Showing papers by "Carleton University published in 1984"

A new finite element model for welding heat sources

Abstract: A mathematical model for weld heat sources based on a Gaussian distribution of power density in space is presented. In particular a double ellipsoidal geometry is proposed so that the size and shape of the heat source can be easily changed to model both the shallow penetration arc welding processes and the deeper penetration laser and electron beam processes. In addition, it has the versatility and flexibility to handle non-axisymmetric cases such as strip electrodes or dissimilar metal joining. Previous models assumed circular or spherical symmetry. The computations are performed with ASGARD, a nonlinear transient finite element (FEM) heat flow program developed for the thermal stress analysis of welds.* Computed temperature distributions for submerged arc welds in thick workpieces are compared to the measured values reported by Christensen1 and the FEM calculated values (surface heat source model) of Krutz and Segerlind.2 In addition the computed thermal history of deep penetration electron beam welds are compared to measured values reported by Chong.3 The agreement between the computed and measured values is shown to be excellent.

Control and Coordination in Multinational Corporations

Abstract: The integration of French and British subsidiaries into US-based multinationals is examined A theory linking the use of control and coordination mechanisms to the need for predictability, flexibility, and the cost of achieving them is investigated by relating organizational structure, technology, foreign commitment, financial performance, and nationality to the use of coordination and control

Design techniques for cascoded CMOS op amps with improved PSRR and common-mode input range

Abstract: Internally compensated CMOS op amps have been widely used in sampled-analog signal processing applications over the past several years. However, the popular two-stage op amp suffers from poor AC power supply rejection to one of the power rails. Two circuits are presented that overcome the power-supply rejection ratio (PSRR) problems of the earlier amplifier: one for virtual ground applications such as switched-capacitor integrators, the other for buffer applications requiring wide common-mode input range. Small signal analysis is developed for the open-loop and PSRR responses of the two amplifiers. In addition, design guidelines are suggested and test results are presented.

Biochemical adaption for freezing tolerance in the wood frog, Rana sylvatica

Abstract: 1. The wood frog,Rana sylvatica, can survice extracellular freezing during overwintering. Under laboratory conditions freezing occurred at about −2°C and animals survived several days at −6°C. 2. Frogs accumulated glucose as a cryoprotectant; glycerol, sorbitol and other sugars were not produced. Average levels of glucose in frozen antimals were 185±40 μmol/ml in blood and 387.8±44.8, 198.3±27.3, 120.8±14.1 and 26.5±2.7 μmol/g wet weight in liver, heart, kidney and leg muscle, respectively. 3. Two methods of cold acclimation, 11 weeks at 3°C or a 1°C per day decrease in temperature from 23°C to 0°C, failed to stimulate an anticipatory rise in glucose levels. Only direct exposure to subzero temperature between 0°C and −2°C stimulated synthesis. 4. Glucose synthesis appeared to be confined to liver with glucose distributed through the blood to other tissues. Freezing exposure resulted in a decrease in liver glycogen content of over 700 μmol/g wet weight while glycogen content of other tissues was not affected. 5. Activities of 17 enzymes in liver and leg muscle were monitored in control and freezing exposed frogs. Freezing exposure increased liver phosphorylase activity by 520% from 3 to 18.6 units/g wet weight and increased phosphorylasea content from 37 to 80%. Freezing also elevated glucose-6-phosphatase activity by 140%. Activities of most other enzymes in liver increased by 30–90% with freezing exposure. Activities of phosphorylase and glucose-6-phosphatase increased in leg muscle with freezing exposure although phosphorylasea content remained at 35%. 6. Freezing exposure resulted in the accumulation of lactate in all tissues. Both total adenylates and adenylate energy charge decreased in liver during freezing. In leg muscle adenylates were unaffected but creatine phosphate reserves were depleted.

At a disadvantage: the occupational attainments of foreign born women in Canada.

