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2007

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Articles 6481 - 6510 of 6763

Full-Text Articles in Physical Sciences and Mathematics

Acoustic Measurement And Modeling Of Waves In Estuarine And Coastal Environments, Justin P. Vandever Jan 2007

Acoustic Measurement And Modeling Of Waves In Estuarine And Coastal Environments, Justin P. Vandever

Dissertations, Theses, and Masters Projects

No abstract provided.

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The Maine Woods: A Legacy Of Controversy, Richard W. Judd Jan 2007

The Maine Woods: A Legacy Of Controversy, Richard W. Judd

Maine Policy Review

In the Margaret Chase Smith Essay, Richard Judd reflects on the history of Maine’s North Woods. He discusses the divergent interests with a stake on the North Woods over the centuries, but notes that there has been a long-standing interest in conservation and in the heritage represented by this vast region.

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Are The Economics Of A Sustainable Maine Forest Sustainable?, Mike Levert, Charles S. Colgan, Charles Lawton Jan 2007

Are The Economics Of A Sustainable Maine Forest Sustainable?, Mike Levert, Charles S. Colgan, Charles Lawton

Maine Policy Review

Mike LeVert, Charles Colgan and Charles Lawton discuss the transformation of the economic environment of Maine’s forests over the past two decades. Paper companies have sold most of their holdings; residential and conservation demand for land has increased; forestland prices have skyrocketed; and new classes of landowners have different strategies, objectives, and time horizons than the old industrial landowners. The authors believe that management of Maine’s forests must now address changes in the economic environment with the same intensity as threats such as the spruce budworm were addressed if we are to keep Maine’s forests as forests.

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Forging A Common Vision For Maine’S North Woods, Robert J. Lilieholm Jan 2007

Forging A Common Vision For Maine’S North Woods, Robert J. Lilieholm

Maine Policy Review

Robert Lilieholm takes stock of the challenges and opportunities facing Maine’s North Woods, the largest undeveloped forested block in the eastern United States. In the face of changing ownership patterns and development pressures, there is lively debate over current land use policies and trends. Lilieholm suggests that a broader, regional vision for the North Woods might better serve the long-term interests of both the area’s forests and its struggling communities.

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Seeing The Forest For The Trees: The Future Of Timber Investing In The North Woods -- A Conversation With Clark S. Binkley, Peter Howell Jan 2007

Seeing The Forest For The Trees: The Future Of Timber Investing In The North Woods -- A Conversation With Clark S. Binkley, Peter Howell

Maine Policy Review

In this conversation with Peter Howell, Clark Binkley draws on his long-term experience as a timberland investment manager to give his analysis of and forecast for timber markets and timber investing in the Northern Forest. While he is not optimistic about the current prospects for such investments, he does believe that there are some opportunities in conservation easements, residential development, and possibly biofuels and carbon credits.

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From Diamond International To Plum Creek: The Era Of Large Landscape Conservation In The Northern Forest, Sara A. Clark, Peter Howell Jan 2007

From Diamond International To Plum Creek: The Era Of Large Landscape Conservation In The Northern Forest, Sara A. Clark, Peter Howell

Maine Policy Review

The last two decades have seen dramatic, unprecedented growth in conservation lands in the Northern Forest, stretching from upstate New York through Maine. The conservation community, in coordination with public agencies, has been able to take advantage of changing forest ownership structure and a significant expansion of public and private funding to support this increase in protected lands. As Sara Clark and Peter Howell discuss, Maine has been a laboratory for some of the largest and most innovative land transactions. Maine is unique in having land conservation strategies focused almost entirely on permanent protection of privately owned land rather than …

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Ecotourism Potential In Maine’S North Woods: A Roundtable Commentary, Ann Czerwonka Jan 2007

Ecotourism Potential In Maine’S North Woods: A Roundtable Commentary, Ann Czerwonka

Maine Policy Review

No abstract provided.

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First Cross-Correlation Analysis Of Interferometric And Resonant-Bar Gravitational-Wave Data For Stochastic Backgrounds, B. P. Abbott, R. Abbott, Mario C. Diaz, R. Grosso, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres Jan 2007

First Cross-Correlation Analysis Of Interferometric And Resonant-Bar Gravitational-Wave Data For Stochastic Backgrounds, B. P. Abbott, R. Abbott, Mario C. Diaz, R. Grosso, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

