batterydata/paper-abstracts huggingface dataset:
The multi-electron redox reaction of an organic radical based composite cathode comprised of poly(2,2,6,6- tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA)-Ketjenblack is investigated using an in situ electrochemical-electron spin resonance (ESR) methodology. The experiments allow each electrochemical state to be associated with the chemical state (or environment) of the radical species upon the cell cycling. In situ ESR spectra of the composite cathode demonstrate a two-electron redox reaction of PTMA that is from an aminoxy anion (n-type, at 2.5–2.6 V vs. Li/Li+) via a radical (at 3.2–3.5 V vs. Li/Li+) to an oxoammonium cation (p-type, at 3.7–4.0 V vs. Li/Li+). In particular, an adjustable n-type doping process of PTMA is first observed during the discharging process. Moreover, two different local environments of radical species are found in the PTMA-Ketjenblack composite electrode that includes both concentrated and isolated radicals. These two types of radical species, showing similarities during the redox reaction process while behaving quite different in the non-faradic reaction of ion sorption/desorption on the electrode surface, govern the electrochemical behavior of PTMA based composite electrode.
We present, for the first time, a new material of symmetric electrochemical supercapacitor in which zinc oxide (ZnO) with carbon aerogel (CA) was used as active material. Physical properties of ZnO/CA composite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that ZnO has single hexagonal structure and the grain size increases with increase of ZnO compository. The result of cyclic voltammetry indicates that the specific capacitance of ZnO/CA composite in 6M KOH electrolyte was approximately 25F/g at 10mV/s for 2:1 composition. AC impedance analysis reveals that ZnO with carbon aerogel powder enhanced the conductivity by reducing the internal resistance. Galvanostatic charge/discharge measurements were done at various current densities, namely 25, 50, 75, and 100mA/cm2. It was found that the cells have excellent electrochemical reversibility and capacitive characteristics in KOH electrolyte. The maximum capacitance of the ZnO/CA supercapacitor was 500F/g at 100mA/cm2. It has been observed that the specific capacitance is constant up to 500 cycles at all current densities, which implies that the dendrite formation was controlled.
Previous investigations have found that smokers with schizophrenia demonstrate reduced performance on cognitive tasks compared to non-smokers. However previous studies have not taken into account other environmental factors associated with cognitive functioning such as exposure to Herpes Simplex Virus type 1 (HSV-1). We examined these factors in a sample consisting of individuals with schizophrenia (n =773), bipolar disorder (n =493), or controls without a psychiatric disorders (n =548). Participants were assessed on a cognitive battery, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and had a blood sample drawn to measure seropositivity to HSV-1. Within each group linear regression models were constructed to determine whether cigarette smoking and HSV-1 seropositivity were jointly associated with cognitive functioning after adjusting for relevant covariates. Within the schizophrenia group, the effect size of lower total cognitive score was −0.279 (p <0.0001) for individuals who were both smokers and HSV-1 seropositive and a significant effect was found in all cognitive domains. The odds of being in the highest quartile of RBANS Total score were significantly lower for smokers (OR=0.58, 95% CI 0.41, 0.82, p =0.002). Smoking was not as consistently associated with levels of cognitive functioning in the bipolar disorder or the non-psychiatric control group. While experimental studies show that nicotine transiently improves functioning on sensory gating and attention tasks known to be deficient in schizophrenia, long-term nicotine exposure via smoking appears to have an adverse effect on cognitive functioning.
Tin-containing nanometric and amorphous intermetallics and alloys are envisaged as negative electrodes for high-capacity lithium ion batteries. Nanocrystalline FeSn2 has been prepared by reduction of Sn2+ and Fe3+ in tetraethylene glycol at 185°C. Microcrystalline FeSn2 has been prepared at 490°C. The properties of nano-FeSn2 and micro-FeSn2 have been observed to be very different. The small particles size hinders the long-range magnetism and consequently the Mössbauer spectra are modified. The nanocrystalline particles of FeSn2 show exothermal effects in the DTA experiment that are not observed in the micrometric particles. Nanocrystalline FeSn2 exhibits a much better electrochemical behavior and electrode stability than microcrystalline FeSn2.
Cumulative technological culture can be defined as the progressive diversification, complexification, and enhancement of technological traits through generations. An outstanding issue is to specify the cognitive bases of this phenomenon. Based on the literature, we identified four potential cognitive factors: namely, theory-of-mind, technical-reasoning, creativity, and fluid-cognitive skills. The goal of the present study was to test which of these factors—or a combination thereof—best predicted the cumulative performance in two experimental, micro-society conditions (Communication and Observation conditions; n = 100 each) differing in the nature of the interaction (verbal, visual) allowed between participants. The task was to build the highest possible tower. Participants were also assessed on the four aforementioned cognitive factors in order to predict cumulative performance (tower height) and attractiveness. Our findings indicate that technical-reasoning skills are the best predictor of cumulative performance (tower height), even if their role may be restricted to the specific technological domain. Theory-of-mind skills may have a facilitator role, particularly in the Communication condition. Creativity can also help in the generation of novel ideas, but it is not sufficient to support innovation. Finally, fluid cognition is not involved in cumulative technological culture. Taken together, these findings suggest that domain-specific knowledge (i.e., technical-reasoning skills) remains critical for explaining cumulative technological culture.
We report a patient (MT) with a highly specific alexia affecting the identification of letters and words but not numbers. He shows a corresponding deficit in writing: his letter writing is impaired while number writing and written calculation is spared. He has no aphasia, no visuo-perceptual or -constructional difficulties, or other cognitive deficits. A similar pattern of performance has to our knowledge only been reported once before [Anderson, S. W., Damasio, A. R., & Damasio, H. (1990). Troubled letters but not numbers. Domain specific cognitive impairments following focal damage in frontal cortex. Brain, 113, 749–766]. This study shows that letter and number reading are dependent on dissociable processes. More interestingly, it points to a common mechanism subserving the perception and production of letters. We suggest that a deficit in a visuo-motor network containing knowledge of the physical shape of letters might explain the pattern of performance displayed by MT.
Sugarcane bagasse, a waste product of the sugarcane industry can be used as a precursor for the preparation of carbon. In this study, a composite consisting of hierarchically functionalized porous carbon (FPC) and β-FeOOH was synthesized via a simple and effective hydrolysis method. The hydrothermal process before the carbonization and activation of the bagasse maintained the hierarchical interconnected porous structure of the sugarcane bagasse. A nitric acid (HNO3) functionalization treatment enabled an in-situ growth of β-FeOOH on the hierarchically structured bagasse. When tested as an anode for lithium-ion batteries, the obtained FPC/β-FeOOH composite showed a high discharge capacity of 898.8 mAh g−1 at 0.2 A g−1 after 350 cycles and achieved a specific capacity of 446.1 mAh g−1 at a current rate of 1 A g−1 after 1000 cycles together with a remarkable coulombic efficiency of 99.9%. This excellent electrochemical performance of the FPC/β-FeOOH composite can be attributed to the synergistic effect of the interconnected porous structure of porous carbon and the electrochemically active tunnel type β-FeOOH nanorods. The strategy developed here is promising in design and fabrication of other composites having interconnected porous structures with high performance.
Being widely considered a powerful tool for improving the capacity retention and rate capability of cathode materials for lithium-ion batteries, surface modification has never been applied for obtaining truly high-rate spinels. The stoichiometric LiMn2O4 and a material containing the LiMn2O4 core and LiNi0.5Mn1.5O4 shell with the shell/core mass ratio of 0.1:1 have been synthesized by means of a citric acid aided route. The samples studied have been characterized using thermal analysis, X-ray diffraction and scanning electron microscopy. The specific discharge capacities of LiMn2O4/LiNi0.5Mn1.5O4 and LiMn2O4 at I =0.5C equal to 107 and 110mAhg−1, respectively. The surface coated LiMn2O4/LiNi0.5Mn1.5O4 shows up an exceptional high-rate ability being able to retain ca. 25mAhg−1 at the current load of 9620mAg−1 (65C), which is 1.625 times higher than for the unmodified LiMn2O4. Such exceptional high-rate properties and better cycling ability of the core-shell LiMn2O4/LiNi0.5Mn1.5O4 compared to parent compounds prove good prospects of surface modification techniques in improving rate capabilities of spinel materials.
