Selective detection of preferential activity of Lanthanum ion at zinc oxide functionalized nanochannel.

A significant increase of rare earth transition metals concentration in water reservoirs caused by the dumping of household materials and petrol-producing industries is a potential threat to human and aquatic life. Here, we demonstrate a model nanofluidic channel for the Lanthanum (La3+) ions recognition. To this end, a single conical nanochannel is first modified with poly allylamine hydrochloride followed by immobilization of synthesized ZnO nanoparticles on the channel surface through electrostatic adsorption. A significant change in the nanopore electrical readout is noticed when the functionalized nanochannel is exposed to an electrolyte solution having La3+cations. The distinctive response by the nanofluidic system towards La3+ions is assumed to be due to ionic radii, hexagonal crystal structure, and associated basal plane interaction between anchored ZnO nanoparticles and La3+ions. We anticipate that this nanofluidic system can be used as a model to design highly sensitive metal ion detection devices.

Implementation of Resonant Electric Based Metamaterials for Electromagnetic Wave Manipulation at Microwave Frequencies.

In this paper, we present the application of a resonant electric based metamaterial element and its two-dimensional metasurface implementation for a variety of emerging wireless applications. Metasurface apertures developed in this work are synthesized using sub-wavelength sampled resonant electric-based unit-cell structures and can achieve electromagnetic wave manipulation at microwave frequencies. The presented surfaces are implemented in a variety of forms, from absorption surfaces for energy harvesting and wireless power transfer to wave-chaotic surfaces for compressive sensing based single-pixel direction of arrival estimation and reflecting surfaces. It is shown that the resonant electric-synthesized metasurface concept offers a significant potential for these applications with high fidelity absorption, transmission and reflection characteristics within the microwave frequency spectrum.

An approach to the pollution haven and pollution halo hypotheses in Asian countries.

Present climate change consists of global warming that is caused by the emission of greenhouse gases, generally carbon dioxide. The study examines the pollution haven, pollution halo, and environmental Kuznets curve for a number of Asian countries during the period of 1985 to 2020. Outcomes suggest that urbanization, gross domestic product per capita, energy consumption, and foreign direct investment inflow have positive effects, while gross domestic product square, foreign direct investment square, and tourism have negative effects on emissions of carbon dioxide. Furthermore, findings support the validity of the environmental Kuznets curve, pollution haven, and pollution halo hypothesis for the selected Asian countries. We also find robust results of rationality of the environmental Kuznets curve hypothesis for Pakistan, Bangladesh, India, China, Indonesia, Korea, Japan, Malaysia, Vietnam, and Singapore; of pollution haven hypothesis for Bangladesh, China, Indonesia, Japan, Pakistan, and Singapore; and of pollution halo hypothesis for Bangladesh, China, Indonesia, Japan, Pakistan, and Singapore.

Machine learning-assisted lens-loaded cavity response optimization for improved direction-of-arrival estimation.

This paper presents a millimeter-wave direction of arrival estimation (DoA) technique powered by dynamic aperture optimization. The frequency-diverse medium in this work is a lens-loaded oversized mmWave cavity that hosts quasi-random wave-chaotic radiation modes. The presence of the lens is shown to confine the radiation within the field of view and improve the gain of each radiation mode; hence, enhancing the accuracy of the DoA estimation. It is also shown, for the first time, that a lens loaded-cavity can be transformed into a lens-loaded dynamic aperture by introducing a mechanically controlled mode-mixing mechanism inside the cavity. This work also proposes a way of optimizing this lens-loaded dynamic aperture by exploiting the mode mixing mechanism governed by a machine learning-assisted evolutionary algorithm. The concept is verified by a series of extensive simulations of the dynamic aperture states obtained via the machine learning-assisted evolutionary optimization technique. The simulation results show a 25[Formula: see text] improvement in the conditioning for the DoA estimation using the proposed technique.

Do technological innovations promote green growth in the European Union?

