This is a bachelor's thesis in Mechanical engineering. The main topic of the thesis is the electrical calculation of the tap changer's shield. Although there are many kinds of tap-changers, this study focuses on VUCL models. The theoretical background of the thesis is that the new shield is suitable and useable in all VUCL models. The primary topic of the thesis is to study that the new shield protects the resistance box in the middle of the tap changers. To do this study, Creo Parametric, Comsol, and SpaceClaim are the programs used. / Detta är en kandidatexamen i maskinteknik. Avhandlingens huvudämne är den elektriska beräkningen av kranbytarens sköld. Även om det finns många olika typer av lindnings fokuserar denna studie på VUCL modeller. Den teoretiska bakgrunden för avhandlingen är att den nya skölden är lämplig och användbar i alla VUCL-modeller. Det primära ämnet för avhandlingen är att studera det nya sköld skyddar motståndet rutan i mitten av lindningskopplare. För att göra denna studie är Creo Parametric, Comsol och SpaceClaim de program som används.

Detta examensarbete utreder den tekniska och ekonomiska passbarheten av batterilagringssystem (BESS) inom den svenska el infrastrukturen. Syftet är att konstruera tre olika affärsfall för att representera den tekniska och den ekonomiska passbarheten av BESS inom den svenska el infrastrukturen, specifikt med uppkoppling mot distributionsnätverket på den regionala nivån, 6 kilovolt till 132 kilovolt (kV). Affärsfallen adresserar dem tekniska funktioner och kunder inom infrastrukturen som utifrån en litteraturstudie anses vara dem mest attraktiva att bygga ett affärsfall utifrån. Litteraturstudien utreder den svenska el infrastrukturens struktur samt dess existerande och uppkommande utmaningar. Studien utforskar även hela spektrumet energilagringssystem (ESS) för att rättfärdiga valet av litium-jon BESS. Litium-jon BESS är närmare undersökt, där systemets operativa parametrar samt komponenter är kartlagda. Vidare undersöks dem tekniska funktionernas tekniska krav och ekonomiska incitament i en marknadsanalys. Slutligen utforskas regler och lagar omkring BESS implementering i den svenska el infrastrukturen samt placeringen och de kostnader för att bygga en BESS anläggning. De tre affärfallen som är konstruerade i denna studie är: Kombinationen av frekvensrelaterade nätverksstödtjänster för en fristående BESS-tillgångsoperatör. Avbrottsfri strömtillförsel för ett datacenter. Skala effekttoppar och kombination av frekvensrelaterade nätverksstöddtjänster för en industri. Litium-jon BESS anses vara den mest tillämpliga tekniken på grund av dess snabba responstid, höga effekt- och energidensitet samt skalbarheten för att passa majoriteten av de tekniska funktioner som undersökts inom studien. Affärsfallens ekonomiska passbarhet utvärderas efter två ekonomiska indikatorer, nuvärdesberäkning (NPV) samt återbetalningstiden. Affärsfall nummer tvås tekniska funktion erbjuder ingen möjlighet att generera en inkomst vilket gör att den kommer bli utvärderad efter kostnad för service, där utgifterna är uppdelade utöver projektets livstid genom linjär amortering. Vidare används linjär amortering för att räkna ut kostnaden per kilo sparat CO2 utöver livstiden på projektet. Både affärsfall 1 (NPV= 231,0 MSEK, återbetalningstid= 7,8 år) samt affärsfall 3 (NPV= 17,3 MSEK, återbetalningstid= 8,8 år) visar en lönsamhet där affärsfall 2 ger en kostnad för service mellan 5,4 och 5,8 MSEK/år och där kostnaden per sparat kilo CO2 mellan 20,9 och 22,7 SEK/kg CO2. Denna studie fokuserar på de tre största distributionsnätverksoperatorerna (DNO) inom distributionsnätverket på en regional nivå: Vattenfall, Eon och Ellevio. Lönsamheten av de undersökta affärsfallen är starkt kopplade till placeringsområde inom nätverket, spänningsnivån och typ av DNO. Möjlighet att koppla upp BESS till en existerande transformatorstation på anläggningen för affärsfall två och tre minskar investeringskostnaden samt driftkostnaderna vilket vidare förbättrar dess lönsamhet. Affärsfall ett behöver gå igenom en noggrann bedömning för att försäkra sig om lönsamheten. NPV samt återbetalningstiden kan påverkas i affärsfall ett och tre på grund av den ständigt förändrande frekvensregleringsmarknaden där priserna är volatila på grund av nya marknadsinitiativ. Att konstruera ett BESS affärsfall medför att flertalet osäkerheter bör räknas in, såsom de ekonomiska incitamenten som inte visar någon garanti på att vara fortsatt lönsamt. Det höga priset på litium-jon batterier saktar ner attraktiviteten av affärsfallen och måste vidare sjunka för att främja ett lönsamt affärsfall. Andra ESS som flödesbatterier och vätgaslagringssystem visar god passbarhet att bli implementerad i den svenska el infrastrukturen men måste vidare utveckla sin tekniska och kommersiella mognadsgrad innan dem kan vara konkurrenskraftiga med litium-jon BESS.  