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Title: Vapor phase oxidation of chloropropenes over heterogeneous catalyst systems.
Creator: Owen, Tim Ellis, Clausen, Chris A., Natural Sciences
Abstract / Description: Florida Technological University College of Natural Sciences Thesis; Propylene Dichloride (PDC) is a byproduct of several Dow processes. The thermal cracking of PDC produces l - cis-chloropropene , I - trans-chloropropene, 2- chloropropene , and allyl chloride . By oxidizing the 1 - and 2-chloropropenes to 3- and 2- chloroacrylic acids, respectively, a potentially valuable product could be made. The chloropropenes, air , and steam were passed over various heterogeneous oxidation catalyst...
Show moreFlorida Technological University College of Natural Sciences Thesis; Propylene Dichloride (PDC) is a byproduct of several Dow processes. The thermal cracking of PDC produces l - cis-chloropropene , I - trans-chloropropene, 2- chloropropene , and allyl chloride . By oxidizing the 1 - and 2-chloropropenes to 3- and 2- chloroacrylic acids, respectively, a potentially valuable product could be made. The chloropropenes, air , and steam were passed over various heterogeneous oxidation catalyst systems to attempt this oxidation . Contact time was varied between 0.0951 to 0.915 sec. Temperature was varied between 275°C to 425°C. The air content of the feed was varied between 41 to 75%. The chloropropene content of the feed was varied between 2.9% to 5.0%. The following supported catalysts were tested Co/Mo (3/7) - alumina pellets, CoMoO4- alumina granules, CoMo O4- silica gel , AcNbMo- alumina pellets , two bed catalyst MoFeTeRe- MoVGeMo - silica gel, CoMoTe- silica gel, and CoMoBi-alumina pellets . No chloroacroleins, or chloroacrylic acids were detected in the reaction products. In general, no CO and from 5- 15% CO2 was obtained in the reaction products with the alumina and silica support materials. Oxidation over the metal catalysts produced 0-10% CO and 5-40% CO2. Severe carbonization of the supports with and without the metal catalysts was observed at the reaction conditions described above. Chloropropenes were found to be unstable, decomposing to carbon at 300°C in an empty reactor at a contact time greater than 0.1 sec. Chloroacrylic acids at a 0.1 sec contact time were tested in the reactor over alumina and silica support materials at 200C and above, and found to be unstable with regard to decomposition to coke. It was concluded that the vapor phase oxidation of chloropropenes over heterogeneous catalysts to chloroacrylic acids is not feasible because of their decomposition to carbon at the prevailing reaction conditions
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Date Issued: 1976
Identifier: CFR0003494, ucf:53026
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0003494

Title: SYNTHESIS OF A NOVEL FAMILY OF AMIDE DERIVATIVES OF PODOCARPIC ACID.
Creator: Nguyen, Dao, Miles, Howard, University of Central Florida
Abstract / Description: As a class, amides are of great interest in biological studies and pharmaceutical application. In this work, podocarpic acid, a natural tricyclic diterpene, derived from Podocarpus species, has been employed to form a novel family of amide derivatives which will later be studied for their potential as new drug leads. Novel amide derivatives of podocarpic acid were synthesized from podocarpic acid in three steps. The first step involved methylation with dimethylsulfate to form methyl-O...
Show moreAs a class, amides are of great interest in biological studies and pharmaceutical application. In this work, podocarpic acid, a natural tricyclic diterpene, derived from Podocarpus species, has been employed to form a novel family of amide derivatives which will later be studied for their potential as new drug leads. Novel amide derivatives of podocarpic acid were synthesized from podocarpic acid in three steps. The first step involved methylation with dimethylsulfate to form methyl-O-methylpodocarpate. This step was followed by iodination with iodine to give iodomethyl-O-methylpodocarpate. Finally amidation with various aliphatic amides using a copper catalyst yielded four amide derivatives of podocarpic acid. However, iodomethyl-O-methylpodocarpate did not react with aromatic amides. This is perhaps because of the reduction in electrophilicity of an aromatic amide versus an aliphatic amide. Thus this research had led to the discovery of a method that is selective for the synthesis of aliphatic amide derivatives of podocarpic acid. Furthermore, five novel derivatives of podocarpic acid have been synthesized. Therefore a small library of novel compounds has been synthesized by utilizing selective methodology, that are now available for future examination of their anticancer and anti-tuberculosis properties.
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Date Issued: 2004
Identifier: CFE0000213, ucf:46269
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000213

Title: BRANCHED AND SPIRAL ORGANIC NANOTUBES BASED ON THE SELF-ASSEMBLY OF BILE ACIDS.
Creator: Zhang, Xuejun, Fang, Jiyu, University of Central Florida
Abstract / Description: The self-assembly of chiral amphiphilic molecules in aqueous solutions is of particular interest because the chirality of individual molecules is often expressed in their supermolecular structures. Self-assembled tubes made of chiral amphiphilic molecules represent useful supramolecular architectures which hold promise as controlled release vehicles for drug delivery, encapsulates for functional molecules, and nanoreactors for chemical reactions. Lithocholic acid (LCA) is a secondary bile...
Show moreThe self-assembly of chiral amphiphilic molecules in aqueous solutions is of particular interest because the chirality of individual molecules is often expressed in their supermolecular structures. Self-assembled tubes made of chiral amphiphilic molecules represent useful supramolecular architectures which hold promise as controlled release vehicles for drug delivery, encapsulates for functional molecules, and nanoreactors for chemical reactions. Lithocholic acid (LCA) is a secondary bile acid with the concentration being identical to that of cholesterol in the hepatic bile and gallbladder. It has a rigid, nearly planar hydrophobic steroid nucleus, with four hydrogen atoms and one hydroxyl group directed toward the concave side, and the convex side with three methyl groups. The ionic head with a carboxyl group is linked to the steroid nucleus through a short alkyl chain. In this thesis work, I study the self-assembly behavior of LCA at the liquid-solid interface, in confined spaces, and bulk solution. We find that the initially formed LCA vesicles further assemble into fractal tubes on glass slides by diffusion-limited aggregation and pronglike tubes by the capillary flow generated in an evaporating vesicle solution confined by two parallel glass slides. While in bulk solution, the LCA vesicles linearly aggregate and fuse into spiral tubes at pH 12.0. The spiral tubes can transition into a straight shape as the pH of solution is reduced to 7.4. The shape transition of the tubes is reversible as the pH of solution is adjusted back to 12.0. The pH-switchable shape transition suggests that the self-assembled LCA tubes can act as a supramolecular chemical spring. Finally, the LCA tubes are endowed with optical functionality by embedding cadmium sulfide nanopaticles (CdS) in the tube walls by the co-assembling synthesis of cadmium sulfide (CdS) nanoparticles with lithocholic acid (LCA) molecules. The fluorescent composite tubes can undergo pH switchable spiral/straight, which are a promising system for a variety of materials and biological applications.
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Date Issued: 2010
Identifier: CFE0003479, ucf:48959
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003479

