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Purpose: Composite sandwich structures are becoming an essential part of engineering appliances due to their excellent mechanical and structural properties, high strength-to-weight as well as stiffness-to-weight ratios. And so, they are widely used in aerospace and marine applications, such as airplane wings, flight control surfaces, turbine blades, ship interiors, and small boats and yachts. Despite their superior properties, the sandwich plates consisting of an aluminum core and carbon fiber-reinforced plastic face sheets exhibit low-frequency resonant modes when subjected to external excitation. Therefore, in this paper, a nonlinear energy sink (NES) is attached to the thermally induced sandwich plate to attenuate the resonant peaks passively in a broad frequency range. Methods: The equation of motion of the sandwich plate-NES system is obtained by utilizing Lagrange Euler’s equation followed by Galerkin discretization. The analytical solution of the system is obtained by the complexification averaging method and arc-length continuation method. The nonlinear and stability analyses are also conducted for the present system. Results: The results show that an optimum NES obtained by the sensitivity analysis of the response curve attenuates the resonant peaks effectively and is applicable in a wide frequency range at various temperatures. Conclusion: Optimum parameters and the location of the NES help to eliminate the complex nonlinear dynamical phenomena at the first resonance frequency in various thermal environments.

Purpose: Composite plates find extensive use in aerospace and marine industries due to light weight, high strength-to-weight ratio and large stiffness. Their stiffness or natural frequency changes due to variation in environmental conditions such as temperature and moisture, and thus their dynamic performance can be adversely affected. Therefore, a nonlinear energy sink (NES) based vibration absorber is proposed that remains effective in a wide range of frequency change. Methods: A cantilever composite laminated plate (CCLP) is modelled using classical laminate plate theory. Moreover, dynamics of the plate-NES system is expressed by Euler–Lagrange equation; discretized in two fixed-free and two free-free modes using the Galerkin method. As the free end is more prone to vibration under excitation, first two resonant peaks in free-free direction of the plate are extensively studied in hygrothermal environment- with and without NES. The particle swarm optimization is used to optimize the NES parameters. Results: Numerical analysis shows that the optimal NES decreases the first mode’s peak amplitude by about 70% and dissipates 68% of the vibration energy, for temperature variation of 20 K and the moisture change of 0.10%. Moreover, the second peak is also reduced by 66.67% for the same hygrothermal conditions. From the numerical analysis, quasi-periodic and phase-locked responses are seen at some points in the amplitude–frequency curve; further explored through post-transient phase portraits, time histories, and Poincaré maps. Moreover, the changes in qualitative behaviour of the CCLP-NES system by varying the NES parameters are examined from the amplitude–frequency curves. A higher NES stiffness and mass increase resonant amplitudes and therefore, the unstable band. Conversely, increased NES damping reduces resonant peaks and the unstable band. Conclusion: The NES works effectively for a range of temperature and moisture variation as well as excitation amplitudes. The study notes jump phenomena near nonlinear resonance peaks at higher NES stiffness and excitation amplitudes, which also widens the unstable band between Limit-Point bifurcation points. Physical realization of the proposed NES can be the focus of the future research.

The study aims to understand the dynamic impact of economic policy uncertainty on the cash holdings patterns of construction firms in India. A dynamic panel regression model was created with cash to total assets as the dependent variable and the policy uncertainty, natural log transformation of total assets as a proxy of size, natural log transformation of dividends, price to book value ratio in times as a proxy of growth opportunities, Indian promoter holding in percentage as a proxy of ownership, debt-equity ratio in times as a measure of leverage, return on total assets in percentage as a measure of profitability and change in sales as a measure of volatility as independent variables. Further, the data was split into two study periods (2003-2011 and 2012-2020) for a detailed investigation of the dynamic relationship between policy uncertainty and firm-level cash holding. The findings suggest that policy uncertainty and its lag, cash holding lag are the prominent drivers of cash holdings for Indian construction firms.

