Strongly Time-Variable Ultra-Violet Metal Line Emission from the Circum-Galactic Medium of High-Redshift Galaxies

We use cosmological simulations from the Feedback In Realistic Environments (FIRE) project, which implement a comprehensive set of stellar feedback processes, to study ultra-violet (UV) metal line emission from the circum-galactic medium of high-redshift (z=2-4) galaxies. Our simulations cover the halo mass range Mh ~ 2x10^11 - 8.5x10^12 Msun at z=2, representative of Lyman break galaxies. Of the transitions we analyze, the low-ionization C III (977 A) and Si III (1207 A) emission lines are the most luminous, with C IV (1548 A) and Si IV (1394 A) also showing interesting spatially-extended structures. The more massive halos are on average more UV-luminous. The UV metal line emission from galactic halos in our simulations arises primarily from collisionally ionized gas and is strongly time variable, with peak-to-trough variations of up to ~2 dex. The peaks of UV metal line luminosity correspond closely to massive and energetic mass outflow events, which follow bursts of star formation and inject sufficient energy into galactic halos to power the metal line emission. The strong time variability implies that even some relatively low-mass halos may be detectable. Conversely, flux-limited samples will be biased toward halos whose central galaxy has recently experienced a strong burst of star formation. Spatially-extended UV metal line emission around high-redshift galaxies should be detectable by current and upcoming integral field spectrographs such as the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope and Keck Cosmic Web Imager (KCWI).Comment: 16 pages, 8 figures, accepted for publication in MNRA

Quasi Switched Capacitor based integrated Boost Series Parallel Fly-back Converter for energy Storage Applications

711-715A quasi-Switched Capacitor technique (QSC) is used to control the switch in Interconnected Boost Series Parallel Fly-Back Converter (IBSPFC). The QSC based IBSPFC does not require any snubber circuits for all the MOSFET switches presented at primary and secondary side and power can also be transferred even if one the winding gets damage. The primary side winding of the fly-back transformer is coupled in series across with bulk capacitor to minimize switch voltage stress and the secondary winding of the 1:1 fly-back transformer is coupled with dc voltage source, three switches and capacitor which forms a Quasi switched capacitor technique. Working techniques of quasi-switched capacitor with IBSPFC have been introduced. A 75v input, 100v output and DC-DC isolated Converter switching at frequency of 100 kHz is modeled using FPGA SPARTAN6LX9 and experimental results have been presented

Exact parameter identification of photovoltaic panel by using datasheet details

This paper deals with two main aspects of Photovoltaic systems. One is the analysis of Photovoltaic panel using the datasheet values provided on the PV panel and the other is to find the exact values of parameters of PV panel. Characterization of PV panels refers to the ability to predict the panel's output for given ambient conditions. To predict the exact characteristics and for exact mathematical modeling of PV panel, it is essential to find the parameters of the solar panel rather than assuming the parameters in modeling. One of the objectives of this study is to find the parameters like series resistance and shunt resistance values in single diode model by analyzing the relationship between different parameters. The analyzing process will cover the parameter estimation from the given datasheet parameters of solar panel, and mathematical algorithm involved in finding the solar panel parameters

H\u3csub\u3e2\u3c/sub\u3e Oxidation Over Supported Au Nanoparticle Catalysts: Evidence for Heterolytic H\u3csub\u3e2\u3c/sub\u3e Activation at the Metal-Support Interface

Water adsorbed at the metal-support interface (MSI) plays an important role in multiple reactions. Due to its importance in CO preferential oxidation (PrOx), we examined H2 oxidation kinetics in the presence of water over Au/TiO2 and Au/Al2O3 catalysts, reaching the following mechanistic conclusions: (i) O2 activation follows a similar mechanism to that proposed in CO oxidation catalysis; (ii) weakly adsorbed H2O is a strong reaction inhibitor; (iii) fast H2 activation occurs at the MSI, and (iv) H2 activation kinetics are inconsistent with traditional dissociative H2 chemisorption on metals. Density function theory (DFT) calculations using a supported Au nanorod model suggest H2 activation proceeds through a heterolytic dissociation mechanism, resulting in a formal hydride residing on the Au and a proton bound to a surface TiOH group. This potential mechanism was supported by infrared spectroscopy experiments during H2 adsorption on a deuterated Au/TiO2 surface, which showed rapid H-D scrambling with surface hydroxyl groups. DFT calculations suggest that the reaction proceeds largely through proton-mediated pathways and that typical Brønstednsted-Evans Polanyi behavior is broken by introducing weak acid/base sites at the MSI. THe kinetics data were successfully reinterpreted in the context of the heterolytic H2 activation mechanism, tying together the experimental and computational evidence and rationalizing the observed inhibition by physiorbed water on the support as blocking the MSI sites required for heterolytic H2 activation. In addition to providing evidence for the unusual H2 activation mechanism, these results offer additional insight into why water dramatically improves CO PrOx catalysis over Au

