McGill University Thèses et mémoires publiés en 1949

The behaviour of high polymers in solution has been extensively investigated by many methods, but the diffusion of high polymers has received little attention experimentally, and limited progress has been made in its theoretical treatment. According to these theories, the rate of diffusion is governed in large measure by the shape of the polymer chain which, however, need not be the same in different solvents. Evidence for a change of shape in different solvents is obtained indirectly from experiments on viscosity, osmotic pressure, sedimentation velocity, and streaming birefringence, while direct evidence is provided by measurements of light scattering. Experimental studies …  Lire la suite

The polymerization of alkylbutadienes has a long history, dating from Grenville William's experiments with isoprene, obtained from the destructive distillation of natural rubber (l). However no large scale production of polymers of butadienes was attempted until World War I, when the Germans manufactured over 2300 tons of polydimethylbutadiene. Until then the natural sources of rubber yielded adequate supplies for world needs. Some research was continued in the field of synthetic rubber andby 1939 the Germans, and later the Western Allies, were able to produce large quantities of synthetic elastomers (the name given to high polymers that possess rubber-like properties). A …  Lire la suite

A monokinetic beam of neutrons (0.07 e.v.) has been scattered by a gas, and the angular dependence of scattering measured over the range 0° to 90°. This isbelieved to be the first measurement of neutrons diffracted by gas molecules. The experiments were performed with a modified neutron crystal spectrometer using a beam of neutronsfrom the Chalk River pile. The gases studied, CO2 and O2, were at room temperature and approximately 60 atmospheres pressure. Observed intensity distributions are compared with calculated patterns. The latter are based on classical interference theory, so take no account of inelasticscattering. Good angular agreement of interference …  Lire la suite

Denstedt, O. (Supervisor)  Lire la suite

The extensive equipment which is described has been built up for the study of magnetic moments of nuclei, particularly for accurate comparison of their gyromagnetic ratios, and the relative spins of isotopes. The nuclear induction and the nuclear absorption resonances of the proton have been observed. The induction resonance of B^11 has been observed at around 10 mc. in an alkaline solution of KB02. Its frequency has been compared with that of the proton in the same field giving a measure of the ratio of the two gyromagnetic ratios: ɤB/ɤP = 0.320904 ± 4.3 x 10^-6 [...]  Lire la suite

The rocks studied in this thesis have been the subject of considerable discussion as to their original nature. J. D. Bateman of the Geological Survey of Canada considers that they are of igneous origin whereas others believe that they are metamorphosed sediments. It was thought that a petrographical study might provide some information that would help to decide the problem and it was with this object in view that this study was undertaken. Cree Lake, in the vicinity of which the rocks occur, is situated 2 miles North of the Sherritt-Gordon Mine, Manitoba, which lies about 20 miles east of …  Lire la suite

Adair, E. (Supervisor)  Lire la suite

Psychologists have found that noise reduces human efficiency. This effect may be considerable even for the most phlegmatic individuals. Moreover, almost everyone objects to unnecessary noises. In recent years there has arisen a very insistent demand for quieter electrical apparatus. This applies particularly to household apparatus such as refrigerator motors, vacuum sweepers and the like. Practically noiseless motors are also required for various drives ( refrigerating plants, circulation pumps of hot water systems, big ventilating systems for rooms, organ bellows etc. ) in non industrial plants such as storerooms, business houses, hotels, hospitals, churches, theatres etc> where all noise should …  Lire la suite

Acronecrosis, or top-necrosis, is a systemic virus disease which manifests itself in certain potato varieties following graft introduction of certain specific plant viruses. Acronecrosis is externally characterized by a necrotic spotting of the uppermost leaves followed by a dying of the plant from the top, downward, in the absence of any mottling. Necrotic areas are invariably found in the stem. These necroses, which are most severe in the distal portions of the plant, originate usually but not always, In the internal phloem and spread into the surrounding tissues. Necroses, similar in their origin and appearance to those in the stem, …  Lire la suite

The original primary object of this research was to study the properties and reactivity of potassium diazomethionate with particular reference to its stability and usefulness as a synthetic tool. It was desired to establish whether potassium diazomethionate was completely analogous in behavior to other aliphatic diazo compounds such as diazomethane and diazoacetic ester as has been suggested in the literature. If this were the case, a ready method of synthesis would be available for a large number of interesting disulphonated aliphatic compounds which had not previously been prepared. A secondary object was to determine whether potassium diazomethionate could be used …  Lire la suite

