batterydata/paper-abstracts huggingface dataset:
SnO2@C nanocomposites are easily synthesized in a large scale by the hydrolysis of Sn4+ ions in a polyacrylic acid (PAA) hydrogel system, followed by the decomposition of Sn(OH)4 and carbonization of PAA by heat treatment in one-system. The SnO2@C nanocomposites contain uniform ultrafine SnO2 nanoparticles (≈4.3 nm) homogenously embedded in a three-dimensional carbon matrix. This unique structure efficiently suppresses the particle pulverization and aggregation of SnO2, thus maintaining the electrode integrity during long-term lithiation/delithiation process. The discharge capacity of SnO2@C nanocomposites is maintained at ∼597.3 mAh g−1 after 220 cycles. This scalable approach has great potential in the applications of high-capacity anodes in Li-ion batteries.
The most critical defect in electrochemical cells is connected with internal short circuit (ISCr) occurrence. It may cause a thermal runaway which can even lead to explosion of the cell. Although the causes are well know (manufacturing defect, overcharging, overdischarging), the timely detection of ISCr is very difficult. This work focuses on the detection of an internal short circuit while the cell is being charged using the time dependence of the capacity evaluation.
Current density distributions and local state of charge (SoC) differences that are caused by temperature gradients inside actively cooled Li-ion battery cells are discussed and quantified. As an example, a cylindrical Li-ion cell with LiFePO4 as cathode material (LiFePO4-cell) is analyzed in detail both experimentally and by means of spatial electro-thermal co-simulations. The reason for current density inhomogeneities is found to be the local electrochemical impedance varying with temperature in different regions of the jelly roll. For the investigated cell, high power cycling and the resulting temperature gradient additionally cause SoC-gradients inside the jelly roll. The local SoCs inside one cell diverge firstly because of asymmetric current density distributions during charge and discharge inside the cell and secondly because of the temperature dependence of the local open circuit potential. Even after long relaxation periods, the SoC distribution in cycled LiFePO4-cells remains inhomogeneous across the jelly roll as a result of hysteresis in the open circuit voltage. The occurring thermal electrical inhomogeneities are expected to influence local aging differences and thus, global cell aging. Additionally the occurrence of inhomogeneous current flow and SoC-development inside non-uniformly cooled battery packs of parallel connected LiFePO4-cells is measured and discussed.
Hybrid manganese dioxide/graphitic petal structures grown on carbon nanotube substrates are shown to achieve high specific capacitance, energy density, power density, and long cycle life for flexible supercapacitor applications. Vertical nanoscale graphitic petals were prepared by microwave plasma chemical vapor deposition on commercial carbon nanotube substrates and subsequently coated with a thin layer of MnO2. The graphitic petal/carbon nanotube architecture without any binder provides an efficient scaffold for maximizing the electrochemical performance of MnO2. A specific capacitance (based on the mass of MnO2) of 580 F g−1 is obtained at a scan rate of 2 mV s−1 in 1 M Na2SO4 aqueous electrolyte. The energy density and power density at 50 A g−1 are 28 Wh kg−1 and 25 kW kg−1, respectively. In addition, the composite electrode shows excellent long-term cyclic stability (less than 10% decrease in specific capacitance after 1000 cycles) while maintaining a small internal resistance. Parallel density functional studies were performed to investigate the stability and electronic structure of the MnO2/graphene interface. Taken together, the work indicates the MnO2/graphitic petal/carbon nanotube composite is a promising electrode material for high-performance supercapacitors.
In this work the limitations in using the core–shell models to simulate the operation of lithium iron phosphate electrodes are discussed and analyzed. The complications arising from the stepwise nature of the core–shell model and erroneous predictions of this model for special conditions are detailed.
The tissue origin of low back pain (LBP) or referred lower extremity symptoms (LES) may be identified in about 70% of cases using advanced imaging, discography and facet or sacroiliac joint blocks. These techniques are invasive and availability varies. A clinical examination is non-invasive and widely available but its validity is questioned. Diagnostic studies usually examine single tests in relation to single reference standards, yet in clinical practice, clinicians use multiple tests and select from a range of possible diagnoses. There is a need for studies that evaluate the diagnostic performance of clinical diagnoses against available reference standards.
