destruction efficiency
Recently Published Documents


TOTAL DOCUMENTS

42
(FIVE YEARS 3)

H-INDEX

9
(FIVE YEARS 0)

2021 ◽  
Vol 2021 (3) ◽  
pp. 37-47
Author(s):  
E. Hladkyi ◽  
◽  
O. Zavoloka ◽  

Up-to-date multiple launch rocket systems (MLRSs) are adopted by many countries of the world, and they are an effective weapon against dispersed multiple targets. Developing and upgrading MLRSs calls for estimating their efficiency with the aim to select an optimum alternative. For an MLRS, the basic measure of area target destruction efficiency is the relative damage area. This measure depends on the damage area of the MLRS itself (extent of damage by one salvo). The paper suggests a relative criterion that allow one to estimate and optimize the salvo damage area. The criterion is based on the ratio of the salvo damage area to the maximum damage area and that of the undamaged area to the coverage area. The coverage area is defined as the area of the enveloping convex polygon for all points of missile impact in a salvo. It is shown that the domain of variation of the suggested criterion is the interval [0, 1]. Using the suggested criterion for 4 points of missile impact with a circular damage area, two basic structures are studied: a rhomb (two regular triangles) and a square. For them, optimum distances between the missile impact points that maximize the destruction level are determined. It is shown that the obtained optimum arrangement of missile impact points allows one to bring the extent of damage for the square structure to the more optimum rhomb layout (represents a part of the hexagonal structure, which is the most efficient from the standpoint of the packing problem). For a 16-missile salvo, it is shown that from the standpoint of the suggested criterion there exists an optimum relation between the missile damage area (radius) and the technical scattering parameters. The maximum value of the criterion for a missile salvo with account for the technical spread does not exceed 0.33 and is much lower than the value that can be obtained for the optimum structures (rhomb and square). The paper shows possibilities of using the criterion in deciding on optimum missile impact points with account for various typical targets within a multiple target and missile damage area configurations other than a circle.


2021 ◽  
Vol 7 (2) ◽  
pp. 150
Author(s):  
Nur Hamzah ◽  
A.M Shiddiq Yunus ◽  
Waqva Enno Al Fadiyah

Exergy analysis is application of the second law thermodynamics which provides information about large exergy, exergy efficiency, destruction, and destruction efficiency in each component of PLTU so can be reference for improvement and optimization in an effort to reduce losses and increase efficiency. The exergy value obtained from calculating mass flowrate, enthalpy, ambient temperature, and entropy. The destruction value is obtained from difference between input exergy value and exergy output. The destruction exergy value from comparison between output exergy value to input exergy value, and destruction efficiency value from comparison of destruction value to total destruction value of PLTU components. The results showed that the largest exergy occurred in boilers, namely 778.225 MW in 2018, 788.824 MW in 2019, and 796.824 MW in 2020, lowest exergy value in CP was 0.160 MW in 2018, 0.176 MW in 2019, and 0.160 MW in 2020. The largest destruction occurred in boilers, namely 163.970 MW with destruction efficiency 79.242% in 2018, 179.450 MW with destruction efficiency 82.111% in 2019, and 199.637 MW with destruction efficiency 83.448% in 2020, lowest exergy destruction value at CP, namely 0.056 MW with destruction efficiency 0.027% in 2018, 0.059 MW with destruction efficiency 0.027% in 2019, and 0.056 MW with destruction efficiency 0.023% in 2020. The exergy efficiency occurred in HPH 2, amounting to 94.750% in 2018, 95.187 % in 2019, and 94.728% in 2020, while lowest of exergy efficiency was in LPH 1, namely 43.637 MW in 2018, 33.512 MW in 2019, and 38.764 MW in 2020.


2021 ◽  
Vol 266 ◽  
pp. 01005
Author(s):  
A.V. Lekomtsev ◽  
I.B. Stepanenko

Treatment of production fluids to meet the requirements of the first quality group for commercial purposes is becoming more relevant every year in the Perm Region. Most operational facilities are in the final stages of development and characterized by the high water content of production fluids, which later leads to the formation of water-in-oil emulsions (WOEs) during transportation and field preparation. When treated by traditional methods, such as thermal and thermo chemical gravity sedimentation, stable WOEs are not amenable to destruction. These preparation methods are easy to use but do not always provide the expected result. In this regard, an urgent task is to develop and implement new technologies for the preparation of hydrocarbons, which can be used separately from traditional methods, or in combination with them. This method is called ultrasound impact (USI). This article describes regularities in the influence of various parameters on the efficiency of stable water-in-oil emulsion destruction during field-based treatment with the use of USI. The paper describes the experience of using USI, as well as the high destruction efficiency of stable water-in-oil emulsions in comparison with traditional methods. The authors of the article conducted pilot tests using a mobile unit for treating production fluids with stable WOEs pre-treated by ultrasound. Following test results, the technological effect has been evaluated and recommendations for the practical application of the proposed method have been made.


2020 ◽  
Vol 500 (2) ◽  
pp. 2543-2553
Author(s):  
F D Priestley ◽  
H Chawner ◽  
M Matsuura ◽  
I De Looze ◽  
M J Barlow ◽  
...  

