batterydata/paper-abstracts huggingface dataset:
We study the optimal transmission policy of a sensor node in an energy-harvesting wireless sensor network. We consider a hybrid wireless sensor network in which a mobile sink is used to collect data. Taking cues from recent works on the value of information (VoI), we posit that the optimal policy maximises the VoI that can be sent for the node to the sink. We model this system as a discrete-time queueing model with two coupled queues. In particular, the sensor node under study operates energy neutral and harvests energy according to a Bernoulli process. Discretising energy into “energy chunks”, the battery is modelled as a first queue, whereas a second queue is introduced to hold the VoI at the sensor node. From the vantage point of the sensor node, this means that the sensor can only send when the sink is sufficiently close. When this is the case, the sensor decides whether to transmit its data or not depending on the amount of available energy and the value of the information. Focusing on the optimal transmission policy, we formulate the optimal control problem as a Markov Decision Process with a level-dependent block-triangular transition probability matrix. We find the optimal policy which maximises the mean VoI transmitted from the node in the long run and numerically show that it is of threshold type. Further, we assess the value function at optimal policy analytically and provide some properties. Finally, we investigate the structure of the optimal policy and the mean VoI collected from the node for different system parameters by means of some numerical experiments.
The pathological increase in the levels of the second messenger nitric oxide (NO) in the vitreous cavity and retina leads to injury and cell death of the retinal pigment epithelium (RPE) cells and eventually may contribute to the occurrence and development of diabetic retinopathy. In this study, we developed a cellular model of retinopathy using D407 cells (a human RPE cell line) exposed to sodium nitroprusside (SNP) and investigated the protective effect of the insulin-like growth factor-1 (IGF-1) towards this insult. Cell death and apoptosis were examined by the methyl thiazolyl tetrazolium assay and Hoechst staining, respectively. Specific inhibitors were used and phosphorylation of relevant signaling proteins was determined by Western blotting. SNP, in a concentration-dependent fashion, increased the production of reactive oxygen species (ROS) and lipid peroxidation process causing cell death by apoptosis of D407 cells. IGF-1, in a time- and dose-dependent manner, conferred protection towards SNP-mediated insult. Both phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) and mitogen-activated protein kinase (MAPK) were activated by IGF-1 in relation to the protective effect. Blockade of the PI3K/Akt pathway abolished the protective effect of IGF-1 whereas inhibition of the MAPK pathway was ineffective. SNP decreased the phosphorylation of Akt in the cells while IGF-1 reversed this inhibitory effect. These results indicate that the protective effect of IGF-1 on D407 exposed to SNP insult is mediated by the PI3K/Akt pathway. This proposal may be exploited in the clinic to improve the viability of insulted retinal cells for maintaining physiological vision.
A battery of in vitro short-term tests revealing different genetic end-points was set up in order to study surface-water genotoxicity after disinfection with different biocides: sodium hypochlorite (NaClO), chlorine dioxide (ClO2) and peracetic acid (PAA). The surface water both before and after disinfection was concentrated by adsorption on C18 silica cartridges and the concentrates containing non-volatile organics were divided into different portions for chemical analyses and biological assays. The following in vitro tests were conducted on the water concentrates dissolved in DMSO: the Salmonella mutagenicity assay with S. typhimurium strains TA98 and TA100; the SOS Chromotest with Escherichia coli, the Microtox® and Mutatox® assays with Vibrio fischeri; and gene conversion, point mutation and mitochondrial DNA mutability assays with D7 diploid Saccharomices cerevisiae strain. The results show that the SOS Chromotest and the yeast assays are highly sensitive in detecting genotoxicity. The surface-water extracts were very often toxic to most of the test organisms considered, partially masking their potential mutagenic activity. Therefore, the assays with E. coli and with S. cerevisiae are more likely to show a mutagenic effect because these organisms are generally less sensitive to most toxic compounds. Among the tested disinfectants, NaClO and ClO2 increased water genotoxicity, whereas PAA was able to slightly reduce raw water activity. However, because the organic compounds in the lake water varied with the season of the year, the disinfection processes, at times, both increased and decreased the raw water activity.
