Metallic Luster Research Articles

Ferrovalleriite, 2(Fe,Cu)S · 1.5Fe(OH)2: Validation as a mineral species and new data

Ferrovalleriite, ideally 2(Fe,Cu)S · 1.5Fe(OH)2, a layered hydroxide-sulfide of the valleriite group and an analog of valleriite with Fe instead of Mg in the hydroxide block, has been approved by the IMA Commission on New Minerals, Nomenclature and Classification as a valid mineral species. It was found in the Oktyabr’sky Mine, Noril’sk, Krasnoyarsk krai, Siberia, Russia. Ferrovalleriite occurs in cavities of massive sulfide ore mainly consisting of cubanite and mooihoekite. In different cases, it is associated with magnetite, Fe-rich chlorite-like phyllosilicate, ferrotochilinite, hibbingite, or rhodochrosite. Ferrovalleriite forms crystals flattened on [001] (from scaly to tabular; up to 5 mm across and up to 0.3 mm thick), typically split and curved. Occasionally, they are combined into aggregates up to 1.5 × 2 cm. Ferrovalleriite is dark bronze-colored, with a metallic luster and black streak. The Mohs’ hardness is ca. 1; VHN is 35 kg/mm2. Cleavage is perfect parallel to {001}, mica-like. Individuals are flexible and inelastic. D(calc) = 3.72 g/cm3. In reflected light, ferrovalleriite is pleochroic from yellowish to gray; bireflectance is moderate. Anisotropy is strong, with bluish gray to yellowish beige rotation colors. Reflectance values [R1–R2 %, (λ, nm)] are: 15.6–16.6 (470), 14.8–20.5 (546), 14.7–22.3 (589), 14.5–24.1 (650). The IR spectrum shows the presence of (OH) groups bonded with Fe cations and the absence of H2O molecules. The chemical composition of the holotype (wt %; electron microprobe, H content is calculated) is as follows: 0.10 Al, 0.03 Mn, 45.31 Fe, 0.07 Ni, 18.29 Cu, 20.37 S, 15.62 O, 0.98 H, total is 100.77. The empirical formula calculated on the basis of 2 S atoms is: Al0.01Fe2.55Cu0.91S2(OH)3.07 = (Fe1.09Cu0.91)Σ2S2 · (Fe1.342+Fe0.123+Al0.01)Σ1.47(OH)3.07. The structure of ferrovalleriite is incommensurate (misfit); two sublattices are present: (1) sulfide sublattice, space group \(R\bar 3m\), R3m or R32; the unit-cell dimensions are: a = 3.792(2), c = 34.06(3) A, V = 424(1) A3 and (2) hydroxide sublattice, space group \(P\bar 3m1\), P3m1 or P321; the unit-cell dimensions: a = 3.202(3), c = 11.35(2)A, V = 100.8(3) A3. Together with this main polytype modification with three-layer (R-cell, Z = 3) sulfide block, the holotype ferrovalleriite contains the modification with one-layer (P-cell, Z = 1) sulfide block (sulfide sublattice with \(P\bar 3m1\), P3m1 or P321, unit cell dimensions: a = 3.789(4), c = 11.35(1) A, V = 141(5) A3). The strongest reflections in the X-ray powder pattern (d, A-I) are: 5.69–100; 3.268–58; 3.163–36; 1.894–34; 1.871–45.

Dervillite, Ag2AsS2, from Lengenbach quarry, Binn valley, Switzerland: occurrence and crystal structure

AbstractDervillite, As2AsS2, has been found in a sample from the Lengenbach quarry in the Binn Valley, Valais, Switzerland. It occurs as very rare crystals up to 200 μm across on jordanite. Dervillite is opaque with a metallic lustre and shows a dark brown streak. The structure is monoclinic, space groupPc, witha= 9.6155(7),b= 12.9331(8),c= 6.8616(5) A ˚ ,b= 99.352(8)º,V= 842.0(1) Å3andZ= 8. In the crystal structure [R1= 0.060 for 2370 reflections withI> 2σ(I)], silver adopts various coordinations extending from quasi linear to quasi tetrahedral whereas arsenic forms very peculiar crystal-chemical environments, such as As(S2As) and As(S2AsAg). Such metalloid–metalloid or metal–metalloid bonds account for the apparent charge imbalance observed in the chemical formula.

