The main objective of this study was to evaluate the feasibility of using nanoscale zero-valent iron (nZVI) as the source of hydrogen to enhance in situ anaerobic biodegradation of trichloroethylene (TCE). In the first part of this study, microcosms were constructed to evaluate the effects of different controlling factors [e.g., different redox conditions (aerobic and anaerobic conditions), different microorganisms (in situ microorganisms, activated sludge, and anaerobic sludge), and different sources of substrates and electron donors (phenol, cane molasses, hydrogen, and nZVI)] on TCE biodegradation. In the second part of this study, batch experiments were conducted to evaluate the feasibility of hydrogen production by nZVI and bimetallic particles. Results from the microcosm study indicate that in-situ microorganisms were capable of degrading TCE under aerobic and anaerobic conditions. Results also show that TCE removal was more effective by activated sludge and anaerobic sludge. Aerobic biodegradation of TCE was enhanced by the addition of phenol and cane molasses. Under anaerobic conditions, TCE removal could be improved when cane molasses and hydrogen were supplied. In addition, anaerobic TCE degradation was more effective with the presence of hydrogen. Results of microcosms conducted with the addition of nZVI reveal that TCE was degraded completely in both live and autoclaved microcosms. This indicates that chemical reductive dechlorination seemed to dominate the removal of TCE in microcosms. Therefore, further studies with higher TCE concentrations or lower nZVI doses need to be conducted to determine the effects of the produced hydrogen on TCE biodegradation. Results from the hydrogen production experiments indicate that efficiency of hydrogen production by nZVI ranged from 30% to 76%. Higher dose of nZVI addition resulted in higher amount of hydrogen production. The total amounts of hydrogen production were correlated with the doses of nZVI. In addition, rates and efficiency of hydrogen production by bimetallic particles were better than those of nZVI. Results of the batch experiments reveal that nZVI and bimetallic particles had good efficiency on hydrogen production. This indicates that nZVI and bimetallic particles have high potential to be used as hydrogen producers. In this study, a simple system consisted of only water and nZVI or bimetallic particles was applied to produce hydrogen. Although TCE in microcosms with nZVI addition was totally consumed by nZVI, results of microcosms with hydrogen addition demonstrated that hydrogen was able to improve the efficiency of anaerobic TCE biodegradation. Thus, it may be feasible to use nZVI as the source of hydrogen to enhance in situ anaerobic biodegradation of TCE. The advantages of using nZVI as the source of hydrogen include: (1) rapid removal of significant contaminant concentrations in the early stage of nZVI injection; (2) creation of a more reducing environment; (3) safer than liquid hydrogen, which is stored in steel containers; and (4) direct hydrogen supply without transfer of biological mechanisms compared to commercial hydrogen release compounds and other organic substrates. Results of this study suggest that biological reductive dechlorination of TCE can be enhanced if proper doses of nZVI are supplied in situ. Knowledge and comprehension obtained in this study will be helpful in designing an enhanced in situ anaerobic bioremediation system for a TCE-contaminated site.

