Showing papers by "Université de Sherbrooke published in 1976"
TL;DR: In this article, the enthalpies of solution of urea (U) in water (W)-tert-butanol (TBA) mixtures and of TBA in W-U mixtures were measured with a solution calorimeter and a flow microcalorimeter.
Abstract: The enthalpies of solution of urea (U) in water (W)-tert-butanol (TBA) mixtures and of TBA in W-U mixtures, the enthalpies of dilution of TBA in W, and the enthalpies of mixing of U and TBA aqueous solutions were measured with a solution calorimeter and a flow microcalorimeter. Enthalpies of transfer of U and TBA to the mixed solvents were derived. Also, pair and triplet interaction parameters between the various solutes were derived from the mixing and dilution experiments. The enthalpic pair parameter hU-TBA is positive, suggesting that the main contribution to this parameter is the decrease in hydrophobic hydration of TBA in the presence of U.
267 citations
TL;DR: In this article, the characteristics and performances of a contacting machine of 20,000 gal/day capacity for the treatment of industrial waste waters are reported, and the characteristics of a contact machine with a capacity of 10,000 g/day for treating industrial waste water containing heavy metals such as Hg, Cd, Zn, Cu, Fe, Ni, Cr6+, Cr3+, Ag, Pb, Sb or cyanide, phosphates and organic matters such as oil, detergents and dyes are reported.
174 citations
TL;DR: In this article, a series of measurements with aqueous electrolyte and nonelectrolyte solutions indicates that there is a small systematic difference between the heat capacities per unit volume determined with a Picker flow microcalorimeter and the original prototype.
Abstract: A series of measurements with aqueous electrolyte and nonelectrolyte solutions indicates that there is a small systematic difference between the heat capacities per unit volume determined with a Picker flow microcalorimeter and the original prototype. Through various tests and comparisons, it is, concluded that the commercial instrument gives results closer to the true values. Most of the previous data obtained in our laboratory have been corrected and expressed relative to aqueous NaCl at 25°C taken as a standard.
157 citations
TL;DR: The Picker flow calorimeter was used to determine the molar heat capacities of ethanol, n-propanol, benzene, ethylbenzene, cyclohexane, and tetrachloromethane at 298.15 K relative to n -heptane (N.B.S. standard sample) as discussed by the authors.
122 citations
TL;DR: In this paper, a mathematical model is presented for the calculation of the two dimensional flow and temperature fields in an inductively coupled plasma, based on the solution of the correcponding momentum, continuity and energy equations simultaneously with the one dimensional magnetic and electric field equations.
Abstract: A mathematical model is presented for the calculation of the two dimensional flow and temperature fields in an inductively coupled plasma. The model is based on the solution of the correcponding momentum, continuity and energy equations simultaneously with the one dimensional magnetic and electric field equations. Results were obtained for a plasma torch, 1.4 cm. radius, and 18.2 cm. long with a four turn induction coil, 2.4 cm. radius and 3 cm. The oscillator frequency was 3 MHz. Calculations were made for argon under atmospheric pressure at a power level of 3.77 KW with different plasma gas flow rate over the range of 5 to 25 gm/min. The results clearly demonstrate the existence of the magnetic pumping effect which is responsible for the formation of two recirculation eddies, one at each end of the coil. As the plasma gas flow rate is increased, the downstream eddy is swept away leaving only one recirculation eddy on the upstream side of the fire-ball. This eddy produces a back flow of the order of 20 m/s. Increasing the plasma gas flow rate is also observed to cause a substantial reduction of the heat flux to the plasma confining tube.
87 citations
72 citations
Patent•
28 Sep 1976TL;DR: In this paper, a train of articulated segments whose angular displacement is controlled by a series of magnetic clutches is used as an endoscope for inspecting a hollow portion in a living body.
Abstract: The disclosure herein describes a carrier adapted to receive observation and/or manipulation instruments; the carrier consists of a train of articulated segments whose angular displacement is controlled by a series of magnetic clutches; the leading segment is guided from the carrier's proximal end, and the guide angle is repeated automatically at the articulations of all following segments; a central channel in each segment accepts instruments for observation and manipulation. One advantageous application of the present carrier is its use as an endoscope for inspecting a hollow portion in a living body.
68 citations
TL;DR: It is concluded that in the human colon perfused in situ there is a gradient of motility preventing aboral propulsion, and during perfusion, liquids are trapped in the right colon.
