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Articles 8521 - 8550 of 33213

Full-Text Articles in Chemistry

A Review Of Methodologies Applied For Determining Particulate Matter Characterization In Urban Regions, Garrett F. Diehl Jun 2020

A Review Of Methodologies Applied For Determining Particulate Matter Characterization In Urban Regions, Garrett F. Diehl

University Honors Theses

This is a literature review on previous research conducted on particulate matter deposited on urban vegetation. This was accomplished by searching six databases, that uncovered 37 peer-reviewed journal articles. The main objective of this review is to present the methodology and findings of the articles analyzed to demonstrate how research in this area of study is being conducted. The findings show that there are variations in the literature and that many variables are not being incorporated into the methods and analyses of particulate matter found on urban vegetation. Understanding how different studies have analyzed particulate matter found on urban vegetation …


Seasonal Transport Of Dissolved Inorganic Carbon And Total Alkalinity Across The Louisiana Shelf, Michelle M. Anderson Jun 2020

Seasonal Transport Of Dissolved Inorganic Carbon And Total Alkalinity Across The Louisiana Shelf, Michelle M. Anderson

LSU Master's Theses

Rivers and wetlands are a major source of terrestrial derived carbon for coastal ocean margins. Unfortunately, Louisiana’s wetlands are threatened by ongoing high rates of erosion, deterioration, and unprecedented rates of river water discharge that changes seasonally, leading to a net loss of terrestrial carbon into the northern Gulf of Mexico (nGOM). There exists a current lack of understanding about the distribution of dissolved inorganic carbon (DIC) and total alkalinity (TAlk) within the shallowest regions of the Louisiana shelf. Even less is known about how the transport of DIC alters seasonally with changes in river outflow and shelf currents. Quantifying …


Design, Synthesis And Characterization Of New Superconductors, Xin Gui Jun 2020

Design, Synthesis And Characterization Of New Superconductors, Xin Gui

LSU Doctoral Dissertations

Design and synthesis of new materials are a long-standing goal for chemistry, physics and material science, especially those with intriguing properties such as magnetism and superconductivity. With consideration and incorporation of the highlights in some existing design rules, we successfully designed and discovered the superconductivity in BaPt2Bi2, SrSnP and YbxPt5P.

With the help of valence electron counting method, we synthesized a new intermetallic compound, BaIr2Ge2, which was then found to be non-superconducting above 1.8 K. Thus, we considered both valence electron counting and chemical pressure adjustment to reach …


Transition Metal-Free Domino Acyl Substitution/Michael Addition Of Alkenyl Grignard Reagents To Lactam Esters: Synthesis Of Lactam-Bearing Homoallylic Ketones, Abdikani Omar Farah, Muhannad Rabah, Timothy K. Beng Jun 2020

Transition Metal-Free Domino Acyl Substitution/Michael Addition Of Alkenyl Grignard Reagents To Lactam Esters: Synthesis Of Lactam-Bearing Homoallylic Ketones, Abdikani Omar Farah, Muhannad Rabah, Timothy K. Beng

All Faculty Scholarship for the College of the Sciences

A solvent-controlled protocol for the direct and transition metal-free addition of alkenyl Grignard reagents to vicinally functionalized sp3-rich morpholinones has been developed, leading to the chemo and regioselective synthesis of lactam-bearing homoallylic ketones. The addition of lithium chloride proved to be essential. In cases where a new stereocenter is generated, the doubly branched homoallylic ketones are obtained in unexpectedly high diastereoselectivities. Efforts to extend the methodology to other heterosubstituted lactams revealed some important reactivity and selectivity differences.


Anchoring The Hydrogen Sulfide Dimer Potential Energy Surface To Juxtapose (H2s)2 With (H2o)2, Morgan A. Perkins, Kayleigh R. Barlow, Katelyn M. Dreux, Gregory S. Tschumper Jun 2020

Anchoring The Hydrogen Sulfide Dimer Potential Energy Surface To Juxtapose (H2s)2 With (H2o)2, Morgan A. Perkins, Kayleigh R. Barlow, Katelyn M. Dreux, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

