255 resultados para Dover
Resumo:
Time-resolved reflectance is proposed and effectively used for the nondestructive measurement of the optical properties in apples. The technique is based on the detection of the temporal dispersion of a short laser pulse injected into the probed medium. The time-distribution of re-emitted photons interpreted with a solution of the Diffusion equation yields the mean values of the absorption and reduced scattering coefficients of the medium. The proposed technique proved valuable for the measurement of the absorption and scattering spectra of different varieties of apples. No major variations were observed in the experimental data when the fruit was peeled, proving that the measured optical properties are referred to the pulp. The depth of probed volume was determined to be about 2 cm. Finally, the technique proved capable to follow the change in chlorophyll absorption during storage.
Resumo:
Mealiness is a textural attribute related to an internal fruit disorder that involves quality loss. It is characterised by the combination of abnormal softness of the fruit and absence of free juiciness in the mouth when eaten by the consumer. Recent research concluded with the development of precise instrumental procedure to measure a scale of mealiness based on the combination of several rheological properties and empirical magnitudes. In this line, time-domain laser reflectance spectroscopy (TDRS) is a medical technology, new in agrofood research, which is capable of obtaining physical and chemical information independently and simultaneously, and this can be of interest to characterise mealiness. Using VIS & NIR lasers as light sources, TDRS was applied in this work to Golden Delicious and Cox apples (n=90), conforming several batches of untreated samples and storage-treated (20°C & 95%RH) to promote the development of mealiness. The collected database was clustered into different groups according to their instrumental test values (Barreiro et al, 1998). The optical coefficients were used as explanatory variables when building discriminant analysis functions for mealiness, achieving a classification score above 80% of correctly identified mealy versus fresh apples.
Resumo:
Non-destructive measurement of fruit quality has been an important objective through recent years (Abbott, 1999). Near infrared spectroscopy (NIR) is applicable to the cuantification of chemicals in foods and NIK "laser spectroscopy" can be used to estimate the firmness of fruits. However, die main limitation of current optical techniques that measure light transmission is that they do not account for the coupling between absorption and scattering inside the tissue, when quantifying the intensity o f reemitted light. The solution o f this l i m i t a t i o n was the goal o f the present work.
Resumo:
A compact system based on time-resolved diffuse reflectance spectroscopy (TDRS) has been developed to measure internal fruit quality parameters and has been applied to the non-destructive estimation of firmness, sugar content and acidity of kiwifruits. This new optical technique, developed in medical applications and related areas, provides a complete optical characterisation of a diffusive sample as it estimates at the same time and independently the light absorption inside the tissues and the scattering across them. The working principle of the technique is the analysis of the attenuation and broadening of the time-distribution of the remitted light, and the correct interpretation with a proper theoretical model. This main advantage compared to conventional optical techniques (which are only able to register the global attenuation spectrum) added to the compact, portable prototype developed along a three-year work opens the possibilities of this new measurement method in the food industry.
Resumo:
La determinación no destructiva de la calidad interna de la fruta ha sido un objetivo prioritario en las investigaciones recientes (Abbott, 1999). La espectroscopia en el infrarrojo (NIR) es aplicable a la cuantificación de compuestos químicos en alimentos; por otro lado se ha comprobado que el uso de láseres es interesante para la estimación no destructiva de la firmeza de los frutos. Sin embargo estas técnicas ópticas más tradicionales tienen el inconveniente de que miden la intensidad de luz transmitida sin poder diferenciar el efecto de la absorción óptica del efecto de la dispersión espacial que sufre la luz en el interior de los tejidos, lo cual dificulta la estimación independiente de aspectos físicos y químicos. La espectroscopia con resolución temporal es una técnica óptica desarrollada para el diagnóstico en medicina, que permite diferenciar ambos fenómenos (absorción y dispersión), proporcionando una caracterización óptica completa de los tejidos. El objetivo del presente trabajo ha sido la aplicación de esta técnica a frutas y hortalizas, y el desarrollo de modelos matemáticos de estimación no destructiva de su calidad interna para su uso en procesos de clasificación.
Resumo:
Mealiness, a textural disorder that produces quality loss, combines softness and absence of juiciness. The only one (destructive) test to measure it, combines information from a mechanical test on fruit probes to classify the samples according to instrumental mealiness. Time-domain laser reflectance spectroscopy (TDRS) is able to assess simultaneously and independently the absorption of the light inside the irradiated body (µa coefficient) and the scattering of the photons across the tissues (µS, transport scattering coeff.) measured at each wavelength. Using VIS&NIR lasers as light sources, TDRS was applied to Golden Delicious and Cox apples (n=90), conforming batches of untreated samples and storage-treated (20°C&95%RH) to induce mealiness development. The collected database was clustered into different groups according to their instrumental mealiness. Optical variables were used to build discriminant functions, achieving classification scores 75-89% of correctly identified mealy apples.
