. (Author/MA)

Publications - GMC 360 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 360 Publication Details Title: Photomicrographs of Petrographic Thin Sections for the Inigok Reference Shell International EP, Inc., 2009, Photomicrographs of Petrographic Thin Sections for the Inigok page for information on ordering data on DVD. Keywords Oil and Gas; Petrographic; Thin Section Top of

Publications - GMC 391 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 391 Publication Details Title: Core descriptions, photographs and thin section photomicro , Inc., 2010, Core descriptions, photographs and thin section photomicro-graphs from the Humble Oil DDH DVD. Keywords Core Drilling; Thin Section Top of Page Department of Natural Resources, Division of

Thin-sectioning and microanalysis of individual extraterrestrial particles

NASA Technical Reports Server (NTRS)

Bradley, J. P.

1986-01-01

A long standing constraint on the study of micrometeorites has centered on difficulties in preparing them for analysis. This is due largely to their small dimensions and consequent practical limitations on sample manipulation. Chondritic micrometeorites provide a good example; although much has been learned about their chemistry and mineralogy almost nothing was known about such basic properties as texture and petrographic associations. The only way to assess such properties is to examine microstructure indigenous to the particles. Unfortunately, almost all micrometeorites, out of necessity, have been crushed and dispersed onto appropriate substances prior to analysis, and most information about texture and petrography was lost. Recently, thin-sections of individual extraterrestrial particles have been prepared using an ultramicrotome equipped with a diamond knife. This procedure has been applied to stratospheric micrometeorites and Solar Max impact debris. In both cases the sections have enabled observation of a variety of internal particle features, including textures, porosity, and petrographic associations. The sectioning procedure is described and analysis results for chondritic micrometeoroids and select particles from Solar Max are presented.

Electronic and optical properties of La-doped S r3I r2O7 epitaxial thin films

NASA Astrophysics Data System (ADS)

Souri, M.; Terzic, J.; Johnson, J. M.; Connell, J. G.; Gruenewald, J. H.; Thompson, J.; Brill, J. W.; Hwang, J.; Cao, G.; Seo, A.

2018-02-01

We have investigated structural, transport, and optical properties of tensile strained (Sr1-xL ax ) 3I r2O7 (x =0 , 0.025, 0.05) epitaxial thin films. While high-Tc superconductivity is predicted theoretically in the system, we have observed that all of the samples remain insulating with finite optical gap energies and Mott variable-range hopping characteristics in transport. Cross-sectional scanning transmission electron microscopy indicates that structural defects such as stacking faults appear in this system. The insulating behavior of the La-doped S r3I r2O7 thin films is presumably due to disorder-induced localization and ineffective electron doping of La, which brings to light the intriguing difference between epitaxial thin films and bulk single crystals of the iridates.

Elastica solution for a nanotube formed by self-adhesion of a folded thin film

NASA Astrophysics Data System (ADS)

Glassmaker, N. J.; Hui, C. Y.

2004-09-01

Schmidt and Eberl demonstrated the construction of tubes with submicron diameters by the method of folding thin solid films [Nature (London) 410, 168 (2001)]. In their method, a thin film is folded 180° and brought into adhesive contact with itself. The resulting sealed loop forms a nanotube with the thickness of the tube walls equal to the thickness of the thin film. The calculation of the diameter of the tube and the shape of its cross section in equilibrium are the subjects of this study. The tube is modeled as a two-dimensional elastica when viewed in cross section, and adhesive behavior is governed by an energy release rate criterion. A numerical technique is used to find elastic equilibria for a large range of material parameters. With these solutions in hand, the problem of designing a nanotube becomes transparent. It is shown that one dimensionless parameter determines the diameter of the nanotube, while another fixes its shape. Each of these parameters is a ratio involving the material's mechanical properties and the film thickness. Before concluding, we verify our model by comparing its results with the experimental observations of Schmidt and Eberl, for their materials.

Berkovich Nanoindentation on AlN Thin Films.

PubMed

Jian, Sheng-Rui; Chen, Guo-Ju; Lin, Ting-Chun

2010-03-31

Berkovich nanoindentation-induced mechanical deformation mechanisms of AlN thin films have been investigated by using atomic force microscopy (AFM) and cross-sectional transmission electron microscopy (XTEM) techniques. AlN thin films are deposited on the metal-organic chemical-vapor deposition (MOCVD) derived Si-doped (2 × 1017 cm-3) GaN template by using the helicon sputtering system. The XTEM samples were prepared by means of focused ion beam (FIB) milling to accurately position the cross-section of the nanoindented area. The hardness and Young's modulus of AlN thin films were measured by a Berkovich nanoindenter operated with the continuous contact stiffness measurements (CSM) option. The obtained values of the hardness and Young's modulus are 22 and 332 GPa, respectively. The XTEM images taken in the vicinity regions just underneath the indenter tip revealed that the multiple "pop-ins" observed in the load-displacement curve during loading are due primarily to the activities of dislocation nucleation and propagation. The absence of discontinuities in the unloading segments of load-displacement curve suggests that no pressure-induced phase transition was involved. Results obtained in this study may also have technological implications for estimating possible mechanical damages induced by the fabrication processes of making the AlN-based devices.

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

NASA Astrophysics Data System (ADS)

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

2008-12-01

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

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

Huntsman, J.R.

Eastern slate belt lithologies in the central Flowers quadrangle consist of metavolcanic and metasedimentary rocks. Very fine-grained quartz-white mica phyllite containing narrow, discontinuous layers of thinly laminated chlorite-rich rock and fine-grained, thinly layered, feldspar crystal felsic metatuff comprise the dominant, mappable units consistent across the quadrangle. An increase in grain size accompanied by a replacement of chlorite-rich lithologies with biotite [+-] garnet assemblages suggest metamorphic grade increases towards the western half of the quadrangle (quartz-muscovite schist and biotite-quartz-muscovite-feldspar gneiss). An early, northeast-trending foliation (050[degree] to 060[degree]) dipping moderately to steeply southeast persists across the quadrangle and is axial planar tomore » tight to isoclinal, recumbent to moderately inclined folds. Later non-coaxial folding produced steeply plunging, northerly trending (000[degree] to 020[degree]), open, asymmetric structures verging towards the east/southeast. Shear zones formed locally along the axial trend of these later folds and produced protomylonitic to mylonitic ( ) fabrics. Map patterns and cross-sectional interpretations are best explained by modification of zig-zag fold interference patterns. Thin section examination reveals garnets growing across the early axial planar foliation. The observed increase in metamorphic grade across the quadrangle matches the regional Alleghanian prograde event and constrains relative timing of observed deformational fabrics. Noticeably absent are regional, late-stage upright folds.« less

Estimating pore and cement volumes in thin section

USGS Publications Warehouse

Halley, R.B.

1978-01-01

Point count estimates of pore, grain and cement volumes from thin sections are inaccurate, often by more than 100 percent, even though they may be surprisingly precise (reproducibility + or - 3 percent). Errors are produced by: 1) inclusion of submicroscopic pore space within solid volume and 2) edge effects caused by grain curvature within a 30-micron thick thin section. Submicroscopic porosity may be measured by various physical tests or may be visually estimated from scanning electron micrographs. Edge error takes the form of an envelope around grains and increases with decreasing grain size and sorting, increasing grain irregularity and tighter grain packing. Cements are greatly involved in edge error because of their position at grain peripheries and their generally small grain size. Edge error is minimized by methods which reduce the thickness of the sample viewed during point counting. Methods which effectively reduce thickness include use of ultra-thin thin sections or acetate peels, point counting in reflected light, or carefully focusing and counting on the upper surface of the thin section.

Semi-thin sections of epoxy resin-embedded mouse embryos in morphological analysis of whole mount in situ RNA hybridization.

PubMed

Mitrecić, D; Cunko, V F; Gajović, S

2008-12-01

Descriptive morphological studies are often combined with gene expression pattern analyses. Unembedded vibratome or cryotome sections are compatible with in situ RNA hybridization, but spatial resolution is rather low for precise microscopic studies necessary in embryology. Therefore, use of plastic embedding media, which allow semi-thin and ultra-thin sectioning for light and electron microscopy, could be an important advantage. This work suggested a new approach based on the whole mount hybridization of mouse embryos and subsequent epoxy resin embedding. Epoxy resin allowed serial sectioning of semi-thin sections with preserved in situ RNA hybridization signal, which was a necessary prerequisite for precise morphological analysis of embryo development.

Recovering 3D Particle Size Distributions from 2D Sections

NASA Technical Reports Server (NTRS)

Cuzzi, Jeffrey N.; Olson, Daniel A.

2017-01-01

We discuss different ways to convert observed, apparent particle size distributions from 2D sections (thin sections, SEM maps on planar surfaces, etc.) into true 3D particle size distributions. We give a simple, flexible and practical method to do this, show which of these techniques gives the most faithful conversions, and provide (online) short computer codes to calculate both 2D- 3D recoveries and simulations of 2D observations by random sectioning. The most important systematic bias of 2D sectioning, from the standpoint of most chondrite studies, is an overestimate of the abundance of the larger particles. We show that fairly good recoveries can be achieved from observed size distributions containing 100-300 individual measurements of apparent particle diameter. Proper determination of particle size distributions in chondrites - for chondrules, CAIs, and metalgrains - is of basic importance for assessing the processes of formation and/or of accretion of theseparticles into their parent bodies. To date, most information of this sort is gathered from 2D samplescut from a rock such as in microscopic analysis of thin sections, or SEM maps of planar surfaces(Dodd 1976, Hughes 1978a,b; Rubin and Keil 1984, Rubin and Grossman 1987, Grossman et al1988, Rubin 1989, Metzler et al 1992, Kuebler et al 1999, Nelson and Rubin 2002, Schneider et al 2003, Hezel et al 2008; Fisher et al 2014; for an exhaustive review with numerous references seeFriedrich et al 2014). While qualitative discrimination between chondrite types can readily be doneusing data of this sort, any deeper exploration of the processes by which chondrite constituents werecreated or emplaced into their parent requires a more quantitative approach.

Resonant Raman spectra of diindenoperylene thin films

NASA Astrophysics Data System (ADS)

Scholz, R.; Gisslén, L.; Schuster, B.-E.; Casu, M. B.; Chassé, T.; Heinemeyer, U.; Schreiber, F.

2011-01-01

Resonant and preresonant Raman spectra obtained on diindenoperylene (DIP) thin films are interpreted with calculations of the deformation of a relaxed excited molecule with density functional theory (DFT). The comparison of excited state geometries based on time-dependent DFT or on a constrained DFT scheme with observed absorption spectra of dissolved DIP reveals that the deformation pattern deduced from constrained DFT is more reliable. Most observed Raman peaks can be assigned to calculated A_g-symmetric breathing modes of DIP or their combinations. As the position of one of the laser lines used falls into a highly structured absorption band, we have carefully analyzed the Raman excitation profile arising from the frequency dependence of the dielectric tensor. This procedure gives Raman cross sections in good agreement with the observed relative intensities, both in the fully resonant and in the preresonant case.

Resonant Raman spectra of diindenoperylene thin films.

PubMed

Scholz, R; Gisslén, L; Schuster, B-E; Casu, M B; Chassé, T; Heinemeyer, U; Schreiber, F

2011-01-07

Resonant and preresonant Raman spectra obtained on diindenoperylene (DIP) thin films are interpreted with calculations of the deformation of a relaxed excited molecule with density functional theory (DFT). The comparison of excited state geometries based on time-dependent DFT or on a constrained DFT scheme with observed absorption spectra of dissolved DIP reveals that the deformation pattern deduced from constrained DFT is more reliable. Most observed Raman peaks can be assigned to calculated A(g)-symmetric breathing modes of DIP or their combinations. As the position of one of the laser lines used falls into a highly structured absorption band, we have carefully analyzed the Raman excitation profile arising from the frequency dependence of the dielectric tensor. This procedure gives Raman cross sections in good agreement with the observed relative intensities, both in the fully resonant and in the preresonant case.

Fast Industrial Inspection of Optical Thin Film Using Optical Coherence Tomography

PubMed Central

Shirazi, Muhammad Faizan; Park, Kibeom; Wijesinghe, Ruchire Eranga; Jeong, Hyosang; Han, Sangyeob; Kim, Pilun; Jeon, Mansik; Kim, Jeehyun

2016-01-01

An application of spectral domain optical coherence tomography (SD-OCT) was demonstrated for a fast industrial inspection of an optical thin film panel. An optical thin film sample similar to a liquid crystal display (LCD) panel was examined. Two identical SD-OCT systems were utilized for parallel scanning of a complete sample in half time. Dual OCT inspection heads were utilized for transverse (fast) scanning, while a stable linear motorized translational stage was used for lateral (slow) scanning. The cross-sectional and volumetric images of an optical thin film sample were acquired to detect the defects in glass and other layers that are difficult to observe using visual inspection methods. The rapid inspection enabled by this setup led to the early detection of product defects on the manufacturing line, resulting in a significant improvement in the quality assurance of industrial products. PMID:27690043

An in vitro method for rapid regeneration of a monopodial orchid hybrid Aranda Deborah using thin section culture.

PubMed

Lakshmanan, P; Loh, C S; Goh, C J

1995-05-01

A thin section culture system for rapid regeneration of the monopodial orchid hybrid Aranda Deborah has been developed. Thin sections (0.6-0.7mm thick) obtained by transverse sectioning of a single shoot tip (6-7mm), when cultured in Vacin and Went medium enriched with coconut water (20% v/v), produced an average 13.6 protocorm-like bodies (PLB) after 45 days, compared to 2.7 PLB formed by a single 6-7 mm long shoot tip under same culture condition. Addition of α-naphthaleneacetic acid to Vacin and Went medium enriched with coconut water further increased PLB production by thin sections. PLB developed into plantlets on solid Vacin and Went medium containing 10% (v/v) coconut water and 0.5 g l(-1) activated charcoal. With this procedure, more than 80,000 plantlets could be produced from thin sections obtained from a single shoot tip in a year as compared to nearly 11,000 plantlets produced by the conventional shoot tip method.

Imaging of fullerene-like structures in CNx thin films by electron microscopy; sample preparation artefacts due to ion-beam milling.

PubMed

Czigány, Zs; Neidhardt, J; Brunell, I F; Hultman, L

2003-04-01

The microstructure of CN(x) thin films, deposited by reactive magnetron sputtering, was investigated by transmission electron microscopy (TEM) at 200kV in plan-view and cross-sectional samples. Imaging artefacts arise in high-resolution TEM due to overlap of nm-sized fullerene-like features for specimen thickness above 5nm. The thinnest and apparently artefact-free areas were obtained at the fracture edges of plan-view specimens floated-off from NaCl substrates. Cross-sectional samples were prepared by ion-beam milling at low energy to minimize sample preparation artefacts. The depth of the ion-bombardment-induced surface amorphization was determined by TEM cross sections of ion-milled fullerene-like CN(x) surfaces. The thickness of the damaged surface layer at 5 degrees grazing incidence was 13 and 10nm at 3 and 0.8keV, respectively, which is approximately three times larger than that observed on Si prepared under the same conditions. The shallowest damage depth, observed for 0.25keV, was less than 1nm. Chemical changes due to N loss and graphitization were also observed by X-ray photoelectron spectroscopy. As a consequence of chemical effects, sputtering rates of CN(x) films were similar to that of Si, which enables relatively fast ion-milling procedure compared to carbon compounds. No electron beam damage of fullerene-like CN(x) was observed at 200kV.

First observation of RDEC for gas (N2) targets with F9+

NASA Astrophysics Data System (ADS)

Kumara, P. N. S.; La Mantia, D. S.; Simon, A.; Kayani, A.; Tanis, J. A.

2017-10-01

Radiative double electron capture (RDEC) is a fundamental atomic process predicted to occur in ion-atom collisions. Several attempts were made to show experimental evidence for RDEC after it was introduced theoretically in 1987. The first successful measurements were done for O8+ ions colliding with a thin carbon foil in 2010, followed by measurements for F9+ projectiles incident on carbon. The works reported here are the first observations giving preliminary results for RDEC in collisions of F9+ projectiles with gas (N2) targets. X-rays were observed in the region of interest and an estimation of RDEC cross section was calculated. These cross sections are compared with recent theoretical calculations.

Cement line staining in undecalcified thin sections of cortical bone

NASA Technical Reports Server (NTRS)

Bain, S. D.; Impeduglia, T. M.; Rubin, C. T.

1990-01-01

A technique for demonstrating cement lines in thin, undecalcified, transverse sections of cortical bone has been developed. Cortical bone samples are processed and embedded undecalcified in methyl methacrylate plastic. After sectioning at 3-5 microns, cross-sections are transferred to a glass slide and flattened for 10 min. Sections of cortical bone are stained for 20 sec free-floating in a fresh solution of 1% toluidine blue dissolved in 0.1% formic acid. The section is dehydrated in t-butyl alcohol, cleared in xylene, and mounted with Eukitt's medium. Reversal lines appear as thin, scalloped, dark blue lines against a light blue matrix, whereas bone formation arrest lines are thicker with a smooth contour. With this technique cellular detail, osteoid differentiation, and fluorochrome labels are retained. Results demonstrate the applicability of a one-step staining method for cement lines which will facilitate the assessment of bone remodeling activity in thin sections of undecalcified cortical bone.

Berkovich Nanoindentation on AlN Thin Films

PubMed Central

2010-01-01

Berkovich nanoindentation-induced mechanical deformation mechanisms of AlN thin films have been investigated by using atomic force microscopy (AFM) and cross-sectional transmission electron microscopy (XTEM) techniques. AlN thin films are deposited on the metal-organic chemical-vapor deposition (MOCVD) derived Si-doped (2 × 1017 cm−3) GaN template by using the helicon sputtering system. The XTEM samples were prepared by means of focused ion beam (FIB) milling to accurately position the cross-section of the nanoindented area. The hardness and Young’s modulus of AlN thin films were measured by a Berkovich nanoindenter operated with the continuous contact stiffness measurements (CSM) option. The obtained values of the hardness and Young’s modulus are 22 and 332 GPa, respectively. The XTEM images taken in the vicinity regions just underneath the indenter tip revealed that the multiple “pop-ins” observed in the load–displacement curve during loading are due primarily to the activities of dislocation nucleation and propagation. The absence of discontinuities in the unloading segments of load–displacement curve suggests that no pressure-induced phase transition was involved. Results obtained in this study may also have technological implications for estimating possible mechanical damages induced by the fabrication processes of making the AlN-based devices. PMID:20672096

Nature and origin of mineral coatings on volcanic rocks of the Black Mountain, Stonewall Mountain and Kane Springs wash volcanic centers, southern Nevada

NASA Technical Reports Server (NTRS)

Taranik, James V.; Noble, Donald C.; Hsu, Liang C.; Spatz, David M.

1987-01-01

Mineral coatings, including desert varnish on volcanic rocks of the semi-arid Basin and Range province are composted of amorphous, translucent films of Fe, Mn, Si, and Al rich compounds. Coatings are chiefly thin films that impregnate intergranularly to depths of about 0.1 to 0.3 mm, rarely deeper. Sixteen coating sections and subsurface interiors were probed by SEM; 20 samples were scanned by infrated spectrometry; 10 samples were scanned for visible-near IR spectra; inductin coupling plasma analyses were collected on 34 samples; 2 desert varnish surgaces were investigated by optical density slice imagery; a few XRD analyses were conducted in addition to the 50 reported in the last period; thin section observation continued; and imagery processing focused on classification techniques. In late May, approximately 10 field days were spent at the Stonewall and Black Mountain study sited conducting more detailed mapping and observation base on imagery results and collecting spectra with the Collins Field Spectrometer. Approximately 100 spectral analyses were collected and are currently being processed.

Method for observation of deembedded sections of fish gonad by scanning electron microscopy

NASA Astrophysics Data System (ADS)

Mao, Lian-Ju

2000-09-01

This article reports a method for examining the intracellular structure of fish gonads using a scanning electron microscope(SEM). The specimen preparation procedure is similar to that for transmission electron microscopy wherein samples cut into semi-thin sections are fixed and embedded in plastic. The embedment matrix was removed by solvents. Risen-free specimens could be observed by SEM. The morphology of matured sperms in the gonad was very clear, and the oocyte internal structures appeared in three-dimensional images. Spheroidal nucleoli and yolk vesicles and several bundles of filaments adhered on the nucleoli could be viewed by SEM for the first time.

In-situ observation of equilibrium transitions in Ni films; agglomeration and impurity effects.

PubMed

Thron, Andrew M; Greene, Peter; Liu, Kai; van Benthem, Klaus

2014-02-01

Dewetting of ultra-thin Ni films deposited on SiO2 layers was observed, in cross-section, by in situ scanning transmission electron microscopy. Holes were observed to nucleate by voids which formed at the Ni/SiO2 interface rather than at triple junctions at the free surface of the Ni film. Ni islands were observed to retract, in attempt to reach equilibrium on the SiO2 layer. SiO2 layers with 120 nm thickness were found to limit in situ heating experiments due to poor thermal conductivity of SiO2. The formation of graphite was observed during the agglomeration of ultra-thin Ni films. Graphite was observed to wet both the free surface and the Ni/SiO2 interface of the Ni islands. Cr forms surface oxide layers on the free surface of the SiO2 layer and the Ni islands. Cr does not prevent the dewetting of Ni, however it will likely alter the equilibrium shape of the Ni islands. © 2013 Published by Elsevier B.V.

Evaluating Mesorectal Lymph Nodes in Rectal Cancer Before and After Neoadjuvant Chemoradiation Using Thin-Section T2-Weighted Magnetic Resonance Imaging

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

Koh, Dow-Mu; Chau, Ian; Tait, Diana

2008-06-01

Purpose: To apply thin-section T2-weighted magnetic resoance imaging (MRI) to evaluate the number, size, distribution, and morphology of benign and malignant mesorectal lymph nodes before and after chemoradiation treatment compared with histopathologic findings. Methods and Materials: Twenty-five patients with poor-risk adenocarcinoma of the rectum treated with neoadjuvant chemoradiation were evaluated prospectively. Thin-section T2-weighted MR images obtained before and after chemoradiation treatment were independently reviewed in consensus by 2 expert radiologists to determine the tumor stage, nodal size, nodal distribution, and nodal stage. Total mesorectal excision surgery after chemoradiation allowed MR nodal stage to be compared with histopathology using {kappa} statistics.more » Nodal downstaging was compared using the Chi-square test. Results: Before chemoradiation, 152 mesorectal nodes were visible (mean, 6.2 mm; 100 benign, 52 malignant) and 4 of 52 malignant nodes were in contact with the mesorectal fascia. The nodal staging was 7/25 N0, 10/25 N1, and 7/25 N2. After chemoradiation, only 29 nodes (mean, 4.1 mm; 24 benign, 5 malignant) were visible, and none were in contact with the mesorectal fascia. Nodal downstaging was observed: 20/25 N0 and 5/25 N1 (p < 0.01, Chi-square test). There was good agreement between MRI and pathologic T-staging ({kappa} = 0.64) and N-staging ({kappa} = 0.65) after chemoradiation. Conclusions: Neoadjuvant chemoradiation treatment resulted in a decrease in size and number of malignant- and benign-appearing mesorectal nodes on MRI. Nodal downstaging and nodal regression from the mesorectal fascia were observed after treatment. MRI is a useful tool for assessing nodal response to neoadjuvant treatment.« less

Apollo-11 lunar sample information catalogue

NASA Technical Reports Server (NTRS)

Kramer, F. E. (Compiler); Twedell, D. B. (Compiler); Walton, W. J. A., Jr. (Compiler)

1977-01-01

The Apollo 11 mission is reviewed with emphasis on the collection of lunar samples, their geologic setting, early processing, and preliminary examination. The experience gained during five subsequent missions was applied to obtain physical-chemical data for each sample using photographic and binocular microscope techniques. Topics discussed include: binocular examination procedure; breccia clast dexrriptuons, thin section examinations procedure typical breccia in thin section, typical basalt in thin section, sample histories, and chemical and age data. An index to photographs is included.

Thin-Section Computed Tomography Manifestations During Convalescence and Long-Term Follow-Up of Patients with Severe Acute Respiratory Syndrome (SARS).

PubMed

Wu, Xiaohua; Dong, Dawei; Ma, Daqing

2016-08-08

BACKGROUND SARS is not only an acute disease, but also leads to long-term impaired lung diffusing capacity in some survivors. However, there is a paucity of data regarding long-term CT findings in survivors after SARS. The aim of this study was to assess the changes in lung function and lung thin-section computed tomography (CT) features in patients recovering from severe acute respiratory syndrome (SARS), especially the dynamic changes in ground-glass opacity (GGO). MATERIAL AND METHODS Clinical and radiological data from 11 patients with SARS were collected. The serial follow-up thin-section CTs were evaluated at 3, 6, and 84 months after SARS presentation. The distribution and predominant thin-section CT findings of lesions were evaluated. RESULTS The extent of the lesions on the CT scans of the 11 patients decreased at 6 and 84 months compared to 3 months. The number of segments involved on 84-month follow-up CTs was less than those at 6 months (P<0.05). The predominant thin-section CT manifestation at 84 months (intralobular and interlobular septal thickening) was different than that at 6 months, at which GGO was predominant. CONCLUSIONS During convalescence after SARS, GGO and intralobular and interlobular septal thickening were the main thin-section CT manifestation. Intralobular and interlobular septal thickening predominated over GGO at 84 months.

Methods for making thin layers of crystalline materials

DOEpatents

Lagally, Max G; Paskiewicz, Deborah M; Tanto, Boy

2013-07-23

Methods for making growth templates for the epitaxial growth of compound semiconductors and other materials are provided. The growth templates are thin layers of single-crystalline materials that are themselves grown epitaxially on a substrate that includes a thin layer of sacrificial material. The thin layer of sacrificial material, which creates a coherent strain in the single-crystalline material as it is grown thereon, includes one or more suspended sections and one or more supported sections.

Novel Thin Film Sensor Technology for Turbine Engine Hot Section Components

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Fralick, Gustave C.

2007-01-01

Degradation and damage that develops over time in hot section components can lead to catastrophic failure of the turbine section of aircraft engines. A range of thin film sensor technology has been demonstrated enabling on-component measurement of multiple parameters either individually or in sensor arrays including temperature, strain, heat flux, and flow. Conductive ceramics are beginning to be investigated as new materials for use as thin film sensors in the hot section, leveraging expertise in thin films and high temperature materials. The current challenges are to develop new sensor and insulation materials capable of withstanding the extreme hot section environment, and to develop techniques for applying sensors onto complex high temperature structures for aging studies of hot propulsion materials. The technology research and development ongoing at NASA Glenn Research Center for applications to future aircraft, launch vehicles, space vehicles, and ground systems is outlined.

A study of thin liquid sheet flows

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

1993-01-01

This study was a theoretical and experimental investigation of thin liquid sheet flows in vacuum. A sheet flow created by a narrow slit of width, W, coalesces to a point at a distance, L, as a result of surface tension forces acting at the sheet edges. As the flow coalesces, the fluid accumulates in the sheet edges. The observed triangular shape of the sheet agrees with the calculated triangular result. Experimental results for L/W as a function of Weber number, We, agree with the calculated result, L/W = the sq. root of 8We. The edge cross sectional shape is found to oscillate from elliptic to 'cigar' like to 'peanut' like and then back to elliptic in the flow direction. A theoretical one-dimensional model was developed that yielded only elliptic solutions for the edge cross section. At the points where the elliptic shapes occur, there is agreement between theory and experiment.

Publications - GMC 186 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 186 Publication Details Title: Petrographic thin-section photographs of cuttings (14220'-14250 for more information. Bibliographic Reference Unknown, 1991, Petrographic thin-section photographs of

Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

NASA Technical Reports Server (NTRS)

Miller, James G.

1997-01-01

In this Progress Report, we describe our recent developments of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns for a thin woven composite in an immersion setup. In addition, we compare apparent signal loss measurements of the thin woven composite for phase-sensitive and phase-insensitive detection methods. All images of diffraction patterns have been included on the accompanying CD-ROM in the Adobe(Trademark) Portable Document Format (PDF). Due to the extensive amount of data, however, hardcopies of only a small representative selection of the images are included within the printed report. This Progress Report presents experimental results that support successful implementation of single element as well as one and two-dimensional ultrasonic array technologies for the inspection of textile composite structures. In our previous reports, we have addressed issues regarding beam profiles of ultrasonic pressure fields transmitted through a water reference path and transmitted through a thin woven composite sample path. Furthermore, we presented experimental results of the effect of a thin woven composite on the magnitude of an insonifying ultrasonic pressure field. In addition to the study of ultrasonic beam profiles, we consider issues relevant to the application of single-element, one-dimensional, and two-dimensional array technologies towards probing the mechanical properties of advanced engineering composites and structures. We provide comparisons between phase-sensitive and phase-insensitive detection methods for determination of textile composite structure parameters. We also compare phase-sensitive and phase-insensitive - - ---- ----- apparent signal loss measurements in an effort to study the phenomenon of phase cancellation at the face of a finite-aperture single-element receiver. Furthermore, in this Progress Report we extend our work on ultrasonic beam profile issues through investigation of the phase fronts of the pressure field. In Section H of this Progress Report we briefly describe the experimental arrangement and methods for data acquisition of the ultrasonic diffraction patterns upon transmission through a thin woven composite. Section III details the analysis of the experimental data followed by the experimental results in Section IV. Finally, a discussion of the observations and conclusions is found in Section V.

7 CFR 29.2663 - Thin Leaf (C Group).

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Thin Leaf (C Group). 29.2663 Section 29.2663... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2663 Thin Leaf (C Group). This group consists of leaves that are thin in body. Grades Grade names and specifications C1L Choice Light-brown Thin Leaf. Thin...

7 CFR 29.2663 - Thin Leaf (C Group).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Thin Leaf (C Group). 29.2663 Section 29.2663... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2663 Thin Leaf (C Group). This group consists of leaves that are thin in body. Grades Grade names and specifications C1L Choice Light-brown Thin Leaf. Thin...

7 CFR 29.2663 - Thin Leaf (C Group).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Thin Leaf (C Group). 29.2663 Section 29.2663... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2663 Thin Leaf (C Group). This group consists of leaves that are thin in body. Grades Grade names and specifications C1L Choice Light-brown Thin Leaf. Thin...

7 CFR 29.2663 - Thin Leaf (C Group).

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Thin Leaf (C Group). 29.2663 Section 29.2663... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2663 Thin Leaf (C Group). This group consists of leaves that are thin in body. Grades Grade names and specifications C1L Choice Light-brown Thin Leaf. Thin...

7 CFR 29.2663 - Thin Leaf (C Group).

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Thin Leaf (C Group). 29.2663 Section 29.2663... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2663 Thin Leaf (C Group). This group consists of leaves that are thin in body. Grades Grade names and specifications C1L Choice Light-brown Thin Leaf. Thin...

Preparation methodologies and nano/microstructural evaluation of metal/semiconductor thin films.

PubMed

Chen, Zhiwen; Jiao, Zheng; Wu, Minghong; Shek, Chan-Hung; Wu, C M Lawrence; Lai, Joseph K L

2012-01-01

Metal/semiconductor thin films are a class of unique materials that are widespread technological applications, particularly in the field of microelectronic devices. Assessment strategies of fractal and tures are of fundamental importance in the development of nano/microdevices. This review presents the preparation methodologies and nano/microstructural evaluation of metal/semiconductor thin films including Au/Ge bilayer films and Pd-Ge alloy thin films, which show in the form of fractals and nanocrystals. Firstly, the extended version of Au/Ge thin films for the fractal crystallization of amorphous Ge and the formation of nanocrystals developed with improved micro- and nanostructured features are described in Section 2. Secondly, the nano/microstructural characteristics of Pd/Ge alloy thin films during annealing have been investigated in detail and described in Section 3. Finally, we will draw the conclusions from the present work as shown in Section 4. It is expected that the preparation methodologies developed and the knowledge of nano/microstructural evolution gained in metal/semiconductor thin films, including Au/Ge bilayer films and Pd-Ge alloy thin films, will provide an important fundamental basis underpinning further interdisciplinary research in these fields such as physics, chemistry, materials science, and nanoscience and nanotechnology, leading to promising exciting opportunities for future technological applications involving these thin films.

Liquid Microjunction Surface Sampling Probe Electrospray Mass Spectrometry for Detection of Drugs and Metabolites in Thin Tissue Sections

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

Van Berkel, Gary J; Kertesz, Vilmos; Koeplinger, Kenneth A.

2008-01-01

A self-aspirating, liquid micro-junction surface sampling probe/electrospray emitter mass spectrometry system was demonstrated for use in the direct analysis of spotted and dosed drugs and their metabolites in thin tissue sections. Proof-of-principle sampling and analysis directly from tissue without the need for sample preparation was demonstrated first by raster scanning a region on a section of rat liver onto which reserpine was spotted. The mass spectral signal from selected reaction monitoring was used to develop a chemical image of the spotted drug on the tissue. The probe was also used to selectively spot sample areas of sagittal whole mouse bodymore » tissue sections that had been dosed orally (90 mg/kg) with R,S-sulforaphane 3 hrs prior to sacrifice. Sulforaphane and its glutathione and N-acetyl cysteine conjugates were monitored with selected reaction monitoring and detected in the stomach and various other tissues from the dosed mouse. No signal for these species was observed in the tissue from a control mouse. The same dosed tissue section was used to illustrate the possibility of obtaining a line scan across the whole body section. In total these results illustrate the potential for rapid screening of the distribution of drugs and metabolites in tissue sections with the micro-liquid junction surface sampling probe/electrospray mass spectrometry approach.« less

Publications - GMC 357 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 357 Publication Details Title: Thin Section and Scanning Electron Microscopy summary Laboratories, Inc., 2008, Thin Section and Scanning Electron Microscopy summary photographs from plugs taken

Publications - GMC 339 | Alaska Division of Geological & Geophysical

Science.gov Websites

petrography from petrographic thin sections of core (4759'-4894') Authors: Unknown Publication Date: Feb 2007 thin sections of core (4759'-4894'): Alaska Division of Geological & Geophysical Surveys Geologic

Ultrafast Phase Mapping of Thin-Sections from An Apollo 16 Drive Tube - a New Visualisation of Lunar Regolith

NASA Technical Reports Server (NTRS)

Botha, Pieter; Butcher, Alan R.; Horsch, Hana; Rickman, Doug; Wentworth, Susan J.; Schrader, Christian M.; Stoeser, Doug; Benedictus, Aukje; Gottlieb, Paul; McKay, David

2008-01-01

Polished thin-sections of samples extracted from Apollo drive tubes provide unique insights into the structure of the Moon's regolith at various landing sites. In particular, they allow the mineralogy and texture of the regolith to be studied as a function of depth. Much has been written about such thin-sections based on optical, SEM and EPMA studies, in terms of their essential petrographic features, but there has been little attempt to quantify these aspects from a spatial perspective. In this study, we report the findings of experimental analysis of two thin-sections (64002, 6019, depth range 5.0 - 8.0 cm & 64001, 6031, depth range 50.0 - 53.1 cm), from a single Apollo 16 drive tube using QEMSCAN . A key feature of the method is phase identification by ultrafast energy dispersive x-ray mapping on a pixel-by-pixel basis. By selecting pixel resolutions ranging from 1 - 5 microns, typically 8,500,000 individual measurement points can be collected on a thin-section. The results we present include false colour digital images of both thin-sections. From these images, information such as phase proportions (major, minor and trace phases), particle textures, packing densities, and particle geometries, has been quantified. Parameters such as porosity and average phase density, which are of geomechanical interest, can also be calculated automatically. This study is part of an on-going investigation into spatial variation of lunar regolith and NASA's ISRU Lunar Simulant Development Project.

In Vivo Fiber-Optic Raman Mapping Of Metastases In Mouse Brains

NASA Astrophysics Data System (ADS)

Stelling, A.; Kirsch, M.; Steiner, G.; Krafft, C.; Schackert, G.; Salzer, R.

2010-08-01

Vibrational spectroscopy, in particular Raman spectroscopy, has potential applications in the field of in vivo diagnostics. Raman and FT-IR spectroscopy analyze the complete biochemical information at any given pixel within the visual field. Here we demonstrate the feasibility of performing Raman spectroscopic measurements on living mice brains using a fiber-optic probe with a nominal spatial resolution of 60 μm. The objectives of this study were to 1) evaluate preclinical models, namely murine brain slices containing experimental tumors, 2) optimize the preparation of pristine brain tissue to obtain reference information, to 3) optimize the conditions for introducing a fiber-optic probe to acquire Raman maps in vivo, and 4) to transfer results obtained from human brain tumors to an animal model. Disseminated brain metastases of malignant melanomas were induced by injecting tumor cells into the carotid artery of mice. The procedure mimicked hematogenous tumor spread in one brain hemisphere while the other hemisphere remained tumor free. Three series of sections were prepared consecutively from whole mouse brains: pristine, 2-mm thick sections for Raman mapping and dried, thin sections for FT-IR imaging, hematoxylin and eosin-stained thin sections for histopathological assessment. Raman maps were collected serially using a spectrometer coupled to a fiber-optic probe. FT-IR images were recorded using a spectrometer with a multi-channel detector. The FT-IR images and the Raman maps were evaluated by multivariate data analysis. The results obtained from the thin section studies were employed to guide measurements of murine brains in vivo. Raman maps with an acquisition time of over an hour could be performed on the living animals. No damage to the tissue was observed.

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

Thangadurai, P.; Lumelsky, Yulia; Silverstein, Michael S.

Transmission electron microscopy (TEM) cross-section specimens of PMMA in contact with gold and Si were prepared by focused ion beam (FIB) and compared with plan-view PMMA specimens prepared by a dip-coating technique. The specimens were characterized by TEM and electron energy loss spectroscopy (EELS). In the cross-section specimens, the thin films of PMMA were located in a Si-PMMA-Au multilayer. Different thicknesses of PMMA films were spin-coated on the Si substrates. The thickness of the TEM specimens prepared by FIB was estimated using EELS to be 0.65 of the plasmon mean-free-path. Along the PMMA-Au interface, Au particle diffusion into the PMMAmore » was observed, and the size of the Au particles was in the range of 2-4 nm. Dip-coating of PMMA directly on Cu TEM grids resulted in thin specimens with a granular morphology, with a thickness of 0.58 of the plasmon mean-free-path. The dip-coated specimens were free from ion milling induced artifacts, and thus serve as control specimens for comparison with the cross-sectioned specimens prepared by FIB.« less

Cross section TEM characterization of high-energy-Xe-irradiated U-Mo

DOE PAGES

Ye, B.; Jamison, L.; Miao, Y.; ...

2017-03-09

U-Mo alloys irradiated with 84 MeV Xe ions to various doses were characterized with transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) techniques. The TEM thin foils were prepared perpendicular to the irradiated surface to allow a direct observation of the entire region modified by ions. Furthermore, depth-selective microstructural information was revealed. Varied irradiation-induced phenomena such as gas bubble formation, phase reversal, and recrystallization were observed at different ion penetration depths in U-Mo.

Publications - GMC 399 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 399 Publication Details Title: Thin section photomicrographs and descriptions for the Ikpikpuk Boyer, D., 2012, Thin section photomicrographs and descriptions for the Ikpikpuk #1, Inigok #1, J.W

Wear resistant pavement study.

DOT National Transportation Integrated Search

2009-01-01

This report documents the construction of three special pavement test sections on I-90 east of Spokane, Washington. The test sections included ultra-thin and thin whitetopping, Modified Class D open graded asphalt concrete, and micro/macro surfacing ...

Electron microscopy of the nuclear membrane of Amoeba proteus.

PubMed

FRAJOLA, W J; GREIDER, M H; KOSTIR, W J

1956-07-25

An electron microscope study of the nuclear membrane of Amoeba proteus by thin sectioning techniques has revealed an ultrastructure in the outer layer of the membrane that is homologous to the pores and annuli observed in the nuclear membranes of many other cell types studied by these techniques. An inner honeycombed layer apparently unique to Amoeba proteus is also described.

A petrographic thin sectioning technique for evaluating composite materials

NASA Technical Reports Server (NTRS)

Parker, D. S.; Yee, A. F.

1989-01-01

Petrographic thin sectioning by a low-speed diamond saw has been used in conjunction with transmission polarized light microscopy for the characterization of the microstructure and deformation mechanisms of a variety of polymer systems. It has proven possible by these means to study three types of thermoplastic matrices for composite applications: PEEK, BPA-based polycarbonate (PC), and a rubber-modified PC. The reinforcing fibers for these matrices were in all cases AS4 carbon fibers, unidirectionally arrayed. Superior analyzability of matrix morphology and subsurface fracture processes is achieved by thin sectioning.

Observations on the preparation of sections of dental hard and soft tissues without conventional embedding procedures.

PubMed

Mok, Y C; Fearnhead, R W

1985-09-01

Inexpensive thin copper discs loaded with diamonds embedded in small slits around the periphery, may be used to cut sections from unembedded tooth samples without disrupting the cellular and extracellular components intimately associated with hard tissue interfaces. The tissue may be unfixed, fixed or cut using fixation or dye solutions as the lubricant. The use of these discs therefore opens up new avenues of histochemical investigation of hard tissue unrestricted by those artefacts associated with conventional or traditional methods of preparation.

7 CFR 29.3648 - Thin Leaf (C Group).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Thin Leaf (C Group). 29.3648 Section 29.3648... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.3648 Thin Leaf (C Group). This group consists of leaves... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth...

7 CFR 29.3648 - Thin Leaf (C Group).

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Thin Leaf (C Group). 29.3648 Section 29.3648... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.3648 Thin Leaf (C Group). This group consists of leaves... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth...

7 CFR 29.3648 - Thin Leaf (C Group).

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Thin Leaf (C Group). 29.3648 Section 29.3648... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.3648 Thin Leaf (C Group). This group consists of leaves... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth...

7 CFR 29.3648 - Thin Leaf (C Group).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Thin Leaf (C Group). 29.3648 Section 29.3648... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.3648 Thin Leaf (C Group). This group consists of leaves... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth...

7 CFR 29.3648 - Thin Leaf (C Group).

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Thin Leaf (C Group). 29.3648 Section 29.3648... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.3648 Thin Leaf (C Group). This group consists of leaves... specifications, and tolerances C1L Choice Quality Light-brown Thin Leaf. Ripe, thin, open leaf structure, smooth...

Time Dependence of Tip Morphology during Cellular/Dendritic Arrayed Growth

NASA Technical Reports Server (NTRS)

Song, H.; Tewari, S. N.

1996-01-01

Succinonitrile-1.9 wt pct acetone has been directionally solidified in 0.7 X 0.7-cm-square cross section pyrex ampoules in order to observe the cell/dendrite tip morphologies, not influenced by the 'wall effects', which are present during growth in the generally used thin (about 200 gm) crucibles. The tips do not maintain a steady-state shape, as is generally assumed. Instead, they fluctuate within a shape envelope. The extent of fluctuation increases with decreasing growth speed, as the micro structure changes from the dendritic to cellular. The influence of natural convection has been examined by comparing these morphologies with those grown, without convection, in the thin ampoules.

Focused ion beam and field-emission microscopy of metallic filaments in memory devices based on thin films of an ambipolar organic compound consisting of oxadiazole, carbazole, and fluorene units

USGS Publications Warehouse

Pearson, Christopher; Bowen, Leon; Lee, Myung Won; Fisher, Alison L.; Linton, Katherine E.; Bryce, Martin R.; Petty, Michael C.

2013-01-01

We report on the mechanism of operation of organic thin film resistive memory architectures based on an ambipolar compound consisting of oxadiazole, carbazole, and fluorene units. Cross-sections of the devices have been imaged by electron microscopy both before and after applying a voltage. The micrographs reveal the growth of filaments, with diameters of 50 nm–100 nm, on the metal cathode. We suggest that these are formed by the drift of aluminium ions from the anode and are responsible for the observed switching and negative differential resistance phenomena in the memory devices.

Acquisition of thin coronal sectional dataset of cadaveric liver.

PubMed

Lou, Li; Liu, Shu Wei; Zhao, Zhen Mei; Tang, Yu Chun; Lin, Xiang Tao

2014-04-01

To obtain the thin coronal sectional anatomic dataset of the liver by using digital freezing milling technique. The upper abdomen of one Chinese adult cadaver was selected as the specimen. After CT and MRI examinations verification of absent liver lesions, the specimen was embedded with gelatin in stand erect position and frozen under profound hypothermia, and the specimen was then serially sectioned from anterior to posterior layer by layer with digital milling machine in the freezing chamber. The sequential images were captured by means of a digital camera and the dataset was imported to imaging workstation. The thin serial section of the liver added up to 699 layers with each layer being 0.2 mm in thickness. The shape, location, structure, intrahepatic vessels and adjacent structures of the liver was displayed clearly on each layer of the coronal sectional slice. CT and MR images through the body were obtained at 1.0 and 3.0 mm intervals, respectively. The methodology reported here is an adaptation of the milling methods previously described, which is a new data acquisition method for sectional anatomy. The thin coronal sectional anatomic dataset of the liver obtained by this technique is of high precision and good quality.

A unified viscous theory of lift and drag of 2-D thin airfoils and 3-D thin wings

NASA Technical Reports Server (NTRS)

Yates, John E.

1991-01-01

A unified viscous theory of 2-D thin airfoils and 3-D thin wings is developed with numerical examples. The viscous theory of the load distribution is unique and tends to the classical inviscid result with Kutta condition in the high Reynolds number limit. A new theory of 2-D section induced drag is introduced with specific applications to three cases of interest: (1) constant angle of attack; (2) parabolic camber; and (3) a flapped airfoil. The first case is also extended to a profiled leading edge foil. The well-known drag due to absence of leading edge suction is derived from the viscous theory. It is independent of Reynolds number for zero thickness and varies inversely with the square root of the Reynolds number based on the leading edge radius for profiled sections. The role of turbulence in the section induced drag problem is discussed. A theory of minimum section induced drag is derived and applied. For low Reynolds number the minimum drag load tends to the constant angle of attack solution and for high Reynolds number to an approximation of the parabolic camber solution. The parabolic camber section induced drag is about 4 percent greater than the ideal minimum at high Reynolds number. Two new concepts, the viscous induced drag angle and the viscous induced separation potential are introduced. The separation potential is calculated for three 2-D cases and for a 3-D rectangular wing. The potential is calculated with input from a standard doublet lattice wing code without recourse to any boundary layer calculations. Separation is indicated in regions where it is observed experimentally. The classical induced drag is recovered in the 3-D high Reynolds number limit with an additional contribution that is Reynold number dependent. The 3-D viscous theory of minimum induced drag yields an equation for the optimal spanwise and chordwise load distribution. The design of optimal wing tip planforms and camber distributions is possible with the viscous 3-D wing theory.

INTERNAL LIMITING MEMBRANE PEELING-DEPENDENT RETINAL STRUCTURAL CHANGES AFTER VITRECTOMY IN RHEGMATOGENOUS RETINAL DETACHMENT.

PubMed

Hisatomi, Toshio; Tachibana, Takashi; Notomi, Shoji; Koyanagi, Yoshito; Murakami, Yusuke; Takeda, Atsunobu; Ikeda, Yasuhiro; Yoshida, Shigeo; Enaida, Hiroshi; Murata, Toshinori; Sakamoto, Taiji; Sonoda, Koh-Hei; Ishibashi, Tatsuro

2018-03-01

To examine retinal changes after vitrectomy with internal limiting membrane (ILM) peeling, we used 3-dimensional optical coherence tomography (3D-OCT) in rhegmatogenous retinal detachment cases. The 68 eyes from 67 patients with rhegmatogenous retinal detachment were studied, including 35 detached macula cases (51%) and 33 attached macula cases. Internal limiting membrane peeling was performed with fine forceps after brilliant blue G staining. The 3D-OCT images were obtained with volume-rendering technologies from cross-sectional OCT images. The 3D-OCT detected 45 eyes (66%) with ILM peeling-dependent retinal changes, including dissociated optic nerve fiber layer appearance, dimple sign, temporal macular thinning, ILM peeling area thinning, or forceps-related retinal thinning. The ILM peeled area was detectable in only 9 eyes with 3D-OCT, whereas it was undetectable in other 59 eyes. The dissociated optic nerve fiber layer appearance was detected in 8 of the total cases (12%), and dimple signs were observed in 14 cases (21%). Forceps-related thinning was also noted in eight cases (24%) of attached macula cases and in four cases (11%) of detached macula cases. No postoperative macular pucker was noted in the observational period. The 3D-OCT clearly revealed spatial and time-dependent retinal changes after ILM peeling. The changes occurred in 2 months and remained thereafter.

Thinness in the era of obesity: trends in children and adolescents in The Netherlands since 1980.

PubMed

Schönbeck, Yvonne; van Dommelen, Paula; HiraSing, Remy A; van Buuren, Stef

2015-04-01

Although children both at the upper and lower tail of the body mass index (BMI) distribution are at greater health risk, relatively little is known about the development of thinness prevalence rates in developed countries over time. We studied trends in childhood thinness and assessed changes in the BMI distribution since the onset of the obesity epidemic. Growth data from 54 814 children aged 2-18 years of Dutch, Turkish and Moroccan origin living in The Netherlands were used. Anthropometric measurements were performed during nationwide cross-sectional growth studies in 1980 (only Dutch), 1997 and 2009. Prevalence rates of thinness grades I, II and III were calculated according to international cut-offs. BMI distributions for 1980, 1997 and 2009 were compared. Since 1980, thinness (all grades combined) reduced significantly from 14.0% to 9.8% in children of Dutch origin, but the proportion of extremely thin children (grade III) remained constant. Thinness in children of Moroccan origin decreased significantly from 8.8% to 6.2% between 1997 and 2009. No significant difference was observed in children of Turkish origin (5.4% in 1997 vs. 5.7% in 2009). Thinness occurred most often in children aged 2-5 years. There were no differences between boys and girls. The BMI distribution widened since 1980, mainly due to an upward shift of the upper centiles. Since the onset of the obesity epidemic, prevalence rates of thinness decreased. However, we found a small but persistent group of extremely thin children. More research is needed to gain insight into their health status. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Paleohistology of Susisuchus anatoceps (Crocodylomorpha, Neosuchia): Comments on Growth Strategies and Lifestyle

PubMed Central

Sayão, Juliana M.; Bantim, Renan A. M.; Andrade, Rafael C. L. P.; Lima, Flaviana J.; Saraiva, Antônio A. F.; Figueiredo, Rodrigo G.; Kellner, Alexander W. A.

2016-01-01

Susisuchus anatoceps is a neosuchian crocodylomorph lying outside the clade Eusuchia, and associated with the transition between basal and advanced neosuchians and the rise of early eusuchians. The specimen MPSC R1136 comprises a partially articulated postcranial skeleton and is only the third fossil assigned to this relevant taxon. Thin sections of a right rib and right ulna of this specimen have been cut for histological studies and provide the first paleohistological information of an advanced non-eusuchian neosuchian from South America. The cross-section of the ulna shows a thick cortex with 17 lines of arrested growth (LAGs), a few scattered vascular canals, and primary and secondary osteons. This bone has a free medullary cavity and a spongiosa is completely absent. Thin sections of the rib show that remodeling process was active when the animal died, with a thin cortex and a well-developed spongiosa. In the latter, few secondary osteons and 4 LAGs were identified. According to the observed data, Susisuchus anatoceps had a slow-growing histological microstructure pattern, which is common in crocodylomorphs. The high number of ulnar LAGs and the active remodeling process are indicative that this animal was at least a late subadult, at or past the age of sexual maturity. This contradicts previous studies that interpreted this and other Susisuchus anatoceps specimens as juveniles, and suggests that full-grown adults of this species were relatively small-bodied, comparable in size to modern dwarf crocodiles. PMID:27149108

The effect of energy and momentum transfer during magnetron sputter deposition of yttrium oxide thin films

NASA Astrophysics Data System (ADS)

Xia, Jinjiao; Liang, Wenping; Miao, Qiang; Depla, Diederik

2018-05-01

The influence of the ratio between the energy and the deposition flux, or the energy per arriving atom, on the growth of Y2O3 sputter deposited thin films has been studied. The energy per arriving atom has been varied by the adjustment of the discharge power, and/or the target-to-substrate distance. The relationship between the energy per arriving atom and the phase evolution, grain size, microstructure, packing density and residual stress was investigated in detail. At low energy per arriving atom, the films consist of the monoclinic B phase with a preferential (1 1 1) orientation. A minority cubic C phase appears at higher energy per arriving atom. A study of the thin film cross sections showed for all films straight columns throughout the thickness, typically for a zone II microstructure. The intrinsic stress is compressive, and increases with increasing energy per atom. The same trend is observed for the film density. Simulations show that the momentum transfer per arriving atom also scales with the energy per arriving atom. Hence, the interpretation of the observed trends as a function of the energy per arriving atom must be treated with care.

Some observations on glass-knife making.

PubMed

Ward, R T

1977-11-01

The yield of usable knife edge per knife (for thin sectioning) was markedly increased when glass knives were made at an included angle of 55 degrees rather than the customary 45 degrees. A large number of measurements of edge check marks made with a routine light scattering method as well as observations made on a smaller number of test sections with the electron microscope indicated the superiority of 55 degrees knives. Knives were made with both taped pliers and an LKB Knifemaker. Knives were graded by methods easily applied in any biological electron microscope laboratory. Depending on the mode of fracture, the yield of knives having more than 33% of their edges free of check marks was 30 to 100 times greater at 55 degrees than 45 degrees.

Internal Membrane Control in Azotobacter vinelandii

PubMed Central

Pate, Jack L.; Shah, Vinod K.; Brill, Winston J.

1973-01-01

Azotobacter vinelandii was grown on N2, NH4+, or NO3−, and an internal membrane network was observed by electron microscopy of thin sections of cells. Cells obtained in early exponential growth contained less internal membrane than did cells from cultures in late exponential growth. It seems likely that O2 has a role in regulating the amount of internal membrane structure. Images PMID:4123239

Cometary particles - Thin sectioning and electron beam analysis

NASA Technical Reports Server (NTRS)

Bradley, J. P.; Brownlee, D. E.

1986-01-01

Thin sections (500 to 1000 angstroms thick) of individual micrometeorites (5 to 15 micrometers) have been prepared with an ultramicrotome equipped with a diamond knife. Electron microscope examination of these sections has revealed the internal structures of chondritic micrometeorites, and a subset of highly porous, fragile particles has been identified. Delicate meteoritic materials such as these are characteristic of debris from cometary meteors.

Structure and Assembly of Intracellular Mature Vaccinia Virus: Thin-Section Analyses

PubMed Central

Griffiths, Gareth; Roos, Norbert; Schleich, Sybille; Locker, Jacomine Krijnse

2001-01-01

In the preceding study (see accompanying paper), we showed by a variety of different techniques that intracellular mature vaccinia virus (vaccinia IMV) is unexpectedly complex in its structural organization and that this complexity also extends to the underlying viral core, which is highly folded. With that analysis as a foundation, we now present different thin-section electron microscopy approaches for analyzing the IMV and the processes by which it is assembled in infected HeLa cells. We focus on conventional epoxy resin thin sections as well as cryosections to describe key intermediates in the assembly process. We took advantage of streptolysin O's ability to selectively permeabilize the plasma membrane of infected cells to improve membrane contrast, and we used antibodies against bone fide integral membrane proteins of the virus to unequivocally identify membrane profiles in thin sections. All of the images presented here can be rationalized with respect to the model put forward for the assembly of the IMV in the accompanying paper. PMID:11602745

Reduced Dimensionality Lithium Niobate Microsystems

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

Eichenfield, Matt

2017-01-01

The following report describes work performed under the LDRD program at Sandia National Laboratories October 2014 and September 2016. The work presented demonstrates the ability of Sandia Labs to develop state-of-the-art photonic devices based on thin film lithium niobate (LiNbO 3 ). Section 1 provides an introduction to integrated LiNbO 3 devices and motivation for developing thin film nonlinear optical systems. Section 2 describes the design, fabrication, and photonic performance of thin film optical microdisks fabricated from bulk LiNbO 3 using a bulk implantation method developed at Sandia. Sections 3 and 4 describe the development of similar thin film LiNbOmore » 3 structures fabricated from LiNbO 3 on insulator (LNOI) substrates and our demonstration of optical frequency conversion with state-of-the-art efficiency. Finally, Section 5 describes similar microdisk resonators fabricated from LNOI wafers with a buried metal layer, in which we demonstrate electro-optic modulation.« less

Thin Film Ceramic Strain Sensor Development for High Temperature Environments

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Fralick, Gustave C.; Gonzalez, Jose M.; Laster, Kimala L.

2008-01-01

The need for sensors to operate in harsh environments is illustrated by the need for measurements in the turbine engine hot section. The degradation and damage that develops over time in hot section components can lead to catastrophic failure. At present, the degradation processes that occur in the harsh hot section environment are poorly characterized, which hinders development of more durable components, and since it is so difficult to model turbine blade temperatures, strains, etc, actual measurements are needed. The need to consider ceramic sensing elements is brought about by the temperature limits of metal thin film sensors in harsh environments. The effort at the NASA Glenn Research Center (GRC) to develop high temperature thin film ceramic static strain gauges for application in turbine engines is described, first in the fan and compressor modules, and then in the hot section. The near-term goal of this research effort was to identify candidate thin film ceramic sensor materials and provide a list of possible thin film ceramic sensor materials and corresponding properties to test for viability. A thorough literature search was conducted for ceramics that have the potential for application as high temperature thin film strain gauges chemically and physically compatible with the NASA GRCs microfabrication procedures and substrate materials. Test results are given for tantalum, titanium and zirconium-based nitride and oxynitride ceramic films.

Geophysical Modelling and Multi-Scale Studies in the Arctic Seiland Igneous Province: Millimeter to Micrometer Scale Mapping of the Magnetic Sources by High Resolution Magnetic Microscopy

NASA Astrophysics Data System (ADS)

Pastore, Z.; Church, N. S.; McEnroe, S. A.; Oda, H.; ter Maat, G. W.

2017-12-01

Rocks samples can have wide range of magnetic properties depending on composition, amount of ferromagnetic minerals, grain sizes and microstructures. These influence the magnetic anomalies from the micro to the global scale making the study of the magnetic properties of interest for multiple applications. Later geological processes such as serpentinization can significantly influence these properties and change the nature of the magnetic anomalies. Particularly, magnetic properties such as remanent magnetization and magnetic susceptibility are directly linked to the magnetic mineralogy composition and grain size and can provide useful information about the geological history of the source. Scanning magnetic microscopy is a highly sensitive and high-resolution magnetometric technique for mapping the magnetic field over a planar surface of a rock sample. The device measures the vertical component of the field above the thin sections and the technique offers a spatial resolution down to tens of micrometers and thus can be used to investigate discrete magnetic mineral grains or magnetic textures and structures, and the magnetic history of the sample. This technique allows a direct correlation between the mineral chemistry (through both electron and optical microscopy) and the magnetic properties. We present as case-study three thin section magnetic scans of two dunite samples from the Reinfjord Ultramafic complex, in northern Norway. The selected thin sections show different magnetic properties which reflect the magnetic petrology. One of the thin sections is from a pristine dunite sample; the other two are highly serpentinized with newly formed magnetite found in multiple, few micrometer thick, veins. We present the preliminary results obtained applying a forward modelling approach on the magnetic anomaly maps acquired over the thin sections. Modelling consists of uniformly-magnetized polygonal bodies whose geometry is constrained by the thickness of the thin section and by the shape of the magnetic grains. The NRM direction in each polygon is modelled to fit the NRM magnetic field. Modelling helps in determining the NRM directions and intensities of discrete magnetic sources inside the thin sections and thus contributes to the study of the link between the magnetic petrology and the magnetic anomalies.

One-dimensional analysis of filamentary composite beam columns with thin-walled open sections

NASA Technical Reports Server (NTRS)

Lo, Patrick K.-L.; Johnson, Eric R.

1986-01-01

Vlasov's one-dimensional structural theory for thin-walled open section bars was originally developed and used for metallic elements. The theory was recently extended to laminated bars fabricated from advanced composite materials. The purpose of this research is to provide a study and assessment of the extended theory. The focus is on flexural and torsional-flexural buckling of thin-walled, open section, laminated composite columns. Buckling loads are computed from the theory using a linear bifurcation analysis and a geometrically nonlinear beam column analysis by the finite element method. Results from the analyses are compared to available test data.

Atomic structures of B20 FeGe thin films grown on the Si(111) surface

NASA Astrophysics Data System (ADS)

Kim, Wondong; Noh, Seungkyun; Yoon, Jisoo; Kim, Young Heon; Lee, Inho; Kim, Jae-Sung; Hwang, Chanyong

We investigated the growth and atomic structures of FeGe thin films on the Si (111) surface by using scanning tunneling microscopy (STM) and transmission electron microscopy (TEM). The 2 5nm- thick FeGe thin films were prepared on the clean Si(111) 7x7 surface by co-deposition of Fe and Ge from separated electron-beam evaporators. With direct deposition on the substrate at the temperature above 550 K, the surface of FeGe films was not smooth and consisted of coarse grains. By the combination of room-temperature annealing and post-annealing process around 800 K, the structure of FeGe thin films evolved into the well crystalized structures. Atom-resolved STM images revealed that there are at least four different surface terminations. We constructed atomic models for each surface terminations based on the bulk atomic arrangement of a B20 chiral structure and confirmed that the observed STM images are successfully reproduced by using computational simulations employing Vienna Ab Initio Simulation package (VASP) with a B20 chiral structure model. TEM cross-sectional images also support our atomic models by revealing clearly the characteristic zigzag features of B20 structures of FeGe(111) thin films.

Calculation of Centrally Loaded Thin-Walled Columns Above the Buckling Limit

NASA Technical Reports Server (NTRS)

Reinitzhuber, F.

1945-01-01

When thin-walled columns formed from flanged sheet, such as used in airplane construction, are subjected to axial load, their behavior at failure varies according to the slenderness ratio. On long columns the axis deflects laterally while the cross section form is maintained; buckling results. The respective breaking load in the elastic range is computed by Euler's formula and for the plastic range by the Engesser- Karman formula. Its magnitude is essentially dependent upon the length. On intermediate length columns, especially where open sections are concerned, the cross section is distorted while the cross section form is preserved; twisting failure results. The buckling load in twisting is calculated according to Wagner and Kappus. On short columns the straight walls of low-bending resistance that form the column are deflected at the same time that the cross section form changes - buckling occurs without immediate failure. Then the buckling load of the total section computable from the buckling loads of the section walls is not the ultimate load; quite often, especially on thin-walled sections, it lies considerably higher and is secured by tests. Both loads, the buckling and the ultimate load are only in a small measure dependent upon length. The present report is an attempt to theoretically investigate the behavior of such short, thin-walled columns above the buckling load with the conventional calculating methods.

Radiation and scattering by thin-wire structures in the complex frequency domain. [electromagnetic theory for thin-wire antennas

NASA Technical Reports Server (NTRS)

Richmond, J. H.

1974-01-01

Piecewise-sinusoidal expansion functions and Galerkin's method are employed to formulate a solution for an arbitrary thin-wire configuration in a homogeneous conducting medium. The analysis is performed in the real or complex frequency domain. In antenna problems, the solution determines the current distribution, impedance, radiation efficiency, gain and far-field patterns. In scattering problems, the solution determines the absorption cross section, scattering cross section and the polarization scattering matrix. The electromagnetic theory is presented for thin wires and the forward-scattering theorem is developed for an arbitrary target in a homogeneous conducting medium.

Synchrotron imaging reveals bone healing and remodelling strategies in extinct and extant vertebrates

PubMed Central

Anné, Jennifer; Edwards, Nicholas P.; Wogelius, Roy A.; Tumarkin-Deratzian, Allison R.; Sellers, William I.; van Veelen, Arjen; Bergmann, Uwe; Sokaras, Dimosthenis; Alonso-Mori, Roberto; Ignatyev, Konstantin; Egerton, Victoria M.; Manning, Phillip L.

2014-01-01

Current understanding of bone healing and remodelling strategies in vertebrates has traditionally relied on morphological observations through the histological analysis of thin sections. However, chemical analysis may also be used in such interpretations, as different elements are known to be absorbed and used by bone for different physiological purposes such as growth and healing. These chemical signatures are beyond the detection limit of most laboratory-based analytical techniques (e.g. scanning electron microscopy). However, synchrotron rapid scanning–X-ray fluorescence (SRS–XRF) is an elemental mapping technique that uniquely combines high sensitivity (ppm), excellent sample resolution (20–100 µm) and the ability to scan large specimens (decimetre scale) approximately 3000 times faster than other mapping techniques. Here, we use SRS–XRF combined with microfocus elemental mapping (2–20 µm) to determine the distribution and concentration of trace elements within pathological and normal bone of both extant and extinct archosaurs (Cathartes aura and Allosaurus fragilis). Results reveal discrete chemical inventories within different bone tissue types and preservation modes. Chemical inventories also revealed detail of histological features not observable in thin section, including fine structures within the interface between pathological and normal bone as well as woven texture within pathological tissue. PMID:24806709

Liquid Microjunction Surface Sampling Coupled with High-Pressure Liquid Chromatography-Electrospray Ionization-Mass Spectrometry for Analysis of Drugs and Metabolites in Whole-Body Thin Tissue Sections

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

Kertesz, Vilmos; Van Berkel, Gary J

2010-01-01

In this work, a commercially available autosampler was adapted to perform direct liquid microjunction (LMJ) surface sampling followed by a high-pressure liquid chromatography (HPLC) separation of the extract components and detection with electrospray ionization mass spectrometry (ESI-MS). To illustrate the utility of coupling a separation with this direct liquid extraction based surface sampling approach, four different organs (brain, lung, kidney, and liver) from whole-body thin tissue sections of propranolol dosed and control mice were examined. The parent drug was observed in the chromatograms of the surface sampling extracts from all the organs of the dosed mouse examined. In addition, twomore » isomeric phase II metabolites of propranolol (an aliphatic and an aromatic hydroxypropranolol glucuronide) were observed in the chromatograms of the extracts from lung, kidney, and liver. Confirming the presence of one or the other or both of these glucuronides in the extract from the various organs was not possible without the separation. These drug and metabolite data obtained using the LMJ surface sampling/HPLC-MS method and the results achieved by analyzing similar samples by conventional extraction of the tissues and subsequent HPLC-MS analysis were consistent.« less

In-situ Observation of Cross-Sectional Microstructural Changes and Stress Distributions in Fracturing TiN Thin Film during Nanoindentation.