<p>This thesis describes the synthesis, structure, equilibriaand other properties of novel thallium(III) monomeric andplatinum-bonded complexes with nitrogen donor ligandsethylenediamine, diethylenetriamine, triethylenetetramine,porphyrin, 2,2'-bipyridine and 1,10-phenanthroline in solutionand in solid.</p><p>The existence of three complexes withthe general formula[Tl(en)_n]³⁺(n = 1-3) and their overall stability constantshave been established in pyridine. All three complexes wereidentified by their²⁰⁵Tl and¹H NMR chemical shifts and²⁰⁵Tl-¹H coupling constants. The formation process of thecomplexes was followed by¹H NMR spectroscopy. The crystal structure of[Tl(en)₃](ClO₄)₃was determined; the thallium(III) ion isN-coordinated in a distorted octahedral geometry. Two [Tl(dien)_n]³⁺(n = 1-2) complexes were proved to exist insolution and the structure of the bis-complex [Tl(dien)₂]²⁺in<i>u-facial</i>isomers was determined in solid. In addition,crystal structures of [Tl(en)₂CN](ClO₄)₂with cyanide bridging between two Tl(en)₂units forming an infinite chain structure and of[Tl(tren)₂(CN)₂](ClO₄) with a distorted pseudo-octahedral coordinationaround thallium were determined. Thallium(III) complexes with2,2'-bipyridine and 1,10-phenanthroline have been studied inDMSO using²⁰⁵Tl,¹³C and¹H NMR spectroscopy. In addition, aseven-coordinated thallium was found in the crystal structureof [Tl(bipy)₃(dmso)](ClO₄)₃, and six-coordinated thallium in pseudo-octahedralgeometry in [Tl(phen)₂Cl₂](ClO₄).</p><p>The solvated complex [Tl(dmso)₆]³⁺has been prepared using concentrated aqueoussolution of Tl(ClO₄)₃by a solvent replacement reaction in DMSO, and thewater-free solid compound [Tl(dmso)₆](ClO₄)₃was crystallized from DMSO. The structure of thecomplex [Tl(dmso)₆]³⁺is a regular octahedron with the Tl-O bonddistance 2.224(3) Å. It represents an easy and secure wayto introduce water-free Tl(III) into organic phase withoutreduction.</p><p>Through several reactions, novel heteronuclear Pt-Tlcomplexes with the composition [(NC)₅Pt-Tl(tpp)]^2-, [(NC)₅Pt-Tl(thpp)]^2-, [(NC)₅Pt-Tl(bipy)_n](n = 1-2), [(NC)₅Pt-Tl(en)_n-1](n = 1-3) and [(NC)₅Pt-Tl(phen)_n](n = 1-2), have been synthesized in solution.Multinuclear NMR (¹⁹⁵Pt,²⁰⁵Tl,¹³C and¹H), Raman spectroscopy and X-ray diffraction dataare fully compatible with formation of unsupported Pt-Tl bondedcomplexes both in solution and in solid. The huge¹J(¹⁹⁵Pt-²⁰⁵Tl) spin-spin coupling constants (48-66 kHz) wereobserved by both¹⁹⁵Pt and²⁰⁵Tl NMR spectroscopy in solution and they providea strong evidence of formation of the Pt-Tl bond in solution.In all six determined crystal structures of the Pt-Tl compoundsa very short Pt-Tl bond is found with distances2.6117(5)-2.6375(5) Å. The calculated values of Pt-Tlforce constants (1.38-1.91 N/cm) are characteristic for asingle metal-metal bond.</p><p>In the Pt-Tl compounds, the oxidation state of the metalions is intermediate between the stable states Pt^II/Pt^IVand Tl^III/Tl^I, respectively, and this is reflected by their¹⁹⁵Pt and²⁰⁵Tl chemical shifts. It turns out that N-donorligands can really stabilize the Pt-Tl bond both in solutionand in solid. The character of the metal-metal bond anditstheoretical basis are discussed.</p><p><b>Keywords:</b>Thallium, Platinum, Cyanide, N-donor ligand,Metal-metal bond, Multinuclear NMR, Raman spectroscopy, X-raydiffraction, Equilibrium, Spin-spin coupling.</p>

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

In this dissertation, the multiple facets of benzodithiophene (BDT) units are explored, with a focus on understanding how the isomerism of the BDT structure affects the macroscopic properties of the oligomeric and polymeric materials created. First, the story focuses on an overview of the BDT synthons and their applications in organic electronics. A straightforward synthesis of BDT and its derivatization to seven π-conjugated building blocks and seven polymers is presented. Then, symmetric (donor)2-acceptor (D2-A) dye architecture for application in dye-sensitized solar cells are investigated. Two isomeric systems are studied, and the branched sensitizers show a greater incident photon-to-current efficiency than the linear dyes. The nature of the accepting core is also varied between dibenzophenazine to dithienophenazine. The sensitizer with the weakest accepting core displays the best photovoltaic performance, due to an increase in the open-circuit voltage of ~100 mV caused by the favorable shift of the metal oxide conduction band. Lastly, a study of the donating building blocks in these (D2-A) sensitizers demonstrates that increasing the number of donor units from two to six thiophene moiety doubles the solar cell performance, due to the improvement of the light harvesting ability.

