Physical Sciences and Mathematics Commons^™

Web Content Management System And Accessibility Awareness: A Comparative Study Of Novice Users And Accessibility Outcomes, Fatima Artiba Diaz

Theses: Doctorates and Masters

Since its creation, the Web has progressively developed and become a vital source of information in every domain and for almost all people. It is crucial to guarantee that the information contained on the Web is available for everyone, especially for people with special needs. Removing accessibility barriers is fundamentally based on tools, skills and support of all contributors, particularly the content creators, to ensure information is navigable and usable in the context of the end users experience. Web Content Management Systems play a significant role in structuring, storing and provision content to the Web and have evolved to address …

Iot-Mqtt Based Denial Of Service Attack Modelling And Detection, Naeem Firdous Syed

Theses: Doctorates and Masters

Internet of Things (IoT) is poised to transform the quality of life and provide new business opportunities with its wide range of applications. However, the bene_ts of this emerging paradigm are coupled with serious cyber security issues. The lack of strong cyber security measures in protecting IoT systems can result in cyber attacks targeting all the layers of IoT architecture which includes the IoT devices, the IoT communication protocols and the services accessing the IoT data. Various IoT malware such as Mirai, BASHLITE and BrickBot show an already rising IoT device based attacks as well as the usage of infected …

Determining Ground-Level Composition And Concentration Of Particulate Matter Across Regional Areas Using The Himawari-8 Satellite, Miles Sowden

Theses: Doctorates and Masters

Speciated ground-level aerosol concentrations are required to understand and mitigate health impacts from dust storms, wildfires and other aerosol emissions. Globally, surface monitoring is limited due to cost and infrastructure demands. While remote sensing can help estimate respirable (i.e. ground level) concentrations, current observations are restricted by inadequate spatiotemporal resolution, uncertainty in aerosol type, particle size, and vertical profile. One key issue with current remote sensing datasets is that they are derived from reflectances observed by polar orbiting imagers, which means that aerosol is only derived during the daytime, and only once or twice per day.

Sub-hourly, infrared (IR), geostationary …

An Investigation Into The Spatial Distribution, Habitat Selection And Resource Usage Of The Red Fox (Vulpes Vulpes) Inhabiting Urban Reserves Within Perth, Western Australia, Michael Thomas Main

Theses: Doctorates and Masters

I attempted to track a population of urban foxes in Kings Park, but due to collar failure, only one collar was retrieved. The GPS telemetry data from this fox produced home range estimates for minimum convex polygon (MCP) and kernel density (KD) of 0.302 km² and 0.331 km², respectively. The fox was predominantly active at night, with a ten-fold increase in movement during nocturnal periods when compared to daytime movements. Roads and man-made tracks were important for facilitating movement of the fox through its home range, with almost 97% of location fixes recorded within 100m of these features. The fox …

Local Binary Pattern Based Algorithms For The Discrimination And Detection Of Crops And Weeds With Similar Morphologies, Vi Nguyen Thanh Le

Theses: Doctorates and Masters

In cultivated agricultural fields, weeds are unwanted species that compete with the crop plants for nutrients, water, sunlight and soil, thus constraining their growth. Applying new real-time weed detection and spraying technologies to agriculture would enhance current farming practices, leading to higher crop yields and lower production costs. Various weed detection methods have been developed for Site-Specific Weed Management (SSWM) aimed at maximising the crop yield through efficient control of weeds. Blanket application of herbicide chemicals is currently the most popular weed eradication practice in weed management and weed invasion. However, the excessive use of herbicides has a detrimental impact …

Exploration Of Cis-1,2-Diaminocyclohexane-Based Conformationally Locked Chiral Ligands In Asymmetric Synthesis, Carim Van Beek

University of the Pacific Theses and Dissertations

Natural products have been demonstrated to be of great significance to the pharmaceutical industry in the development of new drugs and medicine. Unfortunately, synthetic approaches to obtain these natural products often prove increasingly challenging due to the complexity of synthesizing the target drug in the proper stereochemistry. The availability of enantioselective reactions can play a pivotal role in overcoming this challenge, yielding access to optically pure intermediates and products. Chiral ligands based on a trans-1,2-diaminocyclohexane motif are often employed for this purpose and their complexes with transition metals have been demonstrated to act as efficient chiral catalysts in asymmetric reactions. …

