Biodiesel development from high free fatty acid Punnakka oil

Ramaraju A. and Ashok Kumar T. V.

Punnakka oil, non-edible oil available in India, was esterified to produce biodiesel. The procedure involves a two stage process, acid esterification and alkaline esterification. The oil contains high free fatty acid (FFA) content of 19.8%. The acid value of the oil was reduced by acid esterification. The product from this stage was subjected to alkaline esterification to produce biodiesel. The effects of important parameters like methanol to oil ratio, reaction temperature, catalyst concentration and reaction time were studied and optimum conditions were established. A conversion efficiency of 92.5% was obtained with the optimized reaction conditions. The viscosity and other measured properties are within the range specified by biodiesel standards and are close to the properties of petroleum diesel.

Preliminary study on the physical and mechanical properties of tapioca starch / sugarcane fiber cellulose (TS/SCFC) composite

A. R. Jeefferie, O. Nurul Fariha, A. R. Mohd Warikh, M. Y. Yuhazri, Haeryip Sihombing and J. Ramli

This study is to investigate the potential application of Tapioca Starch (TS) and Sugar Cane Fiber Cellulose (SCFC) as a green composite for disposable packaging food container. The experiment is started by preparing and characterizing the SCFC through various characterization tools whereby the effect of various SCFC loading to the fabricated TS composites was then studied to find the best formulation for TS/SCFC composites. Various engineering properties of TS/SCFC composites for testing were carried out to determine the mechanical and physical properties, beside the fracture morphology by using the optical microscope. Through the morphological observation on the mechanical and physical testing fractured surfaces, it had significantly indicates that the role of fiber loading into resulted properties of produced composites. Although the results have shown good performance of composites for both mechanical and physical properties, but the adhesion between SCFC and TS matrix were not well attached. Anyhow, the development of this material for food packaging application will provide great potential solution to the environmental friendly and safe packaging medium, either for food, consumer or environment as a whole.

Improving bandwidth rectangular patch antenna using different thickness of dielectric substrate

Ali A. Dheyab Al-Sajee and Karim A. Hamad

Microstrip patch antenna has some drawbacks of low efficiency, narrow band (<5%), and surface wave losses. In this paper the solution method was used different thickness of dielectric substrate (h= 4, 6 and 8) mm to increase bandwidth, the simulated results for rectangular give bandwidth of (200 MHZ) in case (h=6mm).A rectangular micro strip patch antenna that meets the requirement of operation at (2.4 GHZ), the proposed configurations are simulated and analyzed using microwave office 2000 software package. The VSWR, input impedance, radiation patterns and S11 performance are used for the analysis of the different configurations. Feed point on the patch that gives a good match of 50 ohm, input impedance was found by a method of trial and error.

Production and refining of corn oil from hominy feed: A by-product of dehulling operation

M. Abdulkadir and G. I. Abubakar

The focus of this work is to produce and refine corn oil from the by-product of the local dehulling/degermination of corn with soxhlet apparatus using n-hexane as solvent. The extraction was done for duration of three and six hours using 12g each of unsieved sample and various fractions of the sample. Average oil yield were 14.28% and 14.50% for extraction time of three and six hours respectively. The extracted crude oil was refined to improve its quality by degumming, alkali refining and decolourization. Both the crude and refined corn oil was analyzed to determine some of their properties and subsequently, the results were compared with standard values. There were indications that the oil yield of the sample can be improved upon for it to serve as raw material for the production of corn oil.

Heat transfer in a rectangular enclosure with baffles

M. R. Asif, M. S. Hossain and K. A. Hossain

Abstract:

A numerical study has been carried out to investigate the mixed convective two dimensional flows in a vertical enclosure with heated baffles on side walls. All walls are assumed to be adiabatic, but baffles are considered as isothermally heated. Thus, cold flow is imposed through an opening at the bottom of the left wall and by taking heat from the baffles the fluid becomes heated and exits through outlet at the top of the right wall of the enclosure. Heated baffles are placed both at the left and right wall of the enclosure. The present study simulates a practical system such as a silencer. The consequent mathematical model is governed by the coupled equations of mass, momentum and energy and these equations are discritized. The discritized equations with specified boundary conditions are sought by Successive under Relaxation (SUR) method. A wide range of pertinent parameters such as Reynolds number 50 ≤ Re ≤ 300, Richardson number 0 ≤ Ri ≤ 10 and Prandtl number 0.01 ≤ Pr ≤ 2.0 are considered in the present study. Various results such as the streamlines, isotherms, heat transfer rates in terms of the average Nusselt number and temperature and also heating efficiency in the enclosure are presented for different parameters. It is observed that Maximum heating efficiency is found at higher value of Reynolds and Richardson number.

