Showing papers by "University of New Brunswick published in 1979"

Estimating Average Velocity in Gravel-Bed Rivers

Abstract: Basic data from 67 gravel-bed river reaches in Alberta, Canada, are used to test widely adopted equations for computing average velocity in natural channels for the case of relatively high in-bank flows. Relations proposed by Cowan, Strickler, and Limerinos to estimate Manning's n are tested. The equations of the form presented by Keulegan and Lacey for computing average velocity are also evaluated. Computations based on these methods indicate that the Limerinos-Manning equation is the most acceptable approach for estimating average velocity in gravel-bed river reaches. The Lacey equation provides satisfactory results if no bed material data are available. The basic data are also used to develop best-fit relationships for computing Manning's n and the friction factor for gravel-bed river reaches. Particular emphasis is placed on an evaluation of the significance of bed material data in equations used to compute average velocity in gravel-bed river reaches.

Transverse NMR relaxation of water in wood

Abstract: The transverse NMR relaxation times of hydrogen nuclei of water absorbed in white spruce sapwood [Picea glauca (Meunch) Voss] were measured for moisture contents in the range from 5 to 176%. The spin echo amplitudes resulting from the Carr–Purcell sequence decay nonexponentially suggesting the possibility of at least two different relaxation times for water in wood. A simplified structural model of the wood–water mixture is used to estimate the rates of chemical exchange at room temperature of hydrogen nuclei between various sites in the system. The high-resolution NMR line shape is discussed briefly in terms of this proposed model.

Least squares collocation and regularization

Abstract: Certain geodetic problems such as the downward continuation of gravity information from satellite or aerial altitudes to the surface of the earth or the inverse Stokes problem are improperly posed in the sense that the best approximate solution does not continuously depend on the given observations. In order to obtain a stable solution a technique of regularization is discussed which can be shown to be identical to the method of least squares collocation. The characteristic features of regularization are analysed transferring the problem through a singular value decomposition into the spectral domain which allows an easy interpretation as a special method of filtering. In practical applications the stability depends not only on the observational errors including the computer round-off but in the same way on the number of observations and their distribution. The regularized solution should achieve a proper trade-off between sufficient smoothness and highest possible resolution with a limit defined through the internal accuracy of the computer.

A chromatographic study of the diffusion of N2,CH4 and binary CH4‐N2 mixtures in 4A molecular sieve

Abstract: The kinetics and equilibrium of sorption of CH4, N2 and binary CH4–N2 mixtures in 4A molecular sieve have been studied by a chromatographic method The equilibrium isotherms and zeolitic diffusivities, determined with a helium carrier, show good agreement with previous gravimetric data Counter-diffusion in the binary adsorbed phase was investigated using a mixed carrier gas and following the response to a small step change from a previously established equilibrium position The dynamic response curves for the binary system could be satisfactorily interpreted on the assumption that both components in the mixture diffuse independently with the same intrinsic mobilities as for the single component systems On a etudie, en employant une methode chromatographique, la cinetique et l'equilibre de sorption de CH4 et N2 et de melanges binaires de ces deux gaz, sur un tamis moleculaire 4A Les isothermes d'equilibre et les diffusivites dans les zeolithes, qu'on a determinees avec de l'helium comme gaz porteur, ont bien concorde avec les resultats gravimetriques anterieurs On a etudie la contre-diffusion dans la phase binaire adsorbee, en employant un gaz porteur mixte et en suivant la reponse a une demande echelon de faible amplitude par rapport a une position d'equilibre etablie anterieurement On a pu interpreter d'une maniere satisfaisante les courbes de reponse dynamiques correspondant au systeme binaire, en supposant que les deux composants dud melange diffusent independamment avec les měmes mobilites intrinseques que dans le systeme a un seul composant

Polymorphism for breeding colors in gasterosteus aculeatus. i. their genetics and geographic distribution.

