As a result of the changing needs of society since the early 20th century, approaches to transportation planning have been continually shifting from highway-focused to multimodal, an approach which takes multiple modes of transportation into consideration. This evolution has been reflected in federal transportation legislation and continues to have many implications for transportation agencies, especially state departments of transportation (DOTs). The objective of this thesis is to analyze what state DOTs have done in order to adapt to the shift. More specifically, the project focuses on the organizational and funding structures of state DOTs. First, an organizational structure analysis of all 50 state DOTs was carried out. This analysis looked at how state DOTs incorporate multiple modes of transportation into their organizational structure. Secondly, the results of a statewide multimodal planning survey, to which 35 states responded, were analyzed. The survey gauged to what extent the representative from a given state DOT thought that their agency was conducting multimodal transportation planning. It also analyzed state DOT modal responsibilities, funding options, and characteristics that influence multimodal transportation planning. Lastly, case studies were carried out for six state transportation agencies: Florida DOT, North Carolina DOT, Oregon DOT, Virginia's Transportation Secretariat, Maryland DOT, and Massachusetts DOT. These case studies focused on organizational structure, funding, and multimodal efforts. Findings from the three different aspects of this thesis support the notion that highway is still the dominant mode in statewide transportation planning in most state DOTs. However, this research also supports the idea that this situation is changing, though more rapidly in some states than in others. Though it is not evident that one type of organizational structure is better than another, states have used the reorganization of these structures as a method for adapting to multimodal transportation planning. Overall, state DOTs tend to incorporate multiple modes of transportation into their organizational structure through multimodal divisions, separate modal divisions, or a combination of both. In addition to the organizational structures, some states have also restructured their funding mechanisms in order to make funds more flexible across all modes of transportation so that they may be able to better accommodate multimodal transportation planning. Those state DOTs with transportation trust funds and separate modal programs have generally shown more initiative in embracing a more multimodal approach to transportation planning. Besides organizational and funding structures, leadership, organizational culture, and institutional issues have been recognized as factors that influence the extent of multimodal planning.

Clostridium chauvoei is a gram-positive, spore-forming anaerobic bacterium. It is the pathogenic agent of blackleg, a disease causing serious toxemia and high mortality in cattle, sheep and many other domestic and wild animals. It is considered the most important Clostridium producing economic losses in livestock. Typically, animals infected with blackleg die rapidly without any signs of illness. Animals quickly die within 12 to 48 hours after contracting the disease. Therefore, the control of this disease is done by commercial vaccines consisting of whole formolized cultures. Immunity against C. chauvoei is associated with whole cell, including its somatic and flagellar antigens while in other clostridial diseases, protective immunity is obtained by the use of vaccines containing toxoids. Moreover, it is essential to obtain new information about the somatic antigens of C. chauvoei. Proteomics is the study of the proteome, the protein complement of the genome. The proteome has been defined as the entire complement of proteins expressed by a cell, organism, or tissue type, and accordingly, proteomics is the study of this complement expressed at a given time or under certain environmental conditions. 2-DE with Immobilized pH Gradients (IPGs) combined with protein identification by Mass Spectrometry (MS) is currently the workhorse for proteomics. Much of information about immunogenic component can be derived from proteomics coupled to Western blotting, namely immunoproteomics. Our study constitutes the first immunoproteomic analysis of C. chauvoei to identify candidate immunogenic antigens for development of new vaccines. Analyses were performed by Western blot and dot blot techniques against the whole cell extract proteins of C. chauvoei separated by 2-DE. Firstly, the growth conditions of two different strains, C. chauvoei ATCC 11957 and C. chauvoei 20 were optimized. After mice immunization studies with experimental vaccines prepared, sera were obtained for evaluation of the immunoglobulin G antibody level by ELISA. After high level of antibody response determination, 1-DE, 2-DE and immunoblot studies were performed for the characterization of immunogenic proteins. In the study, a total of 460 protein spots could be detected on the 2-DE gels by the help of Delta2D image analysis software and 30 of them were reacted with polyclonal antibodies against inactivated whole cells of C. chauvoei. Among these 30 spots, and 8 of them could be characterized by MALDI-TOF MS analyses. Of these 8 spots revealed four different gene products (distinct ORFs). Ornithine decarboxylase, methionine adenosyltransferase, glucose-6-phosphate isomerase, and flagellin protein FliB (C) are the characterized proteins. Glucose-6-phosphate isomerase has been identified as an immunogenic protein for a pathogenic microbe and in C. chauvoei for the first time. Methionine adenosyltransferase and ornithine decarboxylation were identified as immunogenic for C. chauvoei for the first time. The last defined protein is the flagellin protein FliB(C) which is known to be major immunogenic protein of C. chauvoei.

