Some pay much but many don’t: Vehicle TCO imputation in travel surveys

Costs of cars are among the most relevant factors influencing travel behavior. However, there is a lack of data about the true costs of car ownership and specifically on how these costs are distributed across different vehicles and across the population. This paper presents a multistage method for imputing car costs by cost item in a German national travel survey data set. Based on vehicle information reported by survey participants, we assign costs to each of the three thousand cars in the data set using the most comprehensive German vehicle cost data base. In addition to combining different data sets, we use model based imputation methods. In order to validate the average costs for private vehicles we analyze the German income and expenditure survey EVS. The average total cost of ownership for a private car in Germany is about 310 Euros per month. This translates to about 30 Eurocents per auto-km. About one third of the costs are fuel, another third is depreciation, and the rest are other mainly fixed costs (insurance, tax, repair and maintenance). However, the cost distribution is strongly skewed with a long tail to the right. Hence, the majority of motorists pay less than average for their private vehicles while few pay more and evidently some pay a lot more. This imputation approach delivers unprecedented vehicle cost information in particular with regard to the distribution of vehicle costs. Such data is key for understanding the fundamentals of mobility choices

MRT-morphologische Varianten des Patello-femoralen Gelenkes bei Patienten mit Patellaluxationen

Ziel der Studie war es anhand einer Vielzahl von verschiedenen Messparametern Risikofaktoren für eine Patellaluxation beziehungsweise ein Risikoprofil für eine Reluxationsgefahr nach bereits stattgehabter Luxation darzustellen. Insgesamt konnten drei Parameter eindeutige Unterschiede zwischen Patienten mit einmaliger Luxation und Reluxationspatienten aufzeigen. Reluxationspatienten hatten wesentlich höhere Werte des Koshino- und Blackburne- Peel-Index als Patienten mit einmaliger Luxation. Beim patello-trochleären Index verhielten sich die Werte genau entgegengesetzt. So zeigten Reluxationspatienten deutlich niedrigere Werte als Patienten mit einfacher Luxation. Alle drei Resultate weisen jeder für sich auf eine Patella alta oder zumindest eine Tendenz zu einem Patella-Hochstand hin. Man kann also davon ausgehen, dass ein erhöhter Koshino- und Blackburne-Peel-Index, beziehungsweise ein zu kleiner patello-trochleärer Index erhebliche Risikofaktoren für Patienten mit Patellaluxation darstellen, in Zukunft eine Reluxation zu erleiden. Inwiefern der Patella Shift und der Patella Tilt in die Beurteilung des initialen Risikoprofils miteingehen sollte und danach die Therapie festgelegt werden kann bleibt offen. Es scheint jedoch, dass diese Parameter dafür geeignet sind, die mediale Raffung als suffizientes Verfahren bzw. als unzureichend zu identifizieren. Mit den Ergebnissen des Insall-Salvati-Index und des Patella shifts zeigten sich wiederum Unterschiede in den unterschiedlichen Altergruppen. So wurde deutlich, dass die Gefahr einer patello-femoralen Instabilität beziehungsweise einer Patellaluxation im Jugendalter am höchsten ist und mit zunehmendem Alter beziehungsweise mit der daraus resultierenden Abnahme des Wachstums rückläufig erscheint. Bei den Messungen des Tibial Slope fiel auf, dass weibliche Patientinnen wesentlich höhere Werte zeigten als männliche. Erhöhte Tibial Slope-Werte spielen im Pathomechanismus der patellofemoralen Instabilität durchaus eine Rolle und liefern somit einen der Gründe, warum Frauen häufiger von Patellaluxationen betroffen sind als Männer [16, 17]. Wie auch schon in den oberen Abschnitten erörtert finden sich in der Literatur eine Vielzahl verschiedener Parameter, die zur Vermessung des Kniegelenkes herangezogen werden können. Allerdings ist nicht jede Messmethode für die Anwendung auf unterschiedliche Bildgebungsmöglichkeiten geeignet. Somit resultieren eine Vielzahl an publizierten Normwerten für unterschiedliche Bildgebungsverfahren. Ziel in Zukunft muss es dennoch sein, noch einheitlicher mit dem Thema patellofemorale Instabilität und Patellaluxation umzugehen. So müssen relevante Begriffe wie Patella alta genauer definiert werden, indem einheitliche Messverfahren angewendet werden und Normwerte beziehungsweise Grenzwerte einheitlich festgelegt werden

Some pay much but many don’t: Vehicle TCO imputation in travel surveys

Costs of cars are among the most relevant factors influencing travel behavior. However, there is a lack of data about the true costs of car ownership and specifically on how these costs are distributed across different vehicles and across the population. This paper presents a multistage method for imputing car costs by cost item in a German national travel survey data set. Based on vehicle information reported by survey participants, we assign costs to each of the three thousand cars in the data set using the most comprehensive German vehicle cost data base. In addition to combining different data sets, we use model based imputation methods. In order to validate the average costs for private vehicles we analyze the German income and expenditure survey EVS. The average total cost of ownership for a private car in Germany is about 310 Euros per month. This translates to about 30 Eurocents per auto-km. About one third of the costs are fuel, another third is depreciation, and the rest are other mainly fixed costs (insurance, tax, repair and maintenance). However, the cost distribution is strongly skewed with a long tail to the right. Hence, the majority of motorists pay less than average for their private vehicles while few pay more and evidently some pay a lot more. This imputation approach delivers unprecedented vehicle cost information in particular with regard to the distribution of vehicle costs. Such data is key for understanding the fundamentals of mobility choices

Mobility-on-demand pricing versus private vehicle TCO: how cost structures hinder the dethroning of the car

This study uses a unique dataset on the cost of motoring in Germany to analyse cost competitiveness of emerging mobility-on-demand (MOD) services. Previous studies have focused on comparing current and projected MOD prices with the average cost of private motoring. This study quantifies which proportion of private car travel would actually turn out to be costlier than MOD given that MOD costs drop below certain levels relative to the cost of private motoring. In this context, not the average but the distribution of the costs of motoring are the key issue. These costs are strongly skewed across the cars in private households when including new and old vehicles: a large proportion of private car kilometres are driven at relatively low cost. The study uses simplified scenario settings with MOD price levels ranging from 0.1 €/km to 1.5 €/km to make predictions of hypothetical modal shifts under the assumption that car user switch to the most economic mode of travel. These modal shifts serve as an indicator of MOD cost competitiveness. The results indicate that MOD prices would have to drop to 0.5 €/km or lower to have a notable impact on use of the private car if cost was the key mode choice criterion. Only if MOD prices drop down to a level of about 0.3 €/km—quite possibly a lower boundary for automated MOD—MOD-enabled mobility packages would be the less costly alternative to the private car for a substantial proportion of mileage. However, even at that MOD price level, the private car would still be the most economic option for the majority of today’s car user kilometres. Our findings illustrate that the skewed distribution of the cost of owning and running private cars—where many of those who drive much drive inexpensively—substantially dampens the disruptive potential of MOD. While we use data from Germany to illustrate this, many of our findings are more widely applicable

The success story of graphite as a lithium-ion anode material – fundamentals, remaining challenges, and recent developments including silicon (oxide) composites

Lithium-ion batteries are nowadays playing a pivotal role in our everyday life thanks to their excellent rechargeability, suitable power density, and outstanding energy density. A key component that has paved the way for this success story in the past almost 30 years is graphite, which has served as a lithium-ion host structure for the negative electrode. And despite extensive research efforts to find suitable alternatives with enhanced power and/or energy density, while maintaining the excellent cycling stability, graphite is still used in the great majority of presently available commercial lithium-ion batteries. A comprehensive review article focusing on graphite as lithium-ion intercalation host, however, appeared to be missing so far. Thus, herein, we provide an overview on the relevant fundamental aspects for the de-/lithiation mechanism, the already overcome and remaining challenges (including, for instance, the potential fast charging and the recycling), as well as recent progress in the field such as the trade-off between relatively cheaper natural graphite and comparably purer synthetic graphite and the introduction of relevant amounts of silicon (oxide) to boost the energy and power density. The latter, in fact, comes with its own challenges and the different approaches to overcome these in graphite/silicon (oxide) composites are discussed herein as well

