Monte Carlo simulations of dusty spiral galaxies: extinction and polarization properties

We present Monte Carlo simulations of dusty spiral galaxies, modelled as bulge + disk systems, aimed to study their extinction and polarization properties. The extinction parameters (absorption and scattering) of dust grains are calculated from Mie's theory for a full distribution of sizes and materials; the radiation transfer is carried on for the four Stokes parameters. Photometric and polarimetric maps of galaxies of different optical depths, inclinations and bulge-to-total ratios have been produced in the B and I bandpasses. As expected, the effect of scattering is to reduce substantially the extinction for a given optical depth, in particular for what concerns the obscuration of bright bulge cores. For the same reason, scattering reduces also the reddening, as evaluated from B-I maps. On the other hand the bluing directly due to forward scattering is hardly appreciable. Radial color gradients are often found. A comparison with ``sandwich'' models shows that they fail dramatically to reproduce the extinction - optical depth relation. The degree of linear polarization produced by scattering is usually of the order of a few percent; it increases with optical depth, and with inclination (less than 80 degrees). The polarization pattern is always perpendicular to the major axis, unless the dust distribution is drastically modified. There is little local correlation between extinction and polarization degree and there is a trend of increasing polarization from the B to the I band. We discuss implications and relevance of the results for studies of the structure and morphology of spiral galaxies and of their interstellar medium.Comment: 43 pages, 13 Postscript figures, Latex AAS manuscript substyle, Ap. J. Accepte

On the Dust Extinction in High-z Galaxies and the Case of Extremely Red Objects

We present the preliminary results of Monte Carlo simulations aimed to investigate the effects of realistic dust extinction (absorption + scattering) on the colours of high-z galaxies. In this paper, we concentrate on the case of spheroidal galaxies, and we obtain attenuation curves in the range 0.1-1.2$\mu$m for different dust spatial distributions, and for a range of values of the dust optical depth, geometrical thickness and inclination of the dust disk. We find that the resultant curves are strongly dependent on the dust geometrical distribution and optical depth. A serendipitous finding is that the strength of the 2200 \AA absorption feature depends not only on the optical depth, but also on the dust geometrical distribution. As a first application, we test our results on two high-z galaxies with extremely red colours (HR10 and HR14) in order to infer clues on their ages, dust content and dust spatial distribution. We confirm that HR10 must be a very dusty galaxy, and we suggest that its stellar component should be strongly embedded in the dust in order to reproduce the observed extremely red colours.Comment: 7 pages, MNRAS LaTeX, 3 figure

Keeping a foot in both camps: Sustainability, city branding and boundary spanners

This study critically examines sustainable development (SD) within the contemporary practices of city branding, a prominent business philosophy that underpins market-led development strategies of urban areas. In pursuing uniqueness, different cities often seem to hint at the very same themes of differentiation, and this reflects the tendency to embrace pre-given sets of place-development discourses. This work casts a critical perspective on SD as one of the global passe-partout themes that has become particularly prominent in contemporary city-brand management practices. In particular, the theory-practice gap in city branding for SD is emphasized and interpreted through the lens of glocalization theories. This viewpoint identifies responsibilized boundary spanners as agents located between the global and local levels that act as mediators in multi-stakeholder networks, ultimately fostering capacities to implement collective actions in city-branding practices

PENGARUH KREATIVITAS DAN MINAT BELAJAR TERHADAP HASIL BELAJAR SISWA PADA MATA PELAJARAN BAHASA INGGRIS KELAS XI AP DAN XI AK DI SMK IPTEK JAKARTA

NURUL ISTIQOMAH TIHARTINI. The Influence Of Creativity And Interest Learning Towards Learning Outcomes Of Students In Subject English Language Class XI AP and XI AK at IPTEK Vocational High School Jakarta. Scientific Paper, Jakarta: Study Program of Economic Education, Concetration of Office Administration Education, Faculty of Economics, State University of Jakarta, July 2018. This Study aims to determine whether there is the influence of creativity and interest learning towards learning outcomes of students in subjects English Language at IPTEK Vocational High School Jakarta. The research was conducted over two month from March to May 2018. The research method used is survey method with the correlation approach. The research population was students class XI AP and XI AK of IPTEK Vocaional High School Jakarta as much 140. The sample used as many as 100 students by using simple random sampling. Data variable Y (learning outcomes) is a secondary data obtained from the value of a class XI AP and XI AK students learning outcomes English Languange. While the data variable X1 (creativity) and the data variable X2 (interest learning) questionnaire using likert scale. Techniques of data analysis using SPSS 24.0. From the result of Ftest, found that Fcount (7,116) > Ftable (3,939). This means that X1 and X2 simultaneously affect the Y. T test produce tcount of X1 is (2,110) ≥ ttable (1,985) and X2 (interest learning) (3,111) ≥ t table (1,985). Because t count > t table ,it can be concluded that there is a positive influence on the interest learning and motivation learning towards learning outcomes. Then a coefficient of determination of test results obtained 0,128 or 12,8%, the remaining 87,2% influenced by other fctors not examined. It is concluded that there are significant positive and significant correlation between creativtity and interest lesarning to learning outcomes of XI AP and XI AK students in subject English Language at Iptek Vocational High School. Keywords: Creativity, Interest Learning, Learning Outcome

