batterydata/paper-abstracts huggingface dataset:
There has been substantial research in the area of innovation, which is widely regarded as a powerful weapon to create competitive advantage. One important reason of the substantial research in innovation is the presence of valid and reliable measures of key innovation characteristics, such as radical, incremental, or disruptiveness innovation. Re-innovation, an extension of innovation, is renowned for its potential in creating competitive advantage with reduced cost and time implications. Unfortunately, very little research in re-innovation has been conducted, possibly because to date it still lacks a psychometrically valid measure. There is also a lack of research on convergent and discriminant validities of the re-innovation construct, resulting in the impossibility to discriminate re-innovation characteristics from radical or incremental innovation characteristics. The purpose of this paper is to develop a valid and reliable scale for measuring the construct of re-innovation. To test its reliability and discriminant and convergent validities, we used data collected from 294 general managers of SBUs in 89 electronics-related companies in Taiwan and performed a series of analyses. The reliability measures, exploratory factor analyses, confirmatory factor analyses, and convergent and discriminant validity tests strongly support our scale. In addition, nomological validity is demonstrated. Hence, this study distinguishes the re-innovation from radical and incremental innovation constructs. Finally, discussion, limitations, and future research are presented.
Drug users have very high rates of lifetime exposure to traumatic events, leading to significant psychiatric complications. In spite of the high rate of lifetime exposure, very little is known about the rate of ongoing re-exposure to new traumatic events in drug users. We investigated the rate of traumatic event re-exposure in male and female injecting drug users using syringe exchange services in Baltimore (N = 197). Participants were assessed monthly for traumatic event re-exposure for 16 months. Averaged over the entire follow-up period, 27% of participants were re-exposed to a traumatic event each month and 72% were re-exposed over the 16-month study period. Women were over twice as likely to report any traumatic event re-exposure as men (adjusted odds ratio [AOR] = 2.48; 95% CI = 1.54–3.99), with the specific events of life-threatening illness, death of a loved one, and injury or illness of a loved one being more common in women than men. Traumatic event re-exposure occurs far more often than previously reported, with women injecting drug users at the highest risk. Reassessment of traumatic events may help to identify people most in need and encourage entry into treatment.
Potential conductivity enhancement due to formation of space charge layers in nanoionic composites was computed numerically for several structures of non-conducting nanoparticles in a bulk ionic conductor. Optimum loading fractions were extracted from simulation results and found to depend strongly on the thickness of the space charge layer relative to the size of the particles. This behavior agreed well with an approximate analytical expression derived herein. In certain cases, significant conductivity enhancement was predicted, even for nanoparticle loadings as small as 0.5 volume %. The model was also applied to a space charge layer depletion scenario, and found to be in good agreement with results from a recent experimental study.
The effect of VC as electrolyte additive on the electrochemical performance of Si film anode was studied in this paper. The charge/discharge test, scanning electron microscopy (SEM), electrochemical impedance spectrum (EIS), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to investigate the cycle performance and SEI layer of Si film anode. It was found that the SEI layer formed in VC-containing electrolyte possessed better properties. It was impermeable to electrolyte and its impedance kept almost invariant upon cycling. The presence of VC in electrolyte brought out the VC-reduced products and decreased the LiF content in SEI layer. The major components of SEI layer were similar in VC-free and VC-containing electrolytes, which contained lithium salt (e.g. ROCO2Li, Li2CO3, LiF), polycarbonate and silicon oxide. It was newly found that silicon oxide could be formed in SEI layer of Si film anode due to the reaction of lithiated silicon with permeated electrolyte in both VC-free and VC-containing electrolytes.
