Effect of Discharge Rate on Positive Active Material of Lead Carbon Battery for Energy Storage
NASA Astrophysics Data System (ADS)
Chen, Kailun; Liu, Hao; Hu, Chen; Gao, Fei; Yang, Kai; Wang, Hao
2017-10-01
Lead carbon battery has been widespread concern with its excellent performance of charge and discharge under High Rate Part State of Charge (HRPSoC) as well as its cycle performance. In this paper, the cycling performance of lead carbon battery for energy storage was tested by different discharge rate. The effects of different discharge rate on the composition and morphology of positive active materials in the cycle was studied by XRD and SEM. The effect of different discharge rate on the ohmic impedance of lead carbon battery was studied by testing Electrochemical Impedance Spectroscopy with different capacity retention rates. The results show that with the increase of the discharge rate, the content of PbO2 in the positive active material increases, the active substance utilization and the particle size of PbO2 crystal declines, and the ohmic impedance of the battery decreases.
Effect of packing material on methane activation in a dielectric barrier discharge reactor
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jo, Sungkwon; Hoon Lee, Dae; Seok Kang, Woo
2013-12-15
The conversion of methane is measured in a planar-type dielectric barrier discharge reactor using γ-Al{sub 2}O{sub 3} (sphere), α-Al{sub 2}O{sub 3} (sphere), and γ-Al{sub 2}O{sub 3} (16–20 mesh). Investigations on the surface properties and shape of the three packing materials clearly indicate that methane activation is considerably affected by the material used. Capacitances inside the discharge gap are estimated from charge–voltage plots, and a comparison of the generated and transferred charges for different packing conditions show that the difference in surface properties between γ- and α-phase Al{sub 2}O{sub 3} affects the discharge characteristics. Moreover, all packing conditions show different chargemore » characteristics that are related to the electron density. Finally, the packing material's shape affects the local electron temperature, which is strongly related to methane conversion. The combined results indicate that both microscale and macroscale variations in a packing material affect the discharge characteristics, and a packing material should be considered carefully for effective methane activation.« less
Nano-Enabled Technologies for Naval Aviation Applications
2015-06-05
4. Reduced self- discharge DEW 1. Active materials (silicon based/anode only); 2. Active materials coated on CNTs surface; 3...polymer film capacitors have the potential to provide higher energy density, higher power density, reduce weight, improve duty cycles (fast discharge and...dependent excess of 200C) 4. Nano-particle dispersion 5. Understanding discharge rate 6. Design and control of the interface 1. Increased
Thermal activated ("thermal") battery technology. Part IIIa: FeS 2 cathode material
NASA Astrophysics Data System (ADS)
Masset, Patrick J.; Guidotti, Ronald A.
This article presents an overview of the pyrite FeS 2 used as cathode material in thermally activated ("thermal") batteries. A large emphasis was placed on the physicochemical properties and electrochemical performance of the pyrite FeS 2, including the discharge mechanisms, self-discharge phenomena, and recent developments.
Battery designs with high capacity anode materials and cathode materials
Masarapu, Charan; Anguchamy, Yogesh Kumar; Han, Yongbong; Deng, Haixia; Kumar, Sujeet; Lopez, Herman A.
2017-10-03
Improved high energy capacity designs for lithium ion batteries are described that take advantage of the properties of high specific capacity anode active compositions and high specific capacity cathode active compositions. In particular, specific electrode designs provide for achieving very high energy densities. Furthermore, the complex behavior of the active materials is used advantageously in a radical electrode balancing design that significantly reduced wasted electrode capacity in either electrode when cycling under realistic conditions of moderate to high discharge rates and/or over a reduced depth of discharge.
In situ study of LaY2Ni9 compound as Ni MH negative-electrode material
NASA Astrophysics Data System (ADS)
Latroche, M.; Isnard, O.
2008-03-01
The behavior of a Ni-MH (metal hydride) negative composite electrode made of LaY2Ni9 active material has been studied dynamically using in situ neutron diffraction during a complete charge-discharge electrochemical cycle. From the analysis of the collected diffraction patterns, the phase identity, phase amount variations and cell volume evolutions have been determined as a function of the electrochemical state of (dis)charge. The active material shows a typical two-phase behavior with equilibrium between a hydrogen-poor α phase and a hydrogen-rich β one. The lower electrochemical reversible capacity as compared to solid-gas properties has been interpreted in terms of hydrogen gas evolving during charge and kinetic limitation due to slow β to α transformation during discharge, which hinders high discharge rates.
NASA Astrophysics Data System (ADS)
Lukes, Petr; Clupek, Martin; Babicky, Vaclav; Sisrova, Irena; Janda, Vaclav
2011-06-01
The effects of tungsten material used as a high-voltage needle electrode on the production of hydrogen peroxide and the degradation of dimethylsulfoxide (DMSO) caused by a pulsed corona discharge in water were investigated. A reactor of needle-plate electrode geometry was used. The erosion of the tungsten electrodes by the discharge was evaluated. The yields of H2O2 production and the decomposition of DMSO by the discharge, which were obtained using the tungsten electrodes, were compared with those determined for titanium electrodes. The electrode erosion increased significantly with an increase in the solution conductivity. A large fraction (50-70%) of the eroded tungsten electrode material was released into the solution in dissolved form as tungstate WO_4^{2-} ions. A correlation between the amount of eroded tungsten material released into the solution and the chemical effects induced by the discharge was determined. Lower yields of H2O2 and a higher degradation of DMSO by the discharge were obtained using the tungsten electrodes than were determined using titanium electrodes. Tungstate ions were shown to play a dominant role in the decomposition of H2O2, which was produced by the discharge using a tungsten electrode. The higher degradation of DMSO that was determined for tungsten was attributed to the tungstate-catalyzed oxidation of DMSO by H2O2, in addition to the oxidation of DMSO by OH radicals. Such a mechanism was supported by the detection of degradation by-products of DMSO (methanesulfonate, sulfate and dimethyl sulfone). The catalytic role of tungstate ions in the plasmachemical activity of the discharge generated using a tungsten electrode was also demonstrated on a pH-dependent decomposition of H2O2 and DMSO.
Self-discharge of electrochemical capacitors based on soluble or grafted quinone.
Shul, Galyna; Bélanger, Daniel
2016-07-28
The self-discharge of hybrid electrochemical capacitors based on the redox activity of electrolyte additives or grafted species to the electrode material is investigated simultaneously for the cell and each individual electrode. Electrochemical capacitors using a redox-active electrolyte consisting in hydroquinone added to the electrolyte solution and a redox-active electrode based on anthraquinone-grafted carbon as a negative electrode are investigated. The results are analyzed by using Conway kinetic models and compared to those of a common electrochemical double layer capacitor. The self-discharge investigation is complemented by charge/discharge cycling and it is shown that processes affecting galvanostatic charge/discharge cycling and the self-discharge rate occurring at each electrode of an electrochemical capacitor are different but related to each other. The electrochemical capacitor containing hydroquinone in the electrolyte exhibits a much quicker self-discharge rate than that using a negative electrode based on grafted anthraquinone with a 50% decay of the cell voltage of the fully charged device in 0.6 and 6 h, respectively. The fast self-discharge of the former is due to the diffusion of benzoquinone molecules (formed at the positive electrode during charging) to the negative electrode, where they are reduced, causing a quick depolarization. The grafting of anthraquinone molecules on the carbon material of the negative electrode led to a much slower self-discharge, which nonetheless occurred, by the reaction of the reduced form of the grafted species with electrolyte species.
NASA Astrophysics Data System (ADS)
Segi, Takashi; Masuda, Ryo; Kobayashi, Yasuhiro; Tsubota, Takayuki; Yoda, Yoshitaka; Seto, Makoto
2016-12-01
Layered rocksalt type oxides, such as Li(Ni1/3Mn1/3Co1/3)O2, are widely used as the cathode active materials of lithium-ion rechargeable batteries. Because the nickel ions are associated with the role of the charge compensation at discharge and charge, the 61Ni Mössbauer measurements at 6 K using synchrotron radiation were performed to reveal the role of Ni. The Ni ions of the active materials play two roles for the redox process between the charge and discharge states of lithium-ion batteries. Half of the total Ni ions change to the low-spin Ni3+ with Jahn-Teller distortion from the Ni2+ ions of the discharge state. The remainder exhibit low-spin state divalent Ni ions.
Simulation of electrochemical behavior in Lithium ion battery during discharge process.
Chen, Yong; Huo, Weiwei; Lin, Muyi; Zhao, Li
2018-01-01
An electrochemical Lithium ion battery model was built taking into account the electrochemical reactions. The polarization was divided into parts which were related to the solid phase and the electrolyte mass transport of species, and the electrochemical reactions. The influence factors on battery polarization were studied, including the active material particle radius and the electrolyte salt concentration. The results showed that diffusion polarization exist in the positive and negative electrodes, and diffusion polarization increase with the conducting of the discharge process. The physicochemical parameters of the Lithium ion battery had the huge effect on cell voltage via polarization. The simulation data show that the polarization voltage has close relationship with active material particle size, discharging rate and ambient temperature.
Simulation of electrochemical behavior in Lithium ion battery during discharge process
Chen, Yong; Lin, Muyi; Zhao, Li
2018-01-01
An electrochemical Lithium ion battery model was built taking into account the electrochemical reactions. The polarization was divided into parts which were related to the solid phase and the electrolyte mass transport of species, and the electrochemical reactions. The influence factors on battery polarization were studied, including the active material particle radius and the electrolyte salt concentration. The results showed that diffusion polarization exist in the positive and negative electrodes, and diffusion polarization increase with the conducting of the discharge process. The physicochemical parameters of the Lithium ion battery had the huge effect on cell voltage via polarization. The simulation data show that the polarization voltage has close relationship with active material particle size, discharging rate and ambient temperature. PMID:29293535
Determination of the “NiOOH” charge and discharge mechanisms at ideal activity
Merrill, Matthew; Worsley, Marcus; Wittstock, Arne; ...
2014-01-24
Here, optimization of electrodeposition conditions produced Ni(OH) 2 deposits chargeable up to 1.84 ± 0.02 e – per Ni on and the resulting nickel oxide/hydroxide active material could subsequently deliver 1.58 ± 0.02 e – per Ni ion (462 mA h/g) over a potential range <0.2 V. The ability of the “NiOOH” active material to deliver an approximately ideal charge and discharge facilitated a coulometric and thermodynamic analysis through which the charge/discharge mechanisms were determined from known enthalpies of formation. The (dis)charge states were confirmed with in situ Raman spectroscopy. The mechanisms were additionally evaluated with respect to pH andmore » potential dependence, charge quantities, hysteresis, and fluoride ion partial inhibition of the charge mechanism. The results indicate that the “NiOOH” (dis)charges as a solid-state system with mechanisms consistent with known nickel and oxygen redox reactions. A defect chemistry mechanism known for the LiNiO 2 system also occurs for “NiOOH” to cause both high activity and hysteresis. Similar to other cation insertion nickel oxides, the activity of the “NiOOH” mechanism is predominantly due to oxygen redox activity and does not involve the Ni4 + oxidation state. The “NiOOH” was produced from cathodic electrodeposition of Ni(OH) 2 from nickel nitrate solutions onto highly oriented pyrolytic graphite at ideal electrodeposition current efficiencies and the deposition mechanism was also characterized.« less
Structural models for nickel electrode active mass
NASA Technical Reports Server (NTRS)
Cornilsen, Bahne C.; Karjala, P. J.; Loyselle, P. L.
1987-01-01
Raman spectroscopic data allow one to distinguish nickel electrode active mass, alpha and beta phase materials. Discharges active mass is not isostructural with beta-Ni(OH)2. This is contrary to the generally accepted model for the discharged beta phase of active mass. It is concluded that charged active mass displays a disordered and nonstoichiometric, nonclose packed structure of the R3 bar m, NiOOH structure type. Raman spectral data and x ray diffraction data are analyzed and shown to be consistent with this structural model.
Lightweight fibrous nickel electrodes for nickel-hydrogen batteries
NASA Technical Reports Server (NTRS)
Britton, Doris L.
1989-01-01
The NASA Lewis Research Center is currently developing nickel electrodes for nickel-hydrogen batteries. These electrodes are lighter in weight and have higher energy densities than the heavier state-of-the-art sintered nickel electrodes. Lightweight fibrous materials or plaques are used as conductive supports for the nickel hydroxide active material. These materials are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. Evaluation is performed in half cells structured in the bipolar configuration. Initial performance tests include capacity measurements at five discharge levels, C/2, 1.0C, 1.37C, 2.0C, and 2.74C. The electrodes that pass the initial tests are life cycle-tested in a low Earth orbit regime at 80 percent depth of discharge.
Thermally activated ("thermal") battery technology. Part IV. Anode materials
NASA Astrophysics Data System (ADS)
Guidotti, Ronald A.; Masset, Patrick J.
In this paper, the history of anode materials developed for use in thermally activated ("thermal") batteries is presented. The chemistries (phases) and electrochemical characteristics (discharge mechanisms) of these materials are described, along with general thermodynamic properties, where available. This paper is the last of a five-part series that presents a general review of thermal-battery technology.
NASA Astrophysics Data System (ADS)
Masset, Patrick J.; Guidotti, Ronald A.
This article presents an overview of cathode materials (except the pyrite FeS 2) used or envisaged in thermally activated ("thermal") batteries. The physicochemical properties and electrochemical performance of different cathode families (oxides, sulfides) are reviewed, including discharge mechanisms, when known.
Charge–discharge properties of tin dioxide for sodium-ion battery
DOE Office of Scientific and Technical Information (OSTI.GOV)
Park, Jinsoo; Park, Jin-Woo; Han, Jeong-Hui
Highlights: • The electrochemical reaction of SnO2 as an anode for Na-ion batteries was studied. • The SnO2 electrode delivered the initial discharge capacity of 747 mAh/g. • Alarge irreversible capacity (597 mAh/g)was observedin the first cycle. • The in-plain crack in the electrode caused the incompletereduction of SnO{sub 2}. - Abstract: Tin dioxide was investigated as an anode material for sodium-ion batteries. The Na/SnO{sub 2} cell delivered a first discharge capacity of 747 mAh/g, but the first charge capacity was 150 mAh/g. The irreversible capacity in the first cycle was examined through characterization by X-ray diffraction and scanning electron microscopy.more » X-ray diffraction analysis revealed that the SnO{sub 2} active material was not reduced fully to metallic Sn. Furrows and wrinkles were formed on the electrode surface owing to the volumetric expansion upon first discharge, which led to a deterioration of the electrode structure and a loss of electrical contact between the active materials. The analysis is summarized in the schematic drawing.« less
Chen, Chih-Yao; Sano, Teruki; Tsuda, Tetsuya; Ui, Koichi; Oshima, Yoshifumi; Yamagata, Masaki; Ishikawa, Masashi; Haruta, Masakazu; Doi, Takayuki; Inaba, Minoru; Kuwabata, Susumu
2016-01-01
A comprehensive understanding of the charge/discharge behaviour of high-capacity anode active materials, e.g., Si and Li, is essential for the design and development of next-generation high-performance Li-based batteries. Here, we demonstrate the in situ scanning electron microscopy (in situ SEM) of Si anodes in a configuration analogous to actual lithium-ion batteries (LIBs) with an ionic liquid (IL) that is expected to be a functional LIB electrolyte in the future. We discovered that variations in the morphology of Si active materials during charge/discharge processes is strongly dependent on their size and shape. Even the diffusion of atomic Li into Si materials can be visualized using a back-scattering electron imaging technique. The electrode reactions were successfully recorded as video clips. This in situ SEM technique can simultaneously provide useful data on, for example, morphological variations and elemental distributions, as well as electrochemical data. PMID:27782200
Ultrasonic Abrasive Removal Of EDM Recast
NASA Technical Reports Server (NTRS)
Mandel, Johnny L.; Jacobson, Marlowe S.
1990-01-01
Ultrasonic abrasive process removes layer of recast material generated during electrical-discharge machining (EDM) of damper pocket on turbine blade. Form-fitted tool vibrated ultrasonically in damper pocket from which material removed. Vibrations activate abrasive in pocket. Amount of material removed controlled precisely.
A theoretical model to determine the capacity performance of shape-specific electrodes
NASA Astrophysics Data System (ADS)
Yue, Yuan; Liang, Hong
2018-06-01
A theory is proposed to explain and predict the electrochemical process during reaction between lithium ions and electrode materials. In the model, the process of reaction is proceeded into two steps, surface adsorption and diffusion of lithium ions. The surface adsorption is an instantaneous process for lithium ions to adsorb onto the surface sites of active materials. The diffusion of lithium ions into particles is determined by the charge-discharge condition. A formula to determine the maximum specific capacity of active materials at different charging rates (C-rates) is derived. The maximum specific capacity is correlated to characteristic parameters of materials and cycling - such as size, aspect ratio, surface area, and C-rate. Analysis indicates that larger particle size or greater aspect ratio of active materials and faster C-rates can reduce maximum specific capacity. This suggests that reducing particle size of active materials and slowing the charge-discharge speed can provide enhanced electrochemical performance of a battery cell. Furthermore, the model is validated by published experimental results. This model brings new understanding in quantification of electrochemical kinetics and capacity performance. It enables development of design strategies for novel electrodes and future generation of energy storage devices.
NASA Astrophysics Data System (ADS)
Sierczynska, Agnieszka; Lota, Katarzyna; Lota, Grzegorz
Nickel hydroxide is used as an active material in positive electrodes of rechargeable alkaline batteries. The capacity of nickel-metal hydride (Ni-MH) batteries depends on the specific capacity of the positive electrode and utilization of the active material because of the Ni(OH) 2/NiOOH electrode capacity limitation. The practical capacity of the positive nickel electrode depends on the efficiency of the conductive network connecting the Ni(OH) 2 particle with the current collector. As β-Ni(OH) 2 is a kind of semiconductor, the additives are necessary to improve the conductivity between the active material and the current collector. In this study the effect of adding different carbon materials (flake graphite, multi-walled carbon nanotubes (MWNT)) on the electrochemical performance of pasted nickel-foam electrode was established. A method of production of MWNT special type of catalysts had an influence on the performance of the nickel electrodes. The electrochemical tests showed that the electrode with added MWNT (110-170 nm diameter) exhibited better electrochemical properties in the chargeability, specific discharge capacity, active material utilization, discharge voltage and cycling stability. The nickel electrodes with MWNT addition (110-170 nm diameter) have exhibited a specific capacity close to 280 mAh g -1 of Ni(OH) 2, and the degree of active material utilization was ∼96%.
Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material
Doeff, Marca M.; Peng, Marcus Y.; Ma, Yanping; Visco, Steven J.; DeJonghe, Lutgard C.
1996-01-01
An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M.sub.x Z.sub.y Mn.sub.(1-y) O.sub.2, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell.
Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material
Doeff, M.M.; Peng, M.Y.; Ma, Y.; Visco, S.J.; DeJonghe, L.C.
1996-09-24
An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M{sub x}Z{sub y}Mn{sub (1{minus}y)}O{sub 2}, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell. 11 figs.
NASA Technical Reports Server (NTRS)
Eckert, Juergen; Varma, Ravi; Diebolt, Lisa; Reid, Margaret
1998-01-01
The objectives of this presentation are: identify atomic-level signatures of electrochemical activity of the active material on the Ni positive plates of Ni-H2 batteries, relate finding to cycling conditions and histories, and develop INS spectroscopy as a non-destructive testing technique for the evaluation of Ni-positive plates of Ni-H2 batteries.
Layton, Aimee M.; Whitworth, James; Peacock, James; Bartels, Matthew N.; Jellen, Patricia A.; Thomashow, Byron M.
2014-01-01
The purpose of this study was to determine the feasibility and acceptability of utilizing a smartphone based application to monitor compliance in patients with cardiac disease around discharge. For 60 days after discharge, patients' medication compliance, physical activity, follow-up care, symptoms, and reading of education material were monitored daily with the application. 16 patients were enrolled in the study (12 males, 4 females, age 55 ± 18 years) during their hospital stay. Five participants were rehospitalized during the study and did not use the application once discharged. Seven participants completed 1–30 days and four patients completed >31 days. For those 11 patients, medication reminders were utilized 37% (1–30-day group) and 53% (>31-day group) of the time, education material was read 44% (1–30) and 53% (>31) of the time, and physical activity was reported 25% (1–30) and 42% (>31) of the time. Findings demonstrated that patients with stable health utilized the application, even if only minimally. Patients with decreased breath sounds by physical exam and who reported their health as fair to poor on the day of discharge were less likely to utilize the application. Acceptability of the application to report health status varied among the stable patients. PMID:25574165
Discharge current distribution in stratified soil under impulse discharge
NASA Astrophysics Data System (ADS)
Eniola Fajingbesi, Fawwaz; Shahida Midi, Nur; Elsheikh, Elsheikh M. A.; Hajar Yusoff, Siti
2017-06-01
The mobility of charge particles traversing a material defines its electrical properties. Soil (earth) have long been the universal grounding before and after the inception of active ground systems for electrical appliance purpose due to it semi-conductive properties. The soil can thus be modelled as a single material exhibiting semi-complex inductive-reactive impedance. Under impulse discharge such as lightning strikes to soil this property of soil could result in electric potential level fluctuation ranging from ground potential rise/fall to electromagnetic pulse coupling that could ultimately fail connected electrical appliance. In this work we have experimentally model the soil and lightning discharge using point to plane electrode setup to observe the current distribution characteristics at different soil conductivity [mS/m] range. The result presented from this research indicate above 5% shift in conductivity before and after discharge which is significant for consideration when dealing with grounding designs. The current distribution in soil have also be successfully observed and analysed from experimental result using mean current magnitude in relation to electrode distance and location, current density variation with depth all showing strong correlation with theoretical assumptions of a semi-complex impedance material.
Dudney, Nancy J.; Li, Juchuan
2015-01-09
It is not simple to pull all the energy from a battery. For a battery to discharge, electrons and ions have to reach the same place in the active electrode material at the same moment. To reach the entire volume of the battery and maximize energy use, internal pathways for both electrons and ions must be low-resistance and continuous, connecting all regions of the battery electrode. Traditional batteries consist of a randomly distributed mixture of conductive phases within the active battery material. In these materials, bottlenecks and poor contacts may impede effective access to parts of the battery. On pagemore » 149 of this issue, Kirshenbaum et al. (1) explore a different approach, in which silver electronic pathways form on internal surfaces as the battery is discharged. Finally, the electronic pathways are well distributed throughout the electrode, improving battery performance.« less
NASA Astrophysics Data System (ADS)
Levenson, SYa; Gendlina, LI; Kulikova, EG
2018-03-01
The paper reviews vibration feeders used to discharge storage reservoirs in mineral mining. In spotlight are vibrofeeders equipped with an active member of low flexural rigidity developed at Chinakal Institute of Mining. The authors present the results of the physical and numerical studies on vibratory discharge of cohesive rocks from a bunker.
Nontraditional, Safe, High Voltage Rechargeable Cells of Long Cycle Life.
Braga, Maria Helena; M Subramaniyam, Chandrasekar; Murchison, Andrew J; Goodenough, John B
2018-05-23
A room-temperature all-solid-state rechargeable battery cell containing a tandem electrolyte consisting of a Li + -glass electrolyte in contact with a lithium anode and a plasticizer in contact with a conventional, low cost oxide host cathode was charged to 5 V versus lithium with a charge/discharge cycle life of over 23,000 cycles at a rate of 153 mA·g -1 of active material. A larger positive electrode cell with 329 cycles had a capacity of 585 mAh·g -1 at a cutoff of 2.5 V and a current of 23 mA·g -1 of the active material; the capacity rose with cycle number over the 329 cycles tested during 13 consecutive months. Another cell had a discharge voltage from 4.5 to 3.7 V over 316 cycles at a rate of 46 mA·g -1 of active material. Both the Li + -glass electrolyte and the plasticizer contain electric dipoles that respond to the internal electric fields generated during charge by a redistribution of mobile cations in the glass and by extraction of Li + from the active cathode host particles. The electric dipoles remain oriented during discharge to retain an internal electric field after a discharge. The plasticizer accommodates to the volume changes in the active cathode particles during charge/discharge cycling and retains during charge the Li + extracted from the cathode particles at the plasticizer/cathode-particle interface; return of these Li + to the active cathode particles during discharge only involves a displacement back across the plasticizer/cathode interface and transport within the cathode particle. A slow motion at room temperature of the electric dipoles in the Li + -glass electrolyte increases with time the electric field across the EDLC of the anode/Li + -glass interface to where Li + from the glass electrolyte is plated on the anode without being replenished from the cathode, which charges the Li + -glass electrolyte negative and consequently the glass side of the Li + -glass/plasticizer EDLC. Stripping back the Li + to the Li + -glass during discharge is enhanced by the negative charge in the Li + -glass. Since the Li + -glass is not reduced on contact with metallic lithium, no passivating interface layer contributes to a capacity fade; instead, the discharge capacity increases with cycle number as a result of dipole polarization in the Li + -glass electrolyte leading to a capacity increase of the Li + -glass/plasticizer EDLC. The storage of electric power by both faradaic electrochemical extraction/insertion of Li + in the cathode and electrostatic stored energy in the EDLCs provides a safe and fast charge and discharge with a long cycle life and a greater capacity than can be provided by the cathode host extraction/insertion reaction. The cell can be charged to a high voltage versus a lithium anode because of the added charge of the EDLCs.
Variation of alluvial-channel width with discharge and character of sediment
Osterkamp, W.R.
1979-01-01
Use of channel measurements to estimate discharge characteristics of alluvial streams has shown that little agreement exists for the exponent of the width-discharge relation. For the equation Q = aWAb, where Q is mean discharge and WA is active-channel width, it is proposed that the exponent, b, should be of fixed value for most natural, perennial, alluvial stream channels and that the coefficient, a, varies with the characteristics of the bed and bank material.Three groups of perennial stream channels with differing characteristics were selected for study using consistent procedures of data collection. A common feature of the groups was general channel stability, that is, absence of excessive widening by erosive discharges. Group 1 consisted of 32 channels of gradient exceeding 0.0080, low suspended-sediment discharge, high channel roughness, and low discharge variability. Group 2 consisted of 13 streams in Kansas having at least 70 percent silt and clay in the bed material and having similar discharge variability, climate, gradient, and riparian vegetation. Group 3, in southern Missouri, consisted of discharge channels of 18 springs having similar conditions of very low discharge variability, climate and vegetation, but variable bed and bank material. Values for the exponent for the three groups of data are 1.98, 1.97, and 1.97, respectively, whereas values of the coefficients are 0.017, 0.042, and 0.011 when discharge is expressed in cubic meters per second and width is in meters. The relation for high-gradient channels (group 1) is supported by published data from laboratory flumes.The similarity of the three values of the exponent demonstrates that a standard exponent of 2.0, significant to two figures, is reasonable for the width-mean discharge relation of perennial, alluvial stream channels, and that the exponent is independent of other variables. Using a fixed exponent of 2.0, a family of simple power-function equations was developed expressing the manner in which channel sediment affects the width-discharge relation.
All-Iron Redox Flow Battery Tailored for Off-Grid Portable Applications.
Tucker, Michael C; Phillips, Adam; Weber, Adam Z
2015-12-07
An all-iron redox flow battery is proposed and developed for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. The design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe2 (SO4 )3 active material and 1.2 m NaCl supporting electrolyte. With these materials, an average power density around 20 mW cm(-2) and a maximum energy density of 11.5 Wh L(-1) are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh(-1) , or only US$0.034 per mobile phone charge. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Code of Federal Regulations, 2010 CFR
2010-07-01
... quality certifications and, if applicable, coastal zone consistency determinations. For activities which... and, if applicable, coastal zone consistency determinations should be provided using the procedures of...
Code of Federal Regulations, 2011 CFR
2011-07-01
... quality certifications and, if applicable, coastal zone consistency determinations. For activities which... and, if applicable, coastal zone consistency determinations should be provided using the procedures of...
Streamflow characteristics related to channel geometry of streams in western United States
Hedman, E.R.; Osterkamp, W.R.
1982-01-01
Assessment of surface-mining and reclamation activities generally requires extensive hydrologic data. Adequate streamflow data from instrumented gaging stations rarely are available, and estimates of surface- water discharge based on rainfall-runoff models, drainage area, and basin characteristics sometimes have proven unreliable. Channel-geometry measurements offer an alternative method of quickly and inexpensively estimating stream-flow characteristics for ungaged streams. The method uses the empirical development of equations to yield a discharge value from channel-geometry and channel-material data. The equations are developed by collecting data at numerous streamflow-gaging sites and statistically relating those data to selected discharge characteristics. Mean annual runoff and flood discharges with selected recurrence intervals can be estimated for perennial, intermittent, and ephemeral streams. The equations were developed from data collected in the western one-half of the conterminous United States. The effect of the channel-material and runoff characteristics are accounted for with the equations.
40 CFR 437.1 - General applicability.
Code of Federal Regulations, 2010 CFR
2010-07-01
... centralized silver recovery from used photographic or x-ray materials activities. The discharge resulting from centralized silver recovery from used photographic or x-ray materials that is treated at a CWT facility along... Nickel Subcategory), Subpart X (Secondary Precious Metals Subcategory), Subpart Z (Secondary Tantalum...
40 CFR 437.1 - General applicability.
Code of Federal Regulations, 2011 CFR
2011-07-01
... centralized silver recovery from used photographic or x-ray materials activities. The discharge resulting from centralized silver recovery from used photographic or x-ray materials that is treated at a CWT facility along... Nickel Subcategory), subpart X (Secondary Precious Metals Subcategory), subpart Z (Secondary Tantalum...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhu, Yinhai; Xiang, Xiaoxia; Liu, Enhui, E-mail: liuenhui99@sina.com.cn
Highlights: ► Microporous carbon was prepared by chemical activation of phenol-melamine-formaldehyde resin. ► Activation leads to high surface area, well-developed micropores. ► Micropores lead to strong intercalation between carbon and lithium ion. ► Large surface area promotes to improve the lithium storage capacity. -- Abstract: Microporous carbon anode materials were prepared from phenol-melamine-formaldehyde resin by ZnCl{sub 2} and KOH activation. The physicochemical properties of the obtained carbon materials were characterized by scanning electron microscope, X-ray diffraction, Brunauer–Emmett–Teller, and elemental analysis. The electrochemical properties of the microporous carbon as anode materials in lithium ion secondary batteries were evaluated. At a currentmore » density of 100 mA g{sup −1}, the carbon without activation shows a first discharge capacity of 515 mAh g{sup −1}. After activation, the capacity improved obviously. The first discharge capacity of the carbon prepared by ZnCl{sub 2} and KOH activation was 1010 and 2085 mAh g{sup −1}, respectively. The reversible capacity of the carbon prepared by KOH activation was still as high as 717 mAh g{sup −1} after 20 cycles, which was much better than that activated by ZnCl{sub 2}. These results demonstrated that it may be a promising candidate as an anode material for lithium ion secondary batteries.« less
Performance of lightweight nickel electrodes
NASA Technical Reports Server (NTRS)
Britton, Doris L.
1988-01-01
The NASA Lewis Research Center is currently developing nickel electrodes for nickel-hydrogen (Ni-H2) batteries. These electrodes are lighter in weight and have higher energy densities than the heavier state-of-the-art (SOA) sintered nickel electrodes. In the present approach, lightweight materials or plaques are used as conductive supports for the nickel hydroxide active material. These plaques (fiber and felt, nickel plated plastic and graphite) are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. Evaluation is performed in half cells structured in the bipolar configuration. Initial performance tests include capacity measurements at five discharge levels, C/2, 1.0C 1.37C, 2.0C and 2.74C. The electrodes that pass the initial tests are life cycle tested in a low Earth orbit regime at 80 percent depth of discharge. Different formulations of nickel fiber materials obtained from several manufacturers are currently being tested as possible candidates for nickel electrodes. One particular lightweight fiber mat electrode has accumulated over 3000 cycles to date, with stable capacity and voltage. Life and performance data of this electrode were investigated and presented. Good dimensional stability and active material adherence have been demonstrated in electrodes made from this lightweight plaque.
Composite Cathodes for Dual-Rate Li-Ion Batteries
NASA Technical Reports Server (NTRS)
Whitacre, Jay; West, William; Bugga, Ratnakumar
2008-01-01
Composite-material cathodes that enable Li-ion electrochemical cells and batteries to function at both high energy densities and high discharge rates are undergoing development. Until now, using commercially available cathode materials, it has been possible to construct cells that have either capability for high-rate discharge or capability to store energy at average or high density, but not both capabilities. However, both capabilities are needed in robotic, standby-power, and other applications that involve duty cycles that include long-duration, low-power portions and short-duration, high-power portions. The electrochemically active ingredients of the present developmental composite cathode materials are: carbon-coated LiFePO4, which has a specific charge capacity of about 160 mA h/g and has been used as a high-discharge-rate cathode material and Li[Li(0.17)Mn(0.58)Ni(0.25)]O2, which has a specific charge capacity of about 240 mA h/g and has been used as a high-energy-density cathode material. In preparation for fabricating the composite material cathode described, these electrochemically active ingredients are incorporated into two sub-composites: a mixture comprising 10 weight percent of poly(vinylidine fluoride); 10 weight percent of carbon and 80 weight percent of carbon coated LiFePO4; and, a mixture comprising 10 weight percent of PVDF, and 80 weight percent of Li[Li(0.17)Mn(0.58)Ni(0.25)]O2. In the fabrication process, these mixtures are spray-deposited onto an aluminum current collector. Electrochemical tests performed thus far have shown that better charge/discharge performance is obtained when either 1) each mixture is sprayed on a separate area of the current collector or (2) the mixtures are deposited sequentially (in contradistinction to simultaneously) on the same current-collector area so that the resulting composite cathode material consists of two different sub-composite layers.
Plasma discharge elemental detector for a mass spectrometer
NASA Astrophysics Data System (ADS)
Heppner, R. A.
1983-06-01
A material to be analyzed is injected into a mirowave-induced plasma discharge unit, in which the material is carried with a flow of buffer gas through an intense microwave energy field which produces a plasma discharge in the buffer gas. As the material exits from the plasma discharge, the material is sampled and conveyed along a capillary transfer tube to a mass spectrometer where it is analyzed. The plasma discharge causes dissociation of complex organic molecules into simpler molecules which return to the neutral ground state before they are analyzed in the mass spectrometer. The buffer gas is supplied to one end portion of the discharge tube and is withdrawn from the other end portion by a vacuum pump which maintains a subatmospheric pressure in the discharge tube. The sample material is injected by a capillary injection tube into the buffer gas flow as it enters the plasma discharge zone. The dissociated materials are sampled by an axial sampling tube having an entrance where the buffer gas exits from the plasma discharge zone. The sample material may be supplied by a gas chromatography having a capillary effluent line connected to the capillary injection tube, so that the effluent material is injected into the microwave induced plasma discharge. The microwave field is produced by a cavity resonator through which the discharge tube passes.
Roberts, Matthew R; Madsen, Alex; Nicklin, Chris; Rawle, Jonathan; Palmer, Michael G; Owen, John R; Hector, Andrew L
2014-04-03
The phase changes that occur during discharge of an electrode comprised of LiFePO 4 , carbon, and PTFE binder have been studied in lithium half cells by using X-ray diffraction measurements in reflection geometry. Differences in the state of charge between the front and the back of LiFePO 4 electrodes have been visualized. By modifying the X-ray incident angle the depth of penetration of the X-ray beam into the electrode was altered, allowing for the examination of any concentration gradients that were present within the electrode. At high rates of discharge the electrode side facing the current collector underwent limited lithium insertion while the electrode as a whole underwent greater than 50% of discharge. This behavior is consistent with depletion at high rate of the lithium content of the electrolyte contained in the electrode pores. Increases in the diffraction peak widths indicated a breakdown of crystallinity within the active material during cycling even during the relatively short duration of these experiments, which can also be linked to cycling at high rate.
2014-01-01
The phase changes that occur during discharge of an electrode comprised of LiFePO4, carbon, and PTFE binder have been studied in lithium half cells by using X-ray diffraction measurements in reflection geometry. Differences in the state of charge between the front and the back of LiFePO4 electrodes have been visualized. By modifying the X-ray incident angle the depth of penetration of the X-ray beam into the electrode was altered, allowing for the examination of any concentration gradients that were present within the electrode. At high rates of discharge the electrode side facing the current collector underwent limited lithium insertion while the electrode as a whole underwent greater than 50% of discharge. This behavior is consistent with depletion at high rate of the lithium content of the electrolyte contained in the electrode pores. Increases in the diffraction peak widths indicated a breakdown of crystallinity within the active material during cycling even during the relatively short duration of these experiments, which can also be linked to cycling at high rate. PMID:24790684
Nickel hydroxide positive electrode for alkaline rechargeable battery
Young, Kwo; Wang, Lixin; Mays, William; Reichman, Benjamin; Chao-Ian, Hu; Wong, Diana; Nei, Jean
2018-04-03
Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.
Nickel hydroxide positive electrode for alkaline rechargeable battery
Young, Kwo; Wang, Lixin; Mays, William; Reichman, Benjamin; Chao-Ian, Hu; Wong, Diana; Nei, Jean
2018-02-20
Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.
DOE R&D Accomplishments Database
MacDiarmid, A. G.
1984-02-01
The chief thrust of the research has been directed towards the evaluation of polyacetylene (CH){sub x}, the prototype conducting polymer as an electrode- active material in novel, rechargeable batteries employing nonaqueous electrolytes. The p-doped material, [(CH{sup +y})A{sub y}{sup -}]{sub x}, (where A{sup -} is an anion) in conjunction with a Li anode, shows excellent discharge characteristics, e.g., very little change in discharge voltage with change in discharge current and a high power density. Its energy density is also good but it shows poor shelf life. When (CH){sub x} is used as a cathode (Li anode), which results in the formation of the n-doped polymer, [Li{sub y} {sup +}(CH/sup -y/)]{sub x}, during discharge, good discharge plateaus and power densities are obtained together with excellent shelf life and good recyclability. The energy density is, however only moderate. Cells employing an [M{sub y}{sup +}(CH/sup -y/)]{sub x} (where M = Li, Na) anode and a TiS{sub 2} cathode show very good discharge and recycling characteristics but their energy density is poor.
Impact of Multifunctional Bimetallic Materials on Lithium Battery Electrochemistry.
Durham, Jessica L; Poyraz, Altug S; Takeuchi, Esther S; Marschilok, Amy C; Takeuchi, Kenneth J
2016-09-20
Electric energy storage devices such as batteries are complex systems comprised of a variety of materials with each playing separate yet interactive roles, complicated by length scale interactions occurring from the molecular to the mesoscale. Thus, addressing specific battery issues such as functional capacity requires a comprehensive perspective initiating with atomic level concepts. For example, the electroactive materials which contribute to the functional capacity in a battery comprise approximately 30% or less of the total device mass. Thus, the design and implementation of multifunctional materials can conceptually reduce or eliminate the contribution of passive materials to the size and mass of the final system. Material multifunctionality can be achieved through appropriate material design on the atomic level resulting in bimetallic electroactive materials where one metal cation forms mesoscale conductive networks upon discharge while the other metal cations can contribute to atomic level structure and net functional secondary capacity, a device level issue. Specifically, this Account provides insight into the multimechanism electrochemical redox processes of bimetallic cathode materials based on transition metal oxides (MM'O) or phosphorus oxides (MM'PO) where M = Ag and M' = V or Fe. One discharge process can be described as reduction-displacement where Ag(+) is reduced to Ag(0) and displaced from the parent structure. This reduction-displacement reaction in silver-containing bimetallic electrodes allows for the in situ formation of a conductive network, enhancing the electrochemical performance of the electrode and reducing or eliminating the need for conductive additives. A second discharge process occurs through the reduction of the second transition metal, V or Fe, where the oxidation state of the metal center is reduced and lithium cations are inserted into the structure. As both metal centers contribute to the functional capacity, determining the kinetically and thermodynamically preferred reduction processes at various states of discharge is critical to elucidating the mechanism. Specific advanced in situ and ex situ characterization techniques are conducive to gaining insight regarding the electrochemical behavior of these multifunctional materials over multiple length scales. At the material level, optical microscopy, scanning electron microscopy, and local conductivity measurement via a nanoprobe can track the discharge mechanism of an isolated single particle. At the mesoscale electrode level, in situ data from synchrotron based energy dispersive X-ray diffraction (EDXRD) within fully intact steel batteries can be used to spatially map the distribution of silver metal generated through reduction displacement as a function of discharge depth and discharge rate. As illustrated here, appropriate design of materials with multiple electrochemically active metal centers and properties tuned through strategically conceptualized materials synthesis may provide a path toward the next generation of high energy content electroactive materials and systems. Full understanding of the multiple electrochemical mechanisms can be achieved only by utilizing advanced characterization tools over multiple length scales.
Pushing the Limits: 3D Layer-by-Layer-Assembled Composites for Cathodes with 160 C Discharge Rates.
Mo, Runwei; Tung, Siu On; Lei, Zhengyu; Zhao, Guangyu; Sun, Kening; Kotov, Nicholas A
2015-05-26
Deficiencies of cathode materials severely limit cycling performance and discharge rates of Li batteries. The key problem is that cathode materials must combine multiple properties: high lithium ion intercalation capacity, electrical/ionic conductivity, porosity, and mechanical toughness. Some materials revealed promising characteristics in a subset of these properties, but attaining the entire set of often contrarian characteristics requires new methods of materials engineering. In this paper, we report high surface area 3D composite from reduced graphene oxide loaded with LiFePO4 (LFP) nanoparticles made by layer-by-layer assembly (LBL). High electrical conductivity of the LBL composite is combined with high ionic conductivity, toughness, and low impedance. As a result of such materials properties, reversible lithium storage capacity and Coulombic efficiency were as high as 148 mA h g(-1) and 99%, respectively, after 100 cycles at 1 C. Moreover, these composites enabled unusually high reversible charge-discharge rates up to 160 C with a storage capacity of 56 mA h g(-1), exceeding those of known LFP-based cathodes, some of them by several times while retaining high content of active cathode material. The study demonstrates that LBL-assembled composites enable resolution of difficult materials engineering tasks.
Development of a Micro-Fiber Nickel Electrode for Nickel-Hydrogen Cell
NASA Technical Reports Server (NTRS)
Britton, Doris L.
1996-01-01
The development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (NiH2) program at the NASA Lewis Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen fuel cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active materials. Initial tests include activation and capacity measurements at different discharge levels followed by half-cell cycle testing at 80 percent depth-of-discharge in a low Earth orbit regime. The electrodes that pass the initial tests are life cycle tested in a boiler plate nickel-hydrogen cell before flightweight designs are built and tested.
Development of a micro-fiber nickel electrode for nickel-hydrogen cell
NASA Technical Reports Server (NTRS)
Britton, Doris L.
1995-01-01
Development of a high specific energy nickel electrode is the main goal of the lightweight nickel electrode program at the NASA Lewis Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active material. Initial tests include activation and capacity measurements at different discharge levels followed by half-cell cycle testing at 80 percent depth-of-discharge in a low-Earth-orbit regime. The electrodes that pass the initial tests are life cycle-tested in a boiler plate nickel-hydrogen cell before flightweight designs are built and tested.
NASA Astrophysics Data System (ADS)
He, Feng; Li, Kai; Yin, Cong; Ding, Yingchun; Tang, Hao; Wang, Ying; Wu, Zhijian
2018-01-01
To effectively restrain the dissolution of soluble polysulfides and fully utilize the active sulfur materials in lithium-sulfur (Li-S) batteries, host materials with unique compositions and porous structures have been pursued. Herein, we have investigated the mechanism of the excellent activity of oxygenated g-C3N4 for Li-S batteries from theoretical perspective, and the further experiment confirms that our O-g-C3N4-S cathode exhibits much better electrochemical performance compared with those in previous reports. Our DFT calculations reveal that the oxygenated material has better electrical conductivity and stronger adsorption ability with the Li2Sx species compared with the pristine g-C3N4 and other two-dimensional (2D) materials. Furthermore, we have confirmed experimentally that the O-g-C3N4-S composite cathode exhibits excellent electrochemical performance in Li-S batteries with high reversible discharge capacity of 1030 mAh g-1 after 100 cycles at 0.2 C, great rate capability with the discharge capacity of 364 mAh g-1 even at 5.0 C, and outstanding long-term cyclic stability with the discharge capacity of 465 mAh g-1 after 1000 cycles at 1.0 C (capacity decay was only 0.046% per cycle). Our results also suggest that theoretical study will play a significant role in predicting and screening novel materials with better performance.