Examensarbetet är utfört i samarbete med Omexom Infratek Sverige AB med målet att bidra till en större förståelse av BESS roll i den svenska el infrastrukturen och vidare bidra till att konstruera ett tekniskt erbjudande för Omexom Infratek Sverige AB. / This master thesis investigates the technical and economic feasibility of battery energy storage systems (BESS) in the Swedish electrical infrastructure. The aim is to construct three business cases to represent the technical and economic feasibility of BESS implementation in the Swedish electrical infrastructure in the distribution network on the regional level, 6 kilovolts to 132 kilovolts (kV). The business cases address the technical functions and customers within the infrastructure that is recognized through a literature study to build the most attractive and incentivized business cases from. The literature study investigates the Swedish electrical infrastructure’s structure and its existing and upcoming challenges. It investigates the spectrum of energy storage systems (ESS) to justify the choice of the lithium-ion (Li-ion) BESS. The Li-ion BESS is closer examined, where the systems operational parameters and components are mapped out. Furthermore, the technical functions technical requirements and economic incentives are investigated in a market analysis. Lastly, considerations regarding regulations and permits, the placement of BESS within the infrastructure and its surrounding costs is evaluated. The three business cases that are constructed within the thesis are:  Combination of frequency related grid support services for a standalone BESS asset operator. Uninterruptable power supply for a data center. Peak shaving and a combination of frequency related grid support services for an industrial plant.  The, Li-ion BESS is considered to most applicable technology due its fast response time, high power and energy density and scalability to suit the majority of technical functions investigated in the thesis. The business cases economic feasibility is evaluated after two economic indicators, the net present value (NPV) and the payback period. Business case two’s technical function offers no possible revenues and is evaluated as a cost for service where the expenses is divided throughout the project lifetime through linear amortization and the cost per saved kg CO2 is calculated over the lifetime of the BESS. Both business case 1 (NPV= 231.0 MSEK, payback period= 7.8 years) and case 3 (NPV=17.3 MSEK, payback period= 8.8 years) show profitability where business case 2 gives a cost per service between 5.4 and 5.8 MSEK/year and cost per saved kg CO2 between 20.9 and 22.7 SEK/kg CO2.  This thesis focuses on the three largest distribution network operators (DNO) in the distribution network on a regional level: Vattenfall, Eon, and Ellevio. The profitability of the business cases investigated are strongly connected to the location in the network, the voltage connection level, and the type of DNO. Being able to connect to an existing substation on site as for business cases 2 and 3 will lower the capital and operational costs and further improve the profitability. Business case 1 needs a thorough assessment of placement in the electrical infrastructure in Sweden to assure profitability. The NPV and payback period in business cases 1 and 3 could conflict with the interchanging frequency regulation market where prices are rather volatile due to new market initiatives. Therefore, looking forward, building a BESS business case to be implemented comes with lots of uncertainties as the economic incentives shows no guarantee to continuously be profitable. The high price of Li-ion batteries is slowing down the attractiveness of the business cases and need to further decrease to promote profitable business cases. Other ESS technologies as flow batteries and hydrogen storage systems show good applicability to be implemented in the Swedish electrical infrastructure but needs to develop its technical and commercial maturity until it can become competitive with Li-ion BESS.  The master thesis is performed in conjunction with Omexom Infratek Sverige AB with the aim to contribute to a broader understanding of the role of BESS in the Swedish electrical infrastructure and to help building BESS technical offers for Omexom Infratek Sverige AB.

