Harnessing the abundant availability of spectral resources at millimeter wave (mmWave) frequencies is an attractive solution to meet the escalating data rate demands. Additionally, it has been shown ...that full-duplex (FD) communication has the potential of doubling the bandwidth efficiency. However, the presence of significant residual self-interference (SI), which is especially more pronounced at mmWave frequencies because of the non-linearities in the hardware components, erodes the full potential of FD in practice. Conventionally, the residual SI is canceled in the baseband using digital processing with the aid of a transmit precoder. In this work, we propose a hybrid beamforming design for FD mmWave communications, where the SI is canceled by the joint design of beamformer weights at the radio-frequency and the precoder as well as combiner in the baseband. Our proposed design preserves the dimensions of the transmit signal, while suppressing the SI. We demonstrate that our joint design is capable of reducing the SI by upto 30 dB, hence performing similarly to the interference-free FD system while being computationally efficient. Our simulation results show that the proposed design significantly outperforms eigen-beamforming.
This article attempts to offer a critique of cultural critic D. R. Nagaraj’s theoretical approach to the analysis of contemporary Dalit literature. According to Nagaraj, contemporary Dalit literature ...is a literature of decultured Dalits which articulates rights and entitlements in liberal polity. Rejecting claims of a separate aesthetics for Dalit literature, he locates Dalit literary contributions in the broad sphere of Indian culture and argues for a new aesthetics for Indian culture. His aim is to recover from the Indian tradition the civilizational contribution of Dalit writers, such as folk and oral cultural forms. This framework undermines the theoretical innovation and aesthetic significance of contemporary Dalit literature. Proposing Dalit literature as a form of contemporary politics in the sphere of modern Indian literary culture, Marathi Dalit critic and writer Baburao Bagul presents Dalit literature as a modern, written, and Ambedkarite tradition that reconfigured modernity, invented new modes of writing, and imagined Dalit as a generic identity, lived experience, and perspective in modern Indian literary history. Dalit literature is human and democratic, Bagul argues, as it draws on the humanist legacy of Buddha, Christ, Phule, Ambedkar, and also the Western Enlightenment. A reading of some Dalit texts, following the discussion of Bagul, illustrates the limitations of Nagaraj’s approach.
Among the main contributors to the gross domestic product of all countries are their natural resources, whose improper utilization adds problems to the lack of proper data on their availability and ...structure/property correlations. If these data were made available, they would help in achieving objectives of value addition and employment generation. This paper describes the availability of some of the Brazilian lignocellulosic fibers, their market, extraction methods, reported morphology, properties and their present applications. Some perspectives for these fibers are also presented, considering their growing importance and their whole spectrum of promising opportunities and challenges for Brazil and other developing countries.
Harnessing the substantial bandwidth available at millimeter wave (mmWave) carrier frequencies has proved to be beneficial to accommodate a large number of users with increased data rates. However, ...owing to the high propagation losses observed at mmWave frequencies, directional transmission has to be employed. This necessitates efficient beam-alignment for a successful transmission. Achieving perfect beam-alignment is however challenging, especially in the scenarios when there is a rapid movement of vehicles associated with ever-changing traffic density, which is governed by the topology of roads as well as the time of the day. Therefore, in this paper, we take the approach of fingerprint based beam-alignment, where a set of beam pairs constitute the fingerprint of a given location. Furthermore, given the time-varying traffic density, we propose a multi-fingerprint based database for a given location, where the base station (BS) intelligently adapts the fingerprints with the aid of learning. Additionally, we propose multi-functional beam transmission as an application of our proposed design, where the beam-pairs that satisfy the required received signal strength (RSS) participate in increasing the spectral efficiency or improving the end-to-end performance in some other way. Explicitly, the BS leverages the plurality of beam-pairs to attain both multiplexing and diversity gains. Furthermore, if the plurality of beam-pairs is higher than the number of RF chains, the BS may also employ beam-index modulation to further improve the spectral efficiency. We demonstrate that having multiple fingerprint-based beam-alignment provides superior performance than that of the single fingerprint based beam-alignment. Furthermore, we show that our learning-aided multiple fingerprint design provides a better fidelity compared to that of the benchmark scheme also employing multiple fingerprint but dispensing with learning. Additionally, our reduced-search based learning-aided beam-alignment design performs similarly to beam-sweeping based beam-alignment, even though an exhaustive beam-search is carried out by the latter. More explicitly, our design is capable of maintaining the target performance in dense vehicular environments, while both single fingerprint and line-of-sight (LOS) based beam-alignment suffer from blockages.
