batterydata/paper-abstracts huggingface dataset:
Highly efficient electrocatalysts for oxygen evolution reaction play key roles in various energy storage/conversion devices. Promoting the reaction rates and decreasing the overpotentials of the electrocatalysts for oxygen evolution reaction are critical for their practical application. Herein, we realize the first successful synthesis of Co2N0.67 with three-dimensional architecture of hierarchical meso-macroporous nanoflowers stacked by the nanoplates with polystyrene spheres as the template. The Co2N0.67 nanoflowers exhibit both low overpotential (258 mV at 10 mA cm−2) and low Tafel slope (52.22 mV dec−1) as well as superior stability for oxygen evolution reaction in alkaline medium, which makes Co2N0.67 nanoflowers to be one of best earth-abundant elements based electrocatalysts toward oxygen evolution reaction to date. Importantly, being different from the previous observation that the cobalt nitrides with higher nitrogen content possess lower oxygen evolution reaction electrocatalytic abilities, we find Co2N0.67 exhibits higher oxygen evolution reaction activity than Co5.47N. The density functional theory calculations reveal that during the oxygen evolution reaction, the oxidation step from O* to OOH* on Co2N0.67 and Co5.47N is considered as the rate-determining step, making oxygen evolution reaction to be more thermodynamically favorable on Co2N0.67 than that on Co5.47N.
The role of color in perceptual priming still remains unclear. We investigated the influence of color during the identification of natural images using a perceptual priming paradigm. In a learning phase, two groups of participants were presented with either colored or gray-scaled variants of photos. A control group did not participate in the learning phase. We measured the level of fragmentation by which a stimulus was correctly recognized in a retrieval phase. Results indicate that colored (compared to gray-scaled) stimuli improved subsequent identification performance of colored and gray-scaled stimuli. These findings imply that color enhances the effects of perceptual priming.
In this paper, LiFe1−x Gd x PO4/C composites (x =0, 0.02, 0.04, 0.06, 0.07, 0.08) are synthesized via a high-temperature solid-phase reaction. The structure and electrochemical behavior of the materials are investigated using a wide range of techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), particle size analysis, galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS). It is found that the maximum discharge capacity of the as-prepared LiFe0.93Gd0.07PO4/C composite can reach up to 150.7mAhg−1, 125.9mAhg−1, 106.0mAhg−1 and 81.3mAhg−1 at rates of 0.2C, 1C, 5C and 10C, respectively. And at 0.1C rate, the initial discharge capacity of the composite monotonically increases with temperature from 66.3 to 122.2mAhg−1 in the range of −30 to 0°C. It is also demonstrated that the presence of a small amount of Gd3+ ion in the sample prepared in this work can reduce the charge-transfer resistance, resulting in the enhanced electrochemical catalytic activity.
The CuS@reduced graphene oxide (CSG) was synthesized and used as an anode material in lithium ion batteries (LIBs). CuS nanoparticles were homogeneously dispersed on the surfaces of reduced graphene oxide (rGO) nanosheets via a hydrothermal method. The rGO nanosheets in the CSG hydrids can improve the electrical conductivity and structure stability of CSG. The LIB with a CSG anode displays excellent performance, with a first discharge capacity up to 851 mAh/g, a reversible capacity of 648.1 mAh/g in the initial cycle, and an enhanced cyclic performance with a discharge capacity of 710.7 mAh/g at the 100th cycle, which corresponds to 114.3% of the theoretical value of CSG and 83.5% of the first discharge capacity accompanied by an excellent Coulombic efficiency of 99.1% at a current density of 0.2C, which is much larger than (close to 4.5 times) that with a pure CuS anode at the 100th cycle (159.7 mAh/g). This phenomenon can be attributed to the synergistic action of CuS nanoparticles and rGO nanosheets in the “double-sandwich-like” CSG hybrids. These results indicate that CSG is an excellent anode material and has promising prospects in lithium ion batteries applications.
