ALBERT

Description: Calcium silicate hydrate (C-S-H) alteration was studied with flow-through experiments at 25°C and pH 9.2. Three materials with apparent Ca/Si ratios (C/S ratios) of 1.47, 1.38 and 0.86 were investigated. Physical (thermogravimetric analyses/differential thermal analysis), mineralogical (X-ray diffraction) and chemical (electron probe microanalysis, transmission electron microscopy/energy dispersive X-ray spectrometry) analyses were performed to characterize the reacting minerals. Initial stoichiometric C/S ratios were 1.22, 1.22 and 0.85, respectively. The excess of Ca is attributed mainly to the presence of calcium hydroxide intimately mixed in with C-S-H particles. The C-S-H chemical compositions were monitored during flow-through experiments in order to determine the mineral stoichiometry needed for reaction kinetics. Under our experimental conditions the stoichiometric C/S ratios decreased continuously with time. A close to stoichiometric dissolution was observed after 2 days of experiments. Using an integrated approach, the kinetics was found to be a function of the C/S. A decrease in layer-to-layer distance in the early stage of the alteration process is interpreted as interlayer Ca/Na exchange (Na being part of the pH buffering solution). A second dissolution step, marked by a close to stoichiometric release of Ca and Si, undoubtedly results from layer dissolution. The structural similarity of C-S-H and tobermorite was confirmed.

Description: 〈div data-abstract-type="normal"〉〈p〉The new mineral feynmanite, Na(UO〈span〉2〈/span〉)(SO〈span〉4〈/span〉)(OH)·3.5H〈span〉2〈/span〉O, was found in both the Blue Lizard and Markey mines, San Juan County, Utah, USA, where it occurs as a secondary phase on pyrite-rich asphaltum in association with chinleite-(Y), gypsum, goethite, natrojarosite, natrozippeite, plášilite, shumwayite (Blue Lizard) and wetherillite (Markey). The mineral is pale greenish yellow with a white streak and fluoresces bright greenish white under a 405 nm laser. Crystals are transparent with a vitreous lustre. It is brittle, with a Mohs hardness of ~2, irregular fracture and one perfect cleavage on {010}. The calculated density is 3.324 g cm〈span〉–3〈/span〉. Crystals are thin needles or blades, flattened on {010} and elongate on [100], exhibiting the forms {010}, {001}, {101} and {10〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190522072108342-0385:S0026461X18001172:S0026461X18001172_inline1.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉}, and are up to ~0.1 mm in length. Feynmanite is optically biaxial (–), with α = 1.534(2), β = 1.561(2) and γ = 1.571(2) (white light); 2V〈span〉meas.〈/span〉 = 62(2)°; no dispersion; and optical orientation: 〈span〉X〈/span〉 = 〈span〉b〈/span〉, 〈span〉Y〈/span〉 ≈ 〈span〉a,〈/span〉〈span〉Z〈/span〉 ≈ 〈span〉c〈/span〉. It is weakly pleochroic: 〈span〉X〈/span〉 = colourless, 〈span〉Y〈/span〉 = very pale green yellow and 〈span〉Z〈/span〉 = pale green yellow (〈span〉X〈/span〉 Y Z). Electron microprobe analyses (WDS mode) provided (Na〈span〉0.84〈/span〉Fe〈span〉0.01〈/span〉)(U〈span〉1.01〈/span〉O〈span〉2〈/span〉)(S〈span〉1.01〈/span〉O〈span〉4〈/span〉)(OH)·3.5H〈span〉2〈/span〉O. The five strongest powder X-ray diffraction lines are [〈span〉d〈/span〉〈span〉obs〈/span〉 Å(〈span〉I〈/span〉)(〈span〉hkl〈/span〉)]: 8.37(100)(010), 6.37(33)(〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190522072108342-0385:S0026461X18001172:S0026461X18001172_inline2.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉01,101), 5.07(27)(〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190522072108342-0385:S0026461X18001172:S0026461X18001172_inline3.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉11,111), 4.053(46)(004,021) and 3.578(34)(120). Feynmanite is monoclinic, has space group 〈span〉P〈/span〉2/〈span〉n〈/span〉, 〈span〉a〈/span〉 = 6.927(3), 〈span〉b〈/span〉 = 8.355(4), 〈span〉c〈/span〉 = 16.210(7) Å, β = 90.543(4)°, 〈span〉V〈/span〉 = 938.1(7) Å〈span〉3〈/span〉 and 〈span〉Z〈/span〉 = 4. The structure of feynmanite (〈span〉R〈/span〉〈span〉1〈/span〉 = 0.0371 for 1879 〈span〉I〈/span〉〈span〉o〈/span〉 〉 2σ〈span〉I〈/span〉) contains edge-sharing pairs of pentagonal bipyramids that are linked by sharing corners with SO〈span〉4〈/span〉 groups, yielding a [(UO〈span〉2〈/span〉)〈span〉2〈/span〉(SO〈span〉4〈/span〉)〈span〉2〈/span〉(OH)〈span〉2〈/span〉]〈span〉2–〈/span〉 sheet based on the phosphuranylite anion topology. The sheet is topologically identical to those in deliensite, johannite and plášilite. The dehydration of feynmanite to plášilite results in interlayer collapse involving geometric reconfiguration of the sheets and the ordering of Na.〈/p〉〈/div〉

