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Nomex honeycomb composite (NHC) has been increasingly used in the automotive, aerospace and defence applications due to its excellent thermal and mechanical properties. Its complex cellular hexagonal thin-walled configuration along with heterogeneous, soft and brittle nature pose substantial processing defects such as burr formation, tearing of walls, surface roughness, dimensional inaccuracy and low machining quality during conventional machining (CM). These surface defects have a substantial influence on the operating life and functional performance of its sandwiched structural members. Hybrid ultrasonic vibration assisted machining (HUSVAM) technology has been introduced to overcome such limitations. For an in depth research on HUSVAM of NHC using ultrasonic toothed disc cutter (UTDC), three dimensional finite element model was developed and experimental validation was carried out. The numerical simulation and experimental results were found to be in good agreement with one another. The influence of various machining parameters including the ultrasonic tool vibration amplitude (UTVA), feed rate (FR), depth of cut (DoC) and spindle angular speed (SAS) on NHC cutting forces, chip formation and surface quality was investigated using both HUSVAM and CM techniques. Furthermore, stresses, deformation and forces near tool-workpiece interaction along with the surface topography and morphologies were also analysed and compared for various operating conditions. A reduction in the cutting forces was found with the increase of SAS and UTVA (up to 65.47 % and 65.74 %, respectively). Although, the cutting forces were observed to increase by increasing the DoC and FR (up to 159.45 % and 126.33 %, respectively). DoC has a greater impact on the cutting forces among all machining parameters according to 4 levels, 4 factors (L16) orthogonal experiments based on Taguchi method. The results show that the chip formation and machining quality of NHC core can be improved with HUSVAM technique using UTDC. HUSVAM also reduced the cutting forces (up to 73 %) compared to CM. The ultrasonic toothed disc cutter generated large number of burr with very short length, no tearing defects and no uncut fibers as observed from scanning electron microscopy of NHC hexagonal cell structure, walls and triple points. A burr formation of less than 10 % was realized during HUSVAM of NHC cores for Fx≤3N, while it was found up to 20 % if Fx>3N, compared to at least 40 % during CM. The finite element model developed can be used to investigate the influence of HUSVAM on modern difficult to machine materials for enhanced surface quality.

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Pro-environmental behavior has a significant role to play in environmental sustainability. There has been little research done on environmental higher education-renewable energy consumption nexus. This study examines the impact of environmental higher education on renewable energy consumption in China from 1997 to 2021. The ARDL results show that higher environmental education enhances renewable energy consumption in long run. Findings also show that internet usage and economic development encourage renewable energy consumption in the long run. However, financial development and internet usage have a short-term impact on renewable energy consumption in China. The QARDL estimates are robust, and the finding shows that environmental higher education has a positive impact on renewable energy consumption in short and long run at higher quantiles. The empirical findings have environmental implications for China in terms of achieving long-term environmental sustainability by embracing patterns of pro-environmental behavior.

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Lead-free ceramics are promising candidates for replacing lead-based piezoelectric materials such as lead-zirconate-titanate (PZT) if they can compete in dielectric and ferroelectric characteristics. In this work, for lead-free piezoelectric ceramic, 0.74(Bi0.5Na0.5TiO3)-0.26(SrTiO3) (BNT-ST26) and niobium-substituted (Nb-BNT-ST26) ceramics were synthesized by solid-state reactions. The evolution of niobium substitution to the perovskite phase structure of BNT-ST26 ceramics was confirmed by X-ray diffraction (XRD) analysis and Raman spectra. Electromechanical properties of Nb-BNT-ST26 ceramics initially increased with the addition of niobium up to 0.5% and decreased with a further increase in Nb content. Temperature-dependent dielectric curves showed that the depolarization temperature (Td) decreased below room temperature because of Nb substitution. The composition with 0.5% Nb yielded a maximum bipolar strain (Smax) of 0.265% and normalized strain of d33* ~ 576 pm/V under an electric field of 4.6 kV/mm at room temperature. At this critical concentration of 0.5% Nb, maximum saturation polarization of 26 µC/cm2 was achieved. The dielectric constant with temperature peaks became more diffused and the depolarization temperature decreased with the increasing Nb content. The study concludes that Nb-doped BNT-ST26 is an excellent material for high-temperature, stable, frequency-dependent, lead-free piezoelectric devices.

