batterydata/paper-abstracts huggingface dataset:
The lithium-rich layered oxide; xLi2MnO3·(1-x)LiMeO2 (Me=Co, Ni, Mn, etc.) is one of the most promising cathode materials for lithium-ion batteries in electric vehicles and energy storage systems due to its high energy density, low cost, and excellent thermal stability. In this work, Li1.2Ni0.13Co0.13Mn0.54O2 was synthesized and novel coating was applied to enhance the performance. The pristine Li1.2Ni0.13Co0.13Mn0.54O2 powder was synthesized by an aqueous solution method, followed by calcination at 900°C in air, and the surface was then modified by coating with samaria doped ceria (SDC). Both the pristine and the surface modified materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and electrochemical measurements. The SDC coating with 1wt.% was found to be the most effective in improving the discharge capacity. Specifically, it delivered 261mAhg−1 at 0.1C rate with lower initial irreversible capacity loss. This superior electrochemical performance is attributed to the function of SDC as protective layer suppressing the side reaction between the electrode and the electrolyte, and decreasing the electron charge transfer resistance, as evidenced by the collected electrochemical impedance spectroscopy (EIS) data.
Recent advances in power electronic technology for interfacing dispersed energy resources to distribution grids offer potential solutions to several technical and economical problems in distribution networks. In particular, Dispersed Generation (DG) can be used to provide the usual energy service as well as some ancillary services, such as load following, back-up service, and compensation of Power Quality disturbances. In this paper, a fuel cell-based DG system is proposed for providing energy and ancillary services. The novelty of the system is that it can operate with a ‘system strategy’ (aimed at compensating for the disturbances in the whole system or in some privileged areas of the network) thanks to a suitable control technique of the power electronic interfaces. In this way, the benefits of using the dispersed generation system are maximized. Computer simulations were performed on an actual distribution grid to demonstrate the effectiveness of the compensation actions.
Three phenomenological force and swelling models are developed to predict mechanical phenomena caused by Li-ion intercalation: a 1-D force model, a 1st order relaxation model, and a 3-D swelling model. The 1-D force model can estimate the Li-ion intercalation induced force for actual pack conditions with preloads. The model incorporates a nonlinear elastic stiffness to capture the mechanical consequences of Li-ion intercalation swelling. The model also separates the entire state of charge range into three regions considering phase transitions. The 1st order relaxation model predicts dynamic swelling during relaxation periods. A coefficient of relaxation is estimated from dynamic and quasi-static swelling at operational conditions. The 3-D swelling model predicts the swelling shape on the battery surface for all states of charge. This model introduces an equivalent modulus of elasticity, which is dependent on the state of charge, to capture material transformations of the electrodes, and the orthotropic expansion of the jellyroll in a direction perpendicular to the electrode surfaces. Considering the simplicity of the measurements and direct physical correlations between stress and strain, the proposed models can enhance battery management systems and power management strategies.
Additional evidence is needed in order to clarify the latent structure of executive functions in young children. The current study included seven standardized measures of executive functioning from the NEPSY battery (Korkman, Kirk, & Kemp, 1998), administered to preschoolers (N = 186), mean age = 3 y 6 mo. Results indicated that in the 3-5 years interval, a unitary factor solution best accounted for the data, compared to a 3-factor solution (the NEPSY subdomains), or a 2-factor solution (working memory and inhibition). Our results support previous research, revealing that executive functioning is a relatively undifferentiated construct in young children.
High levels of digital media use with screen-based devices has been found to threaten several aspects of child and adolescent health. However, the rapid change in digital media use behavior in our society over the past decade has rendered much of the existing evidence outdated.
Patients with advanced cancer frequently experience anxiety, depression and poor quality of life (QOL), as well as physical symptoms such as fatigue and weakness. Physical exercise has potential to help control these symptoms but the optimal training prescription is still not clear. We performed a study comparing medical Qigong (QG) and standard endurance and strength training (SET) in patients with advanced stage non-small cell lung (NSCLC) and gastrointestinal (GI) cancers.