This study assessed the prevalence and type of associated neuropsychiatric problems in children and adults with 22q11 deletion syndrome. One-hundred consecutively referred individuals with 22q11 deletion syndrome were given in-depth neuropsychiatric assessments and questionnaires screens. Autism spectrum disorders (ASDs) and/or attention deficit/hyperactivity disorder (ADHD) were diagnosed in 44 cases. ASD was diagnosed in 23 cases of whom only 5 had autistic disorder. ADHD was diagnosed in 30 individuals. In nine of these cases with ASD or ADHD there was a combination of these diagnoses. Mental retardation (MR) with or without ASD/ADHD was diagnosed in 51 individuals. ASD, ADHD, and/or MR were present in 67 cases. Females had higher IQ than males. The results of this study showed that the vast majority of all individuals with 22q11 deletion syndrome have behavior and/or learning problems and more than 40% meet criteria for either ASD, ADHD or both. Neuropsychiatric and neuropsychological evaluations are indicated as parts of the routine clinical assessment of individuals with 22q11 deletion syndrome.
Widespread interest in the development of environmentally safe management actions has prompted research into the use of sensory cues to manipulate the movements of invasive species. The push–pull approach, for which attractive and repellent semiochemicals operate synergistically to guide individuals toward traps, has proven successful in insect pest management applications. We examined the effectiveness of a natural repellent (an alarm cue) and a natural attractant (a partial sex pheromone) in push-only (repel), pull-only (attract), and push–pull configurations, to guide invasive sea lamprey (Petromyzon marinus) toward and into a target trap during spawning migration into rivers. Using PIT telemetry to monitor sea lamprey movement within the river, we found that the alarm cue was capable of strongly altering sea lamprey distribution, “pushing” them toward target areas and generating rates of encounter with trap entrances sufficient to achieve trapping-for-control targets. Encounter rate with trap entrances was not improved, but performed more consistently, with the addition of the attractant in the push–pull configuration. There was evidence this could stem from a transition in internal state of motivation, from migration to reproduction. Use of the attractant alone was ineffective. No odor combination improved trap captures. We conclude that push–pull strategies will prove effective in guiding sea lamprey movements and recommend two improvements for subsequent testing in management scenarios: (1) use of a superior attractant (e.g. a sea lamprey migratory cue derived from conspecific larvae), and (2) its subsequent application to a capture methodology based on the entrainment of individuals near trap entrances.
The aim of the present longitudinal study is to understand the longitudinal relation between depressive symptoms and daily hassles (i.e., general and acculturation hassles) in a high-risk population of unaccompanied refugees. We investigated the validity of three stress-mental health models: the stress exposure model, the stress generation model, and the reciprocal model. Data were collected from 918 unaccompanied refugees in Norway in three waves. Of the initial sample, the majority (82.1%) were male (Mage = 19.01 years, SD = 2.54 years). The data were analyzed with auto-regressive cross-lagged modeling and latent growth curve modeling. The results supported the stress exposure model for the relation between depressive symptoms and acculturation hassles, indicating that acculturation hassles predicted the subsequent levels of depressive symptoms rather than vice versa. On the other hand, the reciprocal model was supported for the relation between depressive symptoms and general hassles indicating a bidirectional, mutual relation. Unconditional latent growth models further showed that depression level remained unchanged over time, while levels of acculturation and general hassles decreased. The implications for clinical practice and immigration policy are discussed.
Hierarchical nanostructures containing three-dimensional (3D) spheres are promising materials due to their unique physicochemical characteristics. In this study, a 3D hierarchical walnut kernel shape conducting polymer binder (CPB) is facilely fabricated via emulsion polymerization method. CPB exert beneficial properties as a good adhesive for LiFePO4 cathodes, and an efficient conducting material for Li+ inside the cathode, providing a facile pathway for ion movement. Unlike one-dimensional (1D) binders, the unique 3D hierarchical structure exhibits multi-dimensional bonding interactions with active materials and therefore offers robust contacts between both components. When the active material loses its original contact with the binder during potential cycling, CPB can successfully recover its 3D hierarchical network, thus creating a self-healing effect. CPB-based LiFePO4 electrode shows remarkedly improved electrochemical performances compared to other well-known binders, such as poly(vinylidene fluoride).
