Current Search: Oxidation (x)
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Title
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RAMAN SPECTRA OF ZIRCONIA CERAMICS.
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Creator
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KIM, JAE HOON, Florida Atlantic University, Medina, Fernando D., Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Raman spectroscopy was used to investigate how phase structure and phase stability of zirconia mixtures depend on temperature, type and concentration of added rare earth oxides, and fabrication process. All 8wt% yttria samples exhibited the tetragonal structure between 300 and 10 K. The TZP sample, prepared under pressure and fully hardened, exhibited the most completely stabilized tetragonal structure. The plasma coating process did not improve the stability of the tetragonal structure....
Show moreRaman spectroscopy was used to investigate how phase structure and phase stability of zirconia mixtures depend on temperature, type and concentration of added rare earth oxides, and fabrication process. All 8wt% yttria samples exhibited the tetragonal structure between 300 and 10 K. The TZP sample, prepared under pressure and fully hardened, exhibited the most completely stabilized tetragonal structure. The plasma coating process did not improve the stability of the tetragonal structure. Adding ceria to zirconia did not completely stabilize the tetragonal structure, while adding alumina actually destabilized it. Mode Gruneisen parameters, obtained from changes in frequency for yttria samples with different concentration, agreed with published results under pressure, except for one Eg mode. The negative value obtained for this mode was ascribed to changes in cation-anion interactions. The temperature dependence of the linewidth for this mode was quantitatively explained by cubic anharmonic interactions.
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Date Issued
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1987
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PURL
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http://purl.flvc.org/fcla/dt/14401
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Subject Headings
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Zirconium oxide, Spectrum analysis
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Format
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Document (PDF)
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Title
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SURFACE CONTROLLED PHOTOCONDUCTIVITY TRANSIENTS IN ZINC DOPED POLYCRYSTALLINE STANNIC-OXIDE.
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Creator
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WOLFE, GORDON WAYNE, Florida Atlantic University
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Abstract/Description
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A study was made of the photoconductivity transients in zinc-doped polycrystalline stannic oxide. The current rises and decays during and following illumination were observed for varying time, intensity, and wavelength of illumination, and for different ambient temperatures. This experimental data was analyzed assuming that the photoconductivity transients are surface controlled processes involving the chemisorption and desorption of oxygen. Models used to describe the observed data were...
Show moreA study was made of the photoconductivity transients in zinc-doped polycrystalline stannic oxide. The current rises and decays during and following illumination were observed for varying time, intensity, and wavelength of illumination, and for different ambient temperatures. This experimental data was analyzed assuming that the photoconductivity transients are surface controlled processes involving the chemisorption and desorption of oxygen. Models used to describe the observed data were based on either an Elovich-type phenomenological rate equation or a mechanistic physical description of the processes involved. These models, using the observed data, were then compared for ranges of validity and self-consistency.
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Date Issued
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1971
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PURL
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http://purl.flvc.org/fcla/dt/13471
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Subject Headings
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Photoconductivity, Metal oxide semiconductors, Semiconductor doping, Oxide ceramics
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Format
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Document (PDF)
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Title
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Coexistence of ferromagnetic and antiferromagnetic phases in gadolinium-doped lanthanum(0.7) calcium(0.3) manganese oxygen(3).
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Creator
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Terashita, Hirotoshi, Florida Atlantic University, Neumeier, John
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Abstract/Description
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Magnetic and electrical properties for La(1-x)Gd(x)0.7Ca(0.3)MnO3 were studied at ambient and high pressure. For x > 0.1 the ferromagnetic saturation moment M is smaller than that expected for complete ferromagnetic alignment of the Mn moments. Gd substitution lowers both the paramagnetic-ferromagnetic transition temperature T(C), the metal-insulator transition temperature T(MI) and dramatically increases the electrical resistivity rho. T(MI) is observed to be significantly lower than T(C)...
