batterydata/paper-abstracts huggingface dataset:
Lithium bis(oxalato)borate (LiBOB), a new electrolyte salt for lithium batteries, is actively involved in the formation of the solid electrolyte interphase (SEI) at the anode. Part of this formation is an irreversible reductive reaction taking place at potentials of around 1.75V versus Li/Li+ and contributing to the irreversible capacity of anode materials in the first cycle. Cyclic voltammetry has been performed on several carbon materials as well as on Li4Ti5O12 and pre-treated glassy carbon electrodes in order to achieve a better understanding of the underlying processes. It is found that the intensity of the 1.75V peak depends on the BET specific surface area and the surface chemistry of the active material and increases with the amount of oxygen-containing surface functionalities. It is not specific to carbonaceous materials but is also observed on carbon-free anodes like Li4Ti5O12. In addition, the effect of several potential impurities and of film-forming additives on the filming behaviour of LiBOB-containing electrolytes has been investigated.
Rösser N, Heuschmann P, Wersching H, Breitenstein C, Knecht S, Flöel A. Levodopa improves procedural motor learning in chronic stroke patients. Objective To test the hypothesis that administration of dopamine precursor levodopa improves procedural motor learning (defined as the ability to acquire novel movement patterns gradually through practice) in patients with residual motor deficits in the chronic phase after stroke (≥1y after stroke). Design A double-blind, placebo-controlled, randomized crossover design. Setting Neurology department in a German university. Participants Eighteen patients with chronic motor dysfunction because of stroke (13 men, 5 women; age range, 53–78y; mean time poststroke ± SD, 3.3±2.1y). Intervention Patients received 3 doses of levodopa (100mg of levodopa plus 25mg of carbidopa) or placebo before 1 session of procedural motor learning. Main Outcome Measures Procedural motor learning performed by using the paretic hand assessed by using a modified version of the serial reaction time task with a probabilistic sequence. The primary outcome measure was the difference in reaction times between random and sequential elements. Results Levodopa significantly improved our primary outcome measure, procedural motor learning, compared with placebo (P<.05). Reaction times to random elements, analysis of error rates, psychophysical assessments, and performance in a simple motor task were comparable between conditions, indicating that better learning under levodopa was not caused by differences in response styles, arousal, mood, or motor reaction times but that levodopa modulated learning. Conclusions Our results show that levodopa may improve procedural motor learning in patients with chronic stroke, in line with our hypothesis. These findings suggest that this interventional strategy in combination with customary rehabilitative treatments could significantly improve the outcome of neurorehabilitation in the chronic stage after stroke. (Clinicaltrials.gov identifier NCT00126087.)
The purpose of this paper is to provide an analytical review of wind turbine-generator systems for stand-alone applications. The review focuses on variable-speed wind turbines, as the future trend in wind energy conversion, in contrast with the traditional fixed-speed wind turbines. Indirect-drive and direct-drive turbines are comparatively evaluated. The concerns about long-term availability of permanent magnet materials and its impact on the future of permanent magnet synchronous generator are addressed. Having cost and efficiency in mind, viability of indirect-drive squirrel cage induction generator for stand-alone wind energy conversion systems is discussed. As an efficient induction machine design, permanent magnet induction generator is also examined. Finally, the potential of using switched reluctance machine, as a generator, in a direct-drive wind turbine system is investigated.
The Xth Symposium on Fast Ionic Conductors marks the anniversary of such biannual meetings of the Polish Solid State Ionics Society. The Symposium was held in September 13–17, 2006 at Augustów in Poland and brought together scientists working on different topics from the field of Solid State Ionics. The meeting brought together 73 participants including PhD and MSc students, people from battery industry and experts in the field of fast ionic conductors and their applications in energy storage and conversion devices, sensors and optical displays who presented a selection of lectures on topics related to the scope of the Symposium. The conference was opened with the lecture on “ Progress in polymer batteries” presented by Prof. Michel Armand and closed with the lecture presented by Prof. Patrick Moseley on “The challenge of the HEV duty cycle—can lead-acid compete with NiMH and Li-ion”. Alltogether 33 plenary, keynote and short lectures were presented on topics related with the preparation, characterization and application of fast ionic conductors. The young participants of the Symposium presented their results during the poster session. This special issue of Journal of Power Sources is a collection of the best papers presented during the Symposium and covers the area of basic research on fast ionic conductors together with studies devoted to the application of these materials in batteries, fuel cells sensors and optical devices.
