scholarly journals The 3550 year BP-1944 A.D.magma-plumbing system of Somma-Vesuvius: constraints on its behaviour and present state through a review of Sr-Nd isotope data

2009 ◽  
Vol 47 (4) ◽  
Author(s):  
L. Pappalardo ◽  
M. Piochi ◽  
G. Mastrolorenzo
Keyword(s):  
Magma Chamber ◽  
Large Scale ◽  
Crustal Contamination ◽  
Plinian Eruption ◽  
Isotopic Ratios ◽  
Major Activity ◽  
Equilibrium Crystallization ◽  
Effusive Activity ◽  
Deep Reservoir ◽  
The One

Vesuvius, dominating the densely-populated Neapolitan area, is one of the most dangerous volcanoes in the World. Its destructive power derives from energetic subplinian and plinian eruptions, such as the one which occurred in 79 A.D. Generally such large-scale events follow a long period of quiescence; a behaviour interpreted as the gradual build-up of magma volumes between periods of major activity. After the 1631 subplinian eruption until the last 1944 A.D. eruption, it experienced an almost continuous and less energetic explosive/effusive activity. The erupted magmas are characterized by undersaturated potassic to ultrapotassic nature, and compositional and Sr-isotopic variability. Furthermore geobarometric studies indicate two different crystallization depths located at 4 and >11 km, respectively. According to most of the recent literature, the eruptions were triggered by the injection in a shallower magma chamber, of isotopically distinct magma batches derived from heterogeneous mantle source(s) and/or contamination processes occurred within the deep reservoir. In our review of petrochemical data, we consider the period between the 3550 years BP plinian eruption and the 472 A.D. sub-plinian eruption, which includes 79 A.D. event, and the most recent period of activity which started in 1631 A.D. and lasted up to the 1944 A.D. eruption, characterized by a near continuous effusive/explosive activity. For both periods we identify a correlation between Sr-isotopical features of magmas and their crystallization depth. In particular, we show that pyroxenes have Sr-isotopic ratios lower than 0.7074 and an equilibrium crystallization depth of 22-11 km. Moreover feldspars have higher 87Sr/86Sr values (0.7075-7) and an equilibrium crystallization depth of about 4 km. Therefore the most radiogenic magmas did not derive from a deeper reservoir but their higher Sr-isotopic ratios have been acquired at a shallower depth likely by crustal contamination during magma evolution. In contrast, the lower Sr-isotope compositions characterise the less contaminated magmas coming from deeper crustal levels. On the basis of this evidence, the temporal Sr-isotopical variation of magma which erupted in the 1631-1944 A.D. period probably derives from the progressive withdrawal of the shallow magma chamber, which was completely empty before the 1805-1944 A.D. period of volcanism. Therefore the effusive and explosive events of the most recent 1805-1944 A.D. period were fed directly by the deep reservoir located at a depth exceding 11 km.

scholarly journals Mechanisms controlling explosive-effusive transition of Teide-Pico Viejo complex dome eruptions.

2020 ◽  
Author(s):  
Olaya Dorado ◽  
Joan Andújar ◽  
Joan Martí ◽  
Adelina Geyer
Keyword(s):  
Magma Chamber ◽  
Magma Mixing ◽  
Mafic Magma ◽  
Main Body ◽  
Density Currents ◽  
Volcanic System ◽  
Effusive Activity ◽  
Tenerife Island ◽  
Explosive Phase ◽  
The One