Non-destructive characterization of oriental porcelain glazes and blue underglaze pigments using μ-EDXRF, μ-Raman and VP-SEM

The study of ancient materials with recognized cultural and economic value is a challenge to scientists and conservators, since it is usually necessary an approach through non-destructive techniques. Difficulties in establishing a correct analytical strategy are often significantly increased by the lack of knowledge on manufacture technologies and raw materials employed combined with the diversity of decay processes that may have acted during the lifetime of the cultural artefacts. A non-destructive characterization was performed on the glaze and underglaze pigments from a group of Chinese porcelain shards dated from the late Ming Dynasty (1368–1644) excavated at the Monastery of Santa Clara-a-Velha in Coimbra (Portugal). Chemical analysis was performed using micro-energy dispersive X-ray fluorescence spectrometry (μ-EDXRF). Mineralogical characterization was achieved by Raman microscopy (μ-Raman) and observation of small-surface crystallization dark spots with a metallic lustre in areas with high pigment concentration was done by variable pressure scanning electron microscopy (VP-SEM). Cobalt aluminate was identified as the blue underglaze pigment and a comparison of blue and dark blue pigments was performed by the ratio of Co, Mn, and Fe oxides, indicating a compositional difference between the two blue tonalities. Manganese oxide compounds were also identified as colouring agents in dark blue areas and surface migration of manganese compounds was verified.

Spectroellipsometric and ion beam analytical studies on a glazed ceramic object with metallic lustre decoration

In this work recently produced and commercially available glazed ceramic object with metallic lustre decoration was studied by using a spectroscopic ellipsometer with rotating compensator. The thickness and metal content of the surface lustre layers are determined by ion beam analytical techniques, i.e., Rutherford backscattering spectrometry and external beam particle-induced X-ray emission and the results were utilized in the construction of multilayer optical models for the evaluation and interpretation of the spectroellipsometric measurements.

Barikaite, Pb10Ag3(Sb8As11)Σ19S40, a new member of the sartorite homologous series

AbstractBarikaite, ideally Pb10Ag3(Sb8As11)Σ19S40, is a new mineral species from the Barika Au-Ag deposit, Azarbaijan Province, western Iran. It was formed in fractures developed in silica bands situated in massive banded pyrite and baryte ores. These fractures house veinlets that contain a number of Ag-As-Sb-Pb-rich sulfosalts, tetrahedrite-tennantite, realgar, pyrite and electrum. Barikaite appears as inclusions in guettardite. The mineral is opaque, greyish black with a metallic lustre; it is brittle without any discernible cleavage. In reflected light barikaite is greyish white, pleochroism is distinct, white to dark grey. Internal reflections are absent. In crossed polars, anisotropism is distinct with rotation tints in shades of grey. The reflectance data (%, in air) are: 37.0, 39.3 at 470 nm, 34.1, 36.9 at 546 nm, 33.1, 36.2 at 589 nm and 31.3, 34.1 at 650 nm. The Mohs hardness is 3–3½, microhardness VHN50 exhibits the range 192 – 212, with a mean value of 200 kg mm–2. The average results of five electron-microprobe analyses in a grain are (in wt.%): Pb 35.77(33), Ag 5.8(1), Tl 0.15(08), Sb 18.33(09), As 15.64(16), S 24.00(15), total 99.69(10) wt.%, corresponding to Pb9.31Ag2.90Tl0.04(Sb8.12As11.26)Σ19.36S40.37 (on the basis of 32Me + 40S = 72 a.p.f.u.). The simplified formula, Pb10Ag3(Sb8As11)Σ19S40, is in accordance with the results of a crystal-structure analysis, and requires Pb 37.89, Ag 5.91, Sb 17.79, As 15.05 and S 23.42 (wt.%). The variation of chemical composition is minor, the empirical formula ranging from Pb10.39Ag2.32Tl0.02Sb7.52As11.27S40.49 to Pb9.24Ag2.93Tl0.04Sb8.13As11.35S40.31. Barikaite has monoclinic symmetry, space group P21/n and unit-cell parameters a 8.5325(7) Å, b 8.0749(7) Å, c 24.828(2) Å, and b 99.077(6)o, Z = 1. Calculated density for the empirical formula is 5.34 (g cm–3). The strongest eight lines in the (calculated) powder-diffraction pattern [d in Å(I)(hkl)] are: 3.835(63)(022), 3.646(100)(016), 3.441(60)(212), 3.408(62)(14), 2.972(66)(16), 2.769(91)(222), 2.752(78)(24) and 2.133(54)(402). Barikaite is the N = 4 member of the sartorite homologous series with a near-equal role of As and Sb, which have an ordered distribution pattern in the structure. It is a close homeotype of rathite and more distantly related to dufrénoysite (both distinct, pure arsenian N = 4 members) and it completes the spectrum of Sb-rich members of the sartorite homologous series. The new mineral and its name have been approved by the IMA-CNMNC (IMA 2012-055).