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A bulk of literature has examined the asymmetric impact of renewable energy consumption on CO2 emissions by using the advanced econometric approach. While the asymmetric role of renewable energy production in the CO2 equation is largely unknown, our present study quantifies the asymmetric relationship between renewable energy production, natural resources, economic progress, and CO2 emission for Pakistan by using the NARDL approach. It is found that positive change in renewable energy production has a positive effect on CO2 emissions, while a negative change in renewable energy production has a negative effect on CO2 emissions in the long run. Furthermore, a positive and negative change in natural resources contributes negatively to CO2 emissions in the long run. The results reveal that a positive change in economic progress significantly increases CO2 emissions in the long run. Based on findings, Pakistan's government should encourage local and international investors to increase their investment in the production of renewable energy by reducing environmental degradation.

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It is observed that an educated labor force can increase the absorption capacity of the economy and improve the effectiveness of green technologies that lead to a reduction in potential CO2 emissions. The study investigates whether an educated labor force contributes to the management of the green economy or not in BRCS economies. Panel ARDL-PMG and NARDL-PMG approaches have been employed for empirical analysis for data ranging from 1995 to 2019. According to the ARDL-PMG results, a highly educated labor force contributes to alleviating CO2 emissions in the long run. In contrast, the findings of NARDL-PMG infer that positive component of a highly educated labor force has a significant negative impact on CO2 emissions, while negative component of a highly educated labor force has a positive impact on CO2 emissions in the long run. The study suggests that BRCS countries' policymakers should promote education and training for the labor force to maintain a reduction in CO2 emissions.

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With rapid economic growth, BRICS is facing enormous burdens of carbon emission and severe issues of income inequality. However, behind this economic success, the BRICS economies also face few thoughtful challenges to improve environmental quality by catching up the sustainable development goals. Consequently, the existing empirical research is concerned with the dynamic links between income inequality and CO2 emissions by using the novel nonlinear ARDL approach, but small attention has been paid to the BRICS in literature. Therefore, we observed that a negative and positive change in income inequality has positive effect on CO2 emissions in Russia and South Africa in the long run, although a positive change in income inequality has positive effects on CO2 emissions in Brazil, Russia, and China, while a negative change in income inequality has negative effect on CO2 emissions in India, Brazil, and Russia in the short run. Hence, the findings value specific attention from policymakers in BRICS economies.

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This empirical study investigates the dynamic effects of economic freedom on economic growth and air quality for Pakistan over the period 1990-2019. The ARDL results suggest that economic freedom and other variables do not have any visible impact on economic growth and pollution in the short-run. However, in the long-run, economic freedom significantly mitigates air pollution whereas inflation instability increases emissions. The NARDL results show that a partial sum of positive change in economic freedom is negatively linked with economic growth in the short term but has positive effect in the long term. However, the negative change in economic freedom has negative but insignificant impact on growth confirming asymmetric effects. The results for the pollution model show that a partial sum of positive change in economic freedom has positive impact on emissions both in the short and long-runs, whereas a negative change has no significant effect in the short-run and has negative impact in the long-run. Thus, economic freedom supports economic activities that, in turn, escalate emissions in the atmosphere.

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This study contemplates the factors that influence consumer intention, before and during the eruption of COVID-19, for the selection of healthy packaged food in Pakistan. The extant studies have identified two distinct attitudes of consumers about food label information: one is its usefulness and the second elucidates the avoidance. Hence forth, the current study contributes to the extant literature while signifying both reasons which motivate consumers to read food labels and reasons which discourage consumers from consult food labels at the point of purchase. Moreover, the impact of subjective norms and self-efficacy for healthy packaged food intentions has also been examined for both before the emergence of COVID-19 and during the spread of COVID-19. The underpinning of the proposed model has been justified by the behavioral reasoning theory. The cross-sectional data of 14,455 students has was collected from 10 universities through Microsoft Teams and Zoom. AMOS 21 was employed for the final analysis. The results indicate that before COVID-19 the subjective norms and self-efficacy were not the stimulating factors for the selection of healthy packaged food. On the contrary, during the COVID-19 outbreak, the subjective norms and self-efficacy divulged a significant effect. Moreover, the reasons to consult food labels are positively significant whereas the reasons to avoid food labels have negatively affected the consumer, both before COVID-19 and during COVID-19 outbreak, while endorsing healthy packaged food. Conclusively, COVID-19 has been proved to be a deterrent for unhealthy packaged food lovers while being a blessing for healthy packaged food.