68 citations
01 Jan 1976
TL;DR: In this paper, the authors measured the densities and volumetric specific heats of the cationic surfactant n-nonyltrimethylammonium bromide (NTABr) in water and in urea-water mixtures in the temperature range 5 to 50°C using a flow digital densimeter and a flow microcalorimeter.
Abstract: The densities and volumetric specific heats of the cationic surfactant n-nonyltrimethylammonium bromide (NTABr) have been measured in water and in urea-water mixtures in the temperature range 5 to 50°C, using, respectively, a flow digital densimeter and a flow microcalorimeter. From the experimental data, the apparent molal volumes ϕv and heat capacities ϕc have been determined. The apparent molal volume at infinite dilution ϕv0 in water increases with temperature and the transfer function ΔVNTABr0 (H2O → 3 M urea) is positive and decreases with temperature. The apparent molal heat capacity at infinite dilution ϕC0 in water passes through a maximum when plotted against temperature, while the transfer function ΔVNTABr0 (H2O → 3 M urea) is negative and tends to zero at low temperature. The concentration dependence of ϕV and ϕC in the premicellar region varies significantly with temperature and with the presence of urea and is consistent with the behavior of typical hydrophobic solutes. The absolute values of the change in volume and heat capacity during micellization, ΔVm and ΔCm, decrease with temperature and in the presence of urea and can be used to predict the temperature and pressure dependence of the CMC.
54 citations
TL;DR: The growth of Chinese hamster somatic cells was inhibited by 0.2 mg/cc of 2-deoxygalactose, suggesting resistance resulted from the possible absence of galactokinase synthesis or from a structural mutation, possible a missence mutation, in the galactogenic gene.
Abstract: The growth of Chinese hamster somatic cells was inhibited by 0.2 mg/cc of 2-deoxygalactose. Mutants partially or fully resistant to 2-deoxygalactose were isolated in a single-step or two-step selection. Some of them did not grow as well as the wild type; one of them which lacked galactokinase (EC.2.7.1.6) activity did not grow at all in galactose medium. The galactokinase kinetic properties (Vmax & Kmax) of the other mutants and of the wild type were different. Therefore resistance resulted either from the possible absence of galactokinase synthesis or from a structural mutation, possibly a missence mutation, in the galactokinase gene.—A simple diagnostic test for juvenile cataract is proposed.
51 citations
TL;DR: In this article, the frequencies of acoustic phonons have been measured in the layer-type substance TiSe2 by neutron inelastic scattering techniques, and as expected from the two-dimensional nature of such substances the in-plane longitudinal sound velocity is much larger than that perpendicular to the layer.
TL;DR: A significant release of prostaglandin E2 in the venous blood during the course of vesical distension could be demonstrated and the functional significance, mechanisms of release and mode of action of these highly active lipids are discussed.
TL;DR: The freezing point depression of the ternary systems water-alkali halides alcohols was measured with a precision Advanced Instrument osmometer as discussed by the authors, and the salting-out constants were calculated.
Abstract: The freezing-point depression of the ternary systems water-alkali halidesalcohols was measured with a precision Advanced Instrument osmometer. From the corresponding freezing-point depression of the binary systems the salting-out constantsk
s were calculated. The effect of ionic size was investigated withtert-butanol, and the effect of alcohol chain length with NaCl. The trends ofk
s with ionic size are similar to those of typical nonelectrolyte systems, andk
s varies linearly with the volumes of the normal alcohols.
TL;DR: For all dyads, both amount and depth of disclosure were significantly greater for free-choice topics where field-dependent pairs showed a significantly higher amount of disclosure as well as greater depth than field independents.
Abstract: 16 dyads composed of subjects matched for cognitive style (8 field-dependent, 8 field-independent male medical students) discussed 5 topics—three “required” followed by 2 “free-choice.” Half of the dyads (4 field-dependent, 4 field-independent) had consumed .80 ml 94% alcohol per kg body weight; the other half received only a mixer (orange juice) with 4 ml alcohol poured on top. Amount of self-disclosure (total time spent in discussion) was not affected by alcohol ingestion; over-all depth of disclosure as rated by two judges, however, was significantly greater in the alcohol condition. For all dyads, both amount and depth of disclosure were significantly greater for free-choice topics where field-dependent pairs showed a significantly higher amount of disclosure as well as greater depth than field independents.
TL;DR: It is concluded that the neurons in different nuclei synthesize LH-RH and transport it to the ME portal system, primarily through the nerve fibers and secondarily by the ventricular route, and thus controls the gonadotropin secretion.
