LCA of a Proton Exchange Membrane Fuel Cell Electric Vehicle Considering Different Power System Architectures

Fuel cell electric vehicles are a promising solution for reducing the environmental impacts of the automotive sector; however, there are still some key points to address in finding the most efficient and less impactful implementation of this technology. In this work, three electrical architectures of fuel cell electric vehicles were modeled and compared in terms of the environmental impacts of their manufacturing and use phases. The three architectures differ in terms of the number and position of the DC/DC converters connecting the battery and the fuel cell to the electric motor. The life cycle assessment methodology was employed to compute and compare the impacts of the three vehicles. A model of the production of the main components of vehicles and fuel cell stacks, as well as of the production of hydrogen fuel, was constructed, and the impacts were calculated using the program SimaPro. Eleven impact categories were considered when adopting the ReCiPe 2016 midpoint method, and the EF (adapted) method was exploited for a final comparison. The results highlighted the importance of the converters and their influence on fuel consumption, which was identified as the main factor in the comparison of the environmental impacts of the vehicle

Forces exerted during exercises by patients with adolescent idiopathic scoliosis wearing fiberglass braces

OBJECTIVE: To quantify and compare the forces exerted by scoliosis patients in fiberglass braces during exercises usually prescribed in departments where casts are made. The exercises are intended to increase corrective forces, activate muscles, stimulate ventilation and help the patient psychologically. SETTING: Outpatient care. PATIENTS: 17 consecutive adolescent patients wearing fiberglass brace for idiopathic scoliosis. INTERVENTIONS: Exercises (kyphotization, rotation, "escape from the pad") in different positions (sitting, supine, on all fours). MAIN OUTCOME MEASURE: Pressure detected by the F-Socket System between the rib hump and the pad of the brace. RESULTS: In static and dynamic conditions, the position adopted did not alter the total pressure exerted by the brace, although the part of the sensor stimulated did vary. Kyphotization and rotation exercises produced a significant increase of pressure (+ 58.9% and +29.8%, respectively); however, the "escape from the pad" exercise, despite its name, did not produce any significant variation of pressure. CONCLUSION: Exercises in the brace allow adjunctive forces to be applied on soft tissues and through them, presumably on the spine. Different exercises can be chosen to obtain different actions. Physical exercises and sporting activities are useful in mechanical terms, although other important actions should not be overlooked

Integrated Electro-Thermal Model for Li-Ion Battery Packs

Lithium-ion battery is considered one of the most attractive energy storage systems for electric vehicles. However, one of its main drawbacks is the sensitivity to temperature. In a battery pack composed of lithium-ion batteries, during the charge/discharge operations, the temperature gradually increases, especially in the batteries positioned in the central part of the battery pack. This leads the central batteries to age faster and exposes them to the risk of a thermal runaway. In order to mitigate these problems, thermal management systems are needed. However, for the implementation of the control, it is important to know the temperature distribution inside the whole pack. In this paper, an integrated electro-thermal model capable of estimating the thermal behavior of each battery cell, composing the battery pack, only knowing the total current and ambient temperature, is proposed and analyzed. The proposed model was tuned and validated by means of experimental results. The circuital approach used in this model gives good results with a low degree of complexity