Showing papers by "Georgia Institute of Technology published in 2022"
TL;DR: In this paper, a cotton-derived cellulose film was used as the separator for aqueous zinc-ion batteries (Zn-MnO2), which can effectively inhibit zinc dendrites and harmful side reactions.
138 citations
TL;DR: The Post-hospitalisation COVID-19 study (PHOSP-COVID) as mentioned in this paper is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID19 across the UK.
118 citations
TL;DR: In this article, a review of the current advances and future directions in plastic waste upcycling technologies are discussed, focusing on the production of high-value materials from plastic waste conversion methods, including pyrolysis, gasification, photoreforming, and mechanical reprocessing.
113 citations
TL;DR: In this paper , the authors derived the expanded Maxwell's equations in differential form by assuming that the medium is moving as a rigid translation object and further developed with including the polarization density term Ps in displacement vector owing to electrostatic charges on medium surfaces as produced by effect such as triboelectrification, based on which the first principle theory for the TENGs is developed.
65 citations
TL;DR: In this article, a breeze-driven triboelectric nanogenerator (BD-TENG) was proposed to efficiently harvest breeze energy in the farmland environment, which can be widely used in farmland environments to provide energy for agricultural sensor networks.
63 citations
TL;DR: In this paper , an in situ electrically driven tunable metasurface by harnessing the full potential of a phase-change materials alloy, Ge 2 Sb 2 Te 5 (GST), was demonstrated.
Abstract: Abstract Phase-change materials (PCMs) offer a compelling platform for active metaoptics, owing to their large index contrast and fast yet stable phase transition attributes. Despite recent advances in phase-change metasurfaces, a fully integrable solution that combines pronounced tuning measures, i.e., efficiency, dynamic range, speed, and power consumption, is still elusive. Here, we demonstrate an in situ electrically driven tunable metasurface by harnessing the full potential of a PCM alloy, Ge 2 Sb 2 Te 5 (GST), to realize non-volatile, reversible, multilevel, fast, and remarkable optical modulation in the near-infrared spectral range. Such a reprogrammable platform presents a record eleven-fold change in the reflectance (absolute reflectance contrast reaching 80%), unprecedented quasi-continuous spectral tuning over 250 nm, and switching speed that can potentially reach a few kHz. Our scalable heterostructure architecture capitalizes on the integration of a robust resistive microheater decoupled from an optically smart metasurface enabling good modal overlap with an ultrathin layer of the largest index contrast PCM to sustain high scattering efficiency even after several reversible phase transitions. We further experimentally demonstrate an electrically reconfigurable phase-change gradient metasurface capable of steering an incident light beam into different diffraction orders. This work represents a critical advance towards the development of fully integrable dynamic metasurfaces and their potential for beamforming applications.
62 citations
TL;DR: In this paper, the modified Ti3C2Tx is combined with soybean stalk-derived nanofibrillated cellulose, which can improve mechanical properties, prevent dense packing of Ti3c2Tx, and facilitate the transport of electrolyte ions.
55 citations
TL;DR: In this paper, the relative contribution of various shedding routes on SARS-CoV-2 RNA loads in wastewater was assessed using a Monte Carlo framework, and the authors concluded that the greatest source of variability was viral load in excreta.
47 citations
TL;DR: In this article, cobalt and nitrogen co-doped carbonized wood sponge (CoNCWS800) was prepared successfully for peroxymonosulfate (PMS) activation to degrade sulfamethoxazole (SMX).
46 citations
TL;DR: In this article , the authors extended a previously validated microsimulation model that estimated the short and long-term effect of increased drinking during the COVID-19 pandemic in individuals in the United States born between 1920 and 2012.
42 citations
TL;DR: In this paper , a simple and effective method is proposed for quantitatively identifying and extracting the piezoelectric charge from the hybrid signal generated by a polyvinylidene fluoride-based device.
