Responsible sourcing of critical metals

This is the author accepted manuscript. The final version is available from Mineralogical Society of America via the DOI in this recordMost critical raw materials, such as the rare earth elements (REE), are starting products in long manufacturing supply chains. It is difficult for consumers, buying cars or smartphones for example, to engage with the original mines and demand environmental and social best practice. Geoscientists can become involved in responsible sourcing because geology is related to environmental impact factors such as energy requirements, resource efficiency, radioactivity and the amount of rock mined. The energy and material inputs and emissions and waste from mining and processing can be quantified using life cycle assessment (LCA). Preliminary LCA studies for REE show little over all difference between ‘hard rocks’ such as carbonatites and easily leachable ion adsorption clays, mainly because of the embodied energy in chemicals used for leaching, dissolution and separation.This work is part funded by the NERC SoS RARE project, NE/M011429/1

Making American Art an Engaging General Education Course

Humanities courses are often populated with students who primarily take these offerings to meet General Education requirements. American art classes can provide opportunities for students to think analytically and consider what is included as well as what is omitted in visual and textual formats. This article provides examples and the pedagogical rationales for a range of in-class and out-of-class activities that enable active learning, critical thinking, creativity, and kinesthetic engagement. Creating on-line resources to replace a textbook, taking field trips on or adjacent to campus, and exhibition critique and label-writing activities can be easily adapted to campus- and online-learning settings at little or no cost. These approaches address some of the challenges that the academy, like the museum, face: who, how, and what one learns; how to balance the canon with works of art, topics, issues, and ideas related to those who have traditionally not been represented; and how to equalize access to institutions

Facing Philadelphia: The social functions of silhouettes, miniatures, and daguerreotypes, 1760-1860

In 1807, Charles Fraser lauded fellow miniature artist Edward Greene Malbone\u27s ability to produce such striking resemblances, that they will never fail to perpetuate the tenderness of friendship, to divert the cares of absence, and to aid affection in dwelling on those features and that image which death has forever wrested from it. The explanations traditionally given for the commissioning of portraits--the perpetuation of family or institutional memory--correspond with Fraser\u27s comments. Yet these explanations rarely incorporate the social context: the communities in which images were produced and the individual, familial, or group meanings of portraits.; Facing Philadelphia: The Social Functions of Silhouettes, Miniatures, and Daguerreotypes, 1760-1860 explores some of the forces that shaped a century of portrait patronage in one of America\u27s most prosperous urban centers. My research reveals that different sectors of Philadelphia\u27s elites had decided preferences for specific types of portraits. These patterns suggest that production and patronage were rooted in the meanings that portraits had for certain groups, meanings that were connected to social, economic, religious, and political conditions in Philadelphia.;Whether stark silhouettes for Quakers or individual artists\u27 miniatures for the established mercantile elite, the appeal of small-scale portraits was partially due to their appearance and to their traditional desirability as gifts. Novelty, price, and availability helped create demand for daguerreotypic likenesses. Yet local scientific interest, Quaker mores regarding material life, and the desire for engravings and miniatures based on photographic images also determined daguerreotype patronage. The connections among the different sectors of the art market also suggest ways in which the distinctions between high and low art become blurred upon closer examination.;In their portrait choices, Philadelphians extended long-term cultural practices and modified others in ways that embodied local needs as well as incorporated broader national and international trends. They used small-scale portraits in particular ways, adapting widely available forms to specific, socially derived needs. Through their commission and use of portraits, Philadelphians simultaneously crafted their identities and shaped art markets

