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Full-Text Articles in Physical Sciences and Mathematics

Impact Of Cerium Oxide Nanoparticles On Cilantro (Coriandrum Sativum), Maria Isabel Morales Jan 2013

Impact Of Cerium Oxide Nanoparticles On Cilantro (Coriandrum Sativum), Maria Isabel Morales

Open Access Theses & Dissertations

Studies have shown that plants exposed to ENPs suffer different types of stress. Other studies have revealed that plants can take up and accumulate CeO2 NPs without modification. Thus, these NPs could enter the food chain through edible plants, posing a threat for human health. Cilantro (Coriandrum sativum) is a worldwide culinary and medicinal plant consumed either as a fresh herb or a spice. In this research, cilantro plants were germinated and cultivated for 30 days in organic soil treated with CeO2 NPs at concentrations varying from 0 to 500 mg kg!1. Subsequently, plant organs were analyzed by using spectroscopic …


Novel Copper (Ii) Mediated Transfection Nano-Systems And Biological Properties Of Pyridinium Surfactants, Sarit Pal Jan 2013

Novel Copper (Ii) Mediated Transfection Nano-Systems And Biological Properties Of Pyridinium Surfactants, Sarit Pal

Open Access Theses & Dissertations

Efficacy of gene therapy is relied upon the improvement of gene delivery vectors into mammalian cells. Although viral-based polynucleotide carriers are still considered as the most common method for gene delivery but the cost effectiveness, nonspecific lethal immune response has evoked the renaissance of non-viral synthetic delivery systems. An initial discovery by Felgnar et al showed Cationic Liposomes (CLs) (having an overall positive charge) when mixed with DNA to form CL-DNA complexes can enhance the transfer of polynucleotides into cells followed by its expression. Presently, a flurry of experimental works is taking place for the better understanding of structural characterization …


Method Development For A Chemical And Biological Analysis Of Glucocorticoids In Wastewater, Maria Carmen Lozano Jan 2013

Method Development For A Chemical And Biological Analysis Of Glucocorticoids In Wastewater, Maria Carmen Lozano

Open Access Theses & Dissertations

Glucocorticoids are a class of steroid hormones that can either be produced synthetically or naturally by the adrenal glands. The synthetic glucocorticoids are highly prescribed in the United States for their anti-inflammatory and immunosuppressive properties to treat a variety of ailments and diseases; however, these have been implicated in a number of adverse human conditions such as obesity, metabolic syndrome, immune-suppression, delayed puberty, adrenal insufficiency and Cushing Syndrome, among others. Ongoing research has shown that synthetic and natural hormones are transported to aquatic environments via mammalian excretion or wastewater effluent, and as a result, the release of glucocorticoids into the …


Organic Photovoltaics: A Charge Transfer Perspective In The Study Of Donor-Acceptor Systems, Marco Olguin Jan 2013

Organic Photovoltaics: A Charge Transfer Perspective In The Study Of Donor-Acceptor Systems, Marco Olguin

Open Access Theses & Dissertations

The present research involves the study of donor-acceptor (D/A) dyad complexes from a charge transfer energy perspective. The aim is to provide insight and predictive understanding into the charge transfer processes of the molecular-level components in donor-acceptor based organic solar cells using computational methods to describe photochemical processes at the quantum mechanical level within the Density Functional Theory (DFT) approximation. Predictive understanding is anchored in reproducing experimental results, wherein the present work a perturbative excited-state DFT method is described in detail and shown to give Charge Transfer (CT) energies in excellent agreement with benchmark experimental data. With an accurate excited …


Determination Of The Effects Of Zno And Ceo2 Nanoparticles In Mesquite (Prosopis Juliflora) And Soybean (Glycine Max): Synchrotron And Spectroscopic Approaches, Jose Angel Hernandez Viezcas Jan 2013

Determination Of The Effects Of Zno And Ceo2 Nanoparticles In Mesquite (Prosopis Juliflora) And Soybean (Glycine Max): Synchrotron And Spectroscopic Approaches, Jose Angel Hernandez Viezcas