Title: PART I : ISOLATION OF DIPENTYL 2-(4-(PENTAN-3-YL) PHENYL) MALONATE FROM SANGUISORBA OFFICINALIS LABILL PART II: SYNTHESIS OF A NOVEL FAMILY OF ETHERS OF PODOCARPIC ACID.
Creator: Yalavarty, Manjeera, Miles, Howard, University of Central Florida
Abstract / Description: The goal of part I of this thesis was to isolate pure anti cancer compounds from the Russian plant Sanguisorba officinalis. This plant was selected for investigation because it showed 100% activity against leukemia (L1210 mouse leukemia cells) during the preliminary screening of approximately 100 Russian plant extracts. This work has resulted in the isolation of novel compound 11 using traditional chromatography techniques. Compound 11 was characterized with spectroscopic techniques such as...
Show moreThe goal of part I of this thesis was to isolate pure anti cancer compounds from the Russian plant Sanguisorba officinalis. This plant was selected for investigation because it showed 100% activity against leukemia (L1210 mouse leukemia cells) during the preliminary screening of approximately 100 Russian plant extracts. This work has resulted in the isolation of novel compound 11 using traditional chromatography techniques. Compound 11 was characterized with spectroscopic techniques such as IR, 1H NMR, 13C NMR, DEPT, DQCOSY and MS. Compound 11 was assigned the structure dipentyl 2-(4-(pentan-3-yl) phenyl) malonate. The goal of part II of this thesis was to synthesize novel ethers of podocarpic acid. Ethers are of great interest in biological studies and pharmaceutical applications because of their wide variety of uses in the treatment of various diseases. A novel family of ether derivatives was synthesized using podocarpic acid (a natural tricyclic diterpene derived from podocarpus species) as a template. Novel ether derivatives of podocarpic acid were synthesized from podocarpic acid in three steps. The first step involved methylation of podocarpic acid with dimethyl sulfate to form methyl-o-methyl podocarpate. The second step was iodination of methyl-o-methyl podocarpate with iodine in presence of a mercury catalyst to form 13-iodo methyl-o-methyl podocarpate. This was followed by formation of novel aliphatic ethers using a copper catalyst. Thus this research had led to the discovery of new methodology for synthesis of three novel aliphatic ether derivatives of podocarpic acid. These ethers will be tested for their biological activity against various types of cancer, tuberculosis by National Institutes of Health.
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Date Issued: 2005
Identifier: CFE0000625, ucf:46551
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000625

Title: SYNTHESIS OF NOVEL AZIRIDINE DERIVATIVES OF PODOCARPIC ACID.
Creator: Rhoden, Stephen, Miles, Howard, University of Central Florida
Abstract / Description: Podocarpic acid (a diterpenoid resin acid extracted from the Podocarpacea specie of plants) has shown cytotoxicity against carcinoma of the nasopharynx. Since this discovery has been made, research has been performed in order to alter the structure of the resin acid so as to increase the anticancer activity. The carboxylic acid and phenol functional groups, which are present in podocarpic acid, make it possible to synthesize new derivatives selectively at the C-15, C-13, and C-7 positions as...
Show morePodocarpic acid (a diterpenoid resin acid extracted from the Podocarpacea specie of plants) has shown cytotoxicity against carcinoma of the nasopharynx. Since this discovery has been made, research has been performed in order to alter the structure of the resin acid so as to increase the anticancer activity. The carboxylic acid and phenol functional groups, which are present in podocarpic acid, make it possible to synthesize new derivatives selectively at the C-15, C-13, and C-7 positions as well as by substitution of the phenol hydroxyl group. Thus numerous derivatives can be prepared, in high yield, for the purpose of investigating their potential, as new drug leads for the treatment of cancer. In this study, Doyle's catalyst (Dirhodium tetrakis caprolactamate) was used to form a novel derivative in high yield (85%) which contained a 3-membered aziridine ring at the C-6 and C-7 position. The main thrust of this research involved the formation a series of novel derivatives of the aziridine compound by utilizing phenol and m-chlorophenol as nucleophiles to open the aziridine ring. These novel compounds will now be sent to the National Institute of Health (NIH) for bioassay against 60 human cancer cell lines.
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Date Issued: 2007
Identifier: CFE0001759, ucf:52849
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001759

Title: Liquid Crystal-Based Biosensors for the Detection of Bile Acids.
Creator: He, Sihui, Wu, Shintson, Kuebler, Stephen, Kik, Pieter, Fang, Jiyu, University of Central Florida
Abstract / Description: Bile acids are physiologically important metabolites, which are synthesized in liver as the end products of cholesterol metabolism and then secreted into intestine. They are amphiphilic molecules which play a critical role in the digestion and absorption of fats and fat-soluble vitamins through emulsification. The concentration of bile acids is an indicator for liver function. Individual suffering from liver diseases has a sharp increase in bile acid concentrations. Hence, the concentration...
Show moreBile acids are physiologically important metabolites, which are synthesized in liver as the end products of cholesterol metabolism and then secreted into intestine. They are amphiphilic molecules which play a critical role in the digestion and absorption of fats and fat-soluble vitamins through emulsification. The concentration of bile acids is an indicator for liver function. Individual suffering from liver diseases has a sharp increase in bile acid concentrations. Hence, the concentration level of bile acids has long been used as a biomarker for the early diagnosis of intestinal and liver diseases.Conventional methods of bile acid detection such as chromatography-mass spectrometry and enzymatic reactions are complex and expensive. It is highly desired to have a simple, fast, and low-cost detection of bile acids that is available for self-testing or point-of-care testing. To achieve this goal, we develop a liquid crystal-based biosensor for the detection of bile acids. The sensor platform is based on the anchoring transition of liquid crystals (LCs) at the sodium dodecyl sulfate (SDS)-laden LC/aqueous interface for the detection of bile acids in aqueous solution. The first part of this dissertation focuses on the detection mechanism of bile acids. Our studies show that the displacement of SDS from the LC/aqueous interface by the competitive adsorption of bile acids induces a homeotropic-to-planar anchoring transition of the LC at the interface, providing an optical signature for the simple and rapid detection of bile acids. The adsorption of bile acids on the interface was found to follow Langmuir-Freundlich isotherm. The adsorption kinetics of different bile acids is compared. We find that both the number and position of hydroxyl groups of bile acids affect their adsorption kinetics. The different optical patterns of LC films formed by the adsorption of bile acids are also discussed. The second part of this dissertation studies the effect of solution conditions, surfactants, and liquid crystals on the detection limit of the LC-based biosensor for bile acids. Low pH and high ionic strength in the aqueous solution can reduce the electrostatic interaction between SDS and bile acids, which leads to a decreased detection limit. Surfactants with smaller headgroup and lower packing density also help to reduce the detection limit. To further reduce the detection limit, we investigate the effect of LC structures and find that LCs with a shorter chain length give lower detection limits. Also, by substituting a phenyl ring with a cyclohexane ring, we find that the detection limit is further reduced due to the decrease of the interaction between the phenyl rings of LCs. By mixing different LCs together, the detection limit can be linearly tuned from 160 (&)#181;M to 1.5 (&)#181;M, which is comparable to the traditional methods. But the LC-based biosensors have much simpler design and manufacture process.The third part of this dissertation is to apply this LC-based biosensor to the detection of urinary bile acids. We test the influence of several potential interfering species such as urea, creatinine, uric acid and ascorbic acid by conducting experiments in synthetic urine. By adjusting the concentration of SDS, we are able to eliminate the impact of those interfering species, and demonstrate that the LC-based biosensors can selectively detect urinary bile acids in human urine, suggesting its potential for screening liver dysfunctions. The final part of this dissertation is to investigate the application of LC-based biosensors in detecting the lipolysis process by porcine pancreatic lipase (PPL). It has been a long-standing argument over the role of bile salts on the activity of PPL. Thus, we study the time course of the hydrolysis of phospholipid L-dipalmitoylphosphatidylcholine (L-DPPC) by PPL at LC/aqueous interface. The hydrolysis of L-DPPC leads to a homeotropic-to-tilted anchoring transition of the LC at the interface, which allows the hydrolysis process to be monitored by a polarizing optical microscope. The microscopy image analysis reveals a lag-burst kinetics where a lag phase is followed by a burst phase. The effect of bile acids on these two phases is studied. We find that the activity of PPL both in the presence and absence of colipase can be improved by increasing the concentration of bile acids. The improvement becomes more distinct in the presence of colipase.
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Date Issued: 2015
Identifier: CFE0005804, ucf:50028
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005804

