batterydata/paper-abstracts huggingface dataset:
Metallic lithium is the most promising negative electrode for high-energy rechargeable batteries due to its extremely high specific capacity and its extremely low redox potential. However, the low cycle efficiency and lithium dendrite formation during the charge/discharge processes consistently hinder its practical application. In this report, we present a stabilized Li electrode on which a Li+ ion conductive inorganic/organic composite protective layer (CPL) is coated. With the introduction of the CPL, the Li dendrite growth and electrolyte decomposition are effectively suppressed; consequently, stable Li plating/stripping at high current densities up to 10 mA cm−2 is possible. Nanoindentation tests demonstrate that the shear modulus of the CPL at narrow indentations is 1.8 times higher than that of the Li metal, which provides a theoretical understanding for its efficacy. Moreover, the LiCoO2/Li cell incorporating CPL exhibits excellent cycling stability up to 400 cycles at 1 mA cm−2 (1 C-rate), which demonstrates practical applicability in Li ion batteries through replacing the graphite anode with a CPL-coated Li metal anode.
Reduced graphene oxide (RGO) decorated ternary Cu2SnS3 composite has been synthesized by one-step facile hydrothermal route. The formation of Cu2SnS3 nanoparticles and reduction of graphene oxide occur at the same time during the hydrothermal process. The Cu2SnS3 nanoparticles with a size of 5–10nm are uniformly distributed on the RGO, which prevents effectively the agglomeration of Cu2SnS3 nanoparticles. The Cu2SnS3/RGO composite electrode exhibits an initial reversible capacity of 704mAhg−1 and 560mAhg−1 after 100cycles. Such excellent electrochemical performance can be attributed to the presence of RGO, which improves the electronic conductivity and prevents the agglomeration of Cu2SnS3 nanoparticles. In addition, the Cu induced by the Cu2SnS3 reaction with lithium ions during the discharge process can increase the electronic conductivity.
Fabrication of carbon micro/nanostructures by carbon microelectromechanical systems (carbon-MEMS) technique on conductive substrate stably is of great significance but difficulty, for the poor adhesive property and low -temperature resistance of the substrate. In this study, three-dimensional carbon micro/nanostructures are fabricated on stainless steel (SS) substrate for the first time by carbon-MEMS technique and oxygen plasma etching process without extra conductive layer fabrication process. The effects of oxygen plasma etching time and the height of photoresist array on the morphologies of carbon micro/nanostructures are investigated. The carbon micro/nanostructures were then electrodeposited with manganese dioxide (MnO2) thin film as microelectrodes for supercapacitors, and the electrochemical performances of the microelectrodes were demonstrated. At the current density of 0.05 mA cm−2, the MnO2/carbon micro/nanostructures microelectrode deposited with 5 min show a large specific capacitance of 453.47 F g−1. It also shows excellent long-term cycling stability of ∼94% capacitance retention even after 6000 cycling tests. This study shows that the MnO2/carbon micro/nanostructures microelectrodes have great potential for supercapacitors as micro-energy storage devices, and the proposed approach of fabricating carbon hierarchical micro/nanostructures array on a conductive substrate is promising for large-scale micro/nanostructures manufacturing.
Habit reversal training (HRT) has been proven effective for reducing tics in children with Tourette's syndrome (TS). However, the availability of the intervention is limited. Videoconference technology represents a promising mode through which HRT may be disseminated to underserved areas. Using a multiple-baseline across participants design, the current study tested the effectiveness of videoconference-delivered HRT for 3 children with TS. Similar to results from randomized controlled trials studying face-to-face delivered HRT, videoconference-delivered HRT was effective for reducing tics. All three children demonstrated significant tic reduction following videoconference HRT delivery. All participants and their families rated the delivery modality as acceptable and the therapeutic relationship as strong. These results suggest that videoconference delivery may be a promising method for disseminating behavior therapy for tics.
