Wyniki wyszukiwania - BazTech

1

Mathematical model+ of a long-distance conveyor

Pihnastyi Oleh M., Khodusov Valery D., Kotova Anna V.

Mining Science

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2023

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Vol. 30

27--43

EN

The model of the multi-conveyor transport system of a conveyor type is given in the article. The conveyor is considered as a complex dynamic distributed system. The analytical expression which allows calculating linear density and material flow at any point of the transport route for a specific instant in time is obtained. The conveyor belt speed and the material flow from the accumulative bunker to the input of the conveyor are represented as given time functions. The decision analysis for the steady and transient periods of the transport system operation is accomplished. The estimated duration of the transient process is given. The model is of interest for the design of highly efficient flow control systems for long-ranged multi-conveyor transport systems of a conveyor type.

2

Safe locker - a secure cargo transport control support IT system

Anus Artur, Buchwald Paweł

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2019

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Vol. 23, No 1

19--28

EN

The article presents the assumptions and architectural implementation of a cargo transport control support system, as well as the preliminary results of tests of the operation of this system in environmental conditions identical with the conditions of natural operation.The aim of the article is the publication of the research results collected during the design, implementation and operation of the system, which relate to the proposed solutions for selected problems that emerged during the development of the system by the research and development team. The article also presents the completed development work and possibilities in the field of the system improvement due to security reasons through integration with modern data processing systems based on a block chain (Blockchain).

3

GPU software and architecture comparison for numerical simulation of partial deferential equations

May Jon B., Pera Donato

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2018

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Vol. 22. No 1

85--100

EN

This paper will show a comparison between the Kepler, Maxwell and Pascal GPU architectures using CUDA-Fortran, with and without dynamic calls, to efficiently solve partial differential equations. The target is to show the possibility of using affordable hardware, such astheGTX670,GTX970 andGTX1080 NVIDIA GPUs, which are commonly found in personal and portable computers, for scientific applications. For simplicity we consider a standard wave equation where we use a second order finite difference method for the spatial and time discretizations to obtain the numerical solution. We found that, as we increase the spatialre solution of the domain we also increase the performance difference between the GPU and the Central Processing Unit (CPU).

4

Near face slurrying performance modeling with elliptical and spherical geometries

Suglo R. S., Frimpong S, Szymański J. K., Płaneta S.

Transport Przemysłowy i Maszyny Robocze

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2012

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Nr 4

54--60

EN

Surface mine production scheduling is complicated by tine fact that tine operations in most open pit mines are conducted on multiple benches and often involve the simultaneous excavation of both ore and waste. These production schedules and plans are used to maintain and maximize the expected profit, determine tine future investment in mining, optimize the return on investment, evaluate alternative investment options, and conserve and develop the mine's resources. The geometrical pit volumes, pit expansion rates and the volume of materials to be handled at any given time on the different benches in a multi-bench, multi-face open pit mine have to be calculated to determine the equipment requirements.

PL

Sporządzanie harmonogramów produkcji w kopalniach odkrywkowych jest skomplikowane, ponieważ urabianie w większości wyrobisk odkrywkowych prowadzone jest na wielu poziomach (półkach) i często wiąże się ono z jednoczesnym urabianiem zarówno skał nadkładu, jak i rudy. Te harmonogramy i plany produkcji są wykorzystywane do: utrzymania i maksymalizacji oczekiwanego zysku, określania przyszłych wydatków inwestycyjnych, optymalizacji stopy zwrotu z inwestycji, oceny alternatywnych opcji inwestycyjnych oraz utrzymania i udostępnienia zasobów eksploatacyjnych. Geometryczne objętości odkrywki, objętości robót udostępniających, objętości urabianej i transportowanej skały płonnej oraz rudy w danym momencie na różnych poziomach wielopoziomowej kopalni i na wielu frontach urabiania muszą być obliczane, w celu określenia wymagań sprzętowych. W artykule wykorzystano algorytmy Matlab w obliczeniach geometrycznych i równania różniczkowe cząstkowe typu parabolicznego (PDE) dla określenia objętości odkrywek i prędkości postępu robót wybierkowych w przypadku frontów eksploatacji typu eliptycznego i kołowego w hipotetycznej kopalni piasków roponośnych. Otrzymane wyniki obliczeń geometrycznych z użyciem algorytmów Matlab są niemal takie same jak te, uzyskane od PDE dla różnych konfiguracji odkrywek. Tak więc równania PDE mogą być z powodzeniem stosowane w obliczeniach objętości, aby otrzymać te same wartości, które uzyskano w wyniku obliczeń geometrycznych. Jednak obliczenia z użyciem PDE do określenia prędkości postępu robot wybierkowych we wszystkich kierunkach są zwykle zakończone, gdy warunki brzegowe wzdłuż małej osi lub krótszych wymiarów są osiągnięte. Należy również zauważyć, że generalnie obliczenia PDE mają tendencję do zawyżania urobionych objętości w przypadku pogłębiania odkrywki w stosunku do obliczeń geometrycznych. Wyniki analizy ekonomicznej wskazują, że zarówno obecny system wydobycia (CMS), jak i cykliczny «koparka-przenośnik» (CycEx CBCS) są opłacalne przy wysokich wartościach zaktualizowanych netto (≥3,20 $ x1010), wskaźnikach rentowności (> 19%) i wewnętrznych stopach zwrotu (> 29,02%) oraz bardzo krótkich zaktualizowanych okresach zwrotu nakładów inwestycyjnych ≤ 3,24 miesięcy). Opcja CycEx CBCS jest bardziej opłacalna niż opcja CMS. Jej wartość zaktualizowana netto jest 1,27 razy większa od opcji CMS. Wskaźnik rentowności i wewnętrzna stopa zwrotu z opcji CBCS CycEx są odpowiednio 2,24 i 1,13 razy wyższe w porównaniu z opcją CMS. Ponadto, zaktualizowany okres zwrotu nakładów inwestycyjnych opcji CycEx CBCS jest prawie o połowę krótszy od tego dla opcji CMS. W przypadku opcji CMS koszt operacyjny wynosi 1,386 $/tonę (2,774 $/baryłkę), natomiast w przypadku opcji CBCS CycEx wynosi on 0,779 $/tonę (1,558 $/baryłkę). Tak więc jednostkowy koszt operacyjny opcji CMS jest około 1,78 razy wyższy od tego dla CBCS CycEx). Te wyniki pokazują, że opcja CycEx CBCS jest wyraźcie lepszym rozwiązaniem dla firm górniczych wydobywających złoża piasków olejowych i inwestujących w nie.