Twelve stationary points have been characterized on the (H2S)2 potential energy surface using the MP2 and CCSD(T) methods with large, correlation consistent basis sets. To the best of our knowledge, five of the structures have not been identified elsewhere and are presented here for the first time. A similar analysis was performed on the ten, well-known structures of the water dimer in order to facilitate direct comparisons between the corresponding (H2O)2 and (H2S)2 configurations. Harmonic vibrational frequency computations identify three (H2S)2 configurations as minima, four as transition states, …


Copper And Ruthenium Pyridyltriazole Complexes And Their Reactivity Toward Carbon Dioxide And Water, Fatemeh Khamespanah Jun 2020

Copper And Ruthenium Pyridyltriazole Complexes And Their Reactivity Toward Carbon Dioxide And Water, Fatemeh Khamespanah

LSU Doctoral Dissertations

A variety of pyridyltriazole ligands are readily available via click type cycloaddition of alkynylpyridines and azides. We made functionalized tetradentate m-xylylenebis(pyridyltriazole) (m-xpt) ligands with NH2 and NMe2 electron-donating and NO2 electron-withdrawing substituents on the pyridine moieties. Complexation of these ligands with Cu(II) gives dimeric macrocycles with square pyramidal geometry at Cu centers. Previous work in our lab with the unsubstituted [Cu2(m-xpt)2(NO3)2]2+ complex showed reduction to Cu(I) by using ascorbate as reducing agent. Oxidation of the Cu(I) solution in air results in formation of …


A Highly Elastic And Fatigue-Resistant Natural Protein-Reinforced Hydrogel Electrolyte For Reversible-Compressible Quasi-Solid-State Supercapacitors, Jingya Nan, Gaitong Zhang, Tianyu Zhu, Zhongkai Wang, Lijun Wang, Hongsheng Wang, Fuxiang Chu, Chunpeng Wang, Chuanbing Tang Jun 2020

A Highly Elastic And Fatigue-Resistant Natural Protein-Reinforced Hydrogel Electrolyte For Reversible-Compressible Quasi-Solid-State Supercapacitors, Jingya Nan, Gaitong Zhang, Tianyu Zhu, Zhongkai Wang, Lijun Wang, Hongsheng Wang, Fuxiang Chu, Chunpeng Wang, Chuanbing Tang

Faculty Publications

Compressible solid-state supercapacitors are emerging as promising power sources for next-generation flexible electronics with enhanced safety and mechanical integrity. Highly elastic and compressible solid electrolytes are in great demand to achieve reversible compressibility and excellent capacitive stability of these supercapacitor devices. Here, a lithium ion-conducting hydrogel electrolyte by integrating natural protein nanoparticles into polyacrylamide network is reported. Due to the synergistic effect of natural protein nanoparticles and polyacrylamide chains, the obtained hydrogel shows remarkable elasticity, high compressibility, and fatigue resistance properties. More significantly, the supercapacitor device based on this hydrogel electrolyte exhibits reversible compressibility under multiple cyclic compressions, working well …


Synthesis, Characterisation And Biological Evaluation Of Tyramine Derived Schiff Base Ligand And Its Transition Metal(Ii) Complexes, Abdul Khader Jailani, N.S.K. Gowthaman, Mookkandi Palsamy Kesavan Jun 2020

Synthesis, Characterisation And Biological Evaluation Of Tyramine Derived Schiff Base Ligand And Its Transition Metal(Ii) Complexes, Abdul Khader Jailani, N.S.K. Gowthaman, Mookkandi Palsamy Kesavan

Karbala International Journal of Modern Science

In this study, a new tyramine derived Schiff base ligand (L) (L=1,3-phenylene-bis-4-aminoantipyrinyl-4-aminoethylphenol) and its derived transition metal(II) complexes [Cu(L)Cl2](1), [Ni(L)Cl2](2), [Co(L)Cl2] (3) and [Zn(L)Cl2] (4) have been synthesized and well characterized by the way of different spectroscopic and analytical techniques. Analytical and spectroscopic studies result suggests that metal(II) complexes more probably have octahedral geometry. DNA binding tendency of L and metal(II) complexes 1-4 have been assessed by probing their ability to bind with Calf Thymus DNA (CT-DNA) via electronic absorption and cyclic voltammetry titration methods. The results clearly reveal that the metal(II) …