The present study aims to investigate the impact of climate change technologies on green growth for a panel of overall European economies, Eastern, and Western European economies over 2000 to 2017. The study estimates the STIRPAT (stochastic impacts by regression on population, affluence, and technology) and IPAT (human impact, population, affluence, and technology) models with a particulate focus to address the issue of cross-sectional dependence and cross-sectional heterogeneity in the model by using Westerlund cointegration approach and fully modified ordinary least square (FMOLS) approach. After confirming the cointegration relationship, the findings indicate that in the case of IPAT model, energy-related climate change technology contributes towards green growth, while in case of STRIPAT model, environment-related budget tends to have favorable impact on green growth. However, other variables, such as transport and production-related climate change technologies along with energy consumption, tend to have negative impact on green growth. The findings are almost robust concerning Eastern and Western Europe. The findings indicate that renewable energy is pro-growth and thus the authorities concerned need to promote and encourage the use of renewable energy. In this regard, the role of public-private-partnership is important as well as policymakers need to allocate environment-related specific budget and extend exemption in taxes on the use of environment-friendly technologies. Renewable energy programs ensure an improved return on green growth, although costly to implement. Attention needs to be focused on technologies related to wind power, solar electricity, biogas for electricity and heat generation, and biofuels for transport from low initial levels. Thus, policymakers should focus on the positive impact of environmental regulations. Polluting industries should be taxed to adopt clean technologies and clean industries should be supported with tax exemption as an incentive. Moreover, the research and development (R&D) budget should be increased.

Single-pixel polarimetric direction of arrival estimation using programmable coding metasurface aperture.

This paper presents a single-pixel polarimetric compressive sensing (CS)-based direction of arrival (DoA) estimation technique using a cavity backed programmable coding metasurface aperture. The single-pixel DoA retrieval technique relies on a dynamically modulated waveform diversity, enabling spatially incoherent radiation masks to encode the incoming plane waves on the radar aperture using a single channel. The polarimetric nature of the wave-chaotic coded metasurface ensures that the DOA estimation is sensitive to the polarization state of the incoming waves. We show that the polarimetric single-pixel DoA concept can be realized by encoding the polarization information of the incoming waves at the physical layer level within the antenna. A dynamically reconfigurable wave-chaotic metasurface, which possesses a structured sparsity of dual-polarized coded metamaterial elements, is proposed for the proof of concept. It is shown that by encoding and compressing the source generated far-field incident waves into a single channel, we can retrieve high fidelity polarimetric DoA information from compressed measurements.

Millimeter-wave multi-mode circular antenna array for uni-cast multi-cast and OAM communication.

This paper investigates uni-/multi-cast and orbital angular momentum (OAM) mode data transmission in orthogonal directions by the utilization of a new circular antenna array, operating at 28 GHz. In the horizontal plane the proposed antenna array operates as multimode transmitter (i.e., it provides broad-, uni- and/or multi-cast communication), while in the vertical direction OAM transmission occurs (i.e., it is capable of generating up to 15 spatially orthogonal OAM modes). Antenna array is designed using twelve, low-complexity, electromagnetically coupled microstrip patch antennas with high radiation efficiency. Each of these can transmit power of equivalent order of magnitude in both horizontal (i.e., broadside radiation pattern) and vertical direction (i.e., endfire radiation pattern) over electromagnetic waves of orthogonal electric components. This property leads to the formation of uni-/multi-cast and OAM modes in the horizontal plane and vertical direction, respectively. Antenna was tested through full-wave electromagnetic analysis and measurements in terms of impedance matching, mutual coupling and radiation pattern: good agreement between simulated and measurement results was observed. Specifically, it presents up to 8.65 dBi and 6.48 dBi realized gain under the uni-cast (in the horizontal plane) and OAM mode (in the vertical plane), respectively. The proposed antenna array is perfect candidate for high spectral efficiency data transmission for 5G and beyond wireless applications, where orthogonality in communication links and OAM multiplexing is a requirement.

Design and analysis of Maxwell fisheye lens based beamformer.

Antenna arrays and multi-antenna systems are essential in beyond 5G wireless networks for providing wireless connectivity, especially in the context of Internet-of-Everything. To facilitate this requirement, beamforming technology is emerging as a key enabling solution for adaptive on-demand wireless coverage. Despite digital beamforming being the primary choice for adaptive wireless coverage, a set of applications rely on pure analogue beamforming approaches, e.g., in point-to-multi point and physical-layer secure communication links. In this work, we present a novel scalable analogue beamforming hardware architecture that is capable of adaptive 2.5-dimensional beam steering and beam shaping to fulfil the coverage requirements. Beamformer hardware comprises of a finite size Maxwell fisheye lens used as a scalable feed network solution for a semi-circular array of monopole antennas. This unique hardware architecture enables a flexibility of using 2 to 8 antenna elements. Beamformer development stages are presented while experimental beam steering and beam shaping results show good agreement with the estimated performance.