In the quest for greater autonomy, there is an increasing need for solutions that would enable a large set of robots to coalesce and perform complicated multi-robot tasks. This problem, also known as the multi-robot coalition formation problem has been traditionally approached as a single objective optimization problem. However, robots in the real world have to optimize multiple conflicting criteria such as battery life, number of completed tasks, and distance traveled. Researchers have only recently addressed the robot coalition formation problem as a multi-objective optimization problem, however the proposed solutions have computational bottlenecks that make them unsuitable for real time robotic applications. In this paper we address the issue of scalability by proposing parallelized algorithms in the CUDA programming framework. NSGA-II and PAES algorithm have been parallelized due to their suitability to the coalition formation domain as outlined in our previous work. The parallelized versions of these algorithms have been applied to both the additive and non-additive coalition formation environments. Simulations have been performed in the player/stage environment to validate the applicability of our approach to real robot situations. Results establish that the multi-point PAES parallel variant yields significant performance gains in terms of running time and solution quality when the problem is scaled to deal with large inputs. This suggests that the algorithm may be viable for real time robotic applications. Experiments demonstrate significant speedup when the proposed parallel algorithms were compared with the serial solutions proposed earlier.
Valve-regulated lead-acid (VRLA) batteries with gelled electrolyte appeared as a niche market during the 1950s. During the 1970s, when glass-fiber felts became available as a further method to immobilize the electrolyte, the market for VRLA batteries expanded rapidly. The immobilized electrolyte offers a number of obvious advantages including the internal oxygen cycle which accommodates the overcharging current without chemical change within the cell. It also suppresses acid stratification and thus opens new fields of application. VRLA batteries, however, cannot be made completely sealed, but require a valve for gas escape, since hydrogen evolution and grid corrosion are unavoidable secondary reactions. These reactions result in water loss, and also must be balanced in order to ensure proper charging of both electrodes. Both secondary reactions have significant activation energies, and can reduce the service life of VRLA batteries, operated at elevated temperature. This effect can be aggravated by the comparatively high heat generation caused by the internal oxygen cycle during overcharging. Temperature control of VRLA batteries, therefore, is important in many applications.
LiO2 secondary batteries outclass other battery systems in terms of energy density, at least on a theoretical point of view. However, these systems suffer issues from both the metallic lithium electrode and the oxygen electrode. For example, the cathode discharge product (lithium peroxide) is a semiconductor of large bandgap (5 eV), which yields severe cyclability issues, as the re-charge is limited. Using electrolyte additives may be one option to mitigate (if not solve) this issue. Herein, a new redox mediator compound (N,N′-Bis(salicylidene)ethylenediaminocobalt (II), noted Co-salen) is studied with regards to its impact on the oxygen reduction and evolution reactions in non-aqueous medium. Its performances are compared to those of a Cobalt porphyrin (noted Co(II)-Po). Electrochemical experiments in three-electrode setup, Differential Electrochemical Mass Spectrometry (DEMS) and UV–Visible spectroscopy, demonstrate that Co-salen can also greatly improve the oxygen reduction kinetics (the ORR onset potential is positively-shifted by 230 mV in the presence of Co-salen), thanks to the formation of a complex with oxygen in solution. Secondly, Co-salen enables to efficiently transport electrons in the solution, and help to recover the electrode surface (the re-charge of large Li2O2 particles becomes possible). Therefore, enhancing both the oxygen reduction and the oxygen evolution reactions (ORR and OER) with only one additive in the electrolyte is feasible, and places Co-salen among the best compounds to be used as redox shuttles for non-aqueous LiO2 batteries.
This paper develops the small signal modelling of the storage systems. In order to attain an equalized energy utilisation factor among the high energy density based storage elements, a dynamic exponent based decentralized state of charge (SoC) management scheme is integrated. Moreover, due to the low relative inertia of the microgrid, the system may undergo a power imbalance condition with the varying generation and demand. Thus, to improve the system inertia a high power dense storage element is incorporated into the system. A fuzzy-based decentralized state of power management scheme (SoP) is proposed in the study. To ensure the robustness of the proposed SoC and SoP management scheme, the microgrid is extensively tested under the dynamically varying generation and load scenarios. The system stability of the proposed approach is further cross-verified through the Nyquist stability criterion.