Carboxymethyl cellulose (CMC), a green and low-cost binder, is used to make lithium-ion battery composite electrodes containing the high voltage cathode material Li2MnO3–LiMO2. This combination of materials results in a homogeneous electrode, which is proved by electron microscopy. The results of the electrochemical investigation indicate that CMC operates well at very high voltages (4.8V). Compared to the PVDF binder, the CMC-based electrode shows an improved cycling stability as well as a very promising rate capability.
Gross DP, Battié MC, Asante AK. The Patient-Specific Functional Scale: validity in workers' compensation claimants. Objective To examine the construct and predictive validity of the Patient-Specific Functional Scale (PSFS) in workers' compensation claimants. Design Prospective cohort study with 1-year follow-up. Setting A workers' compensation rehabilitation facility. Participants Subjects included 294 claimants with a variety of musculoskeletal disorders. The sample was predominantly male (70%), with a mean age of 44 years. Subjects completed a battery of measures at baseline including the PSFS, the Pain Disability Index (PDI), and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Interventions Not applicable. Main Outcome Measures Outcomes for determining predictive validity included administrative indicators of timely return to work and recovery during the 1-year follow-up. Analysis included Pearson correlation and multivariable Cox and logistic regression. Results At baseline, the PSFS correlated moderately (r range, 0.3−0.5) with other indicators of functional limitation (PDI, SF-36 role−physical subscale) but negligibly with the SF-36 mental health and role−emotional subscales. The PSFS was associated with timely recovery (adjusted hazard ratio, 1.16; 95% confidence interval, 1.07–1.27) with increasing functional limitation related to delayed recovery. Conclusions Results provide construct and predictive validity evidence for the PSFS as an indicator of functional limitation in workers' compensation claimants.
The main aim of the paper is to propose hierarchical modeling as a suitable methodology to perform control-oriented analysis of planar solid oxide fuel cells (P-SOFC). At the high level of the hierarchical structure is a one-dimensional, steady-state model, developed referring to the state of the art in the field of SOFC modeling. Validation is conducted via comparison with both experimental tests and standard references derived from literature. In the proposed modeling structure, at the low-level is the control-oriented model, developed on the basis of the information provided by the higher level model and assuming the SOFC behaves as a first-order system. The thermal dynamics is considered dominant with respect to both electrochemistry and mass transfer dynamics. Therefore, SOFC transients are modeled applying the conservation of energy principle (heat balance) to a lumped control volume, including interconnect, electrolyte and electrodes. Due to the lack of suitable experimental data, model accuracy is verified by comparing the simulated fuel cell response to similar data available in literature, generated by means of a physical comprehensive model. Extensive simulations of the fuel cell dynamic behavior are performed to analyze in detail the SOFC dynamics with respect to load changes. Furthermore, an application example is given, dealing with the development of a PI controller to limit temperature rise across the cell within a safe range.
Objective The aim of this study was to compare cardiovascular autonomic function tests (AFT) and vibration perception threshold (VPT) of patients with type 2 diabetes mellitus (T2DM) with controls. Research Design/Methods The study was conducted on 60 diabetic patients comparing with 30 controls. The cardiovascular AFT and VPT were assessed in both groups. Results Among cardiovascular AFT, E:I ratio [1.24 (1.2–1.32) vs 1.3 (1.24–1.4), p =0.001], and Valsalva ratio [1.28 (1.22–1.4) vs 1.6 (1.5–1.73), p =0.001], the indicators of parasympathetic reactivity were reduced in T2DM. Rise in DBP during handgrip, an indicator of sympathetic reactivity was lower in T2DM [12 (10–14) vs 16 (14–18) mmHg, p =0.001] whereas, fall in SBP during head up tilt [4 (4–8) vs 5 (4–8) mmHg] was comparable. VPT (somatic sensation) was comparable between T2DM and control. Conclusion Autonomic involvement is more marked than somatic, and parasympathetic involvement is more marked than the sympathetic, possibly reflecting severity and chronological pattern of their involvement.
