615 research outputs found
Fleet Asset Management Opportunities Arising from Transient Monitoring of Power Transformers and Shunt Reactors
Power transformers and shunt reactors are strategic assets for every system operator and their downtime should be kept as low and controlled as
possible. During their multi-decade service life, they are regularly exposed to transient overvoltages. These situations stress their insulation systems
and can cause accelerated deterioration and aging. Since the shapes of these overvoltages are usually unknown, an additional approach to assessing
the health index can be realized using monitoring systems with transient recorders. Analyzing the transient overvoltages using frequency domain
severity factor, a quantification of additional stress on the transformer’s/shunt reactor’s insula
Lightning caused overvoltages on power transformers recorded by on-line transient overvoltage monitoring system
Transient overvoltages generated by lightning strikes or switching operations represent
a significant risk to bushings and windings of power transformers. They cause stress on the
insulation system and can, over time, cause dielectric failure and damage to power transformers.
Many transformer failures are reported as dielectric failures and they are not necessarily linked
to any particular event when they occur but may be the result of prior damage from transient
overvoltage events. Lightning and switching overvoltage waveforms appearing at transformer
terminals in real operating conditions may significantly differ from standard impulse voltage
waveforms used during laboratory testing. The number and amplitudes of overvoltages which
stress the insulation depend on various parameters such as the lightning strike density in the
considered area, since it determines how often the transformer is stressed by lightning
overvoltages. Since the overvoltage amplitudes at transformer terminals are usually unknown,
an on-line overvoltage transient recorder can be used with the ability to sample, analyse and
store transients in real-time.
In this paper, an on-line transient overvoltage monitoring system (TOMS) for power
transformers is presented that is capable to continuously record in real-time various kinds of
transient overvoltages such as lightning or switching overvoltages. Special attention is paid to
lightning caused transient overvoltages recorded at the terminals of 150 MVA power
transformer. Recorded waveforms originating from lightning strikes to overhead lines are
correlated with data from the lightning location system (LLS) and supervisory control and data
acquisition (SCADA) system. Collected data about overvoltage stresses can be used as the basis
for the assessment of the transformer insulation condition, estimation of health index and for
analysis of various kinds of events such as faults or equipment failures
The landscape of viral associations in human cancers
Here, as part of the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, for which whole-genome and—for a subset—whole-transcriptome sequencing data from 2,658 cancers across 38 tumor types was aggregated, we systematically investigated potential viral pathogens using a consensus approach that integrated three independent pipelines. Viruses were detected in 382 genome and 68 transcriptome datasets. We found a high prevalence of known tumor-associated viruses such as Epstein–Barr virus (EBV), hepatitis B virus (HBV) and human papilloma virus (HPV; for example, HPV16 or HPV18). The study revealed significant exclusivity of HPV and driver mutations in head-and-neck cancer and the association of HPV with APOBEC mutational signatures, which suggests that impaired antiviral defense is a driving force in cervical, bladder and head-and-neck carcinoma. For HBV, HPV16, HPV18 and adeno-associated virus-2 (AAV2), viral integration was associated with local variations in genomic copy numbers. Integrations at the TERT promoter were associated with high telomerase expression evidently activating this tumor-driving process. High levels of endogenous retrovirus (ERV1) expression were linked to a worse survival outcome in patients with kidney cancer
Mineral composition of amaranth (Amaranthus L.) seeds of vegetable and grain usage by ARHIVBSP selection
The questions of the practical usage of the analytical scanning electron microscope JSM 600 LA by JEOL company (Japan) with EDS system - microanalysis for the studying of the ash elemental composition of seeds 9 breeds (Vegetable and Grain application) 4 species genus Amaranthus L. - A. hypochondriacus, A. cruentus, A. hybridus, A. caudatus, A. tricolor. Plant seeds by Federal center of vegetable production selection were envisaged. We studied the concentration of 14 basic elements (in weight %) contained in the mineral part of amaranth seeds. In the amaranth seeds of vegetable forms the accumulation order of the elements is the following: Ca >K >P >Mg >Si >Se >Fe >Mo ≈ S ≈ Cl ≈ Zn >Na >Al. In the seeds of the grain forms the order is different: К >P >Ca >Si >Se >Mg >Fe >Na >Mo >Cl ≈ S ≈ Mn ≈ Zn ≈ Al. The amaranth seeds of the grain forms are rich in macro - and microelements. P, K, Cl and S in the seeds of the grain forms are accumulated on 50, 37, 15 and 5% more and Si, Fe and Al in 2.6 and 1.8 times more than in the vegetable forms seeds. The breeds with the high concentration of the elements are recommended for using in the selection process. The elevated level of the essential macro- and microelements such as Ca, K, P, Mg, Mo, S and Cl stipulates the perspective of the functional products creation on the base of the studied amaranth seeds for the enrichment of the food stuffs
Optimization of Parameters of Adaptive Spray System for Agricultural Sprayer
Introduction. When growing tall-growth crops (cereal crops in late the phases of development, corn, sunflower, etc.), there are used boom sprayers equipped with twin-fluid spray cones with fixed angles of inclination to the vertical of the spray cones. The working fluid is applied with such sprays are more intensively on the front side of the plant leaves while the intensity of covering the plants from the back side with the working fluid decreases. The development of the spray system will allow improving the quality of crop treatment with boom sprayers.