Show moreMagnetic and electrical properties for La(1-x)Gd(x)0.7Ca(0.3)MnO3 were studied at ambient and high pressure. For x > 0.1 the ferromagnetic saturation moment M is smaller than that expected for complete ferromagnetic alignment of the Mn moments. Gd substitution lowers both the paramagnetic-ferromagnetic transition temperature T(C), the metal-insulator transition temperature T(MI) and dramatically increases the electrical resistivity rho. T(MI) is observed to be significantly lower than T(C) for x > 0.1. The disagreement of T(C) and T(MI) is a result of the A-site ion size difference which causes the coexistence of ferromagnetic La-Ca-Mn-O and antiferromagnetic Gd-Ca-Mn-O phases and leads to the anomalous electrical transport properties. Samples with the largest average A-site ionic radius show the highest T(C) or T(MI) and are least sensitive to pressure.
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Date Issued
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1999
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PURL
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http://purl.flvc.org/fcla/dt/15704
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Subject Headings
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Magnetoresistance, Ferromagnetic materials, Manganese oxides
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Format
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Document (PDF)
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Title
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Raman spectroscopic study of yttrium barium(2)(copper(1-x)iron(x))oxygen(7+delta).
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Creator
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Tanabe, Makoto., Florida Atlantic University, Liu, Da Wei
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Abstract/Description
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Polycrystalline bulk samples with the chemical formula YBa2(Cu1-xFex)3O7+delta were fabricated by the standard solid-state reaction method, and studied through magnetic susceptibility and Raman scattering experiments. In the Raman experiments, the Cu(1)-O(1) c-axial Ag stretching mode at ~502cm^-1 was investigated extensively at temperatures ranging from 23K to 773K. The room-temperature Raman spectra indicated a trend for saturation in frequency shift (as a function of iron concentration)....
Show morePolycrystalline bulk samples with the chemical formula YBa2(Cu1-xFex)3O7+delta were fabricated by the standard solid-state reaction method, and studied through magnetic susceptibility and Raman scattering experiments. In the Raman experiments, the Cu(1)-O(1) c-axial Ag stretching mode at ~502cm^-1 was investigated extensively at temperatures ranging from 23K to 773K. The room-temperature Raman spectra indicated a trend for saturation in frequency shift (as a function of iron concentration). This was interpreted as evidence supporting the occurrence of a type of iron clustering in the (001) basal plane. Effects of such a cluster formation upon the mechanism of superconductivity were considered. The low temperature Raman spectra show that the 502cm^-1 mode frequency increased slightly with decreasing temperature for all of the studied values of iron concentration without exhibiting any anomalous behavior. In the high temperature Raman spectra, a significant softening of the 502cm^-1 mode, indicative of a phase transition onset, was observed.
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Date Issued
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1990
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PURL
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http://purl.flvc.org/fcla/dt/14597
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Subject Headings
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Raman spectroscopy, Copper oxide superconductors
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Format
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Document (PDF)
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Title
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Investigation of the oxygen transfer properties of molybdenum-oxide(Et(2)dtc)(2)(THF)(2)I(2).
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Creator
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Falzone, Samuel, Florida Atlantic University, Baird, Donald M.
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Abstract/Description
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Mo2o3 (Et2dtc) 2 (THF) 2I2, readily reduces various oxides. The Mo vio2+2 product of this reaction oxidizes TPP to triphenylphosphine oxide. The transient Mo(iv) species formed in the later reaction rapidly and irreversibly reacts with excess Mo vio2+2 to form the original Mo2 o3 4+ complex. These reactions can be also be coupled to provide catalytic oxygen transfer from PNO to TPP. This catalytic cycle can be monitored using a reverse phase high pressure liquid chromatography method that...
