Showing papers by "Laval University published in 1968"
TL;DR: In this article, Cahn's impurity-drag theory is applied to grain growth and two steady-state grain growth kinetics are possible when the driving force decreases below a critical value.
74 citations
TL;DR: In this paper, the applicability of an extension of the principle of congruence to the data was investigated and the heats of mixing of 23 binary systems were reported at 20, 25 and 30°C.
Abstract: The heats of mixingof 23 binary systems are reported at 20, 25 and 30°C. Of these systems, 14 binaries are mixtures of n-alcohols + n-alkanes and the remaining 9 systems are mixtures of n-alcohols. The applicability of an extension of the principle of congruence to the data was investigated.
Lee chaleurs de demlange pour 23 systemes binaires noat presentees pour des temperatures de 20, 25 et 30°C. Dc ces sysemes, 14 binaires sont des melanges de n-alcools + n- alkanes et les 9 autres systsmes sont des melanges de n-alcools. Une evaluation d'une extension du principle de congruence a etc faite pour ees systemes.
63 citations
TL;DR: The effect of noradrenaline should be investigated in the newborn pig, which seems to have no brown fat, and only about 1 per cent total fat in the body at birth.
Abstract: Moore and Underwood1 showed that subcutaneous injection of noradrenaline in the newborn kitten produced a marked increase in metabolic rate, whereas adrenaline in the same dose was relatively inactive. A similar stimulation of metabolism in the newborn animal after the injection of noradrenaline was observed in the rabbit and rat2 and in the human infant3. Subsequent work on the newborn rabbit showed the probable relation between the effect of noradrenaline and the activity of brown fat. Local heat production in brown fat is increased by the infusion of noradrenaline4. When the brown fat is excised, the rise in oxygen consumption during infusion is greatly reduced5. These observations suggested that the effect of noradrenaline should be investigated in the newborn pig, which seems to have no brown fat, and only about 1 per cent total fat in the body at birth6. The amount increases rapidly to reach about 10 per cent at 1 week of age7.
47 citations
TL;DR: The concept of leadership politique has been studied extensively in the literature, e.g. in this article, where the authors examine sous cette optique le leader politique comme phenomene interpersonnel and social and tente de montrer les conditions requises for son exercice.
Abstract: Le concept du leadership politiqueLe concept du leadership politique n'est qu'une des nombreuses categories de leadership. Et il est particulierement difficile a cerner. Psychologues et sociologues ont depuis longtemps etudie le phenomene du leadership mais, outre qu'ils ne sont pas parvenus a l'elucider de facon satisfaisante, leur problematique ignore des composantes majeures du leadership politique. Neanmoins, il parait acquis que le leadership est une relation entre dirigeants et subordonnes et que c'est comme processus de groupe que cette relation se prete le mieux a l'etude. L'article examine sous cette optique le leadership politique comme phenomene interpersonnel et social et tente de montrer les conditions requises pour son exercice. Quel que soit l'angle sous lequel on la considere, la relation de leadership reproduit un processus circulaire, dirigeants et subordonnes s'influencant mutuellement dans la production des manifestations du groupe. Cette idee sen d'hypothese centrale pour l'examen des traits caracteristiques du leadership politique a tous les niveaux : du leader, de ses lieutenants et des simples membres. Plusieurs questions apparaissent ainsi sous un nouveau jour, notamment celles de l'influence relative des traits personnels et de la situation dans la production du leader, de la nature du leadership au sein de l'organisation bureaucratique et des conditions de « dramaturgic » qui accompagnent l'exercice du leadership. La distinction entre leadership comme style de commandement et comme modele d'organisation de l'autorite ouvre aussi sur des voies prometteuses pour la connaissance du phenomene. Cette distinction est notamment precieuse dans l'examen des conditions d'exercice du leadership, qu'il s'agisse du choix des dirigeants, du controle reciproque des dirigeants et des simples membres ou encore des styles de leadership, democratique ou autoritaire. Il serait souhaitable que les etudes du leadership politique tiennent davantage compte des ouvrages biographiques qui nous apprennent comment les grands leaders ont percu leurs fonctions, leurs rapports avec les hommes et la vie politique.
25 citations
TL;DR: In this paper, a distorted inverse square barrier wave approximation (DISBWA) was proposed to deduce the repulsive core potentials for any ljMlj combination.
25 citations
TL;DR: In this paper, the surface potentials of metals in vacuum within the 10 −5 to 10 −7 torr range were measured by the means of an improved Kelvin probe, and the life of those local modifications of potentials were highly pressure dependent.
24 citations
TL;DR: In monkey, a drastic decrease of 5-HT is found in the ipsilateral striatum following lesions that severed fibers associate with the most dorsomedial part of the cerebral peduncle, suggesting the existence of direct fibers from the region of the upper pons and lower midbrain to the striatum.
