batterydata/paper-abstracts huggingface dataset:
Fine Zn2SnO4 nanoparticles are synthesized via a facile hydrothermal route using potassium sodium tartrate as a structure-directing agent for the first time. The average size of the as-prepared nanoparticles is about 8–10 nm. More significantly, based on the effect of the reaction time and the amounts of tartrate on the morphology evolution of the precursors, a crystal growth mechanism is proposed involving in-situ dissolution-recrystallization accompanied by morphology and phase change. The Zn2SnO4/graphene (Zn2SnO4/G) nanocomposites are further obtained through the incorporation of graphene sheets under another hydrothermal condition. When evaluated as anode for lithium ion batteries, Zn2SnO4/G nanocomposites deliver a high specific capacity of 745 mAh g−1 after 100 cycles at 200 mA g−1 and improved cyclic stability with a capacity of 492 mAh g−1 after 500 cycles at 500 mA g−1. The outstanding electrochemical performance is mainly ascribed to the synergetic effect of fine Zn2SnO4 nanoparticles and graphene nanosheets. Furthermore, our work provides a simple and low-cost synthetic strategy for the controllable fabrication of various structural materials for energy storage.
All-solid-state lithium-sulfur batteries can completely overcome safety issues and fast capacity fading by substitution of organic liquid electrolytes and eliminating polysulfide shuttle. However, the insulating nature of sulfur and large volume change still inhibit all-solid-state lithium-sulfur batteries from achieving favorable electrochemical performances. In this work, linear-chain compound vanadium tetrasulfide (VS4) anchored reduced graphene oxide (rGO-VS4) nanocomposites are successfully synthesized via a simple one-pot hydrothermal method. Furthermore, 10%rGO-VS4@Li7P3S11 nanocomposites with multi-channel continuous electronic/ionic conductive network are prepared by a facile liquid-phase deposition reaction and further employed as an alternative material for sulfur cathode in all-solid-state lithium batteries. Typically, Li/75%Li2S-24%P2S5-1%P2O5/Li10GeP2S12/10%rGO-VS4@Li7P3S11 all-solid-state lithium-sulfur batteries deliver high reversible capacity of 611 mAh g−1 at 0.1 A g−1 after 100 cycles, corresponding to 853 mAh g−1 based on the mass of sulfur. Even after being cycled at 0.5 A g−1 between 1.5 and 3.0 V for 500 cycles, it still shows the discharge specific capacity of 333 mAh g−1 based on sulfur content with excellent cycling stability. The excellent rate capability and cycle performances can be ascribed to the multi-channel continuous electronic/ionic conductive networks and the improved structural stability. In addition, the electrochemical reaction kinetics and capacity contributions as well as reaction mechanisms of 10%rGO-VS4@Li7P3S11 in all-solid-state lithium batteries were revealed by ex-situ characterization techniques.
A series of surface-doped LiMn2O4 samples modified by a Li2CuO2-Li2NiO2 solid solution were synthesized using a simple and facile sol-gel method to achieve the enhanced cycling performance, especially at elevated temperatures. The corresponding phase structure and morphology were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The modified layer on the surface of LiMn2O4 particles, featuring a LiNi δ Mn2–δ O4-like phase, together with a Li2CuO2-Li2NiO2 solid solution, as confirmed by XRD and transmission electron microscopy (TEM), plays a key role in alleviating the dissolution of manganese, thus enhancing the cycling performance and rate capability relative to bare LiMn2O4. The 0.5wt.%-modified LiMn2O4 sample delivers a discharge capacity of 113mAhg−1 and a capacity retention of 93.2% following 300 cycles at 1C and 25°C, which is higher than the values of 96mAhg−1 and 81.2% for bare LiMn2O4. In addition, at 55°C, a capacity retention of 81.2% at 1C is obtained for the 0.5wt.%-modified LiMn2O4 sample after 200 cycles, compared to 70.0% for bare LiMn2O4. Modifying the surface of the latter by a LiNi δ Mn2–δ O4-like phase mixed with a Li2CuO2-Li2NiO2 solid solution, is an effective strategy for improving electrochemical properties.
