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An empirical approach of modeling and assessment for the safe use of commercial electric detonators in radio frequency radiation hazards
No full textIn the modern era of communication technologies using amplitude modulation (AM) and frequency modulation (FM) the transmitting antenna of radio, television, radar, cellular phones, wireless data acquisition systems and global positioning systems (GPS) are the main sources of radio frequency radiation hazards. The transmitting antennas of these communication devices generate electromagnetic fields (EMFs). Electric detonator wires, under certain circumstances work as receiving antenna and pickup enough electrical energy from such fields to initiate unexpected explosion. There have been many cases of detonators being fired accidentally by radio frequency pick up. In this work an attempt has been made to minimize such explosions and to provide a basis for assessing and modeling the parameters of radio frequency radiation hazards associated with commercial electric detonators. This research examines the radiated powers of various frequency bands to determine the safe distance from transmitting antenna. Based on mathematical simulation, two empirical relations have been proposed for the calculation of minimum safe distance (MSD). Using these relations desired MSDs have been calculated for the relevant frequency bands. The obtained values have been compared with the available experimental values showing good agreement between them. The average percentage deviations of calculated MSDs from proposed relations are found between 0.096% and 10.718%, with regression coefficient 0.970 ≤ R ≤ 1. This reflects the soundness of the proposed empirical relations. The blasting engineers, detonator designers and researchers may use these relations as a handy tool to prevent undesired explosions by maintaining minimum safe distance in radio frequency prone hazardous areas
Optimizing Plastic Extrusion Process via Grey Wolf Optimizer Algorithm and Regression Analysis
Get PDFOne of the most widely used methods in the production of plastic products is the extrusion process. There are many factors that affect the product quality throughout the extrusion process. Examining the effects of these factors and determining the optimum process parameters which will provide the desired product characteristics; is important for reducing costs and increasing competitiveness. This study is performed in a manufacturer that produces plastic cups. The aim is to optimize extrusion process parameters of this company in order to achieve 1.15 mm thickness at the produced plastic sheets. For this purpose, the thicknesses of the sheet produced with different process parameters were observed throughout the production processes to be able to model the problem as an optimization problem by means of the regression modelling. Then, the developed model is optimized via the grey wolf optimizer (GWO) algorithm considering the desired 1.15 mm sheet thickness
Variation in morphological, biochemical and antioxidant properties of Lilium polyphyllum
No full textLilium polyphyllum D.Don ex Royle belonging to family Liliaceae is a medicinal plant distributed in temperate to high altitude regions of Himalaya. Its bulbs have been used for anti-aging and vitality properties in >30 formulations of Ayurveda. Therefore, the knowledge on various traits of the plant is necessary so that quality of the finished products could be maintained. Present study investigates, morphological, biochemical and antioxidant properties in different populations of L. polyphyllum. A significant variation was recorded in different morphological parameters (Plant height, leaf number, leaf length, leaf width, bulb diameter, bulb fresh weight). Variation was also recorded for total soluble protein (7.81-11.35 mg/g), soluble sugar (96.14-116.14 mg/g), starch (116.37-122.43 mg/g) and total free amino acid (18.22-26.00 mg/g). Antioxidant properties in the bulb were determined and ABTS activity was 4.22 mM /100 g, DPPH activity recorded 0.85 mM/100 g and FRAP activity was 1.50 mM/100 g dw ascorbic acid equivalent, respectively. The diversity in wild populations of the species may serve as a baseline data for future breeding, domestication and conservation program
Production of Bamboo Fibre Reinforced Epoxy Hybrid Compositewith Nano SiO2 Particles
