batterydata/paper-abstracts huggingface dataset:
Background The current approach to esophageal perforation treatment in children has shifted towards conservative management. However, the consensus of what constitutes conservative management is unclear, with various therapies and protocols described, including the need for various decompression and drainage procedures. Our institution utilizes conservative management with minimal intervention guided by the patient's clinical course. The purpose of this study is to report our management and add to the growing evidence for conservative management of esophageal perforation in children. Methods We performed a retrospective chart review of all patients with an ICD-9 diagnosis of esophageal perforation from January 1995 to July 2009. Patients with postoperative anastomotic leaks with drains in place were excluded, although patients with anastomotic leaks that were not controlled by drains were included. Data collected included patient demographics, etiology, diagnosis, treatment, complications, and outcome. Results Eight patients were identified who met inclusion criteria. Mean age was 28 mo (1 d–10 y), and the average time from causative event to diagnosis was 1.4 d (0–2 d). The etiology for esophageal perforation included esophagoscopy with dilation (n = 4), button battery ingestion (n = 1), coin ingestion (n = 1), nasogastric tube placement (n = 1), and leak after stricture resection (n = 1). All the patients were treated conservatively without primary surgery or thoracic drainage, and the mean time to perforation healing was 10.2 d (1–24 d). The average length of antibiotic therapy was 10 d (0–26 d). Enteral nutrition was utilized in five patients, and total parenteral nutrition (TPN) was utilized in five patients. No patient developed a new-onset esophageal stricture. Conclusion Conservative management, guided by the patient's clinical course, with antibiotics and nutritional support is a safe and effective treatment for esophageal perforations in children.
Spinel Li4Ti5O12 has been considered as one of the most prospective anode materials for Li-ion microbatteries. Homogeneous, transparent and crack-free Li4Ti5O12 coatings with thickness around 110 nm have been prepared by dipping gold-coated quartz substrates in sols prepared using titanium isopropoxide and lithium acetate. The influence of the thermal treatment on the phase composition, structure and electrochemical behavior was studied. Rutile TiO2 (considered as an impurity in this study) is only detected in the coatings treated at 700 °C. XPS and TOF-SIMS depth profiles show a homogeneous distribution, with a Li increase and Ti reduction at the surface. Electrochemical characterization of samples treated at 600 °C presents a redox reaction around 1.55 V indicating that the film is simple phase of Li4Ti5O12. The shift to slightly lower voltage in samples treated at 700 °C is a consequence of Rutile impurities. Larger capacity and good reversibility in the sample heat-treated at 600 °C can be attributed to high crystallinity of Li4Ti5O12 and phase purity. RBS analysis specifies a composition close to Li4Ti5O12 in the case of the pristine and charged samples, and Li7Ti5O12 for the discharged sample. Surface XPS study confirms the presence of an outermost layer containing LiF and Li2CO3.
Three-dimensional porous self-assembled LiFePO4/graphene (LFP/G) composite was successfully fabricated using a facile template-free sol–gel approach. Graphene nanosheets were incorporated into the porous hierarchical network homogenously, which greatly enhances the electrical conductivity and efficient use of the LiFePO4 (LFP), leading to an outstanding electrochemical performance of the hybrid cathodes. The obtained LFP/G composite has a reversible capacity of 146mAhg−1 at 17mAg−1 after 100 cycles, which is more than 1.4 times higher than that of porous LFP (104mAhg−1). Moreover, the porous LFP/G composite also exhibits a desirable tolerance to varied charge/discharge current densities.
The SenseCam is a camera worn on a lanyard around the neck that automatically captures point-of-view images in response to movement, heat and light (every 20–30 s). This device may enhance the accuracy of self-reported dietary intake by assisting participants’ recall of food and beverage consumption. It was the objective of this study to evaluate if the wearable camera, SenseCam, can enhance the 24-h dietary recall by providing visual prompts to improve recall of food and beverage consumption.
