Quantum computing has gained a lot of interest from researchers and industry due to its great potential to solve some complex problems in various fields. One of the biggest challenges is developing hardware suitable for the extremely low operation temperatures required by quantum computers. Specifically, the wiring material of a quantum computer must provide good electrical conductivity while keeping the thermal load to a minimum. Delft Circuits’ cryogenic flexible cable design made from metalized Polyimide (PI) with Silver (Ag) thin films as conductors offers a promising solution for quantum computer i/o systems. This thesis aims to investigate the effect of fabrication and design parameters on the electrical and thermal properties of silver thin films, utilizing the Residual Resistivity Ratio (RRR) as an indicator to assess the thermal load of cryogenic flexible cables. The RRR is calculated by taking the ratio of electrical resistivity measured at room temperature and extremely low temperatures of liquid He (4.2 K). The key parameters for the experimental investigation include oven heat treatment, lamination, silver purity, film thickness, aging and storage. The RRR behavior of samples with varying fabrication and design characteristics is explored through cryogenic measurements. Subsequently, the RRR results are analyzed and supported by material characterization via SEM and XRD. The results show that heat treatment results in higher RRR values due to grain growth and lower grain boundary density, leading to lower electrical resistivity at low temperatures. Heat treatment parameters including temperature, pressure, duration, ambiance, and cooling rate play a significant role in the resulting microstructure of the silver film, and consequently, in their RRR values. Furthermore, the study reveals that the lower purity level leads to decreased RRR values of the silver film due to higher electron scattering caused by impurities. A linear relationship is found between the film thickness and the RRR behavior of silver thin films. Lastly, aging and storage do not result in a significant change in the RRR values of heat-treated silver thin films. This thesis provides a deeper understanding on the influence of fabrication and design parameters on the low-temperature resistivity of silver thin films. It highlights the key role of these parameters in tailoring the microstructure of silver thin films to achieve desired material properties.

The Pd-based metal membranes have been focused on many studies, because they are the most promising candidates for hydrogen separation. If Pd-based membranes are designed in nanoscale, then the introduced high volume fraction of grain boundaries can act as fast diffusion paths for hydrogen atoms that leading to an increase of hydrogen separation rate. However, due to the substantial amounts of grain boundaries, the nanocrystalline material tends to show a rapid grain growth at operating temperature (that leading to the coarse grains), which may lead to the failure of this membrane in further applications. However, grain growth could be effectively inhibited by thermodynamic stabilization method-that is solute segregation to grain boundary region. In this thesis, a thermodynamic grain boundary segregation model is developed and is applied to many types of metallic binary alloys, including the Pd-Cu, Pd-Zr, Pd-Y, Fe-Zr, Y-Fe and so on. From this model, the segregation tendency of alloying constituents is determined, and the solute concentration in grain boundary is obtained. Moreover, the grain boundary energy (GB) of investigated alloys can be calculated via this model, by comparing the calculated GB energy with that of pure Pd, we are able to determine whether these alloys can be stabilized by the segregation-introduced thermodynamic stabilization. These calculated results have been compared with those reported in the literature, verifying the predictability of this model. In addition, X-ray diffraction (XRD) analysis, including the XRD residual stress measurement and X-ray peak broadening analysis have been performed on both Pd0.7Cu0.3 and pure Pd thin films, the experimental results will help us determine whether the solute segregation occurs and whether this alloy can be stabilized by the solute segregation.