The development of episodic memory in children has been of interest to researchers for more than a century. Current behavioral tests that have been developed to assess episodic memory differ substantially in their surface features. Therefore, it is possible that these tests are assessing different memory processes. In this study, 106 children aged 3 to 6years were tested on four putative tests of episodic memory. Covariation in performance was investigated in order to address two conflicting hypotheses: (a) that the high level of difference between the tests will result in little covariation in performance despite their being designed to assess the same ability and (b) that the conceptual similarity of these tasks will lead to high levels of covariation despite surface differences. The results indicated a gradual improvement with age on all tests. Performances on many of the tests were related, but not after controlling for age. A principal component analysis found that a single principal component was able to satisfactorily fit the observed data. This principal component produced a marginally stronger correlation with age than any test alone. As such, it might be concluded that different tests of episodic memory are too different to be used in parallel. Nevertheless, if used together, these tests may offer a robust assessment of episodic memory as a complex multifaceted process.
Powered exoskeleton technology helps turns dreams of recovering mobility after paralysis into reality. One of the most common problems encountered in the use of powered exoskeletons is the detection of the motion intentions of the user. Many approaches to conquering this problem have been developed using Electromyography (EMG) sensors, Electroencephalography (EEG) sensors, Center of Pressure (COP), and so forth. When a method, such as the surface EMG, is contaminated with noise during acquisition, it is important to process that raw EMG signal. Doing so usually takes time, and time delays in such a system can lead to a loss in synchronization between the wearer and the exoskeleton. Many algorithms have been developed for data acquisition and the filtering of raw EMG signals as well as accelerometer data. Our approach involves designing an almost sensor-less low limb exoskeleton that is powered by an electric Direct Current (DC) motor, and the same motor is used to detect motion via monitoring the voltage and the current variation. Experimental results are obtained for the actuating knee flexion-to-extension then extension-to-flexion of a sitting person using the National Instrument (NI) MyRIO as a data acquisition system with NI-LabView. The results support the hypothesis that the developed system can detect human motion and drive the motor in the necessary direction without the use of uncomfortable electrodes (sensors) and their connections. Additionally, the system supported the wearer to move his leg up (extension) without having too much effort to do so. In order to identify muscle activation with the change in the angle along the sagittal plane, an accelerometer has been attached to the system. The proposed approach could help open a new pathway along which researchers could develop low-cost and easy-to-wear powered exoskeletons which could emulate precisely the normal gait of a human.
The Candrive II/Ozcandrive study, a multicentre prospective cohort study examining the predictive validity of tools for assessing fitness to drive, aims to develop an in-office screening tool that will help clinicians identify older drivers who may be unsafe to drive. This paper describes the study protocol. We are following a cohort of drivers aged ≥70 years for up to 4 years. Starting in 2009, 928 participants have been recruited in seven cities in four Canadian provinces, as well as 302 participants in two sites in Melbourne, Australia and Wellington, New Zealand. Participants underwent a comprehensive assessment at baseline and repeat the assessment yearly thereafter, as well as a brief follow-up assessment at 4 and 8 months each year. A recording device is installed in participants’ vehicles to assess driving patterns, and driving records are obtained from licensing authorities to determine the outcomes: at-fault crashes per kilometre driven and violations. To date, the protocol has been generally well adhered to, with 1230 participants, and barriers and challenges are being addressed, as necessary. The Candrive II/Ozcandrive study is unique owing to its size, duration, partnerships with Canadian, Australian and New Zealand stakeholders, and international research collaboration.
