ORCID Profile
0000-0002-5841-2687
Current Organisations
3-Rensselaer Polytechnic Institute
,
2-Princeton University
,
2-University of Oregon
,
1-Macquarie University
,
5-Smithsonian Institution
,
Smithsonian Institution
,
McGill University
,
4-National Museum of Natural History
,
Princeton University
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Publications
A Reduced Organic Carbon Component in Martian Basalts
Publisher: American Association for the Advancement of Science (AAAS)
Date: 13-07-2012
Abstract: Understanding the sources and the formation mechanisms of organic carbon compounds on Mars has implications for our understanding of the martian carbon cycle. Steele et al. (p. 212 , published online 24 May) present measurements of organic material in 11 martian meteorites, including the Tissint meteorite, which fell in the Moroccan desert in July 2011. Ten of the meteorites contain complex hydrocarbons encased within igneous minerals. The results imply that the organics formed as the magma melt crystallized and are thus of abiotic origin.
Drilling Down Into The Cathodoluminescence And Compositional Variation In Jadeite
Publisher: Oxford University Press (OUP)
Date: 07-2012
DOI: 10.1017/S143192761200712X
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.
Quantitative Analysis of Obsidian and Determination of Source Provenance Using an Analytical Dual Beam SEM
Publisher: Oxford University Press (OUP)
Date: 30-07-2021
Low Upper Limit to Methane Abundance on Mars
Publisher: American Association for the Advancement of Science (AAAS)
Date: 18-10-2013
Abstract: On Earth, atmospheric methane is mostly produced biologically. Atmospheric methane has also been detected on Mars, but these reports have been controversial. Based on data from the S le Analysis at Mars instrument suite on the Curiosity rover, which arrived at the surface of Mars in August 2012, Webster et al. (p. 355 , published online 19 September) report no methane, with an upper limit of only 1.3 parts per billion by volume, about 6 times lower than previous measurements.
Solving the Micro to Macro Problem: A New Application for Milli X-ray Fluorescence X-ray Spectrum Imaging
Publisher: Oxford University Press (OUP)
Date: 07-2009
DOI: 10.1017/S1431927609098146
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
Nurse Manners'* Guide to Politically Correct Behavior
Publisher: Wiley
Date: 09-1991
DOI: 10.1111/J.1547-5069.1991.TB00668.X
Abstract: The vascular receptors activated following sympatho-adrenal stimulation were determined by analysing the effects of 'selective' antagonists on the vasopressor response to spinal sympathetic nerve activation in the pithed rat. The net vascular response to adrenal stimulation was a balance between alpha-adrenoceptor-mediated vasoconstriction and beta-adrenoceptor-mediated vasodepression. Part of the alpha-adrenoceptor-mediated response was 'prazosin-sensitive' (alpha 1) and the remainder was abolished by rauwolscine (alpha 2). As with adrenal stimulation, direct sympathetic nerve stimulation of the vasculature evoked pressor responses which were partly resistant to prazosin. Rauwolscine only partly blocked the prazosin-sensitive component. Reserpine pretreatment led to smaller responses than prazosin plus rauwolscine. Thus, the response resistant to alpha-adrenoceptor antagonists could be mediated, in part, by adrenoceptors distinct from alpha-adrenoceptors, as currently defined. alpha, beta-Methylene ATP reduced the nerve-mediated pressor response after alpha-adrenoceptor blockade or reserpine pretreatment but not in drug-free controls. The results suggest that stimulation of the adrenal medulla can produce a vasopressor response which consists of summating alpha 1- and alpha 2-adrenoceptor-mediated components, and is identical to the effect of injected adrenaline. In contrast, the response to vasopressor nerve stimulation appears to be essentially mediated by alpha 1-adrenoceptors, with a facilitatory influence from alpha 2-adrenoceptors. A further response obtained after alpha-adrenoceptor blockade may contain a purinergic component and another which is adrenergic but not mediated by stimulation of alpha-adrenoceptors.
Phase changes in boron ignition and combustion
Publisher: Elsevier BV
Date: 11-1999
Martian Fluvial Conglomerates at Gale Crater
Publisher: American Association for the Advancement of Science (AAAS)
Date: 31-05-2013
Abstract: The Mars Science Laboratory spacecraft containing the Curiosity rover, was launched from Earth in November 2011 and arrived at Gale crater on Mars in August 2012. Zeitlin et al. (p. 1080 ) report measurements of the energetic particle radiation environment inside the spacecraft during its cruise to Mars, confirming the hazard likely to be posed by this radiation to astronauts on a future potential trip to Mars. Williams et al. (p. 1068 , see the Perspective by Jerolmack ) report the detection of sedimentary conglomerates (pebbles mixed with sand and turned to rock) at Gale crater. The rounding of the rocks suggests abrasion of the pebbles as they were transported by flowing water several kilometers or more from their source.
Formation and Structure of a Tin−Iron Oxide Solid-State System with Potential Applications in Carbon Monoxide Sensing through the Use of Cyanogel Chemistry
Publisher: American Chemical Society (ACS)
Date: 13-02-1998
DOI: 10.1021/CM970646Z
Seneca sandstone: a heritage stone from the USA
Publisher: Geological Society of London
Date: 20-09-2018
DOI: 10.1144/SP486.4
Morphologies, Isotopes, Crystal Structures, and Microstructures of Presolar Al2O3 Grains: a NanoSIMS, EBSD, EDS, CL, and FIB-TEM study
Publisher: Oxford University Press (OUP)
Date: 08-2014
Progress on yttria-stabilized zirconia sensors for hydrothermal pH measurements
Publisher: Elsevier BV
Date: 08-2003
Chaos Theory and Nursing Revisited
Publisher: SAGE Publications
Date: 10-1994
DOI: 10.1177/089431849400700405
Abstract: Three batches of the first instar Significant diet-based variations were observed in the head length, head width, thoracic length, thoracic width, abdominal length, abdominal width, and total length ( Based on all the growth and developmental parameters, the D
Imaging Rough Paper to Evaluate Methods for Soot Removal
Publisher: Oxford University Press (OUP)
Date: 2022
DOI: 10.1017/S1551929521001516
Abstract: Here, we use a variety of microscopic imaging techniques, including scanning electron microscopy, 3D visible light microscopy, and portable microscopy to capture the topography of rough paper. Paper coated with a model soot was cleaned with either a firm vinyl eraser or softer, putty-like kneaded eraser and reimaged to characterize the disposition of remaining soot. Although both methods remove soot from the upper-most surface of the paper, only the kneaded eraser can conform to the complex topography to remove soot from the interstices between paper fibers.
