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Contemporary Problems In Aerosol Aggregation And Gelation, Pai Liu

McKelvey School of Engineering Theses & Dissertations

Aggregation of nanoparticles in aerosols is a fundamental phenomenon with important implications to diverse fields ranging from material synthesis to pollutant control. The past few decades have witnessed extensive research on investigating the structure and growth mechanism of aerosol aggregates with sizes spanning across several orders of magnitude. This dissertation focuses on some contemporary problems that remain unaddressed in this topical area. Aerosol aggregates in sub-micron regimes, which are formed via the irreversible collision and aggregation of solid nanoparticle monomers, are fractal-like in their morphology. A mathematical description of this seemingly random structure dates to the seminal works by Forest …

State-To-State Inelastic Rotational Cross Sections In Five-Atom Systems With The Multiconfiguration Time Dependent Hartree Method, Steve Ndengue, Yohann Scribano, Fabien Gatti, Richard Dawes

Chemistry Faculty Research & Creative Works

We present a MultiConfiguration Time Dependent Hartree (MCTDH) method as an attractive alternative approach to the usual quantum close-coupling method that approaches some computational limits in the calculation of rotational excitation (and de-excitation) between polyatomic molecules (here collisions between triatomic and diatomic rigid molecules). We have performed a computational investigation of the rotational (de-)excitation of the benchmark rigid rotor H₂O-H₂ system on a recently developed Potential Energy Surface of the complex using the MCTDH method. We focus here on excitations and de-excitations from the 0₀₀, 1₁₁, and 1₁₀ states of H_{2 …}

Designing, Constructing, And Employing Two-Dimensional Ultrafast Spectroscopy To Resolve Complex Kinetics, Jason R. Darvin

Theses and Dissertations

Multiple population-period transient spectroscopy (MUPPETS) is a two dimensional ultrafast time resolved spectroscopy technique. MUPPETS uses three pairs of optical pulses over two time periods to separate homogeneous and heterogeneous causes of rate dispersion. This dissertation details improvements to the MUPPETS optical assembly enabling measurements on systems that previously fell outside of the MUPPETS 2-ns time window. In addition, the theoretical groundwork is laid to unveil the hidden coordinate controlling rate exchange using 2D and 3D correlation functions.

The first project details improvements made to the MUPPETS assembly. A detailed method was developed to eliminate astigmatism, coma, and spherical aberration …

Leaving Ligand Effects On Reactivity And Solubility Of Monofunctional Platinum(Ii) Anticancer Complexes, Heidi Linn Hruska Millay

Masters Theses & Specialist Projects

Monofunctional platinum(II) complexes, such as phenanthriplatin and pyriplatin, have notably different characteristics from the bifunctional anticancer complexes, such as cisplatin and oxaliplatin, which have detrimental toxicities and resistance associated with them. The unique properties of the monofunctional complexes may be exploited to target cancer cells without producing the toxic side effects associated with the current FDA-approved platinum-based anticancer drugs. To advance the understanding of these monofunctional platinum(II) complexes, this study replaced the chloride leaving ligand with an acetate group, which should increase solubility and alter the rate of reactivity with key amino acid and nucleotide targets. Phenanthriplatin and pyriplatin compounds …

Sorption Of Copper (Ii), Nickel (Ii) And Cobalt (Ii) Ions Into The Ionite Modified By Polyphinylchloride And Polyethylene Polyamine, Kh Ismoilova, D Bekchanov, Sh Khasanov, M Baltaeva

Scientific journal of the Fergana State University

IPolyphinylchloride was modified by polyethylene polyamine, and the ionites were studied in static conditions by the artificial solution of copper (II), nickel (II) and cobalt (II) ions. In static conditions, factors affecting the sorption process, such as time, temperature and concentration dependence were investigated. The results of the inquiry process were studied by IR analysis

Sorption Of Copper (Ii), Nickel (Ii) And Cobalt (Ii) Ions Into The Ionite Modified By Polyphinylchloride And Polyethylene Polyamine, Kh Ismoilova, D Bekchanov, Sh Khasanov, M Baltaeva

Scientific journal of the Fergana State University

IPolyphinylchloride was modified by polyethylene polyamine, and the ionites were studied in static conditions by the artificial solution of copper (II), nickel (II) and cobalt (II) ions. In static conditions, factors affecting the sorption process, such as time, temperature and concentration dependence were investigated. The results of the inquiry process were studied by IR analysis