In response to the ever-increasing threat of the negative impacts of climate change, there has been a renewed international focus on the integration of renewable energy to meet their demands. One such project is located at Tezpur University in the state of Assam, India. In this project, a large PV project of 1 MWp capacity was installed in 2018, followed by a 91 kWh Li-ion battery system in 2020. While the system has been installed, an optimal operational algorithm (OA) is needed for the system to operate and meet the needs of the connected load. This thesis will consider several OAs for the battery system. The charging schedule for the system will be optimised based on data for the substation system. First, data from the electrical load and power outages with a time resolution of one minute were considered. Upon analysis of this data, an initial algorithm was proposed and its effectiveness was evaluated based on selected key performance indicators (KPIs). Next, a linear programming approach was used to optimise the battery charging schedule based on electricity cost, PV power production, and electric load. Based on the results of the optimisation, input from the proprietors of the energy management system, and results from the initial algorithm, a second advanced algorithm was created and its effectiveness was again evaluated based on the same KPIs. It was found that the two main goals within this project, initiating appropriate charging times to limit grid power usage while also maintaining sufficient energy reserves whenever a power outage occurs. While diesel usage cannot be completely eliminated, it can be greatly reduced for shorter power outages. Additionally, a high degree of load autonomy can be achieved before the diesel generator becomes necessary to activate. / Som svar på det ständigt ökande hotet om klimatförändringens negativa effekter har det skett en förnyad internationell fokus på integrering av förnybar energi för att tillgodose deras behov. Ett sådant projekt finns på Tezpur University i delstaten Assam i Indien. Under detta projekt installerades ett stort solcellsprojekt med en kapacitet på 1 MWp under 2018, med följt av ett 91 kWh Li-ion-batterisystem under 2020. Medan systemet har installerats behövdes en optimal driftalgoritm för att systemet skulle kunna fungera och uppfylla behoven hos den anslutna lasten. I den här avhandlingen kommer flera driftalgoritmer för batterisystemet att diskuteras. Laddningsschemat för systemet kommer att optimeras utifrån data för understationssystemet. Först beaktades data från den elektriska belastningen med en minutupplösning och frekvensen av strömavbrott. Efter analys av dessa data samt föreslogs en första algoritm och dess effektivitet utvärderades utifrån utvalda nyckelindikatorer för prestanda. Därefter användes en metod för multivariabel linjär programmering för att optimera schemat för batteriladdning baserat på elkostnad, produktion av solcellseffekt och elektrisk belastning. På grundval av resultaten av optimeringen, input från ägarna till energihanteringssystemet och resultaten från den ursprungliga algoritmen skapades en andra avancerad algoritm och dess effektivitet utvärderades återigen utifrån samma nyckelindikatorer. Det visade sig att de två huvudmålen inom detta projekt, att initiera lämpliga laddningstider för att begränsa elanvändningen och samtidigt upprätthålla tillräckliga energireserver när ett strömavbrott inträffar. Dieselanvändningen kan inte helt elimineras, men den kan minskas avsevärt vid kortare strömavbrott. Dessutom kan en hög grad av lastautonomi uppnås innan dieselgeneratorn måste aktiveras.

Die vorliegende Arbeit konzentriert sich auf die Synthese von neuartigen hohlen MoSx-Nanomaterialien mit kontrollierbarer Größe und Form durch die kolloidale Template Methode. Ihre möglichen Anwendungen in wässrigen Energiespeichersystemen, einschließlich Superkondensatoren und Li-Ionen-Batterien (LIBs), wurden untersucht. Im ersten Teil wurde eine neue Nanostruktur aus hohlen Kohlenstoff-MoS2-Kohlenstoff-nanoplättchen erfolgreich durch eine L-Cystein unterstützte hydrothermale Methode unter Verwendung von Gibbsit als Templat und Polydopamin (PDA) als Kohlenstoffvorläufer synthetisiert. Nach dem Kalzinieren und Ätzen des Gibbsit Templates wurden gleichförmige Hohlplättchen erhalten, die aus einer sandwichartigen Anordnung von teilweise graphitischem Kohlenstoff und zweidimensional geschichteten MoS2 Flocken bestehen. Die Plättchen haben eine ausgezeichnete Dispergierbarkeit und Stabilität in Wasser sowie eine gute elektrische Leitfähigkeit aufgrund des durch die Kalzinierung von Polydopaminbeschichtungen erzeugten Kohlenstoffs gezeigt. Das Material wird dann in einem symmetrischen Superkondensator mit 1 M Li2SO4 als Elektrolyt aufgebracht, der eine spezifische Kapazität von 248 F/g (0.12 F/cm2) bei einer konstanten Stromdichte von 0.1 A/g und eine ausgezeichnete elektrochemische Stabilität über 3000 Zyklen aufweist, was darauf hindeutet, dass hohle Kohlenstoff-MoS2-Kohlenstoffnanoplättchen vielversprechende Materialien