Brushless doubly fed machine magnetic field distribution characteristics and their impact on the analysis and design

This paper contributes to the characterisation of the brushless doubly fed induction generator (BDFIG), which is attractive as a variable speed generator in applications (offshore wind turbine) with minimum maintenance requirements. The BDFIG has two three-phase stator windings of different pole numbers housed within the same stator slots and a shortcircuited rotor winding capable of coupling fields of different pole numbers. The stator windings and rotor winding create a magnetic field distribution with a range of characteristics different to those of conventional induction generators. This paper presents an analysis to identify the field characteristics and discusses their impact on the analysis and design of the BDFIG. The characteristics are determined from an analysis of the sum of two rotating sinusoidal field waveforms and confirmed by comparison with time-stepping finite element results and measured magnetic flux density data

Impact of transmission topology for protective operations in multi-terminal HVDC networks

This paper presents an outcome of a comprehensive study which evaluates the transient behaviour of point-to-point and multi-terminal high voltage direct current (MT-HVDC) networks. The behaviour of the HVDC system during a permanent pole-to-pole and pole-to-ground fault is assessed considering a range of fault resistances, fault positions along the line, and operational conditions. The emphasis of this investigation is on DC fault characteristics which would facilitate a reliable method of faulty line discrimination in a multi-terminal direct current (MTDC) system using local measurements only (i.e. assuming that no communication media is used). All the simulated waveforms (and subsequent analysis) utilise the sampling frequency of 96 kHz in compliance with IEC-61869 and IEC-61850:9-2 for DC-side voltages and currents

A novel axial flux permanent magnet generator for wind turbines

This paper presents the development of a framework used to optimize and experimentally validate a novel axial flux direct-drive (DD) permanent magnet generator (PMG) for the offshore wind turbine market. This technology aims to offer significant levelized cost of energy (LCoE) reductions via capital expenditure and operating expense (CAPEX and OPEX) savings – a key objective for the offshore industry. The DD-PMG technology uses ferrite magnets to create the magnetic field, which is a significant source of cost reduction. The use of ferrite could also eliminate an industry wide reliance on Neodymium Iron Boron (NdFeB), the scarce and expensive rare-earth magnet used in existing designs. Another advantage of a ferrite-based design is that it’s less sensitive to the cooling problems that currently face existing DD-PMGs. This paper describes the development and testing of two prototype machines at nominal 2 kW and 70 kW power ratings. Moreover, the finite element analysis (FEA) and analytical steps employed to develop optimized designs together with the experimental verification are presented. The simulated and experimental results show good agreement which provides confidence in the design and modelling work completed

Structural propertis of micropowders composition SiO2:CuO & SiO2:Cu° prepared by sol-gel method

The aim of the research was to obtain and study the functional characteristics of composite materials of the composition SiO2, SiO2:CuO and SiO2:Cu°, synthesized on the basis of Aerosil A-300. The basis for obtaining micropowders from pyrogenic silica was an aqueous dispersion of aerosil containing copper nitrate with a concentration (in molar percent) SiO2:Cu (NO3)2×3H2O = 1:0.25; 1:0.40 and 1:0.5. The aqueous dispersion (sol) of the specified composition was subjected to successive drying and annealing in air to T = 800 ºС (holding time was 1 h). The micro-powder formed as a result of such heat treatment had a phase composition of SiO2:CuO. Further annealing of such composite micro-powders in a hydrogen atmosphere (at Т = 800 ºС, holding time - 1 h) made it possible to transform bivalent copper oxide Cu (II) into the state of reduced copper (Cuº).The phase transformations of copper nitrate into its oxide (II) or reduced copper (under the action of thermal treatment of micropowders in an appropriate gas environment) were studied using the method of X-ray phase analysis. The morphology of the structure of the synthesized xerogels was studied by scanning electron microscopy. The processing of the obtained SEM images was carried out using the Gwyddion program (techniques were used to create an inverted "mask" for the surface of the sample under study). The elemental composition of the synthesized micropowders was determined by the (EDX) method. Based on the data obtained and studies carried out by other authors for materials of this kind, assumptions were made about the possibility of using synthesized powders of SiO2 xerogels containing micro- and nanoparticles of reduced metals (as well as metal oxides) as effective biologically active substances with a wide range medical purposes, as well as construction materials used to create microsensors with a selective sensitivity zone

