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The goal of this study is to find a more organized and directed approach to build models for mixture systems. An attempt is made to generate and then compare Scheffe (mixture) models with those generated by McGee using the ‘conventional’ method for neoprene data. The models are judged on their ability to predict physical properties of neoprene by comparing the following: predicted and actual values by inspection; the calculated % error of prediction; the squared multiple correlation coefficients; adjusted squared multiple correlation coefficients; the Fisher statistic and significance probability. Scheffe models do not have an intercept term and test statistics which appear on the computer printout are inflated. Pseudocomponents and Scheffe-equivalent models are procedures used to obtain accurate test statistics to describe the selected Scheffe models. The effectiveness of these two procedures is evaluated. Results indicate that Scheffe models are better predictors for the physical properties of neoprene than those generated by McGee using the ‘conventional’ method in 1980. Scheffe-equivalent equations are found to be more reliable than pseudocomponents for generating accurate test statistics to describe the selected Scheffe models.

Seismic isolation, in which a flexible layer is used to separate a structure from the ground below, is a proven method for reducing earthquake demands that has been recently introduced into the 2015 Canadian building code. Typical installations of seismic isolation use rigid diaphragms to bound the end plates of the isolators, which is easily implemented in new build scenarios but requires extensive excavation and foundation work in retrofit applications. An alternative form of isolation involves placing the isolation plane on top of first floor columns, potentially resulting in flexible boundary conditions. There have been very few experimental programs that mimic these flexible boundary conditions. To address conditions that may be found in column-top isolation design schemes, such as flexible framing and lightly axially loaded corner bearings, an experimental program on a quarter-scale column-top isolation system was conducted. The goals of the investigation were to investigate how rotations of both top and bottom bearing end plates impact key design assumptions such as horizontal stiffness, rotational stiffness, and stability, and how these effects change with axial load. Experimental findings showed that flexible boundary conditions reduce horizontal stiffness based on the sum of rotation at the ends, regardless of the rotation of one bearing end plate with respect to the other. This decrease is dependent on axial load, with more axial load leading to a higher decrease in horizontal stiffness. The rotational stiffness significantly decreases with bearing shear strain and models that use linear, elastic rotational springs underrepresent rotations at the boundaries. Lastly, traditionally used design limits for stability can be used for bearings of moderate shape factor (S1 = 19.6 used in testing) bounded by flexible framing, but these theoretical limits can overestimate the experimental determined limits by nearly double for bearings of low shape factors (S1 = 7.9 used in testing). / Thesis / Master of Applied Science (MASc) / Seismic isolation, in which a flexible layer is used to separate a structure from the ground below, is a proven method for reducing earthquake demands that has been recently introduced into Canadian building code. Typical installations of seismic isolation use rigid diaphragms to bound the end plates of the isolators, which is more easily implemented in new build scenarios but requires extensive excavation and foundation work in retrofit applications. An alternative form of isolation involves placing the isolation plane on top of first floor columns, potentially resulting in flexible boundary conditions. To address this, an experimental program on a quarter-scale column-top isolation system was conducted to investigate how rotations of both top and bottom bearing end plates impact key design assumptions such as horizontal stiffness, rotational stiffness, and stability. This research can help to expand the number and types of buildings isolation can be applied to, creating more resilient communities.

The report of the Baruch Committee on the rubber situation included a recommendation for a production of 60,000 ton per year production of Thiokol by the end of 1943. Thiokol is a type of synthetic rubber formed by the reaction between organic dihalides and inorganic polysulfides. They find wide application where resistance to petroleum oils, organic solvents, and low permeability. The purpose of this investigation was to design a Thiokol with a production of 2000 tons per year. Research was conducted to determine operating conditions for the production of sodium polysulfide, one of the raw materials for the production of Thiokol, and conditions for the Thiokol production. The information for the design of the ethylene dichloride, the other raw material of Thiokol, was obtained from literature. The studies of the polysulfide solution showed that 13.83 grams of sulfur would react with every 10. 2 grams of caustic when sulfur was in excess. The amount of sulfur that reacted was independent of the amount of excess sulfur. Other studies indicated that a dilution of 100 cc. of water per 10.2 grams of caustic was desirable, and that a period of 12 minutes of boiling gave the highest polysulfide content. Further time of boiling was not deleterious, but neither did the amount of sulfur as polysulfide increase. A complete sulfur analysis of the polysulfide solution showed a polysulfide content approximately 3.2 times that of the monosulfide indicating higher polysulfides than tetrasulfide being formed. Experiments conducted with the polysulfide solution as prepared and using just ethylene dichloride gave unsatisfactory results, although products obtained using lower temperatures were slightly better than those with higher temperatures. Magnesium chloride was unsatisfactory as a dispersing agent using the polysulfide as prepared, but ethyl alcohol gave satisfactory results. Studies of dilution yielded products of high values ranging from 91 to 75. Large amounts of freshly precipitated were satisfactory as dispersing agents but with small amounts the value of the product was 60. The highest valued product obtained was with 5 cc. of ethyl alcohol and dilution, but a satisfactory product, value 85, was obtained with one gram of magnesium chloride and dilution. Since the latter was more economical, these conditions were selected for the design of the Thiokol plant. Preconstruction cost accounting of the designed plant indicate an annual cost of $610,087 per year and a surplus of $589, 912 per year. This is based on a selling price of $0.30 per pound for Thiokol. / M.S.