als Kandidaten für Superkondensatoren sind. Im zweiten Teil wurde 21 molare LiTFSI, das sogenannte "Wasser-in-Salz" (WIS) Elektrolyt, in Superkondensatoren mit hohlen Kohlenstoffnanoplättchen als Elektrodenmaterial untersucht. Im Vergleich zu dem im ersten Teil verwendeten 1 molaren Li2SO4-Elektrolyten wurden bei dem vorliegenden WIS Elektrolyt signifikante Verbesserungen in einem breiteren und stabilen Potentialfenster festgestellt, das durch die geringere Leitfähigkeit mit dem Gegenstück leicht beeinflusst wird. Die elektrochemische Impedanzspektroskopie (EIS) wurde ausgiebig eingesetzt, um einen Einblick in die Reaktionsmechanismen der WIS-Superkondensatoren zu erhalten. Zusätzlich wurde auch der Einfluss der Temperatur auf die elektrochemische Leistung im Temperaturbereich zwischen 15 und 55 °C untersucht, was eine hervorragende spezifische Kapazität von 128 F/g bei dem optimierten Zustand von 55 °C ergab. Die EIS-Messungen deckten die Abnahme der angepassten Widerstände mit der Temperaturerhöhung und umgekehrt auf und beleuchteten direkt die Beziehung zwischen elektrochemischer Leistung und Arbeitstemperatur von Superkondensatoren für zuverlässige praktische Anwendungen. Im dritten Teil wurde MoS3, ein amorphes, kettenförmig strukturiertes Übergangsmetall Trichalcogenid, als vielversprechende Anode in "Wasser-in-Salz" Li-Ionen-Batterien (WIS-LIBs) nachgewiesen. Die in diesem Teil verwendeten hohlen MoS3-Nanosphären wurden mittels einer skalierbaren Säurefällungsmethode bei Raumtemperatur synthetisiert, wobei sphärische Polyelektrolytbürsten (SPB) als Schablonen verwendet wurden. Beim Einsatz in WIS-LIBs mit LiMn2O4 als Kathodenmaterial erreicht das präparierte MoS3 eine hohe spezifische Kapazität von 127 mAh/g bei einer Stromdichte von 0.1 A/g und eine gute Stabilität über 1000 Zyklen sowohl in Knopf- als auch in Pouch-Zellen. Der Arbeitsmechanismus von MoS3 in WIS-LIBs wurde auch durch Ex-situ-Röntgenbeugungsmessungen (XRD) untersucht. Während des Betriebs wird MoS3 während der anfänglichen Li-Ionen-Aufnahme irreversibel in Li2MoO4 umgewandelt und dann allmählich in eine stabilere und reversible LixMoOy-Phase (2≤y≤4)) entlang der Zyklen umgewandelt. Amorphes Li-defizientes Lix-mMoOy/MoOz wird bei der Delithiierung gebildet. Die Ergebnisse der vorliegenden Studie zeigen einfache Ansätze zur Synthese hohler MoSx-Nanomaterialien mit kontrollierbarer Morphologie unter Verwendung einer Template-basierten Methode, die auf die vielversprechende Leistung von MoSx für wässrige Energiespeicheranwendungen zurückzuführen sind. Die elektrochemischen Untersuchungen von hohlen MoSx-Nanomaterialien in wässrigen Elektrolyten geben Einblick in die Reaktionsmechanismen von wässrigen Energiespeichersystemen und treiben die Entwicklung von Metallsulfiden für wässrige Energiespeicheranwendungen voran. / The present thesis focuses on the synthesis of novel hollow MoSx nanomaterials with controllable size and shape through the colloidal template method. Their possible applications in aqueous energy storage systems, including supercapacitors and Li-ion batteries (LIBs), have been studied. In the first part, hollow carbon-MoS2-carbon nanoplates have been successfully synthesized through an L-cysteine-assisted hydrothermal method by using gibbsite as the template and polydopamine (PDA) as the carbon precursor. After calcination and etching of the gibbsite template, uniform hollow platelets, which are made of a sandwich-like assembly of partial graphitic carbon and two-dimensional layered MoS2 flakes, have been obtained. The platelets have shown excellent dispersibility and stability in water, and good electrical conductivity due to carbon coating generated by the calcination of polydopamine. The material is then applied in a symmetric supercapacitor using 1 M Li2SO4 as the electrolyte, which exhibits a specific capacitance of 248 F/g (0.12 F/cm2) at a constant current density of 0.1 A/g and an excellent electrochemical stability over 3000 cycles, suggesting that hollow carbon-MoS2-carbon nanoplates are promising candidate materials for supercapacitors. In the second part, 21 m LiTFSI, so-called “water-in-salt” (WIS) electrolyte, has been studied in supercapacitors with hollow carbon nanoplates as electrode materials. In comparison with 1 M Li2SO4 electrolyte used in the first part, significant improvements on a broader and stable potential window have been revealed in the present WISE, which is slightly influenced by the lower conductivity with the counterpart. The electrochemical impedance spectroscopy (EIS) has been extensively employed to provide an insight look on the formation of solid electrolyte interphase in the WIS-supercapacitors. Additionally, the effect of temperature on the electrochemical performance has also been investigated in the temperature range between 15 and 55 °C, yielding eminent specific capacitance of 128 F/g at the optimized condition of 55 °C. The EIS measurements disclosed the decrease of fitted resistances with the increase of temperature and vise versa, directly illuminating the relationship