Abstract: Using data on the wage and salary of labor force participants aged 25-64 from the 1973 Canadian Mobility Study this study on the occupational status of Canadian female immigrant employess finds that immigrant women in the Canadian labor force have occupational statuses which are lower on the average than those of other sex and nativity groups and which appear to reflect not only their level of occupational status related resources but their membership to 2 negative groups--female and foreign-born. However considerable stratification by birth place exists among groups of female immigrant workers. The analysis indicates that the double disadvantage of being female and foreign-born is a less of a factor for the occupational attainments of women born in the US and UK than it is for born elsewhere. There are 3 possible explanations for the existence of the dual disadvantage: 1) the social image of the desirability of foreign-born female immigrants and their capabilities may play a role; 2) the formation of ethnically and linguistically bounded local economies which is a feature of immigrant receiving societies may shape the employment patterns of women more so than mens influenced by the non-North American norms concerning male approval of the work lives of women; and 3) the more general exploitation of workers in a class society and the relations between core-capitalist economies and dependent ones on the periphery may be responsible for placing immigrant women in a position of double disadvantage.

Hypnotic amnesia as a strategic enactment: breaching amnesia in highly susceptible subjects.

Abstract: Hypnotically amnesic subjects frequently maintain their amnesia in the face of strong and repeated exhortations to recall honestly and to try their best to recall. Some investigators have argued that these subjects lose control over memory processes and, consequently, are unable to recall the material for which amnesia had been suggested. We propose instead that amnesic subjects maintain control over their memory processes. They often fail to breach amnesia because to do so would conflict with their self-presentation as deeply hypnotized. In two interrelated experiments we demonstrated that highly susceptible hypnotically amnesic subjects could be easily induced to recall all of the "forgotten" target items by defining successful recall as supportive of rather than as inconsistent with a self-presentation as deeply hypnotized. In the first part of Experiment 1, all subjects showed amnesia despite repeated demands to recall honestly. In the second part of this experiment, subjects were led to believe that they possessed a "hidden part" to their mind that remained aware of the target items covered by the amnesia suggestion. Each subject recalled all of the forgotten items when the experimenter contacted their hidden part. In Experiment 2 we replicated this effect and also demonstrated that the characteristics of subjects' hidden reports were a function of the instructions they received and did not reflect the operation of a dissociated cognitive subsystem that subconsciously held the forgotten items. These findings are inconsistent with traditional theorizing about hypnosis, but offer strong support for the hypothesis that hypnotic amnesia is a strategic enactment under the subject's voluntary control.

The Romano-Persian Peace Treaties of A.D. 299 and 363

Abstract: The Romano-Persian treaties of 299 and 363, the first between Diocletian and his colleagues and the Persian king Nerseh, the second between Jovian and Sapor II, are in themselves, though they survi...

The etiology of children's stereotypes about sex differences in emotionality

Abstract: Contemporary preschool-aged children have pronounced sex-role stereotypes about emotionality. They feel that anger is a male characteristic, while fear, sadness, and happiness are female characteristics. Four studies investigated several possible sources of these stereotypes, including parental stereotypes, parental reinforcement practices, television programming, and actual sex-differences in emotionality. The results suggest that each of these sources may potentially contribute to children's stereotypes about emotionality.

Neuropsychological deficits following head injury in children.

Abstract: Children who had sustained head injuries were divided into three groups on the basis of severity of injury defined according to neurological criteria, and their performance on a battery of neuropsychological tests was compared. The groups were matched for age and sex. Performance IQ and timed tests of motor speed, fine-motor coordination, tactual-spatial functions, and verbal fluency showed significantly greater deficits for severely injured patients than for those who were mildly or moderately injured. Relations between neurologic indices of severity of injury and psychological outcome measures were investigated. Glasgow Coma Scale severity scores and the duration of altered consciousness were related to performance on several major neuropsychological functions. Acute intracranial pressure measures were unrelated to outcome. Comparisons of neuropsychological profiles indicated that the pattern of deficit after severe head injury is more distinctive than are those after mild and moderate injuries...

