Numerical modeling of soil flow and pressure distribution on a simple tillage tool using computational fluid dynamics

Soils, in general, undergo both elastic and plastic deformations upon loading. Strain dependant anisotropic elasto-plastic models are required for realistic modeling for soil-tool mechanics that will address issues like stress history and soil anisotropy. Although several such models have been proposed, the science of coupled poro-mechanical analysis of an unsaturated soil has not been fully addressed.Tillage tool modeling is primarily concerned with the analysis of soil deformation patterns and development of force prediction models for design optimization. Most of the models are based on quasi-static soil failure patterns that cause difficulty in accurately predicting soil-tool behaviour and soil forces for high speed operation. In recent years efforts have been made to improve the conventional analytical and experimental models by numerical approaches. Numerical simulations of soil-tool interactions using finite element modeling (FEM) and discrete element method (DEM) were mostly based on a solid mechanics approach. Due to limitations of constitutive relations, predictions of these numerical models have not been able to address tillage dynamics with high shear rates. The contribution of this research was to study the dynamics of soil-tool interaction using computational fluid dynamics (CFD) from the perspective of soil visco-plastic behavior.A motorised soil rheometer was developed for evaluating soil visco-plastic parameters for CFD simulations. The apparatus was used to determine soil yield stress and viscosity at different soil moisture and compaction levels.Three-dimensional CFD analyses were carried out using a commercial software CFX 4.4 to observe soil failure patterns around a tool and the pressure distribution on and around the tool. Duct flow as well as free-surface flow simulations of visco-plastic soil as a non-Newtonian Bingham material indicated soil deformation comprising of ‘plastic flow’ and ‘plug flow’ patterns. The soil failure front advancement demonstrated a critical speed range of 4 to 6.5 m s-1 where advancement of the failure front did not increase with speed. Soil pressure on the tool surface increased with the tool operating speed. Pressure distribution on the tool surface and draft requirement agreed well with the published literature based on experimental results and FEM analysis. The CFD approach, in its first attempt to tillage process, demonstrated its greater potential for dynamic modeling of soil-tool interaction

Turn-to-turn fault diagnosis of an Induction motor by the analysis of Transient and Steady state Stator current

This work proposes an online diagnosis of turn-to-turn stator winding fault of an induction motor through the combine use of Wavelet Transform (WT) and Fast Fourier Transform (FFT). Both steady state and non-stationary transient part of motor stator currents are assessed for detection of this inter turn short circuit fault. First non-stationary part is assessed by formation of contour of the coefficients of Continuous Wavelet Transform (CWT) of stator current – result shows significant change of amplitude at certain frequencies. Secondly, the supply frequency is filtered off from the steady part of motor current. Then on this filtered signal (i) Fast Fourier Transform (FFT) is performed where from spectrums are observed at different percentage of inter turn short condition and (ii) performing Discrete Wavelet Transform (DWT) detailed wave energy has been calculated using Parseval’s theorem. Work has been performed both under load and no-load condition of the motor. The proposed method has been validated in a laboratory prototype. Results indicate that the proposed technique is suitable for real-time application Keywords: CWT, DWT, FFT, fault diagnosis, induction motor, inter-turn short, wave energ

Phytol: A review of biomedical activities

© 2018 Elsevier Ltd. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (Auguist 2018) in accordance with the publisher’s archiving policyPhytol (PYT) is a diterpene member of the long-chain unsaturated acyclic alcohols. PYT and some of its derivatives, including phytanic acid (PA), exert a wide range of biological effects. PYT is a valuable essential oil (EO) used as a fragrance and a potential candidate for a broad range of applications in the pharmaceutical and biotechnological industry. There is ample evidence that PA may play a crucial role in the development of pathophysiological states. Focusing on PYT and some of its most relevant derivatives, here we present a systematic review of reported biological activities, along with their underlying mechanism of action. Recent investigations with PYT demonstrated anxiolytic, metabolism-modulating, cytotoxic, antioxidant, autophagy- and apoptosis-inducing, antinociceptive, anti-inflammatory, immune-modulating, and antimicrobial effects. PPARs- and NF-κB-mediated activities are also discussed as mechanisms responsible for some of the bioactivities of PYT. The overall goal of this review is to discuss recent findings pertaining to PYT biological activities and its possible applications

Development of Nickel-Based Hybrid Metal Oxide Nanocomposite Electrodes for Advanced Electrochemical Supercapacitor and Electric Field Emission Application

