Estimation of biodiesel properties from chemical composition – an artificial neural network (ANN) approach

Biodiesel, produced from renewable feedstock represents a more sustainable source of energy and will therefore play a significant role in providing the energy requirements for transportation in the near future. Chemically, all biodiesels are fatty acid methyl esters (FAME), produced from raw vegetable oil and animal fat. However, clear differences in chemical structure are apparent from one feedstock to the next in terms of chain length, degree of unsaturation, number of double bonds and double bond configuration-which all determine the fuel properties of biodiesel. In this study, prediction models were developed to estimate kinematic viscosity of biodiesel using an Artificial Neural Network (ANN) modelling technique. While developing the model, 27 parameters based on chemical composition commonly found in biodiesel were used as the input variables and kinematic viscosity of biodiesel was used as output variable. Necessary data to develop and simulate the network were collected from more than 120 published peer reviewed papers. The Neural Networks Toolbox of MatLab R2012a software was used to train, validate and simulate the ANN model on a personal computer. The network architecture and learning algorithm were optimised following a trial and error method to obtain the best prediction of the kinematic viscosity. The predictive performance of the model was determined by calculating the coefficient of determination (R2), root mean squared (RMS) and maximum average error percentage (MAEP) between predicted and experimental results. This study found high predictive accuracy of the ANN in predicting fuel properties of biodiesel and has demonstrated the ability of the ANN model to find a meaningful relationship between biodiesel chemical composition and fuel properties. Therefore the model developed in this study can be a useful tool to accurately predict biodiesel fuel properties instead of undertaking costly and time consuming experimental tests

SPH-DEM approach to numerically simulate the deformation of three-dimensional RBCs in non-uniform capillaries

© 2016 The Author(s). Background: Blood continuously flows through the blood vessels in the human body. When blood flows through the smallest blood vessels, red blood cells (RBCs) in the blood exhibit various types of motion and deformed shapes. Computational modelling techniques can be used to successfully predict the behaviour of the RBCs in capillaries. In this study, we report the application of a meshfree particle approach to model and predict the motion and deformation of three-dimensional RBCs in capillaries. Methods: An elastic spring network based on the discrete element method (DEM) is employed to model the three-dimensional RBC membrane. The haemoglobin in the RBC and the plasma in the blood are modelled as smoothed particle hydrodynamics (SPH) particles. For validation purposes, the behaviour of a single RBC in a simple shear flow is examined and compared against experimental results. Then simulations are carried out to predict the behaviour of RBCs in a capillary; (i) the motion of five identical RBCs in a uniform capillary, (ii) the motion of five identical RBCs with different bending stiffness (K b ) values in a stenosed capillary, (iii) the motion of three RBCs in a narrow capillary. Finally five identical RBCs are employed to determine the critical diameter of a stenosed capillary. Results: Validation results showed a good agreement with less than 10% difference. From the above simulations, the following results are obtained; (i) RBCs exhibit different deformation behaviours due to the hydrodynamic interaction between them. (ii) Asymmetrical deformation behaviours of the RBCs are clearly observed when the bending stiffness (K b ) of the RBCs is changed. (iii) The model predicts the ability of the RBCs to squeeze through smaller blood vessels. Finally, from the simulations, the critical diameter of the stenosed section to stop the motion of blood flow is predicted. Conclusions: A three-dimensional spring network model based on DEM in combination with the SPH method is successfully used to model the motion and deformation of RBCs in capillaries. Simulation results reveal that the condition of blood flow stopping depends on the pressure gradient of the capillary and the severity of stenosis of the capillary. In addition, this model is capable of predicting the critical diameter which prevents motion of RBCs for different blood pressures

A multiscale coarse grained model for simulating mechanical responses of plant food tissues

Plant food materials are highly sensitive to the external mechanical responses. Simulation of the material behaviour under mechanical loading is important in many engineering applications. Several researchers have used tissue based (macroscale) and cellular based (microscale) numerical models to assess the plant material behaviour. In doing so, generally, finite element modelling and meshfree based discretization strategies are commonly used and the latter has been proven to be more flexible, accurate and more robust in numerical simulations. This study aims to develop a coarse grained (CG) model for a cellular system of plant food tissue in microscale. The basic idea here is to maintain the accuracy given by the cellular scale while minimizing the computational cost for the simulations. The developed model accounts for the deformation of a coarse grained system under an external mechanical load. In order to represent the viscoelastic behaviour of a plant food material, we use a spring damper system connected to coarse grained beads. The model predictions show a satisfactory agreement with the morphological changes given by the cellular model. This developed CG model has laid a solid foundation for the further development of the multiscale model for the plant tissue

Effect of Commercial Level Modified Atmospheric Storage for Paddy (Oryza sativa)

