Showing papers by "University of Alberta published in 1973"
TL;DR: In this article, a pilot scale binary distillation column operated under the control of an IBM 1800 digital computer has been studied for disturbances in feed flow rate, and two alternate control systems, namely a noninteracting control system and a ratio control system were evaluated.
644 citations
TL;DR: In this paper, several possible solutions to the problem of creeping flow relative to an isolated permeable sphere are discussed and compared quantitatively, and the most satisfactory solutions are based upon Brinkman's extension of Darcy's Law.
334 citations
TL;DR: In this article, a 21-day laboratory experiment by a culture of four aerobic bacteria isolated from an oil-contaminated soil was conducted, and the progress of the experiment was measured by the changes induced in the chemical composition of the oil fraction boiling above 270°C, similar to the variations in composition found in the MC5 oils of Saskatchewan, Canada.
269 citations
TL;DR: Goodness of Fit in Generalized Least Squares Estimation The American Statistician: Vol 27, No 3, pp 106-108 as discussed by the authors, The American Statistical Journal
Abstract: (1973) Goodness of Fit in Generalized Least Squares Estimation The American Statistician: Vol 27, No 3, pp 106-108
239 citations
TL;DR: No discontinuities were observed during the continuous titration with NADH of the lactate dehydrogenases of ox muscle, pig heart, pig muscle, rabbit muscle, dogfish muscle or lobster tail muscle and a single macroscopic dissociation constant was sufficient to describe NAD(+) binding at the concentrations tested.
Abstract: 1. No discontinuities were observed during the continuous titration with NADH of the lactate dehydrogenases of ox muscle, pig heart, pig muscle, rabbit muscle, dogfish muscle or lobster tail muscle. The binding was monitored by either the enhanced fluorescence of bound NADH or the quenched fluorescence of the protein. A single macroscopic dissociation constant, independent of protein concentration, could be used to describe the binding to each enzyme, and there was no need to postulate the involvement of molecular relaxation effects. 2. The affinity for NADH decreases only threefold between pH6 and 8.5. Above pH9 the affinity decreases more rapidly with increasing pH and is consistent with a group of about pK9.5 facilitating binding. Muscle enzymes bind NADH more weakly than does the pig heart enzyme. 3. Increasing temperature and increasing concentrations of ethanol both weaken NADH binding. 4. NADH binding is weakened by increasing ionic strength. NaCl is more effective than similar ionic strengths derived from sodium phosphate or sodium pyrophosphate. 5. Commercial NAD(+) quenches the protein fluorescence of the heart and muscle isoenzymes. Highly purified NAD(+) does not, and its binding was monitored by competition for the NADH-binding sites. A single macroscopic dissociation constant is sufficient to describe NAD(+) binding at the concentrations tested. The dissociation constant is about 0.3mm and is not sensitive to changed ionic strength and to changed pH in the range pH6-8.5.
227 citations
TL;DR: In this paper, the strong subadditivity of quantum-mechanical entropy and the Wigner-Yanase-Dyson conjecture was proved for the first time, and they proved that quantum entropy is strong under the assumption
Abstract: We have proved the strong subadditivity of quantum-mechanical entropy and the Wigner-Yanase-Dyson conjecture.
222 citations
TL;DR: In this article, a geometric model for an homogeneous and isotropic porous medium composed of spherical particles is proposed, which requires a minimum of geometric simplifications and lends itself to the study of hydrodynamic as well as diffusive flow processes.
Abstract: A geometric model for an homogeneous and isotropic porous medium composed of spherical particles is proposed. This model requires a minimum of geometric simplifications and lends itself to the study of hydrodynamic as well as diffusive flow processes, permitting in each application a mathematically rigorous and fully predictive analysis leading to mathematical representations of the respective flow parameters.
This particular investigation seeks to evaluate, and to provide physical insight into, diffusive flow processes occurring within an homogeneous swarm of spherical particles.
201 citations
TL;DR: This paper is a report of direct evidence of frequent multiple male parentage within single litters in natural populations of deer mice (Peromyscus maniculatus), suggesting that in these populations the social units must be large enough to include two, or probably more, breeding males.
Abstract: The possibility that populations of' small mammals are subdivided into highly isolated demes of small size has been a point of contention in the literature. Much of the evidence supporting this demic structure concept has been accumulated by studies on house mice (Mus musculus) (e.g., Selander, 1970; Anderson, 1964, 1965). Anderson (1970) has used this evidence as support for a model of local population subdivision involving highly complex spatial and temporal structuring, which he suggests is likely to be characteristic of rodent populations in general. This paper is a report of direct evidence of frequent multiple male parentage within single litters in natural populations of deer mice (Peromyscus maniculatus). Thus in these populations the social units (if, in fact, they exist) must be large enough to include two, or probably more, breeding males. This is quite unlike the social structure described by Brown (1969) in Apodernus populations and Selander (1970) in Mus populations, in which one dominant male is thought to do most, if not all, of the breeding.