<p>The Teide-Pico Viejo (PT-PV) stratovolcanoes constitute one of the major potentially active volcanic complexes in Europe. PT-PV was traditionally considered as non-explosive system however, recent studies (ie. García et al. 2014) have pointed out that the explosive character of phonolitic magmas, including plinian and subplinian eruptions and generation of pyroclastic density currents, have also been significant within the last 30 kyr volcanological record. This explosive activity is mostly associated to satellite dome vents, like the one studied in this work, Pico Cabras. Dome-forming eruptions usually present sudden transitions between explosive and effusive activity. A better knowledge of this type of eruptions and about the main mechanisms controlling the changes in eruptive dynamics is required to undertake a comprehensive volcanic hazard assessment of Tenerife Island. In this study, we conduct a petrological and mineral characterization of the different eruption phases of Pico Cabras (pumice and lava flow samples for the explosive and effusive activity, respectively) with the aim of determining the factors that control these changes in the volcanic activity. Products were characterized with Scanning Electrom Microscope, and mineral phases, glass and volatile species (F, Cl) were analysed with electron microprobe and micro-XRF. The pre-eruptive conditions of the magma (pressure, temperature and water dissolved in the magma) were determined first by using available geothermobarometers, geohygrometers (Masotta et al., 2013; Mollo et al., 2015) and compared to those retrieved by using available phase equilibria experiments from the literature (ie. Andújar and Scaillet, 2012).</p><p>Our results suggest the presence of a compositionally stratified magma chamber at 1 kbar±0.5kbar prior to Pico Cabras eruption in which the differences in the eruptive styles are controlled by the temperature and the amount of volatiles dissolved in the melt. The explosive phase is related to the upper part of the magma chamber at 725ºC±25ºC and 3,5-5 wt% H<sub>2</sub>O and the effusive phase with the main body of the chamber at 880ºC±30ºC and 2,5-3 wt% H<sub>2</sub>O. Feldspar zonations show that overturn events occurred in the different layers of the magma chambers (“self-mixing”) and suggest that the eruption was triggered by underplating of mafic magma without magma mixing. Chemical composition of some feldspars from the explosive phase are equivalent to those found in El Abrigo eruption, the last caldera-forming episode (ca. 190 ka), demonstrating that PT-PV volcanic system is still capable of producing evolved and very explosive magmas.</p><p>This research has been partially funded by a CSIC JaeIntro grant and the EC Grant EVE (DG ECHO Ref: 826292).</p>

First grammar books in the Habsburg Monarchy: individual initiative and regulatory interference by the state (1760s–1770s)

2020 ◽  
Vol 2019 (2 (11)) ◽  
pp. 137-157
Author(s):  
Olga V. Khavanova ◽  
Keyword(s):  
Eighteenth Century ◽  
State Policy ◽  
Large Scale ◽  
Language Use ◽  
Linguistic Diversity ◽  
Mother Tongue ◽  
German Language ◽  
Habsburg Monarchy ◽  
Private Initiative ◽  
The One

The second half of the eighteenth century in the lands under the sceptre of the House of Austria was a period of development of a language policy addressing the ethno-linguistic diversity of the monarchy’s subjects. On the one hand, the sphere of use of the German language was becoming wider, embracing more and more segments of administration, education, and culture. On the other hand, the authorities were perfectly aware of the fact that communication in the languages and vernaculars of the nationalities living in the Austrian Monarchy was one of the principal instruments of spreading decrees and announcements from the central and local authorities to the less-educated strata of the population. Consequently, a large-scale reform of primary education was launched, aimed at making the whole population literate, regardless of social status, nationality (mother tongue), or confession. In parallel with the centrally coordinated state policy of education and language-use, subjects-both language experts and amateur polyglots-joined the process of writing grammar books, which were intended to ease communication between the different nationalities of the Habsburg lands. This article considers some examples of such editions with primary attention given to the correlation between private initiative and governmental policies, mechanisms of verifying the textbooks to be published, their content, and their potential readers. This paper demonstrates that for grammar-book authors, it was very important to be integrated into the patronage networks at the court and in administrative bodies and stresses that the Vienna court controlled the process of selection and financing of grammar books to be published depending on their quality and ability to satisfy the aims and goals of state policy.

The Green New Deal

2019 ◽  
Author(s):  
Robert C. Hockett
Keyword(s):  
New Deal ◽  
Large Scale ◽  
Public Investment ◽  
Climate Science ◽  
Time Frame ◽  
White Paper ◽  
Good News ◽  
Carbon Neutrality ◽  
The One ◽  
In Virtue Of

This white paper lays out the guiding vision behind the Green New Deal Resolution proposed to the U.S. Congress by Representative Alexandria Ocasio-Cortez and Senator Bill Markey in February of 2019. It explains the senses in which the Green New Deal is 'green' on the one hand, and a new 'New Deal' on the other hand. It also 'makes the case' for a shamelessly ambitious, not a low-ball or slow-walked, Green New Deal agenda. At the core of the paper's argument lies the observation that only a true national mobilization on the scale of those associated with the original New Deal and the Second World War will be up to the task of comprehensively revitalizing the nation's economy, justly growing our middle class, and expeditiously achieving carbon-neutrality within the twelve-year time-frame that climate science tells us we have before reaching an environmental 'tipping point.' But this is actually good news, the paper argues. For, paradoxically, an ambitious Green New Deal also will be the most 'affordable' Green New Deal, in virtue of the enormous productivity, widespread prosperity, and attendant public revenue benefits that large-scale public investment will bring. In effect, the Green New Deal will amount to that very transformative stimulus which the nation has awaited since the crash of 2008 and its debt-deflationary sequel.