5

Quantum-chemical Calculations of the Antioxidant Properties of trans-p-coumaric Acid and trans-sinapinic Acid

Urbaniak A., Molski M., Szeląg M.

Computational Methods in Science and Technology

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2012

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Vol. 18, No. 2

XX-XX

EN

Trans-p-coumaric and trans-sinapinic acids are cinnamic acid's derivatives which show strong antioxidant properties. In this work full optimization of both chemical structures and their radical, cation radical and anionic forms in vacuum and water medium has been performed, and antioxidant descriptors: Bond Dissociation Enthalpy, Adiabatic Ionization Potential, Proton Dissociation Enthalpy, Proton Affinity, Electron Transfer Enthalpy, Gas Phase Acidity, Free Gibbs Energy have been calculated. The Highest Occupied and Lowest Unoccupied Molecular Orbital energies have been employed to determine groups in compounds studied with the highest electron density. All calculations were performed using Gaussian 03W software package at the DFT level of theory (B3LYP hybrid functional) together with 6-311+G(2d,2p) basis set. Strong antioxidant properties of both investigated compounds were determined in this study. Based on the results it may be suggested that trans-p-coumaric and transsinapinic acids react according to the Hydrogen Atom Transfer mechanism in vacuum and according to SingleElectron Transfer followed by the Proton Transfer mechanism in water medium. Moreover, in both compounds studied the O-H bond is a preferred place of free radical attack.

6

Detonation engines

Wolański P.

Journal of KONES

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2011

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Vol. 18, No. 3

515-521

EN

In this paper survey of jet engines based on detonation combustion is provided. After short historical view, basic schemes of engines utilizing detonation are described. Possible improvement of propulsion efficiency due to detonative combustion which results in pressure increase is presented and comparison of deflagrative and detonative combustion is discussed. Detailed description of Pulsed Detonation Engines (PDE) as well as Rotating Detonation Engines (RDE) is given. Also basic principle of engine utilizing Standing Detonation is provided. Special attention is given to RDE, since rotating detonation can be applied to all kind of jet engines including, turbine, ramjet and rocket engines. Basic research of rotating detonation in cylindrical chambers for hydrogen-air mixtures is presented. A typical pressure record for experiments carried out in laboratory conditions is given. Schematic diagrams of turbofan engines are compared to classical ones and advantages and disadvantages of application of rotating detonation to these engines is discussed. For ramjet engines, schematic diagram of engine operation is depictured. Special attention is given to the rocket engines utilizing rotating detonation. Experimental research of small models of rockets engines with aerospike nozzle is presented. Test of such engines were carried out for gaseous fuels, such as: hydrogen, methane, ethane and propane with gaseous oxygen. Measurements of pressure and thrust are presented. Finally, possible configuration and applications of combine cycle rocket-ramjet engine utilizing rotating detonation is discussed.

7

The transformational analytical solution for nonlinear convection in the presence of two-way rotation

El-Kholy S. A., Ismail I. A.

Mechanics and Mechanical Engineering

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2004

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Vol. 7, nr 1

119-130

EN

Steady two-dimensional finite amplitude solutions are obtained for the problem of convection in a horizontal fluid layer heated from below and rotated about its vertical axis. The flow is assumed to be laminar and two-dimensional. The density variation is taken into account by the Boussinesq approximation. Different boundaries with prescribed constant temperature are assumed and the solutions are obtained. The transform for summing the variables, which reduce the nonlinear partial differential equation into ordinary differential equation of the high order, is used. The existence of steady subcritical finite amplitude solutions is demonstrated for different Prandtl numbers. A strong reduction in the domain of stable rolls that occurs as the rotation rate is increasing. Convection driven by thermal buoyancy in the presence of the Coriolis force occurs in planetary atmospheres and interiors. Asymptotic expressions for the onset of convection in a horizontal fluid layer of finite extent heated from below and rotating about a vertical axis are derived in the limit of large rotation rates in the case of stress-free upper and lower boundaries. In the presence of the vertical sidewalls the critical Rayleigh number R is much lower than the classical value of the infinity extended layer.