batterydata/paper-abstracts huggingface dataset:
This paper examines educational and behavioral characteristics and special education service use for a subsample of 2477 children enrolled in the National Survey of Child and Adolescent Wellbeing (NSCAW), the first national, longitudinal study of youth following investigation for alleged maltreatment through the child welfare system (CW). Almost one-fifth of children were characterized as severe on educational indices and 47% as severe on behavioral indices. Nineteen percent were currently receiving special education services, 17% had previously received these services, and the remainder had never received them. Over half (51%) of children characterized as severe on educational or behavioral indices were not receiving special education services. Caregivers indicated that youth were being served primarily under categories of Emotional Disturbance (35%) and Speech and Language Impairment (30%). Further exploration of the role of schools, particularly school psychologists, in providing supports for children involved with CW is discussed.
Cells were life-cycled cells using profiles with a 3, 6, or 9% change in state of charge (ΔSOC) at 40, 50, 60, and 70°C. From the voltage response of the cells to the life-cycle profile at each temperature, we separated the overall impedance rise into two simpler terms, R o (ohmic) and R p (polarization), using an equivalent circuit model. The R o data tend to follow the expected trends (40>50>60>70°C). Although the R p data trends show that R p can either decrease or increase asymptotically with time, the overall temperature-dependent behavior is similar to that of R o. We illustrate the types of processes that can occur in one lithium-ion cell chemistry. Based on the initial rates, the processes are complex. The R o term dominates the observable cell impedance, but R p adds a non-trivial contribution.
This paper presents the energy performance evaluation of a marketable net-zero-energy house (NZEH): Solark I at Solar Decathlon China 2013. The assessment methodologies are based on EnergyPlus simulations and measured data. The paper also discusses the reasons for the differences between the results of the simulations and the measurements, analyzes the investment cost, summarizes the lessons learned from the competition, and presents the potential for replicability and transposition from Solark I to implementation in a practical NZEH. The conclusions are that Solark I's investment cost is reasonable, its systems for building-integrated photovoltaics, hot water and heating, and ventilation and air conditioning demonstrated excellent performance based on the results of the energy performance evaluations using EnergyPlus simulations and measured data. Thus, Solark I is a marketable NZEH.
Extensive efforts have been undertaken to develop and optimize new materials for lithium-ion batteries to address power and energy demands of mobile electronics and electric vehicles. However, the introduction of large-format lithium-ion batteries is hampered by high cost, safety concerns, and deficiencies in energy density and calendar life. Advanced materials-processing techniques can contribute solutions to such issues. From that perspective, this work summarizes the materials-processing techniques used to fabricate the cathodes, anodes, and separators used in lithium-ion batteries.
As efficient electrocatalysts for hydrogen evolution reaction (HER), novel MoS2/carbon-doped molybdenum dioxide (MoS2/C-doped MoO2) nanobelts have been successfully synthesized via sulfuration treatment of the C-doped MoO2 nanobelts. Mo3O10(C6H8N)2•2H2O with one-dimensional structure, high conductivity and large surface area has been used as template to produce C-doped MoO2 nanobelts. After the sulfuration treatment, MoS2 nanosheets vertically grow along the axis direction of conducting C-doped MoO2 nanobelts leading to less stacking of MoS2 nanosheets and improved conductivity. The as-prepared MoS2/C-doped MoO2 nanobelts have been examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). The growth mechanism of MoS2/C-doped MoO2 nanobelts has been discussed. The MoS2/C-doped MoO2 nanobelts exhibit excellent HER activity with the low onset overpotential of 120mV (vs. RHE) and a small Tafel slope of 55mVdec−1. The sulfuration treatment of C-doped MoO2 nanobelts could improve the conductivity and decrease the stacking of MoS2 nanosheets, which could provide more exposed active sites and faster rate of electron transfer, thus their electrocatalytic performances for HER have been enhanced drastically. The sulfuration treatment of unique MoOx-based nanostructures may be a potential and efficient strategy to manufacture efficient MoS2-based electrocatalysts for HER.
