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Helix-sense-selective polymerization of poly(3-methyl-4vinylpyridine) have been carried out using the DPEDAHLi

Helical assemblies of proteins are ubiquitous in nature and they perform vital functions in a wide range of organisms. The recent development of direct electron detectors and other imaging techniques in cryo-electron microscopy (cryo-EM) has opened new possibilities in solving helical structures at atomic resolution. Existing software packages for helical processing often require experience in tuning many ad hoc parameters to achieve optimal reconstruction results. REgularised LIkelihood OptimisatioN (RELION), an open-source single-particle analysis package, reduces the need for user expertise by the formulation of an empirical Bayesian framework, and has yielded some of the highest resolution density maps in recent years. Prior information about the helical assemblies can be conveniently incorporated into the statistical framework of RELION and thereby improves the helical reconstructions. This PhD thesis describes the development of a helical processing computation workflow with reduced user intervention in RELION. Chapter 1 introduces the theoretical basis of cryo-EM data acquisition and single-particle data processing, the concepts of helical symmetry, and a previously described method for iterative real-space reconstruction of helical assemblies, to which the RELION implementation bears resemblance. Chapter 2 discusses multiple adaptations to RELION that are necessary for helical processing. Key elements include the imposition and local refinement of helical symmetry, masks on helical segments and references, expressions of angular and translational prior information, manual and automated segment picking as well as initial model generation for helices. Calculations have been performed on four test data sets showing that the developed methods in RELION yield results that are as good as or better than alternative approaches for the tests performed. Chapter 3 describes the same methodology adapted to helical sub-tomogram averaging in RELION. Chapter 4 introduces the local symmetry option developed for special types of filaments with pseudo-helical symmetry. The concept can be extended to general single-particle analysis as well. Chapter 5 describes four helical structures determined in collaboration with other research groups using helical RELION for data processing. Chapter 6 concludes the thesis with a brief summary and future prospects.

Helical anchors are a type of deep foundation element that can be installed quickly in almost any location and can accept the immediate application of operational loads. The use of helical anchors has expanded in recent decades from its established application in the power transmission industry to more traditional civil engineering applications such as residential construction, communication tower installations, and static and seismic structural retrofitting and reconstruction. Despite the wide range of helical anchor applications, few advances have been made in improving the understanding of their behavior. For example, existing helical anchor design methods, for cases where the anchors are loaded in uplift in cohesive soils, are based on the assumption that the soil above the helical plate is mobilized in a manner analogous to that beneath a deep foundation in bearing. An appropriate design method would acknowledge the effect of load directionality on the assumed failure mechanism. This thesis evaluates the existing cylindrical shear and individual plate bearing design methods for helical anchor capacity in uplift. Additionally, new capacity models are proposed to improve prediction accuracy and reduce prediction variability. A load test database of helical anchors loaded in tension is established from tests reported in the literature. The existing and proposed capacity models are compared to the capacities observed during loading tests using the statistical bias and its distribution. Load and Resistance Factor Design (LRFD) resistance factors are derived from closed-form solutions using First Order Second Moment (FOSM) reliability procedures. Finally, load-displacement models are developed through the evaluation of observed individual anchor plate breakout behavior and back-calculation of side shear capacity from load tests on multi-plate anchors. The new displacement models are compared to the load-displacement tests in the database. In general the comparisons indicate that the displacement-based models developed in this thesis provide a reasonable estimate of load-displacement behavior of helical anchors for service-level displacements. These findings provide engineers with new tools for design of helical anchor foundations. / Graduation date: 2012

Hydrogen bonding interactions have been applied to the synthesis of chiral vicinal diamines and the generation of helical chirality. A stereospecific synthesis of vicinal diamines was developed by using the diaza-Cope rearrangement reaction driven by resonance-assisted hydrogen bonds (RAHBs). This process for making a wide variety of chiral diamines requires only a single starting chiral diamine, 1,2-bis(2-hydroxyphenyl)-1,2-diaminoethane (HPEN) and aldehydes. Experimental and computational studies reveal that this process provides one of the simplest and most versatile approaches to preparing chiral vicinal diamines including not only C2 symmetric diaryl and dialkyl diamines but also unsymmetrical alkyl-aryl and aryl-aryl diamines with excellent yields and enantiopurities. Weak forces affecting kinetics and thermodynamics of the diaza-Cope rearrangement were systematically studied by combining experimental and computational approaches. These forces include hydrogen bonding effects, electronic effects, steric effects, and oxyanion effects. As an example of tuning diamine catalysts, a vicinal diamine-catalyzed synthesis of warfarin is described. Detailed mechanistic studies lead to a new mechanism involving diimine intermediates. Decreasing the NCCN dihedral angle by varying the diamine structure results in an increase of the enantioselectivity up to 92% ee. Hydrogen bonds have been used to generate helical chirality in a highly stereospecific manner with a single amino acid and 2,2′-dihydroxybenzophenone. DFT computational and experimental data including circular dichroism (CD), X-ray crystallography and 1H NMR data provide insight into the origin of the stereospecificity. A signalling dizao group can be attached to the receptor for general sensing of amino acid enantiopurity.

