Strength properties of glass fibre concrete

Chandramouli K, Srinivasa Rao P, Seshadri Sekhar T, Pannirselvam N and Sravana P

The present day world is witnessing the construction of very challenging and difficult civil engineering structures. Quite often, concrete being the most important and widely used material is called upon to possess very high strength and sufficient workability properties. Efforts are being made in the field of concrete technology to develop such concretes with special characteristics. Researchers all over the world are attempting to develop high performance concretes by using fibres and other admixtures in concrete up to certain proportions. In the view of the global sustainable developments, it is imperative that fibres like glass, carbon, polypropylene and aramid fibres provide improvements in tensile strength, fatigue characteristics, durability, shrinkage characteristics, impact, cavitation, erosion resistance and serviceability of concrete. Fibres impart energy absorption, toughness and impact resistance properties to fibre reinforced concrete material and these characteristics in turn improve the fracture and fatigue properties of fibre reinforce concrete research in glass fibre reinforced concrete resulted in the development of an alkali resistance fibres high dispersion that improved long term durability This system was named alkali resistance glass fibre reinforced concrete. In the present experimental investigation the alkali resistance glass fibres has been used to study the effect on compressive strength, split tensile strength and flexural strength on M20, M30, M40 and M50 grades of concrete.

Investigations on sawdust and palm kernel shells as aggregate replacement

F. A. Olutoge

The high and rising costs of building construction in developing countries have been a source of concern to government and private developers. This study investigated the use of saw dust and palm kernel shells (PKS) as replacement for fine and coarse aggregates in reinforced concrete slabs. Reinforced concrete slabs measuring 800 x 300 x 75mm were cast. Sawdust and PKS were used to replace both fine and coarse aggregates from 0% to 100% in steps of 25%. Flexural strengths were evaluated at 7, 14 and 28 days and compressive strengths were evaluated at 28 days. Increase in percentage of sawdust or palm kernel shells in concrete slabs led to a corresponding reduction in both flexural and compressive strength values.  It is seen that at a low replacement value of 25% sawdust and PKS can produce lightweight reinforced concrete slabs which could be used where low stress is required at reduced cost. A weight reduction of 14.5% and 17.9% was achieved for sawdust and PKS replacement slabs respectively. It is also seen that the reduction in cost up to 7.43% can be achieved for every cubic meter of slab production with use of sawdust or palm kernel shell.

Performance of mustard and neem oil blends with diesel fuel in C.I. engine

K. Anbumani and Ajit Pal Singh

To study the feasibility of using two edible plant oils mustard (Brassica nigra, Family: Cruciferae) and neem (Azadirachta indica, Family: Meliaceae) as diesel substitute a comparative study on their combustion characteristics on a C.I. engine were made. Oils were esterified (butyl esters) before blending with pure diesel in the ratio of 10:90, 15:85, 20:80, and 25:75 by volume. Pure diesel was used as control. Studies have revealed that on blending vegetable oils with diesel a remarkable improvement in their physical and chemical properties was observed. Cetane number came to be very close to pure diesel. Engine (C.I.) was run at different loads (0, 4, 8, 12, 16, and 20 kg) at a constant speed (1500 rpm) separately on each blend and also on pure diesel. Results have indicated that engine run at 20% blend of oils showed a closer performance to pure diesel. However, mustard oil at 20% blend with diesel gave best performance as compared to neem oil blends in terms of low smoke intensity, emission of HC and NO_x. All the parameters tested viz., total fuel consumption, specific energy consumption; specific fuel consumption, brake thermal efficiency and cylindrical peak pressure were improved. These studies have revealed that both the oils at 20% blend with diesel can be used as a diesel substitute.  Further, esterified mustard oil at 20% blend satisfies the important fuel properties as per ASTM specifications of biodiesel as it lead to an improvement in engine performance and emission characteristics without bringing any modifications in the engine.

