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- Title
- Studies on modern telecommunications planning: Technoeconomical considerations and environmental issues.
- Creator
- Baeza, Daniel Michael., Florida Atlantic University, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The research addressed and presented in this dissertation can be placed within the broad scope of telecommunications technoeconomics. The relevant efforts include the subject-matter of identifying the issues posed by emerging technologies, related revenue considerations and environmental issues in modern telecommunications practice specific to service providers' perspectives. The topic-wise problems studied and analyzed are as follows: (1) A comprehensive portrayal of managerial concerns and...
Show moreThe research addressed and presented in this dissertation can be placed within the broad scope of telecommunications technoeconomics. The relevant efforts include the subject-matter of identifying the issues posed by emerging technologies, related revenue considerations and environmental issues in modern telecommunications practice specific to service providers' perspectives. The topic-wise problems studied and analyzed are as follows: (1) A comprehensive portrayal of managerial concerns and considerations on the technoeconomical perspectives vis-a-vis modern telecommunications; (2) Relevant analytical studies pertinent to: (1) "Greenfield starts" in a fresh, telecommunications deployment in a virgin service zone; (2) Embedded architectures; (3) Technology enhancements; (4) Environmental issues. The greenfield effort is analyzed to portray the feasibility of achieving technoeconomically optimal alternative designs. The embedded architecture refers to the prevailing infrastructure and their optimal usage is indicated via an arbitrated traffic-sharing technique. Concerning technology enhancements, "all-optical" technology is indicated as the ultimate goal. However, in the interim period, the optimal use of transitory technology such xDSL, MPLS, and others, is suggested and studied. Lastly, the environmental implications that coexist with technoeconomical impacts on modern telecommunications deployment are analyzed.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12655
- Subject Headings
- Telecommunication systems--Management, Engineering economy, Telecommunication systems--Environmental aspects
- Format
- Document (PDF)
- Title
- Studies on nonlinear activity and cross-entropy considerations in neural networks.
- Creator
- Abusalah, Salahalddin Tawfiq., Florida Atlantic University, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The objectives of this research as deliberated in this dissertation are two-folded: (i) To study the nonlinear activity in the neural complex (real and artificial) and (ii) to analyze the learning processe(s) pertinent to an artificial neural network in the information-theoretic plane using cross-entropy error-metrics. The research efforts envisaged enclave the following specific tasks: (i) Obtaining a general solution for the Bernoulli-Riccati equation to represent a single parameter family...
Show moreThe objectives of this research as deliberated in this dissertation are two-folded: (i) To study the nonlinear activity in the neural complex (real and artificial) and (ii) to analyze the learning processe(s) pertinent to an artificial neural network in the information-theoretic plane using cross-entropy error-metrics. The research efforts envisaged enclave the following specific tasks: (i) Obtaining a general solution for the Bernoulli-Riccati equation to represent a single parameter family of S-shaped (sigmoidal) curves depicting the nonlinear activity in the neural network. (ii) Analysis of the logistic growth of output versus input values in the neural complex (real and artificial) under the consideration that the boundaries of the sets constituting the input and output entities are crisp and/or fuzzy. (iii) Construction of a set of cross-entropy error-metrics (known as Csiszar's measures) deduced in terms of the parameters pertinent to a perceptron topology and elucidation of their relative effectiveness in training the network optimally towards convergence. (iv) Presenting the methods of symmetrizing and balancing the aforesaid error-entropy measures (in the information-theoretic plane) so as to make them usable as error-metrics in the test domain. (v) Description and analysis of the dynamics of neural learning process in the information-theoretic plane for both crisp and fuzzy attributes of input values. Relevant to these topics portraying the studies on nonlinear activity and cross-entropy considerations vis-a-vis neural networks, newer and/or exploratory inferences are made, logical conclusions are enumerated and relative discussions are presented along with the scope for future research to be pursued.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/12447
- Subject Headings
- Neural networks (Computer science), Entropy (Information theory), Nonlinear control theory
- Format
- Document (PDF)
- Title
- Studies on performance aspects of smart wireless devices and related network services.
