Search results for "induction"
showing 10 items of 769 documents
Input-Output Feedback Linearization Control with On-line MRAS Based Inductor Resistance Estimation of Linear Induction Motors Including the Dynamic E…
2016
This paper proposes the theoretical framework and the consequent application of the input–output feedback linearization (FL) control technique to linear induction motors (LIMs). LIM, additionally to rotating induction motor, presents other strong nonlinearities caused by the dynamic end effects, leading to a space-vector dynamic model with time-varying inductance and resistance terms and a braking force term. This paper, starting from a recently developed dynamic model of the LIM taking into consideration its end effects, defines a FL technique suited for LIMs, since it inherently considers its dynamic end effects. Additionally, it proposes a technique for the on-line estimation of the indu…
Load Torque Estimation Method to Design Electric Drivetrains for Offshore Pipe Handling Equipment
2016
One of the main design objectives for electric drivetrains operating in offshore drilling equipment is to keep them as small, yet as effective, as possible, to minimize space they occupy on drill floor and maximize their performance. However, practical experience shows that typically choices made by design engineers are too conservative due to the lack of enough data characterizing load conditions. This results in too costly and too heavy selected components. Therefore, in the current paper we present a method to estimate required full-scale motor torque using a scaled down experimental setup and its computational model. A gripper arm of an offshore vertical pipe handling machine is selecte…
Sensorless Speed Control for Double-Sided Linear Induction Motor Applications
2019
In this work, a flux and speed observer for double-sided linear induction motor applications is presented and experimentally validated. More in detail, from a Double-Sided Linear Induction Motor (DLIM) prototype, the complete modelling and the determination of the related parameters are here reported. Furthermore, the equations for a d-flux and q-flux observer are conceived and several simulation tests are performed. From the good agreements between the trends over time of the speed estimated by the observer and the simulated one, it can be stated that the observer is well designed. Moreover, in order to experimentally validate the proposed observer, a test bench is set-up for the DLIM/obse…
Heat Pump Induction Motor Faults Caused by Soft Starter Topology — Case Study
2021
This paper presents a case study of electrical machine faults, emerging in heat pump systems. In Nordic countries, heat pumps have been gaining popularity during the past years and have become one of the leading ways of heating in households and smaller public buildings. Although not a very complicated setup, the devices used are still prone to unexpected failures, especially if wrongly chosen, installed or maintained. The paper presents a study conducted on five real-life cases with very similar outcomes and failure modes. The setup of the systems is explained, faults are listed and presented, causes of the faults including modeling and measurement data are provided. The suggestions are gi…
Effect of oocyte morphology on post-warming survival and embryo development in vitrified autologous oocytes.
2019
Abstract Research question Does the presence of dysmorphisms affect post-warming survival and embryo development in vitrified autologous oocytes? Design A retrospective study comparing post-warming survival, fertilization and embryo development between morphologically normal (n = 269) and dysmorphic oocytes (n = 147). Results The survival rate was 81.4% in the morphologically normal oocytes and 87.1% in the dysmorphic oocyte group (OR 1.53; 95% CI 0.86 to 2.72). The fertilization rate was 69.9 versus 66.4% (OR 0.85; 95% CI 0.53 to 1.36), the proportion of good-quality embryos on day 3 was 30.3% versus 32.0% (OR 1.08; 95% CI 0.59 to 1.97) and the blastocyst formation rate was 54.5% versus 60…
Human limbal fibroblast-like stem cells induce immune-tolerance in autoreactive T lymphocytes from female patients with Hashimoto’s thyroiditis
2017
Background Due to their “natural immune privilege” and immunoregulatory properties human fibroblast-like limbal stem cells (f-LSCs) have acquired great interest as a potential tool for achieving immunotolerance. Hashimoto’s thyroiditis (HT) is the most common thyroid autoimmune disease and cause of hypothyroidism. To date, conventional hormone replacement therapy and unspecific immunosuppressive regimens cannot provide a definitive cure for HT subjects. We explored the immunosuppressant potential of human f-LSCs on circulating lymphomonocytes (PBMCs) collected from healthy donors and female HT patients. Methods We assessed the immunophenotyping of f-LSCs, both untreated and after 48 h of pr…
Medroxyprogesterone acetate is a useful alternative to a gonadotropin-releasing hormone antagonist in oocyte donation: a randomized, controlled trial.
2021
Objective To compare ovarian response and reproductive outcomes in oocyte donors undergoing pituitary suppression with medroxyprogesterone acetate (MPA) versus those undergoing conventional treatment with a gonadotropin-releasing hormone (GnRH) antagonist. Design A prospective, randomized, controlled trial of cycles was conducted from October 2017 to June 2019 to evaluate ovarian response in terms of the number of oocytes. The reproductive outcomes of the recipients were retrospectively analyzed later. Setting A university-affiliated private in vitro fertilization center. Patient(s) We randomly divided 318 donors into 2 groups in a 1:1 ratio. The oocytes obtained were assigned to 364 recipi…
Ovarian stimulation for oocyte vitrification does not modify disease-free survival and overall survival rates in patients with early breast cancer
2019
Research question: Does ovarian stimulation for oocyte vitrification affect disease-free survival and overall survival rates in women with early breast cancer? Design: This cohort study included 259 patients with early breast cancer; 148 patients underwent ovarian stimulation, whereas 111 patients did not. Patients were treated between January 2008 and December 2016. To calculate the disease-free survival time and overall survival rate, the time of definitive surgery was defined as the starting point. The follow-up was conducted up to 5 years. Results: Exposed and non-exposed groups were comparable in tumour, node and metastases classification, Nottingham grade, hormonal receptor status, tu…
Hypomethylating agents in relapsed and refractory AML: outcomes and their predictors in a large international patient cohort.
2018
Although hypomethylating agents (HMAs) are frequently used in the frontline treatment of older acute myeloid leukemia (AML) patients, little is known about their effectiveness in relapsed or primary treatment–refractory (RR)-AML. Using an international multicenter retrospective database, we studied the effectiveness of HMAs in RR-AML and evaluated for predictors of response and overall survival (OS). A total of 655 patients from 12 centers received azacitidine (57%) or decitabine (43%), including 290 refractory (44%) and 365 relapsed (56%) patients. Median age at diagnosis was 65 years. Best response to HMAs was complete remission (CR; 11%) or CR with incomplete count recovery (CRi; 5.3%). …
The carriers of the A/G-G/G allelic combination of the c.2039 A>G and c.-29 G>A FSH receptor polymorphisms retrieve the highest number of oocytes in …
2016
The objective of this study was the elucidation of the possible role of the single-nucleotide polymorphisms (SNP) at position -29 and 2039 of the FSH receptor gene (FSHR) as independent predictive markers of ovarian response. Indeed, the tailoring of reproductive treatments is crucial for both maximizing the success of IVF patients and obtaining a reduction in hypo- or hyper-response rates. This prospective, observational study analyzed the association of -29 and 2039 FSHR polymorphisms with the number of retrieved oocytes in 140 patients attending an IVF/ICSI cycle for severe male factors (≤5,000,000 spermatozoa/mL) or tubal factors at the ANDROS Day Surgery Clinic, Palermo, Italy. The res…