DETECTION OF INFLUENZA VIRUSES AMONG HOSPITALIZED CASES SUFFERING FROM SEVERE ACUTE RESPIRATORY ILLNESS (SARI) IN SANA’A CITY, YEMEN

Objective: Influenza is a major cause of morbidity and mortality around the world. So national influenza surveillance have been important for understanding the epidemiology of influenza over time. The aims of this study were to determine the prevalence rate of influenza viruses among hospitalized patients with severe acute respiratory illness (SARI), identify circulating types and subtypes of influenza viruses among them, and determine the risk factors associated with SARI.Methods: A total of 320 hospitalized patients suffering from SARI at Al Joumhouri University hospital in Sana’a city were enrolled; and their age was ranged from < 1 year to ≥ 56 years. Both nasopharyngeal and oro-pharyngeal swabs were collected from each patient and tested by using rRT-PCR technique for the detection of influenza A, influenza B and subtypes of influenza A viruses (A/H1N1 (2009) and A/H3N2).Results: The crude prevalent rate of influenza viruses among SARI patients was 10.9%; the female rate was 12.4%, and the male rate was 9.9%.. The rate of Flu A in the total SARI cases was 5.9% and for Flu B was 5%. In addition 3.8% of SARI patients were suffering from influenza A/H3N2, 2.2% from influenza A/H1N1(2009) infections; and the mortality rate for influenza infections was 17.1%. Also, a high mortality rate was occurred in influenza infections in age groups 36-45 years and 6-15 years. Also, there was a significant association between flu infection; and 46-55 years group (OR=2.8), Winter time (OR=17.5), cardiac diseases (OR=9.1), and diabetic mellitus (OR=3.7).Conclusion: In conclusion: both influenza A and B were represented as a causative agents of SARI, and Influenza A/H3N2 was present subtype followed by A/H1N1(2009). The frequency of influenza viruses ascertain among SARI patients in Yemen highlights the need for health authorities to develop strategies to reduce morbidity among at-risk population in the course of vaccine recommendation.                           Peer Review History: Received 20 July 2019;   Revised 3 August; Accepted 8 September, Available online 15 September 2019 Academic Editor: Dr. DANIYAN Oluwatoyin Michael, Obafemi Awolowo University, ILE-IFE, Nigeria, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 7.5/10 Average Peer review marks at publication stage: 9.5/10 Reviewer(s) detail: Dr. Nada Farrag, Misr International University, Egypt, [email protected] Dr. Nicola Micale, University of Messina, Italy,  [email protected]

Erythropoietin receptor regulates tumor mitochondrial biogenesis through iNOS and pAKT

Erythropoietin receptor (EPOR) is widely expressed in healthy and malignant tissues. In certain malignancies, EPOR stimulates tumor growth. In healthy tissues, EPOR controls processes other than erythropoiesis, including mitochondrial metabolism. We hypothesized that EPOR also controls the mitochondrial metabolism in cancer cells. To test this hypothesis, we generated EPOR-knockdown cancer cells to grow tumor xenografts in mice and analyzed tumor cellular respiration via high-resolution respirometry. Furthermore, we analyzed cellular respiratory control, mitochondrial content, and regulators of mitochondrial biogenesis in vivo and in vitro in different cancer cell lines. Our results show that EPOR controls tumor growth and mitochondrial biogenesis in tumors by controlling the levels of both, pAKT and inducible NO synthase (iNOS). Furthermore, we observed that the expression of EPOR is associated with the expression of the mitochondrial marker VDAC1 in tissue arrays of lung cancer patients, suggesting that EPOR indeed helps to regulate mitochondrial biogenesis in tumors of cancer patients. Thus, our data imply that EPOR not only stimulates tumor growth but also regulates tumor metabolism and is a target for direct intervention against progression

