588 research outputs found

    Thermodynamic Insights into Transitions Between Climate States Under Changes in Solar and Greenhouse Forcing

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    A detailed thermodynamic, sensitivity analysis of the steady state climate system is performed with respect to the solar constant S* and the carbon dioxide concentration of the atmosphere, [CO2]. Using PlaSim, an Earth-like general circulation model of intermediate complexity, S* is modulated between 1,160 and 1,510 Wm-2 for values of [CO2] ranging from 90 to 2,880 ppm. It is observed that in a wide parameter range, which includes the present climate conditions, the climate is multistable, i.e. there are two coexisting attractors, one characterised by warm, moist climates (W) and the other by a completely frozen sea surface (Snowball Earth, SB). For both sets of states, empirical relationships for surface temperature, material entropy production, meridional energy transport, Carnot efficiency and dissipation of kinetic energy are constructed in the para- metric plane ([CO2], S*). Linear relationships are found for the two transition lines (W ? SB and SB ? W) in ([CO2], S*) between S* and the logarithm of [CO2]. The dynamical and thermodynamical properties of W and SB are completely different. W states are dominated by the hydrological cycle and latent heat is prominent in the material entropy production. The SB states are mainly dry cli- mates where heat transport is realized through sensible heat fluxes and entropy mostly generated by dissipation of kinetic energy. It is also shown that the Carnot- like efficiency regularly increases towards each transition between W and SB and that each transition is associated with a large decrease of the Carnot efficiency indicating a restabilisation of the system. Furthermore, it has been found that in SB states, changes in the vertical temperature structure are responsible for the observed changes in the meridional transport

    Social Housing in Tuscany between Urban Integration and Segregation

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    Il contributo illustra i risultati dell'analisi configurazionale degli insediamenti edilizia sociale in alcune città toscane, così da illustrare le caratteristiche configurazioni che accomunano gli interventi più rappresentativi e le capacità di tale tecnica di analisi spaziale di portarli alla luce. Ciò attesta che gli aspetti patologici che caratterizzano tali porzioni di aggregato urbano non sono (o quanto meno non sono solamente) l'effetto di fattori di natura sociale, né il risultato di soluzioni morfologiche e compositive, quanto l'esito di specifiche scelte localizzati e della conseguente realizzazione della particolare griglia dei percorsi che sostanziano l'urbanizzazione. Le medesime risultanze appaiono anche utili a suggerire le più opportune linee di intervento per gli interventi di riqualificazione

    Hermann Kant. Ein bio- bibliografisches Profil

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    The proximity to the power apparatus has cast dark shadows on the literary work of Hermann Kant, who is regarded as one of the most read authors of the GDR. Valerio Furneri embeds Kant's life and work in the all-German context of the 20th century and reinterprets his classics such as Die Aula or Der Aufenthalt. The author does not pursue the claim to rehabilitate the GDR, nor to trivialise Kant's role in it. Instead, the attempt is made to look at Kant's entire work from a temporal distance and to re-evaluate it. Through his works, Kant was able to accompany and depict not only the German-German history, but also European history.Die Nähe zum Machtapparat hat dunkle Schatten auf das literarische Werk von Hermann Kant, der als meistgelesener Schriftsteller der DDR gilt, geworfen. Valerio Furneri bettet Kants Leben und Werk in den gesamtdeutschen Kontext des 20. Jahrhunderts ein und interpretiert vor diesem Hintergrund Klassiker wie Die Aula oder Der Aufenthalt neu. Der Autor verfolgt dabei weder den Anspruch, die DDR zu rehabilitieren, noch Kants Rolle darin kleinzureden. Stattdessen wird der Versuch unternommen, Kants Gesamtwerk aus zeitlicher Distanz zu betrachten und neu zu bewerten. Durch seine Werke gelang es Kant nämlich nicht nur die deutsch-deutsche, sondern auch die europäische Geschichte zu begleiten und abzubilden

