ANSTO :: Browsing by Author "Atanacio, AJ"

Browsing by Author "Atanacio, AJ"

Now showing 1 - 20 of 93

Airborne ultrafine particles in a Pacific Island country: characteristics, sources and implications for human exposure
(Elsevier, 2017-09-25) Isley, CF; Nelson, PF; Taylor, MP; Mazaheri, M; Morawska, L; Atanacio, AJ; Stelcer, E; Cohen, DD; Morrison, AL
The Pacific Islands carry a perception of having clean air, yet emissions from transport and burning activities are of concern in regard to air quality and health. Ultrafine particle number concentrations (PNCs), one of the best metrics to demonstrate combustion emissions, have not been measured either in Suva or elsewhere in the Islands. This work provides insight into PNC variation across Suva and its relationship with particle mass (PM) concentration and composition. Measurements over a short monitoring campaign provide a vignette of conditions in Suva. Ambient PNCs were monitored for 8 day at a fixed location, and mobile PNC sampling for two days. These were compared with PM concentration (TSP, PM10, PM2.5, PM1) and are discussed in relation to black carbon (BC) content and PM2.5 sources, determined from elemental concentrations; for the October 2015 period and longer-term data. Whilst Suva City PM levels remained fairly low, PM2.5 = 10–12 μg m−3, mean PNC (1.64 ± 0.02 × 104 cm−3) was high compared to global data. PNCs were greater during mobile sampling, with means of 10.3 ± 1.4 × 104 cm−3 and 3.51 ± 0.07 × 104 cm−3 when travelling by bus and taxi, respectively. Emissions from road vehicles, shipping, diesel and open burning were identified as PM sources for the October 2015 period. Transport related ultrafine particle emissions had a significant impact on microscale ambient concentrations, with PNCs near roads being 1.5 to 2 times higher than nearby outdoor locations and peak PNCs occurring during peak traffic times. Further data, particularly on transport and wet-season exposures, are required to confirm results. Understanding PNC in Suva will assist in formulating effective air emissions control strategies, potentially reducing population exposure across the Islands and in developing countries with similar emission characteristics. Suva's PNC was high in comparison to global data; high exposures were related to transport and combustion emissions, which were also identified as significant PM2.5 sources. © 2017 Elsevier Ltd.
Ambient air quality and indoor exposure: PM2.5 implications for health in Suva Fiji
(Clean Air Society of Australia and New Zealand, 2018-03-01) Isley, CF; Nelson, PF; Taylor, MP; Morrison, AL; Atanacio, AJ; Stelcer, E; Cohen, DD
Air quality data collected at urban background locations is often assumed to represent a wider urban area. Localised sources and conditions can however cause variation between different microenvironments in the same urban area. Differences in PM2.5 (particulate less than 2.5 μm) composition may also have greater implications for health outcomes than PM2.5 concentration considered alone. Samples of PM2.5 were collected for three outdoor and nine indoor microenvironments across Suva, Fiji in 2014/15. Elemental concentration data have been used to estimate source contributions to PM2.5 for each site. The 12 sites are compared to concurrent ambient measurements at a fixed monitoring site in Suva City and to ambient photometer data. The objective is to determine how well ambient measurements represent air quality across the city, including indoor environments. Surveys were used to determine how much time is spent indoors and outdoors by Suva residents to ascertain potential exposure risks. Results show that PM2.5 concentration and composition varies significantly between the different microenvironments studied. Indoor air quality was affected by both ambient air and indoor sources. Fuel used for cooking, particularly wood and kerosene, influenced indoor PM2.5 and black carbon. Given that the survey showed that people spend more time indoors than outdoors, as experienced elsewhere in the world, ambient measures of PM2.5 concentration and calculated related health risk does not accurately reflect exposures arising from city indoor microenvironments. © 2018 The Clean Air Society of Australia and New Zealand
Analysing the air: experiences and results of long term air pollution monitoring in the Asia-Pacific region using nuclear analysis techniques
(Philippine Nuclear Research Institute, 2015-12-07) Atanacio, AJ
Particles present in the air we breathe are now recognized as a major cause of disease and premature death globally. In fact, a World Health Organization (WHO) report recently ranked ambient air pollution as one of the top 10 causes of death in the world, directly contributing annually to around 3.7 million premature deaths worldwide 65% of which occurred in the Asian region alone. Airborne particulate matter (PM) can be generated from natural sources such as windblown soil or coastal sea-spray; as well as anthropogenic sources such as power stations, industry, vehicles and domestic biomass burning. At low concentration these fine pollution particles are too small to be seen by eye, but penetrate deep into our lungs and even our blood stream as our nose and throat are inefficient at filtering them out. At large concentrations, they can also have wider regional effects including reduced visibility, acid rain and even climate variability. The International Atomic Energy Agency (IAEA) in 2000, recognizing air pollution as a significant local, national and global challenge, initiated a collaborative air pollution study involving 14 countries across the greater Asia-pacific region from 2000 to 2015. This has amassed a database containing more than 14,000 data lines of PM mass concentration and the concentration of up to 40 elements using nuclear analytical techniques. It represents the most comprehensive and long-term airborne PM data set compiled to date for the Asia-Pacific region and as will be discussed, can be used to statistically resolve individual source fingerprints and their contributions to total air pollution using Positive Matrix Factorization (PMF). This sort of data necessary for implementing or reviewing the effectiveness of policy level changes aimed at targeted air pollution reduction.