This cohort sequential study explored the components of working memory that underlie English reading and language acquisition in elementary school children whose first language is Spanish. To this end, children (N =410) in Grades 1, 2, and 3 at Wave 1 were administered a battery of cognitive (short-term memory [STM], working memory [WM], rapid naming, phonological processing, and random letter and number generation), vocabulary, and reading measures in both Spanish and English. These same measures were administered 1 and 2 years later. The results showed that (a) a three-factor structure (phonological STM, visual–spatial WM, and verbal WM) captured the data within both language systems, (b) growth in both the executive and STM storage components was uniquely related to growth in second language (L2) reading and language acquisition, and (c) the contribution of growth in the executive component of WM to growth in L2 processing was independent of growth in storage, phonological knowledge, inhibition, and rapid naming speed. The results suggested that growth in the phonological storage system does not supersede growth of the executive component of WM as a major contributor to growth in children’s L2 reading and language.
A layered lithium-rich oxide, Li[Li0.19Mn0.32Co0.49]O2, is synthesized by introducing manganese and cobalt via oxalates co-crystallization in reverse micellar microemulsion. The physical and electrochemical performances of the as-synthesized oxide are evaluated as cathode of lithium ion battery. The physical characterizations, from X-ray diffraction, scanning electron microscope and transmission electron microscope, indicate that the as-synthesized oxide takes a nanorod morphology of up to 1μm in length and 200nm in diameter, which is composed of about 20nm subunit nanoparticles, and possesses a hierarchical pore structure. Electrochemical measurements demonstrate that the as-synthesized oxide exhibits improved charge/discharge performances: less polarization, larger discharge capacity, higher rate capability, and better cyclic stability, compared to the sample synthesized by introducing the transition metals in solid-state reaction.
This work is a comparative study on lithium cycling on copper in solutions based on ethylene carbonate (EC) and diethyl carbonate (DEC) (3:7, by wt.) and two lithium salts, lithium hexafluorophosphate (LiPF6) and lithium difluoro(oxalato)borate (LiDFOB). Coulombic efficiencies of the long term lithium deposition/dissolution experiments and dissolution-rate (D-rate) tests on copper demonstrated clearly the superior behavior of the LiDFOB-based electrolyte. To clarify the impact of the formed solid electrolyte interphase (SEI) on the Coulombic efficiencies achieved in the electrolytes, voltage drop values of the D-rate tests were compared with measured values of conductivities and AC impedance measurements of the electrolytes. The formed SEI has a larger influence on voltage drop values of a cell than the conductivity of the electrolyte. The correlation between surface chemistry, morphology, and Coulombic efficiencies of lithium deposition on copper was investigated by scanning electron microscopy (SEM) and Raman spectroscopy. All methods demonstrated the strong influence of the investigated lithium salts on the lithium deposition/dissolution performance on copper substrates. The LiDFOB-based electrolyte showed superior SEI properties than the LiPF6-based electrolyte.
Management of municipal solid waste (MSW) has become a significant environmental problem, especially in fast-growing cities. The amount of waste generated increases each year and this makes it difficult to create solutions which due to the increase in waste generation year after year and having to identify a solution that will have minimum impact on the environment. To determine the most sustainable waste management strategy for Chihuahua, it is first necessary to identify the nature and composition of the city’s urban waste. The MSW composition varied considerably depending on many factors, the time of year is one of them. Therefore, as part of our attempt to implement an integral waste management system in the city of Chihuahua, we conducted a study of the characteristics of MSW composition for the different seasons. This paper analyzes and compares the findings of the study of the characterization and the generation of solid waste from households at three different socio-economic levels in the city over three periods (April and August, 2006 and January, 2007). The average weight of waste generated in Chihuahua, taking into account all three seasons, was 0.592kgcapita−1 day−1. Our results show that the lowest income groups generated the least amount of waste. We also found that less waste was generated during the winter season. The breakdown for the composition of the waste shows that organic waste accounts for the largest proportion (45%), followed by paper (17%) and others (16%).