Get PDFThis paper focus on the process of fiber reinforced composites a significant portion of the paper emphasis the use ofdifferent machine, basic concept introduced in this paper of molding method and pouring of epoxy, hardener and nano silicamixture with hand lay-up technique. This study aims to develop fibre-reinforced epoxy hybrid composites by using handlay-up method. In this work different material used are Epoxy LY556, Hardner HY951, SiO2 nano particle (Particle size60-70nm) and 90 degree bidirectionl wooven bamboo fibre. Sample designated are as A10 ( One layer Babboo fibre,0% SiO2) , A12 (2%SiO2), A14 (4%SiO2),B20 (Two-layer bamboo fibre,0% SiO2), B22(2%SiO2), B24(4%SiO2), C30(three layer bamboo fibre, 0% SiO2),C32(2%SiO2) and C34(4%SiO2). Samples were prepared by handlayup method. Theeffect of various weight percent of SiO2on mechanical property were investigated. The maximum value of tensile strengthwas found for sample C32, higher value of flexural strength was found for sample C32, higher value of izod impact test wasfor sample C32 and maximum value of barcol hardness was for sample B22
Modeling of Dry Conditioned Sliding Wear And Friction Behavior of Heat-Treated Silicon Nitride Strengthened Al Metal Matrix Nanocomposites
Get PDFIn the presented work, the sliding wear under dry conditions and friction behaviour of Si3N4 reinforced high-strength Aluminum alloy (AA)7068 nanocomposites have been investigated under various loads, sliding velocity, and rubbing distances. The fabrication of nanocomposites has been done by using the stir casting technique with the advancement of ultrasonication. Scanning electron microscope (SEM), Elemental mapping, and energy dispersive spectroscopy (EDS) are used to analyze the microstructure of prepared nanocomposites and worn surfaces. The wear resistance improves with the incorporation of Si3N4 particles in Al 7068 alloy and further increases by increasing the weight % of reinforcement. The reinforcement is done by 0.5, 1, and 1.5 % Si3N4 by weight. ANOVA reveals that sliding distance is the most dominating factor in the wear loss of samples, and load became the most influential parameter in the coefficient of friction (COF). Microstructure reveals grain boundaries become discontinued after T6 heat treatment. AMNCs containing 1.5wt.% Si3N4 shows minimum wear loss compared to other nanocomposites and alloys
Effects of culture condition and nutrition on the co-production of microbial oil and exopolysaccharide by Sporidiobolus pararoseus JD-2
Get PDFMicrobial oil has been gaining considerable attention from researchers recently as renewable and ecofriendly oil and its potential as feedstock for food industry and biodiesel industry. In this context, we have earlier demonstrated production of microbial oil and exopolysaccharide (EPS) from the yeast Sporidiobolus pararoseus JD-2. In this study, we explored increasing its production by optimizing the culture condition and nutrition. As expected, culture temperature and dissolved oxygen (DO) are the contributing factors for co-producing microbial oil and EPS, in which 28℃ and lower quantum (i.e., 30 mL/500 mL) show the best conditions in shake-flasks fermentation. By contrast, the initial pH from 4 to 8 has no obvious effect on producing microbial oil and EPS. In addition, the culture nutrition (i.e., carbon/nitrogen source) were also discussed, and indicating that 20 g/L of corn steep liquor and 60 g/L of glucose are beneficial to produce microbial oil and EPS (i.e., 34.1±1.2 g/L and 11.5±0.2 g/L, respectively). Meanwhile, the residue glucose should be maintained at 20 g/L, in which the highest production of microbial oil and EPS was obtained (i.e., 34.6±1.7 g/L and 11.7±0.8 g/L, respectively). The biomass, microbial oil and EPS were further increased during optimizing the DO level, which reached to 67.8±2.1 g/L, 34.7±0.6 g/L and 11.8±0.5 g/L during maintaining DO level at 20-30%, respectively. The results suggest that appropriate culture condition and nutrition considerably improve the fermentation performance of S. pararoseus JD-2 and significantly increase co-production of microbial oil and EPS (by 11.2 and 8.3%, respectively) compared to the un-optimized fermentation
Prediction of Ground Water Level using SVM-WOA Approach: A Case Study