Ni/S/Cl systematics and the origin of impact‐melt glasses in Martian meteorite Elephant Moraine 79001
Publisher: Wiley
Date: 13-02-2016
DOI: 10.1111/MAPS.12612
Photoluminescence Spectroscopy of ZnO and TiCh Pigments
Publisher: Oxford University Press (OUP)
Date: 08-2018
A dual beam SEM-based EDS and micro-XRF method for the analysis of large-scale Mesoamerican obsidian tablets
Publisher: Elsevier BV
Date: 02-2021
Sodic pyroxene and sodic amphibole as potential reference materials for in situ lithium isotope determinations by SIMS
Publisher: Wiley
Date: 09-2008
Nanoscale structure and compositional analysis of manganese oxide coatings on the Smithsonian Castle, Washington, DC
Publisher: Elsevier BV
Date: 03-2020
X-ray Diffraction Results from Mars Science Laboratory: Mineralogy of Rocknest at Gale Crater
Publisher: American Association for the Advancement of Science (AAAS)
Date: 27-09-2013
Abstract: The Mars Science Laboratory rover Curiosity scooped s les of soil from the Rocknest aeolian bedform in Gale crater. Analysis of the soil with the Chemistry and Mineralogy (CheMin) x-ray diffraction (XRD) instrument revealed plagioclase (~An57), forsteritic olivine (~Fo62), augite, and pigeonite, with minor K-feldspar, magnetite, quartz, anhydrite, hematite, and ilmenite. The minor phases are present at, or near, detection limits. The soil also contains 27 ± 14 weight percent x-ray amorphous material, likely containing multiple Fe 3+ - and volatile-bearing phases, including possibly a substance resembling hisingerite. The crystalline component is similar to the normative mineralogy of certain basaltic rocks from Gusev crater on Mars and of martian basaltic meteorites. The amorphous component is similar to that found on Earth in places such as soils on the Mauna Kea volcano, Hawaii.
Immiscible silicate liquids at high pressure: The influence of melt structure on elemental partitioning
Publisher: Elsevier BV
Date: 09-1995
Curiosity at Gale Crater, Mars: Characterization and Analysis of the Rocknest Sand Shadow
Publisher: American Association for the Advancement of Science (AAAS)
Date: 27-09-2013
Abstract: The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand micrometers in size contains ~55% crystalline material consistent with a basaltic heritage and ~45% x-ray amorphous material. The amorphous component of Rocknest is iron-rich and silicon-poor and is the host of the volatiles (water, oxygen, sulfur dioxide, carbon dioxide, and chlorine) detected by the S le Analysis at Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations.
Chemical Compound Classification by Elemental Signatures in Castle Dust Using SEM Automated X-ray Particle Analysis
Publisher: Oxford University Press (OUP)
Date: 08-2018
A study of cathodoluminescence and trace element compositional zoning in natural quartz from volcanic rocks: Mapping titanium content in quartz
Publisher: Oxford University Press (OUP)
Date: 20-11-2012
DOI: 10.1017/S1431927612013426
Abstract: This article concerns application of cathodoluminescence (CL) spectroscopy to volcanic quartz and its utility in assessing variation in trace quantities of Ti within in idual crystals. CL spectroscopy provides useful details of intragrain compositional variability and structure but generally limited quantitative information on element abundances. Microbeam analysis can provide such information but is time-consuming and costly, particularly if large numbers of analyses are required. To maximize advantages of both approaches, natural and synthetic quartz crystals were studied using high-resolution hyperspectral CL imaging (1.2–5.0 eV range) combined with analysis via laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Spectral intensities can be deconvolved into three principal contributions (1.93, 2.19, and 2.72 eV), for which intensity of the latter peak was found to correlate directly with Ti concentration. Quantitative maps of Ti variation can be produced by calibration of the CL spectral data against relatively few analytical points. Such maps provide useful information concerning intragrain zoning or heterogeneity of Ti contents with the sensitivity of LA-ICPMS analysis and spatial resolution of electron microprobe analysis.
Condensed-phase species distributions about Al particles reacting in various oxidizers
Publisher: Elsevier BV
Date: 04-1999
Hydration of Hydrophilic Cloth Face Masks Enhances the Filtration of Nanoparticles
Publisher: American Chemical Society (ACS)
Date: 08-03-2021
Interdisciplinary X-Ray Microanalysis: From Planets and Comets to Artifacts and Fine Art
Publisher: Oxford University Press (OUP)
Date: 08-2014
Abundance and Isotopic Composition of Gases in the Martian Atmosphere from the Curiosity Rover
Publisher: American Association for the Advancement of Science (AAAS)
Date: 19-07-2013
Abstract: The S le Analysis at Mars (SAM) instrument on the Curiosity rover that landed on Mars in August last year is designed to study the chemical and isotopic composition of the martian atmosphere. Mahaffy et al. (p. 263 ) present volume-mixing ratios of Mars' five major atmospheric constituents (CO 2 , Ar, N 2 , O 2 , and CO) and isotope measurements of 40 Ar/ 36 Ar and C and O in CO 2 , based on data from one of SAM's instruments, obtained between 31 August and 21 November 2012. Webster et al. (p. 260 ) used data from another of SAM's instruments obtained around the same period to determine isotope ratios of H, C, and O in atmospheric CO 2 and H 2 O. Agreement between the isotopic ratios measured by SAM with those of martian meteorites, measured in laboratories on Earth, confirms the origin of these meteorites and implies that the current atmospheric reservoirs of CO 2 and H 2 O were largely established after the period of early atmospheric loss some 4 billion years ago.
Determination of Major, Minor, and Trace Elements in Jadeite using Scanning micro-X-ray Fluorescence
Publisher: Oxford University Press (OUP)
Date: 07-2017
Aqueous Processes Recorded by Martian Meteorites: Analyzing Martian Water on Earth
Publisher: Mineralogical Society of America
Date: 06-2006
The Petrochemistry of Jake_M: A Martian Mugearite
Publisher: American Association for the Advancement of Science (AAAS)
Date: 27-09-2013
Abstract: “Jake_M,” the first rock analyzed by the Alpha Particle X-ray Spectrometer instrument on the Curiosity rover, differs substantially in chemical composition from other known martian igneous rocks: It is alkaline ( % normative nepheline) and relatively fractionated. Jake_M is compositionally similar to terrestrial mugearites, a rock type typically found at ocean islands and continental rifts. By analogy with these comparable terrestrial rocks, Jake_M could have been produced by extensive fractional crystallization of a primary alkaline or transitional magma at elevated pressure, with or without elevated water contents. The discovery of Jake_M suggests that alkaline magmas may be more abundant on Mars than on Earth and that Curiosity could encounter even more fractionated alkaline rocks (for ex le, phonolites and trachytes).
Microstructural observations of polycrystalline diamond: a contribution to the carbonado conundrum
Publisher: Elsevier BV
Date: 12-1998
From Earth to Outer Space: Laser cleaning semiprecious quartz and a novel application for meteoritic metal
Publisher: Nicolaus Copernicus University Press
Date: 2017
DOI: 10.12775/3875-4.03
Inclusion/host relations involving accessory minerals in high-grade metamorphic and anatectic rocks
Publisher: Springer Science and Business Media LLC
Date: 02-1989
DOI: 10.1007/BF00375308
Capillary ion chromatography with on-column focusing for ultra-trace analysis of methanesulfonate and inorganic anions in limited volume Antarctic ice core samples
Publisher: Elsevier BV
Date: 08-2015
DOI: 10.1016/J.CHROMA.2015.07.034
Abstract: Preservation of ionic species within Antarctic ice yields a unique proxy record of the Earth's climate history. Studies have been focused until now on two proxies: the ionic components of sea salt aerosol and methanesulfonic acid. Measurement of the all of the major ionic species in ice core s les is typically carried out by ion chromatography. Former methods, whilst providing suitable detection limits, have been based upon off-column preconcentration techniques, requiring larger s le volumes, with potential for s le contamination and/or carryover. Here, a new capillary ion chromatography based analytical method has been developed for quantitative analysis of limited volume Antarctic ice core s les. The developed analytical protocol applies capillary ion chromatography (with suppressed conductivity detection) and direct on-column s le injection and focusing, thus eliminating the requirement for off-column s le preconcentration. This limits the total s le volume needed to 300μL per analysis, allowing for triplicate s le analysis with <1mL of s le. This new approach provides a reliable and robust analytical method for the simultaneous determination of organic and inorganic anions, including fluoride, methanesulfonate, chloride, sulfate and nitrate anions. Application to composite ice-core s les is demonstrated, with coupling of the capillary ion chromatograph to high resolution mass spectrometry used to confirm the presence and purity of the observed methanesulfonate peak.