Abstract: Polymer-based piezoelectric devices are promising for developing future wearable force sensors, nanogenerators, and implantable electronics, etc. The electric signals generated by them are often assumed as solely coming from the piezoelectric effect. However, triboelectric signals originated from contact electrification between the piezoelectric devices and the contacted objects can produce non-negligible interfacial electron transfer, which is often combined with the piezoelectric signal to give a triboelectric-piezoelectric hybrid output, leading to an exaggerated measured "piezoelectric" signal. Herein, a simple and effective method is proposed for quantitatively identifying and extracting the piezoelectric charge from the hybrid signal. The triboelectric and piezoelectric parts in the hybrid signal generated by a poly(vinylidene fluoride)-based device are clearly differentiated, and their force and charge characteristics in the time domain are identified. This work presents an effective method to elucidate the true piezoelectric performance in practical measurement, which is crucial for evaluating piezoelectric materials fairly and correctly.
TL;DR: Computer vision is used to quantify street-level factors from street view images in Atlanta, Georgia, USA to indicate that the streetscape factors can significantly contribute to explaining walking mode choice and that streetscape Factors can have a greater association with Walking mode choice than neighborhood- level factors.
Abstract: The built environment characteristics associated with walkability range from neighborhood-level urban form factors to street-level urban design factors. However, many existing walkability indices a...
TL;DR: In this article , a novel lip-language decoding system with self-powered, low-cost, contact and flexible triboelectric sensors and a well-trained dilated recurrent neural network model based on prototype learning is proposed.
Abstract: Lip language is an effective method of voice-off communication in daily life for people with vocal cord lesions and laryngeal and lingual injuries without occupying the hands. Collection and interpretation of lip language is challenging. Here, we propose the concept of a novel lip-language decoding system with self-powered, low-cost, contact and flexible triboelectric sensors and a well-trained dilated recurrent neural network model based on prototype learning. The structural principle and electrical properties of the flexible sensors are measured and analysed. Lip motions for selected vowels, words, phrases, silent speech and voice speech are collected and compared. The prototype learning model reaches a test accuracy of 94.5% in training 20 classes with 100 samples each. The applications, such as identity recognition to unlock a gate, directional control of a toy car and lip-motion to speech conversion, work well and demonstrate great feasibility and potential. Our work presents a promising way to help people lacking a voice live a convenient life with barrier-free communication and boost their happiness, enriches the diversity of lip-language translation systems and will have potential value in many applications.
TL;DR: In this article, a switch reduction scheme on reverse-blocking device bridges is proposed to reduce device count and the number of devices on the dc-link current path, which can be applied to the dc ports of dc-ac, ac-dc, or dc-dc hardswitching or soft-switching CSC-based SSTs.
Abstract: Solid-state dc transformer to integrate low-voltage dc (LVdc) microgrid, wind turbine (WT) generator, photovoltaic (PV), and energy storage (ES) into medium-voltage (MV) direct-current (MVdc) distribution grids is attractive. This article proposes current-source dc solid-state transformer (SST) for MVdc collection system in WT, PV, and ES farms or as an interface between the MVdc grid and the LVdc microgrid. Compared to conventional current-source converter (CSC) based SSTs, a switch reduction scheme on reverse-blocking device bridges is proposed to reduce device count and the number of devices on the dc-link current path. Importantly, the proposed switch reduction scheme is generic and can be applied to the dc ports of dc–ac, ac–dc, or dc–dc hard-switching or soft-switching CSC-based SSTs. Based on this scheme, the proposed current-source dc SSTs are derived, which have reduced electrolytic-capacitor-less dc-link. The proposed dc SSTs also achieve single-stage isolated dc–dc or dc–ac conversion, full-range zero-voltage switching (ZVS) for main switches, zero-current switching (ZCS) for resonant switches, and controlled $ dv/dt $ . The proposed dc SSTs, operating principles, predictive control method, the ZVS, and the controlled $ dv/dt $ under voltage buck-boost ranges are verified with MV simulations and an experimental prototype based on SiC mosfets , diodes, and a nanocrystalline transformer.
TL;DR: Wang et al. as mentioned in this paper conducted the patent analysis combined with text mining to quantitatively analyze 11,840 patents related to industrial wastewater treatment in the Derwent Innovations Index database.
TL;DR: In this article, a triboelectric nanogenerator for respiratory sensing (RS-TENG) has been designed and integrated with facemask, which endows the latter with respiratory monitoring function.
TL;DR: In this article , a triboelectric nanogenerator for respiratory sensing (RS-TENG) has been designed and integrated with facemask, which endows the latter with respiratory monitoring function.
