In this work we focus on the simulation of the process of biomass syngas combustion in the industrial combustion chamber directly linked with gasification chamber, where this gas is continuously producing from the bio...
In this work we focus on the simulation of the process of biomass syngas combustion in the industrial combustion chamber directly linked with gasification chamber, where this gas is continuously producing from the biomass. Conflicting demands from the engineers to have rapid results and hints how to ensure the best conditions for combustion of this particular fuel and to lower the emission of pollutants, with simultaneously deep view inside the process and its stability motivates us to use both the RANS and LES techniques of turbulence modelling, compare it and take their advantages. We designed and performed series of 3D numerical simulations of both cold flow and combustion in complex geometry of industrial burner. It seems to us that the proper approach for modelling of biomass syngas combustion is steady flamelets model. Simulations performed with RANS closure are used as the initialisation of LES models, but their main goal is to predict the long-time oscillation of pressure and temperature observed in the working combustion chamber. On the other hand the main goal of the simulations with LES closure is to predict the proper level of short-time behaviour of the flame and local phenomena.
Dietary habits are one of the main causes of fatal diseases such as cardiovascular disorder, cancer and diabetes. This paper aims to illustrate a proportional relationship between diet and behaviour of the immune syst...
Dietary habits are one of the main causes of fatal diseases such as cardiovascular disorder, cancer and diabetes. This paper aims to illustrate a proportional relationship between diet and behaviour of the immune system which responds when a human body is being attacked by pathogens. However, if a person's diet is well balanced their immune system will improve and vice versa. Nonlinear ordinary differential equations are formulated to describe the behaviour of the immune system and its response when a human body gets infected by a pathogen. This model considers two populations: normal cells and immune cells. In addition, the model has been monitoring the behaviour of the immune system for thirty days using Mathematica 10.0 software. The results prove that well balanced and regular diet can boost the immune system and improve its response to protect a human body from diseases. In conclusion, a balanced diet plays a huge role in reducing the percentage of lethal diseases.
Realistic computer modelling of biological objects requires building of very accurate and realistic computer models based on geometric and material data, type, and accuracy of numerical analyses. This paper presents s...
Realistic computer modelling of biological objects requires building of very accurate and realistic computer models based on geometric and material data, type, and accuracy of numerical analyses. This paper presents some of the automatic tools and algorithms that were used to build accurate and realistic 3D finite element (FE) model of whole-brain. These models were used to solve the forward problem in magnetic field tomography (MFT) based on Magnetoencephalography (MEG). The forward problem involves modelling and computation of magnetic fields produced by human brain during cognitive processing. The geometric parameters of the model were obtained from accurate Magnetic Resonance Imaging (MRI) data and the material properties – from those obtained from Diffusion Tensor MRI (DTMRI). The 3D FE models of the brain built using this approach has been shown to be very accurate in terms of both geometric and material properties. The model is stored on the computer in Computer-Aided Parametrical Design (CAD) format. This allows the model to be used in a wide a range of methods of analysis, such as finite element method (FEM), Boundary Element Method (BEM), Monte-Carlo Simulations, etc. The generic model building approach presented here could be used for accurate and realistic modelling of human brain and many other biological objects.
In the current work numerical and experimental study are conducted to investigate the flow behaviour and thermal comfort in climate-controlled conference hall situated at University of Anbar. In the first part of the ...
In the current work numerical and experimental study are conducted to investigate the flow behaviour and thermal comfort in climate-controlled conference hall situated at University of Anbar. In the first part of the study, numerical investigation is conducted to understand the impact of the air conditioning supply and extracts openings locations on the physical characteristics of the air flow within the conference hall. Moreover, the study investigates the optimal location of the air conditioning units within the system. In this work the main emphases are to study the flow dynamics of the air and the thermal behaviour inside the conference hall with large number of audiences inside it. Typically, the efficiency of an air flow system is evaluated by the successful removal of sensible and latent loads from the system under control. In addition, to maintain the level of air pollutant at a prescribed accepted level to assure the optimal human thermal comfort conditions. This will improve the indoor air quality and the thermal comfort for the audience which is the main goal of the present study. The numerical part of the study is carried out using computational fluid dynamics (CFD) simulation approach. To attain this part, commercially available CFD software ANSYS\Fluent is used. The numerical modelling techniques solved the continuity, momentum, and energy conservation equations. The k – ε model is used to tackle the turbulent nature of the flow studied in this case. The second part of this study is achieved by measuring the velocity, air temperature and relative humidity experimentally by means of the calibrated instruments. The validation of the used approaches is carried out through comparing the attained numerical and experimental results. Good agreement is found between the numerical and experimental predictions obtained during the present work.
Stock market prediction has been the bane and goal for investors, and one of the biggest challenges for artificial intelligence (AI) community. National economies have a great impact by the behaviour of their stock ma...