A revised Law Dome age model (LD2017) and implications for last glacial climate
Publisher: Copernicus GmbH
Date: 23-08-2017
DOI: 10.5194/CP-2017-96
Abstract: Abstract. Here we present a revised Law Dome, Dome Summit South (DSS) ice core age model (denoted LD2017) that significantly improves the chronology over the last 88 ka. An ensemble approach was used, allowing for the computation of both a median age and associated uncertainty as a function of depth. The revised chronology incorporates extended continuous annual layer counting to 853 m using chemical species with seasonally-varying behaviours. The annual layer counted age at 853 m is 2332 years before 2000 (y b2k) with an error of & lus /−7 y, i.e. 2345–2325 y b2k . Below this depth, non-linear interpolation between age ties using a probability density function for age/depth is used to constrain and model the age of the ice. The ice-based age ties below the annual layer counted section are based on matching volcanic event markers, methane (CH4) gas concentration, isotopic composition of ice (δ18O) and the Last Glacial Maximum (LGM) dust peak to other records. For consistency, the timescale used for all matching is the AICC2012 timescale (Veres et al., 2013). The first ice-based age tie is the base of the annual layer counting record (2332 y b2k) and the age ties from ~ 2400–4000 y b2k are volcanic synchronised ice-based age ties. The detection of abrupt changes in CH4 gas concentrations within the DSS record provides further independent gas-based age ties, including the tightly constrained 8200 y b2k event. The improved age control between 9000 and 21000 y b2k is supplemented by CH4 and δ18O ice measurements (Pedro et al., 2011). Over the period 16600 to 18600 y b2k large changes in dust concentration, matched to the EDC dust record, are used to constrain two ice-based age ties. Unlike previous studies, where the modelling was used to simultaneously infer both age and snow accumulation rate, we made an independent estimate of the snow accumulation rate, where required, for the use of gas based age ties.
Volatile, Isotope, and Organic Analysis of Martian Fines with the Mars Curiosity Rover
Publisher: American Association for the Advancement of Science (AAAS)
Date: 27-09-2013
Abstract: S les from the Rocknest aeolian deposit were heated to ~835°C under helium flow and evolved gases analyzed by Curiosity’s S le Analysis at Mars instrument suite. H 2 O, SO 2 , CO 2 , and O 2 were the major gases released. Water abundance (1.5 to 3 weight percent) and release temperature suggest that H 2 O is bound within an amorphous component of the s le. Decomposition of fine-grained Fe or Mg carbonate is the likely source of much of the evolved CO 2 . Evolved O 2 is coincident with the release of Cl, suggesting that oxygen is produced from thermal decomposition of an oxychloride compound. Elevated δD values are consistent with recent atmospheric exchange. Carbon isotopes indicate multiple carbon sources in the fines. Several simple organic compounds were detected, but they are not definitively martian in origin.
Stone-Cold Low Temperature Cathodoluminescence Spectrometry of Quartz (SiO2)
Publisher: Oxford University Press (OUP)
Date: 08-2018
High-temperature phases in ternary Zr–O–N systems
Publisher: Springer Science and Business Media LLC
Date: 10-1999
Abstract: Zirconium aerosol was ignited and burned in atmospheric pressure air in microgravity using a 2.2-s drop tower. Combustion products were collected and analyzed using electron microscopy. The elemental composition analyses indicated that combustion product compositions fell along two linear traces on a ternary Zr–O–N diagram. Currently, the equilibrium Zr–O–N phases are not characterized at temperatures above 2000 °C, typical of zirconium combustion in air, and it is suggested that the phases detected in zirconium combustion products can serve as a guide to further studies of the Zr–O–N system at high temperatures. It is also suggested that experimental metal combustion techniques can be adopted for studying high-temperature metal–gas phase equilibria.
Advances in electron-probe microanalysis and compositional mapping: Applications to the analysis of meteorites
Publisher: Oxford University Press (OUP)
Date: 07-2009
DOI: 10.1017/S1431927609098882
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
Correction to: Harden up: metal acquisition in the weaponized ovipositors of aculeate hymenoptera
Publisher: Springer Science and Business Media LLC
Date: 16-06-2018
X-ray Mapping Analyses of Lunar Meteorite Dhofar 961: Characterization and Origin of the Mafic Impact-Melt Component
Publisher: Oxford University Press (OUP)
Date: 08-2008
DOI: 10.1017/S1431927608088788
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Short- and Long-Term Olivine Weathering in Svalbard: Implications for Mars
Publisher: Mary Ann Liebert Inc
Date: 12-2008
Abstract: Liquid water is essential to life as we know it on Earth therefore, the search for water on Mars is a critical component of the search for life. Olivine, a mineral identified as present on Mars, has been proposed as an indicator of the duration and characteristics of water because it dissolves quickly, particularly under low-pH conditions. The duration of olivine persistence relative to glass under conditions of aqueous alteration reflects the pH and temperature of the reacting fluids. In this paper, we investigate the utility of 3 methodologies to detect silicate weathering in a Mars analog environment (Sverrefjell volcano, Svalbard). CheMin, a miniature X-ray diffraction instrument developed for flight on NASA's upcoming Mars Science Laboratory, was deployed on Svalbard and was successful in detecting olivine and weathering products. The persistence of olivine and glass in Svalbard rocks was also investigated via laboratory observations of weathered hand s les as well as an in situ burial experiment. Observations of hand s les are consistent with the inference that olivine persists longer than glass at near-zero temperatures in the presence of solutions at pH approximately 7-9 on Svalbard, whereas in hydrothermally altered zones, glass has persisted longer than olivine in the presence of fluids at similar pH at approximately 50 degrees C. Analysis of the surfaces of olivine and glass s les, which were buried on Sverrefjell for 1 year and then retrieved, documented only minor incipient weathering, though these results suggest the importance of biological impacts. The 3 types of observations (CheMin, laboratory observations of hand s les, burial experiments) of weathering of olivine and glass at Svalbard show promise for interpretation of weathering on Mars. Furthermore, the weathering relationships observed on Svalbard are consistent with laboratory-measured dissolution rates, which suggests that relative mineral dissolution rates in the laboratory, in concert with field observations, can be used to yield valuable information regarding the pH and temperature of reacting martian fluids.
Plagioclase-ultraphyric basalts of the galapagos archipelago
Publisher: Elsevier BV
Date: 07-1989
EMAS 2017 Workshop - 15th European Workshop on Modern Developments and Applications in Microbeam Analysis & IUMAS-7 Meeting - 7th Meeting of the International union of Microbeam Analysis Societies
Publisher: IOP Publishing
Date: 2018
Focus on community: directions for nursing knowledge development
Publisher: Wiley
Date: 05-1999
DOI: 10.1046/J.1365-2648.1999.01003.X
Abstract: Nurses are challenged to advance the theoretical foundations of community practice. This paper offers ideas on what has been done and what needs to be done to meet this challenge. Within a community health nursing perspective, the paper defines community, proposes an integrated knowledge development framework that focuses on community, analyses contemporary theoretical and philosophical foundations of community in nursing, considers three world-views in which nursing can be framed, and examines parameters for knowledge development for the future.