A theme on web marketing through web traffic

Nanhay Singh, R. K. Chauhan, Raghuraj Singh, Navin Kumar Tyagi, A.K. Solanki and Deepak Kumar Swain

In business, web traffic analysis plays a greater role and it is relatively a new market segment. With the development of World Wide Web (WWW), companies are beginning to get more sophisticated about how they use their web sites and want to know how to increase their return on investment (ROI). This paper reviews the business trends with web traffic analysis and presents marketing research about what is most important to companies and businessman in this segment and proposes to study the different parts that a global web-marketing approach uses and will also focus on the structure that can be deployed to support web marketing. Web-marketing is a multipart work, and it must always be linked to real world marketing. The days of building a web site to simply tell people about your business are over. Now, among plenty other features, you need user interaction by allowing them to access reports, communicate directly and purchase products. You need to be on time with your services and up-to-date with your information in relation to the marketplace. With true eBusiness; it is business requirements, rather than technical elegance, that drive the specification of the web site. Web sites become increasingly personalized to the constituents they are trying to support, namely, customers, investors, and employees. Web mining enables new understanding of user goals on the web. This understanding has broad applications and traditional mining techniques such as association rules have been used in business applications.Web marketing is the process of growing and promoting an organization using online media. Web marketing does not simply mean building a website or promoting a website. Somewhere behind that website is a real organization with real goals.

Application of fuzzy and PSO for DG placement for minimum loss in radial distribution system

M. Padma Lalitha, V. C. Veera Reddy and V. Usha

Abstract:

This paper presents a new methodology using fuzzy and Particle Swarm Optimization (PSO) for the placement of Distributed Generators (DG) in the radial distribution systems to reduce the real power losses and to improve the voltage profile. A two-stage methodology is used for the optimal DG placement. In the first stage, fuzzy approach is used to find the optimal DG locations and in the second stage, PSO is used to find the size of the DGs corresponding to maximum loss reduction. The proposed method is tested on standard IEEE 33 bus test system and the results are presented and compared with an existing method.

Model studies of the interaction of base-metal containing minerals with some biological alteration compounds in ore-bodied environment

Inegbenebor Adedayo and Oginni Felix A.

Abstract:

Studies dealing with the complex behaviors of some N-benzoyl and N-formyl amino acids, and dipeptides with base-metal containing compounds were carried out. The results indicate that coordination sites of N-protected amino acids and dipeptides are different from those of the free amino acids and peptides. Complexes of Zn (II) with N-benzoyl derivatives of L-leucine, L-leucylglycine and N-formyl derivatives of DL-valine, L-phenylalanine, DL-valylglycine and L-phenylalanylglycine were prepared in the course of the studies. The possible stereochemistry of these compounds have been deduced with the help of analytical data, infrared spectra (IR), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). 

Developing a new combined structural roofing system of domes and vaults supported by cementitious straw bricks

Gihan L. K. Garas, Hala G. El Kady and Ayman H. El Alfy

The primary objective of this research was to develop a structural technique for roofing rice straw buildings by domes and vaults through encouraging the specification of innovative materials which may be more sustainable than their traditional counterparts. This paper examines the effectiveness of using rice straw cementitious posts and walls as an innovative natural construction method to support domes and vaults in straw bale buildings. Three proposed mix ratios for rice straw cementitious bricks were mechanically tested.  A finite elements analysis of the proposed roofing system was performed, to check the safety of the roofing material, and their resultant reactions on the rice straw bricks support. Different cases of loading were applied including wind and settlement. Obtained results helped in the decision making of the most economical and environmental friendly brick mix. Besides, the results emphasized that all stresses were within acceptable limits of the Egyptian code of practice.

Measurement and estimation of very fast radiated electromagnetic fields in a 245kv gas insulated substation

J. V. G. Rama Rao, J. Amarnath and S. Kamakshaiah

Abstract:

The transient high frequency electric and magnetic fields are generated in GIS systems during switching operations. In the present work, the measurement of magnetic fields and electric fields have been carried out at various locations of 245KV GIS (Gas insulated substation) during closing operation of disconnector switch 1(DS1) is considered. The results of measured values are compared with the estimated values. The results shows that transient electric and magnetic field  values are correlate with the measured values at bus link, near current transformer (CT) and at cable termination , the calculated values are slightly deviated from the measured values when moves along with XLPE cable. This may be due to a fast attenuation rate of electromagnetic fields with distance away from the DS1. The frequency spectrum of the time varying electric field and magnetic fields at various locations are also estimated. The magnetic field at CT is exceeding standard value during transient period, which is observed in both calculated and measured cases this may leads to malfunctioning of the secondary equipment connected to CT. The above results gives a basic idea of modeling of GIS systems for the estimation of high frequency  electric and magnetic fields and also helps in preparing electromagnetic chart  for the particular GIS system. These results are also use full in order to prepare some precautionary protection measures to avoid malfunctioning of secondary equipment and metering equipment in a GIS systems.

