Materiali Compositi a Matrice Cementizia per i Rinforzi Strutturali

L’utilizzo degli FRP (Fiber Reinforced Polymer) nel campo dell’ingegneria civile riguarda essenzialmente il settore del restauro delle strutture degradate o danneggiate e quello dell’adeguamento statico delle strutture edificate in zona sismica; in questi settori è evidente la difficoltà operativa alla quale si va in contro se si volessero utilizzare tecniche di intervento che sfruttano materiali tradizionali. I motivi per cui è opportuno intervenire con sistemi compositi fibrosi sono: • l’estrema leggerezza del rinforzo, da cui ne deriva un incremento pressoché nullo delle masse sismiche ed allo stesso tempo un considerevole aumento della duttilità strutturale; • messa in opera senza l’ausilio di particolari attrezzature da un numero limitato di operatori, da cui un minore costo della mano d’opera; • posizionamento in tempi brevi e spesso senza interrompere l’esercizio della struttura. Il parametro principale che definisce le caratteristiche di un rinforzo fibroso non è la resistenza a trazione, che risulta essere ben al di sopra dei tassi di lavoro cui sono soggette le fibre, bensì il modulo elastico, di fatti, più tale valore è elevato maggiore sarà il contributo irrigidente che il rinforzo potrà fornire all’elemento strutturale sul quale è applicato. Generalmente per il rinforzo di strutture in c.a. si preferiscono fibre sia con resistenza a trazione medio-alta (>2000 MPa) che con modulo elastico medio-alto (E=170-250 GPa), mentre per il recupero degli edifici in muratura o con struttura in legno si scelgono fibre con modulo di elasticità più basso (E≤80 GPa) tipo quelle aramidiche che meglio si accordano con la rigidezza propria del supporto rinforzato. In questo contesto, ormai ampliamente ben disposto nei confronti dei compositi, si affacciano ora nuove generazioni di rinforzi. A gli ormai “classici” FRP, realizzati con fibre di carbonio o fibre di vetro accoppiate a matrici organiche (resine epossidiche), si affiancano gli FRCM (Fiber Reinforced Cementitious Matrix), i TRM (Textile Reinforced Mortars) e gli SRG (Steel Reinforced Grout) che sfruttano sia le eccezionali proprietà di fibre di nuova concezione come quelle in PBO (Poliparafenilenbenzobisoxazolo), sia un materiale come l’acciaio, che, per quanto comune nel campo dell’edilizia, viene caratterizzato da lavorazioni innovative che ne migliorano le prestazioni meccaniche. Tutte queste nuove tipologie di compositi, nonostante siano state annoverate con nomenclature così differenti, sono però accomunate dell’elemento che ne permette il funzionamento e l’adesione al supporto: la matrice cementizia

Account book of Andrew Croswell, 1794-1802

Andrew Croswell kept this account book while an undergraduate at Harvard College. It contains entries from 1794, the year he entered, until his graduation in 1798. There is also one entry on the back cover apparently made in 1802. The entries, divided by school term, are very detailed. Croswell indicates the cost of the following, among many other expenses and purchases: transportation, most often to Hingham and Plymouth; payment for "passing the bridge"; candles; hiring a horse; wood and having it cut; laundry; quills and pencils; paper and ink; razors, haircuts, hair ribbons; a trunk; clothing and cloth for trousers; furniture; tickets to the theater; door locks; a bowl and spoon; "batts and balls" and "other necessaries"; tobacco; toothbrushes; shoe and boot repair; fruit; wine, brandy and rum; cheese; coffee and tea; butter; lemons; sugar; and wafers. There are also entries for college-related costs, including the payment of quarter bills, buttery bills, Hasty Pudding Club dues, and a fee to the President of Harvard College related to Croswell's graduation. There are also entries pertaining to the cost of celebrating various special occasions, including Election Day, Christmas Eve, "Independent Day," and George Washington's birthday.

New Hampshire, 1816 (Image 2 of 6) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: New Hampshire by recent survey : made under the supreme authority and published according to law by Philip Carrigain ; J.J. Barralet, del. ; W. Harrison, sct., Philada. It was published by Philip Carrigain in 1816. Scale [ca. 1:200,000]. This layer is image 2 of 6 total images, representing the center east portion of the six sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the New Hampshire State Plane coordinate system (NAD 1983 in Feet) (Fipszone 2800). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, public buildings, schools, churches, industry locations (e.g. mills, factories, mines, etc.), selected private buildings with names of property owners, town boundaries, land grants, and more. Relief shown pictorially and by hachures. Includes area notes, text, and table of population. Also includes illustrations: View of the Great Boars Head and Hampton Beach -- The Cap of the White Mountains -- View of the White Mountains from Shelburne; inset maps: States of the Union east of the Hudson with the adjacent British colonies. Scale [ca. 1:1,920,000] -- The middle, southern and western sections of the United States with the territories. Scale [ca. 1:4,900,000]. Includes: ms. additions with updated county boundary & township names.This layer is part of a selection of digitally scanned and georeferenced historic maps of New England from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates, scales, and map purposes.

