The diploma thesis deals with the design of selected parts of reinforced concrete elements of the exhibition room. Simultaneously, the optimization of selected elements according to valid standards and Eurocodes was carried out and the impact of these changes on the economy of construction was developed.

This thesis addresses the study and preparation of documentation for the new building firehouse. The building is considered the location of the fire brigade units. The building is part three storey and part two storey. The building has a steel skeletal support system to ensure stability. The ceiling structure is a composite concrete and steel. Roofed building's flat roof with a classic sequence of layers. Circuit structures are formed with Z and C profiles. Filled with mineral wool. The facade is ventilated. The ground plan is rectangular object, the maximum dimensions are 55,15x27,30 m. The building is basement, covered only with flat roofs.

In this paper, a nanometer-sized gold electrode with an effective radius around several tens of nanometers has been modified with a monolayer of alkanethiols. There are pinholes in the monolayer, and the pinholes can be used as very small electrode. Our evaluation shows that it is possible to have only one pinhole on the monolayer covered electrode. The single pinhole electrode has been used to study the electrochemical behaviors of fast and slow electrochemical reactions. Our results show that the electrochemical response of a slow electrochemical reaction is not a Butler-Volmer response if the electrode is small enough.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20702号 / 工博第4399号 / 新制||工||1683(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 杉村 博之, 教授 河合 潤, 教授 邑瀬 邦明 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23897号 / 工博第4984号 / 新制||工||1778(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 杉村 博之, 教授 山田 啓文, 教授 邑瀬 邦明 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Chemoreceptor dimers mediate bacterial chemotaxis through receptor arrays that form complexes with CheW and the kinase CheA. Both kinase activity and the rate of receptor methylation have been observed to change with receptor density in the signaling complexes of an assembled system. Receptor dimers play a structural and functional important role during the signaling process. The dimer is an established unit of a functional receptor array, but the exact packing arrangement of dimers in the signaling array is not known in detail. Two different models of the packing arrangement have been proposed, based on crystal structures of receptor cytoplasmic fragments: the trimer of dimers and hedgerow models. Here, we determine the importance of CF dimer organization on density dependence of kinase activity, receptor methylation, and we probe CF trimer organization by site-directed TMEA cross-linking. CF dimers were prepared by site-directed cysteine disulfide bond formation to test for a possible monomer-dimer equilibrium process in the density-dependence of kinase activity in the vesicle-assembled system. We found that density transition observed for CF4E is similar for both reduced and disulfide-linked CF, indicating that the CF is organized as dimers even at lower densities. CheR-catalyzed methylation experiment revealed that disulfide-linked CF dimers in solution are insufficient for efficient methylation, assembly of the CFs on a vesicle surface is required. CF trimers were trapped by the trifunctional crosslinker TMEA, but only with vesicle assembled CFs. TMEA crosslinking occurred between residues that were expected to form trimer, but also those that were not. The results provide evidence that CF behavior is highly dynamic in maleimide crosslinking reaction which conducted on vesicle assembled system.

Solar photovoltaics (PV) is expected to be a critical contributor to mitigating the effects of climate change by helping to satisfy net zero emissions. Since crystalline silicon-based solar cells are close to their practical efficiency limit, further reducing the balance of system (BoS) costs is only possible by increasing the cell efficiencies. The most promising candidate is perovskite/silicon (Si) tandem solar cell technology, which allows efficient solar spectrum harvesting. This relatively new technology attracts attention due to its potential to dominate the PV market; however, it also brings challenges that must be overcome, like stability and scalability concerns. This thesis project focuses on optimizing and characterizing recombination junctions (RJs) for monolithic perovskite/Si tandem solar cells aimed at improved performance and stability. Tandem solar cell PV parameter measurements, encapsulated stability measurements, and thin film characterizations are performed for RJ developments. The optimizations are performed for tandem solar cells with solution-processing and hybrid methods. Self-assembled monolayer (SAM) molecules and transparent conductive oxide (TCO) recombination layer (RL) combinations are optimized to obtain tandems with hybrid technique. In addition, the influence of the thickness of TCO RL on the tandem devices’ performance is also investigated, particularly solution-processed tandems. The improvements are observed by thinning down the thickness of TCOs regardless of the material type. 3 Characterizations revealed that ultra-thin ( 5 nm) amorphous indium zinc oxide (IZO) RL allows more workfunction shift, homogeneous surface potential distribution with SAM deposition, and better carrier recombination suppression at the perovskite/hole transport layer (HTL) interface. Ultra-thin RL idea is combined with some optical improvements in the device architecture, and stable high-efficient perovskite/Si tandem solar cells with 32.5% power conversion efficiency (PCE) and 80% fill factor (FF) values are realized. In addition, the preliminary examples of tandem devices with a larger active area (4 cm2 ) are presented. Finally, the remaining challenges and alternative concepts are also discussed.