Title: Is breakdown of fatty acid peroxides involved in the induction of apolipoprotein A1?.
Creator: Gupta, Rajat, Parthasarathy, Sampath, Siddiqi, Shadab, Jewett, Mollie, University of Central Florida
Abstract / Description: Over the past few years the number of deaths caused due to cardiovascular diseases has been increasing and is of major concern. In the United States, 75% of cardiovascular-related deaths have been attributed to atherosclerosis. Western diets containing large quantities of peroxidized lipids are considered atherogenic. Heated oil in the form of fried food brings high levels of peroxidized fat and its decomposition products in the diet. Peroxidized lipids are known to increase the...
Show moreOver the past few years the number of deaths caused due to cardiovascular diseases has been increasing and is of major concern. In the United States, 75% of cardiovascular-related deaths have been attributed to atherosclerosis. Western diets containing large quantities of peroxidized lipids are considered atherogenic. Heated oil in the form of fried food brings high levels of peroxidized fat and its decomposition products in the diet. Peroxidized lipids are known to increase the susceptibility of serum lipoproteins to undergo oxidation, thereby contributing to the progression of atherosclerosis. The intestinal cells are responsible for the absorption of dietary fatty acid peroxides (FAOOH) which has been reported to enhance anti-atherosclerotic effects by inducing apolipoprotein A1 (apoA1) gene and protein levels. Therefore, there is a void in the knowledge of when to expect (")harmful(") or (")beneficial(") effects of dietary lipid peroxides. The formation of toxic products like aldehydes from the decomposition of FAOOH is well documented. On the other hand, carboxylic acids particularly azelaic acid, formed as an end product of FAOOH decomposition has been reported to have anti-atherosclerotic effects. Hence, we hypothesize that intestinal cells may decompose FAOOH to aldehydes, which might get converted to carboxylic acids that can be transported across the intestine. Linoleic acid is the most abundant polyunsaturated fatty acid (PUFA) present in the diet. So, we will use peroxidized linoleic acid (13-HPODE) and incubate with intestine derived cells or Caco -2 cells as an in-vitro model for determining its decomposition to aldehydes and carboxylic acids. We propose that the decomposition products of FAOOH in the presence of intestinal cells might be responsible for causing an increase in apoA1 levels, which might suggest that lipid peroxidation derived products might actually be beneficial for reducing the progression of atherosclerosis as compared to the absorption of intact FAOOH.
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Date Issued: 2013
Identifier: CFE0004856, ucf:49700
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004856

Title: MICRO-SPECTROSCOPY OF BIO-ASSEMBLIES AT THE SINGLE CELL LEVEL.
Creator: Kera, Jeslin, Chakrabarti, Debopam, Schulte, Alfons, University of Central Florida
Abstract / Description: In this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 ?m in the lateral and 3.6 ?m in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation...
Show moreIn this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 ?m in the lateral and 3.6 ?m in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation while providing a strong signal from the contrast generated by the attenuation of propagating light due to absorption. This enables spatially resolved measurements of single live cells and bio-molecules with less than 10^9 molecules in the probe volume. Employing a multichannel detection system, the absorption spectrum of hemoglobin in a single red blood cell is measured on the timescale of seconds. We also extend the spectral range from the visible range to the experimentally more challenging ultra-violet region where characteristic absorption bands of bio-molecules are observed. Exploiting the ultra-violet range, amino acids, nucleic acids solutions, and plant cells are investigated. We measure the spatially resolved absorption spectra at the nucleus of an onion cell and cytoplasm to probe DNA base-pair absorption. Small variations in our micro-absorption data are seen around 260 nm, possibly due to the abundance of DNA in the nucleus. This thesis contributes to the goal of spectroscopic identification of spatial heterogeneities at the single cell level and the label-free detection of proteins and nucleic acids.
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Date Issued: 2017
Identifier: CFH2000356, ucf:45905
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000356