Owing to their unique physical, chemical, and mechanical properties, nanoparticles (NPs) have been used, or are being evaluated for use, in many fields (e.g., personal care and cosmetics, pharmaceutical, energy, electronics, food and textile). However, concerns regarding the environmental and biological implications of NPs are raised alongside the booming nanotechnology industry. Numerous studies on the biological effect of NPs have been done in the last decade, and many mechanisms have been proposed. In brief, mechanisms underlying the adverse biological effect caused by NPs can be summarized as: (i) indirect adverse effect induced by reactive oxygen species (ROS) generated by NPs, (ii) indirect adverse effect induced by released toxic ions, and (iii) adverse effect induced by direct interactions of NPs with biological systems. Up to now, most efforts have been focused on the first two mechanisms. In contrast, adverse biological effects induced by direct nano-bio interactions are the least researched. This is largely because of the complexity and lack of suitable techniques for characterizing the nano-bio interface. This dissertation aims at advancing our understanding of the nano-bio interactions leading to the adverse biological effect of NPs. Specifically, it is comprised of three parts. Firstly, because the aggregation of NPs alters particle size and other physicochemical properties of NPs, the property of NPs reaching and interacting with biological cells is very likely different from that of what we feed initially. Consequently, as the first step and an essential prerequisite for understanding the biological effect of NPs, NP aggregation is investigated and models are developed for predicting the stability and the extent of aggregation of NPs. Secondly, interactions between NPs and cell membrane are studied with paramecium as the model cell. Due to the lack of cell wall, the susceptible cell membrane of paramecium is directly exposed to NPs in the medium. The extent and strength of direct nano-cell membrane interaction is evaluated and quantified by calculating the interfacial force/interaction between NPs and cell membrane. A correlation is further established between the nano-cell membrane interaction and the lethal acute toxicity of NPs. We find NPs that have strong association or interaction with the cell membrane tend to induce strong lethal effects. Lastly, we demonstrate systematic experimental approaches based on atomic force microscope (AFM), which allows us to characterize nano-bio interfaces on the single NP and single-molecular level, coupled with modeling approaches to probe the nano-DNA interaction. Using quantum dots (QDs) as a model NP, we have examined, with the novel application of AFM, the NP-to-DNA binding characteristics including binding mechanism, binding kinetics, binding isotherm, and binding specificity. We have further assessed the binding affinity of NPs for DNA by calculating their interaction energy on the basis of the DLVO models. The modeling results of binding affinity are validated by the NP-to-DNA binding images acquired by AFM. The investigation of the relationship between the binding affinity of twelve NPs for DNA with their inhibition effects on DNA replication suggests that strong nano-DNA interactions result in strong adverse genetic effects of NPs. In summary, this dissertation has furthered our understanding of direct nano-bio interactions and their role in the biological effect of NPs. Furthermore, the models developed in this dissertation lay the basis for building an “ultimate” predictive model of biological effects of NPs that takes into account multiple mechanisms and their interactions, which would save a lot of testing costs and time in evaluating the risk of NPs.

