batterydata/paper-abstracts huggingface dataset:
Mg3Sb2 with a structure of A-type rare earth oxide (hexagonal) was synthesized by mechanical alloying (MA) and evaluated as a negative electrode material for rechargeable lithium batteries. Electrochemical tests demonstrated that the initial charge and discharge capacities of Mg3Sb2 were ca. 850 and 600mAhg−1, respectively. Ex situ XRD of the Mg3Sb2 electrodes showed that several lithium-containing compounds such as LiMgSb and Li3Sb were successively formed during the insertion of lithium into Mg3Sb2. As to LiMgSb synthesized by MA-method, the electrode performance was also investigated; it showed an excellent reversibility at the first cycle and a rechargeable capacity of ca. 200mAhg−1 after the fourth cycle. The cycle life performance of LiMgSb electrode was significantly enhanced in comparison with that of Mg3Sb2.
One of the applications of modern technology in telemedicine is video conferencing. An alternative to traveling to attend a conference or meeting, video conferencing is becoming increasingly popular among hospitals. By using this technology, doctors can help patients who are unable to physically visit hospitals. Video conferencing particularly benefits patients from rural areas, where good doctors are not always available. Telemedicine has proven to be a blessing to patients who have no access to the best treatment. A telemedicine system consists of customized hardware and software at two locations, namely, at the patient’s and the doctor’s end. In such cases, the video streams of the conferencing parties may contain highly sensitive information. Thus, real-time data security is one of the most important requirements when designing video conferencing systems. This study proposes a secure framework for video conferencing systems and a complete management solution for secure video conferencing groups. Java Media Framework Application Programming Interface classes are used to design and test the proposed secure framework. Real-time Transport Protocol over User Datagram Protocol is used to transmit the encrypted audio and video streams, and RSA and AES algorithms are used to provide the required security services. Results show that the encryption algorithm insignificantly increases the video conferencing computation time.
The post-fledging dependence period (PFDP) is one of the most critical stages in the life history of some avian species. Birds are particularly sensitive to mortality during this stage as they must learn essential skills, such as efficient locomotion, proficient food location and predator avoidance. Knowledge of the PFDP would provide valuable information for conservation management of endangered species, many of which experience high juvenile fatality rates. Post-fledging movements of five endangered Cape Vultures were recorded using Global Positioning System/Global System for Mobile communication telemetry in South Africa. Home range sizes, distances travelled from the nest and habitat use were determined over 11 months during the PFDP. Fledglings increased their home range progressively for the first 2 months, then exhibited a rapid increase in home range size associated with dispersal from their natal colony. Maximum net daily distance also rapidly increased following the dispersal period. A preference for protected areas and woody vegetation (representing cliff faces used for roosting) in terms of habitat use for foraging was evident. The knowledge of the movement and habitat use of juvenile Cape Vultures can aid in the effective conservation planning for the species. Conservation programs in identified areas can be focused on power line and wind-farm mitigation, areas of supplementary feeding and anti-poisoning events.
The efficacy of composite Li-ion battery cathodes made by mixing active materials that possessed either high-rate capability or high specific energy was examined. The cathode structures studied contained carbon-coated LiFePO4 and either Li[Li0.17Mn0.58Ni0.25]O2 or LiCoO2. These active materials were arranged using three different electrode geometries: fully intermixed, fully separated, or layered. Discharge rate studies, cycle-life evaluation, and electrochemical impedance spectroscopy studies were conducted using coin cell test structures containing Li-metal anodes. Results indicated that electrode configuration was correlated to rate capability and degree of polarization if there was a large differential between the rate capabilities of the two active material species.
In-situ determination of the battery thermal parameters is important to provide accurate inputs for battery thermal models. This paper develops a method to estimate the multiple thermal parameters of large-format laminated lithium-ion batteries both simultaneously and in-situ. The central area of one battery surface is heated with a circular planar heater, while the temperature responses on the opposite surface at multiple strategically-chosen locations are recorded with the attached thermocouples. This thermal system is modeled in COMSOL v4.2 using a two-dimensional axially-symmetric thermal conduction equation containing thermal parameters such as the thermal capacity, anisotropic thermal conductivities, and thermal interfacial conductance between the Al-plastic film package and the electrode core. Using optimization techniques, these thermal parameters are adjusted step by step till the difference between the simulated and the experimental temperature responses at the corresponding locations reaches a minimum. As one validation of the developed method, the estimated specific heat capacity agreed with the value measured with an accelerating rate calorimeter within 10%. The proposed method can be applied to simultaneously determine the thermal parameters of generic objects consisting of anisotropic internal materials and an outer packaging made of different material.
