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Full-Text Articles in Physical Sciences and Mathematics

Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware, Yuvraj Dineshkumar Patel Dec 2020

Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware, Yuvraj Dineshkumar Patel

Theses

The scalability and power efficiency of the conventional CMOS technology is steadily coming to a halt due to increasing problems and challenges in fabrication technology. Many non-volatile memory devices have emerged recently to meet the scaling challenges. Memory devices such as RRAMs or ReRAM (Resistive Random-Access Memory) have proved to be a promising candidate for analog in memory computing applications related to inference and learning in artificial intelligence. A RRAM cell has a MIM (Metal insulator metal) structure that exhibits reversible resistive switching on application of positive or negative voltage. But detailed studies on the power consumption, repeatability and retention …


Triplex Dna Receptor-Gold Nanoparticle Conjugates For Detection Of Oxidized Dna Base, Qingyu Xing Jan 2016

Triplex Dna Receptor-Gold Nanoparticle Conjugates For Detection Of Oxidized Dna Base, Qingyu Xing

Theses

Oxidations of DNA nucleobases are believed to be one of the sources of aging and some age-dependent disease, such as cancer. Human body have various mechanisms to repair damaged DNA and base-excision-repair is one mechanism for removing those oxidized nucleobases. This mechanism processes in the cells by cutting the oxidized nucleobases from deoxyribose and letting them excrete though urine. Detection of those abnormal nucleobases in urine has been suggested as a convenient way of early cancer diagnosis. 5-OHU (5-hydroxyuracil), the oxidation product of cytosine, is one of those abnormal nucleobases and it potentially forms base pairs with all four DNA …


Thermochemical Properties Of C3 To C5 Unsaturated Carbonyl Alkenes: Enthalpies Of Formation, Entropy, Heat Capacity, Bond Enthalpy, Ruiqi Jian Jan 2014

Thermochemical Properties Of C3 To C5 Unsaturated Carbonyl Alkenes: Enthalpies Of Formation, Entropy, Heat Capacity, Bond Enthalpy, Ruiqi Jian

Theses

α,β and α-γ unsaturated carbonyl compounds are important classes of carbonyl compounds with the general structure R-(O=C)-Cα=Cβ-R’ and R-(O=Cγ)-Cβ-Cα=Cβ-R’. These compounds are utilized in industry and are also produced as intermediates of hydrocarbon oxidation in chemistry of the atmosphere and in combustion. These unsaturated carbonyls are common environmental pollutants, are frequently associated with adverse effects, and are considered to play an important role in human cancer. Their stability, thermochemical properties are important to understanding their reaction paths in atmospheric, combustion and bio related environments. Enthalpy, entropy, and heat capacity of unsaturated alkene molecules, and radicals corresponding to hydrogen atom …


Design And Synthesis Studies Of New S-Adenosyl-L-Methionine Analogues, Shanshan Wu May 2012

Design And Synthesis Studies Of New S-Adenosyl-L-Methionine Analogues, Shanshan Wu

Theses

S-Adenosyl-L-Methionine (SAM), which is involved in methyl group transfers, is the second most abundant coenzyme in the human body. It is made from adenosinetriphosphate (ATP) and methionine catalyzed by adenosyltransferase. Methyltransferases (MTs) transfer the activated methyl group from the sulfur center to a specific position in a variety of substrates, e.g., DNA, RNA, proteins, and secondary metabolites. Methyltransferases have been linked to various diseases, including cancer.