FERDOWSIITE: A NEW MINERAL FROM THE BARIKA ORE DEPOSIT, IRAN

Ferdowsiite is a member of a mineral association subsidiary to the principal metamorphic minerals of the Barika ore deposit in NW Iran. The empirical formula of ferdowsiite (based on 32 apfu , 16Me + 16S) is Ag 7.97 Pb 0.08 Sb 4.75 As 3.15 Bi 0.01 S 16.04. The crystal-structure formula is Ag 8 (Sb 5.49 As 2.51 ) ∑8 S 16 ; the simplified formula is Ag 8 (Sb 5 As 3 ) ∑8 S 16 . The slightly plumbian variety of ferdowsiite has the idealized formula Pb 2x Ag 4−x Sb 3−x AsS 8 with x =~0.2. Ferdowsiite is monoclinic, space group P 2 1 / n , a 8.677(2) A, b 5.799(1) A, c 13.839(3) A, β 96.175(4)°, V 692.28(10) A 3 , Z = 1 for the formula Ag 8 (Sb 5 As 3 ) ∑8 S 16 . Calculated powder X-ray data are listed; main diffraction lines are [ d calc ( I rel ) ( hkl )]: 3.225 (96)(113); 3.205 (100)(212); 2.8995 (78)(020); 2.7559 (90)(301); 2.7073 (79)(105); 1.9401 (22)(206); 1.9226 (22)(404). Plumbian ferdowsiite has the same space group, P 2 1 / n. It has a 8.746(7) A, b 5.805(4) A, c 13.929(10) A, β 96.236(11)°, unit cell volume 703.05 A 3 . The mineral is greyish black, opaque, with dark grey streak and metallic luster. It is brittle with irregular fracture; no cleavage or parting was observed. Calculated density is 5.3 g/cm 3 . In reflected light ferdowsiite is greyish white. Internal reflections are not observable. Pleochroism is distinct, white to grey. Bireflectance is distinct; reflectance values are [λ(nm), R min ,R max ]: 470, 34.9, 37.3; 546, 33.4, 35.9; 589, 32.4, 35.1; 650, 30.7, 33.5. Anisotropism is distinct and rotation tints vary between dark brown and bluish grey. Ferdowsiite is associated with large corroded crystals of arsenquatrandorite and is partly replaced by guettardite. It also corrodes smithite. Ferdowsiite is often associated with tetrahedrite/tennantite and forms worm-like symplectites with it. This symplectite is partly replaced on the surface by guettardite. Ferdowsiite is one more member of the group of ABX 2 -type sulfosalts of silver, combining antimony and arsenic, with a crystal structure different from other members of this group. The closest crystallographic and structural affinity is to the ternary sulfosalt diaphorite.