Aim of the study The clinical usefulness of medications generally depends on their efficacy and safety. Bangpungtongsung-san (BPTS), a traditional herbal medicine, is widely used to treat patients in Korea, Japan (Bofu-tsusho-san), and China (Fang feng tong sheng-san) as an antiobesity prescription. The objective of the present study was to evaluate the subchronic toxicity of a BPTS water extract in Crl:CD SD rats. Materials and methods BPTS was administered to rats orally once daily at doses of 0, 500, 1000, and 2000mg/kg/day for 13 weeks. Toxicological parameters included clinical signs, body weight, water and food consumption, ophthalmological signs, relative organ weight, hematological and serum biochemical parameters, and histopathological assessment. Results No treatment-related adverse effects were observed regarding the physiological parameters examined during the study or in the evaluation of blood, urea, and tissue samples taken from the animals at the end of the study. Conclusions In conclusion, the no-observed-adverse-effect-level for BPTS was determined to be a dietary dose of over 2000mg/kg for both sexes under the present experimental conditions.
We discuss a rapid testing of capacity in Li-ion battery packs with impedance-measuring technology to evaluate their capability in mobile phones. Our measurements of the capacity and impedance at 1kHz for various kinds of battery packs conclusively proved that there is a strong correlation between capacity and impedance. It can be applied even when the pack consists of not only a Li-ion battery but also a Positive Temperature Coefficient (PTC) device and a protection circuit in-series, and this correlation is largely unaffected by the degree of charge. The results we obtained from measuring impedance revealed the possibility of quickly assessing degradation in Li-ion battery packs.
Knee Osteoarthritis (KOA) is a major cause of pain and functional impairment among elders. Currently, there are neither feasible preventive intervention strategies nor effective medical remedies for the management of KOA. Tai Chi, an ancient Chinese mind-body exercise that is reported to enhance muscle function, balance and flexibility, and to reduce pain, depression and anxiety, may safely and effectively be used to treat KOA. However, current evidence is inconclusive. Our study examines the effects of a 12-week Tai Chi program compared with an attention control (wellness education and stretching) on pain, functional capacity, psychosocial variables, joint proprioception and health status in elderly people with KOA. The study will be completed by July 2009.
Novel hierarchical porous carbons (NHPCs) containing 3D carbon nanosheets and slit-mesopores are prepared in this work, using MgAl-layered double hydroxides as template and sucrose as carbon source, and their electrochemical performances as anodes of lithium-ion batteries are also investigated. Owing to the existence of abundant carbon nanosheets and slit-mesopores, the NHPCs electrode exhibits the specific reversible capacity of 1151.9mA h/g at the current density of 50mA/g, which is significantly higher than other hierarchical porous carbons reported in previous literatures. The contributions of carbon nanosheets and mesopores to the electrochemical performance are further clarified by nitrogen adsorption-desorption test, electrochemical impedance spectroscopy, cyclic voltammograms and galvanostatic charge/discharge test. This work not only provides an easy and effective method to prepare hierarchical porous carbon materials, but also is beneficial for the design of high-performance anode materials for lithium ion batteries.
Directing cell behaviour using controllable, on-demand non-biochemical methods, such as electrical stimulation is an attractive area of research. While there exists much potential in exploring different modes of electrical stimulation and investigating a wider range of cellular phenomena that can arise from electrical stimulation, progress in this field has been slow. The reasons for this are that the stimulation techniques and customized setups utilized in past studies have not been standardized, and that current approaches to study such phenomena rely on low throughput platforms with restricted variability of waveform outputs.
Several doped spinel-type Li–Mn oxides of formula LiMn2− x M x O4, where Mn is partly replaced by Co, Cu, Ga, were prepared by the Pechini method in the range of 700–850°C for 4h. Even substitution levels as low as 0.1atom/formula unit produces structural effect that resulted in high cycle performance. The cylcleability maintained regardless of synthesis temperature or powder size. It is suggested that high Mn Valence State by doping significant effect on cylcleability. Also, Spinel lithium manganese oxides with a nominal composition of LiMn2O4 are prepared by using conventional ceramic synthesis method and are coated by a chemical deposition method of Ag particles onto LiMn2O4 powder. The Ag nano-particle coated LiMn2O4 showed excellent cycleability at 2C galvano-static condition. The results indicated that the surface treatment on cathode powder also should be an effective way to improve cyclelife and high current retention. This work aims to elucidate electrochemical properties by doping and coating.
