Sur la dilatation des aluns

in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-arts de Belgique. Sciences. 3e série (1882), III(4), 331-349

Sur la dilatation, la chaleur spécifique des alliages fusibles et leurs rapports avec la loi de la capacité des atomes des corps simples et composés pour la chaleur

in Annales de Chimie et de Physique. 5e série (1876), VII

Sur la diminution de densité qu'éprouvent certains corps à la suite d'une forte compression et sur la raison probable de ce phénomène

in Bulletin de la Classe des Sciences. Académie Royale de Belgique (1903), (12), 1066-1082

Spring, W. Bulletin de la Classe des Sciences, Academie Royale de Belgique (1904), 1903, 1066-82; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010 ... [more ▼]

Spring, W. Bulletin de la Classe des Sciences, Academie Royale de Belgique (1904), 1903, 1066-82; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). At an amount of metals, as well as other materials, very strong pressure causes, (over 10000 atmospheres, instead of a density increase a decrease [with (NH4)2SO4 for example: 1.773 to 1.750). For these by the author, as well as feature examined more near by KAHLBAUM is tried an explanation, by being brought in compound/connection with the variation in volume with melting. It assumed that perfectly spherical bodies under the influence of an all-sided working strong pressure partly do not arrive at "flowing", thus a change of their molecular structure in the sense of a reduction that is experienced viscosity (pseudo fusion). If this view applies, then bodies, which expand when melting, must experience a volume increase with strong pressure also and in reverse. This consequence is confirmed by the experience. Examples of the first type are tin, lead, cadmium, silver, during bismuth when melting pull together and accordingly also with strong pressure at density increase. Author made wires of different metals, by being pressed by close openings, and observed the fact that Bi-wire was first completely flexible and returned only to some bends to the brittle condition whereby the acceptance by high pressure caused one flowing is supported. The obtained wires were divided ever into 2 parts, and heats one half up to near the melting point, whereby S.c. returned to the normal condition. If one dipped now the "started" and the "fluent" wire together into a salt solution of the same metal, then a weak current could be proven by means of a sensitive galvanometer. The voltage/tension amounts to the following: with tin 0.11, lead 0.12, cadmium 0.20, silver 0.98, bismuth 0.385 milivolts. With the four first, lower volume increase melting metals the "fluent" wire cathode was, with bismuth anode. Similar results were obtained with polished metal bars and rolled out volumes. Over the density variations of some metals with 16° the following table gives information. Metal, Density of the, Fluent, Rolled Metals, Started metals. Lead..., 11.3351, 11.3348, 11.3410. Tin..., 7.3011, 7.3016, 7.3137. Cadmium..., 8.6558, 8.6603, 8.6633. Silver..., 10.2485, 10.2531, 10.2696. Bismuth..., 9.8522, -, 9.8354. One must "protect" from this between firm, in which a metal cannot experience noticeable deformation, and which "apparent" firm differentiates, which by the loss of crystalline structure and the ability of flowing is characterized. Certain materials go possessing easily into this condition over (plastic metals), during different this ability in very small measure or at all; materials of the latter type (coal, sand) cannot be combined also through still so high pressure to a uniform mass. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

Sur la discordance entre les variations respiratoires des pressions intracarotidiennes et intrathoraciques

in Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences (1882), XCIV

Sur la discrétisation totale des problèmes paraboliques

in Bulletin de la Société Royale des Sciences de Liège (1992), 61(6), 441-455

We set an algorithm for the numerical resolution of parabolic problems combining the finite element method for the space variables x and the discontinuous Galerkin method for the time t. By using the ... [more ▼]

We set an algorithm for the numerical resolution of parabolic problems combining the finite element method for the space variables x and the discontinuous Galerkin method for the time t. By using the Legendre's polynomials in t, we reduce the resolution of the system of qN linear equations, where N is the amount of finite element degrees of freedom and q-1 is the degree of the approximations with respect to t, to two inversions of NxN matrices and one evaluation of a NxN matrix polynomial of degree q by a technic of Horner's type. The systematic character of the coefficients allows an algorithm with q as a parameter. [less ▲]

Sur la floculation des milieux troubles

in Bulletin de la Classe des Sciences. Académie Royale de Belgique (1900), (7), 483-520

Spring, W. Bull. Acad. roy. Belgique. (1899), 37, 790-815; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). In this very interesting stand the ... [more ▼]