Hydrogen bonding interactions have been applied to the synthesis of chiral vicinal diamines and the generation of helical chirality. A stereospecific synthesis of vicinal diamines was developed by using the diaza-Cope rearrangement reaction driven by resonance-assisted hydrogen bonds (RAHBs). This process for making a wide variety of chiral diamines requires only a single starting chiral diamine, 1,2-bis(2-hydroxyphenyl)-1,2-diaminoethane (HPEN) and aldehydes. Experimental and computational studies reveal that this process provides one of the simplest and most versatile approaches to preparing chiral vicinal diamines including not only C2 symmetric diaryl and dialkyl diamines but also unsymmetrical alkyl-aryl and aryl-aryl diamines with excellent yields and enantiopurities. Weak forces affecting kinetics and thermodynamics of the diaza-Cope rearrangement were systematically studied by combining experimental and computational approaches. These forces include hydrogen bonding effects, electronic effects, steric effects, and oxyanion effects. As an example of tuning diamine catalysts, a vicinal diamine-catalyzed synthesis of warfarin is described. Detailed mechanistic studies lead to a new mechanism involving diimine intermediates. Decreasing the NCCN dihedral angle by varying the diamine structure results in an increase of the enantioselectivity up to 92% ee. Hydrogen bonds have been used to generate helical chirality in a highly stereospecific manner with a single amino acid and 2,2′-dihydroxybenzophenone. DFT computational and experimental data including circular dichroism (CD), X-ray crystallography and 1H NMR data provide insight into the origin of the stereospecificity. A signalling dizao group can be attached to the receptor for general sensing of amino acid enantiopurity.

This research will use a vibrating U-tube which will cause the water around the tube sway in but will manage the helix leaf blade water turbine which (1998) will develop using Gorlov (Gorlov Helical Turbine). It will also study and discuss electricity generating technology. The vertical motion created external force under the U-tube and about the water will cause the fluid to vibrate and lead the tube cause the domestic water turbine to rotate thus generating electricity. In this article discovers the best size for a generating system and the power rate using the Taguchi method and manufactures the U-tube generating system model and the predecessor gauges the data to make the confirmation, the experimental result discovered the Taguchi method and the actual gauging data best tallies the size. The test results show that in the tube, the fluid oscillation frequency and the blade area rate can affect the structure of the system as well as the true power rate while the external force cycle resonance frequency scope generates electricity.

Because of the unique physical properties of liquid crystal molecules, such as: light, electricity, magnetic anisotropy, they exhibit different values, the most known current application on displays in our life. As the liquid crystal molecules can be modified through the functional groups, thereby affecting its physical properties, it caused great interests in synthetic chemists. In this thesis, we synthesized liquid crystal based on dibezo[a,c]phenazine core and the dioxole skeleton was also induced into dove-tail alkyl chain functional group surrounding the central aromatic core . Moreover, we also change the chain length of alkyl chain to explore stacking arrangement structure of the mesophase. By the various instruments to explore the nature of stacking, we preliminary assumed that the mesophase might exhibit the helical stacking with excellent charge mobility, which could be good candidates for optical and electrical applications.

Experiments were conducted in electroosmotic flow (EOF) with 0.005≤Re ≤ 0.039 on mixing enhancement in 3-D helical microchannels. Both inlet velocity and concentration distribution along the flow channel were measurement via £gPIV and £gLIF technique respectively. The experimental results showed that the helical channels can generate nearly fully chaotic flow and achieve the complete mixing in a relatively short channel with three different helical channels (3, 4, and 6 inlet channels), and the four-inlet channel found to have the best mixing efficiency. Finally, the mixing length was correlated into a form of £f/Dh = 2.8Pe0.35 within ¡Ó8% accuracy between the experiments and prediction.

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