batterydata/paper-abstracts huggingface dataset:
We have studied Li intercalation into two nanoparticulate anode materials for lithium ion batteries, namely Nb-doped TiO2 (Nb-TiO2) and Li4Ti5O12 (LTO), by means of scan rate-dependent cyclic voltammetry. The average particle size is 7nm for Nb-TiO2 and 6nm for LTO, respectively. For both materials, we observe a transition in the scan rate dependence of the charge flow, namely from Li intercalation capacity control at low scan rates to diffusion/phase transformation control at higher scan rates. The peak current densities exhibit an approximate power law dependence on the scan rate with exponents between 0.54 and 0.64, even for low scan rates at which the charge flow is close to the Li intercalation capacity. Furthermore, we have tested a method proposed in the literature for differentiating between Faradaic and pseudocapacitive charge storage from scan rate-dependent cyclic voltammograms. The obtained results are not physically meaningful, in particular the obtained negative pseudocapacitive and Faradaic currents. We have analysed the origin of these results, and we show that iso-potential plots of the scan rate-dependent current are not suitable for differentiating between Faradaic and pseudocapacitive processes.
Insight in psychosis is a multi-dimensional phenomenon, and has been hypothesised to have some sort of neuropsychological basis. It is unclear to what extent specific neuropsychological abilities are able to predict insight beyond the effect of generalised cognitive ability. We aimed to test this association, alongside the relationship of insight with illness duration and diagnosis, in a sample of first episode psychosis patients. 110 first episode psychosis patients were recruited and a comprehensive assessment was administered, including insight, symptoms, diagnosis and neuropsychological function. Low insight was related to worse performance in a variety of neuropsychological tasks. Regression analysis tested whether any specific tasks were related to insight (or dimensions of insight) beyond the effect of IQ. Verbal memory had an effect on total insight and all dimensions of insight (except compliance) beyond the effect of IQ. Insight appeared to vary with diagnosis, with those diagnosed with depressive affective psychoses having better insight than those with manic affective psychoses. There was no relationship between insight and DUP, but there was a relationship between time spent in treatment before assessment and insight, even after controlling for severity of symptoms. These results suggest a model of insight in early psychosis with a significant neuropsychological component, particularly with verbal memory but also with generalised cognitive ability. There is likely to be a social component to insight affected by initial time spent in contact with treatment, helping patients to understand and come to terms with their illness.
Rural electrification programs usually do not consider the impact that the increment of demand has on the reliability of off-grid photovoltaic (PV)/battery systems. Based on meteorological data and electricity consumption profiles from the highlands of Bolivian Altiplano, this paper presents a modelling and simulation framework for analysing the performance and reliability of such systems. Reliability, as loss of power supply probability (LPSP), and cost were calculated using simulated PV power output and battery state of charge profiles. The effect of increasing the suppressed demand (SD) by 20% and 50% was studied to determine how reliable and resilient the system designs are. Simulations were performed for three rural application scenarios: a household, a school, and a health centre. Results for the household and school scenarios indicate that, to overcome the SD effect, it is more cost-effective to increase the PV power rather than to increase the battery capacity. However, with an increased PV-size, the battery ageing rate would be higher since the cycles are performed at high state of charge (SOC). For the health centre application, on the other hand, an increase in battery capacity prevents the risk of electricity blackouts while increasing the energy reliability of the system. These results provide important insights for the application design of off-grid PV-battery systems in rural electrification projects, enabling a more efficient and reliable source of electricity.
We studied the pH and temperature effects on copper ions adsorption on green and red clays from Tejera-Esghira in Medenine, Tunisia. Acid-activation was studied to improve the adsorption capacity. X-Ray Diffraction identified kaolinite and illite as major clay minerals. At 20°C, pH5.5 and before acid-activation, the amount adsorbed by the green and red clays was 28.3 and 13.2mg.g−1 respectively and increased to 40.6 and 26.8mg.g−1 after acid-activation, and the adsorption isotherms could be described by the Langmuir model. Thermodynamic parameters showed that the adsorption process was spontaneous and exothermic. In comparison silica gel adsorbed 27.15mg.g−1 copper ions.