Systematic creatinine adjustment of urinary concentrations of biomarkers has been a challenge over the past years because the assumption of a constant creatinine excretion rate appears erroneous and the issue of overadjustment has recently emerged. This study aimed at determining whether systematic creatinine adjustment is to be recommended for urinary concentrations of trace elements (TEs) in environmental settings. Paired 24-h collection and random spot urine samples (spotU) were obtained from 39 volunteers not occupationally exposed to TEs. Four models to express TEs concentration in spotU were tested to predict the 24-h excretion rate of these TEs (TEμg/24h) considered as the gold standard reference: absolute concentration (TEμg/l); ratio to creatinine (TEμg/gcr); TEμg/gcr adjusted to creatinine (TEμg/gcr-adj); and concentration adjusted to specific gravity (TEμg/l-SG). As, Ba, Cd, Co, Cr, Cu, Hg, Li, Mo, Ni, Pb, Sn, Sb, Se, Te, V and Zn were analyzed by inductively coupled argon plasma mass spectrometry. There was no single pattern of relationship between urinary TEs concentrations in spotU and TEμg/24h. TEμg/l predicted TEμg/24h with an explained variance ranging from 0 to 60%. Creatinine adjustment improved the explained variance by an additional 5 to ~60% for many TEs, but with a risk of overadjustment for the most of them. This issue could be addressed by adjusting TE concentrations on the basis of the regression coefficient of the relationship between TEμg/gcr and creatinine concentration. SG adjustment was as suitable as creatinine adjustment to predict TEμg/24h with no SG-overadjustment (except V). Regarding Cd, Cr, Cu, Ni and Te, none of the models were found to reflect TEμg/24h. In the context of environmental exposure, systematic creatinine adjustment is not recommended for urinary concentrations of TEs. SG adjustment appears to be a more reliable alternative. For some TEs, however, neither methods appear suitable.
Porous hierarchical and nitrogen-doped carbon coated ZnFe2O4 (ZnFe2O4@NC) was obtained by combustion method and unique carbon coating technology. Gum Arabic was firstly introduced in the carbon coating process as an additive, which played an important role to control the uniformity of carbon coating layer. The nitrogen-doped carbon layer was obtained through the pyrolysis of glycine. The elemental composition and content of the nitrogen-doped carbon in composites were characterized by X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and thermal gravimetric analysis (TGA). The galvanostatic charge/discharge cycling was used to test the electrochemical performance of ZnFe2O4@NC and pure ZnFe2O4. The sub-micro size ZnFe2O4@NC with unique porous structure showed an excellent electrochemical performance as an anode material, which was higher than that of pure ZnFe2O4. ZnFe2O4@NC could maintain the specific discharge capacity of 1477mAhg−1 at 0.1Ag−1 after 100 cycles and 705mAhg−1 at 1Ag−1 after 1000 cycles, respectively.
This study examines the electrochemical reactions occurring at graphite negative electrodes of lithium-ion batteries in a propylene carbonate (PC) electrolyte that contains different concentrations of lithium salts such as, LiClO4, LiPF6 or LiN(SO2C2F5)2. The electrode reactions are significantly affected by the electrolyte concentration. In concentrated solutions, lithium ions are reversibly intercalated within the graphite to form stage 1 lithium–graphite intercalation compounds (Li–GICs), regardless of the lithium salt used. On the other hand, electrolyte decomposition and exfoliation of the graphene layers occur continuously in the low-concentration range. In situ analysis with atomic force microscopy reveals that a thin film (thickness of ∼8nm) forms on the graphite surface in a concentrated solution, e.g., 3.27molkg−1 LiN(SO2C2F5)2/PC, after the first potential cycle between 2.9 and 0V versus Li+/Li. There is no evidence of the co-intercalation of solvent molecules in the concentrated solution.
Hybridizing battery and capacitor materials to construct hybrid supercapacitors has been regarded as a promising avenue to achieve high energy densities while maintaining high power-output. Herein, we report a lithium ion hybrid supercapacitor with high power and energy densities as well as excellent cycling stability, which is constructed of an N-rich carbon based anode and commercial activated carbon cathode. The N-rich carbon spheres (NRCS) possess high surface area, uniform mesoporous structure, and high level of N-doping, synergically enabling excellent lithium storage properties in terms of high capacity, fast rate capability and long cycling lifespan even at high current rate (638mAhg−1 after 2000 cycles at 2Ag−1). Benefitting from above merits of NRCS, the assembled hybrid supercapacitor delivers a high energy density of 105.8Whkg−1 at 650Wkg−1. Even when power density increases to 10800Wkg−1, 40.4Whkg−1 can be maintained. Long cycling life (capacity retention of 75% after 8000 cycles) is also demonstrated. This work offers a new platform for high-energy hybrid supercapacitors by assembling high-performance porous carbon based anode.