The vitrified wall of Broborg hillfort in Uppland, Sweden – Response to the comments by Mr. Anders Bornfalk Back
Publisher: Elsevier BV
Date: 04-2023
Elemental Mapping of Jade by pXRF and SEM-based Micro-XRF: A Comparative Study
Publisher: Oxford University Press (OUP)
Date: 30-07-2021
Focused ion beam milling: A method of site-specific sample extraction for microanalysis of Earth and planetary materials
Publisher: Mineralogical Society of America
Date: 09-2001
Uranium irradiation history of carbonado diamond; implications for Paleoarchean oxidation in the São Francisco craton
Publisher: Geological Society of America
Date: 07-2016
DOI: 10.1130/G37749.1
Abstract: Carbonado is a porous polycrystalline diamond rock found in central African and Brazilian placer deposits. It contains unsupported radiogenic isotopes of He, Ne, Kr, Xe, and Pb. Here we show that these, and the radiation-related defects introduced to the diamond structure, are a result of uranium precipitation, with no isotopic or spectroscopic evidence of Th enrichment. The daughter products are unsupported due to Proterozoic U remobilization. Combining existing carbonado Pb isotope data with recent studies of the geochronology of the tectonic evolution of the São Francisco craton (eastern South America) reveals that the most likely scenario is Paleoarchean uranium enrichment of carbonado, followed by Mesoproterozoic uranium dissolution. Under all possible scenarios, the carbonado radiation damage history requires U mobilization in the Mesoarchean or late Paleoarchean. This is consistent with recent studies of South Africa and India Mesoarchean paleosols, which also show evidence for local oxygen activity greater than that of the Archean atmosphere and ocean. While those studies rely on whole-rock trace element and transition metal stable isotope measurements, this combination of crystallographic defects, sedimentary geochronology, and radiogenic isotopes supports the same conclusions of nonmarine, near-surface Archean oxygen enhancement.
Welcome to this Microscopy and Microanalysis meeting, M & M 2014 in Hartford, Connecticut!
Publisher: Oxford University Press (OUP)
Date: 08-2014
Element abundances, patterns, and mobility in Nakhlite Miller Range 03346 and implications for aqueous alteration
Publisher: Elsevier BV
Date: 07-2013
Challenges Involved In X-Ray Microanalysis Of The Mineral Kernite [Na2B4O6(OH)2P3H2O]
Publisher: Oxford University Press (OUP)
Date: 07-2009
DOI: 10.1017/S1431927609099322
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
Auger Electron Spectroscopy of Kernite: Coaxing Useful Information Out of a Recalcitrant Specimen
Publisher: Oxford University Press (OUP)
Date: 07-2009
DOI: 10.1017/S1431927609099681
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
The Galapagos volcano Alcedo: A unique ocean caldera
Publisher: Elsevier BV
Date: 10-1985
“Live” Prussian blue fading by time-resolved X-ray absorption spectroscopy
Publisher: Springer Science and Business Media LLC
Date: 30-01-2013
Water by EPMA- New Developments
Publisher: Oxford University Press (OUP)
Date: 08-2008
DOI: 10.1017/S1431927608082615
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Optimizing compositional images of daguerreotype photographs using post processing methods
Publisher: Springer Science and Business Media LLC
Date: 27-05-2016
Investigation of Atomic Layer Deposited Metal Oxide Layers for Conservation of Metal Cultural Heritage Objects*
Publisher: Oxford University Press (OUP)
Date: 08-2014
Hyperspectral X-ray Analysis of Submicrometer-scale Heterogeneities in a Venerable Compositional Standard Provided by Nature: Kakanui Hornblende
Publisher: Oxford University Press (OUP)
Date: 08-2008
DOI: 10.1017/S1431927608089137
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Examination of Heritage and Geological Materials Using Correlated Electron- and X-ray-Beam Microanalysis in the SEM
Publisher: Oxford University Press (OUP)
Date: 08-2019
Micro XRF Imaging of Daguerreotypes
Publisher: Oxford University Press (OUP)
Date: 08-2014
Effect of Fibre Treatment on Tensile Properties in Bamboo Fibre Extraction: A Review Paper
Publisher: Springer Singapore
Date: 2022
Determining the Local Bulk Chemistry of Martian Aqueous Alteration via X-ray Spectrum Imaging: A Link to Global Dust on Mars?
Publisher: Oxford University Press (OUP)
Date: 08-2004
DOI: 10.1017/S1431927604887075
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.
Iron-Magnesium Silicate Bioweathering on Earth (and Mars?)
Publisher: Mary Ann Liebert Inc
Date: 02-2006
Abstract: We examined the common, iron-magnesium silicate minerals olivine and pyroxene in basalt and in mantle rocks to determine if they exhibit textures similar to bioweathering textures found in glass. Our results show that weathering in olivine may occur as long, narrow tunnels (1-3 microm in diameter and up to 100 microm long) and as larger irregular galleries, both of which have distinctive characteristics consistent with biological activity. These weathering textures are associated with clay mineral by-products and nucleic acids. We also examined olivine and pyroxene in martian meteorites, some of which experienced preterrestrial aqueous alteration. Some olivines and pyroxenes in the martian meteorite Nakhla were found to contain tunnels that are similar in size and shape to tunnels in terrestrial iron-magnesium silicates that contain nucleic acids. Though the tunnels found in Nakhla are similar to the biosignatures found in terrestrial minerals, their presence cannot be used to prove that the martian alteration features had a biogenic origin. The abundance and wide distribution of olivine and pyroxene on Earth and in the Solar System make bioweathering features in these minerals potentially important new biosignatures that may play a significant role in evaluating whether life ever existed on Mars.
Quantitative and Qualitative Correlation of CL and X-ray Signals in Cr-bearing Jade from Chichén-Itzá Archaeological Zone, Mexico
Publisher: Oxford University Press (OUP)
Date: 08-2022
Chaos Theory and Some Nursing Considerations
Publisher: SAGE Publications
Date: 03-1994
DOI: 10.1177/089431849400700112
Abstract: The alleged synthesis of nursing and public health has not produced the expected community-as-client emphasis. Public health is characterized as disease-focused, with masculine domination, using a causal model. The explanatory model of chaos challenges nurses to reexamine nursing's theoretical base by questioning assumptions associated with linear thinking. The selected chaotic concepts of a periodicity, attractors, sensitive dependence on initial conditions, phase space, and fractals are discussed here. Each concept's connection to physics and mathematics is cited and considerations for nursing science are outlined. Conclusions include redefining health, nursing, and community in chaotic terms and renaming nursing practice, which has this a periodic and holistic paradigm, as ecologic health nursing.
The geology and geochemistry of Isla Marchena, Galapagos Archipelago: An ocean island adjacent to a mid-ocean ridge
Publisher: Elsevier BV
Date: 06-1990
Reproduction of melting behavior for vitrified hillforts based on amphibolite, granite, and basalt lithologies
Publisher: Springer Science and Business Media LLC
Date: 14-01-2021
DOI: 10.1038/S41598-020-80485-W
Abstract: European Bronze and Iron Age vitrified hillforts have been known since the 1700s, but archaeological interpretations regarding their function and use are still debated. We carried out a series of experiments to constrain conditions that led to the vitrification of the inner wall rocks in the hillfort at Broborg, Sweden. Potential source rocks were collected locally and heat treated in the laboratory, varying maximum temperature, cooling rate, and starting particle size. Crystalline and amorphous phases were quantified using X-ray diffraction both in situ, during heating and cooling, and ex situ, after heating and quenching. Textures, phases, and glass compositions obtained were compared with those for rock s les from the vitrified part of the wall, as well as with equilibrium crystallization calculations. ‘Dark glass’ and its associated minerals formed from hibolite or dolerite rocks melted at 1000–1200 °C under reducing atmosphere then slow cooled. ‘Clear glass’ formed from non-equilibrium partial melting of feldspar in granitoid rocks. This study aids archaeological forensic investigation of vitrified hillforts and interpretation of source rock material by mapping mineralogical changes and glass production under various heating conditions.