We present in situ environmental transmission electron microscopy (ETEM) observation of metallic lithium nucleation, growth and shrinkage in a liquid confining cell, where protrusions are seen to grow from their roots or surfaces, depending on the overpotential. The rate of solid-electrolyte interface (SEI) formation affects root vs. surface growth mode, with the former akin to intermittent volcanic eruptions, giving kinked segments of nearly constant diameter. Upon delithiation, root-grown whiskers are highly unstable, because the segmental shrinkage rate depends on Li+ transport across SEI, which is the greatest around the latest grown segment with the thinnest SEI, and therefore the near-root segment often dissolves first and the rest of the whisker then loses electrical contact. These electrically isolated dead lithium branches are also easily swept away into the bulk electrolyte to become “nano-lithium flotsam” because the hollowed-out SEI tube is very brittle. Our observations are consistent with SEI-obstructed growth by two competing mechanisms; surface growth of dense Eden-like clusters and root growth of whiskers, resulting from the voltage-dependent competition between lithium electrodeposition and SEI formation reactions. Similar phenomena could occur whenever chemical deposition/dissolution competes with irreversible side reactions that form a passivating layer on the evolving surface.
Nickel sulphide (NiS) nanostructures decorated with gold (Au) nanoparticles (NPs) were synthesized via a microwave-assisted hydrothermal technique. Binary phase NiS (α and β) crystalline nanostructures, bare, and decorated with Au NPs were obtained and confirmed by X-ray diffraction (XRD) studies. TEM analysis revealed that the NiS nanostructures were of various shapes. A quantum confinement effect was confirmed by the blue shift PL emissions and high optical energy band gap observed for the as-synthesized sample. A threefold light emission enhancement due to Au NP coatings was obtained when Au metal NP decoration concentrations was varied from 1% to 10%. These enhancements were attributed to the surface plasmon resonance (SPR) excitation of the surface decorated metal NPs which results in an increased rate of spontaneous emission. The PL enhancement factor was observed to vary at different NiS emissions as well as with the size of the Au NPs. The effect of metal NP decoration on the PL emission of NiS is to the best of our knowledge, presented for the first time.
Both functional imaging or EEG studies and studies including neurological patients found the dorsolateral prefrontal cortex (dLPFC) to be an important brain area for the processing of emotion and attention. The aim of the present study was to investigate whether emotion and attention can be modulated through bilateral transcranial direct current stimulation (tDCS) of the dLPFC. Therefore, we measured electroencephalographic occipital (early posterior negativity, EPN) and parietal ERPs (late positive potential, LPP) during an emotional picture viewing paradigm with an additional attentional instruction while applying bilateral anodal and cathodal tDC-stimulation to the left and right dLPFC. Beyond the well-known emotion and attention effects for both EPN and LPP, we found that left cathodal/right anodal tDCS leads to increased LPP amplitudes to target stimuli. In contrast to our hypothesis bilateral tDCS over the dLPFC did not influence emotional processing.
Every day, wastewater treatment requires large amounts of electricity. Microbial Fuel Cells (MFCs) can convert wastewater treatment plants from net power consumers into energy neutral/positive systems by generating electricity from wastewaters. We investigate here the design factors that have major impacts on the performance of two miniature MFCs, and, consequently, of the resulting stack of MFCs. A versatile mathematical model is provided, which simulates the complex MFC system by integrating fluid dynamic principles with mass transport phenomena and (bio)electrochemical reactions. The model is used to support an in-depth study of the two MFCs, which differ for electrode spacing, anodic volume and fluid pattern within the anodic chamber, and to associate any difference in performance to design factors. Finally, system scale-up is demonstrated by generating stacks of the two MFCs. Thanks to the versatility of the model developed, this study becomes a guide for the effective development of future miniature MFCs.
