batterydata/paper-abstracts huggingface dataset:
Most of the newer forms of carbon materials being demonstrated as potential anodes for lithium-ion batteries suffer a serious drawback in terms of their commercial perspectives due to their failure in the retention of a flat plateau in the charging/discharging profile. Here we present a facile and low-cost approach for the fabrication of solvent-free, binder-free anode material for the practical usage. A filter paper was coated with graphite using a pencil lead followed by pyrolysis (PyPF) and tested for its electrochemical performance. Galvanostatic charge/discharge experiments as carried out in half-cell configuration exhibited a specific capacity of 342 mAhg−1 with a constant plateau at 156 mAg−1 with 98% coulombic efficiency. This clearly shows the potential and competency of the material to be an inexpensive commercial anode. The role of graphite coating on filter paper was clearly manifested in the comparative studies with only pyrolyzed filter paper. Furthermore, full cell studies were performed using PyPF as anode and carbon coated LiFePO4 as a cathode. A specific capacity of 120 mAhg−1 at C/5 rate with 141 WhKg−1 energy density with the retention of constant plateau and minimal polarization further emphasize the proficiency of PyPF as an anode for a commercial lithium-ion battery.
The ability to link advanced technologies to market opportunities is a crucial aspect of radical innovation. When markets do not yet exist, it is difficult to persevere, given organizational pressures for immediate profit. To study this problem, eleven radical innovation projects are examined in nine large, mature organizations in a real-time field setting. The sample is augmented by interviews of four additional individuals who have repeated experiences in linking advanced technologies to markets. From results that are qualitative in nature, four themes emerge. First, vision is built and sustained through a variety of mechanisms that may operate in combination or serially. Second, there are a number of roles that individuals play in creating and evangelizing a vision through an organization. Third, there exist a few tools and methods for aiding in developing visions that are not dependent strictly on individual initiative, but these are not systematically employed by organizations. Finally, visions undergo a process of validation and internal acceptance that may depend heavily on reaching out beyond the familiar customer/market set of the firm. Building on these themes, we derive two sets of insights. The first identifies three different ways that visions might develop. We did not discover a singular process across firms or even within a single firm by which visions develop. Second, we identify three elements that occur when a vision is formulated and utilized in organizations: Motivation, Insight and Elaboration. Thus a vision does not arise through a single creative leap, but develops over time and requires focus, discipline, energy, and the involvement of many people. Awareness of this conceptual underpinning of visioning may help managers understand how to encourage this activity and help sustain long-term growth and renewal in their organizations.
This paper is set against the backdrop of an increasingly pervasive discursive coupling of peace with development, and of extremism with underdevelopment. An evolving knowledge economy discourse casts education as both a key determinant of economic development, and as a crucial tool in the battle for “hearts and minds” in a global war against terrorism and extremism. Education for development, and education as anti-extremism are the twin goals of the Filipino CD for Peace – a contribution to the UN-backed International Power Users of ICT (Information Communication Technology) Symposium. In this paper, I examine the ways in which this youth Symposium feeds into and mobilizes powerful logics around the links between education and development/counterterrorism. My argument is that education for development, and one of its articulations, the CD for Peace, are undergirded by and reproduce neoliberal development logics in several overlapping respects. I illustrate the ways in which the language of connection and collaboration reproduces a distinct rationality related both to the transformative potential of (private investment in) ICT and to the production of particular kinds of subjectivities: youth as connected, informed, economically valuable global citizens beyond the reach of extremists. The Power Users project works to (re)construct teenagers as “gurus”; conflict (and poverty, and terrorism) becomes solvable through education and ICT. I show how knowledge economy discourse powerfully constructs youth as learning subjects who come to imagine their own roles and identities in specifically neoliberal ways: not only as learners, but also as advocates for this nexus of technology, education, development and peace.