A Probabilistic Machine Learning Framework For Cloud Resource Selection On The Cloud, Syeduzzaman Khan

University of the Pacific Theses and Dissertations

The execution of the scientific applications on the Cloud comes with great flexibility, scalability, cost-effectiveness, and substantial computing power. Market-leading Cloud service providers such as Amazon Web service (AWS), Azure, Google Cloud Platform (GCP) offer various general purposes, memory-intensive, and compute-intensive Cloud instances for the execution of scientific applications. The scientific community, especially small research institutions and undergraduate universities, face many hurdles while conducting high-performance computing research in the absence of large dedicated clusters. The Cloud provides a lucrative alternative to dedicated clusters, however a wide range of Cloud computing choices makes the instance selection for the end-users. This thesis …

Elephant And Anchors ‒ Photoelectron Photoion Coincidence Spectroscopy Of Small Oxygenated Molecules, Apeter Weidner

University of the Pacific Theses and Dissertations

The dissociative photoionization reactions of two small, oxygenated organics, namely 1,3-dioxolane and methyl vinyl ketone, were studied by photoelectron photoion coincidence (PEPICO) spectroscopy. Experiments involving 1,3-dioxolane were carried out in the photon energy range of 9.5‒13.5 eV. The statistical thermodynamics model shows that a total of six dissociation channels are involved in the formation of three fragment ions, namely C3H5O2+ (m/z 73), C2H5O+ (m/z 45) and C2H4O+ (m/z 44), with two channels contributing to the formation of each. By comparing the results of ab initio quantum chemical calculations to the experimentally derived appearance energies of the fragment ions, the most …

Studies On The Size And Non-Planarity Of Aromatic Stacking Moiety On Conformation Selectivity And Thermal Stabilization Of G-Quadruplexes, Mandeep Singh

University of the Pacific Theses and Dissertations

Targeting DNA has the advantage over proteins for cancer remediation because of the fewer copies of the ligands required for the desired therapeutic effect. Traditionally, covalent DNA binders like alkylating agents have been used to induce genetic instability through the formation of DNA lesions and strand breaks, leading to cellular apoptosis. The primary drawback of this treatment is the non-specific binding that affects both cancerous and non-cancerous cells. G-quadruplexes are the DNA secondary structures that are present in abundance near the promoter regions of the oncogenes and are involved in the regulation of their activities. A ligand-mediated stabilization of G-quadruplexes …

Characterization Of Reduced Graphene Oxide Anode For Application In Algae Biophotovoltaic Platforms, Siti Aisyah Ibrahim

Student Works (2020-2029)

Research interest in recent times has placed much focus on electrode technology for biophotovoltaics (BPV) especially in algal fuel cells (AFCs) application. The purpose of this investigation is therefore directed towards optimizing reduced graphene oxide (rGO) thin film as an electrode for AFCs application by means of annealing and plasma treatment. First stage involves deposition of six (6) layers of rGO thin film using Langmuir-Blodgett (LB) method. The anode electrodes were then annealed at different temperatures under vacuum condition. For plasma treatment meanwhile, a variation of voltage was used to vary the plasma conditions resulting in different surface morphology. To …

Feature Extraction And Description For Retinal Fundus Image Registration, Ramli Roziana

Student Works (2020-2029)

Retinal fundus image registration (RIR) is performed to align two or more fundus images. A general framework of a feature-based RIR technique comprises of preprocessing, feature extraction, feature descriptor, matching and estimating geometrical transformation. The RIR is mainly performed for super-resolution, image mosaicking and longitudinal study applications to assist diagnosis and monitoring retinal diseases. Registering image pair from these applications involve a combination of challenges such as overlapping area and rotation between images. The challenges of the overlapping area and rotation can be addressed at feature extraction and feature descriptor stages of the feature-based RIR technique, respectively. To address the …