Low ionic conductivity is one of the issues for polymer electrolytes to be used in commercial batteries, though they have been viewed as the promising electrolytes in all-solid lithium-ion batteries for several decades. Here, we show an enhanced ionic conductivity in a classic polymer electrolyte by controlling the ionic conductive pathway via a core–shell structure. The enhancement in ionic conductivity is contributed from the formation of a controlled 3D network of the ion conductive amorphous phase. The result suggests that the core–shell structure design can realize the control of the conduction pathway, which is significant for understanding the ionic conductive behaviors as well as for the improvement of the ionic conductivity in polymer electrolytes.
Three carbon nanowalls (CNWs) thin films, synthesized by Radiofrequency Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) using different processing parameters, are studied as electrode materials in the positive half-cell of a Vanadium Redox Flow Battery (VRFB). These 2D-networks of interconnected graphenes exhibit an excellent electrochemical performance towards the V(IV)/V(V) redox couple in terms of a low overpotential and fast electron transfer kinetics. This can be attributed to certain specific features of CNWs such as the arrangement of the graphene planes perpendicular to the substrate, thus facilitating the electron transfer from the substrate and resulting in a large amount of exposed reactive graphitic edge planes. Repetitive cyclic voltammetry measurements, at various scan rates, together with SEM images evidence the long term stability of these materials. The obtained results represent a significant step forward in the development of highly effective VRFB electrode materials.
A cortical parcellation technique accurately maps functional organization in individual brains. Functional networks mapped by this approach are highly reproducible and effectively capture individual variability. The algorithm performs well across different populations and data types and is validated by invasive cortical stimulation mapping in surgical patients.
Lithium ion batteries (LIBs) are attracting intensive interests worldwide because of their potential applications in transportation electrification and utility grid. The intercalation compounds used in LIBs electrochemically react with Li+ ions via single or multiple phase transitions depending on the nature of the material structure as well as the synthesis and operating conditions. For LiNi0.5Mn1.5O4 high voltage spinel, a promising candidate positive electrode material for LIBs, there are three spinel-structured phases sequentially appeared through two successive two-phase reactions during the delithiation/lithiation processes. Here we demonstrate, experimentally and theoretically, that through elemental substitution, the solid solution ranges for both the first and second phases are significantly extended during the electrochemical charge–discharge process. This type of structural changes with more solid solution regions facilitate fast Li+ diffusion by reducing the number of phase boundaries that Li+ ions have to overcome and resulted in less shrinkage of the unit cells at the end of charge process. This work unravels the fundamental interactions between structural and electrochemical properties by using spinel as the platform, which may be widely adopted to explain or tailor the properties of materials for energy storage and conversion.
Now the lithium ion batteries are widely used in electrical vehicles (EV). The battery modeling and state estimation is of great significance. The rigorous physic based electrochemical model is too complicated for on-line simulation in vehicle. In this work, the simplification of physics-based model lithium ion battery for application in battery management system (BMS) on real electrical vehicle is proposed. Approximate method for solving the solid phase diffusion and electrolyte concentration distribution problems is introduced. The approximate result is very close to the rigorous model but fewer computations are needed. An extended single particle model is founded based on these approximated results and the on-line state of charge (SOC) estimation algorithm using the extended Kalman filter with this single particle model is discussed. This SOC estimation algorithm could be used in the BMS in real vehicle.