Abstract: Immunohistochemical localization of luteinizing hormone-releasing hormone (LH-RH), during different phases of the estrus cycle, in the preoptic, suprachiasmatic and arcuate nuclei, and in the OVLT of rats, with special emphasis on the ependymal cells, was studied by light, fluorescent and electron microscopy, by using rabbit anti serum to synthetic LH-RH. The LH-RH neurons in the above mentioned areas, were very active during late diestrus and early proestrus phases. Specialized ependymal cells bordering the 3rd ventricle also showed varied LH-RH positive reaction during different phases of the estrus cycle. Immunofluorescent studies showed cyclic variations in the LH-RH material in the CSF of the preoptic and infundibular recesses, as well as in the 3rd ventricle near OVLT, in that, it was maximum during late diestrus and early proestrus phases. Immediately after this, the LH-RH material started reducing in these areas, and had almost vanished by the time late proestrus was reached. We have also observed that during the proestrus phase, as the LH-RH material started declining in the CSF, it had started building up in the specialized ependyma. Estrus, metaestrus and early diestrus phases showed very weak immunofluorescent LH-RH material in the lumen of the infundibular recess and in the specialized ependyma. Our immuno-electron microscopic observations showed pleomorphic LH-RH granules in the specialized ependyma during late diestrus and proestrus phases. All these observations lead us to believe that LH-RH is not synthesized in the ependymal cells, but is phagocytosed from the CSF of the 3rd ventricle by the specialized ependyma, which transports it to the ME portal system. In males, the fluorescent LH-RH material did not show any noticeable changes. With the present and previous work, it is concluded that the neurons in different nuclei synthesize LH-RH and transport it to the ME portal system, primarily through the nerve fibers and secondarily by the ventricular route. It is also sugested that the ependymal transport of LH-RH to the ME portal system is cyclic and thus controls the gonadotropin secretion.
TL;DR: In this paper, the equilibration and replacement reactions between H2 and D2 have been studied, at 294 K and at pressures comprised between 10−6 and 10−2 Torr, on defined surfaces of iron.
TL;DR: It is concluded that the stomach is the most active site of production of bowel sounds, followed by the colon and then the small bowel, that sounds differ in different sites, and that all this is influenced by viscus content.
TL;DR: In this article, the infrared spectrum of the ν 3 band of 14 NO 2 has been recorded with a resolution and a frequency accuracy much improved over the previous investigations, and the K - and N -line assignments have been greatly extended and a more accurate set of spectroscopic constants derived.
TL;DR: In this article, a search of the chemical literature revealed that the known procedures for the preparation of this compound do not give good yields, and it became necessary to have pure 2-carbomethoxycyclohexanone.
TL;DR: In this article, the preparation and spectroscopic characterization of perylene-TCNQ(3:1) is presented, and the results indicate that the perylene and TCNQ interaction is stronger in the 3:1 complex than in its 1:1 form.
TL;DR: Age-sex specific reference values and frequency distributions are presented for this index as well as for protein and calcium calculated by both parametric and nonparametric methods.
Abstract: We measured serum protein and calcium concentrations in 2340 individuals between 10 and 96 years of age from 900 families chosen by probability methods to give a representative population. These values were used to calculate an index, based on a regression analysis of serum protein on calcium, which was then treated as a new variable. Age-sex specific reference values and frequency distributions are presented for this index as well as for protein and calcium calculated by both parametric and nonparametric methods.
TL;DR: Patients with classical Friedreich's ataxia underwent cardiac catheterization with recordings of retrograde cardiac pressures, measurements of cardiac output and calculation of the left ventricular volumes and mass, finding that severely handicapped patients may present a diffusely hypertrophied and hypokineticleft ventricular myocardium.
Abstract: Thirteen patients with classical Friedreich's ataxia underwent cardiac catheterization with recordings of retrograde cardiac pressures, measurements of cardiac output and calculation of the left ventricular volumes and mass. The cardiomyopathy in Friedreich's ataxia falls into the hypertrophic group of cardiomyopathies with decreased compliance of ventricular myocardium, varying degrees of concentric and asymmetric hypertrophy and outflow tract obstruction. Although there is no clear parallel between the degree of abnormal hemodynamic findings and the degree of neurological impairment, severely handicapped patients may present a diffusely hypertrophied and hypokinetic left ventricular myocardium.
TL;DR: In this article, the effects of isothermal annealing on the hardness, the tensile properties and the microstructure of cold-worked Zr/sub 3/Al (L1/sub 2/ type) was studied.
