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Search for "oxidation state" in Full Text gives 118 result(s) in Beilstein Journal of Nanotechnology.

Synthesis of coaxial nanotubes of polyaniline and poly(hydroxyethyl methacrylate) by oxidative/initiated chemical vapor deposition

  • Alper Balkan,
  • Efe Armagan and
  • Gozde Ozaydin Ince

Beilstein J. Nanotechnol. 2017, 8, 872–882, doi:10.3762/bjnano.8.89

Graphical Abstract
  • purity and controlled wall thickness. Furthermore, the oxidation state of PANI could be controlled by varying the oxidant flowrate for the purpose of achieving conductive emeraldine salt. The oCVD technique is based on step-growth polymerization where the polymerization takes place directly on the
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Published 18 Apr 2017

Graphene functionalised by laser-ablated V2O5 for a highly sensitive NH3 sensor

  • Margus Kodu,
  • Artjom Berholts,
  • Tauno Kahro,
  • Mati Kook,
  • Peeter Ritslaid,
  • Helina Seemen,
  • Tea Avarmaa,
  • Harry Alles and
  • Raivo Jaaniso

Beilstein J. Nanotechnol. 2017, 8, 571–578, doi:10.3762/bjnano.8.61

Graphical Abstract
  • oxidation state in vanadium pentoxide (V2O5) – a good oxygen transfer catalyst that is (thermally) stable in air and vacuum [7][8][9][10]. Therefore, we considered vanadium oxide as a promising material for functionalising a graphene sensor in order to increase its selectivity towards reducing pollutant
  • . The oxidation state of vanadium was determined by means of X-ray photoelectron spectroscopy (XPS). Figure 3 depicts the O 1s and V 2p regions in the XPS spectrum measured from the surface of the sample after the PLD process. Because the source was not monochromatic, the V 2p1/2 region is not usable
  • ’ peaks and the suppression of the 2D peak in the Raman spectrum suggest that a high concentration of defects was introduced during the deposition. According to XPS, the deposited vanadium was in the state V5+, which is the highest stable oxidation state of this element. As a result, an enhancement in the
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Published 07 Mar 2017
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  • the corresponding Auger lines (marked with short vertical lines in Figure 4a) were determined by fitting with Gaussian curves. In general, a lower α indicates a lower electron density at the Sn atom, i.e., a higher oxidation state [31]. In our case the value of alpha changed from 919.14(15) eV in case
  • of pristine samples to 918.73(15) eV for exposed samples. This meant a substantial increase of the oxidation state of the examined layers, which is consistent with the findings from XPS measurements. A change in the oxidation state of tin also led to a change in the relation between tin and oxygen
  • alternative. The (O-Sn4+/O-Sn2+) ratio exhibited a stable tendency; i.e., each consecutive treatment was increasing the presence of higher oxidation states of the elements within the spectra. This confirmed the fact of additional vacuum oxidation of the RGVO SnO2 and indicated that the change of oxidation
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Published 27 Feb 2017

Nanocrystalline TiO2/SnO2 heterostructures for gas sensing

  • Barbara Lyson-Sypien,
  • Anna Kusior,
  • Mieczylaw Rekas,
  • Jan Zukrowski,
  • Marta Gajewska,
  • Katarzyna Michalow-Mauke,
  • Thomas Graule,
  • Marta Radecka and
  • Katarzyna Zakrzewska

Beilstein J. Nanotechnol. 2017, 8, 108–122, doi:10.3762/bjnano.8.12

Graphical Abstract
  • the range of 3–27 nm. Tin exhibits only the oxidation state 4+. The H2 detection threshold for the studied TiO2/SnO2 heterostructures is lower than 1 ppm especially in the case of SnO2-rich samples. The recovery time of SnO2-based heterostructures, despite their large responses over the whole
  • heterostructures are well crystallized, anatase, rutile and cassiterite forms are present. Tin exhibits only the oxidation state 4+. 2) The detection threshold is below 1 ppm H2 for SnO2-rich heterostructures. 3) The addition of a small amount of SnO2 to TiO2 has a much more pronounced effect on the sensor
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Published 12 Jan 2017

Hydrophilic silver nanoparticles with tunable optical properties: application for the detection of heavy metals in water