In recent years, more and more SAM analogues have been reported. These analogues show activities in biological target labeling. The purpose of this thesis is to design and synthesize new SAM analogues to inhibit …


Thermochemistry And Bond Energies Of Acetohydrazide, Amides And Cyclic Alkyl Ethers, Sumit Charaya May 2011

Thermochemistry And Bond Energies Of Acetohydrazide, Amides And Cyclic Alkyl Ethers, Sumit Charaya

Theses

Structure, thermochemical properties, bond energies and internal rotation potentials of Acetic Acid Hydrazide (CH3CONHNH2), Acetamide (CH3CONH2) and N-methyl Acetamide (CH3CONHCH3) and their radicals corresponding to loss of hydrogen atom have been studied. Gas phase standard enthalpies of formation and bond energies were calculated using the DFT methods B3LYP/6-31G(d,p), B3LYP/6-31G(2d,2p) and the composite CBS-QB3 methods employing a series of work reactions to further improve accuracy of the ΔHf°(298K). Molecular structures, vibration frequencies and internal rotor potentials were calculated at DFT level. The enthalpies of the parent molecules CH3-C=ONHNH2 …


Synthesis Towards Synthetic Adenosine Receptor, Rajni Gupta May 2011

Synthesis Towards Synthetic Adenosine Receptor, Rajni Gupta

Theses

Adenosine is a biologically important molecule as it acts as local modulator with cytoprotective function in the body. Adenosine accumulates in the extracellular space in response to metabolic stress and cell damage, and elevations in extracellular adenosine level are found in conditions like myocardial ischemia, hypoxia, inflammation and trauma. Its abnormal concentration therefore could be a marker of many diseases. Therefore determining its concentration can help understand the physiological state of the body. However its selective detection by synthetic receptors is not possible till date.

Efforts have been made here to design molecular tweezer for adenosine. Multistep synthesis was done …


Development Of Pharmacophore And Comfa Study Of Rigid And Flexible Sigma 2 Receptor Ligands, Hemantbhai Patel Jan 2010

Development Of Pharmacophore And Comfa Study Of Rigid And Flexible Sigma 2 Receptor Ligands, Hemantbhai Patel

Theses

In the present study a pharmacophore and CoMFA model was derived for sigma 2 (62) receptors by using Sybyl 7.2 Software Package. The CoMFA studies used 22 bioactive molecules as a training set and 4 molecules as a test set for the o2 receptor ligands. The geometries and electrostatic charges of all molecules were calculated using various levels of calculations. The geometry optimization and electrostatic charges of all 26 molecules were performed by using semiemprical AM1, ab initio HF/6-31G* and density functional B3LYP/6-31G* in Gaussian 98. The pharmacophore model was derived by using Distance Comparisions (DISCOtech) from 4 partially to …


Development Of Pharmacophore And Comfa Studies For Sigma2 Receptor Ligands, Laura Ann Wirpsza Aug 2008

Development Of Pharmacophore And Comfa Studies For Sigma2 Receptor Ligands, Laura Ann Wirpsza

Theses

This study describes the development of a pharmacophore and CoMIFA model for sigma 2 (σ2) receptor ligands. CoMFA studies were performed for 32 bioactive σ2 receptor ligands using the radioligand [H 3] (+) DTG in the presence of pentazocine. The pharmacophore was derived using Distance Comparisons (DISCOtech) from eight partially to highly active ~2 receptor ligands. All 32 compounds were calculated in three methods: AMi, HFI3~21G*, and B3LYP/3~21G* methods. These methods run in Gaussian 98 determined the geometry optimization and electrostatic charges for each molecule. CoMFA maps were developed using SYBYL ver. 7.2 to compare the electrostatic …


Structure And Thermochemistry Of Disulfide-Oxygen Species, Shyamala Pravin Pillai Jan 2008

Structure And Thermochemistry Of Disulfide-Oxygen Species, Shyamala Pravin Pillai

Theses

Sulfur compounds are known to form aerosols that can counteract the greenhouse effect, and recent studies suggest that aerosols can also contribute to global warming; sulfur species are also known as major contributors to acid rain. Both of these atmospheric chemistry interactions involve SO2, which is formed by oxidation of sulfur hydrocarbons and H2S. This study describes the structure, internal rotor potentials, bond energies and determines thermochemical properties (ΔfH°, S° and Cp(T)) on the S-S bridge system in the sulfur bridged molecules CH3SSOH, CH3SS(=O)H, HSSOH, HSS(=O)H and CH3SSOCH …