Abstract: Publisher Summary Studies on the monkey have led to the conclusion that depletion of the striatal 5-HT is associated with the interruption of a group of fibers traveling in the most dorsomedial area of the cerebral peduncle. The decrease of striatal 5-HT, like that of catecholamines, appears to be an important factor in the appearance of tremor in the monkey. Moreover, the presence of a normal concentration of dopamine in the striatum, along with a deficiency of 5-HT, appears to be an important feature in the production of choreiform and ballistic movements. In such animals, the administration of harmaline or harmine exaggerates abnormal movements, such as tremor and choreiform and ballistic movements, or initiates them in animals bearing certain lesions that do not result in this type of spontaneous dyskinesia postoperatively. In monkey, a drastic decrease of 5-HT is found in the ipsilateral striatum following lesions that severed fibers associate with the most dorsomedial part of the cerebral peduncle, suggesting the existence of direct fibers from the region of the upper pons and lower midbrain to the striatum.
21 citations
TL;DR: In this paper, four equations permitting the prediction of heats of mixing of ternary systems from binary data are made. But the results of the experiments were limited to a set of 21 systems of one n-alkane + two n-alcohols.
Abstract: Heats of mixing for 21 ternary systems of one n-alkane + two n-alcohols are reported at 25°C. Evaluation of four equations permitting the prediction of heats of mixing of ternary systems from binary data is made. Scatchard's modified equation for systems containing a polar component was found to be the most accurate.
Les chaleurs de melange pour 21 systemes ternairer composes de n-alkane + deux n-aleools sont presentees a 25°C. Une evaluation de quatre equations permettent de predire les chaleurs de melange des systemes ternaires a partir des donneea pour lee systemea binaires a etc faite. L'gquation modifiee de Scatchard pour dee aystemes contenant un eompose polaire permet de predire les meilleures valeura.
20 citations
18 citations
TL;DR: In this article, the authors investigated the effect of agitator shape on the level of mixing in a flow system and found that the size and shape of the agitators affect the mixing.
Abstract: Variations of the level of mixing in a flow system have been investigated as a function of the following parameters: diameter, shape and speed of the agitator, feed rate and position of the feed inlet.
At agitator speeds inferior to a critical value, a minimum level of mixing is observed which depends on the position of the feed inlet. At speeds superior to the critical value, the level of mixing increases linearly with agitator speed, at a given feed rate, until conditions of perfect mixing are reached. The critical agitator speed and the position of each straight line depend on the agitator size. A modified Reynolds number makes possible a more general correlation.
At a given agitator speed, superior to the critical value, the level of mixing decreases as the feed rate increases, due to the smaller amount of energy imparted by the agitator per unit mass of feed. The effect of agitator shape on the level of mixing is rather pronounced as it affects the flow patterns inside the reservoir.
On a etudie les variations du niveau d'agitation dans un systeme continu en fonction des parametres suivants: diametre, forme et vitesse de l'agitateur, debit d'alimentation et point d'entree de l'alimentation.
Aux vitesses de l'agitateur inferieures a une valeur limite, on observe un niveau minimum d'agitation qui est fonction du point d'entree de l'alimentation. Aux vitesses superieures a la valeur limite, le niveau d'agitation croǐt lineairement avec la vitesse de l'agitateur, a un debit donne, jusqu'a ce que l'agitation soit parfaite. La grosseur de l'agitateur determine la vitesse limite de l'agitateur de měme que la position des droites obtenues. Un nombre de Reynolds modifie permet d'obtenir une correlation plus generate.
A une vitesse de l'agitateur superieure a la valeur limite, le niveau d'agitation decroǐt avec un debit croissant en raison de la plus petite quantite d'energie fournie par l'agitateur par unite de masse de l'alimentation. On note une influence assez marquee de la forme de l'agitateur sur le niveau d'agitation par suite des effets differents sur le mode de circulation interne.
18 citations
TL;DR: The results indicate that the RNA synthesized in the nucleus immediately after injection consisted of messenger RNA (mRNA) and ribosomal precursor RNA, which may constitute a rRNA precursor rather than polycistronic mRNA.
TL;DR: A physiological meaning for the accumulation of extravasated blood during narcosis is suggested, making account of the concomitant inhibition of the respiratory movements, in connection with tricaine induced anaesthesia.
TL;DR: In this article, 2-pyridylethylcarbinol (I) was resolved and the antipodes hydrogenated as free bases and the (+) form gave (+) conhydrine (II) while the (-) form afforded the levorotatory base stereoselectively with minor contamination of the other epimer.
TL;DR: The changing phospholipid pattern of the last instar larva and during metamorphosis has been studied by a new method and reacylation of lysophosphatidylcholine to form phosphatidolcholine is suggested for the first time in an insect.
TL;DR: A method of focusing electromagnetic waves by diffraction alone is proposed, an incident beam is diffracted by a series of circular apertures which have their diffracting edges falling on a surface of revolution.
Abstract: A method of focusing electromagnetic waves by diffraction alone is proposed. An incident beam is diffracted by a series of circular apertures which have their diffracting edges falling on a surface of revolution. A geometrical consideration of the principle involved is presented, followed by a series of experimental results.
TL;DR: In this article, the energy levels of 57Co up to 4 MeV excitation with 25 keV resolution were investigated and several new levels were found, and it was proposed that the levels at 1.22 MeV and 1.68 MeV have spin and parity 9 2 − and 11 2 −, respectively.
