Typescript, etc.

Typescript, etc.

In a preliminary study, different amounts of iron and aluminum phosphates were added to Bf and Ah horizon materials, and potassium phosphate was added to a mixed L-F-H horizon material. The soil materials were then incubated for 16 days and analysed for extractable Al, Fe and P (Olsen's method). Results after incubation showed that the Bf and Ah horizon material had more extractable Fe and Al than the L-F-H material. Extractable P suggested a P deficiency in Bf soil material and a relatively high level of available P in L-F-H material. Addition of large amounts of iron and aluminum phosphates to the Bf and Ah material yielded only slight increases in extractable P. However, the amounts of extract-able P indicated that the phosphate forms added to these soil materials could remain partially extractable for some time and it was inferred that they resembled native soil phosphates rather than fertilizer phosphates. Next, the availability of phosphorus to two conifer species (Pinus patula and Cupressus lusitanica) was tested for the same three forest soil materials. Different amounts of phosphorus were added to these materials, as before, and seedlings of the two plant species were grown for 178 days. Phosphorus uptake by the seedlings was measured and correlated with the concentration of soil phosphorus extracted by five methods (Bray P-l, modified Bray P-l, Olsen, Truog and Mehlich), in order to identify the most suitable extraction method to serve as an index of soil phosphorus availability to the tree seedlings. Seedling growth (height, diameter, and biomass) was least for seedlings grown in Bf and greatest for those grown in L-F-H materials. Seedlings grown in Bf soil material showed, generally, greater biomass for roots than for foliage or stem, but those grown in the least P-deficient (L-F-H)material had greater biomass for foliage than stem or roots. Analysis of P uptake by seedlings indicated slightly higher P concentration in roots than in stem or foliage. Total P uptake was least from Bf and highest from L-F-H materials. Phosphates added to mineral soil gave a substantial relative increase in total P uptake, especially for Bf materials. However, for L-F-H material, added phosphates caused increases in uptake which were mostly large in absolute value, but small relative to uptake from unamended soil. Cupressus lusitanica seedlings accumulated more phosphorus than Pinus patula seedlings with the low P levels, while the opposite was usually the case with the high P levels. Extractable P after seedling growth was lowest in Bf and highest in L-F-H materials and it increased with increase in the amount of phosphates added. 01 sen's method extracted more P from the three soil materials than any of the other extraction methods. There were slight, inconsistent differences in the amounts of P extracted by the Bray P-l and modified Bray P-l methods. While phosphorus concentration in soil extracted by the five methods from the three soil materials where Pinus patula seedlings were grown correlated with each other, P extracted by Mehlich method from the Ah soil material failed to correlate with the other methods except the Olsen method. For pine, concentration of P extracted by all the methods from the three soil materials yielded significant (P≤0.05 and P≤0.10, respectively) correlation with P uptake from the P-deficient Bf, but failed to yield significant (P≤0.10) correlation with P uptake from Ah material. The Olsen, Truog and Bray P-l methods yielded very significant (P≤0.01) correlation with P uptake by cypress from Ah material. Correlation analysis of foliar P concentration with extractable P concentration in soil showed significant (P≤0.05) correlation for P i n us patula. with all methods. All but the Truog method yielded significance at P≤0.01. For Cupressus lusitanica, correlations were better with Bf than with Ah and L-F-H materials, and only the Olsen method yielded significance (P≤0.10) with all three materials. Overall, considering all soil materials and both species, the Olsen method yielded the most satisfactory relationships with P uptake by the seedlings and with foliar P concentration. / Land and Food Systems, Faculty of / Graduate

study was made of the solubility of synthetic hydroxyapatite (Ca₁₀(PO₄)₆(OH₂). The basic calcium phosphate was synthesized in CO₂ free systems, over a pH range of 5.0 to 8.0 using reaction temperatures of 40°, 60°, and 90°C, and reaction periods of 24 and 96 hours. The study was divided into two phases. In one phase the pH of the suspensions, and the calcium and phosphorus concentrations in solution were measured after precipitation and after redispersing the preparations in water. The application of solubility criteria to these studies showed that the differences in solubility obtained by synthesis with varying reaction period and temperature were not brought about by conditions of super saturation. Solubility was found to decrease with increased synthesis reaction period and increased temperature of synthesis. With a given temperature and synthesis reaction period the hydroxyapatite preparations had a uniform solubility. Solubility changed only when the conditions of synthesis were changed. X-ray diffraction analysis of the solid phase indicated that the solubility of hydroxyapatite decreased with increasing crystallinity. Examination with the electron microscope, however, showed that increased crystallinity was not due to increasing crystal size. Owing to the smallness of crystals, it was not possible to examine the hydroxyapatite with a petrographic microscope, and hence it was not possible to detect the presence of amorphous phases. It is possible, then, that small amounts of amorphous substances were present in the solid phase, and, as a result the apparent degree of crystallinity was altered. In the second phase, studies of the Ca:P mole ratios of the preparations showed that Mole ratios were not constant for any mode of synthesis. Further studies indicated that adsorption was of no, or at best, minor importance in determining the Ca:P ratios of hydroxyapatite. Isomorphous substitution with OH¯ions replacing PO₄¯ ions, and H₃O⁺ ions replacing Ca⁺⁺ ions might have occurred, but it was not possible to detect solubility differences which should result from this substitution. Hence it was not possible to correlate solubility with composition of hydroxyapatite. Even though the hydroxyapatite appeared to be of variable composition, it was found that this basic calcium phosphate had a definite pKsp value in the pH range of 5.0 to 8.0. / Land and Food Systems, Faculty of / Graduate

