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Electrical machine condition monitoring is essential in industrial processes for increasing workplace security, ensuring reliability, and cost-effective machine operation. The frequency response analysis (FRA) monitoring technique is gaining heightened popularity due to its reliability. The main purpose of this paper is to investigate the influence of the rotor on motor FRA signature. The frequency response is a highly sensitive technique. Therefore, any small defect in the motor condition will produce a unique frequency response which then can be analyzed and detected early. In this study, two motors are selected, and the corresponding frequency response is measured. To understand the impact of the rotor on the FRA signature two measurements are considered. FRA signature with and without rotor. The results obtained from both measurements are compared and analyzed. For a better understanding of the results, statistical indicators are used. The practical results are based on the measurements taken from the experimental setup

In preeclampsia, widespread maternal endothelial dysfunction is often secondary to excessive generation of placental-derived anti-angiogenic factors, including soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), along with proinflammatory cytokines such as tumour necrosis factor-alpha (TNF-alpha) and activin A, understanding of which offers potential opportunities for the development of novel therapies. The antimalarial hydroxychloroquine is an anti-inflammatory drug improving endothelial homeostasis in lupus. It has not been explored as to whether it can improve placental and endothelial function in preeclampsia. In this in vitro study, term placental explants were used to assess the effects of hydroxychloroquine on placental production of sFlt-1, sEng, TNF-alpha, activin A, and 8-isoprostane after exposure to hypoxic injury or oxidative stress. Similarly, human umbilical vein endothelial cells (HUVECs) were used to assess the effects of hydroxychloroquine on in vitro markers of endothelial dysfunction. Hydroxychloroquine had no effect on the release of sFlt-1, sEng, TNF-alpha, activin A, or 8-isoprostane from placental explants exposed to hypoxic injury or oxidative stress. However, hydroxychloroquine mitigated TNF-alpha-induced HUVEC production of 8-isoprostane and Nicotinanamide adenine dinucleotide phosphate (NADPH) oxidase expression. Hydroxychloroquine also mitigated TNF-alpha and preeclamptic serum-induced HUVEC monolayer permeability and rescued the loss of zona occludens protein zona occludens 1 (ZO-1). Although hydroxychloroquine had no apparent effects on trophoblast function, it may be a useful endothelial protectant in women presenting with preeclampsia.Copyright © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

In preeclampsia, widespread maternal endothelial dysfunction is often secondary to excessive generation of placental-derived anti-angiogenic factors, including soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), along with proinflammatory cytokines such as tumour necrosis factor-alpha (TNF-alpha) and activin A, understanding of which offers potential opportunities for the development of novel therapies. The antimalarial hydroxychloroquine is an anti-inflammatory drug improving endothelial homeostasis in lupus. It has not been explored as to whether it can improve placental and endothelial function in preeclampsia. In this in vitro study, term placental explants were used to assess the effects of hydroxychloroquine on placental production of sFlt-1, sEng, TNF-alpha, activin A, and 8-isoprostane after exposure to hypoxic injury or oxidative stress. Similarly, human umbilical vein endothelial cells (HUVECs) were used to assess the effects of hydroxychloroquine on in vitro markers of endothelial dysfunction. Hydroxychloroquine had no effect on the release of sFlt-1, sEng, TNF-alpha, activin A, or 8-isoprostane from placental explants exposed to hypoxic injury or oxidative stress. However, hydroxychloroquine mitigated TNF-alpha-induced HUVEC production of 8-isoprostane and Nicotinanamide adenine dinucleotide phosphate (NADPH) oxidase expression. Hydroxychloroquine also mitigated TNF-alpha and preeclamptic serum-induced HUVEC monolayer permeability and rescued the loss of zona occludens protein zona occludens 1 (ZO-1). Although hydroxychloroquine had no apparent effects on trophoblast function, it may be a useful endothelial protectant in women presenting with preeclampsia.Copyright © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

In this review, we discuss the potential use of antimalarial drugs as an adjuvant therapy for preeclampsia, focusing on the mechanisms of action of this class of drugs in the context of preeclampsia. In particular, hydroxychloroquine has been shown to have various beneficial effects on patients with systemic lupus erythematosus. There are several pathways targeted by the antimalarial drugs that are similar to the pathophysiology of preeclampsia and hence offering opportunities to develop novel therapies to treat the disease. Given the safety profile of hydroxychloroquine in pregnancy, there is merit in exploring the efficacy of this drug as an adjuvant therapy in women with early onset preeclampsia.Copyright © 2017 Informa UK Limited, trading as Taylor & Francis Group.

