Abstract: In this work, ionic liquids (ILs) for CO2 capturing in typical absorption/stripper process are considered. The use of ionic liquids is considered to be cost-effective because it requires less energy for solvent recovery compared to other conventional processes. A mathematical model is developed for the process based on Peng-Robinson (PR) equation of state (EoS) which is validated with experimental data for various solutions involving CO2. The model is utilized to study the sorbent and energy demand for three types of ILs at specific CO2 capturing rates. The energy demand is manifested by the vapor-liquid equilibrium temperature necessary to remove the captured CO2 from the used solvent in the regeneration step. It is found that higher recovery temperature is required for solvents with higher solubility coefficient. For all ILs, the temperature requirement is less than that required by the typical monoethanolamine (MEA) solvent. The effect of the CO2 loading in the sorbent stream on the process performance is also examined.
Abstract: Most Decision Support Systems (DSS) for waste
management (WM) constructed are not widely marketed and lack
practical applications. This is due to the number of variables and
complexity of the mathematical models which include the
assumptions and constraints required in decision making. The
approach made by many researchers in DSS modelling is to isolate a
few key factors that have a significant influence to the DSS. This
segmented approach does not provide a thorough understanding of
the complex relationships of the many elements involved. The
various elements in constructing the DSS must be integrated and
optimized in order to produce a viable model that is marketable and
has practical application. The DSS model used in assisting decision
makers should be integrated with GIS, able to give robust prediction
despite the inherent uncertainties of waste generation and the plethora
of waste characteristics, and gives optimal allocation of waste stream
for recycling, incineration, landfill and composting.
Abstract: This paper deals optimized model to investigate the
effects of peak current, pulse on time and pulse off time in EDM performance on material removal rate of titanium alloy utilizing copper tungsten as electrode and positive polarity of the electrode. The experiments are carried out on Ti6Al4V. Experiments were
conducted by varying the peak current, pulse on time and pulse off time. A mathematical model is developed to correlate the influences of these variables and material removal rate of workpiece. Design of
experiments (DOE) method and response surface methodology
(RSM) techniques are implemented. The validity test of the fit and adequacy of the proposed models has been carried out through
analysis of variance (ANOVA). The obtained results evidence that as
the material removal rate increases as peak current and pulse on time
increases. The effect of pulse off time on MRR changes with peak ampere. The optimum machining conditions in favor of material removal rate are verified and compared. The optimum machining
conditions in favor of material removal rate are estimated and verified with proposed optimized results. It is observed that the developed model is within the limits of the agreeable error (about
4%) when compared to experimental results. This result leads to desirable material removal rate and economical industrial machining to optimize the input parameters.
Abstract: Software reliability prediction gives a great opportunity to measure the software failure rate at any point throughout system test. A software reliability prediction model provides with the technique for improving reliability. Software reliability is very important factor for estimating overall system reliability, which depends on the individual component reliabilities. It differs from hardware reliability in that it reflects the design perfection. Main reason of software reliability problems is high complexity of software. Various approaches can be used to improve the reliability of software. We focus on software reliability model in this article, assuming that there is a time redundancy, the value of which (the number of repeated transmission of basic blocks) can be an optimization parameter. We consider given mathematical model in the assumption that in the system may occur not only irreversible failures, but also a failure that can be taken as self-repairing failures that significantly affect the reliability and accuracy of information transfer. Main task of the given paper is to find a time distribution function (DF) of instructions sequence transmission, which consists of random number of basic blocks. We consider the system software unreliable; the time between adjacent failures has exponential distribution.
Abstract: The paper presents the results of simple measurements
conducted on a model of a wind-driven venturi-type room ventilator.
The ventilator design is new and was developed employing
mathematical modeling. However, the computational model was not
validated experimentally for the particular application considered.
The paper presents the performance of the ventilator model under
laboratory conditions, for five different wind tunnel speeds. The
results are used to both demonstrate the effectiveness of the new
design and to validate the computational model employed to develop
it.
Abstract: Drilling of glass sheets with different thicknesses have
been carried out by Abrasive Jet Machining process (AJM) in order
to determine its machinability under different controlling parameters
of the AJM process. The present study has been introduced a
mathematical model and the obtained results have been compared
with that obtained from other models published earlier [1-6]. The
experimental results of the present work are used to discuss the
validity of the proposed model as well as the other models.