Data from the LIGO Livingston interferometer and the ALLEGRO resonant-bar detector, taken during LIGO’s fourth science run, were examined for cross correlations indicative of a stochastic gravitational-wave background in the frequency range 850–950 Hz, with most of the sensitivity arising between 905 and 925 Hz. ALLEGRO was operated in three different orientations during the experiment to modulate the relative sign of gravitational-wave and environmental correlations. No statistically significant correlations were seen in any of the orientations, and the results were used to set a Bayesian 90% confidence level upper limit of Ωgw(f)≤1.02, which corresponds to a gravitational-wave strain at 915 …

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Outlet Glacier Dynamics In East Greenland And East Antarctica, Leigh Asher Stearns Jan 2007

Outlet Glacier Dynamics In East Greenland And East Antarctica, Leigh Asher Stearns

Electronic Theses and Dissertations

Ice mass from the interior of Greenland and Antarctica is transported to the ocean by numerous large, fast-flowing outlet glaciers. Changes in the flow configuration of these outlet glaciers modulate ice sheet mass balance and sea level. Several recent studies have highlighted rapid increases in glacier speed in both Greenland and Antarctica, implying that the near-term contribution to sea level from ice sheets is under-estimated by current models. Here, the mass balance and force budget of several large outlet glaciers in East Greenland and East Antarctica are investigated using remote-sensing and field-based measurements. Recent estimates show that Greenland’s contribution to …

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Fundamental Frequency Of Clamped Plates With Circularly Periodic Boundaries, Huseyin Yuce, Chang Y. Wang Jan 2007

Fundamental Frequency Of Clamped Plates With Circularly Periodic Boundaries, Huseyin Yuce, Chang Y. Wang

Publications and Research

A boundary perturbation method is developed to determine the fundamental frequency of vibrating plates. The method is then applied to wavy, star shape and polygonal plates with clamped boundary conditions. Approximate analytical solutions of the fundamental frequency are obtained with an accuracy of O(e^4), where e is the deviation from the unit circle.

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Investigation Of Phospholipid Tubule Morphology For Use In Drug Delivery, Colleen Colson Garrett Jan 2007

Investigation Of Phospholipid Tubule Morphology For Use In Drug Delivery, Colleen Colson Garrett

LSU Doctoral Dissertations

Spherical vesicles consisting of phosphatidylcholines in which diacetylene groups have been inserted in the hydrocarbon tail centers give rise to hollow cylindrical tubes, known as “tubules”. The study of tubules has become an area of intense interest in recent years due to their unusual morphology, which raises several profound theoretical issues and suggests their use in a variety of applications. Tubule hollowness suggests medical and industrial encapsulations as well as filtration and purification applications. These potential uses, e.g., for drug and gene delivery, requires optimization of their morphology for the application. Tubules have many technologically desirable properties, such as a …

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Elementary Reactions Involved In Pollutant-Forming Mechanisms, Cheri Ann Mcferrin Jan 2007

Elementary Reactions Involved In Pollutant-Forming Mechanisms, Cheri Ann Mcferrin

LSU Doctoral Dissertations

The reactions of the hydroxyl radical (OH) with molecular chlorine (Reaction 1), methane (Reaction 2), and propane (Reaction 3) have been studied experimentally using a pulsed laser photolysis/pulsed-laser-induced fluorescence technique over wide ranges of temperatures (297-826, 298-1009, and 296-908 K, respectively) and at pressures between 6.68 and 24.15 kPascals. The rate coefficients for these reactions exhibit no dependence on pressure and exhibit positive temperature dependences that can be represented with modified three-parameter Arrhenius expressions within their corresponding temperature ranges: k1 = 3.59 x 10-16T1.35exp(-745K/T)cm3molecule-1sec-1, k2 = 3.82 x 10-19T2.38 exp(-1136K/T)cm3molecule-1sec-1, and k3 = 6.64 x 10-16T1.46 exp(-271K/T)cm3molecule-1sec-1. For the OH …

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Chemical Differences Of Atherosclerotic Plaques In Native And Bypass Human Coronary Arteries And Diseased And Non-Diseased Human Aortas, Samuel Jean Washington Jan 2007

Chemical Differences Of Atherosclerotic Plaques In Native And Bypass Human Coronary Arteries And Diseased And Non-Diseased Human Aortas, Samuel Jean Washington

LSU Doctoral Dissertations

ABSTRACT Cardiovascular disease, primarily atherosclerosis involves a number of distinct processes that are associated with plaque development. The use of differential gel electrophoresis to determine differences between proteins produced in native and bypass coronary arteries from the same heart has been studied. The analytical techniques presented in this study to characterize plaque samples include two dimensional gel electrophoresis, sodium dodecylsulfate polyacrylamide gel electrophoresis, mass spectrometry, differential gel electrophoresis, and high performance liquid chromatography. An overview of the stages involved in atherosclerosis and the theories implicated in the manifestation of atherosclerosis was presented. A design study using the Box Behnken method …

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An Exploratory Study Of The Videoblogger's Community, John Warmbrodt Jan 2007

An Exploratory Study Of The Videoblogger's Community, John Warmbrodt

Masters Theses

"Videoblogs (vlogs) have emerged as a new form of virtual community. The goal of this study was to explore and understand the videoblogger community by studying the community's structure and the motivations of vloggers"--Abstract, page iii.