- Creator
- Noori, Aziz Ulhaq, Neelakanta, Perambur S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This study is a focused effort on elucidating the performance aspects of modern, handheld wireless devices and associated mobile network services. Specifically addressed thereof are: (i) Assessing the performance details on certain hardware sections of smart handheld devices and (ii) determining the performance profile of market penetration considerations vis-à-vis provisioning mobile networks. To meet the scope of this research, the projected efforts are exercised in compiling relevant...
Show moreThis study is a focused effort on elucidating the performance aspects of modern, handheld wireless devices and associated mobile network services. Specifically addressed thereof are: (i) Assessing the performance details on certain hardware sections of smart handheld devices and (ii) determining the performance profile of market penetration considerations vis-à-vis provisioning mobile networks. To meet the scope of this research, the projected efforts are exercised in compiling relevant literature and deciding the said hardware and technoeconomic performance issues. Hence, written in two parts, Part A is devoted to hardware performance details of smart, handheld devices relevant to (a) delay issues in PCB layouts; (b) crosstalk problems at the baseband level (audio/multimedia) using EMI concepts and (c) ascertaining non-catastrophic EMP/EMI effects at the RF-sections so as to implement protection strategies via compensating networks. Part B is concerned with the technoeconomics of wireless networks in supporting mobile (handheld devices). Correspondingly, two market related considerations versus service performance details are considered. The first one refers to deducing a relative performance index that includes technology (mobile speed) details plus economics profiles of the users in the service area. The second task refers to elucidating a performance index of such services in terms of hedonic pricing heuristics. The theoretical aspects of the test studies as above are supplemented with experimental and/or simulation details as appropriate. Hence, the efficacy of performance details are discussed in real-world applications. Lastly, possible research items for future studies are identified as open-questions.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004395, http://purl.flvc.org/fau/fd/FA00004395
- Subject Headings
- Mobile communication systems -- Standards, Network performance (Telecommunications), Smartphones, Technoeconomcs, Wireless communication systems -- Technological innovations
- Format
- Document (PDF)
- Title
- STUDIES ON POLYETHYLENE GLYCOL-MEDIATED AGGREGATION AND FUSION OF AVIAN ERYTHROCYTES.
- Creator
- BATCHELOR, ROGER ALLEN., Florida Atlantic University
- Abstract/Description
-
Polyethylene glycol (PEG)-induced aggregation, hemolysis and fusion of chicken red blood ceils (CRBC's) was studied in relation to the following parameters: osmotic pressure, polymer concentration, ionic strength, electrolyte species, surface charge removal and glutaraldehyde fixation. Indirect evidence indicated that osmotic pressure does not play a primary role in aggregation and fusion of red blood cells. Maximum aggregation and fusion was obtained in solutions of 20 and 40% PEG,...
Show morePolyethylene glycol (PEG)-induced aggregation, hemolysis and fusion of chicken red blood ceils (CRBC's) was studied in relation to the following parameters: osmotic pressure, polymer concentration, ionic strength, electrolyte species, surface charge removal and glutaraldehyde fixation. Indirect evidence indicated that osmotic pressure does not play a primary role in aggregation and fusion of red blood cells. Maximum aggregation and fusion was obtained in solutions of 20 and 40% PEG, respectively. In contrast, hemolysis increased almost linearily with PEG concentration. The negative electrostatic charge due to the presence of sialic acid on the membrane surface was found to be the primary factor affecting aggregation, hemolysis and fusion. Removal of the charge by neuraminidase or screening with cations enhanced aggregation and fusion while inhibiting hemolysis. The inhibition of aggregation by glutaraldehyde fixation, and hemolysis and fusion results not attributed to surface charges, are discussed in terms of intramembrane interactions with PEG.
Show less - Date Issued
- 1977
- PURL
- http://purl.flvc.org/fcla/dt/13893
- Subject Headings
- Cell hybridization, Erythrocytes, Hemolysis and hemolysins, Membrane fusion
- Format
- Document (PDF)
- Title
- Studies on Stochastic Multi-user Scheduling in Wireless Communication.