The aims of this study were to record behavioral problems in children with epilepsy (CWE), compare the prevalence with that reported among healthy children without epilepsy, and investigate the risk factors. A child behavioral questionnaire for parents comprising 15 items was administered to the main caregiver of 108 CWE and 108 controls matched for age in Kilifi, Kenya. CWE had a higher mean score for reported behavioral problems than controls (6.9 vs 4.9, t =4.7, P <0.001). CWE with active epilepsy also recorded more behavioral problems than those with inactive epilepsy (8.2 vs 6.2, t =−2.9, P =0.005). A significantly greater proportion of CWE (49% vs 26% of controls) were reported to have behavioral problems. Active epilepsy, cognitive impairment, and focal seizures were the most significant independent covariates of behavioral problems. Behavioral problems in African CWE are common and need to be taken into consideration in planning comprehensive clinical services in this region.
The potential for adverse respiratory effects following exposure to electronic (e-) cigarette liquid (e-liquid) flavorings remains largely unexplored. Given the multitude of flavor permutations on the market, identification of those flavor constituents that negatively impact the respiratory tract is a daunting task. In this study we examined the impact of common e-liquid flavoring chemicals on the airway epithelium, the cellular monolayer that provides the first line of defense against inhaled particulates, pathogens, and toxicants.
An amorphous SiO2/C composite anode material is synthesized via a sol–gel route combining with mechanical milling and post heat-treatment processes. The synthesized amorphous SiO2/C composite presents a nanostructure composing of amorphous SiO2 cluster and coating carbon layer. The amorphous SiO2/C electrode exhibits high reversible capacity (∼600 mA h g−1), stable cycling performance and excellent rate-capability. Mechanical milling causes SiO2/C composite amorphization which makes the active material possess good electrochemical activity. The coating carbon layer can not only increase electronic conductivity, but also accommodate part of the volume expansion occurred during discharge/charge process.
Previous research has shown that various user characteristics (e.g., cognitive abilities, personality traits, and learning abilities) can influence user experience during information visualization tasks. These findings have prompted researchers to investigate user-adaptive information visualizations that can help users by providing personalized support based on their specific needs. Whereas existing work has been mostly limited to tasks involving just visualizations, the aim of our research is to broaden this work to include scenarios where users process textual documents with embedded visualizations, i.e., Magazine Style Narrative Visualizations, or MSNVs for short. In this paper, we analyze eye tracking data collected from a user study with MSNVs to uncover processing behaviors that are negatively impacting user experience (i.e., time on task) for users with low abilities in these user characteristics. Our analysis leverages Linear Mixed-Effects Models to evaluate the relationships among user characteristics, gaze processing behaviors, and task performance. Our results identify several MSNV processing behaviors within the visualization that contribute to poor task performance for users with low reading proficiency. For instance, we identify that users with low reading proficiency transition significantly more often compared to their counterparts between relevant and non-relevant bars, and transition more often from bars to the labels. We present our findings as a step toward designing user-adaptive support mechanisms to alleviate these difficulties with MSNVs, and provide suggestions on how our results can be leveraged for creating a set of meaningful interventions for future evaluation (e.g., dynamically highlighting relevant bars and labels in the visualization to help users with low reading proficiency locate them more effectively).
Using well-cycled, thin composite graphite electrodes we analyze carefully the limitations of potentiostatic and galvanostatic intermittent titration techniques (PITT and GITT, respectively) for determination of the differential (incremental) intercalation capacitance, C dif, and the chemical diffusion coefficient, D, of Li ions in these ion-insertion electrodes (IIEs). We demonstrate the superiority of the GITT over PITT to determine these quantities as the former technique allows for a more accurate determination of C dif and hence D which closely approach to the spinodal domain related to the first-order phase transition during ion-insertion. We show that GITT is also more effective in eliminating the parasitic contributions of background currents to the total measured response. A pronounced difference in the initial, intrinsic kinetics of formation of a new phase in the bulk of the old one has been observed depending on the direction of titration (phases less saturated with Li are formed faster during deintercalation than the Li-rich phases in the course of intercalation).
