1,166 research outputs found
Honeaite, a new gold-thallium-telluride from the Eastern Goldfields, Yilgarn Craton, Western Australia
Honeaite, ideal formula Au3TlTe2, is a new mineral from the late Archaean Karonie gold deposit, Eastern Goldfields province, Western Australia. Honeaite is found with native gold, tellurobismuthite, petzite, hessite, calaverite, melonite, mattagamite, frohbergite, altaite, pyrrhotite and molybdenite. These minerals are concentrated in microvughs and microfractures mainly within areas of prehnite alteration of amphibolite. The mineralisation appears to have been deposited under greenschistfacies conditions at lower temperatures than most gold deposits in the Eastern Goldfields. Single-crystal X-ray studies identified the structure of honeaite as orthorhombic, space group Pbcm, and unit cell parameters a = 8.9671(4) Å, b = 8.8758(4) Å, c = 7.8419(5) Å, V = 624.14(6) Å3 (Z = 4). The strongest reflections of the calculated powder X-ray diffraction pattern are [d in Å (I rel)(hkl)]: 2.938(100)(022), 2.905 (39,8)(322, 411), 2.989 (31)(300), 2.833 (23)(310), 1.853 (17)(332). Electron-microprobe analysis (EDS mode) gave (wt%) Au 56.33, Tl 19.68, Te 24.30, total 100.31, leading to an empirical formula (based on 2 Te apfu) of Au3.00Tl1.01Te2.00. Honeaite is black with a metallic lustre and no observed cleavage. The calculated density is 11.18 g/cm3. In reflected plane-polarized light it is slightly bluish grey. Between crossed polars it is weakly anisotropic with dark brown to dark blue rotation tints. Reflectance values in air and in oil are given. Honeaite is named after the late Russell M. Honea (1929–2002).© 2016 E. Schweizerbart'sche Verlagsbuchhandlung, D-70176 Stuttgart. This document is the author's final accepted version of the journal article. You are advised to consult the publisher's version if you wish to cite from it
Analysis of Heat Input Effects in Passive Thermographic NDE
The use of digital imaging techniques for analysing and enhancing IR video frames in thermographic NDE [1–6] allows some improvement in resolution of surface temperature contrast. Of equal importance, however, to the magnitude and longevity of the generated contrast is the magnitude and length of the function governing the input heating rate and source impedance [7], In thermogaphic testing the limiting factor is usually the maximum temperature rise (or drop) over a given time span that the heated (cooled) face of the sample can be subjected to without damage occuring. In this study single step and profiled radiative heat pulses have been assessed numerically and experimentally and compared to contact heating (as with a hot liquid in a flexible bag). The detrimental effects of convective and radiative surface heat losses have been examined and their significance to the testing of low and high diffusivity materials assessed. All results presented here are for the two-sided testing configuration although, in principle, the results are applicable to single sided testing also.</p
Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population
Mineral nutrient malnutrition, and particularly
deficiency in zinc and iron, afflicts over 3 billion people
worldwide. Wild emmer wheat, Triticum turgidum ssp.
