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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

The divider set of explicit parametric geometry

Ugail, Hassan, Aggarwal, A., Bakopoulos, Y., Kotsios, S. January 2008 (has links)
In this paper we describe a novel concept for classification of complex parametric geometry based on the concept of the Divider Set. The Divider Set is an alternative concept to maximal disks, Voronoi sets and cut loci. The Divider Set is based on a formal definition relating to topology and differential geometry. In this paper firstly we discuss the formal definition of the Divider Set for complex 3-dimensional geometry. This is then followed by the introduction of a computationally feasible algorithm for computing the Divider Set for geometry which can be defined in explicit parametric form. Thus, an explicit solution form taking advantage of the special form of the parametric geometry is presented. We also show how the Divider Set can be computed for various complex parametric geometry by means of illustrating our concept through a number of examples
322

Macromolecular organization of flavonoid biosynthesis in Arabidopsis thaliana

Burbulis, Ian E. 02 April 2000 (has links)
Living cells manufacture and degrade thousands of chemical compounds in vivo. To do this cells rely on the activities of thousands of different protein catalysts distributed in aqueous interior compartments. Over the past several decades studies have shown that the thermodynamic and kinetic properties of most proteins, including enzymes, are different in vivo as compared to in vitro. Based on in vitro studies metabolic pathways have traditionally been thought to consist of intermediates randomly diffusing between soluble enzymes and are still portrayed as such in many biochemistry textbooks. A large number of metabolic pathways however are now known to exist as enzyme complexes due to molecular crowding effects in vivo. These differences have contributed to the controversy that surrounds explanations of how metabolic pathways are spatially organized and regulated in the living cell. The organization of enzymes in vivo is now thought to play a significant role in normal cellular physiology but evidence of this role, beyond intermediate channeling, is lacking. The long term goal of this work is to develop an experimental model and test the validity of theories concerning the spatial arrangement of enzymes in regulating metabolic pathways. The studies described in this dissertation have been focused on understanding how living cells organize metabolic pathways. I have examined some of the theoretical aspects of enzyme-enzyme interactions by modeling the complex formed by mitochondrial malate dehydrogenase and citrate synthase. These studies show that MDH and CS may bind in a specific orientation that facilitates the direct transfer of oxaloacetate from MDH to CS through a molecular channel. During these studies it was determined that A. thaliana does not encode stilbene synthase (STS), which catalyzes the first step in a pathway that competes with flavonoid biosynthesis in other plant species. Moreover, it was shown that flavonols are not required for pollen viability in A. thaliana as they are in maize and petunia. I also describe a novel method to clone fragments of DNA without ligase using the polymerase chain reaction (PCR). To establish an experimental model I have used a variety of techniques to analyze interactions between enzymes in the well-characterized flavonoid biosynthetic pathway in Arabidopsis thaliana. Evidence is presented that indicates that the first four enzymes in this pathway form a complex. Collectively this work suggests that the structural organization of enzymes into complexes is an important aspect of cellular metabolism and might directly impact the relative levels of specific compounds that are synthesized in vivo. / Ph. D.
323

Appropriate use of topical haemoglobin in chronic wound management: consensus opinions

Chadwick, P., McCardle, J., Mohamud, L., Tickle, J., Vowden, Kath, Vowden, Peter January 2015 (has links)
No / Oxygen has a crucial role in wound healing; 97% of chronic, non-healing wounds have been shown to have low oxygen levels (Hauser, 1987). Topical oxygen therapy has been shown to be effective in treating non-healing wounds, but is still underutilised. A working group of key opinion leaders met in February 2015 to determine the potential role of topical haemoglobin in non-healing wounds and to develop a clear decision-making pathway for clinical practice, as well as sharing practical tips for use. The group’s consensus recommendations on appropriate use are presented here.
324

A mineralogical and petrographic study of prematoids and layered rocks of the upper critical zone of the western Bushveld Complex, South Africa

26 August 2015 (has links)
D.Phil. / This study which describes rocks of the Upper Critical Zone of the Bushveld Complex is subdivided into three parts. The main rock type of the Upper Critical Zone, the noriteanorthosite, is the subject of the first part. Inclusions in chromite and plagioclase were studied. The inclusions' in chromite were observed at different stages of their formation. The chromite crystals usually overgrow plagioclase, pyroxene and hydrous minerals (biotite, amphibole and clinozoisite) trapping them at grain boundaries or triple junctions of chromite host grains. With 'continuous growth of the host minerals the inclusion starts changing its shape from elongated to circular and the hydrous mineral proportion of the inclusion increases. Simultaneously amphibole changes its composition from pargasitic to tremolitic...
325

