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- Title
- Engaging Students in Ethical Considerations of the Scientific Process Using a Simulated Funding Panel.
- Creator
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Demers, Nora, Nelson, Katherine, Gunnels, Charles W., Bovard, Brian, Cassani, Mary Kay, Douglass, James, Everham, Edwin, Hartley, Anne, Herman, John, Mujtaba, Mustafa, Muller,...
Show moreDemers, Nora, Nelson, Katherine, Gunnels, Charles W., Bovard, Brian, Cassani, Mary Kay, Douglass, James, Everham, Edwin, Hartley, Anne, Herman, John, Mujtaba, Mustafa, Muller, Joanne, Nicolas, Antoine, Southard, Larry, Thomas, Serge, Buzasi, Derek
Show less - Abstract / Description
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All undergraduates majoring in a physical or natural science in the College of Arts and Sciences at Florida Gulf Coast University (FGCU) are required to take an interdisciplinary-science methods course entitled Scientific Process. This course is designed to help professionalize students by introducing them to the history, practice, philosophy, and ethics associated with being a working scientist (Meers, Demers and Savarese 2003). Most students take the course early in their junior year as the...
Show moreAll undergraduates majoring in a physical or natural science in the College of Arts and Sciences at Florida Gulf Coast University (FGCU) are required to take an interdisciplinary-science methods course entitled Scientific Process. This course is designed to help professionalize students by introducing them to the history, practice, philosophy, and ethics associated with being a working scientist (Meers, Demers and Savarese 2003). Most students take the course early in their junior year as the first class in a sequence of research courses that culminates in conducting and presenting independent research during their senior year.
Show less - Date Issued
- 2015-10-01
- Identifier
- fgcu_ir_000397
- Format
- Citation
- Title
- A Case Study for Teaching Quantitative Biochemical Buffer Problems Using Group Work and "Khan Style" Videos .
- Creator
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Reilly, John, Dubetz, Terry A., Davis-McGibony, C. Michele, Ramoutar, Ria, Rudd, Gillian, Brown, David, Frost, Laura, Coticone, Sulekha, Beharry, Zanna, Barreto, Jose
- Abstract / Description
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New technological developments have minimized training, hardware expense, and distribution problems for the production and use of instructional videos, and any science instructor can now make instructional videos for their classes. We created short "Khan style" videos for the topic of buffers in biochemistry and assigned them as homework, followed by group problem-solving sessions in class. We tested the hypothesis that "inverting the classroom" (a popular terminology for the new format)...
Show moreNew technological developments have minimized training, hardware expense, and distribution problems for the production and use of instructional videos, and any science instructor can now make instructional videos for their classes. We created short "Khan style" videos for the topic of buffers in biochemistry and assigned them as homework, followed by group problem-solving sessions in class. We tested the hypothesis that "inverting the classroom" (a popular terminology for the new format) could replace traditional live lectures, which are typically followed by assigning homework problems (traditionally, mostly solved by students working alone). Using the inverted classroom method, we found that most of our students achieved mastery in solving buffer problems on an exam, without any live lecture (the class averages were ~80%). Our survey data showed that both students and faculty reviewers considered the new format to be an effective teaching tool. To validate our results, we included six survey questions concerning rigor and fairness; positive data were obtained in this regard, with a mean of ~4, on a 5-point scale. We included three separate classes in our study with grade data from 67 students and survey data from 42 students.
Show less - Date Issued
- 2014-09-01
- Identifier
- fgcu_ir_000551
- Format
- Citation
- Title
- Dengue virus antibodies enhance Zika virus infection.
- Creator
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Paul, Lauren M, Carlin, Eric R, Jenkins, Meagan M, Tan, Amanda L, Barcellona, Carolyn M, Nicholson, Cindo O, Michael, Scott F, Isern, Sharon
- Abstract / Description
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For decades, human infections with Zika virus (ZIKV), a mosquito-transmitted flavivirus, were sporadic, associated with mild disease, and went underreported since symptoms were similar to other acute febrile diseases. Recent reports of severe disease associated with ZIKV have greatly heightened awareness. It is anticipated that ZIKV will continue to spread in the Americas and globally where competent Aedes mosquito vectors are found. Dengue virus (DENV), the most common mosquito-transmitted...
