474 research outputs found
ENHANCEMENT OF ELECTRICAL CONDUCTIVITY IN POLYVINYL ALCOHOL FILMS BY DOPING WITH Nd3+ IONS
The electrical properties of polyvinyl alcohol (PVA) films have been improved pronouncedly by doping with Neodymium (III) nitrate hexahydrate. Pure PVA and PVA: Nd3+ films have been prepared by solution casting method. Both type of films were characterized by X-ray diffraction technique for structural studies. XRD pattern shows the appreciable shift of 2Ө towards higher value with increase in Nd3+ concentration. This signifies the presence Nd3+ dopant in polymer matrix. Further direct current electrical conductivity (σ) of Nd3+ doped PVA films in the temperature range 500C-1600C has been studied using four probe techniques. For a given concentration σ increases with increase in temperature and with dopant concentration. At 1200C, conductivity of PVA: Nd3+ (10 mol %) film is 7.116 μΩ -1 cm-1 , PVA: Nd3+ (15 mol %) film is 11.176 μΩ-1 cm-1 , PVA: Nd3+ (20 mol %) film is 17.418 μΩ-1 cm-1 and PVA: Nd3+ (25 mol %) film is 23.740 μΩ -1 cm-1 . This result indicated the enhancement of the electrical conductivity of PVA films with Nd3+ concentration
Cognitive Radio Relay Network Performance Analysis by using Game Theory
Cognitive radio plays a vital role in wireless communication system. The cognitive radio consists of a transceiver which is used to check the availability of channel for communication and avoids busy channels by shifting into a unused channel. The scope for spectrum availability and area of coverage is increased by using cognitive radio. In cooperative cognitive relay network the primary traffic the primary users (PUs) will nominate some of the secondary users (SUs) as a relay. To make the secondary users co-operate with the primary user, primary user have to allocate some channel to the secondary user for data transmission. This significantly reduces the performance of the primary users and secondary users. Therefore, performance can be significantly increased by using MIMO in co-operative cognitive radio. By using beam forming technique in spatial domain over the multiple inputs multiple output antenna permits multiple data streams and suppression of interference. Using Nash Equilibrium (NE) to control the power among SUs, the PUs utilities and SUs utilities are obtained in MIMO-CCRN. By using MIMO technique the secondary users can co-operatively relay the data for the primary users while concurrently accessing the same channel to transmit its data. Time domain and spatial domains are examined to improve the efficiency of the spectrum for arranging the MIMO co-operative cognitive radio networks.
DOI: 10.17762/ijritcc2321-8169.16043
Application of Soft Computing for the Prediction of Warpage of Plastic Injection
This paper deals with the development of accurate warpage prediction model for plastic injection molded parts using softcomputing tools namely, artificial neural networks and support vector machines. For training, validating and testing of thewarpage model, a number of MoldFlow (FE) analyses have been carried out using Taguchi’s orthogonal array in the designof experimental technique by considering the process parameters such as mold temperature, melt temperature, packing pressure,packing time and cooling time. The warpage values were found by analyses which were done by MoldFlow PlasticInsight (MPI) 5.0 software. The artificial neural network model and support vector machine regression model have beendeveloped using conjugate gradient learning algorithm and ANOVA kernel function respectively. The adequacy of the developedmodels is verified by using coefficient of determination. To judge the ability and efficiency of the models to predictthe warpage values absolute relative error has been used. The finite element results show, artificial neural network modelpredicts with high accuracy compared with support vector machine model
Influence of process parameters on physical dimensions of AA6063 aluminium alloy coating on mild steel in friction surfacing
AbstractAn attempt is made in the present study to obtain the relationships among process parameters and physical dimensions of AA6063 aluminium alloy coating on IS2062 mild steel obtained through friction surfacing and their impact on strength and ductility of the coating. Factorial experimental design technique was used to investigate and select the parameter combination to achieve a coating with adequate strength and ductility. Spindle speed, axial force and table traverse speed were observed to be the most significant factors on physical dimensions. It was observed that the thickness of the coating decreased as the coating width increased. In addition, the width and thickness of the coatings are higher at low and high torques. At intermediate torque values, when the force is high, the width of the coating is high, and its thickness is thin; and when the force is low, the width and thickness are low. The interaction effect between axial force (F) – table traverse speed (Vx) and spindle speed (N) – table traverse speed (Vx) produced an increasing effect on coating width and thickness, but other interactions exhibited decreasing influence. It has also been observed that sound coatings could be obtained in a narrow set of parameter range as the substrate-coating materials are metallurgically incompatible and have a propensity to form brittle intermetallics
Synthesis of single crystalline (NH4)2V6O16·1.5H2O nest-like structures
Novel nest-like (NH4)2V6O16·1.5H2O structures made of nanobelts have been synthesized by a facile hydrothermal approach. The powder X-ray diffraction pattern of the sample reveals the monoclinic crystalline phase of (NH4)2V6O16·1.5H2O. The scanning electron microscopy images of the sample obtained at 130 °C for 3 days exhibit nest-like morphology. The transmission electron microscopy result reveals that the nanobelts have a smooth surface. The selected area electron diffraction pattern of the nanobelts indicates single crystalline nature. The two major weight losses occur in thermogravimetric analysis which correspond to the removal of water and ammonia molecules. Further, calcination of the (NH4)2V6O16·1.5H2O product results in the formation of orthorhombic phase of shcherbianite V2O5
Interaction of Oleate Molecules on Sillimanite and Garnet minerals.