Aim of the Study. The aim of the research is to determine experimentally the algorithm for changing the angles of inclination of a twin-fluid spray cone that provides the same intensity of applying working liquid to the leaves of high-growth plants.
Materials and Methods. The research was carried out on a test bench by applying colored water to the front and rear sides of a tall-growth plant model moving at a specified speed. The experiment was carried out according to the method of optimal planning. The difference between the content of droplets on the front and rear sides of the tall-growth plant model was taken as an optimization parameter. Variable factors were the spray cone inclination angles and the operating speed of the sprayer.
Results. The algorithm for changing the optimum values of the spray cone inclination angles depending on the sprayer speed was determined based on the equality of the first derivative of the optimization to zero parameter by the value of these angles.
Discussion and Conclusion. According to the algorithm, when the sprayer operating speed increases from 1.2 to 3.2 m/s, the optimal angle of inclination to the front spray cone vertical changes linearly from 25 to 21 degrees, and the rear one ‒ from 46.7 to 57 degrees. This algorithm will allow justifying the technical specifications to develop a processor for automatic control of the spray cone inclination angles cones when the sprayer is operating
Diabetes is an independent predictor of increased mortality following contemporary percutaneous coronary intervention for proximal left anterior descending artery disease
Ozanimod to treat relapsing forms of multiple sclerosis: A comprehensive review of disease, drug efficacy and side effects
Multiple sclerosis (MS) is a prevalent and debilitating neurologic condition characterized by widespread neurodegeneration and the formation of focal demyelinating plaques in the central nervous system. Current therapeutic options are complex and attempt to manage acute relapse, modify disease, and manage symptoms. Such therapies often prove insufficient alone and highlight the need for more targeted MS treatments with reduced systemic side effect profiles. Ozanimod is a novel S1P (sphingosine-1-phosphate) receptor modulator used for the treatment of clinically isolated syndrome, relapsing–remitting, and secondary progressive forms of multiple sclerosis. It selectively modulates S1P1 and S1P5 receptors to prevent autoreactive lymphocytes from entering the CNS where they can promote nerve damage and inflammation. Ozanimod was approved by the US Food and Drug Administration (US FDA) for the management of multiple sclerosis in March 2020 and has been proved to be both effective and well tolerated. Of note, ozanimod is associated with the following complications: increased risk of infections, liver injury, fetal risk, increased blood pressure, respiratory effects, macular edema, and posterior reversible encephalopathy syndrome, among others. Further investigation including head-to-head clinical trials is warranted to evaluate the efficacy of ozanimod compared with other S1P1 receptor modulators
Ozanimod to treat relapsing forms of multiple sclerosis: A comprehensive review of disease, drug efficacy and side effects
Multiple sclerosis (MS) is a prevalent and debilitating neurologic condition characterized by widespread neurodegeneration and the formation of focal demyelinating plaques in the central nervous system. Current therapeutic options are complex and attempt to manage acute relapse, modify disease, and manage symptoms. Such therapies often prove insufficient alone and highlight the need for more targeted MS treatments with reduced systemic side effect profiles. Ozanimod is a novel S1P (sphingosine-1-phosphate) receptor modulator used for the treatment of clinically isolated syndrome, relapsing–remitting, and secondary progressive forms of multiple sclerosis. It selectively modulates S1P1 and S1P5 receptors to prevent autoreactive lymphocytes from entering the CNS where they can promote nerve damage and inflammation. Ozanimod was approved by the US Food and Drug Administration (US FDA) for the management of multiple sclerosis in March 2020 and has been proved to be both effective and well tolerated. Of note, ozanimod is associated with the following complications: increased risk of infections, liver injury, fetal risk, increased blood pressure, respiratory effects, macular edema, and posterior reversible encephalopathy syndrome, among others. Further investigation including head-to-head clinical trials is warranted to evaluate the efficacy of ozanimod compared with other S1P1 receptor modulators
The landscape of viral associations in human cancers
Here, as part of the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, for which whole-genome and-for a subset-whole-transcriptome sequencing data from 2,658 cancers across 38 tumor types was aggregated, we systematically investigated potential viral pathogens using a consensus approach that integrated three independent pipelines. Viruses were detected in 382 genome and 68 transcriptome datasets. We found a high prevalence of known tumor-associated viruses such as Epstein-Barr virus (EBV), hepatitis B virus (HBV) and human papilloma virus (HPV; for example, HPV16 or HPV18). The study revealed significant exclusivity of HPV and driver mutations in head-and-neck cancer and the association of HPV with APOBEC mutational signatures, which suggests that impaired antiviral defense is a driving force in cervical, bladder and head-and-neck carcinoma. For HBV, HPV16, HPV18 and adeno-associated virus-2 (AAV2), viral integration was associated with local variations in genomic copy numbers. Integrations at the TERT promoter were associated with high telomerase expression evidently activating this tumor-driving process. High levels of endogenous retrovirus (ERV1) expression were linked to a worse survival outcome in patients with kidney cancer
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