Electric Pulse Discharge Activated Carbon Supercapacitors for Transportation Application
NASA Astrophysics Data System (ADS)
Nayak, Subhadarshi; Agrawal, Jyoti
2012-03-01
ScienceTomorrow is developing a high-speed, low-cost process for synthesizing high-porosity electrodes for electrochemical double-layer capacitors. Four types of coal (lignite, subbituminous, bituminous, and anthracite) were used as precursor materials for spark discharge activation with multiscale porous structure. The final porosity and pore distribution depended, among other factors, on precursor type. The high gas content in low-grade carbon resulted in mechanical disintegration, whereas high capacitance was attained in higher-grade coal. The properties, including capacitance, mechanical robustness, and internal conductivity, were excellent when the cost is taken into consideration.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Knosp, B.; Jordy, C.; Blanchard, P.
1998-05-01
Laves phase alloys of compositions (Zr, Ti)(Ni, Mn, M){sub x} where M = Cr, V, Co, Al, and 1.9 < x < 2.1 with hexagonal C14 or cubic C15 structure have been studied in order to select the most suitable AB{sub 2} alloys as an active material for nickel-metal hydride (Ni-MH) batteries. With the selected alloy, feasibility of MH negative electrodes using industrial technology and containing more than 97% of the alloy powder has been demonstrated. 22 Ah Ni-MH batteries for electric vehicle application have been assembled, and 600 cycles have been achieved at steady C/3 charge and discharge ratesmore » and 80% depth of discharge.« less
Stormwater Pollution Prevention Plan - TA-60 Material Recycling Facility
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sandoval, Leonard Frank
This Storm Water Pollution Prevention Plan (SWPPP) was developed in accordance with the provisions of the Clean Water Act (33 U.S.C. §§1251 et seq., as amended), and the Multi-Sector General Permit for Storm Water Discharges Associated with Industrial Activity (U.S. EPA, June 2015) issued by the U.S. Environmental Protection Agency (EPA) for the National Pollutant Discharge Elimination System (NPDES) and using the industry specific permit requirements for Sector P-Land Transportation and Warehousing as a guide. This SWPPP applies to discharges of stormwater from the operational areas of the TA- 60 Material Recycling Facility at Los Alamos National Laboratory. Los Alamosmore » National Laboratory (also referred to as LANL or the “Laboratory”) is owned by the Department of Energy (DOE), and is operated by Los Alamos National Security, LLC (LANS). Throughout this document, the term “facility” refers to the TA-60 Material Recycling Facility. The current permit expires at midnight on June 4, 2020.« less
NASA Technical Reports Server (NTRS)
Marshall, J.; Farrell, W.; Houser, G.; Bratton, C.
1999-01-01
In recent laboratory experiments, measurements were made of microsecond radio-wave (RF) bursts emitted by grains of sand as they energetically circulated in a closed, electrically ungrounded chamber. The bursts appeared to result from nanoscale electrical discharging from grain surfaces. Both the magnitude and wave form of the RF pulses varied with the type of material undergoing motion. The release of RF from electrical discharging is a well-known phenomenon, but it is generally measured on much larger energy scales (e.g., in association with lightning or electrical motors). This phenomenon might be used to detect, on planetary surfaces, the motion and composition of sand moving over dunes, the turbulent motion of fine particles in dust storms, highly-energetic grain and rock collisions in volcanic eruptions, and frictional grinding of granular materials in dry debris flows, landslides, and avalanches. The occurrence of these discharges has been predicted from theoretical considerations Additional information is contained in the original.
NASA Astrophysics Data System (ADS)
Akiyama, Hidenori; Katsuki, Sunao; Namihira, Takao; Ishibashi, Kazuo; Kiyosaki, Noriaki
Pulsed power has been used to produce non-thermal plasmas in atmospheric pressure gases that generate a high electric field at the tips of streamer discharges, where high energy electrons, free radicals, ultraviolet rays, and ozone are produced. These manifestations of streamer discharges have been used in the treatment of exhaust gases, removal of volatile and toxic compounds such as dioxin, and the sterilization of microorganisms. Here, large volume streamer discharges in water are described. These streamer discharges in liquids are able to produce a high electric field, high energy electrons, ozone, chemically active species, ultraviolet rays, and shock waves, which readily sterilize microorganisms and decompose molecules and materials. An application of this phenomenon to the cleaning of lakes and marshes is also described.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Luo, Xiangyi; Lu, Jun; Sohm, Evan
The present study aims to explore a new method to improve the catalytic activity of non-precious metals, especially in electrochemical reactions. In this study, highly ionized Fe plasma produced by arc discharge uniformly deposit on porous carbon substrate and form atomic clusters by the Pulsed Arc Plasma Deposition technique. The as-prepared FeOx/C material was tested as a cathode material in rechargeable Li-O2 battery under different current rates. The results show a significantly improvement of the battery performance in both cycle life and reaction rate. Furthermore, XRD and SEM results show that the as-prepared cathode material has the ability to stabilizemore » cathode and reduce side reactions, and current rate is a critical factor of the nucleation of the discharge products.« less
SBAR Panel: NPDES Comprehensive Storm Water Phase II Regulations
SBAR panel on proposed regulations to address currently unregulated discharges of storm water and provide regulatory relief to industrial facilities where industrial materials and activities are not exposed to storm water
40 CFR 230.1 - Purpose and policy.
Code of Federal Regulations, 2010 CFR
2010-07-01
... Guidelines is the precept that dredged or fill material should not be discharged into the aquatic ecosystem... individually or in combination with known and/or probable impacts of other activities affecting the ecosystems...
40 CFR 230.1 - Purpose and policy.
Code of Federal Regulations, 2012 CFR
2012-07-01
... precept that dredged or fill material should not be discharged into the aquatic ecosystem, unless it can... individually or in combination with known and/or probable impacts of other activities affecting the ecosystems...
40 CFR 230.1 - Purpose and policy.
Code of Federal Regulations, 2011 CFR
2011-07-01
... Guidelines is the precept that dredged or fill material should not be discharged into the aquatic ecosystem... individually or in combination with known and/or probable impacts of other activities affecting the ecosystems...
40 CFR 230.1 - Purpose and policy.
Code of Federal Regulations, 2013 CFR
2013-07-01
... Guidelines is the precept that dredged or fill material should not be discharged into the aquatic ecosystem... individually or in combination with known and/or probable impacts of other activities affecting the ecosystems...
40 CFR 230.1 - Purpose and policy.
Code of Federal Regulations, 2014 CFR
2014-07-01
... Guidelines is the precept that dredged or fill material should not be discharged into the aquatic ecosystem... individually or in combination with known and/or probable impacts of other activities affecting the ecosystems...
Laser processing of thick Li(NiMnCo)O2 electrodes for lithium-ion batteries
NASA Astrophysics Data System (ADS)
Rakebrandt, J.-H.; Smyrek, P.; Zheng, Y.; Seifert, H. J.; Pfleging, W.
2017-02-01
Lithium-ion batteries became the most promising types of mobile energy storage devices due to their high gravimetric and volumetric capacity, high cycle life-time, and low self-discharge. Nowadays, the cathode material lithium nickel manganese cobalt oxide (NMC) is one of the most widely used cathode material in commercial lithium-ion batteries due to many advantages such as high energy density (>150 Wh kg-1) on cell level, high power density (650 W kg-1 @ 25 °C and 50 % Depth of Discharge) [1], high specific capacity (163 mAh g-1) [2], high rate capability and good thermal stability in the fully charged state. However, in order to meet the requirements for the increasing demand for rechargeable high energy batteries, nickel-rich NMC electrodes with specific capacities up to 210 mAh g-1 seem to be the next generation cathodes which can reach on cell level desired energy densities higher than 250 Wh kg-1 [3]. Laser-structuring now enables to combine both concepts, high power and high energy lithium-ion batteries. For this purpose, lithium nickel manganese cobalt oxide cathodes were produced via tape casting containing 85-90 wt% of active material with a film thickness of 50-260 μm. The specific capacities were measured using galvanostatic measurements for different types of NMC with varying nickel, manganese and cobalt content at different charging/discharging currents ("C-rates"). An improved lithium-ion diffusion kinetics due to an increased active surface area could be achieved by laser-assisted generating of three dimensional architectures. Cells with unstructured and structured cathodes were compared. Ultrafast laser ablation was used in order to avoid a thermal impact to the material. It was shown that laser structuring of electrode materials leads to a significant improvement in electrochemical performance, especially at high charging and discharging C-rates.
Impact of Multifunctional Bimetallic Materials on Lithium Battery Electrochemistry
DOE Office of Scientific and Technical Information (OSTI.GOV)
Durham, Jessica L.; Poyraz, Altug S.; Takeuchi, Esther S.
Electric energy storage devices such as batteries are complex systems comprised of a variety of materials with each playing separate yet interactive roles, complicated by length scale interactions occurring from the molecular to the mesoscale. Thus, addressing specific battery issues such as functional capacity requires a comprehensive perspective initiating with atomic level concepts. For example, the electroactive materials which contribute to the functional capacity in a battery comprise approximately 30% or less of the total device mass. Thus, the design and implementation of multifunctional materials can conceptually reduce or eliminate the contribution of passive materials to the size and massmore » of the final system. Material multi-functionality can be achieved through appropriate material design on the atomic level resulting in bimetallic electroactive materials where one metal cation forms mesoscale conductive networks upon discharge while the other metal cation can contribute to atomic level structure and net functional secondary capacity, a device level issue. Specifically, this Account provides insight into the multi-mechanism electrochemical redox processes of bimetallic cathode materials based on transition metal oxides (MM’O) or phosphorous oxides (MM’PO) where M = Ag and M’ = V or Fe. One discharge process can be described as reduction-displacement where Ag + is reduced to Ag 0 and displaced from the parent structure. This reduction-displacement reaction in silver-containing bimetallic electrodes allows for the in-situ formation of a conductive network, enhancing the electrochemical performance of the electrode and reducing or eliminating the need for conductive additives. A second discharge process occurs through the reduction of the second transition metal, V or Fe, where the oxidation state of the metal center is reduced and lithium cations are inserted into the structure. As both metal centers contribute to the functional capacity, determining the kinetically and thermodynamically preferred reduction processes at various states of discharge is critical to elucidating the mechanism. Specific advanced in-situ and ex-situ characterization techniques are conducive to gaining insight regarding the electrochemical behavior of these multifunctional materials over multiple length scales. At the material level, optical microscopy, scanning electron microscopy, and local conductivity measurement via a nanoprobe can track the discharge mechanism of an isolated single particle. At the mesoscale electrode level, in-situ data from synchrotron based energy dispersive X-ray diffraction (EDXRD) within fully intact steel batteries can be used to spatially map the distribution of silver metal generated through reduction displacement as a function of discharge depth and discharge rate. As illustrated here, appropriate design of materials with multiple electrochemically active metal centers and properties tuned through strategically conceptualized materials synthesis may provide a path toward the next generation of high energy content electroactive materials and systems. In conclusion, full understanding of the multiple electrochemical mechanisms can be achieved only by utilizing advanced characterization tools over multiple length scales.« less
Impact of Multifunctional Bimetallic Materials on Lithium Battery Electrochemistry
Durham, Jessica L.; Poyraz, Altug S.; Takeuchi, Esther S.; ...
2016-08-26
Electric energy storage devices such as batteries are complex systems comprised of a variety of materials with each playing separate yet interactive roles, complicated by length scale interactions occurring from the molecular to the mesoscale. Thus, addressing specific battery issues such as functional capacity requires a comprehensive perspective initiating with atomic level concepts. For example, the electroactive materials which contribute to the functional capacity in a battery comprise approximately 30% or less of the total device mass. Thus, the design and implementation of multifunctional materials can conceptually reduce or eliminate the contribution of passive materials to the size and massmore » of the final system. Material multi-functionality can be achieved through appropriate material design on the atomic level resulting in bimetallic electroactive materials where one metal cation forms mesoscale conductive networks upon discharge while the other metal cation can contribute to atomic level structure and net functional secondary capacity, a device level issue. Specifically, this Account provides insight into the multi-mechanism electrochemical redox processes of bimetallic cathode materials based on transition metal oxides (MM’O) or phosphorous oxides (MM’PO) where M = Ag and M’ = V or Fe. One discharge process can be described as reduction-displacement where Ag + is reduced to Ag 0 and displaced from the parent structure. This reduction-displacement reaction in silver-containing bimetallic electrodes allows for the in-situ formation of a conductive network, enhancing the electrochemical performance of the electrode and reducing or eliminating the need for conductive additives. A second discharge process occurs through the reduction of the second transition metal, V or Fe, where the oxidation state of the metal center is reduced and lithium cations are inserted into the structure. As both metal centers contribute to the functional capacity, determining the kinetically and thermodynamically preferred reduction processes at various states of discharge is critical to elucidating the mechanism. Specific advanced in-situ and ex-situ characterization techniques are conducive to gaining insight regarding the electrochemical behavior of these multifunctional materials over multiple length scales. At the material level, optical microscopy, scanning electron microscopy, and local conductivity measurement via a nanoprobe can track the discharge mechanism of an isolated single particle. At the mesoscale electrode level, in-situ data from synchrotron based energy dispersive X-ray diffraction (EDXRD) within fully intact steel batteries can be used to spatially map the distribution of silver metal generated through reduction displacement as a function of discharge depth and discharge rate. As illustrated here, appropriate design of materials with multiple electrochemically active metal centers and properties tuned through strategically conceptualized materials synthesis may provide a path toward the next generation of high energy content electroactive materials and systems. In conclusion, full understanding of the multiple electrochemical mechanisms can be achieved only by utilizing advanced characterization tools over multiple length scales.« less
Pollution Impact and Alternative Treatment for Produced Water
NASA Astrophysics Data System (ADS)
Hedar, Yusran; Budiyono
2018-02-01
Oil and gas exploration and production are two of the activities that potentially cause pollution and environmental damage. The largest waste generated from this activity is produced water. Produced water contains hazardous pollutants of both organic and inorganic materials, so that the produced water of oil and gas production cannot be discharged directly to the environment. Uncontrolled discharge can lead to the environmental damage, killing the life of water and plants. The produced water needs to be handled and fulfill the quality standards before being discharged to the environment. Several studies to reduce the contaminants in the produced water were conducted by researchers. Among them were gravity based separation - flotation, separation technique based on filtration, and biological process treatment. Therefore, some of these methods can be used as an alternative waste handling of produced water.
Brannon, Paul J.; Cowgill, Donald F.
1990-01-01
A laser-triggered vacuum switch has a material such as a alkali metal halide on the cathode electrode for thermally activated field emission of electrons and ions upon interaction with a laser beam, the material being in contact with the cathode with a surface facing the discharge gap. The material is preferably a mixture of KCl and Ti powders. The laser may either shine directly on the material, preferably through a hole in the anode, or be directed to the material over a fiber optic cable.
Brannon, P.J.; Cowgill, D.F.
1990-12-18
A laser-triggered vacuum switch has a material such as a alkali metal halide on the cathode electrode for thermally activated field emission of electrons and ions upon interaction with a laser beam, the material being in contact with the cathode with a surface facing the discharge gap. The material is preferably a mixture of KCl and Ti powders. The laser may either shine directly on the material, preferably through a hole in the anode, or be directed to the material over a fiber optic cable. 10 figs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tucker, Michael C.; Phillips, Adam; Weber, Adam Z.
We proposed and developed an all-iron redox flow battery for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. Our design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe 2 (SO 4 ) 3 activemore » material and 1.2 m NaCl supporting electrolyte. Furthermore, with these materials, an average power density around 20 mW cm -2 and a maximum energy density of 11.5 Wh L -1 are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh -1 , or only US$0.034 per mobile phone charge.« less
Kou, Jianwen; Chen, Lai; Su, Yuefeng; Bao, Liying; Wang, Jing; Li, Ning; Li, Weikang; Wang, Meng; Chen, Shi; Wu, Feng
2015-08-19
Layered lithium-rich cathode material, Li1.2Ni0.2-xCo2xMn0.6-xO2 (x = 0-0.05) was successfully synthesized using a sol-gel method, followed by heat treatment. The effects of trace amount of cobalt doping on the structure, morphology, and low-temperature (-20 °C) electrochemical properties of these materials are investigated systematically. X-ray diffraction (XRD) results confirm that the Co has been doped into the Ni/Mn sites in the transition-metal layers without destroying the pristine layered structure. The morphological observations reveal that there are no changes of morphology or particle size after Co doping. The electrochemical performance results indicate that the discharge capacities and operation voltages are drastically lowered along with the decreasing temperature, but their fading rate becomes slower when increasing the Co contents. At -20 °C, the initial discharge capacity of sample with x = 0 could retain only 22.1% (57.3/259.2 mAh g(-1)) of that at 30 °C, while sample with x = 0.05 could maintain 39.4% (111.3/282.2 mAh g(-1)). Activation energy analysis and electrochemical impedance spectroscopy (EIS) results reveal that such an enhancement of low-temperature discharge capacity is originated from the easier interface reduction reaction of Ni(4+) or Co(4+) after doping trace amounts of Co, which decreases the activation energy of the charge transfer process above 3.5 V during discharging.
Overdischarge protection in high-temperature cells and batteries
Redey, Laszlo
1990-01-01
Overdischarge indication and protection is provided in a lithium alloy - metal sulfide, secondary electrochemical cell and batteries of such cells through use of a low lithium activity phase that ordinarily is not matched with positive electrode material. Low lithium activity phases such as Li.sub.0.1 Al.sub.0.9 and LiAlSi in correspondence with positive electrode material cause a downward gradient in cell voltage as an indication of overdischarge prior to damage to the cell. Moreover, the low lithium activity phase contributes lithium into the electrolyte and provides a lithium shuttling current as overdischarge protection after all of the positive electrode material is discharged.
Overdischarge protection in high-temperature cells and batteries
Redey, L.
1990-06-19
Overdischarge indication and protection is provided in a lithium alloy metal sulfide, secondary electrochemical cell and batteries of such cells through use of a low lithium activity phase that ordinarily is not matched with positive electrode material. Low lithium activity phases such as Li[sub 0.1]Al[sub 0.9] and LiAlSi in correspondence with positive electrode material cause a downward gradient in cell voltage as an indication of overdischarge prior to damage to the cell. Moreover, the low lithium activity phase contributes lithium into the electrolyte and provides a lithium shuttling current as overdischarge protection after all of the positive electrode material is discharged. 8 figs.
Section 404 and Swampbuster: Wetlands on Agricultural Lands
Many normal farming, silviculture, and ranching activities that involve discharges of dredged or fill materials into waters of the United States are exempted from Section 404; that is, they do not require a permit.
Documents for SBAR Panel: NPDES Comprehensive Storm Water Phase II Regulations
SBAR panel on proposed regulations to address currently unregulated discharges of storm water and provide regulatory relief to industrial facilities where industrial materials and activities are not exposed to storm water
Xenobiotics removal by adsorption in the context of tertiary treatment: a mini review.
Tahar, Alexandre; Choubert, Jean-Marc; Coquery, Marina
2013-08-01
Many xenobiotics, including several pharmaceuticals and pesticides, are poorly treated in domestic wastewater treatment plants. Adsorption processes, such as with activated carbons, could be a solution to curb their discharge into the aquatic environment. As adsorbent-like activated carbon is known to be expensive, identifying promising alternative adsorbent materials is a key challenge for efficient yet affordable xenobiotic removal from wastewaters. As part of the effort to address this challenge, we surveyed the literature on pharmaceutical and pesticide xenobiotics and built a database compiling data from 38 scientific publications covering 65 xenobiotics and 58 materials. Special focus was given to the relevance and comparability of the data to the characteristics of the adsorbent materials used and to the operating conditions of the batch tests inventoried. This paper gives an in-depth overview of the adsorption capacities of various adsorbents. The little data on alternative adsorbent materials, especially for the adsorption of pharmaceuticals, makes it difficult to single out any one activated carbon alternative capable of adsorbing pesticides and pharmaceuticals at the tertiary stage of treatment. There is a pressing need for further lab-scale experiments to investigate the tertiary treatment of discharged effluents. We conclude with recommendations on how future data should best be used and interpreted.
Code of Federal Regulations, 2011 CFR
2011-07-01
... to shore, and properly dispose of all feed bags, packaging materials, waste rope and netting. (c... the pens through the use of active feed monitoring and management practices. These practices may... prevent discharge to waters of the U.S. (e) Materials storage. (1) Ensure proper storage of drugs...
Code of Federal Regulations, 2010 CFR
2010-07-01
... to shore, and properly dispose of all feed bags, packaging materials, waste rope and netting. (c... the pens through the use of active feed monitoring and management practices. These practices may... prevent discharge to waters of the U.S. (e) Materials storage. (1) Ensure proper storage of drugs...
NASA Astrophysics Data System (ADS)
Sun, Tianhua; Li, Zhangpeng; Liu, Xiaohong; Ma, Limin; Wang, Jinqing; Yang, Shengrong
2016-11-01
Flower-like molybdenum disulfide (MoS2) microstructures are synthesized based on three-dimensional graphene (3DG) skeleton via a simple and facile one-step hydrothermal method, aiming at constructing series of novel composite electrode materials of 3DG/MoS2 with high electrochemical performances for supercapacitors. The electrochemical properties of the samples are evaluated by cyclic voltammetry and galvanostatic charge/discharge tests. Specifically, the optimal 3DG/MoS2 composite exhibits remarkable performances with a high specific capacitance of 410 F g-1 at a current density of 1 A g-1 and an excellent cycling stability with ca. 80.3% capacitance retention after 10,000 continuous charge-discharge cycles at a high current density of 2 A g-1, making it adaptive for high-performance supercapacitors. The enhanced electrochemical performances can be ascribed to the combination of 3DG and flower-like MoS2, which provides excellent charge transfer network and electrolyte diffusion channels while effectively prevents the collapse, aggregation and morphology change of active materials during charge-discharge process. The results demonstrate that 3DG/MoS2 composite is one of the attractive electrode materials for supercapacitors.
Progress in the Development of Lightweight Nickel Electrode for Nickel-Hydrogen Cell
NASA Technical Reports Server (NTRS)
Britton, Doris L.
1999-01-01
Development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (Ni-H2) program at the NASA Glenn Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a lighter weight electrode for the nickel-hydrogen cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active material. Initial tests include activation and capacity measurements at five different discharge levels, C/2, 1.0 C, 1.37 C, 2.0 C, and 2.74 C. The electrodes are life cycle tested using a half-cell configuration at 40 and 80% depths-of-discharge (DOD) in a low-Earth-orbit regime. The electrodes that pass the initial tests are life cycle-tested in a boiler plate nickel-hydrogen cell before flight weight design are built and tested.
New Redox Polymers that Exhibit Reversible Cleavage of Sulfur Bonds as Cathode Materials.
Baloch, Marya; Ben Youcef, Hicham; Li, Chunmei; Garcia-Calvo, Oihane; Rodriguez, Lide M; Shanmukaraj, Devaraj; Rojo, Teofilo; Armand, Michel
2016-11-23
Two new cathode materials based on redox organosulfur polymers were synthesized and investigated for rechargeable lithium batteries as a proof-of-concept study. These cathodes offered good cycling performance owing to the absence of polysulfide solubility, which plagues Li/S systems. Herein, an aliphatic polyamine or a conjugated polyazomethine was used as the base to tether the redox-active species. The activity comes from the cleavage and formation of S-S or N-S bonds, which is made possible by the rigid conjugated backbone. The synthesized polymers were characterized through FTIR spectroscopy and thermogravimetric analysis (TGA). Galvanostatic measurements were performed to evaluate the discharge/charge cycles and characterize the performance of the lithium-based cells, which displayed initial discharge capacities of approximately 300 mA h g -1 at C/5 over 100 cycles with approximately 98 % Coulombic efficiency. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Two examples of intelligent systems based on smart materials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Unsworth, J.
1994-12-31
Two intelligent systems are described which are based on smart materials. The operation of the systems also rely on conventional well known technologies such as electronics, signal conditioning, signal processing, microprocessors and engineering design. However without the smart materials the development and integration into the intelligent systems would not have been possible. System 1 is a partial discharge monitor for on-line continuous checking of the condition of electrical power transformers. The ultrasonic and radio frequency detectors in this system rely on special piezoelectric composite integrated with a compact annular metal ring. Partial discharges set up ultrasonic and radio frequency signalsmore » which are received by the integrated detectors. The signals are amplified, conditioned, signal processed, the time interval between the two signals measured and the level of partial discharge activity averaged and assessed for numerous pairs and alarms triggered on remote control panels if the level is dangerous. The system has the capability of initiating automatic shutdown of the transformer once it is linked into the control computers of the electrical power authority. System 2 is called a Security Cradle and is an intelligent 3D shield designed to use the properties of electro active polymers to prevent hardware hackers from stealing valuable of sensitive information from memory devices (e.g., EPROMS) housed in computer or microprocessor installations.« less
High-discharge-rate lithium ion battery
Liu, Gao; Battaglia, Vincent S; Zheng, Honghe
2014-04-22
The present invention provides for a lithium ion battery and process for creating such, comprising higher binder to carbon conductor ratios than presently used in the industry. The battery is characterized by much lower interfacial resistances at the anode and cathode as a result of initially mixing a carbon conductor with a binder, then with the active material. Further improvements in cycleability can also be realized by first mixing the carbon conductor with the active material first and then adding the binder.
NASA Astrophysics Data System (ADS)
Li, Guangqiang; Jiang, Danlu; Wang, Hui; Lan, Xinzheng; Zhong, Honghai; Jiang, Yang
2014-11-01
A novel electrode material for sodium-ion batteries (NIBs), Na3V2(PO4)3 with a rhombohedral, Na+ superionic conductor (NASICON)-type structure, was synthesised via a solid-state carbon-thermal reduction reaction assisted by mechanochemical activation. Electron microscopy analysis showed that the synthesised Na3V2(PO4)3 particles had an average size of 300 nm, being coated with a uniform layer of carbon 3 nm in thickness. As a cathode material, Na3V2(PO4)3/C exhibited an initial specific discharge capacity of 98.17 mAh g-1 at 0.1C for potentials ranging from 2.5 to 3.8 V. This was owing to the V3+/V4+ redox couple, which corresponded to the two-phase transition between Na3V2(PO4)3 and NaV2(PO4)3. The cathode lost 4.92% of its discharge specific capacity after 50 cycles. As an anode material, Na3V2(PO4)3/C exhibited an initial specific discharge capacity of 63.2 mAh g-1 at 0.1C for potentials ranging from 1.0 to 2.5 V. This was owing to the V2+/V3+ redox couple, which corresponded to the two-phase transition between Na3V2(PO4)3 and Na4V2(PO4)3. The anode lost approximately 5.41% of its discharge specific capacity after 50 cycles. The three-dimensional channel structure of NaV2(PO4)3 and the changes induced in its lattice parameters during the charge/discharge processes were simulated on the basis of density functional theory.
Sougrati, Moulay T.; Darwiche, Ali; Liu, Xiaohiu; ...
2016-03-16
Here we report evidence for the electrochemical activity of transition-metal carbodiimides versus lithium and sodium. In particular, iron carbodiimide, FeNCN, can be efficiently used as a negative electrode material for alkali-metal-ion batteries, similar to its oxide analogue FeO. Based on 57Fe M ssbauer and infrared spectroscopy (IR) data, the electrochemical reaction mechanism can be explained by the reversible transformation of the Fe NCN into Li/Na NCN bonds during discharge and charge. These new electrode materials exhibit higher capacity compared to well-established negative electrode references such as graphite or hard carbon. Contrary to its oxide analogue, iron carbodiimide does not requiremore » heavy treatments (nanoscale tailoring, sophisticated textures, coating etc.) to obtain long cycle life with density current as high as 9 A/g -1 for hundreds of charge/discharge cycles. Similar to the iron compound, several other transition-metal carbodiimides M x(NCN) y with M = Mn, Cr, Zn can cycle successfully versus lithium and sodium. Ultimately, their electrochemical activity and performances open the way to the design of a novel family of anode materials.« less
Emerging issues with silviculture practices in wetlands
Mike. Wylle
2016-01-01
Silviculture activities in wetlands involving discharges of dredge and/or fill material have been exempt from Clean Water Act (CWA) permits after the 1975 amendments to the CWA which were phased in by July 1977.
40 CFR 122.27 - Silvicultural activities (applicable to State NPDES programs, see § 123.25).
Code of Federal Regulations, 2010 CFR
2010-07-01
..., prescribed burning, pest and fire control, harvesting operations, surface drainage, or road construction and... roads) may involve point source discharges of dredged or fill material which may require a CWA section...
Physical and chemical analysis of a Ni/H2 cell
NASA Technical Reports Server (NTRS)
Vaidyanathan, H.; Earl, M. W.; Kirkendall, T. D.
1991-01-01
A cycled aerospace nickel hydrogen (Ni/H2) cell was subjected to destructive physical analysis to determine the reason for a capacity loss after 5,967 cycles at 60 percent depth of discharge. The positive plates in the cell were analyzed in terms of chemical composition, active material utilization, charge efficiency, and thickness increase. The microstructure of a cross section of the positive plate was determined by backscattered electron image analysis. The results suggest that the capacity loss in the cell is caused by low charge acceptance and low active material utilization at the positive plate. The oxidized nickel species content of the positive plate increased due to corrosion of the nickel sintered skeleton. This appears to circumvent the orderly reaction of the active material. Microstructural analysis has indicated that a new phase of active material is formed with cycling.
Kawai, Hiroyuki; Shibata, Yo; Miyazaki, Takashi
2004-05-01
Despite the fact that several reports have demonstrated osteoclast activity on various bioactive ceramics, osteoclast functions on surface-modified titanium have not come under focus. This study aimed to examine whether the increasing surface energy of glow discharge plasma (GDP) involved in protein adhesion containing the RGD (Arg-Gly-Asp) sequence affects osteoclast responses on titanium plates. We examined osteoclast differentiation and survival rates on titanium plates with and without GDP. The amounts of osteoclasts on titanium plates were not increased by GDP after 1 week. However, osteoclast differentiation was greatly activated by GDP pretreatment, as tartrate-resistant acid phosphatase synthesis significantly increased on the titanium plates with GDP. Additionally, since the presence of osteoclasts was detected only on the titanium plates with GDP, even after 4h cultivation in a coculture test, the osteoclasts survival rate was increased by GDP pretreatment. As osteoclast responses were affected even on surface modified metallic materials, we concluded that novel approaches are needed not only for osteoclastic resorption on ceramic materials but also for osteoclast responses on surface-modified metallic materials.
NASA Technical Reports Server (NTRS)
Bolotov, A. V.; Yukhimchuk, S. A.
1985-01-01
An analysis is made of the electrophysical processes occurring at the end surface of rod electrodes during constant and alternating arc discharge in hydrogen. Experiments are reported on the effect of surface temperature of tungsten electrodes on their erosion. The influence of activating additions of thorium oxide, the structure of the tungsten, and the gas surrounding the electrode on the specific thermal loading and the erosion of the electrodes is discussed.
All-Iron Redox Flow Battery Tailored for Off-Grid Portable Applications
Tucker, Michael C.; Phillips, Adam; Weber, Adam Z.
2015-11-20
We proposed and developed an all-iron redox flow battery for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. Our design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe 2 (SO 4 ) 3 activemore » material and 1.2 m NaCl supporting electrolyte. Furthermore, with these materials, an average power density around 20 mW cm -2 and a maximum energy density of 11.5 Wh L -1 are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh -1 , or only US$0.034 per mobile phone charge.« less
Code of Federal Regulations, 2012 CFR
2012-01-01
... 10 Energy 4 2012-01-01 2012-01-01 false Criterion I-Substantial discharge of radioactive material or substantial radiation levels offsite. 840.4 Section 840.4 Energy DEPARTMENT OF ENERGY EXTRAORDINARY NUCLEAR OCCURRENCES § 840.4 Criterion I—Substantial discharge of radioactive material or...
Code of Federal Regulations, 2013 CFR
2013-01-01
... 10 Energy 4 2013-01-01 2013-01-01 false Criterion I-Substantial discharge of radioactive material or substantial radiation levels offsite. 840.4 Section 840.4 Energy DEPARTMENT OF ENERGY EXTRAORDINARY NUCLEAR OCCURRENCES § 840.4 Criterion I—Substantial discharge of radioactive material or...
Code of Federal Regulations, 2010 CFR
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Criterion I-Substantial discharge of radioactive material or substantial radiation levels offsite. 840.4 Section 840.4 Energy DEPARTMENT OF ENERGY EXTRAORDINARY NUCLEAR OCCURRENCES § 840.4 Criterion I—Substantial discharge of radioactive material or...
Code of Federal Regulations, 2011 CFR
2011-01-01
... 10 Energy 4 2011-01-01 2011-01-01 false Criterion I-Substantial discharge of radioactive material or substantial radiation levels offsite. 840.4 Section 840.4 Energy DEPARTMENT OF ENERGY EXTRAORDINARY NUCLEAR OCCURRENCES § 840.4 Criterion I—Substantial discharge of radioactive material or...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Skaggs, B.E.
1995-07-01
The Environmental Protection Agency staff published the final storm water regulation on November 16, 1990. The storm water regulation is included in the National Pollutant Discharge Elimination System (NPDES) regulations. It specifies the permit application requirements for certain storm water discharges such as industrial activity or municipal separate storm sewers serving populations of 100,000 or greater. Storm water discharge associated with industrial activity is discharge from any conveyance used for collecting and conveying storm water that is directly related to manufacturing, processing, or raw material storage areas at an industrial plant. Quantitative testing data is required for these discharges. Anmore » individual storm water permit application was completed and submitted to Tennessee Department of Environment and Conservation (TDEC) personnel in October 1992. After reviewing this data in the permit application, TDEC personnel expressed concern with the fecal coliform levels at many of the outfalls. The 1995 NPDES Permit (Part 111-N, page 44) requires that an investigation be conducted to determine the validity of this data. If the fecal coliform data is valid, the permit requires that a report be submitted indicating possible causes and proposed corrective actions.« less
Process for producing nickel electrode having lightweight substrate
NASA Technical Reports Server (NTRS)
Lim, Hong S. (Inventor)
1996-01-01
A nickel electrode having a lightweight porous nickel substrate is subjected to a formation cycle involving heavy overcharging and under-discharging in a KOH electrolyte having a concentration of 26% to 31%, resulting in electrodes displaying high active material utilization.
NASA Astrophysics Data System (ADS)
Tooming, T.; Thomberg, T.; Kurig, H.; Jänes, A.; Lust, E.
2015-04-01
The electrochemical impedance spectroscopy, cyclic voltammetry, constant current charge/discharge and the constant power discharge methods have been applied to establish the electrochemical characteristics of the electrical double-layer capacitor (EDLC) consisting of the 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) ionic liquid and microporous carbon electrodes. Microporous carbon material used for preparation of electrodes (GDAC - glucose derived activated carbon), has been synthesised from D-(+)-glucose by the hydrothermal carbonization method, including subsequent pyrolysis, carbon dioxide activation and surface cleaning step with hydrogen. The Brunauer-Emmett-Teller specific surface area (SBET = 1540 m2 g-1), specific surface area calculated using the non-local density functional theory in conjunction with stable adsorption integral equation using splines (SAIEUS) model SSAIEUS = 1820 m2 g-1, micropore surface area (Smicro = 1535 m2 g-1), total pore volume (Vtot = 0.695 cm3 g-1) and the pore size distribution were obtained from the N2 sorption data. The SBET, Smicro and Vtot values have been correlated with the electrochemical characteristics strongly dependent on the carbon activation conditions applied for EDLCs. Wide region of ideal polarizability (ΔV ≤ 3.2 V), very short charging/discharging time constant (2.7 s), and high specific series capacitance (158 F g-1) have been calculated for the optimized carbon material GDAC-10h (activation of GDAC with CO2 during 10 h) in EMImBF4 demonstrating that this system can be used for completing the EDLC with high energy- and power densities.
Screening Protocol for the Electrochemical Characterization of Potential Supercapacitor Materials
2009-11-01
Felix Wong; DRDC Atlantic TM 2009-279; R & D pour la défense Canada – Atlantique; Novembre 2009. Introduction ou contexte : Les forces armées ont... 13 Figure 10: The effect of active material... 13 : Typical Constant Current Charge-Discharge Curve for a 1.34 mg Electrode of PAni-2NSA/MWNT at a Constant Current of 0.2 mA
Cadmium migration in aerospace nickel cadmium cells
NASA Technical Reports Server (NTRS)
Mcdermott, P. P.
1976-01-01
The effects of temperature, the nature of separator material, charge and discharge, carbonate contamination, and the mode of storage are studied with respect to the migration of active material from the negative toward the positive plate. A theoretical model is proposed which takes into account the solubility of cadmium in various concentrations of hydroxide and carbonate at different temperatures, the generation of the cadmiate ion, Cd(OH)3(-), during discharge, the migration of the cadmiate ion and particulate Cd(OH)2 due to electrophoretic effects and the movement of electrolyte in and out of the negative plate and, finally, the recrystallization of cadmiate ion in the separator as Cd(OH)2. Application of the theoretical model to observations of cadmium migration in cycled cells is also discussed.
Sinusoidal current and stress evolutions in lithium-ion batteries
NASA Astrophysics Data System (ADS)
Yang, Xiao-Guang; Bauer, Christoph; Wang, Chao-Yang
2016-09-01
Mechanical breakdown of graphite materials due to diffusion-induced stress (DIS) is a key aging mechanism of lithium-ion batteries. In this work, electrochemical-thermal coupled model along with a DIS model is developed to study the DIS distribution across the anode thickness. Special attention is paid to the evolution behavior of surface tangential stress (STS) in the discharge process for graphite at different locations of the anode. For the first time, we report that the evolution of STS, as well as local current, at all locations of the anode, evolve like sinusoidal waves in the discharge process with several crests and troughs. The staging behavior of graphite active material, in particular the sharp change of open-circuit potential (OCP) of graphite in the region between two plateaus, is found to be the root cause for the sinusoidal patterns of current and stress evolution. Furthermore, the effects of various parameters, such as starting state of charge, discharge C-rate and electrode thickness on the current and stress evolutions are investigated.
2015-12-01
The research resulted in a composite material that holds a quasi-permanent electric charge and rapidly discharges the electric charge upon X-ray...quasi-permanent electric charge and rapidly discharge the electric charge upon X-ray exposure. The composite material combined the properties of an...9 7. Schematic of Circuit for Recording Sample’s Capacitor Discharge ............... 12 8. Schematic of Circuit for
NASA Astrophysics Data System (ADS)
Kamgang, J. O.; Naitali, M.; Herry, J.-M.; Bellon-Fontaine, M.-N.; Brisset, J.-L.; Briandet, R.
2009-04-01
This study addressed the effects of treatment with gliding discharge plasma on the surface properties of solid materials, as well as the consequences concerning adherence of a model bacterium. As evaluated by contact angles with selected liquids, plasma treatment caused an increase in surface hydrophilicity and in the Lewis acid-base components of the surface energy of all materials tested. These modifications were more marked for low density polyethylene and stainless steel than for polytetrafluoroethylene. After treatment, the hydrophilicity of the materials remained relatively stable for at least 20 days. Moreover, analysis of the topography of the materials by atomic force microscopy revealed that the roughness of both polymers was reduced by glidarc plasma treatment. As a result of all these modifications, solid substrates were activated towards micro-organisms and the adherence of S. epidermidis, a negatively charged Lewis-base and mildly hydrophilic strain selected as the model, was increased in almost all the cases tested.
Patel, Shrayesh N; Javier, Anna E; Balsara, Nitash P
2013-07-23
Block copolymers that can simultaneously conduct electronic and ionic charges on the nanometer length scale can serve as innovative conductive binder material for solid-state battery electrodes. The purpose of this work is to study the electronic charge transport of poly(3-hexylthiophene)-b-poly(ethylene oxide) (P3HT-PEO) copolymers electrochemically oxidized with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt in the context of a lithium battery charge/discharge cycle. We use a solid-state three-terminal electrochemical cell that enables simultaneous conductivity measurements and control over electrochemical doping of P3HT. At low oxidation levels (ratio of moles of electrons removed to moles of 3-hexylthiophene moieties in the electrode), the electronic conductivity (σe,ox) increases from 10(-7) S/cm to 10(-4) S/cm. At high oxidation levels, σe,ox approaches 10(-2) S/cm. When P3HT-PEO is used as a conductive binder in a positive electrode with LiFePO4 active material, P3HT is electrochemically active within the voltage window of a charge/discharge cycle. The electronic conductivity of the P3HT-PEO binder is in the 10(-4) to 10(-2) S/cm range over most of the potential window of the charge/discharge cycle. This allows for efficient electronic conduction, and observed charge/discharge capacities approach the theoretical limit of LiFePO4. However, at the end of the discharge cycle, the electronic conductivity decreases sharply to 10(-7) S/cm, which means the "conductive" binder is now electronically insulating. The ability of our conductive binder to switch between electronically conducting and insulating states in the positive electrode provides an unprecedented route for automatic overdischarge protection in rechargeable batteries.
NASA Astrophysics Data System (ADS)
Khristoliubova, V. I.; Kashapov, N. F.; Shaekhov, M. F.
2016-06-01
Researches results of the characteristics of the RF discharge jet of low pressure and the discharge influence on the surface modification of high speed and structural steels are introduced in the article. Gas dynamics, power and energy parameters of the RF low pressure discharge flow in the discharge chamber and the electrode gap are studied in the presence of the materials. Plasma flow rate, discharge power, the concentration of electrons, the density of RF power, the ion current density, and the energy of the ions bombarding the surface materials are considered for the definition of basic properties crucial for the process of surface modification of materials as they were put in the plasma jet. The influence of the workpiece and effect of products complex configuration on the RF discharge jet of low pressure is defined. The correlation of the input parameters of the plasma unit on the characteristics of the discharge is established.
VRLA Refined™ lead — A must for VRLA batteries. Specification and Performance
NASA Astrophysics Data System (ADS)
Stevenson, M. W.; Lakshmi, C. S.; Manders, J. E.; Lam, L. T.
VRLA Refined™ lead produced and marketed by Pasminco since 1997 is a very high purity lead with guaranteed low levels of the gassing elements but with optimum bismuth content that produces oxide of finer particle size, higher acid absorption and imparts outstanding electrical performance and endurance especially under conditions of deep cycling. VRLA batteries suffer dry-out, self-discharge, negative plate capacity loss and poor cycle life unless special lead is used for the grids and active material. This paper addresses the lead used for active material.
Degradation diagnosis of aged Li4Ti5O12/LiFePO4 batteries
NASA Astrophysics Data System (ADS)
Castaing, Rémi; Reynier, Yvan; Dupré, Nicolas; Schleich, Donald; Jouanneau Si Larbi, Séverine; Guyomard, Dominique; Moreau, Philippe
2014-12-01
Li4Ti5O12/LiFePO4 cells are cycled under 4 different conditions of discharge profile (galvanostatic or driving-based) and cycling rates (C/8 or 1C) during 4-5 months. All the cells exhibit capacity fade whose extent is not correlated with the aging condition. In order to understand aging phenomena, cells are disassembled at the end of cycle life and the recovered electrodes are analyzed using electrochemistry, electron microscopy, XRD and MAS-NMR. Positive and negative electrodes show no loss in active material and no change in electrochemical activity, active material structure and composite electrode structure. This rules out any irreversible electrode degradation. Lithium stoichiometry estimated by both XRD and electrochemistry is unexpectedly low in the positive electrode when the aging is stopped at full discharge. That indicates a loss of cyclable lithium or electrons leading to cell balancing evolution. That loss may have been caused by parasitic reactions occurring at both electrodes, in accordance with their rich surface chemistry as evidenced by MAS-NMR.
NASA Astrophysics Data System (ADS)
Sabbah, Rami; Kizilel, R.; Selman, J. R.; Al-Hallaj, S.