between electrochemical output and working temperature of supercapacitors for reliable practical applications. In the third part, MoS3, an amorphous chain-like structured transitional metal trichalcogenide, has been demonstrated as a promising anode in the “water-in-salt” Li-ion batteries (WIS-LIBs). Hollow MoS3 nanospheres used in this part have been synthesized via a scalable room-temperature acid precipitation method using spherical polyelectrolyte brushes (SPB) as the template. When applied in WIS-LIBs with LiMn2O4 as the cathode material, the prepared MoS3 achieves a high specific capacity of 127 mAh/g at the current density of 0.1 A/g and good stability over 1000 cycles in both coin cells and pouch cells. The working mechanism of MoS3 in WIS-LIBs has also been studied by ex-situ X-ray diffraction (XRD) measurements. During operation, MoS3 undergoes irreversible conversion to Li2MoO4 during the initial Li ion uptake, and is then gradually converted to a more stable and reversible LixMoOy (2≤y≤4)) phase along cycling. Amorphous Li-deficient Lix-mMoOy/MoOz is formed upon delithiation. The results in the present thesis demonstrate facile approaches for synthesizing hollow MoSx nanomaterials with controllable morphologies using a template-based method, which attribute to the promising performance of MoSx for aqueous energy storage applications. The electrochemical studies of hollow MoSx nanomaterials in aqueous electrolytes provide insight into the reaction mechanisms of aqueous energy storage systems and push forward the development of metal sulfides for aqueous energy storage applications.

La protéine p53 répond à divers stress cellulaires pour induire l'apoptose et l'arrêt du cycle cellulaire. Cela permet à p53 de maintenir l'intégrité du génome, et la fonction de p53 est d'une importance capitale dans la suppression de l'oncogenèse cellulaire. En réponse à divers stress, p53 induit une activation transcriptionnelle par stabilisation, tétramérisation et activation. C'est pourquoi des mutations du gène TP53 sont fréquemment trouvées dans tumeurs. L'homotétramérisation de la protéine p53 via le domaine de tétramérisation est essentielle pour l'expression fonctionnelle de p53, et l'activité transcriptionnelle de p53 est fortement corrélée à la stabilité de la structure tétramérique. p53 a été exprimée depuis les premiers vertébrés jusqu'aux mammifères et aux oiseaux. p53 est en équilibre entre les formes monomériques et tétramériques, et le domaine de tétramérisation de p53 (p53TD) forme une structure ba. En revanche, les poissons tels que le poisson zèbre ont une deuxième hélice dans leurs protéines p63 et p73. p63 et p73 sont des homologues de p53, et il a été démontré que p63 est impliqué dans le développement et la différenciation des organes ectodermiques, et p73 dans le développement du système nerveux. On sait également que p63 et p73 forment des hétérotetrameres pour se réguler négativement l'un l'autre, alors que p53 ne forme pas. Malgré l'importance du rôle de la famille p53 dans l'évolution, les changements dans la stabilité de sa structure tétramérique et leur effet sur sa fonction ne sont pas clairs. C'est pourquoi nous avons tenté d'élucider le mécanisme moléculaire basé sur la structure tétramérique de p53. Dans cette étude, nous avons analysé les effets des mutations dans les tumeurs malignes et des substitutions dans la séquence du domaine de tétramérisation de p53 au cours de l'évolution sur la formation du tétramère, sa stabilité structurelle et la formation d'hétérotétramères, et nous avons étudié le rôle de la fonction de tétramérisation dans les fonctions spécifiques des protéines de la famille p53. La thèse contient cinq chapitres. Le chapitre 1 décris le rôle de la protéine p53 et du domaine de tétramérisation dans la régulation de son activité. Dans le chapitre 2, je détermine l'importance des effets négatifs dominants des mutations du domaine de tétramérisation de p53 dans le syndrome de Li-Fraumeni (LFS). Chapitre 3 discute des différences entre les espèces en ce qui concerne la stabilité structurelle de p53TD au cours de l'évolution des mammifères et des facteurs qui contribuent à ces différences. Dans le chapitre 4, je discute de la structure et de la stabilité des domaines de tétramérisation de p53 chez plusieurs espèces de vertébrés, et en particulier chez les poissons, ainsi que de l'analyse de la formation de l'hétérotramère p53-p63. Dans le dernier chapitre 5, je donne des conclusions. En conclusion, ces études permettent de clarifier l'importance de la formation du tétramère p53 dans l'expression fonctionnelle des membres de la famille p53 et les mécanismes moléculaires de stabilité et d'hétérogénéité dans la formation du tétramère. Cette étude apporte de nouvelles perspectives sur la régulation fonctionnelle et l'évolution d'autres protéines multimériques. / The p53 protein responds to various cellular stresses to induce apoptosis and cell cycle arrest. This enables p53 to maintain genome integrity, and p53 function is of paramount importance in the suppression of cellular oncogenesis. In response to various stresses, p53 induces transcriptional activation through stabilization, tetramerization, and activation. Therefore, mutations in the gene TP53 are frequently found in tumors. 　 