京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第17828号 / 工博第3771号 / 新制||工||1576(附属図書館) / 30643 / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 渡辺 宏, 教授 金谷 利治, 教授 山本 量一 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

The atrocities committed by the Nazis during the second world war meant that the public view of Nazism and fascism in the late 1940s and early 1950s was at a record low. In many countries the government actively sought to combat organizations professing a loyalty to fascism and many groups all over Europe struggled to find new followers and support in the post-war era. In wake of this there were an interesting development within post-war fascist organisations. As a result of their inability to gain support in their nations they began cooperating more with other groups across the borders. One interesting expression of this trend was the formation of a fascist international in 1951. Formed as a result of two international conferences, one in Rome 1950 and one in Malmö 1951, the movement sought to create a federal European state of nationalist states with the purpose of establishing Europe as a third power in the cold war, ideologically independent from the liberal USA and communist Soviet bloc. At Malmö it was decided to form an umbrella organisation named Europäische Soziale Bewegung (ESB), the European social movement. Furthermore, it was decided that the organisation would have permanent secretariat in Malmö which would be organized and led by a commission composed of Per Engdahl, the former SS-officer Karl-Heinz Priester, the French revisionist Maurice Bardéche and the secretary of the MSI Augusto de Marsanich. This study focuses on the correspondence of Per Engdahl during the years of the congresses in order to examine how the personal networks of fascist leaders helped create, form and maintain the international cooperation of ESB. Using the social network perspective argued by Ylva Hasselberg, Leos Müller and Niklas Stenlås, the study found that Engdahl’s connections with key figures in the extreme right played a key part in planning and organizing the congress as well as formulating the ideological programme and the organisations operation. Furthermore, the study found that Engdahl’s network was frequently used to share information and news from the various movements. The study thereafter concludes that Engdahl’s network is good example of how the post-war fascist organisation intertwined and helped develop the international currents of fascism. In doing so, the study contributes to the research of entangled history in transnational fascism studies.

付記する学位プログラム名: 京都大学卓越大学院プログラム「先端光・電子デバイス創成学」 / 京都大学 / 新制・課程博士 / 博士(工学) / 甲第24621号 / 工博第5127号 / 新制||工||1980(附属図書館) / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 竹内 繁樹, 教授 川上 養一, 教授 木本 恒暢 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

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Regardless of the simplicity in molecular structure, polyethylene is used in high-performance applications such as medical prostheses and ballistics. Recent advancements in homogeneous catalysis produced UHMWPE in the low-entangled or dis-entangled state that allowed solvent-free-solid-state processing to achieve ultimate mechanical properties ever achieved for a synthetic polymer. Although several homogeneous complexes are known to produce dis-UHMWPE, existing major challenges are uncontrolled nascent polymer morphology, as a consequence reactor fouling/wall sheeting. In such a scenario, a heterogeneous catalyst that can produce dis-UHWMPE to an extent that the characteristics and properties equivalent to that obtained in homogeneous condition, remains an open challenge. The thesis will discuss the know-how for the synthesis of dis-UHMWPE via heterogeneous route to facilitate industrial production by following fundamental understanding of polymerization catalysis, physics, processing, and testing. In this thesis, in-situ formed nano activator/support MgClx/EtnAly(2-ethyl-1-hexoxide)z is employed with a highly active bis[N-(3-tert-butylsalicylidene)pentafluoroanilinato] titanium (IV) dichloride (Cat. 1) for synthesis of dis-UHMWPE. In addition, the relatively easy formation of the MgClx/RnClmAly(OR’) activators/supports allows tailoring by the selection of different aluminum-alkyls and alcohols, giving access to a variety of co-catalysts. This investigation resulted in UHMWPE having Mw from 3 to an unprecedented 43 M g/mol and Ð from 3 to 38 with very high activities up to 2750 kgPE molcat.-1 bar-1 h-1. The adopted route resulted in nano-support that allows tailoring of the entangled state and control over the nascent morphology without reactor fouling, thus providing feasibility of pursuing the polymerization via a continuous process. The nascent polymer shows formation of single crystals of linear UHMWPE and is suggestive of the low-entangled state. The topological differences, with the commercial entangled sample, are identified solid-state NMR, DSC, and rheology. The disentangled crystals allowed desired chain orientation for securing unprecedented tensile modulus (>200 N/tex) and tensile strength (>4.0 N/tex) via solid-state processing. Additionally, the investigation of creep response in the uniaxial tapes has revealed strong influence of molecular weight and entanglement density. These unique characteristics and unprecedented mechanical properties are equivalent to that perceived using a homogeneous catalysis and are the first of their kind achieved for a polymer synthesized using a heterogeneous catalysis.