Description: Nature Physics 9, 785 (2013). doi:10.1038/nphys2770 Authors: Michael Geiselmann, Renaud Marty, F. Javier García de Abajo & Romain Quidant The much sought after optical transistor—the photonic counterpart of the electronic transistor—is poised to become a central ingredient in the development of optical signal processing. The motivation for using photons rather than electrons comes not only from their faster dynamics, but also from their lower crosstalk and robustness against environmental decoherence, which enable a high degree of integration and the realization of quantum operations. A single-molecule transistor has recently been demonstrated at cryogenic temperatures. Here, we demonstrate that a single nitrogen–vacancy centre at room temperature can operate as an optical switch under non-resonant continuous-wave illumination. We show an optical modulation of more than 80% and a time response faster than 100 ns in the green-laser-driven fluorescence signal, which we control through an independent near-infrared gating laser. Our study indicates that the near-infrared laser triggers a fast-decay channel of the nitrogen–vacancy mediated by promotion of the excited state to a dark band.

Description: The probability laws associated to domain wall depinning under fields and currents have been studied in NiFe and FePt nanowires. Three basic domain wall depinning processes, associated to different potential landscapes, are found to appear identically in those systems with very different anisotropies. We show that these processes constitute the building blocks of any complex depinning mechanism. A Markovian analysis is proposed, that provides a unified picture of the depinning mechanism and an insight into the pinning potential landscape. Scientific Reports 4 doi: 10.1038/srep06509

Description: Pressure ulcers (PU) are serious, reportable events causing pain, infection and prolonged hospitalization, particularly among critically ill patients. The literature on PUs in neonates is limited. The objective was to determine the etiology, severity and influence of gestational age on PUs among hospitalized infants. A two-year prospective study was conducted among 741 neonatal intensive care patients over 31,643 patient-days. Risk factors were determined by comparing the characteristics of infants who developed PUs with those who did not. There were 1.5 PUs per 1000 patient days with 1.0 PU per 1000 days in premature infants and 2.7 per 1000 days in term infants. The number of PUs associated with devices was nearly 80% overall and over 90% in premature infants. Infants with PUs had longer hospitalizations and weighed more than those who did not. Infants with device-related PUs were younger, of lower gestational age and developed the PU earlier than patients with PUs due to conventional pressure. The time to PU development was longer in prematurely born versus term infants. Hospitalized neonates are susceptible to device-related injury and the rate of stage II injury is high. Strategies for early detection and mitigation of device-related injury are essential to prevent PUs. Scientific Reports 4 doi: 10.1038/srep07429

Description: Article In materials with strongly correlated electrons, charge carriers can separate into stripes of different electronic phases. Here, Anissimova et al. present evidence that in La 2−x Sr x NiO 4 these stripes can dynamically fluctuate, which helps to understand phenomena such as insulator–metal transitions. Nature Communications doi: 10.1038/ncomms4467 Authors: S. Anissimova, D. Parshall, G.D. Gu, K. Marty, M.D. Lumsden, Songxue Chi, J.A. Fernandez-Baca, D.L. Abernathy, D. Lamago, J.M. Tranquada, D. Reznik

