Engineering

The transient membrane fouling during the concentration by cross-flow ultrafiltration of soy protein extracts subjected to electroacidification is examined by combining experimentation with computational fluid dynamics (CFD) modeling. Transient reversible (water removal) and irreversible (chemical removal) membrane fouling resistances, permeate flux, protein concentration and protein concentration dependent viscosity were obtained experimentally. A detailed fouling resistance model to describe the reversible and the irreversible fouling resistances was developed in terms of the microscopic local transient and spatial pressure difference, permeate velocity, protein concentration and initial fouling resistance conditions. This fouling resistance model is used in a boundary condition for the permeate velocity when solving the momentum and protein concentration continuity equations with CFD. The model estimates agree with experimentally measured permeate flux, protein concentration and transient irreversible and reversible fouling resistances. In particular, the model estimated accurately the transient reversible and irreversible fouling resistances, a limitation of most previously published models. The model shows considerable axial variation of the reversible fouling resistance and the protein concentration at the membrane surface which supports the inadequacy of the film theory and the assumptions for constant properties. In contrast, the irreversible fouling resistance remains relatively constant with axial position suggesting protein adsorption.

The application of reverse osmosis (RO) to recover nutrients from biomass leachate, with special reference to permeate flux behavior during the filtration of the leachate, is investigated in this paper through a comprehensive laboratory and modeling approach. Various sources of biomass, including soybean straw, switchgrass, and miscanthus, were industrially leached using distilled water with agitation during the extraction experiments. The leachates were filtered using a RO flat sheet membrane module to recover the nutrients and water. On the basis of inductively coupled plasma (ICP) analytical results, calcium, magnesium, phosphorus, and silica for all types of biomass leachate samples had rejection efficiencies of >80%. Permeate flux decreased sharply at the beginning of the filtration, followed by a slight decline during the filtration process. A hybrid intelligent model based on a feed-forward artificial neural network (ANN) was also developed to estimate the permeate flux during the filtration in terms of the filtration time and total solid concentration in the leachate. A Levenberg−Marquardt optimization algorithm was chosen to perform the training phase for the network. An ANN with four neurons in one hidden layer was selected as the optimum structure, such that a maximum percent absolute error of 14% was attained while predicting the permeate flux. A reasonable agreement was observed between the ANN predictions and experimental data, which exhibits the potential usefulness of the hybrid ANN model to predict permeate flux during RO filtration of biomass leachate.

Steam-assisted gravity drainage (SAGD) is an enhanced oil recovery technology for heavy (or viscous) oil and bitumen that involves drilling two horizontal wells in underground formations. Laboratory work, pilot-plant studies, and mathematical model development, which are generally costly, difficult, and time-consuming tasks, are taken into account as important stages in finding an effective and economical method and also predicting the performance of the SAGD technique for a certain heavy-oil reservoir. Currently, smart techniques as accurate and fairly fast tools are highly recommended for these purposes. In this work, an experimental study and an artificial neural network (ANN) linked to an optimization technique, called particle swarm optimization (PSO), were employed to obtain performance parameters such as the cumulative steam-to-oil ratio (CSOR) and recovery factor (RF) for the SAGD process. The outputs of the developed connectionist modeling (i.e., ANN− PSO) were compared with actual data, showing an average error lower than 7%, mostly because of the supremacy of the ANN− PSO method compared to the conventional ANN method and the correlations developed in this study. Furthermore, it is concluded that, among the contributing parameters, reservoir thickness and oil saturation have the most significant impacts on RF and CSOR during SAGD operations. The current study confirms the potential of hybrid connectionist modeling to screen heavy-oil fractured reservoirs for the SAGD process.

This study illustrates the benefits of Celite ® supported lipase sol-gels for the transesterification of triolein to produce methyl oleate. A ping-pong bi-bi kinetic model was developed and validated taking into account the inhibition effects of methanol and glycerol as well as the effect of temperature. Although initial reaction rate models are useful for predicting the kinetics in the absence of products, a kinetic model beyond the initial conditions that considers glycerol inhibition is important. The model developed was consistent with the experimental data (R 2 = 0.95) predicting an increase in methyl oleate production with increasing methanol concentration up to an optimal range of 1.3 M to 2.0 M depending on the temperature. In general, increasing the temperature increased the initial reaction rate for the immobilized lipase over the temperature range of 40-60 • C. Based on the kinetic constants, the maximum velocity of the reverse reaction is about 25% slower than that of the forward reaction and glycerol inhibition has a more significant effect on the reaction kinetics than methanol inhibition. The model developed would be useful for understanding the effects of methanol and glycerol inhibition as well as temperature on the production of methyl oleate using lipase-mediated enzymatic transesterification.