Title: PHYSICOCHEMICAL AND THERMOCHEMICAL PROPERTIES OF SULFONATED POLY(ETHERETHERKETONE) ELECTROLYTE MEMBRANES.
Creator: Rhoden, Stephen, Diaz, Diego, University of Central Florida
Abstract / Description: Fuel cells have long been seen as an alternative to combustion powered and diesel powered engines and turbines. Production of energy via a fuel cell conversion method can generate up to 60% efficiency in comparison to 30% using a combustion powered engine, with low co-production of harmful side-products. The polymer electrolyte membrane (PEM) adapted for the fuel cell application is one of the main components that determines the overall efficiency. This research project was focused towards...
Show moreFuel cells have long been seen as an alternative to combustion powered and diesel powered engines and turbines. Production of energy via a fuel cell conversion method can generate up to 60% efficiency in comparison to 30% using a combustion powered engine, with low co-production of harmful side-products. The polymer electrolyte membrane (PEM) adapted for the fuel cell application is one of the main components that determines the overall efficiency. This research project was focused towards novel PEMs, such as sulfonated poly(etheretherketone) or SPEEK, which are cost-efficient and robust with high proton conductivities under hydrated conditions. The degree of sulfonation (DS) of a particular SPEEK polymer determines the proton conducting ability, as well as the long term durability. For SPEEK with high DS, the proton conduction is facile, but the mechanical stability of the polymer decreases almost proportionally. While low DS SPEEK does not have sufficient sulfonic acid density for fast proton conduction in the membrane, the membrane keeps its mechanical integrity under fully saturated conditions. The main purpose of this work was to address both issues encountered with SPEEK sulfonated to low and high DS. The addition of both solid acids and synthetic cross-links were studied to address the main downfalls of the respective SPEEK polymers. Optimization of these techniques led to increased understanding of PEMs and notably better electrochemical performance of these fuel cell materials. Oxo-acids such as tungsten (VI) oxide (WO3) and phosphotungstic acid (PTA) have been identified as candidate materials for creating SPEEK composite membranes. The chemistry of these oxo-acids is well known, with their use as highly acidic catalyst centers adopted for countless homogeneous and heterogeneous, organic and inorganic reactions. Uniform dispersion of WO3 hydrate in SPEEK solution was done by a sol-gel process in which the filler particles were grown in an ionomer solution, cast and allowed to dry. PTA composites were made by adding the solid acid directly to a solution of the ionomer and casting. The latter casting was allowed to dry and Cs+- exchanged to stabilize the PTA from dissolution and leaching from the membrane. The chemical and physical properties of these membranes were characterized and evaluated using mainly conductometric and X-ray photoelectron spectroscopic methods. Composite SPEEK/ PTA membranes showed a 50% decrease in PEM resistance under hydrogen fuel cell testing conditions, while SPEEK/ WO3 composites demonstrated a ten-fold increase in the membrane's in-plane proton conductivity. The chemical and physical properties of these composites changed with respect to their synthesis and fabrication procedures. This study will expound upon their relations.
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Date Issued: 2010
Identifier: CFE0003470, ucf:48976
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003470

Title: A Binary Approach for Selective Recognition of Nucleic Acids and Proteins.
Creator: Cornett, Evan, Kolpashchikov, Dmitry, Self, William, Ye, Jingdong, University of Central Florida
Abstract / Description: The design of probes for the selective recognition of biopolymers (nucleic acids and proteins) is a fundamental task for studying, diagnosing, and treating diseases. Traditional methods utilize a single component (small molecule or oligonucleotide) that binds directly to the target biopolymer. However, many biopolymers are unable to be targeted with this approach. The overarching goal of this dissertation is to explore a new, binary approach for designing probes. The binary approach requires...
Show moreThe design of probes for the selective recognition of biopolymers (nucleic acids and proteins) is a fundamental task for studying, diagnosing, and treating diseases. Traditional methods utilize a single component (small molecule or oligonucleotide) that binds directly to the target biopolymer. However, many biopolymers are unable to be targeted with this approach. The overarching goal of this dissertation is to explore a new, binary approach for designing probes. The binary approach requires two components that cooperatively bind to the target, triggering a recognition event. The requisite binding of two-components allows the probes to have excellent selectivity and modularity.The binary approach was applied to design a new sensor, called operating cooperatively (OC) sensor, for recognition of nucleic acids, including selectively differentiating between single nucleotide polymorphisms (SNPs). An OC sensor contains two oligonucleotide probe strands, called O and C, each with two domains. The first domain contains a target recognition sequence, whereas the second domain is complementary to a molecular beacon (MB) probe. Binding of both probe strands to the fully matched analyte generates a full MB probe recognition site, allowing a MB to bind and report the presence of the target analyte. Importantly, we show that the OC sensor selectively discriminates between single nucleotide polymorphisms (SNPs) in DNA and RNA targets at room temperature, including those with stable secondary structures. Furthermore, the combinatorial use of OC sensors to create a DNA logic gate capable of analyzing DNA sequences of Mycobacterium tuberculosis is described.The binary approach was also applied to design covalent inhibitors for HIV-1 reverse transcriptase (RT). In this application, two separate pre-reactive groups were attached to a natural RT ligand, deoxythymidine triphosphate (dTTP). Upon binding of both dTTP analogs in the RT active site, the pre-reactive groups are brought into the proper proximity and react with each other forming an intermediate that subsequently reacts with an amino acid side chain from the RT. This leads to covalent modification of RT, and inhibition of its DNA polymerase activity. This concept was tested in vitro using dTTP analogs containing pre-reactive groups derived from ?-lactamase inhibitors clavulanic acid (CA) and sulbactam (SB). Importantly, our in vitro assays show that CA based inhibitors are more potent than zidovudine (AZT), a representative of the dominant class of RT inhibitors currently used in anti-HIV therapy. Furthermore, molecular dynamics simulations predict that complexes of RT with these analogs are stable, and point to possible reaction mechanisms. The inhibitors described in this work may serve as the basis for the development of the first covalent inhibitors for RT. Moreover, the pre-reactive groups used in this study can be used to design covalent inhibitors for other targets by attaching them to different ligands. Overall, the work presented herein establishes the binary approach as a straightforward way to develop new probes to selectively recognize nucleic acids and proteins.
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Date Issued: 2015
Identifier: CFE0006031, ucf:51010
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006031

Title: EFFECTS OF FOOD DEPRIVATION ON BLOOD LIPID CONCENTRATION AND COMPOSITON IN STELLER SEA LIONS (EUMETOPIAS JUBATUS).
Creator: Berman, Michelle, Worthy, Graham, University of Central Florida
Abstract / Description: Steller sea lions, the largest Otariid, fast during their breeding season; during this time they refrain from ingesting food for a period of 12-43 days. Fasting, while undertaking an extremely energetically demanding activity (breeding and pupping), requires specific physiological adaptations. This study examined the physiological response to fasting of two age classes, juveniles and sub-adults, during the breeding and non-breeding seasons to determine how these animals utilize lipids and the...
Show moreSteller sea lions, the largest Otariid, fast during their breeding season; during this time they refrain from ingesting food for a period of 12-43 days. Fasting, while undertaking an extremely energetically demanding activity (breeding and pupping), requires specific physiological adaptations. This study examined the physiological response to fasting of two age classes, juveniles and sub-adults, during the breeding and non-breeding seasons to determine how these animals utilize lipids and the pattern of fatty acid mobilization from lipid stores during fasting. Four juveniles and 5 sub-adults were fasted for one and two weeks, respectively, and blood samples were collected approximately every 3 days for lipid analysis. The concentrations of plasma non-esterified fatty acids (NEFA) were analyzed spectrophotometrically. Serum fatty acid composition was analyzed using gas chromatography (GC) and their individual weight percent (wt %) were correlated with their peak retention time and calculated using the area under each peak. Sixty-nine fatty acids were quantified from each sample. However, only those with concentrations above 0.2 wt. % were included in the analysis. Sub-adult samples were grouped on a percent mass loss basis (0%, 7-8% and 15% mass loss) to facilitate comparison with the juveniles. These data represent the total lipid fatty acid composition of each blood sample. Relative lipid concentration was calculated by multiplying the total lipid fatty acid compositional analysis (wt %) by the NEFA concentrations measured in that respective blood sample. Plasma NEFA concentrations in juvenile Steller sea lions ranged from 1.2 ¡Ó 0.51 mM to 3.7 „b 0.69 during fasting and was within the range of fasting phocids. Concentrations of NEFAs in the sub-adult Steller sea lions ranged from 1.00 mM up to 9.70 mM and were generally higher than fasting phocids. The wt % of only one fatty acid (20:0) was significantly different between the breeding and non-breeding season in fasting juveniles. However, the wt % of seven fatty acids changed significantly during fasting in the juveniles and five of these were most significant in separating the beginning and end of the fasts using principal components analysis. In contrast, the wt % of 10 fatty acids were significantly different during the breeding and non-breeding season fasts of the sub-adults. Additionally, the wt % of 10 fatty acids changed significantly during fasting in the sub-adults and four of these (16:1n-7, 18:2n-6, 20:0, and 20:1n-9) were most significant in separating the beginning and end of the fasts using principal components analysis. These trends reveal the physiological differences between the juvenile and sub-adult Steller sea lions and suggest that the sub-adults may be better physiologically and metabolically adapted to fast than the juveniles in this study.
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Date Issued: 2005
Identifier: CFE0000621, ucf:46526
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000621

