batterydata/paper-abstracts huggingface dataset:
Publisher Summary This chapter explains radio frequency oscillators and frequency synthesizers. Radio frequency oscillators produce radio frequency signals without an input signal. Frequency synthesizers are used to control and vary the frequency of an oscillator very precisely. An oscillator is a device which produces an output signal without requiring an external input signal. An amplifier can be made into an oscillator if its output signal is fed back into its own input terminals to provide an input signal of the correct amplitude and phase. In addition, the configuration of popular oscillators such as Wien, phase shift, Hartley, Colpitts, Clapp, crystal and the phase locked loop are discussed. The criteria for choosing an oscillator depends on frequency stability, amplitude stability, low noise, low power consumption, and size. Frequency stability is important because it enables narrow-band communication systems to be accurately fixed within a frequency band. An unstable frequency oscillator also behaves like an unstable f.m. modulator and produces unwanted f.m. noise. An amplitude unstable oscillator behaves like amplitude modulated modulator because it produces unwanted a.m. modulation noise. Even if the oscillation frequency and amplitude can be held precisely, it is inevitable that noise is produced in an oscillator because of transistor noise which includes flicker noise, shot noise and i/frequency noise. In other words, oscillator noise is inevitable but it should be kept as low as possible. Low power consumption and small size are important in portable equipment.
Rapid gas-evaporation method is proposed and developed, which yields Si nanoparticles (SiNPs) in a few seconds at high yields of 20%–60% from inexpensive and safe bulk Si. Such rapid process is realized by heating the Si source to a temperature ≥2000 °C, much higher than the melting point of Si (1414 °C). The size of SiNPs is controlled at tens to hundreds nanometers simply by the Ar gas pressure during the evaporation process. Self-supporting films are fabricated simply by co-dispersion and filtration of the SiNPs and carbon nanotubes (CNTs) without using binders nor metal foils. The half-cell tests showed the improved performances of the SiNP-CNT composite films as anode when coated with graphitic carbon layer. Their performances are evaluated with various SiNP sizes and Si/CNT ratios systematically. The SiNP-CNT film with a Si/CNT mass ratio of 4 realizes the balanced film-based capacities of 618 mAh/gfilm, 230 mAh/cm3, and 0.644 mAh/cm2 with a moderate Si-based performance of 863 mAh/gSi at the 100th cycle.
A new model of lithium-ion transport processes in the LiFePO4 electrode is proposed. This model takes into account the phase transition LiFePO4 ↔FePO4 accompanying reversible lithium intercalation into the electrode during potential or current steps. The diffusion coefficient of Li+ ion and its dependence on the LiFePO4/FePO4 phase ratio have been determined by means of processing of experimental potential and current transients in accordance with the model's equations. The results of galvanostatic and potentiostatic intermittent titration techniques are in good agreement. The value of diffusion coefficient varies within 10−10–10−16 cm2 s−1 depending on the lithium content in solid solution Li X FePO4 and Li1−X FePO4 (X <0.02) or the LiFePO4/FePO4 phase ratio.
An efficient method is demonstrated to synthesize reduced graphene oxide/CoO nanowires (rGO/CoO) mutually-supporting porous structure, which is in situ prepared by annealing self-assembled graphene oxide (GO)/Co(CO3)0.5(OH)·0.11H2O nanowires composite in N2 atmosphere. The CoO nanowires are uniformly and tightly anchored on the rGO sheet surface, preventing the aggregation of the CoO nanowires and the restacking of rGO sheets. As an anode material for lithium ion batteries (LIBs), rGO/CoO electrode displays excellent electrochemical performance including a high reversible capacity of 994mAhg−1 even after 100 cycles with 96.3% capacity retention of the initial discharge capacity, super rate capability (718, 577, 504, 388 and 262mAhg−1 at 0.8, 3.2, 5, 7 and 10C, respectively, 1C=1Ag−1) and extremely excellent cycling performance at high rates (621mAhg−1 at 1C after 620 cycles; 520mAhg−1 at 3C even after 750 cycles).