The governing feature in writing an acceptance code for any purpose is to specify conditions which will be easily duplicated in all details so that results obtained may be directly compared. These conditions, while being those most easily reproducible, are not always those with which it would be most economical to comply, especially in cases where a manufacturer is making a large number of tests during development of a process or material. In the development of arc-welding electrodes, the properties of the deposited weld metal must be controlled within the limits set out in the following specifications. [...] In view …  Lire la suite

Variable frequency oscillators are an essential element of many radio communication systems. One of the problems in their design is the elimination of undesirable variations in the output frequency. Present day knowledge of the causes of frequency instability in oscillators used in radio communication equipment, and of the methods developed to achieve good stability, is thoroughly outlined. The functions required of a variable frequency oscillator, and means of achieving variable frequency output with crystal control are mentioned. The special conditions applicable to very high frequency oscillators are presented. The record is given of an experimental investigation of the frequency fluctuations …  Lire la suite

The mechanism of headache has been studied physiologically by the neurosurgeon, whose conclusions have sometimes proved difficult to correlate with known anatomical facts. This is because of the relative paucity of knowledge concerning intracranial sensory nerves and nerve endings so that the interpretation of physiological investigations has depended to some extent on speculation. There are at present two main groups, one which would consider the pain of headache as mediated solely or almost entirely by periarterial nerves and receptors, the other which attributes to nerves within certain special locations of dura the chief role in pain conduction. The present study …  Lire la suite

For many years the study of insect pathogens was not regarded as one of the duties of the entomologist. When insects became numerous and caused economic damage, they were combatted either with insecticides or by the introduction of parasitic or predaceous insects. The use of insecticides in the forest is not economical. Forest entomologists therefore resorted largely to the introduction and propagation of parasitic insects. Unfortunately, experience has shown, in many cases, that introduced parasites multiply too slowly to check current insect infestations. Insect pathogens multiply rapidly and at times contribute more to the control of insect pests than all …  Lire la suite

The main aim of this study was to determine the effects of hydrogen ions, and of bicarbonate and CO2 on the respiration and anaerobic glycolysis of brain tissue in vitro. Such an investigation is of interest since these substances are important components of tissue fluids, and are known to vary in concentration. Observations on the effects of pH and of bicarbonate and CO2 on aspects of in vitro metabolism might, therefore, aid in an understanding of their functions in vivo. Further, it is important to know precisely the effects of these factors in order to judge the validity of experiments …  Lire la suite

Purves, Clifford B. (Supervisor)  Lire la suite

The social worker has a contribution to make towards the present intensive program on cancer research. To discover the nature of that contribution is the purpose of this study. The terminally ill have become a most serious social problem in recent years. Since medical science has found cures for the death-dealing infectious diseases, more patients have survived to succumb to the chronic illnesses common to older age groups. Illness resulting from a damaged cardio-vascular system such as arteriosclerosis, a deterioration of the muscular-skeletal system. such as rheumatoid arthritis, a diseased respiratory system such as tuberculosis and diseased body cells producing …  Lire la suite

This thesis is based on the literature of Dominion and Provincial Surveys of Canada and other pertinent sources. In scope, this investigation does not include the Grenville Sub-province because of its indecisive geological relationship to the remainder of the Shield. Archean rocks are classed as such because; 1. they consist largely of vo1canics and illsorted sediments and when in contact with the less deformed (Algonkian Type) rocks are bound to underlie them unconformably. 2. the sediments approximate lithologically the younger Algonkian group, but are more strongly deformed. The purpose of this research is to render a summary of what is …  Lire la suite

Various methods have been employed in the evaluation of item selection methods. Typical among these studies are those made by Barthelmess, Lentz and Long and Sandiford. Barthelmess (l), has used an intercorrelational technique in evaluating various methods of item selection. Validity values were computed for each of the hundred elements of the McCall Multi-Mental Scale, Elementary Form 1, by each of the methods of item selection being studied, namely, Eta, Long, McCall, Vincent, Corrected Vincent and Bi-serial r. These methods were then evaluated on the basis of intercorrelation of each method with all the other methods. Results showed that the …  Lire la suite

Die "Römischen Elegien" Sind in vieler Beziehung ein außerst interessantes Werk; sie bedeuten etwas wesentlich Neues in Goethes Gesamtschaffen und nehmen innerhalb der klassischen - d.h. genauer der klassizistischen - Dichtung eine Sonderstellung ein. Sie sind Ausgangspunkt und zugleich Höhepunkt einer neuen Richtung bei Goethe, der erste große dichterische Niederschlag einer Synthese wesentlich entgegengesetzter Elemente: Nord und Slid, Moderne und Antike,Romantik und Klassik, Wortkunst und Plastik, Natur und Kunst überhaupt. Dies war nur möglich, weil Goethe diese Synthese selbst lebte. [...]  Lire la suite