Resumo:
O consumidor contemporâneo, inserido em um novo ambiente de comunicação, potencializa suas expressões, capaz de avaliar uma marca ou produto e transmitir sua opinião pelas redes sociais, ou seja, o consumidor expressa suas opiniões e desejos dialogando com seus pares de forma espontânea nas redes sociais on-line. É neste ambiente de participação e interação (ciberespaço) que está nosso objeto de estudo, o boca a boca on-line – a voz do consumidor contemporâneo, também conhecido como uma manifestação informativa pessoal ou uma conversa, a opinion sharing. Proporcionado pelos consumidores nas redes sociais on-line, o boca a boca se fortalece em função das possibilidades de interação, característica da sociedade em rede. Nesse cenário, oobjetivo desta pesquisa é caracterizar o boca a boca on-line como um novo fluxo comunicacional entre consumidores, hoje potencializado pelas novas tecnologias da comunicação, capazes de alterar a percepção da marca e demonstrar o uso, pelas marcas, das redes sociais on-line ainda como um ambiente de comunicação unidirecional. Mediante três casos selecionados por conveniência (dois casos nacionais e um internacional), o corpus de análise de nossa pesquisa se limitou aos 5.084 comentários disponibilizados após publicação de matérias jornalísticas no Portal G1 e nas fanpages (Facebook), ambos relativos aos casos selecionados. Com a Análise de Conteúdo dos posts, identificamos e categorizamos a fala do consumidor contemporâneo, sendo assim possível comprovar que as organizações/marcas se valem da cultura do massivo, não dialogando com seus consumidores, pois utilizam as redes sociais on-line ainda de forma unidirecional, além de não darem a devida atenção ao atual fluxo onde se evidencia a opinião compartilhada dos consumidores da sociedade em rede.
Resumo:
Glucose is the preferred carbon source for most eukaryotic cells and has profound effects on many cellular functions. How cells sense glucose and transduce a signal into the cell is a fundamental, unanswered question. Here we describe evidence that two unusual glucose transporters in the yeast Saccharomyces cerevisiae serve as glucose sensors that generate an intracellular glucose signal. The Snf3p high-affinity glucose transporter appears to function as a low glucose sensor, since it is required for induction of expression of several hexose transporter (HXT) genes, encoding glucose transporters, by low levels of glucose. We have identified another apparent glucose transporter, Rgt2p, that is strikingly similar to Snf3p and is required for maximal induction of gene expression in response to high levels of glucose. This suggests that Rgt2p is a high glucose-sensing counterpart to Snf3p. We identified a dominant mutation in RGT2 that causes constitutive expression of several HXT genes, even in the absence of the inducer glucose. This same mutation introduced into SNF3 also causes glucose-independent expression of HXT genes. Thus, the Rgt2p and Snf3p glucose transporters appear to act as glucose receptors that generate an intracellular glucose signal, suggesting that glucose signaling in yeast is a receptor-mediated process.
Resumo:
This series contains seventeen handwritten sermons composed by Nicholas Sever and delivered in the Boston area between 1709 and 1722. Following the completion of his Master's degree at Harvard in 1704, Sever preached in towns around New England including Haverhill in 1709, Dover, New Hampshire (where he was ordained in 1711 and remained until 1715), and in Cambridge as part of his duties as a Harvard Tutor between 1716 and 1728. During these years, Sever also filled in for ministers in nearby parishes. Sever's sermons reflect these engagements, and he occasionally noted the dates and locations where the sermons were delivered in the margin of the first page of the sermon.
Resumo:
The collection holds a heavily interleaved 1791 Triennial Catalogue annotated, in part, by Jeremy Belknap. A note by Harvard Librarian John Langdon Sibley, on the verso of the flyleaf, indicates a second annotator: "It should be observed that this catalogue is in the handwriting of two persons, Dr. Belknap & probably interlineations & additions by Rev. Dr. [John] Eliot. The interlineing part should not be too confidently relied on for accuracy. J. L. Sibley, April 14, 1848." The volume contains biographical notes, newspaper clippings, excerpts from manuscript and printed sources such as New England's First Fruits, the manuscript memoirs of Charles Chauncey, and John Winthrop's Journal, and a 1795 letter from Isaac Mansfield. In the letter, Mansfield references an item he believed to be written by his grandfather, Ames Cheever (Harvard AB 1707), and briefly describes his grandfather. A list of election sermon orators with dates is also pasted into the inside back cover, along with an obituary of the Rev. John Wales (Harvard AB 1728) from the Boston Post-Boy, March 4, 1765.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Map of Piscataquis County Maine, from surveys under the direction of H. F. Walling; field notes under the direction of L. H. Eaton Esq. civil engineer. It was published by Lee & Marsh in 1858. Scale [ca 1:63,360]. This layer is image 1 of 2 total images, representing the northeast portion of the four sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Universal Transverse Mercator projection (UTM Zone 19N, meters, NAD1983). 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, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.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.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Map of Piscataquis County Maine, from surveys under the direction of H. F. Walling; field notes under the direction of L. H. Eaton Esq. civil engineer. It was published by Lee & Marsh in 1858. Scale [ca 1:63,360]. This layer is image 2 of 2 total images, representing the northwest portion of the four sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Universal Transverse Mercator projection (UTM Zone 19N, meters, NAD1983). 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, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.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.
Resumo:
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.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Map of the county of Norfolk, Massachusetts, based upon the details of the trigonometrical survey of the state; the details from actual surveys under the direction of Henry F. Walling. Supt. of the state map. It was published by Smith & Bumstead in 1858. Scale [ca. 1:40,000]. This layer is image 1 of 4 total images, representing the northwest portion of the four sheet source map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). 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, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town and school district boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts 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 (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.