Description: Bluebellite, Cu 6 [I 5+ O 3 (OH) 3 ](OH) 7 Cl and mojaveite, Cu 6 [Te 6+ O 4 (OH) 2 ](OH) 7 Cl, are new secondary copper minerals from the Mojave Desert. The type locality for bluebellite is the D shaft, Blue Bell claims, near Baker, San Bernardino County, California, while cotype localities for mojaveite are the E pit at Blue Bell claims and also the Bird Nest drift, Otto Mountain, also near Baker. The two minerals are very similar in their properties. Bluebellite is associated particularly with murdochite, but also with calcite, fluorite, hemimorphite and rarely dioptase in a highly siliceous hornfels. It forms bright bluish-green plates or flakes up to ~20 μm x 20 μm x 5 μm in size that are usually curved. The streak is pale bluish green and the lustre is adamantine, but often appears dull because of surface roughness. It is non-fluorescent. Bluebellite is very soft (Mohs hardness ~1), sectile, has perfect cleavage on {001} and an irregular fracture. The calculated density based on the empirical formula is 4.746 g cm –3 . Bluebellite is uniaxial (–), with mean refractive index estimated as 1.96 from the Gladstone-Dale relationship. It is pleochroic O (bluish green) 〉〉 E (nearly colourless). Electron microprobe analyses gave the empirical formula Cu 5.82 I 0.99 Al 0.02 Si 0.12 O 3.11 (OH) 9.80 Cl 1.09 based on 14 (O+Cl) a.p.f.u. The Raman spectrum shows strong iodate-related bands at 680, 611 and 254 cm –1 . Bluebellite is trigonal, space group R 3, with the unit-cell parameters: a = 8.3017(5), c = 13.259(1) Å, V = 791.4(1) Å 3 and Z = 3. The eight strongest lines in the powder X-ray diffraction (XRD) pattern are [ d obs /Å ( I ) ( hkl )]: 4.427(99)(003), 2.664(35)(211), 2.516(100)(212I), 2.213(9)(006), 2.103(29)(033,214), 1.899(47)(312,215I), 1.566(48)(140,217) and 1.479(29)(045,143I,324). Mojaveite occurs at the Blue Bell claims in direct association with cerussite, chlorargyrite, chrysocolla, hemimorphite, kettnerite, perite, quartz and wulfenite, while at the Bird Nest drift, it is associated with andradite, chrysocolla, cerussite, burckhardtite, galena, goethite, khinite, mcalpineite, thorneite, timroseite, paratimroseite, quartz and wulfenite. It has also been found at the Aga mine, Otto Mountain, with cerussite, chrysocolla, khinite, perite and quartz. Mojaveite occurs as irregular aggregates of greenish-blue plates flattened on {001} and often curved, which rarely show a hexagonal outline, and also occurs as compact balls, from sky blue to medium greenish blue in colour. Aggregates and balls are up to 0.5 mm in size. The streak of mojaveite is pale greenish blue, while the lustre may be adamantine, pearly or dull, and it is non-fluorescent. The Mohs hardness is ~1. It is sectile, with perfect cleavage on {001} and an irregular fracture. The calculated density is 4.886 g cm –3 , based on the empirical formulae and unit-cell dimensions. Mojaveite is uniaxial (–), with mean refractive index estimated as 1.95 from the Gladstone-Dale relationship. It is pleochroic O (greenish blue) 〉〉 E (light greenish blue). The empirical formula for mojaveite, based on 14 (O+Cl) a.p.f.u., is Cu 5.92 Te 1.00 Pb 0.08 Bi 0.01 O 4 (OH) 8.94 Cl 1.06 . The most intense Raman bands occur at 694, 654 (poorly resolved), 624, 611 and 254 cm –1 . Mojaveite is trigonal, space group R 3, with the unit-cell parameters: a = 8.316(2), c = 13.202(6) Å and V = 790.7(1) Å 3 . The eight strongest lines in the powder XRD pattern are [ d obs/ Å ( I ) ( hkl )]: 4.403(91)(003), 2.672(28)(211), 2.512(100)(212I), 2.110(27)(033,214), 1.889(34)(312,215I,223I), 1.570(39)(404,140,217), 1.481(34)(045,143I,324) and 1.338(14)(422). Diffraction data could not be refined, but stoichiometries and unit-cell parameters imply that bluebellite and mojaveite are very similar in crystal structure. Structure models that satisfy bond-valence requirements are presented that are based on stackings of brucite-like Cu 6 MX 14 layers, where M = (I or Te) and X = (O, OH and Cl). Bluebellite and mojaveite provide a rare instance of isotypy between an iodate containing I 5+ with a stereoactive lone electron pair and a tellurate containing Te 6+ with no lone pair.