Executive functions and, in particular, Attentional (active) Working Memory (WM) have been associated with fluid intelligence. The association contrasts with the hypothesis that children with ADHD exhibit problems with WM tasks requiring controlled attention and may have a good fluid intelligence. This paper examines whether children who are intelligent but present ADHD symptoms fail in attentional WM tasks. The latter result would be problematic for theories assuming the generality of a strict relationship between intelligence and WM. To study these issues, a battery of tests was administered to a group of 58 children who all displayed symptoms of ADHD. All children were between the age of 8 and 11 years, and were described by their teachers as smart. Children were compared to a control group matched for age, schooling, and gender. The battery included a test of fluid intelligence (Raven’s Coloured Matrices), and a series of visuospatial WM tasks. Results showed that children with ADHD were high in intelligence but significantly lower than the controls in WM tasks requiring high attentional control, whereas there was no difference in WM tasks requiring low attentional control. Furthermore, only high attentional control WM tasks were significantly related to Raven’s performance in the control group, whereas all WM tasks were similarly related in the ADHD group. It is concluded that performance in high attentional control WM tasks may be related to fluid intelligence, but also to a specific control component that is independent of intelligence and is poor in children with ADHD.
Sodium pyrophosphate tetrabasic (SPT) is employed as an inorganic additive in the positive electrolyte of a vanadium redox flow battery (VRFB) to improve its long-term stability and electrochemical performance. The results of precipitation tests show that the long-term stability of positive electrolytes (2MV(V) solution in 4M total sulfates with 0.05M SPT additive) is improved compared to the blank one. UV-vis and cyclic voltammetry (CV) measurements also suggest that the addition of SPT can effectively delay the formation of precipitation in positive electrolytes, and no new substances are formed in V(V) electrolytes with SPT. The calcined precipitates extracted from the electrolytes with and without a SPT additive are identified as V2O5 by X-ray diffraction (XRD) analysis. A VRFB single-unit cell employing positive electrolytes with an additive exhibits the high energy efficiency of 74.6% at a current density of 40mA cm2 at the 500th cycle at 20°C, compared to 71.8% for the cell employing the electrolyte without an additive. Moreover, the cell employing the electrolyte with an additive exhibits less discharge capacity fading during cycling in comparison with the pristine one. The disassembled cell without an additive shows a large number of V2O5 precipitation particles on the felt electrode after 500 cycles. Meanwhile, the felt electrode of the cell with an additive has little precipitation. That precipitation gives rise to an imbalance between the positive and negative half-cell electrolytes, which results in a significant capacity loss. The additive has shown positive results under limited laboratory short-term and small-scale conditions.
Publisher Summary Most consumers are naive about the security of their wireless phone calls. The level of security required by an individual consumer will most likely be much less than that required by a unbounded mobile communications (UMC) enterprise solution, but all must have some level of security. The security motivations of a consumer and an enterprise solution will be different. In today's cellular world, security is embedded within the system, and the user is not required to take any action when attaching to the mobile network. Authentication is performed not based on the user but rather on the device. Once past the device authentication phase, a security key exchange protocol sequence is completed, and all signaling and audio traffic from the mobile handset through the mobile network is automatically encrypted. In such a state, any person may use this phone, but all information transmitted or received will be secure.
