81 research outputs found
High-Performance Corrosion-Resistant Polymer/Graphene Nanomaterials for Biomedical Relevance
Initially, pristine polymers were used to develop corrosion-resistant coatings. Later, the trend shifted to the use of polymeric nanocomposites in anti-corrosion materials. In this regard, graphene has been identified as an important corrosion-resistant nanomaterial. Consequently, polymer/graphene nanocomposites have been applied for erosion protection applications. Among polymers, conducting polymers (polyaniline, polypyrrole, polythiophene, etc.) and nonconducting polymers (epoxy, poly(methyl methacrylate), etc.) have been used as matrices for anticorrosion
graphene nanocomposites. The corrosion-resistant polymer/graphene nanocomposites have found several important applications in biomedical fields such as biocompatible materials, biodegradable materials, bioimplants, tissue engineering, and drug delivery. The biomedical performance of the nanomaterials depends on the graphene dispersion and interaction with the polymers and living systems. Future research on the anti-corrosion polymer/graphene nanocomposite is desirable to perceive further advanced applications in the biomedical arenas
Coelectrodeposition of Ternary Mn-Oxide/Polypyrrole Composites for ORR Electrocatalysts: A Study Based on Micro-X-ray Absorption Spectroscopy and X-ray Fluorescence Mapping
Low energy X-ray fluorescence (XRF) and soft X-ray absorption (XAS) microspectroscopies at high space-resolution are employed for the investigation of the coelectrodeposition of composites consisting of a polypyrrole(PPy)-matrix and Mn-based ternary dispersoids, that have been proposed as promising electrocatalysts for oxygen-reduction electrodes. Specifically, we studied MnâCoâCu/PP, MnâCoâMg/PPy and MnâNiâMg/PPy co-electrodeposits. The MnâCoâCu system features the best ORR electrocatalytic activity in terms of electron transfer number, onset potential, half-wave potential and current density. XRF maps and micro-XAS spectra yield compositional and chemical state distributions, contributing unique molecular-level information on the pulse-plating processes. Mn, Ni, Co and Mg exhibit a bimodal distribution consisting of mesoscopic aggregates of micrometric globuli, separated by polymer-rich ridges. Within this common qualitative scenario, the individual systems exhibit quantitatively different chemical distribution patterns, resulting from specific electrokinetic and electrosorption properties of the single components. The electrodeposits consist of Mn3+,4+-oxide particles, accompanied by combinations of Co0/Co2+, Ni0/Ni2+ and Cu0,+/Cu2+ resulting from the alternance of cathodic and anodic pulses. The formation of highly electroactive Mn3+,4+ in the as-fabricated material is a specific feature of the ternary systems, deriving from synergistic stabilisation brought about by two types of bivalent dopants as well as by galvanic contact to elemental meta
Determination of Quantum Capacitance of Niobium Nitrides Nb2N and Nb4N3 for Supercapacitor Applications
none5siThe density of states and quantum capacitance of pure and doped Nb2N and Nb4N3 singlelayer and multi-layer bulk structures are investigated using density functional theory calculations. The calculated value of quantum capacitance is quite high for pristine Nb2N and decent for Nb4N3 structures. However for cobalt-doped unpolarized structures, significant increase in quantum capacitance at Fermi level is observed in the case of Nb4N3 as compared to minor increase in case of Nb2N. These results show that pristine and doped Nb2N and Nb4N3 can be preferred over graphene
as the electrode material for supercapacitors. The spin and temperature dependences of quantum capacitance for these structures are also investigatedopenBharti; Gulzar Ahmed; Yogesh Kumar; Patrizia Bocchetta; Shatendra SharmaBharti, ; Ahmed, Gulzar; Kumar, Yogesh; Bocchetta, Patrizia; Sharma, Shatendr
Polymer/Fullerene Nanocomposite for OptoelectronicsâMoving toward Green Technology