PubMed

Zeilinger, Angelika; Todt, Juraj; Krywka, Christina; Müller, Martin; Ecker, Werner; Sartory, Bernhard; Meindlhumer, Michael; Stefenelli, Mario; Daniel, Rostislav; Mitterer, Christian; Keckes, Jozef

2016-03-07

Load-displacement curves measured during indentation experiments on thin films depend on non-homogeneous intrinsic film microstructure and residual stress gradients as well as on their changes during indenter penetration into the material. To date, microstructural changes and local stress concentrations resulting in plastic deformation and fracture were quantified exclusively using numerical models which suffer from poor knowledge of size dependent material properties and the unknown intrinsic gradients. Here, we report the first in-situ characterization of microstructural changes and multi-axial stress distributions in a wedge-indented 9 μm thick nanocrystalline TiN film volume performed using synchrotron cross-sectional X-ray nanodiffraction. During the indentation, needle-like TiN crystallites are tilted up to 15 degrees away from the indenter axis in the imprint area and strongly anisotropic diffraction peak broadening indicates strain variation within the X-ray nanoprobe caused by gradients of giant compressive stresses. The morphology of the multiaxial stress distributions with local concentrations up to -16.5 GPa correlate well with the observed fracture modes. The crack growth is influenced decisively by the film microstructure, especially by the micro- and nano-scopic interfaces. This novel experimental approach offers the capability to interpret indentation response and indenter imprint morphology of small graded nanostructured features.

Strength Tests on Thin-walled Duralumin Cylinders in Torsion

NASA Technical Reports Server (NTRS)

Lundquist, Eugene E

1932-01-01

This report is the first of a series presenting the results of strength tests on thin-walled cylinders and truncated cones of circular and elliptical section; it comprises the results obtained to date from torsion (pure shear) tests on 65 thin-walled duralumin cylinders of circular section with ends clamped to rigid bulkheads. The effect of variations in the length/radius and radius/thickness ratios on the type of failure is indicated, and a semi-empirical equation for the shearing stress at maximum load is given.

75 FR 29974 - Application(s) for Duty-Free Entry of Scientific Instruments

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-28

... portions of vertebrate and invertebrate organisms embedded in plastic resins and cut into thin sections... vertebrate and invertebrate organisms embedded in plastic resins and cut into thin sections mounted on... Use: The instrument will be used to examine portions of vertebrate and invertebrate organisms embedded...

Astronomy through the microscope: A workshop during the opening night of the 2016 IMC

NASA Astrophysics Data System (ADS)

Netjes, G. J.; de Vet, S.

2016-01-01

During the IMC workshop meteoritical thins sections were shown live with a microscope connected to the beamer. This article will provide a background to thin sections, what we can learn from them and the tour through the solar system we can take with them.

Ureilite Thin Section Preparation

NASA Technical Reports Server (NTRS)

Harrington, R.; Righter, K.

2014-01-01

Preparing thin and thick sections of ureilite type meteorites is a challenge that can confound even the most experienced section preparer. A common characteristic of these samples is the presence of carbon phases, particularly nanodiamonds, in the matrix along silicate grain boundaries, fractures, and cleavage plains [1]. The extreme hardness of the nanodiamonds presents a challenge to the section preparer in the form of high surface relief on the section. This hard material also causes considerable wear and tear on equipment and materials that are used for making the sections. These issues will be discussed and potentially helpful measures will be presented.

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

NASA Astrophysics Data System (ADS)

Grogan, Joseph M.

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

Thin Film Transistors On Plastic Substrates

DOEpatents

Carey, Paul G.; Smith, Patrick M.; Sigmon, Thomas W.; Aceves, Randy C.

2004-01-20

A process for formation of thin film transistors (TFTs) on plastic substrates replaces standard thin film transistor fabrication techniques, and uses sufficiently lower processing temperatures so that inexpensive plastic substrates may be used in place of standard glass, quartz, and silicon wafer-based substrates. The silicon based thin film transistor produced by the process includes a low temperature substrate incapable of withstanding sustained processing temperatures greater than about 250.degree. C., an insulating layer on the substrate, a layer of silicon on the insulating layer having sections of doped silicon, undoped silicon, and poly-silicon, a gate dielectric layer on the layer of silicon, a layer of gate metal on the dielectric layer, a layer of oxide on sections of the layer of silicon and the layer of gate metal, and metal contacts on sections of the layer of silicon and layer of gate metal defining source, gate, and drain contacts, and interconnects.

Role of dilatation and curettage performed for spontaneous or induced abortion in the etiology of endometrial thinning.

PubMed

Azumaguchi, Atsushi; Henmi, Hirofumi; Ohnishi, Hirofumi; Endo, Toshiaki; Saito, Tsuyoshi

2017-03-01

The aim of this study was to clarify the role of dilatation and curettage (D&C) performed for spontaneous or induced abortion in the etiology of endometrial thinning. This was a retrospective and cross-sectional study of 310 infertile patients from January 2013 through December 2015. Endometrial thickness observed 5-7 days after ovulation in a natural menstrual cycle was correlated with the number of D&C noted in each patient's history. Study 1 was an investigation of patients without D&C (group A: n = 232) and patients with D&C performed for spontaneous abortion (group B: n = 46). Study 2 was an investigation of patients in group A and patients with D&C performed for induced abortion (group C: n = 32). A significant negative correlation (P < 0.01) between endometrial thickness and number of D&C was observed in both studies. The mean endometrial thickness of the patients in group A was 10.9 ± 2.1 mm. The mean endometrial thickness of the patients in group B with one and ≥two D&C was 7.9 ± 2.3 and 6.9 ± 2.9 mm, respectively. The mean endometrial thickness of the patients in group C with one and ≥two D&C was 9.1 ± 2.3 and 7.8 ± 2.0 mm, respectively. There was a tendency toward gradual endometrial thinning following repeated procedures and the number of previous D&C was significantly associated with endometrial thinning (P < 0.001) in both studies. D&C performed for spontaneous or induced abortion may play a causal role in endometrial thinning. © 2017 Japan Society of Obstetrics and Gynecology.

Thick crystalline films on foreign substrates

DOEpatents

Smith, Henry I.; Atwater, Harry A.; Geis, Michael W.

1986-01-01

To achieve a uniform texture, large crystalline grains or, in some cases, a single crystalline orientation in a thick (>1 .mu.m) film on a foreign substrate, the film is formed so as to be thin (<1 .mu.m) in a certain section. Zone-melting recrystallization is initiated in the thin section and then extended into the thick section. The method may employ planar constriction patterns of orientation filter patterns.

Thick crystalline films on foreign substrates

DOEpatents

Smith, H.I.; Atwater, H.A.; Geis, M.W.

1986-03-18

To achieve a uniform texture, large crystalline grains or, in some cases, a single crystalline orientation in a thick (>1 [mu]m) film on a foreign substrate, the film is formed so as to be thin (<1 [mu]m) in a certain section. Zone-melting recrystallization is initiated in the thin section and then extended into the thick section. The method may employ planar constriction patterns of orientation filter patterns. 2 figs.

Carbon analyses of IDP's sectioned in sulfur and supported on beryllium films

NASA Technical Reports Server (NTRS)

Bradley, J. P.; Keller, L.; Thomas, K. L.; Vanderwood, T. B.; Brownlee, D. E.

1993-01-01

Carbon is the only major element in interplanetary dust whose abundance, distribution and chemical state are not well understood. Information about carbon could clarify the relationship between the various classes of IDP's, conventional meteorites, and sources (e.g., comets vs. asteroids). To date, the most reliable estimates of C abundance in Interplanetary Dust Particles (IDP's) have been obtained by analyzing particles on thick-flat Be substrates using thin-window energy-dispersive spectroscopy in the SEM. These estimates of C abundance are valid only if C is homogeneously distributed, because detected C x-rays originate from the outer 0.1 micrometers of the particle. An alternative and potentially more accurate method of measuring C abundances is to analyze multiple thin sections (each less than 0.1 less than 0.1 micrometers thick) of IDP's. These efforts however, have been stymied because of a lack of a suitable non-carbonaceous embedding medium and the availability of C-free conductive substrates. We have embedded and thin-sectioned IDP's in glassy sulfur, and transferred the thin sections to Be support films approximately 25 nm thick. The sections were then analyzed in a 200 KeV analytical TEM. S sublimes rapidly under vacuum in the TEM, leaving non-embedded sections supported on Be. Apart from quantitative C (and O) analyses, S sectioning dramatically expands the range of analytical measurements that can be performed on a single IDP.

Multi-scale fracture damage associated with underground chemical explosions

NASA Astrophysics Data System (ADS)

Swanson, E. M.; Sussman, A. J.; Wilson, J. E.; Townsend, M. J.; Prothro, L. B.; Gang, H. E.

2018-05-01

Understanding rock damage induced by explosions is critical for a number of applications including the monitoring and verification of underground nuclear explosions, mine safety issues, and modeling fluid flow through fractured rock. We use core observations, televiewer logs, and thin section observations to investigate fracture damage associated with two successive underground chemical explosions (SPE2 and SPE3) in granitic rock at both the mesoscale and microscale. We compare the frequency and orientations of core-scale fractures, and the frequency of microfractures, between a pre-experiment core and three post-experiment cores. Natural fault zones and explosion-induced fractures in the vicinity of the explosive source are readily apparent in recovered core and in thin sections. Damage from faults and explosions is not always apparent in fracture frequency plots from televiewer logs, although orientation data from these logs suggests explosion-induced fracturing may not align with the pre-existing fracture sets. Core-scale observations indicate the extent of explosion-induced damage is 10.0 m after SPE2 and 6.8 m after SPE3, despite both a similar size and location for both explosions. At the microscale, damage is observed to a range distance of 10.2 ± 0.9 m after SPE2, and 16.6 ± 0.9 and 11.2 ± 0.6 in two different cores collected after SPE3. Additional explosion-induced damage, interpreted to be the result of spalling, is readily apparent near the surface, but only in the microfracture data. This depth extent and intensity of damage in the near-surface region also increased after an additional explosion. This study highlights the importance of evaluating structural damage at multiple scales for a more complete characterization of the damage, and particularly shows the importance of microscale observations for identifying spallation-induced damage.

Ti{sub 2}AlN thin films synthesized by annealing of (Ti+Al)/AlN multilayers

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

Cabioch, Thierry, E-mail: Thierry.cabioch@univ-poitiers.fr; Alkazaz, Malaz; Beaufort, Marie-France

2016-08-15

Highlights: • Epitaxial thin films of the MAX phase Ti{sub 2}AlN are obtained by thermal annealing. • A new metastable (Ti,Al,N) solid solution with the structure of α-T is evidenced. • The formation of the MAX phase occurs at low temperature (600 °C). - Abstract: Single-phase Ti{sub 2}AlN thin films were obtained by annealing in vacuum of (Ti + Al)/AlN multilayers deposited at room temperature by magnetron sputtering onto single-crystalline (0001) 4H-SiC and (0001) Al{sub 2}O{sub 3} substrates. In-situ X-ray diffraction experiments combined with ex-situ cross-sectional transmission electron microscopy observations reveal that interdiffusion processes occur in the multilayer at amore » temperature of ∼400 °C leading to the formation of a (Ti, Al, N) solid solution, having the hexagonal structure of α-Ti, whereas the formation of Ti{sub 2}AlN occurs at 550–600 °C. Highly oriented (0002) Ti{sub 2}AlN thin films can be obtained after an annealing at 750 °C.« less

Catalog of lunar mare basalts greater than 40 grams. Part 1: Major and trace chemistry, with megascopic descriptions and rock and thin section photographs

NASA Technical Reports Server (NTRS)

Lofgren, G. E.; Lofgren, E. M.

1981-01-01

Megascopic descriptions of 133 basaltic rocks returned from the Moon are presented along with photographs of each rock and its thin section, if available. The major and trace element chemistry of each is included wherever possible.

Pipe support for use in a nuclear system

DOEpatents

Pollono, Louis P.; Mello, Raymond M.

1977-01-01

A pipe support for high temperature, thin-walled vertical piping runs used in a nuclear system. A cylindrical pipe transition member, having the same inside diameter as the thin-walled piping, replaces a portion of the piping where support is desired. The outside diameter of the pipe transition member varies axially along its vertical dimension. For a section of the axial length adjacent the upper and lower terminations of the pipe transition member, the outside diameter is the same as the outside diameter of the thin-walled piping to which it is affixed. Intermediate of the termination sections, the outside diameter increases from the top of the member to the bottom. Adjacent the lower termination section, the diameter abruptly becomes the same as the piping. Thus, the cylindrical transition member is formed to have a generally triangular shaped cross-section along the axial dimension. Load-bearing insulation is installed next to the periphery of the member and is kept in place by an outer ring clamp. The outer ring clamp is connected to pipe hangers, which provide the desired support for the vertical thin-walled piping runs.

Stacked thin layers of metaphase chromatin explain the geometry of chromosome rearrangements and banding.

PubMed

Daban, Joan-Ramon

2015-10-08

The three-dimensional organization of tightly condensed chromatin within metaphase chromosomes has been one of the most challenging problems in structural biology since the discovery of the nucleosome. This study shows that chromosome images obtained from typical banded karyotypes and from different multicolour cytogenetic analyses can be used to gain information about the internal structure of chromosomes. Chromatin bands and the connection surfaces in sister chromatid exchanges and in cancer translocations are planar and orthogonal to the chromosome axis. Chromosome stretching produces band splitting and even the thinnest bands are orthogonal and well defined, indicating that short stretches of DNA can occupy completely the chromosome cross-section. These observations impose strong physical constraints on models that attempt to explain chromatin folding in chromosomes. The thin-plate model, which consists of many stacked layers of planar chromatin perpendicular to the chromosome axis, is compatible with the observed orientation of bands, with the existence of thin bands, and with band splitting; it is also compatible with the orthogonal orientation and planar geometry of the connection surfaces in chromosome rearrangements. The results obtained provide a consistent interpretation of the chromosome structural properties that are used in clinical cytogenetics for the diagnosis of hereditary diseases and cancers.

Use of the Thin-Walled Torsion Specimen

DTIC Science & Technology

1992-08-01

similar to the 316 stainless steel but the shear, stress shows a region of lower 16 strain hardening during the reversal. This behavor has been observed...oscillations and match the axial stress seen in experiment. Among these proposals are: the use of the Green -Naghdi stress rate,22 and the formulation of...other references on the topic. In this section, calculations using Jaumann, Green -Naghdi, and plastic spin motivated stress rates ap- plied to

Thin oblique airfoils at supersonic speed

NASA Technical Reports Server (NTRS)

Jone, Robert T

1946-01-01

The well-known methods of thin-airfoil theory have been extended to oblique or sweptback airfoils of finite aspect ratio moving at supersonic speeds. The cases considered thus far are symmetrical airfoils at zero lift having plan forms bounded by straight lines. Because of the conical form of the elementary flow fields, the results are comparable in simplicity to the results of the two-dimensional thin-airfoil theory for subsonic speeds. In the case of untapered airfoils swept back behind the Mach cone the pressure distribution at the center section is similar to that given by the Ackeret theory for a straight airfoil. With increasing distance from the center section the distribution approaches the form given by the subsonic-flow theory. The pressure drag is concentrated chiefly at the center section and for long wings a slight negative drag may appear on outboard sections. (author)

Localized thin-section CT with radiomics feature extraction and machine learning to classify early-detected pulmonary nodules from lung cancer screening

NASA Astrophysics Data System (ADS)

Tu, Shu-Ju; Wang, Chih-Wei; Pan, Kuang-Tse; Wu, Yi-Cheng; Wu, Chen-Te

2018-03-01

Lung cancer screening aims to detect small pulmonary nodules and decrease the mortality rate of those affected. However, studies from large-scale clinical trials of lung cancer screening have shown that the false-positive rate is high and positive predictive value is low. To address these problems, a technical approach is greatly needed for accurate malignancy differentiation among these early-detected nodules. We studied the clinical feasibility of an additional protocol of localized thin-section CT for further assessment on recalled patients from lung cancer screening tests. Our approach of localized thin-section CT was integrated with radiomics features extraction and machine learning classification which was supervised by pathological diagnosis. Localized thin-section CT images of 122 nodules were retrospectively reviewed and 374 radiomics features were extracted. In this study, 48 nodules were benign and 74 malignant. There were nine patients with multiple nodules and four with synchronous multiple malignant nodules. Different machine learning classifiers with a stratified ten-fold cross-validation were used and repeated 100 times to evaluate classification accuracy. Of the image features extracted from the thin-section CT images, 238 (64%) were useful in differentiating between benign and malignant nodules. These useful features include CT density (p  =  0.002 518), sigma (p  =  0.002 781), uniformity (p  =  0.032 41), and entropy (p  =  0.006 685). The highest classification accuracy was 79% by the logistic classifier. The performance metrics of this logistic classification model was 0.80 for the positive predictive value, 0.36 for the false-positive rate, and 0.80 for the area under the receiver operating characteristic curve. Our approach of direct risk classification supervised by the pathological diagnosis with localized thin-section CT and radiomics feature extraction may support clinical physicians in determining truly malignant nodules and therefore reduce problems in lung cancer screening.

Localized thin-section CT with radiomics feature extraction and machine learning to classify early-detected pulmonary nodules from lung cancer screening.

PubMed

Tu, Shu-Ju; Wang, Chih-Wei; Pan, Kuang-Tse; Wu, Yi-Cheng; Wu, Chen-Te

2018-03-14

Lung cancer screening aims to detect small pulmonary nodules and decrease the mortality rate of those affected. However, studies from large-scale clinical trials of lung cancer screening have shown that the false-positive rate is high and positive predictive value is low. To address these problems, a technical approach is greatly needed for accurate malignancy differentiation among these early-detected nodules. We studied the clinical feasibility of an additional protocol of localized thin-section CT for further assessment on recalled patients from lung cancer screening tests. Our approach of localized thin-section CT was integrated with radiomics features extraction and machine learning classification which was supervised by pathological diagnosis. Localized thin-section CT images of 122 nodules were retrospectively reviewed and 374 radiomics features were extracted. In this study, 48 nodules were benign and 74 malignant. There were nine patients with multiple nodules and four with synchronous multiple malignant nodules. Different machine learning classifiers with a stratified ten-fold cross-validation were used and repeated 100 times to evaluate classification accuracy. Of the image features extracted from the thin-section CT images, 238 (64%) were useful in differentiating between benign and malignant nodules. These useful features include CT density (p  =  0.002 518), sigma (p  =  0.002 781), uniformity (p  =  0.032 41), and entropy (p  =  0.006 685). The highest classification accuracy was 79% by the logistic classifier. The performance metrics of this logistic classification model was 0.80 for the positive predictive value, 0.36 for the false-positive rate, and 0.80 for the area under the receiver operating characteristic curve. Our approach of direct risk classification supervised by the pathological diagnosis with localized thin-section CT and radiomics feature extraction may support clinical physicians in determining truly malignant nodules and therefore reduce problems in lung cancer screening.

Fluid Dynamic and Stability Analysis of a Thin Liquid Sheet

NASA Technical Reports Server (NTRS)

McMaster, Matthew S.

1992-01-01

Interest in thin sheet flows has recently been renewed due to their potential application in space radiators. Theoretical and experimental studies of the fluid dynamics and stability of thin liquid sheet flows have been carried out in this thesis. A computer program was developed to determine the cross-sectional shape of the edge cylinder given the cross-sectional area of the edge cylinder. A stability analysis was performed on a non-planer liquid sheet. A study was conducted to determine the effects of air resistance on the sheet.

Three-dimensional reconstruction of root cells and interdental cells in the rat inner ear by serial section scanning electron microscopy.

PubMed

Shodo, Ryusuke; Hayatsu, Manabu; Koga, Daisuke; Horii, Arata; Ushiki, Tatsuo

2017-01-01

In the cochlea, a high K + environment in the endolymph is essential for the maintenance of normal hearing function, and the transport of K + ions through gap junctions of the cochlear epithelium is thought to play an important role in endolymphatic homeostasis. The aim of the present study was to demonstrate the three-dimensional (3D) ultrastructure of spiral ligament root cells and interdental cells, which are located at both ends of the gap junction system of the cochlea epithelium. Serial semi-thin sections of plastic-embedded rat cochlea were mounted on glass slides, stained with uranyl acetate and lead citrate, and observed by scanning electron microscopy (SEM) using the backscattered electron (BSE) mode. 3D reconstruction of BSE images of serial sections revealed that the root cells were linked together to form a branched structure like an elaborate "tree root" in the spiral ligament. The interdental cells were also connected to each other, forming a comb-shaped cellular network with a number of cellular strands in the spiral limbus. Furthermore, TEM studies of ultra-thin sections revealed the rich presence of gap junctions in both root cells and interdental cells. These findings suggest the possibility that both root cells and interdental cells contribute to K + circulation as the end portion of the epithelial cell gap junction system of the cochlea.

Radially and azimuthally polarized laser induced shape transformation of embedded metallic nanoparticles in glass.

PubMed

Tyrk, Mateusz A; Zolotovskaya, Svetlana A; Gillespie, W Allan; Abdolvand, Amin

2015-09-07

Radially and azimuthally polarized picosecond (~10 ps) pulsed laser irradiation at 532 nm wavelength led to the permanent reshaping of spherical silver nanoparticles (~30 - 40 nm in diameter) embedded in a thin layer of soda-lime glass. The observed peculiar shape modifications consist of a number of different orientations of nano-ellipsoids in the cross-section of each written line by laser. A Second Harmonic Generation cross-sectional scan method from silver nanoparticles in transmission geometry was adopted for characterization of the samples after laser modification. The presented approach may lead to sophisticated marking of information in metal-glass nanocomposites.

[Normal and pathological elastic tissue under the electron microscope on thin and ultrathin sections (author's transl)].

PubMed

Adnet, J J; Pinteaux, A; Pousse, G; Caulet, T

1976-04-01

Three simple methods (adapted from optical techniques) for normal and pathological elastic tissue caracterisation in electron microscopy on thin and ultrathin sections are proposed. Two of these methods (orcein and fuchsin resorcin) seem to have a specificity for arterial and breast cancer elastic tissue. Weigert's method gives the best contrast.

Preparation of c-axis perpendicularly oriented ultra-thin L10-FePt films on MgO and VN underlayers

NASA Astrophysics Data System (ADS)

Futamoto, Masaaki; Shimizu, Tomoki; Ohtake, Mitsuru

2018-05-01

Ultra-thin L10-FePt films of 2 nm average thickness are prepared on (001) oriented MgO and VN underlayers epitaxially grown on base substrate of SrTiO3(001) single crystal. Detailed cross-sectional structures are observed by high-resolution transmission electron microscopy. Continuous L10-FePt(001) thin films with very flat surface are prepared on VN(001) underlayer whereas the films prepared on MgO(001) underlayer consist of isolated L10-FePt(001) crystal islands. Presence of misfit dislocation and lattice bending in L10-FePt material is reducing the effective lattice mismatch with respect to the underlayer to be less than 0.5 %. Formation of very flat and continuous FePt layer on VN underlayer is due to the large surface energy of VN material where de-wetting of FePt material at high temperature annealing process is suppressed under a force balance between the surface and interface energies of FePt and VN materials. An employment of underlayer or substrate material with the lattice constant and the surface energy larger than those of L10-FePt is important for the preparation of very thin FePt epitaxial thin continuous film with the c-axis controlled to be perpendicular to the substrate surface.

Internal-external flow integration for a thin ejector-flapped wing section

NASA Technical Reports Server (NTRS)

Woolard, H. W.

1979-01-01

Thin airfoil theories of an ejector flapped wing section are reviewed. The global matching of the external airfoil flow with the ejector internal flow and the overall ejector flapped wing section aerodynamic performance are examined. Mathematical models of the external and internal flows are presented. The delineation of the suction flow coefficient characteristics are discussed. The idealized lift performance of an ejector flapped wing relative to a jet augmented flapped wing are compared.

Ice crystal c-axis orientation and mean grain size measurements from the Dome Summit South ice core, Law Dome, East Antarctica

NASA Astrophysics Data System (ADS)

Treverrow, Adam; Jun, Li; Jacka, Tim H.

2016-06-01

We present measurements of crystal c-axis orientations and mean grain area from the Dome Summit South (DSS) ice core drilled on Law Dome, East Antarctica. All measurements were made on location at the borehole site during drilling operations. The data are from 185 individual thin sections obtained between a depth of 117 m below the surface and the bottom of the DSS core at a depth of 1196 m. The median number of c-axis orientations recorded in each thin section was 100, with values ranging from 5 through to 111 orientations. The data from all 185 thin sections are provided in a single comma-separated value (csv) formatted file which contains the c-axis orientations in polar coordinates, depth information for each core section from which the data were obtained, the mean grain area calculated for each thin section and other data related to the drilling site. The data set is also available as a MATLAB™ structure array. Additionally, the c-axis orientation data from each of the 185 thin sections are summarized graphically in figures containing a Schmidt diagram, histogram of c-axis colatitudes and rose plot of c-axis azimuths. All these data are referenced by doi:10.4225/15/5669050CC1B3B and are available free of charge at https://data.antarctica.gov.au.<

Synergistic effect of indium and gallium co-doping on the properties of RF sputtered ZnO thin films

NASA Astrophysics Data System (ADS)

Shaheera, M.; Girija, K. G.; Kaur, Manmeet; Geetha, V.; Debnath, A. K.; Karri, Malvika; Thota, Manoj Kumar; Vatsa, R. K.; Muthe, K. P.; Gadkari, S. C.

2018-04-01

ZnO thin films were synthesized using RF magnetron sputtering, with simultaneous incorporation of Indium (In) and Gallium (Ga). The structural, optical, chemical composition and surface morphology of the pure and co-doped (IGZO) thin films were characterized by X-Ray diffraction (XRD), UV-visible spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Raman spectroscopy. XRD revealed that these films were oriented along c-axis with hexagonal wurtzite structure. The (002) diffraction peak in the co-doped sample was observed at 33.76° with a slight shift towards lower 2θ values as compared to pure ZnO. The surface morphology of the two thin films was observed to differ. For pure ZnO films, round grains were observed and for IGZO thin films round as well as rod type grains were observed. All thin films synthesized show excellent optical properties with more than 90% transmission in the visible region and band gap of the films is observed to decrease with co-doping. The co doping of In and Ga is therefore expected to provide a broad range optical and physical properties of ZnO thin films for a variety of optoelectronic applications.

Development of Ren Qiou fractured carbonate oil pools by water injection

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

Yu, Z.; Li, G.

1982-01-01

This work gives a brief description on the geologic characteristics of Ren Qiou oil field and its development. Different methods have been used in its reservoir engineering study such as outcrop investigation, fracture and crevice description in tunnels, observation on core samples and their statistical data, thin section observation, casting section, fluorescence section, scanning electron microscope, mercury injection and withdrawal, down-hole television, and geophysical well logging. Physical modeling, 3-dimensional numeric simulation and reservoir performance analysis, and production profiles by production logging in an open hole, have been used to study mechanics of displacing oil by water and the movement ofmore » oil and water in reservoir pools production technologies with double-porosity. Pressure maintenance by bottomwater injection to keep producing wells flowing, acidization with emulsifying acid to penetrate deeply into the reservoir formation, and water plugging with chemical agent, have been used to maintain a consistent annual recovery rate. 11 references.« less

In-situ Observation of Cross-Sectional Microstructural Changes and Stress Distributions in Fracturing TiN Thin Film during Nanoindentation

PubMed Central

Zeilinger, Angelika; Todt, Juraj; Krywka, Christina; Müller, Martin; Ecker, Werner; Sartory, Bernhard; Meindlhumer, Michael; Stefenelli, Mario; Daniel, Rostislav; Mitterer, Christian; Keckes, Jozef

2016-01-01

Load-displacement curves measured during indentation experiments on thin films depend on non-homogeneous intrinsic film microstructure and residual stress gradients as well as on their changes during indenter penetration into the material. To date, microstructural changes and local stress concentrations resulting in plastic deformation and fracture were quantified exclusively using numerical models which suffer from poor knowledge of size dependent material properties and the unknown intrinsic gradients. Here, we report the first in-situ characterization of microstructural changes and multi-axial stress distributions in a wedge-indented 9 μm thick nanocrystalline TiN film volume performed using synchrotron cross-sectional X-ray nanodiffraction. During the indentation, needle-like TiN crystallites are tilted up to 15 degrees away from the indenter axis in the imprint area and strongly anisotropic diffraction peak broadening indicates strain variation within the X-ray nanoprobe caused by gradients of giant compressive stresses. The morphology of the multiaxial stress distributions with local concentrations up to −16.5 GPa correlate well with the observed fracture modes. The crack growth is influenced decisively by the film microstructure, especially by the micro- and nano-scopic interfaces. This novel experimental approach offers the capability to interpret indentation response and indenter imprint morphology of small graded nanostructured features. PMID:26947558

Obtaining Magnetic Properties of Meteorites Using Magnetic Scanner

NASA Astrophysics Data System (ADS)

Kletetschka, G.; Nabelek, L.; Mazanec, M.; Simon, K.; Hruba, J.

2015-12-01

Magnetic images of Murchison meteorite's and Chelyabinsk meteorite's thin section have been obtained from magnetic scanning system from Youngwood Science and Engineering (YSE) capable of resolving magnetic anomalies down to 10-3 mT range from about 0.3 mm distance between the probe and meteorite surface (resolution about 0.15 mm). Anomalies were produced repeatedly, each time after application of magnetic field pulse of varying amplitude and constant, normal or reversed, direction. This process resulted in both magnetizing and demagnetizing of the meteorite thin section, while keeping the magnetization vector in the plane of the thin section. Analysis of the magnetic data allows determination of coercivity of remanence (Bcr) for the magnetic sources in situ. Value of Bcr is critical for calculating magnetic forces applicable during missions to asteroids where gravity is compromised. Bcr was estimated by two methods. First method measured varying dipole magnetic field strength produced by each anomaly in the direction of magnetic pulses. Second method measured deflections of the dipole direction from the direction of magnetic pulses (Nabelek et al., 2015). Nabelek, L., Mazanec, M., Kdyr, S., and Kletetschka, G., 2015, Magnetic, in situ, mineral characterization of Chelyabinsk meteorite thin section: Meteoritics & Planetary Science.

Particle Shape Characterization of Lunar Regolith using Reflected Light Microscopy

NASA Astrophysics Data System (ADS)

McCarty, C. B.; Garcia, G. C.; Rickman, D.

2014-12-01

Automated identification of particles in lunar thin sections is necessary for practical measurement of particle shape, void characterization, and quantitative characterization of sediment fabric. This may be done using image analysis, but several aspects of the lunar regolith make such automations difficult. For example, many of the particles are shattered; others are aggregates of smaller particles. Sieve sizes of the particles span 5 orders of magnitude. The physical thickness of a thin section, at a nominal 30 microns, is large compared to the size of many of the particles. Image acquisition modes, such as SEM and reflected light, while superior to transmitted light, still have significant ambiguity as to the volume being sampled. It is also desirable to have a technique that is inexpensive, not resource intensive, and analytically robust. To this end, we have developed an image acquisition and processing protocol that identifies and delineates resolvable particles on the front surface of a lunar thin section using a petrographic microscope in reflected light. For a polished thin section, a grid is defined covering the entire thin section. The grid defines discrete images taken with 20% overlap, minimizing the number of particles that intersect image boundaries. In reflected light mode, two images are acquired at each grid location, with a closed aperture diaphragm. One image, A, is focused precisely on the front surface of the thin section. The second image, B, is made after the stage is brought toward the objective lens just slightly. A bright fringe line, analogous to a Becke line, appears inside all transparent particles at the front surface of the section in the second image. The added light in the bright line corresponds to a deficit around the particles. Particle identification is done using ImageJ and uses multiple steps. A hybrid 5x5 median filter is used to make images Af and Bf. This primarily removes very small particles just below the front surface of the section. Bf - (Bf/Af) is then computed. The division strongly enhances the fringe and the deficit, while minimizing the correlated information in A and B. The subtraction emphasizes the particle-epoxy boundaries. The resulting image is converted to binary, and then holes are filled. Cracks are removed using a median-based operator.

High resolution study of petroleum source rock variation, Lower Cretaceous (Hauterivian and Barremian) of Mikkelsen Bay, North Slope, Alaska

USGS Publications Warehouse

Keller, Margaret A.; Macquaker, Joe H.S.; Lillis, Paul G.

2001-01-01

Open File Report 01-480 was designed as a large format poster for the Annual Meeting of the American Association of Petroleum Geologists and the Society for Sedimentary Geology in Denver Colorado in June 2001. It is reproduced here in digital format to make widely available some unique images of mudstones. The images include description, interpretation, and Rock-Eval data that resulted from a high-resolution study of petroleum source rock variation of the Lower Cretaceous succession of the Mobil-Phillips Mikkelsen Bay State #1 well on the North Slope of Alaska. Our mudstone samples with Rock-Eval data plus color images are significant because they come from one of the few continuously cored and complete intervals of the Lower Cretaceous succession on the North Slope. This succession, which is rarely preserved in outcrop and very rarely cored in the subsurface, is considered to include important petroleum source rocks that have not previously been described nor explained Another reason these images are unique is that the lithofacies variability within mudstone dominated successions is relatively poorly known in comparison with that observed in coarser clastic and carbonate successions. They are also among the first published scans of thin sections of mudstone, and are of excellent quality because the sections are well made, cut perpendicular to bedding, and unusually thin, 20 microns. For each of 15 samples, we show a thin section scan (cm scale) and an optical photomicrograph (mm scale) that illustrates the variability present. Several backscattered SEM images are also shown. Rock-Eval data for the samples can be compared with the textures and mineralogy present by correlating sample numbers and core depth.

Risk for self-reported anorexia or bulimia nervosa based on drive for thinness and negative affect clusters/dimensions during adolescence: A three-year prospective study of the TChAD cohort.

PubMed

Peñas-Lledó, Eva; Bulik, Cynthia M; Lichtenstein, Paul; Larsson, Henrik; Baker, Jessica H

2015-09-01

This study explored the cross-sectional and predictive effect of drive for thinness and/or negative affect scores on the development of self-reported anorexia nervosa (AN) and bulimia nervosa (BN). K-means were used to cluster the Eating Disorder Inventory-Drive for Thinness (DT) and Child Behavior Checklist Anxious/Depressed (A/D) scores from 615 unrelated female twins at age 16-17. Logistic regressions were used to assess the effect of these clusters on self-reported eating disorder diagnosis at ages 16-17 (n = 565) and 19-20 (n = 451). DT and A/D scores were grouped into four clusters: Mild (scores lower than 90th percentile on both scales), DT (higher scores only on DT), A/D (higher scores only on A/D), and DT-A/D (higher scores on both the DT and A/D scales). DT and DT-A/D clusters at age 16-17 were associated cross-sectionally with AN and both cross-sectionally and longitudinally with BN. The DT-A/D cluster had the highest prevalence of AN at follow-up compared with all other clusters. Similarly, an interaction was observed between DT and A/D that predicted risk for AN. Having elevated DT and A/D scores may increase risk for eating disorder symptomatology above and beyond a high score on either alone. Findings suggest that cluster modeling based on DT and A/D may be useful to inform novel and useful intervention strategies for AN and BN in adolescents. © 2015 Wiley Periodicals, Inc.

Risk for self-reported anorexia or bulimia nervosa based on drive for thinness and negative affect clusters/dimensions during adolescence: A three-year prospective study of the TChAD cohort

PubMed Central

Peñas-Lledó, Eva; Bulik, Cynthia M.; Lichtenstein, Paul; Larsson, Henrik; Baker, Jessica H.

2015-01-01

Objective The present study explored the cross-sectional and predictive effect of drive for thinness and/or negative affect scores on the development of self-reported anorexia nervosa (AN) and bulimia nervosa (BN). Method K-means were used to cluster the Eating Disorder Inventory-Drive for Thinness (DT) and Child Behavior Checklist Anxious/Depressed (A/D) scores from 615 unrelated female twins at age 16–17. Logistic regressions were used to assess the effect of these clusters on self-reported eating disorder diagnosis at ages 16–17 (n=565) and 19–20 (n=451). Results DT and A/D scores were grouped into four clusters: Mild (scores lower than 90th percentile on both scales), DT (higher scores only on DT), A/D (higher scores only on A/D), and DT-A/D (higher scores on both the DT and A/D scales). DT and DT-A/D clusters at age 16–17 were associated cross-sectionally with AN and both cross-sectionally and longitudinally with BN. The DT-A/D cluster had the highest prevalence of AN at follow-up compared with all other clusters. Similarly, an interaction was observed between DT and A/D that predicted risk for AN. Discussion Having elevated DT and A/D scores may increase risk for eating disorder symptomatology above and beyond a high score on either alone. Findings suggest that cluster modeling based on DT and A/D may be useful to inform novel and useful intervention strategies for AN and BN in adolescents. PMID:26013185

3D ECG- and respiratory-gated non-contrast-enhanced (CE) perfusion MRI for postoperative lung function prediction in non-small-cell lung cancer patients: A comparison with thin-section quantitative computed tomography, dynamic CE-perfusion MRI, and perfusion scan.

PubMed

Ohno, Yoshiharu; Seki, Shinichiro; Koyama, Hisanobu; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Takenaka, Daisuke; Kassai, Yoshimori; Yui, Masao; Sugimura, Kazuro

2015-08-01

To compare predictive capabilities of non-contrast-enhanced (CE)- and dynamic CE-perfusion MRIs, thin-section multidetector computed tomography (CT) (MDCT), and perfusion scan for postoperative lung function in non-small cell lung cancer (NSCLC) patients. Sixty consecutive pathologically diagnosed NSCLC patients were included and prospectively underwent thin-section MDCT, non-CE-, and dynamic CE-perfusion MRIs and perfusion scan, and had their pre- and postoperative forced expiratory volume in one second (FEV1 ) measured. Postoperative percent FEV1 (po%FEV1 ) was then predicted from the fractional lung volume determined on semiquantitatively assessed non-CE- and dynamic CE-perfusion MRIs, from the functional lung volumes determined on quantitative CT, from the number of segments observed on qualitative CT, and from uptakes detected on perfusion scans within total and resected lungs. Predicted po%FEV1 s were then correlated with actual po%FEV1 s, which were %FEV1 s measured postoperatively. The limits of agreement were also determined. All predicted po%FEV1 s showed significant correlation (0.73 ≤ r ≤ 0.93, P < 0.0001) and limits of agreement with actual po%FEV1 (non-CE-perfusion MRI: 0.3 ± 10.0%, dynamic CE-perfusion MRI: 1.0 ± 10.8%, perfusion scan: 2.2 ± 14.1%, quantitative CT: 1.2 ± 9.0%, qualitative CT: 1.5 ± 10.2%). Non-CE-perfusion MRI may be able to predict postoperative lung function more accurately than qualitatively assessed MDCT and perfusion scan. © 2014 Wiley Periodicals, Inc.

Shock compression response of highly reactive Ni + Al multilayered thin foils

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

Kelly, Sean C.; Thadhani, Naresh N., E-mail: naresh.thadhani@mse.gatech.edu

2016-03-07

The shock-compression response of Ni + Al multilayered thin foils is investigated using laser-accelerated thin-foil plate-impact experiments over the pressure range of 2 to 11 GPa. The foils contain alternating Ni and Al layers (parallel but not flat) of nominally 50 nm bilayer spacing. The goal is to determine the equation of state and shock-induced reactivity of these highly reactive fully dense thin-foil materials. The laser-accelerated thin-foil impact set-up involved combined use of photon-doppler-velocimetry to monitor the acceleration and impact velocity of an aluminum flyer, and VISAR interferometry was used to monitor the back free-surface velocity of the impacted Ni + Al multilayered target. The shock-compressionmore » response of the Ni + Al target foils was determined using experimentally measured parameters and impedance matching approach, with error bars identified considering systematic and experimental errors. Meso-scale CTH shock simulations were performed using real imported microstructures of the cross-sections of the multilayered Ni + Al foils to compute the Hugoniot response (assuming no reaction) for correlation with their experimentally determined equation of state. It was observed that at particle velocities below ∼150 m/s, the experimentally determined equation of state trend matches the CTH-predicted inert response and is consistent with the observed unreacted state of the recovered Ni + Al target foils from this velocity regime. At higher particle velocities, the experimentally determined equation of state deviates from the CTH-predicted inert response. A complete and self-sustained reaction is also seen in targets recovered from experiments performed at these higher particle velocities. The deviation in the measured equation of state, to higher shock speeds and expanded volumes, combined with the observation of complete reaction in the recovered multilayered foils, confirmed via microstructure characterization, is indicative of the occurrence of shock-induced chemical reaction occurring in the time-scale of the high-pressure state. TEM characterization of recovered shock-compressed (unreacted) Ni + Al multilayered foils exhibits distinct features of constituent mixing revealing jetted layers and inter-mixed regions. These features were primarily observed in the proximity of the undulations present in the alternating layers of the Ni + Al starting foils, suggesting the important role of such instabilities in promoting shock-induced intermetallic-forming reactions in the fully dense highly exothermic multilayered thin foils.« less

Twenty-one-year development of Douglas-fir stands repeatedly thinned at varying intervals.

Treesearch

Donald L. Reukema

1972-01-01

Douglas-fir stands first thinned at about age 38 have been observed for 21 years. Four treatments were compared; no thinning, light thinning at 3-year intervals, moderate thinning at 6-year intervals, and heavy thinning at 9-year intervals. Eighteen years after initial thinnings (the first common end to all thinning cycles), all thinned stands had virtually the same...

Method and system for constructing a rechargeable battery and battery structures formed with the method

DOEpatents

Hobson, David O.; Snyder, Jr., William B.

1995-01-01

A method and system for manufacturing a thin-film battery and a battery structure formed with the method utilizes a plurality of deposition stations at which thin battery component films are built up in sequence upon a web-like substrate as the substrate is automatically moved through the stations. At an initial station, cathode and anode current collector film sections are deposited upon the substrate, and at another station, a thin cathode film is deposited upon the substrate so to overlie part of the cathode current collector section. At another station, a thin electrolyte film is deposited upon so as to overlie the cathode film and part of the anode current collector film, at yet another station, a thin lithium film is deposited upon so as to overlie the electrolyte film and an additional part of the anode current collector film. Such a method accommodates the winding of a layup of battery components into a spiral configuration to provide a thin-film, high capacity battery and also accommodates the build up of thin film battery components onto a substrate surface having any of a number of shapes.

Cellular distribution of uranium after acute exposure of renal epithelial cells: SEM, TEM and nuclear microscopy analysis

NASA Astrophysics Data System (ADS)

Carrière, Marie; Gouget, Barbara; Gallien, Jean-Paul; Avoscan, Laure; Gobin, Renée; Verbavatz, Jean-Marc; Khodja, Hicham

2005-04-01

The major health effect of uranium exposure has been reported to be chemical kidney toxicity, functional and histological damages being mainly observed in proximal tubule cells. Uranium enters the proximal tubule as uranyl-bicarbonate or uranyl-citrate complexes. The aim of our research is to investigate the mechanisms of uranium toxicity, intracellular accumulation and repartition after acute intoxication of rat renal proximal tubule epithelial cells, as a function of its chemical form. Microscopic observations of renal epithelial cells after acute exposure to uranyl-bicarbonate showing the presence of intracellular precipitates as thin needles of uranyl-phosphate localized in cell lysosomes have been published. However the initial site of precipitates formation has not been identified yet: they could either be formed outside the cells before internalization, or directly inside the cells. Uranium solubility as a function and initial concentration was specified by ICP-MS analysis of culture media. In parallel, uranium uptake and distribution in cell monolayers exposed to U-bicarbonate was investigated by nuclear microprobe analyses. Finally, the presence of uranium precipitates was tested out by scanning electron microscopic observations (SEM), while extracellular and/or intracellular precipitates were observed on thin sections of cells by transmission electron microscopy (TEM).

Memristive Properties of Thin Film Cuprous Oxide

DTIC Science & Technology

2011-03-01

Equation Chapter 1 Section 1 MEMRISTIVE PROPERTIES OF THIN FILM CUPROUS OXIDE THESIS Brett C...Force Base, Ohio APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED The views expressed in this thesis are those of the...MEMRISTIVE PROPERTIES OF THIN FILM CUPROUS OXIDE THESIS Presented to the Faculty Department of Engineering Physics Graduate School of

7 CFR 29.2438 - Thin Leaf (C Group).

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Thin Leaf (C Group). 29.2438 Section 29.2438... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2438 Thin Leaf (C Group). This group consists of leaves usually grown at the center portion of the stalk. These leaves normally have a rounded tip, are thinner in...

7 CFR 29.2438 - Thin Leaf (C Group).

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Thin Leaf (C Group). 29.2438 Section 29.2438... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2438 Thin Leaf (C Group). This group consists of leaves usually grown at the center portion of the stalk. These leaves normally have a rounded tip, are thinner in...

7 CFR 29.2438 - Thin Leaf (C Group).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Thin Leaf (C Group). 29.2438 Section 29.2438... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2438 Thin Leaf (C Group). This group consists of leaves usually grown at the center portion of the stalk. These leaves normally have a rounded tip, are thinner in...

7 CFR 29.2438 - Thin Leaf (C Group).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Thin Leaf (C Group). 29.2438 Section 29.2438... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2438 Thin Leaf (C Group). This group consists of leaves usually grown at the center portion of the stalk. These leaves normally have a rounded tip, are thinner in...

7 CFR 29.2438 - Thin Leaf (C Group).

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Thin Leaf (C Group). 29.2438 Section 29.2438... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2438 Thin Leaf (C Group). This group consists of leaves usually grown at the center portion of the stalk. These leaves normally have a rounded tip, are thinner in...

Lα and Mαβ X-ray production cross-sections of Bi by 6-30 keV electron impact

NASA Astrophysics Data System (ADS)

Liang, Y.; Xu, M. X.; Yuan, Y.; Wu, Y.; Qian, Z. C.; Chang, C. H.; Mei, C. S.; Zhu, J. J.; Moharram, K.

2017-12-01

In this paper, the Lα and Mαβ X-ray production cross-sections for Bi impacted by 6-30 keV electron have been measured. The experiments were performed at a Scanning Electron Microscope equipped with a silicon drift detector. The thin film with thick C substrate and the thin film deposited on self-supporting thin C film were both used as the targets to make a comparison. For the thick carbon substrate target, the Monte Carlo method has been used to eliminate the contribution of backscattering particles. The measured data are compared with the DWBA theoretical model and the experimental results in the literature. The experimental data for the thin film with thick C substrate target and the thin film deposited on self-supporting thin C film target are within reasonable gaps. The DWBA theoretical model gives good fit to the experimental data both for L- and M- shells. Besides, we also analyze the reasons why the discrepancies exist between our measurements and the experimental results in the literature.

Electron-microscopical localization of gelsolin in various crustacean muscles.

PubMed

Unger, Andreas; Hinssen, Horst

2010-08-01

Gelsolin was localized by immunoelectron microscopy in fast and slow cross-striated muscles of the lobster Homarus americanus. When ultrathin sections of the muscles were labelled with anti-gelsolin and a gold-conjugated second antibody, 90% of all gold particles in the myoplasm were detected on myofibrils, preferentially in the I-band and AI-region of the sarcomeres. Both the region of the H-zone (lacking thin filaments) and the Z-disc contained no or little gold label. Under physiological conditions, a close association of gelsolin with the thin filaments was observed for both muscle types. The preferential localization of particles in the I- and AI-region indicated that gelsolin was distributed randomly over the whole length of the thin filaments. Preincubation of muscle strips with Ringer solution containing 0.5 mM EGTA resulted in a significantly different distribution pattern; gold particles were now localized preferentially in the cell periphery close to the sarcolemma, with significantly decreased abundance in the centre of the cell. Compared with the muscle under physiological conditions, the number of gold particles over sarcomeric structures was significantly reduced. Thus, binding of gelsolin to the thin filaments is apparently reversible in vivo and depends on the presence of calcium ions. We assume a functional role for gelsolin in the actin turnover processes in invertebrate muscle systems.

A simple method for maintaining relative positions of separate tissue elements during processing for electron microscopy.

PubMed

Stirling, C A

1978-09-01

Molten (328 K) 20% gelatin is used as a 'glue' to hold together separate tissue elements or tissue elements that may be separated when cutting small blocks of tissue for plastic embedding. Standard aldehyde and osmium fixation, dehydration and epoxy embedding are compatible with this as is semi-thin sectioning for light microscopy or thin sectioning for electron microscopy.

Tomography of Bacteria-Mineral Associations Within the Deep sea Hydrothermal Vent Shrimp Rimicaris exoculata.

NASA Astrophysics Data System (ADS)

Anderson, L.; Lechaire, J.; Frebourg, G.; Boudier, T.; Zbinden, M.; Gaill, F.

2005-12-01

The chemical and temperature conditions around deep sea hydrothermal vents are both dynamic and extreme, yet the shrimp Rimicaris exoculata flourishes around these environments on the Mid-Atlantic Ridge (MAR) . The epibiotic bacteria and minerals found within the branchial chamber of the shrimp are of great interest in the search for a chemical model for the Rainbow MAR hydrothermal vent site. Here we examine the close three-dimensional (3D) relationship between bacteria (on inner surface of the branchial chamber wall), and the minerals that surround them. The morphology and chemistry of the minerals were analysed by Transmission Electron Microscopy (TEM) and Energy-filtering Transmission Electron Microscopy (EFTEM, LEO 912 Omega) respectively, and the 3D organisation (TOMO) was established using IMAGE-J (public-domain) tomographic reconstruction software. Samples of Rimicaris exoculata were collected from the Rainbow site (36° 13' N, 2320 m depth). The cuticle of the branchial chamber was cut into 2mm wide sub-samples, dehydrated and impregnated in resin for cutting. Consecutive thin and semi-thin sections of 80μm (for TEM, EFTEM) and 150μm-200μm (for TOMO) were cut and mounted on standard microscope grids. Thin-section grids were observed initially for morphology, to find broad relationships between bacteria and minerals, and also as a tool to find areas for EFTEM analysis and TOMO. The TOMO reconstruction was produced from a `Tilt Series', comprising a number of images taken at one degree increments between -55° and +55°. Tilt series were obtained using the ESIvision program (Version 3.0, Soft' Imaging Software, SIS GmbH, D-49153 Münster, Germany) with additional in-house scripts for automated acquisition. This same procedure was applied to consecutive semi-thin sections through the same sub-sample. The different series for each sub-sample were then overlain to obtain a 3D overview of the bacteria-mineral associations. In many cases the minerals exhibit a sharp boundary against the bacteria, often with a substantial void between bacterial membrane and mineral boundary. Mineral layering and areas of elemental zoning are also observed. Iron is the most prevalent element, with a close association to the bacteria. Future work will combine the elemental data obtained by EFTEM with tomography to produce a 3D elemental map of the minerals surrounding the bacteria, focussing particularly on the bacteria-mineral interface using recently developed EFTET-J software (http://www.snv.jussieu.fr/~wboudier/softs.html).

Facies distribution, depositional environment, and petrophysical features of the Sharawra Formation, Old Qusaiba Village, Central Saudi Arabia

NASA Astrophysics Data System (ADS)

Abbas, Muhammad Asif; Kaminski, Michael; Umran Dogan, A.

2016-04-01

The Silurian Sharawra Formation has great importance as it rests over the richest source rock of the Qusaiba Formation in central Saudi Arabia. The Sharawra Formation has four members including Jarish, Khanafriyah, Nayyal, and Zubliyat. The formation mainly consists of sandstone and siltstone with subordinate shale sequences. The lack of published research on this formation requires fundamental studies that can lay the foundation for future research. Three outcrops were selected from the Old Qusaiba Village in Central Saudi Arabia for field observations, petrographical and petrophysical study. Thin section study has been aided by quantitative mineralogical characterization using scanning electron microscopy - energy dispersive spectroscopy and powder x-ray diffraction (XRD) for both minerals, cements, and clay minerals (detrital and authigenic). The outcrops were logged in detail and nine different lithofacies have been identified. The thin section study has revealed the Sharawra Formation to be mainly subarkosic, while the mica content increases near to its contact with the Qusaiba Formation. The XRD data has also revealed a prominent change in mineralogy with inclusion of minerals like phlogopite and microcline with depths. Field observations delineated a prominent thinning of strata as lithofacies correlation clearly shows the thinning of strata in the southwestern direction. The absence of outcrop exposures further supports the idea of southwestern thinning of strata. This is mainly attributed to local erosion and the presence of thicker shale interbeds in the southeastern section, which was probably subjected to more intense erosion than the northwestern one. The Sharawra Formation rests conformably over the thick transgressive shale sequence, deposited during the post glacial depositional cycle. The lowermost massive sandstone bed of the Sharawra Formation represents the beginning of the regressive period. The shale interbeds in the lower part are evidence of moderate-scale transgressive episodes, while the thin shale interbeds in the middle and upper part of the Sharawra Formation represent small-scale transgressions. Overall, the Sharawra Formation contains a series of repetitive transgressive and regressive events and has been interpreted as a pro-deltaic deposit in previous studies. In the present study, the lowermost sandstone thickly bedded facies lie within the transition zone environment. The siltstone facies and the horizontally stratified facies show a middle shore face environment. The middle shore face environment is present locally. The bioturbation in the uppermost facies is indicative of the upper shore face environment. The porosity values do not vary much, as the average porosity for the sandstone facies is about 15%, for the siltstones it ranges about 7%. The permeability is variable throughout the formation, the values range from 50 to 300 md. Although sandstone has a good porosity and permeability, the siltstone facies exhibit poor petrophysical characteristics. In terms of reservoir characterization, the mineralogical mature, moderately well sorted top most sandstone facies, with appreciable porosity and permeability can be considered as a potential reservoir rock. This study has provided a base for future quantitative studies in this important formation in the area.

Novel Methods of Determining Urinary Calculi Composition: Petrographic Thin Sectioning of Calculi and Nanoscale Flow Cytometry Urinalysis

PubMed Central

Gavin, Carson T; Ali, Sohrab N; Tailly, Thomas; Olvera-Posada, Daniel; Alenezi, Husain; Power, Nicholas E; Hou, Jinqiang; St. Amant, Andre H; Luyt, Leonard G; Wood, Stephen; Wu, Charles; Razvi, Hassan; Leong, Hon S

2016-01-01

Accurate determination of urinary stone composition has significant bearing on understanding pathophysiology, choosing treatment modalities and preventing recurrence. A need exists for improved methods to determine stone composition. Urine of 31 patients with known renal calculi was examined with nanoscale flow cytometry and the calculi collected during surgery subsequently underwent petrographic thin sectioning with polarized and fluorescent microscopy. Fluorescently labeled bisphosphonate probes (Alendronate-fluorescein/Alendronate-Cy5) were developed for nanoscale flow cytometry to enumerate nanocrystals that bound the fluorescent probes. Petrographic sections of stones were also imaged by fluorescent and polarized light microscopy with composition analysis correlated to alendronate +ve nanocrystal counts in corresponding urine samples. Urine samples from patients with Ca2+ and Mg2+ based calculi exhibited the highest alendronate +ve nanocrystal counts, ranging from 100–1000 nm in diameter. This novel urine based assay was in agreement with composition determined by petrographic thin sections with Alendronate probes. In some cases, high alendronate +ve nanocrystal counts indicated a Ca2+ or Mg2+ composition, as confirmed by petrographic analysis, overturning initial spectrophotometric diagnosis of stone composition. The combination of nanoscale flow cytometry and petrographic thin sections offer an alternative means for determining stone composition. Nanoscale flow cytometry of alendronate +ve nanocrystals alone may provide a high-throughput means of evaluating stone burden. PMID:26771074

Efficiency of Hysteresis Rods in Small Spacecraft Attitude Stabilization

PubMed Central

Farrahi, Assal; Sanz-Andrés, Ángel

2013-01-01

A semiempirical method for predicting the damping efficiency of hysteresis rods on-board small satellites is presented. It is based on the evaluation of dissipating energy variation of different ferromagnetic materials for two different rod shapes: thin film and circular cross-section rods, as a function of their elongation. Based on this formulation, an optimum design considering the size of hysteresis rods, their cross section shape, and layout has been proposed. Finally, the formulation developed was applied to the case of four existing small satellites, whose corresponding in-flight data are published. A good agreement between the estimated rotational speed decay time and the in-flight data has been observed. PMID:24501579

Location on chitin in the cyst wall of Entamoeba invadens with colloidal gold tracers.

PubMed

Arroyo-Begovich, A; Cárabez-Trejo, A

1982-04-01

Chitin was located in the cyst wall of Entamoeba invadens with colloidal gold-linked wheat germ agglutinin. Cysts stained differentially from trophozoites when encysting cultures were treated with the gold tracer; cysts acquired a wine-red coloration while, in general trophozoites remained unstained. Observation of cells with the electron microscope revealed that the tracer particles were bound specifically to the walls of the surface of the cyst when cells were exposed in suspension, and to the cyst wall cross-section, when cells were exposed to the tracer in thin section, indicating that chitin fibers were distributed on the surface as well as throughout the matrix of the cyst wall.

Histological evidence for muscle insertion in extant amniote femora: implications for muscle reconstruction in fossils.

PubMed

Petermann, Holger; Sander, Martin

2013-04-01

Since the 19th century, identification of muscle attachment sites on bones has been important for muscle reconstructions, especially in fossil tetrapods, and therefore has been the subject of numerous biological and paleontological studies. At the microscopic level, in histological thin sections, the only features that can be used reliably for identifying tendon-bone or muscle-tendon-bone interactions are Sharpey's fibers. Muscles, however, do not only attach to the bone indirectly with tendons, but also directly. Previous studies failed to provide new indicators for muscle attachment, or to address the question of whether muscles with direct attachment can be identified histologically. However, histological identification of direct muscle attachments is important because these attachments do not leave visible marks (e.g. scars and rugosities) on the bone surface. We dissected the right hind limb and mapped the muscle attachment sites on the femur of one rabbit (Oryctolagus cuniculus), one Alligator mississippiensis, and one turkey (Meleagris cuniculus). We then extracted the femur and prepared four histological thin sections for the rabbit and the turkey and five histological thin sections for the alligator. Sharpey's fibers, vascular canal orientation, and a frayed periosteal margin can be indicators for indirect but also direct muscle attachment. Sharpey's fibers can be oriented to the cutting plane of the thin section at high angles, and two Sharpey's fibers orientations can occur in one area, possibly indicating a secondary force axis. However, only about 60% of mapped muscle attachment sites could be detected in thin sections, and frequently histological features suggestive of muscle attachment occurred outside mapped sites. While these insights should improve our ability to successfully identify and reconstruct muscles in extinct species, they also show the limitations of this approach. © 2013 The Authors Journal of Anatomy © 2013 Anatomical Society.

Histological evidence for muscle insertion in extant amniote femora: implications for muscle reconstruction in fossils

PubMed Central

Petermann, Holger; Sander, Martin

2013-01-01

Since the 19th century, identification of muscle attachment sites on bones has been important for muscle reconstructions, especially in fossil tetrapods, and therefore has been the subject of numerous biological and paleontological studies. At the microscopic level, in histological thin sections, the only features that can be used reliably for identifying tendon–bone or muscle–tendon-bone interactions are Sharpey's fibers. Muscles, however, do not only attach to the bone indirectly with tendons, but also directly. Previous studies failed to provide new indicators for muscle attachment, or to address the question of whether muscles with direct attachment can be identified histologically. However, histological identification of direct muscle attachments is important because these attachments do not leave visible marks (e.g. scars and rugosities) on the bone surface. We dissected the right hind limb and mapped the muscle attachment sites on the femur of one rabbit (Oryctolagus cuniculus), one Alligator mississippiensis, and one turkey (Meleagris cuniculus). We then extracted the femur and prepared four histological thin sections for the rabbit and the turkey and five histological thin sections for the alligator. Sharpey's fibers, vascular canal orientation, and a frayed periosteal margin can be indicators for indirect but also direct muscle attachment. Sharpey's fibers can be oriented to the cutting plane of the thin section at high angles, and two Sharpey's fibers orientations can occur in one area, possibly indicating a secondary force axis. However, only about 60% of mapped muscle attachment sites could be detected in thin sections, and frequently histological features suggestive of muscle attachment occurred outside mapped sites. While these insights should improve our ability to successfully identify and reconstruct muscles in extinct species, they also show the limitations of this approach. PMID:23439026

Evaporation thermal anslysis of Swallow-tailed Axial-grooved Heat Pipe

NASA Astrophysics Data System (ADS)

Zhang, Renping

2018-03-01

A detailed mathematical model that describes evaporating characteristics through thin liquid film at the evaporator section of swallow-tailed axial-grooved heat pipe was developed. The numerical simulation results about thin film profile, liquid-vapour interface temperature, evaporating rate and heat flux at the evaporating thin film region were given by the current investigation and the effect of superheat on the liquid-vapour interface temperature, evaporating mass rate and heat flux was discussed. Meanwhile, thermal model of the meniscus region at the evaporating section was developed to calculate the rate of heat transfer. The ratio of the heat conduction in the evaporating thin liquid film region and total heat rate were also discussed. It is indicated that the thickness of thin liquid film rises in a nearly linear fashion. The disjoining pressure can be neglected with increasing the liquid film thickness, tends to be negligibly small. The heat transfer rate at the intrinsic meniscus cannot be compared with that of the evaporating liquid film region.

High-resolution x-ray diffraction and transmission electron microscopy of multiferroic BiFeO3 films

NASA Astrophysics Data System (ADS)

Qi, Xiaoding; Wei, Ming; Lin, Yuan; Jia, Quanxi; Zhi, Dan; Dho, Joonghoe; Blamire, Mark G.; MacManus-Driscoll, Judith L.

2005-02-01

High-resolution x-ray diffraction and transmission electron microscopy (TEM) have been used to study BiFeO3 thin films grown on the bare and SrRuO3 buffered (001) SrTiO3 substrates. Reciprocal space mapping (RSM) around (002) and (103) reflections revealed that BFO films with a thickness of about 200 nm were almost fully relaxed and had a rhombohedral structure. Cross-sectional, high-resolution TEM showed that the films started to relax at a very early stage of growth, which was consistent with the RSM results. A thin intermediate layer of about 2 nm was observed at the interface, which had a smaller lattice than the overgrown film. Twist distortions about the c axis to release the shear strain introduced by the growth of rhombic (001) BiFeO3 on cubic (001) SrTiO3 were also observed. The results indicate that a strained, coherent BiFeO3 film on (001) SrTiO3 is very difficult to maintain and (111) STO substrates are preferable.

Finite element modelling of AA6063T52 thin-walled tubes under quasi-static axial loading

NASA Astrophysics Data System (ADS)

Othman, A.; Ismail, AE

2018-04-01

The behavior of aluminum alloy 6063T52 thin walled tubes have been present in this paper to determine absorbed energy under quasi-static axial loading. The correlation and comparison have been implemented for each experimental and finite element analysis results, respectively. Wall-thickness of 1.6 and 1.9 mm were selected and all specimen tested under room temperature standard. The length of each specimen were fixed at 125 mm as well as diameter as well as a width and diameter of the tube at 50.8 mm. The two types of tubular cross-section were examined whereas a round and square thin-walled profiles. The specific absorbed energy (SEA) and crush force efficiency (CFE) were analyzed for each specimen and model to see the behavior induced to failure under progressive collapse. Result showed that a correlation less than 5% different between both of comparison experimental and finite element model. It has been found that the thin walled round tube absorbed more energy rather than square profile in term of specific energy with both of either 1.6 or 1.9 of 23.93% and 35.36%, respectively. Overall for crush force efficiency (CFE) of each tube profile around 0.42 to 0.58 value. Indicated that the all specimen profile fail under progressive damage. The calibration between deformed model and experimental specimen were examined and discussed. It was found that the similarity failure mechanism observed for each thin walled profiles.

Axial Crushing of Thin-Walled Columns with Octagonal Section: Modeling and Design

NASA Astrophysics Data System (ADS)

Liu, Yucheng; Day, Michael L.

This chapter focus on numerical crashworthiness analysis of straight thinwalled columns with octagonal cross sections. Two important issues in this analysis are demonstrated here: computer modeling and crashworthiness design. In the first part, this chapter introduces a method of developing simplified finite element (FE) models for the straight thin-walled octagonal columns, which can be used for the numerical crashworthiness analysis. Next, this chapter performs a crashworthiness design for such thin-walled columns in order to maximize their energy absorption capability. Specific energy absorption (SEA) is set as the design objective, side length of the octagonal cross section and wall thickness are selected as design variables, and maximum crushing force (Pm) occurs during crashes is set as design constraint. Response surface method (RSM) is employed to formulate functions for both SEA and Pm.

Grazing Incidence Cross-Sectioning of Thin-Film Solar Cells via Cryogenic Focused Ion Beam: A Case Study on CIGSe

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

Sardashti, Kasra; Haight, Richard; Anderson, Ryan

2016-06-22

Cryogenic focused ion beam (Cryo-FIB) milling at near-grazing angles is employed to fabricate cross-sections on thin Cu(In,Ga)Se2 with >8x expansion in thickness. Kelvin probe force microscopy (KPFM) on sloped cross sections showed reduction in grain boundaries potential deeper into the film. Cryo Fib-KPFM enabled the first determination of the electronic structure of the Mo/CIGSe back contact, where a sub 100 nm thick MoSey assists hole extraction due to 45 meV higher work function. This demonstrates that CryoFIB-KPFM combination can reveal new targets of opportunity for improvement in thin-films photovoltaics such as high-work-function contacts to facilitate hole extraction through the backmore » interface of CIGS.« less

Influence of gating design on microstructure and fluidity of thin sections AA320.0 cast hypo-eutectic Al-Si alloy

NASA Astrophysics Data System (ADS)

Ramadan, Mohamed

2018-05-01

Influence of gating design especially number of ingrates on microstructure and fluidity of thin sections of 2, 4, 6 mm AA320.0 cast hypo-eutectic Al-Si alloy was evaluated for sand casting molding technique. Increasing the number of ingates improves the microstructe to be fine and more globular. About 87 μm of α-Al grain size, 0.6 α-Al grain sphericity and 37 μm dendrite arm spacing DAS are achieved by using 4 ingates in gating system. Increasing the number of ingates up to 3 increases hardness, filling area and related fluditiy of all cast samples. The minimum thickness of 2.5 mm for each ingate should be considered in order to successfully production of high quality light weight thin sections castings in sand mold.