LiFePO4 (LFP) particles were obtained by grinding ingot synthesized in the molten state. This process, followed by jet milling, and then wet milling, provides a simple way to obtain powders with controlled particle size in the range from macroscopic to 25nm. However, at this time, we find that these particles tend to agglomerate to form secondary particles of size ∼100nm. The particles obtained by this process are characterized by X-ray diffraction (XRD). In situ and ex situ scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of milling was also investigated by analysis of physical properties using infrared spectroscopy (FTIR) and magnetic measurements. The electrochemical performance was evaluated in cells containing Li/1M LiPF6 in EC:DEC (1:1)/C-LiFePO4. After carbon coating, the LFP particles which are free of impurities, exhibit high-rate capability. Even with a limited amount of carbon (2wt.%) appropriate for commercial batteries, the capacity is 157mAhg−1 at 0.1C, 120mAhg−1 at 10C, without capacity fading after 60 cycles.
The paper addresses the influence of intense sediment transport (bed load and debris flow) on the efficiency of the structures aimed at the interception of wood logs. In the literature different devices designed to intercept woods are proposed: steel barriers, net barriers, check dam with steel bars positioned in the opening. In this paper we firstly define some fundamental dimensionless parameter governing the phenomenon, in order to determine a rational criterion to evaluate the efficiency of the different kind of devices.In particular, we deepen the interaction between slit check dams and driftwood, in both bed load and debris flow conditions. Starting from the results of this first analysis, we propose some arrangements of steel bars be installed in the check dam.Through a laboratory experimental investigation, by now conduced in simplified conditions (i.e. spherical mono-dispersed sediments), we define some criteria to obtain the best design parameters for the bars, that is their optimal disposition and spacing, in function of the logs characteristics (mainly the lengths). We investigate also the influence of different lengths of the transported woods, finding a general criterion to evaluate an overall length representing the logs ensemble.
Power split configurations exhibit potential on decreasing fuel consumption. However, how to select the best power split configuration among all the possible configurations still need to be explored. In this paper, a one-dimensional searching ECMS (Equivalent Consumption Minimization Strategy) is developed to evaluate fuel consumption for input power split configuration. Additionally, a battery degradation model based on experimental data is applied to evaluate the battery degradation for input power split configuration. According to one-dimensional searching ECMS and battery degradation model, the impact of different input power split configurations on fuel consumption and battery degradation is investigated. Simulations show that configuration T1 has fuel consumption and battery degradation advantages for PHEV city bus application in China. These advantages are observed because the system efficiency operation points of configuration T1 are closer to the high efficiency area than the system efficiency operation points of other input power split configurations. Furthermore, according to the lever model and one-dimensional searching ECMS method, a power split configuration selection method is provided in this paper. The simulation results based on configuration selection method still indicate that configuration T1 appears to have the best fuel economy for PHEV city bus application. Moreover, configuration T5, with a lever length close to 0, exhibits the worst fuel consumption and battery degradation.
LiMn2O4 and LiNi x Al y Mn2 − x − y O4 (x =0.50; y =0.05–0.50) powders have been synthesized via facile sol–gel method using Behenic acid as active chelating agent. The synthesized samples are subjected to physical characterizations such as thermo gravimetric analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electrochemical studies viz., galvanostatic cycling properties, electrochemical impedance spectroscopy (EIS) and differential capacity curves (dQ/dE). Finger print XRD patterns of LiMn2O4 and LiNi x Al y Mn2 − x − y O4 fortify the high degree of crystallinity with better phase purity. FESEM images of the undoped pristine spinel illustrate uniform spherical grains surface morphology with an average particle size of 0.5µm while Ni doped particles depict the spherical grains growth (50nm) with ice-cube surface morphology. TEM images of the spinel LiMn2O4 shows the uniform spherical morphology with particle size of (100nm) while low level of Al–doping spinel (LiNi0.5Al0.05Mn1.45O4) displaying cloudy particles with agglomerated particles of (50nm). The LiMn2O4 samples calcined at 850 °C deliver the discharge capacity of 130 mAh/g in the first cycle corresponds to 94% columbic efficiency with capacity fade of 1.5 mAh/g/cycle over the investigated 10 cycles. Among all four dopant compositions investigated, LiNi0.5Al0.05Mn1.45O4 delivers the maximum discharge capacity of 126 mAh/g during the first cycle and shows the stable cycling performance with low capacity fade of 1 mAh/g/cycle (capacity retention of 92%) over the investigated 10 cycles. Electrochemical impedance studies of spinel LiMn2O4 and LiNi0.5Al0.05Mn1.45O4 depict the high and low real polarization of 1562 and 1100 Ω.