  • Paolo Prosposito,
  • Federico Mochi,
  • Erica Ciotta,
  • Mauro Casalboni,
  • Fabio De Matteis,
  • Iole Venditti,
  • Laura Fontana,
  • Giovanna Testa and
  • Ilaria Fratoddi

Beilstein J. Nanotechnol. 2016, 7, 1654–1661, doi:10.3762/bjnano.7.157

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  • selective sensors for the detection of very low amounts of heavy metal ions from biological and environmental samples has greatly increased [26]. The metal-ion toxicity depends on their physical state, chemical form as well as the oxidation state. Many groups have studied fluorescent chemosensors with
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Published 09 Nov 2016

Microwave synthesis of high-quality and uniform 4 nm ZnFe2O4 nanocrystals for application in energy storage and nanomagnetics

  • Christian Suchomski,
  • Ben Breitung,
  • Ralf Witte,
  • Michael Knapp,
  • Sondes Bauer,
  • Tilo Baumbach,
  • Christian Reitz and
  • Torsten Brezesinski

Beilstein J. Nanotechnol. 2016, 7, 1350–1360, doi:10.3762/bjnano.7.126

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  • transmission X-ray microscopy using a Carl Zeiss TXM and the corresponding data treatment steps are described elsewhere [25]. To determine the oxidation state of Fe, several different Fe-based compounds were measured and used as the references. The fitting of X-ray absorption near edge structure spectra is
  • further insight into both the electrochemical reactions of ZFO with Li and the oxidation state of Fe, combined full-field transmission X-ray microscopy (TXM) and X-ray absorption near edge structure (XANES) spectroscopy was conducted on “pristine” and pre-cycled nanoparticle electrodes at the NANO
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Published 27 Sep 2016

Improved lithium-ion battery anode capacity with a network of easily fabricated spindle-like carbon nanofibers

  • Mengting Liu,
  • Wenhe Xie,
  • Lili Gu,
  • Tianfeng Qin,
  • Xiaoyi Hou and
  • Deyan He

Beilstein J. Nanotechnol. 2016, 7, 1289–1295, doi:10.3762/bjnano.7.120

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  • centered at 2.35 V may be ascribed to the re-oxidation of Mn2+ to a higher oxidation state through a new electrochemical reaction [4][7][27]. After the first cycle, the CV curves are well-overlapped, declaring a good electrochemical reversibility and structural stability of the electrode. These results are
  • then increasing [4][8][23][28]. For this given system, this should be mainly due to the activation of the material, the formation of a higher oxidation state of Mn and the reversibility improvement for the conversion reaction. Figure 3c shows the rate capacity tested by the stepwise increase in the
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Published 14 Sep 2016

Time-dependent growth of crystalline Au0-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica

  • Liz M. Rösken,
  • Felix Cappel,
  • Susanne Körsten,
  • Christian B. Fischer,
  • Andreas Schönleber,
  • Sander van Smaalen,
  • Stefan Geimer,
  • Christian Beresko,
  • Georg Ankerhold and
  • Stefan Wehner

Beilstein J. Nanotechnol. 2016, 7, 312–327, doi:10.3762/bjnano.7.30

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  • that environmental parameters like pH [31][32][68][69][70], temperature [17][40], oxidation state of the metal atoms [71], concentration of metal ions [72] and counter ions [73] affect the morphology and size of the nanoparticles formed by various organisms. LIBS experiments have confirmed the
  • concentration, see Figure 6b. Since LIBS utilizes the light from a micro-plasma generated by a laser beam on the sample’s surface, all information about the chemical state (oxidation state, neighborhood) in the sample (biomass) is lost, only the presence of specific elements can be proven. The amount of gold
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Published 02 Mar 2016

Evaluation of gas-sensing properties of ZnO nanostructures electrochemically doped with Au nanophases

  • Elena Dilonardo,
  • Michele Penza,
  • Marco Alvisi,
  • Cinzia Di Franco,
  • Francesco Palmisano,
  • Luisa Torsi and
  • Nicola Cioffi