Making History: Antiquarian Culture in Mid-Nineteenth-Century Philadelphia

IN 1857, BENSON LOSSING thanked John Fanning Watson for his “suggestions respecting local inquiries,” adding “I am more and more surprised, as I daily look into the reminisces [sic] of the past, at the total apathy of our citizens in regard to historical facts of great interest to all, with which our city abounds. The men and women of the Revolution have almost all departed from among us, yet I occasionally meet one whose recollection is exceedingly clear. From them I glean all that can be got, and hope to add a mite to your most valuable store.” Lossing (1813–91), based in Poughkeepsie, New York, was a key figure in the generation of antiquarians that included Philadelphia’s renowned chronicler John Fanning Watson (1779–1860). Along with John A. McAllister (1822–96), Ferdinand Dreer (1812–1902), Edward Ingraham (1793–1854), Edwin Greble (1806–83), and Frank Marx Etting (1833–90) of Philadelphia, as well as Brantz Mayer (1809–79) of Baltimore, Lossing was among those mid-nineteenth-century collectors who exchanged, discussed, accumulated, published, borrowed, sold, and donated an array of documents, prints and, occasionally, relics related to colonial and early national America. In seeking out the recollections of descendants, images of original building construction, and artists’ “good likenesses” taken directly from national fi gures, their interests and methods helped determine what information from the past was saved. These antiquarians’ preservation and collecting activities played a role in defining and emphasizing what elements of Philadelphia’s past were important, both at the time and in future decades

The superhydrophobicity of polymer surfaces: Recent developments

Superhydrophobicity is the extreme water repellence of highly textured surfaces. The field of superhydrophobicity research has reached a stage where huge numbers of candidate treatments have been proposed and jumps have been made in theoretically describing them. There now seems to be a move to more practical concerns and to considering the demands of individual applications instead of more general cases. With these developments, polymeric surfaces with their huge variety of properties have come to the fore and are fast becoming the material of choice for designing, developing, and producing superhydrophobic surfaces. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1203–1217, 201

Thin-Film Metamaterials called Sculptured Thin Films

Morphology and performance are conjointed attributes of metamaterials, of which sculptured thin films (STFs) are examples. STFs are assemblies of nanowires that can be fabricated from many different materials, typically via physical vapor deposition onto rotating substrates. The curvilinear--nanowire morphology of STFs is determined by the substrate motions during fabrication. The optical properties, especially, can be tailored by varying the morphology of STFs. In many cases prototype devices have been fabricated for various optical, thermal, chemical, and biological applications.Comment: to be published in Proc. ICTP School on Metamaterials (Augsut 2009, Sibiu, Romania

The link between volcanism and plutonism in epizonal magma systems; high-precision U–Pb zircon geochronology from the Organ Mountains caldera and batholith, New Mexico

The Organ Mountains caldera and batholith expose the volcanic and epizonal plutonic record of an Eocene caldera complex. The caldera and batholith are well exposed, and extensive previous mapping and geochemical analyses have suggested a clear link between the volcanic and plutonic sections, making this an ideal location to study magmatic processes associated with caldera volcanism. Here we present high-precision thermal ionization mass spectrometry U–Pb zircon dates from throughout the caldera and batholith, and use these dates to test and improve existing petrogenetic models. The new dates indicate that Eocene volcanic and plutonic rocks in the Organ Mountains formed from ~44 to 34 Ma. The three largest caldera-related tuff units yielded weighted mean [superscript 206]Pb/[superscript 238]U dates of 36.441 ± 0.020 Ma (Cueva Tuff), 36.259 ± 0.016 Ma (Achenback Park tuff), and 36.215 ± 0.016 Ma (Squaw Mountain tuff). An alkali feldspar granite, which is chemically similar to the erupted tuffs, yielded a synchronous weighted mean [superscript 206]Pb/[superscript 238]U date of 36.259 ± 0.021 Ma. Weighted mean [superscript 206]Pb/[superscript 238]U dates from the larger volume syenitic phase of the underlying Organ Needle pluton range from 36.130 ± 0.031 to 36.071 ± 0.012 Ma, and the youngest sample is 144 ± 20 to 188 ± 20 ka younger than the Squaw Mountain and Achenback Park tuffs, respectively. Younger plutonism in the batholith continued through at least 34.051 ± 0.029 Ma. We propose that the Achenback Park tuff, Squaw Mountain tuff, alkali feldspar granite and Organ Needle pluton formed from a single, long-lived magma chamber/mush zone. Early silicic magmas generated by partial melting of the lower crust rose to form an epizonal magma chamber. Underplating of the resulting mush zone led to partial melting and generation of a high-silica alkali feldspar granite cap, which erupted to form the tuffs. The deeper parts of the chamber underwent continued recharge and crystallization for 144 ± 20 ka after the final eruption. Calculated magmatic fluxes for the Organ Needle pluton range from 0.0006 to 0.0030 km3/year, in agreement with estimates from other well-studied plutons. The petrogenetic evolution proposed here may be common to many small-volume silicic volcanic systems