Conventional hydropower systems that can take advantage of low head movement of water require substantial flow rates. However, these systems cannot harvest hydro energy from small sources of water with low head and low discharge, such as streams and creeks. The reciprocating hydropower system discussed in this paper can harvest power from such low flow discharge and low head sources. This paper presents a detailed proof-of-concept study of the hydropower model, including the underlining theoretical principles. Laboratory test results demonstrating the dependence of the lift force in the reciprocating small scale hydropower model as a function of flow velocity, size and rotational speed of the cylinder and comparison of the results with a previous study are also included. Two methods of power harvesting from the output displacement obtained from the hydropower system are discussed. The first employs electromagnetic induction principles and the other is based on a linear inertial generator using a conventional second order spring mass damper system. Finally, results from a finite element analysis of the hydropower system are presented and facilitate future design of the structural aspects of the housing for the reciprocating cylinder.
Why do the bogus cell phones with low abilities can grab small space in the emerging handset market? This study, through in-depth-interview, secondary data, aims to discuss and explore what the purchase's factors are, as well as acceptance and refusing on the bogus cell phones from consumers. Whether the brand image impacts the bogus cell phones or not? The findings has discovered: (1) the purchased desire is to choose from the price, brand image, its appearance design, the function characteristic, as well as the advertisement of the bogus cell phones; (2) consumer who purchases a bogus cell phone is influenced by the crowd's manner and one's behavior; (3) consumer is willing to buy the bogus cell phones with logo; (4) consumers purchase the bogus cell phone without negative news influence; (5) consumers thought that the impostor cell phones not only meet their needs but also make itself become popular; (6) consumers who purchase the bogus cell phones has low moral faith; therefore, they have no comments regarding infringement wisdom property rights; (7) consumers who use the bogus cell phones are the low end consumers.
Plants are invaded by an array of pathogens of which only a few succeed in causing disease. The attack by others is countered by a sophisticated immune system possessed by the plants. The plant immune system is broadly divided into two, viz. microbial-associated molecular-patterns-triggered immunity (MTI) and effector-triggered immunity (ETI). MTI confers basal resistance, while ETI confers durable resistance, often resulting in hypersensitive response. Plants also possess systemic acquired resistance (SAR), which provides long-term defense against a broad-spectrum of pathogens. Salicylic-acid-mediated systemic acquired immunity provokes the defense response throughout the plant system during pathogen infection at a particular site. Trans-generational immune priming allows the plant to heritably shield their progeny towards pathogens previously encountered. Plants circumvent the viral infection through RNA interference phenomena by utilizing small RNAs. This review summarizes the molecular mechanisms of plant immune system, and the latest breakthroughs reported in plant defense. We discuss the plant–pathogen interactions and integrated defense responses in the context of presenting an integral understanding in plant molecular immunity.
One-dimensional steady-state models have been developed for the recovery of Pb(II) ions from lead–acid battery recycling plant effluent by simultaneous lead and lead dioxide deposition, including oxygen evolution/reduction and hydrogen evolution as loss reactions. Both monopolar and bipolar reactor with porous graphite electrodes were modelled, as a design aid for predicting spatial distributions of potentials, concentrations, current densities and efficiencies, as well as specific electrical energy consumptions
and by-pass currents. Since the industrial effluent contains a large excess of supporting electrolyte (Na2SO4), the electrical migrational contribution to reactant transport rates was neglected and the current density–potential relationship was described by the Butler–Volmer equation, allowing for both kinetic and mass transport control. The models were implemented and the governing equations solved using commercial finite element software (FEMLAB). The effects were
investigated of electrolyte velocity, applied cathode potential, dissolved oxygen concentration and inlet Pb(II) ion concentration on single-pass conversion, current efficiency and specific electrical energy consumptions. According to model predictions, de-oxygenation of the inlet process stream was found to be crucial to achieving acceptable (i.e. >0.8) current efficiencies. Bipolar porous electrodes were also determined to be inappropriate for the recovery of Pb(II) from effluents, as the low concentration
involved resulted in the predicted fraction of current lost as by-pass current, i.e. current not flowing in and out of the bipolar electrode, to be greater than 90% for the ranges of the variables studied.