Show moreFor decades, human infections with Zika virus (ZIKV), a mosquito-transmitted flavivirus, were sporadic, associated with mild disease, and went underreported since symptoms were similar to other acute febrile diseases. Recent reports of severe disease associated with ZIKV have greatly heightened awareness. It is anticipated that ZIKV will continue to spread in the Americas and globally where competent Aedes mosquito vectors are found. Dengue virus (DENV), the most common mosquito-transmitted human flavivirus, is both well-established and the source of outbreaks in areas of recent ZIKV introduction. DENV and ZIKV are closely related, resulting in substantial antigenic overlap. Through antibody-dependent enhancement (ADE), anti-DENV antibodies can enhance the infectivity of DENV for certain classes of immune cells, causing increased viral production that correlates with severe disease outcomes. Similarly, ZIKV has been shown to undergo ADE in response to antibodies generated by other flaviviruses. We tested the neutralizing and enhancing potential of well-characterized broadly neutralizing human anti-DENV monoclonal antibodies (HMAbs) and human DENV immune sera against ZIKV using neutralization and ADE assays. We show that anti-DENV HMAbs, cross-react, do not neutralize, and greatly enhance ZIKV infection in vitro. DENV immune sera had varying degrees of neutralization against ZIKV and similarly enhanced ZIKV infection. Our results suggest that pre-existing DENV immunity may enhance ZIKV infection in vivo and may lead to increased disease severity. Understanding the interplay between ZIKV and DENV will be critical in informing public health responses and will be particularly valuable for ZIKV and DENV vaccine design and implementation strategies.
Show less - Date Issued
- 2016-12-16
- Identifier
- 10.1038/cti.2016.72, fgcu_ir_000083, http://doi.wiley.com/10.1038/cti.2016.72
- Format
- Citation
- Title
- Ionic liquids with thioether motifs as synthetic cationic lipids for gene delivery.
- Creator
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Mirjafari, Arsalan, Gaitor, Jamie C., Paul, Lauren M., Reardon, Melissa M., Hmissa, Taha, Minkowicz, Samuel, Regner, Matthew, Sheng, Yinghong, Michael, Scott F., Isern, Sharon
- Abstract / Description
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This study introduces a novel class of imidazolium- and ammonium-based ionic liquids possessing two C12 and C14 tails and thioether linkers designed for lipoplex-mediated DNA delivery. Imidazolium-based ionic liquids displayed efficient gene delivery properties with low toxicity. Thiol–yne click chemistry was employed for the facile and robust synthesis of these thioether-based cationic lipioids with enhanced lipophilicity and low fluidity.
- Date Issued
- 2017-07-04
- Identifier
- fgcu_ir_000525
- Format
- Citation
- Title
- Combustion and Energy Transfer Experiments.
- Creator
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Brown, David, Dubetz, Terry, Schmidt, Diane L., Gillman, Edward, Alberte, Randall, Egiebor, Nosa O., Beatty, Thomas, Isern, Sharon, Barreto, Jose
- Abstract / Description
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Core concepts can be integrated throughout lower-division science and engineering courses by using a series of related, cross-referenced laboratory experiments. Starting with butane combustion in chemistry, we expanded the underlying core concepts of energy transfer into laboratories designed for biology, physics, and engineering.
- Date Issued
- 2007-01-01
- Identifier
- fgcu_ir_000494
- Format
- Citation
- Title
- The campus ecosystem model.
- Creator
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Savarese, Michael, Tolley, Gregory, Everham, Edwin, McDonald, Michael
- Abstract / Description
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Interdisciplinary teaching, research experience, and active, collaborative strategies have all been identified as practices highly favorable to the learning process. By using the university campus as the focus for the study of the entire watershed within which it is situated, the Campus Ecosystem Model presents a context for incorporating these pedagogical elements into a useful framework for undergraduate science education.
- Date Issued
- 2002-03-01
- Identifier
- fgcu_ir_000970
- Format
- Citation
- Title
- Team Teaching “Gender Perspectives”: A Reflection on Feminist Pedagogyin the Interdisciplinary Classroom.
- Creator
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Rosenthal, Martha, Hayford, Michelle, Foote, Nicola, De Welde, Kristine
- Abstract / Description
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The article discusses the promises and hindrances of interdisciplinary feminist pedagogies and collaborative teaching through an integrative case study, as considered and implemented in a team-taught Gender Perspectives course delivered by the authors in 2009 and 2012. Topics mentioned include the theoretical supports and structure of the course, as well as the lessons learned, changes made, and their influence on the classroom environment..