Titaniferous heavy mineral aggregates as a tool in exploration for pegmatitic and aplitic rare-metal deposits (SE Germany)

Black heavy mineral (HM) aggregates of metallic luster and composed of ilmenite and rutile were named “nigrine” (amount of rutile>ilmenite) and “antinigrine” (amount of ilmenite>rutile). They contain inclusions of, e.g., columbite-(Fe), pyrochlore group minerals, wolframite solid solution series (=s.s.s.), monazite, zircon, Fe oxides and sulfides as well as alteration minerals such as pseudorutile and Fe–Ti–Nb–Ta–Al–P compounds, whose precise chemical composition and mineralogical affiliation cannot be determined. These titaniferous HM aggregates are of widespread occurrence in gneisses and shear zones cutting through them as well as alluvial, fluvial and colluvial deposits at different distances from rare-element phosphate pegmatites within the crystalline basement in SE Germany. “Nigrine” and “antinigrine” may be subdivided into three types which formed at different periods relative to the Variscan tectonic disturbances and which show different qualities as markers for the origin and presence of Nb-bearing pegmatites along the western edge of the Bohemian Massif, SE Germany.Type A developed pre- to synkinematically within or near deep-seated shear zones which formed below 730°C as early as 321 to 329Ma. These HM aggregates are poor in Nb and impoverished in accessory minerals. The HM aggregates having developed in shear zones mark the “kitchen” where friction and heating contributed to the formation of felsic intrusive bodies, such as pegmatites and aplites. This type of Ti-bearing HM aggregates may be held as distal proximity indicator.Type B is early postkinematic and enriched in niobian rutile, rife with lots of inclusions, especially columbite-(Fe). It precipitated in the crystalline country rocks at temperatures around 600°C concomitant with the nearby rare-element pegmatites between 302 and 311Ma. It is the most proximal member of this group of HM aggregates.Type C “nigrine” is enriched in W and late postkinematic relative to the shearing processes in the crystalline basement. It formed around 470°C during the same period of time as type C. It does, however, not qualify as a marker for rare-element pegmatites, as it is unrelated to these felsic intrusives.During the late Neogene the Variscan basement was strongly uplifted and many pegmatites were stripped off their roof rocks. As a consequence of this, “nigrine” and “antinigrine” were released from their host rocks and became part of the terrigenous sediments laid down in the drainage systems which upstream cut into the crystalline basement and the pegmatites/aplites. Due to their high resistance to chemical weathering these titaniferous HM aggregates acted as “armored relics” for less resistant minerals such as columbite and pyrochlore. When these titaniferous HM aggregates got decomposed by attrition these mineral inclusions of lesser stability appear in the fluvial sediments further afield from their source than expected, considering the low stability to weathering of single crystals of columbite- and pyrochlore group minerals.“Antinigrine” and “nigrine” may be spotted in the HM suites of drainage systems around pegmatites at a distance of ≤10km with correlation coefficient of RNb–Ti=+0.42, while in the range 2–5km RNb–Ti increases to +0.77, in the range 1–2km RNb–Ti is +0.85 and around 1km from the rare-element pegmatite RNb–Ti stands at +0.92.“Nigrine” and “antinigrine” are no ideal mineral aggregates to form placer-type deposits of their own due to their variegated mineralogy, excluding some Ta-enriched subtypes in Colombia and Sierra Leone. The variable mineralogy detrimental to its use as a source of Ti, is the strong point as an exploration tool for rare-element pegmatites.

