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UNB Scholar is an institutional repository initiative of UNB Libraries intended to collect, preserve, showcase, and promote the open access scholarly output of the UNB community. Use UNB Scholar to explore specific collections, or search all content in the repository. Material submitted to the repository will also be freely discoverable online through Google and other major search engines.
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Recent Submissions
Kinetic Study of Magnetite Precipitation Using a High-Temperature Flow-Through Loop: Experimental Apparatus and Testing Procedure
(American Society of Mechanical Engineers, 2025-04-16) Oancherd, V.; Weerakul, S.; Drost, C.; Palazhchenko, O.; Kongvarhodom, C.
An accurate understanding of material degradation mechanisms and the behavior of the key corrosion products of the materials of construction in nuclear systems is essential in minimizing radiation fields to ensure nuclear worker safety. There are no high-temperature data available on the precipitation constant (kp) of magnetite. Knowledge of this kinetic constant and its temperature dependence would allow for more accurate predictive modeling of the fouling of primary-side sections such as the steam generators. This work summarizes a modification of an experimental loop test section to study the kinetics of magnetite precipitation at temperatures relevant to Canada deuterium uranium (CANDU) reactor primary heat transport systems (PHTSs). A high-temperature, high-pressure flow-through loop was used to simulate the PHTS environment. A cooler test section representative of the temperature range in a typical CANDU-6 steam generator was used to induce supersaturation and precipitation down the length of the cooler. Work is ongoing to accurately quantify both the dissolved aqueous iron in the bulk coolant and the quantity of the precipitated magnetite on the pipe wall, with initial findings reported here.
Identification and characterization of cytochrome P450 monooxygenases for monoterpenoid indole alkaloid diversification
(University of New Brunswick, 2025-03) Mai, Zhan; Qu, Yang
Cytochrome P450 monooxygenases (CYPs) play a crucial role in monoterpenoid indole alkaloid (MIA) biosynthesis, mediating oxidation reactions like hydroxylation, epoxidation, and ring modifications that drive structural diversity. Despite advances in MIA pharmaceutical biosynthesis, many tailoring reactions remain poorly understood. By integrating transcriptomic and metabolomic data from Tabernaemontana litoralis and Vinca minor, I identified a novel MIA, 11-hydroxypseudovincadifformine, and characterized five CYPs involved in MIA oxidation. TliTbE from T. litoralis catalyzes pachysiphine formation, a lochnericine stereoisomer. TliPs18H is the first CYP modifying a pseudoaspidosperma skeleton. TliC10H hydroxylates voaphylline, while VmPs10H in V. minor completes akuammine biosynthesis and hydroxylates related MIAs. VmV10H further oxidizes structurally diverse MIAs. This study expands our understanding of MIA biosynthesis and enzyme function, unlocking new biocatalysts for MIA production and demonstrating the untapped potential of these plants in alkaloid diversification.
A comparison of the class E and class Φ2 inverter topologies for resonant capacitive power transfer
(University of New Brunswick, 2025-03) MacMillan, Matthew James; Rouse, Chris D.
The class E and Φ2 inverter topologies are compared in the context of a load-independent 13.56 MHz resonant capacitive power transfer (RCPT) system intended for electric vehicle charging. In addition to efficiency and power capacity, radiofrequency emissions are evaluated based on the harmonic content of the voltages presented to the transmit resonator. Both inverters deliver over 1 kW to the transmit resonator while maintaining system-level load independence. While the class E implementation is more efficient, the class Φ2 inverter offers solid performance and a significantly reduced second harmonic, making it desirable from an electromagnetic compatibility standpoint.
An improved MicroJIT for templated compilation in OpenJ9
(University of New Brunswick, 2025-03) Kaur, Harpreet; Kent, Kenneth B.
Programs that run on a Java virtual machine (JVM) are initially interpreted. To improve performance, Just-in-Time (JIT) compilers may be employed at run time to translate the program to native code that can be executed directly. In certain environments, the overhead of an optimizing compiler may be too high to be useful, and a non-optimizing compiler could improve performance over interpreted-only mode with limited overhead, memory footprint and compile times. Furthermore, adding a non-optimizing compiler between the interpreter and an optimizing compiler may reduce warm-up times. This is achieved by performing lightweight, template-based compilations to generate native code that runs faster than interpreting the source code, but slower than the optimized code generated by a full JIT compilation.
This work proposes an improved compiler for template-based compilations and evaluates its effectiveness. The aim is to reduce the overhead associated with compiling methods and improving the overall runtime performance. The specific improvements include improving bytecode coverage, supporting static and special methods, handling polymorphism in a template-based compiler and incorporating exception handling. The Eclipse OpenJ9 implementation of the JVM is used as a proof-of-concept to illustrate the solution, coined as MicroJIT. Improving bytecode coverage will allow compiling more methods with MicroJIT, leading to early switching from interpreted to compiled code. The static, special and polymorphic methods are executed using method invocation bytecodes in Java. The method invocation bytecodes provide powerful capabilities for the Java platform and JVM languages. With support missing for these vital reference bytecodes, the initial MicroJIT implementation signals compilation failure when it encounters an unsupported bytecode.
Exception handling helps maintain the normal desired flow in case of unexpected events. A thorough performance testing of MicroJIT was carried out to understand its effectiveness, limitations, performance discrepancies and necessary improvements to combat those. The evaluation reveals promising results, showcasing notable performance gains in terms of reduced compilation times and memory footprint, faster warm-up and improved overall execution efficiency. In terms of average execution times, MicroJIT achieves 35%, 3% and 13% gains over the no-optimizing compiler, default compiler run at MicroJIT invocation threshold and quickstart configuration respectively.
Understanding the factors affecting travel demand for persons with a mobility disability in New Brunswick
(University of New Brunswick, 2025-03) Whitehouse, Madeline; Hanson, Trevor R.
Despite having the second highest rate of disability in Canada, there is little known about how persons with a disability in New Brunswick travel. The purpose of this research was to better understand the barriers to travel persons with a mobility disability experience in New Brunswick. A mail-out stated travel behaviour survey was administered to clients of Ability New Brunswick in Fredericton and Moncton (n = 672, response rate = 15%). Results showed respondents have transportation “all of the time” to make shopping (47%), social (36%), and health trips (56%) and there was strong agreement (62%) that private vehicles are important for travel. There were 13 participants recruited to participate in a semi-automated travel diary to better understand daily travel patterns. Participants made 155 trips, with most (89%) being made using a private vehicle. Stated adaptation interviews revealed participants are reliant on their primary mode of transportation to make trips.