<p dir="ltr">Some of the simplest molecules that are found in abundance in nature, like oxygen, nitrogen, carbon dioxide and water can be playgrounds for complex quantum mechanical phenomenon. Although we can calculate their static properties, like binding energies, equilibrium geometries and ionization/decay rates with extraordinary precision, their dynamics offer new avenues for exploration. Although analytical techniques have been successfully applied in studying single-particle and many-particle systems, few-particle systems like simple molecules are still best understood through a combination of numerical calculations and experimental work. However, the small size of these molecules endows them with dynamics that occur on timescales of a few picoseconds to a few attoseconds, making their experimental study challenging. The overarching goal of this work is the study of such ‘ultrafast’ dynamics in excited state molecules/atoms, by developing and demonstrating novel optical probes of quantum dynamics.</p><p dir="ltr">One way to probe ultrafast dynamics in molecules is by measuring their nonlinear optical response. Such a measurement can potentially track the evolution of the symmetries of excited molecules, shedding light on their transient dynamics. We start chapter 1 with a brief discussion of the formalism behind nonlinear optical spectroscopy. Direct measurement of ultrafast (and ultraweak) optical pulses is discussed as a useful probe of nonlinear processes. After presenting preliminary results on direct electric field reconstruction, experimental work on measuring emitted nonlinear electric fields from impulsively aligned molecules is discussed. In such an experiment, however, contributions from both aligned and unaligned molecules are present, and new experimental capabilities had to be developed to disentangle and measure the ultraweak signal from aligned molecules. Following a detailed discussion of the developed measurement capabilities, results from experiments done on aligned carbon dioxide and nitrogen molecules are discussed.</p><p dir="ltr">Unlike solids, where electronic states can be excited with visible/UV light, binding energies in isolated atoms/molecules are on the order of electron-volts (eVs), and they need vacuum-ultraviolet (VUV) extreme-ultraviolet (EUV) light to excite electronically. Polyatomic molecules, like ethylene, when excited to an electronic state with VUV light, often relax back to the ground state by redistributing energy to their internal degrees of freedom non-adiabatically. These relaxation pathways are important in many chemical and biological systems, and control the yield of chemical reactions ranging from elementary reactions involving few atoms to large biomolecules such as DNA and proteins. For instance, in the photochemical reaction of the protein Rhodopsin, considered to be the primary event in human vision. In chapter 2 we discuss progress made towards extending nonlinear response measurements to study ultrafast dynamics in electronically excited molecules, using a high-harmonic VUV source. Details about the design of the high-harmonic generation beamline, and preliminary experimental data are presented. In chapter 3 we discuss preliminary theoretical work on the development of an EUV entangled-photon source, using two-photon emission from the metastable 2s state in neutral Helium. Such a source, if demonstrated, can possibly even extended to the zeptosecond regime in the future.</p>

No / Using SANS to map the deformation of individual polymer chains in the vicinity of re-entrant corners in a contraction−expansion flow, we show that stress singularities at such corners, predicted by formulations of fluid dynamics that lack a molecular basis, do not cause extreme deformation of the chains. Multiscale modeling based on a nonlinear tube theory incorporating appropriate relaxation processes quantitatively reproduces the observed scattering, thus providing further evidence for the universality of the tube model for polymer flow.

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No description available.

In this thesis, synthesis, characterization and electrical transport of Carbon nanotubes (CNTs) have been discussed. The first chapter contains a brief introduction of various forms of carbon including CNT. The CNTs are currently the materials of intense research interest due to their remarkable mechanical and electrical properties. CNTs can be visualized as a graphene sheet that has been rolled into a seamless tube. CNTs are either single-walled carbon nanotubes (SWCNT) or multi-walled carbon nanotubes (MWCNT). SWCNT is a tube with only one wall and MWCNT has many coaxial tubes and weak Van der Waal forces hold them together. The properties depend on chirality, diameter and length of the tubes. Chirality is defined by the symmetry and the chiral angle formed between the carbon bonds. The atomic structure of CNTs is described in terms of the tube chirality, which is defined by the chiral vector Ch and the chiral angle . The chiral vector is Ch = na1 + ma2, where the integers (n, m) are the number of steps along the zig-zag carbon. Depending on the tube chirality the electrical properties of the CNTs differ; they can be metallic or semiconducting. When n-m = 3p, where p is an integer, the CNTs are metallic and when n-m  3p, the CNTs are semiconducting. Due to the high anisotropy and high aspect ratio, CNTs have many potential applications with great technological importance such as functionalized molecules, conductive wires, bearings of rotational motors, field emitters, hydrogen storage, sensors, polymer composites, nanotube yarn and nanotube filters, X-ray generator, electron sources for microscopy and lithography, gas discharge tubes and vacuum microwave amplifiers, etc. The first chapter gives a brief introduction about various forms of carbon and their properties, particularly of CNTs. The nature of the CNTs depends on the method of production, which controls the degree of graphitization, the tube diameter and the chirality. Most synthesis methods originate from the idea of obtaining adequately active carbon atomic species or clusters from carbon sources and assembling them into CNTs without or with catalysts. The commonly used methods for the synthesis of carbon nanotubes are arc-discharge, Laser ablation, high-pressure catalytic decomposition of carbon monoxide (HiPCO), electrophoretic deposition (EPD), flame synthesis, pyrolysis, chemical vapour deposition (CVD), hot-filament CVD, plasma enhanced chemical vapour deposition (PECVD) using DC, RF, and micro wave power sources, hot-filament dc (HF-dc PECVD), inductively coupled plasma (ICPECVD) and electron cyclotron resonance (ECR PECVD). Although many efforts have been made to develop various synthesis methods, most of them require many steps. Moreover, the complicated and rigorous control of parameters and expensive materials are unavoidable that has put limitation in reproducing the same in large scale. In this chapter, a simple method for the synthesis of CNTs on a large scale that eliminates nearly the entire complex and expensive machinery associated with widely used growth techniques has been discussed. In Chapter 2, the synthesis and characterization of entangled CNTs are discussed. It is shown that entangled CNTs can be synthesized in one step by using double stage furnace. Tetrahydrofuran as carbon source material and nickelocene as catalyst source material have been used to synthesize CNTs. With this method CNTs can be synthesized at a temperature as low as at 600 0C. In this technique the self-developed pressure carries the vapours to the hot zone of the furnace. This has led to think in modifying the double stage furnace. A single stage furnace having temperature gradient is made to synthesize CNTs. The vapours are carried from low temperature zone to hot zone where the carbon species and catalysts react to form CNTs. The advantage of this furnace is that it is one-step process. Using another carbon source material such as Diethyl Ether and nickelocene as catalyst source material CNTs are synthesized. The as synthesized and purified CNTs are characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), transmission electron microscope (TEM), high resolution TEM (HRTEM) and Raman spectroscopy. The CNTs are multi-walled in nature as observed by HRTEM. In Chapter 3, the synthesis of aligned CNTs is discussed by using benzene as carbon source and ferrocene as catalyst source materials. Aligned MWCNTs were synthesized in the temperature range