batterydata/paper-abstracts huggingface dataset:
Methods for estimating inner states in a lithium-ion cell require steady state conditions or accurate models of the dynamic processes. Besides often used inner states such as state-of-charge, state-of-health or state-of-function, relaxation processes strongly influence the mentioned states. Inhomogeneous utilization of electrodes and consequent limitations in the operating conditions have recently been brought to attention. Relaxation measurements after an inhomogeneous current distribution through the thickness of an electrode have not been addressed so far. By using a previously developed laboratory cell, we are able to show an inhomogeneous retrieval of lithium-ions from a graphite electrode through the layer with spatial resolution. After this inhomogeneity caused by a constant current operation, equilibration processes are recorded and can be assigned to two different effects. One effect is an equilibration inside the particles (intra-particle) from surface to bulk and vice versa. The other effect is an assimilation between the particles (inter-particle) to reach a homogeneous state-of-charge in each particle throughout the electrode layer. While intra-particle relaxation is observed to be finished within 4 h, inter-particle relaxation through the layer takes more than 40 h. The overall time for both equilibration processes shows to be in the order of 48 h.
Nutrient and gas exchange between mother and fetus and production of hormones sustaining fetal development are important placental functions carried out by a rich selection of transporter proteins and a variety of metabolizing enzymes. The same proteins handle many xenobiotics which in placenta may pass, accumulate, and change placental functions, causing toxicity. Because of structural and functional variation between species, human placental tissue and human trophoblastic cell lines are the most used systems in the search for placental biomarkers of toxicity. They would be helpful in evaluation of drug toxicity in placenta, and in toxicological risk assessment. Only a few exist so far, e.g. changes in CYP19A1/aromatase by hormonally active compounds, metallothioneins in metal exposure, and level of PAH-DNA adducts associated with fetotoxicity. New possibilities are provided, e.g. by the emerging field of placental epigenetics. Use of placenta and placental biomarkers in regulatory toxicology also awaits further data.
Cation-disordered rock-salt transition-metal oxides and oxyfluorides (DRX) have emerged as promising cathode materials for Li-ion batteries due to their potential to reach high energy densities and accommodate diverse, lower cost transition-metal chemistries compared to conventional layered oxide materials. However, the intricate local coordination environment in DRX also results in complex electrochemical electron transfer involving parallel mechanisms of transition-metal (TM) redox and oxygen (anionic) redox. Without decoupled and quantitative information of these intermixed redox processes, the origin of irreversibility, voltage hysteresis, and capacity fading is obscured, impeding the development of strategies to address these issues. Here we deconvolute the mixed redox processes in a Ni-based DRX, Li1.15Ni0.45Ti0.3Mo0.1O1.85F0.15, by combining 18O isotopic enrichment, differential electrochemical mass spectrometry (DEMS), and ex situ acid titration. The summation of TM-redox and oxygen-redox capacities measured through our approach agrees with the net electron transfer measured by the potentiostat. This study reveals much less Ni oxidation efficiency (59.5%) than its initially designed efficiency (100%) due to competition of oxygen redox, which can occur at potentials as low as 4.1 V (vs. Li/Li+). We propose that the chemical approach presented in this work and its future extension can resolve and quantify various mixed redox processes in different DRX, which allows clear correlations among material design, deconvoluted redox capacities, and battery performance.
It is needed to speed up the development of a sensitive detection platform for simultaneous determination of dihydroxybenzene isomers with harmful properties. Here, two isomorphic Metal–organic frameworks (MOFs) [Zn(Trz)(R-BDC)1/2] (FJU-40-R, R = H or NH2; Trz = 1,2,4-Triazole; H-BDC = terephthalic acid) were selected to derive two N-doping porous carbon (NPC) materials. Further, a strategy for constructing electrochemical sensors for simultaneous determination of hydroquinone (HQ) and catechol (CT) was proposed by the MOF-derived NPC modifying glass carbon electrode (GCE). It was found that HQ and CT had good responses on NPC-FJU-40-H/GCE, but had no obvious responses on NPC-FJU-40-NH2/GCE. NPC-FJU-40-H/GCE displayed excellent reproducibility, stability, and anti-interference. Under the optimal conditions, the linear ranges of HQ and CT on NPC-FJU-40-H/GCE were 1 ~ 70 µmol L−1 and 1 ~ 100 µmol L−1 with the detection limits of 0.18 µmol L−1 for HQ and 0.31 µmol L−1 for CT, respectively. Although the porous carbon (PC) derived from MOFs has been applied in electrochemical sensing, the effect of the ligand functional groups of isomorphic MOFs on the electrochemical properties of the derived PC materials is still lack of relevant research. Our research provided an idea that the electrocatalysis properties of MOF-derived porous carbon materials could be tuned by changing the functional groups in ligands of isomorphic MOFs in electrochemical sensing field.