Solid-state electrolytes with high room-temperature ionic conductivity and fast interfacial charge transport are a requirement for practical solid-state batteries. Here, we report that cationic aluminium species initiate ring-opening polymerization of molecular ethers inside an electrochemical cell to produce solid-state polymer electrolytes (SPEs), which retain conformal interfacial contact with all cell components. SPEs exhibit high ionic conductivity at room temperature (>1 mS cm−1), low interfacial resistances, uniform lithium deposition and high Li plating/striping efficiencies (>98% after 300 charge–discharge cycles). Applications of SPEs in Li–S, Li–LiFePO4 and Li–LiNi0.6Mn0.2Co0.2O2 batteries further demonstrate that high Coulombic efficiency (>99%) and long life (>700 cycles) can be achieved with an in situ SPE design. Our study therefore provides a promising direction for creating solid electrolytes that meet both the bulk and interfacial conductivity requirements for practical solid polymer batteries.
Sulfonated polypropylene separators impregnated with the polymer hydrogel electrolyte were used in electric double layer capacitors (EDLCs). The electrochemical properties of the EDLC with the polymer hydrogel electrolyte were investigated by cyclic voltammetry and charge–discharge cycle tests and compared with a KOH aqueous electrolyte. Furthermore, effects of KOH concentration and temperature on capacitance of the EDLC were studied. As a result, it was found that the capacitance of the EDLC with the polymer hydrogel electrolyte was higher than that with a KOH aqueous solution in the wide range of KOH concentration and temperature.
Three-dimensional, porous graphitic carbon co-doped with cobalt and nitrogen (C-Co-N) is prepared with metal-organic framework (MOF) and employed as Lewis base matrix to host selenium. Owing to the unique structure with abundant micro/meso-pores, the highly-conductive C-Co-N matrix provides highly-efficient channels for electron transfer and ionic diffusion, and sufficient surface area for loading of selenium nanoparticles while mitigating dissolution of polyselenides and suppressing volume expansion. The homogenous distribution of cobalt nanoparticles and nitrogen-group in C-Co-N composite immobilize polyselenides through strong chemical interaction in the operation of Li-Se batteries. With a very high Se loading of 76.5 wt%, the C-Co-N/Se cathode delivers superior electrochemical performance with an ultrahigh reversible capacity of 672.3 mAh g−1 (99.6% of the theoretical value) and a capacity of 574.2 mAh g−1 after 200 cycles, giving a capacity fading of only 0.07% per cycle and a nearly 100% Columbic efficiency. In-situ Raman spectroscopy and density functional theory simulations are employed to investigate the Se (de)lithiation mechanism at the electrolyte/cathode interface, and confirm that the structure and composition of C-Co-N scaffold give rise to efficient cathode host for high-performance Se-based cathodes with dramatically reduced capacity fading.
The mixed oxide, Li(Ni1/3Co1/3Mn1/3)O2, with the layer structure has been prepared by a one-pot method using the molten-salt mixture, LiNO3–LiCl at temperatures 750, 850 and 950°C in air. The compounds were characterized by a variety of techniques. As per Rietveld data, only 4.0 and 2.5% of ‘cation-mixing’ was observed in the compounds prepared at 850 and 950°C, respectively. Cyclic voltammetry with Li metal as counter electrode showed a clear indication of Ni2+/4+ redox couple at ∼3.6–3.9V in all compounds. Charge–discharge cycling was carried out in the range 2.5–4.3, 2.5–4.4 and 2.5–4.5V versus Li at a current rate of 20 or 30mAg−1. The fifth cycle discharge capacities varied from 125 to 145 (±5)mAhg−1 for the compounds prepared at 850 and 950°C. They exhibited excellent capacity-retention without noticeable capacity-fade till 50 cycles irrespective of the voltage cut-off.