In this review, we discuss the potential use of antimalarial drugs as an adjuvant therapy for preeclampsia, focusing on the mechanisms of action of this class of drugs in the context of preeclampsia. In particular, hydroxychloroquine has been shown to have various beneficial effects on patients with systemic lupus erythematosus. There are several pathways targeted by the antimalarial drugs that are similar to the pathophysiology of preeclampsia and hence offering opportunities to develop novel therapies to treat the disease. Given the safety profile of hydroxychloroquine in pregnancy, there is merit in exploring the efficacy of this drug as an adjuvant therapy in women with early onset preeclampsia.Copyright © 2017 Informa UK Limited, trading as Taylor & Francis Group.

This paper proposes a dynamic pollution modelling for evaluating electric field distribution over the composite insulator surface. Axial-symmetric insulator profile under wet contaminated conditions was developed and analysed using Finite Element Method (FEM) software. A nonlinear field-dependent conductivity with simplified assumptions was established to characterise the electrical properties of the pollution layer. Comparative studies showed that simulation of the proposed pollution model results in a more realistic electric field profile, offering better understanding on how the electric field behaves under various wet and contaminated conditions.

This paper proposes a dynamic pollution modelling for evaluating electric field distribution over the composite insulator surface. Axial-symmetric insulator profile under wet contaminated conditions was developed and analysed using Finite Element Method (FEM) software. A nonlinear field-dependent conductivity with simplified assumptions was established to characterise the electrical properties of the pollution layer. Comparative studies showed that simulation of the proposed pollution model results in a more realistic electric field profile, offering better understanding on how the electric field behaves under various wet and contaminated conditions.

A new test rig has been developed specifically for gas research work, which includes a pressure chamber, control measures, and a recovery system of the gas. The air-tight pressure chamber was designed and tested to withstand pressures of up to 5 bar (abs). Through help from a reliable sealing gland, wires were passed through the pressurized gas inside the vessel to the outside to provide a means of controlling the gap length of the electrodes, without the need of removing the gas. Other control measures include humidity, temperature, and pressure readings. The humidity and temperature are read wirelessly and from the readings, the necessary atmospheric corrections can be made according to standards. Safety measures are equally important and were achieved by using a pressure relief valve. The valve is set to release the gas at 6 bar. A recovery system of the gas mixture was used so that after each test, the gas was properly stored in cylinder bottles and not being released into the atmosphere. As it is important to study the `deteriorated' gas for future works, this recovery process provided a means of obtaining the deteriorated gas to be investigated. From initial tests on air breakdown, it was found that U50 increases with pressure. Rod-plane configuration provides lowest U50 values due to its electrode geometry, followed by R12-plane and plane-plane configurations.

This paper investigates the effect of nonlinear grading material in controlling the electric field stress on outdoor polymeric insulator. Excessive electric stress combined with contaminations and moisture are responsible for the surface arcing, which may results in insulator flashover. The electric field and potential distributions along the leakage path on the surface of the insulator were computed using the Finite Element Method (FEM). The grading material was modeled by introducing a nonlinear field-conductivity relationship defined in the FEM package. Comparative studies of field and equipotential profiles for insulators with and without grading material under dry and uniformly contaminated surface conditions are presented.

This paper proposes a dynamic pollution modelling for evaluating electric field distribution over the composite insulator surface. Axial-symmetric insulator profile under wet contaminated conditions was developed and analysed using Finite Element Method (FEM) software. A nonlinear field-dependent conductivity with simplified assumptions was established to characterise the electrical properties of the pollution layer. Comparative studies showed that simulation of the proposed pollution model results in a more realistic electric field profile, offering better understanding on how the electric field behaves under various wet and contaminated conditions.