Superior vena cava (SVC) syndrome is a known but rare complication of pacemaker lead implantation, accounting for approximately less than 0.5% of cases. Its pathophysiology is due to either infection or endothelial mechanical stress, causing inflammation and fibrosis leading to thrombosis, and therefore stenosis of the SVC. Due to the various risks including thrombo-embolic complications and the need to provide symptomatic relief, medical and surgical interventions are sought early. We present the case of a 48-year Caucasian male who presented with localised swelling and pain at the site of pacemaker implantation. Inflammatory markers were normal, but diagnostic imaging revealed three masses along the pacemaker lead passage. A surgical approach using cardiopulmonary bypass and circulatory arrest was used to remove the vegetations. Culture from the vegetations showed Staphylococcus epidermidis. The technique presented here allowed for safe and effective removal of both the thrombus and infected pacing leads, with excellent exposure and minimal post-procedure complications.
Nafion/PVDF blends are employed to prepare the ion exchange membranes for vanadium redox flow battery (VRB) application for the first time. The addition of the highly crystalline and hydrophobic PVDF effectively confines the swelling behavior of Nafion. In VRB single cell test, the Nafion/PVDF binary membranes exhibit higher columbic efficiency than recast Nafion at various current densities. The blend membrane with 20wt% of PVDF (N0.8P0.2) shows energy efficiency of 85% at 80mAcm−2, which is superior to that of recast Nafion. N0.8P0.2 membrane also possesses twice longer duration in OCV decay test and much lower permeation of VO2+ compared with recast Nafion. These results indicate that the addition of PVDF is a simple and efficient way to improve the ion selectivity of Nafion, and the polymer blends with optimized mass fraction of PVDF show good potential for VRB application.
The Program for International Student Assessment (PISA) testing is conducted every 3 years by the Organization for Economic Co-operation and Development (OECD;
The extraction of bimetallic Au-Pt nanoparticles is interesting due to their multiple applications in catalytic processes, electronic devices, photothermal therapies, among others. On the other hand, the tendency of nanoparticles forming agglomerates may modify the behavior of the material, and thus their applications. This study shows a highly reproducible novel synthesis method, which only uses two organic agents (sucrose and ascorbic acid) as the reducing and stabilizing agents from nano-agglomerates of Au-Pt at room temperature. The TEM images show agglomerates with a mass fractal structure. We identified crystalline FCC, corresponding to the Au-Pt alloy. Furthermore, the coexistence of gold and platinum nanoparticles was shown through the EDS analysis. The UV-Vis spectrum showed that the resonance plasmon identified coincides with a great approximation to the results reported in the literature. Additionally, the agglomerates exhibited excellent antibacterial activity against bacteria Escherichia coli.
Core–shell Li4Ti5O12@CeO2 nanosphere has been synthesized by a one-pot co-precipitation method. The structure and morphology of the as-prepared materials have been analyzed by X-ray diffraction and transmission electron microscopy. The results show that CeO2 is successfully coated on the surface of the Li4Ti5O12 besides partial doping of Ce4+ into the Li4Ti5O12 structure. The Li4Ti5O12@CeO2 nanosphere exhibits excellent capacity of 152 mAh g−1 even after 180 cycles at 10 C, with no noticeable capacity fading. Furthermore, the sample shows much improved rate capability at 40 C compared with pure Li4Ti5O12 when used as anode material for lithium-ion batteries. The introduction of CeO2 enhances not only the electric conductivity of Li4Ti5O12, but also the lithium ion diffusivity in Li4Ti5O12, resulting in significantly improved electrochemical performance of the Li4Ti5O12.
Underwater wireless sensor networks (UWSNs) have been developed for underwater applications, such as resource exploration, pollution monitoring, and tactical surveillance. The topology control techniques of UWSNs and terrestrial wireless sensor networks are significantly different because of the particularity of underwater environments and acoustic communication, such as mobility pattern, propagation delay and energy consumption. Due to multifarious factors of underwater environments, node mobility becomes a non-negligible issue. However, GPS may not be feasible because of the limitations of satellite coverage or obstructions in adverse underwater environments. In particular, anchored sensor nodes towed by wires are prone to offset around their static positions, causing each node to move within a spherical crown surface (spherical crown mobility pattern). Nevertheless, most previous studies have not focused on this specific mobility pattern. In the current paper, a mobility model for UWSNs nodes is constructed, and three representative topology control objectives are attained. A distributed radius determination algorithm is designed for the mobility-based topology control problem. Results of theoretic analysis prove that the proposed algorithm is convergent, and it has preferable approximate ratios and polynomial complexity. Performance of the algorithm is analyzed through simulation experiments, which indicate a well-constructed topology. Every objective can still be upgraded without the dynamic location information of mobile nodes.
