Optimal Design and Control of 4-IWD Electric Vehicles based on a 14-DOF Vehicle Model

A 4-independent wheel driving (4-IWD) electric vehicle has distinctive advantages with both enhanced dynamic and energy efficiency performances since this configuration provides more flexibilities from both the design and control aspects. However, it is difficult to achieve the optimal performances of a 4-IWD electric vehicle with conventional design and control approaches. This work is dedicated to investigating the vehicular optimal design and control approaches, with a 4-IWD electric race car aiming at minimizing the lap time on a given circuit as a case study. A 14-DOF vehicle model that can fully evaluate the influences of the unsprung mass is developed based on Lagrangian dynamics. The 14-DOF vehicle model implemented with the reprogrammed Magic Formula tire model and a time-efficient suspension model supports metric operations and parallel computing, which can dramatically improve the computational efficiency. The optimal design and control problems with design parameters of the motor, transmission, mass center, anti-roll bar and the suspension of the race car are successively formulated. The formulated problems are subsequently solved by directly transcribing the original problems into large scale nonlinear optimization problems based on trapezoidal approach. The influences of the mounting positions of the propulsion system, the mass and inertia of the unsprung masses, the anti-roll bars and suspensions on the lap time are analyzed and compared quantitatively. Some interesting findings that are different from the `already known facts' are presented

Optimization of shift schedule for hybrid electric vehicle with automated manual transmission

Currently, most hybrid electric vehicles (HEVs) equipped with automated mechanical transmission (AMT) are implemented with the conventional two-parameter gear shift schedule based on engineering experience. However, this approach cannot take full advantage of hybrid drives. In other words, the powertrain of an HEV is not able to work at the best fuel-economy points during the whole driving profile. To solve this problem, an optimization method of gear shift schedule for HEVs is proposed based on Dynamic Programming (DP) and a corresponding solving algorithm is also put forward. A gear shift schedule that can be employed in real-vehicle is extracted from the obtained optimal gear shift points by DP approach and is optimized based on analysis of the engineering experience in a typical Chinese urban driving cycle. Compared with the conventional two-parameter gear shift schedule in both simulation and real vehicle experiments, the extracted gear shift schedule is proved to clearly improve the fuel economy of the HEV

A Highly Active Star Decahedron Cu Nanocatalyst for Hydrocarbon Production at Low Overpotentials

The electrochemical carbon dioxide reduction reaction (CO_2RR) presents a viable approach to recycle CO_2 gas into low carbon fuels. Thus, the development of highly active catalysts at low overpotential is desired for this reaction. Herein, a high‐yield synthesis of unique star decahedron Cu nanoparticles (SD‐Cu NPs) electrocatalysts, displaying twin boundaries (TBs) and multiple stacking faults, which lead to low overpotentials for methane (CH_4) and high efficiency for ethylene (C_2H_4) production, is reported. Particularly, SD‐Cu NPs show an onset potential for CH_4 production lower by 0.149 V than commercial Cu NPs. More impressively, SD‐Cu NPs demonstrate a faradaic efficiency of 52.43% ± 2.72% for C_2H_4 production at −0.993 ± 0.0129 V. The results demonstrate that the surface stacking faults and twin defects increase CO binding energy, leading to the enhanced CO_2RR performance on SD‐Cu NPs

Patients\u27 Acceptance of Smartphone Health Technology for Chronic Disease Management: A Theoretical Model and Empirical Test

Les quatre textes ont en commun de présenter certaines évolutions récentes de l’histoire politique en Allemagne. Ils prennent tous position face à trois tournants historiographiques. La notion d’histoire culturelle du politique peut servir d’emblème au premier de ces tournants : le politique est envisagé non plus comme une succession d’événements ni comme le fruit de déterminations structurelles dont il serait la superstructure ou l’écume, mais comme l’expression de valeurs et de procédures o..

Presión arterial del recién nacido de madres preeclámpticas eclámpticas Hospital Regional de Cajamarca 2016