Development Of Enzymatic Biofuel Cell Based On Carbon Nanotube Electrodes On Porous Silicon, Fan Yang Jan 2007

Development Of Enzymatic Biofuel Cell Based On Carbon Nanotube Electrodes On Porous Silicon, Fan Yang

Theses

The work presented in this thesis has focused on designing and characterizing biofuel cell electrodes using porous silicon (p-Si) as the substrate or current collecting platform on which carbon nanotubes (CNTs), both single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MiWNTs), were synthesized directly, followed by enzyme catalyst immobilization on the CNTs. Laccase and glucose oxidase (GOx) were used as enzymatic biocatalysts, which were immobilized on the CNT walls and tips using an electrochemical technique. Cyclic voltammetry showed well-defined redox peaks which indicated that the enzyme (GOx and laccase) were successfully immobilized on the CNTs. The amperometric responses of the …


Thermochemical Properties Of Small Oxygenated Sulfur Hydrocarbons And Kinetics - Reaction Pathways Of Methylthiomethyl Radical With Oxygen, Fei Jin Jan 2004

Thermochemical Properties Of Small Oxygenated Sulfur Hydrocarbons And Kinetics - Reaction Pathways Of Methylthiomethyl Radical With Oxygen, Fei Jin

Theses

The thermochemical properties on CH3SCH2OOH and the corresponding two radicals resulting from loss of H atom: CH3SCH2OO and CH2SCH2OOH are important to understand the stability, reaction paths and kinetics of reactions of dimethyl sulfide and other sulfur hydrocarbons (sulfides) in the atmosphere and combustion processes. Thermochemical properties for species and transition states in the methylthiomethyl radical (CH3SCH2) + O2 reaction system are analyzed to evaluate reaction paths and kinetics under these conditions. Isodesmic working reaction are employed to determine the enthalpies of formation …


Synthesis And Application Of Novel Chiral Ionic Liquids Derived From Alpha-Pinene, Yun Wang Aug 2003

Synthesis And Application Of Novel Chiral Ionic Liquids Derived From Alpha-Pinene, Yun Wang

Theses

Two new chiral ionic liquids of oxazolinium cations derived from a-pinene: 9,9-Dimethyl-4-propenyl-5-propyl-3 -oxa-5-azonia-tricyclo [6.1.1.0 2,6] dec-4-ene tetrafluoro borate ([ChIPOZ] [BF4]) and 9,9-Dimethyl-4-propenyl-5-propyl-3-oxa-5-azonia-tricyclo [6.1.1.0 2,6] dec-4-ene hexafluoro phosphate ([ChIPOZ][PF6]). Both these chiral ionic liquids have been applied in enantiomeric copper-catalyzed 1,4-addition reactions with diethyl zinc. The enantiomeric excess for product using [ChIPOZ][BF4] is above 70% and for [ChIPOZ][PF6] is above 30%. Chiral ionic liquids worked as phase transfer catalysts In this reaction.

α-Pinene was used as the "chiral pool" in the synthesis of amino alcohol through a two-step reaction, followed by …


Novel Synthesis Of 2-Methyl-3, 4, 5-Trichloropyrimidine, Daniel M. Goldman May 2002

Novel Synthesis Of 2-Methyl-3, 4, 5-Trichloropyrimidine, Daniel M. Goldman

Theses

A one-step synthesis of the heterocycle 2-methyl-3,4,5-trichloropyrimidine by the cycloaddition of hexachloropropene with acetamidine hydrochloride in methanolic NaOH was attempted. The product was dark amber oil. A by-product of this reaction was sodium chloride. The proposed reaction was expected to proceed via a SN2 nucleophilic displacement of three chlorine atoms on hexachloropropene by acetamidine, the nucleophile. The proposed driving force for this transformation is the lone pair of electrons on the amidine nitrogen along with the electron withdrawing ability of three chlorines on hexachloropropene which induces a partial positive charge on the carbon. It is proposed that the chlorine atoms …