A battery of mouse monoclonal antibodies (mAbs) reactive with porcine peripheral blood (PB) leukocytes was generated. Among the mAbs, 6F10 was found to react probably with cluster of differentiation (CD)8 α-chain, while 7G3 and 3E12 were found to recognize γδ T-cells, as revealed by two-color flow cytometric and immunoprecipitation studies. 7G3 was shown to react with the constant (C) region of the T-cell receptor (TCR) δ-chain by the following facts: (1) 7G3 immunoprecipitated full-length TCR δ-chain protein fused with glutathione S-transferase (GST) produced by Esherichia coli and (2) 7G3 reacted with TCR δ-chain expressing Cos-7 cells transfected with either full-length or N-terminal deleted mutant cDNA, but did not react with Cos-7 cells transfected with C-terminal deleted mutant TCR δ-chain cDNA. All three mAbs produced high-quality immunostaining results on frozen sections, revealing a distinct distribution of γδ T-cells and CD8+ cells. This report precisely characterizes mAbs against porcine TCR for the first time, facilitating molecular biological investigations of the porcine immune system.
A three-dimensional (3D) carbonaceous aerogel derived from biomass bacterial cellulose (BC) is introduced as a flexible framework for iron oxides in Li-ion batteries (LIBs). The 3D carbonized BC (CBC) with highly interconnected nanofibrous structure exhibits good electrical conductivity and mechanical stability. The amorphous Fe2O3 is tightly coated on the nanofibers of CBC through a simple in situ thermal decomposition method. The obtained amorphous Fe2O3 anode (denoted as A-Fe2O3@CBC) exhibits stable cycling performance and high rate capability when assembled into a half-cell, which is supposed to benefit from the well-dispersed Fe2O3 nanoshells and the hierarchical pores in A-Fe2O3@CBC composite. The rational design of the nanostructure could improve the transportation of electrons/ions and effectively alleviate volume changes of Fe2O3 during the electrochemical cycling. Meanwhile, the amorphous nature of the Fe2O3 in anode provides an enhanced capacitive-like lithium storage and flexible structure of the active materials, resulting in much higher specific capacity and longer cycle life when compared with its crystalline counterpart. This work provides a promising approach to design and construct the flexible metal oxide anode materials based on 3D carbonaceous aerogel for high-performance LIBs.
Commercially available anatase TiO2 nanoparticles (ca. 15–20 nm particle size) were investigated as negative electrode material for Li-ion batteries. Despite the high initial specific charge of 200 mAh g−1 at 0.5C, the pristine commercial TiO2 failed to retain the reversible capacity upon cycling, keeping only 23% of the initial value after 80 cycles. X-ray photoelectron spectroscopy (XPS) results together with electrochemical data suggest that the failure in cyclability is of kinetic nature as the loss in specific charge is not completely irreversible. Thermogravimetry analysis revealed that the pristine TiO2 contained a significant amount of TiO(OH)2 (ca. 8%) which can be easily removed by dehydration when annealing in air above 250 °C. Air-annealing of TiO2 at 300 °C resulted in a remarkable improvement in cyclability retaining 83% of initial specific charge after 80 cycles at 0.5C. No further improvement in cyclability was observed for TiO2 annealed at 450 °C suggesting that the dehydration of TiO(OH)2 was the primary source of the improvement. Knowing the role of dehydration of TiO2 allows obtaining a reliable benchmark material via simple air-annealing and becomes a key factor when developing advanced materials from commercial TiO2.
This work reports two quasi-solid composite electrolytes based on LiFT (Lithiated Fluorinated Titania) nanopowder and either 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) or 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMImTFSI) ionic liquid (IL). In details, LiFT nanopowder is doped with ca. 30 wt% of IL, giving rise to materials with formula LiFT/(EMImBF4)0.183 and LiFT/(EMImTFSI)0.087. The resulting composite electrolytes appear as powder-like solids as the IL is completely absorbed by LiFT. The correlation between structure, thermal properties and long-range charge migration processes of the here proposed electrolytes is investigated by several characterization techniques, as follows: i) differential scanning calorimetry (DSC) and high-resolution thermogravimetry (HR-TGA); ii) Fourier-transform infrared spectroscopy in both the medium and the far infrared (FT-MIR and FT-FIR); and iii) broadband electrical spectroscopy (BES). The conductivity of the here proposed composite electrolytes is promising. Indeed, at 30 and 100 °C it corresponds respectively to 1.75 × 10−3 S cm−1 and 1.05 × 10−2 S cm−1 for LiFT/(EMImBF4)0.183, and 1.36 × 10−2 S cm−1 and 4.42 × 10−2 S cm−1 for LiFT/(EMImTFSI)0.087. Finally, LiFT/(EMImTFSI)0.087 is used to fabricate a coin cell prototype, that is tested by galvanostatic cycling for performance and durability.