The so-called “hydrogen economy” became one of the scientific targets among the different renewable energies alternatives, as a result of the efforts to transition from fossil fuels to environmentally-friendly energy sources. In this context, various options to transport and store hydrogen are being explored. Gaztransport & Technigaz (GTT) company, intending to be part of this challenge, is exploring the possibility to transport liquid hydrogen (LH2) in pre-existent ship’s containers initially designed for liquid natural gas (LNG) transportation. This project is about the study of the surface effect of the interaction between hydrogen with iron-based alloys in the case of 304L stainless steel (uncoated and coated with TiO2) and Invar alloy.The methodology consisted of electrochemical induced hydrogen evolution on an iron-based austenitic metal cathode taking advantage of the intermediate adsorbates (atomic hydrogen) generated during the reaction to study the electrochemical adsorption efficiency. Characterisation of the materials, by techniques like XRF, XRD, optical microscopy, and SEM, is conducted before and after hydrogen exposureso that it was possible to evaluate the effect of hydrogen ingress.The results showed that the chemistry of the surfaces is irreversible changed after the electrochemical induced hydrogen sorption/desorption process due to the formation of oxides. The amounts of hydrogen desorbed were quantified after different H2 loading times. In all cases, the amount of hydrogen desorbed showed a maximum after which the hydrogen desorbed decreased significantly. The maximum for uncoated 304L stainless steel was after 24 h, 90 min for the coated 304L, and 2 hfor Invar. The welds are the most vulnerable sections to hydrogen ingress in both cases. XRD results before hydrogen exposure revealed that 304L consists of an austenitic matrix with around 5% of ferrite. An increment of the austenitic volume fraction of 2.2% was observed after the H2 sorption/desorption process. Invar is a purely austenitic phase, and no changes in the phase composition were observed after the H2 sorption/desorption process.

Alkaline water electrolysis will become increasingly important for supplying the world with sufficient renewable energy, and with raw material for the chemical and pharmaceutical industry. Zero Emission Fuels B.V. (ZEF), a technology start-up based in the Netherlands, is developing a small scale alkaline electrolysis cell (AEC), which is integrated in a methanol producing micro-plant. The challenge of this project is to look into the use of polymers for the encapsulation of the ZEF AEC. The conditions of the ZEF AEC are not to be neglected. The system will run in a 30wt% KOH solution at a temperature of 90 °C and a pressure of 50 bar. Not many polymers will be able to withstand these conditions for a desired lifetime of 20 years. Using CES EduPack, a selection of 30 potentially suitable polymers has been made, from which high density polyethylene (HDPE), 40% glass-reinforced polyphenylene sulfide (PPS-40%gf) and polysulfone (PSU) are further investigated. Based on a literature review and a simple KOH ageing test, HDPE is found unsuitable for application in the ZEF AEC. PPS-40%gf and PSU have been subjected to durability testing for a range of different conditions involving a variety of KOH concentrations (15, 30 and 45wt%), and two oxygen partial pressures (O2 at 5 bar and air with pO2=20%) at different temperatures (90, 120 and 170 °C). The purpose of the ageing experiments is to give a better understanding of the effect of these parameters on the structure and integrity of the polymer; and to eventually be able to acquire a lifetime prediction. Extensive characterisation of the exposed samples has been carried out using different techniques, including weight measurement, tensile testing, DMA, creep-recovery testing, DSC, FTIR, XRD and SEM. After 12 weeks of ageing, it is found that glass-filled polymers are unsuitable for application in a strong alkaline solution at elevated temperatures, due to the dissolution of the glass fibres, which leads to a reduction in mechanical and barrier properties. However, the PPS matrix and PSU are found to be resistant to thermo-oxidative and chemical degradation in the tested ageing conditions. Only subtle changes in mechanical, visco-elastic and thermal behaviour are observed, which can be assigned to the effects of physical ageing. Due to the undesirable brittle nature of PPS, it can be concluded that PSU is the most promising candidate for the long-term application in alkaline electrolysis.

