Online Publishing @ NISCAIR
Not a member yet
6870 research outputs found
Sort by
Bandwidth Enhancement Technique of a Dual-Band Circularly Polarized Dielectric Resonator Antenna
Get PDFThis paper presents the rectangular aperture coupled dielectric resonator antenna with dual-band circularly polarized response. The antenna geometry have stair case shaped rectangular dielectric resonator in the form of main radiating element. The specific geometry provides increment of aspect ratio of the dielectric resonator. This allows merging of various resonant frequencies having higher order modes that result in the bandwidth enhancement. This antenna provides 18.63% and 7.68% of -10 dB S11-parameter bandwidth response in operating passbands, respectively. The specific geometry and the introduction of circular slots in ground plane results in the orthogonal modes excitation at the nearby resonant frequencies. Due to this, the circular polarization response at 7.76 and 8.33 GHz frequencies is achieved. The peak gain of 5.8 and 4.6 dBic is obtained in the respective lower and upper operating passbands. Through parametric analysis, tuning of antenna responseis also achieved. The proposed antenna with the optimized parameters may have potential applications in the microwave C- and X-band setups
Silver ferrite embellished graphene oxide heterogenous nanocomposite for efficient electrochemical detection of gallic acid
Get PDFFerrites have attracted the research community owing to their invincible properties corresponding to their magnetic recoverability, recycling efficacy, and environmentally friendly behaviour. They are gaining importance in catalysis, sensors, supercapacitors, batteries, magnetic tunnel ferrofluids, magnetic drug delivery, and information storage. By taking advantage of ferrites, in this study, we have developed a silver ferrite embellished graphene oxide (AgFe2O4/GO) nanocomposite by decorating AgFe2O4 on graphene oxide (GO) by a viable route. The crystal structure, size, morphology, and magnetic behaviour of the fabricated nanocomposites have been investigated with the assistance of fourier transform infrared (FTIR) spectroscopy, RAMAN spectroscopy, X-ray diffraction, and scanning electron microscopic (SEM) techniques. The composite has been examined for the electrocatalytic determination of gallic acid (GA) by cyclic voltammetry and differential pulse voltammetry by its modification of glassy carbon electrode. This modified glassy carbon electrode has shown excellent electrocatalytic behaviour toward the detection of GA. These results can be used as an electrochemical standard in the estimation of total polyphenol content in the foodstuffs and extended to pharmaceutical and industrial applications
Antioxidant activity of sesame oil on oxidative stability of olive oil
Get PDFIn this study, the effects of blending sesame oil with olive oil at different concentrations (5%, 15% and 25%) and storing the oil blend at 60C for 30 days in relation to the physicochemical properties and fatty acid composition were determined. Peroxide value, free fatty acid, p-anisidine, K232 and K270 values were analyzed on the 15th and 30th days in olive oil as well as sesame/olive oil blend. After 15 days of storage, the lowest peroxide value (3.73 meq O2/kg) was obtained in olive oil containing 5% sesame oil, while olive oil containing 25% sesame oil has lowest peroxide value of 4.95 meq O2/kg after 30 days of storage. The lowest free fatty acid values were found in olive oils, with the values of 1.45% for 15th day and 1.67% for 30th day. The result revealed that peroxide and p-anisidine values increased, while the free fatty acid and ultraviolet absorption at 232 and 270 nm decreased during storage at 60C. Minimum free fatty acid (1.45%) was found in olive oil stored for 15 days, while the K values were in the range (0.01-0.02) following analysis on 30th day. This study revealed that addition of sesame oil to olive oil improved the antioxidative property of oil blends
Influence of process parameters on mechanical and microstructural property of dissimilar friction stir welded joints of armor aluminium alloys AA7039 and AA5083
Get PDFFriction stir welding (FSW) is an innovative, green and energy-efficient solid-state welding process. Which has been resolved the problems of defects related to microstructure and mechanical properties of welding joints of soft materials. FSW is also capable to join dissimilar materials of different melting points together with adequate efficiency and effectiveness. Present research work is an attempt to join the two dissimilar armor grad aluminium alloys i.e. AA7039 and AA5083 by FSW. Both materials are utilized as armor materials in defence. The process parameters such as tool rotation speed (RS), welding speed (WS) and tool tilt angle (TA) were utilized for variation at different five levels for experimentation. The experiments were designed by center composite design (CCD) of response surface methodology (RSM). The fabricated joints were examined for the variation in mechanical properties such as ultimate tensile strength (UTS), yield tensile strength (YTS) and percentage elongation (EL). Effects of the inputs parameters on the variation of the responses were validated by analysis of variance (ANOVA). The obtained results of aforesaid properties were utilized for the optimization of input parameters in the desirability approach. The desirability approach revealed that 1440 RPM of tool rotation, 32.1 welding speed and 2.4 tilt angle as an optimized set of parameters, which can fabricate the joint with 263.02 MPa UTS, 211.90 MPa YTS and 14.7% EL. The results of ANOVA and optimization were also verified by a change in the microstructure of FSWed joints
Production and Characterisation of Biodiesel with the mixture of Ambadi oil and Waste Cooking Oil