Description: 〈div data-abstract-type="normal"〉〈p〉The new mineral markeyite (IMA2016-090), Ca〈span〉9〈/span〉(UO〈span〉2〈/span〉)〈span〉4〈/span〉(CO〈span〉3〈/span〉)〈span〉13〈/span〉·28H〈span〉2〈/span〉O, was found in the Markey mine, San Juan County, Utah, USA, where it occurs as a secondary phase on asphaltum in association with calcite, gypsum and natrozippeite. The mineral is pale yellowish-green with white streak and fluoresces bright bluish white under a 405 nm laser. Crystals are transparent and have vitreous to pearly lustre. It is brittle, with Mohs hardness 1½ to 2, irregular fracture and three cleavages: perfect on {001}; good on {100} and {010}. The measured density is 2.68 g cm〈span〉–3〈/span〉. Crystals are blades, flattened on {001} and elongate on [010], exhibiting the forms {100}, {010}, {001}, {110}, {101}, {011} and {111}. Markeyite is optically biaxial (–) with α = 1.538(2), β = 1.542(2) and γ = 1.545(2) (white light); the measured 2V is 81(2)°; the dispersion is 〈span〉r〈/span〉 v (weak); the optical orientation is 〈span〉X〈/span〉 = 〈span〉c〈/span〉, 〈span〉Y〈/span〉 = 〈span〉b〈/span〉, 〈span〉Z〈/span〉 = 〈span〉a〈/span〉; and pleochroism is 〈span〉X〈/span〉 = light greenish yellow, 〈span〉Y〈/span〉 and 〈span〉Z〈/span〉 = light yellow (〈span〉X〈/span〉 〉 〈span〉Y〈/span〉 ≈ 〈span〉Z〈/span〉). Electron microprobe analyses (energy-dispersive spectroscopy mode) yielded CaO 18.60, UO〈span〉3〈/span〉 42.90, CO〈span〉2〈/span〉 21.30 (calc.) and H〈span〉2〈/span〉O 18.78 (calc.), total 101.58 wt.% and the empirical formula Ca〈span〉8.91〈/span〉(U〈span〉1.01〈/span〉O〈span〉2〈/span〉)〈span〉4〈/span〉(CO〈span〉3〈/span〉)〈span〉13〈/span〉·28H〈span〉2〈/span〉O. The six strongest powder X-ray diffraction lines are [〈span〉d〈/span〉〈span〉obs〈/span〉 Å(〈span〉I〈/span〉)(〈span〉hkl〈/span〉)]: 10.12(69)(001), 6.41(91)(220,121), 5.43(100)(221), 5.07(33)(301,002,131), 4.104(37)(401,141) and 3.984(34)(222). Markeyite is orthorhombic, 〈span〉Pmmn〈/span〉, 〈span〉a〈/span〉 = 17.9688(13), 〈span〉b〈/span〉 = 18.4705(6), 〈span〉c〈/span〉 = 10.1136(4) Å, 〈span〉V〈/span〉 = 3356.6(3) Å〈span〉3〈/span〉 and 〈span〉Z〈/span〉 = 2. The structure of markeyite (〈span〉R〈/span〉〈span〉1〈/span〉 = 0.0435 for 3427 〈span〉F〈/span〉〈span〉o〈/span〉 〉 4σ〈span〉F〈/span〉) contains uranyl tricarbonate clusters (UTC) that are linked by Ca–O polyhedra forming thick corrugated heteropolyhedral layers. Included within the layers is an additional disordered CO〈span〉3〈/span〉 group linking the Ca–O polyhedra. The layers are linked to one another and to interlayer H〈span〉2〈/span〉O groups only via hydrogen bonds. The structure bears some similarities to that of liebigite.