The effectiveness of passive cooling by phase change materials (PCM) is compared with that of active (forced air) cooling. Numerical simulations were performed at different discharge rates, operating temperatures and ambient temperatures of a compact Li-ion battery pack suitable for plug-in hybrid electric vehicle (PHEV) propulsion. The results were also compared with experimental results. The PCM cooling mode uses a micro-composite graphite-PCM matrix surrounding the array of cells, while the active cooling mode uses air blown through the gaps between the cells in the same array. The results show that at stressful conditions, i.e. at high discharge rates and at high operating or ambient temperatures (for example 40-45 °C), air-cooling is not a proper thermal management system to keep the temperature of the cell in the desirable operating range without expending significant fan power. On the other hand, the passive cooling system is able to meet the operating range requirements under these same stressful conditions without the need for additional fan power.
NASA Astrophysics Data System (ADS)
Yuasa, Motohiro; Huang, Xinsheng; Suzuki, Kazutaka; Mabuchi, Mamoru; Chino, Yasumasa
2015-11-01
The discharge behaviors of rolled Mg-6 mass%Al-0.3 mass%Mn-2 mass%Ca (AMX602) and Mg-6 mass%Al-0.3 mass%Mn (AM60) alloys used as anodes for Magnesium-air batteries were investigated. The AMX602 alloy exhibited superior discharge properties compared to the AM60 alloy, especially at low current density. The discharge products of the AMX602 alloy were dense and thin, and many cracks were observed at all current densities. In addition, the discharge products were detached at some sites. These sites often corresponded to the positions of Al2Ca particles. The comparison of the discharge and corrosion tests indicated that the dense and thin discharge products of AMX602 were easily cracked by dissolution of the Mg matrix around Al2Ca particles, and the cracks promoted the penetration of the electrolyte into the discharge products, retaining the discharge activity. In contrast, concerning the AM60 alloy, thick discharge products were formed on the surface during discharge, and cracking of the discharge products hardly occurred, degrading the discharge properties. Localized and deeply corroded pits that could result from the detachment of metal pieces from the anode during discharge were partly observed in the AM60 alloy. It is suggested that these detached metal pieces are another reason for the low discharge properties of the AM60 alloy.
Mukherjee, Debdyuti; Gowda Y K, Guruprasada; Makri Nimbegondi Kotresh, Harish; Sampath, S
2017-06-14
Organic materials containing active carbonyl groups have attracted considerable attention as electrodes in Li-ion batteries due to their reversible redox activity, ability to retain capacity, and, in addition, their ecofriendly nature. Introduction of porosity will help accommodate as well as store small ions and molecules reversibly. In the present work, we introduce a mesoporous triptycene-related, rigid network polymer with high specific surface area as an electrode material for rechargeable Li-ion battery. The designed polymer with a three-dimensional (3D), rigid porous network allows free movement of ions/electrolyte as well as helps in interacting with the active anhydride moieties (containing two carbonyl groups). Considerable intake of Li + ions giving rise to very high specific capacity of 1100 mA h g -1 at a discharge current of 50 mA g -1 and ∼120 mA h g -1 at a high discharge current of 3 A g -1 are observed with excellent cyclability up to 1000 cycles. This remarkable rate capability, which is one of the highest among the reported organic porous polymers to date, makes the triptycene-related rigid 3D network a very good choice for Li-ion batteries and opens up a new method to design polymer-based electrode materials for metal-ion battery technology.
NASA Astrophysics Data System (ADS)
Whitacre, J. F.; Wiley, T.; Shanbhag, S.; Wenzhuo, Y.; Mohamed, A.; Chun, S. E.; Weber, E.; Blackwood, D.; Lynch-Bell, E.; Gulakowski, J.; Smith, C.; Humphreys, D.
2012-09-01
An approach to making large format economical energy storage devices based on a sodium-interactive set of electrodes in a neutral pH aqueous electrolyte is described. The economics of materials and manufacturing are examined, followed by a description of an asymmetric/hybrid device that has λ-MnO2 positive electrode material and low cost activated carbon as the negative electrode material. Data presented include materials characterization of the active materials, cyclic voltammetry, galvanostatic charge/discharge cycling, and application-specific performance of an 80 V, 2.4 kW h pack. The results indicate that this set of electrochemical couples is stable, low cost, requires minimal battery management control electronics, and therefore has potential for use in stationary applications where device energy density is not a concern.
NASA Astrophysics Data System (ADS)
Kazemiabnavi, Saeed; Malik, Rahul; Orvananos, Bernardo; Abdellahi, Aziz; Ceder, Gerbrand; Thornton, Katsuyo
2018-04-01
Surface modification of active cathode particles is commonly observed in battery research as either a surface phase evolving during the cycling process, or intentionally engineered to improve capacity retention, rate capability, and/or thermal stability of the cathode material. Here, a continuum-scale model is developed to simulate the galvanostatic charge/discharge of a cathode particle with core-shell heterostructure. The particle is assumed to be comprised of a core material encapsulated by a thin layer of a second phase that has a different open-circuit voltage. The effect of the potential difference between the surface and bulk phases (Ω) on the kinetics of lithium intercalation and the galvanostatic charge/discharge profiles is studied at different values of Ω, C-rates, and exchange current densities. The difference between the Li chemical potential in the surface and bulk phases of the cathode particle results in a concentration difference between these two phases. This leads to a charge/discharge asymmetry in the galvanostatic voltage profiles, causing a decrease in the accessible capacity of the particle. These effects are more significant at higher magnitudes of surface-bulk potential difference. The proposed model provides detailed insight into the kinetics and voltage behavior of the intercalation/de-intercalation processes in core-shell heterostructure cathode particles.
Song, Yu; Liu, Tian-Yu; Yao, Bin; Kou, Tian-Yi; Feng, Dong-Yang; Liu, Xiao-Xia; Li, Yat
2017-04-01
Previous studies show that vanadium oxides suffer from severe capacity loss during cycling in the liquid electrolyte, which has hindered their applications in electrochemical energy storage. The electrochemical instability is mainly due to chemical dissolution and structural pulverization of vanadium oxides during charge/discharge cyclings. In this study the authors demonstrate that amorphous mixed-valence vanadium oxide deposited on exfoliated carbon cloth (CC) can address these two limitations simultaneously. The results suggest that tuning the V 4+ /V 5+ ratio of vanadium oxide can efficiently suppress the dissolution of the active materials. The oxygen-functionalized carbon shell on exfoliated CC can bind strongly with VO x via the formation of COV bonding, which retains the electrode integrity and suppresses the structural degradation of the oxide during charging/discharging. The uptake of structural water during charging and discharging processes also plays an important role in activating the electrode material. The amorphous mixed-valence vanadium oxide without any protective coating exhibits record-high cycling stability in the aqueous electrolyte with no capacitive decay in 100 000 cycles. This work provides new insights on stabilizing vanadium oxide, which is critical for the development of vanadium oxide based energy storage devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Synthesis and Electrochemical Performance of LixMn2-yCoyO4-dCld Cathode Material
2016-06-13
Lithium manganese oxide spinel is a potential candidate for Li- ion battery cathodes because of its...240 mAh/g of active material, and 4) high rate charge and discharge. Keywords: Lithium and Li- ion battery , Lithium manganese oxide spinel, Spinel...demonstrate desirable traits for incorporation into lithium - ion batteries for the military. References 1. David Linden (Ed.); Handbook of Batteries
Qin, CanCan; Cao, JiaLi; Chen, Jun; Dai, GaoLe; Wu, TongFu; Chen, Yanbin; Tang, YueFeng; Li, AiDong; Chen, Yanfeng
2016-06-21
LiNi0.6Co0.2Mn0.2O2 cathode material has been surface-modified by coating with ultrathin TiO2via atomic layer deposition (ALD) technology to improve the electrochemical performance of LiNi0.6Co0.2Mn0.2O2 cathodes for lithium ion batteries. Within the cut-off voltage of 2.5-4.3 V, the coated sample delivers an initial discharge capacity of 187.7 mA h g(-1) at 0.1 C and with a capacity retention about 85.9% after 100 cycles at 1 C, which provides a significant improvement in terms of discharge capacity and cyclability, as compared with those of the bare one. Such enhanced electrochemical performance of the coated sample is ascribed to its high-quality ultrathin coating of amorphous TiO2, which can protect the active material from HF attack, withstand the dissolution of metal ions in the electrode and favor the lithium diffusion of oxide as proved by electrochemical impedance spectroscopy (EIS) tests. TiO2 coating via the ALD process provides a potential approach for battery factories to surface-modify Ni-rich electrode materials so as to realize improvements in electrochemical performance.
Raman structural studies of the nickel electrode
NASA Technical Reports Server (NTRS)
Cornilsen, B. C.
1985-01-01
Raman spectroscopy is sensitive to empirically controlled nickel electrode structural variations, and has unique potential for structural characterization of these materials. How the structure relates to electrochemical properties is examined so that the latter can be more completely understood, controlled, and optimized. Electrodes were impregnated and cycled, and cyclic voltammetry is being used for electrochemical characterization. Structural variation was observed which has escaped detection using other methods. Structural changes are induced by: (1) cobalt doping, (2) the state of change or discharge, (3) the preparation conditions and type of buffer used, and (4) the formation process. Charged active mass has an NiOOH-type structure, agreeing with X-ray diffraction results. Discharged active mass, however, is not isostructural with beta-Ni(OH)2. Chemically prepared alpha phases are not isostructural either. A disordered structural model, containing point defects, is proposed for the cycled materials. This model explains K(+) incorporation. Band assignments were made and spectra interpreted for beta-Ni(OH)2, electrochemical NiOOH and chemically precipitated NiOOH.
2017-03-06
4 Pre-transit discharge region (phase II) ........................................................................... 5 Post...transit Discharge Region (phase III) ...................................................................... 5 2.2. Optical Signature...3 Figure 2 Schematic of a charge/ discharge curve of an electron irradiated insulating material. .. 4
40 CFR 230.72 - Actions controlling the material after discharge.
Code of Federal Regulations, 2010 CFR
2010-07-01
... and disposal sites where the potential for erosion, slumping or leaching of materials into the... containment areas to reduce leaching where leaching of chemical constituents from the discharged material is...
40 CFR 230.72 - Actions controlling the material after discharge.
Code of Federal Regulations, 2013 CFR
2013-07-01
... and disposal sites where the potential for erosion, slumping or leaching of materials into the... containment areas to reduce leaching where leaching of chemical constituents from the discharged material is...
40 CFR 230.72 - Actions controlling the material after discharge.
Code of Federal Regulations, 2011 CFR
2011-07-01
... and disposal sites where the potential for erosion, slumping or leaching of materials into the... containment areas to reduce leaching where leaching of chemical constituents from the discharged material is...
40 CFR 230.72 - Actions controlling the material after discharge.
Code of Federal Regulations, 2012 CFR
2012-07-01
... and disposal sites where the potential for erosion, slumping or leaching of materials into the... containment areas to reduce leaching where leaching of chemical constituents from the discharged material is...
40 CFR 230.72 - Actions controlling the material after discharge.
Code of Federal Regulations, 2014 CFR
2014-07-01
... and disposal sites where the potential for erosion, slumping or leaching of materials into the... containment areas to reduce leaching where leaching of chemical constituents from the discharged material is...
D'Adamo, Raffaele; Specchiulli, Antonietta; Cassin, Daniele; Botter, Margherita; Zonta, Roberto; Fabbrocini, Adele
2014-10-01
The effects on the microtidal lagoon of Lesina of runoff and the discharge of water and material from agricultural activities were investigated combining chemical analyses of pollutants [11 metals and 16 priority polycyclic aromatic compounds (PAHs)], determination of organic matter and grain size, and performance of innovative ecotoxicological tests. For metals, enrichment factors >3 for arsenic, nickel, and copper (Cu) were observed in the eastern zone of the lagoon, which is affected by nearby urban activities with discharge of water and domestic waste and by agricultural input with waters rich in fertilizers. Cu was correlated with no other metal, and its high concentrations (≤77 µg g(-1)) may result from the use of Cu-based fungicides in vineyards. Total PAHs (2,230 ± 3,150 ng g(-1)) displayed a wide range of concentrations with hot spots near freshwater inputs from the part of the catchment area exploited for wheat crops. Pyrolitic contamination also emerged, with higher-mass PAH congeners, such as asphalt, bitumen or coal, usually present in higher fractions as the dominant components. Ecotoxicological evaluations recorded moderate to high toxicity levels; the innovative MOT test bioassay showed good discriminatory ability because it identified a lagoon area whose inputs mainly depend on agricultural activities and which is impacted by metals rather than PAHs. Floods during periods of heavy rain and the discharge of water and material from agricultural activities may impact vulnerable systems, such as the lagoon of Lesina, where the presence of hot spots with remarkably high pollution values was observed.
The Structure and Infrastructure of Chinese Science and Technology
2006-01-01
materi 2.4%, charg.discharg 2.2%, mah 2.0%, lifepo4 2.0%, charg 1.7%, composit 1.3%, oxid 1.2%, discharg.capac 1.1%, licoo2 1.1...charg.discharg 2.2%, mah 2.0%, lifepo4 2.0%, charg 1.7%, composit 1.3%, oxid 1.2%, discharg.capac 1.1%, licoo2 1.1%, cathod.materi 1.0%, electrod
Asif, Muhammad; Tan, Yi; Pan, Lujun; Rashad, Muhammad; Li, Jiayan; Fu, Xin; Cui, Ruixue
2016-09-29
Graphene based nanocomposites have been investigated intensively, as electrode materials for energy storage applications. In the current work, a graphene-CNT-MnO 2 -PANI (GCM@PANI) nanocomposite has been synthesized on 3D graphene grown on nickel foam, as a highly efficient binder free electrode material for supercapacitors. Interestingly, the specific capacitance of the synthesized electrode increases up to the first 1500 charge-discharge cycles, and is thus referred to as an electrode activation process. The activated GCM@PANI nanocomposite electrode exhibits an extraordinary galvanostatic specific capacitance of 3037 F g -1 at a current density of 8 A g -1 . The synthesized nanocomposite exhibits an excellent cyclic stability with a capacitance retention of 83% over 12 000 charge-discharge cycles, and a high rate capability by retaining a specific capacitance of 84.6% at a current density of 20 A g -1 . The structural and electrochemical analysis of the synthesized nanocomposite suggests that the astonishing electrochemical performance might be attributed to the growth of a novel PANI nanoparticle layer and the synergistic effect of CNT/MnO 2 nanostructures.
Mössbauer study of new vanadate glass with large charge-discharge capacity
NASA Astrophysics Data System (ADS)
Kubuki, Shiro; Masuda, Hitomi; Matsuda, Koken; Akiyama, Kazuhiko; Kitajo, Ayuko; Okada, Shigeto; Zsabka, Péter; Homonnay, Zoltán; Kuzmann, Ernõ; Nishida, Tetsuaki
2014-04-01
Charge-discharge capacity and cyclicity of lithium ion battery (LIB) was evaluated in which 15Li2O·10Fe2O3· xSnO2·5P2O5·(70- x)V2O5 glass ( x = 0 and 20 in mol%, abbreviated as xLFSPV) was used as a cathode. A local structure of xLFSPV glass before and after charging was investigated by 57Fe- and 119Sn-Mössbauer spectroscopies. 57Fe-Mössbauer spectrum of xLFSPV glass with ` x' of 20 was composed of a doublet with isomer shift ( δ) of 0.35±0.02 mm s - 1 and quadrupole splitting ( Δ) of 0.88±0.03 mm s - 1 due to distorted FeIIIO4 tetrahedra. 119Sn-Mössbauer spectrum of this glass consisted of a doublet with δ of 0.08±0.01 and Δ of 0.52±0.01 mms - 1 due to distorted SnVIO6 octahedra. After discharging the battery from 4.5 to 1.0 V, larger δ of 0.40±0.03 mm s - 1 and Δ of 0.94±0.04 mm s - 1 were obtained, indicating that both iconicity of Fe-O bonds and local distortion of FeIIIO4 tetrahedra were increased. On the contrary, identical δ of 0.09±0.01 mm s - 1 and Δ of 0.50±0.01 mm s - 1 were observed in the 119Sn-Mössbauer spectrum of 20LFSPV glass after the discharge, indicating that chemical environment of SnIVO6 octahedra was not affected after the discharge. Charge-discharge curve of LIB containing 20LFSPV glass as a cathode active material recorded under the current density of 8.3 mA g - 1 (0.011 mA cm - 2) between 1.0 and 4.5 V showed a large initial charge capacity of 431.1 mAh g - 1 and discharge capacity of 382.3 mAh g - 1, respectively. These results indicate that 20LFSPV glass could be a new cathode active material for LIB.
Water Treatment Using Plasma Discharge with Variation of Electrode Materials
NASA Astrophysics Data System (ADS)
Chanan, N.; Kusumandari; Saraswati, T. E.
2018-03-01
This research studied water treatment using plasma discharge. Plasma generated in this study produced active species that played a role in organic compound decomposition. The plasma reactor consisted of two needle electrodes made from stainless steel, tungsten, aluminium and grafit. It placed approximately 2 mm above the solution and connected with high-AC voltage. A solution of methylene blue used as an organic solution model. Plasma treatment times were 2, 4, 6, 8 and 10 min. The absorbance, temperature and pH of the solution were measured before and after treatment using various electrodes. The best electrode used in plasma discharging for methylene blue absorbance reduction was the graphite electrode, which provided the highest degradation efficiency of 98% at 6 min of treatment time.
Structure and electrochemical behaviour of metastable Mg 50Ti 50 alloy prepared by ball milling
NASA Astrophysics Data System (ADS)
Rousselot, S.; Bichat, M.-P.; Guay, D.; Roué, L.
A 50-50 mixture of Mg and Ti was milled for different times, and the cycling discharge capacities of the resulting compounds were evaluated in KOH media. From Rietveld refinement analysis of the X-ray diffraction patterns, it is shown that a metastable hcp Mg 50Ti 50 compound is formed after 20 h of milling. This material has a very low-electrochemical hydriding activity. However, in the presence of 10 wt.% Pd (added before milling), it displays a maximum discharge capacity of ca. 400 mAh g -1 after three charge/discharge cycles. The irreversible structural evolution of the Mg 50Ti 50 alloy from a hcp phase to a fcc phase upon cycling is demonstrated.
Aufderheide, Tom P.; Kudenchuk, Peter J.; Hedges, Jerris R.; Nichol, Graham; Kerber, Richard E.; Dorian, Paul; Davis, Daniel P.; Idris, Ahamed H.; Callaway, Clifton W.; Emerson, Scott; Stiell, Ian G.; Terndrup, Thomas E.
2013-01-01
Aim The primary aim of this study is to compare survival to hospital discharge with a modified Rankin score (MRS) ≤3 between standard cardiopulmonary resuscitation (CPR) plus an active impedance threshold device (ITD) versus standard CPR plus a sham ITD in patients with out-of-hospital cardiac arrest. Secondary aims are to compare functional status and depression at discharge and at 3 and 6 months post discharge in survivors. Materials and Methods Design Prospective, double-blind, randomized, controlled, clinical trial. Population Patients with non-traumatic out-of-hospital cardiac arrest treated by emergency medical services (EMS) providers. Setting EMS systems participating in the Resuscitation Outcomes Consortium. Sample Size Based on a one-sided significance level of 0.025, power = 0.90, a survival with MRS ≤ 3 to discharge rate of 5.33% with standard CPR and sham ITD, and two interim analyses, a maximum of 14,742 evaluable patients are needed to detect a 6.69% survival with MRS ≤ 3 to discharge with standard CPR and active ITD (1.36% absolute survival difference). Conclusion If the ITD demonstrates the hypothesized improvement in survival, it is estimated that2,700 deaths from cardiac arrest per year would be averted in North America alone. PMID:18487005
ECOLOGICAL RISK ASSESSMENT AND THE PRECAUTIONARY PRINCIPLE
The Precautionary Principle, generated during the late 1980s as a unifying principle for regulating discharge of hazardous material into the North Sea, has been broadened to include a shifting of the burden of proof to the proponent of a proposed activity, adoption of a more holi...
Surface-modified Mg{sub 2}Ni-type negative electrode materials for Ni-MH battery
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cui, N.; Luan, B.; Bradhurst, D.
1997-12-01
In order to further improve the electrode performance of Mg{sub 1.9}Y{sub 0.1}Ni{sub 0.9}Al{sub 0.1} alloy at ambient temperature, its surface was modified by an ultrasound pretreatment in the alkaline solution and microencapsulation with Ni-P coating. The effects of various surface modifications on the microstructure and electrochemical performance of the alloy electrodes were investigated and compared in this paper. It was found that the modification with ultrasound pretreatment significantly improved the electrocatalytic activity of the negative electrode and then reduced the overpotential of charging/discharging, resulting in a remarkable increase of electrode capacity and high-rate discharge capability but having little influence onmore » the cycle life. However, the electrode fabricated from the microencapsulated alloy powder showed a higher discharge capacity, better high-rate discharge capability and longer cycle life as well.« less
Daniels, Michael A.; Heaps, Ronald J.; Wallace, Ronald S.; Pantoya, Michelle L.; Collins, Eric S.
2016-11-01
An energetic material comprising an elemental fuel, an oxidizer or other element, and a carbon nanofiller or carbon fiber rods, where the carbon nanofiller or carbon fiber rods are substantially homogeneously dispersed in the energetic material. Methods of tailoring the electrostatic discharge sensitivity of an energetic material are also disclosed.
Constructing post-surgical discharge instructions through a Delphi consensus methodology.
Scott, Aaron R; Sanderson, Cody J; Rush, Augustus J; Alore, Elizabeth A; Naik, Aanand D; Berger, David H; Suliburk, James W
2018-05-01
Patient education materials are a crucial part of physician-patient communication. We hypothesize that available discharge instructions are difficult to read and fail to address necessary topics. Our objective is to evaluate readability and content of surgical discharge instructions using thyroidectomy to develop standardized discharge materials. Thyroidectomy discharge materials were analyzed for readability and assessed for content. Fifteen endocrine surgeons participated in a modified Delphi consensus panel to select necessary topics. Using readability best practices, we created standardized discharge instructions which included all selected topics. The panel evaluated 40 topics, selected 23, deemed 4 inappropriate, consolidated 5, and did not reach consensus on 8 topics after 4 rounds. The evaluated instructions' reading levels ranged from grade 6.5 to 13.2; none contained all consensus topics. Current post surgical thyroidectomy discharge instructions are more difficult to read than recommended by literacy standards and omit consensus warning signs of major complications. Our easy-to-read discharge instructions cover pertinent topics and may enhance patient education. Delphi methodology is useful for developing post-surgical instructions. Patient education materials need appropriate readability levels and content. We recommend the Delphi method to select content using consensus expert opinion whenever higher level data is lacking. Copyright © 2017 Elsevier B.V. All rights reserved.
Solution Processed PEDOT Analogues in Electrochemical Supercapacitors.
Österholm, Anna M; Ponder, James F; Kerszulis, Justin A; Reynolds, John R
2016-06-01
We have designed fully soluble ProDOTx-EDOTy copolymers that are electrochemically equivalent to electropolymerized PEDOT without using any surfactants or dispersants. We show that these copolymers can be incorporated as active layers in solution processed thin film supercapacitors to demonstrate capacitance, stability, and voltage similar to the values of those that use electrodeposited PEDOT as the active material with the added advantage of the possibility for large scale, high-throughput processing. These Type I supercapacitors provide exceptional cell voltages (up to 1.6 V), highly symmetrical charge/discharge behavior, promising long-term stability exceeding 50 000 charge/discharge cycles, as well as energy (4-18 Wh/kg) and power densities (0.8-3.3 kW/kg) that are comparable to those of electrochemically synthesized analogues.
NASA Astrophysics Data System (ADS)
Wang, Linqian; Wang, Richu; Feng, Yan; Deng, Min; Wang, Naiguang
2017-12-01
Mg-Al-Pb alloy can serve as a good candidate for the anode material in seawater-activated batteries. The effect of solution and aging treatment on electrochemical properties of Mg-9 wt.%Al-2.5 wt.%Pb alloy in 3.5 wt.% NaCl solution was investigated through scanning electron microscopy and electrochemical tests. The results indicate that the discharge activity of Mg-9 wt.%Al-2.5 wt.%Pb alloy decreases after solution treatment, although its anodic efficiency increases slightly. In contrast, its discharge performance and anodic efficiency, which are crucial for the application of batteries, are both enhanced after aging at 200°C for 12 h.
NASA Astrophysics Data System (ADS)
Grichshenko, Valentina; Zhantayev, Zhumabek; Mukushev, Acemhan
2016-07-01
It is known, that during SV exploitation failures of automated systems happens as the result of complex influence of Space leading to SV's shorter life span, sometimes to their lose. All of the SV, functioning in the near-Earth Space (NES), subjected to influence of different Space factors. Causes and character of failure onboard equipment are different. Many researchers think that failures of onboard electronics connected to changing solar activity level. However, by the numerous onboard experiments established that even in the absence of solar burst in magnetostatic days there are registered failures of onboard electronics. In this paper discussed the results of modeling the impact of electrostatic discharge (ESD), occurring in the materials, on a failures of electronic onboard equipment in microgravity. The paper discusses the conditions of formation and influence of electrostatic discharge in microgravity on the elements of the onboard electronics in Space. Developed technique using circuit simulation in ISIS Proteus environment is discussed. Developed the recommendations for noise immunity of on-board equipment from ESD in Space. The results are used to predict the failure rate on-board electronics with the long term of space mission. Key words: microgravity, materials, failures, onboard electronics, Space
Pulgati, Fernando H; Ayup-Zouain, Ricardo N; Landau, Luiz; Fachel, Jandyra M G
2010-08-01
This paper describes the use of Bayesian spatial models to develop the concept of a spatial-temporal mask for the purpose of identifying regions in which before and after drilling effects are most clearly defined and from which the consequences of exposure of macrofauna and meiofauna to the release of drilling discharges can be evaluated over time. To determine the effects of drilling fluids and drill-cuttings on the marine benthic community, it is essential to know not only where discharged materials ended up within the possible impact area, but also the chemical concentrations to which biota were exposed during and after drilling. Barium and light hydrocarbons were used as chemical tracers for water-based and non-aqueous-based fluids in a shallow water site in the Campos Basin, off the coast of Brazil. Since the site showed evidence of exposure to waste material from earlier drilling, the analysis needed to take into account the background concentrations of these compounds. Using the Bayesian models, concentrations at unsampled sites were predicted and regions altered and previously contaminated were identified.
l-Cysteine-Assisted Synthesis of Urchin-Like γ-MnS and Its Lithium Storage Properties
NASA Astrophysics Data System (ADS)
Xu, Dan; Jiao, Ranran; Sun, Yuanwei; Sun, Dezhi; Zhang, Xianxi; Zeng, Suyuan; Di, Youying
2016-10-01
MnS has been attracting more and more attentions in the fields of lithium ion batteries (LIBs) because of its high energy density and low voltage potential. In this paper, we present a simple method for the preparation of urchin-like γ-MnS microstructures using l-cysteine and MnCl2 · 4H2O as the starting materials. The urchin-like γ-MnS microstructures exhibit excellent cycling stability (823.4 mA h g-1 at a current density of 500 mA g-1, after 1000 cycles). And the discharge voltage is about 0.75 V, making it a good candidate for the application as the anode material in LIBs. SEM, TEM, and XRD were employed to inspect the changes of the active materials during the electrochemical process, which clearly indicate that the structural pulverization and reformation of the γ-MnS microstructures play important roles for the maintenance of the electrochemical performance during the charge/discharge process.
Nitrate-Melt Synthesized HT-LiCoO2 as a Superior Cathode-Material for Lithium-Ion Batteries
Sathiya, Mariyappan; Prakash, Annigere S.; Ramesha, Kannadka; Shukla, Ashok K.
2009-01-01
An electrochemically-active high-temperature form of LiCoO2 (HT-LiCoO2) is prepared by thermally decomposing its constituent metal-nitrates at 700 ºC. The synthetic conditions have been optimized to achieve improved performance with the HT-LiCoO2 cathode in Li-ion batteries. For this purpose, the synthesized materials have been characterized by powder X-ray diffraction, scanning electron microscopy, and galvanostatic charge-discharge cycling. Cathodes comprising HT-LiCoO2 exhibit a specific capacity of 140 mAhg-1 with good capacity-retention over several charge-discharge cycles in the voltage range between 3.5 V and 4.2 V, and can sustain improved rate capability in contrast to a cathode constituting LiCoO2 prepared by conventional ceramic method. The nitrate-melt-decomposition method is also found effective for synthesizing Mg-/Al- doped HT-LiCoO2; these also are investigated as cathode materials for Li-ion batteries.
A model of Martian surface chemistry
NASA Technical Reports Server (NTRS)
Oyama, V. I.; Berdahl, B. J.
1979-01-01
Alkaline earth and alkali metal superoxides and peroxides, gamma-Fe2O3 and carbon suboxide polymer, are proposed to be constituents of the Martian surface material. These reactive substances explain the water modified reactions and thermal behaviors of the Martian samples demonstrated by all of the Viking Biology Experiments. It is also proposed that the syntheses of these substances result mainly from electrical discharges between wind-mobilized particles at Martian pressures; plasmas are initiated and maintained by these discharges. Active species in the plasma either combine to form or react with inorganic surfaces to create the reactive constituents.
Zhang, Bin; Xiao, Min; Wang, Shuanjin; Han, Dongmei; Song, Shuqin; Chen, Guohua; Meng, Yuezhong
2014-08-13
Novel hierarchically porous carbon materials with very high surface areas, large pore volumes and high electron conductivities were prepared from silk cocoon by carbonization with KOH activation. The prepared novel porous carbon-encapsulated sulfur composites were fabricated by a simple melting process and used as cathodes for lithium sulfur batteries. Because of the large surface area and hierarchically porous structure of the carbon material, soluble polysulfide intermediates can be trapped within the cathode and the volume expansion can be alleviated effectively. Moreover, the electron transport properties of the carbon materials can provide an electron conductive network and promote the utilization rate of sulfur in cathode. The prepared carbon-sulfur composite exhibited a high specific capacity and excellent cycle stability. The results show a high initial discharge capacity of 1443 mAh g(-1) and retain 804 mAh g(-1) after 80 discharge/charge cycles at a rate of 0.5 C. A Coulombic efficiency retained up to 92% after 80 cycles. The prepared hierarchically porous carbon materials were proven to be an effective host matrix for sulfur encapsulation to improve the sulfur utilization rate and restrain the dissolution of polysulfides into lithium-sulfur battery electrolytes.
Jefferson, S.
1958-11-11
An apparatus utilized in introducing tritium gas into envelope of a gas discharge device for the purpose f maintaining the discharge path in ionized condition is described. ln addition to the cathode and anode, the ischarge device contains a zirconium or tantalum ilament arranged for external excitation and a metallic seed containing tritium, and also arranged to have a current passed through it. Initially, the zirconium or tantalum filament is vaporized to deposit its material adjacent the main discharge region. Then the tritium gas is released and, due to its affinity for the first released material, it deposits in the region of the main discharge where it is most effective in maintaining the discharge path in an ionized condition.
Evaluation of Dielectric-Barrier-Discharge Actuator Substrate Materials
NASA Technical Reports Server (NTRS)
Wilkinson, Stephen P.; Siochi, Emilie J.; Sauti, Godfrey; Xu, Tian-Bing; Meador, Mary Ann; Guo, Haiquan
2014-01-01
A key, enabling element of a dielectric barrier discharge (DBD) actuator is the dielectric substrate material. While various investigators have studied the performance of different homogeneous materials, most often in the context of related DBD experiments, fundamental studies focused solely on the dielectric materials have received less attention. The purpose of this study was to conduct an experimental assessment of the body-force-generating performance of a wide range of dielectric materials in search of opportunities to improve DBD actuator performance. Materials studied included commonly available plastics and glasses as well as a custom-fabricated polyimide aerogel. Diagnostics included static induced thrust, electrical circuit parameters for 2D surface discharges and 1D volume discharges, and dielectric material properties. Lumped-parameter circuit simulations for the 1D case were conducted showing good correspondence to experimental data provided that stray capacitances are included. The effect of atmospheric humidity on DBD performance was studied showing a large influence on thrust. The main conclusion is that for homogeneous, dielectric materials at forcing voltages less than that required for streamer formation, the material chemical composition appears to have no effect on body force generation when actuator impedance is properly accounted for.
McKnight, Diane M.; Smith, R.L.; Harnish, R.A.; Miller, C.L.; Bencala, K.E.
1993-01-01
The relationships between the abundance and activity of planktonic, heterotrophic microorganisms and the quantity and characteristics of dissolved organic carbon (DOC) in a Rocky Mountain stream were evaluated. Peak values of glucose uptake, 2.1 nmol L-1 hr-1, and glucose concentration, 333 nM, occurred during spring snowmelt when the water temperature was 4.0??C and the DOC concentration was greatest. The turnover time of the in situ glucose pool ranged seasonally from 40-1110 hours, with a mean of 272 hr. Seasonal uptake of3H-glucose, particulate ATP concentrations, and direct counts of microbial biomass were independent of temperature, but were positively correlated with DOC concentrations and negatively correlated with stream discharge. Heterotrophic activity in melted snow was generally low, but patchy. In the summer, planktonic heterotrophic activity and microbial biomass exhibited small-scale diel cycles which did not appear to be related to fluctuations in discharge or DOC, but could be related to the activity of benthic invertebrates. Leaf-packs placed under the snow progressively lost weight and leachable organic material during the winter, indicating that the annual litterfall in the watershed may be one source of the spring flush of DOC. These results indicate that the availability of labile DOC to the stream ecosystem is the primary control on seasonal variation in heterotrophic activity of planktonic microbial populations. ?? 1993 Kluwer Academic Publishers.
Ban, Chunmei; Wu, Zhuangchun; Dillon, Anne C.
2017-01-10
An electrode (110) is provided that may be used in an electrochemical device (100) such as an energy storage/discharge device, e.g., a lithium-ion battery, or an electrochromic device, e.g., a smart window. Hydrothermal techniques and vacuum filtration methods were applied to fabricate the electrode (110). The electrode (110) includes an active portion (140) that is made up of electrochemically active nanoparticles, with one embodiment utilizing 3d-transition metal oxides to provide the electrochemical capacity of the electrode (110). The active material (140) may include other electrochemical materials, such as silicon, tin, lithium manganese oxide, and lithium iron phosphate. The electrode (110) also includes a matrix or net (170) of electrically conductive nanomaterial that acts to connect and/or bind the active nanoparticles (140) such that no binder material is required in the electrode (110), which allows more active materials (140) to be included to improve energy density and other desirable characteristics of the electrode. The matrix material (170) may take the form of carbon nanotubes, such as single-wall, double-wall, and/or multi-wall nanotubes, and be provided as about 2 to 30 percent weight of the electrode (110) with the rest being the active material (140).
DISCHARGE DEVICE FOR RADIOACTIVE MATERIAL
Ohlinger, L.A.
1958-09-23
A device is described fur unloading bodies of fissionable material from a neutronic reactor. It is comprised essentially of a wheeled flat car having a receptacle therein containing a liquid coolant fur receiving and cooling the fuel elements as they are discharged from the reactor, and a reciprocating plunger fur supporting the fuel element during discharge thereof prior to its being dropped into the coolant. The flat car is adapted to travel along the face of the reactor adjacent the discharge ends of the coolant tubes.
HIGH ENERGY GASEOUS DISCHARGE DEVICES
Josephson, V.
1960-02-16
The high-energy electrical discharge device described comprises an envelope, a pair of main discharge electrodes supported in opposition in the envelope, and a metallic shell symmetrically disposed around and spaced from the discharge path between the electrodes. The metallic shell comprises a first element of spaced helical turns of metallic material and a second element of spaced helical turns of methllic material insulatedly supported in superposition outside the first element and with the turns overlapping the gap between the turns of the first element.
48 CFR 1352.271-81 - Discharge of liens.
Code of Federal Regulations, 2010 CFR
2010-10-01
...) The contractor shall immediately discharge or cause to be discharged any lien or right in rem of any... done or materials furnished under the contract. If any such lien or right in rem is not immediately discharged, the Government may discharge or cause to be discharged such lien or right at the expense of the...
High discharge efficiency of (Sr, Pb, Bi) TiO3 relaxor ceramics for energy-storage application
NASA Astrophysics Data System (ADS)
Chao, Mingming; Liu, Jingsong; Zeng, Mengshi; Wang, Debin; Yu, Hongtao; Yuan, Ying; Zhang, Shuren
2018-05-01
We report herein on the energy storage and discharge properties of the relaxor ferroelectric ceramic Sr0.8Pb0.1Bi0.1TiO3 (SPBT). This material has a slanted hysteresis loop, and all samples show low remnant polarization and low coercive field, which leads to a high discharge efficiency. The maximum polarization is 10.1 μC/cm2, the minimum coercive field is 0.229 kV/cm, and the maximum efficiency is 94.2%. The discharge current waveforms are sinusoidal, the first discharge period is 140 ns, and the power density is approximately 4.2 × 107 W/kg. The high discharge speed and high discharge power density indicate that SPBT ceramics are very promising materials for energy storage applications.
Ferrocene and cobaltocene derivatives for non-aqueous redox flow batteries.
Hwang, Byunghyun; Park, Min-Sik; Kim, Ketack
2015-01-01
Ferrocene and cobaltocene and their derivatives are studied as new redox materials for redox flow cells. Their high reaction rates and moderate solubility are attractive properties for their use as active materials. The cyclability experiments are carried out in a static cell; the results showed that these materials exhibit stable capacity retention and predictable discharge potentials, which agree with the potential values from the cyclic voltammograms. The diffusion coefficients of these materials are 2 to 7 times higher than those of other non-aqueous materials such as vanadium acetylacetonate, iron tris(2,2'-bipyridine) complexes, and an organic benzene derivative. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Kim, Hyun-Joo; Yong, Hae In; Park, Sanghoo; Kim, Kijung; Kim, Tae Hoon; Choe, Wonho; Jo, Cheorun
2014-10-01
The biological activity of naringin treated with atmospheric pressure plasma was evaluated to investigate whether exposure to plasma can be used as a method to improve the biological activity of natural materials. Naringin was dissolved in methanol (at 500 ppm) and transferred to a container. A dielectric barrier discharge (DBD) (250 W, 15 kHz, ambient air) was then generated. Treatment with the plasma for 20 min increased the radical-scavenging activity, FRAP value, and the total phenolic compound content of naringin from 1.45% to 38.20%, from 27.78 to 207.78 μM/g, and from 172.50 to 225.83 ppm, respectively. Moreover, the tyrosinase-inhibition effect of naringin increased from 6.12% to 83.30% upon plasma treatment. Naringin treated with plasma exhibited antimicrobial activity against foodborne pathogens, especially Salmonella Typhimurium; an activity that was absent before plasma treatment. Structural modifications induced in the naringin molecule by plasma might be responsible for improving the biological activity of naringin. Copyright © 2014 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Britton, Doris L.
1990-01-01
Development of a high specific energy nickel electrode is the main goal of the lightweight nickel electrode program at NASA-Lewis. The approach was to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen cell. Lightweight plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. The electrodes are life cycle tested in a low Earth orbit regime at 40 and 80 percent depths-of-discharge.
NASA Technical Reports Server (NTRS)
Britton, Doris L.
1990-01-01
Development of a high specific energy nickel electrode is the main goal of the lightweight nickel electrode program at NASA-Lewis. The approach was to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen cell. Lightweight plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. The electrodes are life cycle tested in a low earth orbit regime at 40 and 80 percent depths-of-discharge.
33 CFR 155.310 - Containment of oil and hazardous material cargo discharges.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Containment of oil and hazardous material cargo discharges. 155.310 Section 155.310 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS...
Characterization and performance of high power iron(VI) ferrate batteries
NASA Astrophysics Data System (ADS)
Walz, Kenneth A.; Suyama, Amy N.; Suyama, Wendy E.; Sene, Jeosadaque J.; Zeltner, Walter A.; Armacanqui, Edgar M.; Roszkowski, Andrew J.; Anderson, Marc A.
In this paper we report on the high power discharge performance and impedance characteristics of potassium ferrate (K 2FeO 4) and barium ferrate (BaFeO 4) cathodes in zinc alkaline dry cells. The results show that if ferrate materials can be packaged to maximize the cathode surface area, they may offer superior performance over electrolytic manganese dioxide at operating voltages exceeding 1.6 V and currents as high as 100 mA/g of active material.
Effects of space plasma discharge on the performance of large antenna structures in low Earth orbit
NASA Technical Reports Server (NTRS)
Blume, Hans-Juergen C.
1987-01-01
The anomalous plasma around spacecrafts in low Earth orbit represents the coma of an artificial comet. The plasma discharge is caused by an energetic disturbance of charged particles which were formerly in a state of equilibrium. The plasma can effect the passive and active radio frequency operation of large space antennas by inducing corona discharge or strong arcing in the antenna feeds. One such large space antenna is the 15-meter hoop column antenna which consists of a mesh membrane material (tricot knitted gold plated wire) reflector and carbon fiber tension cords. The atomic oxygen in the plasma discharge state can force the wire base metal particles through the gold lattice and oxydize the metal particles to build a Schottky-barrier contact at the point where the wires meet. This effect can cause strong deviations in the reflector performance in terms of antenna pattern and losses. Also, the carbon-fiber cords can experience a strength reduction of 30 percent over a 40-hour exposure time.
High-performance super capacitors based on activated anthracite with controlled porosity
NASA Astrophysics Data System (ADS)
Lee, Hyun-Chul; Byamba-Ochir, Narandalai; Shim, Wang-Geun; Balathanigaimani, M. S.; Moon, Hee
2015-02-01
Mongolian anthracite is chemically activated using potassium hydroxide as an activation agent to make activated carbon materials. Prior to the chemical activation, the chemical agent is introduced by two different methods as follows, (1) simple physical mixing, (2) impregnation. The physical properties such as specific surface area, pore volume, pore size distribution, and adsorption energy distribution are measured to assess them as carbon electrode materials for electric double-layer capacitors (EDLC). The surface functional groups and morphology are also characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analyses respectively. The electrochemical results for the activated carbon electrodes in 3 M sulfuric acid electrolyte solution indicate that the activated Mongolian anthracite has relatively large specific capacitances in the range of 120-238 F g-1 and very high electrochemical stability, as they keep more than 98% of initial capacitances until 1000 charge/discharge cycles.
NASA Astrophysics Data System (ADS)
Schmid, M.; Willert-Porada, M.
2017-05-01
Silica coatings on zinc particles as anode material for alkaline zinc air batteries are expected to reduce early formation of irreversible ZnO passivation layers during discharge by controlling zinc dissolution and precipitation of supersaturated zincates, Zn(OH)42-. Zinc particles were coated with SiO2 (thickness: 15 nm) by chemical solution deposition and with Zn2SiO4 (thickness: 20 nm) by chemical vapor deposition. These coatings formed a Si(OH)4 gel in aqueous KOH and retarded hydrogen evolution by 40%. By treatment in aqueous KOH and drying afterwards, the silica coatings were changed into ZnO-K2O·SiO2 layers. In this work, the electrochemical performance of such coated zinc particles is investigated by different electrochemical methods in order to gain a deeper understanding of the mechanisms of the coatings, which reduce zinc passivation. In particular, zinc utilization and changes in internal resistance are investigated. Moreover, methods for determination of diffusion coefficients, charge carrier numbers and activation energies for electrochemical oxidation are determined. SiO2-coated zinc particles show improved discharge capacity (CVD-coated zinc: 69% zinc utilization, CSD-coated zinc: 62% zinc utilization) as compared to as-received zinc (57% zinc utilization) at C/20 rate, by reducing supersaturation of zincates. Additionally, KOH-modified SiO2-coated zinc particles enhance rechargeability after 100% depth-of-discharge.
Self-discharge performance of Ni-MH battery by using electrodes with hydrophilic/hydrophobic surface
NASA Astrophysics Data System (ADS)
Li, Xiaofeng; Wang, Xiaojie; Dong, Huichao; Xia, Tongchi; Wang, Lizhen; Song, Yanhua
2013-12-01
The polytetrafluoroethylene (PTFE) and carboxymethyl cellulose (CMC) film is separately coated on the surface of the metal hydride (MH) and Ni(OH)2 electrodes to obtain the electrodes with hydrophobic or hydrophilic surface. The effects of the surface treatment on the oxygen and hydrogen evolution from the electrodes are studied by using cyclic voltammetry tests. Although the positive and negative active materials of the Ni-MH batteries show a lower self-decomposition rate after the CMC treatment, the self-discharge rate of the batteries show little change. On the contrary, the self-discharge rate of the batteries decreases from 35.9% to 27.1% by using the PTFE-treated Ni(OH)2 electrodes, which might be related to the suppression of the reaction between NiOOH and H2 by the hydrophobic film.
