Current Issue : April - June Volume : 2014 Issue Number : 2 Articles : 6 Articles
A mathematical model was developed to correlate the four heat penetration parameters of 57 StumboÃ¢â?¬â?¢s tables (18,513 datasets) in\r\ncanned food: g (the difference between the retort and the coldest point temperatures in the canned food at the end of the heating\r\nprocess), fh/u (the ratio of the heating rate index to the sterilizing value), z (the temperature change required for the thermal\r\ndestruction curve to traverse one log cycle), and Jcc, (the cooling lag factor). The quantities g, z, and Jcc, are input variables for\r\npredicting fh/U, while z, Jcc and fh/U are input variables for predicting the value of g, which is necessary to calculate the heating\r\nprocess time B, at constant retort temperature, using BallÃ¢â?¬â?¢s formula. The process time calculated using the g value obtained from\r\nthemathematical model closely followed the time calculated fromthe tabulated g values (rootmean square of absolute errors RMS\r\n= 0.567 min, average absolute error = 0.421 min with a standard deviation SD = 0.380 min). Because the mathematical model can\r\nbe used to predict the intermediate values of any combination of inputs, avoiding the storage requirements and the interpolation of\r\n57 StumboÃ¢â?¬â?¢s tables, it allows a quick and easy automation of thermal process calculations and to perform these calculations using a\r\nspreadsheet....
An implicit iterative algorithm, based on the continuous moving least square (CMLS), is developed to simulate material mixing\r\nin Friction Stir Welding (FSW) process. Strong formulation is chosen for the modeling of the mechanical problem in Lagrangian\r\nframework to avoid the drawback of numerical integration. This algorithm is well adapted to large deformations in the mixing zone\r\nin the neighborhood of the welding tool.We limit ourselves to bidimensional viscoplastic problem to show the performance of the\r\nproposed implicit algorithm. The results show that the proposed algorithm can be employed to simulate FSW....
Control theory concepts have been long used to successfully manage and optimize complex systems. Using system dynamics (SD)\r\nmodeling methodology, which is continuous deterministic simulationmodeling methodology, we apply control theory concepts to\r\ndevelop a suitable performance functional (or objective function) that optimizes the performance of a retail supply chain.Thefocus\r\nis to develop insights for inventory management to prevent stock-outs and unfilled orders and to fill customer orders at the lowest\r\npossible cost to supply chain partners under different scenarios, in a two-player supplier-retailer supply chain. Moderate levels\r\nof inventory, defining appropriate performance functional, appear to be crucial in choosing the right policies for managing retail\r\nsupply chain systems.Thestudy also demonstrated howmultiple objectives can be combined in a single performance functional (or\r\nobjective function) by carefully assigning suitable weights to the components of objectives based on their priority and the existence\r\nof possible trade off opportunities....
The car occupies the daily universe of our society; however, noise pollution, global warming gas emissions, and increased fuel\r\nconsumption are constantly increasing. The electric vehicle is one of the recommended solutions by the raison of its zero emission.\r\nHeating and air-conditioning (HVAC) system is a part of the power system of the vehicle when the purpose is to provide complete\r\nthermal comfort for its occupants, however it requires far more energy than any other car accessory. Electric vehicles have a lowenergy\r\nstorage capacity, and HVAC may consume a substantial amount of the total energy stored, considerably reducing the vehicle\r\nrange, which is one of the most important parameters for EV acceptability. The basic goal of this paper is to simulate the airconditioning\r\nsystem impact on the power energy source of an electric vehicle powered by a lithium-ion battery....
Though there have been many attempts to address growth kinetics in algal photobioreactors, surprisingly little have attempted\r\nan agent-based modelling (ABM) approach. ABM has been heralded as a method of practical scientific inquiry into systems of a\r\ncomplex nature and has been applied liberally in a range of disciplines including ecology, physics, social science, and microbiology\r\nwith special emphasis on pathogenic bacterial growth.We bring together agent-based simulation with the Photosynthetic Factory\r\n(PSF) model, as well as certain key bioreactor characteristics in a visual 3D, parallel computing fashion. Despite being at small scale,\r\nthe simulation gives excellent visual cues on the dynamics of such a reactor, andwe further investigate themodel in a variety of ways.\r\nOur parallel implementation on graphical processing units of the simulation provides key advantages, which we also briefly discuss.\r\nWe also provide some performance data, along with particular effort in visualisation, using volumetric and isosurface rendering....
Rainfall and hence resulting river runoff are the random outcomes of natural processes. In the present research, possibility of predicting average runoff of Kulfo River of Ethiopia has been analyzed through stochastic time series modeling using historical data. In formulating the river runoff predictive model a univariate time series autoregressive integrated moving average (ARIMA) process of time series analysis as suggested by Box and Jenkin is used. In order to make the river runoff data stationary first order differencing is done. ARIMA (1,1,1) model has produced best fit simulation and forecasts of runoff. Statistical measures and error criteria were used to test the validity and performance of the developed ARIMA model. The forecast produced by the model are good enough to be used for the decision making in water supply projects and flood disaster management....
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