973 resultados para Ceramic cutting tools


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Remote monitoring of a power boiler allows the supplying company to make sure that equipment is used as supposed to and gives a good chance for process optimization. This improves co-operation between the supplier and the customer and creates an aura of trust that helps securing future contracts. Remote monitoring is already in use with recovery boilers but the goal is to expand especially to biomass-fired BFB-boilers. To make remote monitoring possible, data has to be measured reliably on site and the link between the power plant and supplying company’s server has to work reliably. Data can be gathered either with the supplier’s sensors or with measurements originally installed in the power plant if the plant in question is not originally built by the supplying company. Main goal in remote monitoring is process optimization and avoiding unnecessary accidents. This can be achieved for instance by following the efficiency curves and fouling in different parts of the process and comparing them to past values. The final amount of calculations depends on the amount of data gathered. Sudden changes in efficiency or fouling require further notice and in such a case it’s important that dialogue toward the power plant in question also works.

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Two newspaper clippings from the Montreal Herald of 1838 and an essay clipped from a book, handsewn into a booklet with paper cover and handwritten title and notes. The burning of the Caroline / Susanna Moodie -- The cutting out of the Caroline : a true story / by Francis W. Rowsell -- Juvenile courage and patriotism : instanced in Canada, during the disturbances at the close of the year 1837

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A photograph with a male dressed in a shirt and bow-tie cutting a log and two other men in suits standing on either side of the log. They are surrounded by a large crowd.

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Calculations regarding quantities needed for cutting and ditching (1 page, handwritten), March 19, 1884.

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Chart of calculations regarding quarrying, cutting, transportation and cement, n.d.

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"Mémoire présenté à la Faculté des Études supérieures en vue de l'obtention du grade de LL.M. en Maîtrise en droit Option recherche"

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La station 3-avant de Pointe-du-Buisson (Beauharnois, Haut-Saint-Laurent, Québec) représente la plus importante collection de récipients de terre cuite datant du Sylvicole moyen ancien (-400 à 500 de notre ère) dans le Nord-Est américain. De plus, on trouve sur ce site une série continue d’occupations couvrant l’ensemble de la période Sylvicole. En dépit de complications d’ordre stratigraphique (terreau homogène et pédoturbations), des concepts et des méthodes évolutionnaires tirés de la théorie de l’hérédité duelle sont appliqués à l’étude de cet assemblage. D’un point de vue anthropologique, que nous apprend l’étude de l’évolution et de la transmission des savoir-faire d’une technologie que nous assumons exclusivement féminine au cours de la période Sylvicole? L’auteur défend que l’archéologie évolutionnaire permet de détecter le contexte de la transmission, c’est-à-dire l’organisation socioéconomique des populations du passé. L’examen des traits stylistiques suggère que la sédentarisation estivale des bandes amérindiennes à partir du Sylvicole moyen tardif favorise une homogénéisation des productions céramiques dans un contexte virilocal qui est la conséquence d’une transmission de type conformiste opérant sur un axe horizontal (entre pairs). Cependant, le passage probable des tribus iroquoiennes à l’uxorilocalité et à la matrilinéarité à la fin du Sylvicole se traduit par une saisissante hétérogénéisation des pots, qui s’explique possiblement par une sélection de marqueurs identitaire d’ordre clanique (transmission verticale entre parents et descendants). L’étude des traits techno-fonctionnels indique une diversification de la vaisselle de terre cuite à mesure que les populations intensifient leurs expériences sur les cultigènes. Dans l’ensemble, cette évolution trahit une attention accrue conférée à la performance des pots en tant que récipients culinaires. Par ailleurs, le concours de la sériation et de datations AMS permet la reconnaisance d’un taxon « Sylvicole moyen moyen » caractérisé par une modification morphologique et décorative des vases. Une enquête comparative portant sur un échantillon de 27 sites archéologiques de l’horizon Pseudo-scallop-shell démontre que la variation populationnelle est structurée en fonction de la localisation des communautés dans un bassin hydrographique spécifique. Par conséquent, l’auteur soumet des pistes en vue de l’élaboration d’une taxonomie robuste et propre au Sylvicole moyen ancien et au Sylvicole moyen moyen. Enfin, des indices de natures diverses (archéologiques, paléoethnobotaniques, ethnolinguistiques, paléoanthropologiques, et d’autres issus de la génétique des populations) suggèrent une identité proto-algonquienne des bandes des deux sous-périodes susmentionnées.