“Community Interests” and the Role of International Law in the Creation of a Global Market for Agricultural Land

2018 ◽  
Author(s):  
Jochen von Bernstorff
Keyword(s):  
International Law ◽  
Large Scale ◽  
Agricultural Land ◽  
Food Sovereignty ◽  
Global Market ◽  
Negative Consequences ◽  
Cultural Rights ◽  
Land Grab ◽  
Large Scale Land ◽  
The One

The chapter explores the notion of “community interests” with regard to the global “land-grab” phenomenon. Over the last decade, a dramatic increase of foreign investment in agricultural land could be observed. Bilateral investment treaties protect around 75 per cent of these large-scale land acquisitions, many of which came with associated social problems, such as displaced local populations and negative consequences for food security in Third World countries receiving these large-scale foreign investments. Hence, two potentially conflicting areas of international law are relevant in this context: Economic, social, and cultural rights and the principles of permanent sovereignty over natural resources and “food sovereignty” challenging large-scale investments on the one hand, and specific norms of international economic law stabilizing them on the other. The contribution discusses the usefulness of the concept of “community interests” in cases where the two colliding sets of norms are both considered to protect such interests.

scholarly journals State Management for Cloud-Native Applications

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 423
Author(s):  
Márk Szalay ◽  
Péter Mátray ◽  
László Toka
Keyword(s):  
Large Scale ◽  
Distributed Databases ◽  
Access Time ◽  
Replica Placement ◽  
State Management ◽  
Placement Decisions ◽  
Dynamic Replication ◽  
Cloud Databases ◽  
Placement Algorithm ◽  
The One

The stateless cloud-native design improves the elasticity and reliability of applications running in the cloud. The design decouples the life-cycle of application states from that of application instances; states are written to and read from cloud databases, and deployed close to the application code to ensure low latency bounds on state access. However, the scalability of applications brings the well-known limitations of distributed databases, in which the states are stored. In this paper, we propose a full-fledged state layer that supports the stateless cloud application design. In order to minimize the inter-host communication due to state externalization, we propose, on the one hand, a system design jointly with a data placement algorithm that places functions’ states across the hosts of a data center. On the other hand, we design a dynamic replication module that decides the proper number of copies for each state to ensure a sweet spot in short state-access time and low network traffic. We evaluate the proposed methods across realistic scenarios. We show that our solution yields state-access delays close to the optimal, and ensures fast replica placement decisions in large-scale settings.

scholarly journals Constructing Large-Scale Genetic Maps Using an Evolutionary Strategy Algorithm

Genetics ◽  
2003 ◽  
Vol 165 (4) ◽  
pp. 2269-2282
Author(s):  
D Mester ◽  
Y Ronin ◽  
D Minkov ◽  
E Nevo ◽  
A Korol
Keyword(s):  
Discrete Optimization ◽  
High Performance ◽  
Large Scale ◽  
Simulated Data ◽  
Real Data ◽  
Genetic Maps ◽  
Chromosome 1 ◽  
Evolutionary Strategy ◽  
Group A ◽  
The One

Abstract This article is devoted to the problem of ordering in linkage groups with many dozens or even hundreds of markers. The ordering problem belongs to the field of discrete optimization on a set of all possible orders, amounting to n!/2 for n loci; hence it is considered an NP-hard problem. Several authors attempted to employ the methods developed in the well-known traveling salesman problem (TSP) for multilocus ordering, using the assumption that for a set of linked loci the true order will be the one that minimizes the total length of the linkage group. A novel, fast, and reliable algorithm developed for the TSP and based on evolution-strategy discrete optimization was applied in this study for multilocus ordering on the basis of pairwise recombination frequencies. The quality of derived maps under various complications (dominant vs. codominant markers, marker misclassification, negative and positive interference, and missing data) was analyzed using simulated data with ∼50-400 markers. High performance of the employed algorithm allows systematic treatment of the problem of verification of the obtained multilocus orders on the basis of computing-intensive bootstrap and/or jackknife approaches for detecting and removing questionable marker scores, thereby stabilizing the resulting maps. Parallel calculation technology can easily be adopted for further acceleration of the proposed algorithm. Real data analysis (on maize chromosome 1 with 230 markers) is provided to illustrate the proposed methodology.

