Presentational/Existential Structures in Spoken versus Written German: Es Gibt and SEIN

This article presents a synchronic, corpus-based examination of spoken German with regard to the distribution and function of presentational/ existential es gibt NP and a range of SEIN NP structures such as da SEIN , locative SEIN , es SEIN , and zero-locative SEIN . In particular, the use of da SEIN has been neglected in previous research. While es gibt is equally frequent in the spoken and written data, SEIN structures are typical of spoken German only, with da SEIN being the most frequent. The article concentrates on clauses with indefinite NPs, while the presentation of events with da and wider da-usage in spoken German are also considered

Study of classroom second language development

A study of classroom second language developmentThe nature of the relationship between the teaching and learning of second languages in the classroom has rarely been the subject of empirical investigation. The teaching profession tends to regard this relationship as a relatively direct one. Teaching which is based on a language syllabus explicitly or implicitly assumes that, given sufficiently frequent presentation and practice, learning will take place in a linear, cumulative fashion, although actual teaching practices may intuitively respond to learning being different. Since teachers are concerned with establishing which methods bring about the desired learner outcomes, interest in the learner is generally restricted to observations of what it is he has learnt and what he still has to learn, rather than how he learns.Second language acquisition research, on the other hand, has tended to focus on the learner, without necessarily relating his behaviour to the learning context. It has also involved mainly informal or only partially formal learners. Relatively few studies have considered learners who were exposed to the second language only in the classroom. At the same time the results of studies with informal or mixed learners have often been assumed to apply also to classroom-only learners. In particular, it has been suggested that second language developm ent follows its own principles and therefore cannot be influenced by instruction.The purpose of the present study is to investigate the acquisition of a second language by classroom-only learners in relation to the teaching learners were exposed to. Subjects of the study are 42 child and 6 adult learners of G erm an, all native speakers of English. The study examines the development of negation and interrogation.We will find that the relationship between learning and teaching is not always a direct one and will interpret this as the result of learners’ organic, creative interlanguage construction. At the same time we will consider the operation of linear, imitative learning processes, which result in the use of formulaic language, as a more direct outcome of the teaching. We will conclude that the acquisition of a second language in the classroom involves both organic, creative and linear, imitative processes

Assessment of UV-Vis LED-assisted Photo-Fenton Reactor for Atrazine Degradation in Aqueous Solution

Atrazine is one of the most used pesticides, although it is extremely toxic for living organisms. In spite of that, the control, removal, and elimination of this agrochemical are still deficient in water treatment plants (just over 25%). For this reason, the main objective of this study was to evaluate atrazine degradation efficiency in aqueous solution using the photo-Fenton system assisted by a light-emitting diode (LED) lamp. The degradation results of 30 mg L-1 atrazine evidenced that our approach presented an efficiency of approximately 98% in only 240 minutes of reaction, and the observed mineralization was 60% of total organic carbon (TOC). Several byproducts were identified (such as HA, DEA, DIA, HDEA, HDIA, and HDEDIA), and the degradation mechanism followed dechlorination and hydroxylation pathways that produce HDEDIA or ammelide. In this way, the photo-Fenton system under an LED lamp showed to be highly efficient at removing atrazine from aqueous solutions, offering several advantages compared to the traditional system, such as lower energy consumption and more environmentally friendly features. DOI: http://dx.doi.org/10.17807/orbital.v13i2.153

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Survey team on : conceptualisations of the role of competencies, knowing and knowledge in mathematics education research

This paper presents the outcomes of the work of the ICME 13 Survey Team on 'Conceptualisation and the role of competencies, knowing and knowledge in mathematics education research'. It surveys a variety of historical and contemporary views and conceptualisations of what it means to master mathematics, focusing on notions such as mathematical competence and competencies, mathematical proficiency, and mathematical practices, amongst others. The paper provides theoretical analyses of these notions-under the generic heading of mathematical competencies-and gives an overview of selected research on and by means of them. Furthermore, an account of the introduction and implementation of competency notions in the curricula in various countries and regions is given, and pertinent issues are reviewed. The paper is concluded with a set of reflections on current trends and challenges concerning mathematical competencie