Macroporous silver films, ordered or fragmented, were fabricated by electrodeposition of silver into the interstitial spaces of templates formed by polystyrene (PS) latex spheres that had been self-assembled onto bare indium tin oxide (ITO) electrodes or onto gold-coated ITO (ITO/Au) electrodes (in which the electrode had been coated by gold sputtering deposition) from two room-temperature ionic liquids (ILs): N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (BMP-TFSI) and N-butyl-N-methylpyrrolidinium dicyanamide (BMP-DCA), respectively, under normal atmospheric conditions. After electrodeposition of silver, the PS spheres were removed by dissolution in tetrahydrofuran (THF) to leave a macroporous silver structure. The higher wettability of ILs onto PS spheres leads to improved penetration of the ILs into the cavities of the PS templates. Electrodeposition is easier if an electrolyte that has a good penetration into the interstitial spaces between the PS spheres. The macroporous silver electrode exhibited much better electrocatalytic performance with respect to nitrate reduction than a regular silver wire electrode. Quantitative determination of nitrate was also examined.
Based on thermodynamic calculations a potential/pH diagram for the Pb/H2SO4/H2O system is plotted. It defines the pH ranges of formation of the different phases and electrode systems, but the system Pb/H2SO4/H2O is kinetically controlled as well. During the anodic polarization of a lead plate immersed in sulfuric acid solution the following electrode systems form: - Lead sulfate electrode (Pb/PbSO4) in the potential region from -0.97V to -0.40V vs. Hg/HgSO4 reference electrode - Lead oxide/lead sulfate electrode (Pb/PbO/PbSO4) at potentials from -0.40V to +0.95V - Lead dioxide electrode (Pb/PbO2) at potentials above +0.95V
This study analyzes the effects of different storage technologies on a hybrid renewable energy system composed of photovoltaic, hydrokinetic and diesel generator. Five types of storage are considered: lead acid, lithium ion, vanadium redox flow, hydrogen and hydrogen-vanadium redox flow. The analysis is mainly based on indicators such as Net Present Cost, Cost of Energy, unmet load and CO2 emissions. HOMER software has been used in this paper with time-sampling models and sensitivity studies to determine the effects of each storage system. The results show that the vanadium redox flow batteries system presents a lower net present cost and cost of energy. The sensitivity analysis shows that the vanadium redox flow system presents a greater variation of the minimum state of charge (SOC) in relation to the net present cost. However, the system composed of hydrogen and fuel cell present the lowest variation. The two proposed strategies for energy control show the same performance. However, when using the Load Tracking Control, the variation of the minimum state of charge with respect to the net cost is greater than the variation obtained when applying the Load Cycle Control.
The commercialization of oxygen-related energy storage/conversion devices, for instance metal-air batteries or fuel cells, is highly dependent on development of low-cost, high performance electrocatalysts for oxygen reduction/oxygen evolution reactions (ORR and OER). In the present study, we employed Co-ZIF-9 as a sacrificial precursor to synthesize highly efficient bifunctional ORR/OER electrocatalysts through tuning the pyrolysis temperature and Fe-doping of the zeolitic imidazolate framework. The synthesized samples were characterized extensively using X-ray photoelectron spectroscopy (XPS), X-ray diffraction, elemental CHN and ICP analyses, and Fourier transform infrared (FTIR) spectroscopy as well as scanning (SEM) and transmission (TEM) electron microscopies. It has been found that the Fe-doping can significantly affect the electrocatalytic activity of the product through improving the number of transferred electrons. The ZIF-9_Fe3_Pyrol exhibited excellent electrocatalytic activity towards ORR (Eonset = 0.90 V vs. RHE) and OER (Eonset = 1.55 V vs. RHE), much better than other evaluated catalysts and comparable to the commercial PtRuC bifunctional catalyst. Moreover, the ZIF-9_Fe3_Pyrol sample outperformed the precious PtRuC catalyst with very little decay in ORR and OER activity over long continuous operation. The ZIF-9_Fe3_Pyrol exhibited excellent performance as a cathode catalyst in rechargeable Zn-air batteries, superior to the one assembled with the state-of-the-art catalyst.
A new gel-type polymer electrolyte (GPE) was made by the copolymerizing acrylonitrile (AN) and (2-methylacrylic acid 3-(bis-carboxymethylamino)-2-hydroxy-propyl ester) (GMA-IDA). The copolymer mixed with a plasticizer—propylene carbonate (PC) and lithium salt to form GPE. The lithium salts are LiCF3SO3, LiBr and LiClO4. FT-IR spectra show that the lithium ion in the LiClO4 system has the strongest interaction with the group based on the plasticized polymer. FT-IR spectra also indicate that CF3SO3 − prefers producing anion–cation association. Moreover, the 13C solid state NMR spectra for the carbons attached to the PC of GPE exhibited different level of chemical shift (158.5ppm) when the different lithium salts were added to the electrolyte. The results of differential scanning calorimeter (DSC) also indicate that the LiClO4 system has more free lithium ions; therefore, it has the maximum conductivity. In this study, the highest conductivity 2.98×10−3 Scm−1 exists in AG2/PC=20/80wt.% system which contain 3mmole(g-polymer)−1 LiClO4. Additionally, the polymer electrolytes, which contain GMA-IDA have better interfacial resistance stability with lithium electrode.
Genetic epidemiology is of topical and increasingly practical relevance. The subject attempts to answer 2 questions: (1) is there a genetic component to a disease, and (2) what genes are involved? This article summarizes genetic epidemiologic methods, describing family- and population-based methods used to locate and identify genes and the advantages and disadvantages of each approach. Health care professionals are faced with more and more genetic information, both from interested patients and from the media, and understanding the principles underlying genetic studies allows such information to be placed in context.
Batteries are used in a wide variety of applications as an energy store to bridge gaps in the primary source of supplied power for a given period of time. In some cases this bridging time, the battery’s “autonomy”, is fixed by local legislation but it is also often set by historically common practices. However, even if common practice dictates a long autonomy time, we are entering a new era of “cost and benefit realism” underpinned by environmentally friendly policies and we should challenge these historical practices at every opportunity if it can lead to resource and cost savings. In some cases the application engineer has no choice in the design autonomy; either follow a piece of local legislation (e.g. 4h autonomy for a “life safety” application), or actually work out what is needed! An example of the latter would be for a remote site, off-grid, using integrated wind/solar power (without emergency generator back-up) where you may have to design-in several days’ battery autonomy. This short paper proposes that a battery’s autonomy should be related to the time expected for the system to be without the primary power source, balanced by the capital costs and commercial risk of power failure. To discuss this we shall consider the factors in selecting the autonomy time and other related aspects for high voltage battery systems used in facility-wide uninterruptible power supply (UPS) systems.
Summary Aims To demonstrate the correlation between morphological and proliferation parameters with the biological behaviour of adrenocortical tumours (ACTs) in different age groups. Methods Seventy-six cases of ACT were evaluated comparing tumours of children (≤15 years, n =24) and adults (>15 years, n =52) regarding morphological features and proliferation rates. These parameters were also compared in clinically benign (CB) and clinically malignant (CM) tumours. Tumours were analysed according to Weiss’ histological parameters. Proliferation rates were assessed by MIB-1 labelling index and silver binding nucleolar organiser regions (AgNORs) were quantified by image analysis. Results ACTs in children presented higher proliferative activity than in adults. In adult's ACTs, MIB-1 labelling index (cut-off, 10%) (P =0.037) and the AgNOR pattern (P <0.001) had influence over the disease-free survival (DFS). The AgNOR pattern type I was associated with CB-ACT and the AgNOR pattern type II with CM-ACT. The AgNOR pattern type III was characteristic of children's ACTs and type IV was characteristic of non-neoplasic adrenal glands. Conclusion ACTs in children had a different morphological spectrum and higher proliferative activity than those tumours in adults, which should be always analysed as a separate group. In adults, our findings reinforce that the morphological criteria proposed by Weiss are an efficient way of differentiating CB-ACT from CM-ACT.