Show moreMo2o3 (Et2dtc) 2 (THF) 2I2, readily reduces various oxides. The Mo vio2+2 product of this reaction oxidizes TPP to triphenylphosphine oxide. The transient Mo(iv) species formed in the later reaction rapidly and irreversibly reacts with excess Mo vio2+2 to form the original Mo2 o3 4+ complex. These reactions can be also be coupled to provide catalytic oxygen transfer from PNO to TPP. This catalytic cycle can be monitored using a reverse phase high pressure liquid chromatography method that will also be discussed. The oxides chosen ranged from pyridine-N-oxide to the biological substrates: diphenylsufoxide, DMSO, nicotinamide-N-oxide, and biotin-S-oxide. Since Mo2o3 (Et2dtc) 2 (THF) 2I2 has the ability to abstract oxygen from these biologically significant substrates, it may result in the reconsideration of the role of Mo(V) complexes in catalytic cycles.
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Date Issued
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1989
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PURL
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http://purl.flvc.org/fcla/dt/14537
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Subject Headings
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Molybdenum, Oxidation-reduction reaction
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Format
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Document (PDF)
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Title
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Ionic Concentrations and Optical Properties of Anodic Oxides on Titantium.
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Creator
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Manty, Brian A., Banter, John C., Florida Atlantic University
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Abstract/Description
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The thicknesses of anodically formed oxides on titanium were determined using optical methods including both transmission and reflectance techniques. A dispersion curve and phase change vs. wavelength plot for the anodically formed oxides were determined for the thickness measurements. Ionic inclusions in the oxide from the anodizing electrolyte were studied using I. R . spectroscopy and x-ray fluorescence. Phosphate, sulfate, bisulfate, and molybdate were detected in the oxides. Anodizing...
Show moreThe thicknesses of anodically formed oxides on titanium were determined using optical methods including both transmission and reflectance techniques. A dispersion curve and phase change vs. wavelength plot for the anodically formed oxides were determined for the thickness measurements. Ionic inclusions in the oxide from the anodizing electrolyte were studied using I. R . spectroscopy and x-ray fluorescence. Phosphate, sulfate, bisulfate, and molybdate were detected in the oxides. Anodizing over a phosphate dope oxide layer resulted in a duplex oxide with the phosphate layer remaining adjacent to the metal. This indicated titaniwn ions are the mobile species during the anodizing process.
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Date Issued
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1969
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PURL
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http://purl.flvc.org/fau/fd/FA00000794
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Subject Headings
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Electrolytic oxidation, Titanium, Optical measurements
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Format
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Document (PDF)
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Title
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The role of methionine sulfoxide reductase in thermal stress response.
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Creator
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Martin, James, Bruce, Lindsay, Schey, Karin, Binninger, David
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Date Issued
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2013-04-05
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PURL
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http://purl.flvc.org/fcla/dt/3361149
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Subject Headings
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Hyperthermia, Heat shock proteins, Methionine, Oxidative stress
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Format
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Document (PDF)
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Title
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Alternative Biological Roles of Methionine Sulfoxide Reductases in Drosophila melanogaster.
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Creator
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Wilson, Kelsey, Binninger, David, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
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Abstract/Description
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The oxidation of methionine (Met) into methionine sulfoxide (met-(o)) leads to deleterious modifications to a variety of cellular constituents. These deleterious alterations can be reversed by enzymes known as methionine sulfoxide reductases (Msr). The Msr (MsrA and MsrB) family of enzymes have been studied extensively for their biological roles in reducing oxidized Met residues back into functional Met. A wide range of studies have focused on Msr both in vivo and in vitro using a variety of...
Show moreThe oxidation of methionine (Met) into methionine sulfoxide (met-(o)) leads to deleterious modifications to a variety of cellular constituents. These deleterious alterations can be reversed by enzymes known as methionine sulfoxide reductases (Msr). The Msr (MsrA and MsrB) family of enzymes have been studied extensively for their biological roles in reducing oxidized Met residues back into functional Met. A wide range of studies have focused on Msr both in vivo and in vitro using a variety of model organisms. More specifically, studies have noted numerous processes affected by the overexpression, under expression, and silencing of MsrA and MsrB. Collectively, the results of these studies have shown that Msr is involved in lifespan and the management of oxidative stress. More recent evidence is emerging that supports existing biological functions of Msr and theorizes the involvement of Msr in numerous biological pathways.