It is generally admitted that Peukert's law has its origin in the diffusion processes occurring in the lead acid battery. Some authors claim however that the derivation of Peukert's law must be based on the existence of semiconducting layers in the electrodes of the lead acid battery. In this paper we review the scarce literature concerning this subject. We find that the presence of semiconducting layers is speculative and that the existence of such layers is not sufficient to verify Peukert's law.
Mobile wireless sensor networks (MWSNs), the continuous movement of sensor nodes, may cause complete disconnection of the network or at best a part of it. The design of such networks should guarantee that all sensor nodes at all times have a path to the sink node(s). Prolonging the lifetimes of the MWSNs is a crucial design issue but should not be at the expense of other essential functions such as connectivity. In this paper, we propose an energy efficient distributed framework for connectivity maintenance of MWSNs. In the proposed framework, sensor nodes of the MWSNs schedule and control their radio frequency (RF) modules based on dynamic coordinated reconstruction mechanism, some senor nodes may lose their connectivity with the network due to mobility, depletion of energy and/or incurred faults. Two protocols are developed to patch up the disconnection of the MWSNs. The first protocol reestablishes the network connection consuming far less energy than state-of-the-art alternatives. However, it is capable of reestablishing the connection when no more than 20% of the MWSN backbone nodes lose connection concurrently. The second protocol extends this limit to operate when up to 35% of the MWSN backbone nodes lose connection simultaneously.
Consumers' emotional requirements, or so-called Kansei needs, have become one of the most important concerns in designing a product. Conventionally, Kansei engineering has been widely used to co-relate these requirements with product parameters. However, a typical Kansei engineering approach relies heavily on the intuition of the person who uses the method in clustering the Kansei adjectives, who may be the engineer or designer. As a result, the selection of Kansei adjectives may not be consistent with the consumers' opinions. In order to obtain a consumer-consistent result, all of the collected Kansei adjectives (usually hundreds) need to be evaluated by every survey participant, which is impractical in most design cases. Therefore, a Kansei clustering method based on a design structure matrix (DSM) is proposed in this work. The method breaks the Kansei adjectives up into a number of subsets so that each participant deals with only a portion of the words collected. Pearson correlations are used to establish the distances among the Kansei adjectives. The subsets are then integrated by merging the identical correlation pairs for an overall Kansei clustering result. The details of the proposed approach are presented and illustrated using a case study on wireless battery drills. The case study reveals that the proposed method is promising in handling Kansei adjective clustering problems. Relevance to industry This study presents a generic method to deal with consumers' Kansei requirements for emotional design in new product development. It appears that the proposed method can be utilized to capture and analyze consumers' Kansei needs as well as to facilitate decision making in practical industrial design cases.
Balance disorders can have substantial adverse implications on the performance of daily activities and lead to an increased risk of falls, which often have severe negative consequences for older adults. Quantitative assessment through computerized force plate-based posturography enables objective assessment of postural control but could not successfully represent specific abilities required during daily activities. The use of virtual reality (VR) could improve the representative design of functional activities and increase the ecological validity of posturographic tests, which would enhance the transferability of results to the real world. In this work, we investigate the feasibility of a simulated bus ride experienced in a surround-screen VR system to assess balance with increased ecological validity. Participants were first evaluated with a posturography test and then with the VR-based bus ride test, while the reactions of their centre of pressure were registered. Lastly, participants provided self-reported measures of the elicited sense of presence during the test. A total of 16 healthy young adults completed the study. Results showed that the simulation could elicit significant medial–lateral excursions of the centre of pressure in response to variations in the optical flow. Furthermore, these responses' amplitude negatively correlated with the participants' posturography excursions when fixating a target. Although the sense of presence was moderate, likely due to the passive nature of the test, the results support the feasibility of our proposed paradigm, based in the context of a meaningful daily living activity, in assessing balance control components.