Water-stable multi-layered lithium-doped carbon (Li x C6) negative electrode using poly(ethylene oxide) (PEO)-lithium bis(trifluoromethansulfonyl)imide (LiTFSI) polymer electrolyte containing N-methyl-N-propylpiperidinium bis(trifluoromethansulfonyl)imide (PP13TFSI) ionic liquid was developed. Electrochemical properties at 60 °C of the aqueous hybrid supercapacitor using activated carbon positive electrode and a multi-layered Li x C6 negative electrode (Li x C6 | PEO-LiTFSI | LTAP) without PP13TFSI exhibited performance similar to that using Li anode (Li | PEO-LiTFSI | LTAP). A drastic decrease in ESR was achieved by the addition of PP13TFSI to PEO-LiTFSI, allowing room temperature operation. The ESR of the multi-layered Li x C6 negative electrode with PEO-LiTFSI-PP13TFSI at 25 °C was 801 Ω cm2, which is 1/6 the value of the multi-layered Li negative electrode with PEO-LiTFSI (5014 Ω cm2). Charge/discharge test of the aqueous hybrid supercapacitor using multi-layered Li x C6 negative electrode with PEO-LiTFSI-PP13TFSI at 25 °C afforded specific capacity of 20.6 mAh (g-activated carbon)−1 with a working voltage of 2.7–3.7 V, and good long-term capability up to 3000 cycles. Furthermore, an aqueous hybrid supercapacitor consisting of a high capacitance RuO2 nanosheet positive electrode and multi-layered Li x C6 negative electrode with PEO-LiTFSI-PP13TFSI showed specific capacity of 196 mAh (g-RuO2)−1 and specific energy of 625 Wh (kg-RuO2)−1 in 2.0 M acetic acid-lithium acetate buffered solution at 25 °C.
Conducting supporters of purified single-walled carbon nanotubes (SWNTs) and graphene oxide (GO) were used to confine pomegranate-structured SnO2 nanospheres for forming SnO2-GO-SWNT composites. As anode material for lithium ion batteries (LIBs), this composite exhibits a stable and large reversible capacity together with an excellent rate capability. In addition, an analysis of the AC impedance spectroscopy has been used to confirm the enhanced mechanism for LIB performance. The improved electrochemical performance should be ascribed greatly to the reinforced synergistic effects between GO and SWNT networks, and their enhanced contribution of the conductivity. These results indicate that this composite has potential for utilization in high-rate and durable LIBs.
Understanding the roles of volatile organic compounds (VOCs) in insect–plant interactions is a key component towards the development of safe pest management strategies and sustainable agriculture. Kairomones in unripe berries of Coffea arabica mediate host recognition of second instar nymphs of Antestia bugs, Antestiopsis thunbergii Gmelin, and are good candidates for the pest management. In the current study, we investigated the VOCs that contribute to deterring the pest from ripe berries. Behavioral assays showed that headspace volatiles collected from ripe berries were significantly avoided by second instar nymphs. A mixture of the ripe berry volatiles and unripe berries (known preferred diet) was also significantly avoided when tested against blank or unripe berries, thereby confirming that VOCs from ripe berries had altered the host recognition process and had an odor masking effect. Coupled gas chromatography/mass spectrometric (GC/MS) analysis of the headspace volatiles revealed a blend of chemicals of which ten elicited electrophysiological activity in antennae of second instar nymphs. Five of these compounds including; 3-hydroxy-2-butanone, 2-heptanone, 2-isopropyl-3-methoxypyrazine [IPMP], 2-isobutyl-3-methoxypyrazine [IBMP] and (E)-β-caryophyllene were identified as unique to the volatiles of ripe berries and they elicited avoidance behavior in second instar nymphs when tested singly and in a blend. In addition, their blend also inhibited responses of nymphs to a synthetic attractant blend (kairomone). Our results suggest that the blend of the five compounds can be exploited as repellents in the management of A. thunbergii by pushing the pest away from coffee plantations or interfering with the pest–host recognition process through masking of suitable host odors.