This paper outlines a survey validation process and presents preliminary findings from a study of Civil and Electrical and Computer engineering graduate perspectives on their program with respect to the Canadian Engineering Accreditation Board (CEAB) Engineering Graduate Attributes. The study’s research question was: What breadth and depth of knowledge, as specified by the Engineering Graduate Attributes, do undergraduate engineering students perceive they have achieved? This research is part of a larger research agenda in these departments in UBC engineering to collect data for the ongoing processes of curriculum improvement and CEAB accreditation. While the Civil and Electrical and Computer Engineering departments at UBC collaborated in this study, different survey instruments were produced for each context. This paper focuses primarily on the Civil Engineering Graduate Attributes Survey Tool.

In this work, a full-integrated very-low power SiGe Power Amplifier (PA) is realized using the IHP (Innovations for High Performance), 0.25µm-SiGe process. The behaviour of the amplifiers has been optimized for the 2.1-2.4 GHz frequency band for a higher 1-dB compression point and high efficiency at a lower supply voltage. The PA delivers an output power of 3.75 mW and 1.25 mW for 2V and 1V, respectively. The PA measurements yielded the following parameters; gain of 13 dB, 1-dB compression point of 5.7 dBm, and Power-Added-Efficiency of 30% for 2V supply voltage. The PA circuit can go down to 1V of supply voltage with a gain of 10 dB, 1-dB compression point of 1 dBm, and Power-Added-Efficiency of 20%. For both supply voltages, the input and the output of the circuit give good reflection performance. With this performance, the PA circuit may be used for low-power biomedical implanted transceiver systems.

There is an emerging need for fully integrated power amplifiers (PAs) for very low-power implanted wireless transceivers. A fully integrated power amplifier circuit operating at 2.45 GHz is presented in this work. The layout of the circuit was designed carefully. Optimization was performed on the interconnections between the circuit components, which resulted in minimized parasitics of the on-silicon metal wires and hence very good performance. Measurement results show that at 1.4 V supply, the PA delivers an output power of 4.5 mW with a 28.5 % power-added efficiency (PAE) and a gain of 19.5 dB. With this performance, the circuit has proved to be well-suited for low-power biomedical implanted transceiver systems

Achieving power-and area-efficient fully integrated transceivers is one of the major challenges faced when designing high-frequency electronic circuits suitable for biomedical applications or wireless sensor networks. The power losses associated with the parasitics of on-chip inductors, transistors, and interconnections have posed design challenges in the full integration of powerefficient CMOS radio-frequency integrated circuits (RF ICs). In addition, the parasitics of on-chip passive components that are integrated on lossy silicon substrates have made CMOS-based integrated circuits inferior to their compound-semiconductor counterparts. The parasitic effects of on-chip interconnections play a key role in RF circuit performance, particularly as the frequency of operation increases. Neglecting these effects leads to the significant degradation in circuit performance or even failure of operation in some cases. Furthermore, unlike transistors, miniaturization of interconnections does not improve their performance. This paper demonstrates the impact of metal layer resistivity and layout parasitics on an RF power amplifier (PA) and a low-noise amplifier (LNA). A nonlinear fully integrated 2.4-GHz class-E PA, with a class-F driver stage, and a 5-GHz LNA are discussed. The circuits were fabricated in a standard 0.18-μm CMOS technology. The layouts of the presented CMOS amplifiers were designed by carefully modeling the interconnection wires during the simulations and optimizing their widths for minimum parasitic effects and hence optimum measured circuit performance. Due to the careful layout design and interconnection optimization, the implemented amplifier circuits showed a good match between the measured and simulated performance characteristics.

In recent years, high strength concrete (HSC) has been widely used. With advent of super plasticizers and micro-silica; HSC with strength higher than 100 MPa can be reached. This helped in many fields of construction; specifically pretensioned bridge girders. This high strength permitted longer spans, larger spacing between girders thus reducing total bridge cost. Lately, designers have been using partially prestressed members technique, which tends to decrease the prestressing steel and eventually leads to more economical sectional design. The Use of HSC partially prestressed girders is very promising, however HSC was found to be more brittle. Accordingly, the girder may exhibit brittle/less ductile behavior and less deformability. There is also lack of knowledge about the effect of HSC on cracking pattern of such members. This study presents experimental observations for the deflection and cracking behaviour along with ductility study of six tested partially prestressed beams.