Carbothermal treatment was used to improve the discharge rate performance of primary lithium/carbon monofluoride (Li/CF x with x =1) batteries. The treatment was carried out by heating a mixture of CF x and carbon black (CB) just below the decomposition temperature of CF x under nitrogen for 2h. In the treatment, poly(vinylidene fluoride-co-hexafluoropropylene) (Kynar) was used as a fluorinated polymer binder to press the CF x /CB mixture into pellets. It was shown that the content of Kynar significantly affected the discharge performance of the resulting treated-CF x (T-CF x ). This can be attributed to the catalytic effect of HF formed by the pyrolysis of Kynar on the decomposition of CF x and on the reaction of CB with the volatile fluorocarbons formed by the decomposition of CF x . The discharge performance of T-CF x cathode was also affected by the temperature of carbothermal treatment and by the ratio of CF x to CB. In this work the best result was obtained from a treatment conducted at 470°C on a 87CF x /10CB/3Kynar (by weight) mixture. In the discharge condition of C/5 and 20°C, the Li/CF x cell with such-obtained T-CF x cathode showed about 95mV higher voltage than the control cell while retaining nearly the same specific capacity. Impedance analyses indicate that the improved discharge performance is mainly attributed to a reduction in the cell reaction resistance (R cr) that includes an ohmic resistance related to the ionic conductivity of the discharge product shell and a Faradic resistance related to the processes of charge-transfer and Li+ ion diffusion in the CF x reaction zone.
Air delivery is typically the greatest parasitic power loss in polymer electrolyte membrane fuel cell (PEMFC) systems. We here present a detailed study of an active water management system for PEMFCs, which uses a hydrophilic, porous cathode flow field, and an electroosmotic (EO) pump for water removal. This active pumping of liquid water allows for stable operation with relatively low air flow rates and low air pressure and parallel cathode channel architectures. We characterize in-plane transport issues and power distributions using a three by three segmented PEMFC design. Our transient and steady state data provide insight into the dynamics and spatial distribution of flooding and flood-recovery processes. Segment-specific polarization curves reveal that the combination of a wick and an EO pump can effect a steady state, uniform current distribution for a parallel channel cathode flow field, even at low air stoichiometries (α air =1.5). The segmented cell measurements also reveal the mechanisms and dynamics associated with EO pump based recovery from catastrophic flooding. For most operating regimes, the EO pump requires less than 1% of the fuel cell power to recover from near-catastrophic flooding, prevent flooding, and extend the current density operation range.
Deep-brain stimulation of the subthalamic nucleus and internal globus pallidus are both surgical options in advanced Parkinson’s disease. The best target is still debated with data suggesting better motor outcome in subthalamic stimulation but higher rates of psychiatric problems. Failure of pallidal stimulation within the first 2 years has been described. Here, we report a patient with good response to pallidal neurostimulation who developed a secondary failure after 10 years of treatment which was successfully reversed by reimplanting the electrodes into the subthalamic nucleus. This case suggests that a controlled comparison of treatment efficacy of pallidal and subthalamic neurostimulation may require a very long follow-up period to yield reliable results.