SYNTHESIS OF STRUCTURALLY NOVEL CARBON MICRO/ NANOSPHERES BY LOW TEMPERATURE-HYDROTHERMAL PROCESS

ABSTRACT Carbon spheres with two to four attached lobes having axial, trigonal and tetrahedral morphology were synthesized at considerably low temperature of 200 °C by a hydrothermal reaction. The source of carbon used was sucrose in sulfuric acid medium. The product obtained was characterized by X-ray diffraction, Fourier transforms infrared and Raman spectroscopy, which have inferred us the graphitic nature of the product. Further Scanning and Transmission electron microscopic studies have revealed the spheres having attractive morphology with attached lobes and nodes like structures. The carbon spheres are having the size ranging from 200 nm to 4 µm. The spheres are solid balls exhibiting metallic luster. They possess surface area and pore volume of 2.956 m 2 g -1 and 0.616 x 10 -2 cm 3 g -1 respectively as obtained from Brunauer-Emmett-Teller method. The yield product obtained was about 70-80 %. Keywords: Hydrothermal Process, Carbon Spheres, Spheres with lobes, Low Temperature Synthesis, Microscopic Techniques.

Effects of Zein on Film-Forming Ability and Properties of Wheat Gluten Films

Zein was added into wheat gluten (WG) to prepare zein composite films (ZCF) in order to improve the properties of films. The film-forming ability, properties, surface microstructure and infrared spectrum of WG films and ZCF were investigated. The results show that the viscosity of film-forming solutions decrease, and uniformity become worse slightly, after zein added. ZCF are yellow, with metal luster, whose toughness and water retention increase. Compared to the control, the ZCF tensile strength (TS), elongation at break (EB) and resistance of oxygen are increased by 33.2%, 17.2% and 11.25%, and water vapor permeability (WVP) and transparency are decreased by 26.0% and 75.4% respectively. ZCF have better antibacterial properties than WG films. The inhibition effect on escherichia coli and staphylococcus aureus are increased by 36.36% and 32.89% respectively. Hydrogen bond interaction of ZCF become weak, and the surface of ZCF become smooth and evenly.

Highly Disordered Carbon as a Superior Anode Material for Room‐Temperature Sodium‐Ion Batteries

Highly Disordered Carbon as a Superior Anode Material for Room‐Temperature Sodium‐Ion Batteries

Terrywallaceite, AgPb(Sb,Bi)3S6, isotypic with gustavite, a new mineral from Mina Herminia, Julcani Mining District, Huancavelica, Peru

A new mineral species, terrywallaceite, ideally AgPb(Sb,Bi) 3 S 6 , has been found in Mina Herminia, Julcani Mining District, Huancavelica, Peru. It is associated with tetrahedrite, gustavite, barite, and pyrite. Terrywallaceite crystals are lath-shaped, metallic-black, with striations parallel to the elongated direction (the c axis). The mineral is opaque with black streak and metallic luster. It is brittle and has a Mohs hardness of ~4; cleavage is good on {010} and no parting was observed. Twinning is pervasive on (100). The calculated density is 6.005 g/cm 3 . Optically, terrywallaceite is grayish white in polished thin section, with weak bireflectance, weak pleochroism (white to pale gray), and weak anisotropy (gray with bluish tint to bluish black in air). An electron microprobe analysis yielded an empirical formula, based on 6 (S+As) apfu, Ag 1.02 Pb 0.87 (Sb 1.53 Bi 1.47 ) ∑=3.00 (S 5.94 As 0.06 ) ∑=6.00 . Terrywallaceite is a member of the lillianite group and isostructural with P 2 1 / c gustavite. Its unit-cell parameters are a = 6.9764(4), b = 19.3507(10), c = 8.3870(4) A, β = 107.519(2)°, and V = 1079.7(1) A 3 . The structure of terrywallaceite contains six symmetrically-nonequivalent S sites and five cation sites [Ag, Pb, M1 (=0.82Bi + 0.18Sb), M2 (=0.60Bi + 0.40Sb), and M3 (=0.95Sb + 0.05Bi)]. The pronounced preference of Sb for the M3 site over M2 and M1 in terrywallaceite is consistent with the site occupancy data reported for Sb-bearing gustavite, and suggests an alternative ideal formula for terrywallaceite of AgPb(Sb,Bi)(Bi,Sb) 2 S 6 , instead of AgPb(Sb,Bi) 3 S 6 .