Background Folate deficiency and the methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism have been linked to negative symptoms in schizophrenia both independently and synergistically. This study examined the effect of folate supplementation on negative symptoms overall and in relation to MTHFR 677C>T genotype. Method Forty-six stable adult schizophrenia outpatients were enrolled and 32 were randomised, double-blind, in a parallel-group, twelve week add-on trial of folate 2mg/d or matching placebo. The primary outcome measure was change from baseline to week 12 on the modified SANS total score using a mixed-model analysis. In addition, we measured the effect of MTHFR genotype on treatment effects and on changes in serum folate by grouping participants with T/T genotype together with C/T genotype and comparing their interactions to patients with C/C genotype. Results Twenty-eight participants completed the trial. Folate supplementation did not significantly affect negative symptoms compared to placebo across the entire cohort. However, there was a significant genotype×treatment effect on negative symptoms (F=7.13, df=1,39, p=0.01). In addition, MTHFR status significantly moderated the relationship between change in serum folate and change in negative symptoms: among participants with at least one copy of the T allele negative symptoms were more likely to improve with increased serum folate (p=0.03). Conclusion We did not detect a therapeutic benefit of folate supplementation in a sample of patients with residual negative symptoms. However, a possible association between genotypes associated with reduced MTHFR activity and benefit from folate supplementation should be investigated further.
Hierarchical CoNiO2 polyhedral mesoporous structure using a novel hydrothermal method followed by the microwave carbon bath irradiation annealing process. The nanostructure, morphology, surface area and magnetic properties are characterized and investigated in detail. These results reveal that the regular hexagon mesoporous structures and the large specific surface area of 53.57 m3/g play an essential role in enhanced electrochemical activity. CoNiO2 modified glass carbon electrode with output power of 720 W (CNO-720/GCE) exhibits perfect electrochemical ultratrace detection toward Cu(II) with low detection limit of 3.1 nM and high sensitivity of 7.554 μA/μM under the optimized experimental conditions, and also shows the excellent repeatability, reproducibility, stability and selectivity. The improved electrochemical performance is associated with the specific hierarchical polyhedral structure, abundant mesporous channels, stable crystal surface and strong affinity toward Cu(II). Therefore, the synthesized CNO-720/GCE nanomaterials can be applied for ultratrace detection of heavy metal ions.
This paper presents a method of structural dynamic analysis with finite element method to identify the cause failure of solder joint caused by the vibration of ultrasonic welding. In this method, explicit FE method and its contact algorithm are used to simulate the energy transmission from vibrational energy to internal energy under some assumptions. Therefore, firstly, its feasibility is verified by 2D coupled thermal–mechanical analysis. Then, based on a certain type of cell phone battery, a 3D FE model is established for analyzing the vibration of the solder joints during ultrasonic welding. According to the simulation, we analyze the cause of the failure from three aspects: the location of the chip, the shape of the PCB and the structure of the housing. Correspondingly, the improvements are presented and applied to trial manufacture. The result from mass production shows that the improvements can decrease the reject ratio by 90% compared with the original design.
The tremendous advances in nanoscience and nanoengineering have sparked the accelerated development of electroanalysis towards highly sensitive and specific detections. In particular, novel nanomaterials with unique physical and chemical properties have been synthesized for electroanalysis in micro- and nano-scales to qualitatively and/or quantitatively examine the changes of compositions and structures for scientific insights and practical applications. In this review, we mainly survey our recent works on electroanalysis in micro- and nano-scales, which covers micro- and nano-fabrication techniques, microelectrodes and powder microelectrodes, direct electrochemistry of proteins, electrochemical analysis of living cells, and electrochemical immunoassay, with emphasis on the performance improvement by engineered functional nanomaterials. These electroanalytical methods have demonstrated their ability and reliability to study fundamental science and provide practical applications. It is our intention that this review could attract increasing interest to explore new electroanalytical methods in micro- and nano-scales and further develop broad important applications for critical chemical/biological sciences.
This paper describes the experimental characterization of a 25cm2 laboratory scale vanadium redox flow battery (V-RFB). The unit cell performance with respect to voltage, coulombic and energy efficiencies under different performance parameters (current densities, operating temperatures, flow rates, electrolyte concentrations and material properties of 5cm×5cm electrodes) are presented. The cell exhibits different characteristics under different operating parameters; the highest energy efficiency is recorded at c.a. 82%, operating at 308K, 60mAcm−2 and 3cm3 s−1 volumetric flow rate for 250cm3 electrolytes (each reservoir) of 1.6moldm−3 V(III)/V(IV) in 4moldm−3 H2SO4. Formation charge of the mixture of vanadium species into single electro-active species at positive and negative electrodes are presented. Estimated time for the electro-active species to complete the formation charge using electrochemical calculation of Faraday’s constant are presented; a discrepancy of 4.5% is found between the theoretical and experimental data using current density of 80mAcm−2.
