State-of-the-art ultra-supercritical variable pressure once-through boiler with improved dynamic characteristics and reliability by reducing mass velocity of furnace wall

2020 ◽  
Vol 2020 (0) ◽  
pp. 0017
Author(s):  
Yuta Watanabe ◽  
Kazuhiro Domoto ◽  
Hiroyuki Nakaharai ◽  
Hiroshi Suganuma ◽  
Kenjiro Yamamoto ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Mass Velocity ◽  
State Of The Art ◽  
Furnace Wall ◽  
Variable Pressure

scholarly journals Smoke recognition network based on dynamic characteristics

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142092566
Author(s):  
Dahan Wang ◽  
Sheng Luo ◽  
Li Zhao ◽  
Xiaoming Pan ◽  
Muchou Wang ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
State Of The Art ◽  
The State ◽  
Detection Accuracy ◽  
Static Characteristics ◽  
Good Tool ◽  
Early Signal ◽  
Fuzzy Objects ◽  
The Difference ◽  
Smoke Recognition

Fire is a fierce disaster, and smoke is the early signal of fire. Since such features as chrominance, texture, and shape of smoke are very special, a lot of methods based on these features have been developed. But these static characteristics vary widely, so there are some exceptions leading to low detection accuracy. On the other side, the motion of smoke is much more discriminating than the aforementioned features, so a time-domain neural network is proposed to extract its dynamic characteristics. This smoke recognition network has these advantages:(1) extract the spatiotemporal with the 3D filters which work on dynamic and static characteristics synchronously; (2) high accuracy, 87.31% samples being classified rightly, which is the state of the art even in a chaotic environments, and the fuzzy objects for other methods, such as haze, fog, and climbing cars, are distinguished distinctly; (3) high sensitiveness, smoke being detected averagely at the 23rd frame, which is also the state of the art, which is meaningful to alarm early fire as soon as possible; and (4) it is not been based on any hypothesis, which guarantee the method compatible. Finally, a new metric, the difference between the first frame in which smoke is detected and the first frame in which smoke happens, is proposed to compare the algorithms sensitivity in videos. The experiments confirm that the dynamic characteristics are more discriminating than the aforementioned static characteristics, and smoke recognition network is a good tool to extract compound feature.

State-of-the-Art Review of Pressure Relief Valve Design, Testing and Modeling

1991 ◽  
Vol 113 (1) ◽  
pp. 46-54 ◽  
Author(s):  
P. M. Petherick ◽  
A. M. Birk
Keyword(s):  
Dynamic Characteristics ◽  
Nuclear Power ◽  
Literature Search ◽  
Failure Modes ◽  
State Of The Art ◽  
Experimental Studies ◽  
Pressure Relief Valve ◽  
Operating Characteristics ◽  
Relief Valve ◽  
Pressure Relief

It is well known that the response of a rail tank car to exterior heating (e.g., fire engulfment) is significantly affected by the operating characteristics of the pressure relief valve (PRV). If the valve jams or fails in some way, it can lead to a violent vessel rupture; therefore, PRV failure modes and mechanisms must be understood. This paper investigates the studies which have been conducted in the area of PRV technology. The original focus of the paper was to conduct a literature search to find the state-of-the-art for the PRV’s which are presently installed on railway tank cars, highway tankers, and stationary LPG storage vessels. When few papers were found which had concentrated on this particular topic, the authors continued the search by considering both the nuclear power and chemical processing industries, where similar technologies are found. The results of the literature search suggest that the PRV’s currently installed on tank cars and highway tankers are based on designs more than 30 yr old. Controlled fire tests and industry’s maintenance programs suggest that PRV’s could be improved. Most experimental studies of PRV’s have concentrated on flow visualization techniques and have not considered PRV dynamic characteristics. The lack of understanding of valve dynamic characteristics has slowed the development of improved PRV dynamic computer models.

scholarly journals The cosmic evolution of the stellar mass–velocity dispersion relation of early-type galaxies

2020 ◽  
Vol 498 (1) ◽  
pp. 1101-1120
Author(s):  
Carlo Cannarozzo ◽  
Alessandro Sonnenfeld ◽  
Carlo Nipoti
Keyword(s):  
Mass Velocity ◽  
Selection Criteria ◽  
Velocity Dispersion ◽  
State Of The Art ◽  
Stellar Mass ◽  
Early Type ◽  
Bayesian Hierarchical ◽  
Cosmic Evolution ◽  
Stellar Velocity ◽  
Intrinsic Scatter