Epidemiologic studies indicate that prolonged exposure to high pollution levels is associated with increased risk of cancer, especially lung cancer. However, under conditions of moderate or low air pollution, epidemiologic evidence does not permit reliable conclusions. Biomarker-based population studies may serve as complementary tools providing a better understanding of the relative contribution of ambient atmospheric pollution to the overall genotoxic burden suffered by city dwellers. However, past efforts to apply biomarkers to studies of low levels exposure to urban air pollution have given inconclusive results, partly because of the absence of adequate data on personal exposure, covering a time-window which is appropriate for the biomarkers being examined, as well as a battery of biomarkers reflecting different stages of the carcinogenic process. In the present paper, the potential of biomarker-based population studies to aid the assessment of the genotoxic and carcinogenic effects of urban air pollution is reviewed by reference to the achievements and limitations of earlier reported studies. The design and methodology adopted in a recently completed large-scale population study, carried out in the context of the European Union Environment and Climate Programme, known by the short name of AULIS project, 1 The authors worked on behalf of the AULIS project network. 1 is discussed and descriptive statistics of the main findings of the project are presented. These findings indicate that for cohorts suffering moderate-to-low exposures to airborne particulate-bound polycyclic aromatic hydrocarbons (PAHs), no simple correlation with biomarkers of genotoxicity existed and suggest that additional factors made a significant contribution to the overall genotoxic burden.
The specific character of biological enzyme catalysts enables combined fuel and oxidant channels and simplified non-compartmentalized fuel cell assemblies. In this work, a microstructured enzymatic biofuel cell architecture is proposed, and species transport phenomena combined with consecutive chemical reactions are studied computationally in order to provide guidelines for optimization. This is the first computational study of this technology, and a 2D CFD model for species transport coupled with laminar fluid flow and Michaelis–Menten enzyme kinetics is established. It is shown that the system is reaction rate limited, indicating that enzyme specific turnover numbers are key parameters for biofuel cell performance. Separated and mixed enzyme patterns in different proportions are analyzed for various Peclet numbers. High fuel utilization is achieved in the diffusion dominated and mixed species transport regimes with separated enzymes arranged in relation to individual turnover rates. However, the Peclet number has to be above a certain threshold value to obtain satisfying current densities. The mixed transport regime is particularly attractive while current densities are maintained close to maximum levels. Optimum performance is achieved by mixed enzyme patterning tailored with respect to individual turnover rates, enabling high current densities combined with nearly complete fuel utilization.
Cu0.04V2O5 was prepared by a precipitation method followed by heat treatment at 300 and 600°C. The material prepared at 300°C showed porous morphology, whereas that prepared at 600°C was highly crystalline. X-ray diffraction, Raman scattering and Fourier transform infrared spectroscopy showed both materials exhibiting the same structure as that of V2O5, with a slight lattice expansion. X-ray absorption spectroscopy confirmed the presence of V4+ cations in Cu0.04V2O5, which would increase the electronic conductivity of V2O5. Cu0.04V2O5 showed better electrochemical performance than V2O5 because of its high electronic conductivity and good structural stability. The material prepared at 600°C delivered a reversible discharge capacity over 160mAhg−1 after 60 cycles at a C rate of C/5.6. The material prepared at 300°C showed good high-rate performance, which delivered a reversible capacity ∼100mAhg−1 when cycled at C/1.9. The discrepancy in the rate performance of Cu0.04V2O5 was attributed to the morphology of materials.
A functional organic small molecule anode material (dilithium 2,5-dihydroxyterephthalate, Li2DHTP) is synthesized via a simple wet chemistry methodology adopting 2,5-dihydroxyterephthalic acid (DHTPA) as the precursor. It delivers a high specific capacity of 165mAh/g over 100cycles with the coulombic efficiency of 98% and shows remarkable rate performance. The organic acid DHTPA also demonstrates electrochemical activity toward Li+ storage and releases but with poor cyclic performance. XRD and FT-IR studies suggest that the de−/lithiation process of chemically replaced Li2DHTP is highly reversible. On the contrary, the de−/lithiation process of electrochemically replaced Li2DHTP intermediate product, where the corresponding DHTPA acid experiences an ion exchange process in the first discharge process, shows quite poor reversibility in the following cycles. The results illustrate that either chemical replacement or electrochemical replacement of DHTPA can generate Li2DHTP electrochemical active material. This methodology might be applied to synthesize advanced organic small molecules conjugated carbonyl materials for energy storage.
