McGill University Thèses et mémoires publiés en 1988

Thermoplastics injection molding involves plastication followed by the injection of the melt into a cold cavity. Packing is employed to compensate for shrinkage due to cooling. Ultimately, the solidified part is ejected from the mold without damage. The successful operation of an injection molding machine requires control of the process variables during each of the consecutive stages in addition to correctly identifying the points of transition from one stage to the next. Pressure and its variation during the injection molding cycle play an important role with regard to productivity, product quality, and product reproducibility. From the practical point of view, …  Lire la suite

Part A traces back the origins of the conflicting claimsto sovereignty over the area now called the West-Bank. The analysis shows that a sovereignty vacuum ensued after Turkey relinquished by treaty its rights and title over Palestine and that subsequently that vacuum remained in the area earmarked for an Arab Palestinian State. Part B peruses the constituent elements for the legality or illegality of the sovereignty claims invoked by the parties concerned: the use of force and the act of selfdefence. Part C demonstrates that Israel has eroded the law of belligerent occupation through a system of military orders, which …  Lire la suite

In the light of new studies of physico-chemical analysis, fabric, and particle interaction, the consideration of the actual constitution of the soil media is required for actual prediction of the soil media performance under loads. This study has been restricted to the prediction of clay performance under compression loading. A micromechanics approach has been used in this research; a microelement scale has been introduced and a set of formulations (i.e., stress transfer, fluid flow equation, and volumetric constitutive equation) has been developed for this scale. The passage from the microelement to the global scale has been established by using evolution …  Lire la suite

This is an attempt to investigate the linguistic question ofderivation in usul ahfiqh (legal theory). Being treated in various linguistic disciplines, especially grammar, the subject matter is studied in light of these disciplines in order to expound the unique contribution of usulists to it. The present study explores the chronological evolution of the subject and presents "derivation" as one example of the methodology applied by usulists to linguistic issues.  Lire la suite

Ma, B. (Supervisor)  Lire la suite

Yong, R. N. (Supervisor)  Lire la suite

In the Islamic tradition, as in other religious traditions, female saints are relatively few and not much scholarly attention has been given to them. Fatimah, the daughter of the Prophet Muhammad, is one such example. It is, however, a point of interest in her case is that in the twentieth century she has captured the attention of writers of Muslim religious literature to such an extent that there now exist at least eleven fairly recent biographies of her in Urdu, English, Arabic and Persian. This is remarkable, given that the earliest sources of Islamic history contain only a minimal amount …  Lire la suite

Briedis, Dalius J. (Supervisor)  Lire la suite

Sclerotinia sclerotiorum is a pathogen of crops grown in the muck soil regions of Quebec. Soil baiting tests indicated that the sclerotia of S. sclerotiorum are attacked and destroyed by the larvae of Bradysia coprophila and mycoparasites. Sclerotia with rinds partially damaged by the larvae were found to be more susceptible to mycoparasitism by Trichoderma viride. Increasing the organic matter content and porosity of soils resulted in increased damage to sclerotia when larvae were present. Studies conducted to determine if larvae could be reared on diets of various fungi and plant tissue showed that mycelia and sclerotia of S. sclerotiorum …  Lire la suite

A standard methodology was developed for performing avoidance-preference tests, using Rainbow Trout (Salmo gairdneri) as the test organism. Experiments were conducted in a hydraulic channel, 9.15 m long by 0.30 m wide, partly divided along its length, and at a flow depth of 0.30 m. The design combined steep and shallow gradient characteristics. The toxicants investigated included Cu(II), Cr(III) and Cr(VI). The lowest avoidance threshold values were established at 2.1 $ mu$g/l for Cu(II) and 0.0026 mg/l and 0.026 mg/l for Cr(III) and Cr(VI) respectively while avoidance reactions increased with levels of toxicant in the channel. Similar experiments were performed …  Lire la suite

The main objective of this research was to determine the short-term effects of cropping on the aggregation and the carbohydrate fraction of a marine clay soil. When compared to a fallow (bare soil) control, cropping to barley and alfalfa for two seasons resulted in significant increases in the size and stability of soil aggregates. The increase in water-stable aggregates $>$2.0 mm was at the expense of aggregates $<$1.0 mm. Under corn, soil aggregation was not different than under fallow. After two seasons, soil under barley or alfalfa contained 15 to 25% more carbohydrates than the fallow or corn treatments. The …  Lire la suite

A significant amount of work has been directed toward the improvement of mine backfill during the past decades. Paste backfill was recently introduced as a superior support system for underground hard rock mining operations. The aim of this study is to examine the applicability of paste backfill to full scale underground operations. The Tailspinner system was developed to produce paste backfill. This system dewaters the full stream tailing material from approximately 55% to 24% water content. These densified tailings are mixed with cement prior to placement in a stope. The utilization of paste backfill possesses several economical and mechanical advantages. …  Lire la suite

The experimental work presented in this thesis explores, in anaesthetized and mid-collicular decerebrate, unanesthetized, cats, the properties of two components of the discharge of sympathetic nerves which are time-locked to the central respiratory cycle and are presumably generated within the central nervous system. One is the inspiration-synchronous burst, the other is a previously unknown late-expiratory burst. The properties of the inspiration-synchronous burst and its temporal relation to the phrenic nerve burst were studied under conditions in which the frequency of the latter was changed over a wide range by superior laryngeal nerve stimulation, by changes in ventilation frequency while the …  Lire la suite

