1,044 research outputs found

    Development and experimental validation of a low-frequency dynamic model for a Hybrid Electric Vehicle

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    This paper describes the development and experimental validation of a high-fidelity Hybrid Electric Vehicle (HEV) simulator that enables testing and calibration of energy management and driveline control strategies. The model is capable of predicting longitudinal vehicle responses that affect energy consumption and drivability in the low-to-mid frequency region (up to 10 Hz). The simulator focuses primarily on the drivetrain dynamics, while the dynamics of the actuators are represented by simplified models. The vehicle simulator is validated by a number of experiments that include electric only, engine only and hybrid operating conditions. The test vehicle has a through-the-road parallel hybrid architecture that utilises a dual electric machine configuration. Experimental results confirm that important driveline phenomena such as shunt, shuffle, torque holes and other transient disturbances related to operating mode changes are accurately predicte

    Repositório de acesso livre para agroecologia e agricultura orgânica do Brasil.

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    Resumo: Considerando que a literatura técnico-científica em Agroecologia e Agricultura Orgânica no Brasil é abundante, está dispersa e de difícil acesso, esse trabalho teve como objetivo criar e gerenciar um banco de dados da literatura no Brasil. Nesse sentido, há consenso na comunidade de especialistas e pesquisadores que estudam a informação, que a alternativa mais adequada e adotada em todo o mundo são os repositórios digitais de acesso aberto. Além de contemplarem os processos necessários para o gerenciamento da informação técnico-científica, os repositórios digitais de acesso aberto contribuem diretamente para a melhoria dos processos de comunicação na Ciência. Assim, o repositório escolhido para armazenar a literatura brasileira em Agroecologia e Agricultura Orgânica foi o Organic Eprints

    Prospective randomized comparison of laparoscopic versus open adrenalectomy for sporadic pheochromocytoma.

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    BACKGROUND: Laparoscopic adrenalectomy for pheochromocytoma remains subject of debate, owing to the systemic consequences of pneumoperitoneum in patients with catecholamine-secreting tumors. METHODS: A prospective randomized study was conducted (2000-2006), evaluating cardiovascular instability during open (n = 9, group A) or laparoscopic (n = 13, group B) adrenalectomy for pheochromocytoma. Haemodynamic parameters were recorded by invasive monitoring. RESULTS: Haemodynamic instability was observed in 3/9 (group A) and 6/13 patients (group B), with a mean of 1.8 and 2.2 hypertensive peaks per patient (p = n.s.). Blood loss (164 +/- 94 cc versus 48 +/- 36 cc, p < 0.05) and operative time (180 +/- 40 versus 158 +/- 45 min, p = n.s.) favored laparoscopic procedures. Postoperative morbidity and mortality were nil. Hospital stay was shorter in group B (p < 0.05). Long-term follow-up was always normal. CONCLUSIONS: Laparoscopic approach for pheochromocytoma can be as safe as open surgery; intraoperative haemodynamic instability, although usually controlled with success, remains a source of concern

    Demography of Dialysis and Transplantation in Children in Europe, 1985: Report from the European Dialysis and Transplant Association Registry

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    At the end of 1985 there were 5482 patients known to the Registry who started renal replacement therapy (RRT) between the ages of 6 months and 15 years. Of these, approximately 25% had died, 30% were still aged less than 15 years, and the other 45% were older. The acceptance rate of new patients over the last 10 years has slowly but steadily increased; six new paediatric patients per million child population probably represents the likely needs of the near future. Hospital haemodialysis remained the main form of renal replacement therapy in new patients, while 3 years after start of RRT, transplantation became the most frequently used replacement therapy; CAPD appeared to be used mainly in children with a short waiting time for transplantation. Out of the 384 grafts reported in 1985, only 16% were from living related donors; among 321 cadaver grafts, 24% were second and only 3% were third grafts. Glomerulonephritis and pyelonephritis accounted for 50% of all primary renal diseases. During the last 5 years, the proportion with glomerulonephritis seems to have decreased slightly. Hyperkalaemia and fluid overload have still to be considered the main causes of death. Only in 17% of all cases was the cause of death reported as unknown or undetermine

    Rehabilitation of young adults during renal replacement therapy in Europe: The presence of disabilities