Reversible circuits are similar to conventional logic circuits except that they are built from reversible gates. In reversible gates, there is a unique, one-to-one mapping between the inputs and outputs, not the case with conventional logic. Also, reversible gates require constant ancilla inputs for reconfiguration of gate functions and garbage outputs that help in keeping reversibility. Reversible circuits hold promise in futuristic computing technologies like quantum computing, quantum dot cellular automata, DNA computing, optical computing, etc. Thus, it is important to minimize parameters such as ancilla and garbage bits, quantum cost and delay in the design of reversible circuits. The first contribution of this dissertation is the design of a new reversible gate namely the TR gate (Thapliyal-Ranganathan) which has the unique structure that makes it ideal for the realization of arithmetic circuits such as adders, subtractors and comparators, efficient in terms of the parameters such as ancilla and garbage bits, quantum cost and delay. The second contribution is the development of design methodologies and a synthesis framework to synthesize reversible data path functional units, such as binary and BCD adders, subtractors, adder-subtractors and binary comparators. The objective behind the proposed design methodologies is to synthesize arithmetic and logic functional units optimizing key metrics such as ancilla inputs, garbage outputs, quantum cost and delay. A library of reversible gates such as the Fredkin gate, the Toffoli gate, the TR gate, etc. was developed by coding in Verilog for use during synthesis. The third contribution of this dissertation is the set of methodologies for the design of reversible sequential circuits such as reversible latches, flip-flops and shift registers. The reversible designs of asynchronous set/reset D latch and the D flip-flop are attempted for the first time. It is shown that the designs are optimal in terms of number of garbage outputs while exploring the best possible values for quantum cost and delay. The other important contributions of this dissertation are the applications of reversible logic as well as a special class of reversible logic called conservative reversible logic towards concurrent (online) and offline testing of single as well as multiple faults in traditional and reversible nanoscale VLSI circuits, based on emerging nanotechnologies such as QCA, quantum computing, etc. Nanoelectronic devices tend to have high permanent and transient faults and thus are susceptible to high error rates. Specific contributions include (i) concurrently testable sequential circuits for molecular QCA based on reversible logic, (ii) concurrently testable QCA-based FPGA, (iii) design of self checking conservative logic gates for QCA, (iv) concurrent multiple error detection in emerging nanotechnologies using reversible logic, (v) two-vectors, all 0s and all 1s, testable reversible sequential circuits.

A system with two magnetic molecules embedded in a junction between non-magnetic leads was studied. In this system electrons tunnel from the localized energy level in region one to the localized energy level in region two generating a flow of electric charge through the quantum dot system. The current density and thus the conductance changes depending on the molecular spin moment. In this work we studied molecules with either spin "up" or spin "down" and with symmetric coupling strengths. The results indicate that the coupling strength between energy level and molecule together with the tunneling rate through the insulating layer play a major role when switching from parallel to anti-parallel molecular spin, for a specific combination of the coupling strength and tunneling rate we could observe a decrease in the current by 99.7% in the non-gated system and 99.4% in the gated system.

One of the major goals of this thesis is to investigate the extent to which correspondence noise, (i.e., the false pairing of dots in adjacent frames) limits motion detection performance in random dot kinematograms (RDKs). The performance measures of interest are Dmax and Dmin i.e., the largest and smallest inter-frame dot displacement, respectively, for which motion can be reliably detected. Dmax and threshold coherence (i.e., the smallest proportion of dots that must be moved between frames for motion to be reliably detected) in RDKs are known to be affected by false pairing or correspondence noise. Here the roles of correspondence noise and receptive field geometry in limiting performance are investigated. The range of Dmax observed in the literature is consistent with the current information-limit based interpretation. Dmin is interpreted in the light of correspondence noise and under-sampling. Based on the psychophysical experiments performed in the early parts of the dissertation, a model for correspondence noise based on the principle of receptive field scaling is developed for Dmax. Model simulations provide a good account of psychophysically estimated Dmax over a range of stimulus parameters, showing that correspondence noise and receptive field geometry have a major influence on displacement thresholds.

This thesis examines companies offering their services for free to Internet users, byemploying digital free business models. As a framework Chris Anderson’s classificationsof “free” business models are used. A sample of eleven companies that provide “free”services was selected and divided into four groups. These were search engine, socialnetworking/community, content based and others. Their profitability was then measuredin relation to their valuation with the help of P/E ratios within and among the groups. Aregression analysis was also conducted to compare profitability of either one of two“free” business models used by the researched companies.Findings were that search engine and social networking/community companies appear tohave profits for the period researched. No strong trend for overvaluation could be foundin either of these groups, except for individual companies with high P/E ratios. Neithercompany within the content based group showed any profits. Their marginal costs weretoo high but this may change with technological progress. Regression analysis could notshow any significant results employing either the “Freemium” or the advertising “free”business model to be more profitable than the other. Significant results could be shownbeing a content based company and being unprofitable. Comparison between specificcompanies gave mixed results but network effects appear to create dominant playerswithin each group. Employing more than only the advertising “free” business modelseems to be efficient in raising revenue per user for social networking/communitycompanies.