Abstract: Subgrade moisture content varies with environmental and soil conditions and has significant influence on pavement performance. Therefore, it is important to establish realistic estimates of expected subgrade moisture contents to account for the effects of this variable on predicted pavement performance during the design stage properly. The initial boundary soil suction profile for a given pavement is a critical factor in determining expected moisture variations in the subgrade for given pavement and climatic and soil conditions. Several numerical models have been developed for predicting water and solute transport in saturated and unsaturated subgrade soils. Soil hydraulic properties are required for quantitatively describing water and chemical transport processes in soils by the numerical models. The required hydraulic properties are hydraulic conductivity, water diffusivity, and specific water capacity. The objective of this paper was to determine isothermal moisture profiles in a soil fill and predict the soil moisture movement above the ground water table using a simple one-dimensional finite difference model.
Abstract: This paper describes a steady state model of a multiple
effect evaporator system for simulation and control purposes. The
model includes overall as well as component mass balance equations,
energy balance equations and heat transfer rate equations for area
calculations for all the effects. Each effect in the process is
represented by a number of variables which are related by the energy
and material balance equations for the feed, product and vapor flow
for backward, mixed and split feed. For simulation 'fsolve' solver in
MATLAB source code is used. The optimality of three sequences i.e.
backward, mixed and splitting feed is studied by varying the various
input parameters.
Abstract: The objectif of the present work is to determinate the
potential of the solar parabolic trough collector (PTC) for use in the
design of a solar thermal power plant in Algeria. The study is based
on a mathematical modeling of the PTC. Heat balance has been
established respectively on the heat transfer fluid (HTF), the absorber
tube and the glass envelop using the principle of energy conservation
at each surface of the HCE cross-sectionn. The modified Euler
method is used to solve the obtained differential equations. At first
the results for typical days of two seasons the thermal behavior of the
HTF, the absorber and the envelope are obtained. Then to determine
the thermal performances of the heat transfer fluid, different oils are
considered and their temperature and heat gain evolutions compared.
Abstract: In theoretical computer science, the Turing machine has played a number of important roles in understanding and exploiting basic concepts and mechanisms in computing and information processing [20]. It is a simple mathematical model of computers [9]. After that, M.Blum and C.Hewitt first proposed two-dimensional automata as a computational model of two-dimensional pattern processing, and investigated their pattern recognition abilities in 1967 [7]. Since then, a lot of researchers in this field have been investigating many properties about automata on a two- or three-dimensional tape. On the other hand, the question of whether processing fourdimensional digital patterns is much more difficult than two- or threedimensional ones is of great interest from the theoretical and practical standpoints. Thus, the study of four-dimensional automata as a computasional model of four-dimensional pattern processing has been meaningful [8]-[19],[21]. This paper introduces a cooperating system of four-dimensional finite automata as one model of four-dimensional automata. A cooperating system of four-dimensional finite automata consists of a finite number of four-dimensional finite automata and a four-dimensional input tape where these finite automata work independently (in parallel). Those finite automata whose input heads scan the same cell of the input tape can communicate with each other, that is, every finite automaton is allowed to know the internal states of other finite automata on the same cell it is scanning at the moment. In this paper, we mainly investigate some accepting powers of a cooperating system of eight- or seven-way four-dimensional finite automata. The seven-way four-dimensional finite automaton is an eight-way four-dimensional finite automaton whose input head can move east, west, south, north, up, down, or in the fu-ture, but not in the past on a four-dimensional input tape.
Abstract: The mathematical modeling of storm surge in sea and
coastal regions such as the South China Sea (SCS) and the Gulf of
Thailand (GoT) are important to study the typhoon characteristics.
The storm surge causes an inundation at a lateral boundary exhibiting
in the coastal zones particularly in the GoT and some part of the SCS.
The model simulations in the three dimensional primitive equations
with a high resolution model are important to protect local properties
and human life from the typhoon surges. In the present study, the
mathematical modeling is used to simulate the typhoon–induced
surges in three case studies of Typhoon Linda 1997. The results
of model simulations at the tide gauge stations can describe the
characteristics of storm surges at the coastal zones.
Abstract: In this article, a high vacuum system for the evaporation of organic semiconductors is introduced and a mathematical model is given. Based on the exact input output linearization a deposition rate controller is designed and tested with different evaporation materials.
Abstract: Subcritical water extraction was investigated as a
novel and alternative technology in the food and pharmaceutical
industry for the separation of Mannitol from olive leaves and its
results was compared with those of Soxhlet extraction. The effects of
temperature, pressure, and flow rate of water and also momentum
and mass transfer dimensionless variables such as Reynolds and
Peclet Numbers on extraction yield and equilibrium partition
coefficient were investigated. The 30-110 bars, 60-150°C, and flow
rates of 0.2-2 mL/min were the water operating conditions. The
results revealed that the highest Mannitol yield was obtained at
100°C and 50 bars. However, extraction of Mannitol was not
influenced by the variations of flow rate. The mathematical modeling
of experimental measurements was also investigated and the model is
capable of predicting the experimental measurements very well. In
addition, the results indicated higher extraction yield for the
subcritical water extraction in contrast to Soxhlet method.