The problem of measuring impedance is an old one, but its currency is renewed every time there is an advance into the radio-frequency spectrum. The trend in the development of Radio science has been towards higher frequencies, and particularly during the recent war has there been a rapid advance in this direction. The need for, and emphasis on, practical results from wartime development and research has led to the by-passing or at any rate incomplete solution of many problems in the frequency range from 100 to 200 mc. Because of the dearth of information and the lack of practical techniques …  Lire la suite

Fodsol soils constitute a large proportion of the soils of Eastern Canada. They are developed under woodland in cool humid conditions where rainfall exceeds evaporation. The profile from the surface downward consists essentially of an organic layer, a leached layer, and a layer of accumulation just above the parent rock. Thus the simplest podso1 profile consists of three horizons, namely: Ao ‘ the raw humus layer; A2, the leached siliceous layer; B, the layer of accumulation of sesquioxides. The Ao horizon of acid peaty organic matter is considered essential to the development of a true podsol. G.W. Robinson makes the …  Lire la suite

The phenomenon of coagulation of colloidal systems is analogous in many respects to a chemical reaction, proceeding at a definite rate dependent on temperature and concentration, and being markedly sensitive to the presence of foreign substances. It is, however, mainly a diffusion-controlled process. The consequence of this is that no equilibrium state can be set up to describe the reacting system. Hence the problem cannot be treated on the basis of either the collision theory of chemical reactions or the theory of the transition state, since both of these depend on an equilibrium configuration of the reactants, activated intermediates and …  Lire la suite

Changes in the physical properties of the atmosphere are caused by geographic influences and dynamic effects. The nature of the surface of the earth over which the air passes is usually the main factor in modifying the air in the lower levels of the troposphere. The ocean area of Hudson Bay in northeastern Canada presents an extensive surface for modification of air. Continental polar air crossing Hudson Bay and continuing into eastern Canada is modified not only by the underlying surface but also by the dynamic effects occurring in the atmosphere during its trajectory over these regions. The amount of …  Lire la suite

Changes in memory and the nature of the mnemonic trace are a source of never-ending interest, as well as of physiological importance, to the investigator. To date, no satisfactory solution has been provided as to exactly what occurs within the trace itself when increasing errors of memory are manifested with the passage of time. Traditionally there have been two opposing theories - one, supported by G. E. Müller, which maintains that forgetting consists principally of an increasing indefiniteness of the trace, and the other, originated by Wulf, who concluded, from studies pursued under Koffka’s direction, that the trace tends, not …  Lire la suite

Cohen, M. (Supervisor)  Lire la suite

The title of this thesis is a broad one and purposely so, for the problem was first conceived in such general terms. But it soon became obvious, that the role of many electrolytes in many different types of heart disease could not possibly be investigated by one person in a short time. Therefore, in approaching such a study, the problem had immediately to be limited. Because potassium is such an important electrolyte in cellular metabolism and because variations in potassium concentrations have such a marked effect upon the functions of the heart, it was decided that this ion should be …  Lire la suite

The grey-wooded soils of Western Canada are becoming increasingly important due to the fact that future settlement will be largely confined to such soils. In the Peace River region today sizeable tracts of wooded soils are being brushed and broken for crop production by modern power machinery. Over the three Prairie Provinces grey-wooded soils consist well in excess of 100,000,000 acres and of the four major soil zones (brown, dark brown, black, grey-wooded) they represent by far the largest area. About two-thirds of the entire province of Alberta is made up of the grey soil zone. Vyatt (39) points out …  Lire la suite

The decomposition of dry bovine serum albumin by alpha-rays has been investigated using an ultracentrifuge with Svedberg optical system and spectrograph. Alpha-particle radiation of 8 x 10^7 to 5 x 10^9 roentgens was obtained from slow neutron capture in boron mixed with albumin samples. In a centrifugal field of 115,000 g buffered aequeous solutions formed from the irradiated samples were found to contain cleavage products ranging in size from effectively non-centrifugible material to apparently normal albumin and aggregation products. Marked increase in absorption, extending toward the visible, was apparently associated with cleavage products of all sizes, but mainly attributable to …  Lire la suite

Aeromycology has been largely dealt with for agricultural or medical reasons. Rust spores, smut spores and spores of many other plant pathogens have been found to exist in a viable state in all layers of our atmosphere. Many workers have shown how these organisms through their numerous air-borne spores may be borne thousands of miles to cause new local infections. The almost continuous exposure of wheat to infection by wheat rust is due to the transportation of the rust spores hundreds of miles by air. The infection starts as a wave in the far south of of our continent with …  Lire la suite