Abstract: Threespine sticklebacks (Gasterosteus aculeatus) usually breed in large colonies during the spring and summer in the shallows of lakes and streams. Males build nests, defend territories, court females, and care for the offspring. At this time the males are a bright red on the anterior ventral region, and it is not surprising that most populations are monomorphic for this reproductive coloration as it is subject to sexual selection by females and also functions as a threat display (Pelkwijk and Tinbergen, 1937; McPhail, 1969; Semler, 1971). The function of red as a threat display allows males in the colonies to obtain and hold nesting sites more successfully, and reduces interference with parental care of the offspring (Pelkwijk and Tinbergen, 1937; Hagen and Moodie, in prep.). Egg predation by males and females in nesting colonies can be extensive (Semler, 1971), so the red display probably decreases such predation. In some populations, however, the frequency of red males is as low as 14% (Semler, 1971; Moodie, 1972), suggesting strong counter-selection. These populations are heavily preyed upon by rainbow and cutthroat trout (Moodie, 1972; Hagen and Gilbertson, 1973). Moodie and Semler suggested that selective predation on the red males is responsible for their low frequency. Indeed Moodie (1972) showed that rainbow trout do prey selectively on red males and the selective predation is apparently strong. McPhail (1969) studied sticklebacks on the Olympic Peninsula of Washington where the breeding males are deep black. These populations are the subject of this paper. Unlike the populations studied by Moodie (1972) and Semler (1971), which are polymorphic for breeding colors, these populations are monomorphic except where they are adjacent to populations of red males. McPhail noted that the distribution of black sticklebacks coincides with that of Novumbra hubbsi, a small fish about the size of sticklebacks that is endemic to a few drainages on the Olympic Peninsula. He also showed that: (1) the red and black reproductive colors of males are genetically controlled, (2) Novumbra preys less successfully on the fry of black males with which it coexists than on the fry of red males, and (3) Novumbra is differentially attracted to reds when given a choice between red and black males at their nests. Thus McPhail argued that where sticklebacks coexist with Novumbra, the red males are at a selective disadvantage as their offspring will suffer greater predation at the nest. The objectives of this paper are to give further data on the genetics of these morphs and quantitative data on the relative frequencies of red and black morphs as correlated with the distribution of Novumbra in Washington.

An Algorithm for Digital Impedance Calculation Using a Single PI Section Transmission Line Model

Abstract: This paper presents a digital impedance calculation algorithm which does not require prior filtering of transmission line voltage and current signals to remove either transient DC offset components or transient high frequency components before calculating the impedance of the line. The algorithm is based on a signie equivalent ?section model of a transmission line. Computational requirements of the algorithm are presented and compared to those of a corresponding algorithm which requires prior filtering out of transient high frequency components before the impedance of the line is calculated.

On n/1/F̄ dynamic deterministic problems

Abstract: We consider sequencing of n jobs which will arrive intermittently and are to be processed on a single machine; the arrival and the processing times of each jobs are assumed known. A schedule is to be developed that minimizes the mean flow time. Two models are considered: (i) when no pre-emption or inserted idle time is allowed in the schedule, and (ii) when pre-emption is allowed but the jobs follow a pre-empt-repeat discipline We illustrate that Cobham's and Phipp's SPT dispatching rule does not guarantee the optimum F even for the non-preemptive model We propose a branch and bound algorithm for both models and discuss our computational experience We also examine the relative performances of the optimum nonpre-emptive sequence, and the optimum pre-empt-repeat sequence over that resulting from SPT dispatching rule on a large number of sets of jobs of varying sizes and tightness.

A simple fixed-point error bound for the fast Fourier transform

Abstract: Error bounds for the computation of the fast Fourier transform in fixed-point arithmetic are derived for any arithmetic number base and for any prime factorization of the data array length. The intended application is for signal processing with minicomputers. Errors arising from inaccurate sine coefficients and from limited arithmetic precision are considered. The arithmetic error depends essentially on shifts of the data array that may be required to avoid overflow of the computer word. Our closest bound requires knowledge of where shifts occur and is best computed in parallel with the Fourier transform. For the case that such program modification is not feasible, we derive an error bound for a posteriori calculation and an a priori error estimate. Our bounds are for the maximum error because little is gained at the expense of considerably greater complexity for probabilistic error bounds.

Electroantennograms from spruce budworm moths (choristoneura fumiferana) (lepidoptera: tortricidae) of different ages and for various pheromone concentrations

Abstract: An electroantennogram (EAG) technique, which indicates electrochemical activity in a whole antenna, was used to study sex pheromone reception in spruce budworm moth antennae. For both males and females the EAG exhibited a phasic depolarization, reaching maximum near the end of a puff stimulation, followed immediately by repolarization which was prolonged by increasing amounts as the source concentration of the pheromone was increased. The dose–response curves for both sexes were sigmoid in shape, but they indicated that female antennae have a higher threshold and a lower peak response than that of males. Antennal response changed with age, being a regular increase and decrease for females and irregular for males.

Adaptation to Displacing Prisms in Human Infants

Abstract: This research reports a first attempt to study adaptation to laterally displacing prisms in human infants of ages six to ten months Twenty infants were tested over four days under conditions similar to those used in adult adaptation studies Evidence was found of vigorous adaptation when infants were exposed to base-right prisms under conditions of active exposure Detailed consideration is given to the conditions and methods of studying adaptation in infants and implications for adult studies

Modes on elliptical cross-section dielectric-tube waveguides

Abstract: The problem of electromagnetic-wave propagation along a dielectric-tube waveguide of elliptical cross-section is considered. The characteristic equations for odd and even hybrid modes are derived in the form of two infinite determinants, which degenerate to the well-known characteristic equation for hybrid modes on circular tubes as the eccentricity tends to zero. The characteristic roots are computed for various eccentricities and tube thicknesses. It is found that there exist two dominant modes which possess zero cutoff frequencies. The modes on the elliptical tube waveguide are designated by observing computer plots of the radial variation of the field components. The phase velocity is shown to be dependent more upon dielectric area than eccentricity. Thin-walled tubes exhibit less dispersion while thick-walled guides behave as solid dielectric rods. Experimental results on zero-eccentricity tubes agree well with theory.

