1,165 research outputs found

    Position-sensorless control of permanent-magnet-assisted synchronous reluctance motor

    Get PDF
    The sensorless control of permanent-magnet-assisted synchronous reluctance (PMASR) motors is investigated, in order to conjugate the advantages of the sensorless control with full exploitation of the allowed operating area, for a given inverter. An additional pulsating flux is injected in the d-axis direction at low and zero speed, while it is dropped out, at large speed, to save voltage and additional loss. A flux-observer-based control scheme is used, which includes an accurate knowledge of the motor magnetic behavior. This leads, in general, to good robustness against load variations, by counteracting the magnetic cross saturation effect. Moreover, it allows an easy and effective correspondence between the wanted torque and flux and the set values of the chosen control variables, that is d-axis flux and q-axis current. Experimental verification of the proposed method is given, both steady-state and dynamic performance are outlined. A prototype PMASR motor will be used to this aim, as part of a purposely assembled prototype drive, for light traction application (electric scooter

    Municipal expected annual loss as an indicator to develop seismic risk maps in Italy

    Get PDF
    This work presents a risk-targeted indicator called Municipal Expected Annual Loss (MEAL) for a quantitative estimation of the seismic risk at territorial level. With MEAL, it is possible to calculate the impact of earthquakes in terms of direct losses, taking account of a wide set of earthquake scenarios on the built environment at municipal level. MEAL is, therefore, able to summarize scenario loss values of each municipality, and define in such a way a risk-targeted metric that can clearly be understood also by different stakeholders dealing with seismic risk management, mitigation, and transfer. The use of MEAL to map seismic risk for the Italian residential building stock is herein presented as a case-study, leading to the development of several maps able to depict seismic risk at different territorial scale levels

    Seismic behavior of precast reinforced concrete column-to-foundation grouted duct connections

    Get PDF
    AbstractThe paper shows the results of an experimental campaign aimed at investigating the cyclic behavior of a column-to-foundation joint for precast concrete elements. The tested connection is realized adopting corrugated steel ducts embedded into the foundation, in which column protruding rebars are anchored by grouting high performance mortar. The experimental program consists in testing six full-scale reinforced concrete square-section columns subject to quasi-static cyclic lateral load with a constant axial compression. A preliminary series of bond tests was carried out to define some experimental variables, i.e., longitudinal rebar diameter and anchorage length. Results of the precast joints are compared with those of two reference cast-in-place specimens with the same geometric characteristics, showing similar hysteretic behavior, energy dissipation and ductility values. Lastly, the plastic hinge height is computed for all the specimens based on experimental concrete strains, and compared to current codes formulations

    Effectiveness of combined extracorporeal shock-wave therapy and hyaluronic acid injections for patients with shoulder pain due to rotator cuff tendinopathy: a person-centered approach with a focus on gender differences to treatment response

    Get PDF
    Background Rotator cuff (RC) tendinopathy is a common shoulder pain condition. Extracorporeal shockwave therapy (ESWT) and hyaluronic acid peritendinous injection are viable treatment options for RC tendinopathy. The aim of this study is to evaluate the response in two different therapeutic rehabilitative approaches, the combined treatment ESWT plus hyaluronic acid injections (E + Hy) compared to ESWT alone (ESWT-al), in a cohort of patients with RC tendinopathy according to gender differences. Methods This is a retrospective longitudinal cohort study of patients with painful RC tendinopathy. Patients that had received a clinical evaluation, a shoulder ultra sound examination, as well as the Shoulder Pain and Disability Index (SPADI) questionnaire, and the Numerical Rating Scale (NRS) for pain at baseline, 1-month (T1) and 2-month follow-ups (T2) were included. Results Medical records of 53 patients were analyzed. In the comparison between baseline to T1 and similarly from baseline to T2, a statistically significant reduction has been reported in the NRS (p < 0.001) and in the SPADI (p < 0.001) in the entire study group. At T1, patients in the E + Hy compared to ESWT-al group, showed a slight but statistically significant reductions in both NRS and SPADI score, while these changes were more evident at T2 (p < 0.001). Interestingly, a gender dimorphism in NRS and in SPADI was found, with female patients that apparently responded better to the combined E + Hy compared to ESWT-al approach. Conclusion This retrospective cohort study suggests that the combination of ESWT plus HyA injections seems to be more effective than ESWT alone in RC tendinopathy in both genders. Moreover, in ESWT alone treatment, male patients reported better outcomes compared to females. However, further randomized controlled trials should be structured to confirm and enforce these conclusions

    Proteolytic Activity of Human Lymphoid Tumor Cells. Correlation with Tumor Progression

    Get PDF
    Matrix metalloproteinase (MMP) expression and production are associated with advanced-stage tumor and contribute to tumor progression, invasion and metastases. The current study was designed to determine the expression and production of MMP-2 (gelatinase A) and MMP-9 (gelatinase B) by human lymphoid tumor cells. Changes in expression and production were also investigated during tumor progression of multiple myeloma and mycosis fungoides. In situ hybridization analysis revealed that lymphoblastic leukemia B cells (SB cell line), multiple myeloma (MM) cells (U266 cell line) and lymphoblastic leukemia T cells (CEM and Jurkat cell lines) express constitutively the mRNA for MMP-2 and/or MMP-9. We demonstrated by gelatin-zymography of cell culture medium that both enzymes were secreted in their cleaved (activated) form. In situ hybridization of bone marrow plasma cells and gelatin- zymography of the medium showed that patients with active MM (diagnosis, relapse, leukemic progression) express higher levels of MMP-2 mRNA and protein than patients with non-active MM (complete/objective response, plateau) and with monoclonal gammopathies of undetermined significance (MGUS). MMP-9 expression and secretion was similar in all patient groups. In patients with mycosis fungoides (MF), the expression of MMP-2 and MMP-9 mRNAs was significantly upregulated with advancing stage, in terms of lesions both positive for one of two mRNAs and with the greatest intensity of expression. Besides MF cells, the MMP-2 and/or MMP-9 mRNAs were expressed by some stromal cell populations (microvascular endothelial cells, fibroblasts, macrophages), suggesting that these cells cooperate in the process of tumor invasion. Our studies identify MMPs as an important class of proteinases involved in the extracellular matrix (ECM) degradation by human lymphoid tumors, and suggest that MMPs inhibitors may lead to important new treatment for their control