Preparation and characterization of vacuum sputter silver coated PLA film

Silver-coated poly(lactide) (PLA) films were prepared by using a vacuum sputter coating method and their film properties were investigated. Smooth-surfaced flexible and free-standing silver-coated PLA films were obtained after coating for 2 min and 10 min. The silver-coated PLA film coated for 2 min was translucent, while that coated for 10 min was opaque with shiny metallic luster. The water vapor barrier and oxygen gas barrier properties decreased significantly (p < 0.05) as time of coating increased, while surface hydrophobicity increased significantly without sacrificing the tensile properties after silver-coating. Film properties, such as optical, film thickness, basis weight, thermal stability, tensile, and gas barrier properties were influenced by the coating time. Noise problem caused by brittleness of the PLA film has been partly mitigated to provide value-added application in the food packaging industry.

Fabrication and Properties of Rapidly Quenched Fe-6.5wt.%Si Alloy Ribbons

Fe-6.5wt.%Si alloy is one excellent soft magnetic material. In the present study, rapid quenching was applied to fabricate ultra-thin ribbons of Fe-6.5wt.%Si alloy by melt spinning. Continuous ribbons of 20 mm wide, 35-45 μm thick were fabricated with optimized experimental parameters. The ribbons exhibited metallic luster appearance, and can be wound without cracks. Microstructure, texture and mechanical properties of the ribbons were investigated. It was found that the rapidly quenched ribbons had intense {100} plane texture, and exhibited some extent of bending capability. Finally the ribbons were cold rolled and the surface smoothness was improved for stacking purpose.

Raman spectroscopy of ferroelectric Sn2P2S6 under high pressure up to 40 GPa: Phase transitions and metallization

We report results of a Raman spectroscopy study of non-oxide ferroelectric tin-hypothiodiphosphate (Sn2P2S6) at ambient temperature under application of high pressure up to 40 GPa. Pressure evolution of the Raman spectra revealed several different compression regimes that are most likely related to phase transitions, with boundaries near &amp;lt;1, ∼5–7, ∼16–19, ∼26–29, and ∼39 GPa. Above 39 GPa, the Raman signal disappeared. Pronounced softening in some phonon modes prior to these crossovers also suggested that these features are related to structural phase transitions. In optical absorption spectroscopy, we confirmed the wide semiconductor band gap Eg of Sn2P2S6, and in particular, found indirect gap of Eg = 2.26 eV and direct one of Eg = 2.42 eV. In visual examinations, we observed that the sample color gradually changed with pressure from yellow to orange, red, and then to opaque. Eventually, at the maximal pressure achieved in our study, the sample demonstrated a metallic luster. Hence, the metallization at 39 GPa was proposed. At decompression, these characteristic features shifted to lower pressures. Thus, besides the known ferroelectric Pn and paraelectric P21/n phases, Sn2P2S6 can adopt several more structures in the pressure range up to 40 GPa, with electronic properties ranging from wide-gap semiconductor to metal. We found that high-pressure behavior of electronic band structure in Sn2P2S6 is, to significant extent, analogous to a case of elemental sulfur.

