Fundamentals, topologies and optimization methods of saturated iron core fault current limiter

The energy transition is a necessity to satisfy the consumption and impact of humanity on the environment. Therefore, to fulfill this demand, renewable energies and microgrids have been developed. Consequently, fault current levels have overcome the circuit breaker capacity in many substations over the years. Then, the development of the fault current limiters has become a potential solution to solve this problem. The literature has presented several topologies over the past decades. The saturated iron-core fault current limiter (SIC-SFCL) has exhibited promising results since this topology is tested in the distribution and transmission system substation. Thus, enforcements to increase the maturity of this equipment have been developed in different areas, for example, design, applied superconductor materials, and optimization models of the SIC-SFCL. This article has presented the fundamental concept of this equipment. Beyond that, the principal topologies have been discussed. The article has delivered further information about the main parts that comprise this equipment. Also, the authors have introduced different characteristics which affect the recovery times of this device. The authors have discussed the optimization methods applied to this equipment and after the conclusion is presented

Optimization of the Superconducting Linear Magnetic Bearing of a Maglev Vehicle

Considering the need for cost/performance prediction and optimization of superconducting maglev vehicles, we develop and validate here a 3D finite element model to simulate superconducting linear magnetic bearings. Then we reduce the 3D model to a 2D model in order to decrease the computing time. This allows us to perform in a reasonable time a stochastic optimization considering the superconductor properties and the vehicle operation. We look for the permanent magnet guideway geometry that minimizes the cost and maximizes the lateral force during a displacement sequence, with a constraint on the minimum levitation force. The displacement sequence reproduces a regular maglev vehicle operation with both vertical and lateral movements. For the sake of comparison, our reference is the SupraTrans prototype bearing. The results of the optimization suggest that the bearing cost could be substantially reduced, while keeping the same performances as the initial design. Alternatively, the performances could be significantly improved for the same original cost

Global Retinoblastoma Presentation and Analysis by National Income Level.

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs

The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries

DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt

Fundamentals, topologies and optimization methods of saturated iron core fault current limiter

The energy transition is a necessity to satisfy the consumption and impact of humanity on the environment. Therefore, to fulfill this demand, renewable energies and microgrids have been developed. Consequently, fault current levels have overcome the circuit breaker capacity in many substations over the years. Then, the development of the fault current limiters has become a potential solution to solve this problem. The literature has presented several topologies over the past decades. The saturated iron-core fault current limiter (SIC-SFCL) has exhibited promising results since this topology is tested in the distribution and transmission system substation. Thus, enforcements to increase the maturity of this equipment have been developed in different areas, for example, design, applied superconductor materials, and optimization models of the SIC-SFCL. This article has presented the fundamental concept of this equipment. Beyond that, the principal topologies have been discussed. The article has delivered further information about the main parts that comprise this equipment. Also, the authors have introduced different characteristics which affect the recovery times of this device. The authors have discussed the optimization methods applied to this equipment and after the conclusion is presented

Evaluation of Distribution Transformers Based on Power Quality Parameters in Front of Different Load Profiles

This article presents a study to monitor the power quality supplied by a power distribution concessionaire operating in the State of Rio de Janeiro, Brazil. Three electric power transformers of the same nominal power installed from a Brazilian company were selected as case studies. The data were collected and analyzed to evaluate the power quality according to the formulation regulated by the Electricity Distribution Procedures in the National Electric System - PRODIST, which is the Brazilian legislation in force for the energy distributors. The experiment consists of checking the supply voltage, the power factor, harmonic distortion, voltage unbalance, and frequency variation. Two of the three transformers analyzed showed a failure in the power quality supplied in the frequency variation indicator and all transformers failed in the Power Factor indicator. Thus, this research verifies the importance of monitoring power quality parameters to ensure that the energy obtained by consumers has sufficient characteristics for the proper functioning of electrical equipment