Al, cu and zr addition to high entropy alloys: The effect on recrystallization temperature

The equimolar Cr, Mn, Fe, Co and Ni alloy, first produced in 2004, was unexpectedly found to be single-phase. Consequently, a new concept of materials was developed: high entropy alloys (HEA) forming a single solid-solution with a near equiatomic composition of the constituting elements. In this study, an equimolar CoCrFeMnNi HEA was modified by the addition of 5 at% of either Al, Cu or Zr. The cold-rolled alloys were annealed for 30 minutes at high temperature to investigate the recrystallization kinetics. The evolution of the grain boundary and the grain size were investigated, from the as-cast to the recrystallized state. Results show that the recrystallized single phase FCC structures exhibits different twin grains density, grain size and recrystallization temperatures as a function of the at.% of modifier alloying elements added. In comparison to the equimolar CoCrFeMnNi, the addition of modifier elements increases significantly the recrystallization temperature after cold deformation. The sluggish diffusion (typical of HEA alloys), the presence of a solute in solid solution as well as the low twin boundary energy are responsible for the lower driving force for recrystallization

Experiencias docentes en pandemia. Las escuelas secundarias argentinas entre la virtualidad y el desafío del regreso a la presencialidad

We analyze here a set of narratives from secondary school teachers during the COVID-19 pandemic in Argentina. The results show the transformation of their practice in the face of forced virtuality and the loss of the materiality of the school. The institution thus appears as the place of “the common” and of strengthening links in a context of uncertainty.Analizamos aquí un conjunto de narrativas de docentes de escuela secundaria durante la pandemia de COVID-19 en la Argentina. Los resultados muestran la transformación de su práctica ante la virtualidad forzada y la pérdida de la materialidad de la escuela. La institución aparece así como el lugar de “lo común” y de fortalecimiento de los vínculos en un contexto de incertidumbre

Innovazione e Circolarità. Il Contributo del Life Cycle Thinking nel Green Deal per la neutralità climatica

Progettare il sistema di facciata di un edificio è un’operazione complessa e multidisciplinare. Questa complessità deriva dall’eterogeneità delle prestazioni che deve assicurare il sistema di involucro durante l’intera vita utile. Alla luce delle sfide imposte dalla transizione verso la neutralità climatica, l’analisi Life Cycle Assessment (LCA) entra sempre più frequentemente nella prassi progettuale richiedendo strumenti specifici per valutare i principali indicatori di impatto ambientale. Sebbene negli ultimi anni vi sia stato un aumento nel numero di software in grado di eseguire analisi LCA, oggi è ancora difficile trovare una reale interoperabilità con gli strumenti di progettazione architettonica. Partendo da tali premesse il contributo propone un framework di lavoro sviluppato in ambiente Visual Programming Language (VPL) in grado di esprimere le prestazioni ambientali del progetto in real time e assicurare un’elevata flessibilità nel progettare edifici capaci di rispondere alle sfide imposte dal cambiamento climatico

Early exploitation of Neapolitan pozzolan (pulvis puteolana) in the Roman theatre of Aquileia, Northern Italy

: The paper reports the results of the analyses on mortar-based materials from the Roman theatre of Aquileia (Friuli Venezia Giulia, Northern Italy), recently dated between the mid-1st Century BCE and the mid-1st Century CE. Samples were characterized by Polarized Light Microscopy on thin sections (PLM), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) and Quantitative Phase Analysis by X-Ray Powder Diffraction (QPA-XRPD). Pyroclastic aggregates (mainly pumices and scattered tuffs), incompatible with the regional geology, were found in two samples from the preparation layers of the ground floor of the building. Their provenance was determined by means of QPA-XRPD, SEM-EDS, X-Ray Fluorescence (XRF) and Laser-Ablation Inductively-Coupled-Plasma Mass-Spectrometry (LA-ICP-MS). Mineralogical and geochemical analyses demonstrated their provenance from the Bay of Naples, thus recognizing them as pulvis puteolana, a type of pozzolanic aggregate outcropping around the modern town of Pozzuoli and prescribed by Vitruvius (De Architectura, 2.6.1) in mortar-based materials to strengthen masonries and produce hydraulic concrete for harbor piers. This evidence represents the oldest analytically-established case of pulvis puteolana exploitation in Northern Italy up to now, and an early use of the material out of Campania adapted for civil constructions in a non-strictly maritime-related environment. Indeed, the theatre was built in the low-lying Aquileia's deltaic plain, prone to water infiltrations that are typical in lagoon-like environments. The data highlight the craftsmen's resilience in adapting and reinterpreting the traditional use of the Neapolitan volcanic materials to deal with the geomorphological challenges of Aquileia's lowland