Relationship between thin-film bond strength as measured by a scratch test, and indentation hardness for bonding agents.

PubMed

Kusakabe, Shusuke; Rawls, H Ralph; Hotta, Masato

2016-03-01

To evaluate thin-film bond strength between a bonding agent and human dentin, using a scratch test, and the characteristics and accuracy of measurement. One-step bonding agents (BeautiBond; Bond Force; Adper Easy Bond; Clearfil tri-S Bond) and two-step bonding agents (Cleafil SE Bond; FL-Bond II) were investigated in this study. Flat dentin surfaces were prepared for extracted human molars. The dentin surfaces were ground and bonding agents were applied and light cured. The thin-film bond strength test of the specimens was evaluated by the critical load at which the coated bonding agent failed and dentin appeared. The scratch mark sections were then observed under a scanning electron microscope. Indentation hardness was evaluated by the variation in depth under an applied load of 10gf. Data were compared by one-way ANOVA with the Scheffé's post hoc multiple comparison test (p<0.05). In addition, thin-film bond strength and indentation hardness were analyzed using analysis of correlation and covariance. The thin-film bond strength of two-step bonding agents were found to be significantly higher than that of one-step bonding agents with small standard deviations. Scratch marks consistently showed adhesive failure in the vicinity of the bonding agent/dentin interface. The indentation hardness showed a trend that two-step bonding agents have greater hardness than one-step bonding agents. A moderately significant correlation (r(2)=0.31) was found between thin-film bond strength and indentation hardness. Thin-film bond strength test is a valid and reliable means of evaluating bond strength in the vicinity of the adhesive interface and is more accurate than other methods currently in use. Further, the thin-film bond strength is influenced by the hardness of the cued bonding agent. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

In situ hybridization at the electron microscope level: localization of transcripts on ultrathin sections of Lowicryl K4M-embedded tissue using biotinylated probes and protein A-gold complexes

PubMed Central

1986-01-01

A technique has been developed for localizing hybrids formed in situ on semi-thin and ultrathin sections of Lowicryl K4M-embedded tissue. Biotinylated dUTP (Bio-11-dUTP and/or Bio-16-dUTP) was incorporated into mitochondrial rDNA and small nuclear U1 probes by nick- translation. The probes were hybridized to sections of Drosophila ovaries and subsequently detected with an anti-biotin antibody and protein A-gold complex. On semi-thin sections, probe detection was achieved by amplification steps with anti-protein A antibody and protein A-gold with subsequent silver enhancement. At the electron microscope level, specific labeling was obtained over structures known to be the site of expression of the appropriate genes (i.e., either over mitochondria or over nuclei). The labeling pattern at the light microscope level (semi-thin sections) was consistent with that obtained at the electron microscope level. The described nonradioactive procedures for hybrid detection on Lowicryl K4M-embedded tissue sections offer several advantages: rapid signal detection: superior morphological preservation and spatial resolution; and signal-to-noise ratios equivalent to radiolabeling. PMID:3084498

Magnetic, in situ, mineral characterization of Chelyabinsk meteorite thin section

NASA Astrophysics Data System (ADS)

Nabelek, Ladislav; Mazanec, Martin; Kdyr, Simon; Kletetschka, Gunther

2015-06-01

Magnetic images of Chelyabinsk meteorite's (fragment F1 removed from Chebarkul lake) thin section have been unraveled by a magnetic scanning system from Youngwood Science and Engineering (YSE) capable of resolving magnetic anomalies down to 10-3 mT range from about 0.3 mm distance between the probe and meteorite surface (resolution about 0.15 mm). Anomalies were produced repeatedly, each time after application of magnetic field pulse of varying amplitude and constant, normal or reversed, direction. This process resulted in both magnetizing and demagnetizing of the meteorite thin section, while keeping the magnetization vector in the plane of the thin section. Analysis of the magnetic data allows determination of coercivity of remanence (Bcr) for the magnetic sources in situ. Value of Bcr is critical for calculating magnetic forces applicable during missions to asteroids where gravity is compromised. Bcr was estimated by two methods. First method measured varying dipole magnetic field strength produced by each anomaly in the direction of magnetic pulses. Second method measured deflections of the dipole direction from the direction of magnetic pulses. Bcr of magnetic sources in Chelyabinsk meteorite ranges between 4 and 7 mT. These magnetic sources enter their saturation states when applying 40 mT external magnetic field pulse.

Effect of dropped plies on the strength of graphite-epoxy laminates

NASA Technical Reports Server (NTRS)

Curry, James M.; Johnson, Eric R.; Starnes, James H., Jr.

1987-01-01

The reduction in the compressive and tensile strengths of graphite-epoxy laminates with thickness discontinuities due to dropped plies was studied by experiment and analysis. The specimens were fabricated with all the dropped plies lumped together in the center of a sixteen-ply quasi-isotropic layup, such that one surface was flat and the slope of the opposite surface changed abruptly at the dropped ply location to accommodate the thickness change. Even though the thick and thin sections are symmetrically laminated, there exists bending-extension coupling due to the geometric eccentricity of the middle planes of the thick and thin sections. Experiments were conducted on fifty-four specimens that differed in the configuration of the dropped plies only. The strength of a laminate with dropped plies is less than the strength of its thin section, and the compressive strength of a laminate with dropped plies is less than its tensile strength. The reduction in strength is directly related to the axial stiffness change between the thick and thin sections. To examine the mechanism of failure, the three-dimensional state of stress in the dropped ply region was evaluated by the finite element method. A tensile interlaminar criterion predicted the correct location of failure, but underestimated the failure load.

SWI or T2*: which MRI sequence to use in the detection of cerebral microbleeds? The Karolinska Imaging Dementia Study.

PubMed

Shams, S; Martola, J; Cavallin, L; Granberg, T; Shams, M; Aspelin, P; Wahlund, L O; Kristoffersen-Wiberg, M

2015-06-01

Cerebral microbleeds are thought to have potentially important clinical implications in dementia and stroke. However, the use of both T2* and SWI MR imaging sequences for microbleed detection has complicated the cross-comparison of study results. We aimed to determine the impact of microbleed sequences on microbleed detection and associated clinical parameters. Patients from our memory clinic (n = 246; 53% female; mean age, 62) prospectively underwent 3T MR imaging, with conventional thick-section T2*, thick-section SWI, and conventional thin-section SWI. Microbleeds were assessed separately on thick-section SWI, thin-section SWI, and T2* by 3 raters, with varying neuroradiologic experience. Clinical and radiologic parameters from the dementia investigation were analyzed in association with the number of microbleeds in negative binomial regression analyses. Prevalence and number of microbleeds were higher on thick-/thin-section SWI (20/21%) compared with T2*(17%). There was no difference in microbleed prevalence/number between thick- and thin-section SWI. Interrater agreement was excellent for all raters and sequences. Univariate comparisons of clinical parameters between patients with and without microbleeds yielded no difference across sequences. In the regression analysis, only minor differences in clinical associations with the number of microbleeds were noted across sequences. Due to the increased detection of microbleeds, we recommend SWI as the sequence of choice in microbleed detection. Microbleeds and their association with clinical parameters are robust to the effects of varying MR imaging sequences, suggesting that comparison of results across studies is possible, despite differing microbleed sequences. © 2015 by American Journal of Neuroradiology.

Multi-scale fracture damage associated with underground chemical explosions

DOE PAGES

Swanson, Erika M.; Sussman, A. J.; Wilson, J. E.; ...

2018-02-22

Understanding rock damage induced by explosions is critical for a number of applications including the monitoring and verification of underground nuclear explosions, mine safety issues, and modeling fluid flow through fractured rock. We use core observations, televiewer logs, and thin section observations to investigate fracture damage associated with two successive underground chemical explosions (SPE2 and SPE3) in granitic rock at both the mesoscale and microscale. We compare the frequency and orientations of core-scale fractures, and the frequency of microfractures, between a pre-experiment core and three post-experiment cores. Natural fault zones and explosion-induced fractures in the vicinity of the explosive sourcemore » are readily apparent in recovered core and in thin sections. Damage from faults and explosions is not always apparent in fracture frequency plots from televiewer logs, although orientation data from these logs suggests explosion-induced fracturing may not align with the pre-existing fracture sets. Core-scale observations indicate the extent of explosion-induced damage is 10.0 m after SPE2 and 6.8 m after SPE3, despite both a similar size and location for both explosions. At the microscale, damage is observed to a range distance of 10.2 ± 0.9 m after SPE2, and 16.6 ± 0.9 and 11.2 ± 0.6 in two different cores collected after SPE3. Additional explosion-induced damage, interpreted to be the result of spalling, is readily apparent near the surface, but only in the microfracture data. This depth extent and intensity of damage in the near-surface region also increased after an additional explosion. This study highlights the importance of evaluating structural damage at multiple scales for a more complete characterization of the damage, and particularly shows the importance of microscale observations for identifying spallation-induced damage.« less

Multi-scale fracture damage associated with underground chemical explosions

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

Swanson, Erika M.; Sussman, A. J.; Wilson, J. E.

Understanding rock damage induced by explosions is critical for a number of applications including the monitoring and verification of underground nuclear explosions, mine safety issues, and modeling fluid flow through fractured rock. We use core observations, televiewer logs, and thin section observations to investigate fracture damage associated with two successive underground chemical explosions (SPE2 and SPE3) in granitic rock at both the mesoscale and microscale. We compare the frequency and orientations of core-scale fractures, and the frequency of microfractures, between a pre-experiment core and three post-experiment cores. Natural fault zones and explosion-induced fractures in the vicinity of the explosive sourcemore » are readily apparent in recovered core and in thin sections. Damage from faults and explosions is not always apparent in fracture frequency plots from televiewer logs, although orientation data from these logs suggests explosion-induced fracturing may not align with the pre-existing fracture sets. Core-scale observations indicate the extent of explosion-induced damage is 10.0 m after SPE2 and 6.8 m after SPE3, despite both a similar size and location for both explosions. At the microscale, damage is observed to a range distance of 10.2 ± 0.9 m after SPE2, and 16.6 ± 0.9 and 11.2 ± 0.6 in two different cores collected after SPE3. Additional explosion-induced damage, interpreted to be the result of spalling, is readily apparent near the surface, but only in the microfracture data. This depth extent and intensity of damage in the near-surface region also increased after an additional explosion. This study highlights the importance of evaluating structural damage at multiple scales for a more complete characterization of the damage, and particularly shows the importance of microscale observations for identifying spallation-induced damage.« less

Highly ordered vertical structure of Synechococcus populations within the one-millimeter-thick photic zone of a hot spring cyanobacterial mat

NASA Technical Reports Server (NTRS)

Ramsing, N. B.; Ferris, M. J.; Ward, D. M.

2000-01-01

A variety of contemporary techniques were used to investigate the vertical distribution of thermophilic unicellular cyanobacteria, Synechococcus spp., and their activity within the upper 1-mm-thick photic zone of the mat community found in an alkaline siliceous hot spring in Yellowstone National Park in Wyoming. Detailed measurements were made over a diel cycle at a 61 degrees C site. Net oxygenic photosynthesis measured with oxygen microelectrodes was highest within the uppermost 100- to 200-microm-thick layer until midmorning, but as the day progressed, the peak of net activity shifted to deeper layers, stabilizing at a depth of 300 microm from midday throughout the afternoon. Examination of vertical thin sections by bright-field and autofluorescence microscopy revealed the existence of different populations of Synechococcus which form discrete bands at different vertical positions. Denaturing gradient gel electrophoresis analysis of PCR-amplified 16S rRNA gene segments from horizontal cryosections obtained at 100-microm-thick vertical intervals also suggested vertical stratification of cyanobacterial, green sulfur bacterium-like, and green nonsulfur bacterium-like populations. There was no evidence of diel migration. However, image analysis of vertical thin sections revealed the presence of a narrow band of rod-shaped Synechococcus cells in which the cells assumed an upright position. These upright cells, located 400 to 800 microm below the surface, were observed only in mat samples obtained around noon. In mat samples obtained at other time points, the cells were randomly oriented throughout the mat. These combined observations reveal the existence of a highly ordered structure within the very thin photic zone of this hot spring microbial mat, consisting of morphologically similar Synechococcus populations that are likely to be differentially adapted, some co-occurring with green sulfur bacterium-like populations, and all overlying green nonsulfur bacterium-like populations.

A Study on Nutritional Status of Rural School going Children in Kavre District.

PubMed

Mansur, D I; Haque, M K; Sharma, K; Mehta, D K; Shakya, R

2015-01-01

Background Childhood is a time of active growth in terms of physical size, mental, emotional and psychological development. Normal growth is dependent on adequate nutrition and encompasses major transformations from birth to adulthood. Nutrition is a focal point for health and well being; and has special significance in countries with disadvantages in socioeconomic and hygienic standards. Objective The objective of the present study was to assess the nutritional status in terms of prevalence of underweight, stunting and thinness among rural school going children. Method The present study was cross-sectional study, conducted on 438 rural school going children (169 male and 259 female) with the age group 4-16 years, during the period from April 2014 to July 2014. Age was recorded in year; height and weight were measured in centimeter and kilogram respectively. BMI was calculated by using standard equation. Result The present study concluded that the nutritional status in terms of prevalence of underweight, stunting and thinness were found to be 30.85%, 24.54% and 10.05% respectively among rural school going children of Kavre district. It was revealed that 37.87% was underweight, 29.59% was stunted and 11.25% was thinness among male children whereas in female children, 26.27% was underweight, 21.24% was stunted and 9.27% was thinness. Hence, high prevalence of underweight, stunting and thinness were observed in male than in female children. Conclusion The present study has successfully documented the nutritional status in terms of prevalence of underweight, stunting and thinness among the rural school going children of Kavre district. The results of the present study will be useful for policy makers in their endeavor to formulate various developmental and health care programs.

A new concept in polymeric thin-film composite nanofiltration membranes with antibacterial properties.

PubMed

Mollahosseini, Arash; Rahimpour, Ahmad

2013-01-01

A new, thin film, biofouling resistant, nanofiltration (NF) membrane was fabricated with two key characteristics, viz. a low rate of silver (Ag) release and long-lasting antibacterial properties. In the new approach, nanoparticles were embedded completely in a polymeric thin-film layer. A comparison was made between the new thin-film composite (TFC), NF membrane and thin-film nanocomposite (TFN), and antibacterial NF membranes. Both types of NF membrane were fabricated by interfacial polymerization on a polysulphone sublayer using m-phenylenediamine and trimesoyl chloride as an amine monomer and an acid chloride monomer, respectively. Energy dispersive X-ray (EDX) microanalysis demonstrated the presence of Ag nanoparticles. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to study the cross-sectional and surface morphological properties of the NF membranes. Permeability and salt rejection were tested using a dead-end filtration cell. Ag leaching from the membranes was measured using inductively coupled mass spectrometry (ICP-MS). Morphological studies showed that the TFC NF membranes had better thin-film formation (a more compact structure and a smoother surface) than TFN NF membranes. Performance experiments on TFC NF membranes revealed that permeability was good, without sacrificing salt rejection. The antibacterial properties of the fabricated membranes were tested using the disk diffusion method and viable plate counts. The antibiofouling properties of the membranes were examined by measuring the quantity of bacterial cells released from the biofilm formed (as a function of the amount of biofilm present). A more sensitive surface was observed compared to that of a typical antibacterial NF membrane. The Ag leaching rates were low, which will likely result in long-lasting antibacterial and biofouling resistant properties.

Effect of turpentine-induced fever during the enamel formation of rat incisor.

PubMed

Tung, Kuochung; Fujita, Haruko; Yamashita, Yasuo; Takagi, Yuzo

2006-06-01

Some epidemiological studies have indicated that diseases resulting in prolonged and sustained fever, such as exanthemata, respiratory infections and otitis media in infantile period or childhood are likely to have a marked deleterious effect on enamel formation, but the relationship between fever and enamel defects is unknown. The purpose of the present study was to induce a persistent high fever and examine the effects on the developing tooth enamel. Twenty male Wistar rats weighting 140+/-10 g were used in this study. For the experimental group, a dose of 2.3 ml/kg steam-distilled turpentine was subcutaneously injected into both hind limbs five times at 12h intervals. Control rats received 2.3 ml/kg of sterile saline into the same injection site. The rectal temperatures of animals were measured at the febrile period. After constant periods, the animals were sacrificed, and the mandibular incisors were examined by contact microradiography (CMR) and histological observation. The febrile state lasted for 57 h and the average temperature rose 1.51 degrees C higher than that of the control group. The ground sections, semi-thin and ultra-thin sections of mandibular incisors were prepared and the enamel was observed. The microradiographs showed a radiolucent line along with the incremental line in the enamel. Moreover, microscopic examination indicated disorientation of enamel prism and crystal-free area within this radiolucent lesion. Persistent high fever pattern was established firmly by the turpentine injections and the process of enamel formation was influenced by the febrile period.

Antarctic Meteorite Newsletter, volume 8, number 1

NASA Technical Reports Server (NTRS)

1985-01-01

Preliminary descriptions and classifications of meteorites examined since the July 1984 newsletter are presented. Each macroscopic description summarizes features that were visible to the eye (with, at most, 50X magnification). Each thin section description represents features that were found in a survey-level examination of a polished thin section that was prepared from a small (usually extrior) chip of the meteorite. Classification is based on microscopic petrography and reconnaissance-level electron-probe microanalyses.

Computer program for thin-wire structures in a homogeneous conducting medium

NASA Technical Reports Server (NTRS)

Richmond, J. H.

1974-01-01

A computer program is presented for thin-wire antennas and scatters in a homogeneous conducting medium. The anaylsis is performed in the real or complex frequency domain. The program handles insulated and bare wires with finite conductivity and lumped loads. The output data includes the current distribution, impedance, radiation efficiency, gain, absorption cross section, scattering cross section, echo area and the polarization scattering matrix. The program uses sinusoidal bases and Galerkin's method.

Behaviour of thin-walled cold-formed steel members in eccentric compression

NASA Astrophysics Data System (ADS)

Ungureanu, Viorel; Kotełko, Maria; Borkowski, Łukasz; Grudziecki, Jan

2018-01-01

Thin-walled cold-formed steel structures are usually made of members of class 4 cross-sections. Since these sections are prematurely prone to local or distortional buckling and due to the fact they do not have a real post-elastic capacity, the failure at ultimate stage of those members, either in compression or bending, always occurs by forming a local plastic mechanism. The present paper investigates the evolution of the plastic mechanisms and the possibility to use them to characterise the ultimate strength of short thin-walled cold-formed steel members subjected to eccentric compression about minor axis, particularly for members with lipped channel cross-section. Five different types of plastic mechanisms for members in compression with different eccentricities are identified and examined on the basis of FE numerical simulations. Preliminary results of experimental validation of numerical results are presented. The research is based on previous studies and some new investigations of the authors.

Applications of Blue Light-curing Acrylic Resin to Forensic Sample Preparation and Microtomy.

PubMed

Groves, Ethan; Palenik, Christopher S

2016-03-01

This study discusses the results of an evaluation of a one-part blue light-curing acrylic resin for embedding trace evidence prior to the preparation of thin sections with a microtome. Through a comparison to several epoxy resins, the physical properties relevant to both trace evidence examination and analytical microscopy in general, including as viscosity, clarity, color, hardness, and cure speed, were explored. Finally, thin sections from paint samples embedded in this acrylic resin were evaluated to determine if, through smearing or impregnation, the resin contributed to the infrared spectra. The results of this study show that blue light-curing acrylic resins provide the desired properties of an embedding medium, generate high-quality thin sections, and can significantly simplify the preparation of paint chips, fibers and a multitude of other types of microscopic samples in the forensic trace evidence laboratory. © 2015 American Academy of Forensic Sciences.

Formation of mono-layered gold nanoparticles in shallow depth of SiO 2 thin film by low-energy negative-ion implantation

NASA Astrophysics Data System (ADS)

Tsuji, H.; Arai, N.; Ueno, K.; Matsumoto, T.; Gotoh, N.; Adachi, K.; Kotaki, H.; Gotoh, Y.; Ishikawa, J.

2006-01-01

Mono-layered gold nanoparticles just below the surface of silicon oxide film have been formed by a gold negative-ion implantation at a very low-energy, where the deviation of implanted atoms was sufficiently narrow comparing to the size of nanoparticles. Gold negative ions were implanted into SiO2 thin films on Si substrate at energies of 35, 15 and 1 keV. The samples were annealed in Ar flow for 1 h at 900 or 1000 °C. Cross-sectional TEM observation for the implantation at 1 keV showed existence of Au nanoparticles aligned in the same depth of 5 nm from the surface. The nanoparticles had almost same diameter of 7 nm. The nanoparticles were found to be gold single crystal from a high-resolution TEM image.

Cross-sectional TEM specimen preparation for W/B{sub 4}C multilayer sample using FIB

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

Mondal, Puspen, E-mail: puspen@rrcat.gov.in; Pradhan, P. C.; Tiwari, Pragya

2016-05-23

A recent emergence of a cross-beam scanning electron microscopy (SEM)/focused-ion-beam (FIB) system have given choice to fabricate cross-sectional transmission electron microscopy (TEM) specimen of thin film multilayer sample. A 300 layer pair thin film multilayer sample of W/B{sub 4}C was used to demonstrate the specimen lift-out technique in very short time as compared to conventional cross-sectional sample preparation technique. To get large area electron transparent sample, sample prepared by FIB is followed by Ar{sup +} ion polishing at 2 kV with grazing incident. The prepared cross-sectional sample was characterized by transmission electron microscope.

Extraction efficiency and implications for absolute quantitation of propranolol in mouse brain, liver and kidney thin tissue sections using droplet-based liquid microjunction surface sampling-HPLC ESI-MS/MS

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

Kertesz, Vilmos; Weiskittel, Taylor M.; Vavek, Marissa

Currently, absolute quantitation aspects of droplet-based surface sampling for thin tissue analysis using a fully automated autosampler/HPLC-ESI-MS/MS system are not fully evaluated. Knowledge of extraction efficiency and its reproducibility is required to judge the potential of the method for absolute quantitation of analytes from thin tissue sections. Methods: Adjacent thin tissue sections of propranolol dosed mouse brain (10- μm-thick), kidney (10- μm-thick) and liver (8-, 10-, 16- and 24- μm-thick) were obtained. Absolute concentration of propranolol was determined in tissue punches from serial sections using standard bulk tissue extraction protocols and subsequent HPLC separations and tandem mass spectrometric analysis. Thesemore » values were used to determine propranolol extraction efficiency from the tissues with the droplet-based surface sampling approach. Results: Extraction efficiency of propranolol using 10- μm-thick brain, kidney and liver thin tissues using droplet-based surface sampling varied between ~45-63%. Extraction efficiency decreased from ~65% to ~36% with liver thickness increasing from 8 μm to 24 μm. Randomly selecting half of the samples as standards, precision and accuracy of propranolol concentrations obtained for the other half of samples as quality control metrics were determined. Resulting precision ( ±15%) and accuracy ( ±3%) values, respectively, were within acceptable limits. In conclusion, comparative quantitation of adjacent mouse thin tissue sections of different organs and of various thicknesses by droplet-based surface sampling and by bulk extraction of tissue punches showed that extraction efficiency was incomplete using the former method, and that it depended on the organ and tissue thickness. However, once extraction efficiency was determined and applied, the droplet-based approach provided the required quantitation accuracy and precision for assay validations. Furthermore, this means that once the extraction efficiency was calibrated for a given tissue type and drug, the droplet-based approach provides a non-labor intensive and high-throughput means to acquire spatially resolved quantitative analysis of multiple samples of the same type.« less

Extraction efficiency and implications for absolute quantitation of propranolol in mouse brain, liver and kidney thin tissue sections using droplet-based liquid microjunction surface sampling-HPLC ESI-MS/MS

DOE PAGES

Kertesz, Vilmos; Weiskittel, Taylor M.; Vavek, Marissa; ...

2016-06-22

Currently, absolute quantitation aspects of droplet-based surface sampling for thin tissue analysis using a fully automated autosampler/HPLC-ESI-MS/MS system are not fully evaluated. Knowledge of extraction efficiency and its reproducibility is required to judge the potential of the method for absolute quantitation of analytes from thin tissue sections. Methods: Adjacent thin tissue sections of propranolol dosed mouse brain (10- μm-thick), kidney (10- μm-thick) and liver (8-, 10-, 16- and 24- μm-thick) were obtained. Absolute concentration of propranolol was determined in tissue punches from serial sections using standard bulk tissue extraction protocols and subsequent HPLC separations and tandem mass spectrometric analysis. Thesemore » values were used to determine propranolol extraction efficiency from the tissues with the droplet-based surface sampling approach. Results: Extraction efficiency of propranolol using 10- μm-thick brain, kidney and liver thin tissues using droplet-based surface sampling varied between ~45-63%. Extraction efficiency decreased from ~65% to ~36% with liver thickness increasing from 8 μm to 24 μm. Randomly selecting half of the samples as standards, precision and accuracy of propranolol concentrations obtained for the other half of samples as quality control metrics were determined. Resulting precision ( ±15%) and accuracy ( ±3%) values, respectively, were within acceptable limits. In conclusion, comparative quantitation of adjacent mouse thin tissue sections of different organs and of various thicknesses by droplet-based surface sampling and by bulk extraction of tissue punches showed that extraction efficiency was incomplete using the former method, and that it depended on the organ and tissue thickness. However, once extraction efficiency was determined and applied, the droplet-based approach provided the required quantitation accuracy and precision for assay validations. Furthermore, this means that once the extraction efficiency was calibrated for a given tissue type and drug, the droplet-based approach provides a non-labor intensive and high-throughput means to acquire spatially resolved quantitative analysis of multiple samples of the same type.« less

High quality nitrogen-doped zinc oxide thin films grown on ITO by sol-gel method

NASA Astrophysics Data System (ADS)

Pathak, Trilok Kumar; Kumar, Vinod; Purohit, L. P.

2015-11-01

Highly transparent N-doped ZnO thin films were deposited on ITO coated corning glass substrate by sol-gel method. Ammonium nitrate was used as a dopant source of N with varying the doping concentration 0, 0.5, 1.0, 2.0 and 3.0 at%. The DSC analysis of prepared NZO sols is observed a phase transition at 150 °C. X-ray diffraction pattern showed the preferred (002) peak of ZnO, which was deteriorated with increased N concentrations. The transmittance of NZO thin films was observed to be ~88%. The bandgap of NZO thin films increased from 3.28 to 3.70 eV with increased N concentration from 0 to 3 at%. The maximum carrier concentration 8.36×1017 cm-3 and minimum resistivity 1.64 Ω cm was observed for 3 at% N doped ZnO thin films deposited on glass substrate. These highly transparent ZnO thin films can be used as a window layer in solar cells and optoelectronic devices.

Metabolic theory predicts animal self-thinning.

PubMed

Jonsson, Tomas

2017-05-01

The metabolic theory of ecology (MTE) predicts observed patterns in ecology based on metabolic rates of individuals. The theory is influential but also criticized for a lack of firm empirical evidence confirming MTE's quantitative predictions of processes, e.g. outcome of competition, at population or community level. Self-thinning is a well-known population level phenomenon among plants, but a much less studied phenomenon in animal populations and no consensus exists on what a universal thinning slope for animal populations might be, or if it exists. The goal of this study was to use animal self-thinning as a tool to test population-level predictions from MTE, by analysing (i) if self-thinning can be induced in populations of house crickets (Acheta domesticus) and (ii) if the resulting thinning trajectories can be predicted from metabolic theory, using estimates of the species-specific metabolic rate of A. domesticus. I performed a laboratory study where the growth of A. domesticus was followed, from hatching until emergence as adults, in 71 cohorts of five different starting densities. Ninety-six per cent of all cohorts in the three highest starting densities showed evidence of self-thinning, with estimated thinning slopes in general being remarkably close to that expected under metabolic constraints: A cross-sectional analysis of all data showing evidence of self-thinning produced an ordinary least square (OLS) slope of -1·11, exactly that predicted from specific metabolic allometry of A. domesticus. This result is furthermore supported by longitudinal analyses, allowing for independent responses within cohorts, producing a mean OLS slope across cohorts of -1·13 and a fixed effect linear mixed effects models slope of -1·09. Sensitivity analysis showed that these results are robust to how the criterion for on-going self-thinning was defined. Finally, also as predicted by metabolic theory, temperature had a negative effect on the thinning intercept, producing an estimate of the activation energy identical to that suggested by MTE. This study demonstrates a direct link between the metabolic rate of individuals and a population-level ecological process and as such provides strong support for research that aims to integrate body mass, via its effect on metabolism, consumption and competition, into models of populations and communities. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Better Finite-Element Analysis of Composite Shell Structures

NASA Technical Reports Server (NTRS)

Clarke, Gregory

2007-01-01

A computer program implements a finite-element-based method of predicting the deformations of thin aerospace structures made of isotropic materials or anisotropic fiber-reinforced composite materials. The technique and corresponding software are applicable to thin shell structures in general and are particularly useful for analysis of thin beamlike members having open cross-sections (e.g. I-beams and C-channels) in which significant warping can occur.

Mouse fetal whole intestine culture system for ex vivo manipulation of signaling pathways and three-dimensional live imaging of villus development.

PubMed

Walton, Katherine D; Kolterud, Asa

2014-09-04

Most morphogenetic processes in the fetal intestine have been inferred from thin sections of fixed tissues, providing snapshots of changes over developmental stages. Three-dimensional information from thin serial sections can be challenging to interpret because of the difficulty of reconstructing serial sections perfectly and maintaining proper orientation of the tissue over serial sections. Recent findings by Grosse et al., 2011 highlight the importance of three- dimensional information in understanding morphogenesis of the developing villi of the intestine(1). Three-dimensional reconstruction of singly labeled intestinal cells demonstrated that the majority of the intestinal epithelial cells contact both the apical and basal surfaces. Furthermore, three-dimensional reconstruction of the actin cytoskeleton at the apical surface of the epithelium demonstrated that the intestinal lumen is continuous and that secondary lumens are an artifact of sectioning. Those two points, along with the demonstration of interkinetic nuclear migration in the intestinal epithelium, defined the developing intestinal epithelium as a pseudostratified epithelium and not stratified as previously thought(1). The ability to observe the epithelium three-dimensionally was seminal to demonstrating this point and redefining epithelial morphogenesis in the fetal intestine. With the evolution of multi-photon imaging technology and three-dimensional reconstruction software, the ability to visualize intact, developing organs is rapidly improving. Two-photon excitation allows less damaging penetration deeper into tissues with high resolution. Two-photon imaging and 3D reconstruction of the whole fetal mouse intestines in Walton et al., 2012 helped to define the pattern of villus outgrowth(2). Here we describe a whole organ culture system that allows ex vivo development of villi and extensions of that culture system to allow the intestines to be three-dimensionally imaged during their development.

The structure and phase of cloud tops as observed by polarization lidar

NASA Technical Reports Server (NTRS)

Spinhirne, J. D.; Hansen, M. Z.; Simpson, J.

1983-01-01

High-resolution observations of the structure of cloud tops have been obtained with polarization lidar operated from a high altitude aircraft. Case studies of measurements acquired from cumuliform cloud systems are presented, two from September 1979 observations in the area of Florida and adjacent waters and a third during the May 1981 CCOPE experiment in southeast Montana. Accurate cloud top height structure and relative density of hydrometers are obtained from the lidar return signal intensity. Correlation between the signal return intensity and active updrafts was noted. Thin cirrus overlying developing turrets was observed in some cases. Typical values of the observed backscatter cross section were 0.1-5 (km/sr) for cumulonimbus tops. The depolarization ratio of the lidar signals was a function of the thermodynamic phase of cloud top areas. An increase of the cloud top depolarization with decreasing temperature was found for temperatures above and below -40 C.

Collisions of low-energy electrons with isopropanol

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

Bettega, M. H. F.; Winstead, C.; McKoy, V.

2011-10-15

We report measured and calculated cross sections for elastic scattering of low-energy electrons by isopropanol (propan-2-ol). The experimental data were obtained using the relative flow technique with helium as the standard gas and a thin aperture as the collimating target gas source, which permits use of this method without the restrictions imposed by the relative flow pressure conditions on helium and the unknown gas. The differential cross sections were measured at energies of 1.5, 2, 3, 5, 6, 8, 10, 15, 20, and 30 eV and for scattering angles from 10 deg. to 130 deg. The cross sections were computedmore » over the same energy range employing the Schwinger multichannel method in the static-exchange plus polarization approximation. Agreement between theory and experiment is very good. The present data are compared with previously calculated and measured results for n-propanol, the other isomer of C{sub 3}H{sub 7}OH. Although the integral and momentum transfer cross sections for the isomers are very similar, the differential cross sections show a strong isomeric effect: In contrast to the f-wave behavior seen in scattering by n-propanol, d-wave behavior is observed in the cross sections of isopropanol. These results corroborate our previous observations in electron collisions with isomers of C{sub 4}H{sub 9}OH.« less

Adherence to blood pressure measurement guidelines in long-term care facilities: A cross sectional study.

PubMed

Ozone, Sachiko; Sato, Mikiya; Takayashiki, Ayumi; Sakamoto, Naoto; Yoshimoto, Hisashi; Maeno, Tetsuhiro

2018-05-01

To assess the extent to which long-term care facilities in Japan adhere to blood pressure (BP) measurement guidelines. Cross-sectional, observational survey. Japan (nationwide). Geriatric health service facilities that responded to a questionnaire among 701 facilities that provide short-time daycare rehabilitation services in Japan. A written questionnaire that asked about types of measurement devices, number of measurements used to obtain an average BP, resting time prior to measurement, and measurement methods when patients' arms were covered with thin (eg, a light shirt) or thick sleeves (eg, a sweater) was administered. Proportion of geriatric health service facilities adherent to BP measurement guidelines. The response rate was 63.2% (443/701). Appropriate upper-arm BP measurement devices were used at 302 facilities (68.2%). The number of measurements was appropriate at 7 facilities (1.6%). Pre-measurement resting time was appropriate (≥5 minutes) at 205 facilities (46.3%). Of the 302 facilities that used appropriate BP measurement devices, 4 (1.3%) measured BP on a bare arm if it was covered with a thin sleeve, while 266 (88.1%) measured BP over a thin sleeve. When arms were covered with thick sleeves, BP was measured on a bare arm at 127 facilities (42.1%) and over a sleeve at 78 facilities (25.8%). BP measurement guidelines were not necessarily followed by long-term care service facilities in Japan. Modification of guidelines regarding removing thick sweaters and assessing BP on a visit-to-visit basis might be needed.

Flexural-torsional vibration of a tapered C-section beam

NASA Astrophysics Data System (ADS)

Dennis, Scott T.; Jones, Keith W.

2017-04-01

Previous studies have shown that numerical models of tapered thin-walled C-section beams based on a stepped or piecewise prismatic beam approximation are inaccurate regardless of the number of elements assumed in the discretization. Andrade recently addressed this problem by extending Vlasov beam theory to a tapered geometry resulting in new terms that vanish for the uniform beam. (See One-Dimensional Models for the Spatial Behaviour of Tapered Thin-Walled Bars with Open Cross-Sections: Static, Dynamic and Buckling Analyses, PhD Thesis, University of Coimbra, Portugal, 2012, https://estudogeral.sib.uc.pt) In this paper, we model the coupled bending-twisting vibration of a cantilevered tapered thin-walled C-section using a Galerkin approximation of Andrade's beam equations resulting in an 8-degree-of-freedom beam element. Experimental natural frequencies and mode shapes for 3 prismatic and 2 tapered channel beams are compared to model predictions. In addition, comparisons are made to detailed shell finite element models and exact solutions for the uniform beams to confirm the validity of the approach. Comparisons to the incorrect stepped model are also presented.

Multi-photon vertical cross-sectional imaging with a dynamically-balanced thin-film PZT z-axis microactuator.

PubMed

Choi, Jongsoo; Duan, Xiyu; Li, Haijun; Wang, Thomas D; Oldham, Kenn R

2017-10-01

Use of a thin-film piezoelectric microactuator for axial scanning during multi-photon vertical cross-sectional imaging is described. The actuator uses thin-film lead-zirconate-titanate (PZT) to generate upward displacement of a central mirror platform, micro-machined from a silicon-on-insulator (SOI) wafer to dimensions compatible with endoscopic imaging instruments. Device modeling in this paper focuses on existence of frequencies near device resonance producing vertical motion with minimal off-axis tilt even in the presence of multiple vibration modes and non-uniformity in fabrication outcomes. Operation near rear resonance permits large stroke lengths at low voltages relative to other vertical microactuators. Highly uniform vertical motion of the mirror platform is a key requirement for vertical cross-sectional imaging in the remote scan architecture being used for multi-photon instrument prototyping. The stage is installed in a benchtop testbed in combination with an electrostatic mirror that performs in-plane scanning. Vertical sectional images are acquired from 15 μm diameter beads and excised mouse colon tissue.

THE FINE STRUCTURE OF Streptomyces coelicolor

PubMed Central

Hopwood, David A.; Glauert, Audrey M.

1960-01-01

Colonies and spore suspensions of Streptomyces coelicolor were fixed for electron microscopy by the method of Kellenberger, Ryter, and Séchaud (1958). In thin sections the nuclear regions have a lower average density than the cytoplasm and the outlines of these regions correspond well with the profiles of the chromatinic bodies observed with the light microscope. The nuclear regions contain fibrils, about 5 mµ in diameter. In contrast, after fixation by the method of Palade (1952) the nuclear material is coagulated into irregular dense masses and tubular structures about 20 mµ in diameter, lying in a nuclear "vacuole." The significance of these observations is discussed in relation to the observations of other workers on the fine structure of the nuclear material of other bacteria and the chromosomes of higher cells. PMID:13715794

Thin bonded P.C.C. resurfacing : final report.

DOT National Transportation Integrated Search

1982-06-01

After the successful experimentation in Iowa with thin-bonded concrete overlays as an alternative to bituminous overlay, the Louisiana DOTD decided to resurface a short section of US 61, north of Baton Rouge, using this technique during April 1981. T...

Revisiting the horizontal redistribution of water in soils: Experiments and numerical modeling.

PubMed

Zhuang, L; Hassanizadeh, S M; Kleingeld, P J; van Genuchten, M Th

2017-09-01

A series of experiments and related numerical simulations were carried out to study one-dimensional water redistribution processes in an unsaturated soil. A long horizontal Plexiglas box was packed as homogenously as possible with sand. The sandbox was divided into two sections using a very thin metal plate, with one section initially fully saturated and the other section only partially saturated. Initial saturation in the dry section was set to 0.2, 0.4, or 0.6 in three different experiments. Redistribution between the wet and dry sections started as soon as the metal plate was removed. Changes in water saturation at various locations along the sandbox were measured as a function of time using a dual-energy gamma system. Also, air and water pressures were measured using two different kinds of tensiometers at various locations as a function of time. The saturation discontinuity was found to persist during the entire experiments, while observed water pressures were found to become continuous immediately after the experiments started. Two models, the standard Richards equation and an interfacial area model, were used to simulate the experiments. Both models showed some deviations between the simulated water pressures and the measured data at early times during redistribution. The standard model could only simulate the observed saturation distributions reasonably well for the experiment with the lowest initial water saturation in the dry section. The interfacial area model could reproduce observed saturation distributions of all three experiments, albeit by fitting one of the parameters in the surface area production term.

International Symposium on Epidemic Hemorrhagic Fever (Hemorrhagic Fever with Renal Syndrome) Held in Wuhan, Hubei, China on 31 October - 2 November 1988

DTIC Science & Technology

1989-10-01

15 Song Gan Prophylaxis of Hemorrhagic Fever With Renal Syndrome, Development of Inactivated Cell Culture Vaccine Against HFRS 11:45 END EPIDEMIOLOGYt...Intraveinous Ribavirin or Placebo 11:15 Yang Zhi-cheng Effect of Ribavirin on the White Blood Cell System and the Platelet of the Patients With EHF...from R. nortegicus ias madc by Hlung T. et al (5. A). It %sas a ers brilliant piecc of %;ork. because by observing thin-sections of infected cells in

the role of magmatism and segmentation in the structural evolution of the Afar Rift

NASA Astrophysics Data System (ADS)

Stab, Martin; Bellahsen, Nicolas; Pik, Raphaël; Quidelleur, Xavier; Ayalew, Dereje; Leroy, Sylvie

2015-04-01

A common issue at volcanic passive margins (VPM) is the lack of observation of the structures that accommodate stretching and thinning. Indeed, the most distal parts and the Ocean-Continent Transition is often masked by thick seaward-dipping reflectors (SDR) sequences. Some current challenges are then to know if the observed thinning fit the divergence (thinning vs dyking); and what is the rheological effect of magma supply that re-thickens the crust during extension? In the Central Afar magmatic rift (Ethiopia), the structures related to rifting since Oligocene are cropping out onshore and are well preserved. We present here a new structural model based on field data and lavas (U-Th/He and K/Ar) datings along a balanced cross-section of the Central Afar Western Margin. We mapped continent-ward normal fault array affecting highly tilted trapp series (29-30 Ma) unconformably overlain by tilted Oligo-Miocene (25-7 Ma) acid series. The main extensional and necking/thinning event took place during the end of this Miocene magmatic episode. The Pliocene flood basalt (Stratoid series) is erupted over an already thinned crust. The bulk extension for the Afar Western Margin is ß ~ 2.50. Our main findings are: - Oligo-Miocene deformation in Central Afar appears to be largely distributed through space and time ("magmatic wide rift"). It has been accommodated in a 200-300 km wide strip being a diffuse incipient plate boundary during the whole rifting history until the formation of present-day magmatic segments. There is a period of tectonic quiescence accompanied with few magma erupted at the surface between 25 Ma and 7 Ma. We suggest that tectonic and magmatic activity was focused at that time on the highly faulted Danakil block and Southern Red Sea, away from our study zone. - ß ~ 2.50 is higher than the thinning factor of ~1.30 observed in geophysical studies. We propose that the continental crust in Central Afar has been re-thickened during extension by the syn-rift magmatic supply. The difference in tectono-magmatic style between Central Afar (distributed extension and thick crust) and Northern Afar Erta Ale segment (narrow graben, thin crust) may be explained by the difference of magma volume (extruded & underplated) brought to the crust during extension. Magma supply in Central Afar thus allows the crust to be stretched without extreme thinning despite high degree of divergence. Thus, break-up may occur in both Central and Northern Afar, not depending on the apparent thickness of the crust but rather on the ability of the system to localize deformation. - There appears to be a link between early-rift transform zones and distribution of magmatic activity that affects in turn the structural style. We suggest that the closest feature from the SDR at mature VPM is the Stratoid series. The difference of volume between the Stratoid and the enormous volume of SDR imaged in seismic studies (e.g South Atlantic) is probably best explained by an initial low mantle potential temperature in Afar. Contrasted structural styles in Afar are the product of magma supply and segmentation, controlling thinning and extension distribution in the rift.

Natural History of the Central Structural Abnormalities in Choroideremia: A Prospective Cross-Sectional Study.

PubMed

Aleman, Tomas S; Han, Grace; Serrano, Leona W; Fuerst, Nicole M; Charlson, Emily S; Pearson, Denise J; Chung, Daniel C; Traband, Anastasia; Pan, Wei; Ying, Gui-Shuang; Bennett, Jean; Maguire, Albert M; Morgan, Jessica I W

2017-03-01

To describe in detail the central retinal structure of a large group of patients with choroideremia (CHM). A prospective, cross-sectional, descriptive study. Patients (n = 97, age 6-71 years) with CHM and subjects with normal vision (n = 44; ages 10-50 years) were included. Subjects were examined with spectral-domain optical coherence tomography (SD OCT) and near-infrared reflectance imaging. Visual acuity (VA) was measured during their encounter or obtained from recent ophthalmic examinations. Visual thresholds were measured in a subset of patients (n = 24) with automated static perimetry within the central regions (±15°) examined with SD OCT. Visual acuity and visual thresholds; total nuclear layer, inner nuclear layer (INL), and outer nuclear layer (ONL) thicknesses; and horizontal extent of the ONL and the photoreceptor outer segment (POS) interdigitation zone (IZ). Earliest abnormalities in regions with normally appearing retinal pigment epithelium (RPE) were the loss of the POS and ellipsoid zone associated with rod dysfunction. Transition zones (TZs) from relatively preserved retina to severe ONL thinning and inner retinal thickening moved centripetally with age. Most patients (88%) retained VAs better than 20/40 until their fifth decade of life. The VA decline coincided with migration of the TZ near the foveal center. There were outer retinal tubulations in degenerated, nonatrophic retina in the majority (69%) of patients. In general, RPE abnormalities paralleled photoreceptor degeneration, although there were regions with detectable but abnormally thin ONL co-localizing with severe RPE depigmentation and choroidal thinning. Abnormalities of the POS and rod dysfunction are the earliest central abnormalities observed in CHM. Foveal function is relatively preserved until the fifth decade of life. Migration of the TZs to the foveal center with foveal thinning and structural disorganization heralded central VA loss. The relationships established may help outline the eligibility criteria and outcome measures for clinical trials for CHM. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Nanoscale size effects on the mechanical properties of platinum thin films and cross-sectional grain morphology

NASA Astrophysics Data System (ADS)

Abbas, K.; Alaie, S.; Ghasemi Baboly, M.; Elahi, M. M. M.; Anjum, D. H.; Chaieb, S.; Leseman, Z. C.

2016-01-01

The mechanical behavior of polycrystalline Pt thin films is reported for thicknesses of 75 nm, 100 nm, 250 nm, and 400 nm. These thicknesses correspond to transitions between nanocrystalline grain morphology types as found in TEM studies. Thinner samples display a brittle behavior, but as thickness increases the grain morphology evolves, leading to a ductile behavior. During evolution of the morphology, dramatic differences in elastic moduli (105-160 GPa) and strengths (560-1700 MPa) are recorded and explained by the variable morphology. This work suggests that in addition to the in-plane grain size of thin films, the transitions in cross-sectional morphologies of the Pt films significantly affect their mechanical behavior.

Quality response of even-aged 80-year-old white oak trees after thinning

Treesearch

David L. Sonderman

1984-01-01

Stem defects were studied over an 18-year period to determine the effect of thinning intensity on quality development of 80-year-old white oak trees. Seventy-nine white oak trees from a thinning study in Kentucky were analyzed from stereo photographs taken in 1960 and 1978. Stem-related defects were measured on the butt 8-foot and second 8-foot sections of each tree....

Normal Modes of Vibration of the PHALANX Gun

DTIC Science & Technology

1993-06-01

Clamps Bricks, Thin Shells, Rigid Elements Mid-Barrel Clamps Bricks, Rigid Elements Barrels Beams with tubular cross-section Stub Rotor Bricks, Thin...Shells Rotor Bricks Needle Bearing Bricks, Springs Casing Thin Shells Thrust Bearing Bricks, Springs Recoil Adapters Bricks, Rigid Elements, Springs... rigid elements were used to connect the barrels to the clamps and stub rotor and the recoil adapter springs to 48 the gun body. "End release codes

Effect of thinning on growth and potential quality of young white oak crop trees

Treesearch

Martin E. Dale; David L. Sonderman

1984-01-01

Relative change in several types of stem defects were studied over a 16-year period to determine the effect of thinning intensity on the development of tree quality. We studied quality changes on sample white oak crop trees that were selected from five density levels created in a 1961 thinning. Branch-related and other stem defects on the butt 16-foot section were...

Damage in a Thin Metal Film by High-Power Terahertz Radiation.

PubMed

Agranat, M B; Chefonov, O V; Ovchinnikov, A V; Ashitkov, S I; Fortov, V E; Kondratenko, P S

2018-02-23

We report on the experimental observation of high-power terahertz-radiation-induced damage in a thin aluminum film with a thickness less than a terahertz skin depth. Damage in a thin metal film produced by a single terahertz pulse is observed for the first time. The damage mechanism induced by a single terahertz pulse could be attributed to thermal expansion of the film causing debonding of the film from the substrate, film cracking, and ablation. The damage pattern induced by multiple terahertz pulses at fluences below the damage threshold is quite different from that observed in single-pulse experiments. The observed damage pattern resembles an array of microcracks elongated perpendicular to the in-plane field direction. A mechanism related to microcracks' generation and based on a new phenomenon of electrostriction in thin metal films is proposed.

Damage in a Thin Metal Film by High-Power Terahertz Radiation

NASA Astrophysics Data System (ADS)

Agranat, M. B.; Chefonov, O. V.; Ovchinnikov, A. V.; Ashitkov, S. I.; Fortov, V. E.; Kondratenko, P. S.

2018-02-01

We report on the experimental observation of high-power terahertz-radiation-induced damage in a thin aluminum film with a thickness less than a terahertz skin depth. Damage in a thin metal film produced by a single terahertz pulse is observed for the first time. The damage mechanism induced by a single terahertz pulse could be attributed to thermal expansion of the film causing debonding of the film from the substrate, film cracking, and ablation. The damage pattern induced by multiple terahertz pulses at fluences below the damage threshold is quite different from that observed in single-pulse experiments. The observed damage pattern resembles an array of microcracks elongated perpendicular to the in-plane field direction. A mechanism related to microcracks' generation and based on a new phenomenon of electrostriction in thin metal films is proposed.

Characteristics of heat transfer fouling of thin stillage using model thin stillage and evaporator concentrates

NASA Astrophysics Data System (ADS)

Challa, Ravi Kumar

The US fuel ethanol demand was 50.3 billion liters (13.3 billion gallons) in 2012. Corn ethanol was produced primarily by dry grind process. Heat transfer equipment fouling occurs during corn ethanol production and increases the operating expenses of ethanol plants. Following ethanol distillation, unfermentables are centrifuged to separate solids as wet grains and liquid fraction as thin stillage. Evaporator fouling occurs during thin stillage concentration to syrup and decreases evaporator performance. Evaporators need to be shutdown to clean the deposits from the evaporator surfaces. Scheduled and unscheduled evaporator shutdowns decrease process throughput and results in production losses. This research were aimed at investigating thin stillage fouling characteristics using an annular probe at conditions similar to an evaporator in a corn ethanol production plant. Fouling characteristics of commercial thin stillage and model thin stillage were studied as a function of bulk fluid temperature and heat transfer surface temperature. Experiments were conducted by circulating thin stillage or carbohydrate mixtures in a loop through the test section which consisted of an annular fouling probe while maintaining a constant heat flux by electrical heating and fluid flow rate. The change in fouling resistance with time was measured. Fouling curves obtained for thin stillage and concentrated thin stillage were linear with time but no induction periods were observed. Fouling rates for concentrated thin stillage were higher compared to commercial thin stillage due to the increase in solid concentration. Fouling rates for oil skimmed and unskimmed concentrated thin stillage were similar but lower than concentrated thin stillage at 10% solids concentration. Addition of post fermentation corn oil to commercial thin stillage at 0.5% increments increased the fouling rates up to 1% concentration but decreased at 1.5%. As thin stillage is composed of carbohydrates, protein, lipid, fiber and minerals, simulated thin stillage was prepared with carbohydrate mixtures and tested for fouling rates. Induction period, maximum fouling resistance and mean fouling rates were determined. Two experiments were performed with two varieties of starch, waxy and high amylose and short chain carbohydrates, corn syrup solids and glucose. Interaction effects of glucose with starch varieties were studied. In the first experiment, short chain carbohydrates individual and interaction effects with starch were studied. For mixtures prepared from glucose and corn syrup solids, no fouling was observed. Mixtures prepared from starch, a long glucose polymer, showed marked fouling. Corn syrup solids and glucose addition to pure starch decreased the mean fouling rates and maximum fouling resistances. Between corn syrup solids and glucose, starch fouling rates were reduced with addition of glucose. Induction periods of pure mixtures of either glucose or corn syrup solids were longer than the test period (5 h). Pure starch mixture had no induction period. Maximum fouling resistance was higher for mixtures with higher concentration of longer polymers. Waxy starch had a longer induction period than high amylose starch. Maximum fouling resistance was higher for waxy than high amylose starch. Addition of glucose to waxy or high amylose starch increased induction period of mixtures longer than 5 h test period. It appears that the bulk fluid temperature plays an important role on carbohydrate mixture fouling rates. Higher bulk fluid temperatures increased the initial fouling rates of the carbohydrate mixtures. Carbohydrate type, depending on the polymer length, influenced the deposit formation. Longer chain carbohydrate, starch, had higher fouling rates compared to shorter carbohydrates such as glucose and corn syrup solids. For insoluble carbohydrate mixtures, fouling was severe. As carbohydrate solubility increased with bulk fluid temperature, surface reaction increased at probe surface and resulted in deposit formation. Higher surface temperatures eliminated induction periods for thin stillage and fouling was rapid on probe surface.

Measurement of fragmentation cross sections of 12C ions on a thin gold target with the FIRST apparatus

NASA Astrophysics Data System (ADS)

Toppi, M.; Abou-Haidar, Z.; Agodi, C.; Alvarez, M. A. G.; Aumann, T.; Balestra, F.; Battistoni, G.; Bocci, A.; Böhlen, T. T.; Boudard, A.; Brunetti, A.; Carpinelli, M.; Cirio, R.; Cirrone, G. A. P.; Cortes-Giraldo, M. A.; Cuttone, G.; de Napoli, M.; Durante, M.; Fernández-García, J. P.; Finck, Ch.; Golosio, B.; Iarocci, E.; Iazzi, F.; Ickert, G.; Introzzi, R.; Juliani, D.; Krimmer, J.; Kummali, A. H.; Kurz, N.; Labalme, M.; Leifels, Y.; Le Fèvre, A.; Leray, S.; Marchetto, F.; Monaco, V.; Morone, M. C.; Nicolosi, D.; Oliva, P.; Paoloni, A.; Piersanti, L.; Pleskac, R.; Randazzo, N.; Rescigno, R.; Romano, F.; Rossi, D.; Rosso, V.; Rousseau, M.; Sacchi, R.; Sala, P.; Salvador, S.; Sarti, A.; Scheidenberger, C.; Schuy, C.; Sciubba, A.; Sfienti, C.; Simon, H.; Sipala, V.; Spiriti, E.; Tropea, S.; Vanstalle, M.; Younis, H.; Patera, V.; FIRST Collaboration

2016-06-01

A detailed knowledge of the light ions interaction processes with matter is of great interest in basic and applied physics. As an example, particle therapy and space radioprotection require highly accurate fragmentation cross-section measurements to develop shielding materials and estimate acute and late health risks for manned missions in space and for treatment planning in particle therapy. The Fragmentation of Ions Relevant for Space and Therapy experiment at the Helmholtz Center for Heavy Ion research (GSI) was designed and built by an international collaboration from France, Germany, Italy, and Spain for studying the collisions of a 12C ion beam with thin targets. The collaboration's main purpose is to provide the double-differential cross-section measurement of carbon-ion fragmentation at energies that are relevant for both tumor therapy and space radiation protection applications. Fragmentation cross sections of light ions impinging on a wide range of thin targets are also essential to validate the nuclear models implemented in MC simulations that, in such an energy range, fail to reproduce the data with the required accuracy. This paper presents the single differential carbon-ion fragmentation cross sections on a thin gold target, measured as a function of the fragment angle and kinetic energy in the forward angular region (θ ≲6° ), aiming to provide useful data for the benchmarking of the simulation softwares used in light ions fragmentation applications. The 12C ions used in the measurement were accelerated at the energy of 400 MeV/nucleon by the SIS (heavy ion synchrotron) GSI facility.

Thin bonded P.C.C. resurfacing : interim report No. 1.

DOT National Transportation Integrated Search

1982-06-01

After the successful experimentation in Iowa with thin-bonded concrete overlays as an alternative to bituminous overlay, the Louisiana DOTD decided to resurface a short section of US 61, north of Baton Rouge, using this technique during April 1981. T...

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

Buck, E.C.; Dietz, N.L.; Bates, J.K.

Uranium contaminated soils from the Fernald Operation Site, Ohio, have been examined by a combination of optical microscopy, scanning electron microscopy with backscattered electron detection (SEM/BSE), and analytical electron microscopy (AEM). A method is described for preparing of transmission electron microscopy (TEM) thin sections by ultramicrotomy. By using these thin sections, SEM and TEM images can be compared directly. Uranium was found in iron oxides, silicates (soddyite), phosphates (autunites), and fluorite. Little uranium was associated with clays. The distribution of uranium phases was found to be inhomogeneous at the microscopic level.

Analysis of asymmetric property with DC bias current on thin-film magnetoimpedance element

NASA Astrophysics Data System (ADS)

Kikuchi, Hiroaki; Sumida, Chihiro

2018-05-01

We theoretically analyzed the magnetoimpedance profile of a thin-film element with a DC bias current using the bias susceptibility theory and Maxwell's equations. Although the analysis model predicts that an element with a rectangular cross section shows symmetric impedance property with respect to the Z-axis with DC bias current, the experimental results showed asymmetric properties. Taking the shape imbalance and trapezoidal cross section of the element into account, we explained the asymmetric impedance properties qualitatively.

Riding the Right Wavelet: Detecting Fracture and Fault Orientation Scale Transitions Using Morlet Wavelets

NASA Astrophysics Data System (ADS)

Rizzo, R. E.; Healy, D.; Farrell, N. J.; Smith, M.

2016-12-01

The analysis of images through two-dimensional (2D) continuous wavelet transforms makes it possible to acquire local information at different scales of resolution. This characteristic allows us to use wavelet analysis to quantify anisotropic random fields such as networks of fractures. Previous studies [1] have used 2D anisotropic Mexican hat wavelets to analyse the organisation of fracture networks from cm- to km-scales. However, Antoine et al. [2] explained that this technique can have a relatively poor directional selectivity. This suggests the use of a wavelet whose transform is more sensitive to directions of linear features, i.e. 2D Morlet wavelets [3]. In this work, we use a fully-anisotropic Morlet wavelet as implemented by Neupauer & Powell [4], which is anisotropic in its real and imaginary parts and also in its magnitude. We demonstrate the validity of this analytical technique by application to both synthetic - generated according to known distributions of orientations and lengths - and experimentally produced fracture networks. We have analysed SEM Back Scattered Electron images of thin sections of Hopeman Sandstone (Scotland, UK) deformed under triaxial conditions. We find that the Morlet wavelet, compared to the Mexican hat, is more precise in detecting dominant orientations in fracture scale transition at every scale from intra-grain fractures (µm-scale) up to the faults cutting the whole thin section (cm-scale). Through this analysis we can determine the relationship between the initial orientation of tensile microcracks and the final geometry of the through-going shear fault, with total areal coverage of the analysed image. By comparing thin sections from experiments at different confining pressures, we can quantitatively explore the relationship between the observed geometry and the inferred mechanical processes. [1] Ouillon et al., Nonlinear Processes in Geophysics (1995) 2:158 - 177. [2] Antoine et al., Cambridge University Press (2008) 192-194. [3] Antoine et al., Signal Processing (1993) 31:241 - 272. [4] Neupauer & Powell, Computer & Geosciences (2005) 31:456 - 471.

Hidden Ice Worlds - Pleistocene glacigenic deposits in Essex, England. Application of the novel systematic approach to thin-section description.

NASA Astrophysics Data System (ADS)

Leszczynska, Karolina; Boreham, Julie; Boreham, Steve

2013-04-01

In the 'Hidden Ice Worlds' research project a novel systematic approach for thin-section description (Leszczynska et al., 2011) is applied to analyse the internal structure of 8 m thick periglacially disturbed sequence from the Royal Oak Pit - a small disused quarry in East Anglia, Essex, east of Chelmsford, near Danbury. Danbury Hill is situated on the south-eastern margin of the Elsterian (Anglian) till sheet. This area was glaciated only once, during the Pleistocene, Elsterian (Anglian) glaciation (480-420 ka BP), however two local ice-sheet margin fluctuations are envisaged (inter alia Turner, 1970 and others). The stratigraphical sequence of the Royal Oak Pit comprises: massive gravel, arranged in sheets, overlain by fine silty-clay and silty-sand with ripple marks and planar cross beds, overlain by a 50 cm thick unit of massive gravel gradually changing into periglacially disturbed silty-clayey-gravel with the bottom 50 cm of fine laminated silty clay. This sequence is situated on the lee side of Danbury Hill, at over 50 m OD. This is an atypical location for the periglacially disturbed deposits of such a substantial thickness (up to 8 m), which usually occur in the lower areas. The deposits at this site were investigated at a macro-scale using field-section logging, ground penetrating radar survey, clast lithology, clay mineralogy analysis and loss-on-ignition and at a micro-scale using thin-section analysis. There are two main aims of the project presented: • To describe the genesis and to discern the main processes associated with the formation of the unusually thick periglacially disturbed unit at the Danbury Hill slope and • To test the novel, tree-based, systematic approach as a guiding tool for thin for thin-section description of Quaternary deposits (Leszczynska et al., 2011). The results of the micromorphological analyses of the deposits from the Royal Oak Pit allow a new hypothesis for the origin of the sequence to be put forward. The main process responsible for the evolution of the deposits consist of multiple phases of freezing and thawing of the deposit and associated physical reworking, subsequent to Elsterian (Anglian). Inversion of the topography is proposed as a necessary condition for the formation and preservation of the periglacially disturbed sequence on hill slope at such elevated location. The novel systematic approach proved to be a useful tool in guiding the thin-section description, regardless of the type of the deposit and the aim of the research. Reference: Leszczynska, K., Boreham, J. and Boreham, S., 2011. A novel methodological approach for thin-section description and its application to periglacially disturbed Pleistocene deposits from Danbury, Essex, UK. Netherlands Journal of Geosciences 90: 271-291. Turner, C., 1970. Middle Pleistocene deposits at Marks Tey, Essex. Philosophical Transactions of the Royal Society of London, series B 257: 373-440.

Multispectral Digital Image Analysis of Varved Sediments in Thin Sections

NASA Astrophysics Data System (ADS)

Jäger, K.; Rein, B.; Dietrich, S.

2006-12-01

An update of the recently developed method COMPONENTS (Rein, 2003, Rein & Jäger, subm.) for the discrimination of sediment components in thin sections is presented here. COMPONENTS uses a 6-band (multispectral) image analysis. To derive six-band spectral information of the sediments, thin sections are scanned with a digital camera mounted on a polarizing microscope. The thin sections are scanned twice, under polarized and under unpolarized plain light. During each run RGB images are acquired which are subsequently stacked to a six-band file. The first three bands (Blue=1, Green=2, Red=3) result from the spectral behaviour in the blue, green and red band with unpolarized light conditions, and the bands 4 to 6 (Blue=4, Green=5, Red=6) from the polarized light run. The next step is the discrimination of the sediment components by their transmission behaviour. Automatic classification algorithms broadly used in remote sensing applications cannot be used due to unavoidable variations of sediment particle or thin section thicknesses that change absolute grey values of the sediment components. Thus, we use an approach based on band ratios, also known as indices. By using band ratios, the grey values measured in different bands are normalized against each other and illumination variations (e.g. thickness variations) are eliminated. By combining specific ratios we are able to detect all seven major components in the investigated sediments (carbonates, diatoms, fine clastic material, plant rests, pyrite, quartz and resin). Then, the classification results (compositional maps) are validated. Although the automatic classification and the analogous classification show high concordances, some systematic errors could be identified. For example, the transition zone between the sediment and resin filled cracks is classified as fine clastic material and very coarse carbonates are partly classified as quartz because coarse carbonates can be very bright and spectra are partly saturated (grey value 255). With reduced illumination intensity "carbonate image pixels" get unsaturated and can be well distinguished from quartz grains. During the evaluation process we identify all falsely classified areas using neighbourhood matrices and reclassify them. Finally, we use filter techniques to derive downcore component frequencies from the classified thin section images for variable thick virtual samples. The filter conducts neighbourhood analyses. After filtering, each pixel of the filtered images carries the information about the frequency of any given component in a defined neighbourhood around (virtual sampling). References Rein, B. (2003) In-situ Reflektionsspektroskopie und digitale Bildanalyse Gewinnung hochauflösender Paläoumweltdaten mit fernerkundlichen Methoden, Habilitation Thesis, Univ. Mainz, 104 p. Jäger, K. and Rein, B. (2005): Identifying varve components using digital image analysis techniques. - in: Heidi Haas, Karl Ramseyer & Fritz Schlunegger (eds.): Sediment 2005 (18th-20th July 2005), Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften, 38, p. 81 Rein, B. and Jäger, K. (subm.) COMPONENTS - Sediment component detection in thin sections by multispectral digital image analysis. Sedimentology.

On the Nature and Extent of Optically Thin Marine low Clouds

NASA Technical Reports Server (NTRS)

Leahy, L. V.; Wood, R.; Charlson, R. J.; Hostetler, C. A.; Rogers, R. R.; Vaughan, M. A.; Winker, D. M.

2012-01-01

Macrophysical properties of optically thin marine low clouds over the nonpolar oceans (60 deg S-60 deg N) are measured using 2 years of full-resolution nighttime data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). Optically thin clouds, defined as the subset of marine low clouds that do not fully attenuate the lidar signal, comprise almost half of the low clouds over the marine domain. Regionally, the fraction of low clouds that are optically thin (f(sub thin,cld)) exhibits a strong inverse relationship with the low-cloud cover, with maxima in the tropical trades (f(sub thin,cld) greater than 0.8) and minima in regions of persistent marine stratocumulus and in midlatitudes (f(sub thin,cld) less than 0.3). Domain-wide, a power law fit describes the cloud length distribution, with exponent beta = 2.03 +/- 0.06 (+/-95% confidence interval). On average, the fraction of a cloud that is optically thin decreases from approximately 1 for clouds smaller than 2 km to less than 0.3 for clouds larger than 30 km. This relationship is found to be independent of region, so that geographical variations in the cloud length distribution explain three quarters of the variance in f(sub thin,cld). Comparing collocated trade cumulus observations from CALIOP and the airborne High Spectral Resolution Lidar reveals that clouds with lengths smaller than are resolvable with CALIOP contribute approximately half of the low clouds in the region sampled. A bounded cascade model is constructed to match the observations from the trades. The model shows that the observed optically thin cloud behavior is consistent with a power law scaling of cloud optical depth and suggests that most optically thin clouds only partially fill the CALIOP footprint.