Eigen frequency and damping in a passive magnetic bearing system

A complete passive magnetic bearing system, consisting in a Permanent Magnet radial bearing and a Superconductive Magnetic Bearing has been simulated and constructed. The forces in both types of magnetic bearings are not linear. The non-linear behavior has been implemented in a FEM model and compared with linear models. A spin down test has been conducted to the built system and the Eigen frequencies have been recorded. The Eigen frequencies calculated with and without the non-linear behavior implemented in the model are very similar

Tracing environmental markers of autoimmunity: introducing the infectome

We recently introduced the concept of the infectome as a means of studying all infectious factors which contribute to the development of autoimmune disease. It forms the infectious part of the exposome, which collates all environmental factors contributing to the development of disease and studies the sum total of burden which leads to the loss of adaptive mechanisms in the body. These studies complement genome-wide association studies, which establish the genetic predisposition to disease. The infectome is a component which spans the whole life and may begin at the earliest stages right up to the time when the first symptoms manifest, and may thus contribute to the understanding of the pathogenesis of autoimmunity at the prodromal/asymptomatic stages. We provide practical examples and research tools as to how we can investigate disease-specific infectomes, using laboratory approaches employed from projects studying the "immunome" and "microbiome". It is envisioned that an understanding of the infectome and the environmental factors that affect it will allow for earlier patient-specific intervention by clinicians, through the possible treatment of infectious agents as well as other compounding factors, and hence slowing or preventing disease development

The Global Retinoblastoma Outcome Study: a prospective, cluster-based analysis of 4064 patients from 149 countries

Background Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. Methods We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1,2017, and Dec 31,2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. Findings The cohort included 4064 children from 149 countries. The median age at diagnosis was 23.2 months (IQR 11.0-36.5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0.8%) of 636 children from high-income countries, 55 (5.4%) of 1027 children from upper-middle-income countries, 342 (19. 7%) of 1738 children from lower-middle-income countries, and 196 (42.9%) of 457 children from low-income countries. Enudeation surgery was available for all children and intravenous chemotherapy was available for 4014 (98.8%) of 4064 children. The 3-year survival rate was 99.5% (95% CI 98.8-100.0) for children from high-income countries, 91.2% (89.5-93.0) for children from upper-middle-income countries, 80.3% (78.3-82.3) for children from lower-middle-income countries, and 57.3% (524-63-0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16.67; 95% CI 4.76-50.00), cT4 advanced tumour compared to cT1 (8.98; 4.44-18.18), and older age at diagnosis in children up to 3 years (1.38 per year; 1.23-1.56). For children aged 3-7 years, the mortality risk decreased slightly (p=0.0104 for the change in slope). Interpretation This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd.Y

Global Retinoblastoma Presentation and Analysis by National Income Level

This cross-sectional analysis reports the retinoblastoma stage at diagnosis across the world during a single year, investigates associations between clinical variables and national income level, and investigates risk factors for advanced disease at diagnosis. Key PointsQuestionIs the income level of a country of residence associated with the clinical stage of presentation of patients with retinoblastoma? FindingsIn this cross-sectional analysis that included 4351 patients with newly diagnosed retinoblastoma, approximately half of all new retinoblastoma cases worldwide in 2017, 49.1\% of patients from low-income countries had extraocular tumor at time of diagnosis compared with 1.5\% of patients from high-income countries. MeaningThe clinical stage of presentation of retinoblastoma, which has a major influence on survival, significantly differs among patients from low-income and high-income countries, which may warrant intervention on national and international levels. ImportanceEarly diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. ObjectivesTo report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and ParticipantsA total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and MeasuresAge at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. ResultsThe cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4\%) were female. Most patients (n=3685 {[}84.7\%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n=2638 {[}62.8\%]), followed by strabismus (n=429 {[}10.2\%]) and proptosis (n=309 {[}7.4\%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5\%) patients having intraocular retinoblastoma and 2 (0.3\%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1\%) having extraocular retinoblastoma and 94 of 498 (18.9\%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 {[}95\% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 {[}95\% CI, 4.30-7.68]). Conclusions and RelevanceThis study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs