batterydata/paper-abstracts huggingface dataset:
To improve electrochemical performance of MnO electrodes, the porous 3D interconnected MnO/C composite aerogel is, at first, fabricated through direct carbonization of polyacrylic acid (PAA)-assisted manganese-based aerogel. Herein, the influences of carbonization temperature and the amount of PAA on the microstructure and lithium storage performance of composites are presented. MnO/C composite aerogel n3-550 (carbothermal reduction at 550 °C with the 30 mmol addition of PAA) shows the minimal MnO crystalline size, and the MnO/C composite aerogel n3-650 (carbothermal reduction at 650 °C with the 30 mmol addition of PAA) has the largest surface area and highest porosity. When evaluated as anodes for lithium ion batteries, the composite n3-550 exhibits the highest reversible capacity of 1081.8 mAh g−1 after 100 cycles at current density of 0.2 A g−1, n3-650 electrode displays the most outstanding rate capability (601 mAh g−1 at 2 A g−1), and the highest coulombic efficiency (initial coulombic efficiency of 69.8% and greater than 98% after the 6th cycles). These excellent electrochemical performances are as a result of the porous interconnected 3D networks composited of hybridized nano-MnO with carbon, providing outstanding electrical conductivity and 3D charge transport channels. This facile and efficient strategy provides a horizon and deep understanding for advancing the design of high-performance oxide based anode materials.
Synthetically produced perfluorinated chemicals (PFCs) are widely used in industrial products because of their anti-wetting and surfactant properties. PFCs are suspected carcinogens and a possible mechanism of action is generation of oxidative stress. We have investigated the potential of five different PFCs to generate reactive oxygen species (ROS) and to induce oxidative DNA damage in HepG2 cells. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) increased the intracellular ROS production by 1.52-fold (95% CI, 1.37–1.67) and 1.25-fold (95% CI, 1.10–1.40), respectively. However, the increase in ROS production was not concentration-dependent and the compounds did not generate DNA damage that could be detected by the alkaline comet assay as strand breakage and alkali-labile sites or formamidopyrimidine-DNA-glycosylase (FPG) sites. Perfluorobutane sulfonate (PFBS) and perfluorohexanoic acid (PFHxA) did not generate ROS or DNA damage. Only the exposure to perfluorononanoic acid (PFNA) caused a modest increase in DNA damage at a cytotoxic concentration level, which was detected as lactate dehydrogenase (LDH) release into the cell medium. This was not related to ROS generation. Collectively, these results indicate that PFCs induce only modest effects in terms of ROS production and DNA damage in a cell line representing the human liver.
Aging leads to alterations in the function of the hippocampus, a brain structure largely involved in learning processes. This study aimed at examining the basal levels and the impact of a learning-associated task on brain-derived neurotrophic factor (BDNF), on BDNF full-length catalytic receptor (TrkB.FL) and on the truncated forms (TrkB.T1 and TrkB.T2) receptor expression (mRNA and protein) in the hippocampus of young (2-month-old) and aged (24-month-old) Wistar rats. Spatial memory was evaluated using a water-maze procedure involving visible and invisible platform location learning. Aged rats showed higher latencies during the first two training days but rapidly exhibited learning performances similar to patterns observed with young rats. Real-time PCR measurements showed that aged rats had significantly higher levels of trkB.FL mRNAs than young rats under basal conditions. In situ hybridization analysis indicated that the highest level of trkB.FL mRNA (mRNA encoding for TrkB.FL receptor) was noted in the dentate gyrus, and in the CA2 and CA3 hippocampal layers. In contrast, there was no marked difference in trkB.T1 signal in any hippocampal region. Training induced a significant reduction in trkB.FL mRNA levels solely in aged rats. In contrast, in young and aged rats, trkB.T2 mRNA levels were significantly increased after training. Measurements of proteins revealed that learning significantly increased TrkB.FL content in aged rats. Untrained aged rats presented higher levels of BDNF and brain-derived neurotrophic factor precursor (proBDNF) proteins than young rats. Training strongly increased precursor BDNF metabolism in young and aged rats, resulting in increased levels of proBDNF in the two groups but in old rats the mature BDNF level did not change. This study shows that Wistar rats present age-related differences in the levels of BDNF and TrkB isoforms and that spatial learning differentially modifies some of these parameters in the hippocampus.
The mechanisms and effects of three typical chelating agents, namely glucose, citric acid and sucrose on the sol-gel synthesis process, electrochemical degradation and structural evolution of 0.5Li2MnO3·0.5LiNi0.5Co0.2Mn0.3O2 (LLMO) materials are systematically compared for the first time. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy analysis indicate that the sample synthesized from sucrose owns well structure, homogenous distribution, low Ni3+ concentration and good surface structural stability during cycling, respectively. Electrochemical tests further prove that the LLMO material obtained from sucrose maintains 258.4mAhg−1 with 94.8% capacity retention after 100 cycles at 0.2C. The superior electrochemical performance can be ascribed to the exceptional complexing mechanism of sucrose, compared to those of the glucose and citric acid. Namely, one mole sucrose can be hydrolyzed into two different monosaccharides and further chelates three M (Li, Ni, Co and Mn) ions to form a more uniform ion-chelated matrix during sol-gel process. This discovery is an important step towards understanding the selection criterion of chelating agents for sol-gel method, that chelating agent with excellent complexing capability is beneficial to the distribution, structural stability and electrochemical properties of advanced lithium-rich layered materials.
Electronics on flexible and transparent substrates have received much interest due to their new functionalities and high-speed roll-to-roll manufacturing processes. The properties of substrates are crucial, including flexibility, surface roughness, optical transmittance, mechanical strength, maximum processing temperature, etc. Although plastic substrates have been used widely in flexible macroelectronics, there is still a need for next-generation sustainable, high-performance substrates which are thermally stable with tunable optical properties and a higher handling temperature. In this communication, we focus on cellulose-based transparent, biodegradable substrates incorporating either nanopaper or a regenerated cellulose film (RCF). We found that both their optical and mechanical properties are dramatically different due to the difference of their building blocks. Highly flexible organic-light-emitting diodes (OLEDs) are also demonstrated on the biodegradable substrates, paving the way for next-generation green and flexible electronics.
The rapid market growth of rechargeable batteries requires electrode materials that combine high power and energy and are made from earth-abundant elements. Here we show that combining a partial spinel-like cation order and substantial lithium excess enables both dense and fast energy storage. Cation overstoichiometry and the resulting partial order is used to eliminate the phase transitions typical of ordered spinels and enable a larger practical capacity, while lithium excess is synergistically used with fluorine substitution to create a high lithium mobility. With this strategy, we achieved specific energies greater than 1,100 Wh kg–1 and discharge rates up to 20 A g–1. Remarkably, the cathode materials thus obtained from inexpensive manganese present a rare case wherein an excellent rate capability coexists with a reversible oxygen redox activity. Our work shows the potential for designing cathode materials in the vast space between fully ordered and disordered compounds.
The oxygen reduction reaction and the oxygen evolution reaction have been studied on mixed oxides Ni x Al1−x Mn2O4 (1≥x≥0) crystallising in the spinel structure. Two different preparation methods have been used: coprecipitation of metal hydroxides and sol–gel. The different activity that is observed is related to the solid-state couple in octahedral sites. AlMn2O4 shows the poorest activity due to intrinsic resistivity. The substitution of Al by Ni increases the catalytic activity, the maximum being that exhibited by NiMn2O4. These electrochemical reactions can be used to detect the nature of the electrodes by way of the electrocatalytic activity.
Ferrigno IS, Cliquet Jr, A, Magna LA, Zoppi Filho A. Electromyography of the upper limbs during computer work: a comparison of 2 wrist orthoses in healthy adults. Objective To examine the effect of wrist orthoses on the electromyography activities of the extensor carpi ulnaris, flexor digitorum superficialis, and fibers of the upper trapezius muscles during computer work. Design A randomized, 3×2 factorial design: orthoses (no orthosis, wearing a custom-made orthosis, wearing a commercial orthosis) and tasks (typing, using the mouse). Setting Laboratory for biomechanics and rehabilitation. Participants Healthy university students (N=23), ranging from 18 to 26 years of age. Intervention Study volunteers performed standardized tasks such as typing and using the mouse while wearing 1 of 2 types of wrist orthoses or no orthosis. Main Outcome Measures We used surface electromyography and considered 100% maximum voluntary contraction to represent the amplitude of electromyographic activity. Results We observed a significant increase in the electromyographic activity of the trapezius (P<.05) with the use of orthoses. No significant difference was observed in the activities of the flexor digitorum superficialis or extensor carpi ulnaris in participants who typed with or without orthoses (P>.05). However, when the participants used the mouse, the extensor muscle presented an increase in activity with both orthoses, and the same pattern was observed in the flexor muscle when the volunteers used the custom-made orthosis. Conclusions Wrist orthoses affected the muscle activities in the upper limbs of healthy adults who were using a computer. Electromyographic activity increased in the trapezius when the subjects used either type of orthosis, and the same pattern was observed in the extensor carpi ulnaris when the subjects used the mouse. The flexor digitorum superficialis presented an increase in activity only when the subjects worked with the mouse and used a custom-made splint.
This paper presents a design methodology for a dc-dc power conversion system (PCS) for battery packs. The methodology provides with an optimal design of the PCS and the associated inductive-capacitive filter interfacing the battery pack with the PCS. The PCS adds superior capability over conventional designs, which is performing current and voltage perturbations at the battery terminals for the so-called electrochemical impedance spectroscopy (EIS). This technique is an option for battery state-of-charge (SoC) and state-of-health (SoH) assessment. The design is optimal in the sense that it minimizes volume and system power losses. Such multi-objective optimization is addressed adopting the theory of weighted sum and Pareto front. The methodology is tested through a case study, addressing a lithium-ion battery pack. The offered analyses permit to identify the impact in system performance of diverse design variables such as dc-link voltage for the PCS and its switching frequency.
Critical materials as well as rare earth elements and precious metals such as platinum, gold and silver are used significantly for computer hard disk drives, mobile phones, hybrid electric vehicles, batteries, renewable energy system and many other applications. It is therefore important to quantify and estimate both current stocks and flows of such materials, as well as future requirement for industries and economies. In this study, which is focused on wind energy system in the European Union (EU) 27, the current consumption and future requirement of critical and precious materials were calculated and estimated using the wind power production dataset from ecoinvent and data from National Renewable Energy Action Plan (NREAP). It is shown that fluorspar has been the most consumed material to date, and will probably be the most required material in the future. Among other critical and valuable materials, the main materials used for current wind energy system are silver, magnesium, indium, gold and tantalum. These materials will also be required significantly by 2020 for the wind energy system in the EU 27. It is argued that these results should be connected to the future energy and material policy and management.
Sodium sulfide (Na2S) has been used as sacrificial material for the presodiation of a Sn4P3 negative electrode in order to realize a high-performance sodium-ion capacitor (NIC). In two-electrode cells with Na counter/reference electrode and 1 mol L−1 NaClO4 electrolyte, sodium could be irreversibly extracted from Na2S at potential lower than 3.8 V vs. Na/Na+, with a capacity close to the theoretical value of 687 mAh g−1. In the realization of the composite positive electrode for a NIC, the relatively high capacity of Na2S allows to reduce its amount to 40 wt%, whereas the other materials are activated carbon (AC, 40 wt%), carbon soot (15 wt%) and binder (5 wt%). Once the pre-sodiation of Sn4P3 is completed, activated carbon being a part of the positive electrode stores charges in the electrical double-layer (EDL), while reversible sodium insertion occurs in the Sn4P3 negative electrode. The full NIC demonstrates stable performance in the voltage range 2.0 V–3.8 V with high specific energy ca. 48 Wh kg−1 at specific power of 1 kW kg−1 (per total mass of electrodes). Hence, Na2S is an excellent sacrificial material, which allows the NICs construction to be simplified and consequently the manufacturing costs to be reduced.