The APAD and ASFID: long-term fine and coarse ambient particulate matter and source fingerprint databases for the Asia-Pacific region
(Clean Air Society of Australia and New Zealand, 2016-08-01) Atanacio, AJ; Cohen, DD; Begum, BA; Ni, BF; Pandit, GG; Sahu, SK; Santoso, M; Lestiani, DD; Lim, JM; Rahman, SA; Elias, MS; Shagjjamba, D; Markwitz, A; Waheed, S; Siddique, N; Pabroa, PCB; Santos, FL; Seneviratne, MCS; Handagiripathira, L; Wimolwattanapun, W; Vuong, TB; Karydas, A
Ambient particulate matter (APM) pollution, often generically referred to as smog or haze, is a global problem impacting every country and region in the world to varying degrees. Countries within the rapidly developing Asia-Pacific region have much higher levels of APM compared with many internationally recognised health goals. This paper presents two new aerosol databases compiled as the result of a long-term project spanning 15 years and involving 14 countries in the Asia-Pacific region under the auspices of the International Atomic Energy Agency (IAEA). The first database, named the Asia-Pacific Aerosol Database (APAD), contains the elemental concentration and associated error and minimum detectable limits (MDL) for 14,016 APM samples collected between 2002 and 2015. The second database, named the Asia-Pacific Source Fingerprint Database (ASFID), contains receptor source fingerprints and source apportionment solutions obtained by each country from their APAD dataset using positive matrix factorisation (PMF) methods. © 2016 The Clean Air Society of Australia and New Zealand
The application of IBA techniques to air pollution source fingerprinting and source apportionment
(Elsevier Science BV, 2014-01-01) Cohen, DD; Stelcer, E; Atanacio, AJ; Crawford, J
IBA techniques have been used to measure elemental concentrations of more than 20 different elements found in fine particle (PM2.5) air pollution. These data together with their errors and minimum detectable limits were used in Positive Matrix Factorisation (PMF) analyses to quantitatively determine source fingerprints and their contributions to the total measured fine mass. Wind speed and direction back trajectory data from the global HYSPLIT codes were then linked to these PMF fingerprints to quantitatively identify the location of the sources. © 2014, Elsevier Ltd.
Application of positive matrix factorisation, multi-linear engine and back trajectory techniques to the quantification of coal-fired power station pollution in metropolitan Sydney
(Pergamon Elsevier Science Ltd, 2012-12-01) Cohen, DD; Crawford, J; Stelcer, E; Atanacio, AJ
Over 900 fine particle Teflon filters were collected within the Sydney Basin between 1 January 2001 and 31 December 2011 and analyzed using simultaneous PIXE, PIGE, RBS and PESA techniques to determine 21 different elements between hydrogen and lead. These elements were used in positive matrix factorization (PMF) and multi-linear engine (ME) techniques together with HYSPLIT wind back trajectory techniques to quantitatively determine source fingerprints and their contributions from coal-fired power stations. The power stations were many kilometers outside the greater Sydney metropolitan area but still had a significant impact on the fine particle mass loadings measured at the sampling site within this metropolitan area. The PM2.5 eleven year average mass at the sampling site was 6.48 mu g m(-3). The corresponding ammonium sulfate estimate was 1.65 mu g m(-3) or 26% of the PM2.5 mass. By applying back trajectory data and (ME) analysis methods, two power related fingerprints, secondary sulfate (2ndryS-Power) and aged industrial sulfur (IndSagedPower) were determined. These two power related fingerprints were responsible for between 14 and 18% of the total PM2.5 mass and 34-47% of the total sulfate measured at the sampling site. That is on average somewhere between a third and a half of all the sulfate measured in the greater Sydney region could be attributed to coal-fired power station emissions. © 2012, Elsevier Ltd.