Global Reaction Model to Describe the Kinetics of Catalytic Pyrolysis of Coffee Grounds Waste

2017 ◽  
Vol 899 ◽  
pp. 173-178 ◽  
Author(s):  
Ronydes Batista Jr. ◽  
Bruna Sene Alves Araújo ◽  
Pedro Ivo Brandão e Melo Franco ◽  
Beatriz Cristina Silvério ◽  
Sandra Cristina Danta ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Large Scale ◽  
Catalytic Pyrolysis ◽  
Petroleum Products ◽  
Reaction Model ◽  
Heating Rates ◽  
Coffee Grounds ◽  
One Step ◽  
Global Reaction ◽  
The One

In view of the constant search for new sources of renewable energy, the particulate agro-industrial waste reuse emerges as an advantageous alternative. However, despite the advantages of using the biomass as an energy source, there is still strong resistance as the large-scale replacement of petroleum products due to the lack of scientifically proven efficient conversion technologies. In this context, the pyrolysis is presented as one of the most widely used thermal decomposition processes. The knowledge of aspects of chemical kinetics, thermodynamics these will, heat and mass transfer, are so important, since influence the quality of the product. This paper presents a kinetic study of slow pyrolysis of coffee grounds waste from dynamic thermogravimetric experiments (TG), using different powder catalysts. The primary thermal decomposition was described by the one-step reaction model, which considers a single global reaction. The kinetic parameters were estimated using nonlinear regression and the differential evolution method. The coffee ground waste was dried at 105°C for 24 hours. The sample in nature was analyzed at different heating rates, being 10, 15, 20, 30 and 50 K/min. In the catalytic pyrolysis, about 5% (w/w) of catalyst were added to the sample, at a heating rate of 30 K/min. The results show that the one-step model does not accurately represent the data of weight loss (TG) and its derivative (DTG), but can do an estimative of the activation energy reaction, and can show the differences caused by the catalysts. Although no one can say anything about the products formed with the addition of the catalyst, it would be necessary to micro-pyrolysis analysis, we can say the influence of the catalyst in the samples, based on the data obtained in thermogravimetric tests.

Chronique d’une écologie décoloniale dans C’est ma terre de Fabrice Bouckat

2020 ◽  
Vol 23 (3) ◽  
pp. 189-205 ◽  
Author(s):  
Françoise Naudillon
Keyword(s):  
West Indies ◽  
Large Scale ◽  
Documentary Film ◽  
Ecological Crisis ◽  
Agent Orange ◽  
Time And Space ◽  
The West ◽  
The One

The documentary film C’est ma terre by Fabrice Bouckat screened during the 2019 edition of Terrafestival is one of the first large-scale films produced locally on the crisis of the chlordecone molecule. This article will examine from a decolonial perspective, how its director, a Martinican with Gabonese origins who lives and works in Guadeloupe, develops a synthetic and universal vision of environmental crises, and thus demonstrates that destruction of ecosystems crosses time and space, cultures and lands, languages and peoples by bringing ecological crisis in the West Indies closer to the one experienced by the Vietnamese victims of Agent Orange.

scholarly journals FOLLOW THE MONEY: A LARGE-SCALE INVESTIGATION OF MONETIZATION AND OPTIMIZATION ON YOUTUBE

2020 ◽  
Author(s):  
Oscar Coromina ◽  
Ariadna Matamoros-Fernández ◽  
Bernhard Rieder
Keyword(s):  
Large Scale ◽  
The Other ◽  
Media Industries ◽  
Global Media ◽  
Media System ◽  
Critical Media ◽  
Revenue Streams ◽  
Dominant Actor ◽  
The One ◽  
The Relationship

While YouTube has become a dominant actor in the global media system, the relationship between platform, advertisers, and content creators has seen a series of conflicts around the question of monetization. Our paper draws on a critical media industries perspective to investigate the relationship between YouTube’s evolving platform strategies on the one side and content creators’ tactical adaptations on the other. This concerns the search for alternative revenue streams as well as content and referencing optimization seeking to grow audiences and algorithmic visibility. Drawing on an exhaustive sample (n=153.770) of “elite” channels (more than 100.000 subscribers) and their full video history (n=138.340.337), we parse links in video descriptions to investigate the appearance and spread of crowdfunding platforms like Patreon, but also of affiliate links, merchandise stores, or e-commerce websites like Etsy. We analyze the evolution of video length and posting frequency in response to platform policy as well as visibility tactics such as metadata and category optimization, keyword stuffing, or title phrasing. Taken together, these elements provide a broad picture of “industrialization” on YouTube, that is, of the ways creators seek to develop their channels into media businesses. While this contribution cannot replace more qualitative, in-depth research into particular channels or channel groups, we hope to provide a representative picture of YouTube’s elite channels and their quest for visibility and success from their beginnings up to early 2020.

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