Studies conducted in developing countries have shown that nearly 10% to 15% of paddy is lost during postproduction operations due to improper post-harvest techniques. These studies also found; major component of these losses occurred during storage due to practices. Hermetically sealed storage can be used as an alternative method for commercial scale paddy storage with a view to cut down post-harvest losses. Very less research studies have been conducted in this important area. Therefore, this study was conducted to evaluate the effect and impacts of commercial scale modified atmospheric storage conditions for altering of physical properties and quality parameters of paddy under tropical climatic conditions prevailing in Sri-Lanka. In the study storing paddy under commercial level modified atmospheric storage conditions for 9 months and compared quality changes of paddy such as physical properties, milling characteristics and other quality parameters compared against, paddy stored in conventional warehouse. Moreover, oxygen level, temperature inside the modified atmospheric storage and warehouse were also measured. It was observed modified atmospheric storage took 6 weeks to reduce oxygen level from 20.5% to 3.2%. Temperature fluctuation inside the modified atmospheric storage was very low in comparison with warehouse storage. Moisture content of initial warehouse samples and modified atmospheric storage were not significantly different. Modified atmospheric storage paddy samples reported similar initial values in terms of quality parameters such as impurities percentage, immature seed (Bol) percentage and damaged seed percentage even after 9 months of storage. Whereas those values were significant changed in warehouse samples. Weight/mass loss of grain during storage period was significantly low in cocoon (modified) samples. Bulk density and paddy kernel hardness values were significantly reduced in both storage methods against its initial values. Rice kernel whiteness was preserved by modified atmospheric storage in comparison to conventional storage. Germination percentage of paddy was significantly reduced from its initial value in both storage methods. Paddy kernel resistance against milling stress increased during modified atmospheric storage. It can be concluded that modified atmospheric storage has more advantages in comparison to conventional warehouse storage for large quantity commercial grain storage. However, modified atmospheric storage condition must be maintained throughout storage period to gain those advantages

A coarse-grained multiscale model to simulate morphological changes of food-plant tissues undergoing drying

Numerical modelling has emerged as a powerful and effective tool to study various dynamic behaviours of biological matter. Such numerical modelling tools have contributed to the optimisations of food drying parameters leading to higher quality end-products in the field of food engineering. In this context, on of the most recent developments is the mesh-free based numerical models, which have demonstrated enhanced capabilities to model cellular deformations during drying, providing many benefits compared to conventional grid-based modelling approaches. However, the potential extension of this method for simulating bulk level tissues has been a challenge due to the increased requirement for higher computaional time and resources. As a solution for this, by incorporating meshfree features, a novel coarse-grained multiscale numerical model is proposed in this work to predict bulk level (macroscale) deformations of food plant tissues during drying

Assessment of soil erosion hazard of Victoria catchment area using GIS as a tool

Victoria reservoir is located at an elevation of340 m to 440 m with a geographical position of7° 15'to T" 19' Nand 800 39' to 800 48' E which has been constructed by damming the River Mahaweli atVictoria fall. in Sri Lanka in 1983. The reservoir storage capacity is 72 1.2 MCM and upstream damsite comprises 1338 km2 in the districts of Kandy, Nuwara-Eliya and Matale. The elevation of thecatchment ranges from 340 m to 2 I00 m.Soil erosion is a major water quality issue in the upland reservoirs. The objective of this paper is toanalyze catchment issues contributing to soil erosion in the Victoria reservoir and to evaluate the soilerosion risk areas in the catchment. Study was carried out from 2002 to 2004.Soil erosion occurs due to natural causes such as rain fall, rainfall runoff and wind, and due to humanactivities. Universal Soil Loss Equation (A = RKLSCP) introduced by Wischmeier and Smith in1965 is a most widely used method for estimating soil erosion. This encounters detachment of soilparticles and its transport by raindrops and surface runoff, which depends on the rainfall erosivity (R),erodibility of soil (K), slope length factor (LS), cover and management factor (C) and the supportpractice factor of the equation.The data on erosivity points were interpolated with SO rn resolution grid cells. The erodibility valuerelevant to each soil group was entered into the attribute table, which was converted into grid cellswith 50 III resolution, containing soil erodibility values. The Triangulated Irregular Network (TIN) wascreated by contour interpolating with 20 m interval, and grid cell was 50 m. Using TIN, slopepercentages map was derived, which was used to obtain LS factor. The C factor values relevant toeach landuse type were entered into the attribute table. The map was converted into grid cells with SOm resolution, containing C factor valuesThe soil erosion of the Victoria catchment was categorized into five erosion categories, namely; low,moderate, high, very high and extremely high, which extend within Kandy, Nuwara-Eliya and Mataledistricts. All categories were spread both in the left and right banks.Extremely high erosion areas extend over 24.34km2 with a percentage of 1.82, Very high erosionareas extend oyer i21 24 km2 with a percentage of 9 06, High erosion areas extend over 302 91 km2 with a percentage of 22.63, Moderate erosion areas extend over 434.01 km2 with a percentage of32.43 and low erosion area extends over 454.97 km with a percentage of 33 .99. The results of mapanalysis were confirmed through field verifications. The soil erosion is high in the high slope regionsand in the areas where soil conservation methods are inadequate or poor.