Owing to the special honeycomb structures and excellent electrical characters of carbon nanotube (CNT) and carbon nanofiber (CNF), they are extensively considered as ideal cornerstones for hydrogen storage materials. Herein, metal cobalt has been uniformly coated on CNT's and CNF's surfaces in nanoscale through a simple ball milling process. Accordingly their X-ray diffraction, scanning electron microscope and transmission electron microscopy measurements clarify the satisfying composite structures. And their electrochemical experimental results demonstrate that the as-obtained CNT/Co and CNF/Co composites have excellent electrochemical hydrogen storage reversibility and considerably high storage capacities of 717.3 mAh g−1 (2.62 wt% hydrogen) and 739.4 mAh g−1 (2.70 wt% hydrogen) under room temperature and ambient pressure, which are much higher than the capacities of individual CNT (29.9 mAh g−1, 0.11 wt% hydrogen) and CNF (49.0 mAh g−1, 0.18 wt% hydrogen) measured in this work. Furthermore their hydrogen storage processes and the mechanism have also been investigated, in which the quasi-reversible CNT (CNF)/Co ↔ CNT (CNF)/Co–H x reaction is the dominant cycle process.
ABSTRACT To improve the cycle performance of LiMn2O4 under high rates at elevated temperature, La-Sr-Mn-O (LSM) solid electrolyte layer is introduced as a coating layer to suppress manganese dissolution. The spinel LiMn2O4 was coated with La-Sr-Mn-O via sol-gel method. The structure and morphology were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and electron diffraction spectroscopy (EDS). The results show LSM thin layer closely coats on the surface of spinel LiMn2O4 with particle size of 400∼800nm. The electrochemical results reveal the as-prepared LSM-coated sample exhabits an cycle stabiltiy under high rates at elevated temperature. The specific discharge capacity is 129.9mAhg−1 at 0.1 C and exhibits 90.6% capacity retention after 500 cycles at 1 C rate. When cycling at 55°C, the composite shows 93.6% capacity retention after 130 cycles. The LSM coating suppresses the dissolution of Mn and reduces the impedances, enhancing the kinetrics of lithium-ion diffusion through the surface layer and the charge transfer reaction. This study may provide new insight into restraining the capacity fading of LiMn2O4 electrodes and show their promising large-scale commercialization of high-power lithium ion batteries.
An advanced electrode for high areal capacity Li ion battery anode has been designed by growing ultra thick mesoporous Co3O4 nanosheet networks on Ni foam. This noval architecture consists of mesoporous Co3O4 nanosheets, which are interconnected with each other to form macropores. Benefiting from the favorable macro/meso-porous structures as well as the large mass loading of the synthesized Co3O4 on three dimensional foam, this unique electrode exhibits an areal capacity as high as 4.39mAhcm−2 and excellent rate capability and cycling stability.
One-dimensional nanorods of MoO2, MoO3 and Magnéli-phase Mo4O11 were effortlessly prepared using the hot-filament metal oxide vapor deposition technique. Long straight and uniform nanorods were grown on indium-tin-oxide (ITO) thin film coated glass substrates. Thermal reduction and oxidation were then used to process 1D Magnéli-phase Mo4O11 nanorods synthesized at 1000, 1050, 1100, 1150, and 1200 °C into 1D MoO2 and MoO3 nanorods, respectively. The nanorods prepared at higher synthesis temperatures were thinner and longer. The 1D Magnéli-phase Mo4O11 nanorods consisted of various combinations of two orthorhombic (α) and monoclinic (η) crystals and varying mixtures of Mo4+, Mo5+ and Mo6+ (3d5/2 and 3d3/2) cations. The 1D MoO2 nanorods were comprised of only monoclinic (η) crystals and various complex mixtures of Mo4+, Mo5+ and Mo6+ (3d5/2 and 3d3/2) cations. The 1D MoO3 nanorods contained only orthorhombic (α) crystals and varying mixtures of Mo5+ and Mo6+ (3d5/2 and 3d3/2) cations. Comparison of the crystal phases and 3d valences showed that the MoO2 nanorods supplied more oxidation states than the Mo4O11 or MoO3 nanorods. According to the results of cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) measurements, and electrochemical impedance (EI) spectroscopy, the capacitive performance of the MoO2 nanorod-based pseudocapacitor was much better than that of the MoO3 and Magnéli-phase Mo4O11 nanorod-based pseudocapacitors. The crystal phases and 3d-valence conversions clearly had a tremendous impact on the capacitive behaviors of the MoO2, MoO3, and Magnéli-phase Mo4O11 nanorod-based pseudocapacitors.