Hyperspectral cathodoluminescence examination of defects in a carbonado diamond
Publisher: Oxford University Press (OUP)
Date: 12-2012
DOI: 10.1017/S1431927612013578
Abstract: Hyperspectral cathodoluminescence mapping is used to examine a carbonado diamond. The hyperspectral dataset is examined using a data clustering algorithm to interpret the range of spectral shapes present within the dataset, which are related to defects within the structure of the diamond. The cathodoluminescence response from this particular carbonado diamond can be attributed to a small number of defect types: N-V 0 , N 2 V, N 3 V, a 3.188 eV line, which is attributed to radiation damage, and two broad luminescence bands. Both the N 2 V and 3.188 eV defects require high-temperature annealing, which has implications for interpreting the thermal history of the diamond. In addition, bright halos observed within the diamond cathodoluminescence, from alpha decay radiation damage, can be attributed to the decay of 238 U.
Rock varnish on architectural stone: microscopy and analysis of nanoscale manganese oxide deposits on the Smithsonian Castle, Washington, DC
Publisher: Springer Science and Business Media LLC
Date: 22-07-2016
Tailoring a sexual health curriculum to the sexual health challenges seen by midwifery, nursing and medical providers and students in Tanzania
Publisher: AOSIS
Date: 31-05-2022
Examination of a 19th Century Daguerreotype Photograph using High Resolution Scanning Transmission Electron Microscopy for 2D and 3D Nanoscale Imaging and Analysis
Publisher: Oxford University Press (OUP)
Date: 08-2014
MICRO-ANALYTICAL STUDY OF THE OPTICAL PROPERTIES OF RAINBOW AND SHEEN OBSIDIANS
Publisher: Mineralogical Association of Canada
Date: 02-2001
A Combined EPMA and Cathodoluminescence Study of Minerals from Franklin NJ
Publisher: Oxford University Press (OUP)
Date: 07-2012
DOI: 10.1017/S1431927612010586
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.
AIDS Education on the College Campus: Roy's Adaptation Model Directs Inquiry
Publisher: Wiley
Date: 12-1992
DOI: 10.1111/J.1525-1446.1992.TB00112.X
Abstract: We assessed the beliefs of 49 college students regarding the acquired immunodeficiency syndrome (AIDS), condom use, and sexual behaviors related to AIDS prevention. Roy's modes of self-concept, interdependence, and role function were used as a framework to find psychosocial determinants that influence safer sex practices. Interdependence was measured by a sexual regard scale. Beliefs regarding both AIDS beliefs and condom were very positive. Students were selectively using safer sex practices most reported avoiding high-risk partners, but only 39% were using condoms. No significant associations were found among the four independent measures of AIDS beliefs, condom beliefs, self-esteem, and sexual regard or with the dependent measure, AIDS safer sex practices. A two-hour safer sex educational module did change several beliefs but did not increase safer sex practices. Most participating students stated they had a good understanding of how AIDS was spread, they knew how to use condoms correctly, and they discussed AIDS with friends and parents.
Pre‐Viking Swedish hillfort glass: A prospective long‐term alteration analogue for vitrified nuclear waste
Publisher: Wiley
Date: 14-04-2018
DOI: 10.1111/IJAG.12351
Semitransparent cathodes for organic light emitting devices
Publisher: AIP Publishing
Date: 15-03-2000
DOI: 10.1063/1.372303
Abstract: We optimize transparent organic light emitting devices (TOLEDs) using compound cathodes consisting of a thermally evaporated metal contact layer capped with indium–tin–oxide (ITO). The ITO is sputtered at rates of up to 1.6 Å/s using a high power radio frequency magnetron process. With a Mg:Ag contact layer, we demonstrate a TOLED with 50% transparency and an operating voltage within 0.3 V of a device with identical organic layers and a conventional Mg:Ag cathode. The operational lifetime of the TOLED is shown to be equal to that of a similar, nontransparent device. We also study the effects of using different contact metals, including Ca, Al and LiF, on the operating characteristics of the TOLEDs. With a thin Ca contact layer, undoped TOLEDs with & % peak transparency operating at (5.9±0.1) V at a brightness of & cd/m2 are demonstrated. These devices have application to transparent, head-up displays and to full color, stacked organic light emitting devices.
Modal abundances of pyroxene, olivine, and mesostasis in nakhlites: Heterogeneity, variation, and implications for nakhlite emplacement
Publisher: Wiley
Date: 19-08-2015
DOI: 10.1111/MAPS.12492
The Anoka, Minnesota iron meteorite as parent to Hopewell meteoritic metal beads from Havana, Illinois
Publisher: Elsevier BV
Date: 05-2017
Hydrogen isotope evidence for loss of water from Mars through time
Publisher: American Geophysical Union (AGU)
Date: 03-2008
DOI: 10.1029/2007GL032721
Chemical heterogeneity in carbonado, an enigmatic polycrystalline diamond
Publisher: Elsevier BV
Date: 02-2001
Compositional Imaging and Analysis of Late Iron Age Glass from the Broborg Vitrified Hillfort, Sweden
Publisher: Oxford University Press (OUP)
Date: 08-2018
Why does Prussian blue fade? Understanding the role(s) of the substrate
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3JA50025J
Exposure and analysis of microparticles embedded in silica aerogel keystones using NF 3‐mediated electron beam–induced etching and energy‐dispersive X‐ray spectroscopy
Publisher: Wiley
Date: 29-04-2016
DOI: 10.1111/MAPS.12655
Comet 81P/Wild 2 Under a Microscope
Publisher: American Association for the Advancement of Science (AAAS)
Date: 15-12-2006
Abstract: The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these s les shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.
Correlation confidence limits for unevenly sampled data
Publisher: Elsevier BV
Date: 07-2016
Elemental Geochemistry of Sedimentary Rocks at Yellowknife Bay, Gale Crater, Mars
Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-01-2014
Abstract: Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions. Analyses of diagenetic features (including concretions, raised ridges, and fractures) at high spatial resolution indicate that they are composed of iron- and halogen-rich components, magnesium-iron-chlorine–rich components, and hydrated calcium sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. The geochemistry of these sedimentary rocks provides further evidence for erse depositional and diagenetic sedimentary environments during the early history of Mars.
