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Nickel-Yttria Stabilized Zirconia (Ni-YSZ) cermets are used as anodes in solid oxide fuel cells. These anodes are stable for tens of thousands of hours during operation and have low cost. In this work, Ni-YSZ anodes are infiltrated with nickel nanoparticles to increase the density of electrochemical reaction sites and improve their performance. However, infiltrated nickel nanoparticles are isolated from one another, so they are not electrochemically active. Two approaches have been utilized to activate infiltrated nickel nanoparticles: in-situ nickel spreading and simultaneous infiltration of nickel with Gd0.1Ce0.9O2-δ (GDC). In-situ nickel spreading, which occurs during exposure to anodic mass transfer limited currents, connects and activates nickel nanoparticles, improving anode performance but inherently causing nanoparticle coarsening. Simultaneous infiltration of Ni and GDC results in substantially improved anode performance, and the infiltrated nanostructures are more stable than infiltrated nickel. Detailed analysis of the electrochemical impedance by equivalent circuit modeling is used to separate the contributions of nickel and GDC infiltrants to the overall cell performance.

Durant ces dernières années, la congestion du trafic urbain et la pollution de l'air sont devenus d'énormes problèmes dans de nombreuses villes dans le monde. Afin de réduire cette congestion, nous pouvons investir dans l'amélioration des infrastructures de la ville. Toutefois, cette solution reste très coûteuse à entreprendre et de ne permet pas de réduire la pollution de l'air. C'est pourquoi nous travaillons sur la mobilité intelligente afin de disposer d'une meilleure utilisation de la voiture. L'application de nouvelles technologies de l'information, tels que les systèmes multi-agents appliqués au contrôle de l'information de la circulation urbaine, a permis de créer et de déployer une gestion plus intelligente du trafic comme le système DRT (transport à la demande). L'objectif des systèmes multi-agents basés sur le DRT est de gérer les taxis de manière intelligente, afin d'accroître le nombre de passagers dans chaque véhicule, et en même temps à réduire le nombre de véhicules dans les rues. Cela permettra de réduire les émissions de CO2 et la pollution de l'air causée par les véhicules, ainsi que la congestion du trafic et les coûts financiers associés. La simulation multi-agents est considérée comme un outil efficace pour les services dynamiques urbains de la circulation. Toutefois, le principal problème est de savoir comment construire un agent à base de modèle pour cette problématique. Ces travaux de recherche présente une solution basée sur les systèmes multi-agents réactifs pour la problématique du transport à la demande (DRT), qui adopte une approche multi-agent de planification urbaine en utilisant des services de contrôle qui satisfont aux principales contraintes : réduction de la période totale creuse, demandes spéciales du client, augmentation du nombre de places utilisées dans un même taxi, utilisation du nombre minimal de véhicules, etc. Dans cette thèse, nous proposons un modèle multi-agents multicouche hybride distribué pour des problématiques en temps réel. Dans la méthode proposée, un agent pour chaque véhicule trouve un ensemble de routes pour sa recherche locale, et choisit un itinéraire en coopérant avec d'autres agents se trouvant dans son domaine de planification. Nous avons examiné expérimentalement, l'efficacité de la méthode proposée. / In recent years, urban traffic congestion and air pollution have become huge problems in many cities in the world. In order to reduce congestion, we can invest in improving city infrastructures. Infrastructure improvements, however, are very costly to undertake and do not reduce air pollution. Hence we can work on intelligent mobility in order to have a more efficient car use. The application of new information technologies, such as multi-agent technologies to urban traffic information control, has made it possible to create and deploy more intelligent traffic management like DRT (Demand Responsive Transport) system. The objective of multi-agent based DRT system is to manage taxis in an intelligent way, to increase the efficient number of passengers in every vehicle, and at the same time to decrease the number of vehicles on streets. This will reduce the CO2 emissions and air pollution caused by the vehicles, as well as traffic congestion and financial costs. Multi-agent simulation has been looked as an efficient tool for urban dynamic traffic services. However, the main problem is how to build an agent-based model for it. This research presents a multi-agent based demand responsive transport (DRT) services model, which adopts a practical multi-agents planning approach for urban DRT services control that satisfies the main constraints: minimize total slack time, client’s special requests, increases taxis’ seats use ratio, and using minimum number of vehicle etc. In this thesis, we propose a multi-agent based multi-layer distributed hybrid planning model for the real-time problem. In the proposed method, an agent for each vehicle finds a set of routes by its local search, and selects a route by cooperation with other agents in its planning domain. By computational experiments, we examine the effectiveness of the proposed method. This research is supported by project “Gestion Temps Réel du Transport Collectif à la Demande” (CPER) Budgetthe French.

This retrospective descriptive study addressed the relationship between reading comprehension skills as measured by the Nelson-Denny Reading Test and the Nurse Entrance Test and indices of academic success (i.e., grade point average of prerequisite science courses and overall grade point average) prior to admission for students in a Bachelor of Science in Nursing program with student success in the first semester of nursing coursework. Overall, there has been a continual decline in average reading ability of college-aged students. Reading is a basic skill for learning and academic success. To successfully complete an academic program of study in preparation to become professional nurses, students must be able to read and apply material from textbooks and journals. With the well-documented nursing shortage, any attrition from a nursing program contributes to the professional dilemma. Correlational and descriptive methods were used to determine the relationships among the variables for 179 students in this selected Bachelor of Science in Nursing (BSN) program. A comparative approach was used to investigate possible cause and effect relationships between measures of academic success of students and reading comprehension abilities. Data were obtained from official academic records and test results for the Nelson-Denny Reading Test and the Nurse Entrance Test. Statistical procedures used to understand and interpret the interactions among and between the variables and included frequency distributions, descriptive statistics, correlational analysis, and a regression model. Results of the study, limited to the students in this BSN program, indicated that reading comprehension, as measured by the Nelson-Denny Reading Test, was better in identifying student risk for academic failure. There was a positive relationship between the grade point average (GPA) for prerequisite science courses, overall cumulative GPA, and GPA for the first semester nursing courses. Early determination of reading comprehension ability provides needed information to direct intervention activities to improve individual reading comprehension abilities and, thus, promote successful academic performance in the first semester of this nursing program and thereafter.

Durant ces dernières années, la congestion du trafic urbain et la pollution de l'air sont devenus d'énormes problèmes dans de nombreuses villes dans le monde. Afin de réduire cette congestion, nous pouvons investir dans l'amélioration des infrastructures de la ville. Toutefois, cette solution reste très coûteuse à entreprendre et de ne permet pas de réduire la pollution de l'air. C'est pourquoi nous travaillons sur la mobilité intelligente afin de disposer d'une meilleure utilisation de la voiture. L'application de nouvelles technologies de l'information, tels que les systèmes multi-agents appliqués au contrôle de l'information de la circulation urbaine, a permis de créer et de déployer une gestion plus intelligente du trafic comme le système DRT (transport à la demande). L'objectif des systèmes multi-agents basés sur le DRT est de gérer les taxis de manière intelligente, afin d'accroître le nombre de passagers dans chaque véhicule, et en même temps à réduire le nombre de véhicules dans les rues. Cela permettra de réduire les émissions de CO2 et la pollution de l'air causée par les véhicules, ainsi que la congestion du trafic et les coûts financiers associés. La simulation multi-agents est considérée comme un outil efficace pour les services dynamiques urbains de la circulation. Toutefois, le principal problème est de savoir comment construire un agent à base de modèle pour cette problématique. Ces travaux de recherche présente une solution basée sur les systèmes multi-agents réactifs pour la problématique du transport à la demande (DRT), qui adopte une approche multi-agent de planification urbaine en utilisant des services de contrôle qui satisfont aux principales contraintes : réduction de la période totale creuse, demandes spéciales du client, augmentation du nombre de places utilisées dans un même taxi, utilisation du nombre minimal de véhicules, etc. Dans cette thèse, nous proposons un modèle multi-agents multicouche hybride distribué pour des problématiques en temps réel. Dans la méthode proposée, un agent pour chaque véhicule trouve un ensemble de routes pour sa recherche locale, et choisit un itinéraire en coopérant avec d'autres agents se trouvant dans son domaine de planification. Nous avons examiné expérimentalement, l'efficacité de la méthode proposée.

The effects of demographic change and the lack of acceptance represent some of the main problems for the public transport infrastructure in rural areas. As a consequence, the development of new transport service options becomes especially relevant for rural communities. The Max-Planck-Institute for Dynamics and Self-Organization developed a new form of Demand Responsive Transport the EcoBus to examine the viability of new DRT systems in rural Germany. Our work draws on customer satisfaction data during the trial runs of the EcoBus. Based on the survey data, this paper develops regression models to explain the determinants of DRT customer satisfaction. Our main findings include the importance of waiting times and the ease of entry for overall customer satisfaction. Nevertheless, we found no evidence that the presence of other guests in the vehicle had any negative impact on customer satisfaction. Findings of other works that women are significantly more likely to use DRT services could not be validated from our data.

Ökad miljömedvetenhet, växande klimatpåverkan och en fortsatt teknologisk utveckling gör att demand responsive transportation (DRT), ses som ett allt mer attraktivt alternativ till traditionell kollektivtrafik för att resa hållbart. Den här uppsatsen undersöker vilka skillnader det finns med DRT-implementationer på landsbygd jämfört med i stadsmiljö, samt vilken roll interaktivitet mellan operatör och resenär kan spela för ett DRT-systems effektivitet.För att svara på detta används en systematisk litteraturstudie och två fallstudier. Resultaten visar att DRT generellt lämpar sig bättre för landsbygd än i stadsmiljö och att DRT fungerar bättre som ett komplement till traditionell kollektivtrafik än som ersättning av den. DRTs potentiella roll i samhället och möjliga framtida forskningsriktningar presenteras och diskuteras. / An increased awareness of environmental issues, climate changes and a continuing technological development makes demand responsive transportation (DRT) a more likely and attractive option for public transportation. This paper examines the differences between various DRT implementations in rural areas compared to cities. It also examines what role interacitivity can play to increase a DRT-systems efficiency.To answer this, a systematic literature review is conducted along with two case studies. The results show that DRT is generally more suited to rural areas compared to cities. It also shows that DRT works better as a complement to public transport, rather than a replacment of it.The potential role of DRT in a society and future research matters are presented and discussed.

The focus of this thesis is to study what and how information flows can be used to improve Demand responsive transport (DRT) systems by understanding potential users and how they could be willing to participate in DRT to a higher degree. The viewpoint of this thesis tends to lean towards a DRT service of a public transport type. This thesis studies users in relation to what interaction and information they perceive to be needed in dealing with a DRT service and the different pros and cons with various approaches. The study gathers information by performing adapted qualitative interviews with a select number of users between the ages of 20-35. The participants give their views on three DRT scenarios and reflect on DRT in general as a concept presented to them through a tangible mocked-up interactive prototype.  The thesis makes several distinct findings. The importance of pricing a DRT service correctly is vital to the users, as several participants in the study relied on pricing for decision-making. It also finds that the usage of zones as nomenclature is confusing to many users. The services must be dependable and punctual to both attract users, keep users, and build trust among the general populace. This study shows that DRT services could be a difficult concept to introduce to users. DRT could be introduced as a complement or as an alternative to conventional public transport. An important factor is a well-designed flow of information in the application to keep the user engaged and involved. It is shown that the usability of the application is a cornerstone for a theoretical DRT service to excel. Context is important where DRT and ridesharing would have a higher success rate. Nighttime in urban areas could be a niche market, due to the irregularity, delay, or interruption of regular public transport services at these hours.

This study investigates the dependency of the internal processes of Li-ion batteries on operating conditions, cycling life, and mechanical damage. Li-ion Batteries are the preferred energy storage solution for many applications, including cell phones and electric vehicles. However, they can pose serious hazards if their safety is compromised, such as after sustaining mechanical damage. An example of such loadings is an electric vehicle crash or a drone's impact landing. Prior work has shown that mechanical damage to the battery may not affect its voltage, capacity, or other primary specifications. Currently, there is no reliable method to check the integrity of battery cells inside an electric vehicle battery pack once it has been subjected to a shock or impact. Here, we report a novel method to determine the time constants and polarizations of the main internal processes of Li-ion cells from their impedance spectra and investigate the effect of mechanical damage and aging on them. We formulate a distribution function of relaxation times to deconvolute the measured impedance spectra to achieve this goal. Our formulation is based on representing the battery dynamics via basis functions formed using a series of passive electrical elements consisting of inductors, resistors, and capacitors. We used a ridge regression optimization to determine the optimal number of elements and their values to represent the battery dynamics in the measured frequency range. We divided the samples into a control (intact) group and a test group, which went through controlled mechanical damage. We cycled the batteries and collected their impedance spectra at various temperatures and state-of-charge (SOC) levels. The experiments were conducted on LFP (Lithium Iron Phosphate) and NMC811 (80% nickel, 10% manganese, and 10% of cobalt in the active cathode material) cells, which are two main types of batteries used in commercial electric vehicles. After deconvoluting the impedance spectra using our formulation and criteria, we identified four peaks in the low- and medium-range frequencies related to diffusion, charge transfer, and solid electrolyte interface, as well as peaks in the high-frequency region related to contact resistances and ionic conductivity through the electrolyte and separator pores. We used the dependency of the peaks on the SOC level and temperatures to assign them to these processes. We represented each process with representative time constants defined as the local maxima of the peak and the area under the curve as the polarization of the process. We showed that the mechanically damaged cells have substantially different high-frequency time constant characteristics than the control group. Further, using our proposed approach, we studied the ability to identify degradation mechanisms during the aging process of a cell at different temperatures and states of charge. For LFP cells, the representative time constants remained almost unchanged during mechanical damage. However, the high-frequency peak height dropped by more than 36% during indentation, compared to less than 2.5% change in the control group. For NMC811 cells, the time constant of the high-frequency peak increased slightly with increased mechanical loading, and the associated peak height dropped by more than 12.9% during indentation and more than 17.8% during three-point bending. For the NMC811 cells, the average activation energy for charge transfer was 62 kJ/mol, while the activation energy for SEI was 49 kJ/mol. These values confirmed the physical relevance of the assigned peaks by verifying them with reported values in the literature. Finally, we analyzed the trend of changes in the impedance spectra (showed as EIS- Electrochemical Impedance Spectroscopy) collected during battery cycling at 0% and 100% SOC for NMC811 cells. The time constant of charge transfer increased significantly with aging, while the time constants of SEI and contact resistance increased slightly, and the high-frequency peaks remained almost constant. Polarization analyses showed significant increases with aging: the polarization of contact resistance, SEI, and charge transfer increased by 2.06, 2.36, and 2.24 times from cycle number 40 to 280 at 0% SOC, and by 1.86, 2.65, and 11.95 times at 100% SOC. Ohmic resistance increased slightly at both 0% and 100% SOC from cycle number 40 to 280. These results align with the observed linear degradation phase, where cells experienced a 4.8% capacity fade until cycle 280. We investigated the contribution of each degradation mode to changes in time constant and polarization of internal processes and degradation mechanisms based on aging stress factors, including large Depth of Discharge, low and high SOC, and a large number of cycles. This research demonstrated the effectiveness of our suggested DRT method in studying the effects of temperature, SOC, aging, and mechanical damage on the internal processes of LFP and NMC811 cells. This non-invasive method can detect hazardous mechanical damage in batteries, making it useful for applications such as electric vehicles after a crash or drones after impact landings. The aging results highlighted the potential of this approach for evaluating changes in the internal processes and degradation mechanisms caused by aging, which is essential for efficient battery management systems and estimating battery state of health. This method can also be used to diagnose battery safety in second-life applications, such as grid energy storage. / Mechanical Engineering

Based on the fact that accessibility in rural areas relies heavily on car traffic, call-driven traffic has been used in different regions to improve public transport usage in rural areas, while it has been difficult to maintain due to high maintenance and long waiting time. Over the past decade, a new demand response transit (DRT) service came into light, which combines with new technologies to provide a more attractive and efficient transport service. Now the Public Transport Authorities have the vision to change this situation of call-driven traffic. In this project, Södertälje and Nykvarn rural area was chosen to be the pilot area of the new DRT service, where a network algorithm was designed to support the routing choices of the new mobility service. The objective of the network algorithm is to achieve an optimal route based on the cost function i.e. operational cost and passengers’ ride time. In addition, the network algorithm is able to test different scenarios, in which user-friendly and operator-friendly scenarios were tested. The result has shown that user-friendly scenarios provide a lower passenger ride time and fleet travel time with the same amount of requests. On top of that, several recommendations regarding improving the service design were proposed in order to optimize customer satisfaction and operation cost. / Baserat på faktumet att tillgängligheten på landsbygden är mer eller mindre byggd på biltrafik så har anropstyrd trafik använts i flera regioner för att förbättra kollektivtrafikanvändningen på landsbygden. Systemet är dock gammalt och lett till svårigheter för drift och underhåll samt långa väntetider. Under det senaste decennium har det utvecklats nya mobilitetslösningar som styrs när behovet uppstår (DRT-service), som kombineras med ny teknik för att ge en mer attraktiv och effektiv transport service. Nu har offentliga transportmyndigheter (PTA) visionen att förbättra denna anropstyrda trafik. I detta projektet valdes landsbygden i Södertälje och Nykvarn som pilotområde för den nya DRT-servicen, där nätverksalgoritmen utformades för att kunna stödja de olika val av vägar för nya mobilitetstjänsten. Målet med nätverksalgoritmen är att uppnå en optimal väg baserad på de kostnadsfunktioner t.ex driktkostnader och passagerarens körtid. Dessutom testas nätverksalgoritmen i olika scenarier, vilket är användarvänliga och driftvänlga scenarier. Resultatet visade att användarvänlga scenarier ger en mindre passagerartid och fordonets resetid gentemot samma mängd av förfrågningar. Dessutom gavs rekomendationer angående hur man kan förbättra tjänstedesignen för att optmiera kundnöjdhet och driftkostnad.