The hallmark characteristic of autism is impaired reciprocal social interaction. While children find social interaction stress-reducing, many children with autism may find social interaction stress-inducing. The current study was designed to examine stress responsivity as measured by cortisol by comparing children with autism to neurotypical peers during an ecologically valid 20-minute playground paradigm.
Research on Eastern Europe stresses the weakness of its civil society and the lack of political and social involvement, neglecting the question: What do people themselves think it means to be a good citizen? This study looks at citizens’ definitions of good citizenship in Poland, Slovenia, the Czech Republic and Hungary, using 2002 European Social Survey data. We investigate mean levels of civic mindedness in these countries and perform regression analyses to investigate whether factors traditionally associated with civic and political participation are also correlated with citizenship norms across Eastern Europe. We show that mean levels of civic mindedness differ significantly across the four Eastern European countries. We find some support for theories on civic and political participation when explaining norms of citizenship, but also demonstrate that individual-level characteristics are differently related to citizenship norms across the countries of our study. Hence, our findings show that Eastern Europe is not a monolithic and homogeneous bloc, underscoring the importance of taking the specificities of countries into account.
Equality between economic progress and environmental sustainability is essential for a developing country like India. In the present time, the economy of India is growing rapidly in a vibrant mode and an efficient way, which in turn demands huge uninterrupted energy supplies. The country's energy needs are met mostly by the usage of fossil fuels and nearly 70% of electricity is generated from coal based power plants. In India, nearly 840 million people depend on traditional biomass to satisfy their energy necessities. Approximately 74 million rural people do not have access to modern lighting systems and around 81 million households do not have access to electricity, which is a major challenge to India's energy security. In order to achieve stable sustainable energy in the long-run, significant progress in renewable energy sectors is needed. Favorably, due to India's geographic location, the country is blessed with abundant renewable energy resources, which has not yet been exploited completely. So the central and state governments of the country have framed various policies and are providing subsidies to encourage the utilization of solar photovoltaic systems. In this paper, a comprehensive review of the potential, current developmental status and prospects of solar energy of India is briefed. The various applications of solar energy such as water heaters, desalination units, pasteurizers, food drying units, water purifier, space heating systems, air-conditioning units, cookers, water pumps, aerators, solar-wind hybrid systems and grid connected photovoltaic systems are explained. The study also mentions the current renewable energy policies, the barriers blocking the progress of the solar manufacturing units and some possible future recommendations that might speed up renewable energy developments in India.
To improve the cycle performance of spinel LiMn2O4 as the positive electrode of 4V lithium secondary batteries, the spinel oxysulfide Li1.02Mg0.1Mn1.9O3.99S0.01 is synthesized by a sol–gel method using adipic acid as a chelating agent. The structural and electrochemical properties of the synthesized material are examined. Highly crystallized Li1.02Mg0.1Mn1.9O3.99S0.01 is synthesized at 750°C in an oxygen atmosphere. Both cation and anion doping of spinel lithium manganese oxides are very effective for improving the cycle performance of lithium batteries.
This paper reports that addition of reduced graphene oxide (rGO) in MgCo2O4 improves the binding of Mg with Co thereby minimizing magnesium dissolution in aqueous alkaline electrolytes and the resulting MgCo2O4/rGO electrodes offered impressive improvements in charge storage properties. An isostructural high performing material, MnCo2O4, is used as a benchmark material in this work. The Mg analogues stored >30% more charges than the Mn-analogues in the 3M LiOH electrolyte despite the former's lower BET surface area; rGO modification further increased charge storage by >60% than the unmodified analogues. Electrochemical measurements show that a larger surface fraction of the Mg analogue is electrochemically active, irrespective of whether or not rGO is present, which arise from, typically for MgCo2O4/rGO, lower internal resistance, lower Warburg impedance, and lower charge transfer resistance than the other electrodes.