Nano-sized TiO2 powders were prepared by a hydrothermal synthetic method for use as anode materials in lithium secondary batteries. The prepared TiO2 samples were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) analysis, transmission electron microscopy (TEM), and electrochemical tests. TiO2 nanoparticles were obtained at sintering temperatures between 200 and 600°C. Calcination of the powders at 500°C results in the formation of TiO2 nano-sized particles of 22nm in crystal size. These deliver a reversible discharge capacity of over 170mAhg−1 between 1.5 and 3.0V with excellent capacity retention over 95% after 100 cycles. It is speculated that the nano-sized TiO2 powders are effective candidates for lithium secondary anode materials.
Objective To explore sleep-related dysfunctional beliefs, stress levels and sleep quality in patients with fibromyalgia in comparison to healthy controls. Methods One hundred sixty-six participants (83 patients with fibromyalgia and 83 healthy controls) completed self-report measures exploring beliefs and attitudes about sleep, perceived stress, sleep quality and levels of pain and fatigue. Results Relative to healthy controls, patients with fibromyalgia revealed significantly higher levels of dysfunctional beliefs and attitudes about sleep and perceived stress. High dysfunctional beliefs were significantly associated with poorer sleep quality and high perceived stress was significantly related to higher sleep disturbances and daytime dysfunction. Conclusions Beliefs about sleep and perceived stress play a significant role in the sleep quality of patients with fibromyalgia. Interventions to improve sleep quality for people with fibromyalgia need to identify and address dysfunctional beliefs about sleep and incorporate stress management approaches.
Composite positive electrodes LiFePO4/C, applicable for rechargeable lithium-ion batteries cycled at high current density, were prepared using spark-plasma-sintering (SPS) technique. LiFePO4/C composite positive electrodes with carbon content of 20wt.% was synthesized at 600°C in the SPS process, and it was found that LiFePO4 particles were covered with fine carbon particles and they formed agglomerates with the size of about 10μm. It resulted in higher electrode density. Charge/discharge tests for the cell using LiFePO4/C composite positive electrodes showed superior cycle performance at the rates of 17–850mAhg−1 (0.1–5C) compared with the cell using the conventionally blended LiFePO4 +C composite positive electrodes. The improvement of the cell performance was attributed to strong binding between LiFePO4 and carbon powders. Consequently, the electrical network remained almost unchanged during electrochemical redox cycling, even at high current rates.
Metal oxides with oxygen vacancies can be exploited as a charge storage material for supercapacitor. This work demonstrates synthesis of lanthanum molybdenum oxide (La2Mo2O9, LMO) using different calcination temperatures (300, 400, 500, 600 and 700 °C). As prepared LMO500 illustrates its utilization as an anion intercalated material for supercapacitors. Among all LMOs, LMO500 electrode exhibits high gravimetric (727.18 F g−1 at 0.5 A g−1) and areal (290.87 mF cm−2 at 0.5 A g−1) capacitance. The superior electrochemical performance of LMO500 can be attributed to complete transformation of its mixed phases (i.e. oxides, hydroxides) to its pure oxides (β-La2Mo2O9). Due to existence of pure phase, devoid of secondary phases, LMO500 exhibits good electron kinetics which affords low charge transfer resistance. The asymmetric supercapacitor (LMO500‖LRGONR) employing lacey reduced graphene oxide nanoribbons (LRGONR) as negative electrode delivers high energy density of 52 Wh kg−1 at a power density of 474 W kg−1 which is more than twice of symmetric cell (LMO500‖LMO500). Other than high energy and power density, LMO500‖LRGONR cell shows 98.74% capacitance retention after 1000 GCD cycles at 1.0 A g−1, endorsing excellent cycle stability.
The goal of this review is to assess renewable power sources as alternatives to the batteries traditionally used for remote environmental monitoring. In this review, we first discuss remote sensors and then we: 1) review the power requirements and traditionally used power sources for remote sensors, 2) describe the working principles of the renewable power sources used for powering remote sensors, 3) evaluate the challenges and potentials of the renewable power sources, and 4) review the power management systems developed for remote power generation and discuss how to use them to generate reliable power. In the description of each of the renewable power sources, we include the current status and future directions of the research. We believe that hybrid systems using more than a single renewable power source can provide more reliable renewable power. We conclude that renewable power sources have been demonstrated to be able to generate sufficient power for remote sensors. Because of the environmental risks and cost of operation associated with batteries, renewable energy sources will need to be used to power remote sensors in the near future.