Carbon abundances, major element chemistry, and mineralogy of hydrated interplanetary dust particles

NASA Technical Reports Server (NTRS)

Keller, L. P.; Thomas, K. L.; Mckay, D. S.

1993-01-01

Hydrated interplanetary dust particles (IDP's) comprise a major fraction of the interplanetary dust particles collected in the stratosphere. While much is known about the mineralogy and chemistry of hydrated IDP's, little is known about the C abundance in this class of IDP's, the nature of the C-bearing phases, and how the C abundance is related to other physical properties of hydrated IDP's. Bulk compositional data (including C and O) for 11 hydrated IDP's that were subsequently examined by the transition electron microscopy (TEM) to determine their mineralogy and mineral chemistry are reported. Our analysis indicates that these hydrated IDP's are strongly enriched in C relative to the most C-rich meteorites. The average abundance of C in these hydrated IDP's is 4X CI chondrite values. The bulk compositions (including C and O) of 11 hydrated IDP's were determined by thin-window, energy-dispersive x ray (EDX) spectroscopy of the uncoated IDP's on Be substrates in the scanning electron microscopy (SEM). As a check on our C measurements, one of the IDP's (L2006H5) was embedded in glassy S, and microtome thin sections were prepared and placed onto Be substrates. Thin-film EDX analyses of multiple thin sections of L2006H5 show good agreement with the bulk value determined in the SEM. Following EDX analysis, the mineralogy and mineral chemistry of each IDP was determined by analyzing ultramicrotome thin sections in a TEM equipped with an EDX spectrometer.

Observation of High-Harmonic Generation from an Atomically Thin Semiconductor [Observation of High Harmonics from and Atomically Thin Semiconductor

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

Liu, Hanzhe; Li, Yilei; You, Yongsing

We report the observation of nonperturbative high-harmonic generation from monolayer MoS 2. Here, the yield is higher in monolayer compared to a single layer of the bulk, an effect attributed to strong electron-hole interactions in the monolayer.

Observation of High-Harmonic Generation from an Atomically Thin Semiconductor [Observation of High Harmonics from and Atomically Thin Semiconductor

DOE PAGES

Liu, Hanzhe; Li, Yilei; You, Yongsing; ...

2016-01-01

We report the observation of nonperturbative high-harmonic generation from monolayer MoS 2. Here, the yield is higher in monolayer compared to a single layer of the bulk, an effect attributed to strong electron-hole interactions in the monolayer.

FDTD modeling of thin impedance sheets

NASA Technical Reports Server (NTRS)

Luebbers, Raymond J.; Kunz, Karl S.

1991-01-01

Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. In this paper it is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods.

One-dimensional analysis of thin-walled beams with diaphragms and its application to optimization for stiffness reinforcement

NASA Astrophysics Data System (ADS)

Jung, Joon Hee; Jang, Gang-Won; Shin, Dongil; Kim, Yoon Young

2018-03-01

This paper presents a method to analyze thin-walled beams with quadrilateral cross sections reinforced with diaphragms using a one-dimensional higher-order beam theory. The effect of a diaphragm is reflected focusing on the increase of static stiffness. The deformations on the beam-interfacing boundary of a thin diaphragm are described by using deformation modes of the beam cross section while the deformations inside the diaphragm are approximated in the form of complete cubic polynomials. By using the principle of minimum potential energy, its stiffness that significantly affects distortional deformation of a thin-walled beam can be considered in the one-dimensional beam analysis. It is shown that the accuracy of the resulting one-dimensional analysis is comparable with that by a shell element based analysis. As a means to demonstrate the usefulness of the present approach for design, position optimization problems of diaphragms for stiffness reinforcement of an automotive side frame are solved.

Systematic approach to study of thinly and thickly sectioned melanoma tissues with scanning acoustic microscopy

NASA Astrophysics Data System (ADS)

Miyasaka, C.; Tittmann, B. R.; Tutwiler, R.; Tian, Y.; Maeva, E.; Shum, D.

2010-03-01

The present study is to investigate the feasibility of applying in-vivo acoustic microscopy to the analysis of cancerous tissue. The study was implemented with mechanical scanning reflection acoustic microscope (SAM) by the following procedures. First, we ultrasonically visualized thick sections of normal and tumor tissues to determine the lowest transducer frequency required for cellular imaging. We used skin for normal tissue and the tumor was a malignant melanoma. Thin sections of the tissue were also studied with the optical and high-frequency-ultrasonic imaging for pathological evaluation. Secondly, we ultrasonically visualized subsurface cellular details of thin tissue specimens with different modes (i.e., pulse and tone-burst wave modes) to obtain the highest quality ultrasonic images. The objective is to select the best mode for the future design of a future SAM for in-vivo examination. Thirdly, we developed a mathematical modeling technique based on an angular spectrum approach for improving image processing and comparing numerical to experimental results.

Dynamic Inland Propagation of Thinning Due to Ice Loss at the Margins of the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Wang, Wei Li; Li, Jun J.; Zwally, H. Jay

2012-01-01

Mass-balance analysis of the Greenland ice sheet based on surface elevation changes observed by the European Remote-sensing Satellite (ERS) (1992-2002) and Ice, Cloud and land Elevation Satellite (ICESat) (2003-07) indicates that the strongly increased mass loss at lower elevations (<2000 m) of the ice sheet, as observed during 2003-07, appears to induce interior ice thinning at higher elevations. In this paper, we perform a perturbation experiment with a three-dimensional anisotropic ice-flow model (AIF model) to investigate this upstream propagation. Observed thinning rates in the regions below 2000m elevation are used as perturbation inputs. The model runs with perturbation for 10 years show that the extensive mass loss at the ice-sheet margins does in fact cause interior thinning on short timescales (i.e. decadal). The modeled pattern of thinning over the ice sheet agrees with the observations, which implies that the strong mass loss since the early 2000s at low elevations has had a dynamic impact on the entire ice sheet. The modeling results also suggest that even if the large mass loss at the margins stopped, the interior ice sheet would continue thinning for 300 years and would take thousands of years for full dynamic recovery.

POWASSAN VIRUS: MORPHOLOGY AND CYTOPATHOLOGY.

PubMed

ABDELWAHAB, K S; ALMEIDA, J D; DOANE, F W; MCLEAN, D M

1964-05-02

Powassan virus, a North American tickborne group B arbovirus, multiplied after simultaneous inoculation into bottles or tubes of virus and trypsinized suspension of continuous-line cultures of rhesus monkey kidney cells, strain LLC-MK2. Cytopathic effects comprising cell rounding and cytoplasmic vacuolation were first observed five days after inoculation. Mixture of Powassan antiserum with virus before inoculation into tissue cultures inhibited the appearance of cytopathic effects. Hemagglutinins for rooster erythrocytes, optimally at pH 6.4 and 22 degrees C., first appeared in tissue culture supernatant fluids four days after inoculation.Electron microscopic observation of thin sections of infected tissue culture cells showed virus particles 360-380 A.U. along outer cell membranes and edges of cytoplasmic vacuoles. In phosphotungstic acid negatively stained preparations, intact virus particles, 400-450 A.U. total diameter, were observed inside infected cells. In particles in which the peripheral layer became discontinuous, geometrically arranged subunits compatible with cubic symmetry were observed.

Preparation of high-quality ultrathin transmission electron microscopy specimens of a nanocrystalline metallic powder.

PubMed

Riedl, Thomas; Gemming, Thomas; Mickel, Christine; Eymann, Konrad; Kirchner, Alexander; Kieback, Bernd

2012-06-01

This article explores the achievable transmission electron microscopy specimen thickness and quality by using three different preparation methods in the case of a high-strength nanocrystalline Cu-Nb powder alloy. Low specimen thickness is essential for spatially resolved analyses of the grains in nanocrystalline materials. We have found that single-sided as well as double-sided low-angle Ar ion milling of the Cu-Nb powders embedded into epoxy resin produced wedge-shaped particles of very low thickness (<10 nm) near the edge. By means of a modified focused ion beam lift-out technique generating holes in the lamella interior large micrometer-sized electron-transparent regions were obtained. However, this lamella displayed a higher thickness at the rim of ≥30 nm. Limiting factors for the observed thicknesses are discussed including ion damage depths, backscattering, and surface roughness, which depend on ion type, energy, current density, and specimen motion. Finally, sections cut by ultramicrotomy at low stroke rate and low set thickness offered vast, several tens of square micrometers uniformly thin regions of ∼10-nm minimum thickness. As major drawbacks, we have detected a thin coating on the sections consisting of epoxy deployed as the embedding material and considerable nanoscale thickness variations. Copyright © 2011 Wiley Periodicals, Inc.

Sol-gel derived Al-Ga co-doped transparent conducting oxide ZnO thin films

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

Serrao, Felcy Jyothi, E-mail: jyothiserrao@gmail.com; Department of Physics, Karnataka Government Research centre SCEM, Mangalore, 575007; Sandeep, K. M.

2016-05-23

Transparent conducting ZnO doped with Al, Ga and co-doped Al and Ga (1:1) (AGZO) thin films were grown on glass substrates by cost effective sol-gel spin coating method. The XRD results showed that all the films are polycrystalline in nature and highly textured along the (002) plane. Enhanced grain size was observed in the case of AGZO thin films. The transmittance of all the films was more than 83% in the visible region of light. The electrical properties such as carrier concentration and mobility values are increased in case of AGZO compared to that of Al and Ga doped ZnOmore » thin films. The minimum resistivity of 2.54 × 10{sup −3} Ω cm was observed in AGZO thin film. The co-doped AGZO thin films exhibited minimum resistivity and high optical transmittance, indicate that co-doped ZnO thin films could be used in transparent electronics mainly in display applications.« less

Mechanical and physicochemical properties study on gellan gum thin film prepared using film casting method

NASA Astrophysics Data System (ADS)

Ismail, Nur Arifah; Razali, Mohd Hasmizam; Amin, Khairul Anuar Mat

2017-09-01

The GG thin films were prepared by film casting technique using gelzan (GG1) and kelcogel (GG2) respectively. The physical appearances of the thin films were observed and their mechanical and chemical properties were investigated. Chemical characterizations were done by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), UV-Vis Spectroscopy, and Scanning Electron Microscopy (SEM). Based on the ATR-FTIR result, GG1 and GG2 thin films show a broad peak in the range of 3600-3200 cm-1 assigned to -OH functional group. A broad peaks also was observed at 3000-2600 cm-1 and 1800-1600 cm-1 which are belong to -CH and C=O functional group, respectively. The UV-Vis Spectroscopy analysis shows that single absorption peak was observed at 260 nm for both films. For mechanical properties, GG1 thin film has high tensile strength (80±12), but low strain at break (2±1), on the other hand GG2 thin film has low tensile strength (3±0.08) but high strain at break (13±0.58). The Water Vapour Transmission Rates (WVTR) and swelling of GG1 and GG2 thin films were (422±113, 415±26) and (987±113, 902±63), respectively.

Three-dimensional observation of an helical hot structure during a sawtooth crash in the WT-3 tokamak.

PubMed

Yamaguchi, S; Igami, H; Tanaka, H; Maekawa, T

2004-07-23

Sawtooth crashes in an Ohmically heated plasma in the WT-3 tokamak have been observed by using soft x-ray computer tomography at three different poloidal cross sections around the torus. Initially, collapsing proceeds slowly with keeping the helical structure of an m = 1/n = 1 hot core around the torus. It accelerates as the helical hot structure is strongly deformed and fades away in the manner that the hot core at the high field side becomes obscure and disappears, while that at the low field side is deformed into a thin crescent aligned along the inversion circle, which survives even at the completion of the crash. Copyright 2004 The American Physical Society

Growth, Structural, Electronic, and Magnetic Characterization of GaN, CrN, Fe Islands on CrN, and Fe/CrN Bilayer Thin Films

NASA Astrophysics Data System (ADS)

Alam, Khan

As a part of my Ph.D research, initially I was involved in construction and calibration of an ultra-high vacuum thin film facility, and later on I studied structural, electronic, and magnetic properties of GaN, CrN, Fe/CrN bilayers, and Fe islands on CrN thin films. All of these films were grown by molecular beam epitaxy and characterized with a variety of state-of-the-art techniques including variable temperature reflection high energy electron diffraction, low temperature scanning tunneling microscopy and spectroscopy, variable temperature vibrating sample magnetometry, variable temperature neutron diffraction and reflectometry, variable temperature x-ray diffraction, x-ray reflectometry, Rutherford backscattering, Auger electron spectroscopy, and cross-sectional tunneling electron microscopy. The experimental results are furthermore understood by comparing with numerical calculations using generalized gradient approximation, local density approximation with Hubbard correction, Refl1D, and data analysis and visual environment program. In my first research project, I studied Ga gas adatoms on GaN surfaces. We discovered frozen-out gallium gas adatoms on atomically smooth c(6x12) GaN(0001¯) surface using low temperature scanning tunneling microscopy. We identified adsorption sites of the Ga adatoms on c(6x12) reconstructed surface. Their bonding is determined by measuring low unoccupied molecular orbital level. Absorption sites of the Ga gas adatoms on centered 6x12 are identified, and their asymmetric absorption on the chiral domains is investigated. In second project, I investigated magneto-structural phase transition in chromium nitride (CrN) thin films. The CrN thin films are grown by molecular beam epitaxy. Structural and magnetic transition are studied using variable temperature reflection high energy electron diffraction and variable temperature neutron diffraction. We observed a structural phase transition at the surface at 277+/-2 K, and a sharp, first-order magnetic phase transition from paramagnetic (room temperature) to antiferromagnetic (low temperature) at 280+/-3 K. Our experiments suggest that the structural transition in CrN thin films occur in out-of-plane direction, and epitaxial constraints suppress the in-plane transition; therefore, the low temperature crystal structure of CrN is tetragonal. This new model explains our structural and magnetic data at low temperatures, but it is different than the previously published orthorhombic model. In third project, I studied exchange bias and exchange spring effect in MBE grown Fe/CrN bilayer thin films. We grew Fe/CrN bilayer thin films on MgO(001) substrate by molecular beam epitaxy, and studied them using variable temperature vibrating sample magnetometry, polarized neutron reflectometry, x-ray reflectivity, and cross-sectional transmission electron microscopy. We observed exchange bias and exchange spring effect in all bilayer thin films. We studied the relationship of exchange bias, blocking temperature, and coercivity with Fe and CrN layers thicknesses. We used polarized neutron beam reflectometry to see if spins at Fe/CrN interface are pinned. We found a thin ferromagnetically ordered CrN layer at the interface. In my final project, I studied growth of submonolayer Fe islands on CrN thin films. These films are prepared in two stages: first, a CrN layer is grown by MBE and then a submonolayer Fe is deposited at room temperature from a carefully degassed e-beam evaporator. The films are studied at liquid helium temperature using low temperature scanning tunneling microscopy and spectroscopy. Islands are seen in STM images, after the Fe deposition, at the edges as well as at the center of atomically flat CrN terraces. However, numerical calculations performed by our collaborator Ponce-P'erez from Benem'erita Universidad Aut'onoma de Puebla show that the Fe islands are energetically unstable on the surface. The Fe atoms substitute Cr atoms in the surface layer and the Cr atoms comes out and form islands. In order to find out elemental composition of the islands, we attempted to map local density of state by measuring differential conductance spectra as a function of bias voltage using LT-STS. We observed three characteristically different spectra; one in the CrN substrate and two in the islands. The CrN substrate curve has a "U" shape near Fermi level and a peak at ≈ 105 mV. The islands spectra show Kondo-like resonances at Fermi level; some islands produce a peak whereas others produce a dip the dI/dV curves near Fermi level. Further investigations are needed to determine the origin of the peak and dip in the island curves, as well as to find the composition of the islands.

Effect of damage on elastically tailored composite laminates

NASA Technical Reports Server (NTRS)

Armanios, Erian; Badir, Ashraf; Berdichevsky, Victor

1991-01-01

A variationally consistent theory is derived in order to predict the response of anisotropic thin-walled closed sections subjected to axial load, torsion and bending. The theory is valid for arbitrary cross-sections made of laminated composite materials with variable thickness and stiffness. Closed form expressions for the stiffness coefficients are provided as integrals in terms of lay-ups parameters and cross-sectional geometry. A comparison of stiffness coefficients and response with finite element predictions and a closed form solution is performed. The theory is applied to the investigation of the effect of damage on the extension-twist coupling in a thin-walled closed section beam. The damage is simulated as a progressive ply-by-ply failure. Results show that damage can have a significant effect on the extension-twist coupling.

Cross Section High Resolution Imaging of Polymer-Based Materials

NASA Astrophysics Data System (ADS)

Delaportas, D.; Aden, P.; Muckle, C.; Yeates, S.; Treutlein, R.; Haq, S.; Alexandrou, I.

This paper describes a methodology for preparing cross sections of organic layers suitable for transmission electron microscopy (TEM) at high resolution. Our principal aim is to prepare samples that are tough enough to allow the slicing into sub-150 nm sections. We also need strong contrast at the organic layer area to make it identifiable during TEM. Our approach is to deposit organic layers on flexible substrates and prepare thin cross sections using ultra-microtomy. We sandwich the organic layer between two metal thin films in order to isolate it and improve contrast. Our methodology is used to study the microstructure of polymer/nanotube composites, allowing us to accurately measure the organic layer thickness, determine nanotube dispersion and assess the effect of nanotube clustering on film structural stability.

SHI irradiation effect on pure and Mn doped ZnO thin films

NASA Astrophysics Data System (ADS)

Khawal, H. A.; Raskar, N. D.; Dole, B. N.

2017-05-01

Investigated the structural, surface, electrical and modifications induced by Swift Heavy Ions (SHI) irradiation on pure and Mn substituted ZnO thin films were observed. Thin films of Zn1-xMnxO (x = 0.00, 0.04) were synthesized using the dip coating technique. All thin films irradiated by Li3+ swift heavy ions with fluence 5 × 1013 ions/cm2. The XRD peak reveals that all the samples exhibit wurtzite structures. Surface morphology of samples was investigated by SEM, it was observed that pristine samples of ZnO thin film shows spherical shape but for 4 % Mn substituted ZnO thin film with 5 × 1013 ions/cm2 fluence, it reveals that big grain spherical morphology like structure respectively. I-V characteristics were recorded in the voltage range -5 to 5 V. All curves were passed through origin and nearly linear exhibit ohmic in nature for the films.

Room temperature ferroelectricity in continuous croconic acid thin films

NASA Astrophysics Data System (ADS)

Jiang, Xuanyuan; Lu, Haidong; Yin, Yuewei; Zhang, Xiaozhe; Wang, Xiao; Yu, Le; Ahmadi, Zahra; Costa, Paulo S.; DiChiara, Anthony D.; Cheng, Xuemei; Gruverman, Alexei; Enders, Axel; Xu, Xiaoshan

2016-09-01

Ferroelectricity at room temperature has been demonstrated in nanometer-thin quasi 2D croconic acid thin films, by the polarization hysteresis loop measurements in macroscopic capacitor geometry, along with observation and manipulation of the nanoscale domain structure by piezoresponse force microscopy. The fabrication of continuous thin films of the hydrogen-bonded croconic acid was achieved by the suppression of the thermal decomposition using low evaporation temperatures in high vacuum, combined with growth conditions far from thermal equilibrium. For nominal coverages ≥20 nm, quasi 2D and polycrystalline films, with an average grain size of 50-100 nm and 3.5 nm roughness, can be obtained. Spontaneous ferroelectric domain structures of the thin films have been observed and appear to correlate with the grain patterns. The application of this solvent-free growth protocol may be a key to the development of flexible organic ferroelectric thin films for electronic applications.

Room temperature ferroelectricity in continuous croconic acid thin films

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

Jiang, Xuanyuan; Lu, Haidong; Yin, Yuewei

2016-09-05

Ferroelectricity at room temperature has been demonstrated in nanometer-thin quasi 2D croconic acid thin films, by the polarization hysteresis loop measurements in macroscopic capacitor geometry, along with observation and manipulation of the nanoscale domain structure by piezoresponse force microscopy. The fabrication of continuous thin films of the hydrogen-bonded croconic acid was achieved by the suppression of the thermal decomposition using low evaporation temperatures in high vacuum, combined with growth conditions far from thermal equilibrium. For nominal coverages ≥20 nm, quasi 2D and polycrystalline films, with an average grain size of 50–100 nm and 3.5 nm roughness, can be obtained. Spontaneous ferroelectric domain structuresmore » of the thin films have been observed and appear to correlate with the grain patterns. The application of this solvent-free growth protocol may be a key to the development of flexible organic ferroelectric thin films for electronic applications.« less

Stable prevalence of obesity in Swedish schoolchildren from 2008 to 2013 but widening socio-economic gap in girls.

PubMed

Moraeus, Lotta; Lissner, Lauren; Sjöberg, Agneta

2014-12-01

The aim of this study was to follow the 5-year prevalence of overweight, obesity and thinness in 7- to 9-year-old children in West Sweden and to investigate whether trends differed according to gender and socio-economic status. Cross-sectional anthropometric measurements of three cohorts in grades one and two were performed in 3492 7- to 9-year-old children in 2008, 2010 and 2013. For body mass index classification, the IOTF/Cole and WHO 2007 references were used. Percentage of inhabitants with high education in the school area was used for socio-economic classification. Between 2008, 2010 and 2013, the overall time-trends in overweight 17.7%, 19.3% and 18.8%, obesity 3.2%, 3.3% and 3.1%, and thinness 6.5%, 4.7% and 6.9%, respectively, were fairly stable using the IOTF/Cole references. Thinness defined by the Cole reference increased in girls. The socio-economic gradient for overweight and obesity was clear by both references, but using the IOTF reference, the gap increased for obesity among girls (p = 0.024). No significant trends were observed with the WHO reference. The overall prevalence of overweight and obesity was stable over 5 years, but we detected growing inequality in obesity and increasing prevalence of thinness in girls. With these regionally representative data, we can draw conclusions about West Sweden, despite an absence of continued national surveillance. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Deep seismic exploration into the Arctic Lithosphere: Arctic-2012 Russian wide-angle seismic experiment

NASA Astrophysics Data System (ADS)

Kashubin, S.

2013-12-01

Integrated geological and geophysical studies of the Earth's crust and upper mantle (the Russian project 'Arctic-2012') were carried out in 2012 in the Mendeleev Rise, central Arctic. The set of studies included wide-angle seismic observations along the line crossing the Mendeleev Rise in its southern part. The DSS seismic survey was aimed at the determination of the Mendeleev Rise crust type. A high-power air gun (120 liters or 7320 cu.in) and ocean stations with multi-component recording (X, Y, Z geophone components and a hydrophone) were used for the DSS. The line was studied using a dense system of observation: bottom station spacing was from 10 to 20 km, excitation point spacing (seismic traces interval) was 315 m. Observation data were obtained in 27 location points of bottom stations, the distance between the first and the last stations was 480 km, the length of the excitation line was 740 km. In DSS wave fields, in the first and later arrivals, there are refracted and reflected waves associated with boundaries in the sedimentary cover, with the top of the basement, and with boundaries in the consolidated crust, including its bottom (Moho discontinuity). The waves could be traced for offsets up to 170-240 km. The DSS line coincides with the near-vertical CMP line worked out with the use of a 4500-m-long seismic streamer and with a 50 m shot point interval that allowed essential detalization of the upper part of the section and taking it into account in the construction of a deep crust model. The deep velocity model was constructed using ray-trace modeling of compressional, shear, and converted waves with the use of the SeisWide program. Estimates were obtained for Vp/Vs velocity ratios, which played an important role in determining the type of crust. The results of the interpretation show that the Mendeleev Rise section corresponds to sections of a thin continental crust of shelf seas and a thinned continental crust of submarine ridges and rises.

Observation of oscillatory relaxation in the Sn-terminated surface of epitaxial rock-salt SnSe { 111 } topological crystalline insulator

NASA Astrophysics Data System (ADS)

Jin, Wencan; Dadap, Jerry; Osgood, Richard; Vishwanath, Suresh; Lien, Huai-Hsun; Chaney, Alexander; Xing, Huili; Liu, Jianpeng; Kong, Lingyuan; Ma, Junzhang; Qian, Tian; Ding, Hong; Sadowski, Jerzy; Dai, Zhongwei; Pohl, Karsten; Lou, Rui; Wang, Shancai; Liu, Xinyu; Furdyna, Jacek

Topological crystalline insulators have been recently observed in rock-salt SnSe { 111 } thin films. Previous studies have suggested that the Se-terminated surface of this thin film with hydrogen passivation is a preferred configuration. In this work, synchrotron-based angle-resolved photoemission spectroscopy, along with density functional theory calculations, are used to demonstrate conclusively that a rock-salt SnSe { 111 } thin film has a stable Sn-terminated surface. These observations are supported by low energy electron diffraction (LEED) intensity-voltage measurements and dynamical LEED calculations, which further show that the Sn-terminated SnSe { 111 } thin film has undergone an oscillatory surface structural relaxation. In sharp contrast to the Se-terminated counterpart, the Dirac surface state in the Sn-terminated SnSe { 111 } thin film yields a high Fermi velocity, 0 . 50 ×106 m/s, which may lead to high-speed electronic device applications. DOE No. DE-FG 02-04-ER-46157.

Combination Of Investment And Centrifugal Casting

NASA Technical Reports Server (NTRS)

Creeger, Gordon A.

1994-01-01

Modifications, including incorporation of centrifugal casting, made in investment-casting process reducing scrap rate. Used to make first- and second-stage high-pressure-fuel-turbopump nozzles, containing vanes with thin trailing edges and other thin sections. Investment mold spun for short time while being filled, and stopped before solidification occurs. Centrifugal force drives molten metal into thin trailing edges, ensuring they are filled. With improved filling, preheat and pour temperatures reduced and solidification hastened so less hot tearing.

21 CFR 862.2270 - Thin-layer chromatography system for clinical use.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Thin-layer chromatography system for clinical use. 862.2270 Section 862.2270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory...

21 CFR 862.2270 - Thin-layer chromatography system for clinical use.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Thin-layer chromatography system for clinical use. 862.2270 Section 862.2270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory...

21 CFR 862.2270 - Thin-layer chromatography system for clinical use.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Thin-layer chromatography system for clinical use. 862.2270 Section 862.2270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory...

21 CFR 177.2550 - Reverse osmosis membranes.

Code of Federal Regulations, 2014 CFR

2014-04-01

... maximum weight is 62 milligrams per square decimeter (4 milligrams per square inch) as a thin film... square decimeter (0.3 milligrams per square inch) as a thin film composite on a suitable support. The... square decimeter (0.03 milligrams per square inch). (3) For the purpose of this section, the reverse...

Observations of brine drainage networks and microstructure of first-year sea ice

NASA Astrophysics Data System (ADS)

Cole, D. M.; Shapiro, L. H.

1998-09-01

Brine drainage networks and the microstructure of first-year sea ice have been examined at two locations near Barrow, northern Alaska. A method for obtaining full-depth sections of ice sheets up to 1.8 m thick is presented and shown to provide information on the spatial distribution and geometry of brine drainage networks on a scale of meters. A number of such sections from the two test sites are presented which reveal a greater variety of main channel and side branch configurations than is typically observed in ice grown in the laboratory. Vertical and horizontal micrographs and thin section photographs were obtained in November 1993, and March and May 1994 at a test site in the relatively protected Elson Lagoon. The resulting time series of photographic records provide detailed information on the size, shape, and spatial distribution of the brine- and gas-filled inclusions and a means to quantify their size and shape changes with time. An example of the changes with time in inclusion sizes and aspect ratios in the vertical and horizontal directions for a depth of 0.2 m, with a given thermal history is also presented.

Thinning factor distributions viewed through numerical models of continental extension

NASA Astrophysics Data System (ADS)

Svartman Dias, Anna Eliza; Hayman, Nicholas W.; Lavier, Luc L.

2016-12-01

A long-standing question surrounding rifted margins concerns how the observed fault-restored extension in the upper crust is usually less than that calculated from subsidence models or from crustal thickness estimates, the so-called "extension discrepancy." Here we revisit this issue drawing on recently completed numerical results. We extract thinning profiles from four end-member geodynamic model rifts with varying width and asymmetry and propose tectonic models that best explain those results. We then relate the spatial and temporal evolution of upper to lower crustal thinning, or crustal depth-dependent thinning (DDT), and crustal thinning to mantle thinning, or lithospheric DDT, which are difficult to achieve in natural systems due to the lack of observations that constrain thinning at different stages between prerift extension and lithospheric breakup. Our results support the hypothesis that crustal DDT cannot be the main cause of the extension discrepancy, which may be overestimated because of the difficulty in recognizing distributed deformation, and polyphase and detachment faulting in seismic data. More importantly, the results support that lithospheric DDT is likely to dominate at specific stages of rift evolution because crustal and mantle thinning distributions are not always spatially coincident and at times are not even balanced by an equal magnitude of thinning in two dimensions. Moreover, either pure or simple shear models can apply at various points of time and space depending on the type of rift. Both DDT and pure/simple shear variations across space and time can result in observed complex fault geometries, uplift/subsidence, and thermal histories.

Disordering of ultra thin WO3 films by high-energy ions

NASA Astrophysics Data System (ADS)

Matsunami, N.; Kato, M.; Sataka, M.; Okayasu, S.

2017-10-01

We have studied disordering or atomic structure modification of ultra thin WO3 films under impact of high-energy ions with non-equilibrium and equilibrium charge incidence, by means of X-ray diffraction (XRD). WO3 films were prepared by thermal oxidation of W deposited on MgO substrate. Film thickness obtained by Rutherford backscattering spectrometry (RBS) is as low as 2 nm. Smoothness of film surface was observed by atomic force microscopy. It is found that the ratio of XRD intensity degradation per 90 MeV Ni+10 ion (the incident charge is lower than the equilibrium charge) to that per 90 MeV Ni ion with the equilibrium charge depends on the film thickness. Also, film thickness dependence is observed for 100 MeV Xe+14. By comparison of the experimental result with a simple model calculation based on the assumption that the mean charge of ions along the depth follows a saturation curve with power-law approximation to the charge dependent electronic stopping power, the characteristic length attaining the equilibrium charge is obtained to be ∼7 nm for 90 MeV Ni+10 ion incidence or the electron loss cross section of ∼1016 cm2, demonstrating that disordering of ultra WO3 films has been observed and a fundamental quantity can be derived through material modification.

Regional High-Frequency Stratigraphic Cyclicity Analysis of the Upper Cretaceous Juana Lopez Member of the Mancos Shale, New Mexico

NASA Astrophysics Data System (ADS)

Wiercigroch, M.; Bhattacharya, J.

2017-12-01

The Earth is considered to have been in a "greenhouse state" during the Cretaceous Period. High-frequency sedimentary cycles are observed throughout the Cretaceous section of the Western Interior Seaway. Even though this warm Cretaceous climate suggests an ice-free planet Earth, there has been much debate as to whether the observed high-frequency sedimentary cycles are climate-driven Milankovitch-scale cycles that would suggest glaciers during the Cretaceous Period. This study tests the hypothesis of a glacio-eustatic origin of high-frequency cyclicity in the Turonian Juana Lopez Member of the Mancos Shale in the San Juan Basin, New Mexico. Data for this study was obtained from two stratigraphic measured sections which are 3.2 km apart, and located southwest of Shiprock. The two sections are found approximately 60 km away from the Turonian shoreline in an offshore marine environment. A high-resolution thin bed facies analysis on both sections reveals the Juana Lopez to be deposited in a fluvial-dominated, mixed wave- and fluvial-influenced environment. The Juana Lopez is shown to be an overall coarsening-upward sequence, displaying a shallowing regressive environment. Correlations between the two sections reveal 13 correlated parasequences identified through the violation of Walther's Law. An average cyclicity frequency of ca 90 kyr was determined for the sequences by bracketing the Inocermus dimidus and Scaphites whitfieldi biostratigraphic zones within the Juana Lopez sections. This cyclicity represents short eccentricity Milankovitch cycles. Many studies have confirmed that the observed Milankovitch-scaled cyclicity in the Cretaceous must be controlled by glacio-eustasy. With similar Milankovitch cyclicity found in the Juana Lopez, the short eccentricity Milankovitch cycles are interpreted as being glacio-eustatic in origin, which supports the presence of ice in the Cretaceous Period.

Peripheral Precocious Puberty Caused by Human Chorionic Gonadotropin Producing Pineal Gland Tumor.

PubMed

Hammadur Rahaman, S K; Khandelwal, Deepak; Khadgawat, Rajesh; Kandasamy, Devasenathipathy; Bakhshi, Sameer

2018-03-15

Pineal gland lesions usually present with central precocious puberty. A 3½-yr-old boy presented with precocious puberty. Clinically and biochemically, it was gonadotropin releasing hormone (GnRH) independent. Serum and CSF beta-hCG levels were increased. Thin section magnetic resonance imaging of brain revealed a pineal gland tumor. He received chemotherapy followed by radiotherapy and responded well. CSF beta-hCG should be measured in all cases of peripheral precocity, and if CSF beta-hCG is elevated, thin section magnetic resonance imaging of brain should be considered.

Evaluation of Reaction Cross Section Data Used for Thin Layer Activation Technique

NASA Astrophysics Data System (ADS)

Ditrói, F.; Takács, S.; Tárkányi, F.

2005-05-01

Thin layer activation (TLA) is a widely used nuclear method to investigate and control the loss of material during wear, corrosion and erosion processes. The process requires knowledge of depth profiles of the investigated radioisotopes produced by charged particle bombardment. The depth distribution of the activity can be determined with direct, very time-consuming step by step measurement or by calculation from reliable cross section, stopping power and sample composition data. These data were checked experimentally at several points performing only a couple of measurements.

Evaluation of Reaction Cross Section Data Used for Thin Layer Activation Technique

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

Ditroi, F.; Takacs, S.; Tarkanyi, F.

2005-05-24

Thin layer activation (TLA) is a widely used nuclear method to investigate and control the loss of material during wear, corrosion and erosion processes. The process requires knowledge of depth profiles of the investigated radioisotopes produced by charged particle bombardment. The depth distribution of the activity can be determined with direct, very time-consuming step by step measurement or by calculation from reliable cross section, stopping power and sample composition data. These data were checked experimentally at several points performing only a couple of measurements.

Local Deplanation Of Double Reinforced Beam Cross Section Under Bending

NASA Astrophysics Data System (ADS)

Baltov, Anguel; Yanakieva, Ana

2015-12-01

Bending of beams, double reinforced by means of thin composite layers, is considered in the study. Approximate numerical solution is proposed, considering transitional boundary areas, where smooth quadratic transition of the elasticity modulus and deformations take place. Deplanation of the cross section is also accounted for in the areas. Their thickness is found equalizing the total stiffness of the cross section and the layer stiffness. Deplanation of the cross section of the transitional area is determined via the longitudinal deformation in the reinforcing layer, accounting for the equilibrium between the internal and the external moment, generated by the longitudinal stresses in the cross section. A numerical example is given as an illustration demonstrating model's plausibility. The model allows the design and the calculation of recycled concrete beams double reinforced by means of thin layers. The approach is in agreement with modern design of nearly zero energy buildings (NZEB).

Optical Coherence Tomography Angiography and Ultra-widefield Fluorescein Angiography for Early Detection of Adolescent Sickle Retinopathy.

PubMed

Pahl, Daniel A; Green, Nancy S; Bhatia, Monica; Lee, Margaret T; Chang, Jonathan S; Licursi, Maureen; Briamonte, Courtney; Smilow, Elana; Chen, Royce W S

2017-11-01

Based on standard screening techniques, sickle retinopathy reportedly occurs in 10% of adolescents with sickle cell disease (SCD). We performed a prospective, observational clinical study to determine if ultra-widefield fluorescein angiography (UWFA), spectral-domain optical coherence tomography (SD-OCT), and optical coherence tomography angiography (OCT-A) detect more-frequent retinopathy in adolescents with SCD. Cross-sectional study. Setting: Institutional. Sixteen adolescents with SCD, aged 10-19 years (mean age 14.9 years), and 5 age-equivalent controls (mean age 17.4 years). Examinations including acuity, standard slit-lamp biomicroscopy, UWFA, SD-OCT, and OCT-A were performed. Sickle retinopathy defined by biomicroscopic changes, Goldberg stages I-V, Penman scale, flow void on OCT-A, or macular thinning on SD-OCT. While 22 of 32 SCD eyes (68.8%) had retinopathy on biomicroscopy, by UWFA 4 of 24 (16.7%) SCD eyes had peripheral arterial occlusion (Goldberg I), and 20 of 24 eyes (83.3%) had peripheral arteriovenous anastomoses (Goldberg II) in addition. No patients had Goldberg stages III-V. By SD-OCT and OCT-A, thinning of the macula and flow voids in both the superficial and deep retinal capillary plexus were found in 6 of 30 (20%) eyes. All 24 eyes with adequate UWFA studies demonstrated sickle retinopathy. SD-OCT and OCT-A, which have not been previously reported in the adolescent population, detected abnormal macular thinning and flow abnormalities undetected by biomicroscopy. These findings suggest that pediatric sickle retinopathy may be more prevalent than previously suspected. If these findings are confirmed with larger cross-sectional and prospective analyses, these approaches may enhance early screening for sickle retinopathy. Copyright © 2017 Elsevier Inc. All rights reserved.

Novel organic semiconductors and a high capacitance gate dielectric for organic thin film transistors

NASA Astrophysics Data System (ADS)

Cai, Xiuyu

2007-12-01

Organic semiconductors are attracting more and more interest as a promising set of materials in the field of electronics research. This thesis focused on several new organic semiconductors and a novel high-kappa dielectric thin film (SrTiO3), which are two essential parts in Organic Thin Film Transistors (OTFTs). Structure and morphology of thin films of tricyanovinyl capped oligothiophenes were studied using atomic force microscopy and x-ray diffraction. Thin film transistors of one compound exhibited a reasonable electron mobility of 0.02 cm2/Vs. Temperature dependent measurements on the thin film transistor based on this compound revealed shallow trap states that were interpreted in terms of a multiple trap and release model. Moreover, inversion of the majority charge carrier type from electrons to holes was observed when the number of oligothiophene rings increased to six and ambipolar transport behavior was observed for tricyanovinyl sexithiophene. Another interesting organic semiconductor compound is the fluoalkylquarterthiophene, which showed ambipolar transport and large hysteresis in the transfer curve. Due to the bistable state at floating gate, the thin film transistor was exploited to study non-volatile floating gate memory effects. The temperature dependence of the retention time for this memory device revealed that the electron trapping was an activated process. Following the earlier work on hybrid acene-thiophene organic semiconductors, new compounds with similar structure were studied to reveal the mechanism of the air-stability exhibited by some compounds. They all formed highly crystalline thin films and showed reasonable device performances which are well correlated with the molecular structures, thin film microstructures, and solid state packing. The most air-stable compound had no observable degradation with exposure to air for 15 months. SrTiO3 was developed to be employed in OTFTs. Optimization of thin film growth was performed using reactive sputtering growth. Excellent SrTiO3 epitaixal thin film growth was revealed on conductive SrTiO 3:Nb substrates. A maximum charge carrier density of 1014 cm-2 was obtained based on pentacene and perylene diimide thin film transistors. Some new physical phenomena, such as step-like transfer characteristic curve and negative transconductance, were observed at such high field effect induced charge carrier density.

Enhanced magnetoelectric coupling in a composite multiferroic system via interposing a thin film polymer

NASA Astrophysics Data System (ADS)

Xiao, Zhuyun; Mohanchandra, Kotekar P.; Lo Conte, Roberto; Ty Karaba, C.; Schneider, J. D.; Chavez, Andres; Tiwari, Sidhant; Sohn, Hyunmin; Nowakowski, Mark E.; Scholl, Andreas; Tolbert, Sarah H.; Bokor, Jeffrey; Carman, Gregory P.; Candler, Rob N.

2018-05-01

Enhancing the magnetoelectric coupling in a strain-mediated multiferroic composite structure plays a vital role in controlling magnetism by electric fields. An enhancement of magnetoelastic coupling between ferroelectric single crystal (011)-cut [Pb(Mg1/3Nb2/3)O3](1-x)-[PbTiO3]x (PMN-PT, x≈ 0.30) and ferromagnetic polycrystalline Ni thin film through an interposed benzocyclobutene polymer thin film is reported. A nearly twofold increase in sensitivity of remanent magnetization in the Ni thin film to an applied electric field is observed. This observation suggests a viable method of improving the magnetoelectric response in these composite multiferroic systems.

Nanoporous structures on ZnO thin films

NASA Astrophysics Data System (ADS)

Gür, Emre; Kılıç, Bayram; Coşkun, C.; Tüzemen, S.; Bayrakçeken, Fatma

2010-01-01

Porous structures were formed on ZnO thin films which were grown by an electrochemical deposition (ECD) method. The growth processes were carried out in a solution of dimethylsulfoxide (DMSO) zinc perchlorate, Zn(ClO 4) 2, at 120 ∘C on indium tin oxide (ITO) substrates. Optical and structural characterizations of electrochemically grown ZnO thin films have shown that the films possess high (0002) c-axis orientation, high nucleation, high intensity and low FWHM of UV emission at the band edge region and a sharp UV absorption edge. Nanoporous structures were formed via self-assembled monolayers (SAMs) of hexanethiol (C 6SH) and dodecanethiol (C 12SH). Scanning electron microscope (SEM) measurements showed that while a nanoporous structure (pore radius 20 nm) is formed on the ZnO thin films by hexanathiol solution, a macroporous structure (pore radius 360 nm) is formed by dodecanethiol solution. No significant variation is observed in X-ray diffraction (XRD) measurements on the ZnO thin films after pore formation. However, photoluminescence (PL) measurements showed that green emission is observed as the dominant emission for the macroporous structures, while no variation is observed for the thin film nanoporous ZnO sample.

Depth-Profiling Electronic and Structural Properties of Cu(In,Ga)(S,Se)2 Thin-Film Solar Cell.

PubMed

Chiang, Ching-Yu; Hsiao, Sheng-Wei; Wu, Pin-Jiun; Yang, Chu-Shou; Chen, Chia-Hao; Chou, Wu-Ching

2016-09-14

Utilizing a scanning photoelectron microscope (SPEM) and grazing-incidence X-ray powder diffraction (GIXRD), we studied the electronic band structure and the crystalline properties of the pentanary Cu(In,Ga)(S,Se)2 (CIGSSe) thin-film solar cell as a function of sample depth on measuring the thickness-gradient sample. A novel approach is proposed for studying the depth-dependent information on thin films, which can provide a gradient thickness and a wide cross-section of the sample by polishing process. The results exhibit that the CIGSSe absorber layer possesses four distinct stoichiometries. The growth mechanism of this distinctive compositional distribution formed by a two-stage process is described according to the thermodynamic reaction and the manufacturing process. On the basis of the depth-profiling results, the gradient profiles of the conduction and valence bands were constructed to elucidate the performance of the electrical properties (in this case, Voc = 620 mV, Jsc = 34.6 mA/cm(2), and η = 14.04%); the valence-band maxima (VBM) measured with a SPEM in the spectroscopic mode coincide with this band-structure model, except for a lowering of the VBM observed in the surface region of the absorber layer due to the ordered defect compound (ODC). In addition, the depth-dependent texturing X-ray diffraction pattern presents the crystalline quality and the residual stress for each depth of a thin-film device. We find that the randomly oriented grains in the bottom region of the absorber layer and the different residual stress between the underlying Mo and the absorber interface, which can deteriorate the electrical performance due to peeling-off effect. An anion interstitial defect can be observed on comparing the anion concentration of the elemental distribution with crystalline composition; a few excess sulfur atoms insert in interstitial sites at the front side of the absorber layer, whereas the interstitial selenium atoms insert at the back side.

The Reliability and Validity of the Thin Slice Technique: Observational Research on Video Recorded Medical Interactions

ERIC Educational Resources Information Center

Foster, Tanina S.

2014-01-01

Introduction: Observational research using the thin slice technique has been routinely incorporated in observational research methods, however there is limited evidence supporting use of this technique compared to full interaction coding. The purpose of this study was to determine if this technique could be reliability coded, if ratings are…

The fine structure of the rectal pads of Zorotypus caudelli Karny (Zoraptera, Insecta).

PubMed

Dallai, R; Mercati, D; Mashimo, Y; Machida, R; Beutel, R G

2016-07-01

The rectal pads of a species of the controversial polyneopteran order Zoraptera were examined using histological sections and TEM micrographs. Six pads are present along the thin rectal epithelium. Each pad consists of a few large principal cells surrounded by flattened junctional cells, which extend also beneath the principal cells. The cells are lined by a thin apical cuticle. No basal cells and no cavity have been observed beneath the pad. Principal cells have a regular layer of apical microvilli and are joined by intercellular septate junctions, which are interrupted by short dilatations of the intercellular space. At these levels the two adjacent plasma membranes are joined by short zonulae adhaerentes. In the cytoplasm, a rich system of strict associations between lateral plasma membranes and mitochondria forms scalariform junctions. Rectal pads share ultrastructural features with similar excretory organs of several neopteran groups, in particular with Blattodea (roaches and termites) and Thysanoptera, and are involved in fluid reabsorption and ion regulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multiple-labelling immunoEM using different sizes of colloidal gold: alternative approaches to test for differential distribution and colocalization in subcellular structures.

PubMed

Mayhew, Terry M; Lucocq, John M

2011-03-01

Various methods for quantifying cellular immunogold labelling on transmission electron microscope thin sections are currently available. All rely on sound random sampling principles and are applicable to single immunolabelling across compartments within a given cell type or between different experimental groups of cells. Although methods are also available to test for colocalization in double/triple immunogold labelling studies, so far, these have relied on making multiple measurements of gold particle densities in defined areas or of inter-particle nearest neighbour distances. Here, we present alternative two-step approaches to codistribution and colocalization assessment that merely require raw counts of gold particles in distinct cellular compartments. For assessing codistribution over aggregate compartments, initial statistical evaluation involves combining contingency table and chi-squared analyses to provide predicted gold particle distributions. The observed and predicted distributions allow testing of the appropriate null hypothesis, namely, that there is no difference in the distribution patterns of proteins labelled by different sizes of gold particle. In short, the null hypothesis is that of colocalization. The approach for assessing colabelling recognises that, on thin sections, a compartment is made up of a set of sectional images (profiles) of cognate structures. The approach involves identifying two groups of compartmental profiles that are unlabelled and labelled for one gold marker size. The proportions in each group that are also labelled for the second gold marker size are then compared. Statistical analysis now uses a 2 × 2 contingency table combined with the Fisher exact probability test. Having identified double labelling, the profiles can be analysed further in order to identify characteristic features that might account for the double labelling. In each case, the approach is illustrated using synthetic and/or experimental datasets and can be refined to correct observed labelling patterns to specific labelling patterns. These simple and efficient approaches should be of more immediate utility to those interested in codistribution and colocalization in multiple immunogold labelling investigations.

Quasi-static axial crushes on woven jute/polyester AA6063T52 composite tubes

NASA Astrophysics Data System (ADS)

Othman, A.; Ismail, AE

2018-04-01

Quasi-static axial loading have been studied in this paper to determine the behaviour of jute/polyester wrapped on aluminium alloy 6063T52. The filler material also was include into crush box specimen, which is polyurethane (PU) and polystyrene (PE) rigid foam at ranging 40 and 45 kg/m3 densities. All specimen profile was fabricated using hand layup techniques and the length of each specimen were fixed at 100 mm as well as diameter and width of the tube at 50.8 mm. The two types of tubular cross-section were studied of round and square thin-walled profiles and the angle of fibre at 450 were analysed for four layers. Thin walled of aluminium was 1.9 mm and end frontal of each specimen of composite were chamfered at 450 to prevent catastrophic failure mode. The specific absorbed energy (SEA) and crush force efficiency (CFE) were analyses for each specimen to see the behaviour on jute/polyester wrapped on metallic structure can give influence the energy management for automotive application. Result show that the four layers’ jute/polyester with filler material show significant value in term of specific absorbed energy compared empty and polyurethane profiles higher 26.66% for empty and 15.19% compared to polyurethane profiles. It has been found that the thin walled square profile of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 27.42% to 13.13% than empty and polyurethane (PU) foam tubes. An introduce filler material onto thin walled composite profiles gave major advantage increases the mean axial load of 31.87% from 32.94 kN to 48.35 kN from empty to polystyrene thin walled round jute/polyester profiles and 31.7% from 23.11 KN to 33.84 kN from empty to polystyrene thin walled square jute/polyester profiles. Failure mechanisms of the axially loaded composite tubes were also observed and discussed.

The potential hydrothermal systems unexplored in the Southwest Indian Ocean

NASA Astrophysics Data System (ADS)

Suo, Yanhui; Li, Sanzhong; Li, Xiyao; Zhang, Zhen; Ding, Dong

2017-06-01

Deep-sea hydrothermal vents possess complex ecosystems and abundant metallic mineral deposits valuable to human being. On-axial vents along tectonic plate boundaries have achieved prominent results and obtained huge resources, while nearly 90% of the global mid-ocean ridge and the majority of the off-axial vents buried by thick oceanic sediments within plates remain as relatively undiscovered domains. Based on previous detailed investigations, hydrothermal vents have been mapped along five sections along the Southwest Indian Ridge (SWIR) with different bathymetry, spreading rates, and gravity features, two at the western end (10°-16°E Section B and 16°-25°E Section C) and three at the eastern end (49°-52°E Section D, 52°-61°E Section E and 61°-70°E Section F). Hydrothermal vents along the Sections B, C, E and F with thin oceanic crust are hosted by ultramafic rocks under tectonic-controlled magmatic-starved settings, and hydrothermal vents along the Section D are associated with exceed magmatism. Limited coverage of investigations is provided along the 35°-47°E SWIR (between Marion and Indomed fracture zones) and a lot of research has been done around the Bouvet Island, while no hydrothermal vents has been reported. Analyzing bathymetry, gravity and geochemical data, magmatism settings are favourable for the occurrence of hydrothermal systems along these two sections. An off-axial hydrothermal system in the southern flank of the SWIR that exhibits ultra-thin oceanic crust associated with an oceanic continental transition is postulated to exist along the 100-Ma slow-spreading isochron in the Enderby Basin. A discrete, denser enriched or less depleted mantle beneath the Antarctic Plate is an alternative explanation for the large scale thin oceanic crust concentrated on the southern flank of the SWIR.

Cosmic strings: Gravitation without local curvature

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

Helliwell, T.M.; Konkowski, D.A.

1987-05-01

Cosmic strings are very long, thin structures which might stretch over vast reaches of the universe. If they exist, they would have been formed during phase transitions in the very early universe. The space-time surrounding a straight cosmic string is flat but nontrivial: A two-dimensional spatial section is a cone rather than a plane. This feature leads to unique gravitational effects. The flatness of the cone means that many of the gravitational effects can be understood with no mathematics beyond trigonometry. This includes the observational predictions of the double imaging of quasars and the truncation of the images of galaxies.

A New Technique to Produce Clean and Thin Silicon Films In Situ in a UHV Electron Microscope for TEM-TED Studies of Surfaces

NASA Astrophysics Data System (ADS)

Ozawa, Soh-ichiro; Yamanaka, Akira; Kobayashi, Kunio; Tanishiro, Yasumasa; Yagi, Katsumichi

1990-04-01

A new technique of in situ oxygen gas reaction thinning of Si films at around 750-800°C in an ultrahigh-vacuum electron microscope was developed. The technique produced films as thin as 10 to 20 nm. Such a thin film allows us to observe surface atomic steps, out-of-phase boundaries and {1/7 0}, {1/7 1/7} and {2/7 0} spots from the Si(111)7× 7 surface. These spots were not observed in previous studies, having been masked by strong inelastic scattering. The technique is useful not only for detecting clear diffraction spots of kinematical intensity for surface structure analysis but also for observation of high-resolution plan-view structure images of clean and adsorbed surfaces.

An Investigation on Axial Deformation Behavior of Thin-Wall Unfilled and Filled Tube with Aluminum Alloy (Al-Si7Mg) Foam Reinforced with SiC Particles

NASA Astrophysics Data System (ADS)

Kumaraswamidhas, L. A.; Rajak, Dipen Kumar; Das, S.

2016-08-01

The objective of this research is to produce superior quality aluminum alloy foam with low relative density and higher resistance against compression deformation. This investigation has studied crash energy capacities of unfilled and filled aluminum alloy foams in mild steel tubes. The foam has been prepared by the melt route process with an addition of 5wt.% silicon carbide particles. The fabricated aluminum alloy foams were characterized by field emission scanning electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, and Material Pro analyzer. It was observed that the foam-filled tubes could absorb more energy as compared to the unfilled tubes before reaching the complete densification point. Also, the aluminum alloy foams had better energy absorption capacity during the crash or impact loading. This article demonstrates the excellent ability of aluminum alloy foam application in the field where there is a need to absorb crash energy. It is to be noted that the amount of energy absorption will be greater for low-density foam filled in thin-wall rectangular section tubes. We have seen an increasing trend in the application of aluminum foams inside the thin-wall mild steel tubes for maximum energy absorption.

[Weight control behaviors in dieting adolescent girls and their relation to body dissatisfaction and obsession with thinness].

PubMed

Contreras, M Liliana A; Morán, Javier K; Frez, Scarlett H; Lagos, Carola O; Marín, María Paz F; de los Ángeles Pinto B, María; Suzarte, Érika A

2015-01-01

Obsession with thinness and body dissatisfaction can lead adolescents to follow unsupervised diets, which could result in risky weight control behaviors such as fasting, vomiting, use of diuretics and laxatives. The aim of the current study is to examine weight control behaviors in dieting adolescents and relate them to body dissatisfaction (BD) and obsession with thinness (OT). A cross-sectional study was conducted on 439 adolescents from Valparaiso public schools to investigate risky weight control behaviors due to BD and OT scales from the Eating Disorders Inventory-2 (EDI-2), comparing restrained eaters and non-restrained eaters. A total of 43% adolescents had followed a weight loss diet without medical supervision. The dieters had higher BD and OT values. Moderate to severe food restriction, based on expert judgment, was observed in 29.6%, and differences in the presence and severity of purging behaviors were found between the 2 groups. One third of the adolescents studied followed diets without professional supervision and had higher BD and OT values, as well as risky weight control behaviors. Overweight and obese adolescents followed more restrictive diets and developed riskier weight control behaviors. Copyright © 2015. Publicado por Elsevier España, S.L.U.

Standard-, Reduced-, and No-Dose Thin-Section Radiologic Examinations: Comparison of Capability for Nodule Detection and Nodule Type Assessment in Patients Suspected of Having Pulmonary Nodules.

PubMed

Ohno, Yoshiharu; Koyama, Hisanobu; Yoshikawa, Takeshi; Kishida, Yuji; Seki, Shinichiro; Takenaka, Daisuke; Yui, Masao; Miyazaki, Mitsue; Sugimura, Kazuro

2017-08-01

Purpose To compare the capability of pulmonary thin-section magnetic resonance (MR) imaging with ultrashort echo time (UTE) with that of standard- and reduced-dose thin-section computed tomography (CT) in nodule detection and evaluation of nodule type. Materials and Methods The institutional review board approved this study, and written informed consent was obtained from each patient. Standard- and reduced-dose chest CT (60 and 250 mA) and MR imaging with UTE were used to examine 52 patients; 29 were men (mean age, 66.4 years ± 7.3 [standard deviation]; age range, 48-79 years) and 23 were women (mean age, 64.8 years ± 10.1; age range, 42-83 years). Probability of nodule presence was assessed for all methods with a five-point visual scoring system. All nodules were then classified as missed, ground-glass, part-solid, or solid nodules. To compare nodule detection capability of the three methods, consensus for performances was rated by using jackknife free-response receiver operating characteristic analysis, and κ analysis was used to compare intermethod agreement for nodule type classification. Results There was no significant difference (F = 0.70, P = .59) in figure of merit between methods (standard-dose CT, 0.86; reduced-dose CT, 0.84; MR imaging with UTE, 0.86). There was no significant difference in sensitivity between methods (standard-dose CT vs reduced-dose CT, P = .50; standard-dose CT vs MR imaging with UTE, P = .50; reduced-dose CT vs MR imaging with UTE, P >.99). Intermethod agreement was excellent (standard-dose CT vs reduced-dose CT, κ = 0.98, P < .001; standard-dose CT vs MR imaging with UTE, κ = 0.98, P < .001; reduced-dose CT vs MR imaging with UTE, κ = 0.99, P < .001). Conclusion Pulmonary thin-section MR imaging with UTE was useful in nodule detection and evaluation of nodule type, and it is considered at least as efficacious as standard- or reduced-dose thin-section CT. © RSNA, 2017 Online supplemental material is available for this article.

Cross-Sectional Study of Malnutrition and Associated Factors among School Aged Children in Rural and Urban Settings of Fogera and Libo Kemkem Districts, Ethiopia

PubMed Central

Herrador, Zaida; Sordo, Luis; Gadisa, Endalamaw; Moreno, Javier; Nieto, Javier; Benito, Agustín; Aseffa, Abraham; Cañavate, Carmen; Custodio, Estefania

2014-01-01

Introduction Little information is available on malnutrition-related factors among school-aged children ≥5 years in Ethiopia. This study describes the prevalence of stunting and thinness and their related factors in Libo Kemkem and Fogera, Amhara Regional State and assesses differences between urban and rural areas. Methods In this cross-sectional study, anthropometrics and individual and household characteristics data were collected from 886 children. Height-for-age z-score for stunting and body-mass-index-for-age z-score for thinness were computed. Dietary data were collected through a 24-hour recall. Bivariate and backward stepwise multivariable statistical methods were employed to assess malnutrition-associated factors in rural and urban communities. Results The prevalence of stunting among school-aged children was 42.7% in rural areas and 29.2% in urban areas, while the corresponding figures for thinness were 21.6% and 20.8%. Age differences were significant in both strata. In the rural setting, fever in the previous 2 weeks (OR: 1.62; 95% CI: 1.23–2.32), consumption of food from animal sources (OR: 0.51; 95% CI: 0.29–0.91) and consumption of the family's own cattle products (OR: 0.50; 95% CI: 0.27–0.93), among others factors were significantly associated with stunting, while in the urban setting, only age (OR: 4.62; 95% CI: 2.09–10.21) and years of schooling of the person in charge of food preparation were significant (OR: 0.88; 95% CI: 0.79–0.97). Thinness was statistically associated with number of children living in the house (OR: 1.28; 95% CI: 1.03–1.60) and family rice cultivation (OR: 0.64; 95% CI: 0.41–0.99) in the rural setting, and with consumption of food from animal sources (OR: 0.26; 95% CI: 0.10–0.67) and literacy of head of household (OR: 0.24; 95% CI: 0.09–0.65) in the urban setting. Conclusion The prevalence of stunting was significantly higher in rural areas, whereas no significant differences were observed for thinness. Various factors were associated with one or both types of malnutrition, and varied by type of setting. To effectively tackle malnutrition, nutritional programs should be oriented to local needs. PMID:25265481

Cross-sectional study of malnutrition and associated factors among school aged children in rural and urban settings of Fogera and Libo Kemkem districts, Ethiopia.

PubMed

Herrador, Zaida; Sordo, Luis; Gadisa, Endalamaw; Moreno, Javier; Nieto, Javier; Benito, Agustín; Aseffa, Abraham; Cañavate, Carmen; Custodio, Estefania

2014-01-01

Little information is available on malnutrition-related factors among school-aged children ≥5 years in Ethiopia. This study describes the prevalence of stunting and thinness and their related factors in Libo Kemkem and Fogera, Amhara Regional State and assesses differences between urban and rural areas. In this cross-sectional study, anthropometrics and individual and household characteristics data were collected from 886 children. Height-for-age z-score for stunting and body-mass-index-for-age z-score for thinness were computed. Dietary data were collected through a 24-hour recall. Bivariate and backward stepwise multivariable statistical methods were employed to assess malnutrition-associated factors in rural and urban communities. The prevalence of stunting among school-aged children was 42.7% in rural areas and 29.2% in urban areas, while the corresponding figures for thinness were 21.6% and 20.8%. Age differences were significant in both strata. In the rural setting, fever in the previous 2 weeks (OR: 1.62; 95% CI: 1.23-2.32), consumption of food from animal sources (OR: 0.51; 95% CI: 0.29-0.91) and consumption of the family's own cattle products (OR: 0.50; 95% CI: 0.27-0.93), among others factors were significantly associated with stunting, while in the urban setting, only age (OR: 4.62; 95% CI: 2.09-10.21) and years of schooling of the person in charge of food preparation were significant (OR: 0.88; 95% CI: 0.79-0.97). Thinness was statistically associated with number of children living in the house (OR: 1.28; 95% CI: 1.03-1.60) and family rice cultivation (OR: 0.64; 95% CI: 0.41-0.99) in the rural setting, and with consumption of food from animal sources (OR: 0.26; 95% CI: 0.10-0.67) and literacy of head of household (OR: 0.24; 95% CI: 0.09-0.65) in the urban setting. The prevalence of stunting was significantly higher in rural areas, whereas no significant differences were observed for thinness. Various factors were associated with one or both types of malnutrition, and varied by type of setting. To effectively tackle malnutrition, nutritional programs should be oriented to local needs.

Transverse vibrations of shear-deformable beams using a general higher order theory

NASA Technical Reports Server (NTRS)

Kosmatka, J. B.

1993-01-01

A general higher order theory is developed to study the static and vibrational behavior of beam structures having an arbitrary cross section that utilizes both out-of-plane shear-dependent warping and in-plane (anticlastic) deformations. The equations of motion are derived via Hamilton's principle, where the full 3D constitutive relations are used. A simplified version of the general higher-order theory is also presented for beams having an arbitrary cross section that includes out-of-plane shear deformation but assumes that stresses within the cross section and in-plane deformations are negligible. This simplified model, which is accurate for long to moderately short wavelengths, offers substantial improvements over existing higher order theories that are limited to beams with thin rectangular cross sections. The current approach will be very useful in the study of thin-wall closed-cell beams such as airfoil-type sections where the magnitude of shear-related cross-sectional warping is significant.

Thin-section ratiometric Ca2+ images obtained by optical sectioning of fura-2 loaded mast cells

PubMed Central

1992-01-01

The availability of the ratiometric Ca2+ indicator dyes, fura-2, and indo-1, and advances in digital imaging and computer technology have made it possible to detect Ca2+ changes in single cells with high temporal and spatial resolution. However, the optical properties of the conventional epifluorescence microscope do not produce a perfect image of the specimen. Instead, the observed image is a spatial low pass filtered version of the object and is contaminated with out of focus information. As a result, the image has reduced contrast and an increased depth of field. This problem is especially important for measurements of localized Ca2+ concentrations. One solution to this problem is to use a scanning confocal microscope which only detects in focus information, but this approach has several disadvantages for low light fluorescence measurements in living cells. An alternative approach is to use digital image processing and a deblurring algorithm to remove the out of focus information by using a knowledge of the point spread function of the microscope. All of these algorithms require a stack of two-dimensional images taken at different focal planes, although the "nearest neighbor deblurring" algorithm only requires one image above and below the image plane. We have used a modification of this scheme to construct a simple inverse filter, which extracts optical sections comparable to those of the nearest neighbors scheme, but without the need for adjacent image sections. We have used this "no neighbors" processing scheme to deblur images of fura-2-loaded mast cells from beige mice and generate high resolution ratiometric Ca2+ images of thin sections through the cell. The shallow depth of field of these images is demonstrated by taking pairs of images at different focal planes, 0.5-microns apart. The secretory granules, which exclude the fura-2, appear in focus in all sections and distinct changes in their size and shape can be seen in adjacent sections. In addition, we show, with the aid of model objects, how the combination of inverse filtering and ratiometric imaging corrects for some of the inherent limitations of using an inverse filter and can be used for quantitative measurements of localized Ca2+ gradients. With this technique, we can observe Ca2+ transients in narrow regions of cytosol between the secretory granules and plasma membrane that can be less than 0.5-microns wide. Moreover, these Ca2+ increases can be seen to coincide with the swelling of the secretory granules that follows exocytotic fusion. PMID:1730775

Temperature studies of optical parameters of (Ag3AsS3)0.6(As2S3)0.4 thin films prepared by rapid thermal evaporation and pulse laser deposition

NASA Astrophysics Data System (ADS)

Studenyak, I. P.; Kutsyk, M. M.; Buchuk, M. Yu.; Rati, Y. Y.; Neimet, Yu. Yu.; Izai, V. Yu.; Kökényesi, S.; Nemec, P.

2016-02-01

(Ag3AsS3)0.6(As2S3)0.4 thin films were deposited using rapid thermal evaporation (RTE) and pulse laser deposition (PLD) techniques. Ag-enriched micrometre-sized cones (RTE) and bubbles (PLD) were observed on the thin film surface. Optical transmission spectra of the thin films were studied in the temperature range 77-300 K. The Urbach behaviour of the optical absorption edge in the thin films due to strong electron-phonon interaction was observed, the main parameters of the Urbach absorption edge were determined. Temperature dependences of the energy position of the exponential absorption edge and the Urbach energy are well described in the Einstein model. Dispersion and temperature dependences of refractive indices were analysed; a non-linear increase of the refractive indices with temperature was revealed. Disordering processes in the thin films were studied and compared with bulk composites, the differences between the thin films prepared by RTE and PLD were analysed.

1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A GRAVITY SECTION IS THE THIRD DAM BUILT BY SEATTLE CITY LIGHT TO PROVIDE WATER FOR GORGE POWERHOUSE AND WAS COMPLETED IN 1961, 1989. - Skagit Power Development, Gorge High Dam, On Skagit River, 2.9 miles upstream from Newhalem, Newhalem, Whatcom County, WA

Basic Principles of Thin-Walled Open Bars Taking into Account Where Influence Shifts of Cross Sections are Concerned

NASA Astrophysics Data System (ADS)

Panasenko, N. N.; Sinelschikov, A. V.