This thesis work preferentially motivates us to investigate intriguing electrochemical energy storage performance of some innovative nickel based hybrid metal oxides nanocomposite which have been rarely studied so far. Besides, some other nickel based transition metal oxide compounds have been publicized first time their potential field emission response for future application. Various dynamic synthesis protocols i.e. co-precipitation, sol-gel, and ultra-sonication have been adopted to prepare hierarchical surface morphology which can boost up electrochemical and FE performances. The enhanced properties of the assynthesized nanoparticles and their composites have been explained in terms of synthesis techniques, surface morphology, electrode and electrolytic properties, and process control. The aforementioned work has been described systematically in six different chapters as follows: Chapter I accentuates a brief introduction to electrochemical supercapacitors and their classification, components and materials, performance & testing, theoretical model of field emission and FE parameters, and their applications etc. Additionally, the theory of DFT and important parameters (i.e. work function, quantum capacitance) related to our experiment has been discussed briefly. The motivation, literature survey, and objective of our nanomaterials used for performance testing have been disclosed. Chapter II provides a detailed description of the synthesis protocols used to synthesize our chosen compounds and their carbon-based composites have been illustrated schematically. The basic theory of experimental techniques used for the structural, morphological, electrochemical, and FE characterization of as-prepared samples was also demonstrated with a diagram. Chapter III deals with the primary characterization results (i.e. XRD, Raman, FTIR, FESEM, TEM, EDS, BET etc.) with electrochemical response of two compounds core@shell NiCo2O4@MnO2 and NiMnO3/NiMn2O4 nano-cotton and their performences further upgraded with inclusion of MWCNT. The electrochemical response (CV, GCD) was observed at different scan rates and current densities using glassy carbon as the working electrode and 3 M KOH as an electrolytic solution. High specific capacitance 824 Fg-1 and 869 Fg-1 was observed for core@shell and nano-cotton and its value further upgraded 1048 Fg-1 and 1037 Fg-1 due to incorporation of MWCNT respectively. Good cyclic stability between ~82.6%-93% was examined over 5000 cycles for all compounds and EIS spectrum before and after testing was inspected. Chapter IV represents the primary experimental results of three nickel based transition metal oxide (NiMn2O4, NiCr2O4, and NiO [CdO]2) with unique nano morphology, high phase purity, balanced stoichiometry, and exclusive surface morphology for FE characterization. The field emission features including current density (J) electric field (E), FN plots, long stability were studied over long period and field enhancement factor (β) 3381, 2074, and 1854 were determined. The DFT calculation was also performed to calculate work function (Ф) using the supercell approach for the calculation of field enhancement factor (β). Chapter V covers the structural, electrochemical, field emission, and in-depth DFT study of two other productive compounds La2NiO4 and NiGa2O4 and further compared with La2NiO4/CNT and NiGa2O4/r-GO respectively. Preceding primary characterization was carried out to confirm their crystal symmetry, elemental indication, and hierarchical porous morphology. The electrochemical and field emission response was examined and compared. Good specific capacitance 426 Fg 1 and 643 Fg-1 was discovered for La2NiO4/CNT and NiGa2O4/r GO in 1M KOH electrolytic solution and Ni foam as a working electrode with capacitance retention 93% and 99.1% over 5000 cycles. Besides, improved field enhancement factor 4144 and 4429 was estimated for their CNT and r-GO based composite FE electrodes. The DFT study reveals exciting features related to charge transfer due to orbital interaction, enhanced electronic states near Fermi level for their carbonous composites leading to enhanced conductivity, increased mobility of electrolytic ions in the open space of CNT or r GO. The lower work function and higher quantum capacitance support the improved charge storage performance and field emission response. Chapter VI concludes the work carried out in the thesis with their future scope. The electrochemical performance and field emission characteristics of all compounds have been compared and discussed best outputs from our research with merits and demerits

Boudinage in homogeneous foliated rocks

Theoretical and experimental studies confirm Platt and Vissers' suggestions that boudin-like structures in homogeneous foliated rocks can develop by deformation following fracture initiation. It is further shown that symmetrical foliation-boudins can develop only in coaxial deformation history with the foliation and the extension fracture remaining mutually perpendicular throughout the entire course of deformation. Asymmetric foliation boundinage may develop either in coaxial or in non-coaxial bulk deformation in the neighbourhood of short segments of fractures. The asymmetry can develop if either the foliation or the fracture or both are oblique to the principal axes of stress

Diagnosis of Broken Rotor Bar Fault of Induction Motor through Envelope Analysis of Motor Startup Current using Hilbert and Wavelet Transform

This paper proposes a new method for extraction of low frequency oscillation from the envelope analysis of Motor Startup Current for diagnosis of Broken Rotor Bar Fault of Induction motor through Wavelet and Hilbert Transforms. The Envelope is the modulus of the Complex Analytic signal generated by using the original signal as the real part and its Hilbert Transform as the imaginary part. The concept of instantaneous frequency introduced in this paper is quite efficient to extract important transient fault informations, specially for non- stationary signal which is nonlinear. This method overcomes the difficulties of traditional FFT and Prony analysis as well as difficulties in selection of mother wavelet. Higher level detail coefficients correspond to narrow band low frequency components below the supply frequency are used to distinguish the faulty motor from the healthy one. Simultaneously this method has higher detectability and higher resolution and it can also deal with short data effectively, so it can be used online. This method has been validated in a laboratory standard

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Not AvailableA RIL population of jute was developed by crossing one resistant accession CIM 036 and a susceptible variety JRC 412. Two cDNA libraries were constructed using pool of mRNA from healthy as well as infected seedlings from all the 177 RIL lines. A significant number of defense genes involved in the defense-response were identified viz. cell wall biosynthesis, reactive oxygen species (ROS), salicylic acid (SA), ethylene, jasmonic acid (JA), abscissic acid (ABA), hormone signaling, hypersensitive response (HR) and programmed cell death (PCD) pathways. Furthermore, microRNA analysis revealed that Trans-acting siRNAs (tasiRNAs) negatively regulate these target transcripts and are characterized by siRNAs spaced in 21-nucleotide (nt) “phased” intervals. We identified highly abundant 22-nt miRNA families that target conserved domains in these SA/JA/ABA precursors and trigger the production of trans-acting siRNAs. SA and JA1 transcripts were found to be cleaved by these 22-nt miRNA generating phasiRNA, suggesting silencing pathogenicity pathway of Macrophomina phaseolina. Gene function annotation was studied in jute-M. phaseolina interaction in each of the 177 lines of a RIL population. tasiRNA based SAR regulation demonstrated master regulator of a large gene family. It is the first report of studying resistance mechanism in jute against M. phaseolina in a RIL population through transcript and miRNA analysisNot Availabl