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Bifurcation analysis of the plane sheet pinch  [PDF]
Joerg Schumacher,Norbert Seehafer
Physics , 1999, DOI: 10.1103/PhysRevE.61.2695
Abstract: A numerical bifurcation analysis of the electrically driven plane sheet pinch is presented. The electrical conductivity varies across the sheet such as to allow instability of the quiescent basic state at some critical Hartmann number. The most unstable perturbation is the two-dimensional tearing mode. Restricting the whole problem to two spatial dimensions, this mode is followed up to a time-asymptotic steady state, which proves to be sensitive to three-dimensional perturbations even close to the point where the primary instability sets in. A comprehensive three-dimensional stability analysis of the two-dimensional steady tearing-mode state is performed by varying parameters of the sheet pinch. The instability with respect to three-dimensional perturbations is suppressed by a sufficiently strong magnetic field in the invariant direction of the equilibrium. For a special choice of the system parameters, the unstably perturbed state is followed up in its nonlinear evolution and is found to approach a three-dimensional steady state.
Combined Water-Oxygen Pinch Analysis with Mathematical Programming for Wastewater Treatment
SONG Li-li,DU Jian,CHAI Shao-bin,YAO Ping-jing,
宋丽丽
,都健,柴绍斌,姚平经

过程工程学报 , 2006,
Abstract: Water-oxygen pinch analysis is an effective method to decrease the wastewater quantity and improve the wastewater quality. But when multiple-contaminants are present, the method is difficult to be carried out. In this paper, the method that combines water-oxygen pinch analysis with mathematical programming is proposed. It obtains the general optimal solution and leads to the reuse stream that cannot be found only by pinch analysis. The new method is illustrated by an example, and the annual cost is reduced by 8.43% compared with the solution of literature.
Pinch analysis based on rigorous physical properties
WESTPHALEN, D. L.;MACIEL, M.R .WOLF;
Brazilian Journal of Chemical Engineering , 1999, DOI: 10.1590/S0104-66321999000300006
Abstract: pinch analysis is a methodology that allows the calculation of minimum hot and cold utilities consumption in a process from the knowledge of some data of the hot and cold streams. these energy targets are calculated through the problem table method, that is based on the description of the process using constant heat capacity flowrates. this hypothesis is not valid in certain situations, particularly when phase changes are involved. a modification to problem table method is proposed, that allows the use of enthalpies rigorously calculated from thermodynamic correlations. one case study is provided, where an error of 240% in hot target is verified if phase changes are neglected.
Pinch analysis based on rigorous physical properties  [cached]
WESTPHALEN D. L.,MACIEL M.R .WOLF
Brazilian Journal of Chemical Engineering , 1999,
Abstract: Pinch Analysis is a methodology that allows the calculation of minimum hot and cold utilities consumption in a process from the knowledge of some data of the hot and cold streams. These energy targets are calculated through the Problem Table Method, that is based on the description of the process using constant heat capacity flowrates. This hypothesis is not valid in certain situations, particularly when phase changes are involved. A modification to Problem Table Method is proposed, that allows the use of enthalpies rigorously calculated from thermodynamic correlations. One case study is provided, where an error of 240% in hot target is verified if phase changes are neglected.
Nuclear dissipation effects on fission and evaporation in systems of intermediate fissility  [cached]
Nadotchy P.N.,Brondi A.,Di Nitto A.,La Rana G.
EPJ Web of Conferences , 2010, DOI: 10.1051/epjconf/20100208003
Abstract: The systems of intermediate fissility 132Ce and 158Er have been studied experimentally and theoretically in order to investigate the dissipation properties of nuclear matter. Cross sections of fusion-fission and evaporation residues channels together with charged particles multiplicities in both channels, their spectra, angular correlations and mass-energy distribution of fission fragments have been measured. Theoretical analysis has been performed using multi-dimensional stochastic approach with realistic treatment of particle evaporation. The results of analysis show that full one-body or unusually strong two-body dissipation allows to reproduce experimental data. No temperature dependent dissipation was needed.