We have successfully developed miniature hydrogen-air proton exchange membrane (PEM) fuel cells (FC) on silicon and poly-dimethylsiloxane (PDMS) base substrates using conventional and non-conventional microfabrication technologies. Prototype base substrates were fabricated by using well-known micromachining technologies, such as photolithography, deep reactive ion etching, and soft lithography. Sputtering, a physical vapor deposition method, was used to deposit catalysts and electrodes directly on the surface of the Nafion PEM. This paper describes the novel microfabrication approaches employed to selectively deposit electrodes and catalyst materials on the membrane with improved morphology and structure of electrodes. The aim was to reduce precious metal catalyst loadings, ohmic (iR) losses, and to improve structural support for the thin-film FC with concurrent reduction in fabrication complexity.
Knowledge of the elastic properties of Li–Si alloys as a function of Li concentration is crucial in the development of reliable deformation and fracture mechanics models for Si anodes in Li-ion batteries. Here, we have studied these properties using first-principles calculations for both amorphous and crystalline phases observed during lithiation of Si anodes. In the case of crystalline alloys, we present the anisotropic elastic tensors as well as the homogenized Young's, shear, and bulk moduli and the Poisson's ratios. We find that while these moduli decrease in an approximately linear manner with increasing Li concentration leading to significant elastic softening (by about one order of magnitude) in both crystalline and amorphous systems, the Poisson's ratios remain in the range of 0.05–0.20 and 0.20–0.30 in the case of crystalline and amorphous systems, respectively. Further, for a given Li concentration, we find that the amorphous structures are elastically somewhat softer than their crystalline counterparts, the difference being more significant (about 30–40%) in Li-poor phases. Our results underscore the importance of including the concentration dependence of elastic constants in the analysis of stress and deformation fields during lithiation and de-lithiation of Si anodes.
Remaining useful life prediction is one of the key requirements in prognostics and health management. While a system or component exhibits degradation during its life cycle, there are various methods to predict its future performance and assess the time frame until it does no longer perform its desired functionality. The proposed data-driven and model-based hybrid/fusion prognostics framework interfaces a classical Bayesian model-based prognostics approach, namely particle filter, with two data-driven methods in purpose of improving the prediction accuracy. The first data-driven method establishes the measurement model (inferring the measurements from the internal system state) to account for situations where the internal system state is not accessible through direct measurements. The second data-driven method extrapolates the measurements beyond the range of actually available measurements to feed them back to the model-based method which further updates the particles and their weights during the long-term prediction phase. By leveraging the strengths of the data-driven and model-based methods, the proposed fusion prognostics framework can bridge the gap between data-driven prognostics and model-based prognostics when both abundant historical data and knowledge of the physical degradation process are available. The proposed framework was successfully applied on lithium-ion battery remaining useful life prediction and achieved a significantly better accuracy compared to the classical particle filter approach.
This investigation reports the fabrication of three different morphologies such as mud-like, cauliflower and interconnected nanoparticles of polypyrrole (ppy) thin films through oxidant assisted successive ionic layer adsorption and reaction (SILAR) method. The influence of oxidants like ammonium per sulfate (APS), ferric chloride (FC) and potassium dichromate (PDC) on structural, morphological, surface areas and electrochemical properties of ppy thin films is examined. Among three different morphologies, interconnected nanoparticles shaped ppy thin films provide a unique three-dimensional (3D) network, high surface area and meso-porous structure which satisfy the requirements for better supercapacitive electrode materials. The electrochemical tests manifest the high specific capacitance of 510Fg−1 at a current density of 0.25mAcm−2 with 85% capacitive retention after 1000cycles. These studies propose that the formation of distinct nanostructures through oxidant dependent chemical polymerization route is a straightforward way for improving the electrochemical properties of ppy based supercapacitors.