Probiotic bacteria have been suggested to stimulate the host immune system. In this study we evaluated the immunomodulatory effects of probiotic Bacillus cereus var. toyoi on the systemic immunity of piglets. A pool of 70 piglets was divided into a probiotic or control group. We determined the ratios of peripheral blood mononuclear cell (PBMC) subsets and measured proliferative responses and cytokine production of PBMCs and effects on vaccination responses. Blood samples of probiotic-treated piglets showed a significantly lower frequency of CD8high/CD3+ T cells and CD8low/CD3+ T cells and a significant higher CD4+/CD8+ ratio. IL-4 and IFN-γ production of polyclonally stimulated PBMCs was on average higher in the probiotic group. Specific proliferative responses of PBMCs to Influenza vaccination antigens were significantly higher and antibody titers against H3N2 Influenza and Mycoplasma vaccination antigens were on average higher in the probiotic group. In conclusion, B. cereus var. toyoi therefore alters the immune status of piglets as indicated by changes in the ratios as well as functionalities of systemic immune cell populations.
While numerous clinical studies have compared the surgical and non-surgical treatment of acute Achilles tendon rupture (ATR), there are no studies that have performed a non-inferiority analysis between treatments.
Objectives: To assess whether patients with OSA have more severe motor, cognitive, and functional impairment at the time of admission to the rehabilitation center and to investigate whether early detection and treatment of OSA using Bi level Positive Air Pressure (BiPAP) impact the outcome of these patients after 1 month of rehabilitation treatment. Design: Single-blind prospective randomized trial. We analyzed differences intra- and intergroups at baseline and at 30 days. We used Kruskall-Wallis test, Mann-Whitney, and the Wilcoxon signed rank tests. P value<0.05 was considered significant. Setting: Stroke Unit. FLENI Rehabilitation Institute. Participants: Patients (N=40) admitted to the rehabilitation unit 2 to 8 weeks after a stroke. Interventions: We performed overnight polysomnography (PSG) in patients. Those with an apnea/hypopnea index >10 per hour were randomized to standardized 30-day rehabilitation program with or without the addition of BiPAP treatment at night. Those subjects with stroke without OSA served as controls. Main Outcomes Measures: FIM, Barthel Index (BI), Fugl-Meyer Upper Extremities (FMUE) and Lower Extremities (FMLE), Frontal Assessment Battery, Addenbrooke Cognitive Examination and Digit Span scales at baseline and at 30 days. Results: All groups showed improvements in FMUE, FMLE, FIM and BI after 30 days. The early BiPAP treatment produced significant improvements of the FMUE score (P=.05) and FMLE score (P=.019). Both groups (OSA with early BiPAP treatment and the non-OSA) showed significant increase of the ACE score after 1 month. Conclusions: Early OSA detection and BiPAP treatment improves significantly motor performance after 1 month. PSG evaluation looking for OSA should be part of the standardized evaluation of stroke patients at admission to stroke rehabilitation facilities.
Accurate modeling of the charge redistribution dominated self-discharge process plays a significant role in power management systems for supercapacitors. Although equivalent circuit models (ECMs) are widely used to describe the nonlinear behaviors of the self-discharge process, they are usually separately established at different initial voltages, which might result in poor prediction performances at other unseen initial voltages. In this study, a three-branch model with a leakage resistance is used to describe the nonlinear dynamic behavior of the supercapacitor self-discharge dominated by charge redistribution and the circuit parameters in ECMs are explicitly modeled as a function of the initial voltage. Polynomial functions with different orders are systematically evaluated by means of fitting and prediction accuracy. The impacts of initial voltage and temperature on the charge redistribution dominated self-discharge process are experimentally investigated with a 3000 F commercial supercapacitor. The modeling results show that a 5th-order polynomial function is sufficient high enough to characterize the nonlinear effect of initial voltage on the charge redistribution dominated self-discharge in terms of prediction accuracy. Moreover, the prediction accuracy of polynomial function based ECMs are significantly better than that of interpolation based ECMs, which further validates the effectiveness of the proposed model.