- Creator
- Wang, Di, Morgera, Salvatore D., Wang, Xin, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
We developed a cross layer design which combines retransmission diversity and multi-user diversity for wireless communication. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is outlined. This design is applied to devise multi-user scheduling schemes, which can optimally capture the available multi-user and retransmission diversities. In addition, the proposed on-line scheduling algorithms can operate even when the...
Show moreWe developed a cross layer design which combines retransmission diversity and multi-user diversity for wireless communication. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is outlined. This design is applied to devise multi-user scheduling schemes, which can optimally capture the available multi-user and retransmission diversities. In addition, the proposed on-line scheduling algorithms can operate even when the underl ying fading channel distribution is unknown, while asymptotically converging to the offline benchmark with guarantees on prescribed fairness and rate requirements. Numerical results are provided to verify the merits of our novel schemes for multi-user transmissions over Nakagami block fading channels.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00012568
- Subject Headings
- Stochastic processes--Data processing, Wireless communication systems, Computer network protocols, Code division multiple access, Modulation (Electronics), Signal processing--Digital techniques
- Format
- Document (PDF)
- Title
- Studies on stomatopod Crustacea from the Indian River region of Florida. II. An annotated check list of the mantis shrimps of the central eastern Florida coast.
- Creator
- Gore, R. H., Becker, L. J., Harbor Branch Oceanographic Institute
- Date Issued
- 1976
- PURL
- http://purl.flvc.org/FCLA/DT/3325504
- Subject Headings
- Stomatopoda--Congresses, Shrimps--Florida, Indian River (Fla. : Lagoon)
- Format
- Document (PDF)
- Title
- Studies on stomatopod Crustacea of the Indian River region of Florida. I. Rediscovery and extension of range of Heterosquilla armata (Smith, 1881).
- Creator
- Gore, R. H., Becker, L. J., Harbor Branch Oceanographic Institute
- Date Issued
- 1975
- PURL
- http://purl.flvc.org/FCLA/DT/3321192
- Subject Headings
- Stomatopoda, Lysiosquillidae, Crustacea--Florida, Shrimps
- Format
- Document (PDF)
- Title
- Studies on the base-promoted conversion of conjugated alkynyl esters to alpha-substituted alpha-allenyl esters.
- Creator
- He, Yuanjun, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
-
We report here the development of an efficient method for the conversion of a variety of conjugated alkynyl esters to alpha-substituted conjugated allenyl esters (racemic) through the use of strong amide bases. Substantially improved yields over typical enolate formation conditions were observed with the use of two equivalents of lithium diisopropylamide. Trapping studies indicate that the second equivalent of base likely leads to the dianion intermediate which upon addition of methyl iodide...
Show moreWe report here the development of an efficient method for the conversion of a variety of conjugated alkynyl esters to alpha-substituted conjugated allenyl esters (racemic) through the use of strong amide bases. Substantially improved yields over typical enolate formation conditions were observed with the use of two equivalents of lithium diisopropylamide. Trapping studies indicate that the second equivalent of base likely leads to the dianion intermediate which upon addition of methyl iodide and trimethylsilyl chloride gives mixtures of alpha-substituted conjugated allenyl and beta,gamma-alkynyl deconjugated esters. Further optimization revealed that additive salts such as LiCl lead primarily to the allenyl product while the use of HMPA as a cosolvent gives the beta,gamma-alkynyl deconjugated alkylation product. The role of base, base concentration and electrophile on product yield and selectivity is also discussed. The optimized conditions resulting from our study of this reaction establishes this method as a viable synthetic tool for the production of alpha-substituted allenyl esters. A new method to prepare racemic alpha-tributylstannyl-alpha-allenyl esters from precursor conjugated alkynyl esters in good yields is reported. Key features of the optimized reaction conditions include the use of multiple equiv. of lithium diisopropylamide in THF with LiCl as a key additive. The allenyl tin reagent reacts with aldehydes in the presence of Lewis acid to give homopropargyl alcohol or allenyl alcohol products depending on the reaction conditions. The addition of boron trifluoride etherate to a solution of the allenyltin and aldehyde gives the homopropargyl alcohol. However, allenyl alcohol products are obtained exclusively with the addition of tin tetrachloride to the allenyl stannane rapidly followed by the addition of aldehyde. The effect of other Lewis acids and reaction variables such as solvent and temperature on the yield and relative stereochemistry of the products will also be described. The Mitsunobu coupling reaction of sterically hindered phenols and alcohols is greatly accelerated by the use of high reaction concentration in combination with sonication. The rate acceleration effect observed with our protocol may simply be based on the high concentration with the sonic waves providing efficient mixing of the highly viscous reaction mixture and generating localized hot spots, or in part, the result of an enhancement of a radical reaction pathway.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/12120
- Subject Headings
- Chemistry, Organic
- Format
- Document (PDF)
- Title
- Studies on the fauna of Curacao and other Caribbean Islands: No. 213. Observations on the light-inhibited activity cycle and feeding behavior of the hydromedusa Olindias tenuis.