Application of secondary ion mass spectrometry in studies of niobium segregation in niobium-doped titanium dioxide
(The Australian Ceramic Society, 2007) Sheppard, LR; Atanacio, AJ; Bak, T; Nowotny, J; Prince, KE
Secondary ion mass spectrometry (SIMS) is a powerful technique in the study of materials that demonstrate compositional changes as a function of depth from the surface. This is due to the high chemical sensitivity of SIMS (sensitive to ppb) and potential for high depth resolution. However, as a semi-quantitative technique, the application of SIMS to quantitative studies can be problematic without knowledge of the appropriate calibration information, which must be obtained through the use of carefully prepared reference specimens. In the present work, SIMS is used in the investigation of surface segregation in niobium doped polycrystalline TiO2. This material has demonstrated important photo-catalytic properties with implications for alternative energy generation and environmentally-friendly water purification, but requires investigation in relation to surface versus bulk processing. The present paper demonstrates the use of SIMS in the quantitatively assessment of segregation in TiO2 and the development of a calibration curve. © 2007, The Australian Ceramic Society
Atomic layer deposition of SIO2 on porous alumina membranes: controlling the pore size and transport properties
(SPIE, 2008-12-30) Velleman, L; Triani, G; Evans, PJ; Atanacio, AJ; Shapter, JG; Losic, D
Atomic layer deposition (ALD) of SiO2 onto nanoporous alumina (PA) membranes was investigated with the aim of adjusting the pore size and transport properties. PA membranes from commercial sources with a range of pore diameters (20 nm, 100 nm and 200 nm) were used and modified by atomic layer deposition using tris(tert-butoxy)silanol and water as the precursor couple. By adjusting the number of deposition cycles, the thickness of the conformal silica coating was controlled, reducing the effective pore diameter, and subsequently changing the transport properties of the PA membrane. Silica coated PA membranes with desired pore diameters from <5 nm to 100 nm were fabricated. In addition to the pore size, the transport properties and selectivity of fabricated silica coated PA membranes were controlled by chemical functionalisation using a silane with hydrophobic properties. Structural and chemical properties of modified membranes were studied by dynamic secondary ion mass spectrometry (DSIMS) and scanning electron microscopy (SEM). Spectrophotometric methods were used to evaluate the transport properties and selectivity of silica coated membranes by permeation studies of hydrophobic and hydrophilic organic molecules. The resultant silica/PA membranes with specific surface chemistry and controlled pore size are applicable for molecular separation, cell culture, bioreactors, biosensing and drug delivery. © 2008 Society of Photo-Optical Instrumentation Engineers (SPIE)
Baseline characterisation of source contributions to daily-integrated PM2.5 observations at Cape Grim using Radon-222
(Elsevier, 2018-08-20) Crawford, J; Chambers, SD; Cohen, DD; Williams, AG; Atanacio, AJ
We discuss 15 years (2000–2015) of daily-integrated PM2.5 samples from the Cape Grim Station. Ion beam analysis and positive matrix factorisation are used to identify six source-type fingerprints: fresh sea salt (57%); secondary sulfate (14%); smoke (13%); aged sea salt (12%); soil dust (2.4%); and industrial metals (1.5%). An existing hourly radon-only baseline selection technique is modified for use with the daily-integrated observations. Results were not significantly different for days on which >20 hours were below the baseline radon threshold compared with days when all 24 hours satisfied the baseline criteria. This relaxed daily baseline criteria increased the number of samples for analysis by almost a factor of two. Two radon baseline thresholds were tested: historic (100 mBq m−3), and revised (50 mBq m−3). Median aerosol concentrations were similar for both radon thresholds, but maximum values were higher for the 100 mBq m−3 threshold. Back trajectories indicated more interaction with southern Australia and the Antarctic coastline for air masses selected with the 100 mBq m−3 threshold. Radon-only baseline selection using the 50 mBq m−3 threshold was more selective of minimal terrestrial influence than a similar recent study using wind direction and back trajectories. The ratio of concentrations between terrestrial and baseline days for the primary sources soil, smoke and industrial metals was 3.4, 2.6, and 5.5, respectively. Seasonal cycles of soil dust had a summer maximum and winter minimum. Seasonal cycles of smoke were of similar amplitude for terrestrial and baseline events, but of completely different shape: peaking in autumn and spring for terrestrial events, compared to summer for baseline conditions. Seasonal cycles of industrial metals had a summer maximum and winter minimum. A significant fraction of the Cape Grim baseline smoke and industrial metal contributions appeared to be derived from long-term transport (>3 weeks since last terrestrial influence). Crown Copyright © 2018 Published by Elsevier Ltd.