详细信息
ISBN:
(纸本)9781538639016
Stock market prediction has been the bane and goal for investors, and one of the biggest challenges for artificial intelligence (AI) community. National economies have a great impact by the behaviour of their stock markets. Markets have become a more accessible investment tool. Attribute that all stock markets have in common is uncertainty. This uncertainty associated with stock value in short and long term future investments are undesirable. Stock market prediction is instrumental in process of investment. Drawbacks of existing system faces technical difficulties such as estimating share of dividends, state vector while implementing stochastic modelling for risk analysis. To overcome drawbacks of existing system, proposed system makes an effort of generating a combination of more than one lakh seventy thousand scenarios to find intrinsic value of company, displaying results in graphical visualization. A large scenario generation of distinct intrinsic stock value done by the system will provide intrinsic stock value for each scenario. A large set of values for all the input parameters for example high growth value, declining growth value, terminal growth value, return on equity needs to be created, so that possible intrinsic value can be generated by system. The system will calculate statistical indicators like mean, median, mode, skewness and kurtosis of large data set consisting intrinsic value of company. Comparing statistically calculated intrinsic value and current market price, system will be able to add a robust statistical reasoning for investment decision. This reasoning will have no human or emotional biases as there will be no human intervention involved for arriving to the final intrinsic value of stock. Monte Carlo simulation is best suited solution for generating random scenarios that fall in line with Brownian walk motion of stock prices.
The paper presents the experimental results obtained on an experimental device where a horizontal rubber wire is stretched by a transversal oscillating force - that is a body with an acceleration sensor attached, plac...
The paper presents the experimental results obtained on an experimental device where a horizontal rubber wire is stretched by a transversal oscillating force - that is a body with an acceleration sensor attached, placed at the middle of it that oscillates freely. A nonlinear model was proposed for the experimental test rig, the differential equation of motion was offered and a series of curves were traced and compared to the experimental ones. One can conclude that the theoretical model certifies very well the behaviour of the real model. An open problem remains the manner of adopting the parameters characteristic to the dissipative element of the system.
Due to high demand for workers and limited technology management in Indonesia, the industries need to focus on increasing worker's productivity in this labour-intensive system. Such system has the inclination to u...
Due to high demand for workers and limited technology management in Indonesia, the industries need to focus on increasing worker's productivity in this labour-intensive system. Such system has the inclination to use workers to actuate the economic cycle. But in employing human workers, we will face the problem of fatigue. This research identifies factors affecting fatigue recovery of workers and obtained the mathematical model for it. The model was built using the experimental design method that involved three workers with age ranging from 20 to 22 years and obtained that variable of activity, treatment and operator have closely related to fatigue recovery. The mathematical model was obtained as equation of Y=-13,856+15,515X1+2,736X2+3,674X3 with X1 is variable of activity, X2 is variable of treatment and X3 is variable of operator. The results of this research would become an indicator for the manufacturing industries in Indonesia to increase labour's productivity.
The existent of Uranium in vicinity of groundwater population can give a threat to the water supplier for human consumption. The objective of the research was to find the most important variables to the existence of t...
The existent of Uranium in vicinity of groundwater population can give a threat to the water supplier for human consumption. The objective of the research was to find the most important variables to the existence of the Uranium. This paper shows some modelling process for above matters by applying Neural Networks of Multilayers Perceptron. Data taken from US Department of Energy. Neural Networks used in this study were learning the representation of the model inside the data, and how best it relation with the output variable that we obtained from prediction. The results showed that the training samples was 87 out of 127, and the testing samples was 40 out of 127. The results were not giving indication that a mathematical model obtained. The conclusion was Conductivity becoming the most important variable to the existence of Uranium, which followed by the second importance that was Arsenic, the third importance was Selenium, the fourth important was Total Alkalinity.
This study aims to investigate the resonance frequency of the human maxillary sinus for the application of acoustically-driven drug delivery. An improved model of the classic Helmholtz resonator formula has been devel...
This study aims to investigate the resonance frequency of the human maxillary sinus for the application of acoustically-driven drug delivery. An improved model of the classic Helmholtz resonator formula has been developed to predict the resonance frequency of a nasal cavity and maxillary sinus combination, using computational fluid dynamics (CFD). To be more specific, a 3-D CFD model of the left side of a healthy human nose, composed of a nasal cavity connected to the maxillary sinus through an ostium, has been developed to undertake direct computational acoustics for predicting the resonance frequency. The simulations of the acoustic airflow in the nasal cavity, ostium, and maxillary sinus were carried out by solving the continuity and Navier-Stokes equations. A series of experiments were conducted for validation of CFD modelling using the resonance frequency of the nasal cavity and maxillary sinus combination as a criterion. The results showed that the classic Helmholtz resonator formula overpredicted the resonance frequency of the realistic nasal cavity and maxillary combination by 50% compared to measured experimental data. However, the results of the CFD simulation demonstrated a good agreement with the experimental data, showing a difference of 10%. Further, it is shown that by accounting for the fluid mass within both the maxillary sinus and the middle meatus the resonance frequency of the nasal cavity and maxillary sinus combination can be accurately predicted.
The current talk presents a 20-segmental 3D mathematical model of the human body for evaluation of the mass-inertial characteristics of all segments of the body. Specific realization of the model is proposed based on ...
The current talk presents a 20-segmental 3D mathematical model of the human body for evaluation of the mass-inertial characteristics of all segments of the body. Specific realization of the model is proposed based on anthropometric data for 2855 Bulgarian females at the age between 30-40 years provided by the representative anthropological investigation of the Bulgarian population (Yordanov et al., 2006). Using the proposed model, after deriving the corresponding analytical expressions needed for the geometrical bodies used in the modeling, we provide analytical expressions and estimate numerically the mass-inertial characteristics of all of the segments of the body: their mass, center of mass, the volume, and the principal moments of inertia. The comparison between our model results and data reported in literature for other Caucasian shows an overall good agreement, thus supporting the validity of the described method. The so developed model is oriented towards application in medicine (orthopaedics and traumatology), rehabilitation robotics, computer simulations, sports, and fields such as ergonomics, criminology, and engineering.
暂无评论