CHAOS IN NURSING
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-1997
Clinical Care of Victims of Interpersonal Violence and Rape in Tanzania: A Qualitative Investigation
Publisher: Informa UK Limited
Date: 07-2021
DOI: 10.2147/IJWH.S301804
Assessment of the reason for the vitrification of a wall at a hillfort. The example of Broborg in Sweden
Publisher: Elsevier BV
Date: 06-2022
Microanalysis of Glass Fluid Storage Vials from The Invertebrate Zoology Collection at the National Museum of Natural History
Publisher: Oxford University Press (OUP)
Date: 30-07-2021
Major to trace element imaging and analysis of iron age glasses using stage scanning in the analytical dual beam microscope (tandem)
Publisher: Springer Science and Business Media LLC
Date: 16-06-2022
DOI: 10.1186/S40494-022-00707-4
Abstract: Dark and clear silicate glasses formed during an iron age vitrification event ≈ 1500 years ago at the Broborg hillfort near Uppsala, Sweden have been analyzed using a scanning electron microscope equipped with a micro-X-ray fluorescence (μXRF) spectrometer. Correlated µXRF and electron beam-induced energy dispersive spectrometry (EDS) X-ray maps were collected via stage-scanning at constant velocity. This coupled procedure represents a new approach for the cultural heritage community to conduct analytical studies of archaeometric specimens composed of metal, ceramic, or mixed inorganic/organic materials, where major and trace element compositions are registered in space for areas up to the centimeter-length scale at micrometer-scale resolution. Overview images were used to select areas for EDS beam scan maps correlated with multispectral cathodoluminescence (CL) imaging and co-located quantitative EDS and μXRF point analysis. Fe, Ca, Mg, Ti, P, Mn, Zr, Zn, and Y are enriched in the dark glass, while Si, Al, K, Na, Ba, Sr, Rb, and Ga are enriched in the clear glass. Unmelted material is comprised predominately of quartz (SiO 2 ) along with trace apatite (Ca 5 (PO 4 ) 3 [Cl,OH]) and zircon (ZrSiO 4 ). Multivariate statistical analysis was used to measure the area fractions of high variance components while lower variance components represented phase mixtures. Differences between calculated melt viscosities for the glass compositions are consistent with field and laboratory observations. Coupled large area EDS and μXRF imaging shows significant promise for informed selection of higher spatial resolution and higher sensitivity follow-up studies, e.g., those performed using synchrotron analysis. Graphical Abstract
An Examination of Kernite (Na2B4O6(OH)2·3H2O) Using X-Ray and Electron Spectroscopies: Quantitative Microanalysis of a Hydrated Low-Z Mineral
Publisher: Oxford University Press (OUP)
Date: 06-09-2011
DOI: 10.1017/S1431927611000602
Abstract: Mineral borates, the primary industrial source of boron, are found in a large variety of compositions. One such source, kernite (Na 2 B 4 O 6 (OH) 2 ·3H 2 O), offers an array of challenges for traditional electron-probe microanalysis (EPMA)—it is hygroscopic, an electrical insulator, composed entirely of light elements, and sensitive to both low pressures and the electron beam. However, the approximate stoichiometric composition of kernite can be analyzed with careful preparation, proper selection of reference materials, and attention to the details of quantification procedures, including correction for the time dependency of the sodium X-ray signal. Moreover, a reasonable estimation of the mineral's water content can also be made by comparing the measured oxygen to the calculated stoichiometric oxygen content. X-ray diffraction, variable-pressure electron imaging, and visual inspection elucidate the structural consequences of high vacuum treatment of kernite, while Auger electron spectroscopy and X-ray photoelectron spectroscopy confirm electron beam-driven migration of sodium and oxygen out of the near-surface region (s ling depth ≈ 2 nm). These surface effects are insufficiently large to significantly affect the EPMA results (s ling depth ≈ 400 nm at 5 keV).
Mineralogy of a Mudstone at Yellowknife Bay, Gale Crater, Mars
Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-01-2014
Abstract: Sedimentary rocks at Yellowknife Bay (Gale crater) on Mars include mudstone s led by the Curiosity rover. The s les, John Klein and Cumberland, contain detrital basaltic minerals, calcium sulfates, iron oxide or hydroxides, iron sulfides, amorphous material, and trioctahedral smectites. The John Klein smectite has basal spacing of ~10 angstroms, indicating little interlayer hydration. The Cumberland smectite has basal spacing at both ~13.2 and ~10 angstroms. The larger spacing suggests a partially chloritized interlayer or interlayer magnesium or calcium facilitating H 2 O retention. Basaltic minerals in the mudstone are similar to those in nearby eolian deposits. However, the mudstone has far less Fe-forsterite, possibly lost with formation of smectite plus magnetite. Late Noachian/Early Hesperian or younger age indicates that clay mineral formation on Mars extended beyond Noachian time.
In Situ Radiometric and Exposure Age Dating of the Martian Surface
Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-01-2014
Abstract: We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 ± 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray–produced 3 He, 21 Ne, and 36 Ar yield concordant surface exposure ages of 78 ± 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.
Filtration Efficiencies of Nanoscale Aerosol by Cloth Mask Materials Used to Slow the Spread of SARS-CoV-2
Publisher: American Chemical Society (ACS)
Date: 25-06-2020
The fate of subducted oceanic slabs in the shallow mantle: Insights from boron isotopes and light element composition of metasomatized blueschists from the Mariana forearc
Publisher: Elsevier BV
Date: 02-2012
Laser Cleaning Iron Meteorite Corrosion, A Microstructural and Compositional Examination
Publisher: Oxford University Press (OUP)
Date: 08-2018
Elemental Compositions of Comet 81P/Wild 2 Samples Collected by Stardust
Publisher: American Association for the Advancement of Science (AAAS)
Date: 15-12-2006
Abstract: We measured the elemental compositions of material from 23 particles in aerogel and from residue in seven craters in aluminum foil that was collected during passage of the Stardust spacecraft through the coma of comet 81P/Wild 2. These particles are chemically heterogeneous at the largest size scale analyzed (â¼180 ng). The mean elemental composition of this Wild 2 material is consistent with the CI meteorite composition, which is thought to represent the bulk composition of the solar system, for the elements Mg, Si, Mn, Fe, and Ni to 35%, and for Ca and Ti to 60%. The elements Cu, Zn, and Ga appear enriched in this Wild 2 material, which suggests that the CI meteorites may not represent the solar system composition for these moderately volatile minor elements.
Development of Redox-Active Optical Mesostructures at Chemically Modified Electrode Interfaces
Publisher: American Chemical Society (ACS)
Date: 08-1995
DOI: 10.1021/IC00120A036
Use of Mineral Reference Standards in EPMA: Instrumental Calibration, Standards Comparison, and Quality Control
Publisher: Oxford University Press (OUP)
Date: 07-2017
REVIEW: USES OF THEORY IN COMMUNITY HEALTH NURSING
Publisher: Wiley
Date: 04-1995
An in-depth look at how physical properties of cleaning materials affect the removal of soot from rough papers
Publisher: Oxford University Press (OUP)
Date: 30-07-2021
Microscopic Identification of Micro-Organisms on Pre-Viking Swedish Hillfort Glass
Publisher: Oxford University Press (OUP)
Date: 08-2018
Volatile and Organic Compositions of Sedimentary Rocks in Yellowknife Bay, Gale Crater, Mars
Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-01-2014
Abstract: H 2 O, CO 2 , SO 2 , O 2 , H 2 , H 2 S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone s les acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H 2 O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO 2 . Concurrent evolution of O 2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.