Poly(siloxanes-g-oligo(ethylene oxide)) with acrylate groups at the terminal position were prepared and examined for the solid polymer electrolyte (SPE) by curing them. Poly(ethylene glycol) dimethyl ether (PEGDME) was added as a plasticizer. Conductivity of the resulting polymer electrolytes was greatly enhanced with increasing amounts of low molecular weight PEGDME. Maximum conductivity was found to be 8×10−4 S/cm at 30°C with an [EO]/[Li] ratio of about 8. These electrolytes showed oxidation stability up to 4.95V against the lithium reference electrode. Reversible electrochemical plating/stripping of lithium was observed on the nickel electrode. The plating/stripping efficiency of lithium on nickel was measured to be about 53%.
Porous structure-tuned cellulose nanofiber paper separators (designated as S-CNP separators) are demonstrated as a promising alternative to commercial polyolefin separators for use in lithium-ion batteries. A new architectural strategy based on colloidal silica (SiO2) nanoparticle-assisted structural control is presented to overcome the difficulty in forming controllable porous structure of pure cellulose nanofiber paper separators (designated as CNP separators) from densely-packed cellulose nanofibers (CNFs). The new S-CNP separators proposed herein incorporate SiO2 nanoparticles as a CNF-disassembling agent (i.e., as non-conductive spacer particles). This structural uniqueness allows loose packing of CNFs, thereby facilitating the evolution of more porous structure. The unusual porous structure of S-CNP separators can be fine-tuned by varying SiO2 contents in the CNF suspension. Notably, the S-CNP separator (fabricated with 5 wt.% SiO2 content) exhibits the highest ionic conduction due to the well-balanced combination of nanoporous structure and separator thickness, thus contributing to excellent cell performance. This study underlines that the colloidal SiO2 nanoparticle-directed structural tuning of CNPs offers a promising route for the fabrication of advanced paper separators with optimized attributes and functionality.
Objectives To examine whether disrupted regulation of REM sleep propensity is implicated in nightmare (NM) pathophysiology. Background Heightened REM propensity induced by REM sleep deprivation is belied by increases in REM %, REM density and the dreamlike quality of dream mentation during post-deprivation recovery sleep. Compromised regulation of REM sleep propensity may be a contributing factor in the pathophysiology of frequent NMs. Methods A preliminary study of 14 subjects with frequent NMs (⩾1NM/week; 27.6±9.9years) and 11 healthy control subjects (<1NM/month; 24.3±5.3years) was undertaken. Subjects completed home sleep/dream logs and underwent three nights of polysomnographic recording with REM sleep deprivation on night 2. Group differences were assessed for a battery of REM sleep and dream measures on nights 1 and 3. Results Several measures, including #skipped early-night REM periods, REM latency, REM/NREM cycle length, early/late REM density, REM rebound, late-night REM% and dream vividness, suggested that REM sleep propensity was abnormally low for the frequent NM group throughout the 3-day study. Conclusions Findings raise the possibility that REM anomalies recorded from NM sufferers sleeping in the laboratory environment reflect a disruption of one or more endogenous regulators of REM sleep propensity.
Titanium dioxide (TiO2) has received increasing attention as promising anode for lithium ion batteries because it offers a distinct safety advantage in comparison to commercialized graphite anodes, whereas it also suffer from the drawbacks of low practical capacity and relatively low electronic conductivity. Herein, one-dimensional mesoporous anatase TiO2 composed of nanocrystals prepared by a facile procedure is reported for the first time. Such peculiar architecture and intrinsical mesoporous can effectively improve pseudocapacitance charge storage, increase contact interface between the active materials and electrolyte, and enhance the structure stability during cycling, therefore contributing to good lithium storage and excellent cycling stability. A reversible capacity of 202.9 mAhg−1is obtained at 30 mAg−1 after 70 cycles. More importantly, 151 mAhg−1 can be obtained at 200 mAg−1 even after 500 cycles.