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A Functional Calculus In A Non Commutative Setting, Fabrizio Colombo, Graziano Gentili, Irene Sabadini, Daniele C. Struppa Jan 2007

A Functional Calculus In A Non Commutative Setting, Fabrizio Colombo, Graziano Gentili, Irene Sabadini, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we announce the development of a functional calculus for operators defined on quaternionic Banach spaces. The definition is based on a new notion of slice regularity, see [6], and the key tools are a new resolvent operator and a new eigenvalue problem. This approach allows us to deal both with bounded and unbounded operators.

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Impacts Of Acid Mine Drainage On Carbon Cycling In Receiving Streams, Ernest W. Fonyuy Jan 2007

Impacts Of Acid Mine Drainage On Carbon Cycling In Receiving Streams, Ernest W. Fonyuy

Doctoral Dissertations

"Field and laboratory investigations of acid mine drainage (AMD) contaminated and uncontaminated waters were conducted in order to determine and model processes and reaction mechanisms that control dissolved inorganic carbon (DIC) transformation and shifts in isotope ratio of DIC (Δ¹³CDIC). The results show that AMD caused variable pH changes, overall decreases in Fe²⁺, alkalinity, and DIC, and increases in (Δ¹³CDIC) in receiving streams. AMD caused more than 50 to > 98% seasonal DIC loss in stream water through CO₂ degassing. High DIC losses corresponded to high Fe²⁺ and lower or no HCO₃⁻ in the water samples, because …

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Synthetic Methods For Biologically Relevant Organofluorine Compounds, Meher Perambuduru Jan 2007

Synthetic Methods For Biologically Relevant Organofluorine Compounds, Meher Perambuduru

Doctoral Dissertations

"This thesis describes novel synthetic methodologies for the synthesis of biologically relevant organofluorine compounds"--Abstract, page iii.

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Incipient Continental Rifting: Insights From The Okavango Rift Zone, Northwestern Botswana, Baraka D. Kinabo Jan 2007

Incipient Continental Rifting: Insights From The Okavango Rift Zone, Northwestern Botswana, Baraka D. Kinabo

Doctoral Dissertations

"In this dissertation aeromagnetic, gravity, and Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM) data from the Okavango Rift Zone in northwest Botswana are used to map the distribution of rift and basement structures. The distribution of these structures provide useful insights into the early stages of continental rifting. The objectives of this study are (1) assessing the role of pre-existing structures on rift basin development, (2) characterizing the geometry of the nascent rift basins, (3) documenting fault growth and propagation patterns, and (4) investigating the border fault development"--Abstract, page iv.

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Knowledge-Based Methods For Automatic Extraction Of Domain-Specific Ontologies, Janardhana R. Punuru Jan 2007

Knowledge-Based Methods For Automatic Extraction Of Domain-Specific Ontologies, Janardhana R. Punuru

LSU Doctoral Dissertations

Semantic web technology aims at developing methodologies for representing large amount of knowledge in web accessible form. The semantics of knowledge should be easy to interpret and understand by computer programs, so that sharing and utilizing knowledge across the Web would be possible. Domain specific ontologies form the basis for knowledge representation in the semantic web. Research on automated development of ontologies from texts has become increasingly important because manual construction of ontologies is labor intensive and costly, and, at the same time, large amount of texts for individual domains is already available in electronic form. However, automatic extraction of …

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Fabrication Of Dna Microarrays On Poly (Methylmethacrylate) Substrates For Biomolecular Reporting, Catherine N. Situma Jan 2007

Fabrication Of Dna Microarrays On Poly (Methylmethacrylate) Substrates For Biomolecular Reporting, Catherine N. Situma

LSU Doctoral Dissertations

DNA microarrays require the use of substrates with well-established surface modification / probe attachment chemistries. Glass/quartz have been widely adopted as typical support materials since their surface modification chemistries which involve the use of siloxane –based chemistries have been widely studied however; these chemistry is susceptible to hydrolytic cleavage especially at high or low pH values. Recently, polymers have been sought as alternative microarray support materials but their surface modification strategies are not well characterized compared to glass. This report will entail surface photo-modification of PMMA polymer substrates by UV irradiation which produces functional scaffolds of carboxylic groups that allow …

