scholarly journals Photoluminescence Imaging of Whole Zircon Grains on a Petrographic Microscope—An Underused Aide for Geochronologic Studies

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 876
Author(s):  
Ryan McAleer ◽  
Aaron Jubb ◽  
Paul Hackley ◽  
Gregory Walsh ◽  
Arthur Merschat ◽  
...  
Keyword(s):  
Cross Sections ◽  
Uv Light ◽  
Heavy Mineral ◽  
Ionization Mass ◽  
History Of ◽  
Backscattered Electron ◽  
Single Zircon ◽  
Secondary Ionization Mass Spectrometry ◽  
Temperature And Pressure ◽  
Rich History

The refractory nature of zircon to temperature and pressure allows even a single zircon grain to preserve a rich history of magmatic, metamorphic, and hydrothermal processes. Isotopic dating of micro-domains exposed in cross-sections of zircon grains allows us to interrogate this history. Unfortunately, our ability to select the zircon grains in a heavy mineral concentrate that records the most geochronologic information is limited by our inability to predict internal zonation from observations of whole grains. Here we document the use of a petrographic microscope to observe and image the photoluminescence (PL) response of whole zircon grains excited under ultraviolet (UV) light, and the utility of this PL response in selecting grains for geochronology. While zircon fluorescence has long been known, there is limited documentation of its utility for and application to geochronologic studies. Our observations of zircon from an un-metamorphosed igneous rock, two meta-igneous rocks, and a placer deposit show that variations in the PL color are readily observable in real-time, both among grains in a population of zircons and within single grains. Analyses of cross-sections of the same grains demonstrate that the changes in PL correlate with zoning in backscattered electron (BSE) and cathodoluminescence (CL) images as well as with changes in U + Th concentration and spectroscopic proxies for radiation damage. In other words, the whole grain PL provides a low-resolution preview of the U + Th zoning expected in a cross-sectioned grain. We demonstrate the usefulness of this “preview” in identifying and selecting the subset of zircon grains in a heavy mineral separate that has metamorphic rims of sufficient width to date by secondary ionization mass spectrometry (SIMS). The data are also used to place preliminary constraints on the age and U + Th concentrations at which a yellow PL response is observed in natural samples. The PL response of zircon is well-known among spectroscopists, and these simple applications demonstrate several ways in which the response might be more effectively used by geochronologists.

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

FORMATION AND DEVELOPMENT OF RURAL ARCHITECTURE IN THE FORMER KETSKAYA VOLOST

2020 ◽  
Vol 22 (2) ◽  
pp. 9-28 ◽  
Author(s):  
E. V. Sitnikova
Keyword(s):  
Cultural Heritage ◽  
18Th Century ◽  
Scientific Methods ◽  
Architectural Analysis ◽  
Tomsk Region ◽  
History Of ◽  
The Rich ◽  
Rural Architecture ◽  
The Village ◽  
Rich History

The article considers the historical and cultural heritage of villages of the former Ketskaya volost, which is currently a part of the Tomsk region. The formation of Ketsky prison and the architecture of large settlements of the former Ketskaya volost are studied. Little is known about the historical and cultural heritage of villages of the Tomsk region and the problems of preserving historical settlements of the country.The aim of this work is to study the formation and development of the village architecture of the former Ketskaya volost, currently included in the Tomsk region.The following scientific methods are used: a critical analysis of the literature, comparative architectural analysis and systems analysis of information, creative synthesis of the findings. The obtained results can be used in preparation of lectures, reports and communication on the history of the Siberian architecture.The scientific novelty is a study of the historical and cultural heritage of large settlements of the former Ketskaya volost, which has not been studied and published before. The methodological and theoretical basis of the study is theoretical works of historians and architects regarding the issue under study as well as the previous  author’s work in the field.It is found that the historical and cultural heritage of the villages of the former Ketskaya volost has a rich history. Old historical buildings, including religious ones are preserved in villages of Togur and Novoilinka. The urban planning of the villages reflects the design and construction principles of the 18th century. The rich natural environment gives this area a special touch. 

scholarly journals The Return of National Self-Sufficiency? Excavating Autarkic Thought in a De-Globalizing Era

2021 ◽  
Author(s):  
Eric Helleiner
Keyword(s):  
Intellectual History ◽  
International Political Economy ◽  
Economic Thought ◽  
John Maynard Keynes ◽  
New Politics ◽  
Self Sufficiency ◽  
National Economic ◽  
History Of ◽  
High Degree ◽  
Rich History