Source of electrical power for an electric vehicle and other purposes, and related methods
LaFollette, Rodney M.
2000-05-16
Microthin sheet technology is disclosed by which superior batteries are constructed which, among other things, accommodate the requirements for high load rapid discharge and recharge, mandated by electric vehicle criteria. The microthin sheet technology has process and article overtones and can be used to form thin electrodes used in batteries of various kinds and types, such as spirally-wound batteries, bipolar batteries, lead acid batteries, silver/zinc batteries, and others. Superior high performance battery features include: (a) minimal ionic resistance; (b) minimal electronic resistance; (c) minimal polarization resistance to both charging and discharging; (d) improved current accessibility to active material of the electrodes; (e) a high surface area to volume ratio; (f) high electrode porosity (microporosity); (g) longer life cycle; (h) superior discharge/recharge characteristics; (j) higher capacities (A.multidot.hr); and k) high specific capacitance.
Source of electrical power for an electric vehicle and other purposes, and related methods
LaFollette, Rodney M.
2002-11-12
Microthin sheet technology is disclosed by which superior batteries are constructed which, among other things, accommodate the requirements for high load rapid discharge and recharge, mandated by electric vehicle criteria. The microthin sheet technology has process and article overtones and can be used to form corrugated thin electrodes used in batteries of various kinds and types, such as spirally-wound batteries, bipolar batteries, lead acid batteries, silver/zinc batteries, and others. Superior high performance battery features include: (a) minimal ionic resistance; (b) minimal electronic resistance; (c) minimal polarization resistance to both charging and discharging; (d) improved current accessibility to active material of the electrodes; (e) a high surface area to volume ratio; (f) high electrode porosity (microporosity); (g) longer life cycle; (h) superior discharge/recharge characteristics; (i) higher capacities (A.multidot.hr); and (j) high specific capacitance.
Battery with a microcorrugated, microthin sheet of highly porous corroded metal
LaFollette, Rodney M.
2005-09-27
Microthin sheet technology is disclosed by which superior batteries are constructed which, among other things, accommodate the requirements for high load rapid discharge and recharge, mandated by electric vehicle criteria. The microthin sheet technology has process and article overtones and can be used to form thin electrodes used in batteries of various kinds and types, such as spirally-wound batteries, bipolar batteries, lead acid batteries silver/zinc batteries, and others. Superior high performance battery features include: (a) minimal ionic resistance; (b) minimal electronic resistance; (c) minimal polarization resistance to both charging and discharging; (d) improved current accessibility to active material of the electrodes; (e) a high surface area to volume ratio; (f) high electrode porosity (microporosity); (g) longer life cycle; (h) superior discharge/recharge characteristics; (i) higher capacities (A.multidot.hr); and (j) high specific capacitance.
NASA Astrophysics Data System (ADS)
Chow, H. M.; Yang, L. D.; Lin, Y. C.; Lin, C. L.
2017-12-01
In this paper, the effects of material removal rate and abrasive grain protrusion on the metal-based diamond grinding wheel were studied to find the optimal parameters for adding powder and wire discharge. In addition, this kind of electric discharge method to add powder on the metal-based diamond grinding wheel on line after dressing and truing will be applied on tungsten carbide to study the grinding material removal rate, grinding wheel wear, surface roughness, and surface micro-hardness.
Lipp, G. Daniel
1994-04-26
A method and die apparatus for manufacturing a honeycomb body of rhombic cell cross-section by extrusion through an extrusion die of triangular cell discharge slot configuration, the die incorporating feedholes at selected slot intersections only, such that slot segments communicating directly with the feedholes discharge web material and slot segments not so connected do not discharge web material, whereby a rhombic cell cross-section in the extruded body is provided.
NASA Astrophysics Data System (ADS)
Ma, Ting; Muslim, Arzugul; Su, Zhi
2015-05-01
Nano structured LiMnBO3/C cathode materials are synthesized by a fast microwave solid-state reaction method using MnCO3, Li2CO3, H3BO3 and glucose as starting materials for the first time. The crystal structure, morphology and electrochemical properties of LiMnBO3/C composites are characterized by X-ray diffraction (XRD), raman spectroscopy (Ramon), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and charge-discharge tests. The result shows that not only monoclinic LiMnBO3/C but also hexagonal LiMnBO3/C cathode materials can be successfully synthesized by microwave solid-state method with power of 240 W in different time. Compared with h-LiMnBO3/C and mixed phase LiMnBO3/C, m-LiMnBO3/C displays lower charge-transfer resistance and the Warburg impedance, so it reveals a higher first discharge capacity of 156.3 mAh g-1 at 0.05 C within 1.8V-4.6 V, The value increases up to 173.2 mAh g-1 caused by the activation process. Even after 50 cycles, the discharge capacity of m-LiMnBO3/C still remains at 148.2 mAh g-1.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Park, Jin-Woo; Kim, Icpyo; Kim, Ki-Won
Highlights: • The sulfur/activated carbon composite is fabricated using commercial activated carbons. • The sulfur/activated carbon composite with coal shows the best performance. • The Li/S battery has capacities of 1240 mAh g{sup −1} at 1 C and 567 mAh g{sup −1} at 10 C. - Abstract: We prepared sulfur/active carbon composites via a simple solution-based process using the following commercial activated carbon-based materials: coal, coconut shells, and sawdust. Although elemental sulfur was not detected in any of the sulfur/activated carbon composites based on Thermogravimetric analysis, X-ray diffraction, and Raman spectroscopy, Energy-dispersive X-ray spectroscopy results confirmed its presence in themore » activated carbon. These results indicate that sulfur was successfully impregnated in the activated carbon and that all of the activated carbons acted as sulfur reservoirs. The sulfur/activated carbon composite cathode using coal exhibited the highest discharge capacity and best rate capability. The first discharge capacity at 1 C (1.672 A g{sup −1}) was 1240 mAh g{sup −1}, and a large reversible capacity of 567 mAh g{sup −1} was observed at 10 C (16.72 A g{sup −1}).« less
Code of Federal Regulations, 2013 CFR
2013-01-01
... or substantial radiation levels offsite. 140.84 Section 140.84 Energy NUCLEAR REGULATORY COMMISSION... § 140.84 Criterion I—Substantial discharge of radioactive material or substantial radiation levels... radioactive material offsite, or that there have been substantial levels of radiation offsite, when, as a...
Code of Federal Regulations, 2014 CFR
2014-01-01
... or substantial radiation levels offsite. 140.84 Section 140.84 Energy NUCLEAR REGULATORY COMMISSION... § 140.84 Criterion I—Substantial discharge of radioactive material or substantial radiation levels... radioactive material offsite, or that there have been substantial levels of radiation offsite, when, as a...
Battery materials for ultrafast charging and discharging.
Kang, Byoungwoo; Ceder, Gerbrand
2009-03-12
The storage of electrical energy at high charge and discharge rate is an important technology in today's society, and can enable hybrid and plug-in hybrid electric vehicles and provide back-up for wind and solar energy. It is typically believed that in electrochemical systems very high power rates can only be achieved with supercapacitors, which trade high power for low energy density as they only store energy by surface adsorption reactions of charged species on an electrode material. Here we show that batteries which obtain high energy density by storing charge in the bulk of a material can also achieve ultrahigh discharge rates, comparable to those of supercapacitors. We realize this in LiFePO(4) (ref. 6), a material with high lithium bulk mobility, by creating a fast ion-conducting surface phase through controlled off-stoichiometry. A rate capability equivalent to full battery discharge in 10-20 s can be achieved.
Reduced Graphene Oxide-Wrapped FeS2 Composite as Anode for High-Performance Sodium-Ion Batteries
NASA Astrophysics Data System (ADS)
Wang, Qinghong; Guo, Can; Zhu, Yuxuan; He, Jiapeng; Wang, Hongqiang
2018-06-01
Iron disulfide is considered to be a potential anode material for sodium-ion batteries due to its high theoretical capacity. However, its applications are seriously limited by the weak conductivity and large volume change, which results in low reversible capacity and poor cycling stability. Herein, reduced graphene oxide-wrapped FeS2 (FeS2/rGO) composite was fabricated to achieve excellent electrochemical performance via a facile two-step method. The introduction of rGO effectively improved the conductivity, BET surface area, and structural stability of the FeS2 active material, thus endowing it with high specific capacity, good rate capability, as well as excellent cycling stability. Electrochemical measurements show that the FeS2/rGO composite had a high initial discharge capacity of 1263.2 mAh g-1 at 100 mA g-1 and a high discharge capacity of 344 mAh g-1 at 10 A g-1, demonstrating superior rate performance. After 100 cycles at 100 mA g-1, the discharge capacity remained at 609.5 mAh g-1, indicating the excellent cycling stability of the FeS2/rGO electrode.
Ike, Innocent S; Sigalas, Iakovos; Iyuke, Sunny
2016-01-14
Self-discharge is known to have considerable adverse effects on the performance and application of electrochemical capacitors (ECs). Thus, obtaining an understanding of EC self-discharge mechanism(s) and subsequent derivation and solution of EC models, subject to a particular mechanism or combination of mechanisms during charging, discharging and storage of the device, is the only way to solve problems associated with EC self-discharge. In this review, we summarize recent progress with respect to EC self-discharge by considering the two basic types, electric double-layer capacitors (EDLC) and pseudocapacitors, and their hybrids with their respective charge storage mechanisms, distinguishable self-discharge mechanisms, charge redistribution and charge/energy loss during self-discharge. It was clearly observed that most of the voltage reduction is not purely due to the self-discharge effect but is basically due to redistribution of charge carriers deep inside pores and can therefore be retrieved from a capacitor during long-time discharging. Tuning the self-discharge rate is therefore feasible for single-walled carbon nanotube (SWNT) ECs and can be achieved by simply adjusting the surface chemistry of the nanotubes. The effects of surface chemistry modification on EC self-discharge are very important in studying and suppressing the self-discharge process and will benefit potential applications of ECs with respect to energy retention. Self-discharge can be averted by the use of redox couples that are transformed to insoluble species via electrolysis and adsorbed onto the activated carbon electrode in redox-couple EDLCs, thus transforming the EDLC electrolyte into a material that can store charge. Self-discharge in ECs can also be successfully suppressed by utilizing an ion-interchange layer (ion-exchange membrane), separator or CuSO4 mobile electrolyte that can be converted into an insoluble species by electrolysis during the charge/discharge process. This will help in producing a modern-day blueprint for ECs with high capacitance and improved energy sustainability.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Azam, M.A., E-mail: asyadi@utem.edu.my; Jantan, N.H.; Dorah, N.
2015-09-15
Highlights: • Activated carbon and single-walled CNT based electrochemical capacitor. • Electrochemical analysis by means of CV, charge/discharge and impedance. • 1 M LiPF{sub 6} non-aqueous solution as an electrolyte. • AC/SWCNT electrode exhibits a maximum capacitance of 60.97 F g{sup −1}. - Abstract: Carbon nanotubes have been extensively studied because of their wide range of potential application such as in nanoscale electric circuits, textiles, transportation, health, and the environment. Carbon nanotubes feature extraordinary properties, such as electrical conductivities higher than those of copper, hardness and thermal conductivity higher than those of diamond, and strength surpassing that of steel, amongmore » others. This research focuses on the fabrication of an energy storage device, namely, an electrochemical capacitor, by using carbon materials, i.e., activated carbon and single-walled carbon nanotubes, of a specific weight ratio as electrode materials. The electrolyte functioning as an ion carrier is 1 M lithium hexafluorophosphate. Variations in the electrochemical performance of the device, including its capacitance, charge/discharge characteristics, and impedance, are reported in this paper. The electrode proposed in this work exhibits a maximum capacitance of 60.97 F g{sup −1} at a scan rate of 1 mV s{sup −1}.« less
48 CFR 3052.217-97 - Discharge of liens (USCG).
Code of Federal Regulations, 2010 CFR
2010-10-01
...) (a) The Contractor shall immediately discharge or cause to be discharged, any lien or right in rem of... materials furnished under this contract. (b) If any such lien or right in rem is not immediately discharged... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Discharge of liens (USCG...
Ha, Jeonghyun; Park, Seung-Keun; Yu, Seung-Ho; Jin, Aihua; Jang, Byungchul; Bong, Sungyool; Kim, In; Sung, Yung-Eun; Piao, Yuanzhe
2013-09-21
A composite of modified graphene and LiFePO4 has been developed to improve the speed of charging-discharging and the cycling stability of lithium ion batteries using LiFePO4 as a cathode material. Chemically activated graphene (CA-graphene) has been successfully synthesized via activation by KOH. The as-prepared CA-graphene was mixed with LiFePO4 to prepare the composite. Microscopic observation and nitrogen sorption analysis have revealed the surface morphologies of CA-graphene and the CA-graphene/LiFePO4 composite. Electrochemical properties have also been investigated after assembling coin cells with the CA-graphene/LiFePO4 composite as a cathode active material. Interestingly, the CA-graphene/LiFePO4 composite has exhibited better electrochemical properties than the conventional graphene/LiFePO4 composite as well as bare LiFePO4, including exceptional speed of charging-discharging and excellent cycle stability. That is because the CA-graphene in the composite provides abundant porous channels for the diffusion of lithium ions. Moreover, it acts as a conducting network for easy charge transfer and as a divider, preventing the aggregation of LiFePO4 particles. Owing to these properties of CA-graphene, LiFePO4 could demonstrate enhanced and stably long-lasting electrochemical performance.
Synthesis and structural stability of Cr-doped Li2MnSiO4/C cathode materials by solid-state method
NASA Astrophysics Data System (ADS)
Cheng, Hong-Mei; Zhao, Shi-Xi; Wu, Xia; Zhao, Jian-Wei; Wei, Lei; Nan, Ce-Wen
2018-03-01
The crystal structure of the Li2MnSiO4 cathode material would collapse during the charge and discharge process because of that the Mn-O coordination polyhedron changed from [MnO4] into [MnO6] in the process of Mn+2 to Mn+4, but the Cr element could remain [CrO4] crystal ligand from Cr+2 to Cr+4, so Cr element substitution was used to improve the structural stability of the Li2MnSiO4 cathode material. In this work, Li2Mn1-xCrxSiO4/C nanocomposites were synthesized by solid-state method. XRD, SEM and TEM observations show that the as-prepared Li2Mn1-xCrxSiO4/C materials presents an orthorhombic crystal structure (S.G. Pmn21), the particle size of Li2Mn1-xCrxSiO4/C powder ranges from 50 to 100 nm. The XRD and XPS results indicate that Cr+2 is successfully doped into Li2MnSiO4 lattice and has well compatibility with Li2MnSiO4. The electrochemical results display that Li2Mn92.5%Cr7.5%SiO4/C exhibits significantly enhanced cycle stability and discharge capability. The initial discharge capacity of the Li2Mn92.5%Cr7.5%SiO4/C sample is 255 mAh g-1, and the discharge capacity was still about 60 mAh g-1 after 50 cycles. Furthermore, the XRD patterns, TEM images and Raman analysis reveal that the Cr doping enhances the structural stability of Li2Mn1-xCrxSiO4/C and improves the electrochemical activity of the cathode. Thus, the Li2Mn92.5%Cr7.5%SiO4/C have shown potential applications for lithium ion batteries.
Electrochemical properties of lithium iron phosphate cathode material using polymer electrolyte
NASA Astrophysics Data System (ADS)
Kim, Jae-Kwang; Choi, Jae-Won; Cheruvally, Gouri; Shin, Yong-Jo; Ahn, Jou-Hyeon; Cho, Kwon-Koo; Ahn, Hyo-Jun; Kim, Ki-Won
2007-12-01
Carbon-coated lithium iron phosphate (LiFePO4/C) cathode material was synthesized by mechano-chemical activation method. The performance of LiFePO4/C in lithium battery was tested with an electrospun polymer-based electrolyte. Liquid electrolyte of 1M lithium hexafluorophosphate (LiPF6) in ethylene carbonate/dimethyl carbonate (EC/DMC) (1 : 1vol) was incorporated in electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (P(VdF-HFP)) microfibrous membrane to prepare the polymer electrolyte (PE). The cell based on Li|PE|Li FePO4/C exhibited an initial discharge capacity of 142 mAh g-1 at 0.1 C-rate at room temperature. Good cycling performance even under the high current density of 2 C could be obtained. Impedance spectroscopy was applied to investigate the material behavior during 0.1 C-rate charge-discharge cycling. When the fresh cell and the cell after different cycles were compared, impedance resistance was found to decrease with cycling. Impedance study indicated good cycle life for the cell when tested at room temperature.
NASA Astrophysics Data System (ADS)
Javed, Muhammad Sufyan; Dai, Shuge; Wang, Mingjun; Xi, Yi; Lang, Qiang; Guo, Donglin; Hu, Chenguo
2015-08-01
The exploration of high Faradic redox active materials with the advantages of low cost and low toxicity has been attracting great attention for producing high energy storage supercapacitors. Here, the high Faradic redox active material of Cu7S4-NWs coated on a carbon fiber fabric (CFF) is directly used as a binder-free electrode for a high performance flexible solid state supercapacitor. The Cu7S4-NW-CFF supercapacitor exhibits excellent electrochemical performance such as a high specific capacitance of 400 F g-1 at the scan rate of 10 mV s-1 and a high energy density of 35 Wh kg-1 at a power density of 200 W kg-1, with the advantages of a light weight, high flexibility and long term cycling stability by retaining 95% after 5000 charge-discharge cycles at a constant current of 10 mA. The high Faradic redox activity and high conductance behavior of the Cu7S4-NWs result in a high pseudocapacitive performance with a relatively high specific energy and specific power. Such a new type of pseudocapacitive material of Cu7S4-NWs with its low cost is very promising for actual application in supercapacitors.The exploration of high Faradic redox active materials with the advantages of low cost and low toxicity has been attracting great attention for producing high energy storage supercapacitors. Here, the high Faradic redox active material of Cu7S4-NWs coated on a carbon fiber fabric (CFF) is directly used as a binder-free electrode for a high performance flexible solid state supercapacitor. The Cu7S4-NW-CFF supercapacitor exhibits excellent electrochemical performance such as a high specific capacitance of 400 F g-1 at the scan rate of 10 mV s-1 and a high energy density of 35 Wh kg-1 at a power density of 200 W kg-1, with the advantages of a light weight, high flexibility and long term cycling stability by retaining 95% after 5000 charge-discharge cycles at a constant current of 10 mA. The high Faradic redox activity and high conductance behavior of the Cu7S4-NWs result in a high pseudocapacitive performance with a relatively high specific energy and specific power. Such a new type of pseudocapacitive material of Cu7S4-NWs with its low cost is very promising for actual application in supercapacitors. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03363b
NASA Astrophysics Data System (ADS)
Kurimoto, Naoya; Omoda, Ryo; Mizumo, Tomonobu; Ito, Seitaro; Aihara, Yuichi; Itoh, Takahito
2018-02-01
Quinoid compounds are important candidates of organic active materials for lithium-ion batteries. However, its high solubility to organic electrolyte solutions and low redox potential are known as their major drawbacks. To circumvent these issues, we have designed and synthesized a tandem-tetracyanoquinonedimethane type cathode-active material, 11,11,12,12,13,13,14,14-octacyano-1,4,5,8-anthradiquinotetramethane (OCNAQ), that has four redox sites per molecule, high redox potential and suppressed solubility to electrolyte solution. Synthesized OCNAQ has been found to have two-step redox reactions by cyclic voltammetry, and each step consists of two-electron reactions. During charge-discharge tests using selected organic cathode-active materials with a lithium metal anode, the cell voltages obtained from OCNAQ are higher than those for 11,11-dicyanoanthraquinone methide (AQM) as expected, due to the strong electron-withdrawing effect of the cyano groups. Unfortunately, even with the use of the organic active material, the issue of dissolution to the electrolyte solution cannot be suppressed completely; however, appropriate choice of the electrolyte solutions, glyme-based electrolyte solutions in this study, give considerable improvement of the cycle retention (98% and 56% at 10 and 100 cycles at 0.5C, respectively). The specific capacity and energy density obtained in this study are 206 mAh g-1 and 554 mWh g-1 with respect to the cathode active material.
Lithium-Polymer battery based on polybithiophene as cathode material
NASA Astrophysics Data System (ADS)
Chen, J.; Wang, J.; Wang, C.; Too, C. O.; Wallace, G. G.
Stainless-steel mesh electrodes coated with polybithiophene, obtained by electrochemical polymerization (constant potential and constant current), have been investigated as cathode materials in a lithium-polybithiophene rechargeable battery by cyclic voltammetry, electrochemical impedance spectroscopy and long-term charge-discharge cycling process. The effects of different growth methods on the surface morphology of the films and the charge-discharge capacity are discussed in detail. The results show that polybithiophene-hexafluorophosphate is a very promising cathode material for manufacturing lithium-polymer rechargeable batteries with a highly stable discharge capacity of 81.67 mAh g -1 after 50 cycles.
NASA Technical Reports Server (NTRS)
Coakley, P.; Kitterer, B.; Treadaway, M.
1982-01-01
Charging and discharging characteristics of dielectric samples exposed to 1-25 keV and 25-100 keV electrons in a laboratory environment are reported. The materials examined comprised OSR, Mylar, Kapton, perforated Kapton, and Alphaquartz, serving as models for materials employed on spacecraft in geosynchronous orbit. The tests were performed in a vacuum chamber with electron guns whose beams were rastered over the entire surface of the planar samples. The specimens were examined in low-impedance-grounded, high-impedance-grounded, and isolated configurations. The worst-case and average peak discharge currents were observed to be independent of the incident electron energy, the time-dependent changes in the worst case discharge peak current were independent of the energy, and predischarge surface potentials are negligibly dependent on incident monoenergetic electrons.
Lead/acid battery design and operation
NASA Astrophysics Data System (ADS)
Manders, J. E.; Bui, N.; Lambert, D. W. H.; Navarette, J.; Nelson, R. F.; Valeriote, E. M.
In keeping with the tradition of previous meetings, the Seventh Asian Battery Conference closed with the delegates putting questions to an expert panel of battery scientists and technologies. The proceedings were lively and the subjects were as follows. Grid alloys: gassing characteristics; influence of minor constituents on metallurgical and electrochemical characteristics; latest trends in composition; alloys for cast-on straps. Battery manufacture and operation: plate formation ( α-PbO 2: β-PbO 2 ratio); dendritic shorts. Separators: contribution to battery internal resistance; influence of negative-plate enveloping; reduced backweb. Valve-regulated lead/acid batteries: positive active-material: negative active-material ratio; hydrogen evolution and dry-out; negative-plate self-discharge; tank vs. box formation.
NASA Astrophysics Data System (ADS)
Young, Benjamin; Heskett, David; Nguyen, Cao Cuong; Woicik, Joseph; Lucht, Brett
From portable electronics to space exploration, the desire for more capable rechargeable batteries is driving a search for high capacity anodes. There is much interest in incorporating silicon as a partial or full replacement for the current graphite material in the most popular batteries because it could potentially hold much more charge. There is a significant challenge, however, in that storing so much more lithium in either electrode as the battery is charged and discharged as this causes an accompanying increase in the physical size fluctuation of the electrodes. Specifically, in the anode where this investigation focuses, the active material may experience a 300% volume change between the charged and discharged state. This makes a long lifetime difficult to achieve because the passivation layer protecting the electrolyte material from decomposition is compromised upon each cycle. One approach to accommodating the large volumetric fluctuation without sacrificing lifetime is to find a better material to include in the anode substrate to act as a binder. Ideally, such a material would permit the anode to fluctuate without breaking. Polyvinylidene fluoride (PVdF) is not successful for silicon-based anodes and we present Hard X-ray photoelectron spectroscopy studies of batteries incorporating three alternatives. The alternative binders outperform the PVdF and we present possible explanations. DOE EPSCoR and RI College Faculty Research Fund.
Supercapacitors from Activated Carbon Derived from Granatum.
Wang, Qiannan; Yang, Lin; Wang, Zhao; Chen, Kexun; Zhang, Lipeng
2015-12-01
Granatum carbon (GC) as electrode materials for supercapacitors is prepared via the chemical activation with different activating agent such as ZnC2 and KOH with an intention to improve the surface area and their electrochemical performance. The structure and electrochemical properties of GC materials are characterized with N2 adsorption/desorption measurements, scanning electron microscope (SEM), cyclic voltammetry (CV), galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy (EIS). The obtained results show that the specific surface area of the granatum-based activated carbons increased obviously from 573 m2 x g(-1) to 1341 m2 x g(-1) by ZnC2 activation and to 930 m2 x g(-1) by KOH treatment. Furthermore, GCZ also delivers specific capacitance of 195.1 Fx g(-1) at the current density of 0.1 A x g(-1) in 30 wt.% KOH aqueous electrolyte and low capacitance loss of 28.5% when the current density increased by 10 times.
Revisions to the Clean Water Act Regulatory Definition of Discharge of Dredged Material; Final Rule
The U.S. Army Corps of Engineers (Corps) and the Environmental Protection Agency (EPA) promulgated a final rule Amending a Clean Water Act (CWA) section 404 regulation that defines the term discharge of dredged material.
33 CFR 51.9 - Discharge review procedures.
Code of Federal Regulations, 2010 CFR
2010-07-01
... GUARD DISCHARGE REVIEW BOARD § 51.9 Discharge review procedures. (a) Preliminary. Prior to a review... that reasonable bounds of relevancy and materiality are adhered to in the taking of evidence. (3) An...
NASA Astrophysics Data System (ADS)
Grigoryev, Evgeny G.
2011-01-01
Simultaneous electro discharge sintering of high strength structure of tungsten carbide—cobalt composite and connection it with high-speed steel substrate is investigated and suitable operating parameters are defined. Tungsten carbide—cobalt and high-speed steel joining was produced by the method of high voltage electrical discharge together with application of mechanical pressure to powder compact. It was found that the density and hardness of composite material reach its maximum values at certain magnitudes of applied pressure and high voltage electrical discharge parameters. We show that there is an upper level for the discharge voltage beyond which the powder of composite material disintegrates like an exploding wire. Due to our results it is possible to determine optimal parameters for simultaneous electro discharge sintering of WC-Co and bonding it with high-speed steel substrate.
Electrode characteristics of nanocrystalline AB{sub 5} compounds prepared by mechanical alloying
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Z.; Chen, Z.; Zhou, D.
1998-10-01
Nanocrystalline LaNi{sub 5} and LaNi{sub 4.5}Si{sub 0.5} synthesized by mechanical alloying were used as negative materials for Ni-MH batteries. It was found that the electrodes prepared with the nanocrystalline powders had similar discharge capacities, better activation behaviors, and longer cycle lifetimes, compared with the negative electrode prepared with polycrystalline coarse-grained LaNi{sub 5} alloy. The properties of the electrodes prepared with these nanocrystalline materials were attributed to the structural characteristics of the compounds caused by mechanical alloying.
In-situ study of the cracking of metal hydride electrodes by acoustic emission technique
NASA Astrophysics Data System (ADS)
Didier-Laurent, S.; Idrissi, H.; Roué, L.
Pulverisation phenomena occurring during the charge/discharge cycling of metal hydride materials were studied by acoustic emission coupled to electrochemical measurements. Two kinds of materials were studied: a commercial LaNi 5-based alloy and a ball-milled MgNi alloy. In both alloys, two populations of acoustic signals were detected during charging steps: P1, showing peak frequencies between 230 and 260 kHz, high energy and low rise time, and P2 with peak frequencies between 150 and 180 kHz, lower energy and longer rise time. Population P2 is related to the hydrogen evolution reaction whereas P1 is associated with pulverisation phenomena. No acoustic activity was detected during discharge. We also investigated pulverisation phenomena through cycles by monitoring the P1 population. It appears that pulverisation occurs mainly during the five first cycles for LaNi 5 with a maximum at the second cycle, while pulverisation takes place all along the cycling for MgNi, but at a decreasing rate. By comparing the P1 activities, it appears that the pulverization phenomenon is less intensive on the MgNi electrode than on the LaNi 5-based electrode.
NASA Astrophysics Data System (ADS)
Xu, Yi; Li, Liuhe; Luo, Sida; Lu, Qiuyuan; Gu, Jiabin; Lei, Ning; Huo, Chunqin
2017-01-01
Enhanced glow discharge plasma immersion ion implantation and deposition (EGD-PIII&D) have been proved to be highly effective for depositing diamond-like carbon (DLC) films on the inner surface of the slender quartz tube with a deposition rate of 1.3 μm/min. Such a high-efficiency DLC films deposition was explained previously as the short electrons mean free path to cause large collision frequency between electrons and neutral particles. However, in this paper, we found that the inner surface material of the tube itself play a vital role on the films deposition. To disclose the mechanism of this phenomenon, the effect of different inner surface materials on plasma discharge was experimentally and theoretically investigated. Then a self-enhancing plasma discharge is discovered. It is found that secondary electrons emitted from the inner surface material, whatever it is the tube inner surface or deposited DLC films, can dramatically enhance the plasma discharge to improve the DLC films deposition rate.
NASA Astrophysics Data System (ADS)
He, Shuijian; Chen, Linlin; Xie, Chencheng; Hu, Huan; Chen, Shuiliang; Hanif, Muddasir; Hou, Haoqing
2013-12-01
Due to their cycling stability and high power density, the supercapacitors bridge the power/energy gap between traditional dielectric capacitors and batteries/fuel cells. Electrode materials are key components for making high performance supercapacitors. An activated carbon nanowhiskers (ACNWs) wrapped-on graphitized electrospun nanofiber (GENF) network (ACNWs/GENFN) with 3D porous structure is prepared as a new type of binder-free electrode material for supercapacitors. The supercapacitor based on the ACNWs/GENFN composite material displays an excellent performance with a specific capacitance of 176.5 F g-1 at current density of 0.5 A g-1, an ultrahigh power density of 252.8 kW kg-1 at current density of 800 A g-1 and an outstanding cycling stability of no capacitance loss after 10,000 charge/discharge cycles.
Singh, Ashutosh K; Sarkar, Debasish; Karmakar, Keshab; Mandal, Kalyan; Khan, Gobinda Gopal
2016-08-17
We report a facile method to design Co3O4-MnO2-NiO ternary hybrid 1D nanotube arrays for their application as active material for high-performance supercapacitor electrodes. This as-prepared novel supercapacitor electrode can store charge as high as ∼2020 C/g (equivalent specific capacitance ∼2525 F/g) for a potential window of 0.8 V and has long cycle stability (nearly 80% specific capacitance retains after successive 5700 charge/discharge cycles), significantly high Coulombic efficiency, and fast response time (∼0.17s). The remarkable electrochemical performance of this unique electrode material is the outcome of its enormous reaction platform provided by its special nanostructure morphology and conglomeration of the electrochemical properties of three highly redox active materials in a single unit.
Effects of phosphoric acid on the lead-acid battery reactions
NASA Astrophysics Data System (ADS)
Ikeda, Osamu; Iwakura, Chiaki; Yoneyama, Hiroshi; Tamura, Hideo
1986-10-01
The addition of a small amount of phosphoric acid to 5 M H2SO4 (commercial electrolyte of lead-acid batteries) results in various positive effects on the lead-acid battery reactions: (1) depression of the corrosion rate of the lead substrate through a preferential formation of alpha-PbO2 on the substrate surface; (2) retardation of hard sulfate formation or of deactivation of active materials; and (3) change in the crystal morphology of PbSO2 formed on the discharge of PbO2. Most of these effects results from chemisorption of phosphoric acid on PbSO4 crystals produced in the discharge process of PbO2.
High performance supercapacitor from activated carbon derived from waste orange skin
NASA Astrophysics Data System (ADS)
Ahmed, Sultan; Hussain, S.; Ahmed, Ahsan; Rafat, M.
2018-05-01
Activated carbon due to its inherent properties such as large surface area and low cost is most frequently used electrode material for supercapacitor. Activated carbon has been previously derived from various biomass such as coconut shell, coffee bean etc. Herein, we report the synthesis of activated carbon from waste orange skin. The material was synthesized employing chemical activation method and the success of synthesis was confirmed by its physical and electrochemical properties. The physical properties of the as-prepared sample were studied using the techniques of XRD, SEM, Raman spectroscopy and N2 adsorption/desorption analysis while its electrochemical properties were studied in two-electrode assembly using liquid electrolyte (consisting of 1 M solution of LiTFSI dispersed in ionic liquid EMITFSI) and employing the techniques of cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge- discharge. The synthesized sample of activated carbon exhibits high specific capacitance of 115 F g-1 at 10 mV s-1. Also, the activated carbon electrode shows the retention of ˜75% in initial capacitance value for more than 2000 initial cycles, indicating the as-prepared activated carbon can be profitably used as electrode material for energy storage devices.
Li/Ag 2VO 2PO 4 batteries: the roles of composite electrode constituents on electrochemistry
Bock, David C.; Bruck, Andrea M.; Pelliccione, Christopher J.; ...
2016-11-01
In this study, we utilize silver vanadium phosphorous oxide, Ag 2VO 2PO 4, as a model system to systematically study the impact of the constituents of a composite electrode, including polymeric and conductive additives, on electrochemistry. Notably, although highly resistive, this bimetallic cathode can be discharged as a pure electroactive material in the absence of a conductive additive as it generates an in situ conductive matrix via a reduction displacement reaction resulting in the formation of silver metal nanoparticles. Also, three different electrode compositions were investigated: Ag 2VO 2PO 4 only, Ag 2VO 2PO 44 with binder, and Ag 2VOmore » 2PO 4 with binder and carbon. Constant current discharge, pulse testing and impedance spectroscopy measurements were used to characterize the electrochemical properties of the electrodes as a function of depth of discharge. In situ EDXRD was used to spatially resolve the discharge progression within the cathode by following the formation of Ag 0. Ex situ XRD and EXAFS modeling were used to quantify the amount of Ag 0 formed. Results indicate that the metal center reduced (V 5+ or Ag +) was highly dependent on composite composition (presence of PTFE, carbon), depth of discharge (Ag 0 nanoparticle formation), and spatial location within the cathode. The addition of a binder was found to increase cell polarization, and the percolation network provided by the carbon in the presence of PTFE was further increased with reduction and formation of Ag 0. Lastly, this study provides insight into the factors controlling the electrochemistry of resistive active materials in composite electrodes.« less
Li/Ag 2VO 2PO 4 batteries: the roles of composite electrode constituents on electrochemistry
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bock, David C.; Bruck, Andrea M.; Pelliccione, Christopher J.
In this study, we utilize silver vanadium phosphorous oxide, Ag 2VO 2PO 4, as a model system to systematically study the impact of the constituents of a composite electrode, including polymeric and conductive additives, on electrochemistry. Notably, although highly resistive, this bimetallic cathode can be discharged as a pure electroactive material in the absence of a conductive additive as it generates an in situ conductive matrix via a reduction displacement reaction resulting in the formation of silver metal nanoparticles. Also, three different electrode compositions were investigated: Ag 2VO 2PO 4 only, Ag 2VO 2PO 44 with binder, and Ag 2VOmore » 2PO 4 with binder and carbon. Constant current discharge, pulse testing and impedance spectroscopy measurements were used to characterize the electrochemical properties of the electrodes as a function of depth of discharge. In situ EDXRD was used to spatially resolve the discharge progression within the cathode by following the formation of Ag 0. Ex situ XRD and EXAFS modeling were used to quantify the amount of Ag 0 formed. Results indicate that the metal center reduced (V 5+ or Ag +) was highly dependent on composite composition (presence of PTFE, carbon), depth of discharge (Ag 0 nanoparticle formation), and spatial location within the cathode. The addition of a binder was found to increase cell polarization, and the percolation network provided by the carbon in the presence of PTFE was further increased with reduction and formation of Ag 0. Lastly, this study provides insight into the factors controlling the electrochemistry of resistive active materials in composite electrodes.« less
Does activity limitation predict discharge destination for postacute care patients?
Chang, Feng-Hang; Ni, Pengsheng; Jette, Alan M
2014-09-01
This study aimed to examine the ability of different domains of activity limitation to predict discharge destination (home vs. nonhome settings) 1 mo after hospital discharge for postacute rehabilitation patients. A secondary analysis was conducted using a data set of 518 adults with neurologic, lower extremity orthopedic, and complex medical conditions followed after discharge from a hospital into postacute care. Variables collected at baseline include activity limitations (basic mobility, daily activity, and applied cognitive function, measured by the Activity Measure for Post-Acute Care), demographics, diagnosis, and cognitive status. The discharge destination was recorded at 1 mo after being discharged from the hospital. Correlational analyses revealed that the 1-mo discharge destination was correlated with two domains of activity (basic mobility and daily activity) and cognitive status. However, multiple logistic regression and receiver operating characteristic curve analyses showed that basic mobility functioning performed the best in discriminating home vs. nonhome living. This study supported the evidence that basic mobility functioning is a critical determinant of discharge home for postacute rehabilitation patients. The Activity Measure for Post-Acute Care-basic mobility showed good usability in discriminating home vs. nonhome living. The findings shed light on the importance of basic mobility functioning in the discharge planning process.
Ma, Xiaomei; Zhou, Yongning; Chen, Min; Wu, Limin
2017-05-01
The development of environment-friendly and high-performance carbon materials for energy applications has remained a great challenge. Here, a novel and facile method for synthesis of olive-like nitrogen-doped carbon embedded with germanium (Ge) nanoparticles using widespread and nontoxic dopamine as carbon and nitrogen precursors is demonstrated, especially by understanding the tendency of pure GeO 2 nanoparticles forming ellipsoidal aggregation, and the chelating reaction of the catechol structure in dopamine with metal ions. The as-synthesized Ge/N-C composites show an olive-like porous carbon structure with a loading weight of as high as 68.5% Ge nanoparticles. A lithium ion battery using Ge/N-C as the anode shows 1042 mAh g -1 charge capacity after 2000 cycles (125 d) charge/discharge at C/2 (1C = 1600 mA g -1 ) with a capacity maintaining efficiency of 99.6%, significantly exceeding those of the previously reported Ge/C-based anode materials. This prominent cyclic charge/discharge performance of the Ge/N-C anode is attributed to the well-dispersed Ge nanoparticles in graphitic N-doped carbon matrix, which facilitates high rates (0.5-15 C) of charge/discharge and increases the anode structure integrity. The synthesis strategy presented here may be a very promising approach to prepare a series of active nanoparticle-carbon hybrid materials with nitrogen doping for more and important applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
System and method for altering characteristics of materials using an electrohydraulic discharge
Banerjee, Sujit
2003-06-03
System and method for oxidizing contaminants to alter specific properties, such as tack, of contaminants. The present invention reduces the tack of the stickies and pitch by exposing the materials for a short duration to low-energy pulsed electrical discharges between a pair of electrodes that are submerged in a liquid medium, such as a fiber stream, water, a pulp slurry, or whitewater. An electrical discharge in the liquid medium oxidizes materials, which may be dissolved or suspended therein, such as stickies, pitch, sulfide, ink, toner, and other substances, thereby reducing tack, odor, and/or zeta potential, as well as producing other desirable effect.
Zhong, Taiyang; Chen, Dongmei; Zhang, Xiuying
2016-11-09
Identification of the sources of soil mercury (Hg) on the provincial scale is helpful for enacting effective policies to prevent further contamination and take reclamation measurements. The natural and anthropogenic sources and their contributions of Hg in Chinese farmland soil were identified based on a decision tree method. The results showed that the concentrations of Hg in parent materials were most strongly associated with the general spatial distribution pattern of Hg concentration on a provincial scale. The decision tree analysis gained an 89.70% total accuracy in simulating the influence of human activities on the additions of Hg in farmland soil. Human activities-for example, the production of coke, application of fertilizers, discharge of wastewater, discharge of solid waste, and the production of non-ferrous metals-were the main external sources of a large amount of Hg in the farmland soil.
Improvement of the conductive network of positive electrodes and the performance of Ni-MH battery
NASA Astrophysics Data System (ADS)
Morimoto, Katsuya; Nakayama, Kousuke; Maki, Hideshi; Inoue, Hiroshi; Mizuhata, Minoru
2017-06-01
The pretreatment to modify the valence of cobalt by discharging at 0.2 C rate for 7.5 h before the first initial activation charge process is effective in improving the surface electronic conductivity among fine particles of positive electrode active materials. The discharge curves indicate the same locus within 1800 cycles, and the capacity of the pretreated battery is stable for over 4000 cycles. However, in-situ cell pretreatment with constant current has negative influence on other components. During the constant current pretreatment, the cell voltage rapidly falls to -0.5 V in the first 10 s of in-situ pretreatment. Therefore, we investigate the pretreatment by supplying a constant voltage to the battery instead of a constant current, and find the effective condition to improve the electrochemical performance and not to have any influence on other components of the battery.
Code of Federal Regulations, 2011 CFR
2011-07-01
... those cases where the discharge of fill material is also the discharge of dredged material, i.e., beach... statement for the project, new technology or unexpected events such as storms or high waters may require maintenance or remedial work not fully addressed in existing environmental documents or state permits. In...
Code of Federal Regulations, 2010 CFR
2010-07-01
... those cases where the discharge of fill material is also the discharge of dredged material, i.e., beach... statement for the project, new technology or unexpected events such as storms or high waters may require maintenance or remedial work not fully addressed in existing environmental documents or state permits. In...
Investigation of Fumed Silica/Aqueous NaCl Superdielectric Material.
Jenkins, Natalie; Petty, Clayton; Phillips, Jonathan
2016-02-20
A constant current charge/discharge protocol which showed fumed silica filled to the point of incipient wetness with aqueous NaCl solution to have dielectric constants >10⁸ over the full range of dielectric thicknesses of 0.38-3.9 mm and discharge times of 0.25->100 s was studied, making this material another example of a superdielectric. The dielectric constant was impacted by both frequency and thickness. For time to discharge greater than 10 s the dielectric constant for all thicknesses needed to be fairly constant, always >10⁸, although trending higher with increasing thickness. At shorter discharge times the dielectric constant consistently decreased, with decreasing time to discharge. Hence, it is reasonable to suggest that for time to discharge >10 s the dielectric constant at all thicknesses will be greater than 10⁸. This in turn implies an energy density for a 5 micron thick dielectric layer in the order of 350 J/cm³ for discharge times greater than 10 s.
Investigation of Fumed Silica/Aqueous NaCl Superdielectric Material
Jenkins, Natalie; Petty, Clayton; Phillips, Jonathan
2016-01-01
A constant current charge/discharge protocol which showed fumed silica filled to the point of incipient wetness with aqueous NaCl solution to have dielectric constants >108 over the full range of dielectric thicknesses of 0.38–3.9 mm and discharge times of 0.25–>100 s was studied, making this material another example of a superdielectric. The dielectric constant was impacted by both frequency and thickness. For time to discharge greater than 10 s the dielectric constant for all thicknesses needed to be fairly constant, always >109, although trending higher with increasing thickness. At shorter discharge times the dielectric constant consistently decreased, with decreasing time to discharge. Hence, it is reasonable to suggest that for time to discharge >10 s the dielectric constant at all thicknesses will be greater than 109. This in turn implies an energy density for a 5 micron thick dielectric layer in the order of 350 J/cm3 for discharge times greater than 10 s. PMID:28787918
Research on the degradation mechanism of pyridine in drinking water by dielectric barrier discharge.
Li, Yang; Yi, Rongjie; Yi, Chengwu; Zhou, Biyun; Wang, Huijuan
2017-03-01
Pyridine, an important chemical raw material, is widely used in industry, for example in textiles, leather, printing, dyeing, etc. In this research, a dielectric barrier discharge (DBD) system was developed to remove pyridine, as a representative type of nitrogen heterocyclic compound in drinking water. First, the influence of the active species inhibitors tertiary butanol alcohol (TBA), HCO 3 - , and CO 3 2- on the degradation rate of pyridine was investigated to verify the existence of active species produced by the strong ionization discharge in the system. The intermediate and final products generated in the degradation process of pyridine were confirmed and analyzed through a series of analytical techniques, including liquid chromatography-mass spectrometry (LC-MS), high performance liquid chromatography (HPLC), ion chromatography (IC), total organic carbon (TOC) analysis, ultraviolet (UV) spectroscopy, etc. The results showed that the degradation of pyridine was mainly due to the strong oxidizing power of ozone and hydroxyl radical produced by the DBD system. Several intermediate products including 3-hydroxyl pyridine, fumaric acid, 2, 3-dihydroxypyridine, and oxalic acid were detected. Nitrogen was removed from the pyridine molecule to form nitrate. Through analysis of the degradation mechanism of pyridine, the oxidation pathway was deduced. The study provided a theoretical and experimental basis for the application of DBD strong ionization discharge in treatment of nitrogen heterocyclic compounds in drinking water. Copyright © 2016. Published by Elsevier B.V.