2017-11-01

The finite element method is considered to be the most effective in relation to the calculation of strength and stability of buildings and engineering constructions. As a rule, for the modelling of supporting 3-D frameworks, finite elements with six degrees of freedom are used in each of the nodes. In practice, such supporting frameworks represent the thin-walled welded bars and hot-rolled bars of open and closed profiles in which cross-sectional deplanation must be taken into account. This idea was first introduced by L N Vorobjev and brought to one of the easiest variants of the thin-walled bar theory. The development of this approach is based on taking into account the middle surface shear deformation and adding the deformations of a thin-walled open bar to the formulas for potential and kinetic energy; these deformations depend on shearing stress and result in decreasing the frequency of the first tone of fluctuations to 13%. The authors of the article recommend taking into account this fact when calculating fail-proof dynamic systems.

Examination of the influence of coatings on thin superalloy sections. Volume 2: Detailed procedures and data. [corrosion resistance

NASA Technical Reports Server (NTRS)

Kaufman, M.

1974-01-01

The effects of an aluminide coating, Codep B-1, and of section thickness were investigated on two cast nickel base superalloys, Rene 80 and Rene 120. Cast section thicknesses ranged from 0.038 cm to 0.15 cm. Simulated engine exposures for 1000 hours at 899C or 982C in a jet fuel burner rig with cyclic air cooling were studied, as were the effects of surface machining before coating and re-machining and re-coating after exposures. The properties evaluated included tensile at room temperature., 871C and 982C, stress rupture at 760C, 871C, 982C and 1093C, high cycle mechanical fatigue at room temperature., and thermal fatigue with a 1093C peak temperature. Thin sections had tensile strengths similar to standard size bars up to 871C and lower strengths at 982C and above, with equivalent elongation, and stress rupture life was lower for thin sections at all test conditions. The aluminide coating lowered tensile and rupture strengths up to 871C, with greater effects on thinner specimens. Elevated temperature exposure lowered tensile and rupture strengths of thinner specimens at the lower test temperatures. Surface machining had little effect on properties, but re-machining after exposure reduced thickness and increased metallurgical changes enough to lower properties at most test conditions.

Thin HSIL of the Cervix: Detecting a Variant of High-grade Squamous Intraepithelial Lesions With a p16INK4a Antibody.

PubMed

Reich, Olaf; Regauer, Sigrid

2017-01-01

The WHO defines thin high-grade squamous intraepithelial lesions (HSIL) as a high-grade intraepithelial lesion of the cervix that is usually ≤9 cells thick. These lesions usually develop in early metaplastic squamous epithelium without anteceding low-grade squamous intraepithelial lesions (LSIL). The prevalence of thin HSIL is not well documented. We evaluated different characteristics of thin HSIL at time of treatment. We studied 25 formalin-fixed and paraffin-embedded conization specimens processed as step-serial sections. HSIL≤9 cells thick were classified as thin HSIL. HSIL≥10 cells thick were classified as classic HSIL. Immunohistochemical p16 staining was used to confirm lesions of thin HSIL. Overall, 19 (76%) specimens contained both thin HSIL and classic HSIL, 4 (16%) contained thin HSIL only, 1 (4%) contained classic-type HSIL only, and 1 (4%) contained thin HSIL and LSIL. Thin HSILs developed in both the columnar surface epithelium and deep cervical glandular epithelium. Most thin HSILs were 5 cells thick. All HSILs (thin and classic) were located inside the transformation zone and had a median horizontal extension of 8 mm (range, 0.3 to 21 mm). Our findings suggest that thin HSILs are frequent findings, that they coexist with classic HSIL, and preferably arise in the exposed parts of the transformation zone including the glandular crypts.

Zinc isotope ratio imaging of rat brain thin sections from stable isotope tracer studies by LA-MC-ICP-MS.

PubMed

Urgast, Dagmar S; Hill, Sarah; Kwun, In-Sook; Beattie, John H; Goenaga-Infante, Heidi; Feldmann, Jörg

2012-10-01

Zinc stable isotope tracers (⁶⁷Zn and ⁷⁰Zn) were injected into rats at two different time points to investigate the feasibility of using tracers to study zinc kinetics at the microscale within distinct tissue features. Laser ablation coupled to multi-collector ICP-MS was used to analyse average isotope ratios in liver thin sections and to generate bio-images showing zinc isotope ratio distribution in brain thin sections. Average isotope ratios of all samples from treated animals were found to be statistically different (P < 0.05) from samples from untreated control animals. Furthermore, differing isotope ratios in physiological features of the brain, namely hippocampus, amygdala, cortex and hypothalamus, were identified. This indicates that these regions differ in their zinc metabolism kinetics. While cortex and hypothalamus contain more tracer two days after injection than 14 days after injection, the opposite is true for hippocampus and amygdala. This study showed that stable isotope tracer experiments can be combined with laser ablation MC-ICP-MS to measure trace element kinetics in tissues at a microscale level.

Oxygen vacancy induced room temperature ferromagnetism in (In1-xNix)2O3 thin films

NASA Astrophysics Data System (ADS)

Chakraborty, Deepannita; Kaleemulla, S.; Kuppan, M.; Rao, N. Madhusudhana; Krishnamoorthi, C.; Omkaram, I.; Reddy, D. Sreekantha; Rao, G. Venugopal

2018-05-01

Nickel doped indium oxide thin films (In1-xNix)2O3 at x = 0.00, 0.03, 0.05 and 0.07 were deposited onto glass substrates by electron beam evaporation technique. The deposited thin films were subjected to annealing in air at 250 °C, 350 °C and 450 °C for 2 h using high temperature furnace. A set of films were vacuum annealed at 450 °C to study the role of oxygen on magnetic properties of the (In1-xNix)2O3 thin films. The thin films were subjected to different characterization techniques to study their structural, chemical, surface, optical and magnetic properties. All the synthesized air annealed and vacuum annealed films exhibit body centered cubic structure without any secondary phases. No significant change in the diffraction peak position, either to lower or higher diffraction angles has been observed. The band gap of the films decreased from 3.73 eV to 3.63 eV with increase of annealing temperature from 250 °C to 450 °C, in the presence of air. From a slight decrease in strength of magnetization to a complete disappearance of hysteresis loop has been observed in pure In2O3 thin films with increasing the annealing temperature from 250 °C to 450 °C, in the presence of air. The (In1-xNix)2O3 thin films annealed under vacuum follow a trend of enhancement in the strength of magnetization to increase in temperature from 250 °C to 450 °C. The hysteresis loop does not disappear at 450 °C in (In1-xNix)2O3 thin films, as observed in the case of pure In2O3 thin films.

Electronic structure evolution in doping of fullerene (C{sub 60}) by ultra-thin layer molybdenum trioxide

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

Wang, Chenggong; Wang, Congcong; Kauppi, John

2015-08-28

Ultra-thin layer molybdenum oxide doping of fullerene has been investigated using ultraviolet photoemission spectroscopy (UPS) and X-ray photoemission spectroscopy (XPS). The highest occupied molecular orbital (HOMO) can be observed directly with UPS. It is observed that the Fermi level position in fullerene is modified by ultra-thin-layer molybdenum oxide doping, and the HOMO onset is shifted to less than 1.3 eV below the Fermi level. The XPS results indicate that charge transfer was observed from the C{sub 60} to MoO{sub x} and Mo{sup 6+} oxides is the basis as hole dopants.

Dual-Beam Sample Preparation | Materials Science | NREL

Science.gov Websites

images showing cutting of trenches to remove a wafer section and transferring that section to a grid post section and transferring that section to a grid post. Here the wafer section is lifted out and seen from , extracted from the wafer then transferred and welded to a TEM grid post. Final thinning down to a thickness

Use of a thin-section archive and enterprise 3D software for long-term storage of thin-slice CT data sets.

PubMed

Meenan, Christopher; Daly, Barry; Toland, Christopher; Nagy, Paul

2006-01-01

Rapid advances are changing the technology and applications of multidetector computed tomography (CT) scanners. The major increase in data associated with this new technology, however, breaks most commercial picture archiving and communication system (PACS) architectures by preventing them from delivering data in real time to radiologists and outside clinicians. We proposed a phased model for 3D workflow, installed a thin-slice archive and measured thin-slice data storage over a period of 5 months. A mean of 1,869 CT studies were stored per month, with an average of 643 images per study and a mean total volume of 588 GB/month. We also surveyed 48 radiologists to determine diagnostic use, impressions of thin-slice value, and requirements for retention times. The majority of radiologists thought thin slice was helpful for diagnosis and regularly used the application. Permanent storage of thin slice CT is likely to become best practice and a mission-critical pursuit for the health care enterprise.

Using Cf-252 for single event upset testing

NASA Astrophysics Data System (ADS)

Howard, J. W.; Chen, R.; Block, R. C.; Becker, M.; Costantine, A. G.; Smith, L. S.; Soli, G. A.; Stauber, M. C.

An improved system using Cf-252 and associated nuclear instrumentation has been used to determine single event upset (SEU) cross section versus linear energy transfer (LET) curve for several static random access memory (SRAM) devices. Through the use of a thin-film scintillator, providing energy information on each fission fragment, individual SEU's and ion energy can be associated to calculate the cross section curves. Results are presented from tests of several SRAM's over the 17-43 MeV-cm squared/mg LET range. Values obtained for SEU cross sections and LET thresholds are in good agreement with the results from accelerator testing. The equipment is described, the theory of thin-film scintillation detector response is summarized, experimental procedures are reviewed, and the test results are discussed.

Optical limiting properties of optically active phthalocyanine derivatives

NASA Astrophysics Data System (ADS)

Wang, Peng; Zhang, Shuang; Wu, Peiji; Ye, Cheng; Liu, Hongwei; Xi, Fu

2001-06-01

The optical limiting properties of four optically active phthalocyanine derivatives in chloroform solutions and epoxy resin thin plates were measured at 532 nm with 10 ns pulses. The excited state absorption cross-section σex and refractive-index cross-section σr were determined with the Z-scan technique. These chromophores possess larger σex than the ground state absorption cross-section σ0, indicating that they are the potential materials for reverse saturable absorption (RSA). The negative σr values of these chromophores add to the thermal contribution, producing a larger defocusing effect, which may be helpful in further enhancing their optical limiting performance. The optical limiting responses of the thin plate samples are stronger than those of the chloroform solutions.

Construction and monitoring of thin overlay and crack sealant test sections at the Pecos test track.

DOT National Transportation Integrated Search

2014-10-01

In this project, several crack sealant sections were constructed at the Pecos RTC. Six different sealants were : applied in routed and non-routed configurations on both older and newer pavement. The following summer, : the sections were revaluated in...

Fabrication and characterization of lead-free BaTiO3 thin film for storage device applications

NASA Astrophysics Data System (ADS)

Sharma, Hakikat; Negi, N. S.

2018-05-01

The lead-free BaTiO3 (BT) thin film solution has been prepared by sol-gel method. The prepared solution spin coated on Pt/TiO2/SiO2/ Si substrate. The fabricated thin film was analyzed by XRD and Raman spectrometer for structural conformation. Uniformity of thin film was examined by Atomic force microscope (AFM). Thickness of the film was measured by cross sectional FESEM. Activation energies for both positive and negative biasing have been calculated from temperature dependent leakage current density as a function of electric field. For ferroelectric memory devices such as FRAM the hysteresis loop plays important role. Electric filed dependent polarization of BT thin film measured at different switching voltages. With increasing voltage maximum polarization increases.

Examining the Magnetic Properties of LaCoO3 Thin Films Using Magnetic Force Microscopy

NASA Astrophysics Data System (ADS)

Berg, Morgann; Posadas, Agham; de Lozanne, Alex; Demkov, Alexander

2011-03-01

In contrast to the non-magnetic ground state of bulk LaCo O3 (LCO) at low temperatures, ferromagnetism has been observed in elastically strained thin film specimens. The origins of ferromagnetism in strained LCO thin films have been obscured by conflicting experimental results. Pulsed laser deposition (PLD) is the current standard of preparation techniques used to grow thin films of LCO, but results from thin film LCO samples prepared by PLD have been questioned on the basis of chemical inhomogeneity and film defects. Using magnetic force microscopy, we investigate the microscale magnetic properties of strained thin films of LCO prepared by molecular beam epitaxy and deposited on lanthanum aluminate and strontium titanate substrates. We observe these properties across a temperature range surrounding the Curie temperature (Tc ~ 80 K) and compare our results to global magnetic characteristics of these films as measured by a SQUID magnetometer. Supported by NSF-DMR and NSF-IGERT.

Organic Field Effect Transistor Using Amorphous Fluoropolymer as Gate Insulating Film

NASA Astrophysics Data System (ADS)

Kitajima, Yosuke; Kojima, Kenzo; Mizutani, Teruyoshi; Ochiai, Shizuyasu

Organic field effect transistors are fabricated by the active layer of Regioregular poly (3-hexylthiophene-2,5-diy)(P3HT) thin film. CYTOP thin film made from Amorphous Fluoropolymer and fabricated by spin-coating is adopted to a gate dielectric layer on Polyethylenenaphthalate (PEN) thin film that is the substrate of an organic field effect transistor. The surface morphology and molecular orientation of P3HT thin films is observed by atomic force microscope (AFM) and X-Ray diffractometer (XRD). Grains are observed on the CYTOP thin film via an AFM image and the P3HT molecule is oriented perpendicularly on the CYTOP thin film. Based on the performance of the organic field effect transistor, the carrier mobility is 0.092 cm2/Vs, the ON/OFF ratio is 7, and the threshold voltage is -12 V. The ON/OFF ratio is relatively low and to improve On/Off ratio, the CYTOP/Polyimide double gate insulating layer is adopted to OFET.

Thin Disk Accretion in the Magnetically-Arrested State

NASA Astrophysics Data System (ADS)

Avara, Mark J.; McKinney, Jonathan; Reynolds, Christopher S.

2016-01-01

Shakura-Sunyaev thin disk theory is fundamental to black hole astrophysics. Though applications of the theory are wide-spread and powerful tools for explaining observations, such as Soltan's argument using quasar power, broadened iron line measurements, continuum fitting, and recently reverberation mapping, a significant large-scale magnetic field causes substantial deviations from standard thin disk behavior. We have used fully 3D general relativistic MHD simulations with cooling to explore the thin (H/R~0.1) magnetically arrested disk (MAD) state and quantify these deviations. This work demonstrates that accumulation of large-scale magnetic flux into the MAD state is possible, and then extends prior numerical studies of thicker disks, allowing us to measure how jet power scales with the disk state, providing a natural explanation of phenomena like jet quenching in the high-soft state of X-ray binaries. We have also simulated thin MAD disks with a misaligned black hole spin axis in order to understand further deviations from thin disk theory that may significantly affect observations.

Shear thinning effects on blood flow in straight and curved tubes

NASA Astrophysics Data System (ADS)

Cherry, Erica M.; Eaton, John K.

2013-07-01

Simulations were performed to determine the magnitude and types of errors one can expect when approximating blood in large arteries as a Newtonian fluid, particularly in the presence of secondary flows. This was accomplished by running steady simulations of blood flow in straight and curved tubes using both Newtonian and shear-thinning viscosity models. In the shear-thinning simulations, the viscosity was modeled as a shear rate-dependent function fit to experimental data. Simulations in straight tubes were modeled after physiologically relevant arterial flows, and flow parameters for the curved tube simulations were chosen to examine a variety of secondary flow strengths. The diameters ranged from 1 mm to 10 mm and the Reynolds numbers from 24 to 1500. Pressure and velocity data are reported for all simulations. In the straight tube simulations, the shear-thinning flows had flattened velocity profiles and higher pressure gradients compared to the Newtonian simulations. In the curved tube flows, the shear-thinning simulations tended to have blunted axial velocity profiles, decreased secondary flow strengths, and decreased axial vorticity compared to the Newtonian simulations. The cross-sectionally averaged pressure drops in the curved tubes were higher in the shear-thinning flows at low Reynolds number but lower at high Reynolds number. The maximum deviation in secondary flow magnitude averaged over the cross sectional area was 19% of the maximum secondary flow and the maximum deviation in axial vorticity was 25% of the maximum vorticity.

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

Jin, Wencan; Vishwanath, Suresh; Liu, Jianpeng

Topological crystalline insulators have been recently predicted and observed in rock-salt structure SnSe {111} thin films. Previous studies have suggested that the Se-terminated surface of this thin film with hydrogen passivation has a reduced surface energy and is thus a preferred configuration. In this paper, synchrotron-based angle-resolved photoemission spectroscopy, along with density functional theory calculations, is used to demonstrate that a rock-salt SnSe {111} thin film epitaxially grown on Bi 2Se 3 has a stable Sn-terminated surface. These observations are supported by low-energy electron diffraction (LEED) intensity-voltage measurements and dynamical LEED calculations, which further show that the Sn-terminated SnSe {111}more » thin film has undergone a surface structural relaxation of the interlayer spacing between the Sn and Se atomic planes. In sharp contrast to the Se-terminated counterpart, the observed Dirac surface state in the Sn-terminated SnSe {111} thin film is shown to yield a high Fermi velocity, 0.50 x 10 6 m/s, which suggests a potential mechanism of engineering the Dirac surface state of topological materials by tuning the surface configuration.« less

Experiment to verify the permeability of Hele-Shaw cells

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

Hartline, B.K.; Lister, C.R.B.

1978-04-01

A fluid layer sandwiched between 2 flat plates (Hele-Shaw cell) has been assumed to model a saturated porous medium with permeability, D2/12, dependent only on the gap width, D. For situations where the properties of the porous matrix are important, such as thermal convection, the total cross section (Y) of the sandwich should enter into the computation of permeability. To decide which of these approaches is valid, the onset of convection was observed in a Hele-Shaw cell with constant gap width but spatially varying wall thickness. Convection begins in the thin-walled section at a lower temperature difference than it doesmore » where the walls are thick. Data confirm that D3/12Y is the permeability of Hele-Shaw cells used to model thermal convection in porous layers.« less

Microwave integrated circuit for Josephson voltage standards

NASA Technical Reports Server (NTRS)

Holdeman, L. B.; Toots, J.; Chang, C. C. (Inventor)

1980-01-01

A microwave integrated circuit comprised of one or more Josephson junctions and short sections of microstrip or stripline transmission line is fabricated from thin layers of superconducting metal on a dielectric substrate. The short sections of transmission are combined to form the elements of the circuit and particularly, two microwave resonators. The Josephson junctions are located between the resonators and the impedance of the Josephson junctions forms part of the circuitry that couples the two resonators. The microwave integrated circuit has an application in Josephson voltage standards. In this application, the device is asymmetrically driven at a selected frequency (approximately equal to the resonance frequency of the resonators), and a d.c. bias is applied to the junction. By observing the current voltage characteristic of the junction, a precise voltage, proportional to the frequency of the microwave drive signal, is obtained.

Wearable strain sensors based on thin graphite films for human activity monitoring

NASA Astrophysics Data System (ADS)

Saito, Takanari; Kihara, Yusuke; Shirakashi, Jun-ichi

2017-12-01

Wearable health-monitoring devices have attracted increasing attention in disease diagnosis and health assessment. In many cases, such devices have been prepared by complicated multistep procedures which result in the waste of materials and require expensive facilities. In this study, we focused on pyrolytic graphite sheet (PGS), which is a low-cost, simple, and flexible material, used as wearable devices for monitoring human activity. We investigated wearable devices based on PGSs for the observation of elbow and finger motions. The thin graphite films were fabricated by cutting small films from PGSs. The wearable devices were then made from the thin graphite films assembled on a commercially available rubber glove. The human motions could be observed using the wearable devices. Therefore, these results suggested that the wearable devices based on thin graphite films may broaden their application in cost-effective wearable electronics for the observation of human activity.

Thinning and site quality influence aboveground tree carbon stocks in yellow-poplar forests of the southern Appalachians.

Treesearch

Tara Keyser

2010-01-01

Little information exists regarding the effects of intermediate stand management activities (e.g., thinning) on C storage. This lack of information has created uncertainty regarding trade-offs between the benefits observed following thinning and C storage. Using long-term growth data, this study examines the effect of thinning on C storage while controlling for the...

Accuracy and sampling error of two age estimation techniques using rib histomorphometry on a modern sample.

PubMed

García-Donas, Julieta G; Dyke, Jeffrey; Paine, Robert R; Nathena, Despoina; Kranioti, Elena F

2016-02-01

Most age estimation methods are proven problematic when applied in highly fragmented skeletal remains. Rib histomorphometry is advantageous in such cases; yet it is vital to test and revise existing techniques particularly when used in legal settings (Crowder and Rosella, 2007). This study tested Stout & Paine (1992) and Stout et al. (1994) histological age estimation methods on a Modern Greek sample using different sampling sites. Six left 4th ribs of known age and sex were selected from a modern skeletal collection. Each rib was cut into three equal segments. Two thin sections were acquired from each segment. A total of 36 thin sections were prepared and analysed. Four variables (cortical area, intact and fragmented osteon density and osteon population density) were calculated for each section and age was estimated according to Stout & Paine (1992) and Stout et al. (1994). The results showed that both methods produced a systemic underestimation of the individuals (to a maximum of 43 years) although a general improvement in accuracy levels was observed when applying the Stout et al. (1994) formula. There is an increase of error rates with increasing age with the oldest individual showing extreme differences between real age and estimated age. Comparison of the different sampling sites showed small differences between the estimated ages suggesting that any fragment of the rib could be used without introducing significant error. Yet, a larger sample should be used to confirm these results. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Early Changes in the Ultrastructure of Streptococcus faecalis After Amino Acid Starvation

PubMed Central

Higgins, M. L.; Shockman, G. D.

1970-01-01

Thin sections of Streptococcus faecalis (ATCC 9790) starved of one essential amino acid (threonine or valine) initially show rapid increases in (i) cell wall thickness, (ii) the apparent size of the central nucleoid region, and (iii) mesosomal membranes. The most rapid increases in all three variables occurred during the first 1 to 2 hr of starvation. After this initial period, the rates progressively decreased over the 20-hr observation period. During threonine starvation, the mesosomal membrane that accumulated in the first hour was subsequently degraded and reached a level similar to that found in exponential-phase cells after 20 hr. With valine starvation, mesosomal membrane continued to slowly accumulate over the entire 20-hr observation period. The mesosomes of the starved cells retained the same “stalked-bag” morphology of those in exponential-phase cells. These cytological observations agree with previously published biochemical data on membrane lipid and wall content after starvation. Images PMID:4987306

Anisotropy in Alpedrete granite cutting (Rift, Grain and Hardway directions) and effect on bush hammered heritage ashlars

NASA Astrophysics Data System (ADS)

Freire-Lista, David Martin; Fort, Rafael

2015-04-01

Many monuments and cities that are part of humanity's heritage have been built with carved granite ashlars. This dimension stone is one of the most used due to its abundance and durability. Traditional quarrymen have used anisotropic planes to cut granite blocks in the quarry for improved cutting performance. These planes are called Rift, Grain and Hardway (R, G, H) according to the ease of cutting. The aim of this study is to determine the response of each of the three orthogonal cutting planes R, G and H to the craft styling with bush hammer, based on their decay. Alpedrete granite was selected for this research, it is a monzogranite quarried in the Sierra de Guadarrana (Spanish Central System) foothills, in the province of Madrid, Spain. It is one of the most representative of Madrid's heritage granites. Alpedrete granite is also used as building stone in other European cities. From an Alpedrete granite bush hammered ashlar, three thin sections were cut parallel to the H plane; these thin sections cut R and G bush hammered planes. Also three thin sections have been cut parallel to the R plane at a distance of 2 mm, 10 mm and 30 mm from the bush hammered surface. All thin sections have been treated with fluorescein. In each of the thin sections a micrograph mosaic was performed covering the entire area (about 10 cm2, 300 photomicrographs) and printed with 120 increases. The length and spacing of inter-, intra- and trans-crystalline microcracks were quantified and measured. Microcracks were subdivided based on affected minerals in each R, G and H planes. Through these observations it was found that Alpedrete Granite R plane (easier to cut) is determined by exfoliation microcracks orientation. That is, R plane is parallel to the exfoliations microcracks, which are intra-crystalline and straight. The cutting of stones in the R plane is due to the coalescence of straight microcracks in the plane. This plane minimizes the effort and cost of subsequent carving so it has been used preferably as wall façades in heritage building ashlars. That is, the ashlars exposed surface. In other words, the exfoliation microcracks are oriented vertically in heritage ashlars. R planes bush hammering produces many new microcracks and propagation of exfoliation microcracks, generating significant decay with parallel and oblique microcracks to the bush hammered surface to a depth of more than 10 mm. G and H planes bush hammering generates coalescence and increased length of intra-crystalline exfoliation microcracks in the R plane; although, with less generation of new microcracks and less surface decay. To understand the decay in bush hammered granite ashlars and sculptures it is essential to study the orientation and distribution of exfoliations microcracks, which follow the R orientation stone in the quarry. This orientation should be reproduced when performing artificial accelerated ageing tests, especially with stones used in heritage buildings. Acknowledgements This study was funded by the Community of Madrid under the GEOMATERIALS 2 project (S2013/MIT-2914). The authors are members of the Complutense University of Madrid's Research Group: 'Alteración y Conservación de los Materiales Pétreos del Patrimonio' (ref. 921349)

Two-component scattering model and the electron density spectrum

NASA Astrophysics Data System (ADS)

Zhou, A. Z.; Tan, J. Y.; Esamdin, A.; Wu, X. J.

2010-02-01

In this paper, we discuss a rigorous treatment of the refractive scintillation caused by a two-component interstellar scattering medium and a Kolmogorov form of density spectrum. It is assumed that the interstellar scattering medium is composed of a thin-screen interstellar medium (ISM) and an extended interstellar medium. We consider the case that the scattering of the thin screen concentrates in a thin layer represented by a δ function distribution and that the scattering density of the extended irregular medium satisfies the Gaussian distribution. We investigate and develop equations for the flux density structure function corresponding to this two-component ISM geometry in the scattering density distribution and compare our result with the observations. We conclude that the refractive scintillation caused by this two-component ISM scattering gives a more satisfactory explanation for the observed flux density variation than does the single extended medium model. The level of refractive scintillation is strongly sensitive to the distribution of scattering material along the line of sight (LOS). The theoretical modulation indices are comparatively less sensitive to the scattering strength of the thin-screen medium, but they critically depend on the distance from the observer to the thin screen. The logarithmic slope of the structure function is sensitive to the scattering strength of the thin-screen medium, but is relatively insensitive to the thin-screen location. Therefore, the proposed model can be applied to interpret the structure functions of flux density observed in pulsar PSR B2111 + 46 and PSR B0136 + 57. The result suggests that the medium consists of a discontinuous distribution of plasma turbulence embedded in the interstellar medium. Thus our work provides some insight into the distribution of the scattering along the LOS to the pulsar PSR B2111 + 46 and PSR B0136 + 57.

Evidence for tectonic, lithologic, and thermal controls on fracture system geometries in an andesitic high-temperature geothermal field

NASA Astrophysics Data System (ADS)

Massiot, Cécile; Nicol, Andrew; McNamara, David D.; Townend, John

2017-08-01

Analysis of fracture orientation, spacing, and thickness from acoustic borehole televiewer (BHTV) logs and cores in the andesite-hosted Rotokawa geothermal reservoir (New Zealand) highlights potential controls on the geometry of the fracture system. Cluster analysis of fracture orientations indicates four fracture sets. Probability distributions of fracture spacing and thickness measured on BHTV logs are estimated for each fracture set, using maximum likelihood estimations applied to truncated size distributions to account for sampling bias. Fracture spacing is dominantly lognormal, though two subordinate fracture sets have a power law spacing. This difference in spacing distributions may reflect the influence of the andesitic sequence stratification (lognormal) and tectonic faults (power law). Fracture thicknesses of 9-30 mm observed in BHTV logs, and 1-3 mm in cores, are interpreted to follow a power law. Fractures in thin sections (˜5 μm thick) do not fit this power law distribution, which, together with their orientation, reflect a change of controls on fracture thickness from uniform (such as thermal) controls at thin section scale to anisotropic (tectonic) at core and BHTV scales of observation. However, the ˜5% volumetric percentage of fractures within the rock at all three scales suggests a self-similar behavior in 3-D. Power law thickness distributions potentially associated with power law fluid flow rates, and increased connectivity where fracture sets intersect, may cause the large permeability variations that occur at hundred meter scales in the reservoir. The described fracture geometries can be incorporated into fracture and flow models to explore the roles of fracture connectivity, stress, and mineral precipitation/dissolution on permeability in such andesite-hosted geothermal systems.

Moessbauer study in thin films of FeSi2 and FeSe systems

NASA Technical Reports Server (NTRS)

Escue, W. J.; Aggarwal, K.; Mendiratta, R. G.

1978-01-01

Thin films of FeSi2 and FeSe were studied using Moessbauer spectroscopy information regarding dangling bond configuration and nature of crystal structure in thin films was derived. A significant influence of crystalline aluminum substrate on film structure was observed.

Thin film memory matrix using amorphous and high resistive layers

NASA Technical Reports Server (NTRS)

Thakoor, Anilkumar P. (Inventor); Lambe, John (Inventor); Moopen, Alexander (Inventor)

1989-01-01

Memory cells in a matrix are provided by a thin film of amorphous semiconductor material overlayed by a thin film of resistive material. An array of parallel conductors on one side perpendicular to an array of parallel conductors on the other side enable the amorphous semiconductor material to be switched in addressed areas to be switched from a high resistance state to a low resistance state with a predetermined level of electrical energy applied through selected conductors, and thereafter to be read out with a lower level of electrical energy. Each cell may be fabricated in the channel of an MIS field-effect transistor with a separate common gate over each section to enable the memory matrix to be selectively blanked in sections during storing or reading out of data. This allows for time sharing of addressing circuitry for storing and reading out data in a synaptic network, which may be under control of a microprocessor.

Twisting of thin walled columns perfectly restrained at one end

NASA Technical Reports Server (NTRS)

Lazzarino, Lucio

1938-01-01

Proceeding from the basic assumptions of the Batho-Bredt theory on twisting failure of thin-walled columns, the discrepancies most frequently encountered are analyzed. A generalized approximate method is suggested for the determination of the disturbances in the stress condition of the column, induced by the constrained warping in one of the end sections.

Picrosirius Red and Polarization Microscopy - A Tool for Gender Differentiation.

PubMed

Gowda, Bk Charan; Kokila, Ganganna; Gopinathan, Pillai Arun; Praveen, Kunigal Shivaprakash

2017-01-01

Forensic dentistry is a branch of dentistry which in collaboration with legal profession serves an important role to maintain justice system of a country. Forensic dentists play a major role in identification of an individual. Within the literature various methods have been found to be useful in gender differentiation. An attempt was made for differentiation of gender using picrosirius red and polarization microscopy. To evaluate picrosirius red and polarization microscopy as a tool for gender differentiation by observing birefringence pattern and distribution of thick and thin collagen fibers in males and females. Labial mucosal tissue obtained from 30 deceased individuals (18 male and 12 female) during autopsy was fixed in 10% formalin at 12 th hour. Tissue was processed, sectioned and stained using picrosirius red stain and the birefringence pattern of collagen fibers were studied with polarization microscope. The results were statistically analyzed using Z-test and one-way ANOVA to draw the significance. The proportion of thick and thin fibres among males and females were compared. It was found that there was statistically significant difference in proportion of thick and thin fibers between male and female. Thick fibres in males were (78.13%) more than females (65.74%) and thin fibres were more in females (34.24%) than males (21.32%). Picrosirius red and polarization microscopy may be used as a tool for gender differentiation. Yet the manner of death has to be considered during gender differentiation using this method, as in the present study out of 30 cases studied three cases of death due to debilitating diseases and poison consumption showed altered collagen distribution.

Cutting thin sections of bone

NASA Technical Reports Server (NTRS)

Ashley, W. W.

1972-01-01

Medical equipment for obtaining repetitive planoparallel sections of bone to study healing of bone structure under high gravity stress is described. Device consists of modified saw with diamond cutting edges. Construction of device and manner of use are explained.

Observation of shift in band gap with annealing in hydrothermally synthesized TiO2-thin films

NASA Astrophysics Data System (ADS)

Pawar, Vani; Jha, Pardeep K.; Singh, Prabhakar

2018-05-01

Anatase TiO2 thin films were synthesized by hydrothermal method. The films were fabricated on a glass substrate by spin coating unit and annealed at 500 °C for 2 hours in ambient atmosphere. The effect of annealing on microstructure and optical properties of TiO2 thin films namely, just deposited and annealed thin film were investigated. The XRD data confirms the tetragonal crystalline structure of the films with space group I41/amd. The surface morphology suggests that TiO2 particles are almost homogeneous in size and annealing of the film affect the grain growth of the particles. The band gap energy increases from 2.81 to 3.34 eV. On the basis of our observation, it can be concluded that the annealing of TiO2 thin films enhances the absorption range and it may find potential application in the field of solar cells.

Ultrastructural identification of noradrenergic nerve terminals and vasopressin-containing neurons of the paraventricular nucleus in the same thin section.

PubMed

Silverman, A J; Hou-Yu, A; Oldfield, B J

1983-09-01

Since many peptidergic cell groups receive a diverse and complex monoaminergic innervation, we have developed a double-label procedure to visualize a peptide and a catecholamine in the same ultrathin section. Radiolabeled norepinephrine (NE) is applied locally and its reuptake into NE terminals is demonstrated by ultrastructural radioautography. Controls in this and other studies demonstrate that the NE labels only NE (and possibly epinephrine) terminals and not dopaminergic or serotonergic terminals. In the same tissue, vasopressin is localized by immunocytochemistry on unembedded sections that are subsequently embedded in epoxy resins for thin sectioning. The procedure as described here shows that NE terminals in the periventricular zone of the paraventricular nucleus of the hypothalamus innervate both vasopressin-positive and vasopressin-negative structures. This technique is useful in determining the chemical connectivity of the hypothalamus.

The aerodynamic properties of thick aerofoils suitable for internal bracing

NASA Technical Reports Server (NTRS)

Norton, F H

1920-01-01

The object of this investigation was to determine the characteristics of various types of wings having sufficient depth to entirely inclose the wing bracing, and also to provide data for the further design of such sections. This type of wing is of interest because it eliminates the resistance of the interplane bracing, a portion of the airplane that sometimes absorbs one-quarter of the total power required to fly, and because these wings may be made to give a very high maximum lift. Results of the investigation of the following subjects are given: (1) effect of changing the upper and lower camber of thick aerofoils of uniform section; (2) effect of thickening the center and thinning the tips of a thin aerofoil; (3) effect of adding a convex lower surface to a tapered section; (4) effect of changing the mean thickness with constant center and tip sections; and (5) effect of varying the chord along the span.

Theory of thin-walled rods

NASA Technical Reports Server (NTRS)

Goldenveizer, A L

1951-01-01

Starting with the Love equations for bending of extensible shells, "principal stress states" are sought for a thin-walled rod of arbitrary but open cross section. Principal stress states exclude those local states arising from end conditions which damp out with distance from the ends. It is found that for rods of intermediate length, long enough to avoid local bending at a support, and short enough that elementary torsion and bending are not the most significant stress states, four principal states exist. Three of these states are associated with the planar distribution of axial stress and are equivalent to the engineering theory of extension and bending of solid sections. The fourth state resembles that which has been called in the literature "bending stress due to torsional", except that cross sections are permitted to bend and the shear along the center line of the cross section is permitted to differ from zero.

Self-Limited Growth in Pentacene Thin Films

PubMed Central

2017-01-01

Pentacene is one of the most studied organic semiconducting materials. While many aspects of the film formation have already been identified in very thin films, this study provides new insight into the transition from the metastable thin-film phase to bulk phase polymorphs. This study focuses on the growth behavior of pentacene within thin films as a function of film thickness ranging from 20 to 300 nm. By employing various X-ray diffraction methods, combined with supporting atomic force microscopy investigations, one crystalline orientation for the thin-film phase is observed, while three differently tilted bulk phase orientations are found. First, bulk phase crystallites grow with their 00L planes parallel to the substrate surface; second, however, crystallites tilted by 0.75° with respect to the substrate are found, which clearly dominate the former in ratio; third, a different bulk phase polymorph with crystallites tilted by 21° is found. The transition from the thin-film phase to the bulk phase is rationalized by the nucleation of the latter at crystal facets of the thin-film-phase crystallites. This leads to a self-limiting growth of the thin-film phase and explains the thickness-dependent phase behavior observed in pentacene thin films, showing that a large amount of material is present in the bulk phase much earlier during the film growth than previously thought. PMID:28287698

Self-Limited Growth in Pentacene Thin Films.

PubMed

Pachmajer, Stefan; Jones, Andrew O F; Truger, Magdalena; Röthel, Christian; Salzmann, Ingo; Werzer, Oliver; Resel, Roland

2017-04-05

Pentacene is one of the most studied organic semiconducting materials. While many aspects of the film formation have already been identified in very thin films, this study provides new insight into the transition from the metastable thin-film phase to bulk phase polymorphs. This study focuses on the growth behavior of pentacene within thin films as a function of film thickness ranging from 20 to 300 nm. By employing various X-ray diffraction methods, combined with supporting atomic force microscopy investigations, one crystalline orientation for the thin-film phase is observed, while three differently tilted bulk phase orientations are found. First, bulk phase crystallites grow with their 00L planes parallel to the substrate surface; second, however, crystallites tilted by 0.75° with respect to the substrate are found, which clearly dominate the former in ratio; third, a different bulk phase polymorph with crystallites tilted by 21° is found. The transition from the thin-film phase to the bulk phase is rationalized by the nucleation of the latter at crystal facets of the thin-film-phase crystallites. This leads to a self-limiting growth of the thin-film phase and explains the thickness-dependent phase behavior observed in pentacene thin films, showing that a large amount of material is present in the bulk phase much earlier during the film growth than previously thought.

Indirect Fabrication of Lattice Metals with Thin Sections Using Centrifugal Casting

PubMed Central

Mun, Jiwon; Ju, Jaehyung; Thurman, James

2016-01-01

One of the typical methods to manufacture 3D lattice metals is the direct-metal additive manufacturing (AM) process such as Selective Laser Melting (SLM) and Electron Beam Melting (EBM). In spite of its potential processing capability, the direct AM method has several disadvantages such as high cost, poor surface finish of final products, limitation in material selection, high thermal stress, and anisotropic properties of parts. We propose a cost-effective method to manufacture 3D lattice metals. The objective of this study is to provide a detailed protocol on fabrication of 3D lattice metals having a complex shape and a thin wall thickness; e.g., octet truss made of Al and Cu alloys having a unit cell length of 5 mm and a cell wall thickness of 0.5 mm. An overall experimental procedure is divided into eight sections: (a) 3D printing of sacrificial patterns (b) melt-out of support materials (c) removal of residue of support materials (d) pattern assembly (e) investment (f) burn-out of sacrificial patterns (g) centrifugal casting (h) post-processing for final products. The suggested indirect AM technique provides the potential to manufacture ultra-lightweight lattice metals; e.g., lattice structures with Al alloys. It appears that the process parameters should be properly controlled depending on materials and lattice geometry, observing the final products of octet truss metals by the indirect AM technique. PMID:27214495

The role of detrital anhydrite in diagenesis of aeolian sandstones (Upper Rotliegend, The Netherlands): Implications for reservoir-quality prediction

NASA Astrophysics Data System (ADS)

Henares, S.; Bloemsma, M. R.; Donselaar, M. E.; Mijnlieff, H. F.; Redjosentono, A. E.; Veldkamp, H. G.; Weltje, G. J.

2014-12-01

The Rotliegend (Upper Permian) reservoir interval in the Southern Permian Basin (SPB) contains low-permeability streaks corresponding to anhydrite-cemented intervals. An integrated study was conducted using core, cuttings, thin sections and well-log data from a gas exploration well and two geothermal wells that target the zone of interest. This study aims at understanding the origin and nature of these low-permeability streaks, as well as their impact on reservoir properties, and to establish a predictive model of their spatial distribution. High-resolution XRF core-scanning analysis allowed to extrapolate spot observations in thin sections to the entire core. Diagenetic history includes grain rearrangement and anhydrite, haematitic clay coatings, dolomite rims, quartz overgrowths, kaolinite and second-generation carbonates as cementing phases. Coupling of all data reveals the detrital origin of the anhydrite/gypsum grains which were deposited together with the coarse-grained sand fraction in an aeolian sandflat environment. Such partially or completely dissolved grains acted as local sources of anhydrite cement and as nuclei for precipitation, explaining its preferential occurrence in coarse-grained laminae. Thick gypscretes in the vicinity likely supplied the anhydrite/gypsum grains. A conceptual model is proposed, including the location of nearby gypscretes and the prevailing west-southwest aeolian transport direction on the southern rim of the SPB.

OCT of early dental caries: a comparative study with histology and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Hewko, Mark D.; Choo-Smith, Lin-P'ing; Ko, Alex C.; Leonardi, Lorenzo; Dong, Cecilia C.; Cleghorn, Blaine; Sowa, Michael G.

2005-03-01

Early dental caries result from destruction of the tooth's outer mineral matrix by acid-forming bacteria found in dental plaques. Early caries begin as surface disruptions where minerals are leached from the teeth resulting in regions of decreased mineral matrix integrity. Visually, these early carious regions appear as white spots due to the higher backscattering of incident light. With age these areas may become stained by organic compounds. Optical coherence tomography (OCT) examination of human teeth demonstrates a difference in penetration depth of the OCT signal into the carious region in comparison with sound enamel. However, while OCT demonstrates a structural difference in the enamel in the region of the caries, this technique provides little insight into the source of this difference. Raman spectroscopy provides biochemical measures derived from hydroxyapatite within the enamel as well as information on the crystallinity of the enamel matrix. The differences in the biochemical and morphological features of early caries and intact sound enamel are compared. Histological thin sections confirm the observations by OCT morphological imaging while Raman spectroscopy allows for biochemical identification of carious regions by a non-destructive method. Visual examination and conventional radiographic imaging of the intact tooth are used in clinical assessment prior to optical measurements. The combination of OCT, Raman spectroscopy and thin section histology aid in determining the changes that give rise to the visual white spot lesions.

Indirect Fabrication of Lattice Metals with Thin Sections Using Centrifugal Casting.

PubMed

Mun, Jiwon; Ju, Jaehyung; Thurman, James

2016-05-14

One of the typical methods to manufacture 3D lattice metals is the direct-metal additive manufacturing (AM) process such as Selective Laser Melting (SLM) and Electron Beam Melting (EBM). In spite of its potential processing capability, the direct AM method has several disadvantages such as high cost, poor surface finish of final products, limitation in material selection, high thermal stress, and anisotropic properties of parts. We propose a cost-effective method to manufacture 3D lattice metals. The objective of this study is to provide a detailed protocol on fabrication of 3D lattice metals having a complex shape and a thin wall thickness; e.g., octet truss made of Al and Cu alloys having a unit cell length of 5 mm and a cell wall thickness of 0.5 mm. An overall experimental procedure is divided into eight sections: (a) 3D printing of sacrificial patterns (b) melt-out of support materials (c) removal of residue of support materials (d) pattern assembly (e) investment (f) burn-out of sacrificial patterns (g) centrifugal casting (h) post-processing for final products. The suggested indirect AM technique provides the potential to manufacture ultra-lightweight lattice metals; e.g., lattice structures with Al alloys. It appears that the process parameters should be properly controlled depending on materials and lattice geometry, observing the final products of octet truss metals by the indirect AM technique.

The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 1, Section 1: Coatings and Interfaces

DTIC Science & Technology

1989-10-15

Cut Prestressed Film H.M. Jensen on a Substrate J.W. Hutchinson K.S. Kim 8. Measuring the Strength and Stiffness T.P. Weihs of Thin Film Materials by...for Thin Films T.P. Weihs Using Micro-Cantilever Beams J.C. Bravman W.D. Nix 10. Analysis of Elastic and Plastic Deformation A.K. Bhattacharya...Associated with Indentation Testing of Thin W.D. Nix Films on Substrates 11. Finite Elenent Simulidion of Indentation A.K. 13hattacharya Experimnents W.D

Metal-insulator transition in tin doped indium oxide (ITO) thin films: Quantum correction to the electrical conductivity

NASA Astrophysics Data System (ADS)

Kaushik, Deepak Kumar; Kumar, K. Uday; Subrahmanyam, A.

2017-01-01

Tin doped indium oxide (ITO) thin films are being used extensively as transparent conductors in several applications. In the present communication, we report the electrical transport in DC magnetron sputtered ITO thin films (prepared at 300 K and subsequently annealed at 673 K in vacuum for 60 minutes) in low temperatures (25-300 K). The low temperature Hall effect and resistivity measurements reveal that the ITO thin films are moderately dis-ordered (kFl˜1; kF is the Fermi wave vector and l is the electron mean free path) and degenerate semiconductors. The transport of charge carriers (electrons) in these disordered ITO thin films takes place via the de-localized states. The disorder effects lead to the well-known `metal-insulator transition' (MIT) which is observed at 110 K in these ITO thin films. The MIT in ITO thin films is explained by the quantum correction to the conductivity (QCC); this approach is based on the inclusion of quantum-mechanical interference effects in Boltzmann's expression of the conductivity of the disordered systems. The insulating behaviour observed in ITO thin films below the MIT temperature is attributed to the combined effect of the weak localization and the electron-electron interactions.

Direct observation of fatigue in epitaxially grown Pb(Zr,Ti)O3 thin films using second harmonic piezoresponse force microscopy

NASA Astrophysics Data System (ADS)

Murari, Nishit M.; Hong, Seungbum; Lee, Ho Nyung; Katiyar, Ram. S.

2011-08-01

Here, we present a direct observation of fatigue phenomena in epitaxially grown Pb(Zr0.2Ti0.8)O3 (PZT) thin films using second harmonic piezoresponse force microscopy (SH-PFM). We observed strong correlation between the SH-PFM amplitude and phase signals with the remnant piezoresponse at different switching cycles. The SH-PFM results indicate that the average fraction of switchable domains decreases globally and the phase delays of polarization switching differ locally. In addition, we found that the fatigue developed uniformly over the whole area without developing region-by-region suppression of switchable polarization as in polycrystalline PZT thin films.

Nucleation of fcc Ta when heating thin films

DOE PAGES

Janish, Matthew T.; Mook, William M.; Carter, C. Barry

2014-10-25

Thin tantalum films have been studied during in-situ heating in a transmission electron microscope. Diffraction patterns from the as-deposited films were typical of amorphous materials. Crystalline grains were observed to form when the specimen was annealed in-situ at 450°C. Particular attention was addressed to the formation and growth of grains with the face-centered cubic (fcc) crystal structure. As a result, these observations are discussed in relation to prior work on the formation of fcc Ta by deformation and during thin film deposition.

Low-head feeding system for thin section castings

DOEpatents

Daniel, Sabah S.; Kleeb, Thomas R.; Lewis, Thomas W.; McDermott, John F.; Ozgu, Mustafa R.; Padfield, Ralph C.; Rego, Donovan N.; Vassilicos, Achilles

1990-01-01

A feed system is provided for conveying molten metal to a thin section caster having mold surfaces moving exclusively in the direction of casting. The feed system has a passage of circular cross section adjacent to one end thereof for receiving molten metal and a rectangular cross section at the delivery end thereof adjacent to the caster. The feed system is designed for supplying molten metal to the caster at low pressure for "closed-pool" type caster operation. The point of highest elevation in the metal flow passage of the feed system is on the upper surface of a transition portion where the cross section changes from circular to rectangular adjacent to the nozzle. The level or height of the high point above the centerline of the nozzle exit is selected so as to be less than the pressure of the metal measured in inches at the nozzle exit. This feature enables the maintenance of positive pressure in the metal within the feed system so that ingress of air into the metal is prevented.

Swift heavy ion induced modification in morphological and physico-chemical properties of tin oxide nanocomposites

NASA Astrophysics Data System (ADS)

Jaiswal, Manoj Kumar; Kanjilal, D.; Kumar, Rajesh

2013-11-01

Nanocomposite thin films of tin oxide (SnO2)/titanium oxide (TiO2) were grown on silicon (1 0 0) substrates by electron beam evaporation deposition technique using sintered nanocomposite pellet of SnO2/TiO2 in the percentage ratio of 95:5. Sintering of the nanocomposite pellet was done at 1300 °C for 24 h. The thicknesses of these films were measured to be 100 nm during deposition using piezo-sensor attached to the deposition chamber. TiO2 doped SnO2 nanocomposite films were irradiated by 100 MeV Au8+ ion beam at fluence range varying from 1 × 1011 ions/cm2 to 5 × 1013 ions/cm2 at Inter University Accelerator Center (IUAC), New Delhi, India. Chemical properties of pristine and ion irradiation modified thin films were characterized by Fourier Transform Infrared (FTIR) spectroscopy. FTIR peak at 610 cm-1 confirms the presence of O-Sn-O bridge of tin (IV) oxide signifying the composite nature of pristine and irradiated thin films. Atomic Force Microscope (AFM) in tapping mode was used to study the surface morphology and grain growth due to swift heavy ion irradiation at different fluencies. Grain size calculations obtained from sectional analysis of AFM images were compared with results obtained from Glancing Angle X-ray Diffraction (GAXRD) measurements using Scherrer’s formulae. Phase transformation due to irradiation was observed from Glancing Angle X-ray Diffraction (GAXRD) results. The prominent 2θ peaks observed in GAXRD spectrum are at 30.67°, 32.08°, 43.91°, 44.91° and 52.35° in the irradiated films.

Al K x-ray production for incident /sup 16/O ions: The influence of target thickness effects on observed target x-ray yields

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

Gray, T.J.; Richard, P.; Gealy, G.

1979-04-01

Thin solid Al targets ranging in thickness from approx. 1 to 30 ..mu..g/cm/sup 2/ were bombarded by /sup 16/O ions wih incident energies from 0.25 to 2.25 MeV/amu. The effects of target thickness on the measured Al K x-ray yield for ions incident without an initial K-shell vacancy were determined. Comparisons of the data for Al K x-ray production in vanishingly thin targets (and 29-..mu..g/cm/sup 2/ targets) were made to perturbed-stationary-state calculations (PSS) for O ions on Al targets. The PSS calculations contained corrections for Coulomb deflection and binding energy (PSS(CB)) and for Coulomb deflection, binding energy, and polarization (PSS(CBP)).more » Further, two different PSS calculation procedures were employed: calculations without radial cutoffs employed in the binding-energy contribution (PSS), and calculations with radial cutoffs employed in the binding-energy correction (NPSS). The PSS(CBP) calculations agree with the measured Al K x-ray production cross section for data taken in the limit of a vanishingly thin target. The NPSS(CBP) calculations agree with the data taken for a 29-..mu..g/cm/sup 2/ Al target. The latter agreement is fortuitous, as the increase observed in the measured target x-ray yield for the 29-..mu..g/cm/sup 2/ target, in comparison to the yield extracted as rhox ..-->.. 0 at each bombarding energy, is due to K-shell--to--K-shell charge exchange. Comparisons are made with previously published data for /sup 16/O ions incident on finite-thickness Al targets.« less

Tectono-thermal Evolution of a Distal Rifted Margin: Constraints From the Calizzano Massif (Prepiedmont-Briançonnais Domain, Ligurian Alps)

NASA Astrophysics Data System (ADS)

Decarlis, Alessandro; Fellin, Maria Giuditta; Maino, Matteo; Ferrando, Simona; Manatschal, Gianreto; Gaggero, Laura; Seno, Silvio; Stuart, Finlay M.; Beltrando, Marco

2017-12-01

The thermal evolution of distal domains along rifted margins is at present poorly constrained. In this study, we show that a thermal pulse, most likely triggered by lithospheric thinning and asthenospheric rise, is recorded at upper crustal levels and may also influence the diagenetic processes in the overlying sediments, thus representing a critical aspect for the evaluation of hydrocarbon systems. The thermal history of a distal sector of the Alpine Tethys rifted margin preserved in the Ligurian Alps (Case Tuberto-Calizzano unit) is investigated with thermochronological methods and petrologic observations. The studied unit is composed of a polymetamorphic basement and a sedimentary cover, providing a complete section through the prerift, synrift, and postrift system. Zircon fission track analyses on basement rocks samples suggest that temperatures exceeding 240 ± 25°C were reached before 150-160 Ma (Upper Jurassic) at few kilometer depth. Neoformation of green biotite, stable at temperatures of 350 to 450°C, was synkinematic with this event. The tectonic setting of the studied unit suggests that the heating-cooling cycle took place during the formation of the distal rifted margin and terminated during Late Jurassic (150-160 Ma). Major crustal and lithospheric thinning likely promoted high geothermal gradients ( 60-90°C/km) and triggered the circulation of hot, deep-seated fluids along brittle faults, causing the observed thermal anomaly. Our results suggest that rifting can generate thermal perturbations at relatively high temperatures (between 240 and 450°C) at less than 3 km depth in the distal domains during major crustal thinning preceding breakup and onset of seafloor spreading.

Clinical, pathological and thin-section CT features of persistent multiple ground-glass opacity nodules: comparison with solitary ground-glass opacity nodule.

PubMed

Kim, Tae Jung; Goo, Jin Mo; Lee, Kyung Won; Park, Chang Min; Lee, Hyun Ju

2009-05-01

To retrospectively compare the clinical, pathological, and thin-section CT features of persistent multiple ground-glass opacity (GGO) nodules with those of solitary GGO nodules. Histopathologic specimens were obtained from 193 GGO nodules in 136 patients (87 women, 49 men; mean age, 57; age range 33-81). The clinical data, pathologic findings, and thin-section CT features of multiple and solitary GGO nodules were compared by using t-test or Fisher's exact test. Multiple GGO nodules (n=105) included atypical adenomatous hyperplasia (AAH) (n=31), bronchioloalveolar carcinoma (BAC) (n=33), adenocarcinoma (n=34) and focal interstitial fibrosis (n=7). Solitary GGO nodules included AAH (n=8), BAC (n=15), adenocarcinoma (n=55) and focal interstitial fibrosis (n=10). AAH (P=.001) and BAC (P=.029) were more frequent in multiple GGO nodules, whereas adenocarcinoma (P<.001) was more frequent in solitary GGO nodules. Female sex (P<.001), nonsmoker (P=.012) and multiple primary lung cancers (P<.001) were more frequent for multiple GGO nodules, which were smaller (12 mm+/-7.9) than solitary GGO nodules (17 mm+/-8.1) (P<.001). Air-bronchogram (P=.019), bubble-lucency (P=.004), and pleural retraction (P<.001) were more frequent in solitary GGO nodules. There was no postoperative recurrence except for one patient with multiple GGO nodules and one with solitary GGO nodule. Clinical, pathological, and thin-section CT features of persistent multiple GGO nodules were found to differ from those of solitary GGO nodules. Nevertheless, the two nodule types can probably be followed up and managed in a similar manner because their prognoses were found to be similar.

Studies on annealed ZnO:V thin films deposited by nebulised spray pyrolysis method

NASA Astrophysics Data System (ADS)

Malini, D. Rachel

2018-04-01

Structural, optical and photoluminescence properties of annealed ZnO:V thin films deposited by nebulized spray pyrolysis technique by varying vanadium concentration are studied. Thickness of thin films varies from 1.52µm to 7.78µm. V2O5, VO2 and ZnO peaks are observed in XRD patterns deposited with high vanadium concentration and the intensity of peaks corresponding to ZnO decreases in those samples. Morphological properties were studied by analysing SEM images and annealed thin films deposited at ZnO:V = 50:50 possess dumb bell shape grains. Emission peaks corresponding to both Augur transition and deep level transition are observed in the PL spectra of the samples.

Electrical instability of high-mobility zinc oxynitride thin-film transistors upon water exposure

NASA Astrophysics Data System (ADS)

Kim, Dae-Hwan; Jeong, Hwan-Seok; Kwon, Hyuck-In

2017-03-01

We investigate the effects of water absorption on the electrical performance and stability in high-mobility zinc oxynitride (ZnON) thin-film transistors (TFTs). The ZnON TFT exhibits a smaller field-effect mobility, lower turn-on voltage, and higher subthreshold slope with a deteriorated electrical stability under positive gate bias stresses after being exposed to water. From the Hall measurements, an increase of the electron concentration and a decrease of the Hall mobility are observed in the ZnON thin film after water absorption. The observed phenomena are mainly attributed to the water molecule-induced increase of the defective ZnXNY bond and the oxygen vacancy inside the ZnON thin film based on the x-ray photoelectron spectroscopy analysis.

Thinning Factors and Crustal Thicknesses at the Propagating Tip of Sea-floor Spreading in the Woodlark Basin

NASA Astrophysics Data System (ADS)

Gozzard, S. P.; Kusznir, N.; Goodliffe, A.; Manatschal, G.

2007-12-01

Understanding how the continental crust and lithosphere thins at the propagating tip of sea-floor spreading is the key to understanding the continental breakup process. The Woodlark Basin, a young ocean basin located in the Western Pacific to the east of Papua New Guinea, commenced formation at approximately 8.4Ma and is propagating westwards at a rate of approximately 140km/Myr. Immediately to the west of the most recent segment of sea-floor spreading propagation, in the vicinity of the Moresby Seamount, evidence from bathymetry, subsidence and seismic Moho depth suggests that continental lithosphere is being thinned. In this study we have determined lithosphere thinning in the vicinity of the Moresby Seamount at the level of the whole lithosphere, the whole crust and the upper crust. Whole lithosphere thinning factors have been determined from subsidence analysis; whole continental crustal thinning factors have been determined from gravity inversions and upper crustal thinning factors have been determined from fault analysis. Three 2D seismic profiles surrounding the Moresby Seamount have been flexurally backstripped to the base of the syn-rift sediments to determine the water loaded subsidence. Using the McKenzie lithosphere extension model, modified to include volcanic addition at high thinning factors, whole thinning factors for the lithosphere have been determined from the water loaded subsidence. Results show that thermal subsidence alone cannot account for the observed subsidence, and that an additional initial subsidence is needed. Whole lithosphere thinning factors increase from an average of 0.5 to 0.8 across the Moresby Seamount eastwards towards the propagating tip. A satellite gravity inversion incorporating a lithosphere thermal gravity anomaly correction has been used to determine Moho depth, crustal thickness and thinning factors for the propagating tip in the Woodlark Basin. Moho depths are consistent with depths obtained from receiver function analysis (Ferris et al. 2006). Crustal thickness estimates do not include a correction for sediment thickness and are upper bounds. Crustal thinning factors in the vicinity of the Moresby Seamount are similar to those observed for the whole lithosphere. Fault analysis of the three 2D profiles have been used to determine upper crustal thinning factors. Upper crustal thinning factors between 0.1 to 0.2 are observed for the vicinity of the Moresby Seamount, substantially lower than thinning factors predicted for the whole lithosphere and continental crust, suggesting depth-dependent lithosphere thinning. Crustal thicknesses predicted from gravity inversion immediately to the east of the Moresby Seamount are substantially greater than would be expected for oceanic lithosphere in this region, while highly thinned, has not completely ruptured.

Seismic structure of the uppermost mantle beneath the Kenya rift

USGS Publications Warehouse

Keller, Gordon R.; Mechie, J.; Braile, L.W.; Mooney, W.D.; Prodehl, C.

1994-01-01

A major goal of the Kenya Rift International Seismic Project (KRISP) 1990 experiment was the determination of deep lithospheric structure. In the refraction/wide-angle reflection part of the KRISP effort, the experiment was designed to obtain arrivals to distances in excess of 400 km. Phases from interfaces within the mantle were recorded from many shotpoints, and by design, the best data were obtained along the axial profile. Reflected arrivals from two thin (< 10 km), high-velocity layers were observed along this profile and a refracted arrival was observed from the upper high-velocity layer. These mantle phases were observed on record sections from four axial profile shotpoints so overlapping and reversed coverage was obtained. Both high-velocity layers are deepest beneath Lake Turkana and become more shallow southward as the apex of the Kenya dome is approached. The first layer has a velocity of 8.05-8.15 km/s, is at a depth of about 45 km beneath Lake Turkana, and is observed at depths of about 40 km to the south before it disappears near the base of the crust. The deeper layer has velocities ranging from 7.7 to 7.8 km/s in the south to about 8.3 km/s in the north, has a similar dip as the upper one, and is found at depths of 60-65 km. Mantle arrivals outside the rift valley appear to correlate with this layer. The large amounts of extrusive volcanics associated with the rift suggest compositional anomalies as an explanation for the observed velocity structure. However, the effects of the large heat anomaly associated with the rift indicate that composition alone cannot explain the high-velocity layers observed. These layers require some anisotropy probably due to the preferred orientation of olivine crystals. The seismic model is consistent with hot mantle material rising beneath the Kenya dome in the southern Kenya rift and north-dipping shearing along the rift axis near the base of the lithosphere beneath the northern Kenya rift. This implies lithosphere thickening towards the north and is consistent with a thermal thinning of the lithosphere from below in the south changing to thinning of the lithosphere due to stretching in the north. ?? 1994.

Importing, Working With, and Sharing Microstructural Data in the StraboSpot Digital Data System, Including an Example Dataset from the Pilbara Craton, Western Australia.

NASA Astrophysics Data System (ADS)

Roberts, N.; Cunningham, H.; Snell, A.; Newman, J.; Tikoff, B.; Chatzaras, V.; Walker, J. D.; Williams, R. T.

2017-12-01

There is currently no repository where a geologist can survey microstructural datasets that have been collected from a specific field area or deformation experiment. New development of the StraboSpot digital data system provides a such a repository as well as visualization and analysis tools. StraboSpot is a graph database that allows field geologists to share primary data and develop new types of scientific questions. The database can be accessed through: 1) a field-based mobile application that runs on iOS and Android mobile devices; and 2) a desktop system. We are expanding StraboSpot to include the handling of a variety of microstructural data types. Presented here is the detailed vocabulary and logic used for the input of microstructural data, and how this system operates with the anticipated workflow of users. Microstructural data include observations and interpretations from photomicrographs, scanning electron microscope images, electron backscatter diffraction, and transmission electron microscopy data. The workflow for importing microstructural data into StraboSpot is organized into the following tabs: Images, Mineralogy & Composition; Sedimentary; Igneous; Metamorphic; Fault Rocks; Grain size & configuration; Crystallographic Preferred Orientation; Reactions; Geochronology; Relationships; and Interpretations. Both the sample and the thin sections are also spots. For the sample spot, the user can specify whether a sample is experimental or natural; natural samples are inherently linked to their field context. For the thin section (sub-sample) spot, the user can select between different options for sample preparation, geometry, and methods. A universal framework for thin section orientation is given, which allows users to overlay different microscope images of the same area and keeps georeferenced orientation. We provide an example dataset of field and microstructural data from the Mt Edgar dome, a granitic complex in the Paleoarchean East Pilbara craton, Australia. StraboSpot provides a single place for georeferenced geologic data at every spatial scale, in which data are interconnected. Incorporating microstructural data into an open-access platform will give field and experimental geologists a library of microstructural data across a range of tectonic and experimental contexts.

Neutrophil migration through preexisting holes in the basal laminae of alveolar capillaries and epithelium during streptococcal pneumonia.

PubMed

Walker, D C; Behzad, A R; Chu, F

1995-11-01

The purpose of this study was to determine whether or not there are preexisting holes in the endothelial and epithelial basal laminae of alveolar walls and to determine the path taken by neutrophils as they migrate from the capillaries to the airspace of the alveoli during inflammation. Using transmission electron microscopy and serial thin sections of normal rabbit and mouse lung, we have demonstrated the presence of slit-like holes in the capillary basal laminae and round holes in the basal laminae of type 2 pneumocytes. The slits in the capillary basal laminae were observed at the intersection of the thick and thin walls where endothelium, pericytes, and fibroblasts make close contact. The round holes in the type 2 cell basal laminae were observed at sites of close contact with fibroblasts. Neutrophils were observed to migrate through these slits and holes during streptococcal pneumonia in rabbit lungs. We conclude that during inflammation in the lung, migrating neutrophils displace pericytes and fibroblasts from the slits in the capillary basal lamina and then crawl through these slits into the alveolar interstitium. We postulate that neutrophils find their way to type 2 pneumocytes by following interstitial fibroblasts. We believe that neutrophils displace fibroblasts from their close contacts with the type 2 cells and then crawl through the holes in the basal lamina into the basal lateral space of the type 2 cells. From there, neutrophils migrate into the alveolar airspace.

Modelling blazar flaring using a time-dependent fluid jet emission model - an explanation for orphan flares and radio lags

NASA Astrophysics Data System (ADS)

Potter, William J.

2018-01-01

Blazar jets are renowned for their rapid violent variability and multiwavelength flares, however, the physical processes responsible for these flares are not well understood. In this paper, we develop a time-dependent inhomogeneous fluid jet emission model for blazars. We model optically thick radio flares for the first time and show that they are delayed with respect to the prompt optically thin emission by ∼months to decades, with a lag that increases with the jet power and observed wavelength. This lag is caused by a combination of the travel time of the flaring plasma to the optically thin radio emitting sections of the jet and the slow rise time of the radio flare. We predict two types of flares: symmetric flares - with the same rise and decay time, which occur for flares whose duration is shorter than both the radiative lifetime and the geometric path-length delay time-scale; extended flares - whose luminosity tracks the power of particle acceleration in the flare, which occur for flares with a duration longer than both the radiative lifetime and geometric delay. Our model naturally produces orphan X-ray and γ-ray flares. These are caused by flares that are only observable above the quiescent jet emission in a narrow band of frequencies. Our model is able to successfully fit to the observed multiwavelength flaring spectra and light curves of PKS1502+106 across all wavelengths, using a transient flaring front located within the broad-line region.

LA-ICP-MS Study of Trace Elements in the Chanuskij Metal

NASA Technical Reports Server (NTRS)

Petaev, Michail I.

2005-01-01

This progress report covers work done during the second year of the 3-year proposal. During this year we resolved many issues relevant to the analytical technique developed by us for measuring trace elements in meteoritic metals. This technique was used to measure concentrations of Fe, Ni, Co, Cr, Cu, Ga, Ge, As, Mo, Ru, Rh, Pd, Sb, W, Re, Os, Ir, Pt, and Au in eight large (120 - 160 microns) metal grains from both "igneous" and "metamorphic" lithologies of the Chanuskij silicate inclusions. The first application of OUT technique to metal grains from thin sections showed some limitations. Small thickness of metal grains in the thin section limited the signal to 3-4 time-slices instead of 10- 1 1 ones in polished sections of iron meteorites studied before.