- Creator
- Larson, R. J., Harbor Branch Oceanographic Institute
- Date Issued
- 1986
- PURL
- http://purl.flvc.org/FCLA/DT/3352197
- Subject Headings
- Hydromedusa, Medusae, Hydrozoa--Caribbean Sea, Olindiadidae, Feeding Behavior
- Format
- Document (PDF)
- Title
- Studies on the mechanism by which sulindac sensitizes cancer cells to oxidative stress.
- Creator
- Kreymerman, Alexander, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Sulindac is a known NSAID that has also been shown to have anti-cancer activity that is not related to its ability to inhibit COX 1 and 2. During the past 15 years there have been a large number of studies attempting to elucidate its mechanism of action. Our laboratory has shown that sulindac can both protect normal cells and enhance the killing of cancer cells under oxidative stress from H2O2 and TBHP. However, except for mitochondrial dysfunction and ROS production, the mechanism by which...
Show moreSulindac is a known NSAID that has also been shown to have anti-cancer activity that is not related to its ability to inhibit COX 1 and 2. During the past 15 years there have been a large number of studies attempting to elucidate its mechanism of action. Our laboratory has shown that sulindac can both protect normal cells and enhance the killing of cancer cells under oxidative stress from H2O2 and TBHP. However, except for mitochondrial dysfunction and ROS production, the mechanism by which sulindac sensitized the cancer cells to oxidative stress remains unknown. Results of this research project suggest that the effect of sulindac and oxidative stress not only involves mitochondrial ROS production, but also aspects of the preconditioning response. In normal cells this leads to survival by a preconditioning pathway, likely involving PKCε. . However, cancer cells react by initiating a pathway leading to apoptosis involving PKCδ.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3183124
- Subject Headings
- Proteins, Chemical modification, Cellular signal transduction, Biochemical markers, Diagnostic use, Drug resistance in cancer cells, Oxidation-reduction reaction
- Format
- Document (PDF)
- Title
- Studies on the outdoor cultivation of Ulva lactuca L.
- Creator
- DeBusk, T. A., Blakeslee, M., Ryther, John H., Harbor Branch Oceanographic Institute
- Date Issued
- 1986
- PURL
- http://purl.flvc.org/fau/fd/FA00007023
- Subject Headings
- Ulva, Chlorophyta, Green algae--Growth, Algae culture
- Format
- Document (PDF)
- Title
- Studies on the performance of reticles used in passive homing system.
- Creator
- Hoque, Md Monirul., Florida Atlantic University, Neelakanta, Perambur S.
- Abstract/Description
-
Most infrared based target-seeking systems operate as passive detectors of the target with no energy being required to be transmitted from the seeker in order to detect a target. Reticles are used commonly in these passive homing seekers to modulate the incoming radiation from the target. Since signals are invariably corrupted by noise, the analysis of signal-to-noise characteristics of a passive homing system is crucial in elucidating its performance towards successful homing on the target....