Research literature on foreign assistance suggests that the U.S. provides aid in order to serve both its own strategic interests as well as the development needs of aid recipient countries. Maintaining a focus on Africa, this report uses newly available data for official development assistance and attempts to verify whether prevailing hypotheses regarding the motivations behind U.S. aid giving still hold true. Specifically, the report analyzes whether aid giving patterns align with 1) the development needs of recipient countries as understood through the lens of internationally established priorities, or 2) with good political and economic policies within recipient countries vis-à-vis democratic institutions and open markets, or 3) with U.S. national strategic interests (be they political, military, or economic interests). A statistical analysis of U.S. Official Development Assistance (ODA) to 53 countries in Africa over the period of 1970 to 2010 was carried out for this purpose. The results suggest that, when it comes to aid that is specifically addressed towards development projects in Africa, the strategic considerations and political priorities of the U.S. are just as important, if not more important, than the development needs or economic performance of recipient countries. Political allies and countries that democratize receive more aid from the U.S., ceteris paribus. In addition, it was found that more aid is given to countries with larger populations - a result that contradicts earlier literature on aid's motivations. The report is organized as follows. I begin in Section 1 by providing a general overview of U.S. foreign aid. In Section 2, I detail why Africa is a significant continent for such an analysis of U.S. aid, and outline some of the trends in aid to Africa. The third section summarizes some of the most important existing hypotheses about why the U.S. gives development aid. Section 4 describes the data and methodology used for this study and provides a discussion of the results obtained from the statistical analysis. Finally, in Section 6, I conclude by offering broader policy implications and sketching out avenues for future research. / text

Liver transplantation is the best therapy for patients with end-stage liver diseases and unresectable early hepatocellular carcinoma (HCC). Living donor liver transplantation (LDLT) has been successfully implemented as an alternative to deceased donor liver transplantation (DDLT) and likewise offers comparable excellent survival rate. However, the inferior post-transplant oncological outcomes are found in LDLT recipients with HCC. The liver grafts used in LDLT are usually small-for-size and less effective in coping with shear stress from transient portal hypertension, which results in small-for-size liver graft injury. Acute phase small-for-size liver graft injury may promote late phase tumor recurrence, whereas the underlying mechanism remains unclear. CXCL10, an inflammatory chemokine, initiates liver inflammatory response during hepatic ischemia-reperfusion (IR) injury and may link acute phase small-for-size liver graft injury and late phase tumor recurrence, yet the precise mechanisms remain elusive. Endothelial progenitor cells (EPCs) participate in tissue repair for graft recovery and also provide an angiogenic environment for tumor growth. Myeloid derived suppressor cells (MDSCs) and regulatory T cells (Tregs) can suppress the activation of the immune system and play a critical role in graft rejection and cancer development. We here established the rat orthotopic liver transplantation with whole graft or small-for-size graft model to study the impact of acute phase small-for-size liver graft injury on the mobilization of EPCs, MDSCs and Tregs, and intragraft CXCL10 and its receptor, CXCR3,gene expressions. We further subjected CXCL10-/-mice and CXCR3-/-mice to hepatic IR injury and major hepatectomy to study the role of CXCL10/CXCR3 signaling on the mobilization of EPCs, MDSCs and Tregs. We also investigated the effect of CXCL10 on EPC migration and tube formation in vitroas well as intratumoral microvessel density (MVD) in the rat liver transplantation with tumor growth model and EPCs on tumor growth in nude mice. Key findings: 1. Liver transplantation with small-for-size graft resulted in severe intragraft vascular injury and higher CXCL10 andCXCR3 gene expressions as well as more EPC, MDSC and Treg cell mobilizationin circulation than whole graft. 2. CXCL10-/-mice and CXCR3-/-mice had less circulating EPCs, MDSCs and Tregs than WT mice after hepatic IR injury and major hepatectomy. 3. CXCL10 recruited EPCs in dose-dependent and CXCR3-dependent manners and promoted EPC tube formation in vitro. 4. Higher intratumoral MVD was observed in small-for-size graft than in whole graft in liver transplantation with tumor growth model. 5. Tumor grew more quickly by combining EPC infusionin nude mouse orthotopic liver tumor model. In conclusion, acute phase small-for-size liver graft injury significantly mobilizes EPCs, MDSCs and Tregs after transplantation through CXCL10/CXCR3 signaling. More EPC mobilization and intragraft differentiation after transplantation with small-for-size liver graft may be related to higher intratumoral MVD in small-for-size liver graft after transplantation with tumor development. Therefore, targeting at post-transplant CXCL10/CXCR3 signaling may not only attenuate early phase liver graft injury but also prevent late phase tumor recurrence. / published_or_final_version / Surgery / Doctoral / Doctor of Philosophy