P-doped strontium titanate grown using two target pulsed laser deposition for thin film solar cells

NASA Astrophysics Data System (ADS)

Man, Hamdi

Thin-film solar cells made of Mg-doped SrTiO3 p-type absorbers are promising candidates for clean energy generation. This material shows p-type conductivity and also demonstrates reasonable absorption of light. In addition, p-type SrTiO3 can be deposited as thin films so that the cost can be lower than the competing methods. In this work, Mg-doped SrTiO3 (STO) thin-films were synthesized and analyzed in order to observe their potential to be employed as the base semiconductor in photovoltaic applications. Mg-doped STO thin-films were grown by using pulsed laser deposition (PLD) using a frequency quadrupled Yttrium Aluminum Garnet (YAG) laser and with a substrate that was heated by back surface absorption of infrared (IR) laser light. The samples were characterized using X-ray photoelectron spectroscopy (XPS) and it was observed that Mg atoms were doped successfully in the stoichiometry. Reflection high energy electron diffraction (RHEED) spectroscopy proved that the thin films were polycrystalline. Kelvin Probe work function measurements indicated that the work function of the films were 4.167 eV after annealing. UV/Vis Reflection spectroscopy showed that Mg-doped STO thin-films do not reflect significantly except in the ultraviolet region of the spectrum where the reflection percentage increased up to 80%. Self-doped STO thin-films, Indium Tin Oxide (ITO) thin films and stainless steel foil (SSF) were studied in order to observe their characteristics before employing them in Mg-doped STO based solar cells. Self-doped STO thin films were grown using PLD and the results showed that they are capable of serving as the n-type semiconductor in solar cell applications with oxygen vacancies in their structure and low reflectivity. Indium Tin Oxide thin-films grown by PLD system showed low 25-50 ?/square sheet resistance and very low reflection features. Finally, commercially available stainless steel foil substrates were excellent substrates for the inexpensive growth of these novel solar cells.

Powassan Virus: Morphology and Cytopathology

PubMed Central

Abdelwahab, K. S. E.; Almeida, J. D.; Doane, F. W.; McLean, D. M.

1964-01-01

Powassan virus, a North American tickborne group B arbovirus, multiplied after simultaneous inoculation into bottles or tubes of virus and trypsinized suspension of continuous-line cultures of rhesus monkey kidney cells, strain LLC-MK2. Cytopathic effects comprising cell rounding and cytoplasmic vacuolation were first observed five days after inoculation. Mixture of Powassan antiserum with virus before inoculation into tissue cultures inhibited the appearance of cytopathic effects. Hemagglutinins for rooster erythrocytes, optimally at pH 6.4 and 22° C., first appeared in tissue culture supernatant fluids four days after inoculation. Electron microscopic observation of thin sections of infected tissue culture cells showed virus particles 360-380 A.U. along outer cell membranes and edges of cytoplasmic vacuoles. In phosphotungstic acid negatively stained preparations, intact virus particles, 400-450 A.U. total diameter, were observed inside infected cells. In particles in which the peripheral layer became discontinuous, geometrically arranged subunits compatible with cubic symmetry were observed. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5 PMID:14146854

The structure of a cometary type I tail - Ground-based and ICE observations of P/Giacobini-Zinner

NASA Technical Reports Server (NTRS)

Slavin, J. A.; Goldberg, B. A.; Smith, E. J.; Mccomas, D. J.; Bame, S. J.

1986-01-01

Comparison of ground-based and in situ observations of P/Giacobini-Zinner are used to investigate the morphology of a type I cometary tail. ICE magnetic field and plasma measurements show a well-defined cometary magnetotail composed of two magnetic lobes in pressure equilibrium with a central plasma sheet. A dependence of ion tail width on IMF direction is found which strongly suggests that the classical type I ion tails observed on the ground consist predominantly of emissions from the slab-shaped plasma sheet separating the magnetic lobes. The width of the G-Z magnetotail is determined to be 9.8 (+ or - 0.5) x 10 to the 3rd km with a quasi-circular cross section. The results of this study also indicate that some of the dynamical thinnings and thickenings observed in long type I tails may be caused by IMF variations changing the angle with which the plasma sheet is viewed at earth.

Improving FTIR imaging speciation of organic compound residues or their degradation products in wall painting samples, by introducing a new thin section preparation strategy based on cyclododecane pre-treatment.

PubMed

Papliaka, Zoi Eirini; Vaccari, Lisa; Zanini, Franco; Sotiropoulou, Sophia

2015-07-01

Fourier transform infrared (FTIR) imaging in transmission mode, employing a bidimensional focal plane array (FPA) detector, was applied for the detection and spatially resolved chemical characterisation of organic compounds or their degradation products within the stratigraphy of a critical group of fragments, originating from prehistoric and roman wall paintings, containing a very low concentration of subsisted organic matter or its alteration products. Past analyses using attenuated total reflection (ATR) or reflection FTIR on polished cross sections failed to provide any evidence of any organic material assignable as binding medium of the original painting. In order to improve the method's performance, in the present study, a new method of sample preparation in thin section was developed. The procedure is based on the use of cyclododecane C12H24 as embedding material and a subsequent double-side polishing of the specimen. Such procedure provides samples to be studied in FTIR transmission mode without losing the information on the spatial distribution of the detected materials in the paint stratigraphy. For comparison purposes, the same samples were also studied after opening their stratigraphy with a diamond anvil cell. Both preparation techniques offered high-quality chemical imaging of the decay products of an organic substance, giving clues to the painting technique. In addition, the thin sections resulting from the cyclododecane pre-treatment offered more layer-specific data, as the layer thickness and order remained unaffected, whereas the samples resulting from compression within the diamond cell were slightly deformed; however, since thinner and more homogenous, they provided higher spectral quality in terms of S/N ratio. In summary, the present study illustrates the appropriateness of FTIR imaging in transmission mode associated with a new thin section preparation strategy to detect and localise very low-concentrated organic matter subjected to deterioration processes, when the application of FTIR in reflection mode or FTIR-ATR fails to give any relevant information.

Response of Debris-Covered and Clean-Ice Glaciers to Climate Change from Observations and Modeling

NASA Astrophysics Data System (ADS)

Rupper, S.; Maurer, J. M.; Schaefer, J. M.; Roe, G.; Huybers, K. M.

2017-12-01

Debris-covered glaciers form a significant percentage of the glacier area and volume in many mountainous regions of the world, and respond differently to climatic forcings as compared to clean-ice glaciers. In particular, debris-covered glaciers tend to downwaste with very little retreat, while clean-ice glaciers simultaneously thin and retreat. This difference has posed a significant challenge to quantifying glacier sensitivity to climate change, modeling glacier response to future climate change, and assessing the impacts of recent and future glacier changes on mountain environments and downstream populations. In this study, we evaluate observations of the geodetic mass balance and thinning profiles of 1000 glaciers across the Himalayas from 1975 to 2016. We use this large sampling of glacier changes over multiple decades to provide a robust statistical comparison of mass loss for clean-ice versus debris-covered glaciers over a period relevant to glacier dynamics. In addition, we force a glacier model with a series of climate change scenarios, and compare the modeled results to the observations. We essentially ask the question, "Are our theoretical expectations consistent with the observations?" Our observations show both clean-ice and debris-covered glaciers, regionally averaged, thinned in a similar pattern for the first 25-year observation period. For the more recent 15-year period, clean ice glaciers show significantly steepened thinning gradients across the surface, while debris-covered glaciers have continued to thin more uniformaly across the surface. Our preliminary model results generally agree with these observations, and suggest that both glacier types are expected to have a thinning phase followed by a retreat phase, but that the timing of the retreat phase is much later for debris-covered glaciers. Thus, these early results suggest these two glacier types are dynamically very similar, but are currently in different phases of response to recent climate change. This difference in phase of response will be carefully evaluated by integrating the modeling and observational components of this work. In addition, we will use this integrated framework to assess the expected impacts of differing glacier response on glacier-related resources in the Himalayas over the coming century.

A Computer Program which Uses an Expert Systems Approach to Identifying Minerals.

ERIC Educational Resources Information Center

Hart, Allan Bruce; And Others

1988-01-01

Described is a mineral identification program which uses a shell system for creating expert systems of a classification nature. Discusses identification of minerals in hand specimens, thin sections, and polished sections of rocks. (Author/CW)

Self-assembled micro-/nanostructured WO3 thin films by aqueous chemical growth and their applications in H2 and CO2 sensing

NASA Astrophysics Data System (ADS)

Sone, B. T.; Nkosi, S. S.; Nkosi, M. M.; Coetsee-Hugo, E.; Swart, H. C.; Maaza, M.

2018-05-01

Application of thin film technology is increasing in many areas such as energy production, energy saving, telecommunications, protective and smart coatings, etc. This increased application creates a need for simple, cost-effective methods for the synthesis of highly multifunctional metal oxide thin films. The technique of Aqueous Chemical Growth is presented in this paper as a simple inexpensive means of producing WO3 thin films that find applications in gas sensing, electrochromism and photocatalysis. We demonstrate, through this technique, that heterogeneous nucleation and growth of WO3 thin films on plain glass substrates takes place at low pHs and low temperatures (75-95 °C) without the use of surfactants and template directing methods. The substrates used needed no surface-modification. On the plain glass substrates (soda lime silicates) a variety of micro-nanostructures could be observed most important of which were nanoplatelets that acted as a basic building block for the self-assembly of more hierarchical 3-d microspheres and thin films. The dominant crystallographic structure observed through X-ray diffraction analysis was found to be hexagonal-WO3 and monoclinic WO3. The thin films produced showed a fair degree of porosity. Some of the thin films on glass showed ability to sense, unaided, H2 at 250 °C. Sensor responses were observed to be 1 - 2 orders of magnitude. The films also demonstrated potential to sense CO2 even though this could only be achieved using high concentrations of CO2 gas at temperatures of 300 °C and above. The sensor responses at 300 °C were estimated to be less than 1 order of magnitude.

Thermal runaway and microwave heating in thin cylindrical domains

NASA Astrophysics Data System (ADS)

Ward, Michael J.

2002-04-01

The behaviour of the solution to two nonlinear heating problems in a thin cylinder of revolution of variable cross-sectional area is analysed using asymptotic and numerical methods. The first problem is to calculate the fold point, corresponding to the onset of thermal runaway, for a steady-state nonlinear elliptic equation that arises in combustion theory. In the limit of thin cylindrical domains, it is shown that the onset of thermal runaway can be delayed when a circular cylindrical domain is perturbed into a dumbell shape. Numerical values for the fold point for different domain shapes are obtained asymptotically and numerically. The second problem that is analysed is a nonlinear parabolic equation modelling the microwave heating of a ceramic cylinder by a known electric field. The basic model in a thin circular cylindrical domain was analysed in Booty & Kriegsmann (Meth. Appl. Anal. 4 (1994) p. 403). Their analysis is extended to treat thin cylindrical domains of variable cross-section. It is shown that the steady-state and dynamic behaviours of localized regions of high temperature, called hot-spots, depend on a competition between the maxima of the electric field and the maximum deformation of the circular cylinder. For a dumbell-shaped region it is shown that two disconnected hot-spot regions can occur. Depending on the parameters in the model, these regions, ultimately, either merge as time increases or else remain as disconnected regions for all time.

Investigation of the spatial distribution of second-order nonlinearity in thermally poled optical fibers.

PubMed

An, Honglin; Fleming, Simon

2005-05-02

The spatial distribution of second-order nonlinearity in thermally poled optical fibers was characterized by second-harmonic microscopy. The second-order nonlinearity was found to be confined to a thin layer close to the anode surface and progressed further into the silica as the poling time increased. Position uncertainty of the anode metal wire was observed to have an effect, as the nonlinear layers were found not always symmetrically located around the nearest points between the anode and cathode. Optical microscopy results were obtained on etched poled fiber cross-sections and compared with those from second-harmonic microscopy.

Separated flows receptivity for external disturbances

NASA Astrophysics Data System (ADS)

Zanin, B. Yu.

2017-10-01

Results of experimental investigations of the flow over a straight-wing model in a low-turbulence wind tunnel are reported. The influence of a turbulent wake due to a thin filament on the structure of boundary layer on the model surface was examined. Also the fishing line was installed in the test section of the wind tunnel and the effect of line on the boundary-layer flow structure is considered. Flow visualization in boundary layer and hot-wire measurements were performed. The wake and the grid substantially modified the boundary layer flow pattern: the separation disappeared from the wing surface, and the formation of longitudinal structures was observed.

Space Shuttle Stiffener Ring Foam Failure Analysis, a Non-Conventional Approach

NASA Technical Reports Server (NTRS)

Howard, Philip M.

2015-01-01

The Space Shuttle Program made use of the excellent properties of rigid polyurethane foam for cryogenic tank insulation and as structural protection on the solid rocket boosters. When foam applications de-bond, classical methods of failure analysis did not provide root cause of the failure of the foam. Realizing that foam is the ideal media to document and preserve its own mode of failure, thin sectioning was seen as a logical approach for foam failure analysis to observe the three dimensional morphology of the foam cells. The cell foam morphology provided a much greater understanding of the failure modes than previously achieved.

Characterising the grey matter correlates of leukoaraiosis in cerebral small vessel disease.

PubMed

Lambert, Christian; Sam Narean, Janakan; Benjamin, Philip; Zeestraten, Eva; Barrick, Thomas R; Markus, Hugh S

2015-01-01

Cerebral small vessel disease (SVD) is a heterogeneous group of pathological disorders that affect the small vessels of the brain and are an important cause of cognitive impairment. The ischaemic consequences of this disease can be detected using MRI, and include white matter hyperintensities (WMH), lacunar infarcts and microhaemorrhages. The relationship between SVD disease severity, as defined by WMH volume, in sporadic age-related SVD and cortical thickness has not been well defined. However, regional cortical thickness change would be expected due to associated phenomena such as underlying ischaemic white matter damage, and the observation that widespread cortical thinning is observed in the related genetic condition CADASIL (Righart et al., 2013). Using MRI data, we have developed a semi-automated processing pipeline for the anatomical analysis of individuals with cerebral small vessel disease and applied it cross-sectionally to 121 subjects diagnosed with this condition. Using a novel combined automated white matter lesion segmentation algorithm and lesion repair step, highly accurate warping to a group average template was achieved. The volume of white matter affected by WMH was calculated, and used as a covariate of interest in a voxel-based morphometry and voxel-based cortical thickness analysis. Additionally, Gaussian Process Regression (GPR) was used to assess if the severity of SVD, measured by WMH volume, could be predicted from the morphometry and cortical thickness measures. We found significant (Family Wise Error corrected p < 0.05) volumetric decline with increasing lesion load predominately in the parietal lobes, anterior insula and caudate nuclei bilaterally. Widespread significant cortical thinning was found bilaterally in the dorsolateral prefrontal, parietal and posterio-superior temporal cortices. These represent distinctive patterns of cortical thinning and volumetric reduction compared to ageing effects in the same cohort, which exhibited greater changes in the occipital and sensorimotor cortices. Using GPR, the absolute WMH volume could be significantly estimated from the grey matter density and cortical thickness maps (Pearson's coefficients 0.80 and 0.75 respectively). We demonstrate that SVD severity is associated with regional cortical thinning. Furthermore a quantitative measure of SVD severity (WMH volume) can be predicted from grey matter measures, supporting an association between white and grey matter damage. The pattern of cortical thinning and volumetric decline is distinctive for SVD severity compared to ageing. These results, taken together, suggest that there is a phenotypic pattern of atrophy associated with SVD severity.

Heterogeneous structure of the incoming plate in the Japan Trench

NASA Astrophysics Data System (ADS)

Nakamura, Y.; Fujie, G.; Yamaguchi, A.; Kodaira, S.; Miura, S.

2017-12-01

We have conducted seismic surveys in around the Japan Trench subduction zone, northeastern Japan, to investigate the structural features of the incoming Pacific plate and the frontal prism. Thickness of the hemiplegic sediments on the deposited on the incoming Pacific plate shows the variation along trench axis between 200 and 600 ms two-way travel time (TWT). This is remarkably thinner than other subduction zones with megathrust earthquakes like Sumatra subduction zone. Off Miyagi, central part of the Japan Trench which is the main ruptured region of 2011 Tohoku earthquake, has 200 - 300 ms TWT of the incoming sediments thickness. Off Iwate, northern part of the Japan Trench, has thicker incoming sediments 500 ms TWT, and Off Fukushima, southern part of the Japan Trench, has 300 - 400 ms TWT. We found at least three areas with anomalously thin sediments; Area I: 38N 145N, Area II: 39.5N 144.5E, Area III: 39N 144.5N. At the Area I, located on the outer rise off Miyagi, the receiver function analysis using Ocean Bottom Seismograph data revealed the existence of PS conversion surfaces below the interpreted basement on the seismic sections. This implies that the interface between sediments and the igneous basement is located below the interpreted basement reflections. Previous studies suggested the existence of the petit spots in this Area I. Area II shows apparently very thin sediments near the trench axis on seismic profiles, where the petit spot volcanism was observed. Shallow sediment sampling conducted in this area indicates no major surface erosion. These observations suggest that the petit spot volcanism, like sill intrusion, masked the original deeper basement reflections and caused the apparent thin sediments on seismic profiles. Area III also has thin sediments and rough basement topography, which has possibly been caused by another petit spot activity. Petit spot area with apparent very thin sediments in the trench axis (Area II) is located next to the northern edge of the large slip zone of the 2011 Tohoku earthquake. The volcanic activities like petit spots on the incoming plate introduce heterogeneous input into the subduction zone, which could be important factors to control the megathrust seismo- and tsunamigenesis in the subduction zone.

Nanoskiving: A new method for nanofabrication

NASA Astrophysics Data System (ADS)

Xu, Qiaobing

"Nanoskiving" is the name we have given to a technique for the fabrication of nanostructures by combining deposition of thin films on a topographically patterned polymeric substrate using physical vapor methods and sectioning with an ultramicrotome. Ultramicrotomy was originally developed as a tool for sectioning biological specimens for analysis by optical or electron microscopy. The imaging of biological specimens requires the ability to slice mum to sub-mum thick sections and the imaging is done through the thinnest dimension of the section. Nanoskiving utilizes an ultramicrotome because of its ability to section sub-100 nm slices reproducibly. In this thesis, I will describe the fabrication by nanoskiving of the diverse nanostructures and their applications in electronics and optics. Nanoskiving is experimentally simple, and requires little in the way of facilities (for example, access to a cleanroom or a high-resolution e-beam writer is unnecessary). It is applicable to many classes of structures and materials with which conventional methods of nanofabrication (e.g. EUV or X-ray photolithography, e-beam lithography (EBL) focused ion-beam (FIB)) fail. This method begins with the deposition of thin metallic films on an epoxy substrate by e-beam evaporation or sputtering. After embedding the thin metallic film in an epoxy matrix, sectioning (in a plane perpendicular or parallel to the metal film) with an ultramicrotome generates nanometer-thick sections of epoxy containing metallic nanostructures. The cross-section of the metal wires embedded in the resulting thin epoxy sections is controlled by the thickness of the evaporated metal film (which can be as small as 20 nm), and the thickness of the sections cut by the microtome (as small as 30 nm, using a standard 35° diamond knife). The embedded nanostructures can be transferred to, and positioned on planar or curved substrates by manipulating the thin polymer film. Removal of the epoxy matrix by etching with an oxygen plasma generates free-standing metallic nanostructures. Chapter 1 is an overview of nanoskiving---a technique that combines thin-film deposition of metal on a topographically contoured substrate with sectioning using an ultramicrotome---as a method of fabricating nanostructures. Nanoskiving provides a simple and convenient procedure to produce arrays (over areas of mm2 to cm2) of structures with cross-sectional dimensions in the thirty-nanometer regime embedded in epoxy. The ability to control the dimensions of nanostructures, combined with the ability to manipulate and position them, enables the fabrication of nanostructures with geometries that are difficult to prepare by other methods. Two classes of applications--- in optics and in electronics---demonstrate the utility of nanostructures fabricated by nanoskiving. Chapter 2 shows the fabrication by nanoskiving of complex nanostructures that are difficult or impossible to achieve by other nanofabrication methods. These include multilayer structures, structures on curved surfaces, structures that span gaps, structures in less familiar materials, structures with high-aspect ratios, and large-area structures comprising two-dimensional periodic arrays. Chapter 3 demonstrates the Fabrication patterned arrays of gold structures (for example, rings) with wall thickness of 40 nm, and with high aspect ratios up to 25. Chapter 4 introduces the fabrication by nanoskiving of gold nanowires of uniform, controllable length, width, and height, and describes a systematic study of the dependence of the surface plasmon resonance on the geometry of these wires. Chapter 5 describes the fabrication of arrays of closed and open, loop-shaped nanostructures over mm2 area by nanoskiving. These arrays of metallic structures serve as frequency-selective surfaces at mid-infrared wavelengths. Chapter 6 describes a procedure to fabricate an array of nanoelectrodes that can be addressed from the back face of the slab of epoxy resin.

Non-resonant microwave absorption in high-T c thin films

NASA Astrophysics Data System (ADS)

Durny, R.; Dulcic, A.; Crepeau, R. H.; Freed, J. H.; Kus, P.

1990-11-01

Magnetic-field-dependent non-resonant microwave absorption in thin film samples of various high- Tc superconductors is reported. Complex types of signals were observed as the temperature was lowered from Tc to ≈ 10 K. Possible correlation between the thin film quality and the occurrence of the signals is suggested.

Ice-sheet thinning and acceleration at Camp Century, Greenlan

NASA Astrophysics Data System (ADS)

Colgan, W. T.

2017-12-01

Camp Century, Greenland (77.18 °N, 61.12 °W, 1900 m), is located approximately 150 km inland from the ice-sheet margin in Northwest Greenland. In-situ and remotely-sensed measurements of ice-sheet elevation at Camp Century exhibit a thinning trend between 1964 and the present. A comparison of 1966 and 2017 firn density profiles indicates that a portion of this ice-sheet thinning is attributable to increased firn compaction rate. In-situ measurements of increasing ice surface velocity over the 1977-2017 period indicate that enhanced horizontal divergence of ice flux is also contributing to ice dynamic thinning at Camp Century. This apparent ice dynamic thinning could potentially result from a migrating local flow divide or decreasing effective ice viscosity. In a shorter-term context, observations of decadal-scale ice-sheet thinning and acceleration at Camp Century highlights underappreciated transience in inland ice form and flow during the satellite era. In a longer-term context, these multi-decadal observations contrast with inferences of millennial-scale ice-sheet thickening and deceleration at Camp Century.

First observation of magnetoelectric effect in M-type hexaferrite thin films

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

Mohebbi, Marjan; Ebnabbasi, Khabat; Vittoria, Carmine

2013-05-07

The magnetoelectric (ME) effect in M-type hexaferrite thin films is reported. Prior to this work, the ME effect in hexaferrite materials was observed only in bulk polycrystalline materials. Thin films of SrCo{sub 2}Ti{sub 2}Fe{sub 8}O{sub 19} were grown on sapphire (0001) using pulsed laser deposition. The thin films were characterized by X-ray diffractometer, scanning electron microscope, energy-dispersive spectroscopy, vibrating sample magnetometer, and ferromagnetic resonance. We measured saturation magnetization of 1250 G, g-factor of 2.66, and coercive field of 20 Oe for these magnetoelectric M-type hexaferrite thin films. The magnetoelectric effect was confirmed by monitoring the change rate in remanence magnetizationmore » with the application of DC voltage at room temperature and it gave rise to changes in remanence in the order of 12.8% with the application of only 1 V (DC voltage). We deduced a magnetoelectric coupling, {alpha}, of 6.07 Multiplication-Sign 10{sup -9} s m{sup -1} in SrCo{sub 2}Ti{sub 2}Fe{sub 8}O{sub 19} thin films.« less

Effect of flash lamp annealing on electrical activation in boron-implanted polycrystalline Si thin films

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

Do, Woori; Jin, Won-Beom; Choi, Jungwan

2014-10-15

Highlights: • Intensified visible light irradiation was generated via a high-powered Xe arc lamp. • The disordered Si atomic structure absorbs the intensified visible light. • The rapid heating activates electrically boron-implanted Si thin films. • Flash lamp heating is applicable to low temperature polycrystalline Si thin films. - Abstract: Boron-implanted polycrystalline Si thin films on glass substrates were subjected to a short duration (1 ms) of intense visible light irradiation generated via a high-powered Xe arc lamp. The disordered Si atomic structure absorbs the intense visible light resulting from flash lamp annealing. The subsequent rapid heating results in themore » electrical activation of boron-implanted Si thin films, which is empirically observed using Hall measurements. The electrical activation is verified by the observed increase in the crystalline component of the Si structures resulting in higher transmittance. The feasibility of flash lamp annealing has also been demonstrated via a theoretical thermal prediction, indicating that the flash lamp annealing is applicable to low-temperature polycrystalline Si thin films.« less

Electronic Structure of the Metastable Epitaxial Rock-Salt SnSe {111 } Topological Crystalline Insulator

NASA Astrophysics Data System (ADS)

Jin, Wencan; Vishwanath, Suresh; Liu, Jianpeng; Kong, Lingyuan; Lou, Rui; Dai, Zhongwei; Sadowski, Jerzy T.; Liu, Xinyu; Lien, Huai-Hsun; Chaney, Alexander; Han, Yimo; Cao, Michael; Ma, Junzhang; Qian, Tian; Wang, Shancai; Dobrowolska, Malgorzata; Furdyna, Jacek; Muller, David A.; Pohl, Karsten; Ding, Hong; Dadap, Jerry I.; Xing, Huili Grace; Osgood, Richard M.

2017-10-01

Topological crystalline insulators have been recently predicted and observed in rock-salt structure SnSe {111 } thin films. Previous studies have suggested that the Se-terminated surface of this thin film with hydrogen passivation has a reduced surface energy and is thus a preferred configuration. In this paper, synchrotron-based angle-resolved photoemission spectroscopy, along with density functional theory calculations, is used to demonstrate that a rock-salt SnSe {111 } thin film epitaxially grown on Bi2Se3 has a stable Sn-terminated surface. These observations are supported by low-energy electron diffraction (LEED) intensity-voltage measurements and dynamical LEED calculations, which further show that the Sn-terminated SnSe {111 } thin film has undergone a surface structural relaxation of the interlayer spacing between the Sn and Se atomic planes. In sharp contrast to the Se-terminated counterpart, the observed Dirac surface state in the Sn-terminated SnSe {111 } thin film is shown to yield a high Fermi velocity, 0.50 ×106 m /s , which suggests a potential mechanism of engineering the Dirac surface state of topological materials by tuning the surface configuration.

Highly transparent and lower resistivity of yttrium doped ZnO thin films grown on quartz glass by sol-gel method

NASA Astrophysics Data System (ADS)

Kaur, Narinder; Sharma, Sanjeev K.; Kim, Deuk Young; Singh, Narinder

2016-11-01

We prepared highly transparent yttrium-doped ZnO (YZO) thin films on quartz glass by a sol-gel method, and then annealed them at 600 °C in vacuum. All samples showed hexagonal wurtzite structure with a preferential orientation along the (002) direction. We observed the average grain size of Y: 2 at% thin film to be in the range of 15-20 nm. We observed blue shift in the optical bandgap (3.29 eV→3.32 eV) by increasing the Y concentration (0-2 at%), due to increasing the number of electrons, and replacing the di-valent (Zn2+) with tri-valent (Y3+) dopants. Replacing the higher ionic radii (Y3+) with smaller ionic radii (Zn2+) expanded the local volume of the lattice, which reduced the lattice defects, and increased the intensity ratio of NBE/DLE emission (INBE/IDLE). We also observed the lowest (172 meV) Urbach energy of Y: 2 at% thin film, and confirmed the high structural quality. Incorporation of the appropriate Y concentration (2 at%) improved the crystallinity of YZO thin films, which led to less carrier scattering and lower resistivity.

Electronic Structure of the Metastable Epitaxial Rock-Salt SnSe { 111 } Topological Crystalline Insulator

DOE PAGES

Jin, Wencan; Vishwanath, Suresh; Liu, Jianpeng; ...

2017-10-25

Topological crystalline insulators have been recently predicted and observed in rock-salt structure SnSe {111} thin films. Previous studies have suggested that the Se-terminated surface of this thin film with hydrogen passivation has a reduced surface energy and is thus a preferred configuration. In this paper, synchrotron-based angle-resolved photoemission spectroscopy, along with density functional theory calculations, is used to demonstrate that a rock-salt SnSe {111} thin film epitaxially grown on Bi 2Se 3 has a stable Sn-terminated surface. These observations are supported by low-energy electron diffraction (LEED) intensity-voltage measurements and dynamical LEED calculations, which further show that the Sn-terminated SnSe {111}more » thin film has undergone a surface structural relaxation of the interlayer spacing between the Sn and Se atomic planes. In sharp contrast to the Se-terminated counterpart, the observed Dirac surface state in the Sn-terminated SnSe {111} thin film is shown to yield a high Fermi velocity, 0.50 x 10 6 m/s, which suggests a potential mechanism of engineering the Dirac surface state of topological materials by tuning the surface configuration.« less

Thin Film Ceramic Strain Sensor Development for Harsh Environments: Interim Report on Identification of Candidate Thin Film Ceramics to Test for Viability for Static Strain Sensor Development

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Fralick, Gustave C.; Hunter, Gary W.

2006-01-01

The need to consider ceramic sensing elements is brought about by the temperature limits of metal thin film sensors in propulsion system applications. In order to have a more passive method of negating changes of resistance due to temperature, an effort is underway at NASA Glenn to develop high temperature thin film ceramic static strain gauges for application in turbine engines, specifically in the fan and compressor modules on blades. Other applications can be on aircraft hot section structures and on thermal protection systems. The near-term interim goal of the research effort was to identify candidate thin film ceramic sensor materials to test for viability and provide a list of possible thin film ceramic sensor materials and corresponding properties to test for viability. This goal was achieved by a thorough literature search for ceramics that have the potential for application as high temperature thin film strain gauges, reviewing potential candidate materials for chemical and physical compatibility with our microfabrication procedures and substrates.

Thin Film Ceramic Strain Sensor Development for Harsh Environments: Identification of Candidate Thin Film Ceramics to Test for Viability for Static Strain Sensor Development

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Fralick, Gustave C.; Hunter, Gary W.

2006-01-01

The need to consider ceramic sensing elements is brought about by the temperature limits of metal thin film sensors in propulsion system applications. In order to have a more passive method of negating changes of resistance due to temperature, an effort is underway at NASA GRC to develop high temperature thin film ceramic static strain gauges for application in turbine engines, specifically in the fan and compressor modules on blades. Other applications include on aircraft hot section structures and on thermal protection systems. The near-term interim goal of this research effort was to identify candidate thin film ceramic sensor materials to test for viability and provide a list of possible thin film ceramic sensor materials and corresponding properties to test for viability. This goal was achieved by a thorough literature search for ceramics that have the potential for application as high temperature thin film strain gauges, reviewing potential candidate materials for chemical & physical compatibility with NASA GRC's microfabrication procedures and substrates.

Microstructural investigation of nickel silicide thin films and the silicide-silicon interface using transmission electron microscopy.

PubMed

Bhaskaran, M; Sriram, S; Mitchell, D R G; Short, K T; Holland, A S; Mitchell, A

2009-01-01

This article discusses the results of transmission electron microscopy (TEM)-based investigation of nickel silicide (NiSi) thin films grown on silicon. Nickel silicide is currently used as the CMOS technology standard for local interconnects and in electrical contacts. Films were characterized with a range of TEM-based techniques along with glancing angle X-ray diffraction. The nickel silicide thin films were formed by vacuum annealing thin films of nickel (50 nm) deposited on (100) silicon. The cross-sectional samples indicated a final silicide thickness of about 110 nm. This investigation studied and reports on three aspects of the thermally formed thin films: the uniformity in composition of the film using jump ratio maps; the nature of the interface using high resolution imaging; and the crystalline orientation of the thin films using selected-area electron diffraction (SAED). The analysis highlighted uniform composition in the thin films, which was also substantiated by spectroscopy techniques; an interface exhibiting the desired abrupt transition from silicide to silicon; and desired and preferential crystalline orientation corresponding to stoichiometric NiSi, supported by glancing angle X-ray diffraction results.

Measurement of the differential cross sections of 6Li(d,d0) for Ion Beam Analysis purposes

NASA Astrophysics Data System (ADS)

Ntemou, E.; Aslanoglou, X.; Axiotis, M.; Foteinou, V.; Kokkoris, M.; Lagoyannis, A.; Misaelides, P.; Patronis, N.; Preketes-Sigalas, K.; Provatas, G.; Vlastou, R.

2017-09-01

In the present work, the 6Li(d,d0)6Li elastic scattering differential cross sections were measured in the energy range Ed,lab = 940-2000 keV for Elastic Backscattering Spectroscopy (EBS) purposes, using thin lithium targets, made by evaporating isotopically enriched 6LiF powder on self-supporting carbon foils, with an ultra-thin Au layer on top for normalization purposes. The experiment was carried out in deuteron beam energy steps of 20 or 30 keV and for the laboratory scattering angles of 125°, 140°, 150°, 160°, and 170°.

Immunoelectron microscopic double labeling of alkaline phosphatase and penicillinase with colloidal gold in frozen thin sections of Bacillus licheniformis 749/C.

PubMed Central

Guan, T; Ghosh, A; Ghosh, B K

1985-01-01

The subcellular distribution of alkaline phosphatase and penicillinase was determined by double labeling frozen thin sections of Bacillus licheniformis 749/C with colloidal gold-immunoglobulin G (IgG). Antipenicillinase and anti-alkaline phosphatase antibodies were used to prepare complexes with 5- and 15-nm colloidal gold particles, respectively. The character of the labeling of membrane-bound alkaline phosphatase and penicillinase was different: the immunolabels for alkaline phosphatase (15-nm particles) were bound to a few sites at the inner surface of the plasma membrane, and the gold particles formed clusters of various sizes at the binding sites; the immunolabels for penicillinase (5-nm particles), on the other hand, were bound to the plasma membrane in a dispersed and random fashion. In the cytoplasm, immunolabels for both proteins were distributed randomly, and the character of their binding was similar. The labeling was specific: pretreating the frozen thin sections with different concentrations of anti-alkaline phosphatase or penicillinase blocked the binding of the immunolabel prepared with the same antibody. Binding could be fully blocked by pretreatment with 800 micrograms of either antibody per ml. Images PMID:3876329

Reconstruction of three-dimensional porous media using a single thin section

NASA Astrophysics Data System (ADS)

Tahmasebi, Pejman; Sahimi, Muhammad

2012-06-01

The purpose of any reconstruction method is to generate realizations of two- or multiphase disordered media that honor limited data for them, with the hope that the realizations provide accurate predictions for those properties of the media for which there are no data available, or their measurement is difficult. An important example of such stochastic systems is porous media for which the reconstruction technique must accurately represent their morphology—the connectivity and geometry—as well as their flow and transport properties. Many of the current reconstruction methods are based on low-order statistical descriptors that fail to provide accurate information on the properties of heterogeneous porous media. On the other hand, due to the availability of high resolution two-dimensional (2D) images of thin sections of a porous medium, and at the same time, the high cost, computational difficulties, and even unavailability of complete 3D images, the problem of reconstructing porous media from 2D thin sections remains an outstanding unsolved problem. We present a method based on multiple-point statistics in which a single 2D thin section of a porous medium, represented by a digitized image, is used to reconstruct the 3D porous medium to which the thin section belongs. The method utilizes a 1D raster path for inspecting the digitized image, and combines it with a cross-correlation function, a grid splitting technique for deciding the resolution of the computational grid used in the reconstruction, and the Shannon entropy as a measure of the heterogeneity of the porous sample, in order to reconstruct the 3D medium. It also utilizes an adaptive technique for identifying the locations and optimal number of hard (quantitative) data points that one can use in the reconstruction process. The method is tested on high resolution images for Berea sandstone and a carbonate rock sample, and the results are compared with the data. To make the comparison quantitative, two sets of statistical tests consisting of the autocorrelation function, histogram matching of the local coordination numbers, the pore and throat size distributions, multiple-points connectivity, and single- and two-phase flow permeabilities are used. The comparison indicates that the proposed method reproduces the long-range connectivity of the porous media, with the computed properties being in good agreement with the data for both porous samples. The computational efficiency of the method is also demonstrated.

Synthesis and characterization of cobalt doped nickel oxide thin films by spray pyrolysis method

NASA Astrophysics Data System (ADS)

Sathisha, D.; Naik, K. Gopalakrishna

2018-05-01

Cobalt (Co) doped nickel oxide (NiO) thin films were deposited on glass substrates at a temperature of about 400 °C by spray pyrolysis method. The effect of Co doping concentration on structural, optical and compositional properties of NiO thin films was investigated. X-ray diffraction result shows that the deposited thin films are polycrystalline in nature. Surface morphologies of the deposited thin films were observed by FESEM and AFM. EDS spectra showed the incorporation of Co dopants in NiO thin films. Optical properties of the grown thin films were characterized by UV-visible spectroscopy. It was found that the optical band gap energy and transmittance of the films decrease with increasing Co doping concentration.

Approaches in controllable generation of artificial pinning center in REBa2Cu3O y -coated conductor for high-flux pinning

NASA Astrophysics Data System (ADS)

Yoshida, Y.; Miura, S.; Tsuchiya, Y.; Ichino, Y.; Awaji, S.; Matsumoto, K.; Ichinose, A.

2017-10-01

This paper reviews the progress of studies to determine optimum shapes of the artificial pinning center (APC) of REBa2Cu3O y thin films and coated conductors towards superconducting magnets operating at temperatures of 77 K or less. Superconducting properties vary depending on the kind and quantity of BaMO3 materials. Therefore, we study changes in the shapes of nanorods that are due to the difference in the quality of additives and growth temperature. In addition, we aim to control the APC using an optimum shape that matches the operating temperature. In particular, we describe the shape control of nanorods in SmBCO thin films and coated conductors by employing lower temperature growth (LTG) technology using seed layers. From the cross-sectional transmission electron microscopy observations, we confirmed that using the LTG method, the BaHfO3 (BHO) nanorods, which were comparatively thin and short in length, formed a firework structure in the case of SmBCO films with coated conductors. The superconducting properties in the magnetic field of the SmBCO-coated conductor with the optimum amount of BHO showed that {F}{{p}}\\max = 1.6 TN m-3 on a single crystalline substrate and 1.5 TN m-3 on metallic substrate with a biaxially textured MgO layer fabricated by ion-beam assisted deposition method tape 4.2 K.

Crustal thickness and images of the lithospheric discontinuities in the Gibraltar arc and surrounding areas

NASA Astrophysics Data System (ADS)

Mancilla, Flor de Lis; Stich, Daniel; Morales, José; Martín, Rosa; Diaz, Jordi; Pazos, Antonio; Córdoba, Diego; Pulgar, Javier A.; Ibarra, Pedro; Harnafi, Mimoun; Gonzalez-Lodeiro, Francisco

2015-12-01

The Gibraltar arc and surrounding areas are a complex tectonic region and its tectonic evolution since Miocene is still under debate. Knowledge of its lithospheric structure will help to understand the mechanisms that produced extension and westward motion of the Alboran domain, simultaneously with NW-SE compression driven by Africa-Europe plates convergence. We perform a P-wave receiver function analysis in which we analyse new data recorded at 83 permanent and temporary seismic broad-band stations located in the South of the Iberian peninsula. These data are stacked and combined with data from a previous study in northern Morocco to build maps of thickness and average vP/vS ratio for the crust, and cross-sections to image the lithospheric discontinuities beneath the Gibraltar arc, the Betic and Rif Ranges and their Iberian and Moroccan forelands. Crustal thickness values show strong lateral variations in the southern Iberia peninsula, ranging from ˜19 to ˜46 km. The Variscan foreland is characterized by a relatively flat Moho at ˜31 km depth, and an average vP/vS ratio of ˜1.72, similar to other Variscan terranes, which may indicate that part of the lower crustal orogenic root was lost. The thickest crust is found at the contact between the Alboran domain and the External Zones of the Betic Range, while crustal thinning is observed southeastern Iberia (down to 19 km) and in the Guadalquivir basin where the thinning at the Iberian paleomargin could be still preserved. In the cross-sections, we see a strong change between the eastern Betics, where the Iberian crust underthrusts and couples to the Alboran crust, and the western Betics, where the underthrusting Iberian crust becomes partially delaminated and enters into the mantle. The structures largely mirror those on the Moroccan side where a similar detachment was observed in northern Morocco. We attribute a relatively shallow strong negative-polarity discontinuity to the lithosphere-asthenosphere boundary. This means relatively thin lithosphere ranging from ˜50 km thickness in southeastern Iberia and northeastern Morocco to ˜90-100 km beneath the western Betics and the Rif, with abrupt changes of ˜30 km under the central Betics and northern Morocco. Our observations support a geodynamic scenario where in western Betics oceanic subduction has developed into ongoing continental subduction/delamination while in eastern Betics this process is inactive.

Research notes : studded tire damage repair : the first year.

DOT National Transportation Integrated Search

1998-02-01

The Oregon Department of Transportation has monitored rutting caused by studded tires since 1974. In the past decade, the damage has increased rapidly. The overlay was divided into four sections. Each section received a different type of thin asphalt...

Shear thinning in soft particle suspensions

NASA Astrophysics Data System (ADS)

Voudouris, Panayiotis; van der Zanden, Berco; Florea, Daniel; Fahimi, Zahra; Wyss, Hans

2012-02-01

Suspensions of soft deformable particles are encountered in a wide range of food and biological materials. Examples are biological cells, micelles, vesicles or microgel particles. While the behavior of suspenions of hard spheres - the classical model system of colloid science - is reasonably well understood, a full understanding of these soft particle suspensions remains elusive. The relation between single particle properties and macroscopic mechanical behavior still remains poorly understood in these materials. Here we examine the surprising shear thinning behavior that is observed in soft particle suspensions as a function of particle softness. We use poly-N-isopropylacrylamide (p-NIPAM) microgel particles as a model system to study this effect in detail. These soft spheres show significant shear thinning even at very large Peclet numbers, where this would not be observed for hard particles. The degree of shear thinning is directly related to the single particle elastic properties, which we characterize by the recently developed Capillary Micromechanics technique. We present a simple model that qualitatively accounts for the observed behavior.

Longitudinal MR cortical thinning of individuals and its correlation with PET metabolic reduction: a measurement consistency and correctness studies

NASA Astrophysics Data System (ADS)

Lin, Zhongmin S.; Avinash, Gopal; McMillan, Kathryn; Yan, Litao; Minoshima, Satoshi

2014-03-01

Cortical thinning and metabolic reduction can be possible imaging biomarkers for Alzheimer's disease (AD) diagnosis and monitoring. Many techniques have been developed for the cortical measurement and widely used for the clinical statistical studies. However, the measurement consistency of individuals, an essential requirement for a clinically useful technique, requires proper further investigation. Here we leverage our previously developed BSIM technique 1 to measure cortical thickness and thinning and use it with longitudinal MRI from ADNI to investigate measurement consistency and spatial resolution. 10 normal, 10 MCI, and 10 AD subjects in their 70s were selected for the study. Consistent cortical thinning patterns were observed in all baseline and follow up images. Rapid cortical thinning was shown in some MCI and AD cases. To evaluate the correctness of the cortical measurement, we compared longitudinal cortical thinning with clinical diagnosis and longitudinal PET metabolic reduction measured using 3D-SSP technique2 for the same person. Longitudinal MR cortical thinning and corresponding PET metabolic reduction showed high level pattern similarity revealing certain correlations worthy of further studies. Severe cortical thinning that might link to disease conversion from MCI to AD was observed in two cases. In summary, our results suggest that consistent cortical measurements using our technique may provide means for clinical diagnosis and monitoring at individual patient's level and MR cortical thinning measurement can complement PET metabolic reduction measurement.

Room-temperature observation and current control of skyrmions in Pt/Co/Os/Pt thin films

NASA Astrophysics Data System (ADS)

Tolley, R.; Montoya, S. A.; Fullerton, E. E.

2018-04-01

We report the observation of room-temperature magnetic skyrmions in Pt/Co/Os/Pt thin-film heterostructures and their response to electric currents. The magnetic properties are extremely sensitive to inserting thin Os layers between the Co-Pt interface, resulting in reduced saturation magnetization, magnetic anisotropy, and Curie temperature. The observed skyrmions exist in a narrow temperature, applied-field and layer-thickness range near the spin-reorientation transition from perpendicular to in-plane magnetic anisotropy. The skyrmions have an average diameter of 2.3 μ m and transport measurements demonstrate these features can be displaced by means of spin-orbit torques with current densities as low as J =2 ×108A / m2 and display a skyrmion Hall effect.

Dark-field transmission electron microscopy of cortical bone reveals details of extrafibrillar crystals.

PubMed

Schwarcz, Henry P; McNally, Elizabeth A; Botton, Gianluigi A

2014-12-01

In a previous study we showed that most of the mineral in bone is present in the form of "mineral structures", 5-6nm-thick, elongated plates which surround and are oriented parallel to collagen fibrils. Using dark-field transmission electron microscopy, we viewed mineral structures in ion-milled sections of cortical human bone cut parallel to the collagen fibrils. Within the mineral structures we observe single crystals of apatite averaging 5.8±2.7nm in width and 28±19nm in length, their long axes oriented parallel to the fibril axis. Some appear to be composite, co-aligned crystals as thin as 2nm. From their similarity to TEM images of crystals liberated from deproteinated bone we infer that we are viewing sections through platy crystals of apatite that are assembled together to form the mineral structures. Copyright © 2014 Elsevier Inc. All rights reserved.

Stratigraphy and depositional history of the Apollo 17 drill core

NASA Technical Reports Server (NTRS)

Taylor, G. J.; Warner, R. D.; Keil, K.

1979-01-01

Lithologic abundances obtained from modal analyses of a continuous string of polished thin sections indicate that the Apollo 17 deep drill core can be divided into three main zones: An upper zone (0-19 cm depth) characterized by high abundances of agglutinates (30%) and a high ratio of mare to non-mare lithic fragments (less than 0.8); a coarse-grained layer (24-56 cm) rich in fragments of high-Ti mare basalts and mineral fragments derived from them, and poor in agglutinates (6%); and a lower zone (56-285 cm) characterized by variable but generally high agglutinate abundances (25%) and a low ratio of mare to nonmare lithic fragments (0.6). Using observations of the geology of the landing site, the principles of cratering dynamics, and the vast amount of data collected on the core, the following depositional history for the section of regolith sampled by the Apollo 17 drill core: was devised.

Microstructural and magneto-transport characterization of Bi2SexTe3-x topological insulator thin films grown by pulsed laser deposition method

NASA Astrophysics Data System (ADS)

Jin, Zhenghe; Kumar, Raj; Hunte, Frank; Narayan, Jay; Kim, Ki Wook; North Carolina State University Team

Bi2SexTe3-x topological insulator thin films were grown on Al2O3 (0001) substrate by pulsed laser deposition (PLD). XRD and other structural characterization measurements confirm the growth of the textured Bi2SexTe3-x thin films on Al2O3 substrate. The magneto-transport properties of thick and thin Þlms were investigated to study the effect of thickness on the topological insulator properties of the Bi2SexTe3 - x films. A pronounced semiconducting behavior with a highly insulating ground state was observed in the resistivity vs. temperature data. The presence of the weak anti-localization (WAL) effect with a sharp cusp in the magnetoresistance measurements confirms the 2-D surface transport originating from the TSS in Bi2SexTe3-x TI films. A high fraction of surface transport is observed in the Bi2SexTe3-x TI thin films which decreases in Bi2SexTe3-x TI thick films. The Cosine (θ) dependence of the WAL effect supports the observation of a high proportion of 2-D surface state contribution to overall transport properties of the Bi2SexTe3-x TI thin films. Our results show promise that high quality Bi2SexTe3-x TI thin films with significant surface transport can be grown by PLD method to exploit the exotic properties of the surface transport in future generation spintronic devices. This work was supported, in part, by National Science Foundation ECCS-1306400 and FAME.

FROZEN THIN SECTIONS OF FRESH TISSUE FOR ELECTRON MICROSCOPY, WITH A DESCRIPTION OF PANCREAS AND LIVER

PubMed Central

Christensen, A. Kent

1971-01-01

A simple method has been developed that allows frozen thin sections of fresh-frozen tissue to be cut on a virtually unmodified ultramicrotome kept at room temperature. A bowl-shaped Dewar flask with a knifeholder in its depths replaces the stage of the microtome; a bar extends down into the bowl from the microtome's cutting arm and bears the frozen tissue near its lower end. When the microtome is operated, the tissue passes a glass or diamond knife in the depths of the bowl as in normal cutting. The cutting temperature is maintained by flushing the bowl with cold nitrogen gas, and can be set anywhere from about -160°C up to about -30°C. The microtome is set for a cutting thickness of 540–1000 A. Sections are picked up from the dry knife edge, and are placed on membrane-coated grids, flattened with the polished end of a copper rod, and either dried in nitrogen gas or freeze-dried. Throughout the entire process the tissue is kept cold and does not come in contact with any solvent. The morphology seen in frozen thin sections of rat pancreas and liver generally resembles that in conventional preparations, although freezing damage and low contrast limit the detail that can be discerned. Among unusual findings is a frequent abundance of mitochondrial granules in material prepared by this method. PMID:4942776

Thinness in young schoolchildren in Serbia: another case of the double burden of malnutrition?

PubMed

Djordjic, Visnja; Jorga, Jagoda; Radisavljevic, Snezana; Milanovic, Ivana; Bozic, Predrag; Ostojic, Sergej M

2018-04-01

Thinness is rarely highlighted or regularly monitored among children in developed countries although it may be rather frequent and pose a significant risk to children's health. We aimed to describe the prevalence of mild, moderate and severe thinness among young Serbian schoolchildren. Cross-sectional study of schoolchildren aged 6-9 years. Children were assessed for weight, height and BMI as part of the WHO European Childhood Obesity Surveillance Initiative in Serbia. Thinness grades were defined as gender- and age-specific cut-offs for BMI according to the International Obesity Task Force criteria. Serbia, September to November 2015. Students (n 4861) in grades 2 and 3 (6-9 years, 2397 girls). Overall prevalence of thinness in Serbian schoolchildren was 9·6 %. Mild thinness was clearly the largest category with a prevalence of 7·6 %, moderate thinness was present in 1·7 % of children and severe thinness was found in 0·3 % of children. OR indicated a significant risk of being thin for girls (1·44 times higher compared with boys) and children attending schools with no health-focused educational programme (1·57 times more likely to be thin than peers enrolled in schools with such programmes). In addition, OR for thinness tended to be 1·23 times higher in children living in an economically disadvantaged region of Serbia (P=0·06). A rather high prevalence of thinness highlights this malnutrition disorder as an emerging health issue that should trigger public health policies to tackle thinness, especially in girls of young age and children living in economically disadvantaged areas.

An acetate precursor process for BSCCO (2223) thin films and coprecipitated powders

NASA Technical Reports Server (NTRS)

Haertling, Gene H.

1992-01-01

Since the discovery of high temperature superconducting oxides much attention has been paid to finding better and useful ways to take advantage of the special properties exhibited by these materials. One such process is the development of thin films for engineering applications. Another such process is the coprecipitation route to producing superconducting powders. An acetate precursor process for use in thin film fabrication and a chemical coprecipitation route to Bismuth based superconducting materials has been developed. Data obtained from the thin film process were inconclusive to date and require more study. The chemical coprecipitation method of producing bulk material is a viable method, and is preferred over the previously used solid state route. This method of powder production appears to be an excellent route to producing thin section tape cast material and screen printed devices, as it requires less calcines than the oxide route to produce quality powders.

Balanced sections and the propagation of décollement: A Jura perspective

NASA Astrophysics Data System (ADS)

Laubscher, Hans

2003-12-01

The propagation of thrusting is an important problem in tectonics that is usually approached by forward (kinematical) modeling of balanced sections. Although modeling techniques are similar in most foreland fold-thrust belts, it turns out that in the Jura, there are modeling problems that require modifications of widely used techniques. In particular, attention is called to the role of model constraints that complement the set of observational constraints in order to fully define the model. In the eastern Jura, such model constraints may be inferred from the regional geology, which shows a peculiar noncoaxial relation between thrusts and subsequent folds. This relation implies changes in the direction of translation and the mode of deformation in the course of the propagation of décollement. These changes are conjectured to be the result of a change in partial decoupling between the thin-skinned fold-thrust system (nappe) and the obliquely subducted foreland. As a particularly instructive case in point, a cross section through the Weissenstein range is discussed. A two-step forward (kinematical) model is proposed that uses both local observational constraints as well as model constraints inferred from regional data. As a first step, a fault bend fold is generated in the hanging wall of a thrust of 1500 m shortening. As a second step, this structure is transferred by flexural slip into the actual fold observed at the surface. This requires an additional 1600 m of shortening and leads to folding of the original thrust. Thereafter, the footwall is deformed so as to respect the constraint that this deformation must fit into the space defined by the folded thrust as the upper boundary and the décollement surface as the lower boundary, and that, in addition, should be confined to the area immediately below the fold. In modeling the footwall deformation a mix of balancing methods is used: fault propagation folds for the competent intervals of the stratigraphic column and area balancing for the incompetent ones. Further propagation of décollement into the foreland is made possible by the folding process, which is dominated by a sort of kinking and which is the main contribution to structural elevation and hence to producing a sort of critical taper of the moving thin-skinned wedge.

Chaotic non-planar vibrations of the thin elastica. Part I: Experimental observation of planar instability

NASA Astrophysics Data System (ADS)

Cusumano, J. P.; Moon, F. C.

1995-01-01

In this two-part paper, the results of an investigation into the non-linear dynamics of a flexible cantilevered rod (the elastica) with a thin rectangular cross-section are presented. An experimental examination of the dynamics of the elastica over a broad parameter range forms the core of Part I. In Part II, the experimental work is related to a theoretical study of the mechanics of the elastica, and the study of a two-degree-of-freedom model obtained by modal projection. The experimental system used in this investigation is a rod with clamped-free boundary conditions, forced by sinusoidally displacing the clamped end. Planar periodic motions of the driven elastica are shown to lose stability at distinct resonant wedges, and the resulting motions are shown in general to be non-planar, chaotic, bending-torsion oscillations. Non-planar motions in all resonances exhibit energy cascading and dynamic two-well phenomena, and a family of asymmetric, bending-torsion non-linear modes is discovered. Correlation dimension calculations are used to estimate the number of active degrees of freedom in the system.

Wrinkles, loops, and topological defects in twisted ribbons

NASA Astrophysics Data System (ADS)

Chopin, Julien

Nature abounds with elastic ribbon like shapes including double-stranded semiflexible polymers, graphene and metal oxide nanoribbons which are examples of elongated elastic structures with a strongly anisotropic cross-section. Due to this specific geometry, it is far from trivial to anticipate if a ribbon should be considered as a flat flexible filament or a narrow thin plate. We thus perform an experiment in which a thin elastic ribbon is loaded using a twisting and traction device coupled with a micro X-ray computed tomography machine allowing a full 3D shape reconstruction. A wealth of morphological behaviors can be observed including wrinkled helicoids, curled and looped configurations, and faceted ribbons. In this talk, I will show that most morphologies can be understood using a far-from-threshold approach and simple scaling arguments. Further, we find that the various shapes can be organized in a phase diagram using the twist, the tension, and the geometry of the ribbon as control parameters. Finally, I will discuss the spontaneous formation of topological defects with negatively-signed Gaussian charge at large twist and small but finite stretch.

Traps in AlGaN /GaN/SiC heterostructures studied by deep level transient spectroscopy

NASA Astrophysics Data System (ADS)

Fang, Z.-Q.; Look, D. C.; Kim, D. H.; Adesida, I.

2005-10-01

AlGaN /GaN/SiC Schottky barrier diodes (SBDs), with and without Si3N4 passivation, have been characterized by temperature-dependent current-voltage and capacitance-voltage measurements, and deep level transient spectroscopy (DLTS). A dominant trap A1, with activation energy of 1.0 eV and apparent capture cross section of 2×10-12cm2, has been observed in both unpassivated and passivated SBDs. Based on the well-known logarithmic dependence of DLTS peak height with filling pulse width for a line-defect related trap, A1, which is commonly observed in thin GaN layers grown by various techniques, is believed to be associated with threading dislocations. At high temperatures, the DLTS signal sometimes becomes negative, likely due to an artificial surface-state effect.

Fatal verminous pharyngitis and esophagitis caused by Streptocara incognita in mute swans (Cygnus olor).

PubMed

Alić, A; Prasović, S; Hodzić, A; Besirović, H; Residbegović, Emina; Omeragić, J

2013-03-01

Streptocara spp. infections are reported to cause gastritis, proventriculitis, esophagitis, and pharyngitis in various waterfowls, especially diving ducks. In the present paper, we describe severe fatal diphtheritic pharyngitis and esophagitis caused by Streptocara incognita in three female mute swans (Cygnus olor) in Bosnia and Herzegovina. Prior to death, the swans were showing signs of lethargy, anorexia, and reluctance to move. At necropsy, in all swans severe diphtheritic pharyngitis and esophagitis with deep, dark red hemorrhagic ulcerations were observed. Numerous thin, white, up to 1-cm-long nematodes, identified as S. incognita, were observed embedded in the pharyngeal and esophageal mucosa under the diphtheritic membranes. Histopathology revealed severe fibrinonecrotic inflammation with numerous cross-sections of the parasites. To the authors' knowledge, this is the first report of severe, fatal streptocariasis in mute swans.

Insect Thin Films as Sun Blocks, Not Solar Collectors

NASA Astrophysics Data System (ADS)

Koon, Daniel W.; Crawford, Andrew B.

2000-05-01

We measured the visible reflectance spectra of whole wing sections from three species of iridescent butterflies and moths, for normal incidence, integrated over all reflected angles. In this manner, we separated the optics of the thin films causing the iridescence from the optics of the rest of the scale. We found that iridescence reduces solar absorption by the wing in all cases, typically by approximately 20% or less, in contrast to claims by Miaoulis and Heilman Ann. Entomol. Soc. Am. 91, 122 (1998) that the thin-film structures that produce iridescence act as solar collectors.

Spanwise transition section for blended wing-body aircraft

NASA Technical Reports Server (NTRS)

Hawley, Arthur V. (Inventor)

1999-01-01

A blended wing-body aircraft includes a central body, a wing, and a transition section which interconnects the body and the wing on each side of the aircraft. The two transition sections are identical, and each has a variable chord length and thickness which varies in proportion to the chord length. This enables the transition section to connect the thin wing to the thicker body. Each transition section has a negative sweep angle.

Presenting Thin Media Models Affects Women's Choice of Diet or Normal Snacks

ERIC Educational Resources Information Center

Krahe, Barbara; Krause, Christina

2010-01-01

Our study explored the influence of thin- versus normal-size media models and of self-reported restrained eating behavior on women's observed snacking behavior. Fifty female undergraduates saw a set of advertisements for beauty products showing either thin or computer-altered normal-size female models, allegedly as part of a study on effective…

Electron Microscopy Characterization of Vanadium Dioxide Thin Films and Nanoparticles

NASA Astrophysics Data System (ADS)

Rivera, Felipe

Vanadium dioxide (VO_2) is a material of particular interest due to its exhibited metal to insulator phase transition at 68°C that is accompanied by an abrupt and significant change in its electronic and optical properties. Since this material can exhibit a reversible drop in resistivity of up to five orders of magnitude and a reversible drop in infrared optical transmission of up to 80%, this material holds promise in several technological applications. Solid phase crystallization of VO_2 thin films was obtained by a post-deposition annealing process of a VO_{x,x approx 2} amorphous film sputtered on an amorphous silicon dioxide (SiO_2) layer. Scanning electron microscopy (SEM) and electron-backscattered diffraction (EBSD) were utilized to study the morphology of the solid phase crystallization that resulted from this post-deposition annealing process. The annealing parameters ranged in temperature from 300°C up to 1000°C and in time from 5 minutes up to 12 hours. Depending on the annealing parameters, EBSD showed that this process yielded polycrystalline vanadium dioxide thin films, semi-continuous thin films, and films of isolated single-crystal particles. In addition to these films on SiO_2, other VO_2 thin films were deposited onto a-, c-, and r-cuts of sapphire and on TiO_2(001) heated single-crystal substrates by pulsed-laser deposition (PLD). The temperature of the substrates was kept at ˜500°C during deposition. EBSD maps and orientation imaging microscopy were used to study the epitaxy and orientation of the VO_2 grains deposited on the single crystal substrates, as well as on the amorphous SiO_2 layer. The EBSD/OIM results showed that: 1) For all the sapphire substrates analyzed, there is a predominant family of crystallographic relationships wherein the rutile VO_2{001} planes tend to lie parallel to the sapphire's {10-10} and the rutile VO_2{100} planes lie parallel to the sapphire's {1-210} and {0001}. Furthermore, while this family of relationships accounts for the majority of the VO_2 grains observed, due to the sapphire substrate's geometry there were variations within these rules that changed the orientation of VO_2 grains with respect to the substrate's normal direction. 2) For the TiO_2, a substrate with a lower lattice mismatch, we observe the expected relationship where the rutile VO_2 [100], [110], and [001] crystal directions lie parallel to the TiO_2 substrate's [100], [110], and [001] crystal directions respectively. 3) For the amorphous SiO_2 layer, all VO_2 crystals that were measurable (those that grew to the thickness of the deposited film) had a preferred orientation with the the rutile VO_2[001] crystal direction tending to lie parallel to the plane of the specimen. The use of transmission electron microscopy (TEM) is presented as a tool for further characterization studies of this material and its applications. In this work TEM diffraction patterns taken from cross-sections of particles of the a- and r-cut sapphire substrates not only solidified the predominant family mentioned, but also helped lift the ambiguity present in the rutile VO_2{100} axes. Finally, a focused-ion beam technique for preparation of cross-sectional TEM samples of metallic thin films deposited on polymer substrates is demonstrated.

Thin-sectioning and analysis of fine-grained meteoritic materials

NASA Technical Reports Server (NTRS)

Brooks, Donald A. (Editor); Bradley, John P.

1992-01-01

The overall theme of the work was the identification of the sources and formation/aggregation mechanisms of the various classes of interplanetary dust particles (IDP's) and to clarify the relationship between IDP's and conventional meteorites. IDP's are believed to be derived from a much broader range of parent bodies than conventional meteorites. Some of these parent bodies (e.g., comets) have escaped that post accretional processing that has affected the parent bodies of meteorites. Therefore, IDP's are likely to preserve a record of early solar system and possibly presolar grain forming reactions. Using analytical electron microscopy (AEM) and more recently micro-infrared (IR) microspectroscopy to examine ultramicrotomed thin sections, we have addressed the questions of IDP formation mechanisms, sources, and their relationship to conventional meteorites. The following sections describe specific findings resulting from these studies.

Experimental Observation of Thin-shell Instability in a Collisionless Plasma

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

Ahmed, H.; Doria, D.; Sarri, G.

We report on the experimental observation of the instability of a plasma shell, which formed during the expansion of a laser-ablated plasma into a rarefied ambient medium. By means of a proton radiography technique, the evolution of the instability is temporally and spatially resolved on a timescale much shorter than the hydrodynamic one. The density of the thin shell exceeds that of the surrounding plasma, which lets electrons diffuse outward. An ambipolar electric field grows on both sides of the thin shell that is antiparallel to the density gradient. Ripples in the thin shell result in a spatially varying balancemore » between the thermal pressure force mediated by this field and the ram pressure force that is exerted on it by the inflowing plasma. This mismatch amplifies the ripples by the same mechanism that drives the hydrodynamic nonlinear thin-shell instability (NTSI). Our results thus constitute the first experimental verification that the NTSI can develop in colliding flows.« less

Experimental Observation of Thin-shell Instability in a Collisionless Plasma

NASA Astrophysics Data System (ADS)

Ahmed, H.; Doria, D.; Dieckmann, M. E.; Sarri, G.; Romagnani, L.; Bret, A.; Cerchez, M.; Giesecke, A. L.; Ianni, E.; Kar, S.; Notley, M.; Prasad, R.; Quinn, K.; Willi, O.; Borghesi, M.

2017-01-01

We report on the experimental observation of the instability of a plasma shell, which formed during the expansion of a laser-ablated plasma into a rarefied ambient medium. By means of a proton radiography technique, the evolution of the instability is temporally and spatially resolved on a timescale much shorter than the hydrodynamic one. The density of the thin shell exceeds that of the surrounding plasma, which lets electrons diffuse outward. An ambipolar electric field grows on both sides of the thin shell that is antiparallel to the density gradient. Ripples in the thin shell result in a spatially varying balance between the thermal pressure force mediated by this field and the ram pressure force that is exerted on it by the inflowing plasma. This mismatch amplifies the ripples by the same mechanism that drives the hydrodynamic nonlinear thin-shell instability (NTSI). Our results thus constitute the first experimental verification that the NTSI can develop in colliding flows.

Comparison of the agglomeration behavior of thin metallic films on SiO2

NASA Astrophysics Data System (ADS)

Gadkari, P. R.; Warren, A. P.; Todi, R. M.; Petrova, R. V.; Coffey, K. R.

2005-07-01

The stability of continuous metallic thin films on insulating oxide surfaces is of interest to applications such as semiconductor interconnections and gate engineering. In this work, we report the study of the formation of voids and agglomeration of initially continuous Cu, Au, Ru and Pt thin films deposited on amorphous thermally grown SiO2 surfaces. Polycrystalline thin films having thicknesses in the range of 10-100 nm were ultrahigh vacuum sputter deposited on thermally grown SiO2 surfaces. The films were annealed at temperatures in the range of 150-800 °C in argon and argon+3% hydrogen gases. Scanning electron microscopy was used to investigate the agglomeration behavior, and transmission electron microscopy was used to characterize the microstructure of the as-deposited and annealed films. The agglomeration sequence in all of the films is found to follow a two step process of void nucleation and void growth. However, void growth in Au and Pt thin films is different from Cu and Ru thin films. Residual stress and adhesion were observed to play an important part in deciding the mode of void growth in Au and Pt thin films. Last, it is also observed that the tendency for agglomeration can be reduced by encapsulating the metal film with an oxide overlayer.