198 citations
186 citations
TL;DR: In this article, the authors present expressions for incremental matrices that remain valid in the equilibrium equations and in the linear incremental equilibrium equations for truss elements, in-plane bending elements, membrane elements, and plate flexural elements.
Abstract: A common technique in geometrically nonlinear finite element analysis is to express the total potential in terms of Lagrangian displacement coordinates, differentiate the potential to obtain the equilibrium equations, and form the differentials of the equilibrium equations to obtain linear incremental equilibrium equations. The geometric nonlinearities in the strain-displacement equations give rise to incremental matrices in the preceding equations. The form of these matrices is not unique in the expression for the total potential. The paper presents expressions for incremental matrices that remain valid in the equilibrium equations and in the linear incremental equilibrium equations. The construction of such matrices is illustrated for truss elements, in-plane bending elements, membrane elements, and plate flexural elements. An examination of some of the recent literature indicates that some investigators have used inappropriate forms of these incremental matrices.
180 citations
TL;DR: The fatty acid composition and cholesterol content of the membrane lipids of Acholeplasma laidlawii B were systematically altered and the rates at which glycerol and erythritol passively diffuse into intact cells and into liposomes prepared from the total membrane lipid were measured.
TL;DR: In this article, the authors present a model for plane tilturbulent impinginging jets, which they call PLANE TURBULENT IMPINGING JETS.
Abstract: (1973). PLANE TURBULENT IMPINGING JETS. Journal of Hydraulic Research: Vol. 11, No. 1, pp. 29-59.
TL;DR: Evidence is provided that the efflux of [3H]‐noradrenaline from adrenergic nerves occurs by a cocaine‐sensitive, carrier‐mediated process, which is compatible with, but not conclusive proof for, the Na+‐gradient hypothesis.
Abstract: 1. The mechanism of efflux of (-)-[(3)H]-noradrenaline was examined in rabbit atria, which were pretreated with reserpine and pargyline.2. Between 40 and 100 min, efflux occurred predominantly from a single intraneuronal compartment.3. Efflux was rapidy increased by (-)- and (+)-noradrenaline, tyramine and (+/-)-metaraminol, but not by (+/-)-isopropylnoradrenaline or (+/-)-normetanephrine. The increase in efflux produced by (-)-noradrenaline was inhibited by cocaine and desipramine but not by lidocaine.4. Spontaneous effluxes, and those accelerated by (-)-noradrenaline, were temperature-sensitive.5. Efflux was increased by ouabain, omission of K(+), metabolic inhibition and lowering of the external Na(+) concentration. These effects were significantly reduced by cocaine and desipramine but not by lidocaine.6. These findings provide evidence that the efflux of [(3)H]-noradrenaline from adrenergic nerves occurs by a cocaine-sensitive, carrier-mediated process. The characteristics of the efflux process are compatible with, but not conclusive proof for, the Na(+)-gradient hypothesis.
TL;DR: In this article, a brief description of the dielectric dispersion and relaxation as a function of frequency and temperature is given, and important aspects of the behavior of dielectrics mixtures with respect to frequency, temperature, and composition are summarized and referenced.
Abstract: A brief description is given of the dielectric dispersion and relaxation as a function of frequency and temperature. Important aspects of the behavior of dielectric mixtures with respect to frequency, temperature, and composition are summarized and referenced. The dielectric constant and loss factor of many materials are tabulated as functions of frequency, temperature, moisture content, and composition. Materials are classified as Agricultural, Biological, Foods, Forest Products, Leather, Rubber, and Soils and Minerals. The data were collected for use in the application of microwaves to non-communication uses.
TL;DR: In this paper, the authors extended the classical Smith Predictor method for single variable systems to a class of linear multivariable systems, and proposed a multivariable Smith predictor for both continuous-time and discrete-time systems.
Abstract: The classical Smith Predictor method for single variable systems is extended to a class of linear multivariable systems. Derivations of the multivariable Smith Predictor are presented for both continuous-time and discrete-time systems which contain time delays in the control variables and/or output variables. As in the classical method, use of the multivariable Smith Predictor eliminates the time delays from the characteristic equation of the closed-loop system
TL;DR: In patients with obstructive lung disease, diazepam produced insignificant changes in heart rate, diastolic blood pressure, and total peripheral resistance, and in patients with normal pulmonary function, the only significant differences in the effects ofdiazepam on cardiopulmonary function were in diastolics blood pressure and left ventricular stroke work, which were more affected in the control subjects than in the patients.
