779 resultados para Physics--Study and teaching (Higher)--Massachusetts--Cambridge--18th century


Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This research studies the self-heating produced by the application of an electric current to conductive cement pastes with carbonaceous materials. The main parameters studied were: type and percentage of carbonaceous materials, effect of moisture, electrical resistance, power consumption, maximum temperature reached and its evolution and ice melting kinetics are the main parameters studied. A mathematical model is also proposed, which predicts that the degree of heating is adjustable with the applied voltage. Finally, the results have been applied to ensure that cementitious materials studied are feasible to control ice layers in transportation infrastructures.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A systematic investigation of the thermal decomposition of viscoelastic memory foam (VMF) was performed using thermogravimetric analysis (TGA) to obtain the kinetic parameters, and thermogravimetric analysis coupled to Fourier Transformed Infrared Spectrometry (TGA-FTIR) and thermogravimetric analysis coupled to Mass Spectrometry (TGA-MS) to obtain detailed information of evolved products on pyrolysis and oxidative degradations. Two consecutive nth-order reactions were employed to correlate the experimental data from dynamic and isothermal runs performed at three different heating rates (5, 10 and 20 K/min) under an inert atmosphere. On the other hand, for the kinetic study of the oxidative decomposition, the data from combustion (synthetic air) and poor oxygen combustion (N2:O2 = 9:1) runs, at three heating rates and under dynamic and isothermal conditions, were correlated simultaneously. A kinetic model consisting of three consecutive reactions presented a really good correlation in all runs. TGA-FTIR analysis showed that the main gases released during the pyrolysis of VMF were determined as ether and aliphatic hydrocarbons, whereas in combustion apart from the previous gases, aldehydes, amines and CO2 have also been detected as the main gases. These results were confirmed by the TGA-MS.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Handwritten volume containing the Articles, weekly orations, and clerk's journal for the Harvard Latin Society recorded by the club's clerk, Jonathan Mayhew (Harvard AB 1744). The Articles define the Society's mission as to "improve ourselves in the knowledge of the Latin Tongue." The ten articles are signed to by ten members of the classes of 1743 and 1744. The journal which records the weekly meetings from April 14, 1742 through June 17, 1742 includes a transcription of the weekly oration in Latin; the first two entries are also translated into English. On the last page of the book, the "clerk's journal" provides a summary of each meeting with the date, the moderator, and the orators.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This diary, effectively a commonplace book, documents Flynt's daily activities and personal reflections from 1723 to 1747. Many entries concern his dealings with family members, business associates, acquaintances, ministers, and political officials. The diary includes a list of books Flynt loaned to others from 1723 to 1743 and detailed financial entries from 1724 to 1747. These entries provide information about the costs of goods and services, as well as Flynt's consumption habits; they detail where he traveled, what he ate and drank (including, apparently, many pounds of almonds), what he read, and many other aspects of daily life. The diary also contains entries related to Flynt's land holdings and other investments, as well as copies of meeting minutes from several sessions of the Harvard Board of Overseers.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

These diaries of Benjamin Guild document his travels as a Presbyterian pastor in Massachusetts and Rhode Island. The daily entries describe people Guild met and dined with, the food he ate (including strawberries, currants, watermelon, English cherries, and lobster), the funerals he attended, and the sermons he gave. Many entries relate to his health concerns (the ague and eye trouble), sleeping habits, and widespread public health concerns (including smallpox, dysentery, "nervous fevers," consumption, and "putrid fever"). The diaries also contain passing references to the activities of American, British, French, and German soldiers during the American Revolution; the invasion of Canada and battles occurring in New York are noted. In August 1778, after visiting Providence, Rhode Island, Guild comments on the disordered state of the city after American soldiers passed through it. He also recounts a visit by officers of the French fleet to the Harvard College library in September 1778 and describes his dinner on board the French man-of-war, Sagitaire. One entry describes an elaborate ball sponsored by John Hancock, held for French soldiers and "Boston ladies," and another refers to the "incursion" of Indians. Many of Guild's diary entries pertain to his work as a Harvard College Tutor; these entries describe his lectures at the College, meetings with colleagues, personnel decisions, and the examination of students. He also describes books he is reading and his opinions of them, the purchase and sale of books, and his desire to learn Hebrew and French. In addition, multiple entries refer to a man named Prince, who was perhaps Guild's slave. Prince sometimes accompanied Guild on his travels.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A miscellaneous collection of letter and legal documents relating to Barbados, especially prize causes, inheritance and slaves.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Two-page handwritten Greek translations created by Harvard sophomore Benjamin Wadsworth on folio-sized paper. The document contains Greek translations of two letters from J. Garretson's "English exercises for school-boys to translate into Latin," copied by Wadsworth in 1766. The first page contains two sections: "As it is in English. A Letter from one friend to another," containing a copy of Garretson's Epistle IV from "E.C.," and a Greek translation of the letter beginning "Kypie..." The second page contains a Greek translation of Garretson's Epistle III from "B.J," and a note by Wadsworth: "A Letter from one Brother to another. Taken out of Garetson's English Exercise. The 3rd Exercise. or 135st page. There is not room or I would write down the English out of which I translated it. September the 2d A.D. 1766. When I was a sophomore." The document is bordered with hand-drawn double lines.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Small notebook kept by James Baker in the late 1750s; the dates 1755, 1756, and 1758 were written in the book. The volume contains Latin theses, Latin translations from the Book of Genesis, and three pages of English text recording an argument about the soul. The notebook has a string binding and pages of different size. The text does not appear to follow a system of organization and includes scribbles and struck-out words.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Bound volume containing a handwritten Greek grammar compiled by Joseph Drury beginning in 1763. The last sixteen pages contain a historical poem beginning, “Mason might once assert a Poets Claim. / But he must needs write.” The poem contains references to the “Great Patriot P—,“ the Roman conquest of Gall, Caeser, Versailles, and includes the verses, “How the King doth all his Cooks excel / Besides he longs to kiss his P / Saving your presence Louis keeps a whore.”

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Notes on measuring height and distance, trigonometry, spherical projection, and other mathematical equations. Probably William Winthrop (1753-1825; Harvard AB 1770).