Dynamic performance of a 10-kW proton exchange membrane fuel cell (PEMFC)–battery hybrid system to power servers in data centers has been experimentally evaluated in our previous work [1]. The present work is a numerical study based on the previous work to identify the dynamic characteristics and present basic insights for the system control strategy during transients. The hybrid system dynamic model has been developed using the MATLAB–Simulink®, which consists of a one-dimensional, two-phase dynamic model of the PEMFC, lumped dynamic model of an air blower and a battery. The system model is verified by comparing the dynamic behavior of the power generated by the PEMFC and battery with the experimental data at the step change of the system demand power between 0 and 1.5, 3.0, 4.5, 6.0, 7.5, and 9.0 kW. During the step load increases, the system instantly obtained the total amount of external load power from the battery within 0.1 s in every case and gradually decreased until approximately 4 s or 6 s as the power generated by the fuel cell is gradually increased. The dynamic response of the system model is compared with the experimental data at various load profiles of three, six, and nine servers.
The spinel-type transition metal oxides play key role in realizing cost-effective energy storage systems by exhibiting outstanding electrochemical activity and stability. Free standing 3D hierarchical mesoporous ZnCo2O4 microspheres are grown on nickel foam (NF) substrate using hydrothermal route followed by annealing treatment. 3D hierarchical mesoporous ZnCo2O4 microspheres with high surface area and uniform mesoporous distribution exhibits high electrochemical performance. The ZnCo2O4/NF electrode material deliver superior specific capacitance of 1143Fg−1 at a current density of 1.25Ag−1 in aqueous 2M KOH solution and exhibits long-term cycling stability with specific capacitance of 880Fg−1 after 6000 cycles at 12.5Ag−1. Furthermore, ZnCo2O4/NF electrode maintains current density upto 105Ag−1 in 1M KOH mixed with 0.5M methanol when applied as electro-catalyst for methanol electro-oxidation. The high electrochemical performance is mainly attributed to faster ion/electron transfer and an enhanced electrochemical kinetics. The present simple, and cost-effective synthesis approach can open new era for large-scale applications of the novel materials for different electrochemical applications.
Comorbidity of motor and speech/language impairments was investigated in 363 preschool children between the ages of 5 and 6 years (boys: 205, age 6.04±0.48 years; girls: 158, age 5.98±0.53 years). The children were sampled from two municipals of Taiwan, and were determined to present no apparent neurological, musculoskeletal, cardiopulmonary system impairment or mental insufficiency. They were administered with three speech/language tests and a motor test (Movement Assessment Battery for Children, or M-ABC). The results showed a significant correlation between the total score of the motor test and the total score of each of the speech and language tests. Regression analysis that controlled for IQ (C-TONI) further showed that manual dexterity, but not ball skills or balance, of M-ABC was predictive of all scores on the speech and language tests. To determine a deficit on a test, a score at or below the 10th percentile of the norm or a score at or below 1.25SD from the group mean was established as the cutoff. For the speech/language impairment, a deficit on at least two out of the three tests also applied. Following these criteria, 22 children (6.1%) were identified to have Developmental Speech and Language Disorder (DSLD), and 45 (12.4%) to have Developmental Coordination Disorder (DCD). Comorbid DSLD and DCD were found in six children (1.65%). Chi-square analysis revealed a significant correlation between DSLD and DCD (p <.03). The odds of DSLD was higher (by about three-fold) among the children with DCD than among the children without (0.15 vs. 0.05). Comorbid motor and speech/language impairments in preschool children appear to be a significant clinical condition that requires the attention of the therapeutic community. Manual dexterity, in particular, seems to be an important clue for understanding the shared mechanism of motor and speech/language impairments.