The process step of formation is one key process to guarantee high performance, long-lasting and safe automotive lithium-ion cells. Since the formation of the cell is the most expensive process in cell manufacturing, reducing process cost and time is advanced. The state-of-the-art formation process includes the cycling of lithium-ion cells each on its own power electronic channel which amounts to about 38% of the total formation costs. Therefore, this paper proposes an optimized formation method by serial-connected lithium-ion cells. Due to small resistance and capacity deviations conditioned by manufacturing tolerances, charge balancing is necessary for formation of serial-connected cells. This paper introduces several serial interconnection circuits for serial cell formation, like passive balancing or drop out system. Furthermore, the associated influences on the formation process parameters, e.g. the charging profile and the charge current control are investigated. The comprehensive comparison of serial formation techniques reveals cost reduction potentials and challenges regarding the process control.
The discharge and charge mechanisms of the Li-S battery involve the formation of soluble lithium polysulfide species that can diffuse through the battery and cause issues related to capacity fade and poor Coulombic efficiency. In order to control the behavior of the lithium polysulfides, thiol-based electrolyte additives such as biphenyl-4,4′-dithiol (BPD) were used to enhance capacity retention in lithium-sulfur batteries by controlling polysulfide dissolution. In situ Raman spectroscopy, in situ UV–vis spectroscopy, and electrospray ionization mass spectrometry show that an additional sulfur reduction process observed at ~2.1 V vs. Li/Li+ as a result of BPD addition is associated with the formation of BPD-short chain polysulfide complexes such as BPD-Sn anion (1≤n≤4). The interaction between BPD and short chain polysulfide postpones formation of soluble short chain polysulfides and alters the kinetics of the dissolution process. A smooth SEI/Li entangled phase is found on the Li anode with BPD addition. The BPD additive increases the capacity retention of lithium-sulfur batteries, mainly due to the formation of various BPD-polysulfide complexes which prevents polysulfide dissolution. Comparison with other thiol-based additives shows that the optimal additive balances solubility and polysulfide-additive stabilization.
Metals capable of forming alloys with Li are of great interest as an alternative to present carbon electrodes, hence the importance of knowing their interactions with electrolytes is necessary. Herein we report further on the high-voltage extra irreversibility of Sn electrodeposited thin films vs. Li in EC–DMC 1M LiPF6 electrolytes. We show that this high-voltage irreversibility is strongly dependent upon the electrolyte composition as demonstrated by its disappearance in EC-free electrolytes. This finding coupled with IR spectroscopy measurements provides direct evidence for the tin-driven catalytic degradation of EC during the discharge of Sn/Li cells. From an electrochemical survey of various metals, capable of alloying with Li, we found that Bi and Pb behaved like Sn while Si and Sb did not act as catalysts towards EC degradation. A rationale for such behaviour is proposed, a procedure to bypass EC degradation with the addition of VC is presented, and an explanation for the non-observance of catalytic-driven EC degradation for Sn/C composites is provided.
Cognitive flexibility, a core aspect of executive functioning, is required for the speeded shifting between different tasks and sets. Using an interindividual differences approach, we examined whether cognitive flexibility, as assessed by the Delis–Kaplan card-sorting test, is associated with gray matter volume (GMV) and functional connectivity (FC) of regions of a core network of multiple cognitive demands as well as with different facets of trait impulsivity. The core multiple-demand network was derived from three large-scale neuroimaging meta-analyses and only included regions that showed consistent associations with sustained attention, working memory as well as inhibitory control. We tested to what extent self-reported impulsivity as well as GMV and resting-state FC in this core network predicted cognitive flexibility independently and incrementally. Our analyses revealed that card-sorting performance correlated positively with GMV of the right anterior insula, FC between bilateral anterior insula and midcingulate cortex/supplementary motor area as well as the impulsivity dimension “Premeditation.” Importantly, GMV, FC and impulsivity together accounted for more variance of card-sorting performance than every parameter alone. Our results therefore indicate that various factors contribute individually to cognitive flexibility, underlining the need to search across multiple modalities when aiming to unveil the mechanisms behind executive functioning.