562 research outputs found
X-ray spectra reveal the reawakening of the repeat changing-look AGN NGC 1566
We present simultaneous XMM-Newton and NuSTAR observations of the repeat
changing-look AGN NGC 1566, which dramatically increased in brightness in the
IR to X-ray bands in 2018. The broad-band X-ray spectrum was taken at the peak
of the outburst and is typical of Seyfert 1 AGN. The spectrum shows a soft
excess, Compton hump, warm absorption and reflection, ruling out tidal
disruption as the cause of the outburst and demonstrating that a 'standard'
accretion disk can develop very rapidly. The high resolution grating spectrum
reveals that the outburst has launched a ~ 500 km/s outflow, and shows
photoionised emission lines from rest-frame gas. We discuss possible mechanisms
for the outburst, and conclude that it is most likely caused by a disk
instability.Comment: 5 pages, 2 figures, accepted to MNRAS letter
Mechanical properties of geopolymer concretes reinforced with waste steel fibers
The article presents the research that try to determinate the possibilities of utilization the waste came from used tires to create the composites based on geopolymer matrix. The tire is multicomponent construction. It mainly consists of elastomer (rubber), metal and textile fibres such called textile cord. A lot of components causes difficulties in the tire recycling process. The main aim of the research was determinate the possibilities of recycling the waste steel from used tires in geopolymer composites and develop the eco-friendly material for construction industry. The matrix based on fly ash from power station located in city named Skawina (Poland) and fine sand at a ratio of 1:1. The process of activation was made by 10M sodium hydroxide solution combined with the sodium silicate solution. In order to manufacture these composites the addition of 2% and 3.5% of waste steel fibres by mass was applied. Also specimen without steel fiber reinforcement were made to get reference specimens. The waste steel fibres came from recycling company from Argentina - 'Regomax'. The specimens were prepared according to the methodology described in the standard EN 12390-1. The research methods used were: microstructure research, tensile strength and compressive strength tests as well as analysis of breakthroughs.Fil: Gailitis, R. Riga Technical University; LetoniaFil: Korniejenko, K. Cracow University Of Technology; PoloniaFil: Lach, M. Riga Technical University; LetoniaFil: Sliseris, J. Riga Technical University; LetoniaFil: Moran, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Rodriguez, Exequiel Santos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Mikula, J. Cracow University Of Technology; Poloni
Implementation Challenges in Wrapping Interventions Around Families Living with Parental Mental Illness
Summary: Parental mental illness challenges service providers in adult mental health, child welfare and children’s mental health systems of care. This presentation describes the development and implementation of Family Options, a family-centered, strengths-based, family-driven intervention for families living with parental mental illness. Findings from the Family Options implementation study suggest strategies for the replication of the intervention, as well as recommendations for the enhancement of existing programs like children’s systems of care to meet parents’ needs and improve outcomes for all family members
Development and modeling the heat exchange element concepts of convection high temperature compressed air heater
Рассмотрен способ интенсификации теплообмена, при рекуперативном нагреве воздуха до температур порядка 800-1000°С. Проанализировано влияние на процесс теплообмена высоты и толщины продольного ребра, а так же их стоимостные показатели. Выбрана конструкция теплообменного элемента для дальнейшей проработки. Проведено численное моделирование выбранной конструкции в пакете CFD.Тhe method heat transfer enhancement was considered in regenerative air heating to temperatures of about 800-1000 ° C. Impact the fins height and longitudinal thickness on heat transfer were analyzed, as well as their cost parameters were analyzed. The design of the heat exchanger element has been selected for further development. Numerical simulation of the chosen design conducted in CFD.Исследование выполнено в Уральском федеральном университете за счет гранта Российского научного фонда (проект №14-19-00524)
The Effects of Small Metal Additions (Co,Cu,Ga,Mn,Al,Bi,Sn) on the Magnetocaloric Properties of the Gd5Ge2Si2 Alloy
The structural and magnetic properties of arc-melted and homogenized (1300 °C, 1 h) alloys of Gd5Ge1.9Si2X0.1 (X = Cu, Co, Ga, Mn, Al, Bi, or Sn) were investigated by powder x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and magnetometry. The addition of Cu, Ga, Mn, and Al completely eliminated the large hysteresis losses present in the undoped Gd5Ge2Si2 alloy between 270 and 330 K, broadened the magnetic entropy change ΔSm peak, and shifted its peak value from 275 to 305 K similar to that observed earlier for Gd5Ge1.9Si2Fe0.1. The addition of Bi or Sn had a negligible effect on either the alloy hysteresis losses or the characteristics of the ΔSm vs T peak. The microstructure of the alloy doped with Cu, Co, Ga, Mn, or Al consisted of a majority phase (depleted of silicon) and a minor intergranular phase (rich in silicon and of the corresponding metal additive). For Bi or Sn doping, the microstructure consisted of only the Gd5Ge2Si2 phase. Low temperature x-ray diffraction data on an Fe-doped sample showed the same spectra at 245 and 300 K, consistent with the majority phase possessing an orthorhombic structure. Refrigeration capacity calculations show that Gd5Ge1.9Si2X0.1 (X = Fe,Cu,Co,Ga,Mn, or Al) alloys are superior magnetic refrigerants compared to the undoped Gd5Ge2Si2 alloy
Effects of Metazachlor on Vitellogenin Induction in Zebrafish (Danio rerio)
The influence of metazachlor on vitellogenesis in juvenile (20 days old) zebrafish (Danio rerio) was investigated after ambient water exposure to concentrations of 0.1, 1.0 and 5.0 mg l-1 of the chloroacetanilide herbicide Butisan 400 SC containing approximately 35.6% (w/w) metazachlor. After 20 days of exposure, vitellogenin concentrations in whole-body homogenates of the fish were measured by direct sandwich ELISA. The results were compared to vitellogenin concentrations in fish from both negative (no exposure) and positive (exposed to natural oestrogen 17β-oestradiol) control groups. Exposure to Butisan 400 SC at a concentration of 5.0 mg l-1 induced vitellogenin synthesis significantly compared to the control fish (p < 0.05). The oestrogenic effect of 17β-oestradiol was confirmed
To the problem of optimization design air boiler heat exchange element scheme IGCC
Different approaches are considered for calculating the heat exchange element of an air boiler. The technical characteristics of the heat exchange element, namely the heat transfer coefficient, specific surface area, length and air speed, are studied, depending on the pipe diameter and air.Рассмотрены различные подходы для расчета теплообменного элемента воздушного котла. Исследованы технические характеристики теплообменного элемента, а именно коэффициент теплоотдачи, удельная поверхность, длина теплообменного элемента и скорость воздуха, в зависимости от диаметра труб и давления воздуха
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