scholarly journals Experimental data revealing explosion characteristics of methane, air, and coal mixtures

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24627-24637 ◽  
Author(s):  
Jun Deng ◽  
Jiao Qu ◽  
Qiu-Hong Wang ◽  
Yang Xiao ◽  
Yu-Chi Cheng ◽  
...  

The explosion characteristics of methane–air–coal dust mixtures were investigated using an XKWB-1 sealed explosion system.

Author(s):  
Simona Candiani ◽  
Mario Pestarino

The central and peripheral nervous systems of amphioxus adults and larvae are characterized by morphofunctional features relevant to understanding the origins and evolutionary history of the vertebrate CNS. Classical neuroanatomical studies are mainly on adult amphioxus, but there has been a recent focus, both by TEM and molecular methods, on the larval CNS. The latter is small and remarkably simple, and new data on the localization of glutamatergic, GABAergic/glycinergic, cholinergic, dopaminergic, and serotonergic neurons within the larval CNS are now available. In consequence, it has been possible begin the process of identifying specific neuronal circuits, including those involved in controlling larval locomotion. This is especially useful for the insights it provides into the organization of comparable circuits in the midbrain and hindbrain of vertebrates. A much better understanding of basic chordate CNS organization will eventually be possible when further experimental data will emerge.


Although the Romanian institutional landscape and its policies have dramatically improved since the 1990s, the low institutional capacity of its tax system remains mysteriously constant, despite continued efforts at improvement in this area and the fact that experimental data show that Romanians have apparently high tax morale. This puzzling situation is tackled in this chapter by detailing the institutional legacies upon which the post-Communist tax system has been built and tracing the evolution of tax policies over a quarter of a century within the context of post-Communist transformations. The chapter offers a nuanced explanation based on a combination of policy inadequacy and instability, tax evasion and corruption, and low spending on infrastructure, all of which limit the chances of creating an adequate legitimacy for the tax system.


RSC Advances ◽  
2015 ◽  
Vol 5 (93) ◽  
pp. 76249-76256 ◽  
Author(s):  
A. Popovič ◽  
L. Bencze ◽  
J. Koruza ◽  
B. Malič

The analytical description of excess functions was made possible using more advanced treatment of experimental data with respect to literature.


2020 ◽  
Vol 11 (13) ◽  
pp. 3441-3447 ◽  
Author(s):  
Suresh C. Rathnayaka ◽  
Shahidul M. Islam ◽  
Ida M. DiMucci ◽  
Samantha N. MacMillan ◽  
Kyle M. Lancaster ◽  
...  

Experimental data and computational modeling indicates an active role for the bridging sulfide ligand in a synthetic CuZ model.


2021 ◽  
Vol 11 (4) ◽  
pp. 1609
Author(s):  
Sergei Aliukov ◽  
Konstantin Osintsev

This study focuses on the development of new methodological approaches to dust-preparation and burning of separated particles, including through the use of polyfractional ensembles. Coal dust screening by means of sieve analysis is described in standard methods. However, in order to further use the results obtained during mathematical modeling of particle motion in fuel-air mixture and exothermal reactions of oxidation while burning in a torch, it must be possible to differentiate and integrate continuous functions. The methodology is based on the continuity of particle motion in a mixture with air in the calculation of aerodynamic and heat-mass exchange processes in a torch. The paper employs new scientific approaches to transforming and normalizing a continuously differentiable function described by the Gauss curve. We propose to combine mathematical modeling of such functions with methods of approximation of piece-linear functions developed by Professor S. V. Aliukov. The implementation of such methods helps reduce calculation errors of particle size and deviations thereof from average equivalent diameter and to avoid the Gibbs effect while differentiating. The paper contains analytical calculations based on the proposed method and experimental data. Quantitative and qualitative results of comparing analytical and experimental data are also presented. We provide recommendations on the further use and extension of the range of the results obtained in a computer simulation of fuel production and burning processes in a torch.


Author(s):  
A. Gómez ◽  
P. Schabes-Retchkiman ◽  
M. José-Yacamán ◽  
T. Ocaña

The splitting effect that is observed in microdiffraction pat-terns of small metallic particles in the size range 50-500 Å can be understood using the dynamical theory of electron diffraction for the case of a crystal containing a finite wedge. For the experimental data we refer to part I of this work in these proceedings.


Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.


Author(s):  
Bernd Tesche ◽  
Tobias Schilling

The objective of our work is to determine:a) whether both of the imaging methods (TEM, STM) yield comparable data andb) which method is better suited for a reliable structure analysis of microclusters smaller than 1.5 nm, where a deviation of the bulk structure is expected.The silver was evaporated in a bell-jar system (p 10−5 pa) and deposited onto a 6 nm thick amorphous carbon film and a freshly cleaved highly oriented pyrolytic graphite (HOPG).The average deposited Ag thickness is 0.1 nm, controlled by a quartz crystal microbalance at a deposition rate of 0.02 nm/sec. The high resolution TEM investigations (100 kV) were executed by a hollow-cone illumination (HCI). For the STM investigations a commercial STM was used. With special vibration isolation we achieved a resolution of 0.06 nm (inserted diffraction image in Fig. 1c). The carbon film shows the remarkable reduction in noise by using HCI (Fig. 1a). The HOPG substrate (Fig. 1b), cleaved in sheets thinner than 30 nm for the TEM investigations, shows the typical arrangement of a nearly perfect stacking order and varying degrees of rotational disorder (i.e. artificial single crystals). The STM image (Fig. 1c) demonstrates the high degree of order in HOPG with atomic resolution.


Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.


Sign in / Sign up

Export Citation Format

Share Document