Plazma vodikovo redukcijsko pretaljivanje - opcija za izradu čelika u budućnosti

The steel industry is a mayor source of global CO2-emission. Lager reductions of greenhouse gases are the challenge to develop new processes, like Hydrogen Plasma Smelting Reduction (HPSR). The scientific basis and results of HPSR laboratory experiments led to the development of a concept for an HPSR-plant on industrial scale. A technology assessment shows the potential for a cheaper and most environmental friendly steelmaking in the future, when extensive development work has been done.Industrija čelika je glavni izvor globalne emisije CO2. Veće smanjivanje stakleničkih plinova predstavlja izazov za razvoj novih procesa poput plazma vodikovog redukcijskog pretaljivanja (HPSR). Znanstvena dostignuća I rezultati HPSR laboratorijskih pokusa doveli su do razvoja koncepta za HPSR postrojenja na industrijskoj razini. Tehnološki trošak pokazuje mogućnost jeftinije i ekološki povoljnijeg načina izrade čelika u budućnosti kada prestane intenzivni razvoj

Characterizing absolutely irreducible integer-valued polynomials over discrete valuation domains

Rings of integer-valued polynomials are known to be atomic, non-factorial rings furnishing examples for both irreducible elements for which all powers factor uniquely (\emph{absolutely irreducibles}) and irreducible elements where some power has a factorization different from the trivial one. In this paper, we study irreducible polynomials $F \in \operatorname{Int}(R)$ where $R$ is a discrete valuation domain with finite residue field and show that it is possible to explicitly determine a number $S\in \mathbb{N}$ that reduces the absolute irreducibility of $F$ to the unique factorization of $F^S$. To this end, we establish a connection between the factors of powers of $F$ and the kernel of a certain linear map that we associate to $F$. This connection yields a characterization of absolute irreducibility in terms of this so-called \emph{fixed divisor kernel}. Given a non-trivial element $\boldsymbol{v}$ of this kernel, we explicitly construct non-trivial factorizations of $F^k$, provided that $k\ge L$, where $L$ depends on $F$ as well as the choice of $\boldsymbol{v}$. We further show that this bound cannot be improved in general. Additionally, we provide other (larger) lower bounds for $k$, one of which only depends on the valuation of the denominator of $F$ and the size of the residue class field of $R$

Coping und Selbstwirksamkeit bei Personen mit Panikattacken

Panikattacken, angstbezogene Kognitionen, Coping, Selbstwirksamkeit, Internetpanic attacks, anxiety-related cognitions, coping, self-efficacy, online-stud

Razvoj i stanje LD-postupka

Entwicklung des LD-Verfahrens und Anteil an der Welt Stahlproduktion - Verfahrenstechnische und metallurgische Merkmale des LD-Prozesses - Abbrand von Kohlenstoff und Verschlackung der Eisenbegleitelemente - Zustand von Schmelze und Schlacke zu Blasende - Schlackenverwertung und Umweltschutz - Leistungsdaten von LD-Stahlwerken.Razvoj LD-postupka i njegov udio u svjetskoj proizvodnji čelika - Procesne i metalurške značajke LD-procesa - Izgaranje ugljika i prijelaz željezo - pratećih elemenata u trosku - Stanje taline i troske na kraju upuhavanja - Iskorištavanje troske i zaštita okoliša - Podaci o učinkovitosti LD-čeličana

Solar heating and cooling with absorption chiller and latent heat storage

Part of: Thermally driven heat pumps for heating and cooling. – Ed.: Annett Kühn – Berlin: Universitätsverlag der TU Berlin, 2013 ISBN 978-3-7983-2686-6 (print) ISBN 978-3-7983-2596-8 (online) urn:nbn:de:kobv:83-opus4-39458 [http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-39458]Performance figures and control strategies of an innovative solar heating and cooling system (SHC-System) composed of an aqueous lithium bromide-water single-effect absorption chiller with 10 kW cooling capacity, a dry heat rejection system and a low phase change temperature (28-29°C) latent heat storage based on salt hydrates are given. During cooling season the latent heat storage serves as a secondary heat sink supporting the dry air cooler at high ambient temperatures to ensure 32°C coolant to the absorption chiller at any time. In the heating season the latent heat storage buffers heat surplus of the solar collectors latently by melting the phase change material (PCM) calcium chloride hexahydrate. As a result of the constant temperature during charging, solar thermal collector efficiency is increased and furthermore the overall heat dissipation is reduced. The results on the one hand show a positive effect on the cooling capacity, electrical and thermal Coefficient of Performance (COP) of the absorption chiller, which are significantly increased especially at hot days compared to solely dry air cooled systems. On the other hand a high solar fraction in the heating period, due to constantly low storage temperatures, is achieved

Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

Within the “Compartmentalised Smart Factory” approach of the ONE-FLOW project the implementation of different catalysts in “compartments” provided by Pickering emulsions and their application in continuous flow is targeted. We present here the development of heterogeneous Pd-catalysts that are ready to be used in combination with biocatalysts for catalytic cascade syntheses of active pharmaceutical ingredients (APIs). In particular, we focus on the application of the catalytic systems for Suzuki-Miyaura cross coupling reactions, which is the key step in the syntheses of the targeted APIs valsartan and sacubitril. An immobilised enzyme will accomplish the final product formation via hydrolysis. In order to create large interfacial area for the catalytic reactions and to keep the reagents separated until required, the catalyst particles are used to stabilise Pickering emulsions of oil and water. A set of Ce-Sn-Pd-oxides with the molecular formula Ce0.99-xSnxPd0.01O2-(x= 0-0.99) has been prepared utilising a simple single-step solution combustion method. The high applicability of the catalysts for different functional groups and their minimal leaching behaviour is demonstrated with various Suzuki-Miyaura cross coupling reactions in batch as well as in continuous flow employing the so-called “Plug & Play reactor”. Finally, we demonstrate the use of these particles as the sole emulsifier of oil + water emulsions for a range of oils