This thesis is concerned with the measurement and characterization of radio signal spatial fading in urban micro-environments. Automated field strength measurements at ten FM broadcast frequencies were conducted in a small region of a built up urban center (the McGill University campus, Montreal, Canada). The measurements show that the received signal comprises two independent fading components: long term fading (average power variations over large spatial intervals), and short term fading (rapid power fluctuations over small spatial intervals). A number of statistical and time series analysis methods (probability density, quantile-quantile plots, autocovariance, crosscovariance, spectral density) were exploited to characterize the fading …  Lire la suite

Severe D-1 directional Fourier truncation of the equations for D-dimensional (D = 2, 3) incompressible flow leads to a small number of coupled PDE's in one space dimension with the same inviscid quadratic invariants as the original set. Numerically generated equilibria for inviscid truncated versions of the reduced systems agree with predicted energy-enstrophy (D = 2) and energy (D = 3) equipartition spectra based on statistical mechanical equilibrium. Viscous calculations for forced and decaying turbulence at high Reynolds number are consistent with k$ sp{-5/3}$ inverse energy and k$ sp{-3}$ direct enstrophy cascading inertial ranges in two dimensions and with a …  Lire la suite

A pultrusion process using staggered cylindrical pins in a molten polymer reservoir is one method of pre-compounding long glass fibre-reinforced thermoplastic materials. This material, if well impregnated with resin, will maintain much of its aspect ratio during subsequent moulding. The longer fiber length translates into improved mechanical properties versus conventional extrusion compounded material. This research studies the effect of a novel pin shape and configuration on the wetting of glass roving during thermoplastic pultrusion compounding. Experimental pultrusion studies using polypropylene indicate that alternating concave (collecting) and convex (spreading) contoured pins promote superior resin impregnation compared to conventional cylindrically shaped pins. …  Lire la suite

Crowley, David (Supervisor)  Lire la suite

InP obtained by metal-organic vapor phase epitaxy, with properties similar to GaAs, shows mobilities approaching the theoretical maxima at low temperatures. However, the corresponding values remain abnormally low at room temperature where a pronounced electronic excitation to the conduction band is observed simultaneously. This reduction of the mobility is attributed to the presence of deep centers that are electrically inactive at low temperatures but become excited when the temperature increases. A model based on an iterative solution to the Boltzmann equation and accounting for the usual scattering mechanisms, including inelastic interactions, is able to explain the data perfectly and shows …  Lire la suite

The effect of shear rate on the ADP-induced aggregation of human blood platelets in flow through tubes was studied over the full physiologically significant range. The extent of single platelet aggregation at 0.2 $ mu$M ADP in citrated platelet-rich plasma, PRP, was greatest at mean tube shear rate, G = 314 s$ sp{-1}$; however, aggregate size steadily decreased from G = 39.3 to 1800 s$ sp{-1}$. At 1.0 $ mu$M ADP the rate of aggregation increased up to G = 1800 s$ sp{-1}$ where virtually no unaggregated platelets remained after 43 s of flow, although, aggregate size was still limited …  Lire la suite

Wilkinson, Frances (Supervisor)  Lire la suite

Compositionally related glasses and ceramics of the Na$ sb2$O$ cdot$CaO$ cdot$Al$ sb2$O$ sb3 cdot$TiO$ sb2 cdot$SiO$ sb2$ system (sphene glass-ceramics) doped with Eu$ sp{3+}$ were examined using site-selective spectroscopic techniques (FLN). In sphene glass-ceramics, Eu$ sp{3+}$ preferentially partitions into the crystalline sphene phase. The partition ratio is concentration dependent, decreasing at higher concentrations, because of the limited solid solubility of Eu$ sp{3+}$ in sphene. The concentration occurs at the time of phase separation; Eu$ sp{3+}$ preferentially enters the more ionic (CaO, TiO$ sb2$)- rich droplet phase which eventually becomes sphene. In sphene, Eu$ sp{3+}$ substitutes for Ca$ sp{2+}$ appearing in …  Lire la suite

The purpose of this study is to develop a general algorithm to solve in a robust, flexible and fast way the short-term scheduling problems of two different multi-reservoir hydroelectric power systems. The first system consists of four reservoirs in series, the second corresponds to that of the Ste Maurice river. The solution method is based on the discrete maximum principle. Gradient method is used for the solution of the two-point boundary value problem. Two algorithms are suggested for dealing with difficulties posed by the state variable constraints. The first uses the augmented lagrangian method, the second is iterative. Both algorithms …  Lire la suite

Analysis of mitochondrial DNA (mtDNA) sequence variation among 244 American shad (Alosa sapidissima) from 14 rivers spanning the (Florida-Quebec) range of the species revealed several unusual features of shad mtDNA polymorphism. Two types of heteroplasmy, one involving a length polymorphism and the other a restriction site are common in shad. The length polymorphism involves a novel tandem triplication of a 1.5-kb sequence in the D-loop region. Both forms of heteroplasmy stem from multiple mutational events. The mtDNA data indicate that shad populations are reproductively discrete, and suggest that differences in the reproductive traits of northern and southern shad populations have …  Lire la suite

Acheson, Nicholas H. (Supervisor)  Lire la suite

The effects of aging on estrogen receptor (ER) levels and dynamics were assessed in hypothalamus (HYPO), pituitary (PIT), and uterus (UT) of female mice, 0-24 h following a bolus of estradiol. Nuclear ER levels were reduced and dynamics were altered in all tissues of aged mice. Age-related reductions of nuclear ER were associated with both losses of ER and reduced ability of cell nuclei to bind ER. Irrespective of age, ER dynamics differed among tissues. The duration of elevated nuclear ER was longest, and the rate of replenishment of cytosolic ER was fastest, in HYPO. Transient loss of ER was …  Lire la suite

Cantin, Marc (Supervisor)  Lire la suite

Gordon, Julius (Supervisor)  Lire la suite