Coating Of Aluminum Powder With Polymers In Supercritical Carbon Dioxide, Li Yuan May 2001

Coating Of Aluminum Powder With Polymers In Supercritical Carbon Dioxide, Li Yuan

Theses

Eleven polymers were used to produce coatings (2-20 nm) on the surface of an aluminum powder to modify its properties. The polymers studied are polyisobutylene (PIB), poly (vinylidene fluoride) (PVF), poly (methyl methacrylate) (PMMA), polystyrene (PS), poly(ethylene terephthalate) (PETP), poly(4-vinylbiphenyl) (PVB), poly(4-vinylpyridine) (PVP), poly(4-bromo styrene) (PBS), poly (vinylidene fluorideco-hexafluoropropylene) (PVFH), poly (styrene-co-methyl methacrylate) (PSMMA), poly (vinyl chloride-co-vinyl acetate) (PVCVA). Supercritical carbon dioxide was used as a solvent and as a transport medium. Coated aluminum powders exhibit enhanced resistance to the dissolution in basic solutions. The protective properties of the polymeric films were quantified based on the dissolution rate. Polymeric films …


Structures, Intermolecular Rotation Barriers, And Thermodynamic Properties Of Chlorinated Methanols And Chlorinated Methyl Hydroperoxides, Hongyan Sun May 2000

Structures, Intermolecular Rotation Barriers, And Thermodynamic Properties Of Chlorinated Methanols And Chlorinated Methyl Hydroperoxides, Hongyan Sun

Theses

Thermochemical property data on chlorinated methanols and methyl hydroperoxides are important in oxidation, combustion and atmospheric photochemistry of chlorocarbons, Enthalpy, entropy, and heat capacities are determined for three chlorinated methanols and three chlorinated methyl hydroperoxides using density frnctional, B3LYP/6-31G(d,p), B3LYP/6-311+G(3df,2p), ab initio QCISD(T)/6-31G(d,p) and the composite CBSQ/B3LYP/6-31G(d,p) calculation methods. Molecular structures and vibration frequencies are determined at the B3LYP/6-31G(d,p) density functional calculation level. Vibration frequencies are scaled for zero point energies and for thermal corrections. ΔH°f 298 are determined at each calculation level using the ΔHrxn,298 with known enthalpies of other reactants and products in each of five …


Thermochemical Properties Of Methyl And Chloro-Methyl Hyplochlorites And Ethers And Reaction Of Methyl Radical With Clo, Dawoon Jung May 2000

Thermochemical Properties Of Methyl And Chloro-Methyl Hyplochlorites And Ethers And Reaction Of Methyl Radical With Clo, Dawoon Jung

Theses

Hypochlorites are formed from reactions of chlorine monoxide (ClO) addition to unsaturates and association with radicals. ClO is a prevalent and an important species in chemistry of the atmosphere and in combustion systems where chlorine is present. Thermochemical property data on these oxy-chlorocarbon species are important to understanding the reaction pathways and kinetics in these environments. Enthalpy, ΔHf°298, entropy, S°298, and heat capacities, Cp(T) from 300 to 1500 K are determined for methyl hypochlorite and three chloro-methyl hypochlorites and formaldehyde-C1 atomcomplex radicals (CH2O--Cl, CHClO--CI, CCI2O--Cl) by density functional, and ab …


Comparative Molecular Field Analysis (Comfa) Of Phenyl Ring Substituted Methylphenidates, Milind Misra Aug 1999

Comparative Molecular Field Analysis (Comfa) Of Phenyl Ring Substituted Methylphenidates, Milind Misra