Distributed algorithms for finding centers and medians in networks

Abstract: On considere le probleme de determiner d'une maniere repartie les centres et milieux d'un reseau. On presente et analyse des algorithmes solution qui requierent, afin d'etre executes, la connaissance topologique seulement locale de chaque nœud: chaque nœud a besoin seulement de connaitre ses propres voisins

The use of Doppler-shifted echoes as a flutter detection and clutter rejection system: the echolocation and feeding behavior of Hipposideros ruber (Chiroptera: Hipposideridae)

Abstract: Hipposideros ruber use CF/FM echolocation calls to detect the wing flutter of their insect prey. Fluttering prey were detected whether the insects were flying or sitting on a surface, and prey in either situation were captured with equal success (approximately 40% of capture attempts). Stationary prey were ignored. The bats did not use visual cues or the sounds of wing flutter to locate their prey. Wing flutter detection suggests that H. ruber exploit the Doppler-shifted information in echoes of their echolocation calls. These bats fed primarily upon moths, usually those of between 10 and 25 mm wingchord, although moths of less than 5 mm and greater than 40 mm wingchord were also attacked and captured. They showed no evidence of selecting moths on the basis of species or other taxonomic distinction, and occasionaly captured other insects.

Theoretical Prediction and Experimental Substantiation of the Ground Pressure Distribution and Tractive Performance of Tracked Vehicles

Abstract: An analytical framework for predicting the ground pressure distribution and tractive performance of tracked vehicles is presented. It takes into account all major design parameters of the vehicle as well as the pressure—sinkage and shearing characteristics and the response to repetitive loading of the terrain. The subsequent substantiation of the analytical method by means of full-scale tests made with an instrumented vehicle is described. A comparison between the theoretical prediction and test results is made and it is found that there is a fairly close agreement between them. This paper includes three sections: (i) an analytical method for predicting the normal pressure distribution; (ii) an analytical method for predicting the shear stress distribution and tractive performance; (iii) experimental substantiation of the analytical framework by means of full-scale tests. The analytical framework presented is suitable for evaluating the effects of vehicle design parameters and terrain conditions on the pe...

Purification and properties of aerobic and anoxic forms of pyruvate kinase from red muscle tissue of the channelled whelk, Busycotypus canaliculatum.

Abstract: Aerobic and anoxic variants of radular retractor muscle pyruvate kinase (PK-aerobic and Pk-anoxic) from the gastropod mollusc, Busycotypus canaliculatum, were purified to homogeneity and respective specific activities of 368 and 186 mumol of product min-1 mg protein-1. Both PK variants were apparent homotetramers with native molecular masses of about 235 kDa, but differed in several other physical characteristics including pI (5.81 +/- 0.06 for PK-aerobic, 5.42 +/- 0.03 for PK-anoxic) and chromatographic behavior on several columns used during their respective purifications. The two enzymes differed greatly in several kinetic properties. Affinity for phosphoenolpyruvate was more than tenfold greater for PK-aerobic (K0.5 = 0.067 +/- 0.002 mM; h = 0.99 +/- 0.10), whereas the cooperative effect for phosphoenolpyruvate binding was greatly enhanced for PK-anoxic (K0.5 = 0.85 +/- 0.02 mM, h = 2.57 +/- 0.01). Although the affinities for the second substrate, ADP, were identical for both enzyme forms (apparent Km = 0.25 mM) pK-anoxic showed greater substrate inhibition by high concentrations of ADP. Likewise, affinities for K+ and Mg2+ were similar but PK-anoxic showed a greater degree of cooperativity with Mg2+ (h = 2.50 +/- 0.02) than did PK-aerobic (h = 1.70 +/- 0.06). Saturating concentrations of fructose 1,6-bisphosphate (50 microM) activated PK-anoxic resulting in an enzyme with properties similar to fructose-1,6-bisphosphate-activated PK-aerobic, with K0.5 values for phosphoenolpyruvate of about 0.04 mM and Hill coefficients of 1.1. PK-anoxic showed much stronger regulation by the allosteric inhibitors MgATP, phenylalanine, proline and alanine. Fructose 1,6-bisphosphate partially relieved the inhibitions by ADP, MgATP, alanine, proline and arginine phosphate of both enzyme forms. However, at 0.1 mM phosphoenolpyruvate PK-aerobic was much more sensitive to activation by fructose 1,6-bisphosphate, Ka values being 0.05 +/- 0.01 microM for PK-aerobic and 1.3 +/- 0.1 microM for PK-anoxic. In the presence of 1.0 mM alanine and 1.5 mM MgATP much higher concentrations of fructose 1,6-bisphosphate were required for activation of PK-anoxic (Ka = 5.2 +/- 0.4 microM) than for PK-aerobic (Ka = 0.02 +/- 0.01 microM). Variations in pH over the range likely occurring in vivo during anaerobiosis caused no significant additional kinetic differences between the two enzyme forms. The dissimilarity in kinetic properties of PK-aerobic and PK-anoxic indicate that red muscle PK activity is probably strongly depressed in vivo during anoxia stress.