Title: The Formation and Characterization of Mesoscopic J- and H-aggregates with Controlled Morphologies by the Co- and Templated Assembly of Cyanine Dyes.
Creator: Rhodes, Samuel, Fang, Jiyu, Jiang, Tengfei, Dong, Yajie, Florczyk, Stephen, Pang, Sean, University of Central Florida
Abstract / Description: The supramolecular aggregates of ?-conjugated molecules have become an area of great interest to the scientific community in recent years for their promise in biosensors and optoelectronic devices. Among various supramolecular aggregates, J- and H-aggregates of ?-conjugated dye molecules are particularly interesting because of their unique optical and excitonic properties that are not given by individual molecules. H-aggregates are composed of dye molecules in a face-to-face stacking, giving...
Show moreThe supramolecular aggregates of ?-conjugated molecules have become an area of great interest to the scientific community in recent years for their promise in biosensors and optoelectronic devices. Among various supramolecular aggregates, J- and H-aggregates of ?-conjugated dye molecules are particularly interesting because of their unique optical and excitonic properties that are not given by individual molecules. H-aggregates are composed of dye molecules in a face-to-face stacking, giving rise to a blue-shifted absorption band compared with the monomer band and a strong emission quenching. In contrast, J-aggregates represent an edge-to-edge stacking of dye molecules, showing a red-shifted absorption band with respect to the monomer band and a strong fluorescence emission. However, the use of J- and H-aggregates in biosensors and optoelectronic devices remains a challenge because of the difficulty of controlling their sizes and morphologies. In this dissertation, we develop two different paths for controlling the size and morphology of J- and H-aggregates. First, we show that the co-assembly of cyanine dyes and lithocholic acid (LCA) in ammonia solution can lead to the formation of mesoscopic J- and H-aggregate fibers, depending on the condition under which the co-assembly occurs. Second, we report the formation of mesoscopic J-aggregate tubes by using the preformed LCA tubes as a template. The structure, optical, and electronic properties of these J- and H-aggregate fiber and tubes are studied as a function of temperature. Finally, we exploit their applications as photo-induced electron transfer supramolecular probes for the detection of dopamine, an important neurotransmitter in central and peripheral nervous systems.
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Date Issued: 2018
Identifier: CFE0007412, ucf:52718
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007412

Title: Polyelectrolyte complexes based on poly(acrylic acid): mechanics and applications.
Creator: Lu, Xiaoyan, Zhai, Lei, Zou, Shengli, Chumbimuni Torres, Karin, Kolpashchikov, Dmitry, Dong, Yajie, University of Central Florida
Abstract / Description: Poly(acrylic acid) (PAA) is a weak polyelectrolyte presenting negative charge at basic conditionwhen the carboxylic group loses a proton. These carboxylate group can interact with polycationsand metal ions to form stable polyelectrolyte complexes (PECs), leading to tunable propertiesand multifunctional nanoscale structures through chemical reactions. This research focuses onnanofiber and nanoparticle fabricated by PAA-based PECs. We demonstrated the effect of ferricion concentration on the...
Show morePoly(acrylic acid) (PAA) is a weak polyelectrolyte presenting negative charge at basic conditionwhen the carboxylic group loses a proton. These carboxylate group can interact with polycationsand metal ions to form stable polyelectrolyte complexes (PECs), leading to tunable propertiesand multifunctional nanoscale structures through chemical reactions. This research focuses onnanofiber and nanoparticle fabricated by PAA-based PECs. We demonstrated the effect of ferricion concentration on the mechanical properties of PAA-based single naonofiber by using dark fieldmicroscopy imaging and persistence length analysis. The application of PAA-based nanofibermats loaded with MnO2 for supercapacitors was also explored. As a free-standing and flexiblesupercapacitor electrode, the nanofiber mat exhibited outstanding properties including high specificcapacitance, excellent reversible redox reactions, and fast charge/discharge ability. Since PAA is abiocompatible polymer, PAA-based PEC was applied as a drug-carrier in a drug delivery system.In this project, core-shell nanoparticles were fabricated with chitosan as the core and PAA as theshell to incorporate with the drug gemcitabine. Several parameters were investigated to obtainthe optimal nanoparticle size. The as-prepared drug delivery system shows prolonged releasingprofile.
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Date Issued: 2018
Identifier: CFE0007045, ucf:52004
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007045

Title: COMPARATIVE STUDY OF ETHANOL AND METHANOL ELECTRO-OXIDATION ON A PLATINUM/CERIA COMPOSITE ELECTRODE IN ALKALINE AND ACID SOLUTIONS: ELECTRO-CATALYTIC PERFORMANCE AND REACTION KINETICS.
Creator: Hidalgo, Carlos, Diaz, Diego, University of Central Florida
Abstract / Description: A comparative study of the electro-oxidation of ethanol and methanol was carried out on a Pt/ceria composite electrode prepared by electro-deposition. Modification of the Pt electrode was realized by co-deposition from a 1.0 mM K2PtCl6 solution that also contained a 20 mM suspension of ceria. The electro-catalytic activities and stabilities of the Pt/ceria catalyst towards ethanol electro-oxidation reactions (EOR) and methanol electro-oxidation reactions (MOR) were investigated by...
Show moreA comparative study of the electro-oxidation of ethanol and methanol was carried out on a Pt/ceria composite electrode prepared by electro-deposition. Modification of the Pt electrode was realized by co-deposition from a 1.0 mM K2PtCl6 solution that also contained a 20 mM suspension of ceria. The electro-catalytic activities and stabilities of the Pt/ceria catalyst towards ethanol electro-oxidation reactions (EOR) and methanol electro-oxidation reactions (MOR) were investigated by potentiodynamic and potentiostatic methods in 0.5 M sulfuric acid and 1.0 M sodium hydroxide solutions at various concentrations of ethanol and methanol. The kinetics of ethanol and methanol on a Pt/ceria composite electrode were measured in 0.5 M sulfuric acid and 1.0 M sodium hydroxide solutions using a rotating disk electrode (RDE). Cyclic voltammetry was employed in temperatures ranging from 15 to 55°C to provide quantitative and qualitative information on the kinetics of alcohol oxidation. The temperature dependence of the electro-catalytic activities afforded the determination of apparent activation energies for ethanol and methanol oxidation.
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Date Issued: 2011
Identifier: CFE0003628, ucf:48853
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003628