    Hermann Kant. Ein bio- bibliografisches Profil

    No full text
    The proximity to the power apparatus has cast dark shadows on the literary work of Hermann Kant, who is regarded as one of the most read authors of the GDR. Valerio Furneri embeds Kant's life and work in the all-German context of the 20th century and reinterprets his classics such as Die Aula or Der Aufenthalt. The author does not pursue the claim to rehabilitate the GDR, nor to trivialise Kant's role in it. Instead, the attempt is made to look at Kant's entire work from a temporal distance and to re-evaluate it. Through his works, Kant was able to accompany and depict not only the German-German history, but also European history.Die Nähe zum Machtapparat hat dunkle Schatten auf das literarische Werk von Hermann Kant, der als meistgelesener Schriftsteller der DDR gilt, geworfen. Valerio Furneri bettet Kants Leben und Werk in den gesamtdeutschen Kontext des 20. Jahrhunderts ein und interpretiert vor diesem Hintergrund Klassiker wie Die Aula oder Der Aufenthalt neu. Der Autor verfolgt dabei weder den Anspruch, die DDR zu rehabilitieren, noch Kants Rolle darin kleinzureden. Stattdessen wird der Versuch unternommen, Kants Gesamtwerk aus zeitlicher Distanz zu betrachten und neu zu bewerten. Durch seine Werke gelang es Kant nämlich nicht nur die deutsch-deutsche, sondern auch die europäische Geschichte zu begleiten und abzubilden

    Special issue: Process safety in times of a pandemic

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    Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Safety and Security Scienc

    Dalla città diffusa ai boschi verticali

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    Stefano Boeri Architetti. Il motivo che tiene insieme la sobria modernità proposta da Stefano Boeri è proprio la ricerca di una crasi tra la vasta scala e quella architettonica, crasi inevitabilmente ottenuta attraverso un compromesso tra le due

    The intentionality of matter: the personal character of nature in Edith Stein's "Potency and act"

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    In the closing chapter, Francesco Valerio Tommasi elaborates upon the analogy between person and nature in Stein. As he emphasizes, Stein attributes to nature an objectively spiritual dimension, a hidden form of intentionality. As the author suggests, for Stein nature turns out to be a living sign of the spirit—thus, a sign expressing spiritual values, such as emotions. This perspective is present in both the lectures on The Constitution of the Human Person and Potency and Act: the phenomenological reflection on personhood is combined, Tommasi argues, with a Thomist view that brings Stein to conceiving the life of the entire cosmos as a spirit (or act) informing it and shaping it into a living sign of the creation

    Rhenium(V) and Technetium(V) Nitrido Complexes with Mixed 2 Tridentate pigreco-Donor and Monodentate pigreco-Acceptor Ligands

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    Mixed-ligand [M(N)(SNS)(PPh3)] complexes (M = Tc, Re) (1, 2) were prepared by reaction of the precursor [M(N)Cl2(PPh3)2] with ligand 2,2′-dimercaptodiethylamine [H2SNS = NH(CH2CH2SH)2] in refluxing dichloromethane/ethanol mixtures. In these compounds, 2,2′-dimercaptodiethylamine acts as a dianionic tridentate chelating ligand bound to the [M≡N]2+ group through the two π-donor deprotonated sulfur atoms and the protonated amine nitrogen atom. Triphenylphosphine completes the coordination sphere, acting as a monodentate ligand. [M(N)(NS2)(PPh3)] complexes can assume two different isomeric forms depending on the syn and anti orientations of the hydrogen atom bound to the central nitrogen atom of the SNS ligand with respect to the M≡N moiety. X-ray crystallography of the syn isomer of complex 2 demonstrated that it has a distorted trigonal bipyramidal geometry with the nitrido group and the two sulfur atoms defining the equatorial plane, the phosphorus atom of the monophosphine and the protonated amine nitrogen of the tridentate ligand spanning the two reciprocal trans positions along the axis perpendicular to the trigonal plane. Synthesis of the analogous Tc derivatives with tris(2-cyanoethyl)phosphine, [Tc(N)(SNS)(PCN)] [(PCN = P(CH2CH2CN)3], required the preliminary preparation of the new precursor [Tc(N)(PCN)2Cl2]2 (3), which was prepared by reacting [n-NBu4][Tc(N)Cl4] with a high excess of PCN. The crystal structure of compound 3 consists of a noncrystallographic centrosymmetric dimer of Tc(V) nitrido complexes having an octahedral geometry. In this arrangement, the apical positions are occupied by two tris(2-cyanoethyl)phosphine groups and the equatorial positions by the nitrido group whereas the two Cl– anions and one cyano ligand belong to the other octahedral component of the dimer. By reacting the new precursor [Tc(N)(PCN)2Cl2]2 with the ligand H2SNS the complex [Tc(N)(SNS)(PCN)] (5) was finally obtained in acetonitrile solution. The new Tc(III) complex trans-[Tc(PCN)2Cl4][n-NBu4] (4) was also isolated from the reaction solution used for preparing complex 3 as side product and characterized by X-ray diffraction. The crystal structure of 4 consists of independent trans-[TcCl4(PCN)2]− anions situated on crystallographic centers of symmetry and tetrabutylammonium cations in general positions
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