The power ramp rate capabilities of a 5 kW proton exchange membrane fuel cell (PEMFC) system are studied theoretically and experimentally for grid support service applications. The fuel supply is implemented with a fixed-geometry ejector and a discrete control solution without any anode-side pressure fluctuation suppression methods. We show that the stack power can be ramped up from 2.0 kW to 4.0 kW with adequate fuel supply and low anode pressure fluctuations within only 0.1 s. The air supply is implemented with a centrifugal blower. Air supply ramp rates are studied with a power increase executed within 1 and 0.2 s after the request, the time dictated by grid support service requirements in Finland and the UK. We show that a power ramp-up from 2.0 kW to 3.7 kW is achieved within 1 s with an initial air stoichiometry of 2.5 and within 0.2 s with an initial air stoichiometry of 7.0. We also show that the timing of the power ramp-up affects the achieved ancillary power capacity. This work demonstrates that hydrogen fueled and ejector-based PEMFC systems can provide a significant amount of power in less than 1 s and provide valuable ancillary power capacity for grid support services.
Urinary cadmium levels (U-Cd) were measured in 1770 adults (aged 18–65 years) as a representative sample of the Spanish workforce. The geometric mean (GM) was 0.28 μg/l with 95% CI: 0.27–0.32 μg/l (GM: 0.20 μg/g 95% CI: 0.18–022 μg/g creatinine). The 95% percentile was 1.03 μg/l. U-Cd increased with age, with women showing higher U-Cd than men (p<0.001; 0.24 μg/g vs 0.17 μg/g). A multivariate analysis confirmed that sex, age and smoking habit significantly influence U-Cd. Smoking habit increases U-Cd by ∼90% per 10 years of age, almost twice the increase observed for non-smoking. Female smokers had 85% higher U-Cd than non-smokers, whereas the corresponding value for male smokers and non-smokers was 45%. No regional differences were observed with respect to the national reference level. The Spanish population studied here exhibits similar urinary cadmium levels to its European counterparts in Germany and slightly lower levels than in France, the Czech Republic, Italy and the United Kingdom. This paper provides the first baseline information concerning cadmium exposure in the Spanish adult population on a national scale. As such, these findings will help us to establish reference levels, follow temporal trends and identify high-exposure groups, thereby enabling comparisons with other countries and contributing to the improvement of public health and environmental quality.
This work demonstrates ink-jet printed LiFePO4-based composite porous electrodes for microbattery application. As binder and dispersant, we found that aqueous inks with more suitable rheological properties with respect to ink-jet printing are prepared with the low molecular weight poly-acrylic-co-maleic acid copolymer, rather than with the carboxymethyl cellulose standard binder of the lithium-ion technology. The ink-jet printed thin and porous electrode shows very high rate charge/discharge behavior, both in LiPF6/ethylene carbonate-dimethyl carbonate (LP30) and lithium bis(trifluoromethane)sulfonylimide salt (Li-TFSI) in N-methyl-N-propylpyrrolidinium bis(trifluoromethane)suflonylimide ionic liquid (PYR13-TFSI) electrolytes, as well as good cyclability.
Despite improvements in frontline pediatric acute lymphoblastic leukemia (ALL) treatment, relapse remains a concern. Research in adult cancer patients suggests that patient-reported symptoms may predict survival, but the relationship between symptoms and relapse for pediatric ALL has received little attention.
This study reports differential expression of endoglucanase (EG) and β-glucosidase (βG) isoforms of Aspergillus terreus. Expression of multiple isoforms was observed, in presence of different carbon sources and culture conditions, by activity staining of poly acrylamide gel electrophoresis gels. Maximal expression of four EG isoforms was observed in presence of rice straw (28 U/g DW substrate) and corn cobs (1.147 U/ml) under solid substrate and shake flask culture, respectively. Furthermore, the sequential induction of EG isoforms was found to be associated with the presence of distinct metabolites (monosaccharides/oligosaccharides) i.e., xylose (X), G1, G3 and G4 as well as putative positional isomers (G1/G2, G2/G3) in the culture extracts sampled at different time intervals, indicating specific role of these metabolites in the sequential expression of multiple EGs. Addition of fructose and cellobiose to corn cobs containing medium during shake flask culture resulted in up-regulation of EG activity, whereas addition of mannitol, ethanol and glycerol selectively repressed the expression of three EG isoforms (Ia, Ic and Id). The observed regulation profile of βG isoforms was distinct when compared to EG isoforms, and addition of glucose, fructose, sucrose, cellobiose, mannitol and glycerol resulted in down-regulation of one or more of the four βG isoforms.