γ-Butyrolactone (GBL) increases the irreversible capacity of lithium ion battery when it is employed as the solvent for the lithium bis(oxalate)borate (LiBOB)-based electrolyte. To solve this problem, four sulfites are introduced to the electrolyte. The effects of ethyl sulfite (ES), propylene sulfite (PS), dimethyl sulfite (DMS) and diethyl sulfite (DES) on the LiBOB/GBL-based electrolytes are studied. The ionic conductivity, electrochemical stability, cycle performance and thermal stability of the sulfite containing electrolytes are tested and compared with that of the common electrolyte and the 1M LiBOB/GBL electrolyte. The results indicate that the cyclic sulfites ES and PS show little benefit to the performance of the electrolyte. However, the linear sulfites DMS and DES could increase the ionic conductivity of the electrolyte and form an effective SEI film on the anode surface. In particular, the 1M LiBOB/GBL+DMS (3:1 wt.) electrolyte mitigates the irreversible capacity and enhances the first coulomb efficiency and the capacity retention. The thermal stability of the DMS containing electrolyte is also improved and is better than that of the common electrolyte. These beneficial effects make them possibly to be a promising cosolvent for the LiBOB/GBL electrolyte.
Following modest growth in 2017 for the North American PM and MIM industries, MPIF reported a favorable outlook for 2018 despite a serious shortage of skilled employees. The concurrently-held POWDERMET and AMPM conferences continue to surpass previous successes.
Non-rainfall atmospheric water input (NRWI), which is comprised of fog, dew and soil water vapour adsorption (WVA), has been proven to be an important water source in arid and semiarid environments. Its minor contribution to the water balance and the difficulty in measuring it have resulted in a wide variety of measurement methods (duration and quantification), especially for dew. Microlysimeters seem to be the most realistic method for dew measurement on natural surfaces and they can also detect WVA. This paper presents an automated microlysimeter that enables accurate studies of NRWI and evaporation on soil and small plants. Furthermore, we have developed a field strategy for their long term placement and installation which prevents damage from rainfall, soil movement or other field conditions, keeping the microlysimeters balanced and dry. This design allows the measurement of evaporation and NRWI on different cover types, including small plants. By monitoring the surface temperatures, dewfall and water vapour adsorption can be distinguished and the relative contribution of dew and WVA on the NRWI can also be found. Our automated microlysimeter design, construction and field installation have proven to be an useful and effective tool in an NRWI study.
Seasonal heat storage technologies are the key for a widespread use of solar thermal energy in residential applications. This can be achieved using hygroscopic salts encapsulated in a porous matrix with a high pore volume. Using strontium bromide encapsulated in the mesoporous MIL-101(Cr) Metal-Organic Framework, a heat storage density of 233 kW h/m³ could be achieved, by using water vapor at a partial pressure as low as 1.25 kPa. This excellent result is partly due to the high salt content (63 wt. %), but also to unexpected modifications of the water sorption isotherms of SrBr2 once it is encapsulated. At a temperature of 30 °C, ideal for space heating in low energy dwellings, it may be suggested that the salt is partially soluble upon water sorption.
In the aftermath of the Paris Agreements, many countries around the globe have pledged to reduce the amount of greenhouse gas emissions being released into the atmosphere. To do so, it is important that the amount of renewable energy in the electricity grid increases. However, there are worries of the capacity of the grid to cope with intermittent energy sources. To assess the feasibility of a 100% renewable energy system in Japan, the authors conducted an hourly simulation of future electricity production based on wind, solar and tidal data. The system was shown to be stable, and the authors calculated the required capacity of electrical batteries that would be necessary to balance such a system.