Alzheimer’s disease (AD) is the most common and most costly chronic neurodegenerative disease globally. AD develops over an extended period prior to cognitive symptoms, leaving a “window of opportunity” for targeted risk-reduction interventions. Further, this pre-dementia phase includes early physiological changes in sleep and autonomic regulation, for which wearable biosensor devices may offer a convenient and cost-effective method to assess AD-risk.
A simple method is applied to prepare nanocrystalline ZnS using zinc nitrate and thiourea in aqueous solutions. Cubic sphalerite ZnS is obtained in phase pure form when S/Zn mole ratio is 1 and 2. A mixed phase of hexagonal wurtzite and cubic sphalerite ZnS is obtained when S/Zn mole ratio is 4. Transmission electron microscope and X-ray diffraction confirm the formation of ZnS nanoparticles. These nanoparticles are immobilized on the surface of paraffin impregnated graphite electrode (PIGE) and electrochemical characterization in neutral solutions by cyclic voltammetry revealed that the material is ideal to be used as electrode in electrochemical double layer capacitors. The most singularly interesting result is the voltages observed in 0.1M LiCl, NaCl, NaI and KI solutions. They are 3.0, 2.7, 2.0 and 1.8V versus Ag/AgCl and significantly higher than the expected value of 1.23 V (pH∼7) in aqueous medium. Such a large voltages are usually obtained for non-aqueous electrolytes and the present study showed a surprising and significant interesting result that can be owed to the over potentials of H2/O2/Cl2 gas evolutions. An attempt to understand these highly significant results in terms of band edge bendings (conduction band and valence band) associated with the positive and negative ion adsorption at the interface of semiconductor ZnS/solution is made.
A new type vanadium oxide deposit with a porous, three-dimensional (3-D) network architecture plated at 0.7V (vs. Ag/AgCl) from 25mM VOSO4 with 5mM H2O2 shows capacitive-like behavior at 250mVs−1 and C S ≈167Fg−1 at 25mVs−1 in 3M KCl for pseudocapacitor applications. This work also emphasizes that anodic deposition of vanadium oxide does occur at a potential much more negative to oxygen evolution from aqueous VOSO4 solutions due to the presence of V5+ by adding H2O2. Through the X-ray photoelectron spectroscopic analyses, this oxide deposit, mainly consisting of V5+ with 11mol.% V4+, shows a hydrous nature. The unique power characteristics of this hydrous vanadium oxide are reasonably attributed to its intrinsic porous and crystalline structure produced by means of this novel anodic deposition process at a potential much more negative to the oxygen evolution reaction.
To explore personological and psychopathological characteristics in individuals with obesity presenting for bariatric surgery compared with individuals with obesity not seeking bariatric surgery and healthy individuals to help clinician decision for surgical treatment.
Small-scale renewable energy systems and smart technologies are enabling energy consumers to become producers and service providers as well. This Perspective explores this ‘prosumption’ phenomenon, highlighting three promising prosumer market models and the challenges for future implementation.
Metal supported cells as developed according to the DLR SOFC concept by applying plasma deposition technologies were investigated for use as solid oxide electrolyser cells (SOEC) for high temperature steam electrolysis. Cells consisting of a porous ferritic steel support, a diffusion barrier layer, a Ni/YSZ hydrogen electrode, a YSZ electrolyte and a LSCF oxygen electrode were electrochemically characterised by means of i-V characteristics and electrochemical impedance spectroscopy measurements including a long-term test over 2000 h. The cell voltage during electrolysis operation at a current density of −1.0 A cm−2 was 1.28 V at an operating temperature of 850 °C and 1.4 V at 800 °C. A long-term test run over 2000 h with a steam content of 43% at 800 °C and a current density of −0.3 A cm−2 showed a degradation rate of 3.2% per 1000 h. The impedance spectra revealed a significantly enhanced polarisation resistance during electrolysis operation compared to fuel cell operation which was mainly attributed to the hydrogen electrode.
