This handbook covers basic concepts in mechanical engineering and mechatronics, including stress and strain, mechanics of solids, internal combustion engines, refrigeration, fluid mechanics, control ...systems, actuation, robotics, electro-mechanical systems, hydraulics, and more. --
Abstract
High quality silver (Ag) decorated CeO
2
nanoparticles were prepared by a facile one-step chemical method. The samples were characterized by X-ray diffraction (XRD), scanning electron ...microscopy (SEM), High resolution transmission electron microscopy (HR-TEM), fourier transform infrared spectrometer (FT-IR), electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), UV–Visible absorption (UV–Vis), photoluminescence (PL) and thermogravimetric analysis. The decoration of Ag on CeO
2
surface was confirmed by XRD, EPR and HR-TEM analysis. Harmful textile pollutant Rose Bengal dye was degraded under sunlight using the novel Ag decorated CeO
2
catalyst. It was found that great enhancement of the degradation efficiency for Ag/CeO
2
compared to pure CeO
2
, it can be ascribed mainly due to decrease in its band gap and charge carrier recombination rate. The Ag/CeO
2
sample exhibited an efficient photocatalytic characteristic for degrading RB under visible light irradiation with a high degradation rate of 96% after 3 h. With the help of various characterizations, a possible degradation mechanism has been proposed which shows the effect of generation of oxygen vacancies owing to the decoration of Ag on the CeO
2
surface.
► Review of methods for trend detection in the presence of serial correlation. ► Identification of temporal and spatial changes in maximum and minimum temperature over India. ► More than one method ...should be used to detect temporal changes satisfactorily. ► Substantial change in minimum temperature during 1970–2003 over India. ► Significant temporal changes in temperature are found over North Central region of India.
Present study performs the spatial and temporal trend analysis of annual, monthly and seasonal maximum and minimum temperatures (tmax, tmin) in India. Recent trends in annual, monthly, winter, pre-monsoon, monsoon and post-monsoon extreme temperatures (tmax, tmin) have been analyzed for three time slots viz. 1901–2003, 1948–2003 and 1970–2003. For this purpose, time series of extreme temperatures of India as a whole and seven homogeneous regions, viz. Western Himalaya (WH), Northwest (NW), Northeast (NE), North Central (NC), East coast (EC), West coast (WC) and Interior Peninsula (IP) are considered. Rigorous trend detection analysis has been exercised using variety of non-parametric methods which consider the effect of serial correlation during analysis. During the last three decades minimum temperature trend is present in All India as well as in all temperature homogeneous regions of India either at annual or at any seasonal level (winter, pre-monsoon, monsoon, post-monsoon). Results agree with the earlier observation that the trend in minimum temperature is significant in the last three decades over India (Kothawale et al., 2010). Sequential MK test reveals that most of the trend both in maximum and minimum temperature began after 1970 either in annual or seasonal levels.
Display omitted
•A hybrid short-term wind speed prediction model for high accuracy is proposed.•The Ensemble Empirical Mode Decomposition algorithm is adopted to decompose the original wind speed ...data.•The Adaptive Wavelet Neural Network is developed to predict the wind time series data.•Results from a real-world case study in India are reported along with comprehensive comparison.•Attained high accuracy, less uncertainty and low computational burden in forecasts by the proposed method for the first time.
Wind energy is one of the emerging sustainable sources of electricity. Wind is intermittent in nature. The typical grid operation of wind energy is complex. The significance of wind energy generation and integration with the grid is increasing day by day. An accurate wind speed forecasting method will help the utility planners and operators to meet the balance of supply and demand by generating wind energy. In this paper, a statistical-based wind speed prediction is implemented without utilizing the numerical weather prediction inputs. This analytical study proposes a hybrid short-term prediction approach that can successfully preprocess the original wind speed data to enhance the forecasting accuracy. The most efficient signal decomposition algorithm, Ensemble Empirical Mode Decomposition is used for preprocessing. This ensemble empirical mode decomposition technique decomposes the original wind speed data. Each decomposed signal is regressed to forecast the future wind speed value by utilizing the Adaptive Wavelet Neural Network model. The proposed hybrid approach is subsequently investigated with respect to the wind farm of South India. The results from a real-world case study in India are reported along with comprehensive comparison. The prediction performance delivered high accuracy, less uncertainty and low computational burden in the forecasts attained. The developed hybrid model outperforms the six other benchmark models such as persistence method, back propagation neural network, radial basis function neural network, Elman neural network, Gaussian regression neural network, and wavelet neural network.