Beilstein J. Nanotechnol. 2016, 7, 22–31, doi:10.3762/bjnano.7.3

Graphical Abstract
  • electron microscopy (TEM, SEM), as well as X-ray photon electron spectroscopy (XPS), revealing the successful decoration of ZnO spherical and rod-like nanostructures, obtained at 300 and 550 °C, respectively, with nano-phase gold at the elemental oxidation state. The main focus of this study is to
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Published 08 Jan 2016

Green and energy-efficient methods for the production of metallic nanoparticles

  • Mitra Naghdi,
  • Mehrdad Taheran,
  • Satinder K. Brar,
  • M. Verma,
  • R. Y. Surampalli and
  • J. R. Valero

Beilstein J. Nanotechnol. 2015, 6, 2354–2376, doi:10.3762/bjnano.6.243

Graphical Abstract
  • and prism-like NPs [22]. Polyoxometalates Polyoxometalates (POMs) are anionic structures with transition metal atoms in their highest oxidation state. These materials can exhibit tremendous structural variety and interesting properties such as reversible electron exchange behavior that make them ideal
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Published 10 Dec 2015

The role of low-energy electrons in focused electron beam induced deposition: four case studies of representative precursors

  • Rachel M. Thorman,
  • Ragesh Kumar T. P.,
  • D. Howard Fairbrother and
  • Oddur Ingólfsson

Beilstein J. Nanotechnol. 2015, 6, 1904–1926, doi:10.3762/bjnano.6.194

Graphical Abstract
  • was monitored by XPS and RAIRS. The XPS spectra showed that the fractional Pt coverage stayed constant, but a partial reduction of Pt(IV) to a lower oxidation state took place. The C/Pt ratio decreased from the initial 9:1 of the precursor molecule to about 8:1 upon electron irradiation, as is shown
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Published 16 Sep 2015

Thermal treatment of magnetite nanoparticles

  • Beata Kalska-Szostko,
  • Urszula Wykowska,
  • Dariusz Satula and
  • Per Nordblad

Beilstein J. Nanotechnol. 2015, 6, 1385–1396, doi:10.3762/bjnano.6.143

Graphical Abstract
  • structural and magnetic measurements, depict that nanoparticles of the same size but different oxidation state are not in the same magnetic state at RT. This is extremely important with regards to their application. A slow heat treatment allows modification of the oxidation state, but not of the particle
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Published 23 Jun 2015

Heterometal nanoparticles from Ru-based molecular clusters covalently anchored onto functionalized carbon nanotubes and nanofibers

  • Deborah Vidick,
  • Xiaoxing Ke,
  • Michel Devillers,
  • Claude Poleunis,
  • Arnaud Delcorte,
  • Pietro Moggi,
  • Gustaaf Van Tendeloo and
  • Sophie Hermans

Beilstein J. Nanotechnol. 2015, 6, 1287–1297, doi:10.3762/bjnano.6.133

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  • molecular mixed-metal clusters as precursors for depositing heterometal nanoparticles on carbon nanotubes and nanofibers. The advantages of such precursors are that they present well-defined molecular structures and exchangeable ligands, the metal atoms are in the zero oxidation state and bimetal
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Published 10 Jun 2015

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

  • Philipp Adelhelm,
  • Pascal Hartmann,
  • Conrad L. Bender,
  • Martin Busche,
  • Christine Eufinger and
  • Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

Graphical Abstract
  • one-electron transfer per formula unit. In this process, the de-/intercalation of one Li-ion is linked to a change in the transition metal oxidation state by one (Co3+/4+, Fe2+/3+, Mn3+/4+, etc.), as illustrated in Figure 2a. However, since the positive electrode materials often suffer from stability
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Published 23 Apr 2015

Tm-doped TiO2 and Tm2Ti2O7 pyrochlore nanoparticles: enhancing the photocatalytic activity of rutile with a pyrochlore phase

  • Desiré M. De los Santos,
  • Javier Navas,
  • Teresa Aguilar,
  • Antonio Sánchez-Coronilla,
  • Concha Fernández-Lorenzo,
  • Rodrigo Alcántara,
  • Jose Carlos Piñero,
  • Ginesa Blanco and
  • Joaquín Martín-Calleja