Adsorption of oleate on sillimanite and garnet was studied using electrokinetic measurements. Both the systems exhibit a characteristic shift in iep by increasing the concentration of oleate in solution. This shift in iep has been quantified in terms of specific interaction between the surface sites and oleate molecules. The shift in iep was estimated separately for both the systems using the equation derived on the basis of electrical double layer theory. The specific free energy of adsorption was
estimated to be 7.94 kcal/mole for sillimanite-oleate system and 7.49 kcal/mole for gamet-oleate system
Preemptive Routing & Intrusion Detection for MANETs
An ad-hoc network will often change rapidly in topology, this courses for routes in the network to often disappear and new to arise. The Ad-hoc On-Demand Distance Vector Routing Protocol(AODV), is based on the principle of discover routes as needed. In this paper we will extend the definition of AODV with the ability to discover multiple routes to a host and switch between them, if an active route is becoming weak and there is a risk that it will disappear. We will refer to it as pre-emptive AOMDV . We will show that the performance of pre-emptive AOMDV do handle changes in topology better than AODV it self. To show the effect of extending AODV, the suggested protocol is implemented in a simulator. Performance enhancements will be presented from different scenarios, to compare pre-emptive AOMDV with the ordinary AODV. In this paper we also focus on intrusion detection based on Finite State Machine and cache memory in ad hoc networks. Security is one of the most important issues in current networks. The most common cases of attacks in mobile Ad hoc networks can be drop of routing packets and changes in the incoming packets which aims at disrupting the network routing and overall network reduce performance. The presented approach based on FSM focuses at recognizing the malicious nodes within the network in a fast and accurate way, then it deals with rapid introduction of the malicious nodes to other nodes in the network to prevent sending multiple packets and drop and packet change. Finally, we will show the significant improvement in comparison with others, we simulated our methods by NS2 software
Formulation And Evaluation Of Mouth Dissolving Tablets Of Amoxapine
The objective of the present study is to design and formulate orodispersible tablets of Amoxapine using novel Co-processed superdisintegrants by employing direct compression method. Amoxapine is used to treat symptoms of depression. Amoxapine is a class II drug with high permeability and low solubility. There is a need to develop a formulation of Amoxapine that will enhance the bioavailability of the drug by decreasing the disintegration time. Thus improves patient compliance generate rapid response enhances bioavailability and also reduces dose of drug. In this study ODTs are prepared by direct compression method using novel super disintigrants in different proportions .The powder blend is subjected to pre compression parameters including bulk density, true density, tapped density, cars index, Hausner’s ratio and angle of repose. The formulations are evaluated for weight variation, hardness, wetting time, water absorption test, disintegration time and in vitro dissolution studies and all formulations complies its Pharmacopoeial standards. The tablets are evaluated and the results compared for all four super disintigrants revealed cross povidone to be the most efficious super disintigrants to formulate mouth dissolving tablets of Naproxen sodium as suggested by the dispersion time , disintegration time and drug dissolution profile
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