Antarctic icebergs distributions 1992-2014

Basal melting of floating ice shelves and iceberg calving constitute the two almost equal paths of freshwater flux between the Antarctic ice cap and the Southern Ocean. The largest icebergs (>100 km2) transport most of the ice volume but their basal melting is small compared to their breaking into smaller icebergs that constitute thus the major vector of freshwater. The archives of nine altimeters have been processed to create a database of small icebergs (<8 km2) within open water containing the positions, sizes, and volumes spanning the 1992–2014 period. The intercalibrated monthly ice volumes from the different altimeters have been merged in a homogeneous 23 year climatology. The iceberg size distribution, covering the 0.1–10,000 km2 range, estimated by combining small and large icebergs size measurements follows well a power law of slope −1.52 ± 0.32 close to the −3/2 laws observed and modeled for brittle fragmentation. The global volume of ice and its distribution between the ocean basins present a very strong interannual variability only partially explained by the number of large icebergs. Indeed, vast zones of the Southern Ocean free of large icebergs are largely populated by small iceberg drifting over thousands of kilometers. The correlation between the global small and large icebergs volumes shows that small icebergs are mainly generated by large ones breaking. Drifting and trapping by sea ice can transport small icebergs for long period and distances. Small icebergs act as an ice diffuse process along large icebergs trajectories while sea ice trapping acts as a buffer delaying melting.

Escuela pública el libre pensamiento : una reflexión actual en torno a Cordonet.

El sistema público de enseñanza se degrada no sólo por carencia de recursos o por errores pedagógicos, sino también por la falta de convicción en sus propias virtudes. El autor retrocede hasta la Revolución Francesa para clarificar cuáles son los fines específicos de la escuela y cuáles sus fines sobreañadidos, como el esfuerzo por paliar la desigualdades. Esta reflexión se hace a través del análisis que sobre la escuela pública hace el Marqués de Cordonet (1743-1794), ilustre matemático y filósofo, en su obra 'Cinco memorias sobre la instrucción pública'.

Pressupostos epistemológicos e a experimentação no ensino de Química: o caso de Lavoisier

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Opuscules physiques et chymiques /

Mode of access: Internet.

Trattato elementare di chimica : presentato in un ordine nuovo dietro le scoperte moderne, con figure /

Mode of access: Internet.

Trattato elementare di chimica : presentato in un ordine nuovo dietro le scoperte moderne, con figure /

ICCU,

Dizionarii vecchio e nuovo nuovo e vecchio di nomenclatura chimica : il secondo de' quali contiene la chiave e le regole del nuovo sistema di chimica di Vincenzo Dandolo veneto : che serve di supplemento al Trattato elementare di chimica del sig. Lavoisier /

Sulla respirazione dissertazione inedita del sig . Lavoisier diretta a Vincenzo Dandolo e dallo stesso portata dal francese nell' italiano idioma con alcune note illustrative ; Sulla traspirazione dissertazione inedita dei signori Lavoisier e Seguin diretta a Vincenzo Dandolo e dallo stesso portata dal francese nell' italiano idioma

Tratado elemental de Química : presentado baxo nuevo orden y conforme a los descubrimientos modernos, con láminas /

Palau,

Traité élémentaire de chimie : présenté dans un ordre nouveau et d'aprés les découvertes modernes ... /

Mode of access: Internet.

Oeuvres de Lavoisier.

Mode of access: Internet.

Opuscules physiques et chimiques /

Mode of access: Internet.

Histoire des législateurs chimistes : Lavoisier, Berthollet y Humphy Davy /

Mode of access: Internet.