Battery choice and management for New Generation Electric Vehicles

Different types of electric vehicles (EVs) have been recently designed with the aim of solving pollution problems caused by the emission of gasoline-powered engines. Environmental problems promote the adoption of new-generation electric vehicles for urban transportation. As it is well known, one of the weakest points of electric vehicles is the battery system. Vehicle autonomy and, therefore, accurate detection of battery state of charge (SoC) together with battery expected life, i.e., battery state of health, are among the major drawbacks that prevent the introduction of electric vehicles in the consumer market. The electric scooter may provide the most feasible opportunity among EVs. They may be a replacement product for the primary-use vehicle, especially in Europe and Asia, provided that drive performance, safety, and cost issues are similar to actual engine scooters. The battery system choice is a crucial item, and thanks to an increasing emphasis on vehicle range and performance, the Li-ion battery could become a viable candidate. This paper deals with the design of a battery pack based on Li-ion technology for a prototype electric scooter with high performance and autonomy. The adopted battery system is composed of a suitable number of cells series connected, featuring a high voltage level. Therefore, cell equalization and monitoring need to be provided. Due to manufacturing asymmetries, charge and discharge cycles lead to cell unbalancing, reducing battery capacity and, depending on cell type, causing safety troubles or strongly limiting the storage capacity of the full pack. No solution is available on the market at a cheap price, because of the required voltage level and performance, therefore, a dedicated battery management system was designed, that also includes a battery SoC monitoring. The proposed solution features a high capability of energy storing in braking conditions, charge equalization, overvoltage and undervoltage protection and, obviously, SoC information in order to optimize autonomy instead of performance or vice-versa

Est modus in rebus.

In the July 2013 issue of the American Journal of Neuroradiology an editorial appeared, authored by Dr H.J. Cloft, entitled "Capitalism and Commodities: My Two Cents."[1][1] In the editorial, Dr Cloft explains that nowadays "more that 20 years after the invention of the Guglielmi Detachabl

Sensorless Direct Field-Oriented Control of Three-Phase Induction Motor Drives for Low-Cost Applications

A sensorless direct rotor field-oriented control (SDRFOC) scheme of three-phase induction motors for low-cost applications is presented in this paper. The SDRFOC algorithm is based on a sensorless closed-loop rotor flux observer whose main advantages are simplicity and robustness to motor parameter detuning. The whole algorithm has been developed and implemented on a low-cost fixed-point digital signal processor controller. Experimental results are presented for a 0.5-kW induction motor drive for a primary vacuum pump used in industry applications

Prostate Multiparametric MRI: Common Pitfalls in Primary Diagnosis and How to Avoid Them

Abstract Purpose of Review To provide the radiologist with basic knowledge about normal and abnormal findings in the prostatic mp-MRI, taking a look at the possible diagnostic pitfalls commonly seen in daily clinical practice, allowing him to recognize and consequently avoid them. Recent Findings Prostate mp-MRI has now become commonly used in most diagnostic imaging centers, as a precise, accurate and above all non-invasive tool, useful in the diagnosis, staging and follow-up of prostate diseases, first of all prostatic carcinoma. For this reason, it is important to take into account the existence of numerous possible anatomic and pathologic processes which can mimick or masquerade as prostate cancer. Summary Through the combination of anatomical (T2WI) and functional sequences (DWI/ADC and DCE), the mp-MRI of the prostate provides all the information necessary for a correct classification of patients with prostate disease, cancer in particular. It is not uncommon, however, for the radiologist to make errors in the interpretation of imaging due to conditions, pathological or otherwise, that mimic prostate cancer and that, consequently, affect the diagnostic/therapeutic process of patients. The strategy, and what this pictorial review aims at, is to learn to recognize the potential pitfalls of the prostatic mp-MRI and avoid them