Evaluation Of Structure And Properties Of Various Sol–Gel Nanocoatings On Biomedical Titanium Surface, Mohsin Talib Mohammed, Sarah Mohammed Hussein Jun 2020

Evaluation Of Structure And Properties Of Various Sol–Gel Nanocoatings On Biomedical Titanium Surface, Mohsin Talib Mohammed, Sarah Mohammed Hussein

Karbala International Journal of Modern Science

This study deals with the preparation and characterization of different bioceramic nanofilms formed on the surface of new metastable β-titanium (Ti) alloy. The films of pure TiO2, pure HA, TiO2/HA bilayer and HA/TiO2 composite were coated successfully on Ti surface by sol-gel using spray pyrolysis deposition technique. The surface characteristics of coated substrates, such as thickness, topography, morphology, phase transformations and wear behavior, were evaluated and compared to uncoated substrate. The results showed that the sol-gel is a promising technique to create biocoatings on Ti surface with outstanding structure and properties for biomedical applications.


Transition State Theory Application To H2 Gas Sensitivity Of Pristine And Pd Doped Sno2 Clusters, Mudar Ahmed Abdulsattar Jun 2020

Transition State Theory Application To H2 Gas Sensitivity Of Pristine And Pd Doped Sno2 Clusters, Mudar Ahmed Abdulsattar

Karbala International Journal of Modern Science

The reaction of H2 and O2 gases with pristine and Pd doped Sn10O16 clusters is investigated using transition state theory and density functional theory. The reaction of hydrogen and oxygen molecules is controlled by a transition state that implies crossing an activation energy hill to react with the SnO2 cluster. Our investigation performs thermodynamic calculations, including Gibbs free energy, enthalpy, and entropy of activation and reaction in the temperature range 25-500 °C. The results show that the Gibbs free energy of activation of H2 gas reaction is 0.23 and 0.18 eV for pristine …


On The Dynamic Behaviour Of Automobile Pulleys Under Cyclic Loading, Haval Kamal Asker, Thaker Saleh Dawood Jun 2020

On The Dynamic Behaviour Of Automobile Pulleys Under Cyclic Loading, Haval Kamal Asker, Thaker Saleh Dawood

Karbala International Journal of Modern Science

This paper investigates the dynamic characteristics of pulley systems with different numbers of bolt holes. Models with four, six and eight bolt holes were chosen for the pulley. Three sets of cyclic pressure were applied to the pulley system to resemble the different running revolutions of an engine. The study investigates the effect of the number of holes on the system’s stiffness and natural frequency. Finite element models were used to simulate the obtained deformations, stresses and frequency response function (FRF) for pulley models comprising four, six and eight bolt holes under different cyclic pressures. The results show that the …


Optically Thick Radiating Free Convective Mhd Nanofluid Flow Over An Exponentially Accelerated Plate, D.P. Bhatta, S.R. Mishra, J.K. Dash Jun 2020

Optically Thick Radiating Free Convective Mhd Nanofluid Flow Over An Exponentially Accelerated Plate, D.P. Bhatta, S.R. Mishra, J.K. Dash

Karbala International Journal of Modern Science

The present analysis investigates an unsteady conducting water-based nanofluid embedding with porous medium over an exponentially accelerated vertical plate. The plate is accelerated with moving ramped temperature. However, water is treated as the base fluid with Copper (Cu) and Titanium Oxide (TiO2) as nanoparticles. Effects of thermal radiation, heat source, and radiation absorption are taken care of in the energy equation which may enhance the heat transfer properties of nanofluid. The crux of the investigation is to find the closed-form solution of nonlinear coupled partial differential equations. Laplace Transform technique is employed to solve these equations. The influence …


A Support Vector Machine-Based Prediction Model For Electrochemical Machining Process, Subham Agarwal Mr., Shruti Sudhakar Dandge Ms., Shankar Chakraborty Prof. Jun 2020

A Support Vector Machine-Based Prediction Model For Electrochemical Machining Process, Subham Agarwal Mr., Shruti Sudhakar Dandge Ms., Shankar Chakraborty Prof.