Theses

Comparative Molecular Field Analysis (CoMFA) was performed on 30 methylphenidate analogues having phenyl ring substituents at the 2-, 3-, and 4-positions in an attempt to explain the structure-activity relationships of the analogues. Several CoMFA studies were carried out using different conformations of methylphenidate as the template structures for the corresponding alignment rules. The identification of the bioactive conformation was variously based on the interfeature distances in WIN 35,428, on cluster analysis, and on a comparison of active methylphenidate analogues. The sensitivity of the models to various CoMFA parameters was compared. These parameters included altering the size and spacing of the …


Sustainable Green Manufacturing Of Energetic Materials, Ted Alex Formeza May 1999

Sustainable Green Manufacturing Of Energetic Materials, Ted Alex Formeza

Theses

Pollution from manufacturing processes of the major energetic materials currently used in the U.S., 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), 1,3,5,7-tetranitro-1,3,5,7 tetraazacyclooctane (HMX) was briefly evaluated. It was found that acetic acid was a major pollutant. It appeared that the British Process could be controlled to reduce the polluting effluents better than the Bachmann Process used in the U.S. Most of the effort for producing the next generation of energetic materials is currently centered around the production of 1,3,3-trinitroazetidine (TNAZ). We evaluated five synthetic routes for producing TNAZ. We reduced the number of potential processes by carefully considering possible changes in the schemes that …


Catalyctic Reduction Of Nitric Oxide By Copper Catalyzed Granular Activated Carbon In The Presence Of Oxygen, Shan Xiao May 1999

Catalyctic Reduction Of Nitric Oxide By Copper Catalyzed Granular Activated Carbon In The Presence Of Oxygen, Shan Xiao

Theses

The catalytic reduction of nitric oxides by solid carbonaceous material consisting primarily of granular activated carbon or (GAC) was studied in a fix bed catalytic reactor in order to develop the technology for removing NO and soot simultaneously from diesel engine exhaust. The catalytic activity and conversion of NO as a function of reaction temperature was evaluated as a function of space velocity. The results show that at lean condition and high gaseous hourly space velocity, vis., 50,000 ~ 80,000, Cu-ZSM-5 does not perform as well with CO and GAC as it does with gaseous hydrocarbons(HC). Plain GAC has low …


Role Of Zeta Potential In Micro-Carrier Process, Pallavi Mehta Jan 1999

Role Of Zeta Potential In Micro-Carrier Process, Pallavi Mehta

Theses

The micro-carrier process recently developed at NJIT is a new high rate settling technology for water and wastewater treatment. This process utilizes the micro-cater as a flocculating enhancement agent to achieve rapid removal of colloidal particles. This thesis consist of two parts, namely, 1) A review of the flocculation process utilized in water and wastewater treatment, and 2) An experimental program to evaluate the role of zeta potential in the flocculation process.

The results of this study indicated that the DLVO theory (Darjaguin, Landau, Overbeek, Verwey theory) is applicable to micro-cater process in the absence of polyelectrolytes. The best flocculation …


Development And Field Testing Of Pulse Introduction Membrane Extraction (Pime) For Measurement Of Ground Water Contamination, Anthony San Juan Aug 1998

Development And Field Testing Of Pulse Introduction Membrane Extraction (Pime) For Measurement Of Ground Water Contamination, Anthony San Juan

Theses

VOCs are a class of aromatic and aliphatic compounds with a variety of functional groups, and are in general detrimental to human health even at trace levels. Conventional analysis of VOCs in groundwater usually involves sampling at site followed by laboratory analysis. This results in long turn around times, high cost and also errors associated with sample preservation during transportation and storage. In order to address these problems, a field portable instrument referred to as Pulse Introduction Membrane Extraction (PIME) has been developed for monitoring trace level halogenated organic contaminants in ground water. A membrane extraction approach has been used, …


In Vitro Cytotoxicity Study Of Glutaraldehyde And No-React Treated Bioprosthetic Heart Valves And The Aortic Wall, Roger Ongosi May 1998

In Vitro Cytotoxicity Study Of Glutaraldehyde And No-React Treated Bioprosthetic Heart Valves And The Aortic Wall, Roger Ongosi