Beilstein J. Nanotechnol. 2015, 6, 605–616, doi:10.3762/bjnano.6.62

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  • values reported in the literature for Ti(IV) [26]. The FWHM of the Ti 2p3/2 peak (0.98 eV) is quite consistent with this assignment [27]. Therefore, the predominant oxidation state for Ti in our samples was assumed to be Ti4+, while the presence of Ti3+ in TiO2 [28] was negligible. The BE for Tm 4d5/2 in
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Published 02 Mar 2015

Overview of nanoscale NEXAFS performed with soft X-ray microscopes

  • Peter Guttmann and
  • Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 595–604, doi:10.3762/bjnano.6.61

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  • NEXAFS-TXM. As a result of this investigation it was found that neither Cd nor S diffuse into the CuO phase after the deposition of CdS on the CuO nanowires [60][61]. The possibility to study the oxidation state of Mn dopants in titanate nanostructures was reported in [62]. Additionally, using the
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Published 27 Feb 2015

Palladium nanoparticles anchored to anatase TiO2 for enhanced surface plasmon resonance-stimulated, visible-light-driven photocatalytic activity

  • Kah Hon Leong,
  • Hong Ye Chu,
  • Shaliza Ibrahim and
  • Pichiah Saravanan

Beilstein J. Nanotechnol. 2015, 6, 428–437, doi:10.3762/bjnano.6.43

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  • deposition of Pd NPs. The decrease of BET surface area and average pore diameter was due to a minor blocking of the pores in anatase TiO2 by the deposited Pd NPs [48]. In order to determine the chemical composition and oxidation state of the prepared photocatalysts, X-ray photoelectron spectroscopy (XPS) was
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Published 11 Feb 2015

Morphology, structural properties and reducibility of size-selected CeO2−x nanoparticle films

  • Maria Chiara Spadaro,
  • Sergio D’Addato,
  • Gabriele Gasperi,
  • Francesco Benedetti,
  • Paola Luches,
  • Vincenzo Grillo,
  • Giovanni Bertoni and
  • Sergio Valeri

Beilstein J. Nanotechnol. 2015, 6, 60–67, doi:10.3762/bjnano.6.7

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  • = 1020 K, is shown. In the spectrum it is possible to observe features from both Ce3+ and Ce4+ ionic species, as already observed for ceria NPs. In fact a core–shell model was proposed [24][25] for the oxidation state of the CeO2−x NPs, which assumes that the core of the nanoparticle is composed of CeO2
  • exposure for every value of the X-ray source operating power, in order to detect if the longer exposure affected the oxidation state. Fit results are shown in Figure 4b. Five different power values have been used: 40 W, 100 W, 150 W, 200 W, 270 W, the last one being the one that was used conventionally to
  • NPs have been investigated and it was demonstrated that the concentration of Ce3+ ions decreases as a function of particle size for this kind of synthesis method. We investigated in detail how the combination of X-ray power, exposure and UHV conditions influence the oxidation state of the NPs and
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Published 07 Jan 2015

Manganese oxide phases and morphologies: A study on calcination temperature and atmospheric dependence

  • Matthias Augustin,
  • Daniela Fenske,
  • Ingo Bardenhagen,
  • Anne Westphal,
  • Martin Knipper,
  • Thorsten Plaggenborg,
  • Joanna Kolny-Olesiak and
  • Jürgen Parisi

Beilstein J. Nanotechnol. 2015, 6, 47–59, doi:10.3762/bjnano.6.6

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  • such as particle size, surface area and Mnx+ oxidation state is required. Here, Mn3O4 and Mn5O8 nanoparticles as well as mesoporous α-Mn2O3 particles were synthesized by calcination of Mn(II) glycolate nanoparticles obtained through an economical route based on a polyol synthesis. The preparation of
  • ) glycolate particles were calcined for 2 h in Ar and O2 atmospheres at different temperatures between 320 and 550 °C to investigate the dependence of the particle size, their morphology and the Mnx+ oxidation state in the resulting manganese oxide on the calcination temperature and atmosphere. The X-ray
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Published 06 Jan 2015

Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

  • Rudolf Herrmann,
  • Markus Rennhak and
  • Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2413–2423, doi:10.3762/bjnano.5.251