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Date Issued
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2018
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PURL
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http://purl.flvc.org/fau/fd/FA00005980
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Subject Headings
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Drosophila melanogaster, Methionine Sulfoxide Reductases, Oxidative stress
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Format
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Document (PDF)
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Title
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A Study on the Potential Role of Stress Granules and Processing Bodies in Eliminating Oxidatively Damaged RNA.
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Creator
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Pourkalbassi, Delaram, Li, Zhongwei, Florida Atlantic University, Charles E. Schmidt College of Medicine, Department of Biomedical Science
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Abstract/Description
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Oxidative stress (OS) is strongly implicated in age-related neurodegeneration and other diseases. Under OS, the production of excessive oxidants leads to increased damages to cellular components. Recently, RNA has been discovered as a major target of oxidative damage, including the creation of abasic sites. In this work, we developed a method for quantifying abasic RNA in cell. Using this method, we have examined the potential role of the RNA-processing cellular foci, stress granule (SG) and...
Show moreOxidative stress (OS) is strongly implicated in age-related neurodegeneration and other diseases. Under OS, the production of excessive oxidants leads to increased damages to cellular components. Recently, RNA has been discovered as a major target of oxidative damage, including the creation of abasic sites. In this work, we developed a method for quantifying abasic RNA in cell. Using this method, we have examined the potential role of the RNA-processing cellular foci, stress granule (SG) and processing bodies (PB) in eliminating abasic RNA in situ. We demonstrated that RNA is a major target of oxidative damage, constituting the majority of OS-induced abasic nucleic acids in HeLa cell. Importantly, the level of abasic RNA is strongly correlated with SG abundance. Furthermore, inhibition of SG/PB formation causes accumulation of abasic RNA, suggesting that SG/PB participates in removing oxidized RNA and protects cells under OS, which offers novel targets for therapeutic intervention in age-related diseases.
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Date Issued
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2016
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PURL
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http://purl.flvc.org/fau/fd/FA00004702
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Subject Headings
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Aging -- Physiological aspects., Oxidative stress., RNA -- Metabolism.
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Format
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Document (PDF)
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Title
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Unraveling the molecular mechanism of human polynucleotide phosphorylase (hPNPase) in controlling oxidized RNA.
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Creator
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Malla, Sulochan, Li, Zhongwei, Florida Atlantic University, Department of Biomedical Science, Charles E. Schmidt College of Science
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Abstract/Description
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Oxidation by reactive oxygen species is the major source of RNA damaging insult in living organisms. Increased RNA oxidation has been strongly implicated in a wide range of human diseases; predominantly neurodegeneration. Oxidized RNA should be removed from the cellular system to prevent their deleterious effect to the cells and organisms. In eukaryotic cells, mitochondria are the major intracellular sources of ROS and may cause greater damage to the mitochondrial RNA. In this study, we first...
Show moreOxidation by reactive oxygen species is the major source of RNA damaging insult in living organisms. Increased RNA oxidation has been strongly implicated in a wide range of human diseases; predominantly neurodegeneration. Oxidized RNA should be removed from the cellular system to prevent their deleterious effect to the cells and organisms. In eukaryotic cells, mitochondria are the major intracellular sources of ROS and may cause greater damage to the mitochondrial RNA. In this study, we first investigated the RNA oxidation, by measuring the level of 8-hydroxy-Guanosine (8-oxo-Guo), inside mitochondria and cytoplasm in cultured human cells. We discovered that the mitochondrial 8-oxo-Guo is higher than its cytoplasmic counterparts under both normal growth and oxidative stress condition. Next, we explored the role of human polynucleotide phosphorylase (hPNPase) in controlling RNA oxidation inside mitochondria and cytoplasm. hPNPase binds to oxidized RNA with higher affinity, reduces the 8-oxo-Guo level in total RNA and protects cells against oxidative stress. In this study, the molecular mechanism of hPNPase in 8-oxo-Guo reduction was investigated. First, the effect of hPNPase activities on the 8-oxo-Guo level in mitochondria and cytoplasm was examined. The knockdown of hPNPase increased both the mitochondrial and cytoplasmic 8-oxo-Guo, whereas overexpression had the opposite effect. Second, our study revealed that hSUV3, an RNA helicase that forms a functional complex with hPNPase in mitochondria, was dispensable in reducing 8-oxo-Guo levels.