Objectives To examine neurocognitive and balance performance in recreational athletes, prior to and following a dual-task training intervention compared to single-task controls in order to assess the utility and feasibility of these interventions in the clinical setting. Design Controlled laboratory study. Methods Thirty healthy, physically active recreational athletes (dual-task group=15; single-task group=15; age: 20.3±1.9 years) completed neurocognitive and balance assessments before and after a four-week intervention. Sensory Organization Test composite score and ratio scores, Balance Error Scoring System total score, and nine CNS Vital Signs composite scores served as outcome measures. Mixed model analyses of variance were used to examine each measure. Results The single-task group showed greater improvement for complex attention (F 1,26 =5.48, p =.027) following the training period. Both groups improved their performance on the complex attention domain (F 1,26 =6.73, p =.015), the Balance Error Scoring System score (F 1,26 =42.34, p <.001), and the Sensory Organization Test vestibular ratio score (F 1,28 =6.55, p =.016) following the intervention. Conclusions Our findings suggest combining cognitive and balance tasks as performed does not provide additional benefit to performing these tasks independently among healthy individuals, but appear to be feasible in this setting. Future research should examine integration of single-task and dual-task exercises for concussed patients.
To impede the shuttle effect of lithium sulfur (LiS) batteries and improve the battery performance, carbon coated halloysite nanotubes (HNT@C) composites were synthesized and applied as sulfur host materials for LiS batteries. The unique one-dimensional tubular structure and abundant alumina-silicates components of HNT clay were synergistically utilized to physically confine and chemically adsorb lithium polysulfides, which could play important role to suppress the shuttle effect of polysulfides. Moreover, to solve the insulating issue of HNT, conducting carbon was deposited on the surface of HNT through polydopamine (PDA) coating and pyrolysis. The electrical conductivity of HNT@C host was thus significantly enhanced. As a result, the cycling stability and rate capability of the sulfur cathode were improved. In addition, the effect of carbon content on the properties of HNT@C composites and the electrochemical performance of the sulfur cathode were investigated. With carbon content of 3%, HNT@C hosted sulfur cathode delivered an initial discharge capacity of 922.7 mAh g−1 at current rate of 0.1C. Also, the capacity still retained about 82% after 500 cycles at 1C and the corresponding capacity decay is as low as 0.036% per cycle. This work can not only extend the application of HNT clay in energy storage but also provide a low-cost and promising HNT@C host material for advanced LiS batteries.
Carbonized cellulose nanofibrils (CNF) have been employed to improve the rate performance of activated carbon (AC) traditionally used in supercapacitors. Because of the large amount of surface functionalities, CNF form strongly interconnected composite with AC, which turns into a free-standing carbon nanofibers/AC film after carbonization. In the film, the carbon nanofibers are ‘welded’ on AC particles and integrate them into one piece of carbon. The interaction between AC and carbon nanofibers, originating from the strong AC-nanocellulose affinity, is much stronger than the traditional physically mixed AC/nanocarbon composite and also significantly reduces the contact resistance in the composite. Conductive atomic force microscope (C-AFM) analysis reveals that the network of carbonized CNF possesses markedly better electron transport efficiency than the AC particles. When tested as supercapacitor electrode at commercial level mass loading, the composite film exhibits 2 times slower capacitance fading at high current and 3 times higher maximum power density than the bare AC. In addition, using the nanocellulose, which is derived from renewable resources, increases the total electrode cost only by a small margin, thereby making the composite a competitive electrode material for electricity storage on a large scale.