Nondestructive Microanalysis of Thin-Film Coatings on Historic Metal Threads
Publisher: American Chemical Society (ACS)
Date: 15-09-2021
Growth and Characterization of Photoactive and Electroactive Zirconium Bisphosphonate Multilayer Films
Publisher: American Chemical Society (ACS)
Date: 1996
DOI: 10.1021/CM9600586
Filter Inserts Impact Cloth Mask Performance against Nano- to Micro-Sized Particles
Publisher: American Chemical Society (ACS)
Date: 12-07-2021
Abstract: The United States Centers for Disease Control and Prevention and World Health Organization recognize that wearing cloth face coverings can slow the transmission of respiratory diseases via source control. Adding a partial layer of material with a high filtration efficiency (FE, e . g ., polypropylene sheets that meet the HEPA standard) as an insert can potentially provide additional personal protection however, data on the necessary areal coverage are sparse. The relationship between insert area ratio (IAR) relative to fabric area, FE, differential pressure (Δ P, a surrogate for breathability), and quality factor (QF, a ratio including FE and Δ P ) utilizing two fabrics (rayon and 100% cotton lightweight flannel) and three insert materials (HEPA vacuum bag, sterilization wrap and paper coffee filter) was investigated. The effect of inserts on particle flows mimicking human exhalation is semiquantitatively and qualitatively examined using flow visualization techniques. The following was found: (1) The relationship between FE, Δ P , and QF is complex, and a trade-off exists between personal protection from filtration during inhalation and source control from leakage during exhalation (2) FE and Δ P of the composite covering increase with IAR, and the rate is dependent upon insert type (3) improvements (decrements) in the QF of the composite assemblage require inserts with a higher (lower) QF than the fabric and larger differences yield greater gains (losses) (4) the increased Δ P from an insert results in increased leakage during exhalation (5) to minimize leaks, Δ P must be as low as possible and (6) small relative areas not covered by an insert ( i . e ., IAR slightly smaller than 1) strongly deteriorate the benefits of an insert similar to small leaks in a covering.
The kinematic differences between off-spin and leg-spin bowling in cricket
Publisher: Informa UK Limited
Date: 29-04-2016
DOI: 10.1080/14763141.2016.1161819
Abstract: Spin bowling is generally coached using a standard technical framework, but this practice has not been based upon a comparative biomechanical analysis of leg-spin and off-spin bowling. This study analysed the three-dimensional (3D) kinematics of 23 off-spin and 20 leg-spin bowlers using a Cortex motion analysis system to identify how aspects of the respective techniques differed. A multivariate ANOVA found that certain data tended to validate some of the stated differences in the coaching literature. Off-spin bowlers had a significantly shorter stride length (p = 0.006) and spin rate (p = 0.001), but a greater release height than leg-spinners (p = 0.007). In addition, a number of other kinematic differences were identified that were not previously documented in coaching literature. These included a larger rear knee flexion (p = 0.007), faster approach speed (p < 0.001), and flexing elbow action during the arm acceleration compared with an extension action used by most of the off-spin bowlers. Off-spin and leg-spin bowlers also deviated from the standard coaching model for the shoulder alignment, front knee angle at release, and forearm mechanics. This study suggests that off-spin and leg-spin are distinct bowling techniques, supporting the development of two different coaching models in spin bowling.
Mineral Reference Standards and Quantitative Electron-Probe Microanalysis
Publisher: Oxford University Press (OUP)
Date: 07-2012
DOI: 10.1017/S1431927612010525
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.
Harden up: metal acquisition in the weaponized ovipositors of aculeate hymenoptera
Publisher: Springer Science and Business Media LLC
Date: 26-03-2018
Effect of oxygen fugacity on trace-element partitioning between immiscible silicate melts at atmospheric pressure: A proton and electron microprobe study
Publisher: Elsevier BV
Date: 11-1994
Home- and Laboratory-based Microscopy of Face Covering Materials
Publisher: Oxford University Press (OUP)
Date: 30-07-2021
A two thousand year annual record of snow accumulation rates for Law Dome, East Antarctica
Publisher: Copernicus GmbH
Date: 28-11-2014
Abstract: Abstract. Accurate high resolution records of snow accumulation rates in Antarctica are crucial for estimating ice sheet mass balance and subsequent sea level change. Snowfall rates at Law Dome, East Antarctica, have been linked with regional atmospheric circulation to mid-latitudes as well as regional Antarctic snowfall. Here, we extend the Law Dome accumulation record from 750 to 2035 years, using recent annual layer dating that extends to AD −22. Accumulation rates were calculated as the ratio of measured to modelled layer thicknesses, multiplied by the long term mean accumulation rate. The modelled layer thicknesses were based on a power law vertical strain rate profile fitted to observed annual layer thickness. The periods AD 380–442, AD 727–783 and AD 1970–2009 have above average snow accumulation rates, while AD 663–704, AD 933–975 and AD 1429–1468 were below average. The calculated snow accumulation rates show good correlation with atmospheric reanalysis estimates, and significant spatial correlation over a wide expanse of East Antarctica, demonstrating that the Law Dome record captures larger scale variability across a large region of East Antarctica well beyond the immediate vicinity of the Law Dome summit. Spectral analysis reveals periodicities in the snow accumulation record which may be related to ENSO and Interdecadal Pacific Oscillation frequencies.
Systematics of cathodoluminescence and trace element compositional zoning in natural quartz from volcanic rocks: Ti mapping in quartz
Publisher: Oxford University Press (OUP)
Date: 08-2008
DOI: 10.1017/S1431927608088995
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Structure of a Novel Layered Zirconium Diphosphonate Compound: Zr2(O3PCH2CH2-viologen-CH2CH2PO3)F6.cntdot.2H2O
Publisher: American Chemical Society (ACS)
Date: 10-1994
DOI: 10.1021/CM00046A045
An MCIA-like complex is required for mitochondrial complex I assembly and seed development in maize
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.MOLP.2022.08.001
Abstract: During adaptive radiation, mitochondria have co-evolved with their hosts, leading to gain or loss of subunits and assembly factors of respiratory complexes. Plant mitochondrial complex I harbors ∼40 nuclear- and 9 mitochondrial-encoded subunits, and is formed by stepwise assembly during which different intermediates are integrated via various assembly factors. In mammals, the mitochondrial complex I intermediate assembly (MCIA) complex is required for building the membrane arm module. However, plants have lost almost all of the MCIA complex components, giving rise to the hypothesis that plants follow an ancestral pathway to assemble the membrane arm subunits. Here, we characterize a maize crumpled seed mutant, crk1, and reveal by map-based cloning that CRK1 encodes an ortholog of human complex I assembly factor 1, zNDUFAF1, the only evolutionarily conserved MCIA subunit in plants. zNDUFAF1 is localized in the mitochondria and accumulates in two intermediate complexes that contain complex I membrane arm subunits. Disruption of zNDUFAF1 results in severe defects in complex I assembly and activity, a cellular bioenergetic shift to aerobic glycolysis, and mitochondrial vacuolation. Moreover, we found that zNDUFAF1, the putative mitochondrial import inner membrane translocase ZmTIM17-1, and the isovaleryl-coenzyme A dehydrogenase ZmIVD1 interact each other, and could be co-precipitated from the mitochondria and co-migrate in the same assembly intermediates. Knockout of either ZmTIM17-1 or ZmIVD1 could lead to the significantly reduced complex I stability and activity as well as defective seeds. These results suggest that zNDUFAF1, ZmTIM17-1 and ZmIVD1 probably form an MCIA-like complex that is essential for the biogenesis of mitochondrial complex I and seed development in maize. Our findings also imply that plants and mammals recruit MCIA subunits independently for mitochondrial complex I assembly, highlighting the importance of parallel evolution in mitochondria adaptation to their hosts.