NASA Astrophysics Data System (ADS)
Wang, Keliang; Xu, Ming; Gu, Yan; Gu, Zhengrong; Fan, Qi Hua
2016-11-01
N-doped porous carbon materials derived from urea-modified lignin were prepared via efficient KOH activation under carbonization. The synthesized N-doped carbon materials, which displayed a well-developed porous morphology with high specific surface area of 3130 m2 g-1, were used as electrode materials in symmetric supercapacitors with aqueous and solid electrolytes. In consistent with the observed physical structures and properties, the supercapacitors exhibited specific capacitances of 273 and 306 F g-1, small resistances of 2.6 and 7.7 Ω, stable charge/discharge at different current densities for over 5000 cycles and comparable energy and power density in 6 mol L-1 KOH liquid and KOH-PVA solid electrolytes, respectively.
Consolidation of materials by pulse-discharge processes
NASA Astrophysics Data System (ADS)
Strizhakov, E. L.; Nescoromniy, S. V.
2017-07-01
The article presents the research and the analysis of the pulse-discharge processes of capacitor discharge sintering: CD Stud Welding, capacitor discharge percussion welding (CDPW), high-voltage capacitor welding with an inductive-dynamic drive (HVCW with IDD), pulse electric current sintering (PECS) of powders. The comparative analysis of the impact parameter is presented.
NASA Astrophysics Data System (ADS)
Gopiraman, Mayakrishnan; Deng, Dian; Kim, Byoung-Suhk; Chung, Ill-Min; Kim, Ick Soo
2017-07-01
Highly porous carbon nanoarchitectures (HPCNs) were derived from biomass materials, namely, corn fibers (CF), corn leafs (CL), and corn cobs (CC). We surprisingly found that by a very simple activation process the CF, CL, and CC materials can be transformed into exciting two-dimensional (2D) and three-dimensional (3D) carbon nanoarchitectures with excellent physicochemical properties. FESEM and HRTEM results confirmed a three different carbon forms (such as foams-like carbon, carbon sheets with several holes and cheese-like carbon morphology) of HPCNs. Huge surface area (2394-3475 m2/g) with excellent pore properties of HPCNs was determined by BET analysis. Well condensed graphitic plans of HPCNs were confirmed by XRD, XPS and Raman analyses. As an electrode material, HPCNs demonstrated a maximum specific capacitance (Cs) of 575 F/g in 1.0 M H2SO4 with good stability over 20,000 cycles. The CC-700 °C showed a tremendous Cs of 375 F/g even at 20000th cycles. To the best of our knowledge, this is the highest Cs by the biomass derived activated carbons in aqueous electrolytes. The CC-700 °C exhibited excellent charge-discharge behavior at various current densities (0.5-10 A g-1). Notably, CC-700 °C demonstrated an excellent Cs of 207 F/g at current density of 10 A g-1. An extraordinary change-discharge behavior was noticed at low current density of 0.5 A g-1.
Elucidating anionic oxygen activity in lithium-rich layered oxides
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, Jing; Sun, Meiling; Qiao, Ruimin
Recent research has explored combining conventional transition metal redox with anionic lattice oxygen redox as a new and exciting direction to search for high-capacity lithium-ion cathodes. For this study, we probe the poorly understood electrochemical activity of anionic oxygen from a material perspective by elucidating the effect of the transition metal on oxygen redox activity. We study two lithium-rich layered oxides, specifically lithium nickel metal oxides where metal is either manganese or ruthenium, which possess similar structure and discharge characteristics, but exhibit distinctly different charge profiles. By combining X-ray spectroscopy with operando differential electrochemical mass spectrometry, we reveal completely differentmore » oxygen redox activity in each material, likely resulting from the different interaction between the lattice oxygen and transition metals. This work provides additional insights into the complex mechanism of oxygen redox and development of advanced high-capacity lithium-ion cathodes.« less
Elucidating anionic oxygen activity in lithium-rich layered oxides
Xu, Jing; Sun, Meiling; Qiao, Ruimin; ...
2018-03-05
Recent research has explored combining conventional transition metal redox with anionic lattice oxygen redox as a new and exciting direction to search for high-capacity lithium-ion cathodes. For this study, we probe the poorly understood electrochemical activity of anionic oxygen from a material perspective by elucidating the effect of the transition metal on oxygen redox activity. We study two lithium-rich layered oxides, specifically lithium nickel metal oxides where metal is either manganese or ruthenium, which possess similar structure and discharge characteristics, but exhibit distinctly different charge profiles. By combining X-ray spectroscopy with operando differential electrochemical mass spectrometry, we reveal completely differentmore » oxygen redox activity in each material, likely resulting from the different interaction between the lattice oxygen and transition metals. This work provides additional insights into the complex mechanism of oxygen redox and development of advanced high-capacity lithium-ion cathodes.« less
Characteristics of electromagnetic interference generated by arc discharges. [in spacecraft
NASA Technical Reports Server (NTRS)
Leung, Philip
1986-01-01
Electromagnetic interference (EMI) signatures resulting from arc discharges are characterized, and the effects of electrostatic discharges (ESDs) on the design of spacecraft systems are investigated. EMI characterization experiments were performed on Mylar, Teflon, Kapton, fused silica, and fiberglass in a vacuum chamber with acrylic walls; the experimental design and procedures are described. Discharge current pulses and RF spectra generated by the sample materials are examined. The relation between the magnitude of EMI generated during an ESD event and the material, environment, and geometry is studied. The solar-array/plasma interaction is analyzed; particular attention is given to the rate of discharge as a function of plasma density. The physical mechanisms of ESD-generated EMI are discussed. The data reveal that ESD parameters are dependent on the test environment.
NASA Astrophysics Data System (ADS)
Béléké, Alexis Bienvenu; Higuchi, Eiji; Inoue, Hiroshi; Mizuhata, Minoru
2014-02-01
We report the durability of the optimized nickel-aluminum layered double hydroxide/carbon (Ni-Al LDH/C) composite prepared by liquid phase deposition (LPD) as cathode active materials in nickel metal hydride (Ni-MH) secondary battery. The positive electrode was used for charge-discharge measurements under two different current: 5 mA for 300 cycles in half-cell conditions, and 5.8 mA for 569 cycles in battery regime, respectively. The optimized Ni-Al LDH/C composite exhibits a good lifespan and stability with the capacity retention above 380 mA h gcomp-1 over 869 cycles. Cyclic voltammetry shows that the α-Ni(OH)2/γ-NiOOH redox reaction is maintained even after 869 cycles, and the higher current regime is beneficial in terms of materials utilization. X-ray diffraction (XRD) patterns of the cathode after charge and discharge confirms that the α-Ni(OH)2/γ-NiOOH redox reaction occurs without any intermediate phase.
Kim, Hyun-Ju; Jin, Bong-Soo; Bae, Dong-Sik; Kim, Seong-Bae; Kim, Hyun-Soo
2013-05-01
LiMn0.6Fe0.4PO4/C cathode material is synthesized via a modified-solid state reaction method. The calcination temperature is adjusted in the range of 500-700 degrees C for 10 h. The crystal structure, morphology, and carbon coating layer of the synthesized LiMn0.6Fe0.4PO4/C are analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), respectively. The electrochemical performance of LiMn0.6Fe0.4PO4/C, such as initial capacity, rate capability, cycling performance and EIS is also evaluated. The synthesized cathode material shows around 100-200 nm of primary particle size with no impurities. The highest initial discharge capacity of 162.1 mA h g(-1) and columbic efficiency of 98.5% are obtained at a heat treatment temperature of 600 degrees C. In addition, LiMn0.6Fe0.4PO4/C active material shows the high capacity retention of 85% at 5 C compared to 0.2 C. It also shows the excellent capacity retention of 97.5% after the 50th charge/discharge.
Electrochemical activity in oxyborates toward lithium
NASA Astrophysics Data System (ADS)
Pralong, V.; Le Roux, B.; Malo, S.; Guesdon, A.; Lainé, F.; Colin, J. F.; Martin, C.
2017-11-01
We report the lithium insertion into a copper iron oxyborate, i.e. Cu2FeBO5. Four electrons are involved in the course of the first discharge, which is ascribed to the Cu2+/Cu redox couple. The reaction is associated with a collapse of the structure but this material shows a reversible and stable capacity of 180 mAh/g at 2.35 V vs. Li+/Li.
Corrosion and Discharge Behaviors of Al-Mg-Sn-Ga-In in Different Solutions
NASA Astrophysics Data System (ADS)
Xiong, Hanqing; Yin, Xiang; Yan, Yang; Dai, Yilong; Fan, Sufeng; Qiao, Xueyan; Yu, Kun
2016-08-01
Al-0.5 wt.%Mg-0.08 wt.%Sn-0.05 wt.%Ga-0.05 wt.%In and Al-0.5 wt.%Mg-0.08 wt.%Sn-0.05 wt.%Ga alloys were prepared by melting, casting and cold rolling. Corrosion and discharge behaviors of the two experimental alloys were investigated by electrochemical measurement, self-corrosion rate measurement, air battery testing, and scanning electron microscopy. The results showed that Al-Mg-Sn-Ga-In alloy exhibited higher electrochemical activity than Al-Mg-Sn-Ga alloy in 2 M NaCl solution, while it showed lower electrochemical activity than Al-Mg-Sn-Ga alloy in 4 M NaOH solution. By comparison with the air battery based on Al-Mg-Sn-Ga alloy, the battery with Al-Mg-Sn-Ga-In alloy cannot exhibit better discharge performance in 4 M NaOH electrolyte. However, the performance of the air battery based on Al-Mg-Sn-Ga-In alloy was greatly improved due to the In-rich inclusions and the uniform corroded morphology in 2 M NaCl electrolyte. Thus, Al-Mg-Sn-Ga-In alloy was a good anode material for Al-air battery in 2 M NaCl electrolyte.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moradi, M; Li, Z; Qi, JF
In this work we investigated an energy-efficient biotemplated route to synthesize nanostructured FePO4 for sodium-based batteries. Self-assembled M13 viruses and single wall carbon nanotubes (SWCNTs) have been used as a template to grow amorphous FePO4 nanoparticles at room temperature (the active composite is denoted as Bio-FePO4-CNT) to enhance the electronic conductivity of the active material. Preliminary tests demonstrate a discharge capacity as high as 166 mAh/g at C/10 rate, corresponding to composition Na0.9FePO4, which along with higher C-rate tests show this material to have the highest capacity and power performance reported for amorphous FePO4 electrodes to date.
Long life nickel electrodes for a nickel-hydrogen cell. I Initial performance
NASA Technical Reports Server (NTRS)
Lim, H. S.; Verzwyvelt, S. A.; Blaser, C.; Keener, K. M.
1983-01-01
In order to develop a long life nickel electrode for a Ni/H2 cell, an investigation was begun to study the effects of sinter structure and active material loading level on the long life performance of nickel electrodes. This paper is a report on the initial performance of these electrodes as a part of an accelerated life test program. Seven different types of nickel plaques were made which included three levels of both their mechanical strength and median pore size. These plaques were impregnated with three levels of active material loading. The resultant electrodes were tested by a 200-cycle stress test which was conducted in flooded electrolyte, and also for initial performance in a Ni/H2 boiler plate cell. An interesting and unexpected observation was that an increased initial utilization of the active material was due more to its complete discharge to the lower average oxidation state than its increased charge acceptance in the charged state.
NASA Astrophysics Data System (ADS)
Tsubota, Toshiki; Maguchi, Yuta; Kamimura, Sunao; Ohno, Teruhisa; Yasuoka, Takehiro; Nishida, Haruo
2015-12-01
The combination of addition of Fe (as a catalyst for graphitization) and CO2 activation (a kind of gaseous activation) was applied to prepare a porous carbon material from bamboo powder (a waste product of superheated steam treatment). Regardless of the heat treatment temperature, many macropores were successfully formed after the heating process by removal of Fe compounds. A turbostratic carbon structure was generated in the Fe-added sample heated at 850°C. It was confirmed that the added Fe acted as a template for pore formation. Moreover, it was confirmed that the added Fe acted as a catalyst for graphitization. The resulting electrochemical performance as the electrode of an electrical double-layer capacitor, as demonstrated by cyclic voltammetry, electrochemical impedance spectroscopy, and charge-discharge testing, could be explained based on the graphitization and activation effects. Addition of Fe could affect the electrical properties of carbon material derived from bamboo.
Electrochemical Performance of a V2O5 Cathode for a Sodium Ion Battery
NASA Astrophysics Data System (ADS)
Van Nghia, Nguyen; Long, Pham Duy; Tan, Ta Anh; Jafian, Samuel; Hung, I.-Ming
2017-06-01
In this paper, layered vanadium pentoxide (V2O5) is employed as a cathode material for a sodium ion battery. The V2O5 particle sizes range from 200 nm to 500 nm and the shapes of the aggregated V2O5 particles are non-homogeneous and irregular. The material exhibits a first discharge capacity of approximately 208.1 mAh g-1. The structure of V2O5 changes to a NaxV2O5 structure after Na+ insertion at the first discharge; the structure of NaxV2O5 remains stable␣during cycling. After 40 cycles, the discharge capacity retains 61.2% of the capacity of the second cycle. The capacity of V2O5 at a high charge/discharge current rate of 1.0 C is 49.1% of capacity at 0.1 C. Furthermore, the capacity returns to the initial value as the discharge rate returns to 0.1 C. The results of electrochemical performance tests indicate that V2O5 is a potential cathode material for sodium ion batteries.
NASA Astrophysics Data System (ADS)
Abdurrahman, N. M.; Priyono, B.; Syahrial, A. Z.; Subhan, A.
2017-07-01
The effect of Acetylene Black (AB) additive contents in lithium titanate/Li4Ti5O12 (LTO) anode on Li-ion Batteries performance is studied in this work. The LTO active material for Li-ion batteries anode was successfully synthesized using sol-gel method to form TiO2 xerogel continued by mixing process with LiOH in ball-mill and then sintered to obtain spinel LTO. The LTO powder is characterized by X-Ray Diffraction (XRD), scanning electron microscopy-Energy Dispersive Spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET). The spinel LTO and TiO2 rutile were detected by XRD diffractogram. The LTO powder is in the form of agglomerates structure. This powder then was mixed with PVDF binder (10%wt) and AB additives with various amount from 10%wt (LTO2 Ac-1), 12%wt (LTO2 Ac-2), and 15%wt (LTO2 Ac-3) of total weight solid content to form electrode sheet. Half-cell coin battery was made with lithium metal foil as a counter electrode. Cyclic voltammetry (CV), Electrochemical-impedance spectroscopy (EIS), and charge discharge (CD) test used to examine the battery performance. The highest resistance value is obtained in LTO2 Ac-3 sample with 15%wt of AB. It might be caused by the formation of side reaction product on electrode surface at initial cycle due to high reactivity of LTO2 Ac-3 electrode. The highest initial capacity at CV test and CD test was obtained in LTO2 Ac-1 (10%wt AB) sample, due to the best proportion of active material content in the compound. While, in the charge-discharge test at high current rate, the best sample rate-capability performance belongs to LTO2 Ac-3 sample (15%wt AB), which still have 24.12 mAh/g of discharge capacity at 10 C with 71.34% capacity loss.
Investigations of Effect of Rotary EDM Electrode on Machining Performance of Al6061 Alloy
NASA Astrophysics Data System (ADS)
Robinson Smart, D. S.; Jenish Smart, Joses; Periasamy, C.; Ratna Kumar, P. S. Samuel
2018-04-01
Electric Discharge Machining is an essential process which is being used for machining desired shape using electrical discharges which creates sparks. There will be electrodes subjected to electric voltage and which are separated by a dielectric liquid. Removing of material will be due to the continuous and rapid current discharges between two electrodes.. The spark is very carefully controlled and localized so that it only affects the surface of the material. Usually in order to prevent the defects which are arising due to the conventional machining, the Electric Discharge Machining (EDM) machining is preferred. Also intricate and complicated shapes can be machined effectively by use of Electric Discharge Machining (EDM). The EDM process usually does not affect the heat treat below the surface. This research work focus on the design and fabrication of rotary EDM tool for machining Al6061alloy and investigation of effect of rotary tool on surface finish, material removal rate and tool wear rate. Also the effect of machining parameters of EDM such as pulse on & off time, current on material Removal Rate (MRR), Surface Roughness (SR) and Electrode wear rate (EWR) have studied. Al6061 alloy can be used for marine and offshore applications by reinforcing some other elements. The investigations have revealed that MRR (material removal rate), surface roughness (Ra) have been improved with the reduction in the tool wear rate (TWR) when the tool is rotating instead of stationary. It was clear that as rotary speed of the tool is increasing the material removal rate is increasing with the reduction of surface finish and tool wear rate.
A method for estimating mean and low flows of streams in national forests of Montana
Parrett, Charles; Hull, J.A.
1985-01-01
Equations were developed for estimating mean annual discharge, 80-percent exceedance discharge, and 95-percent exceedance discharge for streams on national forest lands in Montana. The equations for mean annual discharge used active-channel width, drainage area and mean annual precipitation as independent variables, with active-channel width being most significant. The equations for 80-percent exceedance discharge and 95-percent exceedance discharge used only active-channel width as an independent variable. The standard error or estimate for the best equation for estimating mean annual discharge was 27 percent. The standard errors of estimate for the equations were 67 percent for estimating 80-percent exceedance discharge and 75 percent for estimating 95-percent exceedance discharge. (USGS)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Abdullin, I.Sh.; Bragin, V.E.; Bykanov, A.N.
Gas discharge plasma modification of polymer materials and metals is one of the known physical approaches for improving of materials biocompatibility in ophthalmology and surgery. The surface treatment in RF discharges can be effectively realized in the discharge afterglow and in the discharge region itself too. This modification method is more convenient and produces more uniform surfaces in comparison with other discharge types. The carried out experiments and published up to now results show that interaction of UV radiation, fluxes of ions, electrons and metastable particles with material`s surface changes chemical composition and surface structure. The exerting of these agentsmore » on the sample surface produces the following effects. There are processes of physical and plasma-chemical surface etching producing effective surface cleaning of different types of contaminations. It may be surface contaminations by hydrocarbons because of preliminary surface contacts with biological or physical bodies. It may be surface contaminations caused by characteristic properties of chemical technology too. There is a surface layer with thickness from some angstroms up to few hundreds of angstroms. The chemical content and structure of this layer is distinguished from the bulk polymer properties. The presence of such {open_quotes}technological{close_quotes} contaminations produces the layer of material substantially differing from the base polymer. The basic layer physical and chemical properties for example, gas permeation rate may substantially differ from the base polymer. Attempts to clean the surface from these contaminations by chemical methods (solutions) have not been successful and produced contaminations of more deep polymer layers. So the plasma cleaning is the most profitable method of polymer treatment for removing the surface contaminations. The improving of wettability occurs during this stage of treatment.« less
Conductive MOF electrodes for stable supercapacitors with high areal capacitance.
Sheberla, Dennis; Bachman, John C; Elias, Joseph S; Sun, Cheng-Jun; Shao-Horn, Yang; Dincă, Mircea
2017-02-01
Owing to their high power density and superior cyclability relative to batteries, electrochemical double layer capacitors (EDLCs) have emerged as an important electrical energy storage technology that will play a critical role in the large-scale deployment of intermittent renewable energy sources, smart power grids, and electrical vehicles. Because the capacitance and charge-discharge rates of EDLCs scale with surface area and electrical conductivity, respectively, porous carbons such as activated carbon, carbon nanotubes and crosslinked or holey graphenes are used exclusively as the active electrode materials in EDLCs. One class of materials whose surface area far exceeds that of activated carbons, potentially allowing them to challenge the dominance of carbon electrodes in EDLCs, is metal-organic frameworks (MOFs). The high porosity of MOFs, however, is conventionally coupled to very poor electrical conductivity, which has thus far prevented the use of these materials as active electrodes in EDLCs. Here, we show that Ni 3 (2,3,6,7,10,11-hexaiminotriphenylene) 2 (Ni 3 (HITP) 2 ), a MOF with high electrical conductivity, can serve as the sole electrode material in an EDLC. This is the first example of a supercapacitor made entirely from neat MOFs as active materials, without conductive additives or other binders. The MOF-based device shows an areal capacitance that exceeds those of most carbon-based materials and capacity retention greater than 90% over 10,000 cycles, in line with commercial devices. Given the established structural and compositional tunability of MOFs, these results herald the advent of a new generation of supercapacitors whose active electrode materials can be tuned rationally, at the molecular level.
Conductive MOF electrodes for stable supercapacitors with high areal capacitance
NASA Astrophysics Data System (ADS)
Sheberla, Dennis; Bachman, John C.; Elias, Joseph S.; Sun, Cheng-Jun; Shao-Horn, Yang; Dincă, Mircea
2017-02-01
Owing to their high power density and superior cyclability relative to batteries, electrochemical double layer capacitors (EDLCs) have emerged as an important electrical energy storage technology that will play a critical role in the large-scale deployment of intermittent renewable energy sources, smart power grids, and electrical vehicles. Because the capacitance and charge-discharge rates of EDLCs scale with surface area and electrical conductivity, respectively, porous carbons such as activated carbon, carbon nanotubes and crosslinked or holey graphenes are used exclusively as the active electrode materials in EDLCs. One class of materials whose surface area far exceeds that of activated carbons, potentially allowing them to challenge the dominance of carbon electrodes in EDLCs, is metal-organic frameworks (MOFs). The high porosity of MOFs, however, is conventionally coupled to very poor electrical conductivity, which has thus far prevented the use of these materials as active electrodes in EDLCs. Here, we show that Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 (Ni3(HITP)2), a MOF with high electrical conductivity, can serve as the sole electrode material in an EDLC. This is the first example of a supercapacitor made entirely from neat MOFs as active materials, without conductive additives or other binders. The MOF-based device shows an areal capacitance that exceeds those of most carbon-based materials and capacity retention greater than 90% over 10,000 cycles, in line with commercial devices. Given the established structural and compositional tunability of MOFs, these results herald the advent of a new generation of supercapacitors whose active electrode materials can be tuned rationally, at the molecular level.
Lithium Titanate Confined in Carbon Nanopores for Asymmetric Supercapacitors.
Zhao, Enbo; Qin, Chuanli; Jung, Hong-Ryun; Berdichevsky, Gene; Nese, Alper; Marder, Seth; Yushin, Gleb
2016-04-26
Porous carbons suffer from low specific capacitance, while intercalation-type active materials suffer from limited rate when used in asymmetric supercapacitors. We demonstrate that nanoconfinement of intercalation-type lithium titanate (Li4Ti5O12) nanoparticles in carbon nanopores yielded nanocomposite materials that offer both high ion storage density and rapid ion transport through open and interconnected pore channels. The use of titanate increased both the gravimetric and volumetric capacity of porous carbons by more than an order of magnitude. High electrical conductivity of carbon and the small size of titanate crystals allowed the composite electrodes to achieve characteristic charge and discharge times comparable to that of the electric double-layer capacitors. The proposed composite synthesis methodology is simple, scalable, and applicable for a broad range of active intercalation materials, while the produced composite powders are compatible with commercial electrode fabrication processes.
NASA Astrophysics Data System (ADS)
Dong, Jiajun; Zhang, Tong; Zhang, Dong; Zhang, Weiwei; Zhang, Huafang; Liu, Ran; Yao, Mingguang; Liu, Bingbing
2017-01-01
Onion-like carbon nanospheres (OCNSs) with an average diameter of 43 nm were produced on a large scale via a combustion method and examined as an anode material for lithium ion batteries. The OCNSs exhibit a remarkable electrochemical cycling behavior and a capacity much higher than that of graphite. The capacity increases significantly with increasing charge-discharge cycles and reaches a value of 178% of the initial value (from 586 mA h g-1to 1045 mA h g-1) after 200 cycles. Further investigation provides unambiguous experimental evidence that such a remarkable capacity increase is related to the stable onion-like structure of the OCNSs and to the existence of large numbers of disordered/short graphitic fragments, which gradually provide more active sites for Li ion storage. The unique electrochemical performance of OCNSs provides a new way to design a high-performance anode material for rechargeable batteries.
Methods for natural gas and heavy hydrocarbon co-conversion
Kong, Peter C [Idaho Falls, ID; Nelson, Lee O [Idaho Falls, ID; Detering, Brent A [Idaho Falls, ID
2009-02-24
A reactor for reactive co-conversion of heavy hydrocarbons and hydrocarbon gases and includes a dielectric barrier discharge plasma cell having a pair of electrodes separated by a dielectric material and passageway therebetween. An inlet is provided for feeding heavy hydrocarbons and other reactive materials to the passageway of the discharge plasma cell, and an outlet is provided for discharging reaction products from the reactor. A packed bed catalyst may optionally be used in the reactor to increase efficiency of conversion. The reactor can be modified to allow use of a variety of light sources for providing ultraviolet light within the discharge plasma cell. Methods for upgrading heavy hydrocarbons are also disclosed.
Nonthermal plasma systems and methods for natural gas and heavy hydrocarbon co-conversion
Kong, Peter C.; Nelson, Lee O.; Detering, Brent A.
2005-05-24
A reactor for reactive co-conversion of heavy hydrocarbons and hydrocarbon gases and includes a dielectric barrier discharge plasma cell having a pair of electrodes separated by a dielectric material and passageway therebetween. An inlet is provided for feeding heavy hydrocarbons and other reactive materials to the passageway of the discharge plasma cell, and an outlet is provided for discharging reaction products from the reactor. A packed bed catalyst may optionally be used in the reactor to increase efficiency of conversion. The reactor can be modified to allow use of a variety of light sources for providing ultraviolet light within the discharge plasma cell. Methods for upgrading heavy hydrocarbons are also disclosed.
Facile hydrothermal synthesis of one-dimensional nanostructured α-MnO2 for supercapacitors
NASA Astrophysics Data System (ADS)
Wei, Hongmei; Wang, Jinxing; Yang, Shengwei; Zhang, Yangyang; Li, Tengfei; Zhao, Shuoqing
2016-09-01
α-MnO2 recently becomes a promising candidate of electrode materials for high effective supercapacitors in which it possesses of unique structure of 2×2 tunnels that can provide more electrons and ions diffusion paths. In this work, different morphologies MnO2 with α-phase crystalline structure have been prepared via a one-step facile hydrothermal method by adding various reagents. Compositions, microstructures and morphologies of these as-synthesized materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and electrochemical properties of α-MnO2 electrodes were studied by the cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) in 1 M Na2SO4 aqueous solution. The specific capacitance of nanowires were 158 F g-1 while the specific capacitance of nanorods were 106 F g-1 at current density of 4 A g-1, and improved performance of the wire-like electrode material was probably ascribed to the larger specific surface area that can provide relatively more active sites for high capacity. Meanwhile, both the nanowires and nanorods of MnO2 presented fine cycle stability after continuous multiple charge/discharge times.
Characterization of DC Magnetron Sputtering Plasma Used for Deposition of Amorphous Carbon Nitride
NASA Astrophysics Data System (ADS)
Camps, Enrique; Escobar-Alarcón, Luis; López, J.; Zambrano, G.; Prieto, P.
2006-12-01
Amorphous carbon nitride (a-CNx) thin films are attractive due to their potential applications, in different areas. This material can be hard and used as a protective coating, or can be soft and porous and used as the active element in gas sensors, it can also be used as a radiation detector due to its thermoluminescent response. The use of this material for one or another application, will depend on the material's structure, which can be changed by changing the deposition parameters. When using the d.c. magnetron sputtering technique it means mainly the change of discharge power, type of Ar/N2 gas mixture, and the working gas pressure. The variation of these deposition parameters has an important influence on the characteristics of the plasma formed in the discharge. In this work we studied the plasma characteristics, such as the type of excited species, plasma density, and electron temperature under different deposition conditions, using Optical Emission Spectroscopy (OES), and a single Langmuir probe. These parameters were correlated with the properties of a-CNx films deposited under those characterized regimes, in order to establish the role that the plasma parameters play on the formation of the different structures of CNx films.
Traveling wire electrode increases productivity of Electrical Discharge Machining /EDM/ equipment
NASA Technical Reports Server (NTRS)
Kotora, J., Jr.; Smith, S. V.
1967-01-01
Traveling wire electrode on electrical discharge machining /EDM/ equipment reduces the time requirements for precision cutting. This device enables cutting with a minimum of lost material and without inducing stress beyond that inherent in the material. The use of wire increases accuracy and enables tighter tolerances to be maintained.
NASA Astrophysics Data System (ADS)
Hamdan, Ahmad; Cha, Min Suk
2018-06-01
Plasmas in- or in-contact with liquids have been extensively investigated due to their high potential for a wide range of applications including, but not limited to, water treatment, material synthesis and functionalization, bio-medical applications, and liquid fuel reformation. Recently, we successfully developed a discharge using two immiscible liquids, having very different electrical permittivities, which could significantly intensify the electric field intensity. Here, we establish nanosecond discharges at the interface n-heptane-water (with respective relative dielectric permittivities of 2 and 80) to enable the synthesis of carbon-based nanomaterials. A characterization of the as-synthesized material and the annealed (500 °C) material, using various techniques (Fourier-transform, infra-red, scanning and transmission electron microscopes, etc), shows that the as-synthesized material is a mixture of two carbon-based phases: a crystalline phase (graphite like) embedded into a phase of hydrogenated amorphous carbon. The existence of two-phases may be explained by the non-homogeneity of the discharge that induces various chemical reactions in the plasma channel.
Atmospheric-pressure electric discharge as an instrument of chemical activation of water solutions
NASA Astrophysics Data System (ADS)
Rybkin, V. V.; Shutov, D. A.
2017-11-01
Results of experimental studies and numerical simulations of physicochemical characteristics of plasmas generated in different types of atmospheric-pressure discharges (pulsed streamer corona, gliding electric arc, dielectric barrier discharge, glow-discharge electrolysis, diaphragmatic discharge, and dc glow discharge) used to initiate various chemical processes in water solutions are analyzed. Typical reactor designs are considered. Data on the power supply characteristics, plasma electron parameters, gas temperatures, and densities of active particles in different types of discharges excited in different gases and their dependences on the external parameters of discharges are presented. The chemical composition of active particles formed in water is described. Possible mechanisms of production and loss of plasma particles are discussed.
Preliminary zoning for risk assessment and remediation purposes in Portman Bay.
NASA Astrophysics Data System (ADS)
Pérez-Sirvent, Carmen; Martínez-Sanchez, MJose; Garcia-Lorenzo, MariLuz; Hernandez-Cordoba, Manuel; Molina, Jose; Gonzalez, Eva; Perez-Espinosa, Victor
2014-05-01
Portman bay is a singular point of mining impact in the Mediterranean area. The site is located in the province of Murcia, south-eastern Spain, and was completely inundated with more than 63 million tonnes of mining waste discharged through a huge washing plant. Wastes from mining activities mainly consisted of ore materials (galena, pyrite and sphalerite), phyllosilicates, in addition to siderite, iron oxides and sometimes alteration products such as jarosite, alunite, kaolinite and greenalite. These materials were submitted to a concentration process by floatation with sea water and as a result of the discharge, the whole of the bay was filled up with wastes which also extended into the Mediterranean Sea. In the last years of activity, wastes were even poured alternatively in the sea or over the sediments filling the bay. These actions have produced a very high heterogeneity in the sediments. Although after the end of the discharges it has been possible to reach a certain degree of balance, the sediments, especially those closest to the sea, are subjected to marine dynamics and the effects of rainfall and runoffs. In 2007, a recuperation pilot project was developed and financed by the Spanish Government. In the first step of this project, the complete physical, chemical and mineralogical characterization of sediments, both in surface and at depth was carried out. Twenty surface samples were collected (<1 m) and twelve sediment cores were also collected at the same time. To determine the total trace element content, zinc and iron levels were determined by flame atomic absorption spectrometry, while lead, cadmium and copper levels were determined by electrothermal atomization atomic absorption spectrometry. The arsenic content was measured by atomic fluorescence spectrometry using an automated continuous flow hydride generation spectrometer. The reliability of the results was verified by analyzing standard reference materials. The mineralogical composition was determined using Cu-Kα radiation with an X-ray Diffractometer and appropriate software. Data for metal leached, Acid-volatile sulphide (AVS) and simultaneously extracted metals (SEM) were also obtained. The results allowed two types of materials to be differentiated. The first one with a fine particle size, is related with the direct discharge of wastes and contains jarosite and other minerals resulting of supergenic alteration. The pH is low and both the level of heavy metals and chemical reactivity are high. The second, different material is black sand, a sediment of coarse texture in which stable minerals, phylosilicates, iron oxides and hydroxides, siderite, pyrite and quartz predominate. The pH is close to neutrality and despite a high heavy metals level, the chemical reactivity is low. The data allowed a preliminary zoning of the risk in the area to be established, and this was the starting point to outline the remediation project.
An Investigation of Low Earth Orbit Internal Charging
NASA Technical Reports Server (NTRS)
Parker, Linda Neergaard; Minow, Joseph; Willis, Joseph
2014-01-01
Built internal charging model for spacecraft design and anomaly assessment that calculates number of internal discharges given material properties and environment characteristics. As shielding decreases, the number of discharges increases. Ungrounded MLI produced a significant number of discharges even through thin layers.
Improved ultraviolet resonance lamp
NASA Technical Reports Server (NTRS)
Bass, A. M.
1970-01-01
Removal of the seal area from the path of the lamp discharge eliminates the gradual deterioration of lithium fluoride window surfaces from condensation of products formed by interaction of a resonant rare-gas discharge with window sealing materials. The discharge is confined to the inner tube.
2014-08-10
Electrostatic discharge Ignition Aluminum Thermites Energetic materials a b s t r a c t Powder energetic materials are highly sensitive to electrostatic...Fundamentals, in: Heat Conduction, Wiley, Hoboken, NJ, 2012. [12] Davin G. Piercey, Thomas M. Klapotke, Nanoscale aluminum metal oxide ( thermite ) reactions for...propagation velocity in thermites with a nanoscale oxidizer, Propellants Explos. Pyrotechn. 39 (3) (2014) 407 415. [18] Kevin Moore, Michelle L
Fiorentini, Carla; Falzano, Loredana; Fabbri, Alessia; Stringaro, Annarita; Logozzi, Mariaantonia; Travaglione, Sara; Contamin, Stéphanette; Arancia, Giuseppe; Malorni, Walter; Fais, Stefano
2001-01-01
Macropinocytosis, a ruffling-driven process that allows the capture of large material, is an essential aspect of normal cell function. It can be either constitutive, as in professional phagocytes where it ends with the digestion of captured material, or induced, as in epithelial cells stimulated by growth factors. In this case, the internalized material recycles back to the cell surface. We herein show that activation of Rho GTPases by a bacterial protein toxin, the Escherichia coli cytotoxic necrotizing factor 1 (CNF1), allowed epithelial cells to engulf and digest apoptotic cells in a manner similar to that of professional phagocytes. In particular, we have demonstrated that 1) the activation of all Rho, Rac, and Cdc42 by CNF1 was essential for the capture and internalization of apoptotic cells; and 2) such activation allowed the discharge of macropinosomal content into Rab7 and lysosomal associated membrane protein-1 acidic lysosomal vesicles where the ingested particles underwent degradation. Taken together, these findings indicate that CNF1-induced “switching on” of Rho GTPases may induce in epithelial cells a scavenging activity, comparable to that exerted by professional phagocytes. The activation of such activity in epithelial cells may be relevant, in mucosal tissues, in supporting or integrating the scavenging activity of resident macrophages. PMID:11452003
Rate Dependency of Silver Vanadium Phosphorous Oxide Reduction
NASA Astrophysics Data System (ADS)
Cheng, Po-Jen
2011-12-01
The silver vanadium phosphorus oxide (Ag2VO2PO 4) is a high-capacity and good-compatibility material for the cathode in the battery. Due to their innovative properties, they are used as cathode in lithium batteries. Therefore, when the lithium batteries begin to discharge, the anodes of the cell perform an electrochemical oxidation and release electrons. In the mean time, the cathodes in the cells perform the electrochemical reduction and catch the electrons. For reduction of Ag2VO2PO 4, two silver ions (Ag+) catch two electrons to form silver particles, and the vanadium ions (V5+) catch two electrons to form V3+. It means that four electrons will be released by lithium anode. We call this four electrons discharge as 100% discharge. In my most of the projects, the Ag2VO2PO4 material is tested by differential scanning calorimetry (DSC) to check purity. My study is based on the discharge of batteries, and I focus on the morphology and the intensity of silver particles on the cathode after discharge. Depending on different adjustment of factors, such as discharge time, discharge rate, storage time, storage temperature, I try to investigate the silver intensity, conductivity as a function of DOD (Depth of Discharge). The silver particles could be examined by optical microscope, and scanning electron microscope (SEM). Moreover, I do some x-ray diffraction analysis to quantify the silver particles after discharge. Also, I perform magnetic susceptibility measurement to check the mechanism of the reduction of vanadium ions. Under the research on silver ions and vanadium ions, I will know a big frame of reduction process on silver vanadium phosphorous oxide and the time effect on this cathode material.
Mesoporous nitrogen-doped carbon-glass ceramic cathodes for solid-state lithium-oxygen batteries.
Kichambare, Padmakar; Rodrigues, Stanley; Kumar, Jitendra
2012-01-01
The composite of nitrogen-doped carbon (N-C) blend with lithium aluminum germanium phosphate (LAGP) was studied as cathode material in a solid-state lithium-oxygen cell. Composite electrodes exhibit high electrochemical activity toward oxygen reduction. Compared to the cell capacity of N-C blend cathode, N-C/LAGP composite cathode exhibits six times higher discharge cell capacity. A significant enhancement in cell capacity is attributed to higher electrocatalytic activity and fast lithium ion conduction ability of LAGP in the cathode. © 2011 American Chemical Society
Shen, ShouYu; Hong, YuHao; Zhu, FuChun; Cao, ZhenMing; Li, YuYang; Ke, FuSheng; Fan, JingJing; Zhou, LiLi; Wu, LiNa; Dai, Peng; Cai, MingZhi; Huang, Ling; Zhou, ZhiYou; Li, JunTao; Wu, QiHui; Sun, ShiGang
2018-04-18
Owing to high specific capacity of ∼250 mA h g -1 , lithium-rich layered oxide cathode materials (Li 1+ x Ni y Co z Mn (3- x-2 y-3 z)/4 O 2 ) have been considered as one of the most promising candidates for the next-generation cathode materials of lithium ion batteries. However, the commercialization of this kind of cathode materials seriously restricted by voltage decay upon cycling though Li-rich materials with high cobalt content have been widely studied and show good capacity. This research successfully suppresses voltage decay upon cycling while maintaining high specific capacity with low Co/Ni ratio in Li-rich cathode materials. Online continuous flow differential electrochemical mass spectrometry (OEMS) and in situ X-ray diffraction (XRD) techniques have been applied to investigate the structure transformation of Li-rich layered oxide materials during charge-discharge process. The results of OEMS revealed that low Co/Ni ratio lithium-rich layered oxide cathode materials released no lattice oxygen at the first charge process, which will lead to the suppression of the voltage decay upon cycling. The in situ XRD results displayed the structure transition of lithium-rich layered oxide cathode materials during the charge-discharge process. The Li 1.13 Ni 0.275 Mn 0.580 O 2 cathode material exhibited a high initial medium discharge voltage of 3.710 and a 3.586 V medium discharge voltage with the lower voltage decay of 0.124 V after 100 cycles.
Pushing the Theoretical Limit of Li-CFx Batteries: A Tale of Bi-functional Electrolyte
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rangasamy, Ezhiylmurugan; Li, Juchuan; Sahu, Gayatri
2014-01-01
In a typical battery, electrodes deliver capacities less or equal the theoretical maxima of the electrode materials.1 The inert electrolyte functions solely as the ionic conductor without contribution to the cell capacity because of its distinct mono-function in the concept of conventional batteries. Here we demonstrate that the most energy-dense Li-CFx battery2 delivers a capacity exceeding the theoretical maximum of CFx with a solid electrolyte of Li3PS4 (LPS) that has dual functions: as the inert electrolyte at the anode and the active component at the cathode. Such a bi-functional electrolyte reconciles both inert and active characteristics through a synergistic dischargemore » mechanism of CFx and LPS. Li3PS4 is known as an inactive solid electrolyte with a broad electrochemical window over 5 V.3 The synergy at the cathode is through LiF, the discharge product of CFx, which activates the electrochemical discharge of LPS at a close electrochemical potential of CFx. Therefore, the solid-state Li-CFx batteries output 126.6% energy beyond their theoretic limits without compromising the stability of the cell voltage. The extra energy comes from the electrochemical discharge of LPS, the inert electrolyte. This bi-functional electrolyte revolutionizes the concept of conventional batteries and opens a new avenue for the design of batteries with an unprecedentedly high energy density.« less
Leonard, Robert B.; Janzer, Victor J.
1978-01-01
Radioactive hot springs issue from a fault zone in crystalline rock of the Boulder batholith at Alhambra, Jefferson County, in southwestern Montana. The discharge contains high concentrations of radon, and the gross alpha activity and the concentration of adium-226 exceed maximum levels recommended by the Environmental Protection Agency for drinking water. Part of the discharge is diverted for space heating, bathing, and domestic use. The radioactive thermal waters at measured temperatures of about 60°C are of the sodium bicarbonate type and saturated with respect to calcium carbonate. Radium-226 in the rock and on fractured surfaces or coprecipitated with calcium carbonate probably is the principal source of radon that is dissolved in the thermal water and discharged with other gases from some wells and springs. Local surface water and shallow ground water are of the calcium bicarbonate type and exhibit low background activity. The temperature, percent sodium, and radioactivity of mixed waters adjacent to the fault zone increase with depth. Samples from most of the major hot springs in southwestern Montana have been analyzed for gross alpha and beta activity. The high level of radioactivity at Alhambra appears to be related to leaching of radioactive material from siliceous veins by ascending thermal waters and is not a normal characteristic of hot springs issuing from fractured crystalline rock in Montana.
Yang, Chaofan; Zhang, Xiaosong; Huang, Mengyi; Huang, Junjie; Fang, Zebo
2017-04-12
LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM) is regarded as a promising material for next-generation lithium ion batteries due to the high capacity, but its practical applications are limited by the poor electronic conductivity. Here, a one-step method is used to prepare carbon coated LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM/C) by applying active carbon as reaction matrix. TEM shows LiNi 1/3 Co 1/3 Mn 1/3 O 2 particles are homogeneously coated by carbon with a thickness about 10 nm. NCM/C delivers the discharge capacity of 191.2 mAh g -1 at 0.5 C (85 mA g -1 ) with a columbic efficiency of 91.1%. At 40 C (6800 mA g -1 ), the discharge capacity of NCM/C is 54.6 mAh g -1 , whereas NCM prepared through sol-gel route only delivers 13.2 mAh g -1 . After 100 charge and discharge cycles at 1 C (170 mA g -1 ) the capacity retention is 90.3% for NCM/C, whereas it is only 72.4% for NCM. The superior charge/discharge performance of NCM/C owes much to the carbon coating layer, which is not only helpful to increase the electronic conductivity but also contributive to inhibit the side reactions between LiNi 1/3 Co 1/3 Mn 1/3 O 2 and the liquid electrolyte.
