Degradation behavior of commercial lithium-ion pouch cells containing LiCoO2 cathode and graphite anode was investigated for a cycling under continuous overcharge condition. This condition is frequently experienced in electric vehicles in an event of Battery Management System (BMS) failure. Failure of BMS results in an unbalanced module further resulting in overcharging or overdischarging the cells. Commercial cells with 5Ah capacity were continuously cycled at different upper cutoff voltages and 1C-rate to develop a better understanding of the overcharge process. The results show that as the upper cutoff voltage is extended, the cell gains a higher initial capacity. However, the cycle life of the cell diminishes significantly. The extent of overcharge was found to be an important parameter not only for the electrochemical performance but also for cell integrity. Cells overcharged beyond 4.5 V had a significant volume increase and a rapid increase in the capacity fade. The cell starts to swell at this stage and a considerable increase in the temperature and internal resistance of the cells is observed. Thermal imaging of the cell revealed non-uniform temperature distribution and localized degradation sites were identified. Evidence of lithium plating and electrolyte deposits on anode was observed in cells charged beyond 4.4 V, with SEM-EDS verifying their presence. A comparative study of various State of Health (SoH) estimation parameters is presented and the proposed parameter Φ_R based on internal resistance measurement is found to be a good indicator of aggravated degradation in cells.<br>

Šiame darbe teoriniame ir praktiniame lygmenyse analizuojami karteliniai susitarimai. Teorinėje darbo dalyje analizuojami kartelio veikimo modeliai bei kartelių sukeliama žala ekonomikai, taip pat aptariami tyrimo metodai, kuriais gali būti nustatytas dėl kartelinių susitarimų atsiradęs antkainis. Praktiniu kartelinių susitarimų pavyzdžiu pasirinktas Lietuvos pieno bendrovių atvejis. Darbe tiriama, ar 2007 m. įvykęs staigus pieno kainos pakilimas buvo susijęs su karteliniais susitarimais, ar objektyviomis ekonominėmis priežastimis. Taigi pagrindinis šio darbo tikslas – įvertinti galimą kartelinių susitarimų įtaką Lietuvos pieno perdirbimo bendrovių produkcijos kainų kilimui. Šiam tikslui pasiekti atliekamas antkainio nustatymo tyrimas, naudojant keturis skirtingus metodus: prieš ir po, liniuotės (abu paremti palyginamąja kainų analize); kaštų / pelno (kaštų ir pelno duomenų analizė) bei ekonometrinius – fiktyvaus kintamojo ir prognozavimo (regresinė analizė). Atlikus tyrimą nustatyta, kad staigus pieno kainos kilimas buvo iš dalies pagrįstas objektyviu ekonominiu veiksniu – pagrindinės žaliavos (natūralaus pieno) brangimu. Tačiau šia situacija pieno perdirbimo bendrovės pasinaudojo, ir, sudariusios kartelinius susitarimus, ekonomiškai nepagrįstai pakėlė kainas. Regresinė analizė atskleidė, kad įtariamu laikotarpiu (2007 m. rugsėjo – 2008 m. vasario mėn.) dėl kartelinių susitarimų atsirado vidutinis 21,9 proc. pieno pakelio antkainis, t.y. kaina pakilo beveik penktadaliu... [toliau žr. visą tekstą] / This paper investigates cartel agreements on theoretical and practical levels. In the theoretical part of the paper the models of cartels and economic damage caused by cartels have been analyzed. Besides, research methods which help to determine cartel overcharge have been reviewed. The recent case of Lithuanian dairy industry is the basis for the practical analysis. In this paper it has been investigated, whether the sudden increase of dairy product prices in 2007 was related to cartel agreements or it was based on objective economic reasons. Thus, the purpose of this paper is to estimate the supposed influence of cartel agreements on the prices of Lithuanian dairy products. A research based on four different methods is used to estimate the overcharge. Those methods are as follows: before-and-after, yardstick (both of these are based on comparative analysis of prices); cost / profit based (cost and profit data analysis) and econometric modeling: dummy variable approach and forecasting approach (based on regression analysis). As a result it was estimated that a sudden increase on the price of milk was partly based on an objective economic factor – the increase of price of the basic raw material – raw milk. However, this situation has been used for dishonest purposes of the manufacturers of milk and the price was raised economically unreasonably. Regression analysis has revealed that during the suspected period (from September 2007 to February 2008) the average cartel... [to full text]

Lithium-ion batteries (LIBs) are the most commonly used type of rechargeable batteries with a global market estimated at $11 billion, which is predicted to grow to $60 billion by 2020. The global commercialization of Li-ion batteries is impeded by issues such as poor cycle life (5000 cycles achieved in some LIBs) in high energy and power density applications because of the rising internal resistance due to aging and safety concerns such as overcharge which ultimately leads to thermal runaway and explosions. A battery’s performance mainly depends on external factors such as electrode thickness and degree of compacting, and the type of conductive additive and electrolyte mixture used, and internal factors such as its internal temperature and state of charge. The performance suffers due to aging or erroneous mechanisms such as decomposition of the electrode or electrolyte material affecting the lifetime. In this thesis, an attempt is made to improve the lifetimes of the Li-ion batteries by incorporating suitable electrolyte additives, which were incorporated in the battery electrolyte to prevent overcharge. Also, several conductive electrode additives were incorporated as filler materials in an anode to explore the effects on its discharge capacities.

A presente dissertação de mestrado visa a estudar a responsabilidade civil por danos decorrentes da prática de cartel, a qual é considerada como a mais grave infração à ordem econômica. No primeiro capítulo, o fenômeno do cartel é estudado sob a perspectiva econômica, analisando-se as principais características e efeitos da conduta. No segundo capítulo, examina-se a disciplina jurídica do cartel no direito brasileiro, estudando-se as normas que preveem a responsabilização pela prática de cartel na lei concorrencial e na esfera penal. O terceiro capítulo pretende analisar os objetivos e o papel da responsabilidade civil no contexto mais amplo da política de defesa da concorrência. O quarto capítulo estuda a reparação civil dos danos decorrentes do cartel no direito federal norte-americano e no direito comunitário europeu. O quinto capítulo examina a responsabilidade civil por danos decorrentes da prática de cartel no direito brasileiro. Nesse contexto, são examinados os pressupostos da reparação civil (ato ilícito, culpa, nexo causal e dano), a legitimidade ativa e passiva para as ações indenizatórias, a interação entre a responsabilidade civil e o programa de leniência, bem como a prescrição da pretensão indenizatória. No sexto capítulo, são analisadas algumas propostas de reforma do ordenamento jurídico brasileiro para aperfeiçoamento do sistema de reparação civil em matéria de cartel. Finalmente, a conclusão procura expor de maneira sistematizada as principais ideias apresentadas ao longo do trabalho, bem como avaliar o estágio atual da responsabilidade civil por danos decorrentes da prática de cartel no direito brasileiro. / This dissertation aims to study the civil liability for damages arising from cartel behavior, which is considered the most serious antitrust violation. The first chapter studies the cartel from an economic perspective, analyzing the key features and effects of the conduct. The second chapter examines the legal framework regarding cartel behavior under Brazilian law, by studying the rules that provide for the responsibility for cartel under antitrust law and at the criminal level. The third chapter aims to analyze the objectives and the role of civil liability in the broader context of antitrust policy. The fourth chapter studies the civil liability for damages arising from cartel behavior in US federal law and European Community law. The fifth chapter examines the civil liability for damages resulting from cartel behavior in Brazilian law. In this context, the chapter examines the requisites for civil liability (tort, fault, causation and damage), standing to sue and to be sued, the interaction between the indemnification claims and the leniency program, as well as the statute of limitations. The sixth chapter discusses some proposals to reform the Brazilian legal framework with the purpose of improving the system of civil liability concerning cartel behavior. Finally, the conclusion seeks to expose in a systematic way the main ideas presented throughout the work, and to assess the current state of civil liability for damages resulting from cartel behavior in Brazilian law.

A presente pesquisa objetiva analisar os principais aspectos relacionados ao tema de danos em cartel: sobrepreço, efeito repasse (pass-on) e multa ótima. Com o aumento de políticas de combate a cartéis, pelo sério caráter lesivo à concorrência e à sociedade, intensificaram-se os esforços para estimar o impacto econômico no bem-estar provocado por tais condutas. O estudo confirma que a principal medida de dano econômico do cartel é o sobrepreço, ainda que os demais fatores, como o repasse (pass-on) e o efeito perda de vendas também devam ser considerados na mensuração do dano privado. Metodologias para o cálculo destes três componentes foram mapeadas, revelando que as técnicas disponíveis não são complexas, até fáceis de serem aplicadas, quando se tem amplo acesso a dados. Como avaliação empírica, apresenta-se o caso inédito do cartel dos compressores, sobre danos causados por tão nociva prática, comprovando-se que os valores de sobrepreço calculado estão em linha com a literatura. Por fim, a tese apresenta o histórico de multas impostas por autoridades, em casos de cartel, em diversas jurisdições, e questiona a efetividade dos montantes aplicados para devida dissuasão ou restabelecimento do bem-estar à sociedade. Análise de casos condenados pelo CADE recentemente mostram que as multas não têm sido suficientes para impor dissuasão, recomendando-se o uso de parâmetros que tragam racionalidade econômica e desestimulem as práticas anticompetitivas. / The present research had the aim of analyzing the main aspects related to cartel damages: overcharge, pass-on effect and optimal fine. With the growth of anti-cartel enforcement efforts and given the detrimental nature of conduct, efforts to estimate the economic impact on the welfare have increased. The study shows that the main measure of economic damage of the cartel is the overcharge, although other factors such as the pass-on effect and the output effect cannot be neglected in the calculation of private damage. Methodologies for these three components were mapped, revealing that the available techniques are not complex and even easy to apply when data is available. An empirical evaluation is presented using an unprecedented in the Brazilian market \"compressors cartel case\", showing an overcharge in line with the literature. Finally, the thesis presents the history of fines imposed by authorities in cartel cases in several jurisdictions and questions the effectiveness of the amounts applied for a proper deterrence or restoration of welfare to society. Case studies condemned by CADE recently show that fines have not been sufficient to impose deterrence, recommending the use of parameters that bring economic rationality and discourage anticompetitive practices.

A presente pesquisa objetiva analisar os principais aspectos relacionados ao tema de danos em cartel: sobrepreço, efeito repasse (pass-on) e multa ótima. Com o aumento de políticas de combate a cartéis, pelo sério caráter lesivo à concorrência e à sociedade, intensificaram-se os esforços para estimar o impacto econômico no bem-estar provocado por tais condutas. O estudo confirma que a principal medida de dano econômico do cartel é o sobrepreço, ainda que os demais fatores, como o repasse (pass-on) e o efeito perda de vendas também devam ser considerados na mensuração do dano privado. Metodologias para o cálculo destes três componentes foram mapeadas, revelando que as técnicas disponíveis não são complexas, até fáceis de serem aplicadas, quando se tem amplo acesso a dados. Como avaliação empírica, apresenta-se o caso inédito do cartel dos compressores, sobre danos causados por tão nociva prática, comprovando-se que os valores de sobrepreço calculado estão em linha com a literatura. Por fim, a tese apresenta o histórico de multas impostas por autoridades, em casos de cartel, em diversas jurisdições, e questiona a efetividade dos montantes aplicados para devida dissuasão ou restabelecimento do bem-estar à sociedade. Análise de casos condenados pelo CADE recentemente mostram que as multas não têm sido suficientes para impor dissuasão, recomendando-se o uso de parâmetros que tragam racionalidade econômica e desestimulem as práticas anticompetitivas. / The present research had the aim of analyzing the main aspects related to cartel damages: overcharge, pass-on effect and optimal fine. With the growth of anti-cartel enforcement efforts and given the detrimental nature of conduct, efforts to estimate the economic impact on the welfare have increased. The study shows that the main measure of economic damage of the cartel is the overcharge, although other factors such as the pass-on effect and the output effect cannot be neglected in the calculation of private damage. Methodologies for these three components were mapped, revealing that the available techniques are not complex and even easy to apply when data is available. An empirical evaluation is presented using an unprecedented in the Brazilian market \"compressors cartel case\", showing an overcharge in line with the literature. Finally, the thesis presents the history of fines imposed by authorities in cartel cases in several jurisdictions and questions the effectiveness of the amounts applied for a proper deterrence or restoration of welfare to society. Case studies condemned by CADE recently show that fines have not been sufficient to impose deterrence, recommending the use of parameters that bring economic rationality and discourage anticompetitive practices.

A presente dissertação de mestrado visa a estudar a responsabilidade civil por danos decorrentes da prática de cartel, a qual é considerada como a mais grave infração à ordem econômica. No primeiro capítulo, o fenômeno do cartel é estudado sob a perspectiva econômica, analisando-se as principais características e efeitos da conduta. No segundo capítulo, examina-se a disciplina jurídica do cartel no direito brasileiro, estudando-se as normas que preveem a responsabilização pela prática de cartel na lei concorrencial e na esfera penal. O terceiro capítulo pretende analisar os objetivos e o papel da responsabilidade civil no contexto mais amplo da política de defesa da concorrência. O quarto capítulo estuda a reparação civil dos danos decorrentes do cartel no direito federal norte-americano e no direito comunitário europeu. O quinto capítulo examina a responsabilidade civil por danos decorrentes da prática de cartel no direito brasileiro. Nesse contexto, são examinados os pressupostos da reparação civil (ato ilícito, culpa, nexo causal e dano), a legitimidade ativa e passiva para as ações indenizatórias, a interação entre a responsabilidade civil e o programa de leniência, bem como a prescrição da pretensão indenizatória. No sexto capítulo, são analisadas algumas propostas de reforma do ordenamento jurídico brasileiro para aperfeiçoamento do sistema de reparação civil em matéria de cartel. Finalmente, a conclusão procura expor de maneira sistematizada as principais ideias apresentadas ao longo do trabalho, bem como avaliar o estágio atual da responsabilidade civil por danos decorrentes da prática de cartel no direito brasileiro. / This dissertation aims to study the civil liability for damages arising from cartel behavior, which is considered the most serious antitrust violation. The first chapter studies the cartel from an economic perspective, analyzing the key features and effects of the conduct. The second chapter examines the legal framework regarding cartel behavior under Brazilian law, by studying the rules that provide for the responsibility for cartel under antitrust law and at the criminal level. The third chapter aims to analyze the objectives and the role of civil liability in the broader context of antitrust policy. The fourth chapter studies the civil liability for damages arising from cartel behavior in US federal law and European Community law. The fifth chapter examines the civil liability for damages resulting from cartel behavior in Brazilian law. In this context, the chapter examines the requisites for civil liability (tort, fault, causation and damage), standing to sue and to be sued, the interaction between the indemnification claims and the leniency program, as well as the statute of limitations. The sixth chapter discusses some proposals to reform the Brazilian legal framework with the purpose of improving the system of civil liability concerning cartel behavior. Finally, the conclusion seeks to expose in a systematic way the main ideas presented throughout the work, and to assess the current state of civil liability for damages resulting from cartel behavior in Brazilian law.

Les batteries lithium-ion dominent le marché des appareils nomades et celui des véhicules électriques. Néanmoins elles posent des problèmes de sécurité liés à leur électrolyte, contenant des carbonates inflammables et volatils. Pour sécuriser ces systèmes, les liquides ioniques (LI) sont étudiés comme électrolytes alternatifs. Ce sont des sels liquides à température ambiante, réputés stables thermiquement et non inflammables. Ce caractère sécuritaire des LI, souvent avancé, est pourtant peu étayé par des expériences probantes. Les travaux de cette thèse visent à comprendre le comportement de ces LI en situations abusives, telles qu'un échauffement de la batterie, un feu ou une surcharge. Les températures de décomposition de LI contenant les cations imidazolium ou pyrrolidinium différemment substitués et l'anion bis(trifluoromethanesulfonyl)imide ont été déterminées par analyse thermogravimétrique (ATG). Une analyse critique des données (de la littérature et de nos mesures) a permis de définir une procédure optimisée, pour obtenir des résultats reproductibles et comparables. Des électrolytes constitués de mélanges de carbonates ou de LI et de sels de lithium ont été analysés par ATG dynamique et isotherme, et leurs produits de décomposition ont été identifiés. Leur comportement au feu a été testé par la mesure des chaleurs de combustion, des délais d'inflammation et l'identification des gaz générés. Des tests de cyclage électrochimique ont été menés avec ces mêmes électrolytes dans des systèmes lithium-ion constitués des électrodes Li4Ti5O12 et LiNi1/3Mn1/3Co1/3O2. L'évolution des électrolytes et des surfaces des électrodes en situation de surcharge a été examinée / Lithium-ion batteries are dominating both the nomad device and electric vehicle markets. However they raise safety concerns related to their electrolyte, which consists of flammable and volatile carbonate mixtures and toxic salts. The replacement of the latter by ionic liquids (IL), liquid salts claimed to be thermally stable and non-flammable, could provide a safer alternative. Yet this often claimed feature has been poorly examined by experiments. The work of this thesis investigates IL behaviour under abuse conditions such as overheating, fire or overcharge. Decomposition temperatures of IL based on differently substituted imidazolium or pyrrolidinium cations and the bis(trifluoromethanesulfonyl)imide anion were determined by thermogravimetric analysis (TGA). A critical study of gathered data (from literature and our work) led to the determination of an optimised procedure to obtain reproducible and comparable results. Electrolytes based on carbonates mixtures or IL and containing lithium salt were studied by dynamic and isothermal TGA, and their decomposition products were identified. Their combustion behaviour was also tested by measuring heats of combustion and ignition delays. Emitted gases were analysed and quantified. Electrochemical cycling tests were carried out with these electrolytes in lithium-ion systems based on Li4Ti5O12 and LiNi1/3Mn1/3Co1/3O2 electrodes. The evolution of the electrolytes and electrodes surface was also examined under overcharge

Thesis (M.A. Commerce (Economics)) -- University of Limpopo, 2019 / South Africa had targeted the oil and gas sector for investment through the industrial action plan as a special economic zone. However, certain economic fundamentals might negate the anticipated sector financial development. This study investigate how economic risk exposure influence oil & gas sector stock market returns from 2007 to 2015 on a monthly basis. The four macroeconomic variables used to measure economic risk exposure are Brent crude oil prices, the USD/ZAR exchange rate, broad money supply and gold prices. The adopted techniques include the GARCH model to incorporate volatility, the Johansen cointegration and Granger causality techniques. The results of the study found that change in Brent crude oil prices and broad money supply had a positive and significant impact on changes in oil & gas sector stock returns. Changes in exchange rate and gold prices had a negative and significant impact on the sector returns. The long-run relationship established one cointegrating equation in the series. Only Brent crude oil prices indicated a bi-directional Granger causality on the sector returns. Based on the findings, it is recommended that government may use exchange rate as a policy tool to attract interest in the sector. Regarding money supply, the reserve bank should further preserve its effective regulatory infrastructure including the laws, regulations and standards towards the achievement and maintenance of a stable financial system. Portfolio managers, risk managers and investors should monitor the gold price to mitigate losses due to its strength as a safe haven asset.

Although wireless sensor networks have been successfully used for environmental monitoring, one of the major challenges that this technology has been facing is supplying continuous and reliable electrical power during long-term field deployment. Batteries require repetitive visits to the deployment site to replace them once discharged; admittedly, they can be recharged from solar panels, but this only works in open areas where solar radiation is unrestricted. This dissertation introduces a novel approach to design and implement a reliable efficient solar energy harvester to continuously, and autonomously, provide power to wireless sensor nodes for long-term applications. The system uses supercapacitors charged by a solar panel and is designed to reduce power consumption to very low levels. Field tests were conducted for more than a year of continuous operation and under a variety of conditions, including areas under dense foliage. The resulting long-term field data demonstrates the feasibility and sustainability of the harvester system for challenging applications. In addition, we analyzed solar radiation data and supercapacitor charging behavior and showed that the harvester system can operate battery free, running on the power provided by supercapacitors. A battery is included only for backup in case the supercapacitor storage fails. The proposed approach provides continuous power supply to the system thereby significantly minimizing data loss by power failure and the frequency of visits to the deployment sites.