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<p> A report follows in which five different conditions of support of stepped crane columns were investigated. In each case the curvature or moment equations representing the column in its just-buckled condition are determined. The general solution of each differential equation is then found and solved in terms of the boundary conditions to obtain a transcendental equation which gives the critical buckling length. This transcendental equation is solved for the lowest possible value to get the critical buckling length. This lowest value is compared to the Euler critical buckling value in order to get the effective length factor.</p> / Thesis / Master of Engineering (MEngr)

<p> A detailed synopsis of the state-of-the-art in the field of the Structural Analysis of sandwich beams is presented. Deficiencies, inaccuracies, lack of clarity, and the imposition. of unnecessary assumptions of behaviour found -in the related bibliography are presented in a comparative fashion. A method of analysis with obvious advantages over the others studied in this thesis is derived, and its use is suggested. The presentation of all methods of analysis is made under the most general cases of dimensions and loadings to make them as applicable as possible to the common cases encountered in sandwich components for the building industry. </p> <p> Experimental work carried out on several materials with some potential to be used in sandwich members for buildings and the tests carried out on some sandwich beams and beam-columns are reported. </p> / Thesis / Master of Engineering (MEngr)

This thesis presents advancements in the development of hybrid and data-driven models of distillation columns. First, it introduces a hybrid model structure that incorporates a novel multiplicative correction term for inferential monitoring. This model architecture outperforms previous hybrid structures, especially in extrapolation conditions, and can be adapted for different conditions. Second, it presents a methodology for selecting temperature measurement for inferential models. This methodology demonstrates that nonlinear columns can be effectively modeled with linear models requiring two temperature measurements per section (previous works state requiring more) when the measurements are selected systematically. Finally, an iterative Real-Time Optimization (RTO) based on an augmented inferential data-driven model is demonstrated. The accuracy of the model enables estimation of the sensitivity matrix of the plant from the model without the need for additional plant measurements. The proposed RTO framework produces results similar to those achieved by optimizing rigorous tray to tray distillation models. / Thesis / Candidate in Philosophy / This thesis presents advancements in the development of hybrid and data-driven models of distillation columns. First, it introduces a hybrid model structure that incorporates a novel multiplicative correction term for inferential monitoring. This model architecture outperforms previous hybrid structures, especially in extrapolation conditions, and can be adapted for different conditions. Second, it presents a methodology for selecting temperature measurement for inferential models. This methodology demonstrates that nonlinear columns can be effectively modeled with linear models requiring two temperature measurements per section (previous works state requiring more) when the measurements are selected systematically. Finally, an iterative Real-Time Optimization (RTO) based on an augmented inferential data-driven model is demonstrated. The accuracy of the model enables estimation of the sensitivity matrix of the plant from the model without the need for additional plant measurements. The proposed RTO framework produces results similar to those achieved by optimizing rigorous tray to tray distillation models.

No description available.

yes / This paper presents a relatively simple column strengthening procedure using unbonded wire rope and T-shaped steel plate units. Twelve strengthened columns and an unstrengthened control column were tested to failure under concentric axial load to explore the significance and shortcomings of the proposed strengthening technique. The main variables investigated were the volume ratio of wire ropes as well as geometrical size and configuration of T-shaped steel plates. Axial load capacity and ductility ratio of columns tested were compared with predictions obtained from the equation specified in ACI 318-05 and models developed for conventionally tied columns, respectively. The measured axial load capacities of all strengthened columns were higher than predictions obtained from ACI 318-05, indicating that the ratio of the measured and predicted values increased with the increase of volume ratio of wire ropes and flange width of T-shaped steel plates. In addition, at the same lateral reinforcement index, a much higher ductility ratio was exhibited by strengthened columns having a volume ratio of wire ropes above 0·0039 than tied columns. The ductility ratio of strengthened columns tested increased with the increase of flange width, thickness, and web height of T-shaped steel plates. A mathematical model for the prediction of stress–strain characteristics of confined concrete using the proposed strengthening technique is developed, that was in good agreement with test results.

Design practice at the present day trends toward more and more complex forms of the reinforced concrete frame. / Master of Science

In trying to approach, analytically, the results of the tests on the experimental plate, the case of an interior panel of an infinitely large slab was used, This case produced solutions of greater negative stresses at the columns and lesser positive stresses at the center, than the experimental results. If an analogy is drawn between the slab supported on its welded columns and a single span bent, the relationship between the experimental results and the analytical results is similar to the relationship between the beam of the elastic bent and the beam of one with infinitely stiff columns. If this thesis is to be used as part of a basis for further exploration into the interaction of slabs and columns, it is suggested that the plate-bent analogy be carried further, Just as the moment values in the beam of the elastic bent lie between the values found by considering infinitely stiff columns and columns with no stiffness, so will the moment values in the slab lie between the cases of the interior panel of an infinitely large slab and a single panel hinged at the four corners. It is therefore suggested that analytical solution based on a single panel hinged at the four corners would produce a limit for the positive moments at the center of the plate. / Master of Science

Wide-bore, fused-silica capillary columns can be an excellent replacement for packed columns in many cases. They can provide higher surface inertness and thermal stability, as well as higher efficiency or speed of analysis. Wide-bore, open-tubular (WBOT) columns with thick films have higher sample capacities than conventional narrow-bore capillary columns and can be used in unmodified packed-column gas chromatographs. The majority of gas chromatographic analyses are still performed using packed columns. Many chromatographers associate open-tubular columns exclusively with split injection, often perceived as less repeatable or quantitative. Also, many packed-column methods use application-specific stationary phases which are not readily available on capillary columns. WBOT columns with standard phases can often be substituted due to higher available efficiencies. While several studies have been published on qualitative differences, there is little comparative quantitative data available on O.53â mm I.D. and packed columns. / Master of Science

Historically, environmental research associated with Appalachian coal surface mines focused on acid mine drainage and reclamation. Recent studies suggest that electrical conductivity (EC) levels above 500 ?S cm-1 can impair Appalachian streams, shifting the focus towards limiting release of total dissolved solids (TDS) and associated elements of concern. Previous column studies utilized an unsaturated bi-weekly leaching design to evaluate the behavior of overburden with respect to TDS, pH, and trace metals. The objective of this study was to determine the effects of column saturation, leaching solution chemistry, and leaching cycle on the release of TDS and associated elements from an unweathered sandstone. Treatments evaluating potential saturation, leaching solution pH, and leaching cycle included saturated, standard method, vacuum, and standpipe fitted columns; simulated acid rain, de-ionized water, and CaCO3 leaching solutions; and 2x week-1, 1x week-1, 2x month-1, and 1x day-1 leaching cycles. Saturation level in the column significantly impacted leachate pH, EC level, and the release of sulfate, bicarbonate, and associated cations by potentially affecting trace sulfide oxidation and carbonate dissolution reactions. Little evidence of saturation was noted with the standard method. Leaching solution bulk chemistry did not alter leachate chemistry. Longer times between dosing cycles corresponded to higher EC, bicarbonate, and associated cation levels, especially over time. Sulfate, Ca, and Se exhibited the greatest percent release based on total mass losses during peak elution. For managing TDS, time between precipitation events and saturation level can strongly affect short and long-term EC level, its major contributors, and elements of concern. / Master of Science