We study the influence of a one-time stop in the course of manufacturing of products by the SLM technology on the structure and mechanical properties of specimens of Inconel 718 alloy with an aim to ...establish their serviceability. The specimens are produced on the equipment of different manufacturers both with stops in the process of printing and without stops. The mechanical properties are determined in tensile tests according to the requirements of GOST 1497 (ІСО 6892-84). It is shown that they are improved both in the case of continuous technological processes and in the presence of a stop in the course of production of the specimens.
We describe a FORTRAN 77 implementation of the optimal jet definition for identification of jets in hadronic final states of particle collisions. We discuss details of the implementation, explain ...interface subroutines and provide a usage example. The source code is available from
http://www.inr.ac.ru/~ftkachov/projects/jets/.
Title of program: Optimal Jet Finder (OJF_014)
Catalogue identifier: ADSB
Program Summary URL:
http://cpc.cs.qub.ac.uk/summaries/ADSB
Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland
Computer: Any computer with the FORTRAN 77 compiler
Tested with: g77/Linux on Intel, Alpha and Sparc; Sun f77/Solaris (thwgs.cern.ch); xlf/AIX (rsplus.cern.ch); MS Fortran PowerStation 4.0/Win98
Programming language used: FORTRAN 77
Memory required: ∼1 MB (or more, depending on the settings)
Number of bytes in distributed program, including examples and test data: 251
463
Distribution format: tar gzip file
Keywords: Hadronic jets, jet finding algorithms
Nature of physical problem: Analysis of hadronic final states in high energy particle collision experiments often involves identification of hadronic jets. A large number of hadrons detected in the calorimeter is reduced to a few jets by means of a
jet finding algorithm. The jets are used in further analysis which would be difficult or impossible when applied directly to the hadrons. Grigoriev et al.
hep-ph/0301185 provide a brief introduction to the subject of jet finding algorithms and a general review of the physics of jets can be found in Rep. Prog. Phys. 36 (1993) 1067.
Method of solution: The software we provide is an implementation of the so-called
optimal jet definition (
OJD). The theory of OJD was developed by Tkachov Phys. Rev. Lett. 73 (1994) 2405; 74 (1995) 2618; Int. J. Mod. Phys. A 12 (1997) 5411; 17 (2002) 2783. The desired jet configuration is obtained as the one that minimizes
Ω
R
, a certain function of the input particles and jet configuration.
Restrictions on the complexity of the program: The size of the largest data structure the program uses is (maximal number of particles in the input) × (maximal number of jets in the output) × 8 bytes. (For the standard settings <1 MB). Therefore, there is no memory restriction for any conceivable application for which the program was designed.
Typical running time: The running time depends strongly on the physical process being analyzed and the parameters used. For the benchmark process we studied,
e
+
e
−→
W
+
W
−→
4
jets
, with the average number of ∼80 particles in the input, the running time was
<10
−2
s on a modest PC (per event with
n
tries=1). For a fixed number of jets the complexity of the algorithm grows linearly with the number of particles (cells) in the input, in contrast with other known jet finding algorithms for which this dependence is cubic. The reader is referred to Grigoriev et al.
hep-ph/0301185 for a more detailed discussion of this issue.
Towards a standard jet definition Grigoriev, D Yu; Jankowski, E; Tkachov, F V
Physical review letters,
08/2003, Letnik:
91, Številka:
6
Journal Article
Recenzirano
Odprti dostop
In a simulated measurement of the W-boson mass, evaluation of Fisher's information shows the optimal jet definition Int. J. Mod. Phys. A, () to yield the same precision as the k(T) algorithm while ...being much faster at large multiplicities.
Synthesis of carbon nanotubes from acetone Melezhik, A. V.; Smykov, M. A.; Filatova, E. Yu ...
Theoretical foundations of chemical engineering,
07/2013, Letnik:
47, Številka:
4
Journal Article
Recenzirano
The process of synthesizing carbon nanotubes (CNTs) using the method of catalytic gas-phase pyrolysis has been studied using acetone as a source of carbon. CNTs with outer diameters of 8–10 nm were ...prepared. The highest yield of the CNTs with the best quality is achieved when (Co, Mo)/MgO-Al
2
O
3
catalyst is used. When (Fe, Co, Mo)/Al
2
O
3
is used, the yield and quality of CNTs are lower. For comparison, CNTs obtained on the same catalysts but with propylene as the source of carbon have been investigated. It has been shown that, in this case, the best yield is achieved if (Fe, Co, Mo)/Al
2
O
3
catalyst is used. According to the thermogravimetric data, CNT prepared at optimal conditions from acetone have fewer structural defects than those prepared from polypropylene. The optimal temperature and concentration conditions of the CNT synthesis from acetone have been determined. Based on the kinetic data, it has been assumed that the growth of CNTs takes place due to the ketene formed under the thermal decomposition of acetone. The ecological aspects of the CNT preparation from hydrocarbons and acetone are considered.
We construct an algorithm for calculating the residual life of the near-surface layer of back-up rolls of rolling mills according to the development of pitting. Within the framework of the ...numerical-analytical two-stage model of evaluating the contact durability of rolling solids of revolution under conditions of boundary friction (lubrication) proposed earlier, we construct and analyze the trajectories of propagation of edge cracks at the shear and rupture stages. A criterion of transition between these mechanisms is proposed. Furthermore, we evaluate the durability of rolls with the help of characteristics of the cyclic crack resistance of 9KhF, GH, and SKH roll steels. Using disk specimens made of 9KhS roll steel, we study the dependence of contact durability on the friction coefficient between the rolling solids of revolution, the size of contact area, contact pressure, the slope of the initial shear crack, etc. Finally, we compare the results of theoretical and experimental investigations.
Systems of grid equations that approximate elliptic boundary value problems on locally modified grids are considered. The triangulation, which approximates the boundary with second order of accuracy, ...is generated from an initial uniform triangulation by shifting nodes near the boundary according to special rules. This "locally modified" grid possesses several significant features: this triangulation has a regular structure, the generation of the triangulation is rather fast, this construction allows to use multilevel preconditioning (BPX-like) methods. The proposed iterative methods for solving elliptic boundary value problems approximately are based on two approaches: The fictitious space method, i.e. the reduction of the original problem to a problem in an auxiliary (fictitious) space, and the multilevel decomposition method, i.e. the construction of preconditioners by decomposing functions on hierarchical grids. The convergence rate of the corresponding iterative process with the preconditioner obtained is independent of the mesh size. The construction of the grid and the preconditioning operator for the three dimensional problem can be done in the same way.
Systems of grid equations that approximate elliptic boundary value problems on locally modified grids are considered. The triangulation, which approximates the boundary with second order of accuracy, ...is generated from an initial uniform triangulation by shifting nodes near the boundary according to special rules. This "locally modified" grid possesses several significant features: this triangulation has a regular structure, the generation of the triangulation is rather fast, this construction allows to use multilevel preconditioning (BPX-like) methods. The proposed iterative methods for solving elliptic boundary value problems approximately are based on two approaches: The fictitious space method, i.e. the reduction of the original problem to a problem in an auxiliary (fictitious) space, and the multilevel decomposition method, i.e. the construction of preconditioners by decomposing functions on hierarchical grids. The convergence rate of the corresponding iterative process with the preconditioner obtained is independent of the mesh size. The construction of the grid and the preconditioning operator for the three dimensional problem can be done in the same way.
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