Karbala International Journal of Modern Science

Manufacturing of quality products is one of the core measures to address competitiveness in industries. Hence, it is always necessary to accomplish quality prediction at early stages of a manufacturing process to attain high quality products at the minimum possible cost. To achieve this goal, the past researchers have developed and investigated the applications of different intelligent techniques for their effective deployment at various stages of manufacturing processes. In this paper, support vector machine (SVM), a supervised learning system based on a novel artificial intelligence paradigm, is employed for prediction of three responses, like material removal rate, surface roughness and …


Influence Of Carbon Fibres On Strain Sensing And Structural Properties Of Rc Beams Without Stirrups, Arvind Kumar Cholker, Manzoor Ahmad Tantray Jun 2020

Influence Of Carbon Fibres On Strain Sensing And Structural Properties Of Rc Beams Without Stirrups, Arvind Kumar Cholker, Manzoor Ahmad Tantray

Karbala International Journal of Modern Science

In present study, effect of micro carbon fibres on strain sensing property and structural behavior of the reinforced concrete (RC) beams in absence of stirrups was experimentally investigated. A total of three RC beams of dimensions, 125 mm width, 350 mm height and 1500 mm long were manufactured without stirrups. All the three beams had different longitudinal reinforcement ratios (0.9%, 1.43% and 1.03 %) and uniform strength of concrete of 36.5 MPa. All the beams had carbon fibre based concrete (CFBC) at top and bottom surface in mid span for a length of 350mm and depth of 78 mm. All …


Approximating Fixed Points In Modular Spaces, Salwa Salman Abed, Meena Fouad Abduljabbar Jun 2020

Approximating Fixed Points In Modular Spaces, Salwa Salman Abed, Meena Fouad Abduljabbar

Karbala International Journal of Modern Science

A generic two theorems for the two step iterative sequence of multivalued mappings are proved in a complete convex real modular space, and then cite some corollaries that are special cases of these theorems.


Editorial Board Jun 2020

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.


Investigating Geochemical Processes Of Fluid-Rock Interactions On Materials Related To Energy And Environment, Zelong Zhang Jun 2020

Investigating Geochemical Processes Of Fluid-Rock Interactions On Materials Related To Energy And Environment, Zelong Zhang

LSU Doctoral Dissertations

Understanding the potential processes of radionuclides released from nuclear waste forms is essential to the safe disposal and containment of nuclear waste. Iodoapatite, a potential waste form for radioiodine, was chosen as a model system to examine the impact by common aqueous anions on iodine release processes. Four semi-dynamic leaching tests were performed using 0.1 mol/L NaCl, Na2CO3, Na3PO4, and Na2SO4 solutions respectively under 90 °C, 1 bar, fixed S/V ratio 5/m (sample surface area to solution volume), and with 24-hour replacement of the leaching solutions. Solution analysis and …


Novel Reusable Renewable Resource-Based Benign Nanocomposites For Removal And Recovery Of Phosphorus From Contaminated Water, Amita Nakarmi Jun 2020

Novel Reusable Renewable Resource-Based Benign Nanocomposites For Removal And Recovery Of Phosphorus From Contaminated Water, Amita Nakarmi

Theses and Dissertations

Phosphorus (P) is a pollutant which degrades water quality and is a cause of concern for eutrophication of water. This research dissertation discusses the synthesis of novel, renewable resource-based, single metallic and bimetallic nanocomposite media, their use in Phosphorus remediation as phosphate, and their regeneration for reuse. The media consist of chemically modified pine wood chips in addition to metal oxides/hydroxides. Iron is used for single metallic media, while cerium/aluminum and cerium/manganese are used for mixed bimetallic media. The synthetic method is environmentally friendly and economically viable. These nanocomposites may find use in the removal of P from contaminated waters, …


Benzosiloles With Crystallization-Induced Emission Enhancement Of Electrochemiluminescence: Synthesis, Electrochemistry, And Crystallography, Liuqing Yang, Donghyun Koo, Jackie Wu, Jonathan M. Wong, Tyler Day, Ruizhong Zhang, Harshana Kolongoda, Kehan Liu, Jian Wang, Zhifeng Ding, Brian Pagenkopf Jun 2020

Benzosiloles With Crystallization-Induced Emission Enhancement Of Electrochemiluminescence: Synthesis, Electrochemistry, And Crystallography, Liuqing Yang, Donghyun Koo, Jackie Wu, Jonathan M. Wong, Tyler Day, Ruizhong Zhang, Harshana Kolongoda, Kehan Liu, Jian Wang, Zhifeng Ding, Brian Pagenkopf