With fossil fuels being phased out and growing global interest in a hydrogen economy, there is demand for re-purposing existing pipelines for transportation of hydrogen gas. However, hydrogen is known to have adverse affects on the properties of steels. Hydrogen will dissolve in the steel matrix and contribute to a reduction of mechanical properties, causing Hydrogen Embrittlement (HE). There is currently a knowledge gap about the behaviour of pipeline steels and their welds in a gaseous hydrogen environment that prevents re-purposing of pipelines for hydrogen transport. In this work, a combined approach of modelling and in-situ mechanical testing was used to assess the HE susceptibility of X60 pipeline steel and its girth welds. To this end, a novel tensile setup featuring in-situ charging with high pressure H2 gas and a sample geometry representing miniature pipelines was developed and validated. To our best knowledge, this setup design has not been reported elsewhere, making this a breakthrough design. An FEA modelling approach was used to estimate the pre-charging duration as well as to gain an insight into the stress states inside the notched samples. It was found that both the base and weld metals lose ductility when subjected to gaseous H2. The base metal showed 27% loss of ductility when subjected to 100 bar H2, which further increased to 40% in notched samples. A trend of increasing loss of ductility was found with increasing pressure for the weld metal, which showed up to 14% loss of ductility at 100 bar H2. The weld metal also retained more of its reduction in cross-sectional area after fracture in H2 as compared to N2 than the base metal. Other characteristics like yield strength and UTS were not affected by the hydrogen gas. The fracture mechanism in the both metals was found to change from microvoid coalescence (MVC) fracture to quasi-cleavage (QC) fracture. The base metal fracture mechanism changed to QC completely, while the weld metal only showed partial QC fracture. In the base metal, ductile fracture mechanisms like HELP and possibly AIDE were found to be dominant even in the QC fracture mode. It was concluded that the weld metal is less susceptible to HE than the base metal in a gaseous hydrogen environment. For both metals, HE effects were only observed at high amounts of plastic strain, which is outside of the operating conditions of a pipeline. However, before pipelines can be repurposed for hydrogen transport, fatigue testing should be performed to assess the influence of existing defects and cyclic loading conditions on the HE performance of both steels.

Surface compositions play a predominant role in the efficiency and lifetime of membranes and catalysts. The surface composition can change during operation due to segregation, thus controlling and predicting the surface composition is essential. Computational modelling can aid in predicting the alloy's stability, along with designing surface alloys and near-surface alloys which can outperform existing catalysts. A computational model to predict surface segregation in ternary alloys is developed. The model is based on Miedema's semi-empirical model that is used to predict mixing enthalpies. The segregation enthalpy is parameterized to describe pairwise interactions between nearest-neighbours and then used in Monte Carlo simulations. Monte Carlo simulations enable to predict short-range ordering in the surface and subsurfaces; both affect the performance of a material as a catalyst. The computational model obtained in this work is able to screen through a vast range of alloy compositions and can qualitatively predict the alloy's stability in a gas environment. In this thesis the model is applied to design a novel ternary Pd-based material for membranes that can be used to separate hydrogen from a gas mixture. Addition of specific amounts of Cu and Zr to Pd results in a material with reduced H2S poisoning as compared to a pure Pd surface as well as an enhanced permeability. The computational model obtained in this work allows to systematically assess the composition of ternary surface alloys and near-surface alloys and is a large improvement over the trial and error approaches currently used.

In order to meet the shipping industry's emissions reduction goals, it is imperative to explore and adopt alternative marine fuels. Methanol (or methyl alcohol) is expected to play a large role in the future. However, current regulations limit the attractiveness of methanol as marine fuel due to the inability to use the space around a venting point on deck. Hazardous area zones are installed around fuel tank vapour outlets due to the flammability and toxicity of methanol vapour. Consequently, these areas become very impractical. This thesis investigates the ventilation of the fuel tank vapour below the waterline instead on deck in order to be able to limit/eliminate these areas. Therefore, the main research question is: "What is the concentration of methanol at deck level when methanol is vented below the waterline?" An Eulerian based CFD model and a simple integral model are used to predict the methanol concentration above the waterline. The integral model predicts the gas concentration above the waterline based on the gas flow rate reaching the surface and the radial inflow rate of air. The CFD model tracks parcels (group of bubbles with the same properties) using the force balance in the discrete phase model. Both of the models are successfully validated against experimental data from the "Rotvoll experiment" wherein methane was released at the bottom of a water basin. The CFD model showed strong superiority over the integral model, o.a. due to the lack of gas dissolution in the integral model. The numerical models are applied to the case wherein a mixture of methanol and nitrogen is vented due to an overpressure. The overpressure could be caused by for example the failure of the vapour return line when bunkering or a fire. The bunker tanks are protected by a pressure relief valve, which reduces the overpressure by directing the gases in the bunker tank towards the venting location below the waterline. The flow rate characteristic (pressure - flow rate) of the pressure relief valve determines the rate at which the gases are injected in the water. The gas dissolution showed strong dependence on the departure bubble diameter and the venting depth. Different cases with different initial bubble sizes and different venting depths were simulated. The CFD model showed that in the most critical case (lowest venting depth 0.5m and largest initial bubble size 0.08m) the gas dissolution is large enough such that no methanol vapour reaches the deck of the ship and barge. The subsea venting of methanol-nitrogen vapour proved to be a safe alternative compared to the venting above deck.

Studies on the impact of Hydrogen on the electrochemical and mechanical behaviour of Iron-based materials have been increasingly conducted in the past few years. This is mainly due to the ever-growing demand for sustainable energy sources, which involve Hydrogen and to meet the high structural and economic demands from the automobile sector and other industrial demands for which high strength steels like dual-phase steels have been developed. Steels may absorb hydrogen both throughout the production process and during different phases of use. High-strength steels (particularly dual phase steels) and martensitic stainless steels are highly susceptible to hydrogen embrittlement. Moreover, hydrogen embrittlement is already possible at quantities as low as 0.1 ppm[1]. Therefore, understanding Metal-hydrogen interactions is essential. This thesis aims to study the effect of Hydrogen charging on three different iron-based materials and the possible effect on the electrochemical/corrosion performance. The Iron-based materials used in the study are Pure Iron, DP1000 and AISI 420. The methodology involves using an electrochemical procedure based on potentiostatic Hydrogen charging and Cyclic Voltammetry (CV), applied on these Iron-based materials having different phases to monitor H-uptake in the materials. The materials are charged with Hydrogen both on the active and passive surfaces. The electrochemical method is capable of measuring the diffusible H concentration (including mobile Hydrogen) for the steel alloys under H-charging conditions. Using X-Ray Diffraction (XRD) Technique, microstructural analysis is carried out on Pure Iron, DP1000 and AISI 420 stainless steel to identify the different phases interacting with Hydrogen. To gain additional insights relating to the electrochemical/corrosion performance of the investigated materials and into the H-related findings, potentiostatic polarization techniques, Electrochemical Impedance Spectroscopy (EIS) and Scanning Kelvin Probe (SKP) are carried out. As a result, it was discovered that Pure Iron had the maximum amount of diffusible Hydrogen under the charging conditions tested, followed by DP1000 and then AISI 420 Steel with the lowest amount. EIS technique was useful in identifying a trend between the barrier properties of the passive layer and the H desorption values for the three materials. The results also revealed that materials charged with Hydrogen on active and passive surfaces behaved differently with respect to the amount of Hydrogen desorption. The microstructural features of the active surface and the passive oxide film that formed on the materials are further discussed in relation to this.

The effects of precipitates in the microstructure of an AA7075 aluminium alloy on: the dislocation behaviour, dislocation structure and dislocation structure evolution during plastic deformation were investigated using the physical yield criterion model by van Liempt and Sietsma. The model was in fact applied for the first time to aluminium and an AA7075 aluminium alloy. By constructing an extended Kocks-Mecking plot from the measured tensile and interrupted tensile data the dislocation density, average dislocation segment length and physical yield stress were determined. The aim of the present study was to get a better understanding of the role of precipitates in the evolution of the dislocation structure during plastic deformation. The recovery of anelastic strain during loading and subsequent unloading after plastic deformation was investigated as well. The yield criterion was used to study the anelastic loading, while a constitutive unloading model by Torkabadi et al. was used to study the unloading behaviour. The models were combined to define the fraction of unrecoverable anelastic strain. The anelastic strain is related to springback. Therefore a better understanding of the anelastic strain could be useful for making better predictions of springback after metal forming. The physical yield criterion was further extended by incorporating a continuous uniform dislocation segment length distribution. Insight on the dislocation segment length distribution, and the evolution thereof during plastic deformation, could help to better understand the mechanical behaviour of metals. The evolution of the dislocation structure during plastic deformation is impeded by the presence of precipitates in the microstructure. Therefore, the physical interpretation of α in the Taylor equation which quantifies the dislocation structure, proposed by Arachebelata et al., was modified to incorporate the effects of precipitates in the microstructure. The dislocation structure parameter α should remain constant. However, the average dislocation segment length obtained from the extended Kocks-Mecking plot does not decrease sufficiently to accommodate a constant α. The introduction of the length between precipitates, which is independent from work hardening, into the Taylor equation ensures that α does remain constant, whilst in addition it provides an estimate of the distance between the precipitates. Anelastic strain, caused by reversible glide of dislocations in the pre-yield regime, is introduced into or recovered from the metal during loading and unloading respectively. The anelastic unloading strain determined from the interrupted tensile tests was found to be smaller than what was expected according to the model. Three possible causes were identified: not all Frank-Read sources are at their critical state when unloading is initiated, dislocation loops propagating through the crystal undo portions of the anelastic unloading strain and the retracting dislocations remain stuck behind obstacles whilst retracting under the reducing applied stress. The constitutive model was found to be not suitable for studying the dislocation behaviour during unloading because the change of dislocation segment length with plastic deformation is not accounted for. The development of a physical unloading model is therefore recommended. The distribution of the dislocation segment lengths could explain the non-zero value of the work hardening rate Θ at the abrupt change of slope between the pre and post-yield regime in the extended Kocks-Mecking plot. The value of Θ at this point could be an indication of the distribution width. The continuous uniform distribution is a rather unrealistic description of the dislocation segment length distribution. Therefore, other distribution types are proposed for the further development of the dislocation segment length distribution model of the physical yield criterion.

Large-scale hydrogen storage is a crucial part of the energy transition. The usage of salt caverns has a great potential in this process, but there are open questions regarding the construction’s lifetime which need to be investigated prior to their implementation. In this work, potential construction steels were studied. The conditions in a salt cavern were imitated on laboratory scale with an experimental high-pressure setup. Two steels, J55 and H2-ready X56, were systematically exposed to pressure/temperature cycles, gas (H2 and N2), water and brine. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) techniques were used for the characterisation of the steels’ surface, focussing on corrosion effects and crack formation. For both steels, a significant impact of moisture and salt ions could be shown. However, only for J55, intensification of corrosion and cracking on the surface due to hydrogen gas exposure was found. Pronounced crack formation over the entire surface of J55 was revealed. For X56 significantly less crack formation could be observed. Overall, the results strongly indicate better resistance of X56 than J55 against the conditions in a salt cavern, used for hydrogen storage.

Fossil fuels have been the primary source of rising energy requirements for humankind. However, the extensive use of fossil fuels has led to an increase in Earth's surface temperature. To tackle rising energy demands and the increase in Earth's surface temperature, various organizations like Inter-governmental Panel for Climate Change and the European Environmental Agency have suggested the use of renewable energy as an alternative energy supply. E.g., the use of hydrogen as an alternative fuel in transportation will reduce greenhouse gas emissions. Besides, converting CO2 and N2 to fuels and industrial feedstock like CO or NH¬3 can curb the Earth's increasing surface temperature. As a result of this, in this thesis, the catalysts for the synthesis of hydrogen from water-splitting (hydrogen evolution reaction- HER), conversion of CO2 to CO via carbon dioxide reduction reaction (CO2RR), and reduction of N2 from air to NH3 (Nitrogen reduction reaction-N2RR) are studied. The conventional catalysts used for these reactions are Pt for HER, Cu for CO2RR Cu, and Ru for N2RR. Although these catalysts are active and exhibit a high yield of products, they have some disadvantages, such as the long-term availability and cost of Pt and Ru. On the other hand, Cu suffers from the low selectivity for the conversion from CO2 to CO. To overcome these disadvantages; scientists have developed a new kind of catalyst with a higher specific activity, known as the Single-Atom Catalysts (SAC). The SACs use fewer precious elements than the conventional bulk catalysts without compromising the activity. The use of binding energy (EB) as a descriptor for the reactions mentioned has been proven in the literature. Therefore, EB is used in this thesis to predict novel SACs through high-throughput DFT calculations using 3-N doped graphene as the substrate. The descriptor for HER is the EB of H atom, for CO2RR is EB of CO, and that of N2RR is EB of N on the respective catalyst surfaces. These calculated binding energies are compared against the descriptor EB on the conventional catalysts to obtain the novel SACs. With EB as the descriptor, the candidate catalysts for HER are B, Cr, Mn, Fe, Co, Ni, Ge, Ru, In, Sb, La, and Pb. The candidate catalysts for N2RR are Ru, Mo, and Cr. The candidate catalysts for CO2RR are Mg, Al, Ca, Zn and Se,. In addition to this, the charge dissipation of the adsorbent species on the SAC and the effect of atomic size on the EB is studied. It was seen that the computational predictions go hand in hand with the predictions of existing experiments for HER and CO2RR.