Thick-film electrodes of Si particles coated with Ni, Ni–Sn, and Ni–P were fabricated by electroless deposition followed by gas deposition to form the anode of a Li-ion battery. The electrode of Ni-coated Si showed remarkably improved cycling performance with a discharge capacity of 580mAhg−1 at the 1000th cycle, which is possibly caused by its higher elastic modulus than that of the uncoated Si electrode. The electrode of Si coated with Ni–P, which consisted of Ni3P, with the lower coating amount exhibited a higher initial capacity and excellent cycling performance with a capacity of 790mAhg−1 at the 1000th cycle, whereas poor performance was obtained for the electrode of Si coated with Ni–Sn. The excellent performance in the case of Ni–P coating is attributed to the smaller amount of coating, the high elastic modulus, and the lower reactivity of Ni3P with Li ions in comparison with Ni3Sn in Ni–Sn.
In order to improve the cyclability of Sn negative electrode, we tried preparing the Sn film negative electrode by a pulse electrodeposition. Based on the SEM observations, the crystal grains of the Sn film after the pulse electrodeposition were comparatively homogeneous and their grain size was ca. 1μm. The discharge capacity and the charge–discharge efficiency at the 1st cycle were 679.3mAhg−1 and 93.0%, respectively. The charge–discharge tests indicated that the initial electrochemical characteristic of Sn film electrode prepared by a pulse electrodeposition was much better than that of the Sn film electrode prepared by a constant current electrodeposition. The GD-OES profile suggested that Li+ ions were easily extracted during the discharge reaction. In addition, it was found that no exfoliation of the film was observed after the 1st discharge though the cracking in the film was observed after the 1st discharge. Consequently, the Sn film electrode prepared by a pulse electrodeposition exhibited a better cyclability for the initial 10 cycles compared to the Sn film electrode prepared by a constant current electrodeposition. By reducing the particle size and repressing the morphological change, the initial electrochemical characteristics were considerably improved.
The Li+ insertion and extraction characteristics at n-type and p-type Si(100) electrodes with different carrier density and doping type are investigated by cyclic voltammetry and constant current measurements. The insertion and extraction potentials are demonstrated to vary with cycling and the occurrence of an activation effect is shown in n-type electrodes where the charge capacity and voltammetric currents are found to be much higher than p-type electrodes. A rate-dependent redox process influenced by the surface region electronic density, which influences the magnitude of cyclic voltammetry current is found at Si(100) surface regions during Li insertion and extraction. At p-type Si(100) surface regions, a thin, uniform film forms at lower currents, while also showing a consistently high (>70%) Coulombic efficiency for Li extraction. The p-type Si(100) surface region does not undergo crack formation after deintercalation and the amorphization was demonstrated using transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) and Raman scattering demonstrate that highly doped n-type Si(100) retains Li as a silicide and converts to an amorphous phase as a two-step phase conversion process. The findings show the succinct dependence of Li insertion and extraction processes for uniformly doped Si(100) single crystals and how the doping type and its effect on the semiconductor-solution interface dominate Li insertion and extraction, composition, crystallinity changes and charge capacity.
The microbial fuel cell (MFC) is a green and sustainable technology for electricity energy harvest from biomass, in which exoelectrogens use metabolism and extracellular electron transfer pathways for the conversion of chemical energy into electricity. However, Shewanella oneidensis MR-1, one of the most well-known exoelectrogens, could not use xylose (a key pentose derived from hydrolysis of lignocellulosic biomass) for cell growth and power generation, which limited greatly its practical applications.
Ni nanorods prepared by electrochemical growth through an anodized aluminium oxide membrane were used as substrate for the electrodeposition of MnO2 either in potentiostatic mode or by a pulsed method. Electrochemical deposition parameters were chosen for an homogeneous deposit onto Ni nanorods. Resulting Ni supported MnO2 electrodes were tested for electrochemical performances as nanostructured negative electrodes for supercapacitors. They exhibited initial capacitances up to 190F/g and remarkable performances at high charge/discharge rates.