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Date Issued
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2019
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PURL
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http://purl.flvc.org/fau/fd/FA00013392
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Subject Headings
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RNA, Reactive Oxygen Species, Mitochondria, Oxidative stress
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Format
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Document (PDF)
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Title
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Role and Regulation of Methionine Sulfoxide Reductase (Msr) in a model of oxidative stress tolerance: Trachemys scripta.
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Creator
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Reiterer, Melissa, Milton, Sarah, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
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Abstract/Description
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The detrimental effects of oxidative stress caused by the accumulation of Reactive Oxygen Species (ROS) have been acknowledged as major factors in aging, senescence and several neurodegenerative diseases and conditions such as Parkinson’s disease and stroke (ischemia/reperfusion). Mammalian models are extremely susceptible to these stresses that follow the restoration of oxygen after anoxia; however, some organisms including the freshwater turtle Trachemys scripta can withstand several bouts...
Show moreThe detrimental effects of oxidative stress caused by the accumulation of Reactive Oxygen Species (ROS) have been acknowledged as major factors in aging, senescence and several neurodegenerative diseases and conditions such as Parkinson’s disease and stroke (ischemia/reperfusion). Mammalian models are extremely susceptible to these stresses that follow the restoration of oxygen after anoxia; however, some organisms including the freshwater turtle Trachemys scripta can withstand several bouts of anoxia and repeated reoxygenation without any apparent pathology. T. scripta thus provides us with an alternate vertebrate model in which we can investigate physiological mechanisms of neuroprotection without the damaging effects that come with oxidative stress. The major objective of this study was to investigate the protective mechanisms in the turtle brain under conditions of anoxia and oxidative stress. Specifically, the focus is on the Methionine Sulfoxide Reductase system (Msr), an antioxidant and cellular repair system, and how it is regulated to protect the brain against such stressors. Previous studies in my lab have demonstrated that Msr mRNA and protein levels are differentially upregulated during anoxia and reoxygenation. To investigate the regulation of Msr, FOXO3a was directly induced by transfecting a human FOXO3a plasmid into turtle brain cell cultures, as FOXO3a has been shown to regulate MsrA levels in other animal models. Pharmacological manipulation of FOXO3a was also performed using the green tea extract Epigallocatechin gallate (EGCG) as it has been shown to increase expression of FOXO3a during oxidative stress conditions in other models. I found that an induction of human FOXO3a increased FOXO3a levels and showed protection against cell death during oxidative stress. Furthermore, treatment of cells with EGCG increased expression of FOXO3a only when the cells were exposed to oxidative stress and decreased cell death. Induction of FOXO3a and EGCG treatment did not increase MsrA levels, however MsrB3 levels were upregulated under both treatments but only in the presence of oxidative stress. These results suggest that MsrA and MsrB3 protect the cells from oxidative stress damage through different molecular pathways and that EGCG may be a therapeutic target to treat diseases related to damage by oxidative stress.
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Date Issued
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2018
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PURL
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http://purl.flvc.org/fau/fd/FA00013154
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Subject Headings
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Methionine Sulfoxide Reductases, Oxidative Stress, Trachemys scripta
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Format
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Document (PDF)
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Title
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Raman spectroscopic studies of stabilized zirconia at elevated temperatures.