To improve the electrochemical performance of Si–Zr thin films, we have investigated the effect of the replacement of Zr by Ag in the films. The Si–Zr–Ag thin films were prepared by co-sputtering from each pure target and then analyzed for structure, composition and electrochemical performance. The Ag-containing films show a plateau like region in the charge–discharge profiles, while the steep slopes are seen in the Si–Zr film. The Si–Zr–Ag films also show high capacity and good rate capability compared to the Si–Zr film, maintaining a comparable capacity retention with cycles. The improved electrochemical performance of Si–Zr–Ag films is attributed to the highly dispersed Si phase in the film, which was induced by formation of Zr–Ag bonds, and the lower impedance exerted by Ag alloying.
A high-capacity type of all solid-state battery was developed using sulfur electrode and the thio-LISICON electrolyte. New nano-composite of sulfur and acetylene black (AB) with an average particle size of 1–10nm was fabricated by gas-phase mixing and showed a reversible capacity of 900mAhg−1 at a current density of 0.013mAcm−2.
The Bhas 42 cell transformation assay is a short-term system using a clone of the BALB/c 3T3 cells transfected with an oncogenic murine ras gene (v-Ha-ras). The assay has previously been reported to be capable of detecting the tumor-initiating and tumor-promoting activities of chemical carcinogens according to the different protocols, an initiation assay and a promotion assay, respectively. We applied this short-term assay to 98 chemicals to characterize the assay and evaluate its performance for the detection of chemical carcinogenicity. When the assay results were compared with the existing genotoxicity data, the Bhas 42 cell transformation assay could detect a considerable number of Ames-negative and Ames-discordant carcinogens: and the promotion assay detected most of those Ames-negative and -discordant carcinogens. This fact suggested that the Bhas 42 cells behaved as initiated cells in the transformation assay. The performance indices were calculated from the assay results of 52 carcinogens and 37 non-carcinogens. The concordance was 78%, sensitivity 73%, specificity 84%, positive predictivity 86%, negative predictivity 69%, false negative 27% and false positive 16%. Of these values, the concordance, specificity, negative predictivity and false positive were superior and the other performance indices were equivalent to those of conventional genotoxicity tests. From overall results, we concluded that the accuracy of prediction of chemical carcinogenicity would be improved by introducing the Bhas 42 cell transformation assay into the battery of in vitro assays.
A new bismuth hexacyanoferrate (BiHCF) modified carbon ceramic electrodes (CCEs) fabricated by electrodeposition was reported for the first time. The electrochemical behavior of the resulting modified electrodes was investigated by cyclic voltammetry. The BiHCF-modified CCEs presented good electrocatalytic activity toward the oxidation of hydrazine at a reduced overpotential and was used for amperometric detection of hydrazine. The diffusion coefficient (D) of hydrazine in solution and the catalytic rate constant (k cat) were also calculated by chronoamperometric experiments. In addition, the present modified electrode exhibited the advantages of simple preparation, fast response, good stability and reproducibility for hydrazine determination.
Disordered eating is elevated in bariatric surgery patients and is a risk factor for poor surgical outcomes. A systematic review evaluated the definitions and measurement methods used to identify and assess disordered eating in patients following bariatric surgery. One hundred articles were identified featuring 35 questionnaires and 23 interviews. There were numerous variations to diagnostic criteria and amendments to measures to account for the post-surgical eating context. Only 20 % of questionnaires and 4 % of interviews had reported psychometric evaluation in post-surgery samples. Results highlight the need for a consistent definition of disordered eating and for current assessment measures to be (a) adapted to account for the altered gastrointestinal system in patients following surgery and (b) psychometrically evaluated in bariatric surgery patients.