Theses

Valvular failure due to calcification and leaflet disruption of artificial bioprostheses is still a major concern in valve replacement surgery. Previous studies have shown that Glutaraldehyde, a chemical used in the treatment of artificial valves promotes calcification. In this investigation glutaraldehyde and No-React® treated tissue samples of pericardium, cusp and the aortic wall were tested for cytocompatibility using live mouse fibroblast cultures. The samples were cut into 3 X 3 mm2 washed in phosphate buffered saline solution, transferred into cell culture flask containing cells that had been cultured for 24 hours and incubated at 37 "C in 5 % CO2. …


Catalyctic Reduction Of Nitric Oxide By Carbon Monoxide And Copper Loaded Granular Activated Carbon In The Presence Of Oxygen, Kaiwen Ma May 1998

Catalyctic Reduction Of Nitric Oxide By Carbon Monoxide And Copper Loaded Granular Activated Carbon In The Presence Of Oxygen, Kaiwen Ma

Theses

The reduction reaction of nitric oxide (NO) by carbon monoxide (CO), and granular activated carbon (GAC) in the presence and absence of oxygen was studied in a fixed bed catalytic reactor. The conversion of NO as a function of reaction temperature was evaluated for various reductant to NO ratios and space velocities. The results show that oxygen enhanced the NO+CO reaction over copper (Cu) ion exchanged ZSM-5. About 60% NO conversion to nitrogen (N2) was obtained at 400°C and 2,000 v/v/hr. This result is consistent with the hypothesis that CO is an intermediate in the soot-NO reaction. The …


Thermodynamic Properties Of Chlorocarbons And Kinetic Analysis For A- And B -Addition Of Oh+C2h3cl, Li Zhu Jan 1998

Thermodynamic Properties Of Chlorocarbons And Kinetic Analysis For A- And B -Addition Of Oh+C2h3cl, Li Zhu

Theses

Thermodynamic properties, ΔHf°298, S°298 and Cp(T) 300≤T/K≤1500, for C1, C2 chlorocarbons are calculated by AM1 and PM3 in MOPAC6, then compared with the literature data. AM1- and PM3-derived S°298 and Cp(T) (300≤T/K≤1500) are found to be consistent with the literature (Rd ≤ ± 5%). ΔHf°298 of CH2Cl2, CH2ClCH2Cl, CH2ClCHCl2, CHCl2CHCl2, and C2Cl4 and C2Cl2 calculated by PM3 as well as ΔHf°298 of CCl4, C2HCl3, …


Oxidized Sterols In Patients With Diabetic Heart Disease And Microwave-Mediated Stereoselective Synthesis Of 3-Keto Cholesterol And Cholesterol Epoxide, Cholesteryl Ester Epoxides, Meenakashi N. Kothavale Jan 1997

Oxidized Sterols In Patients With Diabetic Heart Disease And Microwave-Mediated Stereoselective Synthesis Of 3-Keto Cholesterol And Cholesterol Epoxide, Cholesteryl Ester Epoxides, Meenakashi N. Kothavale

Theses

Oxidized low density lipoproteins (ox-LDL) may play important role in mediating hypercholesterolemic endothelial dysfunction. The uptake of modified LDL by macrophages to form foam cells has been implicated in the enhancement of atherosclerosis. Recent reports have suggested that when LDL undergoes oxidation in vitro , it is accompanied by a substantial loss of free and esterified cholesterol leading to the formation of oxidation products of cholesterol ( oxysterols). These compounds are present in human atherosclerotic plaques and in human foam cells.