Phases of Titanium Combustion in Air
Publisher: Elsevier BV
Date: 03-1998
Applying laboratory methods for durability assessment of vitrified material to archaeological samples
Publisher: Springer Science and Business Media LLC
Date: 12-11-2021
DOI: 10.1038/S41529-021-00204-2
Abstract: Laboratory testing used to assess the long-term chemical durability of nuclear waste forms may not be applicable to disposal because the accelerated conditions may not represent disposal conditions. To address this, we examine the corrosion of vitrified archeological materials excavated from the near surface of a ~1500-year old Iron Age Swedish hillfort, Broborg, as an analog for the disposal of vitrified nuclear waste. We compare characterized site s les with corrosion characteristics generated by standard laboratory durability test methods including the product consistency test (PCT), the vapor hydration test (VHT), and the EPA Method 1313 test. Results show that the surficial layer of the Broborg s les resulting from VHT displays some similarities to the morphology of the surficial layer formed over longer timescales in the environment. This work provides improved understanding of long-term glass corrosion behavior in terms of the thickness, morphology, and chemistry of the surficial features that are formed.
A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars
Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-01-2014
Abstract: The Curiosity rover discovered fine-grained sedimentary rocks, which are inferred to represent an ancient lake and preserve evidence of an environment that would have been suited to support a martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and sulfur species. Carbon, hydrogen, oxygen, sulfur, nitrogen, and phosphorus were measured directly as key biogenic elements by inference, phosphorus is assumed to have been available. The environment probably had a minimum duration of hundreds to tens of thousands of years. These results highlight the biological viability of fluvial-lacustrine environments in the post-Noachian history of Mars.
Microstructural study of synthetic sintered diamond and comparison with carbonado, a natural polycrystalline diamond
Publisher: Mineralogical Society of America
Date: 02-2004
A cornucopia of presolar and early solar system materials at the micrometer size range in primitive chondrite matrix
Publisher: Wiley
Date: 08-2007
TOF‐SIMS analysis of cometary matter in Stardust aerogel tracks
Publisher: Wiley
Date: 02-2008
DOI: 10.1111/J.1945-5100.2008.TB00619.X
Abstract: Abstract— Cometary matter in aerogel s les from the Stardust mission was investigated with TOF‐SIMS for its elemental and organic composition. While single grains μm are highly variable in their chemical composition, nanometer‐scale material found in the wall of one track has within a factor of 1.22 bulk CI chondritic element ratios relative to Fe for Na, Mg, A1, Ti, Cr, Mn, and Co. Compared to CI, a depletion in Ca by a factor of four and an enrichment in Ni by a factor of two was observed. These results seem to confirm recent reports of a CI‐like bulk composition of Wild 2. The analysis of organic compounds in aerogel s les is complicated by the presence of contaminants in the capture medium. However, polycyclic aromatic hydrocarbons that could possibly be attributed to the comet were observed.
Bridging the Micro-to-Macro Gap: A New Application for Micro X-Ray Fluorescence
Publisher: Oxford University Press (OUP)
Date: 23-05-2011
DOI: 10.1017/S1431927611000183
Abstract: X-ray elemental mapping and X-ray spectrum imaging are powerful microanalytical tools. However, their scope is often limited spatially by the raster area of a scanning electron microscope or microprobe. Limited s ling size becomes a significant issue when large area ( cm 2 ), heterogeneous materials such as concrete s les or others must be examined. In such specimens, macro-scale structures, inclusions, and concentration gradients are often of interest, yet microbeam methods are insufficient or at least inefficient for analyzing them. Such requirements largely exclude the s les of interest presented in this article from electron probe microanalysis. Micro X-ray fluorescence–X-ray spectrum imaging (μXRF-XSI) provides a solution to the problem of macro-scale X-ray imaging through an X-ray excitation source, which can be used to analyze a variety of large specimens without many of the limitations found in electron-excitation sources. Using a mid-sized beam coupled with an X-ray excitation source has a number of advantages, such as the ability to work at atmospheric pressure and lower limits of detection owing to the absence of electron-induced bremsstrahlung. μXRF-XSI also acts as a complement, where applicable, to electron microbeam X-ray output, highlighting areas of interest for follow-up microanalysis at a finer length scale.
Micro- and Nanoscale Surface Analysis of Late Iron Age Glass from Broborg, a Vitrified Swedish Hillfort
Publisher: Oxford University Press (OUP)
Date: 11-01-2023
Abstract: Archaeological glasses with prolonged exposure to biogeochemical processes in the environment can be used to understand glass alteration, which is important for the safe disposal of vitrified nuclear waste. S les of mafic and felsic glasses with different chemistries, formed from melting hibolitic and granitoid rocks, were obtained from Broborg, a Swedish Iron Age hillfort. Glasses were excavated from the top of the hillfort wall and from the wall interior. A detailed microscopic, spectroscopic, and diffraction study of surficial textures and chemistries were conducted on these glasses. Felsic glass chemistry was uniform, with a smooth surface showing limited chemical alteration (& nm), irrespective of the position in the wall. Mafic glass was heterogeneous, with pyroxene, spinel, feldspar, and quartz crystals in the glassy matrix. Mafic glass surfaces in contact with topsoil were rougher than those within the wall and had carbon-rich material consistent with microbial colonization. Limited evidence for chemical or physical alteration of mafic glass was found the thin melt film that coated all exposed surfaces remained intact, despite exposure to hydraulically unsaturated conditions, topsoil, and associated microbiome for over 1,500 years. This supports the assumption that aluminosilicate nuclear waste glasses will have a high chemical durability in near-surface disposal facilities.
Nanoscale Analysis of Manganeous Oxide Rock Varnish on the Smithsonian Castle, Washington, DC
Publisher: Oxford University Press (OUP)
Date: 08-2019
Soil Diversity and Hydration as Observed by ChemCam at Gale Crater, Mars
Publisher: American Association for the Advancement of Science (AAAS)
Date: 27-09-2013
Abstract: The ChemCam instrument, which provides insight into martian soil chemistry at the submillimeter scale, identified two principal soil types along the Curiosity rover traverse: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic soil component is representative of widespread martian soils and is similar in composition to the martian dust. It possesses a ubiquitous hydrogen signature in ChemCam spectra, corresponding to the hydration of the amorphous phases found in the soil by the CheMin instrument. This hydration likely accounts for an important fraction of the global hydration of the surface seen by previous orbital measurements. ChemCam analyses did not reveal any significant exchange of water vapor between the regolith and the atmosphere. These observations provide constraints on the nature of the amorphous phases and their hydration.
A Comparison of Materials for Dry Surface Cleaning Soot-Coated Papers of Varying Roughness: Assessing Efficacy, Physical Surface Changes, and Residue
Publisher: Informa UK Limited
Date: 20-03-2023
Characterizing the Effectiveness of Atomic Layer Deposited Coatings for the Prevention of Glass Disease
Publisher: Oxford University Press (OUP)
Date: 07-2017
Condensed-phase modifications in magnesium particle combustion in air
Publisher: Elsevier BV
Date: 07-2000
Understanding Effects Responsible for Pinhole Development and Coating Adhesion for Atomic Layer Deposited Coatings on Glass
Publisher: Oxford University Press (OUP)
Date: 08-2018
Manganese in Black Crusts on Seneca Sandstone
Publisher: Oxford University Press (OUP)
Date: 08-2014
Evidence for boron incorporation into the serpentine crystal structure
Publisher: Mineralogical Society of America
Date: 24-06-2011
DOI: 10.2138/AM.2011.3709
A Cathodoluminescene (and Raman) Imaging and Spectroscopic Study of Ancient Polycrystalline Diamond
Publisher: Oxford University Press (OUP)
Date: 31-07-2006
DOI: 10.1017/S1431927606069807
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Three-dimensional Microanalysis Using FIB SEM: Variations in Technique
Publisher: Oxford University Press (OUP)
Date: 07-2009
DOI: 10.1017/S143192760909744X
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
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