Against the pressing challenges of climate change and fossil fuel depletion, renewable energy sources such as solar photovoltaics (PV) are considered a clean and sustainable alternative. PV technologies have grown into a substantial field of research and development through large stocks of scientific publications and patents. Besides cell technologies, the balance of system (BoS) components such as panels, electronics and energy storage form an important research area. The present article studies the development of the PV technological system using patent indicators. It is composed of three parts: First, it defines the system by thoroughly reviewing the various cell and BoS technologies. Second, it introduces a novel methodical approach for identifying its relevant patents. In that sense, the paper contributes with an accurate inventory of international patent classes for PV system. Finally, the geographical, organizational and technical trends over the past six decades are analysed along with a review of the most influential inventions. The analysis shows that 95% of the PV patent applications were filed by inventors from seven countries: Japan, Korea, China, USA, Germany, Taiwan, and France. Most patents were filed by companies and related to thin-film and crystalline-silicon cells as well as panel encapsulation and supporting structures. The analysis reviews the quantity, quality and technological specialization within countries’ patent profiles. It further provides an overview of the technological landscape and freedom-spaces available for manufacturers.
Hybrid renewable energy systems, combining various kinds of technologies, have shown relatively high capabilities to solve reliability problems and have reduced cost challenges. The use of hybrid electricity generation/storage technologies as off-grid stand-alone systems is reasonable to overcome related shortcomings. Solar and wind energy are two rapidly emerging renewable ones that have precedence in comparison to the other kinds. In this regard, the present paper studies four specific locations in Iran, which are candidates for research centers. Based on the solar radiation and average wind speed maps, techno-economically optimized systems are designed by simulating behavior of various combinations of renewable energy systems with different sizing, including wind turbine (WT), photovoltaic (PV), fuel cell (FC), and battery banks. According to the results obtained by a computer program, it is concluded that the hybrid systems including WT and PV with battery backup are less costly compared to the other systems. Moreover, we found that among non-hybrid systems, in most regions of Iran׳s territory PVs are more economical than WTs. Despite of its advantages, FC has not been applied in the optimal systems due to its high initial cost and its low replacement life.
ABSTRACT Background The authors conducted a study to determine if electromagnetic interference of cardiac pacemaker and implantable cardioverter-defibrillator (ICD) activity occurs during the operation of electronic dental devices. Methods The authors tested nine electronic dental devices in vitro to assess their ability to interfere with the function of two pacemakers and two ICDs as determined by electrocardiographic telemetry. Results The pacing activity of both pacemakers and the dual-chamber ICD were inhibited during operation of the battery-operated composite curing light at between 2 and 10 centimeters from the generator or leads. The use of the ultrasonic scaler interfered with the pacing activity of the dual-chamber pacemaker at between 17 and 23 cm from the generator or leads, the single-chamber pacemaker at 15 cm from the generator or leads and both ICDs at 7 cm from the leads. The operation of the ultrasonic cleaning system interfered with the activity of the dual-chamber pacemaker at between 15 and 23 cm from the generator or leads, and of the single-chamber pacemaker at 12 cm. Operation of the electric toothbrush, electrosurgical unit, electric pulp tester, high- and low-speed handpieces, and an amalgamator did not alter pacing function. Conclusion Select electronic dental devices interfere with pacemakers' and ICDs' sensing and pacing activity in vitro. Clinical Implications Use of the ultrasonic scaler, ultrasonic cleaning system and battery-operated composite curing light may produce deleterious effects in patients who have pacemakers or ICDs.