We report facile, one step synthesis of disordered graphitic carbon by high temperature (1000°C) pyrolysis of indanthrone dye (ID). The pyrolysed carbon is disordered in nature and the same is clearly evidenced by various analytical techniques like X-ray diffraction, Raman spectroscopy and high resolution transmission electron microscopy. Na-insertion properties of such indanthrone dye derived disordered graphitic carbon (IDDGC) is evaluated in half-cell assembly (Na/IDDGC). The test cell delivered a reversible capacity of ∼160 mAhg−1 at current density of 25mAg−1. In addition, excellent cycling profiles are noted for such IDDGC, which retains ∼67% of initial reversible capacity after 500 cycles. The present study clearly highlights the importance of disorder in the graphitic carbon for efficient Na-ion storage.
Despite extremely high capacity of Si-based anodes in lithium-ion batteries (LIB), Si-based materials have shown a structural collapse caused by a volumetric expansion/contraction during the cycling process. The conventional electrode structure, which consists of active materials, a current collector, a conducting agent, and a binder, actually showed a low loading of active material due to the other heavy components. In this study, we prepared a 3D flexible Si-composite electrode consisting of core (Si)-shell (Si3N4) NPs (Si@Si3N4) and carbon nanofibers (denoted as Si-composite/CNF). The Si-composite/CNF was directly utilized as an anode in the absence of the other components was electrochemically evaluated using a coin-type cell. The Si-composite/CNF showed a high capacity of 665mAhg−1 at a fairly high current density of 10Ag−1 and an extremely low capacity loss for 2000 cycles.
A neuropeptidase, neprilysin (NEP), is a major amyloid (Aβ)-degrading enzyme involved in the pathogenesis of Alzheimer’s disease (AD). The olfactory system is affected early in AD with characteristic Aβ accumulation, but data on the dynamics of NEP expression in the olfactory system are absent. Our study demonstrates that NEP mRNA expression in rat olfactory bulbs (OB), entorhinal cortex (ECx), hippocampus (Hip), parietal cortex (PCx) and striatum (Str) increases during the first postnatal month being the highest in the OB and Str. By 3 months, NEP mRNA levels sharply decrease in the ECx, Hip and PCx and by 9 months in the OB, but not in the Str, which correlates with declining olfaction in aged rats tested in the food search paradigm. One-month-old rats subjected to prenatal hypoxia on E14 had lower NEP mRNA levels in the ECx, Hip and PCx (but not in the OB and Str) compared with the control offspring and demonstrated impaired olfaction in the odour preference and food search paradigms. Administration to these rats of a histone deacetylase inhibitor, sodium valproate, restored NEP expression in the ECx, Hip and PCx and improved olfaction. Our data support NEP involvement in olfactory function.
Electronic structure changes of sulfurs in amorphous TiS3 and MoS3 for positive electrodes of all-solid-state lithium batteries are examined by X-ray photoelectron spectroscopy (XPS) and the X-ray absorption near edge structure (XANES). The all-solid-state cell with amorphous TiS3 electrode shows the reversible capacity of about 510 mAh g−1 for 10 cycles with sulfur-redox in amorphous TiS3 during charge-discharge process. On the other hand, the cell with amorphous MoS3 shows the 1st reversible capacity of about 720 mAh g−1. The obtained capacity is based on the redox of both sulfur and molybdenum in amorphous MoS3. The irreversible capacity of about 50 mAh g−1 is observed at the 1st cycle, which is attributed to the irreversible electronic structure change of sulfur during the 1st cycle. The electronic structure of sulfur in amorphous MoS3 after the 10th charge is similar to that after the 1st charge. Therefore, the all-solid-state cell with amorphous MoS3 electrode shows relatively good cyclability after the 1st cycle.