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Creator
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Lacher, Nathan, Florida Atlantic University, Liu, David, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Raman spectroscopy was used to determine the phase structure and phase stability of zirconia mixtures for various elevated temperatures, type and concentration of oxides added to zirconia, and fabrication process. All 8 wt.% yttria samples showed mostly the tetragonal structure at room temperature. Three of the four 8 wt.% yttria samples exhibited the tetragonal structure at elevated temperatures, while no conclusion was inferred for the powdered sample. As compared with yttria, ceria is a...
Show moreRaman spectroscopy was used to determine the phase structure and phase stability of zirconia mixtures for various elevated temperatures, type and concentration of oxides added to zirconia, and fabrication process. All 8 wt.% yttria samples showed mostly the tetragonal structure at room temperature. Three of the four 8 wt.% yttria samples exhibited the tetragonal structure at elevated temperatures, while no conclusion was inferred for the powdered sample. As compared with yttria, ceria is a less effective stabilizer with respect to the zirconia tetragonal structure. A monoclinic transformation between 400 K and 800 K was observed in the 4 wt.% yttria sample which had been processed by rapid quenching. Adding alumina to 4 wt.% yttria did not completely stabilize the tetragonal structure at or above room temperature, making it a less effective stabilizer than yttria or ceria. The phase transformation was responsible for the unusual values in the Gr uneisen parameters obtained for the 4 wt.% yttria sample.
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Date Issued
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1990
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PURL
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http://purl.flvc.org/fcla/dt/14589
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Subject Headings
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Zirconium oxide--Spectra, Raman spectroscopy
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Format
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Document (PDF)
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Title
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Novel multiplexer-based architectures for full adder design.
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Creator
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Al-Sheraidah, Abdulkarim K., Florida Atlantic University, Wang, Yuke
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Abstract/Description
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We propose five new Multiplexer-Based architectures for 1-bit full adder design. Using a 2-transistors multiplexer gate to implement the first architecture, we are able to produce a 12-transistor full adder cell, Comparing it to four different 10-transistors low-power full adder cells reported previously in literature, the new adder cell named MBA1-12T out performs all of them in power consumption and speed. By implementing those architectures using the 2-input CMOS multiplexer with pass...
Show moreWe propose five new Multiplexer-Based architectures for 1-bit full adder design. Using a 2-transistors multiplexer gate to implement the first architecture, we are able to produce a 12-transistor full adder cell, Comparing it to four different 10-transistors low-power full adder cells reported previously in literature, the new adder cell named MBA1-12T out performs all of them in power consumption and speed. By implementing those architectures using the 2-input CMOS multiplexer with pass-gates, five new high-performance full adder cells are obtained. Those new adder cells are tested along with the conventional 28-transistor CMOS adder cell. Testing results shows that the new adder cells have higher speed and lower power delay product values than the conventional 28-transistor CMOS adder cell.
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Date Issued
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2000
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PURL
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http://purl.flvc.org/fcla/dt/12667
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Subject Headings
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Metal oxide semiconductors, Complementary, Digital integrated circuits
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Format
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Document (PDF)
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Title
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Structural, magnetic, and electrical properties of ruthenium oxides.
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Creator
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Leao, Juscelino Batista, Florida Atlantic University, Neumeier, John, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Early reports of antiferromagnetism in CaRuO3 will be discussed within the framework of our recent experiments. We have observed that slight Ru deficiency (∼4%) leads to a weak feature in the magnetic susceptibility. Temperature-dependant time-of-flight (TOF) neutron powder diffraction data revealed no long-range magnetic order in the Ruthenium deficient CaRu 0.96O3 sample. More careful analysis of magnetization data indicates that the feature in chi(T) can be attributed to a weak...