Show moreMost infrared based target-seeking systems operate as passive detectors of the target with no energy being required to be transmitted from the seeker in order to detect a target. Reticles are used commonly in these passive homing seekers to modulate the incoming radiation from the target. Since signals are invariably corrupted by noise, the analysis of signal-to-noise characteristics of a passive homing system is crucial in elucidating its performance towards successful homing on the target. The objective of this thesis refers to the analysis of a passive homing system which employs a frequency modulated reticle. Studies pertinent to the feasibility aspect of using electrochromic, nonmoving reticles also constitute a part of the present study. In essence, the effort addressed in this work are concerned with the performance analysis and feasibilities considerations in using nonmoving reticles in passive homing systems in lieu of conventional rotating reticles.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/15138
- Subject Headings
- Reticles, Guided missiles--Guidance systems, Signal processing, Infrared radiation
- Format
- Document (PDF)
- Title
- Studies on the role of vitamin D in asthma patients from a South Florida pulmonary practice.
- Creator
- Munim, Amjad., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Vitamin D insufficiency/deficiency is widespread in asthma, and epidemiological studies point to an association between low serum 25-hydroxyvitamin D level and poor asthma control and increased severity. In humans. Vitamin D is principally derived from sunlight induced cutaneous conversion of 7-dehydrocholesterol to vitamin D and oral supplementation. We sought to determine if established and chronic-persistent adult asthma patients from a South-Florida pulmonary patient population, with...
Show moreVitamin D insufficiency/deficiency is widespread in asthma, and epidemiological studies point to an association between low serum 25-hydroxyvitamin D level and poor asthma control and increased severity. In humans. Vitamin D is principally derived from sunlight induced cutaneous conversion of 7-dehydrocholesterol to vitamin D and oral supplementation. We sought to determine if established and chronic-persistent adult asthma patients from a South-Florida pulmonary patient population, with abundant sunshine availability and oral vitamin D supplementation exhibit vitamin D insufficiency/deficiency. A trend to vitamin D insufficiency was observed in approximately 65% of both adult asthma patients and apparently healthy (non-asthmatic) volunteers. . The transcription factors required for Th9 conversion, PU.1 and IRF-4, were down-regulated by vitamin D. The generation of Th9 cells was inhibited equally by vitamin D and dexamethasone when used alone, but the effect was additive when both steroids were used in combination. Our studies using non-specifically stimulated cells were extended by analyzing the effect of vitamin D on allergen specific stimulation. The response of CD4+ T cells obtained from the blood of house dust mite positive asthmatics was studied. House dust mite allergen elicited a classical Th2 phenotype response (IL-4, IL-5, IL-9, and IL-13 cytokine profile) and vitamin D effectively inhibited those key Th2 cytokines. We conclude that vitamin D appears to be of significant clinical benefit in our cohort of patients, i.e., established chronic adult human asthma, by down-regulating key immune cells including Th9, Th17, and Th2 involved in this disorder.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3360948
- Subject Headings
- Vitamin D, Health aspects, Vitamin D, Physiological effect, Vitamin D, Therapeutic use, Vitamin D, Physiology, Vitamin D in human nutrition, Lungs, Etiology
- Format
- Document (PDF)
- Title
- Studies on traffic characteristics in asynchronous transfer mode telecommunications.
- Creator
- Abeygunawardana, Sumudi Man., Florida Atlantic University, Neelakanta, Perambur S., Hsu, Sam
- Abstract/Description
-
This thesis is concerned with an outline survey on the modern aspects of asynchronous transmission mode (ATM) telecommunication; also considered are certain specific issues such as the performance characteristics of ATM-based telecommunication networks under fluctuating workloads. Estimation of the stochasticity of the jitter associated with the cell-delay arising out of buffering within the network as well as due to signal-to-noise considerations which induce bit-errors and eventually lead...