dicoccoides, genepool harbors a rich allelic repertoire for
mineral nutrients in the grain. The genetic and physiological
basis of grain protein, micronutrients (zinc, iron,
copper and manganese) and macronutrients (calcium,
magnesium, potassium, phosphorus and sulfur) concentration
was studied in tetraploid wheat population of 152
recombinant inbred lines (RILs), derived from a cross
between durum wheat (cv. Langdon) and wild emmer
(accession G18-16). Wide genetic variation was found
among the RILs for all grain minerals, with considerable
transgressive effect. A total of 82 QTLs were mapped for
10 minerals with LOD score range of 3.2–16.7. Most QTLs
were in favor of the wild allele (50 QTLs). Fourteen pairs
of QTLs for the same trait were mapped to seemingly
homoeologous positions, reflecting synteny between the A
and B genomes. Significant positive correlation was found
between grain protein concentration (GPC), Zn, Fe and Cu,
which was supported by significant overlap between the
respective QTLs, suggesting common physiological and/or
genetic factors controlling the concentrations of these
mineral nutrients. Few genomic regions (chromosomes 2A,
5A, 6B and 7A) were found to harbor clusters of QTLs for
GPC and other nutrients. These identified QTLs may
facilitate the use of wild alleles for improving grain
nutritional quality of elite wheat cultivars, especially in
terms of protein, Zn and Fe
Protocol: Health, social care and technological interventions to improve functional ability of older adults: Evidence and gap map
This is the final version. Available on open access from Wiley via the DOI in this frecordThis is a protocol for a Campbell Evidence and Gap Map. The objectives are to identify and assess the available evidence on health, social care and technological interventions to improve functional ability among older adults
The Distances of the Magellanic Clouds
The present status of our knowledge of the distances to the Magellanic Clouds
is evaluated from a post-Hipparcos perspective. After a brief summary of the
effects of structure, reddening, age and metallicity, the primary distance
indicators for the Large Magellanic Cloud are reviewed: The SN 1987A ring,
Cepheids, RR Lyraes, Mira variables, and Eclipsing Binaries. Distances derived
via these methods are weighted and combined to produce final "best" estimates
for the Magellanic Clouds distance moduli.Comment: Invited review article to appear in ``Post Hipparcos Cosmic
Candles'', F. Caputo & A. Heck (Eds.), Kluwer Academic Publ., Dordrecht, in
pres
Hierarchy Theory of Evolution and the Extended Evolutionary Synthesis: Some Epistemic Bridges, Some Conceptual Rifts
Contemporary evolutionary biology comprises a plural landscape of multiple co-existent conceptual frameworks and strenuous voices that disagree on the nature and scope of evolutionary theory. Since the mid-eighties, some of these conceptual frameworks have denounced the ontologies of the Modern Synthesis and of the updated Standard Theory of Evolution as unfinished or even flawed. In this paper, we analyze and compare two of those conceptual frameworks, namely Niles Eldredge’s Hierarchy Theory of Evolution (with its extended ontology of evolutionary entities) and the Extended Evolutionary Synthesis (with its proposal of an extended ontology of evolutionary processes), in an attempt to map some epistemic bridges (e.g. compatible views of causation; niche construction) and some conceptual rifts (e.g. extra-genetic inheritance; different perspectives on macroevolution; contrasting standpoints held in the “externalism–internalism” debate) that exist between them. This paper seeks to encourage theoretical, philosophical and historiographical discussions about pluralism or the possible unification of contemporary evolutionary biology
Sound Frequency and Aural Selectivity in Sound-Contingent Visual Motion Aftereffect
BACKGROUND: One possible strategy to evaluate whether signals in different modalities originate from a common external event or object is to form associations between inputs from different senses. This strategy would be quite effective because signals in different modalities from a common external event would then be aligned spatially and temporally. Indeed, it has been demonstrated that after adaptation to visual apparent motion paired with alternating auditory tones, the tones begin to trigger illusory motion perception to a static visual stimulus, where the perceived direction of visual lateral motion depends on the order in which the tones are replayed. The mechanisms underlying this phenomenon remain unclear. One important approach to understanding the mechanisms is to examine whether the effect has some selectivity in auditory processing. However, it has not yet been determined whether this aftereffect can be transferred across sound frequencies and between ears. METHODOLOGY/PRINCIPAL FINDINGS: Two circles placed side by side were presented in alternation, producing apparent motion perception, and each onset was accompanied by a tone burst of a specific and unique frequency. After exposure to this visual apparent motion with tones for a few minutes, the tones became drivers for illusory motion perception. However, the aftereffect was observed only when the adapter and test tones were presented at the same frequency and to the same ear. CONCLUSIONS/SIGNIFICANCE: These findings suggest that the auditory processing underlying the establishment of novel audiovisual associations is selective, potentially but not necessarily indicating that this processing occurs at an early stage
How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers
Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program
- …