Gold ions and gold-based compounds are extremely lethal to different plant pathogens. This characteristic of gold is well known for numerous roles in the medical field as these nanoparticles have enormous surface area accessible to the microbes. In the present study, gold nanoparticles were synthesized through the bacterium, Bacillus sonorensis.Fourier Transform Infrared Spectroscopy (FTIR) analysis of the reaction mixture assisted to comprehend the nature of the biomolecules elaborate in the development of gold nanoparticles. FTIR spectrogram of the reaction mixture confirmed the existence of bands at 3700 cm−1and 1500 cm−1, which could be assigned to N–H stretch of 1° and 2° amines, amides and C =C bending of aromatic amino acid of protein involved in reduction of Au3+to Au0. Transmission electron microscopy was used to measure the shape and size of gold nanoparticles, which were spherical, circular and hexagonal with size ranging between 10–35 nm, indicating that the synthesized gold particles were of nano-dimensions with satisfactory level of mono-dispersity. In this study, role of gold nanoparticles in different concentrations (0, 20, 40, 60, and 80 ppm) was explored for their toxicity to six plant pathogens i.e., Dematophora necatrix, Fusarium oxysporum, Alternaria aternata, Alternaria mali, Sclerotium rolfsiiand Colletotrichum capsici. Significant growth inhibition was observed in Sclerotium rolfsiiat 80 ppm concentration of gold nanoparticles. Gold nanoparticles preparation (80 ppm) changed the morphology and resulted in 70% growth inhibition of Fusarium oxysporumafter one week of incubation. Similarly, in case of Alternaria alernata,60%–70% growth inhibition and change in morphology was also observed.Inhibition of Alternaria maliup to 50%–60% was observed at 60 and 80 ppm with considerable change in morphology of mycelium after one week of incubation.

Infrastructure has been identified as the backbone of any economy as it provides channels of economic growth. For emerging economies like India, with 31% current urban population and contribution of 63% to GDP; the pie is expected to increase to approximately 40 percentages by 2031 with a GDP contribution of 70%-75%. This creates a need for rapid development as well as the strengthening of existing urban infrastructure to accommodate growing demand and to exploit its economic contribution. The extent of urban infrastructure development is delivered at three levels of governance; Centre, State and urban local bodies (ULBs). ULBs being the last level of governance for infrastructure development in urban India, they are grossly under-equipped to effectively generate revenues and raise capital. The present study has identified issues in the existing financing and assessment framework of ULBs and suggests a framework to rationalise their funding patterns and to bring competitiveness. The paper stresses the need of the proposed framework to bring smart city SPV and other ULBs at the equal platform.

Sustainability at grass root level in rural area is an increasing challenge in India. Various alternatives trade mechanisms have taken shape that proclaim to link farmers to ethical consumers and connect to sustainable procurement at farm level, which are more effective and make positive contributions towards economic, environment, social and governance dimensions of sustainability. This research paper identifies the dimensions of sustainability at farmer's level through systematic literature review, and examines existing procurement frameworks through integrative literature review. It also does the basmati rice procurement and commodity chain process mapping of existing conventional system as well as procurement through fair-trade system. Authors also collect insights from farmers as well as traders involved in both the procurement systems to develop a framework for sustainable procurement of basmati rice in India to reduce economic vulnerability of farmers, increase environment and social harmony through effective governance.

Conventional procurement at farm level, as starting point of the supply chain and a crucial link to farmer livelihoods and impact on sustainability, remains specifically ineffective in India. Initiatives like Fair Trade, in domain of 'alternative trade' mechanisms, have made inroads in global agricultural trade bridging the ethical consumers of the west to marginalised farmers in developing countries like India. This research paper explores indicators on all the dimensions of sustainability through literature as well as through exploratory factor analysis on primary data collected from Indian farmers who follow either conventional system or Fair Trade system to dispose their produce (basmati rice). The study also compares these systems on all indicators and dimensions of sustainability. It also explores the strength, weaknesses, suggestions to improve and reasons for formers to remain in the system. Findings suggest that Fair Trade system is better on almost all dimensions of sustainability than conventional system.