Preparation and Application of TiO2Nanowires-loaded Porous Ti-Ni Alloy

Porous Ti-Ni alloy was prepared by dipping method and vacuum sintering. Glue and Ti-Ni powders (95 wt% Ti+ 5 wt% Ni) were mixed together to get a slurry. Then a piece of open cell polymer foam (20 mm×20 mm×2 mm) was dipped into the slurry. After being stirred in the slurry for 1 h, the polymer foam was pulled out and squeezed to remove extra slurry. The polymer foam loaded with Ti-Ni slurry was sintered at 1473 K in vacuum for 2 h. With the decomposition of polymer foam at high temperature, an open cell porous Ti-Ni alloy with pore diameter about 0.2 mm was obtained. Because of the addition of Ni powders, porous Ti-Ni alloy has obvious metal luster. A hydrothermal process was applied for TiO2 nanowires preparation. 5 g of porous Ti-Ni alloy was placed in 20 mL H2O2 (30%) aqueous solution at 373 K for 16 h. Then the porous Ti-Ni alloy was filtered out and washed with deionized water. After being dried at 373 K for 6 h, TiO2 nanowires-loaded porous Ti-Ni alloy (TWP-alloy) was obtained. Then the TWP-alloy was characterized by X-ray diffraction and scanning electron microscope. The length of TiO2 nanowires on the surface of Ti-Ni porous alloy was about 2 μm and the diameter of the nanowires was about 20 nm. In the XRD pattern of TWP-alloy, the major phase was Ti and minor phase was TiNi. After being heat-treated at 723 K for 4 h, the phase of the TiO2 nanowires coated on porous Ti-Ni alloy was changed into rutile. During the heat-treatment from 298 K to 723 K, no anatase phase was observed. This means the formation of anatase phase was blocked by the dimension effect of TiO2 nanowires. Then a kind of streaming wastewater treatment instrument was as- sembled by using TWP-alloy as anode and porous Ni as cathode. Methyl orange solution was taken as a sample to investigate the wastewater processing efficiency of TWP-alloy. Under the anode voltage of 30 V, the discoloration of methyl orange can get 93% under the flow velocity of 200 mL/min. Keywords porous Ti-Ni alloy; TiO2; nanowires; methyl orange; electrolysis

Flexible graphene–polyaniline composite paper for high-performance supercapacitor

Free-standing graphene paper with a grey metallic luster has been fabricated for the first time, by a convenient one-step method on a large scale. Herein, the assembly of graphene oxide dispersion into ordered paper occurs simultaneously with the chemical reduction of graphene oxide to graphene. The graphene paper presents the advantages of good flexibility, low weight (0.2 g cm−3) and high electrical conductivity (15 Ω sq−1). Moreover, the size and shape of the graphene paper are freely exchanged for those of the Teflon substrate used. The flexible graphene–PANI paper subsequently exhibits excellent supercapacitor performance with an enhanced specific capacitance (763 F g−1) and good cycling stability by electropolymerization of PANI nanorods on the above graphene paper. The method presented here shows great promise for the development of low-cost electrode materials in potential energy storage devices.

R&amp;D Trend on Surface Treatment of Magnesium Alloys

Recently, consumption of magnesium alloys has increased especially in the 3C (computer, communication, camera) and automobile industries. The structural application of magnesium alloys has many advantages due to their low densities, high specific strength, excellent damping and anti-eletromagnetic properties, and easy recycling. However, practical application of these alloys has been limited to narrow uses of mild condition, because they are inferior in corrosion resistance and wear resistance due to their high chemical reactivity and low hardness. Various wet and dry processes are being used or are under development to enhance alloy surface properties. Various conversion coating and anodizing methods have been developed in a view of eco-friendly concept. The conventional technologies, such as diffusion coating, sol-gel coating, hydrothermal treatment, and organic coating, are expected to be newly applicable to magnesium alloys. Surface treatments for metallic luster or coloring are suggested using the control of the micro roughness. This report reviews the recent R&D trends and achievements in surface treatment technologies for magnesium alloys.