Show moreEarly reports of antiferromagnetism in CaRuO3 will be discussed within the framework of our recent experiments. We have observed that slight Ru deficiency (∼4%) leads to a weak feature in the magnetic susceptibility. Temperature-dependant time-of-flight (TOF) neutron powder diffraction data revealed no long-range magnetic order in the Ruthenium deficient CaRu 0.96O3 sample. More careful analysis of magnetization data indicates that the feature in chi(T) can be attributed to a weak ferromagnetic phase which forms below an ordering temperature of T = 147 K. This phase is destroyed with Lanthanum doping (∼2%) and annealing in reducing conditions dramatically shifts this feature. Measurements of the magnetic susceptibility versus temperature of the series Ca1-xLaxRu 0.96O3 (0 ≤ x ≤ 0.12) led to further study of CaRuO 3 and SrRuO3. The structural parameters of CaRuO 3 and SrRuO3 powder samples, obtained from neutron time-of-flight data analysis via Rietveld refinement, will be compared.
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Date Issued
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2002
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PURL
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http://purl.flvc.org/fcla/dt/12954
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Subject Headings
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Ferromagnetism, Ruthenium oxide superconductors, Rietveld method
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Format
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Document (PDF)
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Title
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THICKNESS AND PROPERTIES OF ANODIC ALUMINUM-OXIDE FILMS.
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Creator
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PASTORE, GUILLERMO WILLIGMANN., Florida Atlantic University
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Abstract/Description
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The refractive indices and thicknesses of anodically formed oxides on both pure and 3003 alloy aluminum were determined using a transmission spectrophotometric technique. Dispersion curves were obtained for the films formed on both aluminums, and thicknesses were given as a function of voltage for Barrier-films and as a function of time for porous films. Characteristics of formation were reported for both types of films on pure and 3003 alloy aluminum. These formation characteristics are...
Show moreThe refractive indices and thicknesses of anodically formed oxides on both pure and 3003 alloy aluminum were determined using a transmission spectrophotometric technique. Dispersion curves were obtained for the films formed on both aluminums, and thicknesses were given as a function of voltage for Barrier-films and as a function of time for porous films. Characteristics of formation were reported for both types of films on pure and 3003 alloy aluminum. These formation characteristics are interpreted in terms of the solvent action of the anodizing electrolyte on the oxide. the refractive indices of porous films were found to change with time due to the presence of water in the films. A modification of the thickness calculation method is developed for these porous films. Incorporation of water and sulfate anion in the films were detected using infrared spectroscopy. The structures of the films were studied under the microscope, and related to certain aspects of their behavior.
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Date Issued
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1973
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PURL
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http://purl.flvc.org/fcla/dt/13616
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Subject Headings
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Thin films, Aluminum--Anodic oxidation
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Format
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Document (PDF)
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Title
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Neuroprotection During Acute Oxidative Stress: Role of the PKG Pathway and Identification of Novel Neuromodulatory Agents Using Drosophila Melanogaster.
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Creator
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Caplan, Stacee Lee, Dawson-Scully, Ken, Milton, Sarah L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
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Abstract/Description
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Oxidant stress and injury is inherent in many human diseases such as ischemic vascular and respiratory diseases, heart failure, myocardial infarction, stroke, perinatal and placental insufficiencies, diabetes, cancer, and numerous psychiatric and neurodegenerative disorders. Finding novel therapeutics to combat the deleterious effects of oxidative stress is critical to create better therapeutic strategies for many conditions that have few treatment options. This study used the anoxia-tolerant...
Show moreOxidant stress and injury is inherent in many human diseases such as ischemic vascular and respiratory diseases, heart failure, myocardial infarction, stroke, perinatal and placental insufficiencies, diabetes, cancer, and numerous psychiatric and neurodegenerative disorders. Finding novel therapeutics to combat the deleterious effects of oxidative stress is critical to create better therapeutic strategies for many conditions that have few treatment options. This study used the anoxia-tolerant fruit fly, Drosophila melanogaster, to investigate endogenous cellular protection mechanisms and potential interactions to determine their ability to regulate synaptic functional tolerance and cell survival during acute oxidative stress. The Drosophila larval neuromuscular junction (NMJ) was used to analyze synaptic transmission and specific motor axon contributions. Drosophila Schneider 2 (S2) cells were used to assess viability. Acute oxidative stress was induced using p harmacological paradigms that generate physiologically relevant oxidant species: mitochondrial superoxide production induced by sodium azide (NaN3) and hydroxyl radical formation via hydrogen peroxide (H2O2). A combination of genetic and pharmacological approaches were used to explore the hypothesis that endogenous protection mechanisms control cellular responses to stress by manipulating ion channel conductance and neurotransmission. Furthermore, this study analyzed a group of marine natural products, pseudopterosins, to identify compounds capable of modulating synaptic transmission during acute oxidative stress and potential novel neuromodulatory agents.