La presión arterial del recién nacido está sujeta a variaciones por diversas causas entre ellas la patología materna conocida como la preeclampsia El objetivo de la presente investigación fue determinar y analizar la presión arterial durante las primeras en las primeras 36 horas de vida, en forma periódica, de los recién nacidos hijos de madres preeclámpticas y la presión arterial de los recién nacidos hijos de madres no preeclámpticas, atendidos en el Hospital Regional de Cajamarca durante los meses de enero- febrero del año 2016. El estudio fue de tipo descriptivo, comparativo, correlacional, no experimental, de corte transversal y naturaleza prospectiva. Se incluyeron a 75 recién nacidos, hijos de madres preeclámpticas, y 75 recién nacidos de madres no preeclámpticas que cumplían con los criterios de inclusión y exclusión, atendidos en el Hospital Regional de Cajamarca durante los meses de enero y febrero del año 2016. Se realizaron mediciones de presión arterial en tres ocasiones: 12, 24 y 36 horas de nacimiento. Los resultados encontrados en la presente investigación fueron: edad materna promedio de 28.5 años, en gran porcentaje multíparas (49% y 48% en ambos grupos) y la mayoría con el diagnóstico de preeclampsia severa (52%). Los neonatos nacieron predominantemente por vía vaginal (56% y 86,8%), a término (76% y 94,7%), de sexo masculino con un porcentaje de 54,7% en el primer grupo y sexo femenino en el segundo grupo con 42%; con peso y talla al nacer promedio de 3026.7 gramos y 49.2 centímetros, respectivamente, con un puntaje de Apgar en su mayoría de 8 al minuto y 9 a los cinco minutos, con una cantidad mínima de neonatos con administración prenatales de corticoides (0,7%). Se determinó que la presión arterial se incrementó en las primeras 12 horas de vida en los recién nacidos de madres preeclámpticas, regularizándose, la mayoría, a las 36 horas, continuando elevada en un buen porcentaje (30,7%). En cuanto a los recién nacidos de madres no preeclámpticas una considerable cantidad tuvo presión arterial normal y los que tuvieron presión arterial alta en las primeras horas, se regularizaron a las 36 horasTesi

A Highly Active Star Decahedron Cu Nanocatalyst for Hydrocarbon Production at Low Overpotentials

The electrochemical carbon dioxide reduction reaction (CO_2RR) presents a viable approach to recycle CO_2 gas into low carbon fuels. Thus, the development of highly active catalysts at low overpotential is desired for this reaction. Herein, a high‐yield synthesis of unique star decahedron Cu nanoparticles (SD‐Cu NPs) electrocatalysts, displaying twin boundaries (TBs) and multiple stacking faults, which lead to low overpotentials for methane (CH_4) and high efficiency for ethylene (C_2H_4) production, is reported. Particularly, SD‐Cu NPs show an onset potential for CH_4 production lower by 0.149 V than commercial Cu NPs. More impressively, SD‐Cu NPs demonstrate a faradaic efficiency of 52.43% ± 2.72% for C_2H_4 production at −0.993 ± 0.0129 V. The results demonstrate that the surface stacking faults and twin defects increase CO binding energy, leading to the enhanced CO_2RR performance on SD‐Cu NPs

Single-atom tailoring of platinum nanocatalysts for high-performance multifunctional electrocatalysis

Platinum-based nanocatalysts play a crucial role in various electrocatalytic systems that are important for renewable, clean energy conversion, storage and utilization. However, the scarcity and high cost of Pt seriously limit the practical application of these catalysts. Decorating Pt catalysts with other transition metals offers an effective pathway to tailor their catalytic properties, but often at the sacrifice of the electrochemical active surface area (ECSA). Here we report a single-atom tailoring strategy to boost the activity of Pt nanocatalysts with minimal loss in surface active sites. By starting with PtNi alloy nanowires and using a partial electrochemical dealloying approach, we create single-nickel-atom-modified Pt nanowires with an optimum combination of specific activity and ECSA for the hydrogen evolution, methanol oxidation and ethanol oxidation reactions. The single-atom tailoring approach offers an effective strategy to optimize the activity of surface Pt atoms and enhance the mass activity for diverse reactions, opening a general pathway to the design of highly efficient and durable precious metal-based catalysts

Single-atom tailoring of platinum nanocatalysts for high-performance multifunctional electrocatalysis

Platinum-based nanocatalysts play a crucial role in various electrocatalytic systems that are important for renewable, clean energy conversion, storage and utilization. However, the scarcity and high cost of Pt seriously limit the practical application of these catalysts. Decorating Pt catalysts with other transition metals offers an effective pathway to tailor their catalytic properties, but often at the sacrifice of the electrochemical active surface area (ECSA). Here we report a single-atom tailoring strategy to boost the activity of Pt nanocatalysts with minimal loss in surface active sites. By starting with PtNi alloy nanowires and using a partial electrochemical dealloying approach, we create single-nickel-atom-modified Pt nanowires with an optimum combination of specific activity and ECSA for the hydrogen evolution, methanol oxidation and ethanol oxidation reactions. The single-atom tailoring approach offers an effective strategy to optimize the activity of surface Pt atoms and enhance the mass activity for diverse reactions, opening a general pathway to the design of highly efficient and durable precious metal-based catalysts