Evolution of copper ions in high-silica thin films

The paper studies Thin Films based on Silica which doped with Copper Ions (SiO2:CuO) at A Molar Ratio of (1:0.20; 1:0.30; 1:0.40) Deposited on Quartz and Silicon Substrates. The films were obtained by ion sputtering in a gaseous medium (argon/oxygen) from High- Silica targets obtained by the Sol-Gel method. The morphology and structure of the films were studied using scanning electron microscopy and X-ray phase analysis. X-ray phase analysis of the films revealed that the structure of the films is polycrystalline and has a hexagonal structure. It has been established that the reduction of Cu+2 to Cu+ occurs during film preparation in argon, which is confirmed by the analysis of absorption spectra and XRD data. The obtained frequency dependences of the dielectric permittivity of SiO2:CuO films showed a decrease in the dielectric permittivity and dielectric loss tangent in the range of (103 to 106) Hz. It has been found that when the SiO2:CuO film thickness is less than 100 nm, a thin-film capacitor is not always formed. The calculation of the film band gap shows the presence of two energy bands corresponding to the SiO2:CuO and SiO2:Cu2O compositions. The band gap of Eg(CuO) changes with increasing concentration from 3.564 to 2.598 eV, and Eg(Cu2O) changes with increasing concentration from 5.299 to 3.586 eV. A dip corresponding to the plasmon effect is observed in the transmission spectra in the region of 600–650 nm

Obtaining high silica powders containing copper ions of a given stoichiometric composition

The paper presents the results of studies of the Technological Stages of Obtaining High-Silica Powders Containing Copper Ions by the Sol-Gel Method. It has been shown that metal nanoparticles in a xerogel matrix are nanostructured objects with high chemical and “penetrating” activity with respect to the occurrence of thermally stimulated surface reactions, while the SiO2 matrix retains an amorphous system, whereas CuO and Cu° form a monoclinic crystalline syngony. Based on the results of SEM data, it was suggested that the reduced metal is sorbed into the globular structure of the xerogel, forming a thin composite layer on the SiO2 surface. No pronounced formation of separately localized Cu° micro- and nanoparticles was found. From the obtained high-silica SiO2:CuO and SiO2:Cuº powders, targets were formed for the deposition of thin films by electron-beam or magnetron sputtering with a diameter of up to 80 mm

Combined population genomic screening for three high-risk conditions in Australia: a modelling study

BACKGROUND: No previous health-economic evaluation has assessed the impact and cost-effectiveness of offering combined adult population genomic screening for mutliple high-risk conditions in a national public healthcare system. METHODS: This modeling study assessed the impact of offering combined genomic screening for hereditary breast and ovarian cancer, Lynch syndrome and familial hypercholesterolaemia to all young adults in Australia, compared with the current practice of clinical criteria-based testing for each condition separately. The intervention of genomic screening, assumed as an up-front single cost in the first annual model cycle, would detect pathogenic variants in seven high-risk genes. The simulated population was 18–40 year-olds (8,324,242 individuals), modelling per-sample test costs ranging AU$100–$1200 (base-case AU$200) from the year 2023 onwards with testing uptake of 50 FINDINGS: Over the population lifetime (to age 80 years), the model estimated that genomic screening per-100,000 individuals would lead to 747 QALYs gained by preventing 63 cancers, 31 CHD cases and 97 deaths. In the total model population, this would translate to 31,094 QALYs gained by preventing 2612 cancers, 542 non-fatal CHD events and 4047 total deaths. At AU$200 per-test, genomic screening would require an investment of AU$832 million for screening of 50$23,926 (∼£12,050/€14,110/US$15,345) per QALY gained over the status quo. In scenario analysis with 3$4758/QALY was obtained. Sensitivity analysis for the base case indicated that combined genomic screening would be cost-effective under 70% of simulations, cost-saving under 25% and not cost-effective under 5%. Threshold analysis showed that genomic screening would be cost-effective under the AU$50,000/QALY willingness-to-pay threshold at per-test costs up to AU$325 (∼£164/€192/US$208). INTERPRETATION: Our findings suggest that offering combined genomic screening for high-risk conditions to young adults would be cost-effective in the Australian public healthcare system, at currently realistic testing costs. Other matters, including psychosocial impacts, ethical and societal issues, and implementation challenges, also need consideration. FUNDING: Australian Government, Department of Health, Medical Research Future Fund, Genomics Health Futures Mission (APP2009024). National Heart Foundation Future Leader Fellowship (102604)