Open Access Theses & Dissertations

The rapid growth of nanotechnology is exposing the environment to abnormal concentrations of engineered nanoparticles (NPs). There is concern about the unknown consequences of NPs on the environment and human health. This Dissertation has relied significantly on Synchrotron and other spectroscopic techniques to give insights on the effects, speciation and distribution of two metal oxide nanoparticles (ZnO, CeO2) on two plant species (Mesquite and Soybean). We evaluated the effects of ZnO (10 nm) and CeO2 (8 nm) NPs on a plant species native to the semi-arid regions of North America, Mesquite (Prosopis juliflora velutina). Mesquite plants grown in hydroponic culture …


Interaction Of Ceo2 And Zno Nanoparticles Towards The Symbiotic Association Of Alfalfa (Medicago Sativa) And Sinorhizobium Meliloti In Soil, Susmita Bandyopadhyay Jan 2013

Interaction Of Ceo2 And Zno Nanoparticles Towards The Symbiotic Association Of Alfalfa (Medicago Sativa) And Sinorhizobium Meliloti In Soil, Susmita Bandyopadhyay

Open Access Theses & Dissertations

The production of engineered nanoparticles (ENPs) has rapidly increased due to their wide range of applications in the field of electronics, medicine, chemistry and biology. Consequently, concerns have risen about the environmental release and potential negative impact of NPs. A few reports have described the effects of TiO2 NPs and quantum dots upon nitrogen fixing bacteria. However, the understanding of the interaction of NPs in plant-microbe interface (symbiotic association), like alfalfa (Medicago sativa L.)-Sinorhizobium meliloti, is still in its infancy. Alfalfa is the world's most important forage crop. It grows in association with S. meliloti, which is very important in …


Preparation Of Cobalt/Nickel Molybdenum Sulfide Catalysts Supported By Aqueous Media Soluble Multi-Wall Carbon Nanotubes., Hassan Ahmad Bleibel Jan 2013

Preparation Of Cobalt/Nickel Molybdenum Sulfide Catalysts Supported By Aqueous Media Soluble Multi-Wall Carbon Nanotubes., Hassan Ahmad Bleibel

Open Access Theses & Dissertations

Multi-walled carbon nanotubes (MWCNTs) have been subjected to chemical treatment in order to introduce hydrophilic functional groups on their surfaces. These covalently bonded groups did enhance the solubility of MWCNTs in aqueous media as expected. Functionalized MWCNTs were characterized using FTIR, Raman spectroscopy, TGA, X-ray diffraction, dispersion test and TEM. Then, functionalized MWCNTs were incorporated in the hydrothermal synthesis method of transition metal sulfide catalysts (CoMo, NiMo, and Ethylenediamine-CoMo Sulfides). Catalysts were characterized using X-ray diffraction, TEM, SEM, N2 Gas adsorption-desorption, elemental analysis, and Hydrodesulfurization (HDS) reaction of dibenzothiophene (DBT). The objective was to study the functionalized MWCNTs' effect; being …


Photochemical Synthesis Of Amino Acid And Peptide Oxo-Esters, Alfredo Ornelas Jan 2013

Photochemical Synthesis Of Amino Acid And Peptide Oxo-Esters, Alfredo Ornelas

Open Access Theses & Dissertations

Amino acid and peptide oxo-esters have played an important role in peptide chemistry for many years. Various amino acid esters are commonly used as protecting groups for peptide synthesis in solution. Moreover, activated phenyl ester derivatives have been used for chemical ligation of peptides. However, the synthesis of amino acid and peptide oxo-esters is commonly performed under acidic or basic conditions. Under acidic conditions, acid-sensitive protecting groups may be cleaved, and under basic conditions racemization of amino acid esters is a common problem. Here we present the photochemical synthesis of amino acid and peptide oxo-esters. Based on the photochemical properties …


Purification Of Sodium Sulfate By Crystallization, Perla Teresita Torres Jan 2013

Purification Of Sodium Sulfate By Crystallization, Perla Teresita Torres

Open Access Theses & Dissertations

Sodium sulfate can be recovered from a dilute solution by concentrating it by conventional water treatment techniques like reverse osmosis and electrodialysis; however, those processes also concentrate impurities like arsenic. The sodium sulfate would have commercial use if it can be recovered in an arsenic-free form. This study demonstrated that sodium sulfate could be separated from impurities using slow cooling crystallization in a novel apparatus developed and designed during the experimentation. This device is called a heat exchanger crystallizer and allows slow cooling crystallization in order to grow pure crystals of sodium sulfate decahydrate. Crystals grown in the heat exchanger …