New parallel binary image thinning algorithm

A. Jagan and V. Kamakshiprasad

Abstract:

This paper describes new parallel thinning algorithm for binary images. The use of 3X3 mask for pixel deletability in parallel and pixel deletion criteria needed to preserve the connectivity of the image pattern is exclusively discussed. This algorithm preserves the connectivity of an input image. The experimental result shows the better performance in terms of thinning and excessive erosion. 

Improvement in direct torque control of induction motor using fuzzy logic duty ratio controller

Y. Srinivasa Kishore Babu and G. Tulasi Ram Das

Abstract:

This paper shows the application of fuzzy logic based duty ratio control technique to reduce torque ripple in an induction motor employing Direct Torque Control (DTC). This technique increases the number of voltage vectors beyond the available eight discrete voltage vectors without any increase in the number of semiconductor switches in the inverter. Look-up Table based on-line tuning PI controller is proposed for outer speed control loop to achieve swift response, less overshooting and precision speed control to have wide torque-speed characteristics. A new algorithm for optimized value of stator flux based on the maximum reference value of electromagnetic torque is proposed to operate in conjunction with duty ratio control. The performance of the proposed drive system is evaluated through digital simulation using MATLAB-SIMULINK package. The simulation results clearly depict the superiority of devised method over the existing methods of DTC.

Simulation of progressive failure prediction of filament wound composite tubes subjected to multiple loading with membrane-flexion coupling effects

Umar Farooq and Karl Gregory

Abstract:

This study deals with the computational modeling of ply by ply failure prediction of filament wound composite tubes under internal burst pressure and external compressive loads with consideration to bending shear. Plates and beams resist transverse load through flexural bending while pressure vessels, pipes, domes, caps and shell like structural composite elements react to the load through membrane forces. Bending stresses are usually neglected in studying behaviour of such elements despite the fact that the bending stresses affect damage modes. Standard failure criteria do not exist for the fibre reinforced composite structural elements hence failure predictions are somewhat unreliable. To consider the flexural shear stresses, methodology of comparative approach involving comparison of failure predictions was adopted. Failure predictions from Tsai-Hill and Tsai-Wu criteria were complemented herein with comparison from Hashin’s criteria, which utilize such bending stresses. Interaction of the internal pressure and compressive loads were incorporated into the commercially available finite element analysis software ‘ABAQUS^TM. To evaluate the effect of loads on deformation and induced changes in tubes, the framework of analysis based on the finite element method provides an exciting capability for analyzing the effects of laminates’ lay-up, complicated interaction between the formation of multiple matrix-cracks and de-lamination, orientation and shear effects. Simulation model was developed to use the built-in failure prediction facility of the Hashin criteria. Simple steps were carried out using equations of the other failure criteria to calculate and compare strength parameters for failure predictions. The generated results correlated well and have improved the confidence of accuracy. Simulations can be repeated and extended for similar models subjected to multiple loading. One set of the results consisting of eight un-symmetric plies was selected for presentation herein in the form of legend Tables, graphs and contour plots. The study indicates that the approach is useful to predict reliable failure predictions and design improvements for composite wound tubes.

Fuzzy logic based HPWM-MRAS speed observer for sensorless control of induction motor drive

Haseeb Khan and J. Amarnath

Abstract:

The main aim of this paper is to present hybrid space vector pulse width modulation (HPWM) based model reference adaptive system (MRAS) speed observer for sensorless control of induction motor drive. The proposed method is designed by using the notion of stator flux ripple and the switching times are calculated by utilizing the concept of imaginary switching times that uses the instantaneous values of the reference voltage of the three phases. By using this method ripples present in the torque can be minimized and also the speed performance can be improved in the way that the error between the adaptive model speed and the reference model speed is made as low as possible so that the estimated speed is made as nearly equal as the speed of the reference model. Also in this paper the conventionally used PI controller in the adaptation mechanism of the MRAS observer is replaced by a fuzzy logic controller (FLC). In conventionally used PI controller when the reference speed or the load changes the control parameters are to be changed manually but when a FLC is used in place of PI controller this is not necessarily required. The fuzzy logic is also helpful in keeping the speed relatively constant during the load variations which can be seen from the simulation results. The simulations of the proposed method are performed and the results are presented to validate the proposed method.