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    The aim of this study was to analyse rehabilitation during RRT in 617 young adults from different European countries who started dialysis or transplantation before the age of 15 years. The data were derived from the EDTA Registry patient data files and a special questionnaire that was sent to centres reporting to the EDTA Registry. The duration of RRT was more than 10 years in 63% of patients. Fifty-four percent were living with a functioning graft and 46% were on dialysis. The prevalence and severity of motor, hearing, sight, and mental disabilities were analysed retrospectively. They were found to vary according to primary renal disease and method oftreatment. One-third of patients had one or more disabilities at the start of RRT. Although disability status had changed in many patients by 31 December 1986, some disability remained in one-third of the patients available for study. Disabilities were recorded as mild in the majority of patients. Both improvement and worsening of motor and mental disability occurred more often than changes of hearing capacity and sight. It is concluded that prevention and treatment of disabilities need special attention in children and young adults on RRT in order to improve rehabilitatio

    Rehabilitation of young adults during renal replacement therapy in Europe: 2. Schooling, employment, and social situation

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    The educational status, employment rate and social situation were studied in 617 patients between 21 and 35 years of age who started renal replacement therapy (RRT) as children. The data were derived from a special questionnaire concerning disability and rehabilitation sent to dialysis and transplant centres reporting to the EDTA Registry. Fifty-six percent of patients completed secondary school and one in three went on to vocational training. Eleven percent of patients attended university, and 16% were reported to have gone to a special school for the handicapped. Up to one-third of patients who attended different school types failed to complete their education. There were notable geographical differences in schooling and in employment. Fifty-six percent of all patients were employed. Lack of schooling was considered to be a major reason for unemployment. Sixty-one percent of patients with disabilities and 34% without disabilities were receiving invalidity payments. The place of residence of these patients aged 21-35 was usually the parental home. Compared to the general population of similar age, only a few patients were married (13.5% of the total study group) and 8% had children. In summary, the present report shows that the major factors influencing rehabilitation on RRT are the presence of disabilities, the method of treatment, geographical factors, duration of RRT, and the underlying primary renal diseas

    Factors influencing anaemia in dialysis patients. A special survey by the EDTA-ERA Registry

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    The European Dialysis and Transplantation Association—European Renal Association (EDTA-ERA) Registry conducted a special study on anaemia in dialysis patients because it seemed important to elucidate the various factors that influence the degree of anaemia and the use of regular transfusions in dialysis patients before the introduction of recombinant human erythropoietin (rHuEpo) for larger groups of patients. In a 20% sample of all patients recorded to have been dialysed throughout 1987, statistically significant associations could be found by multifactorial analysis between haemoglobin (Hb) concentration and age, sex, primary renal disease, type of treatment, hours of dialysis per week, and number of years on renal replacement therapy. The type of dialyser membrane did not seem to play a role (although there was weak evidence of an effect of the dialyser). Mean Hb concentration for dialysis patients differed between countries as did the transfusion policy. In view of the high costs of the rHuEpo treatment and potential side-effects, factors such as method of dialysis and hours of haemodialysis per week should be taken into consideration in the treatment of anaemia in dialysis patient

    EDTA Registry Centre Survey, 1986: Report from the European Dialysis and Transplant Association Registry

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    This paper summarises the information given on the 1986 EDTA Registry centre questionnaire which was returned by 82% of the 2,065 known dialysis and transplant centres in 33 European countries. Information is given on the number of patients alive on haemodialysis according to the type of dialysis facilities available where the patient was receiving dialysis and the number of patients receiving special types of dialysis. The centre questionnaire also included questions on testing for HIV infection, serological evidence or symptoms of AIDS and the diagnosis of hepatitis B in patients and staff. The data given in response to these questions are presented together with data on the involvement of dietitians and social workers in the treatment of patients with end stage renal failure. Finally, information on transplant activity in Europe and the treatment policies of transplanting centres is provide

    The Use of Continuous Peritoneal Dialysis in Europe for the Treatment of Children with End-Stage Renal Failure: Data from the EDTA Registry

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    The demographic data on the use of continuous peritoneal dialysis in Europe for children starting renal replacement therapy under the age of 15 years was obtained from data collected by the Registry of the European Dialysis and Transplant Association—European Renal Association (EDTA Registry) on individual patient questionnaires 1980-1986. Continuous ambulatory peritoneal dialysis (CAPD) and its variants appeared to be increasingly utilised as treatment for children with end-stage renal failure (ESRF) and accounted for approximately 25% of all renal replacement therapy (RRT). Important differences in its use in various European countries are demonstrated. The proportional contribution of CAPD to treatment was higher during the first year of RRT and gradually decreased thereafter. No significant sex differences existed in the use of this treatment. Approximately 70% of all patients on CAPD were older than 6 years of age, but it is in those under 6 years that the highest proportion are put on CAPD as first method of treatment for end-stage renal failure. The most common cause of abandonment of this treatment was peritonitis, which contributed 50% of the drop-out rat
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