Boron enhanced H diffusion in amorphous Si formed by in implantation
(Cambridge University Press, 2008-03-25) Johnson, BC; Atanacio, AJ; Prince, KE; McCallum, JC
Boron enhanced H diffusion in amorphous Si (a-Si) layers formed by ion implantation is observed using secondary ion mass spectroscopy (SIMS). Constant concentrations of B were achieved using multiple energy B implantations into thick a-Si layers. The evolution of single H implanted profiles centered on the uniformly B-implanted regions was studied for partial anneals at temperatures in the range 380 – 640 °C. Boron enhanced diffusion is observed and the enhanced diffusion coefficient shows trends with temperature typically associated with a Fermi level shifting dependence. A modified form of the generalized Fermi level shifting model is considered in light of these results. © Materials Research Society 2008
Bulk diffusion of niobium in single-crystal titanium dioxide
(American Chemical Society, 2007-07-19) Sheppard, LR; Atanacio, AJ; Bak, T; Nowotny, J; Prince, KE
The present work reports the tracer diffusion coefficient for Nb-93 in rutile TiO2 single crystals using secondary ion mass spectrometry (SIMS). The determined tracer diffusion coefficient exhibited the following temperature dependence in air (p(O-2) = 21 kPa) over the range 1073-1573 K: D-93Nb= (4.7 m(2) s(-1)) x 10(-7 +/- 0.4) exp ((-244 +/- 9 kJ mol(-1))/RT) Through comparison to the self-diffusion of Ti-44 in rutile TiO2, Nb-93 is interpreted to diffuse via the interstitialcy mechanism. The obtained tracer diffusion data are useful for ensuring compositional control during the processing of Nb-doped TiO2-based semiconductors using solid-state reactions between Nb2O5 and TiO2. © 2007, American Chemical Society
Calculated K, L, and M shell X-ray line intensities for light ion impact on selected targets from Z=6 to 100
(Australian Nuclear Science and Technology Organisation, 2011-09-01) Crawford, J; Cohen, DD; Doherty, G; Atanacio, AJ
A computer code to calculate the K, L, and M α, β and γ X-ray line intensities, KLMabgRatios, is described together with the input tables used to calculate these intensities for light ion bombardment of targets with atomic numbers from Z=6 to 100. The KLMabgRatios program was written with the main aim of updating the 1980’s data files used up till now (Clayton AAEC M113/1986), with more recent experimental and theoretical datasets published in the last 2 years or so. Preferred recommended K, L and M X-ray line intensities for light ion impact on selected targets for atomic numbers between Z=6 and 100 are given for 8 K lines, 17 L lines and 22 M lines as well as their corresponding ωK, ωL and ωM total shell fluorescence yields. In addition a program, wexplore, has been written to carry out Gaussian fits to experimental K, L and M X-ray spectra to better determine L and M X-ray production subshell cross sections for light ion bombardment. A section on the use of this wexplore program is also included in this report.
Can IBA techniques quantify the contributions of deserts, winter domestic heating and coal fired power stations to the ambient fine particle air pollution concentrations in the Sydney Basin?
(Australian National University, 2012-04-12) Cohen, DD; Stelcer, E; Garton, D; Atanacio, AJ
ANSTO has used accelerator based ion beam analysis (IBA) techniques to characterise, fingerprint and source fine particles in and around Australia since the early 1990's. This large database covering many years allows us to now look quantitatively at fine particle sources, including automobiles, smoke, sea spray, soils and industrial emissions. This talk will discuss the accelerator based IBA techniques and how they are used to identify the contributions of windblown soils, wood heating and coal fired power stations to ambient air pollution in the Sydney Basin between 1998 and the present.