A comparative study of sodiation and lithiation of FePO4 host material for secondary sodium- and lithium-ion batteries is performed. To ensure the best possible comparability, NaFePO4 based electrodes are prepared by an electrochemical displacement technique using LiFePO4 as the starting material. The electrodes are identical in view of particle size distribution, active material loading, binder, conductive additives, and carbon coating, etc. All differences in the kinetics are exclusively determined by the substitution of the alkali metal cation. Electrochemical impedance spectroscopy is carried out at different temperatures. Kinetic parameters as the exchange current density and the diffusion coefficients of sodium and lithium in the FePO4 host material are obtained by fitting the data to an appropriate equivalent circuit. The study reveals substantially slower intercalation kinetics and larger activation energies for sodiation in comparison to lithiation of FePO4. This is most likely attributed to the different ionic radii and molar masses of sodium and lithium.
When the membrane in a flow battery or fuel cell is removed, the result is a fluid–fluid interface across which selective ion exchange must occur with minimal reactant crossover. Here, we review five major approaches to the design of membraneless cells reported in the recent literature (from 2004 to mid-2016), including our own contributions. Although most of the reviewed designs were originally developed for microfluidic fuel cells, we proceed to discuss the potential applicability of these designs as membraneless redox flow batteries, given their similarity to fuel cells. The various designs exhibit noticeable performance differences due to differences in their redox couple chemistries, electrolyte compositions, and flow architectures. Therefore, we discuss eight performance metrics that can be determined from cell operation data and electrolyte cost indices and can be used for systematic comparison of various designs. Using these metrics, we present an outlook for promising designs in terms of their potential for wide acceptance or commercialization, with the aim of directing future research.
This paper describes the corrosion behaviour of the positive and negative electrodes of a lead–acid battery in 5M H2SO4 with binary additives such as mixtures of phosphoric acid and boric acid, phosphoric acid and tin sulphate, and phosphoric acid and picric acid. The effect of these additives is examined from the Tafel polarisation curves, double layer capacitance and percentage of inhibition efficiency. A lead salt battery has been fabricated replacing the binary mixture with an alternative electrolyte and the above electrochemical parameters have been evaluated for this lead salt battery. The results are explained in terms of H+ ion transport and the morphological change of the PbSO4 layer.
A metal hydride is used for the first time as anode in a complete all-solid-state battery with sulfur as cathode and LiBH4 as solid electrolyte. The hydride is a nanocomposite made of MgH2 and TiH2 counterparts. The battery exhibits a high reversible capacity of 910 mAh g−1 with discharge plateaus at 1.8 V and 1.4 V. Moreover, the capacity remains to 85% of the initial value over the 25 first charge/discharge cycles.
Nanotechnology is frequently heralded as the next wave of technological advance, poised to enable radical innovation across many industries. But as yet little is known about how firms will ultimately create that value. We do know that nanotechnology is based on process innovation, a category of innovation less well understood than product innovation. And we know that new ventures are an important vehicle for commercializing radical technology. As new ventures seek to commercialize nanotechnology, they evolve value creation strategies to better link fundamental scientific advance with the creation of value for users and investors. This paper asks “How do the successful value creation strategies of technology ventures differ in process vs. product-based innovation?” An investigation of 12 ventures representing the extremes of value creation through process-based (nanotech) and product-based (fuel cell) innovation reveals significant differences in their value creation challenges, in the mechanisms of technology–market matching and alliance building, and in their levels of experimentation. Ventures exploiting process innovation faced greater uncertainty in their value chain positioning, market breadth, customization, and the changes required of their customers in contrast to product-based ventures. Our evidence shows that nanotechnology ventures benefit from prioritizing technology–market matching, alliance building and experimenting with technologies in new value networks.
The relatively high redox potential in the olivine-type LiMPO4 (M =Mn, Fe, Co, Ni) materials has largely been explained by the M–O–P inductive effect which increases the ionic character of transition metal atoms. Here, we identify the additional perturbative effect that slightly but systematically shifts the redox potential. The substitution of iron by manganese in the olivine LiMPO4 framework raises both of the Fe3+/Fe2+ and Mn3+/Mn2+ redox potentials by ∼0.1V. The overall volume expansion upon Mn substitution in the whole Li x (Mn y Fe1−y )PO4 system possibly increases the average metal-oxide bond length and hence the ionicity of each transition metal. The voltage shift in a single cell is small but should be significant in a larger-scale battery where there exist a large number of series connections. The kinetic shift for each of the Fe3+/Fe2+ and Mn3+/Mn2+ redox reactions is also investigated.