Described here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This ...methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.
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Design of adsorbents with high stability and efficiency to achieve rapid uptake and high capacity for dye pollutants is a key challenge in environmental remedies. Herein, we have design and ...synthesized three triazene-based imine and azine functionalized covalent organic frameworks (COFs 1–3) via the formation of imine bonds by the condensation of a flexible tripodal tri aldehyde (TFPT) with linear diamines. The COFs are characterized by elemental analysis, FTIR, solid-state NMR, TGA, FESEM, TEM, and DRS. They exhibit permanent porosity with high surface areas and N2 uptake capacities of 540, 1600, and 2235 cc/g by COFs 1–3, respectively. They are found to be chemically and thermally stable and exhibit moderate hydrogen storage capacities. Photophysical studies reveal that COFs 1–3 exhibited low band gap values of 3.0, 2.5, and 2.25 eV, respectively, indicating their semiconducting nature. All three materials are highly luminescent, and their emission maxima are found to depend on the nature of the diamine linker. Further, COFs 1–3 are highly stable in water and function as robust adsorbents, as evidenced by their high rapid uptake capacity (>96%) toward anionic (MO, CR) and cationic (MB, CV) organic dye pollutants from their respective aqueous solutions (2.5 × 10–5 M).
Invited for the cover of this issue is the group of Jon C. Antilla at Zhejiang Sci‐Tech University. The image depicts asymmetric Rubottom‐type oxidation catalyzed by chiral calcium phosphates. Read ...the full text of the article at 10.1002/chem.202203720.
•First report on the biosynthesis of Ag NPs using Boerhaavia diffusa plant extract.•Act as a good antibacterial agent against various fish bacterial pathogens.•Ag NPs were characterized with UV–Vis, ...XRD, SEM and TEM.•Ag NPs were spherical shape with average size of about 25nm.
Green synthesis of silver nanoparticles was carried out using Boerhaavia diffusa plant extract as a reducing agent. The biosynthesized AgNPs were characterized by SEM-EDAX, XRD, TEM, UV–Vis, and FT-IR spectroscopy techniques. UV–Vis spectroscopy of prepared silver colloidal solution showed absorption maxima at 418nm. XRD and TEM analysis revealed that AgNPs are face-centered, cubic structure being spherical in shape with an average particle size of 25nm. The AgNPs were tested for antibacterial activity against three fish bacterial pathogens viz., Aeromonas hydrophila, Pseudomonas fluorescens and Flavobacterium branchiophilum and they demonstrated highest sensitivity toward F. branchiophilum when compared to other two bacterial pathogens.
Design and synthesis of stable, active and cost-effective electrocatalyst for water splitting applications is an emerging area of research, given the depletion of fossil fuels. Herein, two ...isostructural Ni
redox-active metal-organic frameworks (MOFs) containing flexible tripodal trispyridyl ligand (L) and linear dicarboxylates such as terephthalate (TA) and 2-aminoterphthalate (H
NTA) are studied for their catalytic activity in oxygen evaluation reaction (OER). The 2D-layered MOFs form 3D hydrogen bonded frameworks containing one-dimensional hydrophilic channels that are filled with water molecules. The electrochemical studies reveal that MOFs display an efficient catalytic activity towards oxygen evolution reaction in alkaline conditions with an overpotential as low as 356 mV. Further, these 2D-MOFs exhibit excellent ability to adsorb water vapor (180-230 cc g
at 273 K) and CO
(33 cc g
at 273 K). The presence of hydrophilic functionality in the frameworks was found to significantly enhance the electrocatalytic activity as well as H
O sorption.
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