New Hampshire, 1816 (Image 3 of 6) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: New Hampshire by recent survey : made under the supreme authority and published according to law by Philip Carrigain ; J.J. Barralet, del. ; W. Harrison, sct., Philada. It was published by Philip Carrigain in 1816. Scale [ca. 1:200,000]. This layer is image 3 of 6 total images, representing the southeast portion of the six sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the New Hampshire State Plane coordinate system (NAD 1983 in Feet) (Fipszone 2800). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, public buildings, schools, churches, industry locations (e.g. mills, factories, mines, etc.), selected private buildings with names of property owners, town boundaries, land grants, and more. Relief shown pictorially and by hachures. Includes area notes, text, and table of population. Also includes illustrations: View of the Great Boars Head and Hampton Beach -- The Cap of the White Mountains -- View of the White Mountains from Shelburne; inset maps: States of the Union east of the Hudson with the adjacent British colonies. Scale [ca. 1:1,920,000] -- The middle, southern and western sections of the United States with the territories. Scale [ca. 1:4,900,000]. Includes: ms. additions with updated county boundary & township names.This layer is part of a selection of digitally scanned and georeferenced historic maps of New England from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates, scales, and map purposes.

Connecticut, 1849 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Map of Connecticut : from actual survey, engraved by Daggett & Ely. It was published in 1849 by Brown & Parsons. Scale [ca. 1:331,000]. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Connecticut State Plane Coordinate System (Feet) (FIPS 0600). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, county and town boundaries, churches, courthouses and more. Relief shown by hachures. Insets: Plan of the city of New Haven -- Plan of the city of Hartford -- New England states. Includes profile of the Farmington Canal and list of governors of Connecticut from 1676-1849. This layer is part of a selection of digitally scanned and georeferenced historic maps of New England from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates, scales, and map purposes.

Massachusetts drainage basin studies : from field surveys and data /

no. 1. Blackstone River -- no. 3. Farmington River -- no. 4. Millers River -- no. 5. Deerfield River -- no. 6. Westfield River -- no. 7. Chicopee River.

Sermons on practical subjects;

The funeral sermon has special t.-p.: The loss of a faithful minister a sore affliction; illustrated in a sermon, occasioned by the death of the Rev. Joseph Washburn, A. M., pastor of the First church in Farmington; who died at sea, Dec. 25, 1805. Preached at Farmington June 19, 1806. By Asahel Hooker. Hartford: Printed by Lincoln & Gleason.

An Address to the youth of the Society of Friends.

"At Scipio Quarterly Meeting, held 4th mo. 14th, 1831 ... [and] At Farmington Quarterly Meeting, held 20th of 4th Month, 1831."--t.p. verso.

A history of the town of Industry, Franklin County, Maine, from the earliest settlement in 1787 down to the present time, embracing the cessions of New Sharon, New Vineyard, Anson, and Stark. In two parts, including the history and genealogy of many of the leading families of the town.

Mode of access: Internet.

San Juan River regional coal : environmental impact statement.

"March 1984"--Final.

Juan Antonio González Iglesias: la recepción clásica en un poeta alejandrino posmoderno

Este artículo estudia los elementos clásicos presentes en la poesía de Juan Antonio González Iglesias, poeta y latinista salmantino, en sus poemarios publicados hasta el año 2007. Se estudiará la forma tan peculiar que toma la literatura grecolatina en nuestro poeta, ya que en la posmodernidad la herencia clásica se ve abocada a adoptar nuevas formas, estableciendo así un diálogo con la Antigüedad, de la que se recrean selectivamente algunos elementos. Además, podremos comprobar cómo los elementos clásicos conviven con otros, antiguos y modernos, que se mencionarán cuando se unan a los clásicos.

Sammelrezension zum Thema „Partizipation von Schülerinnen und Schülern in Schule und Unterricht“ [Sammelrezension]

Sammelrezension von: 1. Christoph Leser: Demokratie-Lernen durch Partizipation? Fallrekonstruktive Analysen zur Partizipation als pädagogischer Praxis Pädagogische Fallanthologie, Band 11. Berlin/Farmington Hills, MI: Barbara Budrich 2011 (118 S.; ISBN 978-3-86649-455-8) 2. Elke Kurth-Buchholz: Schülermitbestimmung aus Sicht von Schülern und Lehrern. Eine vergleichende Untersuchung an Gymnasien in Brandenburg und Nordrhein-Westfalen Empirische Erziehungswissenschaft, Band 28. Münster: Waxmann 2011 (272 S.; ISBN 978-3-8309-2438-8)