Although the concept of a lithium–sulfur (Li–S) battery promises an energy density surpassing that of conventional Li-ion cells, prototype cells have lagged far behind. As research on Li–S has progressed, four limiting challenges for the sulfur electrode have now emerged that must be addressed to facilitate their realization, including slow lithium polysulfide deposition kinetics at low electrolyte/sulfur ratios, the lithium polysulfide shuttle, the low electrical conductivity of sulfur active material, and the cracking of solid electrolytes due to the repeated expansion and contraction of sulfur active material. Notably, the challenges of both slow deposition kinetics and the lithium polysulfide shuttle only arise when using sulfur active material with the most common electrolyte solvents used in Li–S cells: liquid ethereal mixtures, such as DOL:DME. Consequently, a reckoning of ether-based electrolytes is at hand, which has shifted research focus toward solid electrolytes and alternative sulfur-based active materials; however, these alternative strategies have their own challenges. Meanwhile, dendrite growth and insufficient coulombic efficiency still plague lithium metal electrodes in both liquid and solid electrolytes at relevant current densities. Many approaches to mitigate dendrite growth have been attempted, including artificial SEIs, nucleation aids, high surface area current collectors and solid electrolytes. Despite successes, further work is needed to attain a sufficient level of performance for lithium metal to be used in commercial Li–S cells. Herein we discuss the strengths and weaknesses of many proposed solutions to these challenges with an eye toward the ever-present goal of competing with conventional Li-ion energy densities.
This review summarizes the current state-of-the art electrode materials used for high-capacity lithium-ion-based batteries and their significant role towards revolutionizing the electrochemical energy storage landscape in the area of consumer electronics, transportation and grid storage application. We discuss the role of nanoscale effects on the electrochemical performance of high-capacity battery electrode materials. Decrease in the particle size of the primary electrode materials from micron to nanometre size improves the ionic and electronic diffusion rates significantly. Nanometre-thick solid electrolyte (such as lithium phosphorous oxynitride) and oxides (such as Al2O3, ZnO, TiO2 etc.) material coatings also improve the interfacial stability and rate capability of a number of battery chemistries. We elucidate these effects in terms of different high-capacity battery chemistries based on intercalation and conversion mechanism.
Stroke is the third leading cause of death and leading cause of adult disability worldwide. Long-term disability is a significant problem among survivors; post-stroke inflammation is well known to contribute to the expansion of the ischemic lesion resulting in significant morbidity and disability. To study the impact of serum level of IL-8 on severity of disability in patients with acute ischemic stroke in the first 48 h post stroke.
A computationally efficient pore network model (PNM) has been developed to incorporate the transport and electrochemical phenomena occurring within porous electrodes. This PNM is validated on a synthetic cubic structure and subsequently run on a network obtained from X-ray computed tomography (X-CT) images of a sample of commercial porous carbon paper commonly used in electrochemical devices. The carbon paper's physical characteristics (pore-size distribution, permeability, porosity and electroactive surface area) are discussed. The concentration distribution of active species is examined considering solely the transient convective and diffusive transport processes initially, and subsequently is compared to the concentration of active species when migration and reactive transport factors are included. The results show non-uniformity in the concentration and pressure distributions in the electrode when considering the pure convective/diffusive transport processes. The migration and reactive processes are subsequently considered and are shown to be influenced by the rate in which the convective/diffusive flow permeates the electrode. A uniform steady decline in volume-averaged state of charge is shown, followed by a pore-scale non-uniform current density and state of charge distribution upon discharge. These results were obtained on a standard single core workstation highlighting the benefits of using a computationally inexpensive model.