Structural systems have been evolving in terms of material properties and construction techniques, and their levels of protection against hazardous events have been the focus of different studies. For instance, the performance of the lateral force resisting systems has been investigated extensively to ensure that such systems would provide an adequate level of strength ductility capacity when subjected to seismic loading. However, with the increased occurrence of accidental and deliberate explosion incidents globally by more than three fold from 2004 to 2012 (Lange 2013), more studies have been focusing on the performance of such systems to blast loads and the different methods to quantify the inflicted damage. Although both blast and seismic design requires structures to sustain a level of ductility to withstand the displacement demands, the distributions of such demands from seismic ground excitation and blast loading throughout the structural system are completely different. Therefore, a ductile seismic force resisting system may not necessarily be sufficient to resist a blast wave. To address this concern, North American standards (ASCE 59-11 (ASCE 2011), CSA S850-12 (CSA 2012a) provide response limits that define the different damage states that components may exhibit prior to collapse. First, I would like to express my deep appreciation to my co-supervisors Prof. Wael El-Dakhakhni and Prof. Michael Tait. I was lucky to be mentored by such professors with high ethical values, and who are humble, supportive, energetic, open-minded, and creative. I am grateful for our discussions that significantly impacted the quality of the dissertation. Special thanks are due to my supervisory committee members, Dr. Lydell Wiebe and Dr. Tracy Becker for their valuable guidance and suggestions. Their helpful comments and discussions during our meetings are greatly appreciated. No words can express my gratitude to my brother and travelling companion Dr. Shady Salem for his continuous support. The experimental work would have never been completed without his help. I would also like to deeply thank Dr. Mohamed Ezzeldin, Mr. Moustafa Morsy, Dr. Ahmad Siam, and their families whom I consider my second family in Canada. Special thanks are due to the Applied Dynamics laboratory (ADL) team; Mr. Kent Wheeler and Mr. Paul Heerema, for the help, advice and dedication they provided, my experience in the ADL would not be the same without them. I would also like to thank Dr. Manuel Campedelli for the time and help he provided. I also like to thank all of my friends and colleagues Dr.

Epithelial ovarian cancer (EOC) is the deadliest female malignancy. The Wnt/β-catenin pathway plays critical roles in regulating embryonic development and physiological processes. This pathway is tightly regulated to ensure its proper activity. In the absence of Wnt ligands, β-catenin is degraded by a destruction complex. When the pathway is stimulated by a Wnt ligand, β-catenin dissociates from the destruction complex and translocates into the nucleus where it interacts with TCF/LEF transcription factors to regulate target gene expression. Aberrant activation of this pathway, which leads to the hyperactivity of β-catenin, has been reported in ovarian cancer. Specifically, mutations of CTNNB1, AXIN, or APC, have been observed in the endometrioid and mucinous subtypes of EOC. In addition, upregulation of the ligands, abnormal activation of the receptors or intracellular mediators, disruption of the β-catenin destruction complex, inhibition of the association of β-catenin/E-cadherin o...

The existing hydrologic model of the Ganaraska River Watershed, developed about twenty years ago, and the Regulatory Flood, estimated using that model, was not considered reflective of current watershed conditions by the Ganaraska River Conservation Authority (GRCA). Also, the Cameco Corporation property near the mouth of the Ganaraska River is potentially affected by the Regulatory Flood limit and the Corporation, therefore, had an interest in accurately defining the Regulatory Flood limit. The GRCA and Cameco agreed to address the necessary technical update with two studies-a hydrology study prepared by the GRCA with the assistance of Schaeffers Consulting Engineers and a hydraulics study prepared by Cameco Corporation with the assistance of AMEC. The peak flow estimates computed with the newly developed hydrologic model, a component deliverable of the recently completed hydrology study, changed from those previously generated using the 1980's vintage simulation model. Therefore, there was a need to update the present Regulatory Flood Plain delineation and mapping to reflect the new flood flow estimates. The objective of this study was to undertake a hydraulic assessment of the Ganaraska River from the mouth of the river at Lake Ontario to the Robertson Street Bridge, as illustrated in Figure 4.1, and to compute the water levels for the purposes of identifying flood proofing elevations for the Cameco site.

Over the course of the year, our company's workplace fitness program quickly became popular throughout the plant, and to my surprise reached full capacity within a few months. In order to keep this program running and made available to everyone, we implemented an extra class, allowing for 10 extra staff per day to attend.