A unique interconnected porous Mn2O3/C@Co3O4 cubic composite, as efficient electro-active electrode for supercapacitors, was successfully synthesized via a facile two-step hydrothermal method. Novel cube-like Mn2O3/C@Co3O4 composite, with a high specific surface area (S BET) and conductivity, could promote charge transfer and improve the overall electrochemical performance. The as-prepared Mn2O3/C@Co3O4 composite exhibited the excellent reversible specific capacitance (523.8 F g−1 at a current density of 0.3 A g−1, much higher than Mn2O3/C), good rate performance (57.2% capacitance retention) and superior cycling stability (90.6% capacitance retention after 3000 cycles). In addition, an asymmetric supercapacitor (Mn-Co//AC) with Mn2O3/C@Co3O4 as the positive electrode and activated carbon (AC) as the negative electrode delivered a maximum energy density of 45.8 Wh kg−1 at a power density of 0.3 kW kg−1.
A novel, non-destructive transmission electron microscopy technique is introduced, which enables the observation of the identical locations of a catalyst before and after electrochemical treatment (IL-TEM). The significance of this method is exemplified by the analysis of a standard, commercially available carbon supported platinum catalyst. We demonstrate that the observed changes of the catalyst particles are a direct consequence of the applied electrochemical treatment; and that selected catalyst regions are representative for the catalyst as a whole. Different electrochemical treatments were applied in order to discuss the potential of the method for studying processes of catalyst degradation.
LiNi0.8Co0.2−x Al x O2 (0≤ x ≤0.1) cathode powders were prepared with a novel co-precipitation method followed by heat-treating at temperatures between 500 and 900°C. The electrochemical properties as cathode material for lithium batteries were predicted with XRD patterns and examined with capacity retention studies. Among the prepared samples, 800°C heat-treated un-substituted LiNi0.8Co0.2O2 sample showed the best cycling performance. However, the initial specific discharge capacity decreases with increase amount of Al-substitution for the LiNi0.8Co0.2−x Al x O2 powders prepared with the same process. It may due to the increase in the amount of electrochemical inactive Al3+ and the increase in the hindrance of Li+ ions diffusion by increasing Al3+ occupancy of interstitial tetrahedral 6c sites in the Al-substituted cathode materials.
Hip fractures are a common type of fragility fracture that afflict 293,000 Americans (over 5,000 per week) and 35,000 Canadians (over 670 per week) annually. Despite the large population impact the optimal fixation technique for low energy femoral neck fractures remains controversial. The primary objective of the FAITH study is to assess the impact of cancellous screw fixation versus sliding hip screws on rates of revision surgery at 24 months in individuals with femoral neck fractures. The secondary objective is to determine the impact on health-related quality of life, functional outcomes, health state utilities, fracture healing, mortality and fracture-related adverse events.
Larson EB, Heinemann AW. Rasch analysis of the Executive Interview (The EXIT-25) and introduction of an abridged version (The Quick Exit). Objectives To evaluate the psychometric properties of the Executive Interview (EXIT-25) and to propose modifications that will improve those properties. Design Rasch analysis of existing datasets contributed by 3 prior projects, all of which examined criterion-related validity of the EXIT-25. Setting A large, urban, academic free-standing rehabilitation facility. Participants The sample of 147 was comprised of 109 adults diagnosed with stroke evaluated during inpatient rehabilitation and 38 adults with traumatic brain injury evaluated during inpatient (n=11) or outpatient rehabilitation (n=27). Interventions Not applicable. Main Outcome Measures The EXIT-25, Repeatable Battery for the Assessment of Neuropsychological Status, and Trails A and B. Results Eleven of the 25 items correlated weakly with the total measure and misfit the rating scale model. Deleting these 11 items improved the internal consistency of the remaining 14 items and enhanced the measure's criterion-related validity. Conclusions The EXIT-25 can be reduced from 25 to 14 items without reducing internal consistency. Convergent validity of the abbreviated measure is supported by moderate-size correlations with standard measures of cognitive deficits.