TL;DR: It is concluded that the postoperative use of intravenous diazepam as an adjunct to the usual analgesic medication has markedly reduced the incidence and severity of psychiatric complications after intracardiac surgery with cardiopulmonary bypass.
Abstract: The present study, based on a series of 79 consecutive unselected patients undergoing open-heart surgery with extracorporeal circulation at the Quebec Institute of Cardiology, was undertaken to determine the occurrence and severity of postoperative psychiatric complications, to discuss some of the factors involved in their pathogenesis, and to test the effectiveness of intravenous diazepam in their prevention and control.
TL;DR: The three principal alkaloids of Venezuelan Aspidosperma cuspa have been identified as burnamine (I), des- O -methylaspidocarpine (XV) and aspidodasycarpine(II) as mentioned in this paper.
TL;DR: In this paper, a generalized zone plate formulation of scalar diffraction theory is used to reconstruct the filter function in the pupil plane. But the amplitudes of the sources are related in a simple way to the Fourier-series expansion of the pupil function.
Abstract: By use of a recently developed formulation of scalar diffraction theory, any complex amplitude filter can be considered as a generalized zone plate. By placing sources having suitable amplitude and phase characteristics at the foci, we can reconstruct the filter function in the pupil plane. The amplitudes of the sources are related in a simple way to the Fourier-series expansion of the pupil function. The techniques of holography can be used to record complex-amplitude filters on photographic film. If three-beam holography is used and if the filter function is real, only real sources are needed.
TL;DR: A simple method has been developed for the measurement of glutamic acid decarboxylase activity with radioactive 1-C14- l -glutamic acid and the results compared with those obtained by a manometric method and by evaluation of GABA.
TL;DR: In this paper, 2.8-Methyl-8-azonium tricyclo [2.2.1.1] nonane chloride (IIa) was obtained in quantitative yield from 2β-chloromethyl-3β-hydroxytropane (Ib).
TL;DR: In this paper, a systeme etudie consiste en un reservoir cylindrique vertical muni d'un agitateur coaxial a turbine and de chicanes, in which l'entree de l'alimentation and la sortie de l's effluent se trouvent dans l'axe du reservoir, the premiere sous l'agitateur and l'autre en surface.
Abstract: Le systeme etudie consiste en un reservoir cylindrique vertical muni d'un agitateur coaxial a turbine et de chicanes. L'entree de l'alimentation et la sortie de l'effluent se trouvent dans l'axe du reservoir, la premiere sous l'agitateur et l'autre en surface.
On a utilise un modele propose par Cholette et Cloutier pour caracteriser les parametres de l'agitation. A une vitesse donnee de l'agitateur, la presence de chicanes a pour effet de diminuer le niveau d'agitation. Cette diminution est une fonction complexe de la largeur des chicanes. La presence de chicanes entraǐne egalement une diminution du court-circuit.
Le couple varie avec le niveau d'agitation; il augmente en presence de chicanes et encore plus pour de grands diametres de l'agitateur.
Les auteurs proposent une representation des differents circuits internes qui permettent d'expliquer les resultats experimentaux.
TL;DR: In this article, the performance of broad band electrically small beamed receiving arrays operating in the high-frequency band (3 to 30 MHz) and in a random noise environment is studied.
Abstract: The performance of broad band electrically small beamed receiving arrays operating in the high-frequency band (3 to 30 MHz) and in a random noise environment is studied. The concepts of system noise figure (SNF) and signal-to-noise ratio improvement factor (SNIF) are proposed as criteria for comparing one array antenna receiving system to any reference antenna system when the conditions of operation are defined. Graphical representations of SNIF for the two- and four-element antenna systems versus a single-element system are presented. SNIF is shown to depend on the geometry of the array, on the phasing network, and on the ratio of atmospheric noise power to internal system noise power.
TL;DR: In this article, a modified principle of congruence is applied to the prediction of heat of mixing of binary systems, and its application to other binary mixtures is also examined.
Abstract: A modified principle of congruence is applied to the prediction of heats of mixing of binary systems. The principle is here applied to n-alkanes binary mixtures and its application to other binary mixtures is also examined.
Une modification du principe de congruence est appliquee pour predire les chaleurs de melange des systemes binaires. Le principe est applique aux melanges binaires de n-alkanes et son utilisation pour d'autres melanges binaires est aussi examinee.
TL;DR: It can be concluded that polyposis of the colon is a multifaceted disease and the mendelian character of the disease cannot be denied in patients belonging to the same family, especially when they are less than 40 years of age.
Abstract: It can be concluded that polyposis of the colon is a multifaceted disease. The mendelian character of the disease cannot be denied in patients belonging to the same family, especially when they are less than 40 years of age. The occurrence of polyposis in patients more than 40 years of age, or in those in whom no familial antecedent can be traced, is more difficult to comprehend. Probably the occurrence of this type of polyposis is on the same basis as that of carcinoma of the colon and, if this is true, it might be termed primary multiple polyposis of the colon.