The Evolving Fuzzy Clustering Approach For Discriminating Neutron And Gamma-Ray Pulses, Shirkhorshidi Ali Seyed

Student Works (2020-2029)

Having a significant amount of data is not useful unless the data can be processed for extracting knowledge and information. One of the elementary steps in crunching data is to break it down into groups. When the data is small and collected in a controlled manner, and when the training data is appropriately labelled, the trivial approach is to use supervised learning to perform the grouping. Supervised methods need training data and information about groups beforehand; however, in the current reality, with an avalanche of data, this information is not available. Nevertheless, the need for grouping data remains. Clustering, as …

Development Of Smartphone-Based Ecl Sensor For Dopamine Detection: Practical Approaches, Hyun J. Kwon, Elmer Rivera, Mabio R. Cohelo Neto, Daniel Marsh, Jonathan Swerdlow, Rodney Lee Summerscales, Padma P. Tadi Uppala

Faculty Publications

In this work, a compact, mobile phone-based ECL sensor apparatus was developed using the phone cameras, screen-printed electrodes (SPE), and mobile app for dopamine detection. Methods of DC voltage application for ECL reaction were comprehensively studied from the mobile phone itself or external power. Under optimized sensing conditions, with disposable carbon SPE and 20 mM coreactant tri-n-propylamine (TPrA), acceptable repeatability and reproducibility were achieved in terms of relative standard deviation (RSD) of intra- and interassays, which were 6.7 and 5.5%, respectively. The biochemical compound dopamine was measured due to its ECL quenching characteristics and its clinical importance. The …

Inventory Models For Perishable Items Under Markdown Policy, Nurzahara Atika Kamaruzaman

Student Works (2020-2029)

As expected, the demand for a fresh product depends on how fresh it is, therefore, it is important to take expiration date into consideration. Based on marketing and economic theory, several factors such as price, inventory level and advertisement play a crucial role in influencing the demand. Hence, we study the effect of these factors in influencing the demand in the inventory model. Since the demand for perishable product declines over time, markdown policy is offered to increase the demand and profit while reducing the inventory. Salvage value is incorporated to the deteriorating units. In this research, we extend previous …

Vanadyl Tetrabutyltetrakis(Dimethylamino) Phthalocyanine Based Thin Films For Organic Sensor And Transistor Applications, Nur Adilah Roslan

Student Works (2020-2029)

Organic electronic devices have been successively making progress into the commercial market to substitute conventional inorganic electronic devices. The endeavor to improve the performance displayed by organic semiconductor materials has urged a substantial number of researchers set to seek new materials. Metal phthalocyanines (MPcs), in particular, have garnered much attention due to their enticing benefits viz., cost efficiency, eco-friendly organic material, as well as thermal and chemical stability. Primarily, this study investigated the physical, morphological, optical, and electrical properties of vanadyl 3,10,17,24-tetra-tert-butyl-1,8,15,22-tetrakis(dimethylamino)-29H,31H-phthalocyanine or synonymously known as vanadyl tetrabutyltetrakis (dimethylamino) phthalocyanine (VTP). Subsequently, this study looked into the potential applications of …

Molecular Dynamics Simulations Of Phase Behaviour And Structural Studies Of Guanidinium Triflate Ionic Liquid And Its Mixture With Water And N-Methyldiethanolamine For Carbon Dioxide Removal, Naimah Haron

Student Works (2020-2029)

Molecular dynamics (MDs) simulations with an all-atom force field have been carried out to understand the phase equilibrium behaviour of aqueous guanidinium triflate [gua][OTf] ionic liquid (IL) (binary system) at 440.15 K, as well as the phase equilibrium behaviour of N-methyl diethanolamine (MDEA) with aqueous [gua][OTf] IL (ternary system) at 298.15 K. This work further elaborated the understanding of absorption mechanism of carbon dioxide (CO2) into ternary system at 298.15 K. For binary system, the simulations measured changes in different physical properties such as density, structural, bonding properties (radial distribution function (RDF)), water clustering and hydrogen bonding) and dynamic property …