Understanding graphically presented information is an important aspect of modern mathematical and science literacy. In our study, we investigated the influence of basic numerical abilities on students’ ability answer mathematical tasks with information presented in graphs. We analyzed data of 750 German students (grades 9–11) and evaluated the determinants of graph reading performance with multiple regression analysis using predictors of basic numerical abilities (such as number line estimation, basic arithmetic operations, etc.), considering also the influences of general cognitive ability, age, and gender. We found that number line estimation, subtraction, and conceptual knowledge were significant predictors of graph reading performance beyond the influences of general cognitive ability. This indicates that basic numerical abilities are still relevant for real-life problem solving in secondary school. We discuss possible mechanisms which directly (through respective arithmetic procedures) as well as indirectly (through mathematization of the problem) effectuate that basic numerical abilities graph reading performance.
A passive thermal management system that uses a phase change material (PCM) is designed and simulated for a lithium-ion (Li-ion) laptop battery pack. The problem of low thermal conductivity of the PCM was significantly improved by impregnating an expanded graphite (EG) matrix with the PCM. The heat generation rate for a commercial 186502.2Ah Li-ion battery was experimentally measured for various constant power discharges. Simulation of the battery pack, composed of six Li-ion batteries, shows that safe operation of the battery pack during the most extreme case requires the volume of the battery pack be almost doubled to fit sufficient PCM in the pack. Improving the properties of the PCM composite have the potential to significantly reduce the volume increase in comparison to the original battery pack volume.
In this study, metal-organic framework (MOF) of ZIF-67 is utilized as a precursor to synthesize nitrogen-doped porous graphitized carbon-supported cobalt disulfide (CoS2@NC) catalyst. The CoS2@NC composite combines the advantages of CoS2 and N-doped carbon with excellent oxygen reduction reaction (ORR) catalytic characteristics. For instance, the CoS2@NC catalyst exhibits an onset potential of −0.105V vs. Ag/AgCl, a half-wave potential of −0.172V and a diffusion-limited current density of 5.49mAcm−2, which are similar to commercial Pt/C with slight inferior difference of 24mV, 10mV and 0.38mAcm−2, respectively. However, the CoS2@NC shows better methanol tolerance and long-term durability than the Pt/C catalyst. The findings above demonstrate that a simple and efficient method is developed for the synthesis of MOF-derived carbon-supported metal sulfides for ORR electrocatalysts.
The sodium battery has the potential to be the next generation rechargeable system which utilizes cheaper and more abundant sodium material but affords nearly the same power as lithium batteries. One of the key barriers for the sodium battery is the lack of stable anode materials which can insert sodium ions reversibly at relatively low potential. This contribution reports the sodium insertion in a series of organic carboxylate based materials: (C8H4Na2O4), (C8H6O4), (C8H5NaO4), (C8Na2F4O4), (C10H2Na4O8), (C14H4O6) and (C14H4Na4O8) at low voltage (below 0.6 V vs. Na/Na+). These organic anode materials can insert reversibly up to 2 Na per molecule with good cycleability. The Na insertion mechanism was proposed and 3.6 V full sodium batteries were made and cycled reversibly at room temperature and at 55 °C.