Unbalance in rotating components is very common. Moreover, rotating components input a force to the supporting structure whose amplitude varies quadratically with the rotor speed. As a rotating machine starts from the static condition and approaches to a higher operating speed, it is possible that several modal frequencies of the support beam get excited. Therefore, a vibration mitigation system is required to be efficient at higher operating speeds as well as to provide enough suppression at lower traversing speeds. Here, a nonlinear energy sink (NES) is attached underneath a simply supported beam subjected to the vertical unbalance force component of the rotor. Euler-Bernoulli beam theory is used for the dynamic modeling of the beam along with the Euler-Lagrange equation to get equations of motion of the beam and NES, which are solved numerically. The complexification averaging method is utilized to get the amplitude-frequency response of the system analytically for stability analysis and comparison with the numerical solution. The optimum values of the absorber parameters are obtained utilizing particle swarm optimization. The optimum NES is capable of efficiently reducing vibration amplitude for several modes of beam excited at different rotor speeds. It is found that the NES tuned at the first mode is effective in amplitude reduction for lower to higher operating speed ranges, whereas the NES tuned at the third mode performs better for higher operating speeds. The optimum NES also performs well for a sufficient range of change in the amount of unbalance of the rotor.

The recent financial crisis in the US and then the debt crisis in Europe have impacted the economical performance of the world in general, particularly the financial performance. With the increase in globalization and cross-border trade, the dependence of one economy on others increases. Portfolio diversification theory proposed by Markowitz, in 1952, suggests that if two markets are not significantly correlated, taking a position in that market helps in reducing the risk of the portfolio. The recent turmoil in these two markets (US and Europe) has affected the entire world and a lot of volatility has been observed in all financial markets around the world. Hence, it becomes imperative to identify the volatility spillover effect from one market to the other at this point. This article examines the volatility spillover of one market on other by taking five exchange rate markets: Great Britain pound (GBP), Euro (EUR), Canadian dollar (CAD) and Australian dollar (AUD) and Japanese yen (JPY) against the US dollar. Data from June 2008 to December 2012 were taken for consideration. Unit root test was used to identify the stationarity of data and the variance decomposition method was applied to identify the degree of influence of one market on other. The volatility spillover index, as suggested by Diebold and Yilmaz (2009), was created to identify the return spillover effect. Outcomes suggest that volatility on JPY and CAD follows the concept ‘better to give than receive’, while GBP as the net receiver goes along with the findings of Nikolaos (2012). A volatility spillover index of 11.11 per cent indicates low possibility of volatility transmission among considered currency pairs. This article will help traders, portfolio managers, policy makers and other market participants identify the source of volatility in considered currency markets and to take corrective measures.

The paper analyses the relationship between share pledging and firm performance and explores the influence of the monitoring mechanism on share pledging using the Indian dataset. The data set includes BSE Midcap firms from March 2009 to March 2019. Following Two-way Fixed Effect Model (2FE) with lagged dependent variables (LDV), we conclude that pledging activity is positively associated with stock volatility and institutional-holding serves as a monitoring mechanism for share pledging.

A new lignan rhamnoside identified as 2,6-di(4′,5′-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane-1-hydroxy-5-O-rhamnopyranoside (1) has been isolated from the ethanolic extract of seed pods of Bauhinia retusa. Its structure was established by extensive spectroscopic techniques (UV, IR, 1D NMR, 2D NMR, HRESIMS).

A new C-glycosyl flavone 7,4′-dihydroxy-5-methoxyflavone-6-C-β-D-glucopyranoside 1has been isolated and characterized form ethanolic extract of leaves part of Glycosmis arborea. The structure of compound was verified by means of high field 1D and 2D NMR (DEPT, COSY, DQF-HSQC, HMBC) and HRMS spectral analysis, respectively.

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