In the work, we developed an aqueous symmetric Ru–Cr binary oxide (Ru0.83Cr0.17O2·nH2O)-based electrochemical capacitor (EC) with unwonted high operating voltage in 1M KOH aqueous solution. Electrochemical performance of the symmetric EC was investigated by current-potential response and galvanostatic charge–discharge techniques. Electrochemical data demonstrated that the symmetric EC with a specific capacitance (SC) of ca. 148Fg−1 surprisingly can operate in a large electrochemical window of 1.4V in 1M KOH electrolyte, ensuring that the symmetric EC delivered an energy density of ca. 40Whkg−1. Moreover, the extended cycle life and good power property were obtained meanwhile, indicating that the Ru0.83Cr0.17O2·nH2O-based EC is a promising candidate for aqueous symmetric devices with high energy density and desirable power property.
Spinel Li4Ti5O12 (LTO) is a promising candidate anode material for Li-ion batteries due to its well-known zero-strain merits. To improve the electronic properties of spinel LTO, which are intrinsically poor, we processed the material into a nanosized architecture to shorten the distance for Li-ion and electron transport using the versatile electrospinning method. Graphene was chosen as an effective carbon coating to improve the surface conductivity of the nanocomposites. The as-prepared graphene-embedded LTO anode material showed improved discharging/charging and cycling properties, particularly at high rates, such as 22C, which makes the nanocomposite an attractive anode material for applications in electric vehicles.
Electric vehicles (EVs) have advantages in the aspect of energy, environment, and vehicle motion control. However, it is still not competitive enough to conventional vehicles because of the limited driving range and the high cost of the battery. Therefore, the energy efficiency is of the most importance for the control of EVs. Existing range extension control systems on EVs mostly focus on longitudinal front and rear axle torque distribution or lower-level yaw moment allocation. It is a challenge to maintain the vehicle’s stability at the cost of the minimum energy when the vehicle is cornering, this paper proposes a phase plane-based controller for EVs, focusing on the energy-efficient upper-level yaw stability control. The phase plane-based controller is automatically adaptive to driving situations through the optimization of weights on the performance of the vehicle handling and stability. Firstly, a friction constrained desired model is presented for the model-following control. Secondly, β - β ̇ phase plane analysis is conducted based on a nonlinear vehicle model to graphically identify the vehicle lateral stability in real time. The self-stable region can be determined by the vehicle velocity, the road friction coefficient, and the wheel steering angle. Then, energy optimizing (i.e. gain scheduling of LQR controllers) rules are designed based on the vehicle lateral stability identification. Finally, the proposed phase plane-based controller is evaluated and the yaw moment costs are compared to other controllers’ in a realistic 7-DOF vehicle model. The results demonstrate that the proposed controller presents an excellent yaw stability control capability, and compared to the widely used Shino’s controller, the proposed controller reduces the energy consumption by 9.68% and 3% at the ‘light’ and ‘severe’ maneuver, respectively.
Ternary transition metal oxides have received intense research interest as electrode materials for lithium ion batteries, due to their high specific capacity originating from the synergic effects of multiple metal active sites. Reducing the size of metal oxides nanoparticles and dispersing these nanoparticles in carbon matrix are considering effective strategies to improve the electrochemical performance of transition metal oxides. Ternary CuCo2O4 nanoclusters ultra-uniformly dispersed in carbon nanofiber matrix forming a pseudo-solid-solution structure are successfully synthesized by a facile electrospinning method followed by an appropriate annealing process. As the anodic electrode for lithium ion batteries, the pseudo-solid-solution CuCo2O4/C electrode exhibits a high reversible specific capacity, improved rate capacity and excellent cycling stability. A discharge capacity of 865mAhg−1 is obtained at the current density of 200mAg−1 after 400 cycles. Surprisingly, the electrode still retains about 610mAhg−1 after 800 cycles even at the current density of 600mAg−1. The superior lithium storage performance of the pseudo-solid-solution CuCo2O4/C composites is mainly attributed to the unique amorphous structure. The ultrafine CuCo2O4 nanoclusters uniformly dispersed in carbon matrix can buffer the volume change and improve the conductivity of the metal oxide based electrode, guaranteeing the structure stability and fast electron transfer.