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Redcanyonite (IMA2016-082), (NH〈span〉4〈/span〉)〈span〉2〈/span〉Mn[(UO〈span〉2〈/span〉)〈span〉4〈/span〉O〈span〉4〈/span〉(SO〈span〉4〈/span〉)〈span〉2〈/span〉](H〈span〉2〈/span〉O)〈span〉4〈/span〉, occurs underground in the Blue Lizard mine, Red Canyon, White Canyon district, San Juan County, Utah, USA. It occurs with natrozippeite, brochantite, devilline, posnjakite, johannite, gypsum, bobcookite, pickeringite, pentahydrite and the NH〈span〉4〈/span〉-analogue of zippeite: ammoniozippeite. Redcanyonite occurs as radial aggregates of red–orange needles and blades individually reaching up to 0.2 mm long, with aggregates measuring up to 1 mm in diameter. Crystals are flattened on {010} and elongated along [100], exhibit perfect cleavage on {010}, and exhibit the forms {010}, {001}, {101} and {10〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190128104130349-0707:S0026461X18001007:S0026461X18001007_inline1.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉}. Twinning is ubiquitous, by 180° rotation on [100]. Redcanyonite is translucent with a pale orange streak, is non-fluorescent, has a Mohs hardness of 2, and has brittle tenacity with uneven fracture. Optically, redcanyonite is biaxial (+), α = 1.725(3), β = 1.755(3), γ = 1.850(5) (white light); 2V (meas.) = 60(2)°, 2V (calc.) = 61.3°; and dispersion is 〈span〉r〈/span〉 v, very strong. Pleochroism is: 〈span〉X〈/span〉 = orange, 〈span〉Y〈/span〉 = yellow and 〈span〉Z〈/span〉 = orange; 〈span〉Y〈/span〉 X Z. The optical orientation is 〈span〉X〈/span〉 = 〈span〉b〈/span〉, 〈span〉Y〈/span〉 ≈ 〈span〉c〈/span〉*, 〈span〉Z〈/span〉 ≈ 〈span〉a〈/span〉. The empirical formula is (NH〈span〉4〈/span〉)〈span〉2.02〈/span〉(Mn〈span〉0.49〈/span〉Cu〈span〉0.09〈/span〉Zn〈span〉0.06〈/span〉)〈span〉Σ0.64〈/span〉H〈span〉+〈/span〉〈span〉0.72〈/span〉[(UO〈span〉2〈/span〉)〈span〉4〈/span〉O〈span〉4〈/span〉(S〈span〉0.99〈/span〉P〈span〉0.01〈/span〉O〈span〉4〈/span〉)〈span〉2〈/span〉](H〈span〉2〈/span〉O)〈span〉4〈/span〉, based on 4 U and 24 O apfu. Redcanyonite is monoclinic, 〈span〉C〈/span〉2〈span〉/m〈/span〉, 〈span〉a〈/span〉 = 8.6572(17), 〈span〉b〈/span〉 = 14.155(3), 〈span〉c〈/span〉 = 8.8430(19) Å, β = 104.117(18)°, 〈span〉V〈/span〉 = 1050.9(4) Å〈span〉3〈/span〉 and 〈span〉Z〈/span〉 = 2. The structure was refined to 〈span〉R〈/span〉〈span〉1〈/span〉 = 0.0382 for 1079 reflections with 〈span〉I〈/span〉〈span〉obs〈/span〉 〉 3σ〈span〉I〈/span〉. Uranyl oxo-sulfate sheets in redcanyonite adopt the well-known zippeite topology, which consists of zigzag chains of uranyl pentagonal bipyramids linked by sulfate tetrahedra to form sheets. The sheets are linked to each other through bonds to interlayer NH〈span〉4〈/span〉〈span〉+〈/span〉 groups and octahedrally coordinated Mn〈span〉2+〈/span〉, and by hydrogen bonds from H〈span〉2〈/span〉O groups. Redcanyonite is named for Red Canyon in southeast Utah, USA.〈/p〉〈/div〉