Donor-acceptor and thiophene based π-conjugated molecules and polymers, along with fullerene derivatives, are extensively used active components in the photoactive layer of organic photovoltaic devices. In this dissertation, we make use of several computational methodologies to investigate structure-property relationships of these organic systems in their molecular forms. We begin with an overview of the field of organic photovoltaics and some of the important problems in organic solar cells that are currently being investigated. This is then followed by a brief review of the electronic-structure methods (e.g. Hartree-Fock theory, Density Functional Theory, and Time-dependent Density Functional Theory) that are employed. We then present the main results of the dissertation. Chapter 3 provides a broad overview on how changes to the donor-acceptor copolymer chemical structure impacts its intrinsic geometric, electronic, and optical properties. Chapter 4 focuses on the characterization of the lowest excited-states and optical absorption spectra in donor-acceptor copolymers. In Chapter 5, we investigate the effects of alkyl side-chain placements in the π-conjugated backbone of oligothiophenes and how that impacts their intramolecular properties as well as the oligomer:fullerene interfacial interactions. Chapter 6 presents our investigation on the role of oligomer:fullerene configuration and reorganization energy on exciton-dissociation and charge-recombination processes. Finally, a synopsis of the work and further considerations are presented in Chapter 7.

published_or_final_version / abstract / Surgery / Master / Master of Surgery

International Development Programmes (IDPs) are United Nations‘ (UN) and developedcountries‘ initiatives to develop world‘s least developed countries. IDPs significantly vary fromother mainstream project management topics, as most often they do not have eye for commercialsuccess or are not of simple charity nature of humanitarian perspective aid. Projects under IDPstry to deliver United Nations‘ and rich countries commitment to provide sustainable developmentto developing world in terms of reducing poverty and hunger, improving health and educationsystem, building capacity to face disasters, eliminating gender discrimination, among others.This significant difference and lack of research in this field has left a gap in established projectmanagement methodologies that could be generalised as specifically suitable for IDPs.The knowledge of project selection methodologies has reached to its extreme variety, as itspreads from the simplest model of a checklist to the highest degree mathematical model.Leading researchers in the field have come to conclusion that project selection methods have tomatch the needs of a specific programme or portfolio to serve its purpose. The uniqueness ofIDPs intensified the necessity of choosing projects by understanding the financial and strategicbenefit they can deliver matching their resource requirement. In absence of straight direction inthe research and real life case observations, the practice in project selection in IDPs has not stillbeen an established procedure.To explore this need the authors of this report examined the theoretical framework of projectselection and their compliance with IDPs unique characteristics. Project selection methodsshowed that due to organisations‘ varied need of delivering financial or strategic objectives, theselection models significantly vary. The use of different financial or strategic criteria withdifferent emphasis on them is highlighted in project selection articles. Further analysis wasfocused on project selection stages and possible challenges evolving in the selection process.The researchers tried to explore project selection methods used in IDPs in Bangladesh byanalyzing four different cases. The examination of the project selection process showed that itmainly follows the multi-stage assessment procedure, with project evaluation conducted by theassessment panel, comprised from the functional experts and in some cases stakeholders‘representatives. Further, from the findings it was evident that the primary theoretical suggestionsfor IDPs project selection methods being strategy driven rather than being commercial in natureis true. In all four cases, the researchers have seen the selectors using scoring and ranking modelthat are specifically designed with higher emphasis on the strategic factors, and that try to deliverdevelopment objective rather than contributing to commercial success. In addition, thechallenges in IDP project selection practice are also discussed. Challenges like deliveringdevelopment needs while trying to make the project sustainable in the long run, managing thepowerful influence of different stakeholders in selecting projects, avoiding country politics,among others are making the project selection more difficult. The main contribution of thisresearch has been establishing a primary selection framework from case evidence withsuggestions on appropriate model, set of criteria which can be used and a set of challenges to beaware of. The study is presented as a basis for further research in this field.