The contemporary environmental-stewardship programmes primarily aimed at curbing the global warming potential by adopting a multidisciplinary approach. Manipulating the feeding strategies has great ...potential in reducing the environmental footprints of livestock production. This study intends to assess the effect of soybean meal (SBM) replacement with varying levels of coated urea (SRU) on both zoo-technical (nutrient digestibility, heat increment, and physio-biochemical parameters) and environmental attributes. The coated urea was used to replace the SBM at 0, 25, 50, and 75 percent levels. Eight adult rams (43.02 ± 0.76) maintained in a conventional shed were used in a replicated 4 x 4 Latin square design. Not all the physiological parameters viz. rectal temperature, pulse rate, and respiratory rate were affected (P>0.05)f by varying levels of SRU incorporation. The SRU fed animals had higher (P<0.05) crude protein digestibility compared to SBM fed animals; however, the replacements did not affect the nutrient digestibility coefficients of DM, OM, NFC, NDFap, ADF, and hemicellulose components. The SRU did not affect various biochemical parameters such as serum glucose, total protein, albumin, globulin, urea, creatinine, ALT, AST, Ca, P and T3, and T4 levels; however, post-prandial serum urea N (SUN) values showed a diurnal quadratic pattern (P<0.05) with a dose-dependent relationship. Further, the SBM replacements had no effect on the calcium excretion, while the SRU incorporation decreased the faecal phosphorous content, thereby abating the eutrophication phenomenon. Although the SBM replacements did not affect in vivo water variables and faecal solid fractions, they managed to decrease the land and virtual water requirement along with global warming potential (GWP) of the entire trial. The GWP-perceptual map unveils the fact that replacement of conventional feed ingredients with NPN compounds aids in eco-friendly livestock production. Further, the conjectural analysis of the carbon footprint methodology revealed that agricultural by-products consideration could cause a huge increase in the GWP share of feed consumed, thus compelling the importance of research pertaining to feed production perspective as equal as ruminal methane amelioration.
Magnetic chitosan composites (MCCs) are a novel material that exhibits good sorption behavior toward various toxic pollutants in aqueous solution. These magnetic composites have a fast adsorption ...rate and high adsorption efficiency, efficient to remove various pollutants and they are easy to recover and reuse. These features highlight the suitability of MCCs for the treatment of water polluted with metal and organic materials. This review outlines the preparation of MCCs as well as methods to characterize these materials using FTIR, XRD, TGA and other microscopy-based techniques. Additionally, an overview of recent developments and applications of MCCs for metal and organic pollutant removal is discussed in detail. Based on current research and existing materials, some new and futuristic approaches in this fascinating area are also discussed. The main objective of this review is to provide up-to-date information about the most important features of MCCs and to show their advantages as adsorbents in the treatment of polluted aqueous solutions.
Display omitted
•Outline of preparation, characterization and properties of magnetic chitosan adsorbents•Inorganic and organic pollutant removal from water using MCCs has been reviewed.•Adsorption kinetics and equilibrium isotherm models were reviewed.•Magnetic separation and adsorption mechanism have been discussed.•The outlook for potential applications and limitations was also discussed.
•The survey of machine learning algorithms for WSNs from the period 2014 to March 2018.•Machine learning (ML) for WSNs with their advantages, features and limitations.•A statistical survey of ...ML-based algorithms for WSNs.•Reasons to choose a ML techniques to solve issues in WSNs.•The survey proposes a discussion on open issues.