A low-cost deuterated electrolyte suitable for in situ neutron diffraction measurements of normal and high voltage Li-ion battery electrodes is reported here. Li[Ni0.4Mn0.4Co0.2]O2/graphite (NMC(442)/graphite) pouch cells filled with 1:0.1:2 (molar ratio) of lithium bis(fluorosulfonyl) imide (LiFSi):LiPF6: ethyl acetate (EA) and LiFSi:LiPF6:deuterated EA (d8-EA) electrolytes were successfully cycled between 2.8V and 4.7V at 40°C for 250h without significant capacity loss, polarization growth, or gas production. The signal-to-noise ratio of neutron powder diffraction patterns taken on NMC(442) powder with a conventional deuterated organic carbonate-based electrolyte and filled with LiFSi:LiPF6:d8-EA electrolyte were virtually identical. Out of all the solvents widely available in deuterated form tested in highly-concentrated systems, EA was the only one providing a good balance between cost and charge-discharge capacity retention to 4.7V. The use of such an electrolyte blend would half the cost of deuterated solvents needed for in situ neutron diffraction measurements of Li-ion batteries compared to conventional deuterated carbonate-based electrolytes.
Objective Cognitive outcome of isolated agenesis of the corpus callosum (ACC) remains a critical prenatal situation with uncertain prognosis. Despite normal IQ and learning skills in most of the patients, the risk of specific learning disability is not clearly established. Moreover, several rare syndromes responsible for severe intellectual disability cannot be diagnosed with current prenatal genetic techniques. Only a few series have been published so far, with a small number of patients, or including both isolated and associated ACC. We describe a clinical prospective series of 46 patients with isolated ACC. Methods Between 2004 and 2013 an isolated ACC (either partial or complete) was diagnosed in 60 women referred to a regional prenatal diagnosis center. Inclusion criteria were: no other malformation on ultrasound (22 weeks) and MRI (28 weeks), no consanguinity, no familial history of developmental delay, no genetic defect on fetal karyotype or Array CGH. All patients were assessed with standardized batteries: Brunet Lézine before 3 years old, WPPSI-III at 3 and 5 years old, WISC-IV at 8 years old. Results Among 60 pregnancies, 12 abortions, one fetal death, one lost outcome, and 46 newborn (76% of the pregnancies). Among the sixteen younger children (<3 y old), one had a severe developmental delay, the others had normal developmental skills. Among the thirty older children (3 to 10 years old), one had a severe intellectual disability (Mowat-Wilson syndrome), nine (30%) had specific learning disabilities (with IQ >70), and 20 (66%) had normal IQ and learning skills. Conclusion A rare risk of a severe cognitive impairment (2/46 patients; 4.3%) cannot be excluded and must be shared with the women. Nevertheless, 30% of patients had specific learning disabilities and two thirds had a normal outcome, which is consistent with other small series of isolated ACC
In this paper an empirical capacity fade model for Li-ion batteries has been developed, calibrated and validated for a NCA/C and a LFP/C Li-ion cell. Based on extensive experimental work, this original, generic model is well suited for system simulation approaches, and is able to describe both cycle and calendar effects on aging. The stress factors taken into account for each aging mode are the state of charge and the temperature for calendar aging, and the temperature and the current for cycle aging. A simple approach has been adopted in order to instantaneously apply either cycle aging or calendar aging according to operating conditions and thus accurately model aging effects due to dynamic operating conditions. This model has then been coupled to an electrothermal model and integrated in a system simulation software application in order to assess the effect of charging rates, charging strategies and V2G on battery lifetime. When compared, the two battery chemistries exhibited different behaviors when submitted to V2G scenarios. Light V2G scenarios caused relatively low aging for the LFP/C based battery but tended to slightly increase the aging of the NCA/C based battery according to simulations.