Description: Calciodelrioite, ideally Ca(VO3)2(H2O)4, is a new mineral (IMA 2012-031) from the uranium-vanadium deposits of the eastern Colorado Plateau in the USA. The type locality is the West Sunday mine, Slick Rock district, San Miguel County, Colorado. The new mineral occurs on fracture surfaces in corvusite- and montroseite-impregnated sandstone and forms as a result of the oxidative alteration of these phases. At the West Sunday mine, calciodelrioite is associated with celestine, gypsum, huemulite, metarossite, pascoite and rossite. The mineral occurs as transparent colourless needles, bundles of tan to brown needles and star bursts of nearly black broad blades composed of tightly intergrown needles. Crystals are elongate and striated parallel to [100], exhibiting the prismatic forms {001} and {011} and having terminations possibly composed of the forms {100} and {611İ}. The mineral is transparent and has a white streak, subadamantine lustre, Mohs hardness of about 2, brittle tenacity, irregular to splintery fracture, one perfect cleavage on {001} and possibly one or more additional cleavages parallel to [100]. Calciodelrioite is soluble in water. The calculated density is 2.451 g cm−3. It is optically biaxial (+) with α = 1.733(3), β = 1.775(3), γ = 1.825(3) (white light), 2Vmeas = 87.3(9)° and 2Vcalc = 87°. The optical orientation is X = b; Z ≈ a. No pleochroism was observed. Electron-microprobe analyses of two calciodelrioite samples and type delrioite provided the empirical formulae (Ca0.88Sr0.07Na0.04K0.01)Σ1.00(V1.00O3)2(H2.01O)4, (Ca0.76Sr0.21Na0.01)Σ0.98(V1.00O3)2(H2.01O)4 and (Sr0.67Ca0.32)Σ0.99(V1.00O3)2(H2.00O)4, respectively. Calciodelrioite is monoclinic, I2/a, with unit-cell parameters a = 14.6389(10), b = 6.9591(4), c = 17.052(2) Å, β = 102.568(9)°, V = 1695.5(3)Å3 and Z = 8. The seven strongest lines in the X-ray powder diffraction pattern [listed as dobs Å(I)(hkl)] are as follows: 6.450(100)(011); 4.350(16)(013); 3.489(18)(020); 3.215(17)(022); 3.027(50)(multiple); 2.560(28)(41İ5,413); 1.786(18)(028). In the structure of calciodelrioite (refined to R1 = 3.14% for 1216 Fo 〉 4σF), V5+O5 polyhedra link by sharing edges to form a zigzag divanadate [VO3] chain along a, similar to that in the structure of rossite. The chains are linked via bonds to Ca atoms, which also bond to H2O groups, yielding CaO3(H2O)6 polyhedra. The Ca polyhedra form a chain along b. Each of the two symmetrically independent VO5 polyhedra has two short vanadyl bonds and three long equatorial bonds. Calciodelrioite and delrioite are isostructural and are the endmembers of the series Ca(VO3)2(H2O)4–Sr(VO3)2(H2O)4. Calciodelrioite is dimorphous with rossite, which has a similar structure; however, the smaller 8-coordinate Ca site in rossite does not accommodate Sr.