The oxidative dehydrogenation of ethylbenzene to styrene

Abstract: The results of a kinetic study of the oxidative dehydrogenation of ethylbenzene to styrene over an organic catalyst (pyrolyzed polymerized acrylonitrile) are reported. The reaction is found to be second order in ethylbenzene and zero order in oxygen with an activation energy of 76.5 kJ/mol. The rate equation is: where R = 8.31 J/niol.K and concentration (CEtB) is expressed as mol/L. The catalyst is more active than conventional metal oxide catalysts and appears to be quite stable under reaction conditions. The results suggest that, using the PPAN catalyst, it may be possible to reduce the operating temperature of the oxidative dehydrogenation of ethylbenzene to about 250-300°C, thereby avoiding some of the problems of the present high temperature process.

Uncertainty and preference for ‘ambiguous’ figures, ‘impossible’ figures and the drawings of M. C. Escher

Abstract: With regard to two kinds of dependent response measures, number of one s exposures and verbal ratings of interestingness and pleasingness, preference was greater for unaltered ‘ambiguous’ figures, drawings of M. C. Escher and ‘impossible’ figures, characterized by greater complexity and uncertainty, than for altered versions of these stimuli. Furthermore, preference increased over the three types of unaltered slides while remaining fairly constant across altered ones. Lastly, number of exposures and ratings of interestingness diminished for unaltered pictures when preceded by their altered versions. The findings were interpreted using Berlyne's notions regarding aesthetic preference, uncertainty, and response conflict.

Precopulatory Behavior of Males and Perception of a Potential Male Pheromone in Spruce Budworm, Choristoneura fumiferana

Abstract: Precopulatory behavior of male spruce budworms was examined by direct observation and sequential photography. Groups of males isolated from females exhibited sexual behavior and engaged in homosexual copulations throughout the day. When both sexes were together, heterosexual matings occurred even in morning hours when females were not calling. In the presence of calling females the incidence of heterosexual matings increased considerably. We conclude that males have an intrinsic basal level of sexual activity which is related neither to the presence of female nor her pheromone. A role of the sex pheromone is to enhance this basal level of male sexual activity. The behavior of sexually excited males in homo- or heterosexual mating attempts was similar in all respects. A sexually excited male always spread its abdominal hairs before mating with a female or a male. Extracts of male abdominal tips or whole wings or the airborne volatiles from males gave EAG responses in both sexes. SEM pictures revealed the existence of structures on the wings and the abdominal tip of males which may be scent glands.

Perceptual Style and Ball Skill Acquisition.

Abstract: The purpose of this study was to determine the relationship between perceptual style (field dependence-independence) as measured by the portable rod and frame test and the learning of a ball catching task for three viewing time treatments. Two groups of subjects (N = 45) who satisfied the criteria for field dependence-independence were subdivided and randomly assigned to one of the three viewing time treatments. There were 15 subjects from each of the perceptual style classifications in each of the 150, 250, and 350 millisecond viewing time treatments. The hypothesis of a relationship between perceptual style and learning on the ball catching task was upheld for two of the viewing time treatments (150 and 250 milliseconds). The field independent subjects demonstrated a significantly greater rate and amount of learning than the field dependent subjects for these viewing time treatments. Both field dependent and field independent subjects demonstrated statistically significant improvements in learn...

A maximum likelihood approach to the “test of inclusion”

Abstract: The method of scoring is used to obtain maximum likelihood estimates of the parameters in the White and Clark learning hierarchy validation model. From the estimate of the proportion of the population possessing only the superordinate skill in a pair of hierarchical skills, and its variance, the hypothesis of inclusion is tested. An illustrative example of the procedure is given.

Kinetics of sorption in bi‐porous molecular sieves — Part I. Mathematical models for systems with rectangular equilibrium isotherm

Abstract: The coupled diffusion equations describing transport in a bi-porous adsorbent (micropore-macropore) have been solved in order to obtain the theoretical uptake curves for such a system when the adsorption equilibrium isotherm is rectangular. Solutions are presented for both the step change boundary condition generally encountered in adsorption from the gas phase and for the more complex case which is encountered in studies of adsorption from the liquid phase, when the composition of the ambient fluid changes significantly during the course of an experiment. The theoretical uptake curves are compared with the corresponding curves for a linear system. On a resolu les equations de la diffusion couplee decrivant les transferts dans un adsorbant bidisperse (avec macropores et micropores) dans le but d'obtenir les courbes theoriques decrivant la retention dans un tel systeme, pour le cas d'une isotherme d'adsorption rectangulaire. On presente des solutions dans les deux cas suivants: Les courbes de retention theoriques sont comparees a celles correspondant au cas d'un systeme lineaire.