    Effectiveness of High-Intensity Laser Therapy Plus Ultrasound-Guided Peritendinous Hyaluronic Acid Compared to Therapeutic Exercise for Patients with Lateral Elbow Tendinopathy

    Get PDF
    Lateral elbow tendinopathy (LET) is a common painful musculoskeletal disorder. Several treatments have been proposed to provide pain reduction and functional recovery, including laser therapy, hyaluronic acid peritendinous injection (Hy-A), and therapeutic exercise (TE). Our study aims to assess the effectiveness of a combined approach with high-intensity laser therapy (HILT) and Hy-A injections compared to TE on pain, muscle strength, and disability in patients with painful LET. A retrospective longitudinal study was carried out by consulting the medical records of patients with a diagnosis of painful LET formulated by clinical and instrumental findings that received functional evaluations, including the Patient-Rated Tennis Elbow Evaluation (PRTEE) and muscle strength measurement at least four times: T0 (“baseline”), 1-month (T1), 3-month (T2), and 6-month follow-ups (T3). Medical records of 80 patients were analyzed. In the HILT + HyA group, the Peak-strength (p < 0.001) and mean strength (p < 0.001) significantly increased compared to the TE group between study times. For the PRTEE-total-score as for the subscales, the HILT + HyA group reported statistically significant reductions only for the comparisons of baseline versus T1 and baseline versus T2. No serious adverse events occurred. Our findings suggest that Hy-A associated with HILT might be more effective than TE for people with LET in the short–medium term

    Special issue on recent advances in quality control of bridges and structures

    Get PDF
    [Excerpt] Many European bridge structures are decades old and need to be refurbished, or even to be replaced. However, the high fnancial investment hinders this, making the extension of their service life the only available choice in the short term. Recognizing and assessing current risk, reducing vulnerabilities through appropriate actions and monitoring the behavior of these structures are thus possible immediate routes to solve this problem.- (undefined

    Neurological vertigo in the emergency room in pediatric and adult age: systematic literature review and proposal for a diagnostic algorithm

    Get PDF
    Neurological vertigo is a common symptom in children and adults presenting to the emergency department (ED) and its evaluation may be challenging, requiring often the intervention of different medical specialties. When vertigo is associated with other specific symptoms or signs, a differential diagnosis may be easier. Conversely, if the patient exhibits isolated vertigo, the diagnostic approach becomes complex and only through a detailed history, a complete physical examination and specific tests the clinician can reach the correct diagnosis. Approach to vertigo in ED is considerably different in children and adults due to the differences in incidence and prevalence of the various causes. The aim of this systematic review is to describe the etiopathologies of neurological vertigo in childhood and adulthood, highlighting the characteristics and the investigations that may lead clinicians to a proper diagnosis. Finally, this review aims to develop an algorithm that could represent a valid diagnostic support for emergency physicians in approaching patients with isolated vertigo, both in pediatric and adult age

    Assessment and governance of Ecosystem Services for improving management effectiveness of Natura 2000 sites

    Get PDF
    The Natura 2000 network is the cornerstone of the EU Biodiversity Strategy aimed at halting the loss of biodiversity and ecosystem services. Yet in many EU Member States the level of development and execution of management plans and conservation measures of Natura 2000 sites is often very low due to scarce financial resources; for this reason management effectiveness is rarely achieved. This paper presents initial insights from the Life+ MGN project and highlights the costs and benefits associated with 2 out of 21 Natura 2000 study sites in Italy in order to present a new governance approach relying on the qualitative and quantitative valuation of Ecosystem Services (ES). Preliminary results suggest that the quantification of costs and benefits related to the Natura 2000 network is crucial for reaching Natura 2000 conservation objectives and measuring management effectiveness

    Recoherence in the entanglement dynamics and classical orbits in the N-atom Jaynes-Cummings model

    Get PDF
    The rise in linear entropy of a subsystem in the N-atom Jaynes-Cummings model is shown to be strongly influenced by the shape of the classical orbits of the underlying classical phase space: we find a one-to-one correspondence between maxima (minima) of the linear entropy and maxima (minima) of the expectation value of atomic excitation J_z. Since the expectation value of this operator can be viewed as related to the orbit radius in the classical phase space projection associated to the atomic degree of freedom, the proximity of the quantum wave packet to this atomic phase space borderline produces a maximum rate of entanglement. The consequence of this fact for initial conditions centered at periodic orbits in regular regions is a clear periodic recoherence. For chaotic situations the same phenomenon (proximity of the atomic phase space borderline) is in general responsible for oscillations in the entanglement properties.Comment: 15 pages (text), 6 figures; to be published in Physical Review
    corecore