Characterisation and properties of low temperature ALD TiO2 films
(Pielaszek Research, 2007-09-18) Triani, G; Evans, PJ; Campbell, JA; Latella, BA; Atanacio, AJ; Attard, DJ; Burford, RP
The atomic layer deposition of films under conditions outside the ALD window involves additional processes that have to be accounted for in order to achieve good quality films. [1] In the present study, the growth of ALD TiO2 films on silicon and polycarbonate in the temperature range 80 - 120°C has been investigated in detail for two combinations of pulsing times. Furthermore, both substrate materials were exposed to a low-pressure water plasma to investigate the effect of pre-treatment on the deposited films. A suite of characterisation techniques including XRD, SIMS, RBS, AFM, XTEM and spectroscopic ellipsometry was used to probe the physical and chemical properties of the films. In addition, microtensile testing of the films enable the interface energy and toughness to be determined. These measurements showed water plasma treatment prior to deposition increased the interface energy and interface toughness from 11 to 26 Jm-2 and 1.24 to 1.96 MPa.m1/2 respectively. The contact angle of the TiO2 films was measured to assess their wettability. These tests involved subjecting the films to single and cumulative exposures of UV radiation followed by measurement of the contact angle. For an 85 nm film on polycarbonate, the contact angle decreased from 60° for the as-deposited surface to 10° following a 15 minute exposure. A 25 nm film yielded a similar decrease though this was only achieved after a 50 minute exposure. 1.M. Ritala and M. Leskelä, in Handbook of Thin Film Materials, Volume 1: Deposition and Processing of Thin Films, H.S. Halwa (ed.), Chap. 2, Academic, NY, 2002. © 2007 Pielaszek Research
Characterisation of arsenic doped HgCdTe grown by molecular beam epitaxy
(IEEE, 2006-12-06) Tsen, GK; Sewell, RH; Atanacio, AJ; Prince, KE; Musca, CA; Dell, JM; Antoszewski, J; Faraone, L
Extrinsic p-type doping of Mercury Cadmium Tel-luride (HgCdTe) epilayers grown by Molecular Beam Epitaxy (MBE) was carried out with an arsenic (As) cracker cell. As-grown samples were characterised via Fourier Transform Infrared Transmission Spectrometry (FTIR), Secondary Ion Mass Spectrometry (SIMS) as well as variable field magneto-transport measurements coupled with the quantitative mobility spectrum analysis (QMSA) to study the Hall effect characteristics. Arsenic activation annealing of the samples were performed and magneto-transport measurements repeated. Results indicate that as-grown samples show n-type behaviour indicating that arsenic incorporate as donors in the material with annealed samples showing p-type characteristics with heavy compensation. © Copyright 2006 IEEE
Characterisation of phase relations and properties in air-oxidised Ti3SiC2
(Elsevier, 2007-09-25) Low, IM; Wren, E; Prince, KE; Atanacio, AJ
The oxidation of Ti3SiC2 in air from 25 to 1450 degrees C is characterised by differential thermal and gravimetric analysis (DTA/TGA), X-ray diffraction (XRD), grazing-incidence synchrotron radiation diffraction (GISRD), neutron diffraction (ND), transmission electron microscopy (TEM), secondary ions mass spectroscopy (SIMS) and Vickers indentation. The diffraction results show that rutile formed at a temperature of similar to 750 degrees C. A glassy phase - formed at > 1000 degrees C - devitrified upon cooling to room temperature to form tridymite but crystallised to cristobalite at temperatures >= 1300 degrees C. Composition depth-profiling of the surface layer oxides by XRD, GISRD and SIMS revealed a graded distribution of phases (TiO2, SiO2 and Ti3SiC2) both at the nanoscale (<= 1100 degrees C) and microscale level (1200 degrees C), which is particularly distinct at the interfaces. The oxide layers also exhibit a graded variation in microhardness. © 2007, Elsevier Ltd.