Three-dimensional (3D) graphene materials, consisting of unstacked two-dimensional (2D) graphene sheets serving as building blocks, have been widely reported in recent years. Various synthetic methods have been employed to prepare graphene materials with diverse 3D architectures, which show potential in a wide range of applications such as energy and environmental technologies. In particular, application of 3D graphene-based materials in metal (Li, Na, K, Mg, Al)-ion battery (MIB) systems has been reported often in recent years. However, the critical roles of 3D graphene materials in MIB systems have not been comprehensively discussed. Herein, we first summarize the configurations and preparation of 3D graphene materials. Second, we illustrate the metal-ion storage mechanisms in graphene layers, i.e. intercalation and adsorption. Third, we emphasize the superior functionalities of 3D graphene architectures as supporting and encapsulated materials in MIB applications. Last, we discuss the merits and drawbacks of various 3D graphene architectures in MIB systems. We aim to present a comprehensive understanding of 3D graphene materials and guide directions for future MIB design.
Hierarchically uniform three-dimensional allium giganteum-like yttrium-based metal-organic framework architectures (Y-MOFs) have been successfully synthesized with use of polyvinylpyrrolidone (PVP) by a modified hydrothermal method. The allium giganteum-like architectures are made up of a large amount of nano-sheets. The morphology and grain size of the samples can be easily adjusted through the elaborate choice of reaction time and the content of PVP additives. A possible growth mechanism is proposed in detail. Under the UV light excitation, the Y-MOFs: xEu (x = 1, 2, 5, 10, 20, 50%) samples exhibit a strong red luminescence. The luminescence intensity increases first and then decreases with x value increasing, showing a maximum at x = 10%. Furthermore, the shape-preserved Y2O3:Eu3+ phosphors can be easily obtained via a heat-treating in the air using the corresponding MOFs as a precursor, which exhibit characteristic red emission and excellent thermal stability.
Although very appealing in developing hollow structured lithium-rich layered transition-metal oxides as cathodes for lithium-ion batteries (LIBs), a great challenge lies in controlling the growth of transition metal elements with desired molar ratios while maintaining intact hollow structures during synthesis. Herein, we propose a scalable strategy to successfully synthesize novel lamellar Li1.2Mn0.54Ni0.13Co0.13O2 hollow (L-LMOH) nanosphere cathode for advanced lithium-ion batteries (LIBs). It is proved that the employment of sulfonated polystyrene (SPS) gel nanospheres as the template plays a key role in the formation of flower-like SPS@ Ni-Co-Mn-precursor nanospheres with desired molar ratios, and a subsequently delicate control in the heating rate leads to the intact L-LMOH nanospheres. It is demonstrated that the use of L-LMOH nanosphere cathode not only delivers outstanding reversible discharge capacities of 281.7mAhg−1 at a current density of 20mAg−1 and 136.6mAhg−1 at 2000mAg−1, but also possess superior cycling stability with a capacity reservation of 80% at 2000mAg−1 after 200 continuous cycles. It is well analyzed that the ingenious design of both unique lamella and hollow architectures synergistically benefits the significantly enhanced rate capability and cycling stability.
Nuclear protein 1 (Nupr1), a small chromatin protein, has a critical role in cancer development, progression and resistance to therapy. Previously, we had demonstrated that Nupr1 cooperates with KrasG12D to induce pancreas intraepithelial neoplasias (PanIN) formation and pancreatic ductal adenocarcinoma development in mice. However, the molecular mechanisms by which Nupr1 influences Kras-mediated preneoplastic growth remain to be fully characterized. In the current study, we report evidence supporting a role for Nupr1 as a gene modifier of KrasG12D-induced senescence, which must be overcome to promote PanIN formation. We found that genetic inactivation of Nupr1 in mice impairs Kras-induced PanIN, leading to an increase in β-galactosidase-positive cells and an upregulation of surrogate marker genes for senescence. More importantly, both of these cellular and molecular changes are recapitulated by the results of mechanistic experiments using RNAi-based inactivation of Nupr1 in human pancreatic cancer cell models. In addition, the senescent phenotype, which results from Nupr1 inactivation, is accompanied by activation of the FoxO3a-Skp2-p27Kip1-pRb-E2F pathway in vivo and in vitro. Thus, combined, these results show, for the first time, that Nupr1 aids oncogenic Kras to bypass senescence in a manner that cooperatively promotes PanIN formation. Besides its mechanistic importance, this new knowledge bears medical relevance as it delineates early pathobiological events that may be targeted in the future as a means to interfere with the formation of preneoplastic lesions early during pancreatic carcinogenesis.