ABSTRACT Dust destruction by supernovae is one of the main processes removing dust from the interstellar medium (ISM). Estimates of the efficiency of this process, both theoretical and observational, typically assume a shock propagating into a homogeneous medium, whereas the ISM possesses significant substructure in reality. We self-consistently model the dust and gas properties of the shocked ISM in three supernova remnants (SNRs), using X-ray and infrared (IR) data combined with corresponding emission models. Collisional heating by gas with properties derived from X-ray observations produces dust temperatures too high to fit the far-IR fluxes from each SNR. An additional colder dust component is required, which has a minimum mass several orders of magnitude larger than that of the warm dust heated by the X-ray emitting gas. Dust-to-gas mass ratios indicate that the majority of the dust in the X-ray emitting material has been destroyed, while the fraction of surviving dust in the cold component is plausibly close to unity. As the cold component makes up virtually all the total dust mass, destruction time-scales based on homogeneous models, which cannot account for multiple phases of shocked gas and dust, may be significantly overestimating actual dust destruction efficiencies, and subsequently underestimating grain lifetimes.


2019 ◽  
Author(s):  
Nigel G. H. Guilford ◽  
HyunWoo Peter Lee ◽  
Kärt Kanger ◽  
Torsten Meyer ◽  
Elizabeth A. Edwards

ABSTRACTFull-scale anaerobic digestion processes for organic solid waste are common in Europe, but generally unaffordable in Canada and the United States because of inadequate regulations to restrict cheaper forms of disposal, particularly landfill. We investigated the viability of solid-state anaerobic digestion (SS-AD) as an alternative that reduces the costs of waste pretreatment and subsequent wastewater treatment. A laboratory SS-AD digester, comprising six 10L leach beds and an upflow anaerobic sludge blanket reactor treating the leachate, was operated continuously for 88 weeks, with a mass balance of 101±2%. The feed was a mixture of cardboard, boxboard, newsprint, and fine paper, and varying amounts of food waste (from 0% to 29% on a COD basis). No process upset or instability was observed. The addition of food waste showed a synergistic effect, raising CH4 production from the fibre mixture from 52.7 L.kg-1COD fibreadded to 152 L.kg-1COD fibreadded, an increase of 190%. Substrate COD destruction efficiency reached 65% and a methane yield of 225 L.kg-1 CODadded was achieved at 29% food waste on a COD basis, and a solids retention time of 42 days. This performance was similar to that of a completely stirred tank reactor digesting similar wastes, but with much lower energy input.Abstract Figure


Catalysts ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 19 ◽  
Author(s):  
Xiangzhi Kong ◽  
Hao Zhang ◽  
Xiaodong Li ◽  
Ruiyang Xu ◽  
Ishrat Mubeen ◽  
...  

Tar removal is one of the greatest technical challenges of commercial gasification technologies. To find an efficient way to destroy tar with plasma, a rotating gliding arc (RGA) discharge reactor equipped with a fan-shaped swirling generator was used for model tar destruction in this study. The solution of toluene, naphthalene and phenanthrene is used as a tar surrogate and is destroyed in humid nitrogen. The influence of tar, CO2 and moisture concentrations, and the discharge current on the destruction efficiency is emphasized. In addition, the combination of Ni/γ-Al2O3 catalyst with plasma was tested for plasma catalytic tar destruction. The toluene, naphthalene and phenanthrene destruction efficiency reached up to 95.2%, 88.9%, and 83.9% respectively, with a content of 12 g/Nm3 tar, 12% moisture, 15% CO2, and a flow rate of 6 NL/min, whereas 9.3 g/kW·h energy efficiency was achieved. The increase of discharge current is advantageous in terms of decreasing black carbon production. The participation of Ni/γ-Al2O3 catalyst shows considerable improvement in destruction efficiency, especially at a relatively high flow rate (over 9 NL/min). The major liquid by-products are phenylethyne, indene, acenaphthylene and fluoranthene. The first two are majorly converted from toluene, acenaphthylene is produced by the co-reaction of toluene and naphthalene in the plasma, and fluoranthene is converted by phenanthrene.


Author(s):  
M. J.-E. Manuel ◽  
T. Temim ◽  
E. Dwek ◽  
A. M. Angulo ◽  
P. X. Belancourt ◽  
...  

A novel laboratory experimental design is described that will investigate the processing of dust grains in astrophysical shocks. Dust is a ubiquitous ingredient in the interstellar medium (ISM) of galaxies; however, its evolutionary cycle is still poorly understood. Especially shrouded in mystery is the efficiency of grain destruction by astrophysical shocks generated by expanding supernova remnants. While the evolution of these remnants is fairly well understood, the grain destruction efficiency in these shocks is largely unknown. The experiments described herein will fill this knowledge gap by studying the dust destruction efficiencies for shock velocities in the range ${\sim}10{-}30~\text{km}/\text{s}$ ($\unicode[STIX]{x03BC}\text{m}/\text{ns}$), at which most of the grain destruction and processing in the ISM takes place. The experiments focus on the study of grain–grain collisions by accelerating small (${\sim}1~\unicode[STIX]{x03BC}\text{m}$) dust particles into a large (${\sim}5{-}10~\unicode[STIX]{x03BC}\text{m}$ diameter) population; this simulates the astrophysical system well in that the more numerous, small grains impact and collide with the large population. Facilities that combine the versatility of high-power optical lasers with the diagnostic capabilities of X-ray free-electron lasers, e.g., the Matter in Extreme Conditions instrument at the SLAC National Accelerator Laboratory, provide an ideal laboratory environment to create and diagnose dust destruction by astrophysically relevant shocks at the micron scale.


Sign in / Sign up

Export Citation Format

Share Document