Analyzing extended STIRPAT model of urbanization and CO2 emissions in Asian countries.

CO2 emissions tend to increase more rapidly in underdeveloped economies as compared to developed countries mainly in China, India, and Asia. One of the aspects that accounts for the increasing CO2 emissions is urbanization (UR) and it is increasing all over the world particularly in Asian and African regions. The present study examines the impact of energy use and UR on carbon emissions over the period 1995 to 2018 while using the extended STIRPAT model for Asian countries. Panel co-integration techniques and Granger causality test are applied on selected variables. FMOLS and DOLS methods are also applied to check for robustness. Findings confirm the presence of long-run co-integration among variables. The outcomes propose that energy consumption and UR have positive impact on CO2 emissions and output. Outcomes also reveal that financial development (FD) has negative effect on emissions of CO2 but positive effect on economic growth. Results of Granger causality technique indicate that long-run causality association exists among emissions of CO2, economic growth, and UR. In the short run (SR), bidirectional causal relationship has been found between trade openness and FD.

Urbanization and energy consumption effects on carbon dioxide emissions: evidence from Asian-8 countries using panel data analysis.

The developing world is facing pivotal challenges in recent times. Among these, global warming has ominous repercussions on every segment of society, thus tracing its underlying causes is imperative. This research attempts to investigate the impact of urbanization and energy consumption on carbon dioxide emissions (CO2) for a panel of 8 Asian countries (Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, and Sri Lanka) over the period 1982 to 2017. The analyses are executed using panel co-integration and Granger causality techniques. The main findings of panel co-integration reveal a long-run relationship between urbanization, energy consumption, and CO2 emissions. Furthermore, the results indicate a positive and significant impact of urbanization and energy consumption on CO2 emissions, indicating that urban development and high energy consumptions are barriers to improve environmental quality in the long run. The results also highlight bi-directional causality between energy consumption and urbanization, while unidirectional causality exists between energy consumption and CO2 emissions. Based on the obtained results, this study offers useful policy implications for plummeting carbon emissions.

Maxwell Fisheye Lens Based Retrodirective Array.

A Maxwell fisheye lens using parallel plate index grading is presented in this study to develop a passive retrodirective antenna array. As a proof-of-concept a design frequency of 10 GHz was selected for fabrication and experiment. The design principals of the lens are discussed, which enables 85% energy flow at the drain probe (also referred to as image point) of the lens. It is shown that the image in the Maxwell fisheye lens has a point symmetry with a reverse phase, which makes it possible to realize passive retrodirective action using the lens. This arrangement is significantly more practical than previous passive retrodirective topologies due to the un-constrained number of connections to radiating elements that it can support without the need for multi-layer technology. In the realization described here, a cross-polarized microstrip patch antenna array is connected to the source and drain probes of the lens structure in order to form the retrodirective array. The strategy for selecting the optimal transmission line lengths required to connect the antennas to the lens for maximum re-radiation power is described and implemented. Experimental results for a prototype high efficiency passive retrodirective array based on the theoretical design considerations presented in this paper are reported.

Frequency-Diverse Computational Direction of Arrival Estimation Technique.

We present a frequency-diverse based direction of arrival (DoA) estimation technique for millimetre-wave (mmW) 5G channel sounding. Frequency-diversity enables the creation of spatially incoherent radiation masks to encode the plane-wave signals incident on the radar aperture using a single antenna. Leveraging the frequency-diversity concept, spatial information of the plane-wave projections on the radar aperture is retrieved, resulting in high-fidelity DoA estimations by means of a simple Fourier transform operation applied to the retrieved plane-wave projection patterns. It is demonstrated that using the frequency-diversity concept, DoA estimation can be achieved through a simple frequency sweep, compressing the incoming plane-waves into a single channel through the transfer function of the radar aperture. This results in a significant simplification in the system hardware, requiring only a single antenna to achieve DoA estimation. It is also shown that the proposed technique can simultaneously detect the DoA information for multiple sources with a diffraction limited resolution.