Spring, W. Bull. Acad. roy. Belgique. (1899), 37, 790-815; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). In this very interesting stand the author gives comprehensive preparation of the philosophy, which led it with its numerous individual investigations, and over the results of these test series. It is possible to seemed that the sedimentary rocks formed, because the apparent is not plastic and weldable bodies accept this characteristics have under pressure. Indeed it showed up with many materials, in particular metals that with pressure alone, without heating up from the powder a connected block develops. This characteristics are proportional with different metals of their weld ability. In addition, with the baud a pressure of 10000 atmospheres is sufficient not yet, in order to cause a cementing. Since a layer height of 50000 m corresponds to this pressure, it is impossible that the sandstones formed alone with pressure. With the metals cementing is based on the ability show also in firm solution and diffusion features. Metals is dissolve mutually it can be combined also in the firm like copper with tin and copper with zinc. On the other hand it does not let itself weld together with zinc with pressure, mix also in the melted lead and zinc (perfectly). The more firmly, the less volatile and a material is less fusible, all the lets is with pressure weld together itself. It shows up with diamond, corundum, quartz and other materials. Without pressure, only by bare laying of smooth surfaces on top of each other such metals, are with each other mixable, can be combined at higher temperature. Two pieces applies mainly for the same metal; with platinum, gold and copper, with the temperature test of 1600 and 1800° the lower melting point was appropriate, just like with such, with those the melting point only for 200° is higher than the test temperature. Also copper and zinc chop lower these conditions together, as a layer brass form 1/4 mm of thickness, also during zinc and lead, zinc and bismuth do not unite. The fact that the solid materials of lower pressure in each other diffuses the results also from the experiments with barium carbonate and sodium sulfate and Barium sulfate and sodium carbonate which from both sides without presence of a solvent with lower pressure became the same equilibrium reached. Chemical reactions in the firm capability of the lower pressure however only then take place, when the volume are not increased. Where by the reaction with Volume decrease is caused, the reaction lower pressure can occur as with mixtures of silver with sulfur with large mobility of the molecules; it does not have to occur however, if the mobility is missing, which with mixtures of zinc and sulfur the case is, although the formation will take place from sulfur zinc also with lower contraction. With agreement a volume distinction occurs, with pressure the coalescence be never caused. with pressure a cleavage is on the contrary often caused with the hydrate of the sulfur arsenic and with the calcium copper acetate. Also transformations of a modification into another, of prism sulfur in octahedral, of graphite in diamond are caused with pressure, and thereby a decreasing of volume occurs. The experiments over the influence of the pressure on firm body did not offer the possibility, the formation of the sedimentary rocks of interpreting in particular the sandstones and conglomerates because quartz does not become plastic and weldable. If however water present with pressure and the formation of a liquid solution is often favored, which works then cementing. In the sandstones and conglomerates consists the binder of amorphously aqueous silicic acid. The author knows by the behavior of these, in particular the younger rocks against caustic potash solution after, by which the amorphous silicic acid is not the quartz grains are dissolved, so that the rock disintegrated. A solution of silicic acid in water can develop with pressure. If one soaks the volume with a colloidal solution of silicic acid, then occurs no caking, because with the drying up, the amorphous silicic acid contracts itself and view the surfaces which can be cemented replaces. One must press evenly as when gluing the wood into pieces together which can be cemented loosely, so that it shrinks with the drying up in the measure like the binder, advances and the relief of that to prevent cementing surfaces. That is caused with the formation of the sandstones with the low pressure of the lay-over sand masses. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved. [less ▲]

Sur la fonction chromatique chez le poulpe

in Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences (1878), LXXXVII

Sur la forme de la contraction du muscle ventriculaire

in Archives Internationales de Physiologie (1906), III

Sur la formulation de l'U.T.C. des problèmes hydroélastiques

Report (1990)

This paper analyses the U.T.C. formulation of hydroelastic problems, where the fluid is represented by an integral formulation. The common features of this formulation with the SAMCEF formulation are ... [more ▼]

This paper analyses the U.T.C. formulation of hydroelastic problems, where the fluid is represented by an integral formulation. The common features of this formulation with the SAMCEF formulation are enlighted and the difficult problem of the fluid-structure connexion is treated in detail. [less ▲]

Sur la limite de visibilité de la fluorescence et sur la limite supérieure du poids absolu des atomes d'hydrogène

in Bulletin de la Classe des Sciences. Académie Royale de Belgique (1905), (5), 201-211

Spring, W. Bulletin de la Classe des Sciences, Academie Royale de Belgique (1905), 201-11; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). A ... [more ▼]

Spring, W. Bulletin de la Classe des Sciences, Academie Royale de Belgique (1905), 201-11; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010). A solution of fluorescein in optically pure water was subjected to the action of a powerful beam of electric light, and the limit of dilution was observed at which a visible green fluorescence was produced. Assuming under these conditions that one cubic millimetre of the solution contained one molecule of fluorescein (C20H10O5K2 = 408), the value 2.5 × 10-21 grams is obtained for the superior limit of the weight of the atom of hydrogen, which is one-twenty-thousand-millionth part of the value 5 × 10-11 calculated by Annaheim (this Journal, 1877, i, 31), but is about seven thousand times as great as the value 3.45 × 10-25 calculated from the kinetic theory of gases. Reprinted with the permission of the American Chemical Society. Copyright © 2010. American Chemical Society (ACS). All Rights Reserved [less ▲]