A mathematical model of four species syn-ecosymbiosis comprising of prey-predation, mutualism and commensalisms-I (Fully washed out state)

R. Srilatha, B. Ravindra Reddy and N. Ch. Pattabhiramacharyulu

Abstract:

This investigation deals with a mathematical model of a four species (S_1, S_2, S₃ and S₄) Syn-Ecological system (Fully Washed out State). S₂ is a predator surviving on the prey S₁: the prey is a commensal to the host S₃ which itself is in mutualism with the fourth species S₄. S₂ and S₄ are neutral. The mathematical model equations characterizing the syn-ecosystem constitute a set of four first order non-linear coupled differential equations. There are in all sixteen equilibrium points. Criteria for the asymptotic stability of one of the sixteen equilibrium points: the fully washed out state is established. The linearised equations for the perturbations over the equilibrium point are analyzed to establish the criteria for stability. The system is noticed to be locally stable. Trajectories of the perturbations have been illustrated.

Resonant frequency variation of rectangular patch antenna due to accumulation of water over its surface

Rajeev R. Wakodkar, Samik Chakraborty and Bhaskar Gupta

Micro strip or patch antennas are at the forefront of modern wireless communication revolution of the recent times. This paper investigates and proposes empirical expressions and neural network model for resonant frequency variation of rectangular patch antenna - such as one mounted flush with rooftop of a vehicle - due to accumulation of water over its surface in rainy condition. The effect is investigated for several frequency bands of interest of modern wireless communication. Empirical expressions for the change in operating frequency with respect to accumulated water layer thickness are presented for rectangular patch antennas without radome and with radome (which is flush with patch surface) of various thicknesses. Finally, an Artificial Neural Network (ANN) is proposed as generalized model and better alternative for empirical expressions.

A review of friction stir welding of AA 6061 aluminium alloy

N. Bhanodaya Kiran Babu, A. Prabhu Kumar and M. Joseph Davidson

Abstract:

This paper discuss about the friction stir welding of joining heat treatable aluminium alloys for aerospace and automobile industries. These welded joints have higher tensile strength to weight ratio and finer microsturcture. FSW of aluminium alloys have the potential to hold good mechanical and metallurgical properties. The aim of this study was to investigate the effect of process parameters on the tensile strength of the welded joints.

Stress and load-displacement analysis of fiber-reinforced composite laminates with a circular hole under compressive load

Manoharan R. and Jeevanantham A. K.

Abstract:

This paper is focused on the analysis of stress-strain and displacement for compressive load on the fibre-reinforced composite laminates. Three different orientations of fibers are analyzed with and without the circular cut-outs. Also different dimensions of circular cut-outs are applied on the laminates at different compressive loading conditions. This analysis is carried out using the finite element software ANSYS. From the result, it is identified that cross-ply composite laminates posses the highest strength as compared to other types of angle orientations. Also it is concluded that the maximum load bearing capacity decreases as the cut-out size increases.

Design, fabrication and performance analysis of a planetary roll mill for fine grinding

Ajaka E. O. and Akinbinu V. A.

Abstract:

Reducing milling cost in mineral processing is a problem that has defiled all serious attempts while milling still takes up to 60% of comminution cost. The planetary roll mill is a new innovation for faster and finer grinding. It is designed and fabricated with grinding rolls rotating in a number of arms inside a grinding sphere. A test run of the complete machine with crushed granite and sandstone shows that the machine grinds to fine consistency within a short period of time. A comparison of the products of the machine with that of a standard Denver Laboratory Ball Mill shows that the machine is about 30% more efficient than the ball mill in terms of duration of grinding to a particular size consistency. One advantage of the planetary roll mill is that is can be used as a ball mill if the need arises. It is therefore recommended that this mill be developed for both research and industrial uses.