Partisan Instability in Canada: Evidence from a New Panel Study

Abstract: One of the critical questions in the debate about the concept of party identification is its stability over time, particularly its stability relative to that of voting behavior. This article utilizes data from a new three-wave panel study to assess the properties of party identification in Canada, and to compare levels of partisan stability in Canada with those in Great Britain and the United States. In addition to directional stability, other features of the party identification concept and its applicability to Canada are examined, notably the constituency of identification across levels of the federal system. Analyses indicate that party identification in Canada is subject to considerable fluctuation, and that the U.S. pattern of relatively stable party identification coupled with substantial short-term swings in voting behavior reflect the institutional characteristics of the U. S. electoral system. The article concludes by suggesting that patterns of partisanship in Canada, although distinctive in certain respects, probably have important commonalities with those in many other contemporary liberal democracies.

Behavioral and ecological factors contributing to American black duck-mallard hybridization

Abstract: Investigation of courtship and pair formation of a wintering population of American black ducks (Anas rubripes) and mallards (A. platyrhynchos) near Ottawa, Ontario, indicated that initially drakes of both species exclusively courted and paired intraspecifically. After all female mallards had paired, the remaining mallard drakes joined black duck courtship groups. Of the 33 unpaired black duck females remaining at this time, only 27% formed intraspecific pairs, whereas 73% selected mallard drakes as mates, despite there being an excess of black duck drakes. Based on these results, a scenario for black duck-mallard hybridization is proposed. It involves ecological factors including the male-biased sex ratio in northern wintering populations, artificial feeding, and roost-site limitation. Other behavioral aspects, such as the earlier pair formation in mallards and the superiority exhibited by mallard drakes when competing for black duck females are discussed. J. WILDL. MANAGE. 48(3):846-852 One factor essential to a species' genetic integrity is its continued reproductive isolation from congenerics through geographic, habitat, or behavioral means (Lack 1971). Two species of dabbling duck, the American black duck and the mallard, are similar both morphologically and behaviorally, and their hybrids appear to be as viable and as fertile as the parental species (Johnsgard 1961). However, geographic range and evolved habitat differences have until recently deterred hybridization between these two species. Prior to 1900, the black duck and mallard were geographically isolated. Heusmann (1974) examined the evolutionary history of the black duck and hypothesized that it evolved during the Pleistocene glacial period when a population along the eastern coast of North America became isolated from western mallard populations. Habitat differences further segregated these populations as the black duck began breeding in the forested regions of the east and the mallard nested in grassland habitats of the west. In the present century, however, land use changes, including the deforestation of the eastern region, have caused a decline in the available breeding habitat of black ducks while simultaneously providing favorable habitat for nesting mallards. Johnsgard (1967) concluded that these environmental modifications were facilitating the colonization, by mallards, of extensive eastern areas formerly occupied by the black duck. The invasion of the mallard into black duck breeding territory has also resulted in the convergence of these two species on wintering grounds. Since the majority of pair bonding in both species occurs throughout the winter (Stotts and Davis 1960, Lebret 1961) and the courtship displays that lead to pair formation are similar (Johnsgard 1960), interspecific pairing can readily occur where these two species winter together. As a result of black duck hybridization with the much larger mallard gene pool and the constant reduction of its nesting habitat, it is believed by many that the black duck as a "pure" species will eventually disappear. The objectives of this study were to examine courtship activity and pair formation in 846 J. Wildl. Manage. 48(3):1984 This content downloaded from 157.55.39.110 on Sat, 24 Sep 2016 06:00:00 UTC All use subject to http://about.jstor.org/terms BLACK DUCK-MALLARD HYBRIDIZATION * Brodsky and Weatherhead 847 black ducks and mallards wintering together at the northern limit of their range and to determine the factors contributing to interspecific pairing between these two species. We thank H. G. Merriam for suggesting the suitability of the Manotick waterfowl population for this study, C. A. Barlow for comments on an earlier draft of this manuscript, and J. Sharkey-Thomas for feeding the ducks. Financial support was provided by the Nat. Sci. and Eng. Counc. of Can. and Carleton Univ.