Title: Fine-scale geographic variation of stable isotope and fatty acid signatures of three fish species in the Indian River Lagoon, FL.
Creator: Odom, Jennifer, Worthy, Graham, Jenkins, David, Paperno, Richard, University of Central Florida
Abstract / Description: The Indian River Lagoon, Florida, is a unique closed (")bar built(") estuary system that has little interchange with the Atlantic Ocean and which is home to many resident species. Three fish species were investigated to see if their isotopic and fatty acid signatures differed based on geographic location. The goal was to assess the degree of resolution of spatial variation that is possible when using stable isotope and fatty acid signature analysis to interpret feeding habits and potential...
Show moreThe Indian River Lagoon, Florida, is a unique closed (")bar built(") estuary system that has little interchange with the Atlantic Ocean and which is home to many resident species. Three fish species were investigated to see if their isotopic and fatty acid signatures differed based on geographic location. The goal was to assess the degree of resolution of spatial variation that is possible when using stable isotope and fatty acid signature analysis to interpret feeding habits and potential linkages between feeding habits and health status. Spotted seatrout (n=40), pinfish (n=60) and white mullet (n=60) were collected over a 4 week period at sites 30 km apart in two distinct biogeographic regions of the IRL. Fish were analyzed for stable isotope (?13C and ?15N) and fatty acid composition. All three species were significantly different from each other in both isotopic and fatty acid signatures. In the North Indian River segment, spotted seatrout, white mullet and pinfish had mean values ((&)#177; SE) for ?13C of -18.00 (&)#177; 0.08, -14.59 (&)#177; 0.07 and -16.88 (&)#177; 0.04 respectively and for ?15N, mean values were 14.43 (&)#177; 0.05, 8.30 (&)#177; 0.04 and 10.43 (&)#177; 0.03 respectively. For the North-Central Indian River segment, spotted seatrout, white mullet and pinfish had mean values for ?13C of -18.98 (&)#177; 0.02, -16.25 (&)#177;0.06 and -16.94 (&)#177; 0.04 respectively and for ?15N, mean values were 14.21 (&)#177; 0.02, 8.07 (&)#177; 0.03 and 10.64 (&)#177;0.03 respectively. When species and location interactions were examined using ANCOVA, a post-hoc Tukey's HSD test showed that ?13C was significantly affected by sampling segment only for spotted seatrout and that there was no significant effect of location on ?15N values. Spotted seatrout was the only species that differed between segments for ?13C. Classification and Regression Tree (CART) analysis was then performed on the (")extended dietary fatty acids(") for each individual species and collection location. In this analysis, all three species were correctly identified to segment (white mullet - MR 2/53 p~ 0.03; spotted seatrout (MR 0/40), and pinfish (MR 0/56) indicating that individual species were exhibiting significant differences in their fatty acid signature over distances of 30 km. The ability to discern fine-scale differences in potential prey allows for the possibility of better resolution of dolphin feeding habits and hence a better understanding of both habitat utilization and health impacts. Due to limited exchange of clean salt water, contaminants can theoretically become a problem and there are indications that the health of the resident population of bottlenose dolphins (Tursiops truncatus) has been declining over recent years.
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Date Issued: 2012
Identifier: CFE0004329, ucf:49434
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004329

Title: FORMATION OF LYOTROPIC LIQUID CRYSTALS THROUGH THE SELF-ASSEMBLY OF BILE ACID BUILDING BLOCKS.
Creator: Tamhane, Karan, Fang, Jiyu, University of Central Florida
Abstract / Description: Liquid crystalline materials (LCMs) have gained much popularity over the past century. The thermotropic forms of these materials have been extensively studied and employed in a range of innovative applications. The lyotropic liquid crystal systems that have been studied in the past have often been formed by the organization of natural and synthetic small molecules in solutions. In this study, we use self-assembled supramolecular structures as building blocks to fabricate lyotropic liquid...
Show moreLiquid crystalline materials (LCMs) have gained much popularity over the past century. The thermotropic forms of these materials have been extensively studied and employed in a range of innovative applications. The lyotropic liquid crystal systems that have been studied in the past have often been formed by the organization of natural and synthetic small molecules in solutions. In this study, we use self-assembled supramolecular structures as building blocks to fabricate lyotropic liquid crystals. We investigate the self-assembly of a naturally occurring bile acid called lithocholic acid (LCA), to form supramolecular fibrous and tubular structures in basic aqueous solutions. We control the morphology of the self-assembled structures by manipulating experimental parameters in order to gain comprehensive knowledge regarding the self-assembly process. We characterize these structures with respect to their morphology i.e. their length, diameter, flexibility and shape using atomic force microscopy, optical microscopy and infrared spectroscopy. We produce lyotropic liquid crystal phases using self-assembled LCA structures through modification of physical parameters such as concentration, temperature, shear and pH. The nature of the lyotropic liquid crystal phases depends upon the morphology of the fibers and tubes. We observe that the short, rigid fibers and tubes form nematic phases while long, flexible fibers and tubes form cholesteric phases. We also study the phase transitions of the liquid crystal (LC) phases by observing their patterns using a polarizing microscope. Observations show that LC phases form in samples with LCA concentration above 0.75%w/w. Since the process of self-assembly is time-dependent, so is the formation of liquid crystal phases. We note that the optimum LCA concentration for LC phase formation is 2%-4%w/w and that the liquid crystal transition temperature is about 70°C.
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Date Issued: 2009
Identifier: CFE0002954, ucf:47972
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002954