Analysis of Controllability for Temporal Networks

Babak Ravandi (7456850) 17 October 2019 (has links)
Physical systems modeled by networks are fully dynamic in the sense that the process of adding edges and vertices never ends, and no edge or vertex is necessarily eternal. Temporal networks enable to explicitly study systems with a changing topology by capturing explicitly the temporal changes. The controllability of temporal networks is the study of driving the state of a temporal network to a target state at deadline t<sub>f</sub> within △t = t<sub>f</sub> - t<sub>0</sub> steps by stimulating key nodes called driver nodes. In this research, the author aims to understand and analyze temporal networks from the controllability perspective at the global and nodal scales. To analyze the controllability at global scale, the author provides an efficient heuristic algorithm to build driver node sets capable of fully controlling temporal networks. At the nodal scale, the author presents the concept of Complete Controllable Domain (CCD) to investigate the characteristics of Maximum Controllable Subspaces (MCSs) of a driver node. The author shows that a driver node can have an exponential number of MCSs and introduces a branch and bound algorithm to approximate the CCD of a driver node. The proposed algorithms are evaluated on real-world temporal networks induced from ant interactions in six colonies and in a set of e-mail communications of a manufacturing company. At the global scale, the author provides ways to determine the control regime in which a network operates. Through empirical analysis, the author shows that ant interaction networks operate under a distributed control regime whereas the e-mails network operates in a centralized regime. At the nodal scale, the analysis indicated that on average the number of nodes that a driver node always controls is equal to the number of driver nodes that always control a node. <br>
326

COORDINATION-DRIVEN SELF-ASSEMBLY OF TERPYRIDINE-BASED SUPRAMOLECULES

Wu, Xiaolei January 2017 (has links)
No description available.
327

Polynuclear complexes as precursor templates for hierarchical microporous graphitic carbon: An unusual approach

Kobielska, Paulina A., Telford, Richard, Rowlandson, J., Tian, M., Shahin, Z., Demessence, A., Ting, V.P., Nayak, Sanjit 17 July 2018 (has links)
Yes / A highly porous carbon was synthesized using a coordination complex as an unusual precursor. During controlled pyrolysis, a trinuclear copper complex, [CuII3Cl4(H2L)2]·CH3OH, undergoes phase changes with melt and expulsion of different gases to produce a unique morphology of copper-doped carbon which, upon acid treatment, produces highly porous graphitic carbon with a surface area of 857 m2 g–1 and a gravimetric hydrogen uptake of 1.1 wt % at 0.5 bar pressure at 77 K. / EPSRC (EP/R01650X/1 for VPT, and EP/E040071/1 for MT) and the University of Bristol
328

Electrochemical and structural studies of one-dimensional copper charge transfer complexes.

Pyrka, Gloria Jean. January 1988 (has links)
The electrochemistry of solid electrodes of charge transfer complexes of tetracyanoquinodimethane (TCNQ) and copper complexes with nitrogen containing chelates, such and dipyridylamine (dpaH), bipyridyl (bpy) and 1,10-dimethyl-2,9-phenanthroline (dmp), has been investigated with cyclic voltammetry. Pressed pellet electrodes of these complexes exhibit a broad electrochemically stable region. The oxidative and reductive breakdown reactions involve solid state reactions into the bulk electrode. These materials also act as electron mediators for glucose oxidation in glucose oxidase modified electrodes. The structure of the model compound, copper(I)(dpaH)₂Cl has been determined to have a distorted tetrahedral coordination sphere. The electrochemistry of solid electrodes of charge transfer complexes of tetrathiafulvalene (TTF) with copper chloride and copper bromide has been investigated with cyclic voltammetry. Pressed pellet electrodes do not exhibit a broad stable region, as do the TCNQ complexes. A preliminary structure of the organic part of tetramethyltetraselenafulvalene copper chloride has been determined from the solution of the Patterson function and exhibits a displacive modulation with a repeat unit of seven TMTSF molecules. (TTF)(SCN)₀ͺ₆₆ and (TTF)Cu(SCN)₂ have been investigated by infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. (TTF)(SCN)₀ͺ₆₆ crystallized in a tetragonal space group with a disordered column of thiocyanate anions. (TTF)Cu(SCN)₂ is an insulator with a two-dimensional network of Cu(SCN)₂⁻ ions. X-ray crystal structures of four compounds prepared in association with copper complex chemistry have been determined; (1) 5,5'-dibromo-2,2'-bithiophene, (2) 3,5,5'-tribromo-2,2'-bithiophene, (3) Cu(dmp)(CN)₂ ⁻ · Bu₄N⁺ and (4) the 1:2 adduct of dimercaptosuccinic acid and dimethylformamide.
329

On the Hermitian Geometry of k-Gauduchon Orthogonal Complex Structures

Khan, Gabriel Jamil Hart 24 September 2018 (has links)
No description available.
330

Contributions to Persistence Theory

Du, Dong 27 June 2012 (has links)
No description available.

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