between 650 - 1100 0C in a single stage furnace without the need for carrier gas nor predeposited metal catalyst substrate. The essential need of CNTs are (1) to obtain aligned nanotubes with millimeter lengths to enable the formation of novel nanotube-polymer composites that incorporate continuous nanotubes throughout their thickness for highly anisotropic thermal and electrical conductivities; and (2) to provide samples for detailed physical characterization - tensile strength, thermal, electrical conductivity, field emission etc. SEM observation reveals the increase in length of nanotubes from 85 m to 1.4 mm with the increase of preparation temperature. The diameter as investigated by high-resolution transmission electron microscopy (HRTEM) remains almost constant 70-80 nm (75-85 layers). Once nanotube formation is established, the growth continues in the same direction and may well be reinforced by the presence of surrounding CNTs i.e. almost every particle produces a nanotube and bundling of neighboring tubes lead to collective vertical growth. The increase in length is due to the enhanced diffusion of active carbon with increasing preparation temperatures. The alignment of CNTs is also observed to the lateral side of the substrate. In Chapter 4, the synthesis and characterization of carbon nanoribbon and singled crystal iron filled CNTs is discussed. Particularly interesting are those CNTs filled with magnetic nanowires, which can provide an effective barrier against oxidation and consequently ensure a long-term stability in the core. The filling of metals within carbon nanotubes has extended the potential application base of these materials to quantum memory elements, high density magnetic storage media, semiconducting devices, field electron emitters, high resolution magnetic atomic force microscopy tips, magnetic field sensors and scanning probe microscopes etc. Tetrahydrofuran as carbon source material and ferrocene as catalyst materials has been used to synthesize mixture of carbon nanoribbons and iron filled CNTs. The techniques used to characterize the materials are XRD, SEM, HRTEM and superconducting quantum interference device (SQUID). The powder XRD pattern shows that the bcc -Fe phase of iron is present. HRTEM studies reveal the presence of multi-walled carbon nanotubes and well-crystallized -Fe phase filled inside the core region. Closer inspection of the HRTEM images indicated that the bcc structure -Fe nanowires are monocrystalline and Fe (110) plane is indeed perpendicular to the G (002) plane. Large coercivity (i.e. 1037 Oe at 300 K and 2023 Oe at 10 K) in the iron filled CNTs and carbon nanoribbons have been observed. The high coercivity is mainly attributed to the following two factors. Firstly, it is known that due to the uniaxial magnetic anisotropy of the nano size iron in the core region of the carbon nanotubes. Secondly, ferromagnetic behavior exhibited by the localized states at the edges of the carbon nanoribbons. The anisotropic electrical transport property of MWCNTs has been discussed in the chapter 5. The activated diffusive nature of transport along axial direction of CNT is explained. The transport perpendicular to the tube direction is explained in terms of a hopping mechanism. The anisotropic resistivity (N/P) value obtained is 3. The temperature dependent magnetoresistance (MR) is studied in magnetic fields up to 11 Tesla at low temperatures both in the parallel and perpendicular direction of an aligned MWCNT mat. In both cases a negative MR is observed. Chapter 6 discusses the preparation of CNT-polymer composites. The temperature dependence of the conductivity and magnetoresistance (MR) has been studied making four-point contact method on the carbon nanotubes polymer composites as result of increasing CNT content. The conductivity increases with increasing carbon nanotube weight percentage. The increase in conductivity as a function of the CNT weight percent is attributed to the introduction of conducting CNT paths in the polymer matrix. With the increasing CNT content the number of interconnections present in a random system is found to vary. Electrical conduction in nanotube mat or nanotube composites is explained by a variable range hopping (VRH) conduction mechanism. The negative magnetoresistance has been observed for the polymer composites. It is consistent with the report on CNTs bundles and polymer composites. Finally a brief summary of the work presented in this dissertation is discussed along with future directions in this research.