Title: Polyelectrolyte and hydrogel stabilized liquid crystal droplets for the detection of bile acids.
Creator: Deng, Jinan, Fang, Jiyu, An, Linan, Chen, Quanfang, Cho, Hyoung Jin, Wu, Shintson, University of Central Florida
Abstract / Description: Liquid crystal (LC) droplets show great potential as an optical probe for sensor applications due to their large surface areas and stimuli-response director configurations. Bile acids with amphipathic properties, which are formed in liver and secreted into the small intestine, play an important role in the digestion of fats and fat-soluble vitamins. After the digestion process, most of bile acids are recycled back to the liver and ready for the next digestion. Only a few of them are excreted...
Show moreLiquid crystal (LC) droplets show great potential as an optical probe for sensor applications due to their large surface areas and stimuli-response director configurations. Bile acids with amphipathic properties, which are formed in liver and secreted into the small intestine, play an important role in the digestion of fats and fat-soluble vitamins. After the digestion process, most of bile acids are recycled back to the liver and ready for the next digestion. Only a few of them are excreted into body fluids. However, there is significant increases in the concentration level of bile acids in body fluids for patients with liver and intestinal diseases, which makes bile acids a biomarker for the early diagnosis of liver and intestinal diseases. Chromatography-mass spectrometry and electrochemical sensors are common methods for the detection of bile acids. However, these detection methods are time consuming, require relatively large sample volumes, and expensive instruments. To date, there is still a demand in the development of simple, low-cost and user-friendly sensing platforms for the rapid detection of bile acids in clinical settings.In this dissertation, two simple and low-cost LC droplet-based sensing platforms were developed for the rapid and real-time detection of bile acids with a small sample volume. First, a miniaturized LC droplet-based sensor platform was designed and fabricated by the integration of polyelectrolytes/surfactant/sulfate ?-cyclodextrin (?-CD) complex-stabilized LC droplets into a microfluidic channel for the selective detection of bile acids in a small amount of solution, in which the ?-CD immobilized at the surface of the LC droplets acts as a selective barricade and the director configuration of the LC droplets serves as an optical probe. Second, a flexible LC droplet-based sensor platform was formed by the integration of surfactant-stabilized LC droplets in biopolymer hydrogel films. The LC droplet-based hydrogel film was cut into small sheets for the real-time detection of bile acids in a small amount of solution, in which the configuration transition of LC droplets induced by the interaction of bile acids with the surfactants absorbing on the surface of LC droplets serves as an optical probe.Cholic acid (CA) and deoxycholic acid (DCA), which are the most related to the liver and intestinal diseases, were detected in phosphate buffered saline (PBS) solution in the presence of the interference species of uric acid (UA) and ascorbic acid (AA) in this dissertation. These miniaturized LC droplet-based sensor platforms can be used to selectively detect CA and DCA in the presence of UA and AA. The detection limit of these sensor platforms for CA and DCA can be tuned by the number of LC droplets and the nature of surfactants. Furthermore, we find that these sensor platforms are more sensitive for DCA with the shorter response time and lower detection limit over CA due to their difference in hydrophobicity. These miniaturized 5CB droplet-based sensor platforms are easily handled, allowing the rapid and real-time detection of bile acids in a small sample volume in the presence of interference species, which are highly desirable for the "point-of-care" analysis of bile acids.
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Date Issued: 2017
Identifier: CFE0006939, ucf:51664
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006939

Title: Optimization of Glycerol or Biodiesel Waste Prefermentation to Improve EBPR.
Creator: Ghasemi, Marzieh, Randall, Andrew, Duranceau, Steven, Lee, Woo Hyoung, Jimenez, Jose, University of Central Florida
Abstract / Description: The enhanced biological phosphorus removal (EBPR) process efficiency relies on different operational and process conditions especially the type of carbon source available in the wastewater. Acetic acid and propionic acid are the two major volatile fatty acids (VFAs) found in domestic wastewater which can drive biological phosphorus (P) removal to the desired level. However, often domestic wastewater does not have a sufficient amount of VFAs. Due to high acetate and propionate production-cost,...
Show moreThe enhanced biological phosphorus removal (EBPR) process efficiency relies on different operational and process conditions especially the type of carbon source available in the wastewater. Acetic acid and propionic acid are the two major volatile fatty acids (VFAs) found in domestic wastewater which can drive biological phosphorus (P) removal to the desired level. However, often domestic wastewater does not have a sufficient amount of VFAs. Due to high acetate and propionate production-cost, it is not economic to add acetate and propionate directly in full-scale wastewater treatment plants. This brought up the idea of using external carbon sources (e. g. molasses has been used successfully) in EBPR systems that can be converted to VFAs through a fermentation process. On the other hand, biodiesel fuels have been produced increasingly over the last decade. Crude glycerol is a biodiesel production major by-product that can be used as an external carbon source in wastewater treatment plant. Therefore, the main objective of this research is to optimize the glycerol/biodiesel waste fermentation process' operational conditions in pursuit of producing more favorable fermentation end-products (i. e. a mixture of acetic acid and propionic acid) by adding glycerol to a prefermenter versus direct addition to the anaerobic zone or fermentation with waste activated sludge. For this reason, different prefermenter parameters namely: mixing intensity, pH, temperature and solids retention time (SRT), were studied in a small scale fermentation media (serum bottles) and bench scale semi-continuous batch prefermenters. Experimental results revealed that glycerol/biodiesel waste fermentation resulted in a significant amount of VFAs production with propionic acid as the superior end-product followed by acetic acid and butyric acid. The VFA production was at its highest level when the initial pH was adjusted to 7 and 8.5. However, the optimum pH with respect to propionic acid production was 7. Increasing the temperature in serum bottles favored the total VFA production, specifically in the form of propionic acid. Regarding the mixing energy inconsistent results were obtained in the serum bottles compared to the bench scale prefermenters. The VFA production in mixed serum bottles at 200 rpm was higher than that of un-mixed ones. On the other hand, the unmixed or slowly mixed bench scale prefermenters showed higher VFA production than the mixed reactors. However, the serum bottles did not operate long enough to account for biomass acclimation and other long-term effects that the prefermenter experiments could account for. As a consequence one of the most important and consistently results was that VFA production was significantly enhanced by reducing mixing intensity from 100 rpm to 7 rpm and even ceasing mixing all together. This was true both for primary solids and glycerol. In addition propionate content was high under both high and low intensity, and adding glycerol also increased the fraction of primary solids that formed propionic acid instead of acetic acid. Increasing the SRT from 2 to 4 days increased the VFA production about 12% on average. In order to investigate the effect of glycerol on EBPR process efficiency two identical A2/O systems were monitored for 3 months. Experimental results suggested that glycerol addition could increase the P removal efficiency significantly. Adding glycerol to the prefermenter rather than the anaerobic zone resulted in a lower effluent soluble ortho phosphorus (SOP) (0.4 mg-P/L vs. 0.6 mg-P/L) but the difference was apparently statistically significant. Future experimentation should be done to determine if this effect is consistent, especially in carbon poor wastewaters. Also it would be desirable to conduct a longer pilot study or a full scale study to determine if this improvement in effluent SOP remains true over a range of temperature and changing influent conditions.
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Date Issued: 2015
Identifier: CFE0006310, ucf:51612
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006310