Electrode materials with homogeneous distribution of boron were obtained by heating mixtures of nanosized carbon-coated lithium iron phosphate and BPO4 in 3-9% weight at 700°C. The materials can be described as nanocomposites containing i) LiFePO4, possibly doped with a low amount of boron, ii) FePO4 and iii) an amorphous layer based on Li4P2O7-derived material that surrounds the phosphate particles. The thermal treatment with BPO4 also triggered changes in the carbon coating graphitic order. Galvanostatic and voltammetric studies in lithium half-cells showed smaller polarisation, higher capacity and better cycle life for the boron-doped composites. For instance, one of the solids, called B6-LiFePO4, provided close to 150 and 140 mAhg-1 (87% and 81% of theoretical capacity, respectively) under C/2.5 and C regimes after several cycles. Improved specific surface area, carbon graphitization, conductivity and lithium ion diffusivity in the boron-doped phospholivine network account for this excellent rate performance. The properties of an amorphous layer surrounding the phosphate particles also account for such higher performance.
A new framework type Li x Ni2(MoO4)3 [0⩽x⩽4] polyanion compound was synthesized via a glycine-nitrate soft-combustion process at low temperature. The annealed powders were characterized by XRD to confirm the phase formation of the stoichiometric product, Ni2(MoO4)3 in its non-lithiated state. The morphology of the annealed product was found to be composed of soft agglomerates embedded by ultrafine spherical grains. Electrochemical redox properties of the synthesized product were confirmed by employing the new material as a cathode in lithium-containing test cells in an aprotic electrolyte environment (1 M LiPF6 in EC+DMC). Slow scan cyclic voltammetry (SSCV) confirmed the redox behavior corresponding to the reduction/oxidation of the transition metals, Ni and Mo between the potential window of 3.5–1.5 V. The lithium insertion/extraction process was confirmed by galvanostatic measurements on the test cells and they exhibited well discernible discharge/charge profiles with a reversible capacity of 170 mAh/g over the potential window of 3.5–1.5 V after the first charge/discharge cycle. Nevertheless, the discharge capacity was found to deteriorate slowly upon repeated cycling, which might presumably be due to disproportion reaction of the host structure beyond the extent of insertion of two lithium ions.
We observe the influence of Al occupancies in Li sites on the formation process of the garnet solid electrolyte of Li7La3Zr2O12 (LLZO). A direct incorporation of Al is first promoted in a Li-insufficient garnet solid electrolyte during the calcination process of 850 °C and then the cubic phase of LLZO is obtained after successive annealing step of 1000 °C. Comparing to pristine LLZO, Al incorporated LLZO shows less formation of Li2CO3, keeping crystallographic and physicochemical properties. This Al incorporation improves both the ionic conductivity and interfacial resistance to poisoning procedure.
The global agriculture, aquaculture, fishing and forestry (AAFF) energy system is subject to three unsustainable trends: (1) the approaching biophysical limits of AAFF; (2) the role of AAFF as a driver of environmental degradation; and (3) the long-term declining energy efficiency of AAFF due to growing dependence on fossil fuels. In response, we conduct a net energy analysis for the period 1971–2017 and review existing studies to investigate the global AAFF energy system and its vulnerability to the three unsustainable trends from an energetic perspective. We estimate the global AAFF system represents 27.9% of societies energy supply in 2017, with food energy representing 20.8% of societies total energy supply. We find that the net energy-return-on-investment (net EROI) of global AAFF increased from 2.87:1 in 1971 to 4.05:1 in 2017. We suggest that rising net EROI values are being fuelled in part by ‘depleting natures accumulated energy stocks’. We also find that the net energy balance of AAFF increased by 130% in this period, with at the same time a decrease in both the proportion of rural residents and also the proportion of the total population working in AAFF—which decreased from 19.8 to 10.3%. However, this comes at the cost of growing fossil fuel dependency which increased from 43.6 to 62.2%. Given the increasing probability of near-term fossil fuel scarcity, the growing impacts of climate change and environmental degradation, and the approaching biophysical limits of global AAFF, ‘Odum’s hoax’ is likely soon to be revealed.