Optoelectronic devices have been developed using the polymer/fullerene nanocomposite, as focused in this review. The polymer/fullerene nanocomposite shows significant structural, electronics, optical, and useful physical properties in optoelectronics. Non-conducting and conducting polymeric nanocomposites have been applied in optoelectronics, such as light-emitting diodes, solar cells, and sensors. Inclusion of fullerene has further broadened the methodological application of the polymer/fullerene nanocomposite. The polymeric matrices and fullerene may have covalent or physical interactions for charge or electron transportation and superior optical features. Green systems have also been explored in optoelectronic devices; however, due to limited efforts, further design innovations are desirable in green optoelectronics. Nevertheless, the advantages and challenges of the green polymer/fullerene nanocomposite in optoelectronic devices yet need to be explored
Removal of Heavy Metals from Wastewater Using Novel Polydopamine-Modified CNTs-Based Composite Membranes
The presence of major heavy metals including Pb2+, Cu2+, Co2+, Ni2+, Hg2+, Cr6+, Cd2+, and Zn2+ in water is of great concern because they cannot degrade or be destroyed. They are toxic even at very low concentrations. Therefore, it is necessary to remove such toxicants from water. In the current study, polydopamine carbon nanotubes (PD-CNTs) and polysulfone (PS) composite membranes were prepared. The structural and morphological features of the prepared PDCN composite membranes were studied using FTIR, XRD, SEM, and EDS. The potential application of PDCNs for heavy metal removal was studied for the removal of Pb2+, Cr6+, and Cd2+ from wastewater. The maximum removal efficiency of 96.1% was obtained for Cr6+ at 2.6 pH using a composite membrane containing 1.0% PD-CNTs. The removal efficiencies decreased by 64.1 and 73.4, respectively, by enhancing the pressure from 0.50 up to 0.85 MPa. Under the same circumstances, the percentages of Pb+2 removal at 0.49 bar by the PDCNS membranes containing 0.5% and 1.0% PD-CNT were 70 and 90.3, respectively, and decreased to 54.3 and 57.0, respectively, upon increasing the pressure to 0.85 MPa. The results showed that PDCNS membranes have immense potential for the removal of heavy metals from water
Green-Synthesized Graphene for SupercapacitorsâModern Perspectives
Graphene is a unique nanocarbon nanostructure, which has been frequently used to form nanocomposites. Green-synthesized graphene has been focused due to environmentally friendly requirements in recent technological sectors. A very important application of green-synthesized graphene-based nanocomposite has been observed in energy storage devices. This state-of-the-art review highlights design, features, and advanced functions of polymer/green-synthesized graphene nanocomposites and their utility in supercapacitor components. Green graphene-derived nanocomposites brought about numerous revolutions in high-performance supercapacitors. The structural
diversity of conjugated polymer and green graphene-based nanocomposites has facilitated the charge transportation/storage capacity, specific capacitance, capacitance retention, cyclability, and durability of supercapacitor electrodes. Moreover, the green method, graphene functionality, dispersion, and matrixânanofiller interactions have affected supercapacitance properties and performance. Future research on innovative polymer and green graphene-derived nanocomposites may overcome design/performance-related challenging factors for technical usages
The Effect of Modifications of Activated Carbon Materials on the Capacitive Performance: Surface, Microstructure, and Wettability
none7siopenKouao Dujearic-Stephane; Meenal Gupta; Ashwani Kumar; Vijay Sharma; Soumya Pandit; Patrizia Bocchetta; Yogesh KumarDujearic-Stephane, Kouao; Gupta, Meenal; Kumar, Ashwani; Sharma, Vijay; Pandit, Soumya; Bocchetta, Patrizia; Kumar, Yoges
Lane Line Detection and Object Scene Segmentation Using Otsu Thresholding and the Fast Hough Transform for Intelligent Vehicles in Complex Road Conditions
