We deployed depth-specific drifters in the western and eastern parts of the South Arm basin of Lake Opeongo and collected zooplankton samples at west and east fixed stations and at additional up- and downwind locations at three depths of the epilimnion under a range of wind conditions. Water currents had highest association with the immediate wind direction and the direction they travelled was dependent on wind strength. Along the main west-east fetch large zooplankton resided high in the epilimnion and were transported eastwards by strong surface currents where they accumulated. Small zooplankton were more uniformly distributed with depth and their accumulation patterns and transport mechanisms are less clear. Along shorter fetches oriented off-angle with the main one accumulations of zooplankton occurred at all downwind locations under heavy winds although the patterns are more variable and complex. These downwind accumulations likely create high quality habitat for warm water fish.

We deployed depth-specific drifters in the western and eastern parts of the South Arm basin of Lake Opeongo and collected zooplankton samples at west and east fixed stations and at additional up- and downwind locations at three depths of the epilimnion under a range of wind conditions. Water currents had highest association with the immediate wind direction and the direction they travelled was dependent on wind strength. Along the main west-east fetch large zooplankton resided high in the epilimnion and were transported eastwards by strong surface currents where they accumulated. Small zooplankton were more uniformly distributed with depth and their accumulation patterns and transport mechanisms are less clear. Along shorter fetches oriented off-angle with the main one accumulations of zooplankton occurred at all downwind locations under heavy winds although the patterns are more variable and complex. These downwind accumulations likely create high quality habitat for warm water fish.

Polymeric monodispersed nanocarriers with controlled shape and size have been fabricated in the literature primarily using top down processes such as imprint lithography. In this dissertation, the geometric and material property limits of imprint based techniques have been studied. The resulting insight has led to the creation of new processes that significantly extend the limits of imprint processes in several ways: (i) Ability to print nanocarriers with ultra-soft biomaterials (<1MPa modulus); (ii) Sub-50nm diameter cylindrical particles with >3:1 aspect ratio with >5x enhanced wafer yield; (iii) Creation of reentrant barrel shapes that have the potential to be valuable in cellular uptake, such shapes being significant as they lead to fundamental demolding challenges in prior imprint processes; and (iv) Multi-layer nanocarriers which can potentially provide sophisticated functionality such as tailored release kinetics of one or more drugs. By understanding the requirements of bio-functional nanocarriers and related manufacturing constraints, a previously explored Bio Jet and Flash Imprint Lithography (Bio J-FIL) process was refined to perform successful imprints and improve the nanocarrier fabrication scalability. Next, two new fabrication processes have been developed. The first process is called Decoupled Functional Imprint Lithography (D-FIL) which allows fabrication of ultra-soft bio-functional materials (modulus of <1 MPa), challenging sizes (sub-50nm diameter cylinders with aspect ratio > 3:1), and reentrant barrel shapes. The second decoupled process, Dual Removable Layer Lithography (DRLL), has been developed to specifically create multi-layered cylindrical nanocarriers. Nanocarriers fabricated with D-FIL and DRLL process have been shown to chemically bind with an imaging agent, and model anti-cancer drugs. Drug (siRNA) retention (>90% over 9 days) and stimuli triggered release studies were performed on sub-100nm cylindrical PEGDA nanocarriers. It was found that these nanocarriers show accelerated triggered drug release when exposed to a hydrolase, Cathepsin B. While the exact mechanisms causing the triggered release are not fully understood, a few possible explanations are provided based on the experiments reported. Finally, the D-FIL, the DRLL, and the refined Bio J-FIL processes have been successfully demonstrated at the prototype scale as well as at the pilot scale in collaboration with an industrial partner, Molecular Imprints Inc. / text

In this study, the effect of speed was investigated on the breakage rate of UG2 platinum ore in a batch mill of 5 dm3 and 175 mm internal diameter. One size fraction method was carried out to perform the experiment. Five mono-sized fractions in the range of 1.180 mm to 0.212 mm separated by √2 series interval were prepared. The fractions were milled at different grinding times (0.5, 2, 4, 15 and 30 min) and three fractions of mill critical speed were considered (20%, 30%, and 40%). The target of critical speed below 50% was due to the need of lower energy consumption in milling processes. The selection and breakage function parameters were determined and compared for fractions of critical speed. First the grinding kinetics of the ore was determined and it was found that the material breaks in non-first order manner. Thereafter, effective mean rate of breakage was determined. It was found that the rate of breakage increased with increase of mill speed and optimum speed was not reached in the range of chosen mill speed fractions. Again the rate of breakage was plotted as a function of particle size, the optimum size was 0.8 mm when milling at 30% critical speed. As for 20% and 30% optimum size was not reached. The selection function parameters estimated at 30% critical speed were 𝑎0 = 0.04 min−1 , 𝛼 = 1.36, 𝜇 = 0.9 mm, and Λ = 3. Breakage function parameters were determined and was noticed that the material UG2 platinum ore is non-normalised, i.e. Φ value was changing from 0.25 to 0.90 depending on feed size and mill speed. The parameters 𝛽 and 𝛾 were constant at 7.3 and 1.17 respectively. / College of Science, Engineering and Technology / M. Tech. (Chemical Engineering)