Graphical Abstract
  • -made. Their principal application is for catalysis. Due to the easy change of the oxidation state (Ce(III) and Ce(IV)) they can act as redox catalysts themselves, e.g., for the regulation of combustion and many other applications [29][30]. Even more important is their use as carrier material for
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Published 16 Dec 2014

UHV deposition and characterization of a mononuclear iron(III) β-diketonate complex on Au(111)

  • Irene Cimatti,
  • Silviya Ninova,
  • Valeria Lanzilotto,
  • Luigi Malavolti,
  • Luca Rigamonti,
  • Brunetto Cortigiani,
  • Matteo Mannini,
  • Elena Magnano,
  • Federica Bondino,
  • Federico Totti,
  • Andrea Cornia and
  • Roberta Sessoli

Beilstein J. Nanotechnol. 2014, 5, 2139–2148, doi:10.3762/bjnano.5.223

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  • . As for the Fe 2p region, the signal is detectable but quite noisy at saturation coverage, and practically negligible at t1. Therefore, no useful information about the Fe oxidation state could be retrieved. STM and DFT characterization Spectroscopic characterization indicates that Fe(dpm)3 adsorbs on
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Published 18 Nov 2014

Towards bottom-up nanopatterning of Prussian blue analogues

  • Virgile Trannoy,
  • Marco Faustini,
  • David Grosso,
  • Sandra Mazerat,
  • François Brisset,
  • Alexandre Dazzi and
  • Anne Bleuzen

Beilstein J. Nanotechnol. 2014, 5, 1933–1943, doi:10.3762/bjnano.5.204

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  • investigation Infrared spectroscopy, and especially the ν(C≡N) vibration band located in the spectral range of 2100–2200 cm−1 is usually used to characterize PBA species. Indeed, the cyanide bridge is extremely sensitive to its environment, including the oxidation state and the spin state of the transition
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Published 31 Oct 2014

Quasi-1D physics in metal-organic frameworks: MIL-47(V) from first principles

  • Danny E. P. Vanpoucke,
  • Jan W. Jaeken,
  • Stijn De Baerdemacker,
  • Kurt Lejaeghere and
  • Veronique Van Speybroeck

Beilstein J. Nanotechnol. 2014, 5, 1738–1748, doi:10.3762/bjnano.5.184

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  • ferromagnetic chains, respectively. This shows that the same oxidation state is present in both cases. Comparison to V charges in MIL-47(V) MOFs with functionalized linkers shows exactly the same charge, indicative of a +IV oxidation state [22]. Note that, as is to be expected from Hirshfeld-I charges, these
  • (≈0.9 μB) than in the antiferromagnetic chains (≈0.8 μB). However, both are indicative of a V4+ oxidation state. Interestingly, all O atoms in the vanadyl chains also show a small magnetization (0.06 and 0.08 μB in the antiferromagnetic and ferromagnetic chain, respectively) with a sign opposite to that
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Published 09 Oct 2014

Non-covalent and reversible functionalization of carbon nanotubes

  • Antonello Di Crescenzo,
  • Valeria Ettorre and
  • Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

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  • dispersion. The precipitation of SWCNTs is induced by reduction of newly formed disulfide bonds. Other experimental evidences have been reported on reversible nanotube dispersion via modulation of the oxidation state of a metal complex used as the dispersant. Nobusawa et al. demonstrated how the addition of
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Published 30 Sep 2014

Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays

  • Christoph Rehbock,
  • Jurij Jakobi,
  • Lisa Gamrad,
  • Selina van der Meer,
  • Daniela Tiedemann,
  • Ulrike Taylor,
  • Wilfried Kues,
  • Detlef Rath and
  • Stephan Barcikowski

Beilstein J. Nanotechnol. 2014, 5, 1523–1541, doi:10.3762/bjnano.5.165

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  • . These processes are favored by crystal defects, UV light activation and composition and oxidation state of the surface of the nanoparticle. Hence toxicity of nanoparticles may be dominated by its catalytic activity at the nano–bio interface [36]. Even though these findings were predominantly applied for
  • a systematic evaluation of adverse effects of less noble metals and metal oxide nanoparticles [154], their applicability to AuAg alloys may still be possible. The driving forces in this context were identified to be the surface potential and oxidation state of the nanoparticles, both potentially
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Published 12 Sep 2014
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