Hydrogen evolution via proton reduction occurs at a high rate at the surface of Pt than at Au electrodes. Using cyclic voltammetry, chemically modified nanometer-sized Au electrodes, prepared by the Laser-Assisted Puller Method, were employed to examine current amplification by electrocalysis at Pt nanoparticles adsorbed on the modified Au electrode surfaces. The electrodes were modified with Self-Assembled Monolayers (SAMs) of cysteamine and soaked in Pt colloid solutions overnight. Monitoring the decrements of the characteristic steady-state catalytic current for proton reduction indicated that aggregates of Pt nanoparticles are adsorbed on the cysteamine monolayers and desorb from them particle by particle. The results also indicate that some particles are strongly attached to the modified electrode surface and do not deplete even after thorough rinsing.

This dissertation demonstrated that the manipulation of substances at the molecular or nanometer level can lead to the discovery and development of new materials with interesting properties and important applications. Chapter 1 describes the development of a nanoscale molecular thin film material for corrosion protection. By using a self-assembled monolayer film with a thickness of only about 1 nanometer as a linkage, a covalent bonding was achieved between a polyurethane top coating and an aluminum alloy substrate. This covalent bonding between polymer top coating and the aluminum alloy substrate significantly improved the corrosion resistance of the substrate. Chapter 2 and Chapter 3 describe the development of a gold nanoparticle-polymer composite material in different forms with a number of applications. Gold nanoparticles are among one of the most extensively studied nanomaterials. When the size of gold is shrunk to the nanometer scale, many interesting and new physical properties start to appear from gold nanoparticles. The optical properties of gold nanoparticles, particularly the surface plasmon resonance absorption, have been investigated in this dissertation for the development of multifunctional nanocomposite materials. Chapter 2 presents the preparation of a gold nanoparticle/poly(methyl methacrylate) (PMMA) nanocomposite film and the application of such films for microstructure fabrication using a direct laser writing technique. Gold nanoparticles are excellent photon-thermal energy converters due to their large absorption cross section at the surface plasmon resonance region. Upon laser irradiation of the nanocomposite film, the thermal energy converted from the absorbed photon energy by gold nanopaticles induced a complete decomposition of PMMA, leading to the formation of various microstructures on the nanocomposite films. Chapter 3 reports the further development of a nanoparticle/polymer composite nanofiber material fabricated through an electrospinning process. The matrix of the nanofiber is made of two polyelectrolytes, poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH). Three methods were developed to incorporate gold nanoparticles into the polymer matrix. The composite nanofiber materials developed in this study demonstrate multifunctional properties, including good electrical conductivity, photothermal response, and surface-enhanced IR absorption. This material may be used for many important applications including catalysis, chemical and biological sensors, and scaffold materials for tissue engineering. In Chapter 4, another most important nanomaterial, carbon naotubes (CNTs), were introduced as fillers to prepare polymer nanocomposites. A dispersion method for multi-walled carbon nanotubes (MWCNTs) using a conjugated conducting polymer, poly(3-hexylthiophene) (P3HT) as the third component and trifluoroacetic acid (TFA) as a co-solvent was developed. Due to the excellent dispersion of carbon nanotubes in PMMA and enhanced conductivity of the nanocomposites by the conjugated conducting polymers, the prepared composite materials has an extremely low percolation threshold of less than 0.006 wt% of MWCNT content. The potential use of MWCNT/conducting polymer composites for energy storage applications such as suppercapacitors was further investigated by Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and charging-discharging cycles. Compared to pure carbon nanotubes, the nanocomposite materials have significantly improved properties and are promising for supercapacitor applications.

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