Abstract: A study has been made of the effects of isothermal annealing on the hardness, the tensile properties and the microstructure of cold-worked Zr/sub 3/Al (L1/sub 2/ type). For material rolled to a true strain of 0.29, complete recrystallization accounts for a recovery of hardness of 65 to 70 percent and for a reduction in yield strength of about 50 percent, independent of temperature. Grain growth accounts for further changes. The yield strength sigma/sub y/ obeys the relationship sigma/sub y/ = sigma/sub 0/ + k/sub y/(anti d)/sup -1/2/ where sigma/sub 0/ and k/sub y/ are constants and anti d is the average grain diameter of the fully recrystallized matrix. Recrystallization and grain growth kinetics, respectively, satisfy the expressions f = 1 -- exp(--kt/sup n/) and anti d = Kt/sup m/ where f is the fraction recrystallized, t is time, k and K are parameters which increase with increasing temperature and m and n are constants. 13 figures (auth)
TL;DR: The data suggest that the pancreatic cholinergic receptor acts as a Ca2-ionophore and that extracellular Ca2+ is utilized in the synthesis of cyclic GMP.
TL;DR: The results suggest that replication originates at the center of the molecule and proceeds in the direction of both ends.
Patent•
10 May 1976TL;DR: In this paper, a method and a system for speech detection on PCM multiplexed voice channels is described, where a decision is reached every M samples regarding the channel activity.
Abstract: The disclosure herein describes a method and a system for speech detection on PCM multiplexed voice channels; for each channel, a decision is reached every M samples regarding the channel activity; in addition, the nature of speech is detected as: voiced (compact or non-compact) or unvoiced (fricative or non-fricative) when the channel is active; pure silence, white noise or echo when the channel is inactive. The decision is based on the joint value of the amplitude, zero crossing of the signal and zero crossing of the signal derivative.
TL;DR: Calcium‐stimulated ATPase activity was studied in a plasma membrane rich fraction of rat pancreas homogenate to study the role of Na6(CO3)2, Na2SO4, and Na2CO3 in the biosynthesis of ATP and its role in cell death.
Abstract: SUMMARY
1. Calcium-stimulated ATPase activity was studied in a plasma membrane rich fraction of rat pancreas homogenate.
2. The enzyme is stimulated to the same maximum rate of ATP hydrolysis by either calcium or magnesium, but the apparent requirement for calcium is five-fold lower than for magnesium.
3. Maximum hydrolytic activity of the enzyme is not increased when additional magnesium is added to the optimal amount of calcium.
4. The enzyme does not require Na+ or K+ for its activation by Ca2+ and is not inhibited by ouabain or 2,4-dinitrophenol.
5. Pancreozymin, in concentrations which evoke secretion of zymogen protein, inhibits the calcium-stimulated ATPase.
6. Carbachol and dibutyryl cyclic AMP, in concentrations which increase the release of digestive proteins, do not alter the activity of the calcium-stimulated enzyme.
7. It is suggested that the plasma membrane calcium-activated enzyme, is not involved in the active calcium extrusion, previously reported to occur with use of the various pancreatic secretagogues tested.
TL;DR: It is suggested that the toxicity of alantolactone is not due to the presence of the alpha-methylene group conjugated to the carbonyl function of the gamma-lactone system.
TL;DR: In this article, an analytic expression for resonant photon scattering by a molecular electronic continuum was obtained using the model of linear potentials, and it was shown that all relevant cross-sections reduce to the linear potential Green's function.
Abstract: An analytic expression is obtained for resonant photon scattering by a molecular electronic continuum. Using the model of linear potentials, it is shown that all relevant cross-sections reduce to the linear potential Green's function. Rayleigh and Raman scattering are examined as a function of incident photon energy and also as a function of vibrational excitation.
TL;DR: In this article, a simple equation has been derived relating the temperature dependence of activity functions with excess enthalpies and excess heat capacities using experimentally determined parameters at 298.15°K, and the predicted functions agree with the measured values within the uncertainty of the activity data.
Abstract: A simple equation has been derived relating the temperature dependence of activity functions with excess enthalpies and excess heat capacities. Using experimentally determined parameters at 298.15°K, it is possible to predict osmotic coefficients and mean activity coefficients of alkali halides in water up to 1 m from 273°K to about 350°K. In general, the predicted functions agree with the measured values within the uncertainty of the activity data. An equation is also given for the pressure dependence of the excess free energies, but it was not possible to check the limitation of this equation due to lack of activity data at various pressures.