- Date Issued
- 2013-01-01
- Identifier
- fgcu_ir_000464
- Format
- Citation
- Title
- A spectrophotometric determination of the energy of activation (Ea) for a complexation reaction: The kinetics of formation of Cr(III)/EDTA.
- Creator
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Brown, David, Dubetz, Terry, Alberte, Randall, Barreto, Jose, Kakareka, Joseph
- Abstract / Description
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For a first-order reaction, the integrated rate expression is ln [Rt]/[Ro] = –kt, where [Ro] and [Rt] represent reactant concentrations at time zero and any time, t, respectively. The formation of a purple complex by Cr(III) and EDTA closely adheres to first-order kinetics and, as the purple complex forms, the absorbance is easily measured over time. To study this reaction, we defined At as the product absorbance at any time, and Af as the final product absorbance. By experimentally...
Show moreFor a first-order reaction, the integrated rate expression is ln [Rt]/[Ro] = –kt, where [Ro] and [Rt] represent reactant concentrations at time zero and any time, t, respectively. The formation of a purple complex by Cr(III) and EDTA closely adheres to first-order kinetics and, as the purple complex forms, the absorbance is easily measured over time. To study this reaction, we defined At as the product absorbance at any time, and Af as the final product absorbance. By experimentally determining Af in advance and measuring At at any time during the reaction, the ratio At /Af reveals the extent of the reaction. The rate constant, k, can ultimately be determined from At /Af at various temperatures with a hand calculator. The thermodynamic parameter, Ea, and the kinetic parameter, A, are then obtained from an Arrhenius plot of ln k versus 1/T. The complexation of Cr(III) by EDTA has several important advantages in this thermodynamic and kinetic study. The stoichiometry between reactants and products is 1:1, the reaction can be driven to completion and is irreversible, the final product has a stable color, and the reactants are almost colorless using the concentrations described. The reaction has a marked temperature dependence that allows students to observe the effect of temperature on the rate constant. An introduction to Ea and A in the second semester of general chemistry is very important because it provides a foundation for later discussions of catalysis.
Show less - Date Issued
- 2005-05-23
- Identifier
- fgcu_ir_000493
- Format
- Citation
- Title
- Multiple Pedagogical Reforms Implemented in a University Science Class to Address Diverse Learning Styles.
- Creator
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Brown, David, Dubetz, Terry, Deiros, David, Ewald, Cynthia, Kakareka, Joseph, Barreto, Jose
- Abstract / Description
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In an attempt to increase student success in the physical sciences, Dubetz et al discuss on the implementing multiple education reforms in general chemistry courses in universities to reach diverse learning styles. The reforms includes on the course structure, administration of a diagnostic exam, course web site, group problem solving, weekly quizzes, homework problems, practice exams, guided-inquiry experiments, and supplemental instruction. The reforms implemented in General Chemistry I and...
Show moreIn an attempt to increase student success in the physical sciences, Dubetz et al discuss on the implementing multiple education reforms in general chemistry courses in universities to reach diverse learning styles. The reforms includes on the course structure, administration of a diagnostic exam, course web site, group problem solving, weekly quizzes, homework problems, practice exams, guided-inquiry experiments, and supplemental instruction. The reforms implemented in General Chemistry I and II result to a significant improvement in grades and decreased attrition rates with positive feedbacks from students that found all reforms useful.
Show less - Date Issued
- 2008-11-01
- Identifier
- fgcu_ir_000490
- Format
- Citation
- Title
- Methimazolium-based ionic liquid crystals: Emergence of mesomorphic properties via a sulfur motif.
- Creator
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McManus, Gregory, Nestor, Stephen T., Heinrich, Benoît, Sykora, Richard E., Douce, Laurent, Mirjafari, Arsalan, Zhang, Xiaofei
- Abstract / Description
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We describe the proficient synthesis and thermotropic mesomorphicity of thioether–functionalized imidazolium–type ionic liquids containing C12 and C18 chains associated with Br− and OTf− anions. The mesomorphic behavior and phase transition temperatures were studied by Polarizing Optical Microscopy (POM), Differential Scanning Calorimetry (DSC) and Small-Angle X-ray Scattering (SAXS). The ionic liquids with bromide anion display Smectic A lamellar phase giving homeotropic and fan-shaped...
