Effect of gear ratio on the dc motor efficiency of a minifuel-cell vehicle cruising at constant speeds

The traction motor is a key component in a fuel-cell vehicle as it converts electrical energy supplied by a fuel cell into mechanical shaft work for vehicle propulsion. Motor size, torque rating and current consumption are important factors in the selection of the optimum drive motor for best energy efficiency. In a practical power train assembly, the motor is coupled to the wheel via a gearing system. This study focuses on the performance with respect to traction motor efficiency relative to the gear ratio selection and variable drive cycles to minimize the power consumption of the vehicle. A test bench with a 1 kW fuel cell was developed and tests were performed at constant speeds between 15 km/h to 30 km/h with different gear ratios. Among the measured and evaluated parameters using Eagle Tree and Inertia data loggers are rpm, current, torque and power. The results show that the gear ratio selection produces a variation in required motor input power at similar drive speeds. It also shows the optimal setting of the gear ratio of more than 70% that suits the best efficiency point of the DC motor according to actual driving requirements

Evaluation of production cross-sections for theranostic 67Cu radionuclide via proton-induced nuclear reaction on 68Zn target

Copper–67 (T1/2 = 61.83 h, ) is a promising radionuclide for theranostic applications especially in radio immunotherapy. However, one of the main drawbacks for its application is related to its limited availability. Various nuclear reaction routes investigated in the last years can result in 67Cu production, although the use of proton beams is the method of choice taken into account in this work. The goal of this work is a revision of the cross-sections aimed at 67Cu yield, which were evaluated for the 68Zn(p,2p)67Cu reaction route up to 80 MeV proton energy. A well-defined statistical procedure, i.e., the Simultaneous Evaluation on KALMAN (SOK), combined with the least-squares concept, was used to obtain the evaluated data together with the covariance matrix. The obtained evaluated data were also compared to predictions provided by the nuclear reaction model codes TALYS and EMPIRE, and a partial agreement among them has been found. These data may be useful for both existing and potential applications in nuclear medicine, to achieve an improvement and validation of the various nuclear reaction models, and may also find applications in other fields (e.g., activation analysis and thin layer activation)

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

A century of trends in adult human height

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5-22.7) and 16.5 cm (13.3-19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries

Regulation of Differential Drive Robots using Continuous Time MPC without Stabilizing Constraints or Costs

In this paper, model predictive control (MPC) of differential drive robots is considered. Here, we solve the set point stabilization problem without incorporating stabilizing constraints and/or costs in the MPC scheme. In particular, we extend recent results obtained in a discrete time setting to the continuous time domain. To this end, so called swaps and replacements are introduced in order to validate a growth condition on the value function and, thus, to rigorously prove asymptotic stability of the MPC closed loop for nonholonomic robots

Doping and characterization of trilayer graphene on 4H-SiC (0001)

International audienc