Room-temperature Na-ion batteries (NIBs) have been generally expected to offer a hopeful perspective for renewable energy storage applications on a large scale. However, a shortage of appropriate anode materials for NIBs has hindered their large-scale applications. Here, we report the strong chemical bonding of tin sulfide on amino-functionalized graphene that is prepared by a facile amine-thermal reaction. In contrast to previous reports on graphene-based composite electrodes, our strategy has the following merits: the one-step formation of amino-functionalized reduced grapheme oxide (RGO) from GO and tight contact of SnS2 nanocrystals at an amino-functionalized graphene interface. This concept has been demonstrated by experimental results which are in congruence with first principles theoretical calculations. When investigated as an anode material for NIBs, the composite maintained a capacity of 680 mA h g−1 after cycling for 100 cycles at a current density of 200 mA g−1, and 480 mA h g−1 after 1000 cycles at 1 A g−1. The outstanding performance results from the unique structure of the hybrid nanosheets.
1-Alkyl-2-(arylazo)imidazole (RaaiR/), a bidentate N(azo), N(imidazolyl) chelator, and bis(diphenylphosphino)methane (dppm), a P, P bridger, have been used to prepare phosphino bridged dinuclear-Cu(I) complexes, [Cu(μ-dppm)(RaaiR/)]2(ClO4)2. The structures of the complexes have been established by spectral (UV–Vis, IR, 1H NMR) data and the confirmation has been done in case of [Cu(μ-dppm)(HaaiEt)]2(ClO4) 2 by single crystal X-ray diffraction studies. Optical stimulation using UV light (365 nm) in methanol solution of the complexes shows that the coordinated RaaiR/ undergoes trans-to-cis isomerization about NNAr. The rate of trans-to-cis isomerization varies 1.11 × 10−8−1.89 × 10−8 s−1 and is largely dependent on mass of the photochrome and strain/steric crowding generated about NN bond. Quantum yields (ϕt→c) of trans-to-cis isomerization, 0.0843–0.1421, are calculated and free ligand shows higher ϕ (0.17–0.26) than their complex phase. The cis-to-trans isomerisation is a thermally induced process. The activation energy (Ea) of cis-to-trans isomerisation is calculated by controlled temperature experiment and is found that Ea (ligands) > Ea (complexes).
This paper presents a powertrain control strategy for a series hybrid electric vehicle (SHEV) based on the integrated design of an active charging scenario and fixed-boundary-layer sliding mode controllers (FBLSMCs). An optimized charging curve for the battery is predetermined rather than subject to engine output and vehicle power demand, which is a total inverse of normal SHEV powertrain control process. This is aimed to remove surge and high-frequency charge current, keep the battery staying in a high state-of-charge (SOC) region and avoid persistently-high charge power, which are positive factors to battery lifetime extension. Then two robust chattering-free FBLSMCs are designed to locate the engine operation in the optimal efficiency area. One is in charge of engine speed control, and the other is for engine/generator torque control. Consequently, not only fuel economy is improved but also battery life expectancy could be extended. Finally, simulation and experimental results confirm the validity and application feasibility of the proposed strategy.
This paper introduces a semi-empirical dynamic model for PEM fuel cell power modules with potential applications in distributed generation. The proposed model is constructed based on the measurements from a Nexa™ PEM fuel cell power module under different load conditions, and the model has been validated by static as well as dynamic tests. The effects of temperature and variations in the internal impedance under different load conditions have been studied. The results have indicated that the model provides an accurate representation of the dynamic and static behaviors of the fuel cell power module.
Poly vinylidene fluoride–hexa fluoro propylene hybrid membranes are prepared by directly blending the copolymer with different sizes of acidified stannous oxide particles. Steric repulsion between the hydrophobic host polymer and hydrophilic acidified particles generates cavities in the hybrid membranes. The infrared and energy dispersive spectroscopic studies confirmed the structural characterization of the hybrid membranes. The high acid moieties of stannous oxide particles conscript higher ion channels whereas the hygroscopic property favors high water molecules retention and provokes the self-humidification of the hybrid membranes. Though high ionic conductivities are achieved for the hybrid membranes, inferior methanol permeabilities are also maintained due to the hydrophobic units and methanol resistive behavior of host polymer and stannous oxide particles, respectively. By the combined efforts of high ion and lower molecular transportation, direct methanol fuel cells performance is facilitated for the fabricated hybrid membranes and influences its potential application in fuel cells field.