Show moreThis thesis is concerned with an outline survey on the modern aspects of asynchronous transmission mode (ATM) telecommunication; also considered are certain specific issues such as the performance characteristics of ATM-based telecommunication networks under fluctuating workloads. Estimation of the stochasticity of the jitter associated with the cell-delay arising out of buffering within the network as well as due to signal-to-noise considerations which induce bit-errors and eventually lead to cell-losses manifesting as delay(s) in the cells being transmitted, is also addressed as a part of this thesis efforts. Relevant theoretical models are proposed, algorithms are developed and simulations are done on the above considerations. Based on these efforts, inferential conclusions are drawn and discussed. Scope for future research and developments towards engineering design of softwares suitable for practical applications by ATM networking planners and traffic forecasters is indicated. Merits and shortcomings of the models are proposed and algorithmic approaches pursued in the present study are also specified with relevant discussions.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15247
- Subject Headings
- Asynchronous transfer mode, Telecommunication--Traffic, Telematics
- Format
- Document (PDF)
- Title
- Studies on transreceive diversity schemes (including "polarization-sense" antenna diversity) for wireless communication systems.
- Creator
- Preedalumpabut, Wichean., Florida Atlantic University, Neelakanta, Perambur S., Morgera, Salvatore D., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The research addressed in this study and deliberated in the dissertation is broadly tied to finding hybrid methods of diversity compatible for modern wireless applications. The hybrid strategy advocated thereof involves a combined use of space- (antenna and polarization), frequency-, and time-diversity schemes in a judicious manner so as to realize a desirable BER versus Eb/No performance across RF links that face multipath and other unwanted EM artifacts. The underlying reason for the hybrid...
Show moreThe research addressed in this study and deliberated in the dissertation is broadly tied to finding hybrid methods of diversity compatible for modern wireless applications. The hybrid strategy advocated thereof involves a combined use of space- (antenna and polarization), frequency-, and time-diversity schemes in a judicious manner so as to realize a desirable BER versus Eb/No performance across RF links that face multipath and other unwanted EM artifacts. The underlying reason for the hybrid scheme as above is to replace multiple-antenna based transreceive diversity. Such multiple antennas would otherwise require large base station real estate and may not be compatible for hand-held (space-constrained) RF units. On the contrary, use of hybrid schemes would restrict multiple number of antennas and conserves the space. After analyzing a set of plausible techniques of hybrid diversity compatible for modern wireless techniques, a focused study has been done on polarization-sense (PS) antenna diversity scheme. Its fruitful application for indoor systems (like Bluetooth(TM)/ZigBee(TM)) against multipath effects is demonstrated via simulation and experimental studies. Further, the PS-antenna diversity is shown to offer improved BER versus Eb/N o performance in pilot channels used in CDMA2000 systems. Also, such PS-diversity is shown to help improving the GPS receiver performance under RFI/jamming environment. The technique and heuristics proposed towards the PS-antenna diversity scheme imply novel and hitherto unexplored efforts in wireless communications. Lastly the dissertation concludes summarizing the results and offers open-questions for further studies.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/12104
- Subject Headings
- Wireless communication systems, Antennas (Electronics)
- Format
- Document (PDF)
- Title
- Studies towards a catalytic asymmetric isomerization of manganese complexed alkynes to allenes using chiral bases.
- Creator
- He, Chang., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
-
The conversion of alkynyl carbonyls to allenyl carbonyls via manganese mediated coordination followed by a base-catalyzed isomerization was carried out using a range of chiral and achiral amine bases. Chiral amidine and chiral DBU derivatives were synthesized to carry out the isomerization enantioselectively. We employed HPLC equipped with a chiral column to determine the enantiomeric excess. We also proved that the mechanism of that the manganese-coordinated alkyne/allene rearrangement...
Show moreThe conversion of alkynyl carbonyls to allenyl carbonyls via manganese mediated coordination followed by a base-catalyzed isomerization was carried out using a range of chiral and achiral amine bases. Chiral amidine and chiral DBU derivatives were synthesized to carry out the isomerization enantioselectively. We employed HPLC equipped with a chiral column to determine the enantiomeric excess. We also proved that the mechanism of that the manganese-coordinated alkyne/allene rearrangement reaction involved an intermediate cumenolate. It was also confirmed that amine base with pKa lower than that of DBU (pKa = 13.6) would not carry out the isomerization. Alkoxy base were also used in isomerization and the mechanism was also investigated.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/192983
- Subject Headings
- Enzyme kinetics, Organometallic compounds, Synthesis, Asymmetric synthesis, Methathesis (Chemistry), Carbonyl compounds, Synthesis
- Format
- Document (PDF)
- Title
- Studies Towards Synthesis of Paraconic Acids.