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Date Issued
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2015
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PURL
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http://purl.flvc.org/fau/fd/FA00004487, http://purl.flvc.org/fau/fd/FA00004487
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Subject Headings
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Drosophila melanogaster -- Life cycles, Oxidative stress -- Ecophysiology, Oxidative stress -- Prevention, Protein kinases, Proteins -- Chemical modification
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Format
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Document (PDF)
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Title
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Submicron CAD design and analysis of MOS Current Mirrors.
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Creator
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Rivas-Torres, Wilfredo, Florida Atlantic University, Roth, Zvi S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
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Abstract/Description
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Current Mirrors are widely used circuits in IC designs. They are used as current sources and loads. The proper selection of a Current Mirror configuration is therefore important. This thesis reviews critical parameters for Current Minors characterization. Six MOS Current Mirror configurations are studied, and their performance characteristics are compared. The proper selection and use of MOSFET models are presented. It is shown that CAD-based design and analysis is indispensable if realistic...
Show moreCurrent Mirrors are widely used circuits in IC designs. They are used as current sources and loads. The proper selection of a Current Mirror configuration is therefore important. This thesis reviews critical parameters for Current Minors characterization. Six MOS Current Mirror configurations are studied, and their performance characteristics are compared. The proper selection and use of MOSFET models are presented. It is shown that CAD-based design and analysis is indispensable if realistic MOS models such as BSIM3 are used. The CAD based analysis and design employs simulation parameter tuning, optimization and swept parameters. The presented CAD techniques allow a designer to make important tradeoffs for different configurations. One of the main thesis observations is that it is not always necessary to use more involved Current Mirror configurations; a Simple Current Mirror Configuration is often sufficient. The thesis also studies the adverse effects on the design caused by process variations.
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Date Issued
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2004
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PURL
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http://purl.flvc.org/fcla/dt/13119
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Subject Headings
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Metal oxide semiconductors--Computer-aided design, Integrated circuits, Metal oxide semiconductor field-effect transistors
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Format
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Document (PDF)
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Title
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The NSAID, Sulindac confers protection against oxidative stress induced damage in retinal pigmented epithelial cells.
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Creator
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Sur, Arunodoy, Biswal, Manas, Kreymerman, Alexander, Weissbach, Herbert, Prentice, Howard, Blanks, Janet C., Graduate College
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Date Issued
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2011-04-08
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PURL
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http://purl.flvc.org/fcla/dt/3164798
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Subject Headings
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Nonsteroidal anti-inflammatory agents, Oxidative stress, Epithelial cells
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Format
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Document (PDF)
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Title
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The evolution of integrated aquaculture systems.
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Creator
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Ryther, John H., Harbor Branch Oceanographic Institute
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Date Issued
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1983
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PURL
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http://purl.flvc.org/FCLA/DT/3343801
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Subject Headings
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Aquaculture, Oxidation ponds, Poly-aquaculture, Mariculture, Algae culture
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Format
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Document (PDF)
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Title
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Sulindac enhances the killing of cancer cells exposed to oxidative stress.
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Creator
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Kreymerman, Alexander, Ayyanathan, Kasirajan, Kesaraju, Shailaja, Dawson-Scully, Ken, Weissbach, Herbert, Graduate College
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Date Issued
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2011-04-08
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PURL
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http://purl.flvc.org/fcla/dt/3164545
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Subject Headings
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Nonsteroidal anti-inflammatory agents, Oxidative stress, Mitochondrial pathology
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Format
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Document (PDF)
Pages