TL;DR: In this article, a wheel-disk-shaped TENG based on natural pollution-free cotton is reported for simultaneously harvesting wind and water energy, which not only presents a feasible solution for sustainable and clean energy harvesting, but also provides a reliable self-powered sensor for environmental monitoring.
TL;DR: The micrometer-sized H-Nb 2 O 5 could achieve fast lithium-ion storage by engineering its planar defects as mentioned in this paper , but its performance was limited by the number of defects.
Abstract: The micrometer-sized H-Nb 2 O 5 could achieve fast lithium-ion storage by engineering its planar defects.
TL;DR: In this paper , the performance enhancement of reversible protonic ceramic electrochemical cells (R-PCECs) using a novel heterostructured air electrode, consisting of a double perovskite PrBaCo1.6Fe 0.2Nb0.2−xO5+δ backbone covered with in situ exsolved nanoparticles of Nb-deficient nanoparticles was reported.
Abstract: The development of active and durable air electrodes is of great significance to the maturity of reversible protonic ceramic electrochemical cells (R-PCECs). This article reports the recent findings in the performance enhancement of R-PCECs using a novel heterostructured air electrode, consisting of a double perovskite PrBaCo1.6Fe0.2Nb0.2O5+δ backbone covered with in situ exsolved nanoparticles of Nb-deficient PrBaCo1.6Fe0.2Nb0.2−xO5+δ. Such a heterostructured electrode is induced by the benign interaction of the electrode and steam during the cell operation, showing a faster surface exchange process, as confirmed by a mapping of high-angle annular dark-field transmission electron microscopy image, and distribution of relaxation time analyses of the electrochemical impedance spectra. The in situ formed Nb-deficient nanoparticles and Nb-rich parental perovskite significantly enhance the catalytic activity and durability of the air electrode toward oxygen reduction/evolution reaction on single cells at 650 °C, achieving a peak power density of 1.059 W cm−2 in fuel cell mode, a current density of 2.148 A cm−2 at 1.3 V in electrolysis cell mode, and good durability of a cycling test at ±0.5 A cm−2 for 200 h in dual modes of fuel cell and electrolysis cell.
TL;DR: In this article , a simple and universal method has been developed to improve the output performance of TENGs by a dielectric enhancement effect, which has been verified by comparison experiments for all types of Tengs.
TL;DR: In this article , the authors proposed a method for quantifying the maximum triboelectric charge and energy densities of a dielectric material based on both theoretical analyses and experimental results.
Abstract: Abstract Triboelectric charge density and energy density are two crucial factors to assess the output capability of dielectric materials in a triboelectric nanogenerator (TENG). However, they are commonly limited by the breakdown effect, structural parameters, and environmental factors, failing to reflect the intrinsic triboelectric behavior of these materials. Moreover, a standardized strategy for quantifying their maximum values is needed. Here, by circumventing these limitations, we propose a standardized strategy employing a contact-separation TENG for assessing a dielectric material’s maximum triboelectric charge and energy densities based on both theoretical analyses and experimental results. We find that a material’s vacuum triboelectric charge density can be far higher than previously reported values, reaching a record-high of 1250 µC m −2 between polyvinyl chloride and copper. More importantly, the obtained values for a dielectric material through this method represent its intrinsic properties and correlates with its work function. This study provides a fundamental methodology for quantifying the triboelectric capability of dielectric materials and further highlights TENG’s promising applications for energy harvesting.
TL;DR: Wang et al. as discussed by the authors found that MSW-derived biochar possesses great potential in wastewater purification by adsorption and catalysis, which facilitates the popularization of the innovative mode "waste control by waste" in aquatic environment remediation.