Show moreWe describe the proficient synthesis and thermotropic mesomorphicity of thioether–functionalized imidazolium–type ionic liquids containing C12 and C18 chains associated with Br− and OTf− anions. The mesomorphic behavior and phase transition temperatures were studied by Polarizing Optical Microscopy (POM), Differential Scanning Calorimetry (DSC) and Small-Angle X-ray Scattering (SAXS). The ionic liquids with bromide anion display Smectic A lamellar phase giving homeotropic and fan-shaped textures. The layered crystallographic structure is reported by Single-Crystal XRD. The electrochemical characteristics of the ionic liquids with C18 side chain have been determined via Cyclic Voltammetry.
Show less - Date Issued
- 2017-08-01
- Identifier
- fgcu_ir_000508
- Format
- Citation
- Title
- Autocatalytic Synthesis of Bifluoride Ionic Liquids by SuFEx Click Chemistry.
- Creator
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McManus, Gregory, Hmissa, Taha, Dhumal, Nilesh R., Zhou, Zu, Nulwala, Hunaid B., Mirjafari, Arsalan, Zhang, Xiaofei
- Abstract / Description
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Ionic liquids with bifluoride anions possess properties such as high conductivity, wide electrochemical windows, and low viscosity that make them attractive materials for various electrochemical devices. However, owing to the lack of reliable synthetic routes, bifluoride‐based ionic liquids have seldom been explored. Herein, an autocatalytic strategy for the HF‐free synthesis of bifluoride‐based sulfonamide ionic liquids based on the sulfur(VI) fluoride exchange (SuFEx) reaction is reported....
Show moreIonic liquids with bifluoride anions possess properties such as high conductivity, wide electrochemical windows, and low viscosity that make them attractive materials for various electrochemical devices. However, owing to the lack of reliable synthetic routes, bifluoride‐based ionic liquids have seldom been explored. Herein, an autocatalytic strategy for the HF‐free synthesis of bifluoride‐based sulfonamide ionic liquids based on the sulfur(VI) fluoride exchange (SuFEx) reaction is reported. This reaction requires no chromatographic purification, and yields are quantitative. The thermophysical properties (phase transition behavior and decomposition temperature) and electrochemical stabilities of the resulting products were studied. The products with alkyl, aryl, and perfluoroalkyl side chains exhibited extraordinarily wide electrochemical windows (up to 6.0 V) with reproducible results among multiple replicate measurements.
Show less - Date Issued
- 2018-08-15
- Identifier
- fgcu_ir_000506
- Format
- Citation
- Title
- Carbon Sequestration and Sedimentation in Mangrove Swamps Influenced by Hydrogeomorphic Conditions and Urbanization in Southwest Florida.
- Creator
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Marchio, Daniel, Savarese, Michael, Bovard, Brian, Mitsch, William
- Abstract / Description
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This study compares carbon sequestration rates along two independent tidal mangrove creeks near Naples Bay in Southwest Florida, USA. One tidal creek is hydrologically disturbed due to upstream land use changes; the other is an undisturbed reference creek. Soil cores were collected in basin, fringe, and riverine hydrogeomorphic settings along each of the two tidal creeks and analyzed for bulk density, total organic carbon profiles, and sediment accretion. Radionuclides 137Cs and 210Pb were...
Show moreThis study compares carbon sequestration rates along two independent tidal mangrove creeks near Naples Bay in Southwest Florida, USA. One tidal creek is hydrologically disturbed due to upstream land use changes; the other is an undisturbed reference creek. Soil cores were collected in basin, fringe, and riverine hydrogeomorphic settings along each of the two tidal creeks and analyzed for bulk density, total organic carbon profiles, and sediment accretion. Radionuclides 137Cs and 210Pb were used to estimate recent sediment accretion and carbon sequestration rates. Carbon sequestration rates (mean ± standard error) for seven sites in the two tidal creeks on the Naples Bay (98 ± 12 g-C m−2·year−1 (n = 18)) are lower than published global means for mangrove wetlands, but consistent with other estimates from the same region. Mean carbon sequestration rates in the reference riverine setting were highest (162 ± 5 g-C m−2·year−1), followed by rates in the reference fringe and disturbed riverine settings (127 ± 6 and 125 ± 5 g-C m−2·year−1, respectively). The disturbed fringe sequestered 73 ± 10 g-C m−2·year−1, while rates within the basin settings were 50 ± 4 g-C m−2·year−1 and 47 ± 4 g-C m−2·year−1 for the reference and disturbed creeks, respectively. These data support our hypothesis that mangroves along a hydrologically disturbed tidal creek sequestered less carbon than did mangroves along an adjacent undisturbed reference creek.