Gender-Related Discourses as Mediators in the Association between Internalization of the Thin-Body Ideal and Indicants of Body Dissatisfaction and Disordered Eating

ERIC Educational Resources Information Center

Morrison, Todd G.; Sheahan, Emer E.

2009-01-01

This study examined whether the gender-related discourses of self-objectification, self-silencing, and anger suppression mediated the association between internalization of the thin-body ideal and body dissatisfaction and eating pathology. We employed a cross-sectional design to study both university (n = 140) and community (n = 76) samples of…

Effects of late rotation thinning on light availability and red oak regeneration within a minor stream bottom in Mississippi

Treesearch

Ellen M. Boerger; Brent R. Frey; Andrew W. Ezell; Tracy Hawkins

2015-01-01

Recent studies suggest a troubling decline in the abundance of red oak species (Quercus spp., Section Erythrobalanus) in bottomland forests of the southeastern United States. We assessed red oak advance regeneration and associated tree species in relation to light availability in a 77-year-old oak-dominated stand 5 years after late rotation thinning. Residual basal...

Permian-Triassic boundary microbialites at Zuodeng Section, Guangxi Province, South China: Geobiology and palaeoceanographic implications

NASA Astrophysics Data System (ADS)

Fang, Yuheng; Chen, Zhong-Qiang; Kershaw, Stephen; Yang, Hao; Luo, Mao

2017-05-01

A previously unknown microbialite bed in the Permian-Triassic (P-Tr) boundary beds of Zuodeng section, Tiandong County, Guangxi, South China comprises a thin (5 cm maximum thickness) stromatolite in the lower part and the remaining 6 m is thrombolite. The Zuodeng microbialite has a pronounced irregular contact between the latest Permian bioclastic limestone and microbialite, as in other sites in the region. The stromatolite comprises low-relief columnar and broad domal geometries, containing faint laminations. The thrombolite displays an irregular mixture of sparitic dark coloured altered microbial fabric and light coloured interstitial sediment in polished blocks. Abundant microproblematic calcimicrobe structures identified here as Gakhumella are preserved in dark coloured laminated areas of the stromatolite and sparitic areas in thrombolites (i.e. the calcimicrobial part, not the interstitial sediment) and are orientated perpendicular to stromatolitic laminae. Each Gakhumella individual has densely arranged segments, which form a column- to fan-shaped structure. Single segments are arch-shaped and form a thin chamber between segments. Gakhumella individuals in the stromatolite and thrombolite are slightly different from each other, but are readily distinguished from the Gakhumella- and Renalcis-like fossils reported from other P-Tr boundary microbialites in having a smaller size, unbranching columns and densely arranged, arch-shaped segments. Renalcids usually possess a larger body size and branching, lobate outlines. Filament sheath aggregates are also observed in the stromatolite and they are all orientated in one direction. Both Gakhumella and filament sheath aggregates may be photosynthetic algae, which may have played an important role in constructing the Zuodeng microbialites. Other calcimicrobes in the Zuodeng microbialite are spheroids, of which a total of five morphological types are recognized from both stromatolite and thrombolite: (1) sparry calcite spheroid without outer sheaths, (2) a large sparry calcite nucleus coated with a thin sparry calcite sheath, (3) a large nucleus of micrite framboid aggregates rimmed by a thin sparry calcite sheath (bacterial clump-like spheroids), (4) a large nucleus of micrite framboid aggregates coated with a thin micritic sheath, and (5) a small sparry nuclei rimmed by coarse-grained, radiated euhedral rays. The irregular contact beneath the Zuodeng microbialites is interpreted as a subaerial exposure surface due to regional regression in South China. The demise of the Zuodeng microbialites may have been due to rapid rise in sea-level because they grew in relatively shallow marine conditions and are overlain by muddy limestones containing pelagic conodonts. Also siliciclastic content increases above the microbialite, suggesting a possible climate-related increase in weathering as the transgression progressed.

Interband Transitions

NASA Astrophysics Data System (ADS)

Varma, Shikha

We have studied thin (1-7 monolayer) overlayers of Hg on Ag(100) and Cu(100) using angle-resolved photoemission and low energy electron diffraction. We have investigated the electronic states of well ordered, disordered and the liquid overlayers of mercury. We show that the electronic structure of the well ordered overlayers is very different than that of the disordered and the liquid overlayers. The well ordered overlayers of Hg on Ag(100) exhibit a new electronic state which is absent for the disordered overlayers of mercury as well as for gaseous mercury. We will argue that this new Hg state is a result of the interaction among the Hg-Hg atoms, when adsorbed on Ag(100). The strain among adlayer atoms also plays a crucial role in the development of the new electronic state. We have used the synchrotron radiation to study the partial cross-section and the branching ratio of the 5d electronic state of Hg. We have measured the partial cross-section and branching ratio of the well-ordered, disordered and liquid overlayers of mercury on Ag(100) and Cu(100). We have observed resonances in the photoemission intensities of the mercury 5d orbitals for thin films of mercury for incident photon energies near the 5p _{3/2}, 4f_{7/2 } and 4f_{5/2} thresholds. The results indicate that interband transitions from the 5p and 4f levels to the 5d orbitals can occur for a thin overlayer of mercury, as a result of final state 5f contributions, though such interband transitions are forbidden for the free isolated Hg atom. These resonances are attributed to the formation of a solid state band structure incorporating new itinerant mercury electronic state. These resonances are absent when the mercury film is disordered or melted. We have measured the branching ratio of the 5d orbital for thin mercury overlayers in the photon energy range between 26 to 105 eV. The branching ratios deviate from the nonrelativistic statistical value of 1.5, reaching values of 8.0. These results indicate the importance of long range crystallographic structure and the effect of many -electron interactions in a thin film of mercury. We have also studied the intra molecular excitations in Br_2 and I_2 molecules using electron energy loss studies. These excitations give the information about the electronic structure of the molecule. From these studies we have identified the separation between the occupied and unoccupied orbitals of adsorbed halogen molecules on Fe(100).

Room temperature magnetism and metal to semiconducting transition in dilute Fe doped Sb1-xSex semiconducting alloy thin films

NASA Astrophysics Data System (ADS)

Agrawal, Naveen; Sarkar, Mitesh; Chawda, Mukesh; Ganesan, V.; Bodas, Dhananjay

2015-02-01

The magnetism was observed in very dilute Fe doped alloy thin film Fe0.008Sb1-xSex, for x = 0.01 to 0.10. These thin films were grown on silicon substrate using thermal evaporation technique. Structural, electrical, optical, charge carrier concentration measurement, surface morphology and magnetic properties were observed using glancing incidence x-ray diffraction (GIXRD), four probe resistivity, photoluminescence, Hall measurement, atomic force microscopy (AFM) and magnetic force microscopy (MFM) techniques, respectively. No peaks of iron were seen in GIXRD. The resistivity results show that activation energy increases with increase in selenium (Se) concentration. The Arrhenius plot reveals metallic behavior below room temperature. The low temperature conduction is explained by variable range-hopping mechanism, which fits very well in the temperature range 150-300 K. The decrease in density of states has been observed with increasing selenium concentration (x = 0.01 to 0.10). There is a metal-to-semiconductor phase transition observed above room temperature. This transition temperature is Se concentration dependent. The particle size distribution ˜47-61 nm is evaluated using AFM images. These thin films exhibit ferromagnetic interactions at room temperature.

Plasmonic excitation-assisted optical and electric enhancement in ultra-thin solar cells: the influence of nano-strip cross section

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

Sabaeian, Mohammad, E-mail: sabaiean@scu.ac.ir; Heydari, Mehdi; Ajamgard, Narges

The effects of Ag nano-strips with triangle, rectangular and trapezoid cross sections on the optical absorption, generation rate, and short-circuit current density of ultra-thin solar cells were investigated. By putting the nano-strips as a grating structure on the top of the solar cells, the waveguide, surface plasmon polariton (SPP), and localized surface plasmon (LSP) modes, which are excited with the assistance of nano-strips, were evaluated in TE and TM polarizations. The results show, firstly, the TM modes are more influential than TE modes in optical and electrical properties enhancement of solar cell, because of plasmonic excitations in TM mode. Secondly,more » the trapezoid nano-strips reveal noticeable impact on the optical absorption, generation rate, and short-circuit current density enhancement than triangle and rectangular ones. In particular, the absorption of long wavelengths which is a challenge in ultra-thin solar cells is significantly improved by using Ag trapezoid nano-strips.« less

Differentiating submarine channel-related thin-bedded turbidite facies: Outcrop examples from the Rosario Formation, Mexico

NASA Astrophysics Data System (ADS)

Hansen, Larissa; Callow, Richard; Kane, Ian; Kneller, Ben

2017-08-01

Thin-bedded turbidites deposited by sediment gravity flows that spill from submarine channels often contain significant volumes of sand in laterally continuous beds. These can make up over 50% of the channel-belt fill volume, and can thus form commercially important hydrocarbon reservoirs. Thin-bedded turbidites can be deposited in environments that include levees and depositional terraces, which are distinguished on the basis of their external morphology and internal architecture. Levees have a distinctive wedge shaped morphology, thinning away from the channel, and confine both channels (internal levees) and channel-belts (external levees). Terraces are flat-lying features that are elevated above the active channel within a broad channel-belt. Despite the ubiquity of terraces and levees in modern submarine channel systems, the recognition of these environments in outcrop and in the subsurface is challenging. In this outcrop study of the Upper Cretaceous Rosario Formation (Baja California, Mexico), lateral transects based on multiple logged sections of thin-bedded turbidites reveal systematic differences in sandstone layer thicknesses, sandstone proportion, palaeocurrents, sedimentary structures and ichnology between channel-belt and external levee thin-bedded turbidites. Depositional terrace deposits have a larger standard deviation in sandstone layer thicknesses than external levees because they are topographically lower, and experience a wider range of turbidity current sizes overspilling from different parts of the channel-belt. The thickness of sandstone layers within external levees decreases away from the channel-belt while those in depositional terraces are less laterally variable. Depositional terrace environments of the channel-belt are characterized by high bioturbation intensities, and contain distinctive trace fossil assemblages, often dominated by ichnofabrics of the echinoid trace fossil Scolicia. These assemblages contrast with the lower bioturbation intensities that are recorded from external levee environments where Scolicia is typically absent. Multiple blocks of external levee material are observed in the depositional terrace area where the proximal part of the external levee has collapsed into the channel-belt; their presence characterizes the channel-belt boundary zone. The development of recognition criteria for different types of channel-related thin-bedded turbidites is critical for the interpretation of sedimentary environments both at outcrop and in the subsurface, which can reduce uncertainty during hydrocarbon field appraisal and development.

Structural and thermoelectric properties of epitaxially grown Bi2Te3 thin films and superlattices

NASA Astrophysics Data System (ADS)

Peranio, N.; Eibl, O.; Nurnus, J.

2006-12-01

Multi-quantum-well structures of Bi2Te3 are predicted to have a high thermoelectric figure of merit ZT. Bi2Te3 thin films and Bi2Te3/Bi2(Te0.88Se0.12)3 superlattices (SLs) were grown epitaxially by molecular beam epitaxy on BaF2 substrates with periods of 12 and 6nm, respectively. Reflection high-energy electron diffraction confirmed a layer-by-layer growth, x-ray diffraction yielded the lattice parameters and SL periods and proved epitaxial growth. The in-plane transport coefficients were measured and the thin films and SL had power factors between 28 and 35μW /cmK2. The lattice thermal conductivity varied between 1.60W/mK for Bi2Te3 thin films and 1.01W/mK for a 10nm SL. The best figures of merit ZT were achieved for the SL; however, the values are slightly smaller than those in bulk materials. Thin films and superlattices were investigated in plan view and cross section by transmission electron microscopy. In the Bi2Te3 thin film and SL the dislocation density was found to be 2×1010cm-2. Bending of the SL with amplitudes of 30nm (12nm SL) and 15nm (6nm SL) and a wavelength of 400nm was determined. Threading dislocations were found with a density greater than 2×109cm-2. The superlattice interfaces are strongly bent in the region of the threading dislocations, undisturbed regions have a maximum lateral sie of 500nm. Thin films and SL showed a structural modulation [natural nanostructure (nns)] with a wavelength of 10nm and a wave vector parallel to (1,0,10). This nns was also observed in Bi2Te3 bulk materials and turned out to be of general character for Bi2Te3. The effect of the microstructure on the thermoelectric properties is discussed. The microstructure is governed by the superlattice, the nns, and the dislocations that are present in the films. Our results indicate that the microstructure directly affects the lattice thermal conductivity. Thermopower and electrical conductivity were found to be negatively correlated and no clear dependence of the two quantities on the microstructure could be found.

Electron Emission Observations from As-Grown and Vacuum-Coated Chemical Vapor Deposited Diamond

NASA Technical Reports Server (NTRS)

Lamouri, A.; Wang, Yaxin; Mearini, G. T.; Krainsky, I. L.; Dayton, J. A., Jr.; Mueller,W.

1996-01-01

Field emission has been observed from chemical vapor deposited diamond grown on Mo and Si substrates. Emission was observed at fields as low as 20 kV/cm. The samples were tested in the as-grown form, and after coating with thin films of Au, CsI, and Ni. The emission current was typically maximum at the onset of the applied field, but was unstable, and decreased rapidly with time from the as-grown films. Thin Au layers, approximately 15 nm thick, vacuum deposited onto the diamond samples significantly improved the stability of the emission current at values approximately equal to those from uncoated samples at the onset of the applied field. Thin layers of CsI, approximately 5 nm thick, were also observed to improve the stability of the emission current but at values less than those from the uncoated samples at the onset of the applied field. While Au and CsI improved the stability of the emission, Ni was observed to have no effect.

Reconsideration of Natural Monuments No. 413 (Mungokri Stromatolite) of Chosun Supergroup, Korea

NASA Astrophysics Data System (ADS)

KONG, Dal Yong; LEE, Seong Joo

2014-05-01

Stromatolite-like structures, so-called "Mungokri Stromatolite", which is located along the cliff of creeks in the vicinity of Oman bridge, Mungok-ri, Yeongwol, Kangweondo was designated as Natural Monument No. 413 in March, 2000. The Mungokri Stromatolite resembles LLH(laterally-linked hemispheroid) type stromatolite, each dome of which is laterally connected forming a stromatolite bed. The Mungokri Stromatolite, however, cannot be regarded as stromatolite because domal structure and fine lamination (the most diagnostic character) cannot be observed both in the field and through the petrological thin section. The smooth surface structure and very thin, irregular cracks characterized in the surface of the Mungokri Stromatolite also differ from those of a normal stromatolite. Such differences strongly suggest that the Mungokri Stromatolite is not a stromatolite but an algal mound. If we take considerations: 1) general lithology and sedimentary structures of Socheong island, 2) observation that angles of columns' inclination are not consistent throughout the stromatolite beds, and that vertical columns are also found in stromatolite beds, 3) igneous intrusion that would have caused structural deformation of sedimentary rocks of Socheong island, the inclination of Socheong stromatolites could be better interpreted as a secondary structural deformation probably after formation of stromatolite columns, rather than as a result of heliotropism. Consequently, renaming of the Mungokri Stromatolite, Natural Monument No. 413, is necessary. [Acknowledgments] This research was financially supported by the National Research Institute of Cultural Heritage.

Environmental magnetism of intertrapean Deccan deposits: unravelling local paleoenvironmental during Phase 1 and 2

NASA Astrophysics Data System (ADS)

Font, Eric; Adatte, Thierry; Ponte, Jorge; Fantasia, Alicia; Mirão, José; Samant, Bandana; Mohabey, Dhananjay; Florindo, Fabio

2014-05-01

The Deccan phase 2 is a crucial period caracterized by the rapid eruptions of huge volume of continental flood basalts correlated in age to the mass extinction of the Cretaceous-Paleogene boundary. However, local to global paleonvironmental changes during the Deccan Phase 2 are still baddly known. Here we provide new environmental magnetic data coupled to scanning electron microscopy of intertrapean deposits from the Deccan Volcanic Province (India) in order to unravel local paleoenvironmental conditions during periods of volcanic quiescence in the aftermath of the Deccan Phase 1 and Phase 2. Our results show that the magnetic mineralogy of these lacustrine and fluvial sediments is composed by several populations of iron oxides and sulphur, with a large range of grain size, probably resulting from different source of magnetic carriers (aeolian, detrital and bio-chemical). The number of magnetic phases identified using unmixing Isothermal Remanence Magnetic techniques is significantly higher (2 to 4) in the Podgavan section equivalent to Phase 2 than in the other studied sections, interpreted to result from higher weathering rates (acidity) by correlation with index of chemical alteration. Detailed scanning electron microscopy analysis of the Podgavan section reveal a complex mineralogy constituted by detrital magnetite, spherical and framboidal magnetite, microsphere of silicon, pyrrhotite, sylvite, manganese oxides and sporangiospores. A peculiar interval observed in the middle part of the Podgavan section, and corresponding to a thin interval of organic-rich clay capped by a thin oxidized level of reddish clays, show the presence of calcite needles and very fine hematite pigment. Hematite pigment are systematically associated to voids and form structures comparable to the blueberry hematite formed on mars. The abrupt transition from organic-rich levels (reducing conditions) to red hematitic clays (oxidation) suggests drastic and abrupt paleoenvironmental changes and acid conditions during the Deccan Phase 2. Keywords: Deccan, lacustrine sediments, environmental magnetism, acid rain, climate, weathering, volcanism.

Ultrastructural characterization of tooth-biomaterial interfaces prepared with broad and focused ion beams.

PubMed

Coutinho, E; Jarmar, T; Svahn, F; Neves, A A; Verlinden, B; Van Meerbeek, B; Engqvist, H

2009-11-01

Current available techniques for transmission electron microscopy (TEM) of tooth-biomaterial interfaces are mostly ineffective for brittle phases and impair integrated chemical and morphological characterization. The aims of this study were (1) to determine the applicability of new focused ion beam (FIB) and broad ion beam (BIB) techniques for TEM preparation of tooth-biomaterial interfaces; (2) to characterize the interfacial interaction with enamel and dentin of a conventional glass-ionomer (Chemfil Superior, DeTrey Dentsply, Germany), a 2-step self-etch (Clearfil SE, Kuraray, Japan) and a 3-step etch-and-rinse (OptiBond FL, Kerr, USA) adhesives; and (3) to characterize clinically relevant interfaces obtained from actual Class-I cavities. After bonding to freshly extracted human third molars, non-demineralized and non-stained sections were obtained using the FIB/BIB techniques and examined under TEM. The main structures generally disclosed in conventional ultramicrotomy samples were recognized in FIB/BIB-based ones. There were not any major differences between FIB and BIB concerning the resulting ultrastructural morphology. FIB/BIB-sections enabled to clearly resolve sub-micron hydroxyapatite crystals on top of hard tissues and the interface between matrix and filler in all materials, even at nano-scale. Some investigated interfaces disclosed areas with a distinct "fog" or "melted look", which is probably an artifact due to surface damage caused by the high-energy beam. Interfaces with enamel clearly disclosed the distinct "keyhole" shape of enamel rods sectioned at 90 degrees , delimited by a thin electron-lucent layer of inter-rod enamel. At regions where enamel crystals ran parallel with the interface, we observed a lack of interaction and some de-bonding along with interfacial void formation. The FIB/BIB methods are viable and reliable alternatives to conventional ultramicrotomy for preparation of thin sections of brittle and thus difficult to cut biomaterial-hard tissue interfaces. They disclose additional ultrastructural information about both substrates and are more suitable for advanced analytic procedures.

Drifting Diaphyses: Asymmetry in Diametric Growth and Adaptation Along the Humeral and Femoral Length.

PubMed

Maggiano, Isabel S; Maggiano, Corey M; Tiesler, Vera G; Chi-Keb, Julio R; Stout, Sam D

2015-10-01

This study quantifies regional histomorphological variation along the human humeral and femoral diaphysis in order to gain information on diaphyseal growth and modeling drift patterns. Three thin sections at 40, 50, and 60% bone length were prepared from a modern Mexican skeletal sample with known age and sex to give a longitudinal perspective on the drifting cortex (12 adults and juveniles total, 7 male and 5 female). Point-count techniques were applied across eight cross-sectional regions of interest using the starburst sampling pattern to quantify percent periosteal and endosteal primary lamellar bone at each diaphyseal level. The results of this study show a posterio-medial drift pattern in the humerus with a posterior rotational trend along the diaphysis. In the femur, we observed a consistent lateral to anteriolateral drift and an increase in primary lamellar bone area of both, periosteal and endosteal origin, towards the distal part of the diaphysis. These observations characterize drifting diaphyses in greater detail, raising important questions about how to resolve microscopic and macroscopic cross-sectional analysis towards a more complete understanding of bone growth and mechanical adaptation. Accounting for modeling drift has the potential to positively impact age and physical activity estimation, and explain some of the significant regional variation in bone histomorphology seen within (and between) bone cross-sections due to differing ages of tissue formation. More study is necessary, however, to discern between possible drift scenarios and characterize populational variation. © 2015 Wiley Periodicals, Inc.

Effect of angle of deposition on the Fractal properties of ZnO thin film surface

NASA Astrophysics Data System (ADS)

Yadav, R. P.; Agarwal, D. C.; Kumar, Manvendra; Rajput, Parasmani; Tomar, D. S.; Pandey, S. N.; Priya, P. K.; Mittal, A. K.

2017-09-01

Zinc oxide (ZnO) thin films were prepared by atom beam sputtering at various deposition angles in the range of 20-75°. The deposited thin films were examined by glancing angle X-ray diffraction and atomic force microscopy (AFM). Scaling law analysis was performed on AFM images to show that the thin film surfaces are self-affine. Fractal dimension of each of the 256 vertical sections along the fast scan direction of a discretized surface, obtained from the AFM height data, was estimated using the Higuchi's algorithm. Hurst exponent was computed from the fractal dimension. The grain sizes, as determined by applying self-correlation function on AFM micrographs, varied with the deposition angle in the same manner as the Hurst exponent.

Thinning southern bottomland hardwoods stands: Insect and disease consideratons

Treesearch

T. Evan Nebeker; Theodor D. Leininger; James S. Meadows; Michael D. Warriner

2005-01-01

The effects of thinning on insects and diseases have not been thoroughly examined in southern bottomland hardwood forests. To adress this issue, a study was initiated at sites in Mississippi and Alabama. These study sites allowed us to make observations concerning insect and disease activity 1-5 years following thinning. On all sites there was an unthinned control and...

Characterization of Alq3 thin films by a near-field microwave microprobe.

PubMed

Hovsepyan, Artur; Lee, Huneung; Sargsyan, Tigran; Melikyan, Harutyun; Yoon, Youngwoon; Babajanyan, Arsen; Friedman, Barry; Lee, Kiejin

2008-09-01

We observed tris-8-hydroxyquinoline aluminum (Alq3) thin films dependence on substrate heating temperatures by using a near-field microwave microprobe (NFMM) and by optical absorption at wavelengths between 200 and 900 nm. The changes of absorption intensity at different substrate heating temperatures are correlated to the changes in the sheet resistance of Alq3 thin films.

Tailoring and optimization of optical properties of CdO thin films for gas sensing applications

NASA Astrophysics Data System (ADS)

Rajput, Jeevitesh K.; Pathak, Trilok K.; Kumar, V.; Swart, H. C.; Purohit, L. P.

2018-04-01

Cadmium oxide (CdO) thin films have been deposited onto glass substrates using different molar concentrations (0.2 M, 0.5 M and 0.8 M) of cadmium acetate precursor solutions using a sol-gel spin coating technique. The structural, morphological, optical and electrical results are presented. X-ray diffraction patterns indicated that the CdO films of different molarity have a stable cubic structure with a (111) preferred orientation at low molar concentration. Scanning electron microscopy images revealed that the films adopted a rectangular to cauliflower like morphology. The optical transmittance of the thin films was observed in the range 200-800 nm and it was found that the 0.2 M CdO thin films showed about 83% transmission in the visible region. The optical band gap energy of the thin films was found to vary from 2.10 to 3.30 eV with the increase in molar concentration of the solution. The electrical resistance of the 0.5 M thin film was found to be 1.56 kΩ. The oxygen sensing response was observed between 20-33% in the low temperature range (32-200 °C).

Lithospheric and crustal thinning

NASA Technical Reports Server (NTRS)

Moretti, I.

1985-01-01

In rift zones, both the crust and the lithosphere get thinner. The amplitude and the mechanism of these two thinning situations are different. The lithospheric thinning is a thermal phenomenon produced by an asthenospherical uprising under the rift zone. In some regions its amplitude can exceed 200%. This is observed under the Baikal rift where the crust is directly underlaid by the mantellic asthenosphere. The presence of hot material under rift zones induces a large negative gravity anomaly. A low seismic velocity zone linked to this thermal anomaly is also observed. During the rifting, the magmatic chambers get progressively closer from the ground surface. Simultaneously, the Moho reflector is found at shallow depth under rift zones. This crustal thinning does not exceed 50%. Tectonic stresses and vertical movements result from the two competing effects of the lithospheric and crustal thinning. On the one hand, the deep thermal anomaly induces a large doming and is associated with extensive deviatoric stresses. On the other hand, the crustal thinning involves the formation of a central valley. This subsidence is increased by the sediment loading. The purpose here is to quantify these two phenomena in order to explain the morphological and thermal evolution of rift zones.

Evaluations of Thin Cirrus Contamination and Screening in Ground Aerosol Observations Using Collocated Lidar Systems

NASA Technical Reports Server (NTRS)

Huang, Jingfeng; Hsu, N. Christina; Tsay, Si-Chee; Holben, Brent N.; Welton, Ellsworth J.; Smirnov, Alexander; Jeong, Myeong-Jae; Hansell, Richard A.; Berkoff, Timothy A.

2012-01-01

Cirrus clouds, particularly sub visual high thin cirrus with low optical thickness, are difficult to be screened in operational aerosol retrieval algorithms. Collocated aerosol and cirrus observations from ground measurements, such as the Aerosol Robotic Network (AERONET) and the Micro-Pulse Lidar Network (MPLNET), provide us with an unprecedented opportunity to examine the susceptibility of operational aerosol products to thin cirrus contamination. Quality assured aerosol optical thickness (AOT) measurements were also tested against the CALIPSO vertical feature mask (VFM) and the MODIS-derived thin cirrus screening parameters for the purpose of evaluating thin cirrus contamination. Key results of this study include: (1) Quantitative evaluations of data uncertainties in AERONET AOT retrievals are conducted. Although AERONET cirrus screening schemes are successful in removing most cirrus contamination, strong residuals displaying strong spatial and seasonal variability still exist, particularly over thin cirrus prevalent regions during cirrus peak seasons, (2) Challenges in matching up different data for analysis are highlighted and corresponding solutions proposed, and (3) Estimation of the relative contributions from cirrus contamination to aerosol retrievals are discussed. The results are valuable for better understanding and further improving ground aerosol measurements that are critical for aerosol-related climate research.

Nonlinear Ballistic Transport in an Atomically Thin Material.

PubMed

Boland, Mathias J; Sundararajan, Abhishek; Farrokhi, M Javad; Strachan, Douglas R

2016-01-26

Ultrashort devices that incorporate atomically thin components have the potential to be the smallest electronics. Such extremely scaled atomically thin devices are expected to show ballistic nonlinear behavior that could make them tremendously useful for ultrafast applications. While nonlinear diffusive electron transport has been widely reported, clear evidence for intrinsic nonlinear ballistic transport in the growing array of atomically thin conductors has so far been elusive. Here we report nonlinear electron transport of an ultrashort single-layer graphene channel that shows quantitative agreement with intrinsic ballistic transport. This behavior is shown to be distinctly different than that observed in similarly prepared ultrashort devices consisting, instead, of bilayer graphene channels. These results suggest that the addition of only one extra layer of an atomically thin material can make a significant impact on the nonlinear ballistic behavior of ultrashort devices, which is possibly due to the very different chiral tunneling of their charge carriers. The fact that we observe the nonlinear ballistic response at room temperature, with zero applied magnetic field, in non-ultrahigh vacuum conditions and directly on a readily accessible oxide substrate makes the nanogap technology we utilize of great potential for achieving extremely scaled high-speed atomically thin devices.

Handling Golgi-impregnated tissue for light microscopy.

PubMed

Berbel, P J; Fairén, A

1983-08-08

The use of cyanocrylic glue to fix pieces of Golgi-stained nervous tissue on a paraffin blank is proposed for obtaining thick sections of unembedded tissue with a sliding microtome. This procedure makes correct orientation of the tissue easy during sectioning and makes it possible to obtain tissue sections quickly. The sections are flat-mounted using epoxy resin, resulting in permanent preparations with excellent optical properties and enabling further thin-sectioning for light and electron microscopic studies.

The properties of thin-section, four-point-contact ball bearings in space

NASA Technical Reports Server (NTRS)

Rowntree, R. A.

1985-01-01

Thin section, four-point-contact ball bearings are increasinly employed in spacecraft mechanisms because of the potential advantages they offer. However, litte was previously known of their torque, thermal conductance and stiffness properties at conditions anticipated for their use in space. An investigation of these properties are described. It was found that frictional (Coulomb) torque, thermal conductance and stiffness all show marked dependence on the bearing preload, the housing design, the bearing external fit (i.e., free fit or interference) and on the thermal gradient across the races. Optimum bearing performance is achieved only if these properties are well understood. The necessary data to understand these properties are provided.

[Thin-section computed tomography of the bronchi; 2. Right upper lobe and left upper division].

PubMed

Matsuoka, Y; Ookubo, T; Ohtomo, K; Nishikawa, J; Kojima, K; Oyama, K; Yoshikawa, K; Iio, M

1990-02-01

Thin (2mm) section contiguous computed tomographic (CT) scans were obtained through the bronchi of the right upper lobe and the left upper division in 30 patients. All segmental bronchi were identified. The right subsegmental bronchi were identified in 100%, and the left subsegmental bronchi in 97%. The type of the orifice of the right bronchus was trifurcated (53%), the extension of B1 was apicoanterior (50%), and the size of B2b was equal to B3a (63%). The extension of the left B3 was subapicoanterior (38%), and the size of B1+2c was equal to B3a (62%).

Quaternary schematics for property engineering of CdSe thin films

NASA Astrophysics Data System (ADS)

Chavan, G. T.; Pawar, S. T.; Prakshale, V. M.; Sikora, A.; Pawar, S. M.; Chaure, N. B.; Kamble, S. S.; Maldar, N. N.; Deshmukh, L. P.

2017-12-01

The synthesis of quaternary Cd1-xZnxSySe1-y (0 ≤ x = y ≤ 0.35) thin films was done through indigenously developed chemical solution growth process. As-obtained thin films were subjected to the physical, chemical, structural and optical characterizations. The nearly hydrophobic nature of the as-deposited films except binary CdSe was observed through the wettability studies. The colorimetric studies supported a change in physical color attributes. The elemental analysis done confirmed the formation of Cd(Zn, S)Se and the chemical states of constituent elements as Cd2+, Zn2+, S2- and Se2-. Structural assessment suggested the formation of the polycrystalline quaternary phase of the hexagonal wurtzite structure. The Raman spectroscopy was also employed for the confirmation studies on Cd1-xZnxSySe1-y thin films. Morphological observations indicated microstructural transformation from an aggregated bunch of nano-sized globular grains into a rhomboid network of petal/flakes like crystallites. The atomic force micrographs (AFM) revealed the enhancement in the hillock structures. From advanced AFM characterizations, we observed that the CdSe thin film has leptokurtic (Sku = 3.23) surface, whereas, quaternary Cd(Zn, S)Se films have platykurtic (Sku < 3) surface. The orientation of the surface morphology was observed through the angular spectrum studies. The optical absorption studies revealed direct allowed transition for the films with a continuous modulation of the energy bandgap from 1.8 eV to 2.31 eV.

Synthesis of 2D Metal Chalcogenide Thin Films through the Process Involving Solution-Phase Deposition.

PubMed

Giri, Anupam; Park, Gyeongbae; Yang, Heeseung; Pal, Monalisa; Kwak, Junghyeok; Jeong, Unyong

2018-04-24

2D metal chalcogenide thin films have recently attracted considerable attention owing to their unique physicochemical properties and great potential in a variety of applications. Synthesis of large-area 2D metal chalcogenide thin films in controllable ways remains a key challenge in this research field. Recently, the solution-based synthesis of 2D metal chalcogenide thin films has emerged as an alternative approach to vacuum-based synthesis because it is relatively simple and easy to scale up for high-throughput production. In addition, solution-based thin films open new opportunities that cannot be achieved from vacuum-based thin films. Here, a comprehensive summary regarding the basic structures and properties of different types of 2D metal chalcogenides, the mechanistic details of the chemical reactions in the synthesis of the metal chalcogenide thin films, recent successes in the synthesis by different reaction approaches, and the applications and potential uses is provided. In the last perspective section, the technical challenges to be overcome and the future research directions in the solution-based synthesis of 2D metal chalcogenides are discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ferroelectric and piezoelectric thin films and their applications for integrated capacitors, piezoelectric ultrasound transducers and piezoelectric switches

NASA Astrophysics Data System (ADS)

Klee, M.; Boots, H.; Kumar, B.; van Heesch, C.; Mauczok, R.; Keur, W.; de Wild, M.; van Esch, H.; Roest, A. L.; Reimann, K.; van Leuken, L.; Wunnicke, O.; Zhao, J.; Schmitz, G.; Mienkina, M.; Mleczko, M.; Tiggelman, M.

2010-02-01

Ferroelectric and piezoelectric thin films are gaining more and more importance for the integration of high performance devices in small modules. High-K 'Integrated Discretes' devices have been developed, which are based on thin film ferroelectric capacitors integrated together with resistors and ESD protection diodes in a small Si-based chip-scale package. Making use of ferroelectric thin films with relative permittivity of 950-1600 and stacking processes of capacitors, extremely high capacitance densities of 20-520 nF/mm2, high breakdown voltages up to 140 V and lifetimes of more than 10 years at operating voltages of 5 V and 85°C are achieved. Thin film high-density capacitors play also an important role as tunable capacitors for applications such as tuneable matching circuits for RF sections of mobile phones. The performance of thin film tuneable capacitors at frequencies between 1 MHz and 1 GHz is investigated. Finally thin film piezoelectric ultrasound transducers, processed in Si- related processes, are attractive for medical imaging, since they enable large bandwidth (>100%), high frequency operation and have the potential to integrate electronics. With these piezoelectric thin film ultrasound transducers real time ultrasound images have been realized. Finally, piezoelectric thin films are used to manufacture galvanic MEMS switches. A model for the quasi-static mechanical behaviour is presented and compared with measurements.

Effects of cluster thinning on vine photosynthesis, berry ripeness and flavonoid composition of Cabernet Sauvignon.

PubMed

Wang, Yu; He, Yan-Nan; Chen, Wei-Kai; He, Fei; Chen, Wu; Cai, Xiao-Dong; Duan, Chang-Qing; Wang, Jun

2018-05-15

Cluster thinning is a common practice for regulating vine yield and grape quality. The effects of cluster thinning on vine photosynthesis, berry ripeness and flavonoid composition of V. vinifera L. Cabernet Sauvignon were evaluated during two seasons. Half of the clusters were removed at pea-size and veraison relative to two controls, respectively. Both cluster thinning treatments significantly increased pruning weight and decreased yield. No effects of cluster thinning on berry growth, ripeness and flavonol composition were observed. Early cluster thinning decreased the photosynthetic rate at pea-size, but the effect diminished at post-veraison. Early cluster thinning significantly promoted the biosynthesis of anthocyanins but decreased the proportion of 3'5'-hydroxylated and acylated anthocyanins at veraison. Late cluster thinning decreased the proportions of 3'5'-hydroxylated and acylated anthocyanins. Additionally, Cluster thinning showed inconsistent effects on flavan-3-ol composition over the two seasons. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structure across the northeastern margin of Flemish Cap, offshore Newfoundland from Erable multichannel seismic reflection profiles: evidence for a transtensional rifting environment

NASA Astrophysics Data System (ADS)

Welford, J. Kim; Hall, Jeremy; Sibuet, Jean-Claude; Srivastava, Shiri P.

2010-11-01

We present the results from processing and interpreting nine multichannel seismic reflection lines collected during the 1992 Erable experiment over the northeastern margin of Flemish Cap offshore Newfoundland. These lines, combined into five cross-sections, provide increased seismic coverage over this lightly probed section of the margin and reveal tectonically significant along-strike variations in the degree and compartmentalization of crustal thinning. Similar to the southeastern margins of Flemish Cap and the Grand Banks, a transitional zone of exhumed serpentinized mantle is interpreted between thinned continental and oceanic crust. The 25 km wide transitional zone bears similarities to the 120 km wide transitional zone interpreted as exhumed serpentinized mantle on the conjugate Irish Atlantic margin but the significant width difference is suggestive of an asymmetric conjugate pair. A 40-50 km wide zone of inferred strike-slip shearing is interpreted and observed to extend along most of the northeastern margin of Flemish Cap. Individual shear zones (SZs) may represent extensions of SZs and normal faults within the Orphan Basin providing further evidence for the rotation and displacement of Flemish Cap out of Orphan Basin. The asymmetry between the Flemish Cap and Irish conjugate pairs is likely due in large part to the rotation and displacement of Flemish Cap which resulted in the Flemish Cap margin displaying features of both a strike-slip margin and an extensional margin.

Preliminary studies of the effect of thinning techniques over muon production profiles

NASA Astrophysics Data System (ADS)

Tomishiyo, G.; Souza, V.

2017-06-01

In the context of air shower simulations, thinning techniques are employed to reduce computational time and storage requirements. These techniques are tailored to preserve locally mean quantities during shower development, such as the average number of particles in a given atmosphere layer, and to not induce systematic shifts in shower observables, such as the depth of shower maximum. In this work we investigate thinning effects on the determination of the depth in which the shower has the maximum muon production {X}\\max μ -{sim}. We show preliminary results in which the thinning factor and maximum thinning weight might influence the determination of {X}\\max μ -{sim}

Computer Program for Steady Transonic Flow over Thin Airfoils by Finite Elements

DTIC Science & Technology

1975-10-01

COMPUTER PROGRAM FOR STEADY JJ TRANSONIC FLOW OVER THIN AIRFOILS BY g FINITE ELEMENTS • *q^^ r ̂ c HUNTSVILLE RESEARCH & ENGINEERING CENTER...jglMMi B Jun’ INC ORGANIMTION NAME ANO ADDRESS Lö^kfteed Missiles & Space Company, Inc. Huntsville Research & Engineering Center,^ Huntsville, Alab...This report was prepared by personnel in the Computational Mechamcs Section of the Lockheed Missiles fc Space Company, Inc.. Huntsville Research

An image warping technique for rodent brain MRI-histology registration based on thin-plate splines with landmark optimization

NASA Astrophysics Data System (ADS)

Liu, Yutong; Uberti, Mariano; Dou, Huanyu; Mosley, R. Lee; Gendelman, Howard E.; Boska, Michael D.

2009-02-01

Coregistration of in vivo magnetic resonance imaging (MRI) with histology provides validation of disease biomarker and pathobiology studies. Although thin-plate splines are widely used in such image registration, point landmark selection is error prone and often time-consuming. We present a technique to optimize landmark selection for thin-plate splines and demonstrate its usefulness in warping rodent brain MRI to histological sections. In this technique, contours are drawn on the corresponding MRI slices and images of histological sections. The landmarks are extracted from the contours by equal spacing then optimized by minimizing a cost function consisting of the landmark displacement and contour curvature. The technique was validated using simulation data and brain MRI-histology coregistration in a murine model of HIV-1 encephalitis. Registration error was quantified by calculating target registration error (TRE). The TRE of approximately 8 pixels for 20-80 landmarks without optimization was stable at different landmark numbers. The optimized results were more accurate at low landmark numbers (TRE of approximately 2 pixels for 50 landmarks), while the accuracy decreased (TRE approximately 8 pixels for larger numbers of landmarks (70- 80). The results demonstrated that registration accuracy decreases with the increasing landmark numbers offering more confidence in MRI-histology registration using thin-plate splines.

Selective Electron Beam Manufacturing of Ti-6Al-4V Strips: Effect of Build Orientation, Columnar Grain Orientation, and Hot Isostatic Pressing on Tensile Properties

NASA Astrophysics Data System (ADS)

Wang, J.; Tang, H. P.; Yang, K.; Liu, N.; Jia, L.; Qian, M.

2018-03-01

Many novel designs for additive manufacturing (AM) contain thin-walled (≤ 3 mm) sections in different orientations. Selective electron beam melting (SEBM) is particularly suited to AM of such thin-walled titanium components because of its high preheating temperature and high vacuum. However, experimental data on SEBM of Ti-6Al-4V thin sections remains scarce because of the difficulty and high cost of producing long, thin and smooth strip tensile specimens (see Fig. 1). In this study, 80 SEBM Ti-6Al-4V strips (180 mm long, 42 mm wide, 3 mm thick) were built both vertically (V-strips) and horizontally (H-strips). Their density, microstructure and tensile properties were investigated. The V-strips showed clearly higher tensile strengths but lower elongation than the H-strips. Hot isostatic pressing (HIP) produced the same lamellar α-β microstructures in terms of the average α-lath thickness in both types of strips. The retained prior-β columnar grain boundaries after HIP showed no measurable influence on the tensile properties, irrespective of their length and orientation, because of the formation of randomly distributed fine α-laths.[Figure not available: see fulltext.

Influence of oxygen on growth of carbon thin films

NASA Astrophysics Data System (ADS)

Kumar, Prabhat; Gupta, Mukul; Phase, D. M.; Stahn, Jochen

2018-04-01

In this work we studied the influence of oxygen gas on growth of carbon thin films in a magnetron sputtering process. X-ray absorption spectroscopy (XAS), x-ray and neutron reflectivity techniques were used to probe carbon thin films deposited with and without oxygen at room temperature. XAS in particularly x-ray absorption near edge spectroscopy (XANES) is powerful technique to identify the nature of hybridization of carbon atoms with other elements. In a XANES pattern, presence of C=O and C-O bonds is generally observed in spite of the fact that oxygen has not been deliberately included in the growth process. In order to confirm the presence of such features, we introduced a small amount of oxygen at 1% during the growth of carbon thin films. Though such additions do not affect the number density as observed by x-ray and neutron reflectivity, they severally affect the C K-edge spectra as evidenced by an enhancement in carbon-oxygen hybridization. Observed results are helpful in analyzing the C K-edge spectra more confidently.

Structured plasma sheet thinning observed by Galileo and 1984-129

NASA Technical Reports Server (NTRS)

Reeves, G. D.; Belian, R. D.; Fritz, T. A.; Kivelson, M. G.; Mcentire, R. W.; Roelof, E. C.; Wilken, B.; Williams, D. J.

1993-01-01

On December 8, 1990, the Galileo spacecraft used the Earth for a gravity assist on its way to Jupiter. Its trajectory was such that it crossed geosynchronous orbit at approximately local midnight between 1900 and 2000 UT. At the same time, spacecraft 1984-129 was also located at geosynchronous orbit near local midnight. Several flux dropout events were observed when the two spacecraft were in the near-Earth plasma sheet in the same local time sector. Flux dropout events are associated with plasma sheet thinning in the near-profile of the near-Earth plasma sheet while 1984-129 provided an azimuthal profile. With measurements from these two spacecraft we can distinguish between spatial structures and temporal change. Our observations confirm that the geosynchronous flux dropout events are consistent with plasma sheet thinning which changes the spacecraft's magnetic connection from the trapping region to the more distant plasma sheet. However, for this period, thinning occurred on two spatial and temporal scales. The geosynchronous dropouts were highly localized phenomena of 30 min duration superimposed on a more global reconfiguration of the tail lasting approximately 4 hours.

Grain Boundaries Act as Solid Walls for Charge Carrier Diffusion in Large Crystal MAPI Thin Films.

PubMed

Ciesielski, Richard; Schäfer, Frank; Hartmann, Nicolai F; Giesbrecht, Nadja; Bein, Thomas; Docampo, Pablo; Hartschuh, Achim

2018-03-07

Micro- and nanocrystalline methylammonium lead iodide (MAPI)-based thin-film solar cells today reach power conversion efficiencies of over 20%. We investigate the impact of grain boundaries on charge carrier transport in large crystal MAPI thin films using time-resolved photoluminescence (PL) microscopy and numerical model calculations. Crystal sizes in the range of several tens of micrometers allow for the spatially and time resolved study of boundary effects. Whereas long-ranged diffusive charge carrier transport is observed within single crystals, no detectable diffusive transport occurs across grain boundaries. The observed PL transients are found to crucially depend on the microscopic geometry of the crystal and the point of observation. In particular, spatially restricted diffusion of charge carriers leads to slower PL decay near crystal edges as compared to the crystal center. In contrast to many reports in the literature, our experimental results show no quenching or additional loss channels due to grain boundaries for the studied material, which thus do not negatively affect the performance of the derived thin-film devices.

Characterization of high-quality kerfless epitaxial silicon for solar cells: Defect sources and impact on minority-carrier lifetime

DOE PAGES

Kivambe, Maulid M.; Powell, Douglas M.; Castellanos, Sergio; ...

2017-11-14

We investigate the types and origins of structural defects in thin (<100 μm) kerfless epitaxial single crystal silicon grown on top of reorganized porous silicon layers. Although the structural defect density is low (has average defect density < 10 4 cm -2), localized areas with a defect density > 10 5 cm -2 are observed. Cross-sectional and systematic plan-view defect etching and microscopy reveals that the majority of stacking faults and dislocations originate at the interface between the porous silicon layer and the epitaxial wafer. Localised dislocation clusters are observed in regions of collapsed/deformed porous silicon and at decorated stackingmore » faults. In localized regions of high extended defect density, increased minority-carrier recombination activity is observed. Evidence for impurity segregation to the extended defects (internal gettering), which is known to exacerbate carrier recombination is demonstrated. In conclusion, the impact of the defects on material performance and substrate re-use is also discussed.« less

Characterization of high-quality kerfless epitaxial silicon for solar cells: Defect sources and impact on minority-carrier lifetime

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

Kivambe, Maulid M.; Powell, Douglas M.; Castellanos, Sergio

We investigate the types and origins of structural defects in thin (<100 μm) kerfless epitaxial single crystal silicon grown on top of reorganized porous silicon layers. Although the structural defect density is low (has average defect density < 10 4 cm -2), localized areas with a defect density > 10 5 cm -2 are observed. Cross-sectional and systematic plan-view defect etching and microscopy reveals that the majority of stacking faults and dislocations originate at the interface between the porous silicon layer and the epitaxial wafer. Localised dislocation clusters are observed in regions of collapsed/deformed porous silicon and at decorated stackingmore » faults. In localized regions of high extended defect density, increased minority-carrier recombination activity is observed. Evidence for impurity segregation to the extended defects (internal gettering), which is known to exacerbate carrier recombination is demonstrated. In conclusion, the impact of the defects on material performance and substrate re-use is also discussed.« less

Characterization of high-quality kerfless epitaxial silicon for solar cells: Defect sources and impact on minority-carrier lifetime

NASA Astrophysics Data System (ADS)

Kivambe, Maulid M.; Powell, Douglas M.; Castellanos, Sergio; Jensen, Mallory Ann; Morishige, Ashley E.; Lai, Barry; Hao, Ruiying; Ravi, T. S.; Buonassisi, Tonio

2018-02-01

We investigate the types and origins of structural defects in thin (<100 μm) kerfless epitaxial single crystal silicon grown on top of reorganized porous silicon layers. Although the structural defect density is low (has average defect density < 104 cm-2), localized areas with a defect density > 105 cm-2 are observed. Cross-sectional and systematic plan-view defect etching and microscopy reveals that the majority of stacking faults and dislocations originate at the interface between the porous silicon layer and the epitaxial wafer. Localised dislocation clusters are observed in regions of collapsed/deformed porous silicon and at decorated stacking faults. In localized regions of high extended defect density, increased minority-carrier recombination activity is observed. Evidence for impurity segregation to the extended defects (internal gettering), which is known to exacerbate carrier recombination is demonstrated. The impact of the defects on material performance and substrate re-use is also discussed.

Optimal Shakedown of the Thin-Wall Metal Structures Under Strength and Stiffness Constraints

NASA Astrophysics Data System (ADS)

Alawdin, Piotr; Liepa, Liudas

2017-06-01

Classical optimization problems of metal structures confined mainly with 1st class cross-sections. But in practice it is common to use the cross-sections of higher classes. In this paper, a new mathematical model for described shakedown optimization problem for metal structures, which elements are designed from 1st to 4th class cross-sections, under variable quasi-static loads is presented. The features of limited plastic redistribution of forces in the structure with thin-walled elements there are taken into account. Authors assume the elastic-plastic flexural buckling in one plane without lateral torsional buckling behavior of members. Design formulae for Methods 1 and 2 for members are analyzed. Structures stiffness constrains are also incorporated in order to satisfy the limit serviceability state requirements. With the help of mathematical programming theory and extreme principles the structure optimization algorithm is developed and justified with the numerical experiment for the metal plane frames.

The Cellient System for Paraffin Histology Can Be Combined with HPV Testing and Morphotyping the Vaginal Microbiome Thanks to BoonFixing

PubMed Central

Boon, Mathilde E.

2013-01-01

The Cellient Automated Cell Block System (Hologic) can be used to process cervical scrapes to paraffin sections. For the first study on this subject, cervical scrapes were fixed in the formalin-free fixative BoonFix. This pilot study was limited to cases classified as atypical squamous lesion of unknown significance (ASCUS) and high-grade squamous lesion (HSIL) as diagnosed in the ThinPrep slide. The Cellient paraffin sections were classified into negative, atypical, CIN 1, CIN 2, and CIN 3. Multiple HPV genotypes were encountered in 79% of the scrapes. This study showed that the Cellient system for paraffin sections can be combined with HPV testing thanks to the formalin-free BoonFix. In two additional studies it was shown that such samples can also be used for morphotyping the vaginal microbiome and preparing cytologic ThinPrep slides. PMID:23577033

The Cellient System for Paraffin Histology Can Be Combined with HPV Testing and Morphotyping the Vaginal Microbiome Thanks to BoonFixing.

PubMed

Boon, Mathilde E

2013-01-01

The Cellient Automated Cell Block System (Hologic) can be used to process cervical scrapes to paraffin sections. For the first study on this subject, cervical scrapes were fixed in the formalin-free fixative BoonFix. This pilot study was limited to cases classified as atypical squamous lesion of unknown significance (ASCUS) and high-grade squamous lesion (HSIL) as diagnosed in the ThinPrep slide. The Cellient paraffin sections were classified into negative, atypical, CIN 1, CIN 2, and CIN 3. Multiple HPV genotypes were encountered in 79% of the scrapes. This study showed that the Cellient system for paraffin sections can be combined with HPV testing thanks to the formalin-free BoonFix. In two additional studies it was shown that such samples can also be used for morphotyping the vaginal microbiome and preparing cytologic ThinPrep slides.

Probing plasmodesmata function with biochemical inhibitors.

PubMed

White, Rosemary G

2015-01-01

To investigate plasmodesmata (PD) function, a useful technique is to monitor the effect on cell-to-cell transport of applying an inhibitor of a physiological process, protein, or other cell component of interest. Changes in PD transport can then be monitored in one of several ways, most commonly by measuring the cell-to-cell movement of fluorescent tracer dyes or of free fluorescent proteins. Effects on PD structure can be detected in thin sections of embedded tissue observed using an electron microscope, most commonly a Transmission Electron Microscope (TEM). This chapter outlines commonly used inhibitors, methods for treating different tissues, how to detect altered cell-to-cell transport and PD structure, and important caveats.

Balanced double-loop mesoscopic interferometer based on Josephson proximity nanojunctions

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

Ronzani, Alberto, E-mail: alberto.ronzani@nano.cnr.it; Altimiras, Carles; Giazotto, Francesco

We report on the fabrication and characterization of a two-terminal mesoscopic interferometer based on three V/Cu/V Josephson junctions having nanoscale cross-section. The junctions have been arranged in a double-ring geometry realized by metallic thin film deposition through a suspended mask defined by electron beam lithography. Although a significant amount of asymmetry between the critical current of each junction is observed, we show that the interferometer is able to suppress the supercurrent to a level lower than 6 parts per thousand, being here limited by measurement resolution. The present nano-device is suitable for low-temperature magnetometric and gradiometric measurements over the micrometricmore » scale.« less

Trend of heat flow in france: relation with deep structures

NASA Astrophysics Data System (ADS)

Vasseur, Guy; Nouri, Yamina; Groupe Fluxchaf

1980-06-01

The trend of heat flow over France is discussed using both direct measurements at equilibrium in boreholes and file data. The two types of data are found to be in agreement. They exhibit high heat flow values over the Massif Central and the Vosges. An E-W cross section across the Massif Central allows us to observe the relationship between the high heat flow values, the thinning of the crust and the uprising of the asthenosphere deduced from seismic and gravity measurements. High heat flow values could be explained using a cinematic model where upward convection occurs in the upper mantle for a period of 40 m.y. with a vertical velocity reaching 5 mm/y.

Solid-phase data from cores at the proposed Dewey Burdock uranium in-situ recovery mine, near Edgemont, South Dakota

USGS Publications Warehouse

Johnson, Raymond H.; Diehl, Sharon F.; Benzel, William M.

2013-01-01

This report releases solid-phase data from cores at the proposed Dewey Burdock uranium in-situ recovery site near Edgemont, South Dakota. These cores were collected by Powertech Uranium Corporation, and material not used for their analyses were given to the U.S. Geological Survey for additional sampling and analyses. These additional analyses included total carbon and sulfur, whole rock acid digestion for major and trace elements, 234U/238U activity ratios, X-ray diffraction, thin sections, scanning electron microscopy analyses, and cathodoluminescence. This report provides the methods and data results from these analyses along with a short summary of observations.

Complete Status Report Documenting Development of Friction Stir Welding for Joining Thin Wall Tubing of ODS Alloys

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

Hoelzer, David T.; Bunn, Jeffrey R.; Gussev, Maxim N.

The development of friction stir welding (FSW) for joining thin sections of the advanced oxide dispersion strengthened (ODS) 14YWT ferritic alloy was initiated in Fuel Cycle Research and Development (FCRD), now the Nuclear Technology Research and Development (NTRD), in 2015. The first FSW experiment was conducted in late FY15 and successfully produced a bead-on-plate stir zone (SZ) on a 1 mm thick plate of 14YWT (SM13 heat). The goal of this research task is to ultimately demonstrate that FSW is a feasible method for joining thin wall (0.5 mm thick) tubing of 14YWT.

Behavior of thin-walled beams made of advanced composite materials and incorporating non-classical effects

NASA Astrophysics Data System (ADS)

Librescu, Liviu; Song, Ohseop

1991-11-01

Several results concerning the refined theory of thin-walled beams of arbitrary closed cross-section incorporating nonclassical effects are presented. These effects are related both with the exotic properties characterizing the advanced composite material structures and the nonuniform torsional model. A special case of the general equations is used to study several problems of cantilevered thin-walled beams and to assess the influence of the incorporated effects. The results presented in this paper could be useful toward a more rational design of aeronautical or aerospace constructions, as well as of helicopter or tilt rotor blades constructed of advanced composite materials.

Membrane interactions between secretion granules and plasmalemma in three exocrine glands

PubMed Central

Tanaka, Y; De Camilli, P; Meldolesi, J

1980-01-01

Three types of membrane interactions were studied in three exocrine systems (the acinar cells of the rat parotid, rat lacrimal gland, and guinea pig pancrease) by freeze- fracture and thin-section electron microscopy: exocytosis, induced in vivo by specific pharmacological stimulations; the mutual apposition of secretory granule membranes in the intact cell; membrane appositions induced in vitro by centrifugation of the isolated granules. In all three glandular cells, the distribution of intramembrane particles (IMP) on the fracture faces of the luminal plasmagranule membrane particles (IMP) on the fracture faces of the lumenal plasmalemma appeared random before stimulation. However, after injection of secretagogues, IMP were rapidly clearly from the areas of granule- plasmalemma apposition in the parotid cells and, especially, in lacrimocytes. In the latter, the cleared areas appeared as large bulges toward the lumen, whereas in the parotid they were less pronounced. Exocytotic openings were usually large and the fracture faces of their rims were covered with IMP. In contrast, in stimulated pancreatic acinar cells, the IMP distribution remained apparently random after stimulation. Exocytoses were established through the formation of narrown necks, and no images which might correspond to early stages of membrane fusion were revealed. Within the cytoplasm of parotid and lacrimal cells (but not in the pancreas), both at rest and after stimulation, secretion granules were often closely apposed by means of flat, circular areas, also devoid of IMP. In thin sections, the images corresponding to IMP-free areas were close granule-granule and granule-plasmalemma appositions, sometimes with focal merging of the membrane outer layers to yield pentalaminar structures. Isolated secretion granules were forced together in vitro by centrifugation. Under these conditions, increasing the centrifugal force from 1,600 to 50,000 g for 10 min resulted in a progressive, statistically significant increase of the frequency of IMP-free flat appositions between parotid granules. In contrast, no such areas were seen between freeze-fractured pancreatic granules, although some focal pentalaminar appositions appeared in section after centrifugation at 50 and 100,000 g for 10 min. On the basis of the observation that, in secretory cells, IMP clearing always develops in deformed membrane areas (bulges, depressions, flat areas), it is suggested that it might result from the forced mechanical apposition of the interacting membranes. This might be a preliminary process not sufficient to initiate fusion. In the pancreas, IMP clearing could occur over surface areas too small to be detected. In stimulated parotid and lacrimal glands they were exceptional. These structures were either attached at the sites of continuity between granule and plasma membranes, or free in the acinar lumen, with a preferential location within exocytotic pockets or in their proximity. Experiments designed to investigate the nature of these blisters and vesicles revealed that they probably arise artifactually during glutaraldehyde fixation. In fact, (a) they were large and numerous in poorly fixed samples but were never observed in thin sections of specimens fixed in one step with glutaraldehyde and OsO(4); and (b) no increase in concentration of phospholipids was observed in the parotid saliva and pancreatic juice after stimulation of protein discharge, as was to be expected if release of membrane material were occurring after exocytosis. PMID:7380885

Enhanced ultraviolet photo-response in Dy doped ZnO thin film

NASA Astrophysics Data System (ADS)

Kumar, Pawan; Singh, Ranveer; Pandey, Praveen C.

2018-02-01

In the present work, a Dy doped ZnO thin film deposited by the spin coating method has been studied for its potential application in a ZnO based UV detector. The investigations on the structural property and surface morphology of the thin film ensure that the prepared samples are crystalline and exhibit a hexagonal crystal structure of ZnO. A small change in crystallite size has been observed due to Dy doping in ZnO. AFM analysis ascertains the grain growth and smooth surface of the thin films. The Dy doped ZnO thin film exhibits a significant enhancement in UV region absorption as compared to the pure ZnO thin film, which suggests that Dy doped ZnO can be used as a UV detector. Under UV irradiation of wavelength 325 nm, the photocurrent value of Dy doped ZnO is 105.54 μA at 4.5 V, which is 31 times greater than that of the un-doped ZnO thin film (3.39 μA). The calculated value of responsivity is found to increase significantly due to the incorporation of Dy in the ZnO lattice. The observed higher value of photocurrent and responsivity could be attributed to the substitution of Dy in the ZnO lattice, which enhances the conductivity, electron mobility, and defects in ZnO and benefits the UV sensing property.

Associations between thin slice ratings of affect and rapport and perceived patient-centeredness in primary care: Comparison of audio and video recordings.

PubMed

Henry, Stephen G; Penner, Louis A; Eggly, Susan

2017-06-01

To investigate associations between ratings of "thin slices" from recorded clinic visits and perceived patient-centeredness; to compare ratings from video recordings (sound and images) versus audio recordings (sound only). We analyzed 133 video-recorded primary care visits and patient perceptions of patient-centeredness. Observers rated thirty-second thin slices on variables assessing patient affect, physician affect, and patient-physician rapport. Video and audio ratings were collected independently. In multivariable analyses, ratings of physician positive affect (but not patient positive affect) were significantly positively associated with perceived patient-centeredness using both video and audio thin slices. Patient-physician rapport was significantly positively associated with perceived patient-centeredness using audio, but not video thin slices. Ratings from video and audio thin slices were highly correlated and had similar underlying factor structures. Physician (but not patient) positive affect is significantly associated with perceptions of patient-centeredness and can be measured reliably using either video or audio thin slices. Additional studies are needed to determine whether ratings of patient-physician rapport are associated with perceived patient-centeredness. Observer ratings of physician positive affect have a meaningful positive association with patients' perceptions of patient-centeredness. Patients appear to be highly attuned to physician positive affect during patient-physician interactions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Weight misperception and psychosocial health in normal weight Chinese adolescents.

PubMed

Lo, Wing-Sze; Ho, Sai-Yin; Mak, Kwok-Kei; Lai, Hak-Kan; Lai, Yuen-Kwan; Lam, Tai-Hing

2011-06-01

To investigate the association between weight misperception and psychosocial health problems among normal weight Chinese adolescent boys and girls. In the Youth Smoking Survey 2003-04, 20 677 normal weight students aged 11-18 years from 85 randomly selected schools throughout Hong Kong were analysed. Students who perceived themselves as very thin, thin, fat or very fat were classified as having weight misperception in contrast to the reference group who correctly perceived themselves as normal weight. Psychosocial health outcomes included headache, feeling stressful, feeling depressed, poorer appetite, sleepless at night, having nightmares and less confidence in getting along with friends. Logistic regression yielded adjusted odds ratios (ORs) for each outcome by weight misperception in boys and girls separately. In girls, misperceived fatness was associated with all outcomes, while misperceived thinness was associated with poorer appetite and less confidence. Boys who misperceived themselves as very thin or fat had greater odds of all outcomes except having nightmares. In general, greater ORs were observed for misperceived fatness than thinness in girls, but similar ORs were observed in boys. Misperceived thinness and fatness accounted for 0.6% to 45.1% of the psychosocial health problems in adolescents. Normal weight adolescents with weight misperception were more likely to have psychosocial health problems, and the associations were stronger for extreme misperceptions (i.e., very fat or very thin) in both boys and girls.

Effect of Thin Cirrus Clouds on Dust Optical Depth Retrievals From MODIS Observations

NASA Technical Reports Server (NTRS)

Feng, Qian; Hsu, N. Christina; Yang, Ping; Tsay, Si-Chee

2011-01-01

The effect of thin cirrus clouds in retrieving the dust optical depth from MODIS observations is investigated by using a simplified aerosol retrieval algorithm based on the principles of the Deep Blue aerosol property retrieval method. Specifically, the errors of the retrieved dust optical depth due to thin cirrus contamination are quantified through the comparison of two retrievals by assuming dust-only atmospheres and the counterparts with overlapping mineral dust and thin cirrus clouds. To account for the effect of the polarization state of radiation field on radiance simulation, a vector radiative transfer model is used to generate the lookup tables. In the forward radiative transfer simulations involved in generating the lookup tables, the Rayleigh scattering by atmospheric gaseous molecules and the reflection of the surface assumed to be Lambertian are fully taken into account. Additionally, the spheroid model is utilized to account for the nonsphericity of dust particles In computing their optical properties. For simplicity, the single-scattering albedo, scattering phase matrix, and optical depth are specified a priori for thin cirrus clouds assumed to consist of droxtal ice crystals. The present results indicate that the errors in the retrieved dust optical depths due to the contamination of thin cirrus clouds depend on the scattering angle, underlying surface reflectance, and dust optical depth. Under heavy dusty conditions, the absolute errors are comparable to the predescribed optical depths of thin cirrus clouds.

The thin section rock physics: Modeling and measurement of seismic wave velocity on the slice of carbonates

NASA Astrophysics Data System (ADS)

Wardaya, P. D.; Noh, K. A. B. M.; Yusoff, W. I. B. W.; Ridha, S.; Nurhandoko, B. E. B.

2014-09-01

This paper discusses a new approach for investigating the seismic wave velocity of rock, specifically carbonates, as affected by their pore structures. While the conventional routine of seismic velocity measurement highly depends on the extensive laboratory experiment, the proposed approach utilizes the digital rock physics view which lies on the numerical experiment. Thus, instead of using core sample, we use the thin section image of carbonate rock to measure the effective seismic wave velocity when travelling on it. In the numerical experiment, thin section images act as the medium on which wave propagation will be simulated. For the modeling, an advanced technique based on artificial neural network was employed for building the velocity and density profile, replacing image's RGB pixel value with the seismic velocity and density of each rock constituent. Then, ultrasonic wave was simulated to propagate in the thin section image by using finite difference time domain method, based on assumption of an acoustic-isotropic medium. Effective velocities were drawn from the recorded signal and being compared to the velocity modeling from Wyllie time average model and Kuster-Toksoz rock physics model. To perform the modeling, image analysis routines were undertaken for quantifying the pore aspect ratio that is assumed to represent the rocks pore structure. In addition, porosity and mineral fraction required for velocity modeling were also quantified by using integrated neural network and image analysis technique. It was found that the Kuster-Toksoz gives the closer prediction to the measured velocity as compared to the Wyllie time average model. We also conclude that Wyllie time average that does not incorporate the pore structure parameter deviates significantly for samples having more than 40% porosity. Utilizing this approach we found a good agreement between numerical experiment and theoretically derived rock physics model for estimating the effective seismic wave velocity of rock.

Coronal Loops: Observations and Modeling of Confined Plasma.