An Otsu-threshold- and Canny-edge-detection-based fast Hough transform (FHT) approach to lane detection was proposed to improve the accuracy of lane detection for autonomous vehicle driving. During the last two decades, autonomous vehicles have become very popular, and it is constructive to avoid traffic accidents due to human mistakes. The new generation needs automatic vehicle intelligence. One of the essential functions of a cutting-edge automobile system is lane detection. This study recommended the idea of lane detection through improved (extended) Canny edge detection using a fast Hough transform. The Gaussian blur filter was used to smooth out the image and reduce noise, which could help to improve the edge detection accuracy. An edge detection operator known as the Sobel operator calculated the gradient of the image intensity to identify edges in an image using a convolutional kernel. These techniques were applied in the initial lane detection module to enhance the characteristics of the road lanes, making it easier to detect them in the image. The Hough transform was then used to identify the routes based on the mathematical relationship between the lanes and the vehicle. It did this by converting the image into a polar coordinate system and looking for lines within a specific range of contrasting points. This allowed the algorithm to distinguish between the lanes and other features in the image. After this, the Hough transform was used for lane detection, making it possible to distinguish between left and right lane marking detection extraction; the region of interest (ROI) must be extracted for traditional approaches to work effectively and easily. The proposed methodology was tested on several image sequences. The least-squares fitting in this region was then used to track the lane. The proposed system demonstrated high lane detection in experiments, demonstrating that the identification method performed well regarding reasoning speed and identification accuracy, which considered both accuracy and real-time processing and could satisfy the requirements of lane recognition for lightweight automatic driving systems
P3â209: Impact of Biomarkers On Diagnostic Confidence in Clinical Assessment of Patients with Suspected Alzheimer's Disease and High Diagnostic Uncertainty: An EADC Study
Background: NIA-AA and IWG diagnostic criteria for Alzheimer's Disease (AD) include core structural, functional, and CSF biomarkers. The impact of core biomarkers in clinical settings is still unclear. This study aimed at measuring the impact of core biomarkers on the diagnostic confidence of uncertain AD cases in a routine memory clinic setting. // Methods: 356 patients with mild dementia (MMSE = 20) or Mild Cognitive Impairment possibly due to AD were recruited in 17 European Alzheimer's Disease Consortium (EADC) memory clinics. The following variables were collected: age; sex; MMSE; neuropsychological evaluation including long term memory, executive functions, language and visuospatial abilities. Core biomarkers were collected following local practices: Scheltensâs visual assessment of medial temporal atrophy (MTA) on MR scan; visual assessment of hypometabolism/hypoperfusion on FDG-PET/SPECT brain scan; CSF AĂ1-42, tau and phospho-tau levels. At diagnostic workup completion, an estimate of confidence that cognitive complaints were due to AD was elicited from clinicians on a structured scale ranging from 0 to 100. Only cases with uncertain diagnoses (confidence between 15% and 85%) were retained for analysis. Generalized linear models were used to describe the relationship between the collected measures and the diagnostic confidence of AD. // Results: Neuropsychological assessment was carried out in almost all cases (98% of the cases). Medial temporal atrophy ratings were done in 40% of cases, assessment of cortical hypometabolism/hypoperfusion in 34%, and CSF AĂ and tau levels in 26%. The markers that better explained the variability of diagnostic confidence were CSF AĂ1-42 level (R2=0.46) and hypometabolism/hypoperfusion (R2=0.45), followed by CSF tau level (R2=0.35), MTA assessment (R2=0.32) and. All figures were highly significant, at p<<0.001. The diagnostic confidence variability due to neuropsychological tests for different domains was lower: MMSE (R2=0.29); long term memory (R2=0.23); executive functions (R2=0.05); language (R2=0.02); visuospatial abilities (R2=0.04) even if significant (p<0.01). //
Conclusions: The use of core biomarkers in the clinical assessment of subjects with suspected AD and high diagnostic uncertainty is still limited. However, when assessed, these biomarkers show a higher impact on diagnostic confidence of AD than the most widespread clinical measures
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