In situ high-resolution transmission electron microscopy (HRTEM) studies of the structural transformations that occur during the synthesis of carbon-coated LiFePO4 (C–LiFePO4) and heat treatment to elevated temperatures were conducted in two different electron microscopes. Both microscopes have sample holders that are capable of heating up to 1500°C, with one working under high vacuum and the other capable of operating with the sample surrounded by a low gaseous environment. The C–LiFePO4 samples were prepared using three different compositions of precursor materials with Fe(0), Fe(II) or Fe(III), a Li-containing salt and a polyethylene-block-poly(ethylene glycol)-50% ethylene oxide or lactose. The in situ TEM studies suggest that low-cost Fe(0) and a low-cost carbon-containing compound such as lactose are very attractive precursors for mass production of C–LiFePO4, and that 700°C is the optimum synthesis temperature. At temperatures higher than 800°C, LiFePO4 has a tendency to decompose. The same in situ measurements have been made on particles without carbon coat. The results show that the homogeneous deposit of the carbon deposit at 700°C is the result of the annealing that cures the disorder of the surface layer of bare LiFePO4. Electrochemical tests supported the conclusion that the C–LiFePO4 derived from Fe(0) is the most attractive for mass production.
Investigation of Cu2S as cathode in lithium cells with ether-based electrolytes shows a discharge voltage plateau at 1.7 and 2.25V in the first cycle which slowly evolve, respectively, to 1.74 and 1.94V in the following cycles. This transition process has been analyzed by ex situ X-ray diffraction, scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The discharged products are identified as Li2S and elemental copper, and the charged product is Cu1.96S, all of which are crystalline during cycling. SEM reveals a pulverization process of particles during the phase transition and the EIS shows a significant reduction in charge transfer resistance after charges. The Cu2S electrodes exhibit a relatively stable discharge capacity of around 250mAhg−1 at rates of C/10, C/5, and C/2 after a capacity decline in the first cycle. Coulombic efficiency starts to decrease in early cycles as the rate increases. The poor cyclability and low Coulombic efficiency at high rates like 1C rate indicate the transition process is limited at high rates due to the large particle size.
This study examined the involvement of verbal and visuo-spatial domains in solving addition problems with carrying in a sample of children diagnosed with developmental dyscalculia (DD) divided into two groups: (i) those with DD alone and (ii) those with DD and dyslexia. Age and stage matched typically developing (TD) children were also studied. The addition problems were presented horizontally or vertically and associated with verbal or visuo-spatial information. Study results showed that DD children's performance on mental calculation tasks was more impaired when they tackled horizontally presented addition problems compared to vertically presented ones that are associated to verbal domain involvement. The performance pattern in the two DD groups was found to be similar. The theoretical, clinical and educational implications of these findings are discussed.
In this work, a novel supercapacitor electrode material named MnO2/b-PEDOT/MWCNTs is synthesized by first preparing the PEDOT hollow spheres (b-PEDOT), and then anchoring the b-PEDOT on the surface of MWCNTs. At last, wrapping MnO2 nano-grains onto the surface of b-PEDOT and these composite spherical grains form a network structure with multiwalled carbon nanotubes (MWCNTs) after the coprecipitation process. Utilizing this hybrid material, a specific capacitance of 270 F g−1 at a current density of 0.3 A g−1 is achieved. A new flexible, low cost and easy fabricated micro-supercapacitor device by using MnO2/b-PEDOT/MWCNTs nanocomposite as electrode material is assemblied, which has a relatively rectangle in shape of standard cyclic voltammetry curves, indicating excellent supercapacitor behavior and a specific capacitance of 110 F g−1 at a current density of 2 A g−1 is achieved. The CV curves of the assemblied micro-supercapacitor under different bending states showed that there is no noticeable difference of electrochemical properties after being folded.