The infamous shuttle effect of polysulfides is the main obstacle severely hindering the practical application of Li–S battery. To address such issue, we fabricated a homogeneous ultrathin Ta2O5 layer deposited on separators via typical pulsed laser deposition. The polar surface of the Ta2O5 coating can not only serve as a barrier inhibiting polysulfides shuttling due to strong chemisorption, but also accelerate the redox kinetics of immobilized polysulfides, which was demonstrated by density functional theory calculations and electrochemical experiments. With the Ta2O5 modified separator, the cell using a cathode prepared by nitrogen-doped graphene achieves good rate capability in contrast to the one with bare commercialized separator. Specifically, even at a high areal sulfur loading of 5.27 mg cm−2, the cell can deliver a high initial areal capacity of 5.3 mAh cm−2 and retains 4.2 mAh cm−2 over 60 cycles, which exceeds commercial lithium-ion batteries (4 mAh cm−2), suggesting its actual application possibility.
Hypoxic-ischaemic encephalopathy is the main determinant of clinical outcome after cardiac arrest. The study was designed to determine long-term neurological and psychological status in cardiac arrest survivors, as well as to compare neuropsychological outcomes between patients treated with mild therapeutic hypothermia (MTH) and patients who did not undergo hypothermia treatment.
Using bimetallic oxide as the electrode material of supercapacitor is emerging as a promising approach to supply better pseudocapacitive performance than that from the electrodes made of corresponding single metal oxides. Herein, Ni-Mn bimetallic oxide nanosheets (Ni-MnBMO) on carbon cloth substrate were synthesized through a facile hydrothermal method. With the help of cyclic voltammetry activation process, the prepared A-Ni-MnBMO electrode exhibits the maximum specific capacitance 574 F g−1 (within a potential range of −0.2–1.2 V vs. Ag/AgCl at 1 A g−1 after excluding the effects of OER) mainly due to the reversible redox reactions of Mn3+/Mn4+. Moreover, to prove its potential as the positive electrode in a supercapacitor, an asymmetric supercapacitor with a voltage range of 2.1 V is fabricated by using functional carbon nanotube as the negative electrode and 1 M Na2SO4 as the electrolyte. As a result, the device can deliver a maximum energy density of 27 Wh kg−1(at 0.5 A g−1) and 82.3% of its initial specific capacitance can be maintained after 8000 cycles of galvanostatic charge and discharge tests at 4 A g−1.
There have been tremendous efforts to develop new synthetic methods for creating novel nanoparticles (NPs) with enhanced and desired properties. Among the many synthetic approaches, NP synthesis through ion exchange is a versatile and powerful technique providing a new pathway to design complex structures as well as metastable NPs, which are not accessible by conventional syntheses. Herein, we introduce kinetic and thermodynamic factors controlling the ion exchange reactions in NPs to fully understand the fundamental mechanisms of the reactions. Additionally, many representative examples are summarized to find related advanced techniques and unique NPs constructed by ion exchange reactions. Cation exchange reactions mainly occur in chalcogenide compounds, while anion exchange reactions are mainly involved in halogen (e.g. perovskite) and metal-chalcogenide compounds. It is expected that NP syntheses through ion exchange reactions can be utilized to create new devices with the required properties by virtue of their versatility and ability to tune fine structures.
Abstract Assisted by soft computing methods, the work we present in this paper focuses on the design of energy-efficient algorithms for binaural hearing aids that aim to separate speech from other sounds the hearing impaired person is not interested in. To do this, the right and left hearing aids need to wirelessly transmit to each other some parameters involved in the speech separation algorithm. The problem is that this transmission appreciably reduces the battery life, the most important constrain for designing advanced algorithms in hearing aids. Reducing the number of bits used to represent the parameters to be transmitted will bring down the power consumption, but at the expense of degrading the ability of the system to separate the speech from the other sound sources. Aiming at solving this problem, our approach, based on quantizing the parameters to be transmitted, basically consists in computing the adequate number of quantization bits by means of a combination of neural networks and genetic algorithms in the effort of finding a balance between low bit rate (and thus, low power consumption) and good separation of speech. The results show that even by using only 2bits/quantized-sample, the quality of the separation is as high as 70% of the limiting non-quantized quality separation factor, which has been found to be 85%.