Abstract: A transient heat transfer mathematical model for the
prediction of temperature distribution in the car body during primer
baking has been developed by considering the thermal radiation and
convection in the furnace chamber and transient heat conduction
governing equations in the car framework. The car cockpit is
considered like a structure with six flat plates, four vertical plates
representing the car doors and the rear and front panels. The other
two flat plates are the car roof and floor. The transient heat
conduction in each flat plate is modeled by the lumped capacitance
method. Comparison with the experimental data shows that the heat
transfer model works well for the prediction of thermal behavior of
the car body in the curing furnace, with deviations below 5%.
Abstract: This paper considers the integration of assembly
operations and product structure to Cellular Manufacturing System
(CMS) design so that to correct the drawbacks of previous researches
in the literature. For this purpose, a new mathematical model is
developed which dedicates machining and assembly operations to
manufacturing cells while the objective function is to minimize the
intercellular movements resulting due to both of them. A
linearization method is applied to achieve optimum solution through
solving aforementioned nonlinear model by common programming
language such as Lingo. Then, using different examples and
comparing the results, the importance of integrating assembly
considerations is demonstrated.
Abstract: Environmental awareness and the recent
environmental policies have forced many electric utilities to
restructure their operational practices to account for their emission
impacts. One way to accomplish this is by reformulating the
traditional economic dispatch problem such that emission effects are
included in the mathematical model. This paper presents a Particle
Swarm Optimization (PSO) algorithm to solve the Economic-
Emission Dispatch problem (EED) which gained recent attention due
to the deregulation of the power industry and strict environmental
regulations. The problem is formulated as a multi-objective one with
two competing functions, namely economic cost and emission
functions, subject to different constraints. The inequality constraints
considered are the generating unit capacity limits while the equality
constraint is generation-demand balance. A novel equality constraint
handling mechanism is proposed in this paper. PSO algorithm is
tested on a 30-bus standard test system. Results obtained show that
PSO algorithm has a great potential in handling multi-objective
optimization problems and is capable of capturing Pareto optimal
solution set under different loading conditions.
Abstract: Thin linear-elastic cylindrical circular shells having a
micro-periodic structure along two directions tangent to the shell
midsurface (biperiodic shells) are object of considerations. The aim
of this paper is twofold. First, we formulate an averaged nonasymptotic
model for the analysis of parametric vibrations or dynamical
stability of periodic shells under consideration, which has constant
coefficients and takes into account the effect of a cell size on the
overall shell behavior (a length-scale effect). This model is derived
employing the tolerance modeling procedure. Second we apply the
obtained model to derivation of frequency equation being a starting
point in the analysis of parametric vibrations. The effect of the microstructure
length oh this frequency equation is discussed.
Abstract: Chemical reaction and diffusion are important phenomena in quantitative neurobiology and biophysics. The knowledge of the dynamics of calcium Ca2+ is very important in cellular physiology because Ca2+ binds to many proteins and regulates their activity and interactions Calcium waves propagate inside cells due to a regenerative mechanism known as calcium-induced calcium release. Buffer-mediated calcium diffusion in the cytosol plays a crucial role in the process. A mathematical model has been developed for calcium waves by assuming the buffers are in equilibrium with calcium i.e., the rapid buffering approximation for a one dimensional unsteady state case. This model incorporates important physical and physiological parameters like dissociation rate, diffusion rate, total buffer concentration and influx. The finite difference method has been employed to predict [Ca2+] and buffer concentration time course regardless of the calcium influx. The comparative studies of the effect of the rapid buffered diffusion and kinetic parameters of the model on the concentration time course have been performed.
Abstract: In the paper the mathematical model of tumor
growth is considered. New capillary network formation,
which supply cancer cells with the nutrients, is taken into the
account. A formula estimating a tumor growth in connection
with the number of capillaries is obtained.
Abstract: Heat pipes are used to control the thermal problem for
electronic cooling. It is especially difficult to dissipate heat to a heat
sink in an environment in space compared to earth. For solving this
problem, in this study, the Poiseuille (Po) number, which is the main
measure of the performance of a heat pipe, is studied by CFD; then, the
heat pipe performance is verified with experimental results. A heat
pipe is then fabricated for a spatial environment, and an in-house code
is developed. Further, a heat pipe subsystem, which consists of a heat
pipe, MLI (Multi Layer Insulator), SSM (Second Surface Mirror), and
radiator, is tested and correlated with the TMM (Thermal
Mathematical Model) through a commercial code. The correlation
results satisfy the 3K requirement, and the generated thermal model is
verified for application to a spatial environment.