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Exploring The Quark-Gluon Content Of Hadrons: From Mesons To Nuclear Matters, Hrayr Hamlet Matevosyan Jan 2007

Exploring The Quark-Gluon Content Of Hadrons: From Mesons To Nuclear Matters, Hrayr Hamlet Matevosyan

LSU Doctoral Dissertations

Even though Quantum Chromodynamics (QCD) was formulated over three decades ago, it poses enormous challenges for describing the properties of hadrons from the underlying quark-gluon degrees of freedom. Moreover, the problem of describing the nuclear force from its quark-gluon origin is still open. While a direct solution of QCD to describe the hadrons and nuclear force is not possible at this time, we explore a variety of developed approaches ranging from phenomenology to first principle calculations at one or other level of approximation in linking the nuclear force to QCD. The Dyson Schwinger formulation (DSE) of coupled integral equations for …

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Exploring The Binding Of Amine And Sulfonamide Ligands In Rhenium(I) Tricarbonyl And Platinum(Ii) Complexes, Anna Maria Christoforou Jan 2007

Exploring The Binding Of Amine And Sulfonamide Ligands In Rhenium(I) Tricarbonyl And Platinum(Ii) Complexes, Anna Maria Christoforou

LSU Doctoral Dissertations

Platinum is the metal present in various classes of inorganic medicinal agents directed at important diseases such as cancer or viral infections. Several new Pt(II) complexes of polyamine ligands bearing a dansyl moiety linked by a sulfonamide group were prepared; in some cases the sulfonamide nitrogen formed a bond to Pt. The sulfonamido group donates strongly to Pt and places the dansyl group close to a vacant coordination position, allowing it to stack with bound guanine base (G) when G binds. The emission of the fluorophore decreases with decreasing distance to Pt. Metal nuclide radiopharmaceuticals contain a metal core and …

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Probing The Association Behavior Of Hydrophobic Organic Compounds With Dissolved Humic Materials, Hadi M. Marwani Jan 2007

Probing The Association Behavior Of Hydrophobic Organic Compounds With Dissolved Humic Materials, Hadi M. Marwani

LSU Doctoral Dissertations

The association mechanism between hydrophobic organic compounds (HOC) and dissolved humic materials (DHM) has continued to be one of the interesting areas in environmental applications. The goal of the research reported in this dissertation is to investigate the association behavior of HOC with DHM. The first part of this research involves steady-state fluorescence measurements of these multi-component systems to study the effect of DHM content on the association mechanism of HOC, in particular using pyrene as a model. Results showed that steady-state fluorescence alone may not provide enough information about the quenching mechanism of pyrene with DHM. Lifetime based fluorescence …

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Factors Influencing The Spatial Distribution Of Natural Resource-Based Industries: The Softwood Lumber Industry In The United States South, Francisco Xavier Aguilar Jan 2007

Factors Influencing The Spatial Distribution Of Natural Resource-Based Industries: The Softwood Lumber Industry In The United States South, Francisco Xavier Aguilar

LSU Doctoral Dissertations

Expanding on the Theory of Location, New Economic Geography, and Porter's Theory of Clusters this dissertation attempts to identify key factors influencing the location of firms in a resource-based industry. The softwood lumber industry in the United States is used as a case study to test several hypotheses concerning these theories. Two U.S. regions, the West and the South, were selected for analysis because they account for over 70 percent of U.S lumber manufacturing capacity. A multi-disciplinary research approach involved three-stages. First, self-reported preferences were analyzed using common factor and conjoint analyses for preferences for location attributes. Surveys were sent …

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Synthesis And Properties Of Isoporphyrins And Related Derivatives For Application In Photodynamic Therapy, Sandra Celinah Mwakwari Jan 2007

Synthesis And Properties Of Isoporphyrins And Related Derivatives For Application In Photodynamic Therapy, Sandra Celinah Mwakwari

LSU Doctoral Dissertations

Isoporphyrins are tautomers of porphyrins with an interrupted macrocyclic conjugation owing to the presence of a sp3 hybridized meso-carbon. Due to their absorption at long wavelengths (~800nm), isoporphyrins are potential candidates as photosensitizers in photodynamic therapy (PDT), a ternary modality of cancer treatment. They are also of biological interest due to their unique redox properties among porphyrin derivatives and could be a new class of near-IR dyes. Isoporphyrins are known to be unstable with respect to transformation back to the fully conjugated porphyrin chromophore except when the meso-carbon is geminally substituted and for this reason a detailed study of this …

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Lanthanide Complexes As Fluorescent Indicators For Neutral Sugars And Cancer Biomarkers, Onur Alpturk Jan 2007