Abstract As the global crisis triggered by the COVID-19 virus unfolded, The Economist magazine published a cover in May 2020 titled “Goodbye globalization: the dangerous lure of self-sufficiency.” The title summed up well the new political interest in the ideology of national economic self-sufficiency in the pandemic context. Unfortunately, contemporary textbooks in the field of international political economy (IPE) say little about this kind of “autarkic” thought. No survey of the history of autarkic thought exists even within specialist IPE literature or in the fields of intellectual history and the history of economic thought. Filling this gap in existing scholarship, this article highlights a rich history of autarkic thought that includes the ideas of famous thinkers such as Jean-Jacques Rousseau, Johann Fichte, Mohandas Gandhi, and John Maynard Keynes. Three core rationales for a high degree of national self-sufficiency have been advanced in the past: (1) insulation from foreign economic influence, (2) insulation from foreign political and/or cultural influence, and (3) the promotion of international peace. At the same time, considerable disagreements have existed among autarkists about some of these rationales and their relative importance, as well as about the precise meaning of national self-sufficiency. These disagreements stemmed not just from differences in their specific goals but also from the different conditions across time and space in which autarkic thought was developed. In addition to improving understanding of the autarkic ideological tradition, this article contributes to emerging scholarship attempting to overcome Western-centrism in IPE scholarship as well as literature exploring the new politics of de-globalization in the current era.

Streptococcus pluranimalium meningoencephalitis in a horse

2021 ◽  
pp. 104063872110234
Author(s):  
Dah-Jiun Fu ◽  
Akhilesh Ramachandran ◽  
Craig Miller
Keyword(s):  
Ribosomal Rna ◽  
Cross Sections ◽  
Nucleotide Sequencing ◽  
Formalin Fixed Paraffin ◽  
Quarter Horse ◽  
Formalin Fixed Paraffin Embedded ◽  
History Of ◽  
The Brain ◽  
Gram Positive Cocci ◽  
Formalin Fixed

A 3-y-old, female Quarter Horse with a history of acute neurologic signs was found dead and was submitted for postmortem examination. Areas of petechial and ecchymotic hemorrhage were present on cross-sections of the cerebrum, cerebellum, and brainstem. Histologic examination of the brain revealed severe, purulent meningoencephalitis and vasculitis with a myriad of intralesional gram-positive cocci. Streptococcus pluranimalium was identified from formalin-fixed, paraffin-embedded tissue obtained from sites with active lesions by PCR and nucleotide sequencing of bacterial 16S ribosomal RNA. S. pluranimalium should be considered as a cause of meningoencephalitis in a horse.

Global Pests, National Pride, Local Problems, and the Crisis of Hungarian Wine, 1867–1914

2021 ◽  
pp. 1-16
Author(s):  
Robert Nemes
Keyword(s):  
World War I ◽  
World War ◽  
Folk Culture ◽  
Wine Production ◽  
National Imagination ◽  
Local Problems ◽  
History Of ◽  
Trade And Exchange ◽  
Rich History

Abstract Hungary has a long, rich history of wine production. Historians have emphasized wine's importance to the development of both the Hungarian economy and Hungarian nationalism. This article ties together these historiographical threads through a case study of a small village in one of Hungary's most famous wine regions. Tracing the village's history from the 1860s to World War I, the article makes three main claims. First, it demonstrates that from the start, this remote village belonged to wider networks of trade and exchange that stretched across the surrounding region, state, and continent. Second, it shows that even as Magyar elites celebrated the folk culture and peasant smallholders of this region, they also cheered the introduction of what they saw as scientific, rational agriculture. This leads to the last argument: wine achieved its place in the pantheon of Hungarian culture at a moment when the local communities that had grown up around its production and stirred the national imagination were undergoing dramatic and irreversible change.

scholarly journals Mechanochemically Gated Photoswitching: Expanding the Scope of Polymer Mechanochromism

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1725-1732 ◽  
Author(s):  
Ross W. Barber ◽  
Molly E. McFadden ◽  
Xiaoran Hu ◽  
Maxwell J. Robb
Keyword(s):  
Mechanical Activation ◽  
Uv Light ◽  
Cycloaddition Reaction ◽  
Polymeric Materials ◽  
Diels Alder ◽  
Information Storage ◽  
Chemical Transformations ◽  
History Of ◽  
Polymer Mechanochemistry ◽  
Stress Sensing