Abstract: Eighteen patients with appreciable obstructive lung disease and 18 patients without measurable mechanical lung impairment were given intravenous diazepam to permit endoscopy. Doses of diazepam required for comparable level of anesthesia were used. There was an increase in the heart rate, and there were decreases in the blood pressure, stroke volume, left ventricular stroke work, and cardiac output in patients with normal pulmonary function. Total peripheral resistance was elevated after 15 minutes. In patients with obstructive lung disease, diazepam produced insignificant changes in heart rate, diastolic blood pressure, and total peripheral resistance. Left ventricular stroke work, stroke volume, and systolic blood pressure were markedly reduced. There was a depression in alveolar ventilation, associated with an increase ill the arterial carbon dioxide tension and a decrease in pH. The only significant differences in the effects of diazepam on cardiopulmonary function were in diastolic blood pressure and left ventricular stroke work, which were more affected in the control subjects than in the patients. O2 saturation was affected more in the patients than in the control subjects.
TL;DR: The fast Fourier transform is employed in the most efficient measurement of the Wiener kernels of a non-linear system so far discovered.
Abstract: A new method is presented for the measurement of the Wiener kernels of a non-linear system. The method uses the complex exponential functions as a set of orthogonal functions with which to expand the kernels. The fast Fourier transform is then employed in the most efficient measurement of the kernels so far discovered.
TL;DR: In this article, the viscosity of basic andesite and olivine melanephelinite has been determined at one atmosphere and at high water pressures and their relationship to melt chemistry has been investigated.
Abstract: THE viscosity of magmas is an important parameter in problems concerning the generation and emplacement of magmatic rocks1,2, but no experimental data exist on hydrous basaltic melts. Here I describe laboratory determinations of the viscosity of some basic melts at one atmosphere and at high water pressures and their relationship to melt chemistry3. Basic rocks ranging in composition from basic andesite to olivine melanephelinite had viscosities between 4,000–100 (±5%) poise at temperatures near the liquidus (1,200° C) at one atmosphere. At higher temperatures (1,400° C) viscosities ranged from 260–15 (±5%) poise (Fig. 1). These results are in fair agreement with previous work using a concentric-cylinder method4–9. I also found, in agreement with previous work9,10, that the redox state of basic melts had only a marginal effect on viscosities.
TL;DR: The growth response induced by testosterone was considerably slower than that by 5α-dihydrotestosterone, indicating that the former is a less potent androgen, and adenosine 3′,5′-monophosphate does not appear to be involved in the effect of androgens on cell proliferation.
TL;DR: This study confirms that a system of bidirectionally coupled relaxation oscillators can account for more characteristics of the gastrointestinal electrical control activity than a relaxation oscillator model with only forward coupling or a cable model.
Abstract: SARNA, S. K., AND E. E. DANIEL. Electrical stimulation of gastric electrical control activity. Am. J. Physiol. 225(l): 125-131. 1973.Gastric electrical control activity in anesthetized dogs was stimulated by voltage pulses of 100 msec duration and lto 25-v amplitude. The gastric control waves could be entrained from any site in the electrically active region on the anterior and posterior sides. The maximum frequency at which the gastric control waves could be entrained by the electronic pacemaker varied from dog to dog. Mean maximum driven frequency (MDF) was 6.98 cycles/ min. The strength of stimulus required to entrain gastric control waves increased for larger differences between the driven frequency and the natural frequency of gastric control waves. Total phase lag between control waves in the corpus and in the antrum increased when the control waves were driven at a frequency higher than their natural frequency. The stomach was divided into three segments by circumferential cuts in muscle layers. The proximal segment that contained the highest intrinsic frequency oscillator had the least MDF (mean 6.92 cycles/min). The mean MDF increased distally (middle segment mean MDF, 7.55 cycles/ min; distal segment mean MDF, 7.74 cycles/min). Intravenous injection of physostigmine (20-60 pg/kg) decreased the MDF of the distal segment, whereas intravenous injection of atropine (5-20 pg/kg) increased its MDF. These drugs, in particular physostigmine, had a small effect on the MDF of the middle segment and very little or no effect on the MDF of the proximal segment. This study confirms that a system of bidirectionally coupled relaxation oscillators can account for more characteristics of the gastrointestinal electrical control activity than a relaxation oscillator model with only forward coupling or a cable model. The study also shows that nerves could have an important role to play in determining some of the characteristics of gastric relaxation oscillators, such as their ability to be driven by electronic pacemakers.
TL;DR: This method yielded fairly pure subcellular fractions: namely, plasma membrane, sarcoplasmic reticulum and mitochondria during a short period of time (4 h) without extraction by salts or other drastic procedures.
TL;DR: In this article, the authors reviewed some selected facets of the use of the projection operator technique in Hartree-Fock type theories and explained the concept of separability that gives an idea of separating the electrons of an atomic or molecular system into sets describing relevant regions (or groups) and sets describing unimportant regions.
