scholarly journals Possible shock-induced crystallization of skeletal quartz from supercritical SiO2-H2O fluid: A case study of impact melt from Kamil impact crater, Egypt

Geology ◽  
2021 ◽  
Author(s):  
Agnese Fazio ◽  
Luigi Folco ◽  
Falko Langenhorst
Keyword(s):  
Hot Spots ◽  
Small Scale ◽  
Related Phenomenon ◽  
Impact Cratering ◽  
Impact Melt ◽  
System Temperature ◽  
Quartz Aggregates ◽  
Induced Crystallization ◽  
Natural Laboratory

Since its discovery, the Kamil crater (Egypt) has been considered a natural laboratory for studying small-scale impact cratering. We report on a previously unknown shock-related phenomenon observed in impact melt masses from Kamil; that is, the shock-triggered formation of skeletal quartz aggregates from silica-rich fluids. These aggregates are unshocked and characterized by crystallographically oriented lamellar voids and rounded vesicles. The distribution of the aggregates can be correlated with former H2O- and impurity-rich heterogeneities in precursor quartz; i.e., fluid inclusions. The heterogeneities acted as hot spots for local melting. Due to the presence of H2O and the high impact pressure and temperature, the formation of a localized supercritical fluid is plausible. Below the upper critical end point of the SiO2–H2O system (temperature <1100 °C and pressure <1 GPa), SiO2 melt and H2O fluid become immiscible, leading to the rapid and complete crystallization of skeletal quartz.

Multilingualism in eastern Indonesia: linguistic evidence of a shift from symmetric to asymmetric multilingualism

2021 ◽  
pp. 136700692110231
Author(s):  
Francesca Romana Moro
Keyword(s):  
Language Contact ◽  
Small Scale ◽  
Modelling Language ◽  
Apparent Paradox ◽  
Eastern Indonesia ◽  
Communicative Strategies ◽  
Linguistic Evidence ◽  
Research Questions ◽  
Bilingual Communities

Aims and Objectives/Purpose/Research Questions: The Alorese in eastern Indonesia are an Austronesian community who have inhabited two Papuan-speaking islands for approximately 600 years. Their language presents a paradox: contact with the neighbouring Papuan languages has led to both complexification and simplification. This article argues that these opposite outcomes of contact result from two distinct scenarios, and formulates a hypothesis about a shift in multilingual patterns in Alorese history. Design/Methodology/Approach: To formulate a hypothesis about the discontinuity of multilingual patterns, this article first sketches the past and present multilingual patterns of the Alorese by modelling language contact outcomes in terms of bilingual optimisation strategies. This is followed by a comparison of the two scenarios to pinpoint similarities and differences. Data and Analysis: Previous research shows that two types of contact phenomena are attested in Alorese: (a) complexification arising from grammatical borrowings from Papuan languages, and (b) morphological simplification. The first change is associated with prolonged child bilingualism and is the result of Papuan-oriented bilingual strategies, while the latter change is associated with adult second language (L2) learning and is the result of universal communicative strategies. Findings/Conclusions Complexification and simplification are the results of two different layers of contact. Alorese was first used in small-scale bilingual communities, with widespread symmetric multilingualism. Later, multilingualism became more asymmetric, and the language started to undergo a simplification process due to the considerable number of L2 speakers. Originality: This article is innovative in providing a clear case study showing discontinuity of multilingual patterns, supported by linguistic and non-linguistic evidence. Significance/Implications: This article provides a plausible explanation for the apparent paradox found in Alorese, by showing that different outcomes of contact in the same language are due to different patterns of acquisition and socialisation. This discontinuity should be taken into account by models of language contact.

scholarly journals Photovoltaics Enabling Sustainable Energy Communities: Technological Drivers and Emerging Markets

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1862
Author(s):  
Alexandros-Georgios Chronis ◽  
Foivos Palaiogiannis ◽  
Iasonas Kouveliotis-Lysikatos ◽  
Panos Kotsampopoulos ◽  
Nikos Hatziargyriou
Keyword(s):  
State Of The Art ◽  
Research Question ◽  
Economic Benefits ◽  
Energy Market ◽  
Small Scale ◽  
Local Energy ◽  
Community Members ◽  
Open Research ◽  
Energy Community

In this paper, we investigate the economic benefits of an energy community investing in small-scale photovoltaics (PVs) when local energy trading is operated amongst the community members. The motivation stems from the open research question on whether a community-operated local energy market can enhance the investment feasibility of behind-the-meter small-scale PVs installed by energy community members. Firstly, a review of the models, mechanisms and concepts required for framing the relevant concepts is conducted, while a clarification of nuances at important terms is attempted. Next, a tool for the investigation of the economic benefits of operating a local energy market in the context of an energy community is developed. We design the local energy market using state-of-the-art formulations, modified according to the requirements of the case study. The model is applied to an energy community that is currently under formation in a Greek municipality. From the various simulations that were conducted, a series of generalizable conclusions are extracted.

scholarly journals Roles, relationships and emotions: Student teachers’ understanding of feedback as interpersonal

2021 ◽  
pp. 003452372198937
Author(s):  
Caroline Elbra-Ramsay
Keyword(s):  
Teacher Education ◽  
Student Teachers ◽  
Small Scale ◽  
First Year ◽  
Case Study Methodology ◽  
Study Methodology ◽  
Undergraduate Programme ◽  
Phenomenological Case Study ◽  
International Teacher

This paper reports the findings of a small-scale study seeking to investigate how student teachers, within a three-year undergraduate programme, understand feedback. Feedback has been central to debates and discussion in the assessment literature in recent years. Hence, in this paper, feedback is positioned within the often-contradictory discourses of assessment, including perspectives on student and teacher feedback. The study focused on two first year undergraduate student teachers at a small university in England and considered the relationships between their understanding of feedback as a student, their understanding of feedback as an emerging teacher, and the key influences shaping these understandings. A phenomenological case study methodology was employed with interviews as the prime method of data collection. Themes emerged as part of an Nvivo analysis, including emotional responses, relationships and dialogue, all of which appear to have impacted on the students’ conceptual understanding of feedback as indelibly shaped by its interpersonal and affective, rather than purely cognitive or ideational, dimensions. The paper therefore seeks to contribute to the wider feedback discourse by offering an analysis of empirical data. Although situated within English teacher education, there are tentative conclusions that are applicable to international teacher education and as well as higher education more generally.

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