FIELD ORIENTED CONTROL OF IPM DRIVES FOR FLUX WEAKENING APPLICATIONS

Interior Permanent Magnet (IPM) drives are adapted to flux-weakening, then to constant power operation over a wide speed range. Most of the control strategies for IPM motor drives are based on the control of the current vector. Flux-weakening is obtained by proper current references, that are calculated according to the magnetic model of the motor. This approach needs the accurate characterization of the motor and it is sensitive to the inaccuracy and the variation of the model parameters. Moreover, in the case of a variable dc-link, an additional voltage loop is necessary to correct the current references values at different dc-link voltage levels. The direct control of the flux vector, in the stator flux oriented frame, is proposed here, with the aim of obtaining the constant voltage operation of the IPM motor drive in the flux weakening range by means of a very simple control algorithm. The proposed direct flux control is tested on an IPM motor drive designed for traction. The exploitation of the maximum torque in all the operating speed range is demonstrated. The control is also capable to adapt its flux and current set-points to different dc-link voltage levels with no need of additional voltage regulators. Discrete-time simulation and experimental results are presented and compared showing good accordance

Body composition in clinical practice

Nutritional status is the results of nutrients intake, absorption and utilization, able to influence physiological and pathological conditions. Nutritional status can be measured for individuals with different techniques, such as CT Body Composition, quantitative Magnetic Resonance Imaging, Ultrasound, Dual-Energy X-Ray Absorptiometry and Bioimpendance. Because obesity is becoming a worldwide epidemic, there is an increasing interest in the study of body composition to monitor conditions and delay in development of obesity-related diseases. The emergence of these evidence demonstrates the need of standard assessment of nutritional status based on body weight changes, playing an important role in several clinical setting, such as in quantitative measurement of tissues and their fluctuations in body composition, in survival rate, in pathologic condition and illnesses. Since body mass index has been shown to be an imprecise measurement of fat-free and fat mass, body cell mass and fluids, providing no information if weight changes, consequently there is the need to find a better way to evaluate body composition, in order to assess fat-free and fat mass with weight gain and loss, and during ageing. Monitoring body composition can be very useful for nutritional and medical interventional. This review is focused on the use of Body Composition in Clinical Practice

A class of measure-valued Markov chains and Bayesian nonparametrics

Measure-valued Markov chains have raised interest in Bayesian nonparametrics since the seminal paper by (Math. Proc. Cambridge Philos. Soc. 105 (1989) 579--585) where a Markov chain having the law of the Dirichlet process as unique invariant measure has been introduced. In the present paper, we propose and investigate a new class of measure-valued Markov chains defined via exchangeable sequences of random variables. Asymptotic properties for this new class are derived and applications related to Bayesian nonparametric mixture modeling, and to a generalization of the Markov chain proposed by (Math. Proc. Cambridge Philos. Soc. 105 (1989) 579--585), are discussed. These results and their applications highlight once again the interplay between Bayesian nonparametrics and the theory of measure-valued Markov chains.Comment: Published in at http://dx.doi.org/10.3150/11-BEJ356 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

The role of feedback on interview self-efficacy and outcome expectations

Applicants’ self-cognitions toward selection procedures are decisive to produce favorable outcomes. Drawing upon the career self-management model, this study explored the impact of performance feedback after a simulated employment interview on interview self-efficacy (ISE) and outcome expectations. Participants (a sample of recent graduates; N = 240) were given timely feedback after the simulated interview with suggestions to improve their performance. The interviewer’s feedback was positively related to participants’ ISE measured after the feedback. A significant relationship between participants’ ISE and outcome expectations emerged. Feedback was related to outcome expectations only indirectly, via ISE. This study contributes to existing knowledge about ISE and provides practitioners with hints to help job seekers to master job search in troubled times. Practitioner notes Interview self-efficacy is a major predictor of performance in the employment interview. We show that performance feedback enhances interview self-efficacy and outcome expectations. Job seekers in training should be given meaningful feedback to raise their interview self-efficacy