Chemistry Publications

Crystallization-induced emission enhancement (CIEE) was demonstrated for the first time for electrochemilunimescence (ECL) with two new benzosiloles. Compared with their solution, the films of the two benzosiloles gave CIEE of 24 times and 16 times. The mechanism of the CIEE-ECL was examined by spooling ECL spectroscopy, X-ray crystal structure analysis, photoluminescence, and DFT calculation. This CIEE-ECL system is a complement to the well-established aggregation-induced emission enhancement (AIEE) systems. Unique intermolecular interactions are noted in the crystalline chromophore. The first heterogeneous ECL system is established for organic compounds with highly hydrophobic properties.


Thermodynamic Characterization Of Free And Surface Water Of Colloidal Unimolecular Polymer (Cup) Particles Utilizing Dsc, Peng Geng, Ashish Zore, Michael R. Van De Mark Jun 2020

Thermodynamic Characterization Of Free And Surface Water Of Colloidal Unimolecular Polymer (Cup) Particles Utilizing Dsc, Peng Geng, Ashish Zore, Michael R. Van De Mark

Chemistry Faculty Research & Creative Works

Colloidal Unimolecular Polymer (CUP) particles are spheroidal, 3-9 nm with charged groups on the surface and a hydrophobic core, which offer a larger surface water fraction to improve the analysis of its characteristics. Differential scanning calorimetry (DSC) was performed to determine the characteristics of surface water. These properties include the amount of surface water, the layer thickness, density, specific heat of the surface water above and below the freezing point of water, melting point depression of free water, effect of charge density and particle size. The charge density on the CUP surface was varied as well as the molecular weight …


An International Laboratory Comparison Of Dissolved Organic Matter Composition By High Resolution Mass Spectrometry: Are We Getting The Same Answer?, Jeffrey A. Hawkes, Juliana D'Andrilli, Jeffrey N. Agar, Mark P. Barrow, Stephanie M. Berg, Núria Catalán, Hongmei Chen, Rosalie K. Chu, Richard B. Cole, Thorsten Dittmar, Rémy Gavard, Gerd Gleixner, Patrick G. Hatcher, Chen He, Nancy J. Hess, Ryan H.S. Hutchins, Amna Ijaz, Hugh E. Jones, William Kew, Maryam Khaksari, Diana Catalina Palacio Lozano, Jitao Lv, Lynn Mazzoleni, Beatriz E. Noriega-Ortega, Helena Osterholz, Nikola Radoman, Shuzhen Zhang, Phoebe Zito, David C. Podgorski Jun 2020

An International Laboratory Comparison Of Dissolved Organic Matter Composition By High Resolution Mass Spectrometry: Are We Getting The Same Answer?, Jeffrey A. Hawkes, Juliana D'Andrilli, Jeffrey N. Agar, Mark P. Barrow, Stephanie M. Berg, Núria Catalán, Hongmei Chen, Rosalie K. Chu, Richard B. Cole, Thorsten Dittmar, Rémy Gavard, Gerd Gleixner, Patrick G. Hatcher, Chen He, Nancy J. Hess, Ryan H.S. Hutchins, Amna Ijaz, Hugh E. Jones, William Kew, Maryam Khaksari, Diana Catalina Palacio Lozano, Jitao Lv, Lynn Mazzoleni, Beatriz E. Noriega-Ortega, Helena Osterholz, Nikola Radoman, Shuzhen Zhang, Phoebe Zito, David C. Podgorski

Michigan Tech Publications, Part 1

High-resolution mass spectrometry (HRMS) has become a vital tool for dissolved organic matter (DOM) characterization. The upward trend in HRMS analysis of DOM presents challenges in data comparison and interpretation among laboratories operating instruments with differing performance and user operating conditions. It is therefore essential that the community establishes metric ranges and compositional trends for data comparison with reference samples so that data can be robustly compared among research groups. To this end, four identically prepared DOM samples were each measured by 16 laboratories, using 17 commercially purchased instruments, using positive-ion and negative-ion mode electrospray ionization (ESI) HRMS analyses. The …


Protonic Capacitor: Elucidating The Biological Significance Of Mitochondrial Cristae Formation, James Weifu Lee Jun 2020