[No abstract available] / Land and Food Systems, Faculty of / Graduate

[No abstract available] / Land and Food Systems, Faculty of / Graduate

It is the purpose of this thesis to review, and to evaluate to a degree, some of the current theories dealing with the effects of vibrations on foundations in contact with the earth. Basic parameters, the means of evaluating them, and their applications are discussed. Conditions leading to vibration and shock problems, the significance of these problems and various correctional methods are presented. The effects of vibrations on foundations, with particular regard to settlement, are considered by means of modifications to the soil characteristics as observed by other writers. Long term consolidation tests were carried out on undisturbed and remolded clay samples, both vibrated and unvibrated. These tests were conducted in order to secure a comparison between actual test results and the conclusions given by the above theory, for what may be considered an extreme case. Cohesive soil is known to be much less sensitive to vibration than cohesionless soil, thus very little work has been done on it in this regard. The degree of independence of cohesionless soil to vibration was investigated within the limits of these tests. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

A study was undertaken of the pedogenesis of a Brown Wooded, a Grey Wooded and a Podzolized Grey Wooded soil developed over the highly calcareous Wycliffe till in the southern portion of the Rocky Mountain Trench, British Columbia. The investigation was divided into three phases. These were a study of the till at the three sites, its genetic relationship to the solum and the relative degree of soil formation and weathering in the three profiles. Analyses included mechanical analyses using the hydrometer and pipette procedures, plasticity measurements and soil reaction. Carbonates were measured by the gravimetric loss of carbon dioxide, exchangeable cations by ammonium acetate extraction and free iron by Mackenzie's dithionite technique. Samples of the clay fraction were separated by sedimentation, cleaned of sesquioxide coatings by Mackenzie's method, and analyzed for total chemical composition. Piper's sodium carbonate fusion and Corey and Jackson's hydrofluoric acid procedure were used to bring the clay into solution. Ferron and Tiron reagents were used for the spectrophotometric analysis of iron and aluminum and iron and titanium, respectively. Silica was determined gravimetrically by Piper's method. Calcium and magnesium were found by the versenate technique of Cheng and Bray after the removal of interfering heavy metals with sodium diethyl thiocarbamate. Potassium was analyzed with a Perkin-Elmer flame photometer. Other tests on the clay included determinations of the cation exchange capacity by Mackenzie's micro-Kjeldahl technique, X-ray diffraction patterns and dehydration curves. A mineralogical study was made of the very fine sand fraction. A method was devised for counting the magnetite grains in samples of from 1,000 to 2,000 heavy minerals using a magnetized needle. It was found that although there was considerable variation in the till at the three sites, particularly in mechanical composition, there were similarities in the mineralogical composition of the fine sand and clay fractions. Indeed, no satisfactory basis could be found for subdividing the till into two types. Variations down the profile of the relative abundance and composition of the coarse fraction, the shape of the summation percentage curves and the proportion of magnetite in the heavy minerals of the very fine sand indicated that the Wycliffe profile was composite while the Kinbasket was an A-B-C profile. The possibility was also noted that the Yoho profile could also be composite. The main soil formation processes were studied, including de-calcification and the movement of iron, organic matter, bases and clay. Results show that most soil development has taken place in Podzolized Grey Wooded profile, with somewhat less in the Grey Wooded soil and least in the Brown Wooded. Mineralogical studies of the very fine sand and clay fractions, however, indicate that there has not been appreciable weathering of the mineral constituents even in the intensely leached A₂[subscript p] horizon of the Podzolized Grey Wooded Soil. / Land and Food Systems, Faculty of / Graduate

In the study of the distribution of organo-clay complexes, thirty-four samples representing eight soil types were collected from the Lower Fraser Valley and the effectiveness of the three methods, viz. simple dispersion, insonation and chelating resin were examined. The use of a chelating resin was found most effective for quantitative studies while insonation was preferred for qualitative studies. For detailed characterization of the organo-clay complexes eight samples were chosen and ultrasonic agitation was used for isolating the organo-clay complexes. The organo-clay complexes varied widely in characteristics. The yield of complexes by simple dispersion, ultrasonic vibration and chelating resin ranged from 0.15 to 10.42, 0.20 to 17.20 and 1.25 to 25.70 percent by weight, respectively. The organo-clay complexes were analysed for their content of carbon, nitrogen, iron, silicon, aluminum along with carbohydrates, humic (HA) and fulvic (FA) acids. The C/N ratio of the selected complexes varied between 5.5 and 17.0 and carbohydrate content accounted for 3.3 to 16.0 percent of the complex carbon. The HA: FA ratio indicated that the major proportion of the organic component in this association was of fulvic nature, except in the case of the Podzolic Bf horizon samples in which about 2/3 of the extractable material was in the humic fraction. X-ray diffraction, infrared (IR) and differential thermal analysis were also conducted. The mineralogy was not observed to differ to a great extent except in the Ae horizon sample of the Orthic Podzol and the Btg of the Orthic Gleysol where montmorillonite was present in significant amounts. In most of the samples examined interlamellar inclusion of the organic matter was also observed. The differential thermal analysis exhibited a band near 320°C probably due to the elimination of some form of organic fraction. The IR studies indicated the bonding of silicon to organic components through oxygen linkages, however, there was no conclusive evidence of amide linkage formation between organic components and clay minerals. / Land and Food Systems, Faculty of / Graduate

An apparatus has been designed to investigate the mechanical behaviour of soils under plane strain. Provision has also been made to consolidate specimens under condition of no lateral yield prior to their shear; thus simulating the consolidation state in natural sedimentary deposits. The apparatus is suited for testing both sands and clays, including undisturbed clay samples from standard size bore hole samplers. The design permits a variety of stress paths to be followed during shear. An experimental procedure for testing both sands and clays has been developed and some test results are described. The results obtained show a general confirmation of existing information on the behaviour of soils under plane strain. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate