Optimum battery capacity for electric vehicles with particular focus on battery degradation

Electric vehicles (EVs) are seen as a key future trend in the automotive industry. These vehicles rely on rechargeable batteries to store energy on board. The optimum size of this energy store, often referred to as the battery capacity measured in ampere-hours (Ah) or kilowatt-hours (kWh), depends on the specific application, design limitations, costs and the degradation of the particular battery pack. Validated by 'real-world' driving data from the Imperial College Racing Green Endurance (RGE) flagship electric supercar, the SRZero, a software model following a quasi-steady, backward-forward facing and equivalent circuit approach is introduced. This model is also supported by the results of the 2010, 2011 and 2012 RAC Future Car Challenges as well as by battery life testing from a lab environment. Furthermore, travel surveys from the United Kingdom (UK), Germany and the United States (US) have been analysed and then converted into input parameters for this algorithm. The work considers five different electric vehicle classes ranging from mini cars to sport utility vehicles (SUVs). Results show that varying kerb weights combined with differing levels of driving resistances (aerodynamic drag, rolling resistance, climbing resistance, etc.) lead to reference 'driving forces' of 70-290 Wh/km for the five reference vehicle classes. On average, SUVs consume more than four times as much energy per unit distance as mini cars. Also, driving behaviour has a significant impact on energy consumption and thus on the optimum nominal battery capacity. Empirical data has shown that the mean driving force can vary up to 23% between drivers who follow exactly the same route at comparable traffic conditions and driving another vehicle of exactly the same make and model. Daily range requirements of EVs vary between 150-700 km based on the 95th percentile of the number of all daily trips or the cumulative distance of all trips combined for the UK, Germany and the US. Thus, optimum nominal battery capacities range between 11-203 kWh. In addition, it is shown that the optimum actual size of a battery pack for an electric vehicle depends on the battery's degradation as well. Over time and number of cycles the available capacity as well as the available power fades. This is mainly due to the effects of increased internal resistance, polarisation, corrosion and passivation. Therefore, first it is recommended to reduce the depth of discharge (DOD) to 80% when the battery is in use. Second, a spare capacity at the beginning of life of around 20-40% is recommended in order to satisfy range and power requirements also towards the end of the EV’s lifetime. It follows that the optimum actual battery capacity is around 1.25-1.75 times the optimum nominal battery capacity for an EV.Open Acces

Role of the Thymus in Transplantation Tolerance in Miniature Swine. I. Requirement of the Thymus for Rapid and Stable Induction of Tolerance to Class I–mismatched Renal Allografts

The almost uniform failure in transplant patients of tolerance-inducing regimens that have been found to be effective in rodents, has made it necessary to examine large animal models before testing of new approaches clinically. Miniature swine have been shown to share many relevant immunologic parameters with humans, and because of their reproducible genetics, have proved extremely useful in providing such a large animal model. We have previously shown that indefinite systemic tolerance to renal allografts in miniature swine is induced in 100% of cases across a two-haplotype class I plus minor histocompatibility antigen disparity by a 12-d course of Cyclosporine A (CyA), in contrast to irreversible rejection observed uniformly without CyA treatment. In the present study, we have examined the role of the thymus during the induction of tolerance by performing a complete thymectomy 21 d before renal transplantation. This analysis demonstrated a striking difference between thymectomized and nonthymectomized animals. Thymectomized swine developed acute cellular rejection characterized by a T cell (CD25+) infiltrate, tubulitis, endothelialitis and glomerulitis, and anti–donor CTL reactivity in vitro. Nonthymectomized and sham thymectomized animals had a mild T cell infiltrate with few CD25+ cells and no anti–donor CTL response in vitro. These results indicate that the thymus is required for rapid and stable induction of tolerance

Adult Living Donor Liver Transplantation with ABO-Incompatible Grafts: A German Single Center Experience

Adult living donor liver transplantations (ALDLTs) across the ABO blood group barrier have been reported in Asia, North Americas, and Europe, but not yet in Germany. Several strategies have been established to overcome the detrimental effects that are attached with such a disparity between donor and host, but no gold standard has yet emerged. Here, we present the first experiences with three ABO-incompatible adult living donor liver transplantations in Germany applying different immunosuppressive strategies. Four patient-donor couples were considered for ABO-incompatible ALDLT. In these patients, resident ABO blood group antibodies (isoagglutinins) were depleted by plasmapheresis or immunoadsorption and replenishment was inhibited by splenectomy and/or B-cell-targeted immunosuppression. Despite different treatments ALDLT could safely be performed in three patients and all patients had good initial graft function without signs for antibody-mediated rejection (AMR). Two patients had long-term graft survival with stable graft function. We thus propose the feasibility of ABO-incompatible ALDLT with these protocols and advocate further expansion of ABO incompatible ALDLT in multicenter trials to improve efficacy and safety

Pantoprazole Does not Affect Serum Trough Levels of Tacrolimus and Everolimus in Liver Transplant Recipients

Background: Liver transplant recipients are frequently treated with proton pump inhibitors. Drug interactions have been described especially with respect to omeprazole. Due to the lower binding capacity of pantoprazole to CYP2C19 this drug became preferred and became the most used proton pump inhibitor in Germany. The data on the influence of pantoprazole on immunosuppressive drugs in liver transplant recipients a very scarce.Methods: The authors performed a single center analysis in liver transplant recipients on the effect of pantoprazole on the serum trough levels of different immunosuppressants. The trough levels were compared over a period of 1 year before and after start or stop of a continuous oral co-administration of 40 mg pantoprazole once daily.Results: The serum trough levels of tacrolimus (n = 30), everolimus (n = 7), or sirolimus (n = 3) remain constant during an observation period of at least 1 year before and after co-administration of pantoprazole. None of the included patients needed a change of dosage of the observed immunosuppressants during the observation period.Conclusions: The oral co-administration of pantoprazole is safe in immunosuppressed liver transplant recipients according to the serum trough levels of tacrolimus, everolimus, and sirolimus. This analysis provides first data on the influence of pantoprazole on immunosuppressive drugs in liver transplant recipients

Acute paranoid psychosis as sole clinical presentation of hepatic artery thrombosis after living donor liver transplantation

<p>Abstract</p> <p>Background</p> <p>Hepatic artery thrombosis is a devastating complication after orthotopic liver transplantation often requiring revascularization or re-transplantation. It is associated with considerably increased morbidity and mortality. Acute cognitive dysfunction such as delirium or acute psychosis may occur after major surgery and may be associated with the advent of surgical complications.</p> <p>Case presentation</p> <p>Here we describe a case of hepatic artery thrombosis after living-donor liver transplantation which was not preceded by signs of liver failure but rather by an episode of acute psychosis. After re-transplantation the patient recovered without sequelae.</p> <p>Conclusion</p> <p>This case highlights the need to remain cautious when psychiatric disorders occur in patients after liver transplantation. The diagnostic procedures should not be restricted to medical or neurological causes of psychosis alone but should also focus vascular complications related to orthotopic liver transplantation.</p

Altered regulation of Prox1-gene-expression in liver tumors

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