ABSTRACT We study the evolution of the observed correlation between central stellar velocity dispersion σe and stellar mass M* of massive ($M_*\gtrsim 3\times 10^{10}\, \mathrm{M_\odot}$) early-type galaxies (ETGs) out to redshift z ≈ 2.5, taking advantage of a Bayesian hierarchical inference formalism. Collecting ETGs from state-of-the-art literature samples, we build a fiducial sample (0 ≲ z ≲ 1), which is obtained with homogeneous selection criteria, but also a less homogeneous extended sample (0 ≲ z ≲ 2.5). Based on the fiducial sample, we find that at z ≲ 1 the M*–σe relation is well represented by $\sigma _{\mathrm{e}}\propto M_*^{\beta }(1+z)^{\zeta}$, with β ≃ 0.18 independent of redshift and ζ ≃ 0.4 (at a given M*, σe decreases for decreasing z, for instance by a factor of ≈1.3 from z = 1 to z = 0). When the slope β is allowed to evolve, we find it increasing with redshift: β(z) ≃ 0.16 + 0.26log (1 + z) describes the data as well as constant β ≃ 0.18. The intrinsic scatter of the M*–σe relation is ≃0.08 dex in σe at given M*, independent of redshift. Our results suggest that, on average, the velocity dispersion of individual massive (M* ≳ 3 × 1011M⊙) ETGs decreases with time while they evolve from z ≈ 1 to z ≈ 0. The analysis of the extended sample, over the wider redshift range 0 ≲ z ≲ 2.5, leads to results similar to that of the fiducial sample, with slightly stronger redshift dependence of the normalization (ζ ≃ 0.5) and weaker redshift dependence of the slope (dβ/dlog (1 + z) ≃ 0.18) when β varies with time. At z = 2 ETGs with $M_*\approx 10^{11}\, \mathrm{M_\odot}$ have, on average, ≈1.7 higher σe than ETGs of similar stellar mass at z = 0.

scholarly journals Dark matter inner slope and concentration in galaxies: from the Fornax dwarf to M87

2014 ◽  
Vol 10 (S311) ◽  
pp. 16-19 ◽  
Author(s):  
G. A. Mamon ◽  
J. Chevalier ◽  
A. J. Romanowsky ◽  
R. Wojtak
Keyword(s):  
Dark Matter ◽  
Mass Velocity ◽  
Globular Clusters ◽  
State Of The Art ◽  
Stellar Mass ◽  
Observational Evidence ◽  
Velocity Anisotropy ◽  
Weak Evidence ◽  
Blue Galaxies ◽  
Red Galaxies

AbstractWe apply two new state-of-the-art methods that model the distribution of observed tracers in projected phase space to lift the mass / velocity anisotropy (VA) degeneracy and deduce constraints on the mass profiles of galaxies, as well as their VA. We first show how a distribution function based method applied to the satellite kinematics of otherwise isolated SDSS galaxies shows convincing observational evidence of age matching: red galaxies have more concentrated dark matter (DM) halos than blue galaxies of the same stellar or halo mass. Then, applying the MAMPOSSt technique to M87 (traced by its red and blue globular clusters) we find that very cuspy DM is favored, unless we release priors on DM concentration or stellar mass (leading to unconstrained slope). For the Fornax dwarf spheroidal (traced by its metal-rich and metal-poor stars), the inner DM slope is unconstrained, with weak evidence for a core if the stellar mass is fixed. This highlights how priors are crucial for DM modeling. Finally, we find that blue GCs around M87 and metal-rich stars in Fornax have tangential outer VA.

Network science and tourism – the state of the art

2017 ◽  
Vol 72 (1) ◽  
pp. 120-131 ◽  
Author(s):  
Rodolfo Baggio
Keyword(s):  
Dynamic Characteristics ◽  
Design Methodology ◽  
Network Science ◽  
State Of The Art ◽  
The State ◽  
Content Type ◽  
Future Developments ◽  
The Subject ◽  
Objective View ◽  
General Perspective

Purpose In recent years, network science has become a dynamic and promising discipline. This study aims to provide a brief summary of the subject and the application to the tourism domain. Design/methodology/approach This paper is based on a non-exhaustive survey of the literature. Findings The state-of-the-art of network science in tourism is explored and discussed, together with possible future developments. Research limitations/implications This paper uses a limited set of works, those deemed the most significant to sketch the situation. The choice might be subjective, but the overall picture is clear. Given what accomplished so far, the methods of network science seem interesting both for their theoretical and practical outcomes. In essence, they provide a better and more objective view on the structural and dynamic characteristics of the tourism phenomenon and of the different tourism systems and components. Originality/value This paper critically reflects on the state of network science and its application to the tourism domain. Even without claiming to be complete, this paper takes a general perspective approach rather than examining single topics or issues.

State-of-the-Art of Joining Technologies for Assembled Camshaft

2012 ◽  
Vol 602-604 ◽  
pp. 2118-2122 ◽  
Author(s):  
Jia Ting Chen ◽  
Lian Fa Yang
Keyword(s):  
Injection Molding ◽  
Dynamic Characteristics ◽  
Future Development ◽  
High Speed ◽  
Joint Strength ◽  
State Of The Art ◽  
Impact Loads ◽  
Current State ◽  
Engine Combustion ◽  
Key Technologies

Assembled camshaft has used gradually in engines for automotive, ship etc. The camshaft bearing a great deal of impact loads and dynamic torque when the engine is high-speed rotation.Its quality directly determines engine combustion and dynamic characteristics. Hence, how to improve the joint strength economically between the shaft and the cam lobes is one of the key technologies needed to be solved. Main methods offered to the designers which can be used for assembled camshaft are: expanding technologies, interference-fits technologies and bonding technologies. It can be divided into joining by mechanical expanding, hydroforming, electromagnetic forming, knurling, welding sintering, injection molding. The advantage and disadvantage of joint techniques are analyzed, the current state of researches are summarized at home and abroad. Then followed are its new approaches in the future development.

Practical Picture Processing

1974 ◽  
Vol 32 ◽  
pp. 338-339
Author(s):  
T. A. Welton
Keyword(s):  
Radiation Damage ◽  
Coherence Length ◽  
Spatial Information ◽  
State Of The Art ◽  
Coherent Radiation ◽  
The State ◽  
Energy Spread ◽  
Electron Micrograph ◽  
Picture Processing ◽  
Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

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