Vanadium oxides may offer high pseudocapacitance but limited electrical conductivity and specific surface area. Atomic layer deposition allowed uniform deposition of smooth nanostructured vanadium oxide coatings on the surface of multi-walled carbon nanotube (MWCNT) electrodes, thus offering a novel route for the formation of binder-free flexible composite electrode fabric for supercapacitor applications with large thickness, controlled porosity, greatly improved electrical conductivity and cycle stability. Electrochemical measurements revealed stable performance of the selected MWCNT–vanadium oxide electrodes and remarkable capacitance of up to ∼1550 F g−1 per active mass of the vanadium oxide and up to ∼600 F g−1 per mass of the composite electrode, significantly exceeding specific capacitance of commercially used activated carbons (100–150 F g−1). Electrochemical performance of the oxide layers was found to strongly depend on the coating thickness.
Cardiac resynchronization therapy is an important and underused tool to help patients with heart failure symptoms, left ventricular systolic dysfunction (LVEF≤35%), and intraventricular conduction system disease (QRS≥120 msec). Cardiac resynchronization therapy paces the heart simultaneously from both right and left ventricles (through the coronary sinus). Approximately three quarters of patients who undergo a successful implant will have some degree of symptomatic improvement and have fewer heart failure hospitalizations. When cardiac resynchronization therapy is combined with a defibrillator, patients may benefit from the added protection against sudden arrhythmic death.
The conventional solution is the use of hydrocyclones to concentrate the particulate load. The resulting concentrate is then filtered through bag or band filters and magnetic separators. Hydrocyclones produce a controlled eddy flow in the liquid and the resulting centrifugal force separates out the particles. As a result, these systems fall into the category of centrifugal separators.Three batteries of multi-cyclones like these, each of which consists of four multi-cyclones that are made of up nine individual cyclones, can reduce a total of 900 m3/h of process water initially to 60 m3/h of concentrate and then return the purified water directly to the body cleaning process.© Nägele Mechanik
Four different electrolytes are prepared by dissolving a Li salt in three different room-temperature ionic liquids (RTILs) and also in a conventional organic solvent. The cathodic (electrochemical reduction) stability of these electrolytes is compared at both ambient and elevated temperature by potential cycling on a TiO2-B electrode. At room temperature, the stability of pyrrolidinium- and piperidinium-based RTILs is comparable with that of the carbonate-based organic solvent, which is in contrast to the severely decomposed imidazolium-based RTIL. At elevated temperature (120°C), the imidazolium-based RTIL undergoes even more significant cathodic decomposition that results in the deposition of a resistive surface film and leads to eventual cell degradation. By contrast, the cathodic decomposition and concomitant film deposition are not serious with pyrrolidinium- and piperidinium-based RTILs even at this high-temperature, so that the TiO2-B/Li cell operates with reasonably good cycle performance. The latter two RTILs appear to be promising solvents for lithium-ion batteries that are durable against occasional exposure to high-temperature.
The sodium deficiency issue of Na0.67[Fe0.5Mn0.5]O2, P2-type layered oxide, is compensated with the addition of Na2C4O4 as sacrificial salt. Na2C4O4 is easy to synthesize and stable, which makes it easy to handle and scale-up. Sodium-free hard carbon anode and sodium-deficient layered oxide cathode, mixed with different amounts of Na2C4O4, are used to assemble Na-ion full-cells and evaluate the effect of the sacrificial salt content in the electrochemical performance of the cells. Ex-situ SEM and XRD analyses confirmed that the Na+ ions formed as a result of the electrochemical decomposition of the salt, are reinserted back into the cathode structure. Thus, Na0.67[Fe0.5Mn0.5]O2 undergoes same phase transitions when tested as full-cell using Na-free hard carbon or with a Naº anode that compensates for the Na deficiency. In comparison with NaN3 sacrificial salt, Na2C4O4 seems to be a better candidate as sodiation agent in terms of safety and handling. The electrochemical performance of the P2-type layered oxide with 31% of Na2C4O4 sacrificial salt outperforms the cathode with NaN3 with improved cycling stability, delivering a reversible capacity of 155 mAh g−1 and an energy density of 165 Wh kg−1.