Show less - Date Issued
- 2016-05-30
- Identifier
- 10.3390/f7060116, fgcu_ir_000086, http://www.mdpi.com/1999-4907/7/6/116
- Format
- Citation
- Title
- Intense Southwest Florida hurricane landfalls over the past 1000 years.
- Creator
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Savarese, Michael, Collins, Jennifer, Squiccimara, Louis, Ercolani, Christian, Muller, Joann
- Abstract / Description
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Recent research has proposed that human-induced sea surface temperature (SST) warming has led to an increase in the intensity of hurricanes over the past 30 years. However, this notion has been challenged on the basis that the instrumental record is too short and unreliable to reveal long-term trends in hurricane activity. This study addresses this limitation by investigating hurricane-induced overwash deposits (paleotempestites) behind a barrier island in Naples, FL, USA. Paleotempestologic...
Show moreRecent research has proposed that human-induced sea surface temperature (SST) warming has led to an increase in the intensity of hurricanes over the past 30 years. However, this notion has been challenged on the basis that the instrumental record is too short and unreliable to reveal long-term trends in hurricane activity. This study addresses this limitation by investigating hurricane-induced overwash deposits (paleotempestites) behind a barrier island in Naples, FL, USA. Paleotempestologic proxies including grain size, percent calcium carbonate, and fossil shells species were used to distinguish overwash events in two sediment cores spanning the last one thousand years. Two prominent paleotempestites were observed in the top 20 cm of both cores: the first identified as Hurricane Donna in 1960 whereas an older paleotempestite (1900–1930) could represent one of three documented storms in the early 1900s. An active period of hurricane overwash from 1000 to 500 yrs. BP and an inactive period from 500 to 150 yrs. BP correlate with reconstructed SSTs from the Main Development Region (MDR) of the North Atlantic Ocean. We observe an increased number of paleotempestites when MDR SSTs are warmer, coinciding with the Medieval Warm Period, and very few paleotempestites when MDR SSTs are cooler, coinciding with the Little Ice Age. Results from this initial Southwest Florida study indicate that MDR SSTs have been a key long-term climate driver of intense Southwest Florida hurricane strikes.
Show less - Date Issued
- 2015-10-15
- Identifier
- fgcu_ir_000965
- Format
- Citation
- Title
- Mechanistic Study of Broadly Neutralizing Human Monoclonal Antibodies against Dengue Virus That Target the Fusion Loop.
- Creator
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Costin, J. M., Zaitseva, E., Kahle, K. M., Nicholson, C. O., Rowe, D. K., Graham, A. S., Bazzone, L. E., Hogancamp, G., Figueroa Sierra, M., Fong, R. H., Yang, S.-T., Lin, L.,...
Show moreCostin, J. M., Zaitseva, E., Kahle, K. M., Nicholson, C. O., Rowe, D. K., Graham, A. S., Bazzone, L. E., Hogancamp, G., Figueroa Sierra, M., Fong, R. H., Yang, S.-T., Lin, L., Robinson, J. E., Doranz, B. J., Chernomordik, L. V., Michael, S. F., Schieffelin, J. S., Isern, S., Scott Michael
Show less - Abstract / Description
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There are no available vaccines for dengue, the most important mosquito-transmitted viral disease. Mechanistic studies with anti-dengue virus (DENV) human monoclonal antibodies (hMAbs) provide a rational approach to identify and characterize neu- tralizing epitopes on DENV structural proteins that can serve to inform vaccine strategies. Here, we report a class of hMAbs that is likely to be an important determinant in the human humoral response to DENV infection. In this study, we identified...