High entropy alloys (HEAs) are new potential materials for hydrogen storage applications which could help with the transition towards sustainable energy sources. The rate of hydrogen kinetics is one of the material properties that is important for the storage and other hydrogen related applications. One of the limiting factors on the rate of hydrogen kinetics is hydrogen diffusivity. Thus far, there has been no reports on hydrogen diffusivity for HEAs in relation to hydrogenation kinetics. Therefore, this project investigates hydrogen diffusivity in equimolar TiVZrHfNb and the influence of hydrogen concentration on hydrogen diffusivity to gain better understanding of hydrogenation kinetics. The selected HEA has been found to absorb the highest amount of hydrogen (2.5 H/M) among other HEAs. The investigation was done by a computational approach using ab initio molecular dynamics. BCC and face-centered cubic (FCC) supercells with different hydrogen concentrations (H/M = 0.2, 0.8, 1.4, 2, 2.4) were simulated at a temperature range of 773 – 973 K. At the same time, experimental electrochemical hydrogen charging using chronoamperometry and cyclic voltammetry was performed in order to compare computational and experimental values of hydrogen diffusivity. The electrochemical hydrogen charging did not result in hydrogen absorption, most probably due to the passivation of the sample surface. From the simulation results, the values of activation energy and pre-exponential factor were estimated to be in the range of 0.26 – 0.48 eV and 0.73 – 2.95 x 10-7 m2/s, respectively. Hydrogen diffusivity was found to be higher in BCC than in FCC. In BCC the hydrogen diffusivity slowly decreases linearly with increasing H/M. In the case of FCC, the hydrogen diffusivity was found to be the highest at 2.4 H/M while at 2 H/M the diffusivity was the lowest. The analysis of hydrogen occupation at 2 H/M shows that most of the hydrogen atoms are trapped inside tetrahedral sites. It is possible that the hydrogen occupation in the tetrahedral sites results in the optimum hydrogen distribution where the repulsive interaction between hydrogen atoms is the lowest. At concentrations above 2 H/M, an additional repulsive force between hydrogen atoms seems to contribute to the increase of hydrogen diffusivity.

In this work, mechanical stability and kinetics of hydrogen (de)sorption of thin Palladium films (100 nm) magnetron sputter deposited on a magnetron sputtered Titanium intermediate layer were studied. In particular of two film morphologies, an open voided columnar morphology and a compact columnar morphology, the substrate-induced stress and its relaxation upon hydride formation were investigated at room temperature. By conducting in-situ X-ray diffraction (XRD) measurements combined with line-broadening analysis of the diffraction profiles, it was observed that the α (H-poor phase) to β (H-rich phase) transition induces stress that could (partially) relax by dislocation generation. After several absorption-desorption cycles (at 0.05 atm p(H2)), however, this stress increase prevents a full transformation to the β phase. When applying a higher partial pressure p(H2) = 0.1 atm for both of the selected open and compact-structured Pd/Ti thin films, a full phase transformation was observed. The corresponding phase transition kinetics, stress states and microstructural behaviors of the open and compact-structured Pd/Ti samples were found to be different. The microstructural changes and the kinetics of phase transformation during H2 (de)sorption are explained in terms of stress development and its relaxation through dislocation/defect generation.