Get PDFWith the continuous global reduction of energy supplies and severe concern over environmental degradation with the use of fossil fuel, biodiesel will play a crucial transponder in these problems. Biodiesel blend with diesel fuel achieves a decreased environmental impact without losing quality of performance and use. There is interest in alternative fuels owing to volatile fossil fuel markets and degradation. New and alternative oil crops must be pursued to expand the horizon of plant-based fuels to satisfy the needs of energy demand. The purpose of this research was to compare the properties of ambadi seed oil biodiesel, waste cooking oil (WCO) biodiesel, and biodiesel of WCO ambadi seed oil mixer. The results of the study indicate that biodiesel with the introduction of WCO in Ambadi seed oil improves the physiochemical properties calorific value, flash point, and fire point. The blending of WCO limited upto AW50 due to increase in density and kinematic viscosity of biodiesel produced
Seismic Response of Y-Shape Multi-Storey Building with Optimum Location of Shear Walls
Get PDFShear walls have extremely high in-plane strength and stiffness and also can counter heavy lateral loads making them quite advantageous in high-rise buildings. It is suggested to incorporate them in structures built in the places where there are chances of large intensity earthquakes or high winds. Positioning of the shear wall plays a very critical task in an asymmetric and irregular building subjected to earthquake forces. In our study, the main aim is to locate the advantageous position of the shear wall in Y-shaped asymmetric and irregular G+14 building in zone IV. The study is done by using a software package, CSI ETABS ver. 18.0.2. We have carried out Response Spectrum Analysis and Time History Analysis for this study. In this study, fourteen test models with unique location of shear wall are considered and parameters such as Time Period, Storey Displacement, Static Eccentricity, Storey Drift, Joint Displacement, Base Shear, and Base Force, are compared with the bare model. Thus, the best location of shear wall is suggested based on models having least static eccentricity, minimum displacement, Minimum drift, Minimum time period, Minimum joint displacement and Maximum base shear
Computation of Time-dependent Probabilities of Vesicle Release and Binding of Neurotransmitters of Postsynaptic Neuron
Get PDFWhen a postsynaptic neuron receives a spike from the axon, its synapse releases neurotransmitters to the synaptic cleft. The probability of vesicle release depends on the amount of calcium ions. The concentration of calcium ions keeps on changing with time. The opening and closing of these channels is controlled by the calcium ion gates operating at different rates. Similarly, the binding of neurotransmitters to the membrane depends on the number of receptors. The existing literature considers probabilities of vesicle release and binding of neurotransmitters as constants. In practice, these two probabilities are time-dependent. This issue is addressed in this paper and new derivations of the time-varying nature of these two probabilities are obtained from simulation study and analysis. The present investigation of estimation of these two time-dependent probabilities will help to develop improved nanoscale neuronal communication models
Purification, Characterization and Application Study of Bacterial Tannase for Optimization of Gallic acid Synthesis from Fruit Waste
Get PDFTannase produced extracellularly by the bacterial strain Bacillus haynesii SSRY4 MN031245 was purified in step-wise manner through ammonium sulphate precipitation, dialysis, followed by anion exchange chromatography. Tannase was purified to 42.0-fold with 36.30% enzyme yield. The enzyme was relatively stable from 30 to 50℃ and pH (4.0–6.0) for up to 4 hours. Partially purified tannase (16.80 U/ml) was able to synthesize 20.304 mg/ml gallic acid from the fruit waste under optimized conditions. The results of application study suggest that bacterial tannase could provide a new source for Gallic acid synthesis from the fruit waste for industrial applications. Our research findings could provide a value chain to fruit waste and help in reducing the waste generation from fruit processing industries
Grade Classification for Water Chestnuts, their Dimensional Properties and Correlation Analysis
Get PDFThe aim of the present study was to devise the grade classification for whole water chestnuts and kernels and to determine their dimensional properties. The data generated during the study will help in designing post-harvest handling equipments for water chestnuts in future. The mean values of length, width and thickness for whole water chestnuts ranged between ≤ 30 - > 45mm; ≤ 23- > 35mm and ≤ 9 - >18mm from grade I (very small) to grade V (very large) respectively, whereas, the corresponding values for whole water chestnut kernels ranged between ≤ 18 - > 36 mm; ≤ 13- > 22mm and ≤ 7 - > 16 mm from grade I to grade V respectively. For all the five devised grades, the mean values of derived dimensional properties were significantly (p<0.05) different in both whole water chestnuts as well as in kernels. Correlation analysis revealed significant (p<0.05) positive correlation among all the dimensional properties of whole water chestnuts. In case of whole water chestnut kernels, all the dimensional properties showed significant positive correlation with each other, except sphericity and aspect ratio, which showed non-significant positive and negative correlations with all the dimensional properties respectively
Real-Time Feedback Control for Knee Prosthesis using Motion Fusion Algorithm in 6-DOF IMU
Get PDFStump angle measurement (SAM) system was developed and tested for its use in the development of a low cost electronic knee prosthesis using an accelerometer to measure “tilt” angle of the residual stump during various phases of gait. This system provided real time feedback to control the actuator position for covering a wide range of mobility for the above knee amputees. However, this system is prone to high frequency noise resulting from gait events. These “noise” spikes triggered false threshold values resulting in incorrect operation of the actuator. In the proposed design, a 6-degree of freedom (6-DOF) sensor replaces the accelerometer from previous design. The modified algorithm uses complimentary filter to process the data from inertial measurement units (IMU). This new system produces sensitive yet smoother output, removing the drawbacks of the earlier system. This paper reports the comparative analysis of the SAM system using 6-DOF and accelerometer. These results using 6-DOF sensor will assist in the further development of an intelligent feedback system for low cost active prosthetic leg