Multiple sclerosis (MS) is both an inflammatory and neurodegenerative disease, with cognition affected in roughly 50% of patientsCognitive impairment is most commonly detected on tests of mental processing speed and episodic memoryNeuropsychological testing is sensitive to MS cognitive disorder and can be applied in brief, routine evaluationsMale patients with low education or intelligence, early onset of MS, and evidence of cerebral gray matter atrophy seem most prone to impairment, whereas high premorbid intelligence is protectiveTo date, evidence for any particular medical therapy improving cognition in MS has been inconsistent, despite being an area of intense investigationFuture MS clinical trials should include cognitive outcome measures and use neuropsychological tests that are reliable and are known to reveal clinically meaningful changes
Multiple sclerosis (MS) is a demyelinating disease of the CNS that causes a wide array of neuropathological changes, including acute proliferation of T cells surrounding axons, axonopathy to the point of transection, and progressive neuronal degeneration presenting as atrophy on brain imaging.1 Cognitive impairment was reported in patients with MS over a century ago,2 but the topic garnered little interest in the clinical and neuroscience literature until the early 1980s when neuroimaging technology provided metrics of neuropathology, and improved psychometric procedures enabled reliable quantification of cognitive abilities. The quality, severity and frequency of cognitive dysfunction were well-established by the mid-1990s.3 Soon thereafter, the first effective disease-modifying therapies emerged, which improved medical outcomes.4,5,6 A more-favorable prognosis for mortality and preserved physical capacities has led to increasing interest in cognitive outcomes and quality of life in patients with MS.
Smart energy storage materials, which not only store electrochemical energy but also exhibit sensitivity to environmental stimuli, can provide novel multi-functionalities. Here, we report a smart shape memory fiber supercapacitor constituted with a highly stretchable shape memory polymer nanocomposite fiber substrate, multi-walled carbon nanotubes (MWCNT) conductive layer and pesudocapacitive polyaniline layer. Using layer by layer (LBL) technology, we first produce a densely packed MWCNT layer that serves as a well-developed conductive current collector network. Then polyaniline, as an active material, was deposited on the surface of the MWCNT layer to further promote the energy storage capability of the fibers. After the infiltration of a polyvinyl alchohol (PVA) based polymer electrolyte into the porous MWCNT and PANI layer, conductivity of ∼50S/cm and stretchability of more than 400% are obtained. The resultant shape memory polymer supercapacitors (SMPFSCs) not only possess shape memory properties, but also exhibit outstanding energy storage performance, with the best pseudo-capacitance exceeding ∼427F/cm3. Such design strategies can also be extended to other polymer substrates, and could open the door to smart (multi-functional) supercapacitor technologies.
Interfacial lithium-ion transfer at the LiMn2O4 thin film electrode/aqueous solution was investigated. The cyclic voltammograms of the film electrode conducted in the aqueous solution was similar to an adsorption-type voltammogram of reversible system, suggesting that fast charge transfer reaction proceed in the aqueous solution system. We found that the activation energy for this interfacial lithium-ion transfer reaction obtains 23–25kJmol−1, which is much smaller than that in the propylene carbonate solution (50kJmol−1). This small activation energy will be responsible for the fast interfacial lithium-ion transfer reaction in the aqueous solution. These results suggest that fast lithium insertion/extraction reaction can be realized by decreasing the activation energy for interfacial lithium-ion transfer reaction.
The dissolution/deposition behaviors of a lithium powder electrode during discharge/charge were examined by scanning electron microscopy (SEM) observation, and compared with those of a lithium foil electrode. For the lithium foil electrode, the dissolution/deposition of lithium was localized in limited areas on the lithium surface, and then the resulting lithium dendritic growth was accelerated after repeated cycling. On the other hand, for the lithium powder electrode, the dissolution/deposition of lithium was distributed throughout the entire body of the lithium electrode, and the lithium dendritic growth was considerably suppressed. Also, the shape of electrodes was maintained as a mixture of the porous powder particles even after several cycles. The effects of current density on the morphological changes and dissolution/deposition behaviors were also observed.