Chemical characterisation and source identification of atmospheric aerosols in the Snowy Mountains, south-eastern Australia
(Elsevier, 2018-07-15) Tadros, CV; Crawford, J; Treble, PC; Baker, AA; Cohen, DD; Atanacio, AJ; Hankin, SI; Roach, R
Characterisation of atmospheric aerosols is of major importance for: climate, the hydrological cycle, human health and policymaking, biogeochemical and palaeo-climatological studies. In this study, the chemical composition and source apportionment of PM2.5 (particulate matter with aerodynamic diameters less than 2.5 μm) at Yarrangobilly, in the Snowy Mountains, SE Australia are examined and quantified. A new aerosol monitoring network was deployed in June 2013 and aerosol samples collected during the period July 2013 to July 2017 were analysed for 22 trace elements and black carbon by ion beam analysis techniques. Positive matrix factorisation and back trajectory analysis and trajectory clustering methods were employed for source apportionment and to isolate source areas and air mass travel pathways, respectively. This study identified the mean atmospheric PM2.5 mass concentration for the study period was (3.3 ± 2.5) μg m−3. It is shown that automobile (44.9 ± 0.8)%, secondary sulfate (21.4 ± 0.9)%, smoke (12.3 ± 0.6)%, soil (11.3 ± 0.5)% and aged sea salt (10.1 ± 0.4)% were the five PM2.5 source types, each with its own distinctive trends. The automobile and smoke sources were ascribed to a significant local influence from the road network and bushfire and hazard reduction burns, respectively. Long-range transport are the dominant sources for secondary sulfate from coal-fired power stations, windblown soil from the inland saline regions of the Lake Eyre and Murray-Darling Basins, and aged sea salt from the Southern Ocean to the remote alpine study site. The impact of recent climate change was recognised, as elevated smoke and windblown soil events correlated with drought and El Niño periods. Finally, the overall implications including potential aerosol derived proxies for interpreting palaeo-archives are discussed. To our knowledge, this is the first long-term detailed temporal and spatial characterisation of PM2.5 aerosols for the region and provides a crucial dataset for a range of multidisciplinary research. Crown Copyright © 2018 Published by Elsevier B.V.
Chemically induced electric field: flat band potential engineering
(SPIE, 2012-10-05) Bak, T; Guo, Z; Li, W; Atanacio, AJ; Nowotny, J
The present work considers engineering of the flat band potential, FBP, of metal oxides in a controlled manner. The aim is to minimise the energy losses related to recombination. The related experimental approaches include imposition of a chemically-induced electric field using the phenomena of segregation, diffusion and the formation of multilayer systems. This paper considers several basic phenomena that allow the modification of the surface charge and the space charge at the gas/solid and solid/liquid interfaces. © (2012) Society of Photo-Optical Instrumentation Engineers (SPIE).
Chromium segregation in Cr-doped TiO2 (rutile): impact of oxygen activity
(Springer Nature, 2019-01-04) Rahman, KA; Sharma, N; Atanacio, AJ; Bak, T; Wachsman, ED; Moffit, M; Nowotny, J
This work considers the effect of chromium surface segregation for polycrystalline Cr-doped TiO2 on surface vs. bulk defect disorder. It is shown that annealing of Cr-doped TiO2 (0.04 at% Cr) in the gas phase of variable oxygen activity at 1273 K results in a gradual transition in the valence of chromium at the surface from predominantly Cr3+ species in reduced conditions, p(O2) = 10−12 Pa, to comparable concentrations of both Cr3+ and Cr6+ species in oxidising conditions, p(O2) = 105 Pa. The reported data is considered in terms of defect equilibria leading to the formation of positively and negatively charged chromium in both the cation sub-lattice and interstitial sites. The derived theoretical models represent the effect of oxygen activity on the surface charge and the resulting electric field leading to migration mechanism of charged chromium species. © 2019 Springer Nature
Comparison of proton and helium induced M subshell X-ray production cross sections with the ECUSAR theory
(Elsevier, 2014-01-01) Cohen, DD; Stelcer, E; Atanacio, AJ; Crawford, J; Doherty, G; Lapicki, G
M subshell X-ray production cross sections have been measured for Mα12, Mβ1, Mγ, M2–N4 and M1–O23 transitions representing all five M subshells. These experimental cross sections have been compared with the ECUSAR theory of Lapicki and four parameter fits are given to the experiment to theory ratios covering the proton and helium ion energy range from 0.5 to 3 MeV on thin W, Au, Pb, Th and U targets.© 2013 Elsevier B.V.

Browsing by Author "Atanacio, AJ"

Results Per Page

Sort Options