Ionic Liquid Functionalized Β-Cyclodextrin Modified Electrode As Electrochemical Sensor For 2,4-Dichlorophenol, Fairuz Liyana Mohd Rasdi

Student Works (2020-2029)

This thesis described the synthesis and characterization of ionic liquid monofunctionalized β-cyclodextrin (β-CD-1-BIMOTs) and ionic liquid difunctionalized β-cyclodextrin (β-CD-2-BIMOTs) for sensor applications. The physical characterizations of these compounds have been conducted using nuclear magnetic resonance (NMR), Fourier transform infra-red (FTIR), energy dispersive x-ray (EDX), x-ray diffraction (XRD) and Brunauer-Emmet-Teller (BET) analyses. These compounds were used as modifiers for carbon paste electrode (CPE). Cyclic voltammetry and chrono-amperometry methods were employed to examine the electrochemical responses of all prepared CPEs. All prepared electrodes show responses towards the target analyte of 2,4-dichlorophenol (2,4-DCP). Both β-CD-1-BIMOTs/CPE and β-CD-2-BIMOTs/CPE give higher current (i) responses compared …

Synthesis And Characterization Of Hybrid Organic Coating System To Reduce Thermal Degradation Of Solar Cells, Mohd Zaini Farah Khaleda

Student Works (2020-2029)

Thermal-decreasing hybrid organic coatings were developed for crystalline solar cells by using two types of binder systems; namely Aminopropyltriethoxysolution (APTES) / Methyltrimethoxysilane (MTMS) binder system (labelled as B1) and Methyltrimethoxysilane (MTMS) / nitric acid (HNO3) binder system (labelled as B2). Three types of nanoparticles; Titanium dioxide, TiO2 (Anatase), Zinc oxide, ZnO and Tin dioxide, SnO2 nanoparticles with different weight percentage were introduced inside each binder system namely; 20 wt%, TiO2 (T1B1 coating), 60 wt% TiO2 (T2B1 coating), 20 wt% ZnO (Z1B1 coating), 60 wt% ZnO (T2B1 coating), 20 wt% SnO2 (S1B1 coating) and 60 wt% SnO2 (S2B1 coating) for B1 …

Effect Of Non-Thermal Atmospheric Pressure Plasma On Wound Bacteria And Cell Proliferation, Mohd Nasir Norhayati

Student Works (2020-2029)

Non-thermal plasma produced in the plasma jet at atmospheric pressure consists of many reactive species and free radicals. The use of the atmospheric plasma jet has been expanded from surface treatment on polymers and biomaterials to the application as plasma medicine. It has been studied as a tools for wound sterilizations, enhance wound healing, topical treatment of skin diseases caused by bacteria infection and cancer therapy in recent research. The current study aims to investigate the effect of plasma on chronic wound bacteria as a supplementary to wound management particularly for compromised patients. The common practice in wound management is …

Phytochemical Investigations Of Goniothalamus Tapis And G. Tapisoides, And Kinetic Mechanism Studies Of Goniothalamin, Pei Theng Rosalind Kim

Student Works (2020-2029)

Phytochemical studies on two species of Annonaceae; Goniothalamus tapis and Goniothalamus tapisoides have been carried out. Isolation and purification of the crude extract of stem bark of G. tapis and G. tapisoides yielded seventeen compounds. G. tapis gave nine compounds; goniothalamin 1, isoaltholactone 41, 3-acetylisoaltholactone 151, cheliensisin A 22, garvensintriol 4, goniopyyprone 26, 7-epi-goniofufurone 49, stigmasterol 133 and β-sitosterol 134. Out of nine compounds, 3-acetyl-isoaltholactone 151 was identified as a new styryl-lactone. The skeleton is similar as the major compound, isoaltholactone 41. But 3-acetylisoaltholactone 151 have different functional group compared to hydroxyl group in isoaltholactone 41, which is acetyl group. …

Cybersecurity Behavioural Model For Students In The Tertiary Institutions, Boluwatife Fatokun Faith

Student Works (2020-2029)