Complex electro-optical analysis is a very useful approach to separate different kinetic processes that occur during ionic insertion reactions in electrochromic oxide materials. In this paper, we use this type of combined technique to investigate ionic and optical changes in different oxide host systems, i.e., in two oxide hosts, specifically WO3 and Nb2O5. A comparison of their electro-optical responses revealed the presence of an ionic trapping contribution to the kinetics of the coloring sites, which was named here as coloring ionic trapping state. As expected, this coloring trapping process is slower in Nb2O5 since the reduction potential of Nb2O5 is more negative (more energy is needed for a higher degree of coloration). A phenomenological solid-state model that encompasses homogeneous charge transfer and valence trapping was proposed to explain the coloring ionic trapping process. Basically the model is able to explain how ionic dynamics at low frequency region, i.e., the slower kinetic step, controls the coloring kinetics, i.e., how it is capable to regulate the coloring rates. Optical transient analyses demonstrated the possibility of the presence of more than one coloring ionic trap, indicating the complexity of the processes involved in coloration phenomenon in metal oxide host systems.
The structural properties of annealed nickel oxide and its composites with activated carbon (synthesized via simple precipitation methods) have been addressed using X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption/desorption method and scanning electron microscopy. The charge storage properties of materials have also been investigated in three- and two-electrode configurations by means of cyclic voltammetry and galvanostatic charging/discharging in alkaline media. The results are consistent with the view that, depending on a method of preparation, the resulting nickel oxide films may exhibit redox characteristics different from that typically observed for nickel oxide-based materials. It is demonstrated that faradaic-type (redox) reactions, that are typical for battery-like materials, contribute predominantly to the high electrode capacity of 257Cg−1 (at 0.1Ag−1). By combining nickel oxide with a capacitive material such as activated carbon within the two-electrode symmetric cell, systems with increased charge-storage capabilities have been obtained. The fact, that the voltage window of nickel oxide-based cell has been broadened positively from 0.6V to 1V upon introduction of activated carbon, has also resulted in the increase of the cell’s energy and power densities as well.
A graphite/graphite oxide (GO) composite electrode for vanadium redox battery (VRB) was prepared successfully in this paper. The materials were characterized with X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. The specific surface area was measured by the Brunauer–Emmett–Teller method. The redox reactions of [VO2]+/[VO]2+ and V3+/V2+ were studied with cyclic voltammetry and electrochemical impedance spectroscopy. The results indicated that the electrochemical performances of the electrode were improved greatly when 3wt% GO was added into graphite electrode. The redox peak currents of [VO2]+/[VO]2+ and V3+/V2+ couples on the composite electrode were increased nearly twice as large as that on the graphite electrode, and the charge transfer resistances of the redox pairs on the composite electrode are also reduced. The enhanced electrochemical activity could be ascribed to the presence of plentiful oxygen functional groups on the basal planes and sheet edges of the GO and large specific surface areas introduced by the GO.
Previous studies have demonstrated the utility and sensitivity of the CogState Brief Battery (CBB) in detecting cognitive impairment in Alzheimer’s disease (AD) and mild cognitive impairment (MCI) and in assessing cognitive changes in the preclinical stages of AD. Thus, the CBB may be a useful screening tool to assist in the management of cognitive function in clinical settings. In this study, we aimed to determine the utility of the CBB in identifying the nature and magnitude of cognitive impairments in MCI and AD.
In some countries, photovoltaic (PV) technology is at a stage of development at which it can compete with conventional electricity sources in terms of electricity generation costs, i.e., grid parity. A case in point is Germany, where the PV market has reached a mature stage, the policy support has scaled down and the diffusion rate of PV systems has declined. This development raises a fundamental question: what are the motives to adopt PV systems at grid parity? The point of departure for the relevant literature has been on the impact of policy support, adopters and, recently, local solar companies. However, less attention has been paid to the motivators for adoption at grid parity. This paper presents an in-depth analysis of the diffusion of PV systems, explaining the impact of policy measures, adopters and system suppliers. Anchored in an extensive and exploratory case study in Germany, we provide a context-specific explanation to the motivations to adopt PV systems at grid parity.