Stability analysis and robust damping of multiresonances in distributed-generation-based islanded microgrids

International audienc

Adaptive Reference Trajectory for Power Quality Enhancement in Three-Phase Four-Wire Standalone Power Supply Systems with Nonlinear and Unbalanced Loads

International audienc

Deep Brain Stimulation in Moroccan Patients With Parkinson's Disease: The Experience of Neurology Department of Rabat

Introduction: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is known as a therapy of choice of advanced Parkinson's disease. The present study aimed to assess the beneficial and side effects of STN DBS in Moroccan Parkinsonian patients.Material and Methods: Thirty five patients underwent bilateral STN DBS from 2008 to 2016 in the Rabat University Hospital. Patients were assessed preoperatively and followed up for 6 to 12 months using the Unified Parkinson's Disease Rating Scale in four conditions (stimulation OFF and ON and medication OFF and ON), the levodopa-equivalent daily dose (LEDD), dyskinesia and fluctuation scores and PDQ39 scale for quality of life (QOL). Postoperative side effects were also recorded.Results: The mean age at disease onset was 42.31 ± 7.29 years [28–58] and the mean age at surgery was 54.66 ± 8.51 years [34–70]. The median disease duration was 11.95 ± 4.28 years [5–22]. Sixty-three percentage of patients were male. 11.4% of patients were tremor dominant while 45.71 showed akinetic-rigid form and 42.90 were classified as mixed phenotype. The LEDD before surgery was 1200 mg/day [800-1500]. All patients had motor fluctuations whereas non-motor fluctuations were present in 61.80% of cases. STN DBS decreased the LEDD by 51.72%, as the mean LEDD post-surgery was 450 [188-800]. The UPDRS-III was improved by 52.27%, dyskinesia score by 66.70% and motor fluctuations by 50%, whereas QOL improved by 27.12%. Post-operative side effects were hypophonia (2 cases), infection (3 cases), and pneumocephalus (2 cases).Conclusion: Our results showed that STN DBS is an effective treatment in Moroccan Parkinsonian patients leading to a major improvement of the most disabling symptoms (dyskinesia, motor fluctuation) and a better QOL

A Hybrid Gearbox Fault Diagnosis Method Based on GWO-VMD and DE-KELM

In this paper, a vibration signal-based hybrid diagnostic method, including vibration signal adaptive decomposition, vibration signal reconstruction, fault feature extraction, and gearbox fault classification, is proposed to realize fault diagnosis of general gearboxes. The main contribution of the proposed method is the combining of signal processing, machine learning, and optimization techniques to effectively eliminate noise contained in vibration signals and to achieve high diagnostic accuracy. Firstly, in the study of vibration signal preprocessing and fault feature extraction, to reduce the impact of noise and mode mixing problems on the accuracy of fault classification, Variational Mode Decomposition (VMD) was adopted to realize adaptive signal decomposition and Wolf Grey Optimizer (GWO) was applied to optimize parameters of VMD. The correlation coefficient was subsequently used to select highly correlated Intrinsic Mode Functions (IMFs) to reconstruct the vibration signals. With these re-constructed signals, fault features were extracted by calculating their time domain parameters, energies, and permutation entropies. Secondly, in the study of fault classification, Kernel Extreme Learning Machine (KELM) was adopted and Differential Evolutionary (DE) was applied to search its regularization coefficient and kernel parameter to further improve classification accuracy. Finally, gearbox vibration signals in healthy and faulty conditions were obtained and contrast experiences were conducted to validate the effectiveness of the proposed hybrid fault diagnosis method

Chronic Myeloid Leukemia and Cesarean Section: The Anesthesiologist’s Point of View

Background. Chronic Myeloid Leukemia (CML) is a myeloproliferative neoplasm related to chromosomal reciprocal translocation t(9;22). Tyrosine kinase inhibitors (TKIs) such as imatinib have drastically revolutionized the course and the prognosis of this hematologic malignancy. As we know, the association pregnancy-CML is an infrequent situation. Also the use of TKI in pregnant women is unsafe with a lack of alternatives and effective therapeutic options. Thus its cessation during gestation puts those patients at high risk of developing blast crisis characterized by poor outcomes. Case Report. A 37-year-old pregnant woman, gravida 2, para 2, with a previous cesarean section in 2011, presented to the obstetric unit. Her medical past revealed that she is a newly diagnosed patient with CML managed by TKI during her preconception period. Due to the perilous use of TKI during her pregnancy, a switch to interferon-α administration was adopted. But after the completion of 36 weeks of gestation, disease progression (relapse with blast crisis), attested by biological worsening, a white blood cell count = 245000/mm3 with 32% blasts in the peripheral blood, urged the medical team to opt for cesarean delivery. She underwent general endotracheal anesthesia without any perioperative incidents and gave birth to a healthy newborn. Ten days later, the patient was started on TKI. Discussion. Although data on this specific and challenging situation are limited, this case highlights the difficulties encountered by the anesthesiologists when choosing the accurate anesthetic strategy and how important it is to weigh the risks and benefits inherent to each technique. Above all, taking into consideration the possible central nervous system (CNS) contamination by circulating blast cells when performing spinal or epidural approach is primordial. This potential adverse event (CNS blast crisis) is extremely scarce but it is responsible for high rates of morbidity and mortality

Improved control strategy for power quality enhancement in standalone systems based on four‐leg voltage source inverters

International audienc

Active resonance damping and harmonics compensation in distributed generation based islanded microgrids

International audienc

Effects of environmental exposure on the mechanical properties of composite tidal current turbine

International audienceIn order to meet the growing demand for energy and also to fight against global warming, Renewable Marine Energies (RME) appeared as a great opportunity for a real ecological and industrial choice. Tidal current turbines are used to extract this energy and installed on the seabed at locations where the nozzle can be prone to the accidental impact and critical loads. The principal objective of this research is to investigate the effects of environmental exposure on the mechanical properties of composite tidal current turbine, the most advanced features currently available in finite element (FE) Abaqus/Explicit have been employed to simulate the behavior of the composite nozzle under static and dynamic loading conditions. To investigate this situation, a parametric analysis is conducted which deals with the effect of velocity and geometry of the impactor. The mechanical behavior has been analyzed as both kinematic effect due to deflection of the composite structure and dynamic effect caused by the interaction between the impactor and the hydrodynamic and hydrostatic pressures over the loading. The stress and the deformation distribution are presented. On the other hand, damage modeling was formulated based on Hashin criteria for intra-laminar damage. This has been accomplished by forming a user-created routine (VUMAT) and executing it in the Abaqus software