The comfort assessment of ships is based on several criteria. There are for example criteria for motions, noise and vibrations. The criteria for motions are nowadays often defined as comfort limits on the accelerations in the ship motions. However, from other industries it followed that the rate of change of the accelerations, the jerk, can also have an influence on the sense of comfort of passengers and crew. The goal of this thesis is to investigate whether it would be useful to add jerk criteria to the comfort assessment of ships. Jerk cannot be measured directly (yet), so it has to be obtained from acceleration measurements or calculations. For this goal filter and processing procedures are defined. To be able to make comparisons different ways of quantifying the jerk are established. One is aimed at peak values, since these are often determining the limit for comfort and operability. The other is focused on quantifying the non-linearity of the response. Research is performed on what the physics behind jerk are, and what phenomena are likely to cause large jerk values. The prime cause is found in slamming. The jerk following from slamming is influenced mostly by the shape of the bow and the speed of immersion in the water. Using the measurement data of two different hulls from other research the effect of varying conditions on the jerk is investigated. From this research it follows that there can be a difference in seakeeping behaviour when looking at jerk instead of accelerations. Since jerk is the third derivative of displacement to time, the non-linearity in this response is relatively high. Therefore non-linear codes are required to calculate the jerk response correctly. The use of a Reynolds Averaged Navier Stokes (RANS) code proves to be able to predict the jerk behaviour correctly. In this thesis only model test measurements and calculations are used. The scaling of jerk to full scale, and difficulties that it might impose, are only discussed theoretically. The general conclusion is that jerk is worth investigating to compare the seakeeping behaviour of ships. Until quantitative limits are available only qualitative comparisons are possible, but these can already give additional insight.

An exponential growth in CO2 concentration over the past few decades has led to an accelerated impact of climate change on planet earth. In a bid to curb these emissions, people across the globe are slowly transitioning towards renewable energy sources with battery technology aiding this growth. Given that battery technology is still in its nascent stage, the “Electrochemical reduction of CO2” could be a viable solution supporting it without decelerating the momentum gained towards renewable development. Although plausible, the direct reduction of CO2 to liquid fuels entails huge energy expenditure thus requiring the implementation of catalysts. Unique in its ability, palladium reversibly reduces CO2 to formic acid making it an interesting candidate for the reduction reaction. In addition to the production of formic acid, palladium is also know to produce carbon monoxide (CO) which completely deactivates the surface preventing further reactions from occurring. Thus the aim of the current study is focused on analysing the electrochemical reduction of CO2 on palladium thin films using surface enhanced infrared absorption spectroscopy to better understand the deactivation mechanisms of CO on the palladium thin film. The smoothness of the as- sputtered 15 nm palladium thin film with a RMS roughness of 0.511 nm and partially coalesced islands were ascertained, thus requiring surface activation to introduce the enhancement mechanism. Experimental analysis of CO2 reduction on the palladium thin film was performed to unearth significant insights through the combination of electrochemical analysis techniques with surface enhanced infrared absorption spectroscopy. Results obtained through implementation of these methodologies provided substantial information not only on the influence of the palladium-hydrogen system on the electrochemical reduction of CO2 but also on the impact of alkali metal cations on the palladium-hydrogen system and the CO2 reduction reaction over the sputtered palladium thin film. CO formation, accumulation and desorption coupled with hydrogen evolution and desorption were some of the few avenues that were enumerated upon during the experimental investigation. The identity of CO chemisorbed on the palladium thin film along with bicarbonate direct/ indirect reduction to form CO was confirmed through the utilization of N2 saturated C13 NaHCO3 solution. In addition to the analysis of the reduction reaction, emphasis on the oxidation of CO was also provided suggesting the formation of dense CO structures with the existence of strong CO dipole – dipole coupling on the palladium surface.