Physio-chemical assessment of beauty leaf (Calophyllum inophyllum) as second-generation biodiesel feedstock

Recently, biodiesels from non-edible vegetable oil, known as second generation biodiesel, are receiving more attention because it can overcome food versus fuel crisis related to edible oils. The Beauty Leaf tree (Calophyllum Inophyllum) is a potential source of non-edible vegetable oil for producing future generation biodiesel because of its sustainability in a wide range of climate conditions, easy cultivation, high fruit production rate, and the high oil content in the seed. In this study, bio-oil was extracted from beauty leaf tree seeds through three different oil extraction methods. The important physical and chemical properties of produced beauty leaf oils were experimentally analysed and compared with commercial edible vegetable oils. Biodiesel was produced using a two-stage esterification process consisting of acid catalysed pre-esterification and alkali catalysed Transesterification. Fatty acid methyl ester (FAME) profile and physicochemical properties including kinematic viscosity, density, higher heating value and acid value were measured using laboratory standard testing equipment following internationally recognized testing procedures. Other fuel properties including oxidation stability, iodine value, cetane number, flash point, cold filter plugging point, cloud point and pour point temperature were estimated using Fatty acid methyl ester (FAME) of biodiesel. Physicochemical properties of beauty leaf oil biodiesels are described briefly and compared with recognised biodiesel standards and commercially available biodiesels produced from edible oil feedstock. Quality of produced biodiesel was assessed based 13 important chemical and physical properties through Preference Ranking Organisation Method for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GAIA) analysis. This study found that Mechanical extraction using the screw press can produce oil from correctly prepared product at a low cost, however overall this method is ineffective with relatively low oil yields. The study found that seed preparation has a significant impact on oil yields, especially in the mechanical oil extraction method. High temperature and pressure in extraction process increases the performance of oil extraction. On the contrary, this process increases the free fatty acid content in the oil. Clear difference was found in physical properties of beauty leaf oils that eventually affected the oil to biodiesel conversion process. However, beauty leaf oils methyl esters (biodiesel) were very consistent and able to meet almost all indicators of biodiesel standards. Furthermore, it showed as a better automobile fuel compared to most of the commercially available biodiesels produced from edible oil sources. Result of this study indicated that, Beauty Leaf oil seed is readily available feedstock to commence the commercial production of 2nd generation biodiesel. The findings of this study are expected to serve as the basis from which industrial scale biodiesel production from Beauty Leaf can be made

A 3-D meshfree numerical model to analyze cellular scale shrinkage of different categories of fruits and vegetables during drying

In order to optimize food drying operations, a good understanding on the related transport phenomena in food cellular structure is necessary. With that intention, a three-dimensional (3-D) numerical model was developed to better investigate the morphological changes and related solid and fluid dynamics of single parenchyma cells of apple, carrot and grape during drying. This numerical model was developed by coupling a meshfree particle based method:Smoothed Particle Hydrodynamics (SPH) with a Discrete Element Method (DEM). Compared to conventional grid-based numerical modelling techniques such as Finite Element Methods (FEM) and Finite Difference Methods (FDM), the proposed model can better simulate deformations and cellular shrinkage within a wide range of moisture content reduction. The model consists of two main components: cell fluid and cell wall. The cell fluid model is based on SPH and represents the cell protoplasm as a homogeneous Newtonian liquid. The cell wall model is based on a DEM and approximates the cell wall to an incompressible Neo-Hookean solid material. A series of simulations were conducted to mimic the gradual shrinkage during drying as a function of moisture content

Optimisation of bio-oil extraction process from Beauty Leaf (Calophyllum inophyllum) oil seed as a second generation biodiesel source

The Beauty Leaf tree (Calophyllum inophyllum) is a potential source of non-edible vegetable oil for producing future generation biodiesel because of its ability to grow in a wide range of climate conditions, easy cultivation, high fruit production rate, and the high oil content in the seed. This plant naturally occurs in the coastal areas of Queensland and the Northern Territory in Australia, and is also widespread in south-east Asia, India and Sri Lanka. Although Beauty Leaf is traditionally used as a source of timber and orientation plant, its potential as a source of second generation biodiesel is yet to be exploited. In this study, the extraction process from the Beauty Leaf oil seed has been optimised in terms of seed preparation, moisture content and oil extraction methods. The two methods that have been considered to extract oil from the seed kernel are mechanical oil extraction using an electric powered screw press, and chemical oil extraction using nhexane as an oil solvent. The study found that seed preparation has a significant impact on oil yields, especially in the screw press extraction method. Kernels prepared to 15% moisture content provided the highest oil yields for both extraction methods. Mechanical extraction using the screw press can produce oil from correctly prepared product at a low cost, however overall this method is ineffective with relatively low oil yields. Chemical extraction was found to be a very effective method for oil extraction for its consistence performance and high oil yield, but cost of production was relatively higher due to the high cost of solvent. However, a solvent recycle system can be implemented to reduce the production cost of Beauty Leaf biodiesel. The findings of this study are expected to serve as the basis from which industrial scale biodiesel production from Beauty Leaf can be made