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Climate change due to global warming is becoming a major global issue over the past few decades. The emission of carbon dioxide (CO2) and other greenhouse gasses cause global warming. Most carbon emissions come from energy sectors, whereas transportation, industrial, and residential sectors are among the chief contributors. The present study investigates the effect of fiscal policy instruments, economic development, and foreign direct investment (FDI) on the sectoral emissions in Belt and Road Initiative (BRI) countries. The data used in this study is taken from the World Development Indicators (WDI) for the period between 2000 and 2018. Dynamic ordinary least squares (DOLS) and fully modified ordinary least squares (FMOLS) have been used to analyze the long-run impact of fiscal policy instruments, economic development, and FDI on CO2 emissions from transportation, energy, and industrial sectors. Furthermore, the pairwise Dumitrescu and Hurlin panel causality test was used to authorize the causal relationship among the variables under consideration. The results reveal that fiscal policy instruments, per capita gross domestic product, FDI, and CO2 emissions show a strong correlation in the industrial, electrical, and transportation sectors. Furthermore, it is shown that public spending is a more reliable tool to reduce CO2 emissions in the transportation and industrial sectors in the BRI region. This study provides useful information for policy-makers on taking preventive and corrective measures to reduce CO2 emissions in different sectors and promote sustainable development.

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To overcome the inherent weakness of polylactic acid (PLA), used as scaffolding materials, multiple samples of Mg/PLA alloy composite materials was made by plastic injection molding. To enhance the interfacial interaction with PLA, magnesium alloy was treated with microarc oxidation (MAO) at four different frequencies, resulting in an improvement in mechanical strength and toughness. The microarc oxidation films consisted mainly of a porous MgO ceramic layer on the Mg rod. Based on the phenomenon of micro-anchoring and electrostatic interaction, a change in frequency during MAO showed considerable improvements in the ductility of the composite materials. The presence of the ceramic layer enriched the interfacial bonding between the Mg rod and outer PLA cladding, resulting in the PLA-clad Mg rod showing a higher tensile strength. In vitro degradation test was carried out in Hank's solution for different time periods. Surface-treated Mg alloy-based composite samples displayed a lower degradation rate as compared to untreated Mg alloy samples. The surface-treated sample at a 800 Hz pulse frequency showed the best degradation resistance and mechanical properties after being immersed in Hank's solution as compared to other samples. Mg-reinforced PLA composite rods are promising candidates for orthopedic implants.

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The social cognitive theory emphasizes the risk-taking behavior of an entrepreneur, which leads him to make the right decisions. In this regard, this study formulates the concept of the cognitive CEO through the DAE statistical technique. Specifically, CEO attributes such as CEO age, CEO compensation, CEO tenure, goodwill, and the number of CEO-attended meetings are used as inputs that influence the intangible assets, the output. Chinese SMEs have been selected for empirical analysis for the years 2014-2018. The empirical results reveal that having a cognitive CEO augmented corporate sustainability, while agency cost and the number of supervisors strongly diminished corporate sustainability. Meanwhile, high earnings per share and high total assets are vehicles for maintaining the sustainable growth of firms. Additionally, it is indicated that firms with a loan burden cannot maintain sustainable corporate growth. Lastly, the execution of 2SLS and GMM instrumental regressions authenticate the veracity of results.

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In this study, electromechanical characteristics of (1-x) Bi0.5Na0.5TiO3-xSrTiO3 (ST26, x = 0.26)/(1-y) Bi0.5Na0.5TiO3-ySrTiO3 (ST10, y = 0.1) (matrix/seed) composites were studied. The ST26 (high relaxor phase) and ST10 (a relaxor ferroelectric (RF), high ferroelectric phase) composite with large (r-ST26-ST10) and small (t-ST26-ST10) grains exhibited frequency-related dielectric properties and large strain response at a low triggering electric field (an incipient piezoelectricity). It is ascribed to a matrix-seed effect originating from the inhomogeneous composition due to the presence of two phases. The r-ST26-ST10 composite sintered at 4 h, prominent material, showed a high normalized dynamic strain (d33*) of ~700 pm/V (large grains) with stable frequency dependence properties at a low field of 40 kV/cm. The properties of the r-ST26-ST10 composite exhibit less decay with frequency-related polarization and strain compared to those of t-ST26-ST10 composite. The increase in soaking time promotes the diffusion and homogenization of the microstructure in composites, leading to changes in the core-shell structure in the solid solution. The polarization and strain of the ST26-ST10 composites with the frequency are linked to the stability of the internal random fields created by non-ergodic relaxor phase of seed and the amount of phase change in the ergodic relaxor matrix.