In this regard we have recently studied the plasma sterol composition in diabetic heart patients We have found cholesterol …


Catalytic Control Of Nitric Oxide With Gaseous Or Solid Reducing Materials, Xiaoyong Tang Jan 1997

Catalytic Control Of Nitric Oxide With Gaseous Or Solid Reducing Materials, Xiaoyong Tang

Theses

Air pollution from mobile sources is an increasingly serious problem throughout most of the industrialized would. Diesel powered vehicles, because of their higher thermal efficiency, tend to emit less carbon monoxide and unburned hydrocarbons than gasoline vehicles, but emit significant quantities of NOx. Therefore, it is essential to develop improved emission control equipment in diesel engines. A fixed bed catalytic reactor was used to study the decomposition of NO and the reduction of NO to N2 by different reductants that can be found in diesel exhaust, such as hydrocarbons, CO and elemental carbon over different catalysts. The …


The Effect Of Deposition Of H2s On The Catalyst Activity Of 1.5 % Pt On [Gamma]-Al2o3, Ping Zhu Oct 1996

The Effect Of Deposition Of H2s On The Catalyst Activity Of 1.5 % Pt On [Gamma]-Al2o3, Ping Zhu

Theses

The impact of hydrogen sulfide (H2S) pretreatment on the oxidation activity of powdered 1.5% Pt/γ-AL2O3 catalyst was investigated in this study. Fresh 1.5% Pt/γ-Al2O3 catalyst was aged with different concentrations of H2S in air at 400 °C for 24 hours. Then, the aged and fresh catalysts were tested to determine the oxidation activity with diagnostic gases which contained either 1% propane or 1% carbon monoxide in dry air. The test results indicated that the catalysts were deactivated for carbon monoxide oxidation and promoted for propane oxidation as a function of …


The Reactions Of Nox With Diesel Soot Over Cu-Zsm-5 Catalyst, Shu Sun May 1996

The Reactions Of Nox With Diesel Soot Over Cu-Zsm-5 Catalyst, Shu Sun

Theses

Air pollution from the exhaust of Diesel engines consisting of relatively high concentrations of NOx and particulates is a difficult problem to overcome because no fully effective technology to control these emission is available. The existing methods to reduce NOx and soot can not satisfy the provisions of the 1990 CAAA (Clean Air Act Amendment). Cu-ZSM-5, a catalyst in which Cu has been ion-exchanged with H+, can catalyze the decomposition of NO to N2 and O2 and reduction to N2 and O2 with light hydrocarbons such as propene or Diesel soot in the presence …


Speciation And Determination Of Trace Lead : Methodology Development And Analysis Of Natural Waters Using Chelex-100 And Gfaas, Xidan Ma May 1996

Speciation And Determination Of Trace Lead : Methodology Development And Analysis Of Natural Waters Using Chelex-100 And Gfaas, Xidan Ma

Theses

The development of a method for speciation, preconcentration, and determination of lead was successfully conducted using Chelex-100 and graphite furnace atomic absorption spectroscopy (GFAAS). Sorption under static conditions and direct measurements in the bead slurry or after fast elution of lead from beads with HNO3 solution was used. The effects of buffers, sorption kinetics, filtration criteria, sample concentration, resin particle size and temperature program for the GFAAS were carefully studied. In this study, synthetic aqueous samples containing lead were preconcentrated under static conditions using the ion exchange resin, Chelex-100, and the resin was directly analyzed using GFAAS. The batch preconcentration …


Construction Of Accurate Molecular Models Using Laser Stereolithography And Determination Of Nmr Spectra For Amiloride Hydrochloride And Its Free Base, Ana Deborah Ofsievich Jan 1996

Construction Of Accurate Molecular Models Using Laser Stereolithography And Determination Of Nmr Spectra For Amiloride Hydrochloride And Its Free Base, Ana Deborah Ofsievich

Theses

Accurate molecular models were constructed by a rapid prototyping process, called stereolithography. This process uses a computer-controlled laser to cure and solidify a photosensitive liquid polymer. Using a computer-aided design (CAD) program, spheres of appropriate van der Waals or CPK radii were drawn and placed in the three dimensional CAD space, in accordance with the atomic coordinates obtained from quantum mechanical calculations and from neutron diffraction data. These design data were used to drive the stereolithography system where the models were built in the same shape as the CAD image. The models built for the purpose of this work consisted …