Prefazione - Acqua. Sostanza e Risorsa

No abstrac

Reaching the boundary between stellar kinematic groups and very wide binaries. III. Sixteen new stars and eight new wide systems in the beta Pictoris moving group

Aims. We look for common proper motion companions to stars of the nearby young beta Pictoris moving group. Methods. First, we compiled a list of 185 beta Pictoris members and candidate members from 35 representative works. Next, we used the Aladin and STILTS virtual observatory tools, and the PPMXL proper motion and Washington Double Star catalogues to look for companion candidates. The resulting potential companions were subjects of a dedicated astro-photometric follow-up using public data from all-sky surveys. After discarding 67 sources by proper motion and 31 by colour-magnitude diagrams, we obtained a final list of 36 common proper motion systems. The binding energy of two of them is perhaps too small to be considered physically bound. Results. Of the 36 pairs and multiple systems, eight are new, 16 have only one stellar component previously classified as a beta Pictoris member, and three have secondaries at or below the hydrogen-burning limit. Sixteen stars are reported here for the first time as moving group members. The unexpected large number of high-order multiple systems, 12 triples and two quadruples among 36 systems, may suggest a biased list of members towards close binaries or an increment of the high-order-multiple fraction for very wide systems.Comment: A&A in pres

Diossido di titanio e alcune sue applicazioni. Spunti didattici

Il diossido di titanio, TiO2, ampiamente utilizzato come pigmento di colore bianco, \ue8 uno dei materiali pi\uf9 studiati nell\u2019ambito della ricerca per le sue propriet\ue0 fotocatalitiche. Esso, infatti, contribuisce alla fotodegradazione di sostanze inquinanti, motivo per cui \ue8 utilizzato nel settore della purificazione dell\u2019aria e dell\u2019acqua e per la realizzazione di vetri autopulenti, disponibili commercialmente. Nel presente lavoro viene suggerito un percorso didattico con l\u2019obiettivo di mettere in evidenza le propriet\ue0 fotocatalitiche del diossido di titanio oltre che pu\uf2 essere utilizzato per affrontare concetti fondamentali quali la struttura a bande dei solidi e la fotocatalisi. Il percorso si articola in pi\uf9 fasi che ricalcano quelle suggerite nei metodi didattici basati sull\u2019indagine come il protocollo delle 5E dell\u2019approccio IBSE. Dopo aver assistito a una dimostrazione che illustra le propriet\ue0 fotocatalitiche del diossido di titanio con l\u2019ausilio di un opportuno pigmento, gli studenti sono guidati nell\u2019indagine dei diversi fattori che influenzano il processo

If You Can’t Take the Heat: Cultural Beliefs about Questionable Conduct, Stigma, Punishment, and Withdrawal among Mexican Police Officers

We introduce the concept of cultural beliefs about questionable conduct, and examine how these beliefs interact with stigma consciousness to influence punishment and two withdrawal behaviors: turnover and absenteeism. We used a sample of Mexican police officers in a border city and implemented a mixed method design, paying attention to the national, occupational, and organizational context of this setting. We conducted a qualitative phase to explore the prevalence and meaning of occupational stigma and four cultural beliefs about questionable conduct: greed, toughness, wariness, and savvy. The results of this phase helped us develop a context-relevant measure of cultural beliefs about questionable conduct using Mexican proverbs. The results of the quantitative phase indicated that, contingent upon stigma consciousness, beliefs about questionable conduct affected received punishment, turnover, and absenteeism. We discuss the theoretical and behavioral implications of our findings for socialization, identity management, occupational stigma, corruption, and ethical behavior

VERSO UN APPRENDIMENTO AUTENTICO DELLA CHIMICA DI BASE: TRASPOSIZIONE DIDATTICA DEI RISULTATI DELLA MODERNA RICERCA SCIENTIFICA.

In questo lavoro viene presentata una proposta riguardante l'uso dei risultati della moderna ricerca in campo chimico per introdurre i concetti fondanti della disciplina nella pratica didattica della Chimica di base nella Scuola Secondaria di Secondo Grado. Con questo approccio, i concetti di base dovrebbero risultare meno astratti e il mondo della ricerca più accessibile

LA SCUOLA SPAIS: RICERCA SCIENTIFICA E DIDATTICA DELLE SCIENZE IN UN CONTESTO MULTIDISCIPLINARE

SPAIS si pone come obiettivo l’individuazione e il conseguente approfondimento delle conoscenze di base che sono necessarie nel campo della chimica, della fisica e delle scienze biologiche e naturali per comprendere e comunicare i contenuti fondamentali della moderna ricerca scientifica e tecnologica. L’edizione 2013 sul tema “ScientificaMente – le Neuroscienze” viene qui presentata evidenziandone particolarmente le implicazioni nella didattica della Chimic

CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS

Context. CARMENES is a stabilised, high-resolution, double-channel spectrograph at the 3.5 m Calar Alto telescope. It is optimally designed for radial-velocity surveys of M dwarfs with potentially habitable Earth-mass planets. Aims. We prepare a list of the brightest, single M dwarfs in each spectral subtype observable from the northern hemisphere, from which we will select the best planet-hunting targets for CARMENES. Methods. In this first paper on the preparation of our input catalogue, we compiled a large amount of public data and collected low-resolution optical spectroscopy with CAFOS at the 2.2 m Calar Alto telescope for 753 stars. We derived accurate spectral types using a dense grid of standard stars, a double least-squares minimisation technique, and 31 spectral indices previously defined by other authors. Additionally, we quantified surface gravity, metallicity, and chromospheric activity for all the stars in our sample. Results. We calculated spectral types for all 753 stars, of which 305 are new and 448 are revised. We measured pseudo-equivalent widths of Halpha for all the stars in our sample, concluded that chromospheric activity does not affect spectral typing from our indices, and tabulated 49 stars that had been reported to be young stars in open clusters, moving groups, and stellar associations. Of the 753 stars, two are new subdwarf candidates, three are T Tauri stars, 25 are giants, 44 are K dwarfs, and 679 are M dwarfs. Many of the 261 investigated dwarfs in the range M4.0-8.0 V are among the brightest stars known in their spectral subtype. Conclusions. This collection of low-resolution spectroscopic data serves as a candidate target list for the CARMENES survey and can be highly valuable for other radial-velocity surveys of M dwarfs and for studies of cool dwarfs in the solar neighbourhood.Comment: A&A, in pres