Importance of tides for periastron precession in eccentric neutron star-white dwarf binaries

Although not nearly as numerous as binaries with two white dwarfs, eccentric neutron star-white dwarf (NS-WD) binaries are important gravitational-wave (GW) sources for the next generation of space-based detectors sensitive to low frequency waves. Here we investigate periastron precession in these sources as a result of general relativistic, tidal, and rotational effects; such precession is expected to be detectable for at least some of the detected binaries of this type. Currently, two eccentric NS-WD binaries are known in the galactic field, PSR J1141-6545 and PSR B2303+46, both of which have orbits too wide to be relevant in their current state to GW observations. However, population synthesis studies predict the existence of a significant Galactic population of such systems. Though small in most of these systems, we find that tidally induced periastron precession becomes important when tides contribute to more than 3% of the total precession rate. For these systems, accounting for tides when analyzing periastron precession rate measurements can improve estimates of the inferred WD component mass and, in some cases, will prevent us from misclassifying the object. However, such systems are rare, due to rapid orbital decay. To aid the inclusion of tidal effects when using periastron precession as a mass measurement tool, we derive a function that relates the WD radius and periastron precession constant to the WD mass.Facultad de Ciencias Astronómicas y Geofísica

Impact of non-idealities on the Performance of an Ultracapacitor based Bidirectional DC/DC Converter

This paper analyses the impact of non-idealities on the performance of an ultracapacitor based bidirectional DC/DC converter. In particular, this work analyses the impact of ON state resistance of the MOSFET switches on the performance of bidirectional DC/DC converter. It is shown that, under particular operating conditions, the ON state resistance of the MOSFET can have a significant impact on the performance of th DC/DC converter and can cause an unstable response. An analytical expression is derived to identify the operating conditions under which the non-idealities can have a significant impact on the performance of the DC/DC converter. Simulation results are presented to aid the analysis reported in this paper. © 2020 IEEE

Multimode Operation of a PV-Battery System fed Brushless DC Motor Drive

Utilization of energy storage systems along with Photovoltaic systems, can provide an efficient solution to overcome the challenges associated with renewable energy sources. This paper proposes an algorithm for the multimode operation of a Brushless DC motor drive fed using a combination of Photovoltaic System and battery-based energy storage. Based on the solar irradiation and the state of charge of the battery, the proposed algorithm identifies a control scheme wherein the entire system operates in Four different modes. The working of the PV-Battery System fed Brushless DC Motor Drive under various operating modes is presented and is verified using simulation analysis performed in MATLAB/Simulink. © 2020 IEEE

Synthesis, in vitro, and in vivo evaluation of novel N-phenylindazolyl diarylureas as potential anti-cancer agents.

Novel N-phenylindazole based diarylureas have been designed, synthesized and evaluated as potential anticancer agents. In vitro cell viability studies of these derivatives illustrate good potency with IC50 values in the range of 0.4–50 μM in several cancer cell lines including murine metastatic breast cancer 4T1, murine glioblastoma GL261, human triple negative breast cancer MDA-MB-231, human pancreatic cancer MIAPaCa-2, and human colorectal cancer cell line WiDr. The ester group in the lead compound 8i was modified to incorporate amino-amides to increase solubility and stability while retaining biological activity. Further in vitro studies reveal that lead candidates inhibit tube length in HUVEC cells. In vivo systemic toxicity studies indicate that these candidate compounds are well tolerated in mice without any significant side effects. Anticancer efficacy studies in WiDr tumor xenograft and 4T1 tumor syngraft models demonstrate that the lead candidate 11 exhibits significant antitumor properties as a single agent in these tumor models

Potential benefits of Glycyrrhiza glabra (Liquorice) herb, its chemical make-up and significance in safeguarding poultry health: Current scientific knowledge

Positive results have been seen when bioactive components from herbal plants are added to poultry diets. Efficacy in feeding, digestion of nutrients, antioxidant health, immunological indices, and other factors can all be improved with the help of these additives, which in turn increases growth rates and improves poultry welfare. Several researchers have used sophisticated herbal formulae that included Glycyrrhiza glabra (Liquorice) as an ingredient. Epidemic illnesses, mainly in the respiratory, digestive, and immunological systems, pose the greatest threat to the poultry business. Flavonoids and glycyrrhizin are two of the bioactive compounds in Liquorice. The roots of this plant contain glycyrrhizin at concentrations of 1-9%, which has numerous pharmacological benefits, including anti-infectious, antioxidant, antiviral, and anti-inflammatory properties. Liquorice extracts are helpful in the treatment of multiple common illnesses. These include problems with the liver, the lungs, and the immunological system. Adding Liquorice to chicken diets improves their productivity in several ways, including fostering organ growth and stimulating digestion and appetite. Liquorice has many beneficial effects on birds, including helping them grow larger bodies, cleansing their systems, and protecting them from free radicals, bacteria, and inflammation. In this article, we'll look at the chemical make-up of liquorice herb, its role in protecting poultry health, and its recent applications and benefits