Protonic Capacitor: Elucidating The Biological Significance Of Mitochondrial Cristae Formation, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

For decades, it was not entirely clear why mitochondria develop cristae? The work employing the transmembrane-electrostatic proton localization theory reported here has now provided a clear answer to this fundamental question. Surprisingly, the transmembrane-electrostatically localized proton concentration at a curved mitochondrial crista tip can be significantly higher than that at the relatively flat membrane plane regions where the proton-pumping respiratory supercomplexes are situated. The biological significance for mitochondrial cristae has now, for the first time, been elucidated at a protonic bioenergetics level: 1) The formation of cristae creates more mitochondrial inner membrane surface area and thus more protonic capacitance for …


Two Beta-Phosphorylamide Compounds As Ligands For Sm3+, Eu3+, And Tb3+: X-Ray Crystallography And Luminescence Properties, Alan R. Lear, Jonah Lenters, Michael G. Patterson, Richard J. Staples, Eric J. Werner, Shannon Biros Jun 2020

Two Beta-Phosphorylamide Compounds As Ligands For Sm3+, Eu3+, And Tb3+: X-Ray Crystallography And Luminescence Properties, Alan R. Lear, Jonah Lenters, Michael G. Patterson, Richard J. Staples, Eric J. Werner, Shannon Biros

Open Access Publishing Support Funded Articles

This paper describes the synthesis of two beta-phosphorylamide ligands and their coordination chemistry with the Ln ions Tb3+, Eu3+, and Sm3+. Both the ligands and Ln complexes were characterized by IR, NMR, MS, and X-ray crystallography. The luminescence properties of the Tb3+ and Eu3+ complexes were also characterized, including the acquisition of lifetime decay curves. In the solid state, the Tb3+ and Sm3+ ligand complexes were found to have a 2:2 stoichiometry when analyzed by X-ray diffraction. In these structures, the Ln ion was bound by both oxygen atoms of each beta-phosphorylamide moiety of the ligands. The Tb3+ and Eu3+ …


Altering An Epoxy-Amine Thermoset's Performance Through Varying Mix Ratios, Kiersten M. Smith Jun 2020

Altering An Epoxy-Amine Thermoset's Performance Through Varying Mix Ratios, Kiersten M. Smith

Master's Theses

Epoxy resins are used in a number of different industries and therefore have application-specific material requirements, from satellites that require materials that operate in space, to paints and coatings that require high scratch resistance and mechanical durability, to medical devices, designed to be in continuous contact with biological fluids. Commercial epoxy products come with manufacturer’s information explaining the epoxy properties and recommended preparation processing conditions, which may include epoxy resin to curing agent mix ratio (Part A : Part B), cure time, and cure temperature, for example. Due to proprietary reasons, it can be difficult to understand why these values …


The Reduction, Sequestration, And/Or Coordination Of Technetium-99 Utilizing Polyoxometalates And Nanomaterials, Colleen Mb Gallagher Jun 2020

The Reduction, Sequestration, And/Or Coordination Of Technetium-99 Utilizing Polyoxometalates And Nanomaterials, Colleen Mb Gallagher

Dissertations, Theses, and Capstone Projects

Research into the sequestration of radionuclides from aqueous media is being conducted due to the contamination of aqueous waste effluents and groundwater with highly toxic long-lived radionuclides. These contaminants are introduced into water and streams from legacy nuclear sites, nuclear reactor operations, nuclear fuel reprocessing, nuclear weapons testing, and plutonium production. A major contributor (~6%) to the waste from thermal neutron fission of uranium-235 is the radionuclide technetium-99 (99Tc). It is considered a long-lived radioisotope with a half-life of 2.1x105 years. It is a weak beta emitter with a max energy of 0.29 MeV and is most …


Pitting Corrosion Of Oerlikon’S Abrasion Resistant Ferritic Stainless Steels, Matthew P. Nalty, Emma Wagstaff Jun 2020

Pitting Corrosion Of Oerlikon’S Abrasion Resistant Ferritic Stainless Steels, Matthew P. Nalty, Emma Wagstaff

Materials Engineering

Existing hardfacing coatings for hydraulic cylinders and brake disc applications crack during use leaving the components susceptible to corrosion. To address this problem, Oerlikon has designed three new alloys to be abrasion and corrosion resistant. This paper reviews the literature necessary to understand and quantify pitting resistance of stainless-steel alloys. It documents one round of testing ASTM G48 method A: Ferric Chloride Pitting Test of Stainless Steels on the new alloys P72-X9, P72-X13, P129-X9, as well as samples of 431, 316, and 2205 stainless steels. This paper also discusses improvements to the G48 testing method and industry use of the …


Synthesis And Characterization Of Porous Carbon Composite Derived From Biomass Waste For Supercapacitor Application, Cheng Kim Sim Jun 2020

Synthesis And Characterization Of Porous Carbon Composite Derived From Biomass Waste For Supercapacitor Application, Cheng Kim Sim

Student Works (2020-2029)

Energy storage devices have gradually dominated human daily activities and indispensable to economy development such as supercapacitor and battery. There are few factors determining the performance of supercapacitor and active material is one of the crucial. Therefore, biomass such as pineapple peel (PP) and green waste (GW) were preferred and prior mixed with manganese and tin carbonate to synthesize carbon composite (PP/GW-ZMO and PP/GW-ZTO) via combustion. Brunauer–Emmett–Teller (BET) was employed to study the textural properties with the highest specific surface area obtained in PP-C (1765.92 m2g-1) and GW-C (1613.92 m2g-1). The existence of composite materials was examined using x-ray diffraction …


New Alkaloids From Selected Malaysian Alstonia And Lycopodium Species And Their Biological Activity, Soon Yee Joanne Yeap Jun 2020

New Alkaloids From Selected Malaysian Alstonia And Lycopodium Species And Their Biological Activity, Soon Yee Joanne Yeap

Student Works (2020-2029)

Two Malaysian plants, Alstonia penangiana Sidiyasa (family: Apocynaceae) and Lycopodium platyrhizoma J.H.Wilce (family: Lycopodiaceae), were investigated for their alkaloidal composition. This project represents the first reported phytochemical study on these two plant species. A total of 94 alkaloids (1−94) were isolated and characterized from the leaf and stem-bark extracts of Alstonia penangiana, a plant endemic to Penang Island, Malaysia. Of these, 32 are new alkaloids. The leaf extract of A. penangiana yielded a total of 15 new alkaloids, including a pair of type-A and type-B macroline isomers (1, 2), four macroline oxindoles (20–23), three talpinine-type oxindoles (41–43), two ajmaline alkaloids …


Catalytic Esterification Of Palm-Based Lauric Acid Diethylene Glycol Via Microwave Heating, Abas Noor Azeerah Jun 2020

Catalytic Esterification Of Palm-Based Lauric Acid Diethylene Glycol Via Microwave Heating, Abas Noor Azeerah

Student Works (2020-2029)

Diethylene glycol esters of fatty acids are mixtures of diethylene glycol mono- and di-esters of saturated and unsaturated fatty acids derived from edible oils and fats. The products are produced either by direct esterification of diethylene glycol with fatty acids or by transesterification of diethylene glycol with oils or fats. This study involved in maximizing the conversion of lauric acid to glycol ester via esterification with diethylene glycol, aided by calcined Zn-Mg-Al catalyst in a 250-ml reactor using both conventional and microwave heating. Preliminary catalytic screening involving tin (II) oxalate, Amberlyst-15 and calcined Zn-Mg-Al catalysts in esterification of lauric acid …


Fabrication, Characterization And Applications Of Chemically Modified Planar Metallic Electrodes From Copper Clad Sheets, Rana T. Alsaidi Jun 2020

Fabrication, Characterization And Applications Of Chemically Modified Planar Metallic Electrodes From Copper Clad Sheets, Rana T. Alsaidi

Theses

In this work, we developed a fabricating method for planar electrodes by milling and cutting copper-clad sheets. The main objectives of this thesis are to produce customized planar electrodes with different geometries with relatively higher reusability compared to the screen-printed electrodes available by commercial vendors. The fabricated electrodes from copper-clad sheets were electroplated with different metals using commercial electroplating baths to produce different metallic planar electrodes. Also, the fabrication of planar electrodes with cavities to be filled with modified carbon paste was done. The electroplated planar electrodes were characterized by the cyclic voltammetry technique. In addition to that, they were …