Wireless sensor network (WSN) is one of the most promising technologies for some real-time applications because of its size, cost-effective and easily deployable nature. Due to some external or internal factors, WSN may change dynamically and therefore it requires depreciating dispensable redesign of the network. The traditional WSN approaches have been explicitly programmed which make the networks hard to respond dynamically. To overcome such scenarios, machine learning (ML) techniques can be applied to react accordingly. ML is the process of self-learning from the experiences and acts without human intervention or re-program. The survey of the ML techniques for WSNs is presented in 1, covering period of 2002–2013. In this survey, we present various ML-based algorithms for WSNs with their advantages, drawbacks, and parameters effecting the network lifetime, covering the period from 2014–March 2018. In addition, we also discuss ML algorithms for synchronization, congestion control, mobile sink scheduling and energy harvesting. Finally, we present a statistical analysis of the survey, the reasons for selection of a particular ML techniques to address an issue in WSNs followed by some discussion on the open issues.
Rare earth Sm and Ce co-substituted nano crystalline cobalt ferrite, CoFe2-x-ySmxCeyO4 (x = y = 0.00, 0.5, 0.1, 0.12 and 0.25) have been synthesized by sol-gel combustion method to study structural, ...morphological and magnetic properties. X-ray diffraction (XRD) revealed the spinel structure with a secondary phase of RE2O3 for higher molar concentration of rare earth ions. Williamson-Hall equation used to determine crystallite size and strain produced. An increase in specific surface area and Strain, while a decrease in the crystallite size were observed with increasing Sm and Ce concentrations. Scanning electron microscopy (SEM) micrographs showed inhomogeneous grain distributions with some agglomerates, an average grain size was found to be 0.15 μm. Energy dispersive x-ray spectroscopy (EDAX) confirmed the stoichiometry of the samples. Surface morphology studies were carried out by Transmission electron microscopy (TEM) studies which corroborates the presence of agglomerations in the sample. Fourier transform infrared spectroscopy (FTIR) spectra confirmed the spinel phase by showing two frequency bands υ1 in frequency range 580-559 cm−1 and lower frequency band υ2 at 392-372 cm-1. The force constants calculated for tetrahedral position was found to be more than that of octahedral position. Based on structural properties a cation distribution was proposed. Vibrating sample magnetometer (VSM) technique at room temperature used to study the magnetic properties, saturation magnetization (Ms), coercivity (Hc), anisotropy constant and initial permeability. Ms and Hc were found decreasing with increasing concentration of rare earth ions which has been attributed to weakening of A-B interaction, due to decrease in particle size and surface effect. Yafet-Kittle (YK) angle was found increasing with rare earth concentrations. The Ms and Hc of cobalt ferrite particles can be tailored for various applications.
Display omitted
•Substitution RE (Sm and Ce) has led to micro strain in the crystal.•Cation distribution has been proposed.•Surface effect played an important role in magnetization.•YK angle increased with RE (Sm, Ce) concentration.
•Conductivity in CoCexSmyFe2-x-yO4 due to Polaron hopping between cations.•RE (Ce and Sm) substitution in CoFe2O4 led to decrease in Impedance.•Conduction process is mainly due to grains.•Magnetic ...particles possess multi-domain with cubic anisotropy at 20 K.•Shows ferromagnetism at low and Super paramagnetism beyond room temperature.
In this study, we report frequency and temperature dependent dielectric, electrochemical impedance and low temperature magnetic properties of Sol-gel auto-combustion synthesized rare-earth (Ce and Sm) co-substituted cobalt ferrite, CoCexSmyFe2-x-yO4 (x = y = 0.00, 0.1, 0.12 and 0.25). The surface morphology and particle size as obtained by XRD studies was confirmed by HRTEM measurements for a representative sample. The dielectric properties such as dielectric constant, loss tangent and AC conductivity have been measured using LCR meter, variation of dielectric parameters with substituent concentrations, frequency range from 0.1 to 10 MHz at room temperature (RT) and temperatures 100–400 °C have been well supported by Maxwell-Wagner interfacial polarization. The AC conductivity increased with applied frequency suggesting that the conduction mechanism is owing to small polaron hopping between cations. Impedance studies shows that, the addition of RE (Ce and Sm) cause a decrease in the Z′ value, with increasing frequency which can be attributed to the space charge polarization effect in the material. Low temperature magnetic measurements in ZFC-FC mode and magnetic isotherms at 20 and 310 K reveals the ferromagnetic nature of RE (Ce, Sm) substituted cobalt ferrite nano particles. The coercive field has been increased at low temperature 20 K compared to that at 310 K, the samples shows super paramagnetism beyond room temperature.
PDF