Title: Self-Assembled Two-Component Organic Tubes: Structures and Applications.
Creator: Liang, Wenlang, Fang, Jiyu, Huo, Qun, Deng, Weiwei, University of Central Florida
Abstract / Description: Bile acids are physiologically important metabolites, which are synthesized in liver as the end products of cholesterol metabolism and then secreted into the intestines. They play a critical role in the digestion and absorption of fats and fat-soluble vitamins through emulsifications. The amphipathic and chiral nature of bile acids makes their unique building blocks for assembling supramolecular structures including vesicles, fibers, ribbons and hollow tubes. Lithocholic acid (LCA) is a...
Show moreBile acids are physiologically important metabolites, which are synthesized in liver as the end products of cholesterol metabolism and then secreted into the intestines. They play a critical role in the digestion and absorption of fats and fat-soluble vitamins through emulsifications. The amphipathic and chiral nature of bile acids makes their unique building blocks for assembling supramolecular structures including vesicles, fibers, ribbons and hollow tubes. Lithocholic acid (LCA) is a secondary bile acid. Our studies show LCA can self-assemble into helical tubes in aqueous solution by the linear aggregation and fusion of vesicles. The objective of this dissertation is to tune the structure of helical tubes and functionalize them by the co-assembly of ionic LCA and cationic cetyltrimethylammonium bromide (CTAB) and ionic LCA and cationic cyanine dye (CD), respectively. The first part of this dissertation focuses on the ionic-assembly of LCA and CTAB to synthesize the helical tubes with varied diameters and pitches. Our studies show that LCA and CTAB can self-assemble into helical tubes in NH4OH aqueous solution. The diameter of the helical tubes can be changed by adjusting the molar ratio of LCA and CTAB. The pitch of the helical tubes can be tuned by varying NH4OH concentrations. Differential scanning calorimetry studies indicate that there is a homogeneous composition distribution in the LCA/CTAB helical tubes. X-ray diffraction analysis studies show that the helical tubes have multibilayer walls with an average d-spacing of 4.11nm. We demonstrate that the helical tubes with varied diameters and pitches can be transformed into helical silica through the sol-gel transcription of tetraethoxysilane (TEOS). The second part of this dissertation is to use the ionic self-assembly of LCA and CD to design light-harvesting tubes by mimicking green sulfur bacteria that are known to be a highly efficient photosynthesizer. X-ray diffraction and optical spectra show that LCA and CD can co-assemble into J- or H-aggregate tubes, depending the condition under which the self-assembly occurs. We demonstrate the feasibility of using the J-aggregate nanotubes in the sensitive and selective detection of mercury (II) ions by the photoinduced electron transfer under sunlight. The presence of mercury (II) ions in aqueous solution could be detected for concentrations as low as 10 pM.
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Date Issued: 2013
Identifier: CFE0005201, ucf:50635
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005201

Title: Evaluation of an On-Line Device to Monitor Scale Formation in a Brackish Water Reverse Osmosis Membrane Process.
Creator: Roque, Jennifer, Duranceau, Steven, Randall, Andrew, Zhang, Husen, University of Central Florida
Abstract / Description: A modified two-element membrane pressure vessel assembly has been used to monitor process operational changes in a full-scale reverse osmosis (RO) water treatment plant (WTP). This study evaluated the effectiveness of the assembly as an on-line monitoring device intended to detect scale formation conditions when connected to an operating RO process train. This study was implemented to support the requirements of a larger University of Central Florida (UCF) research project ongoing at the city...
Show moreA modified two-element membrane pressure vessel assembly has been used to monitor process operational changes in a full-scale reverse osmosis (RO) water treatment plant (WTP). This study evaluated the effectiveness of the assembly as an on-line monitoring device intended to detect scale formation conditions when connected to an operating RO process train. This study was implemented to support the requirements of a larger University of Central Florida (UCF) research project ongoing at the city of Sarasota's Public Works and Utilities (City) water treatment facilities located in Sarasota, Florida. During the time-frame of this study, the City was in the process of eliminating their sulfuric acid feed from the pretreatment system of their existing 4.5 million gallon per day (MGD) RO membrane process. The City was motivated to eliminate its dependence on sulfuric acid to reduce operating costs as well as reduce operation health and safety risks associated with the use of the acid as a pretreatment chemical. Because the City was concerned with secondary process impacts associated with acid elimination, additional measures were desired in order to protect the full-scale process.This thesis reports on the design, fabrication and installation of a third-stage two membrane element pressure vessel (")canary(") sentinel monitoring device (Canary), its effectiveness as an on-line scaling monitor during full-scale acid elimination, and presents the results of the study. The Canary sentinel device was controlled using the normalized specific flux of the two membrane elements fed by a portion of the second stage concentrate of one of the City's full-scale RO process skids. Although the Canary demonstrated the ability to detect changes in an RO process operation, scaling did not occur under the conditions evaluated in this study. An autopsy of one of the Canary elements revealed that no scaling had occurred during the acid elimination process. Therefore, the Canary was found to be useful in its function as a sentinel, even though no scaling was detected by the device after acid elimination at the City's full-scale plant had been accomplished.
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Date Issued: 2012
Identifier: CFE0004433, ucf:49353
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004433

biosensor (3)	+ -
Adrenergic hormones (2)	+ -
Bile acid (2)	+ -
Liquid crystal (2)	+ -
NMR (2)	+ -

Ultrafiltration (2)	+ -
atherosclerosis (2)	+ -
chemistry (2)	+ -
lipids (2)	+ -
mixing energy (2)	+ -
nucleic acids (2)	+ -
sulfuric acid (2)	+ -
volatile fatty acids (2)	+ -
1JCC (1)	+ -
5-methylmellein (1)	+ -
AKGA (1)	+ -
Absorption and Transmission (1)	+ -
Accelerated durability (1)	+ -
Acetic Acid (1)	+ -
Acid Elimination (1)	+ -
Additive Manufacturing (1)	+ -
Adrenergic derived cells (1)	+ -
Amino Acids (1)	+ -
Anisotropic (1)	+ -
Anisotropy (1)	+ -
Azelaic acid (1)	+ -
Backwash Recycle (1)	+ -
Bile Acids (1)	+ -
Bile acids (1)	+ -
Binary Aptamer (1)	+ -

ETD Collection (45)	+ -
Honors Collection (4)	+ -

University of Central Florida (48)	+ -
Duranceau, Steven (8)	+ -
Kolpashchikov, Dmitry (7)	+ -
Fang, Jiyu (6)	+ -
Randall, Andrew (6)	+ -

Blair, Richard (4)	+ -
Campiglia, Andres (4)	+ -
Chumbimuni Torres, Karin (4)	+ -
Clausen, Christian (4)	+ -
Harper, James (4)	+ -
Seal, Sudipta (4)	+ -
Zhai, Lei (4)	+ -
Miles, Howard (3)	+ -
Ye, Jingdong (3)	+ -
Yestrebsky, Cherie (3)	+ -
Zou, Shengli (3)	+ -
Diaz, Diego (2)	+ -
Dong, Yajie (2)	+ -
Ebert, Steven (2)	+ -
Hampton, Michael (2)	+ -
Hoffman, Jay (2)	+ -
Lee, Woo Hyoung (2)	+ -
Naser, Saleh (2)	+ -
Parthasarathy, Sampath (2)	+ -
Rhoden, Stephen (2)	+ -
Sadmani, A H M Anwar (2)	+ -
Santra, Swadeshmukul (2)	+ -
Self, William (2)	+ -
Siddiqi, Shadab (2)	+ -
Stout, Jeffrey (2)	+ -

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