Bi-conical linear array analysis for non uniform amplitude excitation methods

C. Subba Rao and A. Sudhakar

Abstract:

Five element linear biconical array is proposed in this paper. The response of the array for standard non uniform amplitude excitations such as binomial and Dolph chebyscheff distributions are considered. Variation of radiation patterns in horizontal, vertical plane, Gain, beam width, side lobe levels and Directivity are critically investigated. Behavior of Impedance, scattering parameters of the biconical dipole with frequency in array operation are elucidated. The response of the array and levels of various parameters for binomial and Dolph chebyscheff amplitude excitations are critically compared and contrasted. Plots for various parameters are presented. Simple techniques for controlling side lobe levels and beam width of linear biconical dipole array are introduced.

Planar inverted-F antenna on liquid crystal polymer substrate for PCS, UMTS and WIBRO applications

B. T. P. Madhav, VGKM Pisipati, N. V. K Ramesh, Habibulla Khan and P. V. Datta Prasad

Abstract:

In recent years, the demand for compact handheld communication devices has grown significantly. Devices having internal antennas have appeared to fill this need. Antenna size is a major factor that limits device miniaturization. In the past few years, new designs based on the microstrip antennas (MSA) and planar inverted-F antennas have been used for handheld wireless devices because these antennas have low-profile geometry and can be embedded into the devices. This paper presents a planar inverted F antenna on liquid crystal polymer substrate for PCS, UMTS and WIBRO applications. The proposed model is designed and simulated using Ansoft-HFSS. Return loss, input impedance smith chart, 3D-gain; 2D-gain, gain-phi, gain-theta, VSWR, E-field, H-field and Mesh generation are presented from the simulation results.

Effects of UV curing exposure time to the mechanical and physical properties of the epoxy and vinyl ester fiber glass laminates composites

J. Ramli and A. R. Jeefferie

Abstract:

Ultra-violet (UV) curing process is introduced in the curing of polymer matrix composites (PMC) for the application in producing bullet proof vest. Two types of adhesives or matrix materials were used: epoxy and vinyl ester. Each of them were mixed together with different types of photoinitiator; Bisacyl Phosphine Oxide (BaPO) and Alpha Hydroxyl Ketone Peroxide (AHK) at 1.0 per hundred of resin (phr) from the total proportion of the mixture. Sandwich construction of the PMC was done by hand lay-up process where the mixture was wiped on the fiber layers. Samples were then cured under various duration times which are 3, 6, 9 and 12 minutes to compare the overall quality of produced composites under the exposure of the UV light. The laminate was then tested to determine its characteristics of physical properties and its behavior to the applied loads. Morphological observation through Scanning Electron Microscope (SEM) was performed in order to evaluate the quality of adhesion between each fiber layer and matrix wetting behavior. Vinyl ester is not recommended to be used as the matrix since two days is required to make it fully cured unlike epoxy which was cured rapidly once exposed under UV light. On the other hand, the effect of curing time shows the optimum result for density was obtained at 12 minutes of curing time. Curing time between 6 to 9 minutes is found to be optimum for tensile strength value. Three minutes of curing under UV light exposure caused maximum value in penetration resistance or hardness for the resulted composite laminates.

Optimal dispatching in a periodically review in on-line manufacturing system with vendors evaluation

Dipak Ranjan Jana,  K. V. Santha Kumari and B. K. Singh

Abstract:

This paper, we consider dynamic dispatching control of a fully flexible online manufacturing system. Hence, vendors, who supply the materials, play an important role in this system. So, selection of vendors is much important. In a periodically reviewed, online manufacturing system where materials are dispatched from a central control station to different manufacturing sales. After production process, the parts are routed to inspection and quality control room. Hence optimal dispatching policies are pursued to minimize the in-process inventory carrying / holding cost over finite horizon. A dynamic programming formulation is developed for optimal dispatching which shows that the dynamic recursive functions (i.e. cost – to go – function) are convex and monotonic under the condition of low defects rates and relative low cost material handling. From the derivation we conclude that optimal dispatching sales for a combination of zero inventory and Non- zero inventory policies. Thus, the optimal input control is proved to be in the form a pulling system