Intensive research and development carried out at SAFT Research [1,2] has shown that limitation of Ni–MH battery life duration can be directly linked to AB5 alloy corrosion in the negative electrode. A mathematical model taking into account these results has been developed in order to predict battery life as a function of the conditions of utilisation: cycle and calendar life [3]. However, the degradation of the negative electrode is the consequence of two phenomena: surface corrosion of the active alloy and decrepitation of alloy particles during cycling. Up to now, only the kinetic law controlling the evolution of the thickness of the corrosion layer could have been quantified [3]. On the other hand, the kinetic law of decrepitation could not be directly measured, but is only fitted by determining the total amount of corrosion. Thus, an in situ method suitable to quantify the electrochemical surface of the alloy has been developed. Therefore, electrochemical impedance spectroscopy (EIS) has been used to follow the degradation of the negative electrode, as a function of depth of discharge (DOD) during cycling. Alloy corrosion measurements and scanning electron microscope (SEM) analyses have been performed to confirm the validity of the method. It has been found that decrepitation is nearly zero for low levels of low DOD (5%).
Lithium oxide (Li2O) is activated in the presence of a layered composite cathode material (HEM) significantly increasing the energy density of lithium-ion batteries. The degree of activation depends on the current rate, electrolyte salt, and anode type. In full-cell tests, the Li2O was used as a lithium source to counter the first-cycle irreversibility of high-capacity composite alloy anodes. When Li2O is mixed with HEM to serve as a cathode, the electrochemical performance was improved in a full cell having an SiO-SnCoC composite as an anode. The mechanism behind the Li2O activation could also explain the first charge plateau and the abnormal high capacity associated with these high energy cathode materials.
Testing new chemical entities for genotoxicity is an integral part of the preclinical drug-development process. Lowering the detection limit and enhancing the sensitivity of genotoxicity assays is required, as the standard test-battery fails to detect some carcinogens (non-genotoxic) and weak genotoxins. One of the mechanisms that affect the detection of weak genotoxins is related with the DNA-repair efficiency of the cell system used. In the present study, 3-aminobenzamide (3-AB, 30mg/kg body-weight), a poly(ADP-ribose)polymerase inhibitor, was used to evaluate the DNA-damaging potential of zidovudine (AZT, 400mg/kgbw), doxorubicin (DOX, 5mg/kgbw) and cyclophosphamide (CP, 50mg/kgbw, as a positive control) and sucrose (SUC, 3g/kgbw, as a negative control) in Swiss female mice. The endpoints considered included micronucleus formation, DNA breakage (in peripheral blood lymphocytes, bone marrow and liver; comet assay) and chromosome aberrations, as well as immunohistochemistry of PARP-1 and phosphorylated histone H2AX (γ-H2AX). The results clearly indicate that the genotoxicity of zidovudine (AZT), doxorubicin (DOX) and cyclophosphamide (CP) was significantly increased in the combination treatments (3-AB+AZT, 3-AB+DOX, 3-AB+CP) as compared with the respective controls (treatment with AZT, DOX and CP alone). There was no increase in the genotoxicity per se after treatment with SUC, 3-AB or 3-AB+SUC, compared with the control (saline). Correlation analysis suggests that all genotoxicity parameters are well correlated with each other. The results clearly show that the genotoxicity of weak genotoxins can be enhanced and detected in the presence of 3-AB in mice. Thus, this approach can be used in the pre-clinical genotoxicity screening of weak genotoxins.
Patients undergoing total knee arthroplasty (TKA) often experience strength deficits both pre- and post-operatively. As these deficits may have a direct impact on functional recovery, strength assessment should be performed in this patient population. For these assessments, reliable measurements should be used. This study aimed to determine the inter- and intrarater reliability of hand-held dynamometry (HHD) in measuring isometric knee strength in patients awaiting TKA.
An overview of structures technology for future aerospace systems is given. Discussion focuses on developments in component technologies that will improve the vehicle performance, advance the technology exploitation process, and reduce system life-cycle costs. The component technologies described are smart materials and structures, multifunctional materials and structures, affordable composite structures, extreme environment structures, flexible load bearing structures, and computational methods and simulation-based design. The trends in each of the component technologies are discussed and the applicability of these technologies to future aerospace vehicles is described.