The homotetramerization of p53 protein via the tetramerization domain is essential for the functional expression of p53, and p53 transcriptional activity is strongly correlated with the stability of the tetrameric structure. p53 has been expressed from the early vertebrates to mammals and birds. p53 is in equilibrium between monomeric and tetrameric forms, and the p53 tetramerization domain (p53TD) forms a ba structure. In contrast, fish such as Zebrafish have a second helix in their p63 and p73 proteins. p63 and p73 are p53 homologues, and it has been shown that p63 is involved in the development and differentiation of ectodermal organs, and p73 in the development of the nervous system. It is also known that p63 and p73 form heterotetramers to negatively regulate each other, while p53 does not. Despite the importance of the role of the p53 family in evolution, changes in the stability of its tetrameric structure and its effect on its function are not clear. Therefore, we attempted to elucidate the molecular mechanism based on the p53 tetramer structure. In this study, we analyzed the effects of mutations in malignant tumors and substitutions in the p53 tetramerization domain sequence during evolution on tetramer formation, its structural stability, and heterotetramer formation, and investigated the role of the tetramerization function in the specific functions of the p53 family proteins. The thesis contains five chapters. Chapter 1 describes the role of the p53 protein and the tetramerization domain in regulating its activity. In Chapter 2, I determine the importance of dominant negative effects of mutations in the p53 tetramerization domain in Li-Fraumeni syndrome (LFS). Chapter 3 discusses the species differences in p53TD structural stability in mammalian evolution and the factors that contribute to these differences. In Chapter 4, I discuss the structure and stability of the p53 and p63 tetramerization domains in several vertebrate species, and in particularly fish species, as well the analysis of p53-p63 heterotetramer formation. In the final Chapter 5, I provide the conclusions of this study. In conclusion, these studies help to clarify the importance of the formation of the p53 tetramer in the functional expression of p53-family members and the molecular mechanisms of stability and heterogeneity in tetramer formation. This study provides new insights into the functional regulation and evolution of other multimeric proteins.

Lithium alloys with metallic or semi-metallic elements are attractive candidate materials for the next-generation rechargeable Li-ion battery anodes, thanks to their large specific and volumetric capacities. The key challenge, however, has been the large volume changes, and the associated stress buildup and failure during cycling. The chemo-mechanics of alloy-based electrode materials entail interactions among diffusion, chemical reactions, plastic flow, and material property evolutions. In this study, a continuum theory of two-way coupling between diffusion and deformation is formulated and numerically implemented. Analyses based on this framework reveal three major conclusions. First, the stress-to-diffusion coupling in Li/Si is much stronger than what has been known in other electrode materials. Practically, since the beneficial effect of stress-enhanced diffusion is more pronounced at intermediate or higher concentrations, lower charging rates should be used during the initial stages of charging. Second, when plastic deformation and lithiation-induced softening take place, the effect of stress-enhanced diffusion is neutralized. Because the mechanical driving forces tend to retard diffusion when constraints are strong, even in terms of operational charging rate alone, Li/Si nano-particles are superior to Li/Si thin films or bulk materials. Third, the diffusion of the host atoms can lead to significant stress relaxation even when the stress levels are below the yield threshold of the material, a beneficial effect that can be leveraged to reduce stresses because the host diffusivity in Li/Si can be non-negligible at higher Li concentrations. A theory of coupled chemo-mechanical fracture driving forces is formulated in order to capture the effect of deformation-diffusion coupling and lithiation-induced softening on fracture. It is shown that under tensile loading, Li accumulates in front of crack tips, leading to an anti-shielding effect on the energy release rate. For a pre-cracked Li/Si thin-film electrode, it is found that the driving force for fracture is significantly lower when the electrode is operated at higher Li concentrations -- a result of more effective stress relaxation via global yielding. The results indicate that operation at higher concentrations is an effective means to minimize failure of thin-film Li/Si alloy electrodes.