Show moreThere are no available vaccines for dengue, the most important mosquito-transmitted viral disease. Mechanistic studies with anti-dengue virus (DENV) human monoclonal antibodies (hMAbs) provide a rational approach to identify and characterize neu- tralizing epitopes on DENV structural proteins that can serve to inform vaccine strategies. Here, we report a class of hMAbs that is likely to be an important determinant in the human humoral response to DENV infection. In this study, we identified and characterized three broadly neutralizing anti-DENV hMAbs: 4.8A, D11C, and 1.6D. These antibodies were isolated from three different convalescent patients with distinct histories of DENV infection yet demonstrated remarkable similarities. All three hMAbs recognized the E glycoprotein with high affinity, neutralized all four serotypes of DENV, and mediated antibody-depen- dent enhancement of infection in Fc receptor-bearing cells at subneutralizing concentrations. The neutralization activities of these hMAbs correlated with a strong inhibition of virus-liposome and intracellular fusion, not virus-cell binding. We mapped epitopes of these antibodies to the highly conserved fusion loop region of E domain II. Mutations at fusion loop residues W101, L107, and/or G109 significantly reduced the binding of the hMAbs to E protein. The results show that hMAbs directed against the highly conserved E protein fusion loop block viral entry downstream of virus-cell binding by inhibiting E protein-mediated fusion. Characterization of hMAbs targeting this region may provide new insights into DENV vaccine and therapeutic strategies.
Show less - Date Issued
- 2013-01-01
- Identifier
- 10.1128/JVI.02273-12, fgcu_ir_000061, http://jvi.asm.org/cgi/doi/10.1128/JVI.02273-12
- Format
- Citation
- Title
- Click chemistry mediated synthesis of bio-inspired phosphonyl-functionalized ionic liquids.
- Creator
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Mirjafari, Arsalan, Braun, Richard A., Bradfield, Joseph L., Henderson, Codey B., Mobarrez, Niloufar, O'Brien, Richard A., Stenson, Alexandra C., Davis, James H., Sheng, Yinghong
- Abstract / Description
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This study focuses on the synthesis of a class of novel biologically-inspired ionic liquids coupled with a phosphonate group containing short to long side chains (C3–C11) via the Pudovic reaction. The ionic liquids exhibited very low glass transition temperatures and were hydrophobic in character. This method has the attributes of “click” chemistry with outstanding efficiency, simplicity, yields and regioselectivity. The results of their calcium(II) ligating capability are also presented.
- Date Issued
- 2014-11-26
- Identifier
- fgcu_ir_000527
- Format
- Citation
- Title
- Bifunctional hydrophobic ionic liquids: facile synthesis by thiol–ene “click” chemistry.
- Creator
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Mirjafari, Arsalan, Zayas, Manuel Sanchez, Gaitor, Jamie C., Nestor, Stephen T., Minkowicz, Samuel, Sheng, Yinghong
- Abstract / Description
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We describe the facile, robust and orthogonal fabrication of a structurally comprehensive library of hydrophobic trimethoxysilyl-functionalized ionic liquids with C7–C15 thioether spacer, using thiol–ene “click” chemistry. The synthesized ionic liquids displayed very low glass transition temperatures, high thermal stability and were hydrophobic in character. And the ability to serve as surface coating agents was tested by immobilizing them on the surface of iron oxide supermagnetic...
Show moreWe describe the facile, robust and orthogonal fabrication of a structurally comprehensive library of hydrophobic trimethoxysilyl-functionalized ionic liquids with C7–C15 thioether spacer, using thiol–ene “click” chemistry. The synthesized ionic liquids displayed very low glass transition temperatures, high thermal stability and were hydrophobic in character. And the ability to serve as surface coating agents was tested by immobilizing them on the surface of iron oxide supermagnetic nanoparticles and the organic loadings were quantified.
Show less - Date Issued
- 2015-12-18
- Identifier
- fgcu_ir_000526
- Format
- Citation
- Title
- Determining the Enthalpy, Free Energy, and Entropy for the Solubility of Salicylic Acid Using the van’t Hoff Equation: A Spectrophotometric Determination of Keq.
- Creator
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Brown, David, Dubetz, Terry, Barreto, Patricia D., Coates, Cristina M., Cobb, Allison, Barreto, Jose
- Abstract / Description
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The solubility of a substance can be defined as the equilibrium constant (Ks) between the crystalline and dissolved forms of a solute in a saturated solution. In this experiment, we have experimentally determined the equilibrium constant Ks, at different temperatures for the solvation of a saturated solution of salicylic acid in water. A Van’t Hoff plot of ln Ks versus 1/T reveals the enthalpy (DH°), and entropy, (DS°) of the reaction. The free energy (DG°) of the process can then be obtained...