Thermogravimetric analysis of fuel film evaporation
Zongjie Hu,Liguang Li,Shui Yu
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-2091-3
Abstract: Thermogravimetric analysis (TGA) was compared with the petrochemical distillation measurement method to better understand the characteristics of fuel film evaporation at different wall temperatures. The film evaporation characteristics of 90# gasoline, 93# gasoline and 0# diesel with different initial thicknesses were investigated at different environmental fluxes and heating rates. The influences of heating rate, film thickness and environmental flux on fuel film evaporation for these fuels were found. The results showed that the environmental conditions in TGA were similar to those for fuel films in the internal combustion engines, so data from TGA were suitable for the analysis of fuel film evaporation. TGA could simulate the key influencing factors for fuel film evaporation and could investigate the basic quantificational effect of heating rate and film thickness. To get a rapid and sufficient fuel film evaporation, sufficiently high wall temperature is necessary. Evaporation time decreases at a high heating rate and thin film thickness, and intense gas flow is important to promoting fuel film evaporation. Data from TGA at a heating rate of 100°C/min are fit to analyze the diesel film evaporation during cold-start and warming-up. Due to the tense molecular interactions, the evaporation sequence could not be strictly divided according to the boiling points of each component for multicomponent dissolved mixture during the quick evaporation process, and the heavier components could vaporize before reaching their boiling points. The 0# diesel film would fully evaporate when the wall temperature is beyond 250°C.
Numerical Analysis of Black Hole Evaporation  [PDF]
Tsvi Piran,Andrew Strominger
Physics , 1993, DOI: 10.1103/PhysRevD.48.4729
Abstract: Black hole formation/evaporation in two-dimensional dilaton gravity can be described, in the limit where the number $N$ of matter fields becomes large, by a set of second-order partial differential equations. In this paper we solve these equations numerically. It is shown that, contrary to some previous suggestions, black holes evaporate completely a finite time after formation. A boundary condition is required to evolve the system beyond the naked singularity at the evaporation endpoint. It is argued that this may be naturally chosen so as to restore the system to the vacuum. The analysis also applies to the low-energy scattering of $S$-wave fermions by four-dimensional extremal, magnetic, dilatonic black holes.
Pinch Analysis as a Knowledge Management Tool for Optimization in Supply Chain  [cached]
Olusegun Folorunso,Gladys Adewale,Adewale Opeoluwa Ogunde,Julius .Olatunji. Okesola
Computer and Information Science , 2010, DOI: 10.5539/cis.v4n1p79
Abstract: Supply chain managers are trying to maximize the profitable operation of their manufacturing and distribution supply chain, but due to global competition in process industries and complexities of the supply chain processes together with large computational times, it has made optimization of supply chain management (SCM) quite difficult. Recently, Knowledge management (KM) is a new important information technology-based business paradigm for achieving competitive advantage, and it is no surprise that it has received so much attention from researchers. This paper therefore deploys Pinch Analysis, a practicable tool that entails less complex mathematics compared to many other optimization tools, to manage critical knowledge generated in supply chains. In this study, demand and supply explicit knowledge from the organization was represented as composites for the pinch analysis. The developed system gave supply chain managers new insights into SCM and thus aiding quick decision-making and on the overall helped to achieve the much needed competitive advantage.
Energy Targeting for a Brewing Process Using Pinch Analysis  [PDF]
Noah Tibasiima, Aldo Okullo
Energy and Power Engineering (EPE) , 2017, DOI: 10.4236/epe.2017.91002
Abstract: The rising cost of energy and environmental concerns have led the brewing industry to search for techniques of reducing energy consumption in brewery operations. In this paper, pinch analysis was applied to a typical Ugandan based brewery process to target for the energy requirements of the process. Hint software was used for the analysis. At the chosen ΔTmin of 10, the minimum cooling and heating utility requirements of the brewery studied were determined as being 4862.21 kW and 8294.21 kW respectively, with a pinch temperature at 68. It was observed that using the technique, 1806.59 kW of energy could be recovered through process to process heat exchange which presented an energy saving potential of 21.5%. It is recommended that results from this study could be used in the design or retrofit of a heat exchanger network of a brewery for improved energy efficiency. Considerations can also be made for other values of ΔTmin.
Quasi-stationary evolution of systems driven by particle evaporation  [PDF]
L. Velazquez,H. Mosquera Cuesta,F. Guzman
Physics , 2005,
Abstract: We study the quasi-stationary evolution of systems where an energetic confinement is unable to completely retain their constituents. It is performed an extensive numerical study of a gas whose dynamics is driven by binary encounters and its particles are able to escape from the container when their kinetic energies overcome a given cutou Uc .We use a parametric family of differential cross sections in order to modify the effectiveness of this equilibration mechanism. It is verified that when the binary encounters favor an effective exploration of all accessible velocities, the quasi-stationary evolution is reached when the detailed balance is imposed for all those binary collisions which do not provoke particle evaporation. However, the weakening of this effectiveness leads to energy distribution functions which could be very well fitted by using a Michie-King-like profile. We perform a theoretical analysis, in the context of Hamiltonian systems driven by a strong chaotic dynamics and particle evaporation, in order to take into account the effect of the nonhomogeneous character of the confining potential.
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