The behaviours of AA5052 alloy anode of the Al-air battery in alkaline electrolytes are investigated by the hydrogen gas evolution test and the electrochemical measurements. The combination of 8-hydroxyquinoline (8-HQ) and ZnO as the hybrid additives can effectively suppress the self-corrosion of AA5052 anode in alkaline solution, and there is a synergism between 8-HQ and ZnO. The surface analysis demonstrates a complex film is formed via the chelation of 8-HQ with Al3+ ions. The presence of ZnO promotes the stability of the complex film on the alloy matrix, and lowers the hydrogen evolution rate dramatically. A good discharge performance is found for AA5052 alloy anode in the above alkaline solution, and the anodic surface has a strong fluorescence after the discharge. The use of hybrid additives increases the anode utilization efficiency from 56.2% to 70.3%.
The charge–discharge behavior of a Sn negative electrode for use in a sodium secondary battery was investigated in an intermediate temperature ionic liquid, NaFSA–KFSA (x NaFSA = 0.56, x KFSA = 0.44, FSA = bis(fluorosulfonyl)amides), at 363 K. A Na/Sn half-cell was prepared using a Sn-film (10–12 μm t ) electrode. The charge–discharge curves at 0.619 mA cm−2 with cut-off voltages of 0.005 and 1.200 V exhibited three potential plateaus in both the charging (alloying) and discharging (de-alloying) processes, indicating the formation of various alloy phases. Charge and discharge capacities as high as 790 and 729 mA h (g-Sn)−1, respectively, were obtained for the 1st cycle; however, the capacities decreased rapidly due to volume change during the alloying and de-alloying processes. The best cycleability was achieved when the lower and higher cut-off voltages were set to 0.005 and 0.200 V, respectively. In this case, a reversible capacity of about 300 mA h (g-Sn)−1 was obtained for the initial 15 cycles.
Mesocarbon microbeads (MCMB) powders were treated in Ar–H2–SF6 radio frequency inductively coupled thermal plasma. The structure, chemical composition and related electrochemical property changes have been studied. The results demonstrated that the active surface area has a great influence on the electrochemical properties of MCMB powder, and the specific irreversible capacity loss decays non-linearly with the increase of active surface area.
Wireless sensor networks comprise an important research area and a near future for industry and communications. Wireless sensor networks contain resource-constrained sensor nodes that are powered by small batteries, limited process and memory and wireless communication. These features give sensors their versatility and drawbacks, such as their limited operating lifetimes. To feasibly deploy wireless sensor networks with isolated motes, several approaches and solutions have been developed; the most common, apart from using alternative power sources such as solar panels, are those that put sensors to sleep for time periods established by the application. We thus propose a fuzzy rule-based system that estimates the next duty cycle, taking the magnitude being tested and battery charge as input. To show how it works, we compare an analytical delta system to our contribution. As an application to test both systems, a sound pressure monitoring application is presented. The results have shown that the fuzzy rule-based system better predicts the evolution of the magnitude by which errors committed by idle periods decrease. This work also shows that application-oriented duty cycle control can be an alternative for measuring systems, thus saving battery and improving sensor node lifetime, with a reasonable loss of precision.
The prefrontal cortex helps adjust an organism's behavior to its environment. In particular, numerous studies have implicated the prefrontal cortex in the control of social behavior, but the neural circuits that mediate these effects remain unknown. Here we investigated behavioral adaptation to social defeat in mice and uncovered a critical contribution of neural projections from the medial prefrontal cortex to the dorsal periaqueductal gray, a brainstem area vital for defensive responses. Social defeat caused a weakening of functional connectivity between these two areas, and selective inhibition of these projections mimicked the behavioral effects of social defeat. These findings define a specific neural projection by which the prefrontal cortex can control and adapt social behavior.