The technical and economic feasibility study of an innovative wind–solar hybrid renewable energy generation system with rainwater collection feature for electrical energy generation is presented in this paper. The power generated would supply part of the energy requirements of the high-rise building where the system is installed. The system integrates and optimizes several green technologies; including urban wind turbine, solar cell module and rain water collector. The design was conceptualized based on the experiences acquired during the development and testing of a suitable wind turbine for Malaysian applications. It is compact and can be built on top of high-rise buildings in order to provide on-site renewable power to the building. It overcomes the inferior aspect on the low wind speed by channeling and increasing the speed of the high altitude free-stream wind through the power-augmentation-guide-vane (PAGV) before it enters the wind turbine at the center portion. The shape or appearance of the PAGV that surrounds the wind turbine can be blended into the building architecture without negative visual impact (becomes part of the building). The design improves the starting behavior of wind turbines. It is also safer to people around and reduces noise pollution. The techno-economic analysis is carried out by applying the life cycle cost (LCC) method. The LCC method takes into consideration the complete range of costs and makes cash flows time-equivalent. The evaluations show that for a system with the PAGV (30m diameter and 14m high) and an H-rotor vertical axis wind turbine (17m diameter and 9m high) mounted on the top of a 220m high building, the estimated annual energy savings is 195.2MWh/year.
The preparation of polyaniline/LiMn2O4 composite films by electropolymerization of aniline in the presence of LiMn2O4 is reported. Cyclic voltammetry shows three redox couples characteristic of the different oxidation and reduction states of produced polyaniline/LiMn2O4 composite. It was shown by electrochemical impedance spectroscopy that the presence of LiMn2O4 particles enhanced the conductivity of polyaniline films. The morphology and structure of the composites were characterized by FTIR, UV–vis, scanning electron microscopy and X-ray diffraction. The surface morphology of the PANI/LiMn2O4 composite films revealed a coarser structural morphology compared to pure PANI. To obtain additional information about the surface characteristics of the PANI films, their roughness was investigated. X-ray diffraction, EDS and FTIR analysis confirmed the incorporation of LiMn2O4 in the composite films.
The origin of the voltage imbalance in lithium-ion battery packs is often linked to different self-discharge rates. However, there is no information regarding the variance of self-discharge currents nor possible implications for cells connected in series. In this study, initial cell parameter distributions were analyzed via differential voltage analysis (DVA) and variations of calendar aging and reversible self-discharge rates of 24 commercial 18650 nickel-rich/SiC cells were statistically evaluated. After initial characterization, all cells were stored for 10 month at 70% state of charge (SOC) at 25 °C, whereby last two weeks of storage were used for reversible self-discharge determination via voltage decay. The results obtained in this work reveal that initial capacity and impedance variations do not depend on electrode balancing, nor storage capabilities of NMC, silicon or graphite. Furthermore, the evaluation of calendar aging showed, that all cells exhibited constant but different aging rates. However, whereas the relative variance of the impedance remained almost the same, the relative variance of the capacity almost doubled during the storage. The average self-discharge current amounted to 4.2 µA (3.5 Ah cell) with the relative variance of 10%. Model based assessment of different self-discharge currents revealed almost no influence on the voltage imbalance in battery packs.
FeS2 synthesized by hydrothermal method was used for sodium batteries for the first time. A large initial discharge capacity of 771 mAh g− 1 and a high reversible capacity of 521 mAh g− 1 were obtained. The reaction mechanism of electrochemical de-sodiation (charge) was investigated after the initial discharge. Our results have demonstrated that the composition and structure of electrode after the charging to 3.0 V could not recover its original state of FeS2 and a new phase of NaFeS2 was revealed. This should be responsible to the large irreversible capacity in the first cycle and the high discharge and charge plateaus after the initial cycle.
In the present study, a novel alloy composite has been synthesized by ball milling nonstoichiometric AB3-type La0.7Mg0.3Ni3.5 alloy with Ti0.17Zr0.08V0.35Cr0.1Ni0.3 alloy in order to improve the cyclic stability and other electrochemical properties of La0.7Mg0.3Ni3.5 alloy electrode. The phase structure, morphology and electrochemical performances of the composite have been investigated systematically. From X-ray diffraction (XRD) patterns, it can be found that the La0.7Mg0.3Ni3.5 and Ti0.17Zr0.08V0.35Cr0.1Ni0.3 alloys still retain their respective phase structures in the composite. Electrochemical studies show that the cyclic stability of the composite electrode is noticeably improved after 100 charge–discharge cycles in comparison with single La0.7Mg0.3Ni3.5 alloy electrode due to enhanced anti-corrosion performance in the alkaline electrolyte. The discharge capacity retention rate C 100/C max of composite electrode is 62.3%, which is much higher than that of the La0.7Mg0.3Ni3.5 alloy electrode, although the maximum discharge capacity of the former decreases moderately. Both electrochemical impedance spectra (EIS) and linear polarization (LP) studies indicate that the electrochemical kinetics of the composite electrode is also improved. The charge-transfer resistance (R ct), the polarization resistance (R p) and the exchange current density (I 0) of the composite electrode are 160.2mΩ, 129.5mΩ and 201.6mA/g, respectively, which are superior to those of the La0.7Mg0.3Ni3.5 alloy electrode.