Humans are majorly identified as the weakest link in cybersecurity. Tertiary institution student’s face lot of cybersecurity issues due to their increased Internet exposure, however cybersecurity behavioural studies focusing on tertiary students is limited. This study focused on investigating tertiary institutions students’ cybersecurity behaviour, via validated cybersecurity factors, Perceived Vulnerability (PV); Perceived Barriers (PBr); Perceived Severity (PS); Security Self-Efficacy (SSE); Response Efficacy (RE); Cues to Action (CA); Peer Behaviour (PBhv); Computer Skills (CS); Internet Skills (IS); Prior Experience with Computer Security Practices (PE); Perceived Benefits (PBnf); and a newly added factor, Familiarity with Cyber-Threats (FCT), to explore the factors relationship …

An Intra-Severity Classification And Adaptation Technique To Improve Dysarthric Speech Recognition Accuracy, Al-Qatab Bassam Ali Qasem

Student Works (2020-2029)

Dysarthria is a motor speech impairment at the neurological and/or muscular levels that caused difficulty in pronouncing words clearly. Automatic speech recognition (ASR) system is increasingly applied as assistive technology to aid an individual with physical disability particularly the speech impaired community such as dysarthria speakers. However, the development of an effective ASR system is hindered by the data sparsity, either in the coverage of the language or the size of the existing speech databases. The speaker adaptation (SA) technique is one of the solutions to overcome the data sparsity issue of ASR for dysarthric speakers. Our proposed method introduces …

Design And Development Of Electronic Sensor And Monitoring System Of Smart Low-Cost Phototherapy Light System For Non-Invasive Monitoring And Treatment Of Neonatal Jaundice, Paul M. Cabacungan, Carlos Oppus, Gregory L. Tangonan, Nerissa G. Cabacungan, John Paul Mamaradlo, Neil Angelo Mercado

Electronics, Computer, and Communications Engineering Faculty Publications

This paper showcases our previous and continuously improving development at Ateneo Innovation Center (AIC) and partners in designing and further enhancing the existing Low-cost Phototherapy Light System (LPLS) and Improved Low-cost Phototherapy Light System (ILPLS) to the new Smart Low-cost Phototherapy Light System (Smart LPLS) with non-invasive jaundice monitoring for newborns with Neonatal Jaundice (NNJ). Developing this tool will help determine the intensity of yellowish color in infants and can monitor NNJ in a non-invasive way. The system is envisioned to be integrated with Mobile or Near Cloud as part of Smart Nursing Station together with other hospital equipment for …

Question 1: Car Flip; Question 2: A Mole Of People, Larry Weinstein

Physics Faculty Publications

Consider mass, area, power, and food requirements. For more Fermi questions and answers, see Guesstimation 2.0: Solving Today's Problems on the Back of a Napkin, by Lawrence Weinstein (Princeton University Press, 2012). [Extracted from artcle]

Optical-Depth Scaling Of Light Scattering From A Dense And Cold Atomic 87Rb Gas, K. J. Kemp, S. J. Roof, M. D. Havey, I. M. Sokolov, D. V. Kupriyanov, W. Guerin

Physics Faculty Publications

We report investigation of near-resonance light scattering from a cold and dense atomic gas of ⁸⁷Rb atoms. Measurements are made for probe frequencies tuned near the F=2→ F'=3 nearly closed hyperfine transition, with particular attention paid to the dependence of the scattered light intensity on detuning from resonance, the number of atoms in the sample, and atomic sample size. We find that, over a wide range of experimental variables, the optical depth of the atomic sample serves as an effective single scaling parameter which describes well all the experimental data.