In this study, we develop a new optimization-based framework to design and analyze renewable energy systems for the residential sector. To achieve this, we first simulate different scenarios for integrated energy systems, which include different types of renewable resources and various new technologies along with the existing technologies in the current energy system. We then develop a new network optimization model to feature the underlying system, which includes minimizing the energy cost as an object function with different constraints. Finally, we apply the model to the design problem regarding the energy supply system faced by the residential sector of Jeju Island, Korea. As a result, we are able to identify the optimal configuration for the systems, and comparatively analyze the economic performance of the optimal and alternative energy systems. We also analyze the sensitivity of the main cost-drivers for the total required cost.
Goverover Y, Chiaravalloti N, DeLuca J. Self-generation to improve learning and memory of functional activities in persons with multiple sclerosis: meal preparation and managing finances. Objective To examine the utility of using a self-generation strategy to improve learning and performance of everyday functional tasks in persons with multiple sclerosis (MS). Design Mixed-design with both a within- and between-subject factor. Setting Nonprofit rehabilitation research institution. Participants Participants (n=20) with MS and healthy controls (n=18). Interventions Participants completed 2 meal preparation and 2 financial management tasks. One task in each area was presented in the provided condition, in which all instructions were provided to and read by the participants, and the other task was presented in the generated condition, in which participants were asked to generate (fill in the blank) the necessary items needed to perform each step of the task. Main Outcome Measures Correct recall of task items and step sequence immediately and 1 week after initial learning and correct performance of task items and step sequence 30 minutes after initial learning. The maximum possible score in each of the recall tests was 24. Results Although the MS and healthy groups did not differ in overall items recalled, in both groups tasks learned in the generated condition enhanced memory performance significantly for the tasks used when compared with similar tasks learned in the provided condition. Conclusions Self-generation during learning can significantly improve subsequent recall of information and performance of activities of daily living for persons with MS. Implications of these findings for cognitive rehabilitation in MS are discussed.
When fluoroethylene carbonate (FEC) is added to the ethylene carbonate (EC)–diethyl carbonate (DEC) electrolyte, the capacity and cyclability of full-cells employing Si–graphene anode and lithium nickel cobalt aluminum oxide cathode (NCA) cathode are improved due to formation of a thin (30–50 nm) SEI layer with low ionic resistance (∼2 ohm cm2) on the surface of Si–graphene anode. These properties are confirmed with electrochemical impedance spectroscopy and a cross-sectional image analysis using Focused Ion Beam (FIB)-SEM. Approximately 5 wt.% FEC in EC:DEC (1:1 wt.%) shows the highest capacity and most stability. This high capacity and low capacity fade is attributed to a more stable SEI layer containing less CH2OCO2Li, Li2CO3 and LiF compounds, which consume cyclable Li. Additionally, a greater amount of polycarbonate (PC), which is known to form a more robust passivation layer, thus reducing further reduction of electrolyte, is confirmed with X-ray photoelectron spectroscopy (XPS).
Specific capacitances of the carbon nanotube (CNT) electrodes are significantly enhanced by using the nanoporous alumina templates with high pore density and uniform pore diameter. Well-ordered nanoporous alumina templates were fabricated by a two-step anodization method by applying a constant voltage of 25.0V or 20.0V in sulfuric acid solution. The cylindrical pore diameter and pore density of the templates prepared at the anodizing voltage of 25.0V or 20.0V were 53±1nm and 3.1×1010 cm−2 or 38±2nm and 3.8×1010 cm−2, respectively. The CNTs with uniform diameters of 44±2nm in the 53nm pores and of 32±5nm in the 38nm pores, respectively, were grown on the porous alumina template. For the electrochemical double layer capacitors (EDLCs), the aluminum metal below the porous alumina layer was used as a current collector for the CNT electrode without any binding material. The EDLC characteristics were analyzed by measuring the capacitances from cyclic voltammograms and the charge–discharge curves. A maximum value of 175Fg−1 was achieved for the specific capacitances of the CNT electrodes prepared on the alumina templates with high pore density.