A 3.0 Ah pouch-type lithium-ion cell with a high energy density (200 Wh kg−1) was studied to establish a cycle life model of the battery. The cells consisted of graphite and LiNi0.6Co0.2Mn0.2O2 electrodes, and they were cycled at 1 C over a 100 % depth of discharge at different temperatures (25, 35, and 45 °C). A semi-empirical cycle life model was developed using experimental data by adopting a simple time power law and Arrhenius kinetics. The cycle life model agreed well with the experimental data but featured a much higher power law factor (1.3) compared to the value of 0.5 associated with the general t1/2 rule based on the rate of solid electrolyte interphase (SEI) growth. The capacity fading mechanisms that operated within the cells were investigated using electrochemical, physical, and chemical diagnostic methods. These results revealed that the loss of active lithium ions via SEI formation as well as electrode degradation, especially cathode degradation, was responsible for the capacity fading in the cells.
Passive films on highly oriented pyrolytic graphite (HOPG) lithiated in siloxane-based electrolytes were investigated. Microanalysis and electrochemical impedance spectroscopy (EIS) were employed to understand the effects of siloxane molecular structure on film morphology and electrochemical properties. In the experiments, the numbers of silicon and ethylene oxide (EO) side chain groups on the siloxane molecule were varied, and a methylene group was also attached. The morphological and electrochemical properties of the passive film depended strongly on the siloxane molecule structure. The surface morphology of the passive film was similar to films formed in a carbonate electrolyte. However, after lithiation in a siloxane-based electrolyte having two silicones, one EO group, and a spacer group (named 2SM3), no gel-like film was formed. The silicon and oxygen concentrations on HOPG edge planes were greater than on the basal plane, and were reduced for the electrolyte with the 2SM3 spacer group. Conductivity decreased in the range of 1.7–2.0V for all electrolytes. The film resistance and the charge transfer resistance of 2SM3 were the most constant over 0–0.5V, the practical potential range for graphite electrodes in lithium secondary batteries. The results indicate that 2SM3 was well-suited for use as an electrolyte for lithium batteries.
Main challenging issues of sulfur as cathodes for lithium-sulfur (Li-S) batteries are poor conductivity of sulfur and dissolution of long-chain polysulfides (Li2Sx, x = 4 to 8) formed during the redox processes. Herein, we demonstrate an advantageous method for embedding sulfur into the voids of the expanded graphite (EG) layers, forming S-EG composite. A further modification of the surface of S-EG with 3-cyanpropyl-trichlorosilane (CPS) was attempted to functionalize EG with carboxyl groups to form the carboxyl-grafted sulfur/expanded graphite composites, S-(EG-COOH). Thus, in addition to improvement in conductivity of the composites via the conductive framework of EG, the negatively charged carboxyl groups on EG could generate an environment to confine the polysulfide anions formed during charge/discharge cycling. It is demonstrated that modification of the carboxy groups on EG leads to an alteration of the surface properties of the material, including hydrophilicity and electrolyte wettability. Importantly, notable improvement in the initial discharge capacity (1058 mA h g−1) and Coulombic efficiency (87.47%), and cyclability (capacity retention of 70% after 100 cycles) of sulfur indicates that carboxyl groups could relieve the dissolution of polysulfides and promote the charge transfer at the sulfur/electrolyte interface. High dispersion of sulfur in EG, good conductivity with the aid of EG, and fast Li diffusion are ascribed to be responsible for the superior electrochemical performance of S-(EG-COOH).