Kinetic Study Of Silver Nanoparticle Formation, Steven A. Diaz

Ursidae: The Undergraduate Research Journal at the University of Northern Colorado

With the increased use of silver nanoparticles in modern day applications, kinetic information on the mechanism of their formation is useful for further studies on its reactivity in a biological environment. Silver nanoparticles were synthesized using a modified Turkevich method. The synthesized nanoparticles were characterized using UV-Visible spectroscopy. The data obtained were plotted as a function of time, and rate constants for the nucleation (k₁) and autocatalytic surface growth (k₂) were extracted. Comparing the k₁ (~10^-3) and k₂ (~10^-1) values supports a two-step mechanism of slow nucleation and fast autocatalytic …

Pharmacodynamics Of Monoamine Transporter Releasing Agents And Reuptake Inhibitors, Alexa Holloway

Theses and Dissertations

Ligands of the human monoamine transporters encompass a wide range of both illicit and therapeutic drugs that act upon neural circuitry related to reward, motivation, and the processing of salient stimuli. The present study utilizes two methods for analyzing transporter substrates and inhibitors in order to characterize activity and assess potency. The first measures transient changes in intracellular calcium as a surrogate for transporter activity by harnessing the electrical coupling of monoamine transporters and L-type calcium channels. This is used to analyze novel chimera of the strong hDAT inhibitors methylphenidate and ��-PPP in order to assess the contribution of specific …

Non-Covalent And Covalent Interactions Between Phenylacetylene And Quinoline Radical Cations With Polar And Non-Polar Molecules In The Gas Phase, Adam C. Pearcy

Theses and Dissertations

Gas phase molecular clusters present an ideal medium for observing factors that drive chemical reactions without outside interferences from excessive solvent molecules. Introducing an ion into the cluster promotes ion-molecule interactions that may manifest in a variety of non-covalent or even covalent binding motifs and are of significant importance in many fields including atmospheric and astronomical sciences. For instance, in outer space, molecules are subject to ionizing radiation where ion-molecule reactions become increasingly competitive to molecule-molecule interactions. To elucidate individual ion-molecule interaction information, mass spectrometry was used in conjunction with appropriate theoretical calculations.

Three main categories of experiment were conducted …

An Evaluation Of The Adsorption Dynamics Of Phosphate Ions Onto Fe(Ii)-Montmorillonites, Dawei Qin, Shuhua Chang, Min Qiao, Xiaotong Yuan, Wei Liu, Gang Liu

Turkish Journal of Chemistry

Fe(II)-montmorillonites (Fe(II)-MMTs) were prepared by mixing solutions of Fe(II) and montmorillonite at pH 3.5. Two different Fe(II)-MMTs were prepared and the ferrous iron contents were 40 mg/L and 80 mg/L. All samples were characterized by XRD, FT-IR, TGA, DSC, and nitrogen adsorption. By nitrogen adsorption, the pore size can be obtained in the pore diameter curve with average pore widths of 6.67 nm, 9.96 nm, and 17.07 nm, respectively. The removal rate of phosphate increased rapidly during the first 40 min, in which Fe(II)-MMT (1) and Fe(II)-MMT (2) were stronger adsorption systems than MMT. The maximum adsorption was 48.38 mg/g …

Experimental And Modeling Investigation Of The Oh-Initiated Oxidation Of Semi-Solid And Aqueous Saccharide Aerosols, Hanyu Fan

Graduate Theses, Dissertations, and Problem Reports

My research focuses on investigating the impact of moisture-induced and oligomer-induced viscosity changes on OH-initiated oxidation of semi-solid aerosols,and the role of gas-liquid interfaces in regulating aqueous aerosol chemistry. Saccharides, which are a major constituent of aqueous atmospheric aerosols, are chosen as model molecules to form highly oxygenated organic aerosols. The experiments are performed using an atmospheric pressure flow-tube reactor with both online VUV-AMS (Vacuum-Ultraviolet Aerosol Mass Spectrometer) and offline GC-MS analysis techniques. The decay rates of saccharide are determined by measuring the loss signal of saccharide in the particle phase as a function of OH exposure (time-integrated total concentration …