Co3O4–reduced graphene oxide (rGO) nanocomposites are prepared by co-precipitation of Co(OH)2 with graphite oxide (GO) to form a Co(OH)2–GO precursor, followed by thermal treatment. It is found that the ratio between Co3O4 and rGO has a significant effect on their electrochemical activities. The specific capacitance of 636 F g−1 is achieved when the mass ratio of Co3O4 to rGO is equal to 80.3:19.7. A novel asymmetric supercapacitor is further fabricated with the Co3O4–rGO nanocomposite as the anode and activated carbon as the cathode in 6 M aqueous KOH solution as electrolyte. The assembled asymmetric supercapacitor can cycle reversibly in a voltage of 0–1.5 V and exhibits a high energy density of 35.7 Wh kg−1 at power density of 225 W kg−1. Moreover, the asymmetric supercapacitor shows an excellent cycling stability with capacitance retention of 95% after 1000 cycles at a current density of 0.625 A g−1.
Organosilicon compounds containing nitrile and oligo(ethylene oxide) substituents are synthesized as safe electrolytes for high-voltage lithium-ion batteries. We firstly report that these organosilicon electrolytes could be stably cycled at an upper cutoff voltage of 4.4 V in LiCoO2/graphite full cells.
Objectives. (1) Determine the predictive value of a school-based test of cardiovascular fitness (CVF) for insulin resistance (IR); (2) compare a "school-based" prediction of IR to a "laboratory-based" prediction, using various measures of fitness and body composition. Methods. Middle school children () performed the Progressive Aerobic Cardiovascular Endurance Run (PACER), a school-based CVF test, and underwent evaluation of maximal oxygen consumption treadmill testing ( max), body composition (percent body fat and BMI z score), and IR (derived homeostasis model assessment index []). Results. PACER showed a strong correlation with  max/kg ( = 0.83, ) and with  ( = , ). Multivariate regression analysis revealed that a school-based model (using PACER and BMI z score) predicted IR similar to a laboratory-based model (using  max/kg of lean body mass and percent body fat). Conclusions. The PACER is a valid school-based test of CVF, is predictive of IR, and has a similar relationship to IR when compared to complex laboratory-based testing. Simple school-based measures of childhood fitness (PACER) and fatness (BMI z score) could be used to identify childhood risk for IR and evaluate interventions.
The spent Zn–C cell powder, containing ZnMn2O4, ZnO, MnO(OH) and possibly Mn2O3 and Mn3O4, can be leached by a sulfuric acid solution mixed with some glucose. The leaching is found to be dependent on solid to liquid (S/L) ratio, amount of glucose, concentration of sulfuric acid solution, time and pulp agitation speed. For 5g powder (S), 1h leaching time and 300rpm pulp agitation speed, two-level four-factor (24) experimental designs have been carried out to derive models for extraction of both Mn(II) and Zn(II). Amount of glucose (G, g), concentration of H2SO4 solution (C, mol/L), volume of H2SO4 solution as leachant (L, mL) and leaching temperature (T, °C) are considered as factors (variables). The model in both cases consists of mean, factor effects and interaction effects. The four-factor interaction effect is observed in neither of the cases. Some two-factor and three-factor effects are found to have produced positive or negative contributions to dissolution percentage in both cases. The models are examined for comparison with experimental results with good fits and also used for optimization of factors. At optimized condition (G =0.50g, C =2mol/L, L =250mL and T =100°C), an aliquot of 5g powder in 1h and at 300rpm produces a solution containing (7.08±0.10)g/L Mn(II) and (2.20±0.06)g/L Zn(II) corresponding to almost 100% extraction of both metal ions.
Objective: To investigate the efficacy of enhancing the content and bioavailability of micronutrients in diets of stunted rural Malawian children on their growth and body composition, morbidity, anaemia and hair zinc concentrations.