Background Minimal work has used psychometrically robust measures in a systematic fashion to identify and monitor children at risk for cognitive and behavioral comorbidities in current epilepsy care. We piloted a computerized cognitive battery and behavioral questionnaire for children with newly diagnosed epilepsy to determine clinical feasibility and acceptability to parents and patients. Methods We recruited medication-naïve children (ages 8-17 years) with recent-onset seizures and typical developmental history from an outpatient child neurology clinic. Children completed the CNS Vital Signs computerized battery, whereas parents completed the Strengths and Difficulties Questionnaire. Post-test interviews with parents and patients were completed regarding the acceptability of the assessment procedures. Results Forty-four families were eligible, and 39 agreed to participate (89%). All assessments were completed in less than 45 minutes. Parents rated testing in clinic as convenient and important, expressing strong interest in the cognitive and behavioral impact of epilepsy and medication. Children also rated the testing procedure as acceptable and agreed that they would recommend it to peers. Conclusions Our brief battery was tolerated and well received by children and their parents. Computerized testing of children along with a parent questionnaire is a psychometrically viable approach that is acceptable to families. Our protocol is time efficient for clinical use with the potential to detect early cognitive and behavioral difficulties related to epilepsy. Ongoing longitudinal study will provide further information regarding the success of our screening methods in monitoring for disease- or treatment-related changes.
LiFePO4 doped by bivalent cation in Fe-sites show improved rate performance and cyclic stability. Under 10 C rate at room temperature, the capacities of LiFe0.9M0.1PO4 (M=Ni, Co, Mg) maintain at 81.7, 90.4 and 88.7mAh/g, respectively, in comparison with 53.7mAh/g for undoped LiFePO4 and 54.8mAh/g for carbon-coated LiFePO4 (LiFePO4/C). The capacity retention is 95% after 100 cycles for doped samples while this value is only 70% for LiFePO4 and LiFePO4/C. Such a significant improvement in electrochemical performance should be partially related to the enhanced electronic conductivities (from 2.2×10−9 to <2.5×10−7 Scm−1) and probably the mobility of Li+ ions in the doped samples.
Ketjen Black EC 300J with an extremely high mesoporous area and electrical conductivity, was used as an additive in the cathode catalyst layer to improve the DMFC (direct methanol fuel cell) performance. Ketjen Black EC 300J and the catalyst ink were characterized by TEM. The cathode catalyst layers were characterized by SEM, in situ cyclic voltammetry and I–V curve measurements. Ketjen Black EC 300J additive increased the dispersion extent of Pt black particles and improved the Pt utilization. In addition, the pore size and porosity was increased when Ketjen Black EC 300J was added into the cathode catalyst layer. The cathode catalyst layer with Ketjen Black EC 300J additive showed a greater single cell performance than the cathode catalyst layer without any additive, especially in the air-breathing mode. These results suggested that the performance improvement was attributed to the increased Pt utilization, oxygen diffusion and water removal capability when Ketjen Black EC 300J was added into the cathode catalyst layer.
Here we report, an efficient, cheap and simple strategy to obtain electrocatalysts for methanol electro-oxidation reactions. Nickel encapsulated 3-dimensional hierarchical porous graphene and cobalt encapsulated 3-dimensional hierarchical porous graphene composites are obtained by ion exchange/activation method. The well dispersion of nickel and cobalt nanoparticles are observed inside the nickel encapsulated 3-dimensional hierarchical porous graphene and cobalt encapsulated 3-dimensional hierarchical porous graphene composites respectively. Graphene layer over the metals nanoparticles may suppress metal corrosion and enhance their catalytic performance for methanol electro-oxidation reactions. Nickel encapsulated 3-dimensional hierarchical porous graphene exhibits low onset potential of 0.32V (vs Ag/AgCl) and the highest current density of 147.108mAcm−2 at a low overpotential of 0.728V (vs Ag/AgCl). Similarly, cobalt encapsulated 3-dimensional hierarchical porous graphene shows lower onset potential of 0.45V (vs Ag/AgCl) and high current density of 10mAcm−2 at low overpotential of 0.62V (vs Ag/AgCl). More importantly, better methanol electro-oxidation reaction was recorded in 1M KOH and 0.75M methanol solution with a scan rate of 50mVs−1. The nickel-containing electrocatalyst show better performance than cobalt based electrocatalyst under same conditions.