The Maritime Provinces of Canada offer tempting prospects to the petroleum industry, for oil and gas seepages have been reported from widely separated districts since the early settlement of the country. Yet the petroleum production to date has come almost exclusively from the Stony Creek field in New Brunswick, which has yielded only slightly better than one hundred thousand barrels of oil and twelve billion cubic feet of gas. It is the essential purpose of this thesis to investigate further the petroleum possibilities of this area through the medium of paleogeology. Three sources of information have been exploited in the …  Lire la suite

The Knights of Labor had their beginning in the United States in 1869. KNown originally as the “Noble and Holy Order of the Knights of Labor”,they were at first a secret body. This secret nature was due in part at least, to the founder of the Order, Uriah Smith Stephens, who, being himself a Freemason, naturally tended towards secrecy. Mr. Stephens argued: “I don’t know of any great good that has been accomplished except through the agency of secret societies. I believe that all legitimate occupations have their secrets. Ministers and medical men have their associations, merchants their exchanges, lawyers …  Lire la suite

During recent years a large body of information has accumulated regarding the nucleic acids, not only from a standpoint of their structure and properties but also in relation to their functions in the cell. It is a well-established fact that those organs which are most actively engaged in protein synthesis tend also to contain relatively greater amounts of nucleic acids. A considerable amount of information is available concerning the nucleic acid content of the liver of rats of various ages and under various conditions. However, there is comparatively little information regarding the nucleic acid content of the liver of fowl. …  Lire la suite

Certain laboratory measurements require the use of a selective audio frequency amplifier. The limitations of physical size on conventional circuits become important in this frequency range. It is necessary to consider selectivity ease of tuning, economy of components, and stability, in the comparison of various types of amplifiers which operate in the range below 20,000 cycles per second. At radio frequencies, use of the parallel resonant circuit as a selective load impedance for a vacuum tube is highly satisfactory. (Figure 1) When the frequency of resonance is decreased, the product of the inductance and capacitance must be increased inversely as …  Lire la suite

A meter is constructed for the measurement of phase differences of voltages in the lover audio range. This meter possesses many distinct advantages over the prevailing types in range, accuracy, and ease of operation. To test the meter, calculations are made of the phase change in a transmission line at various frequencies, and the results checked with the readings on the phase meter. A very good agreement was found between experimental and predicted values. In the construction of the meter two voltages 90° out of phase are required. These are obtained by the use of a three phase oscillator and …  Lire la suite

The work to be described in this thesis belongs to the larger body of chemical and metallurgical literature usually referred to as metal displacement equilibria. Many systems of this group have been investigated from a purely practical viewpoint. The results obtained have formed the bases of many metallurgical industries. Another group of investigations have been undertaken from a more theoretical viewpoint. The interpretation of these data has been that of pure physical chemistry. Investigation of liquid and solid alloy systems and of the heat and free energy of formation of such systems has led to theories regarding the nature and …  Lire la suite

Venturia inaequalis (Cke.) Wint., the apple scab fungus, grows during the summer on the living leaf, producing a mycelium which develops only between the cuticle and the epidermis. But when the infected leaf dies naturally, this mycelium then grows as a saprophyte and sends its hyphae all through the tissues of the dead leaf. It is during this saprophytic part of its life cycle that the fungus passes through its sexual stage. Ascogonial hyphae arise in the mesophyll of the dead leaves and, after fertilization by antheridia from oppositely sexed thalli, initiate the perithecia. These fruiting structures then are the …  Lire la suite

Conditions in the field of American literature during the first four decades of the twentieth century were not always helpful or encouraging to aspiring writers in the United States. The literature which may be called characteristic of this period began with the novels which writers like Stephen Crane and Theodore Dreiser were publishing around 1900. These men initiated a new period in American writing, which developed in power and maturity especially during the twenties and thirties. For the first fifteen years of the century, however, neither academic criticism nor journalistic opinion were prepared to favor the new growth. Taking American …  Lire la suite

This study in the area of medical social statistics was begun in 1945 when the writer was engaged as a student worker on a fellowship at the Massachusetts General Hospital, Boston, in the Social Service Department. It seemed appropriate at that time to undertake some evaluation of the new scheme in medical social statistics which had been inaugurated at that hospital in January of that year. In the course of enquiring into the background of this new plan, the writer found it both necessary and intensely interesting to examine the reports of the department’s work from its beginning in 1905. …  Lire la suite