Abstract: Publisher Summary This chapter reviews some selected facets of the use of the projection operator technique in Hartree–Fock type theories. In the approximate treatment of many-electron systems, one often applies the variational procedure where the wave function and accordingly the energy of the system are expressed as functionals of electron orbital functions. The virtual orbital energy is usually positive, suggesting that they correspond to a state in the continuum. With the use of the modified Hartree-Fock operator, iterative self-consistent field (SCF) calculation is not required. If the solution to the usual Hartree-Fock equations is known, all that is required is the construction of the modified operator. The new orbital energy has a very simple physical interpretation and is appropriate for use in discussions of excitation energy. This is a definite conceptual improvement as it is difficult to visualize the relationship between the excitation energy and the old orbital energy. The chapter explains the concept of separability that gives an idea of separating the electrons of an atomic or molecular system into sets describing relevant regions (or groups) and sets describing unimportant regions.
TL;DR: The antennular activities of the hermit crab were studied with the aid of motion pictures taken at speeds of 50, 200 and 400 frames/sec and it is proposed that this splaying might facilitate the chemoreceptive process by circulating water around the aesthetasc hairs.
Abstract: 1. The antennular activities of the hermit crab, Pagurus alaskensis , were studied with the aid of motion pictures taken at speeds of 50, 200 and 400 frames/sec. 2. Most movements of the antennule represent one of four types of antennular activity: flicking, rotation, wiping and withdrawal. These activities are described in detail. 3. Water resistance forces contribute to the timing and duration of some antennular movements. 4. Flicking occurs non-rhythmically and flicks of the left and right antennules and never synchronized. The factors which influence the mean frequency of flicking are discussed. 5. The timing of joint movements during a flick, and the morphology of the outer flagellum and the aesthetasc hairs, appear to be adapted to facilitate splaying of the aesthetascs. It is proposed that this splaying might facilitate the chemoreceptive process by circulating water around the aesthetasc hairs. 6. During antennular wiping the endopodites of the 3rd maxillipeds are used to remove debris caught amongst the aesthetasc hairs. Light mechanical stimulation of the aesthetascs is sufficient to elicit wiping. 7. The antennules are reflexively withdrawn from certain stimuli either by extension or by slow or fast flexion. The functional significance of the withdrawal reflexes are discussed in relation to the stimuli involved and the form of the reflexes. 8. Continued application of certain stimuli to the antennules, eyestalks, antennae or body results in tonic flexion withdrawal which involves postural modifications of the antennules, eyestalks and antennae.
TL;DR: In the absence of the adenosine deaminase inhibitor, deamination was the major route of deoxyadenosine metabolism in mouse brain, heart, kidney, and liver and in mouse and human erythrocytes, whereas phosphorylation and deamination were nearly equivalent in sheep ery Throcytes.
TL;DR: Microinjection of radioactive tyrosine, dopa, and dopamine into mature larvae of Drosophila revealed that the sclerotization pathway is similar but not identical to that in Calliphora.
TL;DR: A successful restoration must be considered from the point of view of contour, occlusal anatomy, marginal adaptation, proximal contacts, esthetics, and function.
Abstract: A successful restoration must be considered from the point of view of contour, occlusal anatomy, marginal adaptation, proximal contacts, esthetics, and function. The tooth must be looked upon as a harmonious part of the whole dentition. Al of the above factors are equally important in the success of any dental restoration. The correct external morphology of all restorations is important, but this must be borne in mind particularly during dental procedures involving full-coverage restorations, It is the complete artificial crown that most taxes our ability to recreate the original anatomy. For this reason, the facial and lingual contours of full-coverage restorations and their relationships to periodontal health will be discussed from all aspects. It has been frequently stated that the purpose of the facial and lingual enamel bulge of human teeth is to protect the free gingival margin from the traumatic effects of mastication.l-+ It has been supposed that this bulge deflects food over the gingival crevice and onto the keratinized gingival tissues, which are better able to withstand the impact of the food. This theory has long been supported and has not been seriously challenged. Microbial plaque, especially that which is close to or nearly in contact with the free gingival margin, is the principal etiologic factor in both caries and periodontal disease.5-8 Clinically, it is evident that plaque retention is greatest in regions that are relatively inaccessible to routine oral-hygiene measures. These regions are the interproximal and the facial and lingual cervical areas of the teeth. To maintain these vulnerable regions in a plaque-free state, the close relationship between the morphologic characteristics of the clinical crown and the degree of accessibility must be realized and remembered.
TL;DR: In this article, the effects of flexible boundaries on the normal modes and natural frequencies of low frequency sound transmission in cars are considered. But the authors focus on the case of a single enclosure with a flexible boundary and structural coupling between two enclosures allowing direct and flanking sound.