Lernprozesse in der berufspraktischen Ausbildung von Mathematiklehrpersonen als Tätigkeit in sozialen Netzwerken – eine interdisziplinäre Analyse aus allgemein- und mathematikdidaktischer Perspektive

Berufspraktische Studienelemente wie Praktika stellen ein zentrales Element der Ausbildung von Lehrpersonen dar – und zwar sowohl bezüglich ihrer Relevanz als auch hinsichtlich der Ressourcen, die dafür eingesetzt werden. Von den Lehramtsstudierenden selbst werden Studienelemente mit Praxisbezug als besonders bedeutsam und ertragreich bewertet (Arnold et al., 2014). Trotz dieser unbestrittenen Relevanz von Praktika und anderen Praxisgefäßen ist über Gelingensfaktoren von praxissituierten Lernprozessen aber erst wenig bekannt (König & Rothland, 2018). Einige Studien geben zwar Hinweise, dass die Qualität von Mentoring und Unterrichtsbesprechungen für das Lernen der Studierenden im Praxisfeld bedeutsam sind (Futter, 2016; Kreis, 2012; Kreis & Staub, 2011, 2013). Aber diese Studien erfolgen bislang mehrheitlich aus allgemeindidaktischer Perspektive und kaum aus fachdidaktischer und noch weniger aus einer interdisziplinären Sicht heraus, in der sich allgemeindidaktische und fachdidaktische Anliegen und Forschungstraditionen zur gemeinsamen Bearbeitung relevanter Forschungsfragen zur berufspraktischen Ausbildung verbinden. Bisher kaum beleuchtet ist auch die Frage, welche Rolle die fachlich-fachdidaktische Expertise der Mentor*innen für die systematische Nutzung von Lerngelegenheiten der Studierenden in der Unterrichtsbesprechung spielen. Dies erstaunt insbesondere auch vor dem Hintergrund, dass Studierende im Praxisfeld mit verschiedenen Akteur*innen über ihren Unterricht – auch im Fach Mathematik – sprechen. Mit diesen offenen Fragen befasst sich die interdisziplinär angelegte SNFStudie „Lerngelegenheiten für Lehrstudierende im sozialen Netzwerk Praxisfeld aus allgemein- und mathematikdidaktischer Perspektive (Dia-MaNt)“ (Laufzeit: 07/2021–06/2025) (Kreis & Brunner, 2019). Im Beitrag werden der theoretische Hintergrund und das Design der Studie vorgestellt

IEA SHC Task 42/ECES Annex 29 – A Simple Tool for the Economic Evaluation of Thermal Energy Storages

Proceedings of the 4th International Conference on Solar Heating and Cooling for Buildings and Industry (SHC 2015)Within the framework of IEA SHC Task 42 / ECES Annex 29, a simple tool for the economic evaluation of thermal energy storages has been developed and tested on various existing storages. On that account, the storage capacity costs (costs per installed storage capacity) of thermal energy storages have been evaluated via a Top-down and a Bottom-up approach. The Top-down approach follows the assumption that the costs of energy supplied by the storage should not exceed the costs of energy from the market. The maximum acceptable storage capacity costs depend on the interest rate assigned to the capital costs, the intended payback period of the user class (e.g. industry or building), the reference energy costs, and the annual number of storage cycles. The Bottom-up approach focuses on the realised storage capacity costs of existing storages. The economic evaluation via Top-down and Bottom-up approach is a valuable tool to make a rough estimate of the economic viability of an energy storage for a specific application. An important finding is that the annual number of storage cycles has the largest influence on the cost effectiveness. At present and with respect to the investigated storages, seasonal heat storage is only economical via large sensible hot water storages. Contrary, if the annual number of storage cycles is sufficiently high, all thermal energy storage technologies can become competitive.This study is part of IEA SHC Task 42 / ECES Annex 29 „Compact Thermal Energy Storage - Material Development and System Integration“ (http://task42.iea-shc.org). The work of ZAE Bayern is part of the project PC-Cools_V and supported by the German Federal Ministry for Economic Affairs and Energy under the project code 03ESP138A. University of Zaragoza thanks the Spanish Government for the funding of their work under the projects ENE2008-06687-C02-02, ENE2011-28269-C03-01 and ENE2014-57262-R. University of Lleida would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). The research leading to these results has received funding from the European Union's Seventh Framework Program (FP7/2007-2013) under grant agreement n° PIRSES-GA-2013-610692 (INNOSTORAGE) and European Union’s Horizon 2020 research and innovationprogramme under grant agreement No 657466 (INPATH-TES). Laia Miró would like to thank the Spanish Government for her research fellowship (BES-2012-051861). The University of the Basque Country acknowledges the financial support of the Spanish’s Ministry of Economy and Competitiveness through the MicroTES (ENE2012- 38633) research project. The responsibility for the content of this publication is with the author