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2020

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Articles 14791 - 14806 of 14806

Full-Text Articles in Physical Sciences and Mathematics

A Probabilistic Machine Learning Framework For Cloud Resource Selection On The Cloud, Syeduzzaman Khan Jan 2020

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 …

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Elephant And Anchors ‒ Photoelectron Photoion Coincidence Spectroscopy Of Small Oxygenated Molecules, Apeter Weidner Jan 2020

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 …

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Studies On The Size And Non-Planarity Of Aromatic Stacking Moiety On Conformation Selectivity And Thermal Stabilization Of G-Quadruplexes, Mandeep Singh Jan 2020

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 …

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Characterization Of Reduced Graphene Oxide Anode For Application In Algae Biophotovoltaic Platforms, Siti Aisyah Ibrahim Jan 2020

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 …

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Feature Extraction And Description For Retinal Fundus Image Registration, Ramli Roziana Jan 2020

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 …

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The Evolving Fuzzy Clustering Approach For Discriminating Neutron And Gamma-Ray Pulses, Shirkhorshidi Ali Seyed Jan 2020

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 …

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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 Jan 2020

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 …

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Inventory Models For Perishable Items Under Markdown Policy, Nurzahara Atika Kamaruzaman Jan 2020

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 …

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Vanadyl Tetrabutyltetrakis(Dimethylamino) Phthalocyanine Based Thin Films For Organic Sensor And Transistor Applications, Nur Adilah Roslan Jan 2020

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 …

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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 Jan 2020

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 …

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Ionic Liquid Functionalized Β-Cyclodextrin Modified Electrode As Electrochemical Sensor For 2,4-Dichlorophenol, Fairuz Liyana Mohd Rasdi Jan 2020

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 …

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Synthesis And Characterization Of Hybrid Organic Coating System To Reduce Thermal Degradation Of Solar Cells, Mohd Zaini Farah Khaleda Jan 2020

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 …

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Effect Of Non-Thermal Atmospheric Pressure Plasma On Wound Bacteria And Cell Proliferation, Mohd Nasir Norhayati Jan 2020

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 …

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Phytochemical Investigations Of Goniothalamus Tapis And G. Tapisoides, And Kinetic Mechanism Studies Of Goniothalamin, Pei Theng Rosalind Kim Jan 2020

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. …

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Cybersecurity Behavioural Model For Students In The Tertiary Institutions, Boluwatife Fatokun Faith Jan 2020

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 …

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An Intra-Severity Classification And Adaptation Technique To Improve Dysarthric Speech Recognition Accuracy, Al-Qatab Bassam Ali Qasem Jan 2020

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 …

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