Measurement Of The Single-Spin Asymmetry A⁰ʸ In Quasi-Elastic ³He↑(E,E'N) Scattering At 0.4 < Q2 < 1.0 Gev/C2, E. Long, Y.W. Zhang, M. Mihovilovic, M. Canan, S. Golge, L. Zhu

Physics Faculty Publications

Due to the lack of free neutron targets, studies of the structure of the neutron are typically made by scattering electrons from either ²H or ³He targets. In order to extract useful neutron information from a ³He target, one must understand how the neutron in a ³He system differs from a free neutron by taking into account nuclear effects such as final state interactions and meson exchange currents. The target single spin asymmetry A⁰ʸ is an ideal probe of such effects, as any deviation from zero indicates effects beyond plane wave impulse approximation. New measurements of the target single spin …

Nonlinear Dynamics And Dissipation Of A Curvilinear Vortex Driven By A Strong Time-Dependent Meissner Current, W.P.M.R. Pathirana, A. Gurevich

Physics Faculty Publications

We report numerical simulations of large-amplitude oscillations of a trapped vortex line under a strong ac magnetic field H(t)=H sinωt parallel to the surface. The power dissipated by an oscillating vortex segment driven by the surface ac Meissner currents was calculated by taking into account the nonlinear vortex line tension, vortex mass, and a nonlinear Larkin-Ovchinnikov (LO) viscous drag coefficient η(v). We show that the LO decrease of η(v) with the vortex velocity v can radically change the field dependence of the surface resistance R_i(H) caused by trapped vortices. At low frequencies, …

Quasielastic Lepton Scattering And Back-To-Back Nucleons In The Short-Time Approximation, S. Pastore, J. Carlson, S. Gandolfi, R. Schiavilla, R. B. Wiringa

Physics Faculty Publications

Understanding quasielastic electron and neutrino scattering from nuclei has taken on new urgency with current and planned neutrino oscillation experiments, and with electron scattering experiments measuring specific final states, such as those involving nucleon pairs in "back-to-back" configurations. Accurate many-body methods are available for calculating the response of light (A <= 12) nuclei to electromagnetic and weak probes, but they are computationally intensive and only applicable to the inclusive response. In the present work we introduce a novel approach, based on realistic models of nuclear interactions and currents, to evaluate the short-time (high-energy) inclusive and exclusive response of nuclei. The approach accounts reliably for crucial two-nucleon dynamics, including correlations and currents, and provides information on back-to-back nucleons observed in electron and neutrino scattering experiments. We demonstrate that in the quasielastic regime and at moderate momentum transfers both initial- and final-state correlations and two-nucleon currents are important for a quantitatively successful description of the inclusive response and final-state nucleons. Finally, the approach can be extended to include relativistic-kinematical and dynamical-effects, at least approximately in the two-nucleon sector, and to describe the response in the resonance-excitation region.

Probing Few-Body Nuclear Dynamics Via ³H And ³He (E E'P) Pn Cross-Section Measurements, R. Cruz-Torres, F. Hauenstein, D. Bulumulla, C. Hyde, M. Khachatryan, M.N.H. Rashad, L.B. Weinstein, Et. Al., Jefferson Lab Hall A. Tritium Collaboration

Physics Faculty Publications

We report the first measurement of the (e, e'p) three-body breakup reaction cross sections in helium-3 (³He) and tritium (³H) at large momentum transfer [< Q²> ≈ 1.9 (GeV/c)²] and x_B> 1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40 ≤ p_miss ≤ 500 MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall …

Observation Of In-Plane Magnetic Field Induced Phase Transitions In Fese, Jong Mok Ok, Chang Il Kwon, Yoshimitsu Kohama, Jung Sang You, Sun Kyu Park, Ji-Hye Kim, Y.J. Jo, E.S. Choi, Koichi Kindo, Woun Kang, Ki-Seok Kim, E. G. Moon, Alex Gurevich, Jun Sung Kim

Physics Faculty Publications

We investigate thermodynamic properties of FeSe under in-plane magnetic fields using torque magnetometry, specific heat, and magnetocaloric measurements. Below the upper critical field H_c2, we observed the field induced anomalies at H₁ ∼ 15 T and H₂ ∼ 22 T near H ∥ ab and below a characteristic temperature T* ∼ 2 K. The transition magnetic fields H₁ and H₂ exhibit negligible dependence on both temperature and field orientation. This contrasts to the strong temperature and angle dependence of H_c2, suggesting that these anomalies are attributed to the field induced phase transitions, …