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La pratique des droits de l'homme est souvent décrite comme une entreprise qui vise à établir des standards minimaux pour guider l'action des États et des individus. Dans cet article, je tente de remettre en question la position minimaliste défendue par deux auteurs, James Nickel et James Griffin, en défendant une thèse selon laquelle la philosophie et la morale ne devraient pas être limitées par la pratique et les circonstances du monde. Sans apporter une réponse précise à la question de la faisabilité des droits de l'homme tels qu'on les connaît, je soutiens que le minimalisme défendu par Griffin et Nickel n'est pas nécessaire, ni souhaitable, dans la lutte pour la défense des droits de l'homme, lutte dans laquelle la philosophie a un rôle de premier ordre à jouer.

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Ceramic dielectrics with high dielectric constant in the microwave frequency range are used as filters, oscillators [I], etc. in microwave integrated circuits (MICs) particularly in modern communication systems like cellular telephones and satellite communications. Such ceramics, known as 'dielectric resonators (DRs),donot only offer miniaturisation and reduce the weight of the microwave components. but also improve the efficiency of MICs

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A microwave dielectric ceramic resonator based on BaCe2Ti5O15 and Ba5Nb4O15 have been prepared by conventional solid state ceramic route. The dielectric resonators (DRs) have high dielectric constant 32 and 40 for BaCe2Ti5O15 and Ba5Nb4O15, respectively. The whispering gallery mode (WGM) technique was employed for the accurate determination of the dielectric properties in the microwave frequency range. The BaCe2Ti5O15 and Ba5Nb4O15 have quality factors (Q X F) of 30,600 and 53,000 respectively. The quality factor is found to depend on the azimuthal mode numbers. The temperature coefficient of resonant frequency (Tr) of BaCe2Ti5O15 and Ba5Nb4O15 have been measured accurately using different resonant modes and are + 41 and + 78 ppm/K, respectively

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A new microwave dielectric resonator Ba(Tb1/2Nb1/2)03 has been prepared and characterized in the microwave frequency region. 1 wt% CeO2 is used as additive to reduce the sintering temperature. The sintered samples were characterized by XRD, SEM and Raman spectroscopic methods. Microwave DR properties such as er, Q factor and temperature-coefficient of resonant frequency (Ti) have been measured using a HP 8510 B Network Analyzer. Cylindrical DRs of Ba(Tb1/2Nbi/2)03 showed high Er (~ 37), high Q (~3,200) and low Tf (~10 ppm /°C) at 4 GHz and hence are useful for practical applications

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Microwave ceramic dielectric materials Ca5Nb2TiO12 and Ca5Ta2TiO12 have been prepared by a conventional solid-state ceramic process. The structure was studied by X-ray diffraction and the dielectric properties were characterized at microwave frequencies. The ceramics posses a relatively high dielectric constant, very low dielectric loss (Q5 x f > 30000GHz) and small temperature variation of resonant frequency. These materials are potential candidates for dielectric resonator applications in microwave integrated circuits. [DOI: 10. 1 143/JJAP.41.3834]

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The microwave dielectric properties of ZnAl2O4 spinels were investigated and their properties were tailored by adding different mole fractions of Ti02. The samples were synthesized using the mixed oxide rout.e. The phase purity and crystal structure were identified using X-ray diffraction technique. The sintered specimens were characterized in the microwave frequency range (3-13 GHz). The ZnA12O4 ceramics exhibited interesting dielectric properties (dielectric constant (e,.) = 8.5, unloaded quality factor (Q.) = 4590 at 12.27 GHz and temperature coefficient of resonant frequency (Tf) = -79 ppm/°C). Addition of Ti02 into the spinel improved its properties and the Tf approached zero for 0.83ZnAl2O4- 0.17TiO2• This temperature compensated composition has excellent microwave dielectric properties (Cr _ 12.67, Q, = 9950 at 10.075 GHz) which can be exploited for microwave substrate applications

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In this paper, we report the measurements of thermal diffusivity of nano Ag metal dispersed ceramic alumina matrix sintered at different temperatures using laser induced non-destructive photoacoustic technique. Measurements of thermal diffusivity also have been carried out on specimens with various concentration of nano metal. Analysis of the data is done on the basis of one-dimensional model of Rosencwaig and Gersho. The present measurements on the thermal diffusivity of nano metal dispersed ceramic alumina shows that porosity has a great influence on the heat transport and the thermal diffusivity value. The present analysis also shows that the inclusion of nano metal into ceramic matrix increases its interconnectivity and hence the thermal diffusivity value. The present study on the samples sintered at different temperature shows that the porosity of the ceramics varies considerably with the change in sintering temperature. The results are interpreted in terms of phonon assisted heat transfer mechanism and the exclusion of pores with the increase in sintering temperature.