Show moreThe solubility of a substance can be defined as the equilibrium constant (Ks) between the crystalline and dissolved forms of a solute in a saturated solution. In this experiment, we have experimentally determined the equilibrium constant Ks, at different temperatures for the solvation of a saturated solution of salicylic acid in water. A Van’t Hoff plot of ln Ks versus 1/T reveals the enthalpy (DH°), and entropy, (DS°) of the reaction. The free energy (DG°) of the process can then be obtained from DG° = DH°–TDS°. We suggest that the students gather the data by working collaboratively as a class, sharing the data by writing Ks and T on the board during the experiment. Our experimental design lends itself to rapid data collection and fosters a cooperative team approach in the laboratory, followed by immediate data sharing. A pattern quickly develops during the data-gathering phase and any aberrant data points can be discussed and dealt with by replication. There is minimal heat transfer during the solvation of salicylic acid; indeed, the joules of heat transferred are so small that the experiment would be very difficult to perform calorimetrically (an important lesson for the students to grasp). The experiment is rapid, simple to understand and safe. It makes a superior capstone laboratory at the end of General Chemistry II because it integrates several concepts in equilibrium and thermodynamics.
Show less - Date Issued
- 2007-02-01
- Identifier
- fgcu_ir_000491
- Format
- Citation
- Title
- A Simple Spectrophotometric Determination of an Equilibrium Constant That Does Not Require Any Measurementsof pH, Mass, Volume, Concentration, or Molar Absorptivity: The pKaof Methyl Red.
- Creator
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Brown, David, Dubetz, Terry, Barreto, Patricia D., Barreto, Jose
- Abstract / Description
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This laboratory exercise is intended for first-year chemistry students. It is designed to determine the pKa of Methyl Red with good precision and accuracy, while eliminating the need for pH meters, balances, pipets, or multiple buffer solutions. The experimental design is intended to encourage data sharing in class, requires only simple and rapid calculations, and will generate some thought provoking results about the relationship between pH and pKa.
- Date Issued
- 2007-09-14
- Identifier
- fgcu_ir_000492
- Format
- Citation
- Title
- The orientation of foliicolous lichen campylidia with respect to water runoff and its significance for propagule dispersal.
- Creator
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Sanders, William, Tokamov, Sherzod A., Papkov, Galen
- Abstract / Description
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Some common leaf-dwelling lichen fungi produce asexual spores (conidia) within curved, dorsiventral structures called campylidia. Their shape and tendency to face in the same direction have generated speculation about how dispersal is accomplished. Here we tested the hypothesis that campylidia orient their spore-producing surface against runoff currents and examined the eff ects of hydration to better understand the spore dispersal mechanism.
- Date Issued
- 2016-03-18
- Identifier
- fgcu_ir_000471
- Format
- Citation
- Title
- Studies on solubility and S-alkylation of 2-thiouracil in ionic liquids.
- Creator
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McManus, Gregory, Nestor, Stephen T., Hawkins, Allison N., Xhani, Xhensila, Sykora, Richard E., Nam, Kwangho, Mirjafari, Arsalan
- Abstract / Description
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Ionic liquids have been exploited to assist dissolution of poorly soluble (and poorly bioavailable) drugs, enhancing permeation through physiological barriers to deliver drugs to target sites. Herein, the solubility of 6-methyl-2-thiouracil – a common antithyroid drug, with low solubility in water and common organic solvents – was studied by employing six different imidazolium-based ionic liquids with variable anions. We demonstrate facile, regiospecific S-alkylation of 2-thiouracil with...
Show moreIonic liquids have been exploited to assist dissolution of poorly soluble (and poorly bioavailable) drugs, enhancing permeation through physiological barriers to deliver drugs to target sites. Herein, the solubility of 6-methyl-2-thiouracil – a common antithyroid drug, with low solubility in water and common organic solvents – was studied by employing six different imidazolium-based ionic liquids with variable anions. We demonstrate facile, regiospecific S-alkylation of 2-thiouracil with various lipophilic side chains in high yields (91–94%) and in the absence of catalysts. The reaction yields are correlated with the H-bond formation ability between the ILs' anions and the solute, indicating that the hydrogen bond is perhaps responsible for the high solubility of 2-thiouracil in [C2mim][OAc] and [C2mim][Cl].
Show less - Date Issued
- 2018-06-01
- Identifier
- fgcu_ir_000507
- Format
- Citation