- Creator
- Soto, Karenia, Dragojlovic, Veljko
- Abstract/Description
-
FAU's Office of Undergraduate Research and Inquiry hosts an annual symposium where students engaged in undergraduate research may present their findings either through a poster presentation or an oral presentation.
- Date Issued
- 2011
- PURL
- http://purl.flvc.org/fau/fd/FA00005450
- Format
- Document (PDF)
- Title
- Studies towards synthesis of paraconic acids.
- Creator
- Soto, Karenia, Dragojlovic, Veljko, Harriet L. Wilkes Honors College, Florida Atlantic University
- Abstract/Description
-
Paraconic acids are naturally occurring compounds synthesized by bacteria and fungi. They are known for having antitumor and antibiotic properties. By use of a phasevanishing (PV) halolactonization with PTFE (Teflon) as a phase screen, we were able to synthesize precursors to these compounds. The PV-PTFE halolactonization of alkenoic acids with iodine monochloride gave the corresponding iodolactones, while halolactonization with bromine gave the corresponding bromolactone. Halolactonization...
Show moreParaconic acids are naturally occurring compounds synthesized by bacteria and fungi. They are known for having antitumor and antibiotic properties. By use of a phasevanishing (PV) halolactonization with PTFE (Teflon) as a phase screen, we were able to synthesize precursors to these compounds. The PV-PTFE halolactonization of alkenoic acids with iodine monochloride gave the corresponding iodolactones, while halolactonization with bromine gave the corresponding bromolactone. Halolactonization of 4-pentenoic acid with water as a solvent also gave good results. Future experiments will explore the synthesis of further precursors by means of a photolytic carbonylation of iodolactone and a phenylation-ruthenium tetroxide oxidation sequence.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/fau/fd/FA00003607
- Format
- Document (PDF)
- Title
- Studies towards the synthesis of Cephalostatin 1.
- Creator
- Wu, Mao, Florida Atlantic University, Kerr, Russell G.
- Abstract/Description
-
Cephalostatin 1 has been isolated from the colonial marine worm Cephalodiscus gilchristi (Phylum Hemichordata) in the Indian Ocean. It has shown biomedical potential in preclinical trials as a cell growth inhibitor, active against U. S. murine P388 lymphocyte leukemia ED5010^-7-10^-9 μ/ml and a potent growth inhibitor against solid tumor types. Our research is focusing on developing methodology to produce disteroidal pyrazine and the introduction of delta 14, 15 unsaturation and C-16 hydroxyl...
Show moreCephalostatin 1 has been isolated from the colonial marine worm Cephalodiscus gilchristi (Phylum Hemichordata) in the Indian Ocean. It has shown biomedical potential in preclinical trials as a cell growth inhibitor, active against U. S. murine P388 lymphocyte leukemia ED5010^-7-10^-9 μ/ml and a potent growth inhibitor against solid tumor types. Our research is focusing on developing methodology to produce disteroidal pyrazine and the introduction of delta 14, 15 unsaturation and C-16 hydroxyl groups in Cephalostatin 1A. The synthetic intermediates may be useful for biosynthetic studies and also analogues can be used to study structure-activity relationships.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/15169
- Subject Headings
- Bioactive compounds, Pharmaceutical chemistry, Cancer--Research, Pyridazines
- Format
- Document (PDF)
- Title
- Study abroad in Grenoble, France.
- Creator
- Selby, Megan
- Date Issued
- 2005-06
- PURL
- http://purl.flvc.org/fcla/dt/11559
- Subject Headings
- Expeditionary Learning Outward Bound, Foreign study, Education--Florida, Students--Travel--Europe
- Format
- Document (PDF)