PubMed

Reale, Fabio

Coronal loops are the building blocks of the X-ray bright solar corona. They owe their brightness to the dense confined plasma, and this review focuses on loops mostly as structures confining plasma. After a brief historical overview, the review is divided into two separate but not independent parts: the first illustrates the observational framework, the second reviews the theoretical knowledge. Quiescent loops and their confined plasma are considered and, therefore, topics such as loop oscillations and flaring loops (except for non-solar ones, which provide information on stellar loops) are not specifically addressed here. The observational section discusses the classification, populations, and the morphology of coronal loops, its relationship with the magnetic field, and the loop stranded structure. The section continues with the thermal properties and diagnostics of the loop plasma, according to the classification into hot, warm, and cool loops. Then, temporal analyses of loops and the observations of plasma dynamics, hot and cool flows, and waves are illustrated. In the modeling section, some basics of loop physics are provided, supplying fundamental scaling laws and timescales, a useful tool for consultation. The concept of loop modeling is introduced and models are divided into those treating loops as monolithic and static, and those resolving loops into thin and dynamic strands. More specific discussions address modeling the loop fine structure and the plasma flowing along the loops. Special attention is devoted to the question of loop heating, with separate discussion of wave (AC) and impulsive (DC) heating. Large-scale models including atmosphere boxes and the magnetic field are also discussed. Finally, a brief discussion about stellar coronal loops is followed by highlights and open questions.

Growth front nucleation of rubrene thin films for high mobility organic transistors

NASA Astrophysics Data System (ADS)

Hsu, C. H.; Deng, J.; Staddon, C. R.; Beton, P. H.

2007-11-01

We demonstrate a mode of thin film growth in which amorphous islands crystallize into highly oriented platelets. A cascade of crystallization is observed, in which platelets growing outward from a central nucleation point impinge on neighboring amorphous islands and provide a seed for further nucleation. Through control of growth parameters, it is possible to produce high quality thin films which are well suited to the formation of organic transistors. We demonstrate this through the fabrication of rubrene thin film transistors with high carrier mobility.

Advanced germanium layer transfer for ultra thin body on insulator structure

NASA Astrophysics Data System (ADS)

Maeda, Tatsuro; Chang, Wen-Hsin; Irisawa, Toshifumi; Ishii, Hiroyuki; Hattori, Hiroyuki; Poborchii, Vladimir; Kurashima, Yuuichi; Takagi, Hideki; Uchida, Noriyuki

2016-12-01

We present the HEtero-Layer Lift-Off (HELLO) technique to obtain ultra thin body (UTB) Ge on insulator (GeOI) substrates. The transferred ultra thin Ge layers are characterized by the Raman spectroscopy measurements down to the thickness of ˜1 nm, observing a strong Raman intensity enhancement for high quality GeOI structure in ultra thin regime due to quantum size effect. This advanced Ge layer transfer technique enabled us to demonstrate UTB-GeOI nMOSFETs with the body thickness of only 4 nm.

Three-Dimensional Morphology of a Coronal Prominence Cavity

NASA Technical Reports Server (NTRS)

Gibson, S. E.; Kucera, T. A.; Rastawicki, D.; Dove, J.; deToma, G.; Hao, J.; Hill, S.; Hudson, H. S.; Marque, C.; McIntosh, P. S.;

1,3-Diphenylisobenzofuran: a Model Chromophore for Singlet Fission

DOE PAGES

Johnson, Justin C.; Michl, Josef

2017-09-11

In this review we first provide an introductory description of the singlet fission phenomenon and then describe the ground and electronically excited states of the parent 1,3-diphenylisobenzofuran chromophore (1) and about a dozen of its derivatives. A discussion of singlet fission in thin polycrystalline layers of these materials follows. The highest quantum yield of triplet formation by singlet fission, 200% at 80 K, is found in one of the two known crystal modification of the parent. In the other modification and in many derivatives, excimer formation competes successfully and triplet yields are low. A description of solution photophysics of covalentmore » dimers is described in the next section. Triplet yields are very low, but interesting phenomena are uncovered. One is an observation of a separated-charges (charge-transfer) intermediate in highly polar solvents. The other is an observation of excitation isomerism in both singlet and triplet states, where in one isomer the excitation is delocalized over both halves of the covalent dimer, whereas in the other it is localized on one of the halves. Finally, in the last section we present the operation of a simple device illustrating the use of triplets generated by singlet fission for charge separation.« less

Leveraging Clinical Imaging Archives for Radiomics: Reliability of Automated Methods for Brain Volume Measurement.

PubMed

Adduru, Viraj R; Michael, Andrew M; Helguera, Maria; Baum, Stefi A; Moore, Gregory J

2017-09-01

Purpose To validate the use of thick-section clinically acquired magnetic resonance (MR) imaging data for estimating total brain volume (TBV), gray matter (GM) volume (GMV), and white matter (WM) volume (WMV) by using three widely used automated toolboxes: SPM ( www.fil.ion.ucl.ac.uk/spm/ ), FreeSurfer ( surfer.nmr.mgh.harvard.edu ), and FSL (FMRIB software library; Oxford Centre for Functional MR Imaging of the Brain, Oxford, England, https://fsl.fmrib.ox.ac.uk/fsl ). Materials and Methods MR images from a clinical archive were used and data were deidentified. The three methods were applied to estimate brain volumes from thin-section research-quality brain MR images and routine thick-section clinical MR images acquired from the same 38 patients (age range, 1-71 years; mean age, 22 years; 11 women). By using these automated methods, TBV, GMV, and WMV were estimated. Thin- versus thick-section volume comparisons were made for each method by using intraclass correlation coefficients (ICCs). Results SPM exhibited excellent ICCs (0.97, 0.85, and 0.83 for TBV, GMV, and WMV, respectively). FSL exhibited ICCs of 0.69, 0.51, and 0.60 for TBV, GMV, and WMV, respectively, but they were lower than with SPM. FreeSurfer exhibited excellent ICC of 0.63 only for TBV. Application of SPM's voxel-based morphometry on the modulated images of thin-section images and interpolated thick-section images showed fair to excellent ICCs (0.37-0.98) for the majority of brain regions (88.47% [306924 of 346916 voxels] of WM and 80.35% [377 282 of 469 502 voxels] of GM). Conclusion Thick-section clinical-quality MR images can be reliably used for computing quantitative brain metrics such as TBV, GMV, and WMV by using SPM. © RSNA, 2017 Online supplemental material is available for this article.

Outlet Glacier and Margin Elevation Changes: Near - Coastal Thinning of The Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Abdalati, W.; Krabill, W.; Frederick, E.; Manizade, S.; Martin, C.; Sonntag, J.; Swift, R.; Thomas, R.; Wright, W.; Yungel, J.;

Chlorine gas sensing performance of palladium doped nickel ferrite thin films

NASA Astrophysics Data System (ADS)

Rao, Pratibha; Godbole, R. V.; Bhagwat, Sunita

2016-05-01

NiFe2O4 and Pd:NiFe2O4 (Pd=1 w/o, 3 w/o and 5 w/o) thin films, p-type semiconducting oxides with an inverse spinel structure have been used as a gas sensor to detect chlorine. These films were prepared by spray pyrolysis technique and XRD was used to confirm the structure. The surface morphology was studied using SEM. Magnetization measurements were carried out at room temperature using SQUID VSM, which shows ferrimagnetic behavior of the samples. The reduction in optimum operating temperature and enhancement in response was observed on Pd-incorporation in nickel ferrite thin films. Faster response and recovery characteristic is observed Pd-incorporated nickel ferrite thin films. The long-term stability is evaluated over a period of six months. This feature may be regarded as a significant facet towards their practical application as gas sensors.

Interfacial Control of Dzyaloshinskii-Moriya Interaction in Heavy Metal/Ferromagnetic Metal Thin Film Heterostructures

NASA Astrophysics Data System (ADS)

Ma, Xin; Yu, Guoqiang; Li, Xiang; Wang, Tao; Wu, Di; Olsson, Kevin; Chu, Zhaodong; An, Kyongmo; Xiao, John; Wang, Kang; Li, Xiaoqin

The interfacial Dzyaloshinskii-Moriya Interaction (DMI) in ultrathin magnetic thin film heterostructures provides a new approach for controlling spin textures on mesoscopic length scales. Here we investigate the dependence of the interfacial DMI constant D on a Pt wedge insertion layer in Ta/CoFeB/Pt(wedge)/MgO thin films by observing the asymmetric spin wave dispersion using Brillouin light scattering. Continuous tuning of D by more than a factor of three is realized by inserting less than one monolayer of Pt. The observations provide new insights for designing magnetic thin film heterostructures with tailored D for controlling skyrmions and magnetic domain wall chirality and dynamics. The work at UT-Austin and UCLA are supported by SHINES, an Energy Frontier Research Center funded by the U.S. DoE, Office of Science, Basic Energy Science (BES) under award # DE-SC0012670.

Effects of ion irradiation on the surface mechanical behavior of hybrid sol-gel derived silicate thin films

NASA Astrophysics Data System (ADS)

Ghisleni, Rudy

A study on the effects of ion irradiation on the surface mechanical behavior of hybrid sol-gel derived thin films has been performed. Hybrid organic/inorganic modified silicate thin films were synthesized by sol-gel processing from tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) precursors and spin-coated onto (100) Si substrates. The synthesized films were investigated by nanoindentation, photoluminescence spectroscopy, and Raman spectroscopy. Hybrid TEOS/MTES sol-gel films modified by ion irradiation with deposited electronic energies of 1.87 x 1025 eV/cm3 or higher showed higher values of reduced elastic modulus and hardness than 800°C heat treated films. Thus, ion irradiation was found to be an effective means in converting the polymer sol into ceramic type coatings. The ions used in this study were Cu2+, N2+, Si+, O+, N+, He+, and H+, with incident energies ranging from 100 keV to 2 MeV, and fluences ranging from 1 x 1014 to 1 x 1017 ions/cm2. Both the reduced elastic modulus and hardness were seen to increase monotonically with the increase in ion fluence, with an observed maximum hardness of 7.7 GPa (an unirradiated film hardness was 0.4 GPa) and a maximum reduced elastic modulus of 84.0 GPa (an unirradiated film reduced elastic modulus was 7.1 GPa) for 250 keV N2+ irradiation with a 5 x 1016 ions/cm2 fluence. The electronic stopping power was found to be principally responsible for the film hardening, while the role of nuclear stopping power was minimal. A monotonic increase in hardness with increase in electronic energy deposited to the film surface was found. A model describing the hardening of ion irradiated films was developed. This model characterizes the hardening effectiveness of the ion species considered by two parameters: the constant hardening cross-section and the hardening coefficient. Where the hardening cross-section represents the cross-sectional area hardened by the interaction of an incident ion with the target, and the hardening coefficient represents an index of the cross-sectional area gradient as a function of fluence. The increase in hardness of hybrid sol-gel films following ion irradiation was linked to structural changes. Ion irradiation results in a cross-linked silica film as well as the segregation of amorphous carbon clusters, both of which contributed to increase the mechanical properties of the films.

A modal radar cross section of thin-wire targets via the singularity expansion method

NASA Technical Reports Server (NTRS)

Richards, M. A.; Shumpert, T. H.; Riggs, L. S.

1992-01-01

A modal radar cross section (RCS) of arbitrary wire scatterers is constructed in terms of SEM parameters. Numerical results are presented for both straight and L-shaped wire targets and are compared to computations performed in the frequency domain using the method of moments.

Investigations of electromagnetic scattering by columnar ice crystals

NASA Technical Reports Server (NTRS)

Weil, H.; Senior, T. B. A.

1976-01-01

An integral equation approach was developed to determine the scattering and absorption of electromagnetic radiation by thin walled cylinders of arbitrary cross-section and refractive index. Based on this method, extensive numerical data was presented at infrared wavelengths for hollow hexagonal cross section cylinders which simulate columnar sheath ice crystals.

Trace element distribution in the rat cerebellum

NASA Astrophysics Data System (ADS)

Kwiatek, W. M.; Long, G. J.; Pounds, J. G.; Reuhl, K. R.; Hanson, A. L.; Jones, K. W.

1990-04-01

Spatial distributions and concentrations of trace elements (TE) in the brain are important because TE perform catalytic and structural functions in enzymes which regulate brain function and development. We have investigated the distributions of TE in rat cerebellum. Structures were sectioned and analyzed by the Synchrotron Radiation Induced X-ray Emission (SRIXE) method using the NSLS X-26 white-light microprobe facility. Advantages important for TE analysis of biological specimens with X-ray microscopy include short time of measurement, high brightness and flux, good spatial resolution, multielemental detection, good sensitivity, and nondestructive irradiation. Trace elements were measured in thin rat brain sections of 20 μm thickness. The analyses were performed on sample volumes as small as 0.2 nl with Minimum Detectable Limits (MDL) of 50 ppb wet weight for Fe, 100 ppb wet weight for Cu, and Zn, and 1 ppm wet weight for Pb. The distribution of TE in the molecular cell layer, granule cell layer and fiber tract of rat cerebella was investigated. Both point analyses and two-dimensional semiquantitative mapping of the TE distribution in a section were used. All analyzed elements were observed in each structure of the cerebellum except mercury which was not observed in granule cell layer or fiber tract. This approach permits an exacting correlation of the TE distribution in complex structure with the diet, toxic elements, and functional status of the animal.

Mid-ocean-ridge seismicity reveals extreme types of ocean lithosphere.

PubMed

Schlindwein, Vera; Schmid, Florian

2016-07-14

Along ultraslow-spreading ridges, where oceanic tectonic plates drift very slowly apart, conductive cooling is thought to limit mantle melting and melt production has been inferred to be highly discontinuous. Along such spreading centres, long ridge sections without any igneous crust alternate with magmatic sections that host massive volcanoes capable of strong earthquakes. Hence melt supply, lithospheric composition and tectonic structure seem to vary considerably along the axis of the slowest-spreading ridges. However, owing to the lack of seismic data, the lithospheric structure of ultraslow ridges is poorly constrained. Here we describe the structure and accretion modes of two end-member types of oceanic lithosphere using a detailed seismicity survey along 390 kilometres of ultraslow-spreading ridge axis. We observe that amagmatic sections lack shallow seismicity in the upper 15 kilometres of the lithosphere, but unusually contain earthquakes down to depths of 35 kilometres. This observation implies a cold, thick lithosphere, with an upper aseismic zone that probably reflects substantial serpentinization. We find that regions of magmatic lithosphere thin dramatically under volcanic centres, and infer that the resulting topography of the lithosphere-asthenosphere boundary could allow along-axis melt flow, explaining the uneven crustal production at ultraslow-spreading ridges. The seismicity data indicate that alteration in ocean lithosphere may reach far deeper than previously thought, with important implications towards seafloor deformation and fluid circulation.

Subcellular pigment distribution is altered under far-red light acclimation in cyanobacteria that contain chlorophyll f.

PubMed

Majumder, Erica L-W; Wolf, Benjamin M; Liu, Haijun; Berg, R Howard; Timlin, Jerilyn A; Chen, Min; Blankenship, Robert E

2017-11-01

Far-Red Light (FRL) acclimation is a process that has been observed in cyanobacteria and algae that can grow solely on light above 700 nm. The acclimation to FRL results in rearrangement and synthesis of new pigments and pigment-protein complexes. In this study, cyanobacteria containing chlorophyll f, Synechococcus sp. PCC 7335 and Halomicronema hongdechloris, were imaged as live cells with confocal microscopy. H. hongdechloris was further studied with hyperspectral confocal fluorescence microscopy (HCFM) and freeze-substituted thin-section transmission electron microscopy (TEM). Under FRL, phycocyanin-containing complexes and chlorophyll-containing complexes were determined to be physically separated and the synthesis of red-form phycobilisome and Chl f was increased. The timing of these responses was observed. The heterogeneity and eco-physiological response of the cells was noted. Additionally, a gliding motility for H. hongdechloris is reported.

Accurate simulation of backscattering spectra in the presence of sharp resonances

NASA Astrophysics Data System (ADS)

Barradas, N. P.; Alves, E.; Jeynes, C.; Tosaki, M.

2006-06-01

In elastic backscattering spectrometry, the shape of the observed spectrum due to resonances in the nuclear scattering cross-section is influenced by many factors. If the energy spread of the beam before interaction is larger than the resonance width, then a simple convolution with the energy spread on exit and with the detection system resolution will lead to a calculated spectrum with a resonance much sharper than the observed signal. Also, the yield from a thin layer will not be calculated accurately. We have developed an algorithm for the accurate simulation of backscattering spectra in the presence of sharp resonances. Albeit approximate, the algorithm leads to dramatic improvements in the quality and accuracy of the simulations. It is simple to implement and leads to only small increases of the calculation time, being thus suitable for routine data analysis. We show different experimental examples, including samples with roughness and porosity.

Non-blackbody Disks Can Help Explain Inferred AGN Accretion Disk Sizes

NASA Astrophysics Data System (ADS)

Hall, Patrick B.; Sarrouh, Ghassan T.; Horne, Keith

2018-02-01

If the atmospheric density {ρ }atm} in the accretion disk of an active galactic nucleus (AGN) is sufficiently low, scattering in the atmosphere can produce a non-blackbody emergent spectrum. For a given bolometric luminosity, at ultraviolet and optical wavelengths such disks have lower fluxes and apparently larger sizes as compared to disks that emit as blackbodies. We show that models in which {ρ }atm} is a sufficiently low fixed fraction of the interior density ρ can match the AGN STORM observations of NGC 5548 but produce disk spectral energy distributions that peak at shorter wavelengths than observed in luminous AGN in general. Thus, scattering atmospheres can contribute to the explanation for large inferred AGN accretion disk sizes but are unlikely to be the only contributor. In the appendix section, we present unified equations for the interior ρ and T in gas pressure-dominated regions of a thin accretion disk.

Preservation of rodent bones from El Harhoura 2 cave (Morocco, Neolithic - Middle Palaeolithic): Microstructure, mineralogy, crystallinity and composition

NASA Astrophysics Data System (ADS)

Farre, Bastien; Massard, Pierre; Nouet, Julius; Dauphin, Yannicke

2014-04-01

Thin sections, scanning electron microscopy (SEM), diffraction X (DRX) and infrared spectrometry (FTIR) have been used to study the structure, mineralogy, crystallinity and bulk composition of fossil rodent long bones extracted from a succession of sedimentary layers in a cave from Morocco (Neolithic - Middle Palaeolithic, El Harhoura 2). The microstructure of fossil bones is well-preserved at this scale of observation, and encrusted deposits are rare. All bones are preserved in apatite, but the crystallinity is modified, as well as the crystallite shape, the organic content and the organic-mineral ratio. No fluor enrichment has been observed. Alone or together, the studied parameters do not show a regular trend from the upper to the lower layers of the cave. The preservation of the fossil bones does not confirm the sequence of arid and humid periods inferred from taphonomic analyses.

[Permanent tattoos following injections with Dermo-Jet: anatomoclinical study. Apropos of 5 cases].

PubMed

Lachapelle, J M; Tennstedt, D; Burtonboy, G

1982-01-01

Blue or black tattoos were observed in five patients who had received several intradermal injections (of a lidocaine solution or of a triamcinolone acetonide suspension) with the Dermo-Jet. A histological examination revealed the presence of black masses, rounded or elongated, different in size, distributed throughout dermal tissue. Additionally, conglomerates of black grains in the cytoplasm of histiocytes and of pericytes are precisely observed in semi-thin sections. It has been proved by several investigations that these foreign particles are not of metallic nature. It can be concluded from electron microscopic studies that the particles are fragments of black rubber, from the upper joint of the reservoir. Indeed, some rubber fragments are leached into the reservoir. Some of these are passing through the wire-mesh filter of the nozzle (with the solution or the suspension) when injections are made. Therefore, they are injected intradermally and are permanently tattooing the skin.

Measuring the resolution of uncompressed plastic sections cut using an oscillating knife ultramicrotome.

PubMed

Sader, Kasim; Reedy, Michael; Popp, David; Lucaveche, Carmen; Trinick, John

2007-07-01

Thin sections of biological tissue embedded in plastic and cut with an ultramicrotome do not generally display useful details smaller than approximately 50 A in the electron microscope. However, there is evidence that before sectioning the embedded tissue can be substantially better preserved, which suggests that cutting is when major damage and loss of resolution occurs. We show here a striking example of such damage in embedded insect flight muscle fibres. X-ray diffraction of the embedded muscle gave patterns extending to 13A, whereas sections cut from the same block showed only approximately 50 A resolution. A possible source of this damage is the substantial compression that was imposed on sections during cutting. An oscillating knife ultramicrotome eliminates the compression and it seemed possible that sections cut with such a knife would show substantially improved preservation. We used the oscillating knife to cut sections from the embedded muscle and from embedded catalase crystals. Preservation with and without oscillation was assessed in Fourier transforms of micrographs. Sections cut with the knife oscillating did not show improved preservation over those cut without. Thus compression during cutting does not appear to be the major source of damage in plastic sections, and leaves unexplained the 50 A versus 13A discrepancy between block and section preservation. The results nevertheless suggest that improvements in ultramicrotomy will be important for bringing thin-sectioning and tomography of plastic-embedded cells and tissues to the point where macromolecule shapes can be resolved.

Photo-oxidation-modulated refractive index in Bi2Te3 thin films

NASA Astrophysics Data System (ADS)

Yue, Zengji; Chen, Qinjun; Sahu, Amit; Wang, Xiaolin; Gu, Min

2017-12-01

We report on an 800 nm femtosecond laser beam induced giant refractive index modulation and enhancement of near-infrared transparency in topological insulator material Bi2Te3 thin films. An ultrahigh refractive index of up to 5.9 was observed in the Bi2Te3 thin film in near-infrared frequency. The refractive index dramatically decreases by a factor of ~3 by an exposure to the 800 nm femtosecond laser beam. Simultaneously, the transmittance of the Bi2Te3 thin films markedly increases to ~96% in the near-infrared frequency. The Raman spectra provides strong evidences that the observed both refractive index modulation and transparency enhancement result from laser beam induced photooxidation effects in the Bi2Te3 thin films. The Bi2Te3 compound transfers into Bi2O3 and TeO2 under the laser beam illumination. These experimental results pave the way towards the design of various optical devices, such as near-infrared flat lenses, waveguide and holograms, based on topological insulator materials.

Eco-Friendly and Biodegradable Biopolymer Chitosan/Y₂O₃ Composite Materials in Flexible Organic Thin-Film Transistors.

PubMed

Du, Bo-Wei; Hu, Shao-Ying; Singh, Ranjodh; Tsai, Tsung-Tso; Lin, Ching-Chang; Ko, Fu-Hsiang

2017-09-03

The waste from semiconductor manufacturing processes causes serious pollution to the environment. In this work, a non-toxic material was developed under room temperature conditions for the fabrication of green electronics. Flexible organic thin-film transistors (OTFTs) on plastic substrates are increasingly in demand due to their high visible transmission and small size for use as displays and wearable devices. This work investigates and analyzes the structured formation of aqueous solutions of the non-toxic and biodegradable biopolymer, chitosan, blended with high-k-value, non-toxic, and biocompatible Y₂O₃ nanoparticles. Chitosan thin films blended with Y₂O₃ nanoparticles were adopted as the gate dielectric thin film in OTFTs, and an improvement in the dielectric properties and pinholes was observed. Meanwhile, the on/off current ratio was increased by 100 times, and a low leakage current was observed. In general, the blended chitosan/Y₂O₃ thin films used as the gate dielectric of OTFTs are non-toxic, environmentally friendly, and operate at low voltages. These OTFTs can be used on surfaces with different curvature radii because of their flexibility.

Competitiveness as a moderator of the relation between appearance-related factors and disordered eating behaviors.

PubMed

Schleien, Jenna L; Bardone-Cone, Anna M

2016-06-01

The present study examined competitiveness as a moderator of the relationships between appearance-related factors (i.e., thin-ideal internalization, appearance contingent self-worth) and disordered eating behaviors (i.e., dieting, excessive exercise). Participants were 441 undergraduate females for cross-sectional analyses, with 237 also contributing data longitudinally, 1 year later. Results showed that, in a model including thin-ideal internalization and appearance contingent self-worth and their interactions with competitiveness, thin-ideal internalization (but not appearance contingent self-worth) interacted with competitiveness to identify concurrent levels of both dieting and excessive exercise. Individuals high in both thin-ideal internalization and competitiveness exhibited the highest levels of concurrent dieting and excessive exercise. After controlling for baseline levels of the dependent variables, neither appearance-related factor interacted with competitiveness to predict dieting or excessive exercise. These findings suggest that individuals who are both competitive and accept and strive to achieve the thin ideal may be at risk for disordered eating behaviors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Coupled, Simultaneous Displacement and Dealloying Reactions into Fe-Ni-Co Nanowires for Thinning Nanowire Segments.

PubMed

Geng, Xiaohua; Podlaha, Elizabeth J

2016-12-14

A new methodology is reported to shape template-assisted electrodeposition of Fe-rich, Fe-Ni-Co nanowires to have a thin nanowire segment using a coupled displacement reaction with a more noble elemental ion, Cu(II), and at the same time dealloying predominantly Fe from Fe-Ni-Co by the reduction of protons (H + ), followed by a subsequent etching step. The displacement/dealloyed layer was sandwiched between two trilayers of Fe-Ni-Co to facilitate the characterization of the reaction front, or penetration length. The penetration length region was found to be a function of the ratio of proton and Cu(II) concentration, and a ratio of 0.5 was found to provide the largest penetration rate, and hence the larger thinned length of the nanowire. Altering the etching time affected the diameter of the thinned region. This methodology presents a new way to thin nanowire segments connected to larger nanowire sections and also introduces a way to study the propagation of a reaction front into a nanowire.

Free vibrations of thin-walled semicircular graphite-epoxy composite frames

NASA Technical Reports Server (NTRS)

Carden, Huey D.; Noor, Ahmed K.; Peters, Jeanne M.

1990-01-01

A detailed study is made of the effects of variations in lamination and material parameters of thin walled composite frames on their vibrational characteristics. The structures considered are semicircular thin walled frames with I and J sections. The flanges and webs of the frames are modeled by using 2-D shell and plate finite elements. A mixed formulation is used with the fundamental unknowns consisting of both the generalized displacements and stress resultants in the frame. The frequencies and modes predicted by the 2-D finite element model are compared with those obtained from experiments, as well as with the predictions of a non-dimensional thin walled beam finite element model. A detailed study is made of the sensitivity of the vibrational response to variations in the fiber orientation, material properties of the individual layers, and boundary conditions.

Free vibrations of thin-walled semicircular graphite-epoxy composite frames

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Carden, Huey D.; Peters, Jeanne M.

1990-01-01

A detailed study is made of the effects of variations in lamination and material parameters of thin walled composite frames on their vibrational characteristics. The structures considered are semicircular thin walled frames with I and J sections. The flanges and webs of the frames are modelled by using 2-D shell and plate finite elements. A mixed formulation is used with the fundamental unknowns consisting of both the generalized displacements and stress resultants in the frames. The frequencies and modes predicted by the 2-D finite element model are compared with those obtained from experiments, as well as with the predictions of a 1-D thin walled beam finite element model. A detailed study is made of the sensitivity of the vibrational response to variations in the fiber orientation, material properties of the individual layers, and boundary conditions.

Fem and Experimental Analysis of Thin-Walled Composite Elements Under Compression

NASA Astrophysics Data System (ADS)

Różyło, P.; Wysmulski, P.; Falkowicz, K.

2017-05-01

Thin-walled steel elements in the form of openwork columns with variable geometrical parameters of holes were studied. The samples of thin-walled composite columns were modelled numerically. They were subjected to axial compression to examine their behavior in the critical and post-critical state. The numerical models were articulately supported on the upper and lower edges of the cross-section of the profiles. The numerical analysis was conducted only with respect to the non-linear stability of the structure. The FEM analysis was performed until the material achieved its yield stress. This was done to force the loss of stability by the structures. The numerical analysis was performed using the ABAQUS® software. The numerical analysis was performed only for the elastic range to ensure the operating stability of the tested thin-walled structures.

Trends in adiposity in Brazilian 7-10-year-old schoolchildren: evidence for increasing overweight but not obesity between 2002 and 2007.

PubMed

Leal, Danielle Biazzi; de Assis, Maria Alice Altenburg; González-Chica, David Alejandro; da Costa, Filipe Ferreira

2014-01-01

The negative health consequences of childhood overweight/obesity (OW/OB) are well known. Therefore, an accurate monitoring of the OW/OB prevalence is essential. Anthropometry is the most practical and cost-effective method for nutritional status evaluation. To describe trends in the nutritional status among 7-10-year-old children by investigating changes in the prevalence of stunting, thinness, overweight, obesity, risk and excess abdominal adiposity, and to study changes in height-for-age, body mass index (BMI) and waist circumference (WC). A school-based sample of 7-10-year-old children participated in two cross-sectional studies in 2002 (n = 2936) and 2007 (n = 1232) in Florianopolis, southern Brazil. Prevalence of stunting, risk and excess abdominal adiposity and changes in the distribution of height-for-age, BMI-for-age, WC-for-age z-scores were evaluated. Three BMI-based references were used to define the prevalence of thinness, overweight and obesity. Between 2002-2007, the prevalence of stunting, thinness, obesity and excess abdominal adiposity remained stable, whereas overweight (including obesity) increased 10-23% in boys and 18-21% in girls, depending on the BMI reference used. The risk of abdominal adiposity increased in boys, but not in girls. No significant change was observed in mean height, BMI, WC-for-age z-scores. This study identified a potential levelling off in the prevalence of obesity and excess abdominal adiposity, but a continuing increase in the prevalence of overweight.

Aspects of numerical and representational methods related to the finite-difference simulation of advective and dispersive transport of freshwater in a thin brackish aquifer

USGS Publications Warehouse

Merritt, M.L.

1993-01-01

The simulation of the transport of injected freshwater in a thin brackish aquifer, overlain and underlain by confining layers containing more saline water, is shown to be influenced by the choice of the finite-difference approximation method, the algorithm for representing vertical advective and dispersive fluxes, and the values assigned to parametric coefficients that specify the degree of vertical dispersion and molecular diffusion that occurs. Computed potable water recovery efficiencies will differ depending upon the choice of algorithm and approximation method, as will dispersion coefficients estimated based on the calibration of simulations to match measured data. A comparison of centered and backward finite-difference approximation methods shows that substantially different transition zones between injected and native waters are depicted by the different methods, and computed recovery efficiencies vary greatly. Standard and experimental algorithms and a variety of values for molecular diffusivity, transverse dispersivity, and vertical scaling factor were compared in simulations of freshwater storage in a thin brackish aquifer. Computed recovery efficiencies vary considerably, and appreciable differences are observed in the distribution of injected freshwater in the various cases tested. The results demonstrate both a qualitatively different description of transport using the experimental algorithms and the interrelated influences of molecular diffusion and transverse dispersion on simulated recovery efficiency. When simulating natural aquifer flow in cross-section, flushing of the aquifer occurred for all tested coefficient choices using both standard and experimental algorithms. ?? 1993.

Femtosecond laser cutting of multiple thin corneal stromal lamellae for endothelial bioengineering.

PubMed

Bernard, Aurélien; He, Zhiguo; Forest, Fabien; Gauthier, Anne-Sophie; Peocʼh, Michel; Dumollard, Jean-Marc; Acquart, Sophie; Montard, Romain; Delbosc, Bernard; Gain, Philippe; Thuret, Gilles

2015-02-01

To assess the feasibility of cutting multiple thin stromal lamellae in human donor corneas using a commercial femtosecond laser (FSL) to provide cell carriers for future endothelial graft bioengineering. Eight edematous organ-cultured corneas not suitable for grafting for endothelial reasons were mounted on a Ziemer anterior chamber and cut with a Z6 FSL with 6 successive parallel cuts, from depth to surface. Target thickness of each lamella ranged from 100 to 150 μm depending on initial corneal thickness. Thickness was measured using anterior segment optical coherence tomography before and after cutting on mounted corneas, and on each stromal lamella after detachment. Scanning electron microscopy observation was performed on 4 lamellae and histological cross sections on 1 cornea before detachment. A median of 5 (minimum 3, maximum 7) lamellae was obtained per cornea. All lamellae still attached were the most posterior ones, suggesting that FSL was less efficient because of light scattering by edematous stroma. Cut precision and postdetachment swelling were correlated with anterior-posterior position within the cornea. Median lamella thickness was 127 μm (56-222 μm) before detachment and 196 μm (80-304 μm) after detachment. Surface state was consistent with previously reported FSL lamellar cuts during Descemet stripping automated endothelial keratoplasty. Up to 7 thin lamellae can be cut in stored corneas with an FSL. This method, once optimized primarily by using deswelled, more transparent corneas, could prove effective for recycling unsuitable donor corneas in corneal bioengineering processes.

Effect of high energy ions on the electrical and morphological properties of Poly(3-Hexylthiophene) (P3HT) thin film

NASA Astrophysics Data System (ADS)

Sharma, Trupti; Singhal, R.; Vishnoi, R.; Sharma, G. D.; Biswas, S. K.

2018-05-01

The spin-coated thin films of Poly(3-Hexylthiophene) (P3HT) on the glass and Si (double side polished) substrates have been irradiated with 55 MeV Si+4 swift heavy ions (SHI) at fluences in the range from 1 × 1010 to 1 × 1012 ions/cm2. Structural modifications produced by energetic ions are observed by characterization of pristine and irradiated P3HT thin films. Different techniques like high-resolution X-ray diffraction (HR-XRD), micro-Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR) were used to analyze the structural changes in the material. A significant increase in crystallinity and room temperature electrical conductivity of P3HT film has been detected on exposure to the heavy ions. The observed increase in the electrical conductivity with increased fluences is explained in the light of improved ordering of polymer chains after irradiation. Mott's variable range hopping model has been used to explain the conduction mechanism in the material in the temperature range of 230-350 K. The modification in surface properties also observed using AFM analysis and contact angle measurement. It is observed that nature of the P3HT thin films remains hydrophobic after irradiation.

Optical, mechanical and structural properties of PMMA/SiO2 nanocomposite thin films

NASA Astrophysics Data System (ADS)

Soni, Gyanesh; Srivastava, Subodh; Soni, Purushottam; Kalotra, Pankaj; Vijay, Y. K.

2018-01-01

We have fabricated PMMA/SiO2 nanocomposite flexible thin films of 60 μm thicknesses by using solution casting method in the presence of transverse electric field. In this paper, we have investigated the effect of SiO2 nanoparticle (NP) loading on optical and mechanical properties of the composite thin film. The SEM images show that nanocomposite thin films have a smoother and uniform morphology. The transmittance peak near 1103 cm-1 in FT-IR spectrum confirms the presence of SiO2 NPs in the composite thin film. It is observed that optical bandgap decreases with an increase in the SiO2 NP concentration. Dynamic mechanical analysis shows that presence of SiO2 NP enhances the mechanical strength of the composite thin film.

Modulation of magnetic interaction in Bismuth ferrite through strain and spin cycloid engineering

NASA Astrophysics Data System (ADS)

Yadav, Rama Shanker; Reshi, Hilal Ahmad; Pillai, Shreeja; Rana, D. S.; Shelke, Vilas

2016-12-01

Bismuth ferrite, a widely studied room temperature multiferroic, provides new horizons of multifunctional behavior in phase transited bulk and thin film forms. Bismuth ferrite thin films were deposited on lattice mismatched LaAlO3 substrate using pulsed laser deposition technique. X-ray diffraction confirmed nearly tetragonal (T-type) phase of thin film involving role of substrate induced strain. The film thickness of 56 nm was determined by X-ray reflectivity measurement. The perfect coherence and epitaxial nature of T- type film was observed through reciprocal space mapping. The room temperature Raman measurement of T-type bismuth ferrite thin film also verified phase transition with appearance of only few modes. In parallel, concomitant La and Al substituted Bi1-xLaxFe0.95Al0.05O3 (x = 0.1, 0.2, 0.3) bulk samples were synthesized using solid state reaction method. A structural phase transition into orthorhombic (Pnma) phase at x = 0.3 was observed. The structural distortion at x = 0.1, 0.2 and phase transition at x = 0.3 substituted samples were also confirmed by changes in Raman active modes. The remnant magnetization moment of 0.199 emu/gm and 0.28 emu/gm were observed for x = 0.2 and 0.3 bulk sample respectively. The T-type bismuth ferrite thin film also showed high remnant magnetization of around 20emu/cc. The parallelism in magnetic behavior between T-type thin film and concomitant La and Al substituted bulk samples is indication of modulation, frustration and break in continuity of spiral spin cycloid.

Electron Cooling and Isotropization during Magnetotail Current Sheet Thinning: Implications for Parallel Electric Fields

NASA Astrophysics Data System (ADS)

Lu, San; Artemyev, A. V.; Angelopoulos, V.

2017-11-01

Magnetotail current sheet thinning is a distinctive feature of substorm growth phase, during which magnetic energy is stored in the magnetospheric lobes. Investigation of charged particle dynamics in such thinning current sheets is believed to be important for understanding the substorm energy storage and the current sheet destabilization responsible for substorm expansion phase onset. We use Time History of Events and Macroscale Interactions during Substorms (THEMIS) B and C observations in 2008 and 2009 at 18 - 25 RE to show that during magnetotail current sheet thinning, the electron temperature decreases (cooling), and the parallel temperature decreases faster than the perpendicular temperature, leading to a decrease of the initially strong electron temperature anisotropy (isotropization). This isotropization cannot be explained by pure adiabatic cooling or by pitch angle scattering. We use test particle simulations to explore the mechanism responsible for the cooling and isotropization. We find that during the thinning, a fast decrease of a parallel electric field (directed toward the Earth) can speed up the electron parallel cooling, causing it to exceed the rate of perpendicular cooling, and thus lead to isotropization, consistent with observation. If the parallel electric field is too small or does not change fast enough, the electron parallel cooling is slower than the perpendicular cooling, so the parallel electron anisotropy grows, contrary to observation. The same isotropization can also be accomplished by an increasing parallel electric field directed toward the equatorial plane. Our study reveals the existence of a large-scale parallel electric field, which plays an important role in magnetotail particle dynamics during the current sheet thinning process.

Unexpected spontaneous ignition of Late Glacial sediments from the palaeolake Wukenfurche (NE Germany)

NASA Astrophysics Data System (ADS)

Dräger, Nadine; Brademann, Brian; Theuerkauf, Martin; Wulf, Sabine; Tjallingii, Rik; Słowiński, Michał; Schlaak, Norbert; Błaszkiewicz, Mirosław; Brauer, Achim

2015-04-01

A new finely laminated sediment archive has been recovered from the palaeolake Wukenfurche, NE Germany, comprising the last Glacial to Interglacial transition. The site is located within the Eberswalde ice-marginal valley and south of the terminal moraine that was formed during the Pomeranian phase of the Weichselian glaciation. Two sediment cores were obtained from the presently swampy area in July 2014. From these individual profiles a 14.7 m long continuous composite profile has been compiled by correlation of distinct marker layers. Glacial sand deposits covered by basal peat are found at the base of the cores. A visible volcanic ash layer 6 cm above the transition from basal peat into the overlaying finely laminated lake sediments corresponds most likely to the late Allerød Laacher See Tephra (LST). Preliminary counting on core photographs of the 3.5 m thick package of reddish and black alternating laminae above the LST yields a total of ca. 2500 layer couplets. Further micro-facies analyses on large-scale thin sections will be applied to test if these couplets are of annual origin (i.e. varves). Standard preparation for large-scale thin sections involves freeze-drying (for 48 hours) of 10 cm-long sediment slabs stored in aluminum boxes. Immediately after releasing the vacuum of the freeze-dryer chamber we observed an unexpected spontaneous combustion of the sediment from a particular interval of the profile. The exothermic combustion process lasted for approximately 10 to 20 minutes during which temperatures of up to 350°C have been measured with an infrared camera. Preliminary results suggest that oxidation of iron sulfides contributes to the observed reaction. To our knowledge this is the first time that such spontaneous combustion of lake sediments after freeze-drying has been observed. Details of the combustion process and sediment characteristics will be provided. This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analysis -ICLEA- of the Helmholtz Association, grant number VH-VI-415.

Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication

DOEpatents

Brown, Ian G.; MacGill, Robert A.; Galvin, James E.; Ogletree, David F.; Salmeron, Miquel

1998-01-01

A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing.

Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication

DOEpatents

Brown, I.G.; MacGill, R.A.; Galvin, J.E.; Ogletree, D.F.; Salmeron, M.

1998-11-24

A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing. 8 figs.

Electromagnetic properties of thin-film transformer-coupled superconducting tunnel junctions

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

Finnegan, T.F.; Lacquaniti, V.; Vaglio, R.

1981-09-01

Multisection superconducting microstrip transformers with designed output impedances below 0.1 ..cap omega.. have been fabricated via precise photolithographic techniques to investigate the electromagnetic properties of Nb-Nb oxide-Pb tunnel junctions. The low-impedance transformer sections incorporate a rf sputtered thin-film Ta-oxide dielectric, and the reproducible external coupling achievable with this type of geometry makes possible the systematic investigation of electromagnetic device parameters as a function of tunneling oxide thickness.

Advances in Explosively Formed Fuse Opening Switches

DTIC Science & Technology

1987-06-01

ADVANCES IN EXPLOSIVELY FORMED FUSE OPENING SWITCHES* J. H. Goforth, R. S. Caird, A. E. Greene, I. R. Lindemuth, S. P. Marsh, H. Oona, and R. E...conductor into a series of thin sections. Augmented by an undetermined amount of heating due to the extrusion process, Joule heating in the thin...with initial field fed directly into the generator by a capacitor bank. As described in Ref. 2, these tests demonstrated that the switch would

Direct observation of local magnetic properties in strain engineered lanthanum cobaltate thin films

NASA Astrophysics Data System (ADS)

Park, S.; Wu, Weida; Freeland, J. W.; Ma, J. X.; Shi, J.

2009-03-01

Strain engineered thin film devices with emergent properties have significant impacts on both technical application and material science. We studied strain-induced modification of magnetic properties (Co spin state) in epitaxially grown lanthanum cobaltate (LaCoO3) thin films with a variable temperature magnetic force microscopy (VT-MFM). The real space observation confirms long range magnetic ordering on a tensile-strained film and non-magnetic low-spin configuration on a low-strained film at low temperature. Detailed study of local magnetic properties of these films under various external magnetic fields will be discussed. Our results also demonstrate that VT-MFM is a very sensitive tool to detect the nanoscale strain induced magnetic defects.

Influence of high energy ion irradiation on fullerene derivative (PCBM) thin films

NASA Astrophysics Data System (ADS)

Sharma, Trupti; Singhal, Rahul; Vishnoi, Ritu; Lakshmi, G. B. V. S.; Biswas, S. K.

2017-04-01

The modifications produced by 55 MeV Si4+ swift heavy ion irradiation on the phenyl C61 butyric acid methyl ester (PCBM) thin films (thickness ∼ 100 nm) has been enlightened. The PCBM thin films were irradiated at 1 × 1010, 1 × 1011 and 1 × 1012 ions/cm2 fluences. After ion irradiation, the decreased optical band gap and FTIR band intensities were observed. The Raman spectroscopy reveals the damage produced by energetic ions. The morphological variation were investigated by atomic force microscopy and contact angle measurements and observed to be influenced by incident ion fluences. After 1011 ions/cm2 fluence, the overlapping of ion tracks starts and produced overlapping effects.

Surface-potential undulation of Alq3 thin films prepared on ITO, Au, and n-Si.

PubMed

Ozasa, Kazunari; Ito, Hiromi; Maeda, Mizuo; Hara, Masahiko

2012-01-01

The surface potential (SP) morphology on thin films of tris(8-hydroxyquinolinato) aluminum (Alq3) was investigated with Kelvin probe force microscopy. Thin Alq3 films of 100 nm were prepared on ITO/glass substrates, Au/mica substrates, and n-Si substrates. Cloud-like morphologies of the SP undulation with 200-400 nm in lateral size were observed for all three types of the substrates. New larger peaks were observed in the cloud-like morphologies when the surfaces were exposed shortly to a light, while the SP average was reduced monotonically. The nonuniform distribution of charged traps and mobility was deduced from the SP undulation morphology and its photoexposure dependences.

Investigations of Si Thin Films as Anode of Lithium-Ion Batteries

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

Wu, Qingliu; Shi, Bing; Bareño, Javier

Amorphous silicon thin films having various thicknesses were investigated as a negative electrode material for lithium-ion batteries. Electrochemical characterization of the 20 nm thick thin silicon film revealed a very low first cycle Coulombic efficiency, which can be attributed to the silicon oxide layer formed on both the surface of the as-deposited Si thin film and the interface between the Si and the substrate. Among the investigated films, the 100 nm Si thin film demonstrated the best performance in terms of first cycle efficiency and cycle life. Observations from scanning electron microscopy demonstrated that the generation of cracks was inevitablemore » in the cycled Si thin films, even as the thickness of the film was as little as 20 nm, which was not predicted by previous modeling work. However, the cycling performance of the 20 and 100 nm silicon thin films was not detrimentally affected by these cracks. The poor capacity retention of the 1 mu m silicon thin film was attributed to the delamination.« less

Structural and optical properties of ITO and Cu doped ITO thin films

NASA Astrophysics Data System (ADS)

Chakraborty, Deepannita; Kaleemulla, S.; Rao, N. Madhusudhana; Subbaravamma, K.; Rao, G. Venugopal

2018-04-01

(In0.95Sn0.05)2O3 and (In0.90Cu0.05Sn0.05)2O3 thin films were coated onto glass substrate by electron beam evaporation technique. The structural and optical properties of ITO and Cu doped ITO thin films have been studied by X-ray diffractometer (XRD) and UV-Vis-NIR spectrophotometer. The crystallite size obtained for ITO and Cu doped ITO thin films was in the range of 24 nm to 22 nm. The optical band gap of 4 eV for ITO thin film sample has been observed. The optical band gap decreases to 3.85 eV by doping Cu in ITO.

Synthesis of galium nitride thin films using sol-gel dip coating method

NASA Astrophysics Data System (ADS)

Hamid, Maizatul Akmam Ab; Ng, Sha Shiong

2017-12-01

In this research, gallium nitride (GaN) thin film were grown on silicon (Si) substrate by a low-cost sol-gel dip coating deposition method. The GaN precursor solution was prepared using gallium (III) nitrate hydrate powder, ethanol and diethanolamine as a starting material, solvent and surfactant respectively. The structural, morphological and optical characteristics of the deposited GaN thin film were investigated. Field-emission scanning electron microscopy observations showed that crack free and dense grains GaN thin films were formed. Energy dispersive X-ray analysis confirmed that the oxygen content in the deposited films was low. X-ray diffraction results revealed that deposited GaN thin films have hexagonal wurtzite structure.

Epitaxial Ba2IrO4 thin-films grown on SrTiO3 substrates by pulsed laser deposition

NASA Astrophysics Data System (ADS)

Nichols, J.; Korneta, O. B.; Terzic, J.; Cao, G.; Brill, J. W.; Seo, S. S. A.

2014-03-01

We have synthesized epitaxial Ba2IrO4 (BIO) thin-films on SrTiO3 (001) substrates by pulsed laser deposition and studied their electronic structure by dc-transport and optical spectroscopic experiments. We have observed that BIO thin-films are insulating but close to the metal-insulator transition boundary with significantly smaller transport and optical gap energies than its sister compound, Sr2IrO4. Moreover, BIO thin-films have both an enhanced electronic bandwidth and electronic-correlation energy. Our results suggest that BIO thin-films have great potential for realizing the interesting physical properties predicted in layered iridates.

Imaging the Material Properties of Bone Specimens using Reflection-Based Infrared Microspectroscopy

PubMed Central

Acerbo, Alvin S.; Carr, G. Lawrence; Judex, Stefan; Miller, Lisa M.

2012-01-01

Fourier Transform InfraRed Microspectroscopy (FTIRM) is a widely used method for mapping the material properties of bone and other mineralized tissues, including mineralization, crystallinity, carbonate substitution, and collagen cross-linking. This technique is traditionally performed in a transmission-based geometry, which requires the preparation of plastic-embedded thin sections, limiting its functionality. Here, we theoretically and empirically demonstrate the development of reflection-based FTIRM as an alternative to the widely adopted transmission-based FTIRM, which reduces specimen preparation time and broadens the range of specimens that can be imaged. In this study, mature mouse femurs were plastic-embedded and longitudinal sections were cut at a thickness of 4 μm for transmission-based FTIRM measurements. The remaining bone blocks were polished for specular reflectance-based FTIRM measurements on regions immediately adjacent to the transmission sections. Kramers-Kronig analysis of the reflectance data yielded the dielectric response from which the absorption coefficients were directly determined. The reflectance-derived absorbance was validated empirically using the transmission spectra from the thin sections. The spectral assignments for mineralization, carbonate substitution, and collagen cross-linking were indistinguishable in transmission and reflection geometries, while the stoichiometric/non-stoichiometric apatite crystallinity parameter shifted from 1032 / 1021 cm−1 in transmission-based to 1035 / 1025 cm−1 in reflection-based data. This theoretical demonstration and empirical validation of reflection-based FTIRM eliminates the need for thin sections of bone and more readily facilitates direct correlations with other methods such nanoindentation and quantitative backscatter electron imaging (qBSE) from the same specimen. It provides a unique framework for correlating bone’s material and mechanical properties. PMID:22455306

Field guide to Cretaceous-tertiary boundary sections in northeastern Mexico

NASA Technical Reports Server (NTRS)

Keller, Gerta; Stinnesbeck, Wolfgang; Adatte, Thierry; Macleod, Norman; Lowe, Donald R.

1994-01-01

This guide was prepared for the field trip to the KT elastic sequence of northeastern Mexico, 5-8 February 1994, in conjunction with the Conference on New Developments Regarding the KT Event and Other Catastrophes in Earth History, held in Houston, Texas. The four-day excursion offers an invaluable opportunity to visit three key outcrops: Arroyo El Mimbral, La Lajilla, and El Pinon. These and other outcrops of this sequence have recently been interpreted as tsunami deposits produced by the meteorite impact event that produced the 200 to 300-km Chicxulub basin in Yucatan, and distributed ejecta around the world approximately 65 m.y. ago that today is recorded as a thin clay layer found at the K/T boundary. The impact tsunami interpretation for these rocks has not gone unchallenged, and others examining the outcrops arrive at quite different conclusions: not tsunami deposits but turbidites; not KT at all but 'upper Cretaceous.' Indeed, it is in hopes of resolving this debate through field discussion, outcrop evaluation, and sampling that led the organizers of the conference to sanction this field trip. This field guide provides participants with background information on the KT clastic sequence outcrops and is divided into two sections. The first section provides regional and logistical context for the outcrops and a description of the clastic sequence. The second section presents three representative interpretations of the outcrops by their advocates. There is clearly no way that these models can be reconciled and so two, if not all three, must be fundamentally wrong. Readers of this guide should keep in mind that many basic outcrop observations that these models are based upon remain unresolved. While great measures were taken to ensure that the information in the description section was as objective as possible, many observations are rooted in interpretations and the emphasis placed on certain observations depends to some degree upon the perspective of the author.

Thermally induced chain orientation for improved thermal conductivity of P(VDF-TrFE) thin films

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

Zhao, Junnan; Tan, Aaron C.; Green, Peter F.

2017-01-01

A large increase in thermal conductivityκwas observed in a P(VDF-TrFE) thin film annealed above melting temperature due to extensive ordering of polymer backbone chains perpendicular to the substrate after recrystallization from the melt. This finding may lay out a straightforward method to improve the thin filmκof semicrystalline polymers whose chain orientation is sensitive to thermal annealing.

Investigation of the High Mobility IGZO Thin Films by Using Co-Sputtering Method

PubMed Central

Hsu, Chao-Ming; Tzou, Wen-Cheng; Yang, Cheng-Fu; Liou, Yu-Jhen

2015-01-01

High transmittance ratio in visible range, low resistivity, and high mobility of IGZO thin films were prepared at room temperature for 30 min by co-sputtering of Zn2Ga2O5 (Ga2O3 + 2 ZnO, GZO) ceramic and In2O3 ceramic at the same time. The deposition power of pure In2O3 ceramic target was fixed at 100 W and the deposition power of GZO ceramic target was changed from 80 W to 140 W. We chose to investigate the deposition power of GZO ceramic target on the properties of IGZO thin films. From the SEM observations, all of the deposited IGZO thin films showed a very smooth and featureless surface. From the measurements of XRD patterns, only the amorphous structure was observed. We aimed to show that the deposition power of GZO ceramic target had large effect on the Eg values, Hall mobility, carrier concentration, and resistivity of IGZO thin films. Secondary ion mass spectrometry (SIMS) analysis in the thicknesses’ profile of IGZO thin films found that In and Ga elements were uniform distribution and Zn element were non-uniform distribution. The SIMS analysis results also showed the concentrations of Ga and Zn elements increased and the concentrations of In element was almost unchanged with increasing deposition power.

Phase and electrical properties of PZT thin films embedded with CuO nano-particles by a hybrid sol-gel route

NASA Astrophysics Data System (ADS)

Sreesattabud, Tharathip; Gibbons, Brady J.; Watcharapasorn, Anucha; Jiansirisomboon, Sukanda

2013-07-01

Pb(Zr0.52Ti0.48)O3 or PZT thin films embedded with CuO nano-particles were successfully prepared by a hybrid sol-gel process. In this process, CuO (0, 0.1, 0.2, 0.3, 0.4, 0.5 and 1 wt. %) nanopowder was suspended in an organometallic solution of PZT, and then coated on platinised silicon substrate using a spin-coating technique. The influence of CuO nano-particles' dispersion on the phase of PZT thin films was investigated. XRD results showed a perovskite phase in all films. At the CuO concentration of 0.4-1 wt. %, a second phase was observed. The addition of CuO nano-particles affected the orientation of PZT thin films. The addition was also found to reduce the ferroelectric properties of PZT thin films. However, at 0.2 wt. % CuO concentration, the film exhibited good ferroelectric properties similar to those of PZT films. In addition, the fatigue retention properties of the PZT/CuO system was observed, and it showed 14% fatigue at 108 switching bipolar pulse cycles while the fatigue in PZT thin films was found to be 17% at the same switching bipolar pulse cycles.

Room-temperature growth of thin films of niobium on strontium titanate (0 0 1) single-crystal substrates for superconducting joints

NASA Astrophysics Data System (ADS)

Shimizu, Yuhei; Tonooka, Kazuhiko; Yoshida, Yoshiyuki; Furuse, Mitsuho; Takashima, Hiroshi

2018-06-01

With the eventual aim of forming joints between superconducting wires of YBa2Cu3O7-δ (YBCO), thin films of Nb were grown at room-temperature on SrTiO3 (STO) (0 0 1), a single-crystal substrate that shows good lattice matching with YBCO. The crystallinity, surface morphology, and superconducting properties of the Nb thin films were investigated and compared with those of similar films grown on a silica glass substrate. The Nb thin films grew with an (hh0) orientation on both substrates. The crystallinity of the Nb thin films on the STO substrate was higher than that on the silica glass substrate. X-ray diffraction measurements and observation of the surface morphology by atomic-force microscopy indicated that Nb grew in the plane along the [1 0 0] and [0 1 0] directions of the STO substrate. This growth mode relaxes strain between Nb and STO, and is believed to lead to the high crystallinity observed. As a result, the Nb thin films on the STO substrates showed lower electric resistivity and a higher superconducting transition temperature than did those on the silica glass substrates. The results of this study should be useful in relation to the production of superconducting joints.

Thin-section microscopy of decayed crystalline marble from the garden sculptures of Schoenbrunn Palace in Vienna

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

Weber, J.; Beseler, S.; Sterflinger, K.

2007-11-15

Sterzing marble, a crystalline white marble used in the late-Baroque garden sculptures of Schoenbrunn Palace in Vienna, was studied by means of thin-section and scanning electron microscopy in order to obtain a better understanding of its surface decay caused by atmospheric weathering. Following the classification of distinct phenomena of deterioration by visual on-site inspection, the microstructural features including surface erosion, micro-cracking, soiling, black crust formation, and microbiological infestation are exemplified by microscopical images and are briefly discussed. The results proved useful for evaluating and understanding the various types of marble decay for creating a safer basis for establishing the proceduralmore » principles aimed at conservation and maintenance of the sculptures.« less

Nonlinear analysis of composite thin-walled helicopter blades

NASA Astrophysics Data System (ADS)

Kalfon, J. P.; Rand, O.

Nonlinear theoretical modeling of laminated thin-walled composite helicopter rotor blades is presented. The derivation is based on nonlinear geometry with a detailed treatment of the body loads in the axial direction which are induced by the rotation. While the in-plane warping is neglected, a three-dimensional generic out-of-plane warping distribution is included. The formulation may also handle varying thicknesses and mass distribution along the cross-sectional walls. The problem is solved by successive iterations in which a system of equations is constructed and solved for each cross-section. In this method, the differential equations in the spanwise directions are formulated and solved using a finite-differences scheme which allows simple adaptation of the spanwise discretization mesh during iterations.

Observation of electric potential in organic thin-film transistor by bias-applied hard X-ray photoemission spectroscopy

NASA Astrophysics Data System (ADS)

Watanabe, Takeshi; Tada, Keisuke; Yasuno, Satoshi; Oji, Hiroshi; Yoshimoto, Noriyuki; Hirosawa, Ichiro

2016-03-01

The effect of gate voltage on electric potential in a pentacene (PEN) layer was studied by hard X-ray photoelectron spectroscopy under a bias voltage. It was observed that applying a negative gate voltage substantially increases the width of a C 1s peak. This suggested that injected and accumulated carriers in an organic thin film transistor channel modified the potential depth profile in PEN. It was also observed that the C 1s kinetic energy tends to increase monotonically with threshold voltage.

Effect of ethanol variation on the internal environment of sol-gel bulk and thin films with aging.

PubMed

Gupta, R; Mozumdar, S; Chaudhury, N K

2005-10-15

Sol-gel derived bulk and thin films were prepared from different compositions at low pH ( approximately 2.0) containing varying concentrations of ethanol from 15 to 60% at constant water (H(2)O)/tetraethyl-orthosilicate (TEOS) ratio (R=4). The fluorescence microscopic and spectroscopic measurements on fluorescent probe, Hoechst 33258 (H258) entrapped in these compositions were carried out at different days of storage to monitor the effects of concentration of ethanol on the internal environment of sol-gel materials. Fluorescence microscopic observations on sol-gel thin films, prepared by dip coating technique depicted uniform and cracked surface at withdrawal speed 1cm/min (high speed) and 0.1cm/min (low speed) respectively, which did not change during aging. Fluorescence spectral measurements showed emission maximum of H258 at approximately 535 nm in fresh sols at all concentrations of ethanol which depicted slight blue shift to 512 nm during aging in bulk. No such spectral shift has been observed in sol-gel thin films coated at high speed whereas thin films coated at low speed clearly showed an additional band at approximately 404 nm at 45 and 60% concentration of ethanol after about one month of storage. Analysis of the fluorescence lifetime data indicated single exponential decay (1.6-1.8 ns) in fresh sol and from third day onwards, invariably double exponential decay with a short (tau(1)) and a long (tau(2)) component were observed in sol-gel bulk with a dominant tau(1) at approximately 1.2 ns at all concentrations of ethanol. A double exponential decay consisting of a short component (tau(1)) at approximately 0.2 ns and a long component (tau(2)) at approximately 3.5 ns were observed at all ethanol concentrations in both fresh and aged sol-gel thin films. Further, distribution analysis of lifetimes of H258 showed two mean lifetimes with increased width in aged bulk and thin films. These results are likely to have strong implications in designing the internal environment for applications in biosensors.

Indirect fluorometric detection techniques on thin layer chromatography and effect of ultrasound on gel electrophoresis

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

Yinfa, Ma.

Thin-layer chromatography (TLC) is a broadly applicable separation technique. It offers many advantages over high performance liquid chromatography (HPLC), such as easily adapted for two-dimensional separation, for whole-column'' detection and for handling multiple samples, etc. However, due to its draggy development of detection techniques comparing with HPLC, TLC has not received the attention it deserves. Therefore, exploring new detection techniques is very important to the development of TLC. It is the principal of this dissertation to present a new detection method for TLC -- indirect fluorometric detection method. This detection technique is universal sensitive, nondestructive, and simple. This will bemore » described in detail from Sections 1 through Section 5. Section 1 and 3 describe the indirect fluorometric detection of anions and nonelectrolytes in TLC. In Section 2, a detection method for cations based on fluorescence quenching of ethidium bromide is presented. In Section 4, a simple and interesting TLC experiment is designed, three different fluorescence detection principles are used for the determination of caffeine, saccharin and sodium benzoate in beverages. A laser-based indirect fluorometric detection technique in TLC is developed in Section 5. Section 6 is totally different from Sections 1 through 5. An ultrasonic effect on the separation of DNA fragments in agarose gel electrophoresis is investigated. 262 refs.« less

Effects of air annealing on CdS quantum dots thin film grown at room temperature by CBD technique intended for photosensor applications

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

Shaikh, Shaheed U.; Desale, Dipalee J.; Siddiqui, Farha Y.

2012-11-15

Graphical abstract: The effect of different intensities (40, 60 100 and 200 W) of light on CdS quantum dots thin film annealed at 350 °C indicating enhancement in (a) photo-current and (b) photosensitivity. Highlights: ► The preparation of CdS nanodot thin film at room temperature by M-CBD technique. ► Study of air annealing on prepared CdS nanodots thin film. ► The optimized annealing temperature for CdS nanodot thin film is 350 °C. ► Modified CdS thin films can be used in photosensor application. -- Abstract: CdS quantum dots thin-films have been deposited onto the glass substrate at room temperature usingmore » modified chemical bath deposition technique. The prepared thin films were further annealed in air atmosphere at 150, 250 and 350 °C for 1 h and subsequently characterized by scanning electron microscopy, ultraviolet–visible spectroscopy, electrical resistivity and I–V system. The modifications observed in morphology and opto-electrical properties of the thin films are presented.« less

Arbitrary frequency tunable radio frequency bandpass filter based on nano-patterned Permalloy coplanar waveguide (invited)

NASA Astrophysics Data System (ADS)

Wang, Tengxing; Rahman, B. M. Farid; Peng, Yujia; Xia, Tian; Wang, Guoan

2015-05-01

A well designed coplanar waveguide (CPW) based center frequency tunable bandpass filter (BPF) at 4 GHz enabled with patterned Permalloy (Py) thin film has been implemented. The operating frequency of BPF is tunable with only DC current without the use of any external magnetic field. Electromagnetic bandgap resonators structure is adopted in the BPF and thus external DC current can be applied between the input and output of the filter for tuning of Py permeability. Special configurations of resonators with multiple narrow parallel sections have been considered for larger inductance tenability; the tunability of CPW transmission lines of different widths with patterned Py thin film on the top of the signal lines is compared and measured. Py thin film patterned as bars is deposited on the top of the multiple narrow parallel sections of the designed filter. No extra area is required for the designed filter configuration. Filter is measured and results show that its center frequency could be tuned from 4 GHz to 4.02 GHz when the DC current is applied from 0 mA to 400 mA.

Biased Target Ion Beam Deposition and Nanoskiving for Fabricating NiTi Alloy Nanowires

NASA Astrophysics Data System (ADS)

Hou, Huilong; Horn, Mark W.; Hamilton, Reginald F.

2016-12-01

Nanoskiving is a novel nanofabrication technique to produce shape memory alloy nanowires. Our previous work was the first to successfully fabricate NiTi alloy nanowires using the top-down approach, which leverages thin film technology and ultramicrotomy for ultra-thin sectioning. For this work, we utilized biased target ion beam deposition technology to fabricate nanoscale (i.e., sub-micrometer) NiTi alloy thin films. In contrast to our previous work, rapid thermal annealing was employed for heat treatment, and the B2 austenite to R-phase martensitic transformation was confirmed using stress-temperature and diffraction measurements. The ultramicrotome was programmable and facilitated sectioning the films to produce nanowires with thickness-to-width ratios ranging from 4:1 to 16:1. Energy dispersive X-ray spectroscopy analysis confirmed the elemental Ni and Ti make-up of the wires. The findings exposed the nanowires exhibited a natural ribbon-like curvature, which depended on the thickness-to-width ratio. The results demonstrate nanoskiving is a potential nanofabrication technique for producing NiTi alloy nanowires that are continuous with an unprecedented length on the order of hundreds of micrometers.

Geometrical Effects in Noise Spectra of Superconducting Flux Qubits

NASA Astrophysics Data System (ADS)

Petukhov, Andre; Smelyanskiy, Vadim; Martinis, John

We present theoretical study of geometrical effects related to spin diffusion in superconducting flux qubits. We adopt a model of a long superconducting wire surrounded by a thin oxide layer with spins distributed uniformly over cross-sectional area of the oxide layer. Using a continuous transformation from a round cylinder to a flat wire strip, we demonstrate that the noise spectral density tends to a power law S (ω) ~(ω / Γ) - s with s 3 / 4 , approaching s = 3 / 4 for very thin wires. The ω-s dependence is valid in a broad frequency range above ωΓ stretching up to four orders of magnitude in units of characteristic diffusion decay rate Γ ~ 1 -102 Hz. The effect is highly sensitive to a cross-sectional aspect ratio of a thin wire thus revealing its geometrical origin. We substantiate our findings by detailed comparison with available experimental data and conclude that 3 / 4 power law distinguishes spin diffusion flux noise from generic `` 1 / f '' family. Supported by the AFRL Information Directorate under Grant F4HBKC4162G001.

A sensitivity-enhanced refractive index sensor using a single-mode thin-core fiber incorporating an abrupt taper.

PubMed

Shi, Jie; Xiao, Shilin; Yi, Lilin; Bi, Meihua

2012-01-01

A sensitivity-enhanced fiber-optic refractive index (RI) sensor based on a tapered single-mode thin-core diameter fiber is proposed and experimentally demonstrated. The sensor head is formed by splicing a section of tapered thin-core diameter fiber (TCF) between two sections of single-mode fibers (SMFs). The cladding modes are excited at the first SMF-TCF interface, and then interfere with the core mode at the second interface, thus forming an inter-modal interferometer (IMI). An abrupt taper (tens of micrometers long) made by the electric-arc-heating method is utilized, and plays an important role in improving sensing sensitivity. The whole manufacture process only involves fiber splicing and tapering, and all the fabrication process can be achieved by a commercial fiber fusion splicer. Using glycerol and water mixture solution as an example, the experimental results show that the refractive index sensitivity is measured to be 0.591 nm for 1% change of surrounding RI. The proposed sensor structure features simple structure, low cost, easy fabrication, and high sensitivity.