Get PDFReliable and accurate estimation of Groundwater Level (GWL) fluctuations is essential and vital for sustainable water resources management. Due to uncertainties and interdependencies in hydro-geological processes, GWL prediction is complex by the fact that fluctuation of GWL is extremely nonlinear and non-stationary. Utilising novel methods for accurately predicting GWL is of vital significance in arid regions. In present work, Support Vector Machine (SVM), in combination with Whale Optimisation Algorithm (SVM-WOA), is applied to forecast GWL in Bhubaneswar region (Odisha University of Agricultural Technology). Three quantitative statistical performance assessment indices, coefficient of determination (R2), Mean Squared Error (MSE), and Wilmott Index (WI), is used to assess model performances. Based on the assessment with conventional SVM and RBFN models, the performance of hybrid SVM-WOA model is preeminent. SVM-WOA is capable of predicting nonlinear behavior of GWLs. Proposed modelling technique can be applied in different regions for proper management of groundwater resources and provides significant information, at a short time scale, to estimate variability in groundwater at local level
Synthesis and bio-evaluation of novel acyl derivatives of karanjin
Get PDFDifferent lipidic moieties such as 10-undecenoic, oleic, lipoic, caproic, caprylic and lauric acids were acylated to demethylated karanjin to prepare six lipoconjugated karanjin. All the derivatives were evaluated for antimicrobial, anticancer and antiinflammatory activities and compared with karanjin and its demethylated analog. Lipoconjugation does not seem to improve the activity of karanjin against studied bacterial and fungal strain. However, karanjin, demethylated karanjin and six lipoconjugated karanjin showed moderate to good anticancer activity against prostate and breast cancer cell lines. Mild antiinflammatory response was also observed in case of karanjin and lipoic acid-conjugated karanji
Pressure Dependent Elastic, Mechanical and Ultrasonic Properties of ZnO Nanotube
Get PDFThe impact of pressure on the elastic and acoustic characteristics of the ZnO nanotube are analyzed using the L-J potential approach. This model is applied to evaluate the 2nd and 3rd order elastic parameters (SOECs and TOECs) for ZnO nanotube. Here in this work, the elastic constants are studied with pressure and it is noticed that the elastic moduli of ZnO nanotube increases monotonically as pressure is increases. We also reports that, the hexagonal ZnO nanotube is mechanically stable with pressures according to Born's elastic stability criteria in the present work. The Voigt–Reuss–Hill method are used to compute elastic parameters such as Young's modulus, bulk modulus, shear modulus and Poisson's ratio under different pressure in the present work. The hardness, thermal conductivity, anisotropy constants, ultrasonic velocity and melting point of ZnO nanotube is evaluated using estimated SOECs in the present work. The second order coefficients are being a tool for calculating acoustic velocities along the z-axis for the operating pressure that has been specified. The computation is also satisfactory in estimating the ultrasonic attenuation, Debye temperature and thermal conductivity k (min) under various pressures (0-10GPa) in this research work
A New Adaptive OMP-MAP Algorithm-based Iterative Sparse Channel Estimation for OFDM Underwater Communication
Get PDFA sparse channel estimation approach based on doubly spread underwater acoustic (UWA) channels is widely used todetect coherent acoustic orthogonal frequency division multiplexing (OFDM) signals. A new time-domain channelestimation (CE) technique for OFDM based UWA communication with Rician fading is used to exploit the channel sparsity.First, to improve the estimation accuracy in high noise conditions, we have exploited the channel sparsity to generate aclosed-form equation for the termination condition. Then, in low-level noise instances, the additional criterion to balanceestimation accuracy and computing costs has been established. By incorporating these two requirements within theorthogonal-matching-pursuit (OMP) structure, an adaptive-OMP (AOMP) algorithm has been proposed. The AOMP andmaximum a posteriori probability (MAP) techniques are combined to provide a computationally efficient, and a newAOMP-MAP scheme for estimating the sparse complex channel path gain has been proposed. Further, The minimumvariance unbiased estimator is used to improve the proposed CE technique. Exploiting the experimental channel data,computer simulations reveal that the proposed CE technique obtains the outstanding outcomes