Online preconcentration ICP-MS analysis of rare earth elements in seawater

The rare earth elements (REEs) with their systematically varying properties are powerful tracers of continental inputs, particle scavenging intensity and the oxidation state of seawater. However, their generally low (∼pmol/kg) concentrations in seawater and fractionation potential during chemical treatment makes them difficult to measure. Here we report a technique using an automated preconcentration system, which efficiently separates seawater matrix elements and elutes the preconcentrated sample directly into the spray chamber of an ICP-MS instrument. The commercially available “seaFAST” system (Elemental Scientific Inc.) makes use of a resin with ethylenediaminetriacetic acid and iminodiacetic acid functional groups to preconcentrate REEs and other metals while anions and alkali and alkaline earth cations are washed out. Repeated measurements of seawater from 2000 m water depth in the Southern Ocean allows the external precision (2σ) of the technique to be estimated at <23% for all REEs and <15% for most. Comparison of Nd concentrations with isotope dilution measurements for 69 samples demonstrates that the two techniques generally agree within 15%. Accuracy was found to be good for all REEs by using a five point standard addition analysis of one sample and comparing measurements of mine water reference materials diluted with a NaCl matrix with recommended values in the literature. This makes the online preconcentration ICP-MS technique advantageous for the minimal sample preparation required and the relatively small sample volume consumed (7 mL) thus enabling large data sets for the REEs in seawater to be rapidly acquired

A field and geochemical study of the boundary between the Nanga Parbat-Haramosh massif and the Ladakh arc terrane, northern Pakistan

The Nanga Parbat-Haramosh massif (NPHM) is a north-south trending structural and topographic high, which interrupts the east-west trend of the Himalaya in northern Pakistan. Previously, the massif was thought to be bounded by the Main Mantle thrust (MMT), a north-dipping thrust along which the Kohistan-Ladakh arc was thrust south over the northern margin of the Indian continent. This study presents field and geochemical data suggesting that the eastern boundary of the massif, the Stak fault zone, is a young feature that displaces the suture zone. The Stak fault zone marks the boundary between Precambrian kyanite-sillimanite bearing biotite gneiss of continental affinity and Cretaceous (?) arc lithologies of the western Ladakh terrane. The arc complex consists of amphibolitic country rock that has been intruded by gabbroic to tonalitic plutons. The protolith of the amphibolite is immature oceanic island arc tholeiitic basalt. The mafic to intermediate plutons are dominantly calc-alkaline and could have formed in either a mature island arc setting or a continental margin setting. The Ladakh arc terrane exposes the upper section of an arc, below the sedimentary and volcanic cover. The Stak fault zone is a 3-5 km wide zone containing at least four major high angle faults that separate blocks of various lithologies. The only true mylonite zone occurs along the westernmost fault. A faulted late stage dike is evidence for recent activity along the easternmost fault. The units along the western side of the fault zone are analogous to deep oceanic arc lithologies; tholeiitic amphibolite, banded gneiss, and a section of a layered mafic complex. The units along the eastern side of the fault zone are mineralogically and chemically correlative to the mafic plutons exposed in the western Ladakh terrane. The geometry of the fault zone, the lack of suture zone lithologies, and the evidence for recent activity suggest that the Stak fault zone does not represent the suturing event, when the Kohistan- Ladakh arc was obducted onto the northern margin of India. Instead, the fault zone is likely formed in response to the recent uplift of the NPHM