本篇論文計一冊，約十一餘萬字，主要以西方之符號學理論對李益詩做實際的剖析、 評價、一共分為六章： 第一章緒論：說明研究李益及其詩作之動機，所欲採用的方法及章節之安排。 第二章符號學的文學運用：介紹基本的符號學概念，並歸納數位符號學家及文學批評 家的學說，整理出一套批評中國古典詩的模式，以為實際批評時之標準。 第三章李益的生平及著作：考述作者生平及著作流傳之情形，作為實際批評之參考； 並將李益詩篇依內容大致分為六類，以為下兩章實際批評的基礎。 第四章李益詩剖析（一）從軍詩：實際批評李益詩作中最特出的從軍詩，並附評論。 第五章李益詩剖析（二）：分別實際批評李益之抒懷、詠史、送別、贈答、遊歷及其 他詩作。 第六章結論：前半部總評李益詩之特點及其在文學史上應占的地位；後半部則針對符 號學模式之實際應用提出個人的省思。 研究結困顯示，採用符號學式的批評方法，不但可以正確有效地閱讀詩篇，從而對詩 作本身產生較全面、深刻的了解，同時也能更進一步地認識詩篇寫作之時的文學現象 ，文學傳統及社會、文化等層面，而這方法的純熟與知識的累積，又使我們在面對新 的文學作品時，能夠提出更精確銳利的批評意見。

現今村里組織為台灣地方自治最基層之編組，其運作之健全與否對於地方治理的發展，自有其一定的影響。本文即以里長為研究對象，並以兩個在成立背景及特質強烈對比的里作為研究之個案，探討里長在治理過程是如何拓展個人網絡，並從里長角色、地位與網絡三個部份做點、線、面的分析。 本文的研究方法主要採用參與觀察法並輔以訪談法，觀察地點基本上以里辦公室以及里民會堂為主。而研究問題則要去探討，里長這個角色的目標是如何去完成的？哪些是幫助里長完成角色目標的最適夥伴？里長在治理網絡中要採取何種策略或是工具？接著，里長是如何去拓展能完成角色目標的網絡？ 研究發現部分，本文嘗試提出三點命題：第一個命題：擔任里長的新舊世代會影響其對里長角色的主/被動態度。第二個命題：新世代的里長處理爭議時抱持著資源取向的敵對態度來面對，而舊世代里長則以人情取向的和平態度來應對。第三個命題：新世代的里長在空間資源與物力資源爭取上採取積極取向，人力資源重心放在里民；相對的，舊世代里長在空間資源與物力資源方面採取保守取向，人力資源重心放在政治人物。 / Nowadays the village/Li organization is the most basic unit for Taiwan local self-governance. Its operation has certain influence on the development of local governance. The research objects of this thesis are two Li chiefs who contrast sharply in their background. By analyzing their roles, status and networks, this research attempts to find out how they construct and develop their individual network in the governance process. The research methods of this thesis are participant observation and in-depth interview; the places of observation are the Li office and the public conference hall; the issues of this research are as followed: how is the goal of the Li chief completed? who are the most suitable partners that help the Li chief achieve the goal? what kind of strategies or instruments does the Li chief adopt in the governance network? how does the Li chief develop and construct the network that can achieve the goal? Regarding the findings of the research, this thesis attempts to propose three propositions. The first proposition is that the new and old generation of Li chiefs contribute to the difference between active and passive attitude of the Li chief. The second proposition is that the new generation of Li chief holds a hostile attitude toward disputes, but the old one holds a peaceful attitude in resembling circumstances. The third proposition is that Li chief of the new generation adopts positive orientation toward the spatial and the material resources, and focuses on Li residents in the human resources; however, Li chief of the old generation adopts conservative orientation toward the spatial and the material resources, and focuses on political figures in the human resources.