Oxygen reduction reaction (ORR) is becoming increasingly important with the development of fuel cells and metal-air batteries. Manganese oxides have been one of the focuses of recent research for Pt-alternative ORR catalysts. However, the structure-activity relationships of manganese oxides have not been well studied or understood. In the present work, we report a new finding that there is a strong dependence of the ORR activity of Mn3O4 on its morphology. By adopting different solvents in the wet-chemical synthesis, we are able to tailor the morphology of Mn3O4 from nanoparticles (NP-L, 12.5nm and NP-S, 5.95nm) to nanorods (NR, exposure of Mn3O4 (101)) and nanoflake (NF, exposure of Mn3O4 (001)). Surprisingly, surface-specific activity of NF toward the ORR was found to be one order of magnitude higher than NP-L. The morphology-activity relationships of Mn3O4 were further studied through a combination of electrochemical experiments and density functional theory (DFT) calculations. It was discovered that the formation of *OOH, concomitant with the first electron transfer, is the potential determining step, which is thermo-dynamically more facile on Mn3O4 (001) than (101) plane. The underlying mechanism could be ascribed to the strong interaction between O2 and Mn3O4 (001) surface as indicated by the DFT calculations. The study enlarges our understanding of Mn3O4 catalysis and provides clues for rational design of highly efficient transitional metal oxide electrocatalysts for the ORR.
Safety and high energy density are the two focus issues for current lithium ion batteries. For safety, it has been demonstrated that sulfone electrolytes are much less flammable than the prevailing all-carbonate type, and they are also promising for high voltage batteries due to the high oxidization resistance. However, the high melting points and viscosities greatly restricted their application. Based on our previous work on use of fluidity-enhancing cosolvents to make binary sulfone-carbonate electrolytes, we report here a three-component system that is more conductive and should be even less flammable while additionally having better low temperature stability. The conductivity–viscosity relations have been determined for this electrolyte and are comparable to those of the “standard” carbonate electrolyte. The additional component also produces much improved capacity retention for the LiNi0.5Mn1.5O4 cathode. As with carbonate electrolytes, increase of temperature to 55 °C leads to rapid capacity decrease during cycling, but the capacity loss is due to the salt, not the solvent. The high discharge capacity observed at 25 °C when LiBF4 replaces LiPF6, is fully retained at 55 °C.
Spontaneous functional recovery occurs during the acute phase after stroke onset, but this intrinsic recovery remains limited. Therefore, exploring the mechanism underlying spontaneous recovery and identifying potential strategies to promote functional rehabilitation after stroke are very important. The CD200/CD200R signaling pathway plays an important role in neurological recovery by modulating synaptic plasticity during multiple brain disorders. However, the effect and mechanism of action of the CD200/CD200R pathway in spontaneous functional recovery after stroke are unclear.
An ultra-high ion-selective Nafion composite membrane modified by phosphotungstic acid (PWA) coupled silica for vanadium redox flow battery (VRB) was constructed and prepared through solution casting. The composite membrane exhibits excellent proton conductivity and vanadium ions blocking property by incorporating the nanohybrid composed of silica and PWA into the Nafion ionomer. Simple tuning for the filling amount of the nanohybrid endows the obtained membranes preeminent vanadium barrier property including a minimum vanadium permeability of 3.13 × 10−7 cm2 min−1 and a maximum proton conductivity of 0.081 S cm−1 at 25 °C. These indicate an ion selectivity of 2.59 × 105 S min cm−3, which is 6.8 times higher than that of recast Nafion (0.33 × 105 S min cm−3). As a result, the VRB with the composite membrane shows superior battery performance containing a lower self-discharge rate, higher capacity retention and more robust cyclic stability compared with recast Nafion over a range of current densities from 40 to 100 mA cm−2.