A methyl difluoroacetate (MFA)-based LiPF6 solution was applied as an electrolyte to improve the thermal stability of Li-ion batteries. The addition of vinylene carbonate (VC) improved the electrochemical characteristics of the electrolyte significantly, and satisfactory reversible capacity and cycling performance were obtained with a graphite negative electrode. The thermal stability of the electrolytes was investigated with DSC. Regardless of whether or not VC was used, the electrolyte exothermically decomposed at a temperature higher than 450°C. The thermal behavior of a mixture of lithiated graphite and VC-added electrolyte was also studied in detail. The ratio between the electrolyte and the electrode was a dominant factor in the heat generation of the mixture. A sharp exothermic peak at about 330°C was observed when the electrode was superabundant, but the heat value was much smaller than that obtained with 1moldm−3 LiPF6/EC-DMC electrolyte under the same conditions. When the electrolyte was superabundant, a mild exothermic decomposition of the electrolyte became the dominant reaction in the mixture. X-ray photoelectron spectroscopic analysis was carried out on delithiated graphite electrodes to study the effect of VC additive on solid electrolyte interphase (SEI) modification. VC-added MFA-based electrolyte was considered to be a good candidate for developing safer Li-ion batteries.
For predicting texture suited for South and South East Asia, most of the breeding programs tend to focus on developing rice varieties with intermediate to high amylose content in indica subspecies. However, varieties within the high amylose content class may still be distinguishable by consumers, who are able to distinguish texture that cannot be differentiated by proxy cooking quality indicators.
Thiophene derivatives (THs) are examined as novel functional additives for improving the cycling performance of high-voltage LiCoO2. Our investigation reveals that 2,2′-Bithiophene (2TH) and 2,2′:5′,2′′-Terthiophene (3TH) can be electrochemically polymerize prior to the electrolyte solvent decomposition to form a protective layer of conducting polymer film on the cathode surface, which blocks off severe electrolyte decomposition at high voltages and, therefore, improves the cycling stability of high voltage LiCoO2 cathode. After 100 cycles at a high cutoff voltage of 4.4V, the discharge capacity retention is 50% in the base electrolyte, in contrast, the LiCoO2 cathode cycled in the electrolyte containing 0.1 wt% 3TH displays a high capacity retention of 84.8% at 0.25C rate. This work demonstrates that these thiophene derivatives have considerable potential as functional additives for the applications in high-voltage lithium-ion batteries.
The Mouse Lymphoma Expert Workgroup of the International Workshop for Genotoxicity Tests (IWGT) met in Basel, Switzerland in August of 2009. The Workgroup (WG) was tasked with discussing the appropriate top concentration for non-pharmaceuticals that would be required for the conduct of the mouse lymphoma assay (MLA) when sufficient cytotoxicity [to between 10 and 20% relative total growth (RTG)] has not been attained. The WG approached this task by (1) enumerating the various regulatory decisions/use for MLA data, (2) discussing the appropriate assays to which MLA data and assay performance should be compared and (3) discussing all the proposals put forth concerning the top concentration for non-pharmaceuticals. In addition, one of the members presented a summary of a re-evaluation of the National Toxicology Program MLA data using the IWGT harmonized guidance that was underway as a separate (non IWGT) activity, being conducted by two members of the Expert WG. The WG was asked to vote on each of the various proposals for top concentration for when cytotoxicity is not concentration limiting. While there was general agreement that the top concentration for non-pharmaceuticals should be re-evaluated and likely lowered from the current recommended levels, there was no agreement on a specific new recommendation.