Effect of Applying a Carbon Coating on the Crystal Structure and De-/Lithiation Mechanism of Mn-Doped ZnO Lithium-Ion Anodes

The introduction of transition metal dopants such as Fe and Co in zinc oxide enables substantially enhanced reversible capacities and greater reversibility of the de-/lithiation reactions occurring. Herein, we report a comprehensive analysis of the electrochemical processes taking place in Mn-doped ZnO (Zn$_{0.9}$Mn$_{0.1}$O) and carbon-coated Zn$_{0.9}$Mn$_{0.1}$O upon de-/lithiation. The results shed light on the impact of the dopant chemistry and, especially, its coordination in the crystal structure. When manganese does not replace zinc in the wurtzite structure, only a moderate improvement in electrochemical performance is observed. However, when applying the carbonaceous coating, a partial reduction of manganese and its reallocation in the crystal structure occur, leading to a substantial improvement in the material\u27s specific capacity. These results provide important insights into the impact of the lattice position of transition metal dopants—a field that has received very little, essentially no attention, so far

Structural and Electrochemical Characterization of Zn1−x_{1-x}Fex_{x}O : Effect of Aliovalent Doping on the Li⁺ Storage Mechanism

In order to further improve the energy and power density of state-of-the-art lithium-ion batteries (LIBs), new cell chemistries and, therefore, new active materials with alternative storage mechanisms are needed. Herein, we report on the structural and electrochemical characterization of Fe-doped ZnO samples with varying dopant concentrations, potentially serving as anode for LIBs (Rechargeable lithium-ion batteries). The wurtzite structure of the Zn1−xFexO samples (with x ranging from 0 to 0.12) has been refined via the Rietveld method. Cell parameters change only slightly with the Fe content, whereas the crystallinity is strongly affected, presumably due to the presence of defects induced by the Fe3+ substitution for Zn2+. XANES (X-ray absorption near edge structure) data recorded ex situ for Zn0.9Fe0.1O electrodes at different states of charge indicated that Fe, dominantly trivalent in the pristine anode, partially reduces to Fe2+ upon discharge. This finding was supported by a detailed galvanostatic and potentiodynamic investigation of Zn1−xFexO-based electrodes, confirming such an initial reduction of Fe3+ to Fe2+ at potentials higher than 1.2 V (vs. Li+/Li) upon the initial lithiation, i.e., discharge. Both structural and electrochemical data strongly suggest the presence of cationic vacancies at the tetrahedral sites, induced by the presence of Fe3+ (i.e., one cationic vacancy for every two Fe3+ present in the sample), allowing for the initial Li+ insertion into the ZnO lattice prior to the subsequent conversion and alloying reaction

Impact of the Transition Metal Dopant in Zinc Oxide Lithium-Ion Anodes on the Solid Electrolyte Interphase Formation

Conversion/alloying materials (CAMs) provide substantially higher specific capacities than graphite, the state‐of‐the‐art lithium‐ion battery anode material. The ability to host much more lithium per unit weight and volume is, however, accompanied by significant volume changes, which challenges the realization of a stable solid electrolyte interphase (SEI). Herein, the comprehensive characterization of the composition and evolution of the SEI on transition metal (TM) doped zinc oxide as CAM model compound, is reported, with a particular focus on the impact of the TM dopant (Fe or Co). The results unveil that the presence of iron specifically triggers the electrolyte decomposition. However, this detrimental effect can be avoided by stabilizing the interface with the electrolyte by a carbonaceous coating. These findings provide a great leap forward toward the enhanced understanding of such doped materials and (transition) metal oxide active materials in general