Direct biomass fuel cell (BMFC) for polymeric biomass with anode/catalyst device comprising a mesoporous n-semiconductor film/Co, Ni or Cu thin layer

Efficient direct biomass fuel cell (BMFC) anode/catalysts were successfully prepared that are comprised of [base FTO electrode/mesoporous n-TiO2 thin film/low cost metal thin layer], for which the low cost metal is Co, Ni or Cu, and FTO is a conductive glass electrode coated with an F-doped SnO2 thin layer. The metal thin layer was reductively electrodeposited onto a mesoporous 10μm thick TiO2 thin film coated on an FTO. The anode/catalyst semiconductor (SC) devices in which the metal shows metallic luster were efficient for generating electrical power without any photoirradiation nor bias potentials by using polymeric biomass (BM) compounds such as starch, carboxy-methyl cellulose (CMC), and lignin–sulfonic acid in combination with an O2-reducing cathode the other side of which was exposed to ambient air. The TiO2/Cu device anode/catalyst generated with CMC fuel short circuit current Jsc of 740μAcm−2, open circuit voltage Voc of 0.38V, and fill factor FF of 0.25, leading to the maximum output power Wout of 70μWcm−2. The TiO2/Ni device with starch gave Jsc 870μAcm−2, Voc 0.33V, FF 0.24 and Wout 69μWcm−2. The TiO2/Cu with glucose gave Jsc 850mAcm−2, Voc 0.69V, and FF 0.25, attaining Wout 147μWcm−2. It is important that the capability of electron utilization by the TiO2/Cu device with glucose reached more than 17e− among the theoretical 24e− (=71%) of one glucose molecule. It was strongly suggested that the interface between the TiO2/metal has both the Schottky-junction and Ohmic nature, which interpreted the multi-electron utilization of the biomass. It was proposed that, according to a simple calculation, the device has a potential to be used in a principal sustainable energy resource system.

Kielmeyera aureovinosa (Calophyllaceae): a new species from the Atlantic Rainforest in highlands of Rio de Janeiro state

Kielmeyera aureovinosa M. Gomes is a tree of the Atlantic Rainforest, endemic to the highlands of Rio de Janeiro state, occurring in riverine forest. The new species is distinguished in the genus by having a wine colored stem with metallic luster, peeling, with golden bands: it differs from other species of Kielmeyera section Callodendron by having leaves with sparse resinous corpuscles and flowers with ciliate margined sepals and petals. This paper provides a description of the species, illustrations and digital images; morphological and palynological features of Kielmeyera section Callodendron species are discussed and compared.

Linzhiite, FeSi2, a redefined and revalidated new mineral species from Luobusha, Tibet, China

“Ferdisilicite” (FeSi 2 ) was first described as a member of the Fe–Si alloy mineral series by Gevork’yan (1969), without CNMMN approval. It is redefined here as a new mineral, revalidated with the new name linzhiite with a CNMNC approval (IMA 2010-011). The type sample was found in a podiform chromitite from the Luobusha ophiolite in Tibet, People’s Republic of China. It occurs as irregular grains ranging from 0.04 to 0.5 mm in diameter and intergrowths with zangboite and native silicon. Linzhiite is steel grey in colour, opaque, with a metallic lustre and a greyish-black streak. The mineral is brittle and has a conchoidal fracture. Cleavage was not observed. The Mohs hardness is 6½, and the calculated density is 4.972 g/cm 3 . Reflectance values of the material in air ( R %) are: 26.3 at 470 nm, 30.3 at 546 nm, 32.9 at 589 nm, and 36.3 at 650 nm. The composition (mean of 12 EMP analyses) is Fe 49.09, Si 50.00, Al 0.64 and Mn 0.28 wt%, sum 100.01 wt%. The ideal formula is FeSi 2 . The crystal structure was refined from single-crystal X-ray diffraction data to R = 0.043. The mineral has a tetragonal P 4/ mmm structure, with a = 2.696 (1) A, b = 2.696 (1) A, c = 5.147 (6), V = 37.41 (14) A 3 , Z = 1. The five strongest X-ray powder diffraction lines [ d -spacing in A ( I / I 0 )] are: 5.136 (96), 2.374 (81), 1.896 (55), 1.849 (100), and 1.086 (36). Linzhiite formed in a strongly reducing environment and possibly occurs as xenocrysts derived from mantle sources.