Abstract: A huge amount of municipal solid waste (MSW) is produced with urbanization process, posing serious threats to the surroundings and human health. The preparation of MSW-derived biochar is an effective strategy for the waste reclamation. MSW-derived biochar possesses great potential in wastewater purification by adsorption and catalysis. In this review, biochar prepared from classified MSW (e.g. food waste and waste paper) was found with larger specific surface area and porosity than the mixed MSW-derived biochar. Meanwhile, pre-treatment and post-treatment means are summarized to improve the structure and composition of biochar, which could further strengthen its adsorption capacity and catalytic activity. The -COOH, -C = O, -C = C, -OH group sites and aromatic structure of MSW-derived biochar could adsorb pollutants through electrostatic interaction, surface complexation, ion exchange, hydrogen bonding and π-π interaction. Moreover, thanks to the -COOH, -C = O, -OH groups, N-doped structures, defective sites and iron ion species, the food waste-derived biochar exhibits excellent persulfate activation properties. Finally, the future challenges and research directions are suggested, which is conductive to promoting the resource utilization of MSW. Some consideration and recommendation about MSW-derived biochar for water treatment are provided, which facilitates the popularization of the innovative mode “waste control by waste” in aquatic environment remediation.
TL;DR: In this article, microbubble (MB) ultrasound contrast agents in conjunction with ultrasound energy to locally increase the permeability of brain vessels and modulate the brain TME are discussed.
TL;DR: In this article , a highly reversible fiber-shaped Zn anode with controlled deposition morphology is developed based on theoretical calculation guided design of highly zincophilic 3D metal-organic-frameworks derived carbon with N,O-MOFC scaffold, by regulating electroplating chemistry of the initial nucleation and crystal growth time of zinc metal.
TL;DR: In this article, a population-based cohort study, comprising all Medicare enrollees aged 65 or older in the southeastern United States from 2000 to 2016, was conducted to explore the associations between long-term exposure to fine particulate matter (PM2.5) mass and all-cause mortality among the elderly.
TL;DR: In this article, the presence of these nonlinear gusts are becoming more and more prevalent and they induce flow separation and other complexities when they interact with the lifting surfaces of air vehicles.
Abstract: Gusts of moderate and large magnitude induce flow separation and other complexities when they interact with the lifting surfaces of air vehicles. The presence of these nonlinear gusts are becoming ...
TL;DR: In this paper, a low-cost and multifunctional nanofiller (aminoquinoline-functionalized graphene oxide, AQL-GO) is synthesized, which ingeniously achieved the above-mentioned requirements of polyimide nanocomposites by nucleophilic attack of QL and chaotic packing of the polymer chain.
Abstract: Low-temperature curable and low-dielectric polyimides (PIs) are required in wafer-level packaging (WLP) which is an advanced microelectronic packaging technology. Herein, a low-cost and multifunctional nanofiller (aminoquinoline-functionalized graphene oxide, AQL-GO) is synthesized, which ingeniously achieved the above-mentioned requirements of polyimide nanocomposites by nucleophilic attack of QL and chaotic packing of the polymer chain. The results show that the nanocomposite can be fully cured at only 200 °C and have a low dielectric constant ( 2.96@1 MHz) with 0.5 wt% addition of AQL-GO. Furthermore, the mechanical and thermal properties of all nanocomposites cured at 200 °C (the elongation at break can reach 39.69%, the Young's modulus can reach 2.38 GPa and T5% can reach 530.55 °C) are almost equal or even better than those of pure PI cured at 350 °C. Therefore, the PI/AQL-GO nanocomposites have industrial prospects in advanced microelectronic packaging.
TL;DR: The authors found that finance companies and FinTech lenders increased their lending to small businesses after the 2008 financial crisis and that most of the increase substituted for a reduction in bank lending, and that there was no effect of reduced bank lending on employment, wages, and new business creation by 2016.
Abstract: Abstract We document that finance companies and FinTech lenders increased lending to small businesses after the 2008 financial crisis. We show that most of the increase substituted for a reduction in bank lending. In counties in which banks had a larger market share before the crisis, finance companies and FinTech lenders increased their lending more. We find no effect of reduced bank lending on employment, wages, and new business creation by 2016. Our results suggest that finance companies and FinTech lenders are major suppliers of credit to small businesses and played an important role in the recovery from the 2008 financial crisis. Authors have furnished an Internet Appendix, which is available on the Oxford University Press Web site next to the link to the final published paper online
TL;DR: In this article, a generalized additive model was applied to investigate the relationship between short-term exposure to PM2.5/O3 and COVID-19 confirmed cases, and the statistically significant results indicated that, with every 10 μg/m3 increase in mean pollutant concentration, the number of daily confirmed cases increases by 9.41% (CI: 8.77%-10.04%).