Three-dimensional macroporous structures (‘opals’ and ‘inverse opals’) can be produced by colloidal crystal templating, one of the most intensively studied areas in materials science today. There are several potential advantages of lithium-ion battery electrodes based on inverse opal structures. High electrode surface, easier electrolyte access to the bulk of electrode and reduced lithium diffusion lengths allow higher discharge rates. Highly open structures provide for better mechanical stability to volume swings during cycling. Silicon is one of the most promising anode materials for lithium-ion batteries. Its theoretical capacity exceeds capacities of all other materials besides metallic lithium. Silicon is abundant, cheap, and its use would allow for incorporation of microbattery production into the semiconductor manufacturing. Performance of silicon is restricted mainly by large volume changes during cycling. The objective of this work was to investigate how the inverse opal structures influence the performance of silicon electrodes. Several types of silicon-based inverse opal films were synthesised, and their electrochemical performance was studied. Amorphous silicon inverse opals were fabricated via chemical vapour deposition and characterised by various techniques. Galvanostatic cycling of these materials confirmed the feasibility of the approach taken, since the electrodes demonstrated high capacities and decent capacity retentions. The rate performance of amorphous silicon inverse opals was unsatisfactory due to low conductivity of silicon. The conductivity of silicon inverse opals was improved by crystallisation. Nanocrystalline silicon inverse opals demonstrated much better rate capabilities, but the capacities faded to zero after several cycles. Silicon-carbon composite inverse opal materials were synthesised by depositing a thin layer of carbon via pyrolysis of a sucrose-based precursor onto the silicon inverse opals in an attempt to further increase conductivity and achieve mechanical stabilisation of the structures. The amount of carbon deposited proved to be insufficient to stabilise the structures, and silicon-carbon composites demonstrated unsatisfactory electrochemical behaviour. Carbon inverse opals were coated with amorphous silicon producing another type of macroporous composites. These electrodes demonstrated significant improvement both in capacity retentions and in rate capabilities. The inner carbon matrix not only increased the material conductivity, but also resulted in lower silicon pulverisation during cycling.

Lithium-rich layered transition metal oxide cathode, represented as the chemical formula of xLi₂MnO₃ · (1 - x)LiMO₂(M = Mn, Ni, Co) , retains immense interest as one of the most promising candidates for energy storage system ranging from mobile devices to electric vehicle applications (EV/HEV/PHEV). This battery type benefits from superior theoretical capacity (>250 mAhg^-1), high chemical potential (>4.6 V vs Li⁰), good thermal stability, high discharge capacity and lower cost compared with conventional cathodes (e.g. LiCoO₂, Li(Ni_1/3Mn_1/3Co_1/3)O₂ cathodes). However, there remain major barriers which still need to be improved in order to achieve a successful commercialization for large-scale devices or electric vehicle applications. The irreversible capacity loss of 40-100 mAhg^-1 during the initial electrochemical cycle and the battery fading phenomena (capacity fading/voltage decay) on further cycles are the major problems which have emerged. The Li⁺ ion extraction accompanied by oxygen release from the active material in the form of oxide known as lithia (Li₂O) along with the transition metal migration has been suggested as the dominant processes underlying the capacity fading mechanism. Those processes, in turn, cause a phase transition from a layered structure into a spinel within the electrode material. The interplay of the local atomic environments between Li₂MnO₃ (monoclinic, C2/m) and LiMO₂ (trigonal/hexagonal, R3m) holds the key to developing better cathodes with enhanced stability. In the present thesis, an in operando XAS study using a specially-designed cell of the graphene- coated Li(Li_0.2Mn_0.54Ni_0.13Co_0.13)O₂ cathode is employed to examine the chemical, electronic, and structural states of the transition metals (Mn, Co, and Ni) during electrochemical cycle(s). Precise oxidation states for the transition metals is evaluated by the combined analyses from the XANES and SQUID measurements. The K-edge XANES spectral shift is quantified to investigate the contribution to the charge compensation mechanism by the oxidation change. Absorption features in K-edge XANES are identified. These features describe the electronic state of the individual atoms in the cathode composite, as well as the local distortion from the octahedral structure of MO₆. The Fourier transform of EXAFS offers a satisfactory description of the local structure changes with the connection to the cation arrangement. The description is generally involved with the peak amplitude, position, shape changes (trend), and coordination numbers in the real space. Hence, similarities or discrepancies in the local atomic environments could be compared at different state of charge. Major structural parameters are deduced from the EXAFS fitting process. These parameters can be used to distinguish different atomic environments upon voltage bias levels or investigate the appearance of the Jahn-Teller effect. A new approach to understand the atomic environment upon charge-discharge is demonstrated, namely, a Continuous Cauchy Wavelet Transform (CCWT) which enables the visualization of the EXAFS spectra in three dimensions by decomposing the k-space and R-space (uncorrected for phase shift) signals. The wavelet transform analysis provides possible evidence of the precursor that leads to the spinel phase transition in this battery system.