Dual-ion or dual-graphite batteries based on the mechanism of electrochemical anion intercalation into a graphite cathode have become attractive as an alternative storage technology in recent years. Due to large volume changes of the graphite particles during electrochemical anion intercalation, an appropriate electrode binder is required to sustain the mechanical integrity of the composite electrode and a stable and highly reversible charge/discharge cycling. Therefore, the expansion and contraction behavior of graphite positive electrodes containing different binders, including Na-carboxymethyl cellulose (CMC), poly(vinylidene)difluoride (PVdF) and a CMC/styrene butadiene rubber (SBR) mixture, during anion intercalation/de-intercalation was investigated by in situ electrochemical dilatometry (ECD). These measurements give insights into reversible and irreversible relative height changes at different cycling conditions and, thus, into the long-term cycling stability of the composite electrodes. Long-term cycling measurements reveal that the maximum and minimum electrode thicknesses of PVdF-based electrodes remain constant during anion intercalation/de-intercalation, while the CMC-containing electrodes exhibit a thickness increase in the first cycles and subsequent decrease after reaching a maximum electrode thickness. This instability can most likely be correlated with the mechanical instability of the electrode due to the high stiffness of the CMC binder compared to PVdF and an active material contact loss during cycling. If CMC is applied as binder mixture in combination with SBR, which shows a high flexibility, the thickness decay can be decreased. Our results give new insights into the optimization potentials of composite electrodes for carbon-based cathodes in dual-ion cells that experience large volume expansion during cycling.
As the cathode ternary activated materials with high content of nickel have been widely used in lithium-ion batteries, the recycling of the spent cathode materials has been paid worthy attention. In this work, the sulfate solution with Li, Ni, Co and Mn elements was formed by dissolving the spent LiNi0.5Co0.2Mn0.3O2 cathode materials in 20% sulfuric acid and 30% H2O2, assisted with reflux at 90 °C for 1 h. Based on the above solution, the precursor (Ni0.5Co0.2Mn0.3(OH)2), along with the lithium and sodium sulfates mixture solutions were prepared by co-precipitation at 55 °C. Then Li2CO3 powders and sodium sulfate solution were obtained through evaporating filtered solution separated from the preparation of the precursor and added an amount of Na2CO3, with the removal of 30% water and separation at about 70 °C. The purity of recovered Li2CO3 is about 99.5%. The residual concentrations of Ni, Co and Mn in the filtered solution separated from the preparation of precursor are only 0.041, 0.025, 0.038 ppm left, respectively. The prepared cathode material LiNi0.5Co0.2Mn0.3O2 from the precursor exhibits good cycle performance and shows a stable discharge capacity of 140 mAh g−1 at a current rate of 100 mA g−1 between 2.8 and 4.2 V.
Todorokite-type manganese oxide (τ-MnO2) with p × 3 tunneled structure is especially captivating as charge storage material for rechargeable batteries, since the enlarged tunnel dimensions enable rapid electrode kinetics and superior rate performance. However, its congenitally rich polytypism associated with tunnel heterogeneity impedes our precise understanding of structure-property relationship in this polytypic material. In this regard, this work has taken substantial effort to preliminarily achieve uniform 4 × 3 tunnel-structured τ-MnO2 nanorods, as corroborated via atomically resolved imaging. Afterwards, the (de)lithiation mechanisms of the tunnel-specific phase are investigated via in situ transmission electron microscopy including electron diffraction, high-resolution imaging, and electron energy loss spectroscopy, coupled with density functional theory calculations and phase field simulations. Upon initial lithiation, the intercalation reaction region β (less than 1.43 Li insertion) is observed as result of rapid lithium-ion diffusion through the tunnels with slightly increased lattice constants. By tracing the full lithiation procedure, the evolution of intermediate Mn2O3 phase and the development of final Mn and Li2O phases are identified in the conversion reaction region α (more than 1.43 Li insertion). These results indicate that τ-MnO2 can be applied to a cathode by intercalation reaction and to an anode by conversion reaction in corresponding to voltage ranges in a lithium-based battery. Upon delithiation, we observe an unusual reciprocating-motion reaction front (different from one-way lithiation reaction front), for which the driven dynamics are delineated based on a phase field model. Impressively, a reversible and symmetric conversion reaction between Mn2O3 phase and Mn + Li2O phases is established upon subsequent (de)lithiation cycles. This work can be regarded as a stepping-stone arousing the appetite of a comprehensive understanding of the highly polytypic material with other tunnel-specific phases.