Sense of direction, topological awareness and communication complexity

Abstract: Based on some recent results, it is here argued that the communication complexity of distributed problems can be greatly affected by two factors hereby identified as 'sense of direction' and 'topological awareness'. It is also suggested that 'insensitivity' to either or both factors is an indicator of the inherent difficulty of a distributed problem. A bibliography of recent results is included.

Phosphorylation in vivo of red‐muscle pyruvate kinase from the channelled whelk, Busycotypus canaliculatum, in response to anoxic stress

Abstract: That red muscle pyruvate kinase from anoxic Busycotypus canaliculatum (PK-anoxic) is a phosphoprotein was demonstrated by the anoxia-dependent, in vivo, covalent incorporation of injected [32P]orthophosphate into the enzyme molecule. Specificity in labelling of PK-anoxic was strongly suggested by: (a) coincidental elution of pyruvate kinase activity and radioactivity following chromatography of purified PK-anoxic on Sepharose CL-6B, and (b) comigration of the area containing [32P]phosphate and Coomassie-Blue-staining protein following SDS-polyacrylamide gel electrophoresis of homogenous PK-anoxic. The [32P]phosphate content of the enzyme was calculated to be 7.3 mol phosphate/mol enzyme (233 kDa, 180 units/mg protein). Evidence for the reversibility of this phosphorylation was provided by the consistent kinetic similarities between purified red muscle pyruvate kinase from aerobic animals (PK-aerobic) and homogenous, unlabelled, alkaline phosphatase treated PK-anoxic. Comparison of the electrophoretic mobilities of products derived from acid hydrolysis of purified 32P-labelled PK-anoxic with authentic substances suggest the presence of an O-phospho-L-threonine residue in the protein. That this residue plays a probable role in an interconversion mechanism was suggested by the lack of phosphate exchange of homogenous 32P-labelled PK-anoxic in the presence of all substrates. A possible role of protein phosphorylation as a mechanism for the overall control of molluscan anaerobic metabolism is suggested.

A random wave process

Abstract: The parabolic or forward scattering approximation to the equation describing wave propagation in a random medium leads to a stochastic partial differential equation which has the form of a random Schrodinger equation. Existence, uniqueness and continuity of solutions to this equation are established. The resulting process is a Markov diffusion process on the unit sphere in complex Hilbert space. Using Markov methods a limiting Markov process is identified in the case of a narrow beam limit; this limiting process corresponds to a simple random translation of the beam known as “spot-dancing.”

Why Students Can’t Write Arguments

Abstract: (1984). Why Students Can’t Write Arguments. English in Education: Vol. 18, No. 2, pp. 73-84.