This article has been retracted at the request of the Editor-in-Chief and corresponding author. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). Reason: This article went safely through the peer-review process, but it was unfortunately vitiated at the moment of submission by the infringement of three ethical rules, of which the Editor-in-Chief became aware of a complaint lodged by the interested persons only after publication: (1) Missing agreement from other colleagues including supervisor, (2) missing internal check process of the Institute of Physics, and (3) inappropriate indication of the affiliations since most of the results were obtained in the Institute of Physics rather than in the Harbin Institute of Technology. On the other hand, the colleagues mentioned in point (1) do not agree to be added as co-authors in this article. The corresponding author Dr Jie Shu admits his misconduct and apologizes deeply. He sincerely regrets his improper behaviour.
TiO2 with the ramsdelitte-type (R) structure has a potential use as negative electrode for Li-ion battery due to its high theoretical capacity (335mAhg−1), a weak irreversible loss during the first cycle and a low polarization. However due to its metastability, TiO2 (R) has been rarely reported. In the present work we report on the carbothermal synthesis of some Li x TiO2 delithiated R phases (0< x <0.57), from TiO2 to Li2Ti3O7, with ramsdellite-type structure. The variation of the synthesis parameters such as wt% of carbonaceous additive and reductive gas flow has conducted to the formation of poor lithiated Li x TiO2 phases and Li2TiO3 as additional phase. Their ratio was found to be strongly dependent on the amount of carbonaceous precursor. These new Li x TiO2(R)/Li2TiO3 composites (with (0≤ x ≤0.57)) were characterized by chemical analysis, X-ray diffraction and thermogravimetric analysis and finally by electrochemical tests. High capacities as well as good cycleability have been reached.
Objective Workers exposed to vibrating tools may develop hand-arm vibration syndrome (HAVS). We assessed the somatosensory phenotype using quantitative sensory testing (QST) in comparison to electrophysiology to characterize (1) the most sensitive QST parameter for detecting sensory loss, (2) the correlation of QST and electrophysiology, and (3) the frequency of a carpal tunnel syndrome (CTS) in HAVS. Methods QST, cold provocation tests, fine motor skills, and median nerve neurography were used. QST included thermal and mechanical detection and pain thresholds. Results Thirty-two patients were examined (54±11years, 91% men) at the more affected hand compared to 16 matched controls. Vibration detection threshold was the most sensitive parameter to detect sensory loss that was more pronounced in the sensitivity range of Pacinian (150Hz, x12) than Meissner’s corpuscles (20Hz, x3). QST (84% abnormal) was more sensitive to detect neural dysfunction than conventional electrophysiology (37% abnormal). Motor (34%) and sensory neurography (25%) were abnormal in HAVS. CTS frequency was not increased (9.4%). Conclusion Findings are consistent with a mechanically-induced, distally pronounced motor and sensory neuropathy independent of CTS. Significance HAVS involves a neuropathy predominantly affecting large fibers with a sensory damage related to resonance frequencies of vibrating tools.
H2Ti12O25 nanorods are successfully prepared via hydrothermal reaction following heat treatment at 260°C. The D 50 value and surface area of H2Ti12O25 nanorods are 0.186μm and 35.0637m2 g−1, respectively. For comparison, Bulk-H2Ti12O25 are also prepared by milling assisted soft-chemical method, and the D 50 value and surface area of Bulk-H2Ti12O25 are 0.274μm and 4.3213m2 g−1, respectively. The electrochemical tests show H2Ti12O25 nanorods deliver higher reversible capacity of 191.3mAhg−1 (1C) after 100 cycles, 150.5mAhg−1 (10C) and 132.1mAhg−1 (20C) after 200 cycles, while for Bulk-H2Ti12O25, its reversible capacity is only 171.2mAhg−1 (1C) after 100 cycles, 113.7mAhg−1 (10C) and 83.3mAhg−1 (20C) after 200 cycles. Meanwhile, H2Ti12O25 nanorods exhibit better rate performance at all rates compared with Bulk-H2Ti12O25. The higher discharge/charge capacity and cycling stability at high discharge/charge rate powerfully suggests that H2Ti12O25 nanorods hold great potential as high rate anode material for electric vehicles and hybrid electric vehicles.