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Ce mémoire porte sur les mécanismes de relaxation et de fuite des excitons dans des systèmes de boîtes quantiques(BQs) d’InAs/InP. Les systèmes sont composés d’un sub- strat volumique d’InP, appelé matrice (M), d’un puits quantique d’InAs, nommé couche de mouillage (CM), et des familles de BQs d’InAs. La distinction entre les familles est faite par le nombre de monocouche d’épaisseur des boîtes qui sont beaucoup plus larges que hautes. Une revue de littérature retrace les principaux mécanismes de relaxation et de fuite des excitons dans les systèmes. Ensuite, différents modèles portant sur la fuite thermique des excitons des BQs sont comparés. Les types de caractérisations déjà produites et les spécifications des croissances des échantillons sont présentés. L’approche adoptée pour ce mémoire a été de caractériser temporellement la dynamique des BQs avec des mesures d’absorbtion transitoire et de photoluminescence résolue en temps (PLRT) par addition de fréquences. L’expérience d’absorption transitoire n’a pas fait ressortir de résultats très probants, mais elle est expliquée en détails. Les mesures de PLRT ont permis de suivre en température le temps de vie effectif des excitons dans des familles de BQs. Ensuite, avec un modèle de bilan détaillé, qui a été bien explicité, il a été possible d’identifier le rôle de la M et de la CM dans la relaxation et la fuite des excitons dans les BQs. Les ajustements montrent plus précisément que la fuite de porteurs dans les BQs se fait sous la forme de paires d’électrons-trous corrélées. / This thesis focuses on the mechanisms of relaxation and leakage of excitons in systems of quantum dots (QDs) InAs / InP. The systems are composed of a substrate of InP volume, called matrix (M), of a quantum well of InAs, named wetting layer (CM), and of QD families of InAs. The distinction between the families can be explained by the number of monolayer-thick boxes that are wider than high. A literature review highlights the main relaxation mechanisms and leakage of excitons in systems. Then, different models on the thermal leakage of the QD excitons are compared.Then, a presentation of the different types of characterizations already and of the specifications on the samples growths. The approach used for this thesis is to temporarily characterize the dynamic of the QDs with transient absorption and upconversion. The transient absorption experiment’s results are not very convincing, but are minutely explained. PLRT measures were used to follow in temperature the excitons effective lifetime in the QDs families. Then, with a detailed balance model, which has been well explained, it was possible to identify the role of theMand CM in relaxation and leakage of excitons in QDs. As shown by the adjustement, the escape of carriers in the QDs is made in a correlated electron-hole pairs form.

Deposition of silica shells onto ZnO nanoparticles (NPs) in dimethyl sulfoxide was found to be an efficient tool for terminating the growth of ZnO NPs during thermal treatment and producing stable core–shell ZnO NPs with core sizes of 3.5–5.8 nm. The core–shell ZnO–SiO2 NPs emit two photoluminescence (PL) bands centred at [similar]370 and [similar]550 nm originating from the direct radiative electron–hole recombination and defect-mediated electron–hole recombination, respectively. An increase of the ZnO NP size from 3.5 to 5.8 nm is accompanied by a decrease of the intensity of the defect PL band and growth of its radiative life-time from 0.78 to 1.49 μs. FTIR spectroscopy reveals no size dependence of the FTIR-active spectral features of ZnO–SiO2 NPs in the ZnO core size range of 3.5–5.8 nm, while in the Raman spectra a shift of the LO frequency from 577 cm−1 for the 3.5 nm ZnO core to 573 cm−1 for the 5.8 nm core is observed, which can indicate a larger compressive stress in smaller ZnO cores induced by the SiO2 shell. Simultaneous hydrolysis of zinc(II) acetate and tetraethyl orthosilicate also results in the formation of ZnO–SiO2 NPs with the ZnO core size varying from 3.1 to 3.8 nm. However, unlike the case of the SiO2 shell deposition onto the pre-formed ZnO NPs, individual core–shell NPs are not formed but loosely aggregated constellations of ZnO–SiO2 NPs with a size of 20–30 nm are. The variation of the synthetic procedures in the latter method proposed here allows the size of both the ZnO core and SiO2 host particles to be tuned. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.