Mechanophores are molecules that undergo productive, covalent chemical transformations in response to mechanical force. Over the last decade, a variety of mechanochromic mechanophores have been developed that enable the direct visualization of stress in polymers and polymeric materials through changes in color and chemiluminescence. The recent introduction of mechanochemically gated photoswitching extends the repertoire of polymer mechanochromism by decoupling the mechanical activation from the visible response, enabling the mechanical history of polymers to be recorded and read on-demand using light. Here, we discuss advances in mechanochromic mechanophores and present our design of a cyclopentadiene–maleimide Diels–Alder adduct that undergoes a force-induced retro-[4+2] cycloaddition reaction to reveal a latent diarylethene photoswitch. Following mechanical activation, UV light converts the colorless diarylethene molecule into the colored isomer via a 6π-electrocyclic ring-closing reaction. Mechanically gated photoswitching expands on the fruitful developments in mechanochromic polymers and provides a promising platform for further innovation in materials applications including stress sensing, patterning, and information storage.1 Introduction to Polymer Mechanochemistry2 Mechanochromic Reactions for Stress Sensing3 Regiochemical Effects on Mechanophore Activation4 Mechanochemically Gated Photoswitching5 Conclusions

CHARMONIUM PRODUCTION IN Pb–Pb COLLISIONS AT ALICE: FROM SUPPRESSION TO REGENERATION?

2013 ◽  
Vol 28 (21) ◽  
pp. 1330018 ◽  
Author(s):  
ENRICO SCOMPARIN
Keyword(s):  
Phase Transition ◽  
Cross Sections ◽  
Short Review ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Alice Experiment ◽  
Model Calculations ◽  
Ion Collisions ◽  
Quark Production ◽  
History Of

Heavy quarkonium states are considered as one of the key observables for the study of the phase transition from a system made of hadrons towards a Quark–Gluon Plasma (QGP). In the last 25 years, experiments at CERN and Brookhaven have studied collisions of heavy ions looking for a suppression of charmonia/bottomonia, considered as a signature of the phase transition. After an introduction to the main concepts behind these studies and a short review of the SPS and RHIC results, I will describe the results obtained in Pb – Pb collisions by the ALICE experiment at the LHC. The ALICE findings will be critically compared to those of lower energy experiments, to CMS results, and to model calculations. The large cross-sections for heavy-quark production at LHC energies are expected to induce a novel production mechanism for charmonia in heavy-ion collisions, related to a recombination of [Formula: see text] pairs along the history of the collision and/or at hadronization. The occurrence of such a process at the LHC will be discussed. Finally, prospects for future measurements will be shortly addressed.

Breaking Depression’s Silence within the Church through Friendships

2021 ◽  
Vol 1 ◽  
pp. 103-115
Author(s):  
Robert McBain
Keyword(s):  
Local Church ◽  
Medical Model ◽  
Church Community ◽  
Research Project ◽  
Typical Response ◽  
Doctor Of Ministry ◽  
History Of ◽  
Meaning And Purpose ◽  
The Church ◽  
Rich History

This article explores the silent nature of depression in the local church and suggests that developing Jesus-style friendships can break the silence. It adapts the author’s Doctor of Ministry (DMin) research project, which explored the silent nature of depression in the local church and Christianity’s interpretive healing qualities. This article argues that the church has a rich history of helping sufferers interpret their experiences of depression, but changing worldviews, the growth of the modern medical model, and the effectiveness of pharmaceuticals monopolized health and shoved the church to the periphery of the conversation. Silence became the church’s typical response, which promoted an attitude of stigma and avoidance. The article suggests that developing Jesus-style friendships can help break the silence because social or religious barriers do not restrict such friendships. This model of friendship is crucial for giving depression sufferers a sense of identity, meaning, and purpose within the church community.

Multilingualism, urban change and gentrification in the landscape of a Brussels neighbourhood

Multilingua ◽  
2018 ◽  
Vol 37 (1) ◽  
pp. 25-52 ◽  
Author(s):  
Mieke Vandenbroucke
Keyword(s):  
Inner City ◽  
Urban Landscape ◽  
Urban Change ◽  
Linguistic Change ◽  
Socio Economic Development ◽  
History Of ◽  
The Rich ◽  
Rich History ◽  
Over Time

AbstractThis paper focuses on how different historical stages of socio-economic development in Brussels are played out on the ground over time in one particular inner-city neighbourhood, the Quartier Dansaert. In particular, I document the history of this neighbourhood and how urban change and gentrification have impacted the outlook of multilingualism and the development of multilingual discourses and language hierarchies in its material and semiotic landscape over time. By using the rich history of multilingualism in the Quartier Dansaert as a case-study, I argue in favour of more historically-sensitive and longitudinal approaches to social and, in particular, linguistic change as played out in urban landscape.

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