This work was focused on studies of structural and electrochemical properties of the La-doped AB2-type Zr/Ti-based metal hydride anode alloys. The Ti0.2Zr0.8La0-0.05Ni1.2Mn0.7V0.12Fe0.12 alloys were characterized using SEM, EDS and XRD, which concluded that the major C15 Laves type AB2 compound co-exists with a minor La-Ni intermetallic. NPD study indicated that vanadium together with Ti and Zr partially fills the A site, while the rest of V together with Ni, Mn and Fe statistically fills the B site. NPD showed that in a trihydride (Ti,Zr,V)(Ni,Mn,Fe,V)2D2.9 D atoms occupy A2B2 tetrahedra. The alloys were characterized during high-rate discharge and on cycling. La addition resulted in a significant improvement of the activation performance caused by a catalytic influence of LaNi hydride. The highest content of La greatly accelerated the activation, but it also caused an obvious decrease in discharge capacity and cycling stability. The alloy with an optimized La addition (x = 0.03) demonstrated a maximum discharge capacity of 420 mAh g−1 and the discharge capacity maintained at 79% at 0.71 C, while the capacity retention after 500 cycles was also high, 63%. Based on the EIS results, we conclude that the decay of the alloy electrode is related to the irreversible capacity loss and its pulverization.
This study reports on the novel and sustainable synthesis of high value carbon nanoparticles (CNPs) from waste tyre rubber (WTR), using an innovative high temperature approach. As waste tyres are composed, primarily, of carbon – accounting for some 81.2wt% – they represent a promising source of carbon for many potential applications. However, cost-effective options for their processing are limited and, consequently, billions of waste tyres have accumulated in landfills and stockpiles, posing a serious global environmental threat. The rapid, high temperature transformation of low value WTR to produce valuable CNPs, reported here, addresses this challenge. In this study, the transformation of WTRs was carried out at 1550°C over different reaction times (5s to 20min). The structure and morphology of the resulting CNPs were investigated using X-ray diffraction (XRD), Raman spectroscopy, X-ray photon spectroscopy (XPS), N2 isothermal adsorption method and scanning electron microscopy (SEM). The formation of CNPs with diameters of 30 and 40nm was confirmed by Field Emission Electron Microscopy (FE-SEM). Longer heating times also resulted in CNPs with regular and uniform spherical shapes and a specific surface area of up to 117.7m2/g, after 20min. A mechanism that describes the formation of CNPs through mesophase nuclei intermediate is suggested.
Sodium has been recently attracted considerable attention as a promising charge carrier, but this sudden attention has made the strategy of research somewhat hazy, as most research reports are indeed the examination of typical materials rather than following a solid roadmap for developing practical cells. Although the history of sodium-ion batteries (NIBs) is as old as that of lithium-ion batteries (LIBs), the potential of NIB had been neglected for decades until recently. Most of the current electrode materials of NIBs have been previously examined in LIBs. Therefore, a better connection of these two sister energy storage systems can shed light on the possibilities for the pragmatic design of NIBs. The first step is to realise the fundamental differences between the kinetics and thermodynamics of Na as compared with those of Li. In fact, tiny differences between the electrochemical behaviours of these systems can lead us to new practical ideas for designing suitable materials. Furthermore, NIBs should be considered as new opportunities for energy storage rather than replacing LIBs. Hence, the subtle strategy of research is to learn from LIBs but not replicate them when designing NIBs.
The behavior of polymer electrolytes in lithium batteries is reviewed in the context of molecular scale models as well as on the system scale. It is shown how the molecular structure of the electrolyte strongly influences ion transport through the polymer as well as across the interfaces and determines the values of a number of parameters needed for system models that can predict the performance of the battery (e.g. κ, D, t 0 + and i 0). The interaction of the electrolyte with the electrodes not only leads to transfer of the lithium ion across the interface but also to side reactions that profoundly influence the calendar and life cycle of the battery. Typically these electrochemically induced side reactions generate the SEI layer, but inherent instability of the bulk electrolyte may also play a role in the formation of surface layers. These various reactions can lead to changes in the mechanical properties of the separator and electrode structure that promote life-limiting phenomena such as dendrite growth, passivation and morphology changes. The rheological model of Eisenberg is drawn upon to show how the interactions of the electrolyte with surfaces can lead to distinct changes in mechanical and transport properties that may limit the battery performance and lead to diminished performance with time. The molecular level models may be combined with the rheological models to provide workable models of the interfaces and bulk electrolyte dynamics that in turn can be used to provide a more accurate level of performance prediction from the system models. This connects molecular structure with battery performance and guides the design and synthesis of new and better materials.