Lanthanide Complexes As Fluorescent Indicators For Neutral Sugars And Cancer Biomarkers, Onur Alpturk

LSU Doctoral Dissertations

Simple water soluble lanthanum and europium complexes are effective at detecting neutral sugars as well as glyco- and phospholipids. In solutions at physiologically relevant pH the fluorescent lanthanum complex binds neutral sugars with apparent binding constants comparable to those of arylboronic acids. Interference from commonly occurring anions is minimal. The europium complex detects sialic acid-containing gangliosides at pH 7.0 over an asialoganglioside. This selectivity is attributed, in large part, to the cooperative complexation of the oligosaccharide and sialic acid residues to the metal center, based on analogous prior studies. In MeOH, lysophosphatidic acid (LPA), a biomarker for several pathological conditions …

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Using Power Spectra To Look For Anisotropies In Ultra-High Energy Cosmic Ray Distributions, Megan Alicia Mcewen Jan 2007

Using Power Spectra To Look For Anisotropies In Ultra-High Energy Cosmic Ray Distributions, Megan Alicia Mcewen

LSU Doctoral Dissertations

The origins and compositions of ultra-high energy cosmic rays (UHECR) remains a mystery to this day. The Pierre Auger Observatory (PAO) is being constructed now in the hopes that it will help solve this mystery by detecting more UHECR than any previous experiment. In this dissertation, I will discuss this experiment, and analyze the data collected so far by comparing it with simulated data from possible source distributions. In these simulations, I will track antiprotons, along with other possible cosmic ray primaries, through various models of galactic and extragalactic magnetic fields. Once they reach a certain distance, I will record …

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Xanthene/Benzoxanthene Dyes: Novel Synthetic Metholologies, Applications In Molecular Recognition, Cellular Imaging And The Design Of A Tunable White (Rgb) Light Emitter, Youjun Yang Jan 2007

Xanthene/Benzoxanthene Dyes: Novel Synthetic Metholologies, Applications In Molecular Recognition, Cellular Imaging And The Design Of A Tunable White (Rgb) Light Emitter, Youjun Yang

LSU Doctoral Dissertations

My graduate work has focused on the development of new fluorophore materials towards addressing several interdisciplinary research problems. Selective detection of sialic acid via a boron-amide interaction. Concentration changes of sialic acid can be monitored ratiometrically in the visible region using a boronic acid based chemosensor. The technique shows great promise for the detection of sialic acid, a critical cell surface residue involved in cancer, graft rejection and virulence in certain bacteria. There is no interference from commonly occurring oligosaccharides, aminosugars and most carboxylic acid-containing compounds. Improved synthetic methodology and studies of novel molecular probe architectures. I have developed a …

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Syntheseses [Sic] And Evaluation Of Porphyrin Derivatives For Applications In Medicine And In Material Science, Erhong Hao Jan 2007

Syntheseses [Sic] And Evaluation Of Porphyrin Derivatives For Applications In Medicine And In Material Science, Erhong Hao

LSU Doctoral Dissertations

Chapter 1 presents a concise introduction to porphyrins, especially on the synthesis of meso-tetraphenylporphyrins, which were synthesized during the course of my research and were used for further purposes in the following chapters. Chapter 2 describes the synthesis of a series of cobaltacarborane-porphyrin conjugates for the boron neutron capture therapy (BNCT) of tumors. Using an efficient and high yield ring-opening reaction, N-substituted porphyrins were also synthesized. The spectroscopic and structural properties of these compounds are presented. These high percentage boron and amphiphilic compounds are promising boron delivery agents for BNCT (prelimary cellular studies using some of these compounds have been …

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Synthesis And Functionalizations Of Tetrapyrrole Derivatives, Lijuan Jiao Jan 2007

Synthesis And Functionalizations Of Tetrapyrrole Derivatives, Lijuan Jiao

LSU Doctoral Dissertations

Chapter 1 of this Dissertation presents a brief overview of the history of tetrapyrrole derivatives and of their fundamental properties. Overviews of porphyrins, benzoporphyrins, chlorins and porphycenes are presented. Work presented in Chapter 2 through Chapter 4 mainly focuses on the syntheses and functionalization of chromophore-extended porphyrin derivatives. Several new synthetic routes for the syntheses and functionalizations of extended porphyrins either at the β-position or at the meso-position of porphyrin are developed. From these improved synthetic routes, the regio-selective syntheses of porphyrin derivatives are described. Chapter 2 mainly focuses on the syntheses of β,β'-fused methylenepropanoporphyrins and related porphyrin dimers. Chapter …

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