The Sclerostomes, also known as Redworms and Palisade Worms, belong to the large group of parasitic bursate nematodes provided with a terminal buccal capsule and armed with one or more fringes of cuticle called “leaf -crowns”. They are found universally in horses and other equines, where they may cause serious diseases. The most important genera, from the standpoint of their prevalence in horses, are Strongylus, Triodontophorus, and Trichonema, the latter being generally known as the Cylicostomes. Other genera of the Family Strongylidae which comprise part of the Sclerostome grouping are Craterostomum, Oesophagodontus, and Gyalocephalus. There are approximately fifty different species …  Lire la suite

During two years spent as a technician in the Department of Bacteriology of the Children’s Memorial Hospital, it was noted how frequently cultures from children with upper respiratory tract infections yielded none of the common pathogens by routine laboratory aerobic culture methods. The etiologic agents of cases such as these might well be viral or aerobic bacteria not ordinarily recognized as pathogenic, or anaerobic bacterial species. The anaerobic bacterial flora of the upper respiratory tract has been but little studied, possibly due to the time consuming and cumbersome methods of obtaining anaerobiosis; possibly because relatively little is known about anaerobic …  Lire la suite

The story of blackhead, insofar as scientists have deciphered its perplexing problems, is that of a unique relationship existing between a number of avian hosts, a protozoan parasite and a parasitic nematode vector. Blackhead is acknowledged to be economically the most important disease of turkeys, having forced the abandonment of turkey rearing in many parts. Fortunately, in other susceptible species of birds, the disease seldom causes serious losses. In the caeca of the chicken, and perhaps,too, in the caeca of other susceptible birds, the blackhead organism, Histomonas meleagrldis, lives and multiplies without producing clinical disease except on rare occasions. Another …  Lire la suite

Some of the earliest studies of the blood volume have been in those conditions associated with anemia or polycythemia. The obvious questions that present themselves are; does anemia truly represent a reduction of the red cell mass or is it merely apparent because of an increased plasma volume; is the polycythemia due to an increased red cell mass or a reduction of the plasma volume? Indeed, the early workers suggested that chlorosis was an apparent anemia only, with a normal red cell mass, and that pernicious anemia was a true anemia. The importance of a three dimensional view of the …  Lire la suite

Two theories have been offered to explain the wilting symptoms displayed by plants attacked with vascular invading micro-organisms. These are the bundle plugging theory and the toxin theory. According to the former the movement of water through the water conducting vessels of the stem is hindered or even prevented by the clogging of the vessels with the pathogenic bacteria or fungi and other obstruction materials such as tyloses and gums formed under the stimulation of the pathogen. The proponents of the toxin theory claim that the wilting symptoms are due to toxins formed by the invading organisms or resulting from …  Lire la suite

[...] Cette these a pour but de traiter comment Colette a vu et peint la nature en gdn^ral. Nous avons essays d'analyser son attitude en face du monde, c'est-a-dire, savision du monde aussi bien que la traduction de ce monde qu'elle nous a livre. Et nous avons voulu isoler ce que vision et traduction comportaient d'elements objectifs, ou sentimentaux, ou esthetiques, ou philosophiques. II existe deja a l'University McGill une these de maitrise intitulee Les Animaux dans Colette, qui est surtout une etude psychologique de certains animaux prefers. Nous nous proposons ici, en etudiant la nature, de considerer le sujet …  Lire la suite

[[The]] purpose of this study is twofold: 1) To determine the degree to which the rhythmic electrical activity of the cortex is dependent upon its afferent connections, and 2) to study changes in reactivity of cerebral cortex following its denervation.  Lire la suite

[...] Although much has been written and a great deal of elegent theory developed for numbers of the form x + iy, where i2 = -1 and x and y are real numbers, viz, the ordinary complex numbers; very little has been said concerning an analogous system of numbers of the form x + jy where j2 = 1. This system we shall term the "Hyperbolic Complex Numbers", due to their connection with the hyperbola and the hyperbolic functions. The purpose of this paper will be to develop the number theory properties of this system. [...]  Lire la suite

[...] At the present time, when the birch stands of the forest are being destroyed, both in the maritime provinces and in Quebec, it would seem wise to emphasize the economic importance of keeping the larger infestations of A. pectoralis down to a minimum. [...]  Lire la suite

Howes, F. (Supervisor)  Lire la suite

It is general nowadays for Master's theses to be 'original' or 'creative'. This thesis lays no such claim. In effect it is a re-test of an experiment on visual perception conducted recently at Harvard University by J. Bruner and C. Goodman. Our justification for this deviation from tradition rests in our agreement with our Research Director that an experiment which formulates tests, and validates hypotheses which are of importance to a science is certainly worth repeating. [...]  Lire la suite