Effects on NOx and SO2 Emissions During Co-Firing of Coal with Woody Biomass in Air Staging and Reburning

Co-firing coal with different types of biomass is increasingly being applied in thermal power plants in Europe. The main motive for the use of biomass as the second fuel in coal-fired power plants is the reduction of CO2 emissions, and related financial benefits in accordance with the relevant International regulations and agreements. Likewise, the application of primary measures in the combustion chamber, which also includes air staging and/or reburning, results in a significant reduction in emission of polluting components of flue gases, in particular NOx emissions. In addition to being efficient and their application to new and future thermoblocks is practically unavoidable, their application and existing conventional combustion chamber does not require significant constructional interventions and is therefore relatively inexpensive. In this work results of experimental research of co-firing coals from Middle Bosnian basin with waste woody biomass are presented. Previously formed fuel test matrix is subjected to pulverized combustion under various temperatures and various technical and technological conditions. First of all it refers to the different mass ratio of fuel components in the mixture, the overall coefficient of excess air and to the application of air staging and/or reburning. Analysis of the emissions of components of the flue gases are presented and discussed. The impact of fuel composition and process temperature on the values of the emissions of components of the flue gas is determined. Additionally, it is shown that other primary measures in the combustion chamber are resulting in more or less positive effects in terms of reducing emissions of certain components of the flue gases into the environment. Thus, for example, the emission of NOx of 989 mg/ measured in conventional combustion, with the simultaneous application of air staging and reburning is reduced to 782 mg/, or by about 21%. The effects of the primary measures applied in the combustion chamber are compared and quantified with regard to conventional combustion of coals from Middle Bosnian basin.Article History: Received: November 5th 2017; Revised: Januari 6th 2018; Accepted: February 1st 2018; Available onlineHow to Cite This Article: Hodžić, N., Kazagić, A., and Metović, S. (2018) Experimental Investigation of Co-Firing of Coal with Woody Biomass in Air Staging and Reburning. International Journal of Renewable Energy Development, 7(1), 1-6.https://doi.org/10.14710/ijred.7.1.1-

Lipid composition of liver in rats fed diets supplemented with egg yolks of modified composition

The aim of this study was to examine the effects of diets supplemented with egg yolks of modified composition on the fatty-acid composition and lipid content in rat’s liver. During four weeks of the experiment 64 Wistar rats were divided into four groups of 16 individuals each (eight individuals of both sexes) and fed a commercial feed mixture for rats (group C) or diet containing 70% commercial mixture for rats and 30% freshly cooked egg yolks from laying hens fed diets with 3% fish oil (group F), 3% palm olein (group P) or 3% lard (group L). Dietary supplementation with egg yolks significantly increased the hepatic cholesterol pool in rats, regardless of the type of fat in the diet of laying hens from which the eggs originated. The content of α-linolenic acid in the liver of male rats in group P was 4-6 times higher compared to males in the other groups. Liver lipids and their fatty-acid composition differ by both, sex and dietary modified egg yolk composition in rats

The EBLM project. VII. Spin-orbit alignment for the circumbinary planet host EBLM J0608-59 A/TOI-1338 A

Funding: This work was inpart funded by the U.S.–Norway Fulbright Foundation and a NASATESSGI grant G022253 (PI: Martin). AHMJT received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant 803193/BEBOP), and from a Leverhulme Trust Research Project grant (RPG-2018-418). VKH is also supported by a Birmingham Doctoral Scholarship, and by a studentship from Birmingham’s School of Physics & Astronomy. DVM received funding from the Swiss National Science Foundation (grant P 400P2 186735). SG has been supported by STFC through consolidated grants ST/L000733/1and ST/P000495/1.A dozen short-period detached binaries are known to host transiting circumbinary planets. In all circumbinary systems so far, the planetary and binary orbits are aligned within a couple of degrees. However, the obliquity of the primary star, which is an important tracer of their formation, evolution, and tidal history, has only been measured in one circumbinary system until now. EBLM J0608-59/TOI-1338 is a low-mass eclipsing binary system with a recently discovered circumbinary planet identified by TESS. Here, we perform high-resolution spectroscopy during primary eclipse to measure the projected stellar obliquity of the primary component. The obliquity is low, and thus the primary star is aligned with the binary and planetary orbits with a projected spin-orbit angle β = 2.°8 ± 17.°1. The rotation period of18.1 ± 1.6 d implied by our measurement of vsinI⋆ suggests that the primary has not yet pseudo-synchronized with the binary orbit, but is consistent with gyrochronology and weak tidal interaction with the binary companion. Our result, combined with the known coplanarity of the binary and planet orbits, is suggestive of formation from a single disc. Finally, we considered whether the spectrum of the faint secondary star could affect our measurements. We show through simulations that the effect is negligible for our system, but can lead to strong biases in vsinI⋆ and β for higher flux ratios. We encourage future studies in eclipse spectroscopy test the assumption of a dark secondary for flux ratios ≳1ppt.Publisher PDFPeer reviewe

An eclipsing substellar binary in a young triple system discovered by SPECULOOS

Mass, radius, and age are three of the most fundamental parameters for celestial objects, enabling studies of the evolution and internal physics of stars, brown dwarfs, and planets. Brown dwarfs are hydrogen-rich objects that are unable to sustain core fusion reactions but are supported from collapse by electron degeneracy pressure. As they age, brown dwarfs cool, reducing their radius and luminosity. Young exoplanets follow a similar behaviour. Brown dwarf evolutionary models are relied upon to infer the masses, radii and ages of these objects. Similar models are used to infer the mass and radius of directly imaged exoplanets. Unfortunately, only sparse empirical mass, radius and age measurements are currently available, and the models remain mostly unvalidated. Double-line eclipsing binaries provide the most direct route for the absolute determination of the masses and radii of stars. Here, we report the SPECULOOS discovery of 2M1510A, a nearby, eclipsing, double-line brown dwarf binary, with a widely-separated tertiary brown dwarf companion. We also find that the system is a member of the $45\pm5$ Myr-old moving group, Argus. The system's age matches those of currently known directly-imaged exoplanets. 2M1510A provides an opportunity to benchmark evolutionary models of brown dwarfs and young planets. We find that widely-used evolutionary models do reproduce the mass, radius and age of the binary components remarkably well, but overestimate the luminosity by up to 0.65 magnitudes, which could result in underestimated photometric masses for directly-imaged exoplanets and young field brown dwarfs by 20 to 35%

Quantum Cryptanalysis on Contracting Feistel Structures and Observation on Related-key Settings

In this paper we show several quantum chosen-plaintext attacks (qCPAs) on contracting Feistel structures. In the classical setting, a $d$-branch $r$-round contracting Feistel structure can be shown to be PRP-secure when $d$ is even and $r \geq 2d-1$, meaning it is secure against polynomial-time chosen-plaintext attacks. We propose a polynomial-time qCPA distinguisher on the $d$-branch $(2d-1)$-round contracting Feistel structure, which solves an open problem by Dong et al. In addition, we show a polynomial-time qCPA that recovers the keys of the $d$-branch $r$-round contracting Feistel structure when each round function $F^{(i)}_{k_i}$ has the form $F^{(i)}_{k_i}(x) = F_i(x \oplus k_i)$ for a public random function $F_i$. This is applicable to the Chinese block cipher standard {\texttt{SM4}}, which is a special case where $d=4$. Finally, in addition to quantum attacks under single-key setting, we also show related-key quantum attacks on balanced Feistel structures in the model that adversaries can only control part of the key difference in quantum superposition. Our related-key attacks on balanced Feistel structures can easily be extended to ones on contracting Feistel structures