Exploration of Gas Discharges with GaAs, GaP and ZnSe Electrodes Under Atmospheric Pressure
NASA Astrophysics Data System (ADS)
Kurt, H. Hilal
2018-03-01
This work reports on the electrical and optical characterization of the atmospheric pressure glow discharge regimes for different semiconductor electrodes made of GaAs, GaP and ZnSe. The discharge cell is driven by DC feeding voltages at a wide pressure range of 0.66-120 kPa in argon and air media for different interelectrode gaps. The discharge phenomena including different stages of discharges such as glow and Townsend breakdown have been examined. In addition, the infrared sensitivities of the semiconducting materials are evaluated in the micro-discharge cell and discharge light emission measurements have been performed. The qualities of the semiconducting electrode samples can be determined by seeking the homogeneity of the discharge light emission for the optoelectronic device applications. Operation of optical devices under atmospheric pressures gives certain advantages for manufacturing of the devices including the material processing and surface treatment procedures. Besides, finite element analyses of the overall experimental system have been performed for the abovementioned semiconductors. The electron densities and potential patterns have been determined on the discharge cell plane between the electrodes. The findings have proven that the electron densities along the plasma cell depend on both the semiconductor type and plasma parameters.
NASA Astrophysics Data System (ADS)
Wong, Derek N.; Wetz, David A.; Heinzel, John M.; Mansour, Azzam N.
2016-10-01
Three 26650 LiFePO4 (LFP) cells are cycled using a 40 A pulsed charge/discharge profile to study their performance in high rate pulsed applications. This profile is used to simulate naval pulsed power loads planned for deployment aboard future vessels. The LFP cells studied experienced an exponential drop in their usable high-rate recharge capacity within sixty cycles due to a rapid rise in their internal resistance. Differential capacitance shows that the voltage window for charge storage is pushed outside of the recommended voltage cutoff limits. Investigation into the state of health of the electrodes shows minimal loss of active material from the cathode to side reactions. Post-mortem examination of the anodic surface films reveals a large increase in the concentration of reduced salt compounds indicating that the pulsed profile creates highly favorable conditions for LiPF6 salt to break down into LiF. This film slows the ionic movement at the interface, affecting transfer kinetics, resulting in charge buildup in the bulk anode without successful energy storage. The results indicate that the use of these cells as a power supply for high pulsed power loads is hindered because of ionically resistant film development and not by an increasing rate of active material loss.
High-capacity aqueous zinc batteries using sustainable quinone electrodes
Zhao, Qing; Huang, Weiwei; Luo, Zhiqiang; Liu, Luojia; Lu, Yong; Li, Yixin; Li, Lin; Hu, Jinyan; Ma, Hua; Chen, Jun
2018-01-01
Quinones, which are ubiquitous in nature, can act as sustainable and green electrode materials but face dissolution in organic electrolytes, resulting in fast fading of capacity and short cycle life. We report that quinone electrodes, especially calix[4]quinone (C4Q) in rechargeable metal zinc batteries coupled with a cation-selective membrane using an aqueous electrolyte, exhibit a high capacity of 335 mA h g−1 with an energy efficiency of 93% at 20 mA g−1 and a long life of 1000 cycles with a capacity retention of 87% at 500 mA g−1. The pouch zinc batteries with a respective depth of discharge of 89% (C4Q) and 49% (zinc anode) can deliver an energy density of 220 Wh kg−1 by mass of both a C4Q cathode and a theoretical Zn anode. We also develop an electrostatic potential computing method to demonstrate that carbonyl groups are active centers of electrochemistry. Moreover, the structural evolution and dissolution behavior of active materials during discharge and charge processes are investigated by operando spectral techniques such as IR, Raman, and ultraviolet-visible spectroscopies. Our results show that batteries using quinone cathodes and metal anodes in aqueous electrolyte are reliable approaches for mass energy storage. PMID:29511734
High-capacity aqueous zinc batteries using sustainable quinone electrodes.
Zhao, Qing; Huang, Weiwei; Luo, Zhiqiang; Liu, Luojia; Lu, Yong; Li, Yixin; Li, Lin; Hu, Jinyan; Ma, Hua; Chen, Jun
2018-03-01
Quinones, which are ubiquitous in nature, can act as sustainable and green electrode materials but face dissolution in organic electrolytes, resulting in fast fading of capacity and short cycle life. We report that quinone electrodes, especially calix[4]quinone (C4Q) in rechargeable metal zinc batteries coupled with a cation-selective membrane using an aqueous electrolyte, exhibit a high capacity of 335 mA h g -1 with an energy efficiency of 93% at 20 mA g -1 and a long life of 1000 cycles with a capacity retention of 87% at 500 mA g -1 . The pouch zinc batteries with a respective depth of discharge of 89% (C4Q) and 49% (zinc anode) can deliver an energy density of 220 Wh kg -1 by mass of both a C4Q cathode and a theoretical Zn anode. We also develop an electrostatic potential computing method to demonstrate that carbonyl groups are active centers of electrochemistry. Moreover, the structural evolution and dissolution behavior of active materials during discharge and charge processes are investigated by operando spectral techniques such as IR, Raman, and ultraviolet-visible spectroscopies. Our results show that batteries using quinone cathodes and metal anodes in aqueous electrolyte are reliable approaches for mass energy storage.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Takeuchi, Esther
2016-11-30
Our results for this program “Electrochemically smart bimetallic materials featuring Group 11 metals: in-situ conductive matrix generation and its impact on battery capacity, power and reversibility” have been highly successful: 1) we demonstrated material structures which generated in-situ conductive networks through electrochemical activation with increases in conductivity up to 10,000 fold, 2) we pioneered in situ analytical methodology to map the cathodes at several stages of discharge through the use of Energy Dispersive X-ray Diffraction (EDXRD) to elucidate the kinetic dependence of the conductive network formation, and 3) we successfully designed synthetic methodology for direct control of material properties includingmore » crystallite size and surface area which showed significant impact on electrochemical behavior.« less
Li Storage of Calcium Niobates for Lithium Ion Batteries.
Yim, Haena; Yu, Seung-Ho; Yoo, So Yeon; Sung, Yung-Eun; Choi, Ji-Won
2015-10-01
New types of niobates negative electrode were studied for using in lithium-ion batteries in order to alternate metallic lithium anodes. The potassium intercalated compound KCa2Nb3O10 and proton intercalated compound HCa2Nb3O10 were studied, and the electrochemical results showed a reversible cyclic voltammetry profile with acceptable discharge capacity. The as-prepared KCa2Nb3O10 negative electrode had a low discharge capacity caused by high overpotential, but the reversible intercalation and deintercalation reaction of lithium ions was activated after exchanging H+ ions for intercalated K+ ions. The initial discharge capacity of HCa2Nb3O10 was 54.2 mAh/g with 92.1% of coulombic efficiency, compared with 10.4 mAh/g with 70.2% of coulombic efficiency for KCa2Nb3O10 at 1 C rate. The improved electrochemical performance of the HCa2Nb3O10 was related to the lower bonding energy between proton cation and perovskite layer, which facilitate Li+ ions intercalating into the cation site, unlike potassium cation and perovskite layer. Also, this negative material can be easily exfoliated to Ca2Nb3O10 layer by using cation exchange process. Then, obtained two-dimensional nanosheets layer, which recently expected to be an advanced electrode material because of its flexibility, chemical stable, and thin film fabricable, can allow Li+ ions to diffuse between the each perovskite layer. Therefore, this new type layered perovskite niobates can be used not only bulk-type lithium ion batteries but also thin film batteries as a negative material.
Wiaderek, Kamila M; Borkiewicz, Olaf J; Castillo-Martínez, Elizabeth; Robert, Rosa; Pereira, Nathalie; Amatucci, Glenn G; Grey, Clare P; Chupas, Peter J; Chapman, Karena W
2013-03-13
In-depth analysis of operando X-ray pair distribution function (PDF) data is combined with Li NMR spectroscopy to gain comprehensive insights into the electrochemical reaction mechanism of high-performance iron oxyfluoride electrodes. While the full discharge capacity could be recovered upon charge, implying reversibility of the electrochemical reaction, the atomic structure of the electrode formed after cycling (discharge-charge) differs from the pristine uncycled electrode material. Instead, the "active" electrode that forms upon cycling is a nanocomposite of an amorphous rutile phase and a nanoscale rock salt phase. Bond valence sum analysis, based on the precise structural parameters (bond lengths and coordination number) extracted from the in situ PDF data, suggests that anion partitioning occurs during the electrochemical reaction, with the rutile phase being F-rich and the rock salt phase being O-rich. The F- and O-rich phases react sequentially; Fe in a F-rich environment reacts preferentially during both discharge and charge.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tsuji, Yoichiro; Yamamoto, Osamu; Matsuda, Hiromu
2000-07-01
Ti-V-Cr bcc-type solid solution alloys can absorb a large amount of hydrogen and be applied to active materials of the negative electrode in Ni-MH batteries. However, because of the insolubility of Ni into these alloys, the electrochemical characteristics like discharge capacity and cycle life were poor. In order to increase the discharge capacity of hydrogen absorbing alloy electrodes, Ti-V-Cr bcc-type alloy powders were sintered with Ni in order to form Ni contained surface layer on the alloy surface. As sintering temperature rose up, the surface composition changed from TiNi to Ti{sub 2}Ni. TiNi surface layer showed better electrochemical characteristics. Formore » the Ni adding method, Ni electroless plating was preferred because of good adhesion. As a result of optimized conditions, a discharge capacity of 570 mAh/g and an improvement of cycle life were achieved.« less
Estimating sediment discharge: Appendix D
Gray, John R.; Simões, Francisco J. M.
2008-01-01
Sediment-discharge measurements usually are available on a discrete or periodic basis. However, estimates of sediment transport often are needed for unmeasured periods, such as when daily or annual sediment-discharge values are sought, or when estimates of transport rates for unmeasured or hypothetical flows are required. Selected methods for estimating suspended-sediment, bed-load, bed- material-load, and total-load discharges have been presented in some detail elsewhere in this volume. The purposes of this contribution are to present some limitations and potential pitfalls associated with obtaining and using the requisite data and equations to estimate sediment discharges and to provide guidance for selecting appropriate estimating equations. Records of sediment discharge are derived from data collected with sufficient frequency to obtain reliable estimates for the computational interval and period. Most sediment- discharge records are computed at daily or annual intervals based on periodically collected data, although some partial records represent discrete or seasonal intervals such as those for flood periods. The method used to calculate sediment- discharge records is dependent on the types and frequency of available data. Records for suspended-sediment discharge computed by methods described by Porterfield (1972) are most prevalent, in part because measurement protocols and computational techniques are well established and because suspended sediment composes the bulk of sediment dis- charges for many rivers. Discharge records for bed load, total load, or in some cases bed-material load plus wash load are less common. Reliable estimation of sediment discharges presupposes that the data on which the estimates are based are comparable and reliable. Unfortunately, data describing a selected characteristic of sediment were not necessarily derived—collected, processed, analyzed, or interpreted—in a consistent manner. For example, bed-load data collected with different types of bed-load samplers may not be comparable (Gray et al. 1991; Childers 1999; Edwards and Glysson 1999). The total suspended solids (TSS) analytical method tends to produce concentration data from open-channel flows that are biased low with respect to their paired suspended-sediment concentration values, particularly when sand-size material composes more than about a quarter of the material in suspension. Instantaneous sediment-discharge values based on TSS data may differ from the more reliable product of suspended- sediment concentration values and the same water-discharge data by an order of magnitude (Gray et al. 2000; Bent et al. 2001; Glysson et al. 2000; 2001). An assessment of data comparability and reliability is an important first step in the estimation of sediment discharges. There are two approaches to obtaining values describing sediment loads in streams. One is based on direct measurement of the quantities of interest, and the other on relations developed between hydraulic parameters and sediment- transport potential. In the next sections, the most common techniques for both approaches are briefly addressed.
System and method for altering the tack of materials using an electrohydraulic discharge
Banerjee, Sujit; Corcoran, Howard
2007-11-13
A system and method for altering the tack of a material, namely a polymer used as an adhesive, also known as stickies, or pitch. The present invention reduces the tack of the stickies and pitch by exposing the materials for a short duration to low-energy pulsed electrical discharges between a pair of electrodes that are submerged in a liquid medium, such as a fiber stream, water, a pulp slurry, or whitewater.
System and method for altering the tack of materials using an electrohydraulic discharge
Banerjee, Sujit; Corcoran, Howard
2003-01-01
A system and method for altering the tack of a material, namely a polymer used as an adhesive, also known as stickies, or pitch. The present invention reduces the tack of the stickies and pitch by exposing the materials for a short duration to low-energy pulsed electrical discharges between a pair of electrodes that are submerged in a liquid medium, such as a fiber stream, water, a pulp slurry, or whitewater.
Hairy carbon electrodes studied by cyclic voltammetry and battery discharge testing
NASA Technical Reports Server (NTRS)
Chung, Deborah D. L.; Shui, Xiaoping; Frysz, Christine A.
1993-01-01
Hairy carbon is a new material developed by growing submicron carbon filaments on conventional carbon substrates. Typical substrate materials include carbon black, graphite powder, carbon fibers, and glassy carbon. A catalyst is used to initiate hair growth with carbonaceous gases serving as the carbon source. To study the electrochemical behavior of hairy carbons, cyclic voltammetry (CV) and discharge testing were conducted. In both cases, hairy carbon results surpassed those of the substrate material alone.
An investigation of manganese based electrode materials for use in lithium ion batteries
NASA Astrophysics Data System (ADS)
Sengupta, Surajit
Lithium-based batteries are potential candidates to provide maximum volumetric and gravimetric energy density. One of the most attractive candidates as a cathode material for secondary lithium ion battery systems is the spinel LiMn 2O4 because it is environmentally friendly, less expensive and is capable of providing high energy density as compared to other cathode materials that are currently available. One problem associated with the spinel structure is capacity fading during multiple cycles of charge and discharge operations. This behaviour is due in part to the structural distortion during deep charge and discharge where nearly 100% of the lithium is extracted and inserted inside the spinel structure. Capacity fading can also be caused by dissolution of manganese ions in the electrolyte phase. A solution based method has been adapted for the synthesis of lithium manganese oxide, and chromium and cobalt doped mixed oxide materials using polyvinyl alcohol (PVA) as a chelating agent. It has been found from TGA/DSC analysis that at around 220°C the synthesis reaction is completed. The precursor powders obtained were annealed at different temperatures and times in the range of 250°C to 600°C and from 2 to 8 hours respectively to obtain pure spinel oxides. From X-ray analysis it has been observed that the crystallite size can be controlled in the range of approximately 6 nm to 32 nm depending on the annealing time and the temperature. The morphology of the synthesized materials consisted of submicron sized particles agglomerated with micropores inside the network structure. To observe the effect of physical properties on battery performance cyclic chronopotentiometric evaluation was conducted. It has been found with these synthesized materials that there is an increase in the 1st discharge capacity with an increase in the annealing time and the temperature at both 1C and C/5 rates. This increase is more significant when the annealing temperature is 600°C as compared to that at 250°C. This implies that an increase in particle size may improve the initial discharge capacity. It was observed that at the discharge rate of 1C, the material annealed at 600°C for 8 hours showed the best performance with respect to an average initial discharge capacity, energy density and capacity retention. However, it was found that the initial discharge capacity, the energy density and the capacity retention are poor for highly crystalline, micron sized lithium manganese oxide cathode material. (Abstract shortened by UMI.)
NASA Astrophysics Data System (ADS)
Bodnar, Victoria; Ganeev, Alexander; Gubal, Anna; Solovyev, Nikolay; Glumov, Oleg; Yakobson, Viktor; Murin, Igor
2018-07-01
A pulsed direct current glow discharge time-of-flight mass spectrometry (GD TOF MS) method for the quantification of fluorine in insoluble crystal materials with fluorine doped potassium titanyl phosphate (KTP) KTiOPO4:KF as an example has been proposed. The following parameters were optimized: repelling pulse delay, discharge duration, discharge voltage, and pressure in the discharge cell. Effective ionization of fluorine in the space between sampler and skimmer under short repelling pulse delay, related to the high-energy electron impact at the discharge front, has been demonstrated. A combination of instrumental and mathematical correction approaches was used to cope for the interferences of 38Ar2+ and 1H316O + on 19F+. To maintain surface conductivity in the dielectric KTP crystals and insure its effective sputtering in combined hollow cathode cell, silver suspension applied by the dip-coating method was employed. Fluorine quantification was performed using relative sensitivity factors. The analysis of a reference material and scanning electron microscope-energy dispersive X-ray spectroscopy was used for validation. Fluorine limit of detection by pulsed direct current GD TOF MS was 0.01 mass%. Real sample analysis showed that fluorine seems to be inhomogeneously distributed in the crystals. That is why depth profiling of F, K, O, and P was performed to evaluate the crystals' non-stoichiometry. The approaches designed allow for fluorine quantification in insoluble dielectric materials with minimal sample preparation and destructivity as well as performing depth profiling to assess crystal non-stoichiometry.
NASA Astrophysics Data System (ADS)
Neretti, Gabriele; Cristofolini, Andrea; Borghi, Carlo A.
2014-04-01
The Electro-Hydro-Dynamics (EHD) interaction, induced in atmospheric pressure still air by a surface dielectric barrier discharge (DBD) actuator, had been experimentally studied. A plasma aerodynamic actuator array, able to produce a vectorized jet, with the induced airflow oriented toward the desired direction, had been developed. The array was constituted by a sequence of single surface DBD actuators with kapton as dielectric material. An ac voltage in the range of 0-6 kV peak at 15 kHz had been used. The vectorization had been obtained by feeding the upper electrodes with different voltages and by varying the electrical connections. The lower electrodes had been connected either to ground or to the high voltage source, to produce the desired jet orientation and to avoid plasma formation acting in an undesired direction. Voltage and current measurements had been carried out to evaluate waveforms and to estimate the active power delivered to the discharge. Schlieren imaging allowed to visualize the induced jet and to estimate its orientation. Pitot measurements had been performed to obtain velocity profiles for all jet configurations. A proportional relation between the jet deflection angle and the applied voltage had been found. Moreover, a linear relation had been obtained between the maximum speed in the jet direction and the applied voltage. The active power of the discharge is approximated by both a power law function and an exponential function of the applied voltage.
Electrical Breakdown Phenomena Involving Material Interfaces
2013-06-01
create ozone through chemical reactions involving reactive species created by the electrical discharge [3]. The glow discharge breakdown in such...2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Investigation Of Pre-Ionization And Atmospheric Pulsed Discharge Plasma 5a...growth of the air discharge in the form of a conductive filament consisting of electrons and ions. This filament is created by temporal pulse that
Contaminant removal by wastewater treatment plants in the Stillaguamish River Basin, Washington
Barbash, Jack E.; Moran, Patrick W.; Wagner, Richard J.; Wolanek, Michael
2015-01-01
Human activities in most areas of the developed world typically release nutrients, pharmaceuticals, personal care products, pesticides, and other contaminants into the environment, many of which reach freshwater ecosystems. In urbanized areas, wastewater treatment plants (WWTPs) are critical facilities for collecting and reducing the amounts of wastewater contaminants (WWCs) that ultimately discharge to rivers, coastal areas, and groundwater. Most WWTPs use multiple methods to remove contaminants from wastewater. These include physical methods to remove solid materials (primary treatment), biological and chemical methods to remove most organic matter (secondary treatment), advanced methods to reduce the concentrations of various contaminants such as nitrogen, phosphorus and (or) synthetic organic compounds (tertiary treatment), and disinfection prior to discharge (Metcalf and Eddy, Inc., 1979). This study examined the extent to which 114 organic WWCs were removed by each of three WWTPs, prior to discharge to freshwater and marine ecosystems, in a rapidly developing area in northwestern Washington State. Removal percentages for each WWC were estimated by comparing the concentrations measured in the WWTP influents with those measured in the effluents. The investigation was carried out in the 700-mi2Stillaguamish River Basin, the fifth largest watershed that discharges to Puget Sound (fig. 1).
Clark, Greg M.; Woods, Paul F.
2000-01-01
At most of the stations, and at the stream discharges sampled, the bedload was primarily composed of material greater than 2 millimeters in diameter, the break between sand and gravel. A predominance of sand-sized bedload was noted at only a few stations, and generally only during low stream discharge. The particle-size distribution of bedload sediment at most stations became proportionately coarser as stream discharge increased. During the peak of snowmelt runoff for water years 1999 and 2000, gravel-sized material between 2 and 64 millimeters in diameter comprised more than 70 percent of the bedload transport at most stations. However, at the station on the Coeur d’Alene River at Rose Lake, the bedload was predominantly composed of fine-grained material of less than 1 millimeter in diameter for all measured stream discharges. The slow water velocities at Rose Lake accounted for the predominance of fine-grained sediment transport.
Flowable Conducting Particle Networks in Redox-Active Electrolytes for Grid Energy Storage
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hatzell, K. B.; Boota, M.; Kumbur, E. C.
2015-01-01
This study reports a new hybrid approach toward achieving high volumetric energy and power densities in an electrochemical flow capacitor for grid energy storage. The electrochemical flow capacitor suffers from high self-discharge and low energy density because charge storage is limited to the available surface area (electric double layer charge storage). Here, we examine two carbon materials as conducting particles in a flow battery electrolyte containing the VO2+/VO2+ redox couple. Highly porous activated carbon spheres (CSs) and multi-walled carbon nanotubes (MWCNTs) are investigated as conducting particle networks that facilitate both faradaic and electric double layer charge storage. Charge storage contributionsmore » (electric double layer and faradaic) are distinguished for flow-electrodes composed of MWCNTs and activated CSs. A MWCNT flow-electrode based in a redox-active electrolyte containing the VO2+/VO2+ redox couple demonstrates 18% less self-discharge, 10 X more energy density, and 20 X greater power densities (at 20 mV s-1) than one based on a non-redox active electrolyte. Furthermore, a MWCNT redox-active flow electrode demonstrates 80% capacitance retention, and >95% coulombic efficiency over 100 cycles, indicating the feasibility of utilizing conducting networks with redox chemistries for grid energy storage.« less
Flowable conducting particle networks in redox-active electrolytes for grid energy storage
Hatzell, K. B.; Boota, M.; Kumbur, E. C.; ...
2015-01-09
This paper reports a new hybrid approach toward achieving high volumetric energy and power densities in an electrochemical flow capacitor for grid energy storage. The electrochemical flow capacitor suffers from high self-discharge and low energy density because charge storage is limited to the available surface area (electric double layer charge storage). Here, we examine two carbon materials as conducting particles in a flow battery electrolyte containing the VO 2+/VO 2 + redox couple. Highly porous activated carbon spheres (CSs) and multi-walled carbon nanotubes (MWCNTs) are investigated as conducting particle networks that facilitate both faradaic and electric double layer charge storage.more » Charge storage contributions (electric double layer and faradaic) are distinguished for flow-electrodes composed of MWCNTs and activated CSs. A MWCNT flow-electrode based in a redox-active electrolyte containing the VO 2+/VO 2 + redox couple demonstrates 18% less self-discharge, 10 X more energy density, and 20 X greater power densities (at 20 mV s -1) than one based on a non-redox active electrolyte. Additionally, a MWCNT redox-active flow electrode demonstrates 80% capacitance retention, and >95% coulombic efficiency over 100 cycles, indicating the feasibility of utilizing conducting networks with redox chemistries for grid energy storage.« less
Electrostatic Studies for the 2008 Hubble Service Repair Mission
NASA Technical Reports Server (NTRS)
Buhler, C. R.; Clements, J. S.; Calle, C. I.
2012-01-01
High vacuum triboelectric testing of space materials was required to identify possible Electrostatic Discharge (ESD) concerns for the astronauts in space during electronics board replacement on the Hubble Space Telescope. Testing under high vacuum conditions with common materials resulted in some interesting results. Many materials were able to charge to high levels which did not dissipate quickly even when grounded. Certain materials were able to charge up in contact with grounded metals while others were not. An interesting result was that like materials did not exchange electrostatic charge under high vacuum conditions. The most surprising experimental result is the lack of brush discharges from charged insulators under high vacuum conditions.
How does the anthropogenic activity affect the spring discharge?
NASA Astrophysics Data System (ADS)
Hao, Yonghong; Zhang, Juan; Wang, Jiaojiao; Li, Ruifang; Hao, Pengmei; Zhan, Hongbin
2016-09-01
Karst hydrological process has largely been altered by climate change and human activity. In many places throughout the world, human activity (e.g. groundwater pumping and dewatering from mining) has intensified and surpassed climate change, where human activity becomes the primary factor that affects groundwater system. But it is still largely unclear how the human activity affects spring discharge in magnitude and periodicity. This study investigates the effects of anthropogenic activity on spring discharge, using the Xin'an Springs of China as an example. The Xin'an Spring discharge were divided into two time periods: the pre-development period from 1956 to 1971 and the post-development period from 1972 to 2013. We confirm the dividing time (i.e. 1971) of these two periods using the Wilcoxon rank-sum test. Then the wavelet transform and wavelet coherence were used to analyze the karst hydrological processes for the two periods respectively. We analyze the correlations of precipitation and the Xin'an spring discharge with the monsoons including the Indian Summer Monsoon (ISM) and the West North Pacific Monsoon (WNPM) and the climate teleconnections including El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO), respectively. The results indicated that the spring discharge was attenuated about 19.63% under the influence of human activity in the Xin'an Springs basin. However, human activity did not alter the size of the resonance frequencies between the spring discharge and the monsoons. In contrast, it reinforced the periodicities of the monsoons-driven spring discharge. It suggested that human has adapted to the major climate periodicities, and human activity had the same rhyme with the primary climate periodicity. In return, human activity enhances the correlation between the monsoons and the spring discharge.
RF atmospheric plasma jet surface treatment of paper
NASA Astrophysics Data System (ADS)
Pawlat, Joanna; Terebun, Piotr; Kwiatkowski, Michał; Diatczyk, Jaroslaw
2016-09-01
A radio frequency RF atmospheric pressure plasma jet was used to enhance the wettability of cellulose-based paper of 90 g m-2 and 160 g m-2 grammage as a perspective platform for antibiotic sensitivity tests. Helium and argon were the carrier gases for oxygen and nitrogen; pure water and rapeseed oil were used for goniometric tests. The influence of the flow rate and gas type, the power of the discharge, and distance from the nozzle was examined. The surface structure was observed using an optical microscope. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectra were investigated in order to determine whether cellulose degradation processes occurred. The RF plasma jet allowed us to decrease the surface contact angle without drastic changes in other features of the tested material. Experiments confirmed the significant influence of the distance between the treated sample and reactor nozzle, especially for treatment times longer than 15 s due to the greater concentration of reactive species at the surface of the sample, which decreases with distance—and their accumulation effect with time. The increase of discharge power plays an important role in decreasing the surface contact angle for times longer than 10 s. Higher power had a positive effect on the amount of generated active particles and facilitated the ignition of discharge. However, a too high value can cause a rise in temperature of the material and heat-caused damage.
Truong, Quang Duc; Devaraju, Murukanahally Kempaiah; Tomai, Takaaki; Honma, Itaru
2013-10-23
LiCoPO4 cathode materials have been synthesized by a sol-gel route. X-ray diffraction analysis confirmed that LiCoPO4 was well-crystallized in an orthorhombic structure in the Pmna space group. From the high-resolution transmission electron microscopy (HR-TEM) image, the lattice fringes of {001} and {100} are well-resolved. The HR-TEM image and selected area electron diffraction pattern reveal the highly crystalline nature of LiCoPO4 having an ordered olivine structure. The atom-by-atom structure of LiCoPO4 olivine has been observed, for the first time, using high-angle annular dark-field (HAADF) and annual bright-field scanning transmission electron microscopy. We observed the bright contrast in Li columns in the HAADF images and strong contrast in the ABF images, directly indicating the antisite exchange defects in which Co atoms partly occupy the Li sites. The LiCoPO4 cathode materials delivered an initial discharge capacity of 117 mAh/g at a C/10 rate with moderate cyclic performance. The discharge profile of LiCoPO4 shows a plateau at 4.75 V, revealing its importance as a potentially high-voltage cathode. The direct visualization of atom-by-atom structure in this work represents important information for the understanding of the structure of the active cathode materials for Li-ion batteries.
NASA Astrophysics Data System (ADS)
Hung, Nguyen Thanh; Bae, Joonwon; Kim, Ji Hyeon; Son, Hyung Bin; Kim, Il Tae; Hur, Jaehyun
2018-01-01
We report a new Zn-based nanocomposite anode material (Zn-Ti-C) for lithium-ion batteries synthesized by thermal treatment and a high energy mechanical milling process. X-ray diffraction and high-resolution transmission electron microscopy revealed the formation of active Zn nanoparticles finely dispersed in the hybrid titanium carbide (TiC) and carbon matrix. Electrochemical analyses show that the formation of the TiC and carbon buffer matrix significantly contributed to the improved performance of the Zn-based electrode by mitigating the volume changes of the Zn nanoparticles during the charge/discharge processes. Furthermore, we optimized the stoichiometric ratio of Zn and Ti in terms of specific capacity, cycling performance, and rate capability in the presence of carbon. The material with a 2:1 atomic ratio (ZnTi(2:1)-C) exhibited the best cycle life, with a gravimetric capacity of 363.6 mAh g-1 and a volumetric capacity of 472.7 mAh cm-3 after 300 charge/discharge cycles (78.1% retention). At this ratio, Zn-Ti-C consistently showed the best rate capability measurements up to 3000 mA g-1 (85% of its capacity at 100 mA g-1). Therefore, our Zn-Ti-C composite is a promising alternative negative electrode material for lithium-ion batteries.
Guha, Subhendu; Ovshinsky, Stanford R.
1990-02-02
A method of fabricating doped microcrystalline semiconductor alloy material which includes a band gap widening element through a glow discharge deposition process by subjecting a precursor mixture which includes a diluent gas to an a.c. glow discharge in the absence of a magnetic field of sufficient strength to induce electron cyclotron resonance.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, X. Q.; Sun, X.; Lee, S. J.
In Situ x-ray diffraction studies on Li{sub x}Mn{sub 2}O{sub 4} spinel cathode materials during charge-discharge cycles were carried out by using a synchrotron as x-ray source. Lithium rich (x = 1.03-1.06) spinel materials obtained from two different sources were studied. Three cubic phases with different lattice constants were observed during charge-discharge cycles in all the samples when a Sufficiently low charge-discharge rate (C/10) was used. There are two regions of two-phase coexistence between these three phases, indicating that both phase transitions are first order. The separation of the Bragg peaks representing these three phases varies from sample to sample andmore » also depends on the charge-discharge rate. These results show that the de-intercalation of lithium in lithium-rich spinel cathode materials proceeds through a series of phase transitions from a lithium-rich phase to a lithium-poor phase and finally to a {lambda}-MnO{sub 2} like cubic phase, rather than through a continuous lattice constant contraction in a single phase.« less
A high-capacity carbon prepared from renewable chicken feather biopolymer for supercapacitors
NASA Astrophysics Data System (ADS)
Wang, Qiang; Cao, Qi; Wang, Xianyou; Jing, Bo; Kuang, Hao; Zhou, Ling
2013-03-01
Micropopous chicken feather carbon (CFC) severing as electrode materials for the first time is prepared via the activation with KOH agent to different extents. The structure and electrochemical properties of CFC materials are characterized with N2 adsorption/desorption measurements, X-ray diffraction (XRD), transmission electron microscope (TEM), cyclic voltammetry (CV), galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy (EIS). The obtained results show that CFC activated by KOH with KOH/CFC weight ratio of 4/1 (CFCA4) possesses the specific surface area of 1839 m2 g-1, average micropore diameter of 1.863 nm, and exhibits the highest initial specific capacitance of 302 F g-1 at current density of 1 A g-1 in 1 M H2SO4, and that even after 5000 cycles, CFCA4 specific capacitance is still as high as 253 F g-1. Furthermore, CFCA4 also delivers specific capacitance of 181 F g-1 at current density of 5 A g-1 and 168 F g-1 at current density of 10 A g-1. Accordingly, the microporous activated carbon material derived from chicken feather provides favorable prospect in electrode materials application in supercapacitors.
The assessment of waters ecological state of the Crimea coastal near high-rise construction zones
NASA Astrophysics Data System (ADS)
Vetrova, Natalya; Ivanenko, Tatyana; Mannanov, Emran
2018-03-01
The relevance of our study is determined by the significant level of coastal sea waters pollution by sewage near high-rise construction zones, which determines the violation of the sanitary and hygienic of sea waters `characteristics and limits the possibilities for organizing recreational activities. The purpose of this study is to identify the ecological state of the marine aquatic area by the example of the Western Crimea near high-rise construction zones. The studies confirmed that the recreational and coastal area wastewater is intensely mixed with seawater, as a result, the pollution in the coastal strip of the sea in the area of deep water discharges sharply decrease. This happens because of water rapid rise to the surface and under the influence of the continuous movement of sea water huge masses with deep-water discharge, fresh wastewater is actively mixed with sea water. However, with no doubt, it is inadmissible to discharge sewage into the sea directly from the shore, but only at the estimated distance from the coast. The materials of the article can be useful for the management bodies and organizations involved in monitoring the quality of the coastal zone of the sea, teachers and students of higher educational institutions when assessing the ecological situation of the territories.
NASA Astrophysics Data System (ADS)
Jo, Minsang; Ku, Heesuk; Park, Sanghyuk; Song, Junho; Kwon, Kyungjung
2018-07-01
Li[Ni1/3Co1/3Mn1/3]O2 cathode active materials are synthesized from co-precipitated hydroxide precursors Lix[Ni1/3Co1/3Mn1/3]1-x(OH)2, and the effect of residual Li in the precursors on the lithium-ion battery (LIB) performance of their corresponding cathode active materials is investigated. Three kinds of precursors that contain different amounts of Li are selected depending on different conditions of the solution composition for the co-precipitation and washing process. It is confirmed that the introduction of Li to the precursors reduces the degree of structural perfection by X-ray diffraction analysis. Undesirable cation mixing occurs with the increasing Li content of the precursors, which is inferred from a decline in lattice parameters and the calculated intensity ratio of (003) and (104) peaks. In the voltage range of 3.0-4.3 V, the initial charge/discharge capacities and the rate capability of the cathode active materials are aggravated when Li exists in the precursors. Therefore, it could be concluded that the strict control of Li in a solution for co-precipitation of precursors is necessary in the resynthesis of cathode active materials from spent LIBs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hwang, Sooyeon; Bak, Seong -Min; Kim, Seung Min
2015-08-11
In this work, we investigate the structural modifications occurring at the bulk, subsurface, and surface scales of Li xNi yMn zCo 1-y-zO₂ (NMC; y, z = 0.8, 0.1 and 0.4, 0.3, respectively) cathode materials during the initial charge/discharge. Various analytical tools, such as X-ray diffraction, selected-area electron diffraction, electron energy-loss spectroscopy, and high-resolution electron microscopy, are used to examine the structural properties of the NMC cathode materials at the three different scales. Cut-off voltages of 4.3 and 4.8 V are applied during the electrochemical tests as the normal and extreme conditions, respectively. The high-Ni-content NMC cathode materials exhibit unusual behaviors,more » which is deviate from the general redox reactions during the charge or discharge. The transition metal (TM) ions in the high-Ni-content NMC cathode materials, which are mostly Ni ions, are reduced at 4.8 V, even though TMs are usually oxidized to maintain charge neutrality upon the removal of Li. It was found that any changes in the crystallographic and electronic structures are mostly reversible down to the sub-surface scale, despite the unexpected reduction of Ni ions. However, after the discharge, traces of the phase transitions remain at the edges of the NMC cathode materials at the scale of a few nanometers (i.e., surface scale). This study demonstrates that the structural modifications in NMC cathode materials are induced by charge as well as discharge at multiple length scales. These changes are nearly reversible after the first cycle, except at the edges of the samples, which should be avoided because these highly localized changes can initiate battery degradation.« less
Charging and Discharging Processes of Thermal Energy Storage System Using Phase change materials
NASA Astrophysics Data System (ADS)
Kanimozhi, B., Dr.; Harish, Kasilanka; Sai Tarun, Bellamkonda; Saty Sainath Reddy, Pogaku; Sai Sujeeth, Padakandla
2017-05-01
The objective of the study is to investigate the thermal characteristics of charging and discharge processes of fabricated thermal energy storage system using Phase change materials. Experiments were performed with phase change materials in which a storage tank have designed and developed to enhance the heat transfer rate from the solar tank to the PCM storage tank. The enhancement of heat transfer can be done by using a number of copper tubes in the fabricated storage tank. This storage tank can hold or conserve heat energy for a much longer time than the conventional water storage system. Performance evaluations of experimental results during charging and discharging processes of paraffin wax have discussed. In which heat absorption and heat rejection have been calculated with various flow rate.
NASA Astrophysics Data System (ADS)
Chen, Xuefang; Huang, Ying; Li, Tianpeng; Wei, Chao; Yan, Jing; Feng, Xuansheng
2017-05-01
Novel hierarchical flower-like Sn3O4 assembled by thin Sn3O4 nanosheets, as a kind of mixed-valence tin oxide, decorated on two-dimensional graphene nanosheets has been synthesized via a hydrothermal route and a step solution deoxidization technique. More importantly, as the anode materials for lithium ion batteries, the flower-like Sn3O4/graphene composite has not been investigated in detail. Noticeably, the nanosheets stemming from flower-like Sn3O4 and graphene have been linked together to form a specials three dimensional structure, possessing high active surface area and large enough inner spaces, which is benefit to the diffusion of liquid electrolyte into the electrode materials. In addition, the special structure could provide sufficient free volume to buffer the volume expansion appeared in the process of discharging and charging. The as-prepared flowers-like Sn3O4/graphene displayed excellent electrochemical performance with high capacity and good cycling stability as anode materials for lithium ion batteries. The discharge capacity is 1727 mAh/g in the first cycle at the current density of 60 mA/g. The obtained reversible capacity is 631mAh/g with a coulomb efficiency of 97.04% after 50 cycles. With its better electrochemical properties, the as-prepared flowers-like Sn3O4/graphene has the potential to be the next generation materials as an environmentally benign, abundant, cheap anode materials for lithium ion batteries.
Characterization of Microwave-Induced Electric Discharge Phenomena in Metal–Solvent Mixtures
Chen, Wen; Gutmann, Bernhard; Kappe, C Oliver
2012-01-01
Electric discharge phenomena in metal–solvent mixtures are investigated utilizing a high field density, sealed-vessel, single-mode 2.45 GHz microwave reactor with a built-in camera. Particular emphasis is placed on studying the discharges exhibited by different metals (Mg, Zn, Cu, Fe, Ni) of varying particle sizes and morphologies in organic solvents (e.g., benzene) at different electric field strengths. Discharge phenomena for diamagnetic and paramagnetic metals (Mg, Zn, Cu) depend strongly on the size of the used particles. With small particles, short-lived corona discharges are observed that do not lead to a complete breakdown. Under high microwave power conditions or with large particles, however, bright sparks and arcs are experienced, often accompanied by solvent decomposition and formation of considerable amounts of graphitized material. Small ferromagnetic Fe and Ni powders (<40 μm) are heated very rapidly in benzene suspensions and start to glow in the microwave field, whereas larger particles exhibit extremely strong discharges. Electric discharges were also observed when Cu metal or other conductive materials such as silicon carbide were exposed to the microwave field in the absence of a solvent in an argon or nitrogen atmosphere. PMID:24551491
Characterization of microwave-induced electric discharge phenomena in metal-solvent mixtures.
Chen, Wen; Gutmann, Bernhard; Kappe, C Oliver
2012-02-01
Electric discharge phenomena in metal-solvent mixtures are investigated utilizing a high field density, sealed-vessel, single-mode 2.45 GHz microwave reactor with a built-in camera. Particular emphasis is placed on studying the discharges exhibited by different metals (Mg, Zn, Cu, Fe, Ni) of varying particle sizes and morphologies in organic solvents (e.g., benzene) at different electric field strengths. Discharge phenomena for diamagnetic and paramagnetic metals (Mg, Zn, Cu) depend strongly on the size of the used particles. With small particles, short-lived corona discharges are observed that do not lead to a complete breakdown. Under high microwave power conditions or with large particles, however, bright sparks and arcs are experienced, often accompanied by solvent decomposition and formation of considerable amounts of graphitized material. Small ferromagnetic Fe and Ni powders (<40 μm) are heated very rapidly in benzene suspensions and start to glow in the microwave field, whereas larger particles exhibit extremely strong discharges. Electric discharges were also observed when Cu metal or other conductive materials such as silicon carbide were exposed to the microwave field in the absence of a solvent in an argon or nitrogen atmosphere.
Screening of advanced cladding materials and UN-U3Si5 fuel
NASA Astrophysics Data System (ADS)
Brown, Nicholas R.; Todosow, Michael; Cuadra, Arantxa
2015-07-01
In the aftermath of Fukushima, a focus of the DOE-NE Advanced Fuels Campaign has been the development of advanced nuclear fuel and cladding options with the potential for improved performance in an accident. Uranium dioxide (UO2) fuels with various advanced cladding materials were analyzed to provide a reference for cladding performance impacts. For advanced cladding options with UO2 fuel, most of the cladding materials have some reactivity and discharge burn-up penalty (in GWd/t). Silicon carbide is one exception in that the reactor physics performance is predicted to be very similar to zirconium alloy cladding. Most candidate claddings performed similar to UO2-Zr fuel-cladding in terms of safety coefficients. The clear exception is that Mo-based materials were identified as potentially challenging from a reactor physics perspective due to high resonance absorption. This paper also includes evaluation of UN-U3Si5 fuels with Kanthal AF or APMT cladding. The objective of the U3Si5 phase in the UN-U3Si5 fuel concept is to shield the nitride phase from water. It was shown that UN-U3Si5 fuels with Kanthal AF or APMT cladding have similar reactor physics and fuel management performance over a wide parameter space of phase fractions when compared to UO2-Zr fuel-cladding. There will be a marginal penalty in discharge burn-up (in GWd/t) and the sensitivity to 14N content in UN ceramic composites is high. Analysis of the rim effect due to self-shielding in the fuel shows that the UN-based ceramic fuels are not expected to have significantly different relative burn-up distributions at discharge relative to the UO2 reference fuel. However, the overall harder spectrum in the UN ceramic composite fuels increases transuranic build-up, which will increase long-term activity in a once-thru fuel cycle but is expected to be a significant advantage in a fuel cycle with continuous recycling of transuranic material. It is recognized that the fuel and cladding properties assumed in these assessments are preliminary, and that additional data are necessary for these materials, most significantly under irradiation.
NASA Astrophysics Data System (ADS)
Ciszewski, Mateusz; Benke, Grzegorz; Leszczyńska-Sejda, Katarzyna; Kopyto, Dorota
2017-11-01
A new energy storage material based on molybdate active species has been presented. Molybdenum seems to be a perspective material in supercapacitors because of numerous possible metal oxidation states, electrolyte storage by means of various chemical reactions and availability in comparison to other refractory metals. Material synthesized within this research was composed of reduced graphene oxide matrix and peroxomolybdate(VI)-citrate active dimers. It was showed that peroxomolybdate(VI)-citrate structure enhanced electrochemical activity of symmetric supercapacitor. Simple methodology was used to synthesize a composite with pH adjustment as the key step. The specific capacity calculated from galvanostatic charge/discharge curves was as high as 250 F/g. Material was distinguished by good cyclability with 5% capacity loss after 1000 cycles. The increase in charge transfer resistance, induced by metal-oxygen compound within the carbon matrix was relatively low, compared to parent reduced graphene oxide. Amorphous structure of peroxomolybdate(VI)-modified material was observed with slight increase in the interlayer distance in comparison to parent reduced graphene oxide. The height and lateral size of crystallites were also determined. Significant decrease in the specific surface area of peroxomolybdate(VI)-modified composite was observed, in comparison to the parent reduced graphene oxide.
Advanced Electrode Materials for High Energy Next Generation Li ion Batteries
NASA Astrophysics Data System (ADS)
Hayner, Cary Michael
Lithium ion batteries are becoming an increasingly ubiquitous part of modern society. Since their commercial introduction by Sony in 1991, lithium-ion batteries have grown to be the most popular form of electrical energy storage for portable applications. Today, lithium-ion batteries power everything from cellphones and electric vehicles to e-cigarettes, satellites, and electric aircraft. Despite the commercialization of lithium-ion batteries over twenty years ago, it remains the most active field of energy storage research for its potential improvement over current technology. In order to capitalize on these opportunities, new materials with higher energy density and storage capacities must be developed. Unfortunately, most next-generation materials suffer from rapid capacity degradation or severe loss of capacity when rapidly discharged. In this dissertation, the development of novel anode and cathode materials for advanced high-energy and high-power lithium-ion batteries is reported. In particular, the application of graphene-based materials to stabilize active material is emphasized. Graphene, a unique two-dimensional material composed of atomically thin carbon sheets, has shown potential to address unsatisfactory rate capability, limited cycling performance and abrupt failure of these next-generation materials. This dissertation covers four major subjects: development of silicon-graphene composites, impact of carbon vacancies on graphene high-rate performance, iron fluoride-graphene composites, and ternary iron-manganese fluoride synthesis. Silicon is considered the most likely material to replace graphite as the anode active material for lithium-ion batteries due to its ability to alloy with large amounts of lithium, leading to significantly higher specific capacities than the graphite standard. However, Si also expands in size over 300% upon lithiation, leading to particle fracture and isolation from conductive support, resulting in cell failure within a few charge-discharge cycles. To stabilize silicon materials, composites of silicon nanoparticles were dispersed between graphene sheets and supported by a 3-D network of graphite formed by reconstituted regions of graphene stacks. These free-standing, self-supported composites exhibited excellent Li-ion storage capacities higher than 2200 mAh/g and good cycling stability. In order to improve the advantages graphene can provide as a 3-D scaffold, carbon vacancies were introduced into the basal planes via an acid-oxidation treatment. These vacancies markedly enhance the rate performance of graphene materials as well as silicon-graphene composites. Silicon-graphene composites containing carbon vacancies achieved high accessible storage capacities at fast charge/discharge rates that rival supercapacitor performance while maintaining good cycling stability. Optimal carbon vacancy size and density were determined. Graphene composites were also formed with iron trifluoride (FeF 3), a high-energy cathode material with ability to store up to 712 mAh/g capacity, over 3X more than current state-of-the-art cathode materials. A facile route that combines co-assembly and photothermal reduction was developed to synthesize free-standing, flexible FeF3/graphene papers. The papers contained a uniform dispersion of FeF3 nanoparticles (< 40 nm) and open ion diffusion channels in the porous, conducting network of graphene sheets that resulted in a flexible paper cathode with high charge storage capacity, rate, and cycling performance, without the need for other carbon additives or binder. Free-standing FeF3/graphene composites showed a high storage capacity of >400 mAh/g and improved cycling performance compared to bare FeF3 particles. Lastly, novel ternary iron-manganese fluoride (FexMn 1-xF2) cathode materials were synthesized via a convenient, bottom-up solution-phase synthesis which allowed control of particle size, shape, and surface morphology. The synthesized materials exhibited nanoscale features with average particle size of 20-40 nm. These ternary metal composites exhibited key, desirable properties for next-generation Li-ion battery cathode materials. The described process constituted a translatable route to large-scale production of ternary metal fluoride nanoparticles.
Lin, Frances; Chaboyer, Wendy; Wallis, Marianne; Miller, Anne
2013-08-01
Patient flow from intensive care to acute care units is often problematic and many discharges from intensive care to acute care are unsuccessful on the first attempt. The aim of this study was to explore the factors that influence intensive care patient discharge. This ethnographic study was undertaken in an Australian metropolitan tertiary hospital that had a 14-bed level 3 intensive care unit. Intensive care and acute care unit medical and nursing staff, and other hospital staff who were involved in the intensive care patient discharge process participated in this study. A total of 28 discharges were observed, and 56 one on one interviews were conducted. Data collection techniques including direct observations, semi-structured interviews, and collection of existing documents were used. Activity theory was the theoretical framework that underpinned this study. Three patient activity systems were identified: intensive care patient discharge activity, acute care unit accepting patient activity, and hospital bed management activity. Analysis of the interactions among these activity systems revealed conflicting objects (goals), communication breakdowns, and teamwork issues. Discharge delay was found to be a significant problem, which was associated with limited acute care unit bed availability. Strategies to improve acute care unit bed availability are needed. Routine after-hours ICU discharge could raise patient safety concerns which need to be considered. All team members' input in discharge decision making should be encouraged. Problems identified in clinical handover call for actions to change the handover practice. Activity theory successfully guided the study by providing a practical and descriptive framework for the study, facilitating the understanding of the interrelationships among the activity systems. Copyright © 2012 Elsevier Ltd. All rights reserved.
Effect of KOH concentration and anions on the performance of an NiH 2 battery positive plate
NASA Astrophysics Data System (ADS)
Vaidyanathan, Hari; Robbins, Kathleen; Rao, Gopalakrishna M.
The capacity and voltage behavior of electrochemically impregnated sintered nickel positive plates was examined by galvanostatic charging and discharging in a flooded electrolyte cell. Three different concentrations of potassium hydroxide (KOH) (40%,31% and 26%) and 31% KOH containing dissolved nitrate, sulfate, or silicate were investigated. The end-of-charge voltage at {C}/{10} charge and at 10°C showed the following order: 40% KOH > 31 % KOH alone, and in the presence of the anions > 26% KOH. The mid-discharge voltage at {C}/{2} discharge was higher in 26% KOH, almost the same for 31%Ao KOH with and without the added contaminants, and much lower for 40% KOH. The plate capacity was marginally affected by cycling in all cases except for 40% KOH, where the capacity declined after 1000 cycles at 80% depth-of-discharge (DOD). At the end of cycling all the plates tested experienced a weight loss, except in the case of 31% KOH, as a result of active material extrusion. Cyclic voltammetry of miniature electrodes in 31% KOH showed that the cathodic peak potentials are less polarized at -5 °C (compared to 25 °C) in the presence and absence of silicate. This indicates a slightly higher voltage during discharge in an NiH 2 battery. Furthermore, the features of the current-potential profile were practically unchanged in the presence of silicate.
Metal sulfide for battery applications
NASA Astrophysics Data System (ADS)
Guidotti, Ronald A.
1988-08-01
A number of metal sulfides can be used in batteries as a cathode (reducible) material as part of an electrochemical couple to provide energy. There are a number of physical and chemical characteristics that can be evaluated for screening potential candidates for use in batteries. These include: cell potential vs. Li, thermal and chemical stability, electrical conductivity, allotropic form (phase), reaction kinetics during discharge, type of discharge mechanism, and material rechargeability. These are reviewed in general, with emphasis on sulfides of copper, iron, and molybdenum which are currently being used as cathodes in Li and Li-alloy batteries. The presence of impurities can adversely impact performance when naturally occurring sulfide minerals are used for battery applications. Sandia National Laboratories uses natural pyrite (FeS2) for its high-temperature, thermally activated Li(Si)/FeS2 batteries. The purification and processing procedures for the FeS2 involves both chemical and physical methods. Flotation was found to yield comparable results as HF leaching for removal of silica, but without the negative health and environmental concerns associated with this technique.
TROPICAL COLLECTOR URCHIN, TRIPNEUSTES ...
This document describes a fertilization method to estimate the chronic toxicity of effluents and receiving waters to the gametes of the tropical sea urchin (Tripneustes gratilla). This toxicity test measures the fertilizing capacity of sperm following a static, non-renewal 60-minute exposure and a subsequent 20-minute exposure period following the addition of eggs. The purpose of the test is to determine the concentrations of a test substance diluted in sea water that reduce fertilization of exposed gametes relative to that of the control. This method was developed to provide an assessment of the toxicity of materials discharged into the marine environment, using biota indigenous to tropical Pacific regions, including Hawaii. This method provides an assessment of the toxicity to indigenous biota of materials discharged into the tropical Pacific marine environment. The use of this method contributes to risk based determinations, and the scientific foundation they provide for regulatory criteria at the state, regional or national levels. General impacts from this contribution include improved understanding by managers and scientists of links between human activities, natural dynamics, ecological stressors and ecosystem condition.
Porous Graphene Sponge Additives for Lithium Ion Batteries with Excellent Rate Capability.
Cheng, Qian
2017-04-19
Rate capability as well as power performance of lithium ion batteries (LiBs) is becoming more and more important, especially as the application targets of LiBs move from mobile devices to transportation, such as EVs and HEVs. In this research, we report porous graphene sponge additives for both anode and cathode materials for better rate performance. The charge capacity retention improved from 56% to 77% at 6C and from 7% to 45% at 10C with 0.5 wt% added to the anode, while the discharge capacity retention at the 6C rate improved from 43% to 76% and the 10C rate discharge improved from 16% to 40% with the same amount of MG added to the cathode. The cyclability at high rate was also improved with the MG additive. Moreover, preparation of the MG was facile, cost-effective, and compatible with commercially available active materials. These results demonstrate the suitability of MG for use with LiB additives to ensure better rate capability and high rate cyclability.
Mobility aid for blind figure skaters
NASA Astrophysics Data System (ADS)
Acerbi, A.; Graffigna, J. P.; Polimeni, G.; Fernández, H. H.
2007-11-01
This work is developed within the scope of rehabilitation technology to enable blind and visually impaired persons read non-Braille material commonly available in digital form to normal-vision readers. This approach, therefore, tries to broaden the reaching capacity for these persons and, thus, allow for better inclusion in social, work, educative and even leisure activities. Specifically, it is devised for reading any kind of text in digital form --books, files, documents, Internet information and exchanges, etc.-- that can be loaded in a PC to be later read on the devised Braille reading line. It consists of a string-like platform of electrodes that simulate, through tactile electrostimulation, the letter characters displayed in Braille fashion. Finger-tip feeling from these electric discharges is caused by stimulating the skin nerve receptors underneath the tip. These electric discharges produce a similar effect as when reading embossed-type characters of traditional Braille-relief paper material. After design and development, experiences were made with blind persons, with fairly satisfactory results. At present, further work is under way in order to improve the system.
Preliminary Studies on Oleochemical Wastewater Treatment using Submerged Bed Biofilm Reactor (SBBR)
NASA Astrophysics Data System (ADS)
Ismail, Z.; Mahmood, N. A. N.; Ghafar, U. S. A.; Umor, N. A.; Muhammad, S. A. F.
2017-06-01
Wastewater discharge from the industry into water sources is one of the main reason for water pollution. The oleochemicals industry effluent produces high content of chemical oxygen demand (COD) with value between 6000-20,000 ppm. Effective treatment is required before wastewater effluent is discharged to environment. The aim of the study is to develop submerged bed biofilm reactor (SBBR) with packing materials in the cosmoball® carrier. Water quality such as chemical oxygen demands (COD), turbidity and pH were analysed. The result shows that the initial COD of 6000 ppm was reduced below 200 ppm. The optimum conditions for SBBR were obtained when green sponges used as packing material in cosmoball® effluent flowrate set at 100 mL/min; 1:1 ratio of cosmoball® volume to reactor volume and 1:1 ratio of active sludge (mixed culture) volume to reactor volume. Turbidity and pH were recorded with 9.0 NTU and 7.0 respectively, which indicated that SBBR is feasible as an alternative for conventional biological treatment in oleochemical industry.
46 CFR 153.333 - Cargo pump discharge pressure gauge.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo pump discharge pressure gauge. 153.333 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Pumprooms § 153.333 Cargo pump discharge pressure gauge. Each cargo pump within a pump-room must...
46 CFR 153.333 - Cargo pump discharge pressure gauge.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Cargo pump discharge pressure gauge. 153.333 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Pumprooms § 153.333 Cargo pump discharge pressure gauge. Each cargo pump within a pump-room must...
46 CFR 153.333 - Cargo pump discharge pressure gauge.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 5 2014-10-01 2014-10-01 false Cargo pump discharge pressure gauge. 153.333 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Pumprooms § 153.333 Cargo pump discharge pressure gauge. Each cargo pump within a pump-room must...
46 CFR 153.333 - Cargo pump discharge pressure gauge.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 5 2012-10-01 2012-10-01 false Cargo pump discharge pressure gauge. 153.333 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Pumprooms § 153.333 Cargo pump discharge pressure gauge. Each cargo pump within a pump-room must...
46 CFR 153.333 - Cargo pump discharge pressure gauge.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 5 2013-10-01 2013-10-01 false Cargo pump discharge pressure gauge. 153.333 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Pumprooms § 153.333 Cargo pump discharge pressure gauge. Each cargo pump within a pump-room must...
Du, Zhijia; Wood, David L.; Daniel, Claus; ...
2017-02-09
We present that increasing electrode thickness, thus increasing the volume ratio of active materials, is one effective method to enable the development of high energy density Li-ion batteries. In this study, an energy density versus power density optimization of LiNi 0.8Co 0.15Al 0.05O 2 (NCA)/graphite cell stack was conducted via mathematical modeling. The energy density was found to have a maximum point versus electrode thickness (critical thickness) at given discharging C rates. The physics-based factors that limit the energy/power density of thick electrodes were found to be increased cell polarization and underutilization of active materials. The latter is affected bymore » Li-ion diffusion in active materials and Li-ion depletion in the electrolyte phase. Based on those findings, possible approaches were derived to surmount the limiting factors. Finally, the improvement of the energy–power relationship in an 18,650 cell was used to demonstrate how to optimize the thick electrode parameters in cell engineering.« less
The simultaneous discharge of liquid and grains from a silo
NASA Astrophysics Data System (ADS)
Cervantes-Álvarez, A. M.; Hidalgo-Caballero, S.; Pacheco-Vázquez, F.
2018-04-01
The flow rate of water through an orifice at the bottom of a container depends on the hydrostatic pressure whereas for a dry granular material it is nearly constant. But what happens during the simultaneous discharge of grains and liquid from a silo? By measuring the flow rate as a function of time, we found that (i) different regimes appear, going from the constant flow rate to a hydrostatic-like discharge depending on the aperture size and grain diameter, (ii) the mixed material is always discharged faster than dry grains but slower than liquid, (iii) for the mixture, the liquid level drops faster than the grain level, but they are always linearly proportional to one another, and (iv) a sudden growth in the flow rate happens during the transition from a biphasic discharge to a single phase discharge. These results are associated to the competition between the decrease in hydrostatic pressure above the granular bed and the hydrodynamic resistance. A model combining Darcy's law with Bernoulli and mass conservation equations is proposed, and the numerical results are in good agreement with experiments.
NASA Astrophysics Data System (ADS)
Yang, Li; Ren, Fengzhagn; Feng, Qigao; Xu, Guangri; Li, Xiaobo; Li, Yuanchao; Zhao, Erqing; Ma, Jignjign; Fan, Shumin
2018-04-01
The structural and electrochemical performance of Cu-doped, Li[Ni1/3-xCo1/3 Mn1/3Cux]O2 (x = 0-0.1) cathode materials obtained by means of the sol-gel method are discussed; we used critic acid as gels and spent mixed batteries as the raw materials. The effects of the sintering time, sintering temperature, and Cu doping ratio on the phase structure, morphology, and element composition and the behavior in a galvanostatical charge/discharge test have been systemically studied. The results show that the Cu-doped material exhibits better galvanostatic charge/discharge cycling performance. At 0.2 C, its original discharge specific capacity is 180.4 mAh g-1 and its Coulomb efficiency is 90.3%. The Cu-doped material demonstrate an outstanding specific capacity at 0.2 C, 0.5 C, and 2.0 C. In comparison with the original capacities of 178 mAh g-1, 159.5 mAh g-1, and 119.4 mAh g-1, the discharge capacity after 50 cycles is 160.8 mAh g-1, 143.4 mAh g-1, and 90.1 mAh g-1, respectively. This obvious improvement relative to bare Li[Ni1/3Co1/3Mn1/3]O2 cathode materials arises from an enlarged Li layer spacing and a reduced degree of cation mixing. Therefore, Cu-doped cathode materials have obvious advantages in the field of lithium-ion batteries and their applications.
NASA Astrophysics Data System (ADS)
Yang, Li; Ren, Fengzhagn; Feng, Qigao; Xu, Guangri; Li, Xiaobo; Li, Yuanchao; Zhao, Erqing; Ma, Jignjign; Fan, Shumin
2018-07-01
The structural and electrochemical performance of Cu-doped, Li[Ni1/3-xCo1/3 Mn1/3Cux]O2 ( x = 0-0.1) cathode materials obtained by means of the sol-gel method are discussed; we used critic acid as gels and spent mixed batteries as the raw materials. The effects of the sintering time, sintering temperature, and Cu doping ratio on the phase structure, morphology, and element composition and the behavior in a galvanostatical charge/discharge test have been systemically studied. The results show that the Cu-doped material exhibits better galvanostatic charge/discharge cycling performance. At 0.2 C, its original discharge specific capacity is 180.4 mAh g-1 and its Coulomb efficiency is 90.3%. The Cu-doped material demonstrate an outstanding specific capacity at 0.2 C, 0.5 C, and 2.0 C. In comparison with the original capacities of 178 mAh g-1, 159.5 mAh g-1, and 119.4 mAh g-1, the discharge capacity after 50 cycles is 160.8 mAh g-1, 143.4 mAh g-1, and 90.1 mAh g-1, respectively. This obvious improvement relative to bare Li[Ni1/3Co1/3Mn1/3]O2 cathode materials arises from an enlarged Li layer spacing and a reduced degree of cation mixing. Therefore, Cu-doped cathode materials have obvious advantages in the field of lithium-ion batteries and their applications.
Horn, Susan D.; Corrigan, John D.; Beaulieu, Cynthia L.; Bogner, Jennifer; Barrett, Ryan S.; Giuffrida, Clare G.; Ryser, David K.; Cooper, Kelli; Carroll, Deborah M.; Deutscher, Daniel
2015-01-01
Objective To examine associations of patient and injury characteristics, inpatient rehabilitation therapy activities, and neurotropic medications with outcomes at discharge and 9 months post-discharge for patients with traumatic brain injury (TBI) Design Prospective, longitudinal observational study Setting 10 inpatient rehabilitation centers (9 US, 1 Canada) Participants Consecutive patients (n=2130) enrolled between 2008 and 2011, admitted for inpatient rehabilitation after an index TBI injury Interventions Not applicable Main Outcome Measures Rehabilitation length of stay, discharge to home, and Functional Independence Measure (FIM) at discharge and 9 months post-discharge Results The admission FIM Cognitive score was used to create 5 relatively homogeneous subgroups for subsequent analysis of treatment outcomes. Within each subgroup, significant associations were found between outcomes and patient and injury characteristics, time spent in therapy activities, and medications used. Patient and injury characteristics explained on average 35.7% of the variation in discharge outcomes and 22.3% in 9-month outcomes. Adding time spent and level of effort in therapy activities, as well as percent of stay using specific medications, explained approximately 20.0% more variation for discharge outcomes and 12.9% for 9-month outcomes. After patient, injury, and treatment characteristics were used to predict outcomes, center differences added only approximately 1.9% additional variance explained. Conclusions At discharge, greater effort during therapy sessions, time spent in more complex therapy activities, and use of specific medications were associated with better outcomes for patients in all admission FIM Cognitive subgroups. At 9 months post-discharge, similar but less pervasive associations were observed for therapy activities, but not classes of medications. Further research is warranted to examine more specific combinations of therapy activities and medications that are associated with better outcomes. PMID:26212406
Brown, Christiane; Fraser, Julia E; Inness, Elizabeth L; Wong, Jennifer S; Middleton, Laura E; Poon, Vivien; McIlroy, William E; Mansfield, Avril
2014-01-01
To determine whether attending an aerobic fitness program during inpatient stroke rehabilitation is associated with increased participation in physical activity after discharge. This was a prospective cohort study. Patients who received inpatient stroke rehabilitation and were discharged into the community (n = 61; mean age, 65 years) were recruited. Thirty-five participants attended a standardized aerobic fitness program during inpatient rehabilitation, whereas 26 did not. The Physical Activity Scale for Individuals with Physical Disabilities (PASIPD) and adherence to the American College of Sports Medicine (ACSM) guidelines were assessed up to 6 months after discharge. Participants in the fitness group had PASIPD scores and adherence to ACSM guidelines similar to those of participants in the nonfitness group up to 6 months after discharge. There was no significant correlation between volume of exercise performed during the inpatient program and amount of physical activity after discharge. Participation in an inpatient fitness program did not increase participation in physical activity after discharge in individuals with stroke. A new model of care that encourages patients to pursue physical activity after discharge and reduces the potential barriers to participation should be developed.
The Effects of Insulator Wall Material on Hall Thruster Discharges: A Numerical Study
2001-01-03
An investigation was undertaken to determine how the choice of insulator wall material inside a Hall thruster discharge channel might affect thruster operation. In order to study this, an evolved hybrid particle-in-cell (PIC) numerical Hall thruster model, HPHall, was used. HPHall solves a set of quasi-one-dimensional fluid equations for electrons and tracks heavy particles using a PIC method.
A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions
NASA Technical Reports Server (NTRS)
Reid, Concha M.; Bennett, William R.
2010-01-01
NASAs Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair Lunar Lander and the Extravehicular Activities (EVA) advanced Lunar surface spacesuit. These customers require safe, reliable batteries with extremely high specific energy as compared to state-of-the-art. The specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery-level at 0 degrees Celsius ( C) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation between 0 and 30 C and 200 cycles are targeted. Electrode materials that were considered include layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. Advanced cell chemistry options were evaluated with respect to multiple quantitative and qualitative attributes while considering their projected performance at the end of the available development timeframe. Following a rigorous ranking process, a chemistry that combines a lithiated nickel manganese cobalt oxide Li(LiNMC)O2 cathode with a silicon-based composite anode was selected as the technology that can potentially offer the best combination of safety, specific energy, energy density, and likelihood of success.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Jie; Wu, Jianzhong; Wu, Zexing
In this paper, 3D-transition binary metal oxides have been considered as promising anode materials for lithium-ion batteries with improved reversible capacity, structural stability and electronic conductivity compared with single metal oxides. Here, carbon nanotube supported NiCo 2O 4 nanoparticles (NiCo 2O 4/CNT) with 3D hierarchical hollow structure are fabricated via a simple one-pot method. The NiCo 2O 4 nanoparticles with interconnected pores are consists of small nanocrystals. When used as anode material for the lithium-ion battery, NiCo 2O 4/CNT exhibits enhanced electrochemical performance than that of Co 3O 4/CNT and NiO/CNT. Moreover, ultra-high discharge/charge stability was obtained for 4000 cyclesmore » at a current density of 5 A g –1. The superior battery performance of NiCo 2O 4 nanoparticles is probably attributed to the special structural features and physical characteristics, including integrity, hollow structure with interconnected pores, which providing sufficient accommodation for the volume change during charge/discharge process. Besides, the consisting of ultra-small crystals enhanced the utility of active material, and intimate interaction with CNTs improved the electron-transfer rate.« less
Wang, Jie; Wu, Jianzhong; Wu, Zexing; ...
2017-05-17
In this paper, 3D-transition binary metal oxides have been considered as promising anode materials for lithium-ion batteries with improved reversible capacity, structural stability and electronic conductivity compared with single metal oxides. Here, carbon nanotube supported NiCo 2O 4 nanoparticles (NiCo 2O 4/CNT) with 3D hierarchical hollow structure are fabricated via a simple one-pot method. The NiCo 2O 4 nanoparticles with interconnected pores are consists of small nanocrystals. When used as anode material for the lithium-ion battery, NiCo 2O 4/CNT exhibits enhanced electrochemical performance than that of Co 3O 4/CNT and NiO/CNT. Moreover, ultra-high discharge/charge stability was obtained for 4000 cyclesmore » at a current density of 5 A g –1. The superior battery performance of NiCo 2O 4 nanoparticles is probably attributed to the special structural features and physical characteristics, including integrity, hollow structure with interconnected pores, which providing sufficient accommodation for the volume change during charge/discharge process. Besides, the consisting of ultra-small crystals enhanced the utility of active material, and intimate interaction with CNTs improved the electron-transfer rate.« less
NASA Astrophysics Data System (ADS)
Rauhala, Taina; Leis, Jaan; Kallio, Tanja; Vuorilehto, Kai
2016-11-01
The use of carbide-derived carbon (CDC) as the positive electrode material for lithium-ion capacitors (LICs) is investigated. CDC based LIC cells are studied utilizing two different negative electrode materials: graphite and lithium titanate Li4Ti5O12 (LTO). The graphite electrodes are prelithiated before assembling the LICs, and LTO containing cells are studied with and without prelithiation. The rate capability and cycle life stability during 1000 cycles are evaluated by galvanostatic cycling at current densities of 0.4-4 mA cm-2. The CDC shows a specific capacitance of 120 F g-1 in the organic lithium-containing electrolyte, and the LICs demonstrate a good stability over 1000 charge-discharge cycles. The choice of the negative electrode is found to have an effect on the utilization of the CDC positive electrode during cycling and on the specific energy of the device. The graphite/CDC cell delivers a maximum specific discharge energy of 90 Wh kg-1 based on the total mass of active material in the cell. Both the prelithiated and non-prelithiated LTO/CDC cells show a specific energy of around 30 Wh kg-1.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Name, No
This renewal application for the Industrial Wastewater Reuse Permit (IWRP) WRU-I-0160-01 at Idaho National Laboratory (INL), Materials and Fuels Complex (MFC) Industrial Waste Ditch (IWD) and Industrial Waste Pond (IWP) is being submitted to the State of Idaho, Department of Environmental Quality (DEQ). This application has been prepared in compliance with the requirements in IDAPA 58.01.17, Recycled Water Rules. Information in this application is consistent with the IDAPA 58.01.17 rules, pre-application meeting, and the Guidance for Reclamation and Reuse of Municipal and Industrial Wastewater (September 2007). This application is being submitted using much of the same information contained in themore » initial permit application, submitted in 2007, and modification, in 2012. There have been no significant changes to the information and operations covered in the existing IWRP. Summary of the monitoring results and operation activity that has occurred since the issuance of the WRP has been included. MFC has operated the IWP and IWD as regulated wastewater land treatment facilities in compliance with the IDAPA 58.01.17 regulations and the IWRP. Industrial wastewater, consisting primarily of continuous discharges of nonhazardous, nonradioactive, routinely discharged noncontact cooling water and steam condensate, periodic discharges of industrial wastewater from the MFC facility process holdup tanks, and precipitation runoff, are discharged to the IWP and IWD system from various MFC facilities. Wastewater goes to the IWP and IWD with a permitted annual flow of up to 17 million gallons/year. All requirements of the IWRP are being met. The Operations and Maintenance Manual for the Industrial Wastewater System will be updated to include any new requirements.« less
Raman structural studies of the nickel electrode
NASA Technical Reports Server (NTRS)
Cornilsen, Bahne C.
1994-01-01
The objectives of this investigation have been to define the structures of charged active mass, discharged active mass, and related precursor materials (alpha-phases), with the purpose of better understanding the chemical and electrochemical reactions, including failure mechanisms and cobalt incorporation, so that the nickel electrode may be improved. Although our primary tool has been Raman spectroscopy, the structural conclusions drawn from the Raman data have been supported and augmented by three other analysis methods: infrared spectroscopy, powder X-ray Diffraction (XRD), and x-ray absorption spectroscopy (in particular EXAFS, Extended X-ray Absorption Fine Structure spectroscopy).
Super Dielectric Material Based Capacitors: Punched Membrane/Gel
NASA Astrophysics Data System (ADS)
Petty, C. W.; Phillips, J.
2018-05-01
Extensive testing showed, as predicted, that punched membranes, filled with a gel containing aqueous salt solutions, behave as superdielectric materials (SDM). Punched membrane superdielectrics employed herein consisted of a commercial cellulose based membrane material, Celgard 16 μ thick, a material frequently used as a separator material in supercapacitors, into which macroscopic holes (ca. 2.5 mm) were punched with a laser cutter, and the holes subsequently filled with a gel-like material composed of fumed silica, NaCl and water. The gross dielectric constants measured, generally > 105, and the energy densities, > 40 J/cm3 during slow discharge, were in the range expected for superdielectric materials. The measured capacitance and energy density tracked the number of holes punched/area filled with the dielectric gel. Also, the observed power law decrease in all parameters including energy, power and capacitance, followed the same trends observed in other classes of SDM. Control studies included testing dielectrics composed of Celgard into which no holes were punched, but the SDM gel spread, also produced values consistent with the SDM model: no measurable capacitance using the standard protocol. Finally, the values measured suggest these materials rival the energy density of some common battery types at low discharge rates, and surpass the best commercial supercapacitors at low discharge rates.
NASA Astrophysics Data System (ADS)
Dagg, M. J.; Bianchi, T.; McKee, B.; Powell, R.
2008-07-01
In June 2003, we conducted a two-part field exercise to examine biogeochemical characteristics of water in the lower Mississippi river during the 4 days prior to discharge and in the Mississippi river plume over 2 days after discharge. Here we describe the fates of materials immediately after their discharge through Southwest Pass of the Mississippi delta into the northern Gulf of Mexico. Changes in surface water properties immediately after discharge were much larger and more rapid than changes prior to discharge. Total suspended matter (TSM) declined, probably due to sinking, dissolved macronutrients were rapidly diminished by mixing and biological uptake, and phytoplankton populations increased dramatically, and then declined. This decline appeared to begin at salinities of approximately 10 and was nearly complete by 15. A large increase in dissolved organic carbon (DOC) occurred over approximately the same salinity range. Weak winds (<2 m s -1) during and preceding this cruise apparently led to the formation of an extensive but thin freshwater lens from the river. This lens spread widely without much mixing, and the bloom of phytoplankton that occurred between discharge and a salinity of 10 was probably a freshwater community seeded from the lower river. Phytoplankton bloomed for a period of about 1-2 days, then declined dramatically, apparently releasing large amounts of DOC. Macronutrients from the river were utilized by the river phytoplankton community in the extensive freshwater lens. This contrasted with the more typical situation in which river nutrients stimulate a marine phytoplankton bloom at salinities in the mid-20s. We concluded that the direct effects of dissolved and particulate bio-reactive materials discharged by the Mississippi river were spatially restricted at this time to low-salinity water, at least as surface phenomena. After being transported through the lower river essentially unaltered, these materials were biogeochemically processed within days and tens of km. More generally, the mixing rate of plume water with receiving oceanic water has profound effects on the food web structure and biogeochemical cycling in the plume.
NASA Astrophysics Data System (ADS)
Takahashi, Y.; Misawa, T.; Yagi, T.; Pyeon, C. H.; Kimura, M.; Masuda, K.; Ohgaki, H.
2015-10-01
The detection of special nuclear materials (SNM) is an important issue for nuclear security. The interrogation systems used in a sea port and an airport are developed in the world. The active neutron-based interrogation system is the one of the candidates. We are developing the active neutron-based interrogation system with a D-D fusion neutron source for the nuclear security application. The D-D neutron source is a compact discharge-type fusion neutron source called IEC (Inertial-Electrostatic Confinement fusion) device which provides 2.45 MeV neutrons. The nuclear materials emit the highenergy neutrons by fission reaction. High-energy neutrons with energies over 2.45 MeV amount to 30% of all the fission neutrons. By using the D-D neutron source, the detection of SNMs is considered to be possible with the attention of fast neutrons if there is over 2.45 MeV. Ideally, neutrons at En>2.45 MeV do not exist if there is no nuclear materials. The detection of fission neutrons over 2.45 MeV are hopeful prospect for the detection of SNM with a high S/N ratio. In the future, the experiments combined with nuclear materials and a D-D neutron source will be conducted. Furthermore, the interrogation system will be numerically investigated by using nuclear materials, a D-D neutron source, and a steel container.
Three-dimensional N-doped graphene/polyaniline composite foam for high performance supercapacitors
NASA Astrophysics Data System (ADS)
Zhu, Jun; Kong, Lirong; Shen, Xiaoping; Chen, Quanrun; Ji, Zhenyuan; Wang, Jiheng; Xu, Keqiang; Zhu, Guoxing
2018-01-01
Three-dimensional (3D) graphene aerogel and its composite with interconnected pores have aroused continuous interests in energy storage field owning to its large surface area and hierarchical pore structure. Herein, we reported the preparation of 3D nitrogen-doped graphene/polyaniline (N-GE/PANI) composite foam for supercapacitive material with greatly improved electrochemical performance. The 3D porous structure can allow the penetration and diffusion of electrolyte, the incorporation of nitrogen doping can enhance the wettability of the active material and the number of active sites with electrolyte, and both the N-GE and PANI can ensure the high electrical conductivity of total electrode. Moreover, the synergistic effect between N-GE and PANI materials also play an important role on the electrochemical performance of electrode. Therefore, the as-prepared composite foam could deliver a high specific capacitance of 528 F g-1 at 0.1 A g-1 and a high cyclic stability with 95.9% capacitance retention after 5000 charge-discharge cycles. This study provides a new idea on improving the energy storage capacity of supercapacitors by using 3D graphene-based psedocapacitive electrode materials.
NASA Astrophysics Data System (ADS)
Li, Yiju; Ye, Ke; Cheng, Kui; Yin, Jinling; Cao, Dianxue; Wang, Guiling
2015-01-01
In this report, graphene nanosheets (GNS)/nickel sulfide (NiS) based material for high-performance supercapacitor is prepared by "dip and dry" and electrodeposition methods. Commercial flexible make-up cottons (MCs) are chose as skeletons to construct homogeneous three-dimensional (3D) interconnected graphene-wrapped macro-networks, which can support structures for high loading of active electrode materials and facilitate the access of electrolytes to active electrode materials. The hybrid GNS/NiS based MCs (denoted as MCs@GNS@NiS) electrode yields relatively high specific capacitance of 775 F g-1 at a charge/discharge specific current of 0.5 A g-1 and good capacitance retention of 88.1% after 1000 cycles at 2 A g-1. Furthermore, the MCs@GNS@NiS electrode delivers a high energy density of 11.2 Wh kg-1 at even a high power density of 1008 W kg-1. Therefore, such low-cost and high-performance energy MCs based on GNS/NiS hierarchical nanostructures offer great promise in large-scale energy storage device applications.
Charging and discharging Teflon
NASA Technical Reports Server (NTRS)
Passenheim, B. C.; Vanlint, V. A. J.
1981-01-01
The charging and discharging characteristics of several common satellite materials exposed to 0-30KV electrons are measured. Teflon is discussed because the charging characteristics are radically altered immediately after a spontaneous discharge. The exterior geometry of the test structure is shown. In all cases dielectric samples were 82 cm in diameter mounted on the front of a 120 cm diameter cylinder supported on an 85 cm, 0.95 cm thick plexiglass disc. Dielectric materials investigated were: back surface aluminized Kapton, back surface silvered Teflon, silicon alkyd white thermal control paint, and 50 cm by 50 cm array of 0.030 cm thick MgF2 coated fused silica solar cell cover slips.
NASA Astrophysics Data System (ADS)
Kojima, Y.; Muto, S.; Tatsumi, K.; Kondo, H.; Oka, H.; Horibuchi, K.; Ukyo, Y.
We investigate the local structural changes in a positive electrode of a lithium ion secondary battery (LiNi 0.8Co 0.15Al 0.05O 2 (NCA) as the active material) associated with charge-discharge cycling at elevated temperatures by scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS). STEM-EELS spectral imaging reveals the evolution of a NiO-like phase localized near the surface and grain boundary regions after many cycles. The amounts of capacity fading and resistance increase are discussed based on the results of the semiquantitative estimation of NiO-like and other product phases. We also identify the chemical state of lithium in the NiO-like phase substituting for Ni.
Controlled porosity in electrodes
Chiang, Yet-Ming; Bae, Chang-Jun; Halloran, John William; Fu, Qiang; Tomsia, Antoni P.; Erdonmez, Can K.
2015-06-23
Porous electrodes in which the porosity has a low tortuosity are generally provided. In some embodiments, the porous electrodes can be designed to be filled with electrolyte and used in batteries, and can include low tortuosity in the primary direction of ion transport during charge and discharge of the battery. In some embodiments, the electrodes can have a high volume fraction of electrode active material (i.e., low porosity). The attributes outlined above can allow the electrodes to be fabricated with a higher energy density, higher capacity per unit area of electrode (mAh/cm.sup.2), and greater thickness than comparable electrodes while still providing high utilization of the active material in the battery during use. Accordingly, the electrodes can be used to produce batteries with high energy densities, high power, or both compared to batteries using electrodes of conventional design with relatively highly tortuous pores.
Direct and continuous strain control of catalysts with tunable battery electrode materials
Wang, Haotian; Xu, Shicheng; Tsai, Charlie; ...
2016-11-24
We report a method for using battery electrode materials to directly and continuously control the lattice strain of platinum (Pt) catalyst and thus tune its catalytic activity for the oxygen reduction reaction (ORR). Whereas the common approach of using metal overlayers introduces ligand effects in addition to strain, by electrochemically switching between the charging and discharging status of battery electrodes the change in volume can be precisely controlled to induce either compressive or tensile strain on supported catalysts. Lattice compression and tension induced by the lithium cobalt oxide substrate of ~5% were directly observed in individual Pt nanoparticles with aberration-correctedmore » transmission electron microscopy. As a result, we observed 90% enhancement or 40% suppression in Pt ORR activity under compression or tension, respectively, which is consistent with theoretical predictions.« less
Distributor means for charging particulate material into receptacles
Greaves, Melvin J.
1977-06-14
Disclosed are receptacles, such as shaft furnaces illustrated by a blast furnace and an upright oil shale retort, embodying rotatable charge distributor means for distributing particulate charge material in the furnace, which charge distributor means can provide a high uniformity of distribution of various sizes of particles and also can provide and maintain a stock line of desired contour and heighth in the receptacle. The distributor means includes a hopper having rigidly fixed to it a plurality of downwardly extending chutes with lower discharge portions that discharge in concentric circular zones at the stock line. The distributor means includes a segmented portion at the juncture of the hopper and the chutes that divides the charge material discharged into the hopper in proportion to the area of the circular zone at the stock line that is fed by the chute. The distributor means embodies means for providing mass flow of the particulate charge material through the chutes to the stock line and for avoiding segregation between larger and smaller particles of charge material deposited at the stock line.
Relationship between Leakage Current and Pollution Deposits on the Surface of Polymeric Insulator
NASA Astrophysics Data System (ADS)
Miyake, Takuma; Seo, Yuya; Sakoda, Tatsuya; Otsubo, Masahisa
Application of polymeric materials used for housing insulators is considered. However, because polymeric insulator is organic matter, the aged deterioration is anxious. The lifetime of polymeric insulator is influenced by environmental conditions such as ultraviolet, acid rain, and polluted deposits. A change of the surface condition of polymeric material causes the dry band arc discharge and the discharge may lower the insulation strength. To investigate the relationship between insoluble pollution and occurrence of dry band arc discharge, we performed a salt-fog test with ethylene vinyl acetate (EVA) samples. The results showed that the heavy erosion caused by frequent dry band arc discharges occurred even in the case of a light polluted condition. Additionally, a very characteristic increase tendency in leakage current with a period of about 5 h was observed during the mist period.
Passivation Layer and Cathodic Redox Reactions in Sodium-Ion Batteries Probed by HAXPES.
Doubaji, Siham; Philippe, Bertrand; Saadoune, Ismael; Gorgoi, Mihaela; Gustafsson, Torbjorn; Solhy, Abderrahim; Valvo, Mario; Rensmo, Håkan; Edström, Kristina
2016-01-08
The cathode material P2-Nax Co2/3 Mn2/9 Ni1/9 O2, which could be used in Na-ion batteries, was investigated through synchrotron-based hard X-ray photoelectron spectroscopy (HAXPES). Nondestructive analysis was made through the electrode/electrolyte interface of the first electrochemical cycle to ensure access to information not only on the active material, but also on the passivation layer formed at the electrode surface and referred to as the solid permeable interface (SPI). This investigation clearly shows the role of the SPI and the complexity of the redox reactions. Cobalt, nickel, and manganese are all electrochemically active upon cycling between 4.5 and 2.0 V; all are in the 4+ state at the end of charging. Reduction to Co(3+), Ni(3+), and Mn(3+) occurs upon discharging and, at low potential, there is partial reversible reduction to Co(2+) and Ni(2+). A thin layer of Na2 CO3 and NaF covers the pristine electrode and reversible dissolution/reformation of these compounds is observed during the first cycle. The salt degradation products in the SPI show a dependence on potential. Phosphates mainly form at the end of the charging cycle (4.5 V), whereas fluorophosphates are produced at the end of discharging (2.0 V). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Stable "superoxide" opens the door to a new class of batteries | Argonne
between LiO2 and Ir3Li may be responsible for the LiO2 discharge product found for the Ir-rGO cathode material. The lattice match between LiO2 and Ir3Li may be responsible for the LiO2 discharge product found for the Ir-rGO cathode material
Pediatric cardiac surgery Parent Education Discharge Instruction (PEDI) program: a pilot study.
Staveski, Sandra L; Zhelva, Bistra; Paul, Reena; Conway, Rosalind; Carlson, Anna; Soma, Gouthami; Kools, Susan; Franck, Linda S
2015-01-01
In developing countries, more children with complex cardiac defects now receive treatment for their condition. For successful long-term outcomes, children also need skilled care at home after discharge. The Parent Education Discharge Instruction (PEDI) program was developed to educate nurses on the importance of discharge teaching and to provide them with a structured process for conducting parent teaching for home care of children after cardiac surgery. The aim of this pilot study was to generate preliminary data on the feasibility and acceptability of the nurse-led structured discharge program on an Indian pediatric cardiac surgery unit. A pre-/post-design was used. Questionnaires were used to evaluate role acceptability, nurse and parent knowledge of discharge content, and utility of training materials with 40 nurses and 20 parents. Retrospective audits of 50 patient medical records (25 pre and 25 post) were performed to evaluate discharge teaching documentation. Nurses' discharge knowledge increased from a mean of 81% to 96% (P = .001) after participation in the training. Nurses and parents reported high levels of satisfaction with the education materials (3.75-4 on a 4.00-point scale). Evidence of discharge teaching documentation in patient medical records improved from 48% (12 of 25 medical records) to 96% (24 of 25 medical records) six months after the implementation of the PEDI program. The structured nurse-led parent discharge teaching program demonstrated feasibility, acceptability, utility, and sustainability in the cardiac unit. Future studies are needed to examine nurse, parent, child, and organizational outcomes related to this expanded nursing role in resource-constrained environments. © The Author(s) 2014.
Neubauer, Florian B; Sederberg, Audrey; MacLean, Jason N
2014-01-01
During the generalization of epileptic seizures, pathological activity in one brain area recruits distant brain structures into joint synchronous discharges. However, it remains unknown whether specific changes in local circuit activity are related to the aberrant recruitment of anatomically distant structures into epileptiform discharges. Further, it is not known whether aberrant areas recruit or entrain healthy ones into pathological activity. Here we study the dynamics of local circuit activity during the spread of epileptiform discharges in the zero-magnesium in vitro model of epilepsy. We employ high-speed multi-photon imaging in combination with dual whole-cell recordings in acute thalamocortical (TC) slices of the juvenile mouse to characterize the generalization of epileptic activity between neocortex and thalamus. We find that, although both structures are exposed to zero-magnesium, the initial onset of focal epileptiform discharge occurs in cortex. This suggests that local recurrent connectivity that is particularly prevalent in cortex is important for the initiation of seizure activity. Subsequent recruitment of thalamus into joint, generalized discharges is coincident with an increase in the coherence of local cortical circuit activity that itself does not depend on thalamus. Finally, the intensity of population discharges is positively correlated between both brain areas. This suggests that during and after seizure generalization not only the timing but also the amplitude of epileptiform discharges in thalamus is entrained by cortex. Together these results suggest a central role of neocortical activity for the onset and the structure of pathological recruitment of thalamus into joint synchronous epileptiform discharges.
Neubauer, Florian B.; Sederberg, Audrey; MacLean, Jason N.
2014-01-01
During the generalization of epileptic seizures, pathological activity in one brain area recruits distant brain structures into joint synchronous discharges. However, it remains unknown whether specific changes in local circuit activity are related to the aberrant recruitment of anatomically distant structures into epileptiform discharges. Further, it is not known whether aberrant areas recruit or entrain healthy ones into pathological activity. Here we study the dynamics of local circuit activity during the spread of epileptiform discharges in the zero-magnesium in vitro model of epilepsy. We employ high-speed multi-photon imaging in combination with dual whole-cell recordings in acute thalamocortical (TC) slices of the juvenile mouse to characterize the generalization of epileptic activity between neocortex and thalamus. We find that, although both structures are exposed to zero-magnesium, the initial onset of focal epileptiform discharge occurs in cortex. This suggests that local recurrent connectivity that is particularly prevalent in cortex is important for the initiation of seizure activity. Subsequent recruitment of thalamus into joint, generalized discharges is coincident with an increase in the coherence of local cortical circuit activity that itself does not depend on thalamus. Finally, the intensity of population discharges is positively correlated between both brain areas. This suggests that during and after seizure generalization not only the timing but also the amplitude of epileptiform discharges in thalamus is entrained by cortex. Together these results suggest a central role of neocortical activity for the onset and the structure of pathological recruitment of thalamus into joint synchronous epileptiform discharges. PMID:25232306
Welland, Michael J.; Lau, Kah Chun; Redfern, Paul C.; ...
2015-12-10
An atomistically informed mesoscale model is developed for the deposition of a discharge product in a Li-O 2 battery. This mescocale model includes particle growth and coarsening as well as a simplified nucleation model. The model involves LiO 2 formation through reaction of O 2 - and Li + in the electrolyte, which deposits on the cathode surface when the LiO 2 concentration reaches supersaturation in the electrolyte. A reaction-diffusion (rate-equation) model is used to describe the processes occurring in the electrolyte and a phase-field model is used to capture microstructural evolution. This model predicts that coarsening, in which largemore » particles grow and small ones disappear, has a substantial effect on the size distribution of the LiO 2 particles during the discharge process. The size evolution during discharge is the result of the interplay between this coarsening process and particle growth. The growth through continued deposition of LiO 2 has the effect of causing large particles to grow ever faster while delaying the dissolution of small particles. The predicted size evolution is consistent with experimental results for a previously reported cathode material based on activated carbon during discharge and when it is at rest, although kinetic factors need to be included. Finally, the approach described in this paper synergistically combines models on different length scales with experimental observations and should have applications in studying other related discharge processes, such as Li 2O 2 deposition, in Li-O 2 batteries and nucleation and growth in Li-S batteries.« less
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-28
... Activities: Application To Pay Off or Discharge an Alien Crewman AGENCY: U.S. Customs and Border Protection... information collection requirement concerning the Application to Pay Off or Discharge an Alien Crewman (Form I... Discharge an Alien Crewman. OMB Number: 1651-0106. Form Number: I-408. Abstract: CBP Form I-408, Application...
Effects of Cryogenic Temperatures on Spacecraft Internal Dielectric Discharges
NASA Technical Reports Server (NTRS)
Ferguson, Dale c.; Schneider, Todd A.; Vaughn, Jason A.
2009-01-01
Abstract Most calculations of internal dielectric charging on spacecraft use tabulated values of material surface and bulk conductivities, dielectric constants, and dielectric breakdown strengths. Many of these properties are functions of temperature, and the temperature dependences are not well known. At cryogenic temperatures, where it is well known that material conductivities decrease dramatically, it is an open question as to the timescales over which buried charge will dissipate and prevent the eventual potentially disastrous discharges of dielectrics. In this paper, measurements of dielectric charging and discharging for cable insulation materials at cryogenic temperatures (approx. 90 K) are presented using a broad spectrum electron source at the NASA Marshall Space Flight Center. The measurements were performed for the James Webb Space Telescope (JWST), which will orbit at the Earth-Sun L2 point, and parts of which will be perennially at temperatures as low as 40 K. Results of these measurements seem to show that Radiation Induced Conductivity (RIC) under cryogenic conditions at L2 will not be sufficient to allow charges to bleed off of some typical cable insulation materials even over the projected JWST lifetime of a dozen years or more. After the charging and discharging measurements are presented, comparisons are made between the material conductivities that can be inferred from the measured discharges and conductivities calculated from widely used formulae. Furthermore, the measurement-inferred conductivities are compared with extrapolations of recent measurements of materials RIC and dark conductivities performed with the charge-storage method at Utah State University. Implications of the present measurements are also given for other spacecraft that may operate at cryogenic temperatures, such as probes of the outer planets or the permanently dark cratered areas on the moon. The present results will also be of interest to those who must design or operate spacecraft in more moderate cold conditions. Finally, techniques involving shielding and/or selective use of somewhat conductive insulators are presented to prevent arc-inducing charge buildup even under cryogenic conditions.
Waltemeyer, S.D.
1995-01-01
A sediment-transport model to simulate channel change was applied to a 1-mile reach of Cuchillo Negro Creek at the Interstate 25 crossing at Truth or Consequences, New Mexico, using the Bridge-Stream Tube model for Alluvial River Simulation (BRI-STARS). The 500-year flood discharge was estimated to be 10,700 cubic feet per second. The 100-year, 500-year, and regional maximum discharges were used to design synthetic and discretized hydrographs using a flood volume equation. The regional maximum discharge relation was developed for New Mexico based on 259 streamflow-gaging stations' maximum peak discharge. The regional maximum-peak discharge for the site was determined to be 81,700 cubic feet per second. Bed-material particle-size distribution was determined for six size classes ranging from 1 to 30 millimeters. The median diameter was 4.6 millimeters at the bed surface and 9.0 millimeters 13 feet below the bed surface. Bed-material discharge for use in the model was estimated to be 18,770 tons per day using hydraulic properties, water temperature, and Yang's gravel equation. Channel-change simulations showed a maximum channel degradation of 1.38 feet for the regional maximum-peak discharge hydrograph.
Electrophysiology of neurones of the inferior mesenteric ganglion of the cat.
Julé, Y; Szurszewski, J H
1983-01-01
Intracellular recordings were obtained from cells in vitro in the inferior mesenteric ganglia of the cat. Neurones could be classified into three types: non-spontaneous, irregular discharging and regular discharging neurones. Non-spontaneous neurones had a stable resting membrane potential and responded with action potentials to indirect preganglionic nerve stimulation and to intracellular injection of depolarizing current. Irregular discharging neurones were characterized by a discharge of excitatory post-synaptic potentials (e.p.s.p.s.) which sometimes gave rise to action potentials. This activity was abolished by hexamethonium bromide, chlorisondamine and d-tubocurarine chloride. Tetrodotoxin and a low Ca2+ -high Mg2+ solution also blocked on-going activity in irregular discharging neurones. Regular discharging neurones were characterized by a rhythmic discharge of action potentials. Each action potential was preceded by a gradual depolarization of the intracellularly recorded membrane potential. Intracellular injection of hyperpolarizing current abolished the regular discharge of action potential. No synaptic potentials were observed during hyperpolarization of the membrane potential. Nicotinic, muscarinic and adrenergic receptor blocking drugs did not modify the discharge of action potentials in regular discharging neurones. A low Ca2+ -high Mg2+ solution also had no effect on the regular discharge of action potentials. Interpolation of an action potential between spontaneous action potentials in regular discharging neurones reset the rhythm of discharge. It is suggested that regular discharging neurones were endogenously active and that these neurones provided synaptic input to irregular discharging neurones. PMID:6140310
Electrophysiology of neurones of the inferior mesenteric ganglion of the cat.
Julé, Y; Szurszewski, J H
1983-11-01
Intracellular recordings were obtained from cells in vitro in the inferior mesenteric ganglia of the cat. Neurones could be classified into three types: non-spontaneous, irregular discharging and regular discharging neurones. Non-spontaneous neurones had a stable resting membrane potential and responded with action potentials to indirect preganglionic nerve stimulation and to intracellular injection of depolarizing current. Irregular discharging neurones were characterized by a discharge of excitatory post-synaptic potentials (e.p.s.p.s.) which sometimes gave rise to action potentials. This activity was abolished by hexamethonium bromide, chlorisondamine and d-tubocurarine chloride. Tetrodotoxin and a low Ca2+ -high Mg2+ solution also blocked on-going activity in irregular discharging neurones. Regular discharging neurones were characterized by a rhythmic discharge of action potentials. Each action potential was preceded by a gradual depolarization of the intracellularly recorded membrane potential. Intracellular injection of hyperpolarizing current abolished the regular discharge of action potential. No synaptic potentials were observed during hyperpolarization of the membrane potential. Nicotinic, muscarinic and adrenergic receptor blocking drugs did not modify the discharge of action potentials in regular discharging neurones. A low Ca2+ -high Mg2+ solution also had no effect on the regular discharge of action potentials. Interpolation of an action potential between spontaneous action potentials in regular discharging neurones reset the rhythm of discharge. It is suggested that regular discharging neurones were endogenously active and that these neurones provided synaptic input to irregular discharging neurones.
Graphene-Based Materials for Lithium-Ion Hybrid Supercapacitors.
Ma, Yanfeng; Chang, Huicong; Zhang, Miao; Chen, Yongsheng
2015-09-23
Lithium-ion hybrid supercapacitors (LIHSs), also called Li-ion capacitors, have attracted much attention due to the combination of the rapid charge-discharge and long cycle life of supercapacitors and the high energy-storage capacity of lithium-ion batteries. Thus, LIHSs are expected to become the ultimate power source for hybrid and all-electric vehicles in the near future. As an electrode material, graphene has many advantages, including high surface area and porous structure, high electric conductivity, and high chemical and thermal stability, etc. Compared with other electrode materials, such as activated carbon, graphite, and metal oxides, graphene-based materials with 3D open frameworks show higher effective specific surface area, better control of channels, and higher conductivity, which make them better candidates for LIHS applications. Here, the latest advances in electrode materials for LIHSs are briefly summarized, with an emphasis on graphene-based electrode materials (including 3D graphene networks) for LIHS applications. An outlook is also presented to highlight some future directions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Li, Li; Bian, Yifan; Zhang, Xiaoxiao; Guan, Yibiao; Fan, Ersha; Wu, Feng; Chen, Renjie
2018-01-01
A "grave-to-cradle" process for the recycling of spent mixed-cathode materials (LiCoO 2 , LiCo 1/3 Ni 1/3 Mn 1/3 O 2 , and LiMn 2 O 4 ) has been proposed. The process comprises an acid leaching followed by the resynthesis of a cathode material from the resulting leachate. Spent cathode materials were leached in citric acid (C 6 H 8 O 7 ) and hydrogen peroxide (H 2 O 2 ). Optimal leaching conditions were obtained at a leaching temperature of 90 °C, a H 2 O 2 concentration of 1.5 vol%, a leaching time of 60 min, a pulp density of 20 g L -1 , and a citric acid concentration of 0.5 M. The leaching efficiencies of Li, Co, Ni, and Mn exceeded 95%. The leachate was used to resynthesize new LiCo 1/3 Ni 1/3 Mn 1/3 O 2 material by using a sol-gel method. A comparison of the electrochemical properties of the resynthesized material (NCM-spent) with that synthesized directly from original chemicals (NCM-syn) indicated that the initial discharge capacity of NCM-spent at 0.2 C was 152.8 mA h g -1 , which was higher than the 149.8 mA h g -1 of NCM-syn. After 160 cycles, the discharge capacities of the NCM-spent and NCM-syn were 140.7 mA h g -1 and 121.2 mA h g -1 , respectively. After discharge at 1 C for 300 cycles, the NCM-spent material remained a higher capacity of 113.2 mA h g -1 than the NCM-syn (78.4 mA h g -1 ). The better performance of the NCM-spent resulted from trace Al doping. A new formulation based on the shrinking-core model was proposed to explain the kinetics of the leaching process. The activation energies of the Li, Co, Ni, and Mn leaching were calculated to be 66.86, 86.57, 49.46, and 45.23 kJ mol -1 , respectively, which indicates that the leaching was a chemical reaction-controlled process. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Carter, Rachel; Huhman, Brett; Love, Corey T.; Zenyuk, Iryna V.
2018-03-01
X-ray computed tomography (X-ray CT) across multiple length scales is utilized for the first time to investigate the physical abuse of high C-rate pulsed discharge on cells wired individually and in parallel.. Manufactured lithium iron phosphate cells boasting high rate capability were pulse power tested in both wiring conditions with high discharge currents of 10C for a high number of cycles (up to 1200) until end of life (<80% of initial discharge capacity retained). The parallel assembly reached end of life more rapidly for reasons unknown prior to CT investigations. The investigation revealed evidence of overdischarge in the most degraded cell from the parallel assembly, compared to more traditional failure in the individual cell. The parallel-wired cell exhibited dissolution of copper from the anode current collector and subsequent deposition throughout the separator near the cathode of the cell. This overdischarge-induced copper deposition, notably impossible to confirm with other state of health (SOH) monitoring methods, is diagnosed using CT by rendering the interior current collector without harm or alteration to the active materials. Correlation of CT observations to the electrochemical pulse data from the parallel-wired cells reveals the risk of parallel wiring during high C-rate pulse discharge.
40 CFR 230.10 - Restrictions on discharge.
Code of Federal Regulations, 2010 CFR
2010-07-01
... diversity, productivity, and stability. Such effects may include, but are not limited to, loss of fish and... economic values. (d) Except as provided under section 404(b)(2), no discharge of dredged or fill material...
33 CFR 155.430 - Standard discharge connections for oceangoing ships of 400 gross tons and above.
Code of Federal Regulations, 2010 CFR
2010-07-01
... Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR VESSELS Vessel Equipment § 155.430 Standard discharge connections for...
Zhang, Jian; Zhou, Huang; Zhu, Jiawei; Hu, Pei; Hang, Chao; Yang, Jinlong; Peng, Tao; Mu, Shichun; Huang, Yunhui
2017-07-26
Developing facile and low-cost porous graphene-based catalysts for highly efficient oxygen reduction reaction (ORR) remains an important matter for fuel cells. Here, a defect-enriched and dual heteroatom (S and N) doped hierarchically porous graphene-like carbon nanomaterial (D-S/N-GLC) was prepared by a simple and scalable strategy, and exhibits an outperformed ORR activity and stability as compared to commercial Pt/C catalyst in an alkaline condition (its half-wave potential is nearly 24 mV more positive than Pt/C). The excellent ORR performance of the catalyst can be attributed to the synergistic effect, which integrates the novel graphene-like architectures, 3D hierarchically porous structure, superhigh surface area, high content of active dopants, and abundant defective sites in D-S/N-GLC. As a result, the developed catalysts are used as the air electrode for primary and all-solid-state Zn-air batteries. The primary batteries demonstrate a higher peak power density of 252 mW cm -2 and high voltage of 1.32 and 1.24 V at discharge current densities of 5 and 20 mA cm -2 , respectively. Remarkably, the all-solid-state battery also exhibits a high peak power density of 81 mW cm -2 with good discharge performance. Moreover, such catalyst possesses a comparable ORR activity and higher stability than Pt/C in acidic condition. The present work not only provides a facile but cost-efficient strategy toward preparation of graphene-based materials, but also inspires an idea for promoting the electrocatalytic activity of carbon-based materials.
Large area atmospheric-pressure plasma jet
Selwyn, Gary S.; Henins, Ivars; Babayan, Steve E.; Hicks, Robert F.
2001-01-01
Large area atmospheric-pressure plasma jet. A plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two planar, parallel electrodes are employed to generate a plasma in the volume therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly spacing the rf-powered electrode. Because of the atmospheric pressure operation, there is a negligible density of ions surviving for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike the situation for low-pressure plasma sources and conventional plasma processing methods.
Atmospheric-pressure plasma jet
Selwyn, Gary S.
1999-01-01
Atmospheric-pressure plasma jet. A .gamma.-mode, resonant-cavity plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two concentric cylindrical electrodes are employed to generate a plasma in the annular region therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly shaping the rf-powered electrode. Because of the atmospheric pressure operation, no ions survive for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike low-pressure plasma sources and conventional plasma processing methods.
NASA Astrophysics Data System (ADS)
Czerwiński, A.; Obrębowski, S.; Kotowski, J.; Rogulski, Z.; Skowroński, J. M.; Krawczyk, P.; Rozmanowski, T.; Bajsert, M.; Przystałowski, M.; Buczkowska-Biniecka, M.; Jankowska, E.; Baraniak, M.
Reticulated vitreous carbon (RVC ®) and RVC ® plated with lead were investigated as carriers for the negative electrode of lead-acid cell. The RVC ® and Pb/RVC ® carriers were pasted with active paste (received from JENOX Ltd., Polish producer of lead-acid batteries) and prepared to be used in lead-acid cell. Comparative study of electrodes based on RVC ® and Pb/RVC ® has been done using constant-current charging/discharging, constant-potential discharging and cycling voltammetry measurements. Scanning electron microscopy (SEM) was employed to determine the morphology of the lead layer deposited on the RVC surface. Hybrid flooded single lead-acid cells containing one negative electrode, based on new type of carrier (RVC ® or Pb/RVC ®), sandwiched between two positive electrodes, based on the Pb-Ca grids, were assembled and subjected to electrochemical tests. It has been found that both materials, RVC ® and Pb/RVC ®, can be used as carriers of negative electrode, but the latter seems to have better influence on the discharge performance.
Li, Na; Xu, Jianxiong; Chen, Han; Wang, Xianyou
2014-07-01
Supercapacitors are successfully prepared from ordered mesoporous carbon (OMC) synthesized by employing the mesoporous silica, SBA-15 as template and furfuryl alcohol as carbon source. It is found that the carbonized temperature greatly influences the physical properties of the synthesized mesoporous carbon materials. The optimal carbonized temperature is measured to be 600 degrees C under which OMC with the specific surface area of 1219 m2/g and pore volume of 1.31 cm3/g and average pore diameter of - 3 nm are synthesized. The OMC materials synthesized under different carbonized temperature are used as electrode material of supercapacitors and the electrochemical properties of the OMC materials are compared by using cyclic voltammetry, electrochemical impedance spectroscopy, galvanostatic charge-discharge and self-discharge tests. The results show that the electrochemical properties of the OMC materials are directly related to the specific surface area and pore volume of the mesoporous carbon and the electrode prepared from the OMC synthesized under the carbonized temperature of 600 degrees C (OMC-600) exhibits the most excellent electrochemical performance with the specific capacitance of 207.08 F/g obtained from cyclic voltammetry at the scan rate of 1 mV/s, small resistance and low self-discharge rate. Moreover, the supercapacitor based on the OMC-600 material exhibits good capacitance properties and stable cycle behavior with the specific capacitance of 105 F/g at the current density of 700 mA/g, and keeps a specific capacitance of 98 F/g after 20000 consecutive charge/discharge cycles.
Radio Wave Generation by a Collision or Contact between Various Materials
NASA Astrophysics Data System (ADS)
Takano, T.; Hanawa, R.; Saegusa, K.; Ikeda, H.
2014-12-01
In fracture of rock, radio wave emission was found experimentally [1]. This phenomenon could be used to detect a rock fracture during an earthquake or a volcanic activity [2]. The cause of the radio wave is expected to be micro-discharges, which are generated by an inhomogeneous potential distribution around micro-cracks. In order to better understand the phenomena and clarify the cause of radio wave emission, we carried out experiments to detect the emission in the cases of a collision or contact between various materials. We used receiving systems with great sensitivities and sufficient frequency bandwidths at 1 MHz-, 300 MHz-, 2 GHz-, and 18 GHz-bands. The specimen materials are as follows: Steel (2) Brass (3) Copper (4)Small coin (5)Celluloid. We obtained the following results: The signal was detected for the specimen of (1) to (4), but not for (5). The signal is composed of intermittent spikes which include waves with a frequency close to the center frequency of each frequency band. The power is strongest at the lower frequencies among all frequency bands. The more details will be given in the presentation. The origin of radio wave emission from the metal is supposed to be discharges between materials in these experiments. It is surprising that even a small coin can generate a significant amount of radio wave. Accordingly, it is inferred that all amount of charges are discharged through a conductive metal. On the other hand, celluloid did not generate radio wave, though the specimen was sufficiently charged by brushing. It is inferred that a quite localized charge was discharged but the remaining charges were blocked due to poor conductivity. Extending this hypothesis, large-scale contact should have occurred between broken fragments for the radio wave generation in the aforementioned rock fracture experiments. Turbulence of the fragments is a candidate for the explanation. [1] K. Maki et al., "An experimental study of microwave emission from compression failure of rocks" (in Japanese), Jour. of the Seismological Society of Japan, vol.58, no.4, pp.375-384, 2006.[2] T. Takano al., "Detection of microwave emission due to rock fracture as a new tool for geophysics: A field test at a volcano in Miyake Island, Japan", Journal of Applied Geophysics, 94, pp.1-14, 2013.
Drainage Asperities on Subduction Megathrusts
NASA Astrophysics Data System (ADS)
Sibson, R. H.
2012-12-01
Geophysical observations coupled with force-balance analyses suggest that the seismogenic shear zone interface of subduction megathrusts is generally fluid-overpressured to near-lithostatic values (λv = Pf/σv > 0.9) below the forearc hanging-wall, strongly modulating the profile of frictional shear resistance. Fluid sources include the accretionary prism at shallow levels and, with increasing depth, metamorphic dehydration of material entrained within the subduction shear zone together with progressive metamorphism of oceanic crust in the downgoing slab. Solution transfer in fine-grained material contained within the deeper subduction shear zone (150 < T < 350°C) likely contributes to hydrothermal sealing of fractures. A dramatic difference may therefore exist between low prefailure permeability surrounding the megathrust and high postfailure fracture permeability along the rupture zone and adjacent areas of aftershock activity. Observed postseismic changes in the velocity structure of the fore-arc hanging-wall led Husen and Kissling (2001) to propose massive fluid loss across the subduction interface following the 1995 Antofagasta, Chile, Mw8.0 megathrust rupture. Such trans-megathrust discharges represent a variant of 'fault-valve' action in which the subduction interface itself acts as a seal trapping overpressured fluids derived from metamorphic dehydration beneath. In low-permeability assemblages the maximum sustainable overpressure is limited by the activation or reactivation of brittle faults and fractures under the prevailing stress state. Highest overpressures tend to occur at low differential stress in compressional stress regimes. Loci for fluid discharge are likely determined by stress heterogeneities along the megathrust (e.g. the hangingwall of the rupture at its downdip termination). Discharge sites may be defined by swarm aftershocks defining activated fault-fracture meshes. However, fluid loss across a subduction interface will be enhanced when the stress-state in the forearc hanging-wall switches from compressional reverse-slip faulting before failure to extensional normal-slip faulting postfailure, as occurred during the 2011 Mw9.0 Tohoku megathrust rupture. Mean stress and fault-normal stress then change from being greater than vertical stress prefailure, to less than vertical stress postfailure. Postfailure reductions in overpressure are expected from a combination of poroelastic effects and fluid loss through fault-fracture networks, enhancing vertical permeability. Mineralised fault-fracture meshes in exhumed fore-arc assemblages (e.g. the Alaska-Juneau Au-quartz vein swarm) testify to the episodic discharge of substantial volumes of hydrothermal fluid (< tens of km3). Localized drainage from the subduction interface shear zone increases frictional strength significantly, giving rise to a postfailure strength asperities. Anticipated strength increases from such fluid discharge depends on the magnitude of the drop in overpressure but are potentially large (< hundreds of MPa). Time to the subsequent failure is then governed by reaccumulation of fluid overpressure as well as shear stress along the subduction interface.
Space Environment Effects on Materials : An Overview
NASA Technical Reports Server (NTRS)
Garrett, Henry B.
2006-01-01
A general overview on the space environment and its effects on materials is presented. The topics include: 1) Impact of Space Effects on Spacecraft Costs; 2) Space Environment Effects on Spacecraft by Source; 3) Primary Source of Space Effects: The Sun; 4) The Earth's Environment; 5) Trapped Radiation Belts; 6) Aurora Are Everywhere; 7) Spacecraft Interactions; 8) Atmospheric Effects; 9) Contaminant Effects on Materials; 10) Meteoroid/Debris Effects on Materials; 11) Spacecraft Surface Charging; 12) Surface Discharge Effects; 13) Internal Electrostatic Discharge--Satellite Killer; 14) Plasma Interactions DS-1 Ion Engines; 15) Radiation Effects on Spacecraft Systems and Materials; 16) Total Ionizing Dose Effects Total Ionizing Dose Effects; 17) Man-Made Sources of Space Effects Man-Made Sources of Space Effects; and 18) Space Environments Versus Interactions.
Ra and Rn isotopes as natural tracers of submarine groundwater discharge in Tampa Bay, Florida
Swarzenski, P.W.; Reich, C.; Kroeger, K.D.; Baskaran, M.
2007-01-01
A suite of naturally occurring radionuclides in the U/Th decay series (222Rn, 223,224,226,228Ra) were studied during wet and dry conditions in Tampa Bay, Florida, to evaluate their utility as groundwater discharge tracers, both within the bay proper and within the Alafia River/estuary — a prominent free-flowing river that empties into the bay. In Tampa Bay, almost 30% of the combined riverine inputs still remain ungauged. Consequently, groundwater/surface water (hyporheic) exchange in the discharging coastal rivers, as well as submarine groundwater discharge (SGD) within the bay, are still unresolved components of this system's water and material budgets. Based on known inputs and sinks, there exists an excess of 226Ra in the water column of Tampa Bay, which can be evaluated in terms of a submarine groundwater contribution to the bay proper. Submarine groundwater discharge rates calculated using a mass balance of excess 226Ra ranged from 2.2 to 14.5 L m− 2 day− 1, depending on whether the estuarine residence time was calculated using 224Ra/xs228Ra isotope ratios, or whether a long term, averaged model-derived estuarine residence time was used. When extrapolated to the total shoreline length of the bay, such SGD rates ranged from 1.6 to 10.3 m3 m− 1 day− 1. Activities of 222Rn were also elevated in surface water and shallow groundwater of the bay, as well as in the Alafia River estuary, where upstream activities as high as 250 dpm L− 1 indicate enhanced groundwater/surface water exchange, facilitated by an active spring vent. From average nutrient concentrations of 39 shallow, brackish, groundwater samples, rates of nutrient loading into Tampa Bay by SGD rates were estimated, and these ranged from 0.2 to 1.4 × 105 mol day− 1 (PO43−), 0.9–6.2 × 105 mol day− 1 (SiO4−), 0.7–5.0 × 105 mol day− 1 (dissolved organic nitrogen, DON), and 0.2–1.4 × 106 mol day− 1 (total dissolved nitrogen, TDN). Such nutrient loading estimates, when compared to average river discharge estimates (e.g., TDN = 6.9 × 105 mol day− 1), suggest that SGD-derived nutrient fluxes to Tampa Bay are indeed important components to the overall nutrient economy of these coastal waters.
Kumar, Vishal; Singh, Amarjeet; Tewari, Manoj K.; Kaur, Sukhpal
2016-01-01
Problem Statement: Neurosurgical patients require special care not only in the hospital but also after their discharge from the hospital. Comprehension and compliance to the instructions given by the doctors/nurses at the time of discharge is important in home care of these patients. Many such patients suffer from various co-morbidities. Variable periods of convalescence affect health-related quality of life in these patients. Purpose of the Study: To determine the degree of compliance of neurosurgery patients and their family caregivers with the discharge advice given by the consultantsTo evaluate the quality of life of these patientsTo know the problems faced by these patients at home. Materials and Methods: This cross-sectional interview-based descriptive study was conducted in 2010 in Chandigarh. These patients were visited at their home. A scale was evolved to evaluate comprehension and compliance to the advice given at the time of discharge, according to the criteria developed by Clark et al. Lawton Brody instrumental activity of daily life and Spitzer quality of life index were used to assess patients' quality of life after the operation. Verbatim responses were recorded for the purpose of qualitative research. Results: Overall, 58 patients and their caregivers were interviewed at home. Mean age of the patients was 38.9 years. Out of 37 patients, 35 showed good comprehension and 33 patients had a good compliance with the instructions given for medication. The condition of 74.1% patients improved after the operation. Depression was reported in 31% of the patients. Many (36.2%) patients had to quit their job due to the disease. Almost half (47.4%) of the patients were independent in daily activities of their life while being evaluated on Barthel activity of daily life index. Conclusion and Recommendations: It is in the long term that the true complexity and impact of operations become apparent. After operation, such patients are likely to have a range of physical, emotional, cognitive, behavioral, and social problems, which may result in difficulties for both patients and their family caregivers. Provision of mechanism of prioritized follow-up care to the operated bedridden neurosurgery patients should be made. PMID:27695540
Radioactive liquid wastes discharged to ground in the 200 Areas during 1976
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mirabella, J.E.
An overall summary is presented giving the radioactive liquid wastes discharged to ground during 1976 and since startup (for both total and decayed depositions) within the Production and Waste Management Division control zone (200 Area plateau). Overall summaries are also presented for 200 East Area and for 200 West Area. The data contain an estimate of the radioactivity discharged to individual ponds, cribs and specific retention sites within the Production and Waste Management Division during 1976 and from startup through December 31, 1976; an estimate of the decayed activities from startup through 1976; the location and reference drawings of eachmore » disposal site; and the usage dates of each disposal site. The estimates for the radioactivity discharged and for decayed activities dicharged from startup through December 31, 1976 are based upon Item 4 of the Bibliography. The volume of liquid discharged to the ponds also includes major nonradioactive streams. The wastes discharged during 1976 to each active disposal site are detailed on a month-to-month basis, along with the monthly maximum concentration and average concentration data. An estimate of the radioactivity discharged to each active site along with the remaining decayed activities is given.« less
NASA Technical Reports Server (NTRS)
Green, Nelson W.; Dawson, Stephen F.
2015-01-01
NASA is currently considering a mission to investigate the moons of Jupiter. When designing a spacecraft for this type of mission, there are a number of engineering challenges, especially if the mission chooses to utilize solar arrays to provide the spacecraft power. In order for solar arrays to be feasible for the mission, their total mass needed to fit within the total budget for the mission, which strongly suggested the use of carbon composite facesheets on an aluminum core for the panel structure. While these composite structures are a good functional substitution for the metallic materials they replace, they present unique challenges when interacting with the harsh Jovian space environment. As a composite material, they are composed of more than one material and can show different base properties depending in differing conditions. Looking at the electrical properties, in an Earth-based environment the carbon component of the composite dominates the response of the material to external stimulus. Under these conditions, the structures strongly resembles a conductor. In the Jovian environment, with temperatures reaching 50K and under the bombardment from energetic electrons, the non-conducting pre-preg binding materials may come to the forefront and change the perceived response. Before selecting solar arrays as the baseline power source for a mission to Jupiter, the response of the carbon composites to energetic electrons while held at cryogenic temperatures needed to be determined. A series of tests were devised to exam the response of a sample solar array panel composed of an M55J carbon weave layup with an RS-3 pre-preg binder. Test coupons were fabricated and exposed to electrons ranging from 10 keV to 100 keV, at 1 nA/cm2, while being held at cryogenic temperatures. While under electron bombardment, electrical discharges were observed and recorded with the majority of discharges occurring with electron energies of 25 keV. A decrease in temperature to liquid nitrogen temperatures showed a marked increase in the magnitude of these discharges. The results indicate that dielectric discharges are primarily produced due to the presence of large regions of the non-conductive pre-preg on the surface of the carbon sheets. The frequency and magnitude of discharges decreased when layers of the pre-preg material were removed from the composite surface. These tests indicate that solar array panels may be used in the Jovian environment, but that electrostatic discharges can be expected on the carbon composite solar arrays.
A neurophysiologic model for aggressive behavior in the cat.
Andy, O J; Giurintano, L P; Giurintano, S L
1978-01-01
A neurophysiologic model for aggressive behavior in the cat is proposed. Stimulus-bound and seizure-bound aggression was evaluated in relation to limbic and basal ganglia induced seizures (after-discharges). Electrically induced limbic and basal ganglia after-discharges were used because they are known to implicate septohypothalamic sites from which aggression can be elicited by direct stimulation. The occurrence of behavioral aggression is correlated with the discharge characteristics of a single discharging system and with two interacting discharging systems. Aggression is composed of autonomic and somato-motor components which poses relatively low and high thresholds, respectively, for their activation. Aggression occurring during a combined septum and amygdala discharge was more intense and prolonged than with a septum discharge alone. Participation of a slow frequency discharging basal ganglia system activated seizure-bound aggression in an otherwise nonaggressive limbic seizure. The limbic and basal ganglia stimulations and after-discharges lowered the excitability threshold of the aggression system and made it more vulnerable to being activated by external stimuli, such as visual and auditory stimuli. These observations are reminiscent of patients with aggressive behavior associated with psychomotor seizures.
NASA Astrophysics Data System (ADS)
Kumar, Ajay; Jayakumar, O. D.; Bazzi, Khadije; Nazri, Gholam-Abbas; Naik, Vaman M.; Naik, Ratna
2015-03-01
Lithium iron silicate (Li2FeSiO4) has the potential as cathode for Li ion batteries due to its high theoretical capacity (~ 330 mAh/g) and improved safety. The application of Li2FeSiO4 as cathode material has been challenged by its poor electronic conductivity and slow lithium ion diffusion in the solid phase. In order to solve these problems, we have synthesized mesoporous Li2FeSiO4/C composites by sol-gel method using the tri-block copolymer (P123) as carbon source. The phase purity and morphology of the composite materials were characterized by x-ray diffraction, SEM and TEM. The XRD pattern confirmed the formation of ~ 12 nm size Li2FeSiO4 crystallites in composites annealed at 600 °C for 6 h under argon atmosphere. The electrochemical properties are measured using the composite material as positive electrode in a standard coin cell configuration with lithium as the active anode and the cells were tested using AC impedance spectroscopy, cyclic voltammetry, and galvanostatic charge/discharge cycling. The Li2FeSiO4/C composites showed a discharge capacity of ~ 240 mAh/g at a rate of C/30 at room temperature. The effect of different annealing temperature and synthesis time on the electrochemical performance of Li2FeSiO4/C will be presented.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-10
... Activities: Application To Pay Off or Discharge an Alien Crewman AGENCY: U.S. Customs and Border Protection...: Application To Pay Off or Discharge an Alien Crewman (Form I-408). This is a proposed extension of an...: Application To Pay Off or Discharge an Alien Crewman. OMB Number: 1651-0106. Form Number: I-408. Abstract: CBP...
Mou, Jirong; Deng, Yunlong; Song, Zhicui; Zheng, Qiaoji; Lam, Kwok Ho; Lin, Dunmin
2018-05-22
High-voltage LiNi0.5Mn1.5O4 is a promising cathode candidate for lithium-ion batteries (LIBs) due to its considerable energy density and power density, but the material generally undergoes serious capacity fading caused by side reactions between the active material and organic electrolyte. In this work, Li+-conductive Li2SnO3 was coated on the surface of LiNi0.5Mn1.5O4 to protect the cathode against the attack of HF, mitigate the dissolution of Mn ions during cycling and improve the Li+ diffusion coefficient of the materials. Remarkable improvement in cycling stability and rate performance has been achieved in Li2SnO3-coated LiNi0.5Mn1.5O4. The 1.0 wt% Li2SnO3-coated LiNi0.5Mn1.5O4 cathode exhibits excellent cycling stability with a capacity retention of 88.2% after 150 cycles at 0.1 C and rate capability at high discharge rates of 5 C and 10 C, presenting discharge capacities of 119.5 and 112.2 mAh g-1, respectively. In particular, a significant improvement in cycling stability at 55 °C is obtained after the coating of 1.0 wt% Li2SnO3, giving a capacity retention of 86.8% after 150 cycles at 1 C and 55 °C. The present study provides a significant insight into the effective protection of Li-conductive coating materials for a high-voltage LiNi0.5Mn1.5O4 cathode material.
Li, Linsen; Meng, Fei; Jin, Song
2012-11-14
The increasing demands from large-scale energy applications call for the development of lithium-ion battery (LIB) electrode materials with high energy density. Earth abundant conversion cathode material iron trifluoride (FeF(3)) has a high theoretical capacity (712 mAh g(-1)) and the potential to double the energy density of the current cathode material based on lithium cobalt oxide. Such promise has not been fulfilled due to the nonoptimal material properties and poor kinetics of the electrochemical conversion reactions. Here, we report for the first time a high-capacity LIB cathode that is based on networks of FeF(3) nanowires (NWs) made via an inexpensive and scalable synthesis. The FeF(3) NW cathode yielded a discharge capacity as high as 543 mAh g(-1) at the first cycle and retained a capacity of 223 mAh g(-1) after 50 cycles at room temperature under the current of 50 mA g(-1). Moreover, high-resolution transmission electron microscopy revealed the existence of continuous networks of Fe in the lithiated FeF(3) NWs after discharging, which is likely an important factor for the observed improved electrochemical performance. The loss of active material (FeF(3)) caused by the increasingly ineffective reconversion process during charging was found to be a major factor responsible for the capacity loss upon cycling. With the advantages of low cost, large quantity, and ease of processing, these FeF(3) NWs are not only promising battery cathode materials but also provide a convenient platform for fundamental studies and further improving conversion cathodes in general.
A comprehensive inpatient discharge system.
O'Connell, E. M.; Teich, J. M.; Pedraza, L. A.; Thomas, D.
1996-01-01
Our group has developed a computer system that supports all phases of the inpatient discharge process. The system fills in most of the physician's discharge order form and the nurse's discharge abstract, using information available from sign-out, order entry, scheduling, and other databases. It supplies information for referrals to outside institutions, and provides a variety of instruction materials for patients. Discharge forms can be completed in advance, so that the patient is not waiting for final paperwork. Physicians and nurses can work on their components independently, rather than in series. Response to the system has been very favorable. PMID:8947755
Laboratory simulation of irradiation-induced dielectric breakdown in spacecraft charging
NASA Technical Reports Server (NTRS)
Yadlowsky, E. J.; Churchill, R. J.; Hazelton, R. C.
1980-01-01
The discharging of dielectric samples irradiated by a beam of monoenergetic electrons is investigated. The development of a model, or models, which describe the discharge phenomena occuring on the irradiated dielectric targets is discussed. The electrical discharge characteristics of irradiated dielectric samples are discussed and the electrical discharge paths along dielectric surfaces and within the dielectric material are determined. The origin and destination of the surface emitted particles is examined and the charge and energy balance in the system is evaluated.
Can Concentration - Discharge Relationships Diagnose Material Source During Extreme Events?
NASA Astrophysics Data System (ADS)
Karwan, D. L.; Godsey, S.; Rose, L.
2017-12-01
Floods can carry >90% of the basin material exported in a given year as well as alter flow pathways and material sources. In turn, sediment and solute fluxes can increase flood damages and negatively impact water quality and integrate physical and chemical weathering of landscapes and channels. Concentration-discharge (C-Q) relationships are used to both describe export patterns as well as compute them. Metrics for describing C-Q patterns and inferring their controls are vulnerable to infrequent sampling that affects how C-Q relationships are interpolated and interpreted. C-Q relationships are typically evaluated from multiple samples, but because hydrological extremes are rare, data are often unavailable for extreme events. Because solute and sediment C-Q relationships likely respond to changes in hydrologic extremes in different ways, there is a pressing need to define their behavior under extreme conditions, including how to properly sample to capture these patterns. In the absence of such knowledge, improving load estimates in extreme floods will likely remain difficult. Here we explore the use of C-Q relationships to determine when an event alters a watershed system such that it enters a new material source/transport regime. We focus on watersheds with sediment and discharge time series include low-frequency and/or extreme events. For example, we compare solute and sediment patterns in White Clay Creek in southeastern Pennsylvania across a range of flows inclusive of multiple hurricanes for which we have ample ancillary hydrochemical data. TSS is consistently mobilized during high flow events, even during extreme floods associated with hurricanes, and sediment fingerprinting indicates different sediment sources, including in-channel remobilization and landscape erosion, are active at different times. In other words, TSS mobilization in C-Q space is not sensitive to the source of material being mobilized. Unlike sediments, weathering solutes in this watershed tend to exhibit a relatively chemostatic C-Q pattern, except during the runoff-dominated Hurricane Irene, when they exhibit a diluting C-Q pattern. Finally, we summarize the vulnerability of these observations to shifts in sampling effort to highlight the utility and limitations of C-Q-derived export patterns.
Micro- and nano-CT textural analysis of an experimental volcanic fulgurite.
NASA Astrophysics Data System (ADS)
Cimarelli, Corrado; Yilmaz, Tim; Colombier, Mathieu; Villanova, Julie; Höfer, Lucas; Hess, Kai-Uwe; Ruthensteiner, Bernhard; Dingwell, Donald
2017-04-01
Fulgurites are natural glasses formed by cloud to ground lightning discharges causing rapid heating into rocks or unconsolidated sediments. Volcanic lightning can determine the re-melting and even ablation of newly formed or just deposited volcanic tephra during explosive eruptions. In this case the pristine material is already constituted by glass that can be further modified by the discharge. Although volcanic lightning discharges are generally less energetic than those produced by thunderclouds, the high temperatures reached by the lightning channel are well in excess of the low melting temperature of glass material. Here we have experimentally reproduced a fulgurite by single impulse voltage discharges (134 kV, 331 A, 10.5 J) on a target glass material. We have chosen borosilicate glass fibers (180 microns nominal length) as starting material to better account for the structural and chemical modification of the single particles after discharge-melting. The structure of the small fulgurite is best resolved through X-ray micro- and nano-computed tomography. Micro-CT analysis was carried out on a phoenix nanotom m with a voxelsize of 1 µm3. Additionally a 3D reconstruction with a voxel size of 150 nm3 has been analyzed at the new nano-analysis beamline ID16B at the ESRF. 3D analysis was carried out using Avizo 9.2 software, which allows non-destructive analysis of the fragile structure of the sample. The sample shows the channel-like structure typical for natural fulgurites with an inner void channel and internal wall constituted by the melted fibers. About 33% of the total solid volume of the fulgurite is melted to form the inner wall. The inner wall is characterized by nano- to micro-metric vesicles determined by volatile exsolution (mainly H2O) during the instantaneous heating and trapped in the low viscosity melt by the subsequent rapid quenching. Progressively outward the fulgurite shows the intricate delicate structure of the pristine glass fibers. Our results demonstrate that structural and chemical alteration of low viscosity glass material is possible by small impulse discharges with relatively low currents, thus reproducing a plausible scenario for electrical discharges during volcanic eruptions. Our experiment opens the opportunity for systematic constrained experimental investigation of the modification induced by volcanic lightning on tephra.
NASA Technical Reports Server (NTRS)
Minow, Joseph I.
2014-01-01
(1) High energy (>100keV) electrons penetrate spacecraft walls and accumulate in dielectrics or isolated conductors; (2) Threat environment is energetic electrons with sufficient flux to charge circuit boards, cable insulation, and ungrounded metal faster than charge can dissipate; (3) Accumulating charge density generates electric fields in excess of material breakdown strenght resulting in electrostatic discharge; and (4) System impact is material damage, discharge currents inside of spacecraft Faraday cage on or near critical circuitry, and RF noise.
Nanocomposite of graphene and metal oxide materials
Liu, Jun; Aksay, Ilhan A.; Choi, Daiwon; Wang, Donghai; Yang, Zhenguo
2013-10-15
Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10 C.
Nanocomposite of graphene and metal oxide materials
Liu, Jun; Aksay, Ilhan A.; Choi, Daiwon; Wang, Donghai; Yang, Zhenguo
2012-09-04
Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10C.
Nanocomposite of graphene and metal oxide materials
Liu, Jun; Aksay, Ilhan A.; Choi, Daiwon; Wang, Donghai; Yang, Zhenguo
2015-06-30
Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10 C.
Watanabe, Satoru; Watanabe, Toshinari; Ito, Kazuhiro; Miyakawa, Naomichi; Ito, Setsuro; Hosono, Hideo; Mikoshiba, Shigeo
2011-06-01
12CaO·7Al 2 O 3 electride, a sub-nanoporous compound having a work function of 2.4 eV, was examined as a candidate cathode material in fluorescent lamps. The electron emission yield was higher and the discharge voltage was lower for 12CaO·7Al 2 O 3 than for existing cathode materials such as Ni, Mo or W; therefore, the energy consumption of the fluorescent lamps can be improved using 12CaO·7Al 2 O 3 cathodes. Prototype glow-discharge lamps using 12CaO·7Al 2 O 3 were constructed and exhibited reasonable durability.
Watanabe, Satoru; Watanabe, Toshinari; Ito, Kazuhiro; Miyakawa, Naomichi; Ito, Setsuro; Hosono, Hideo; Mikoshiba, Shigeo
2011-01-01
12CaO·7Al2O3 electride, a sub-nanoporous compound having a work function of 2.4 eV, was examined as a candidate cathode material in fluorescent lamps. The electron emission yield was higher and the discharge voltage was lower for 12CaO·7Al2O3 than for existing cathode materials such as Ni, Mo or W; therefore, the energy consumption of the fluorescent lamps can be improved using 12CaO·7Al2O3 cathodes. Prototype glow-discharge lamps using 12CaO·7Al2O3 were constructed and exhibited reasonable durability. PMID:27877401
Novel Co(OH)2 with cotton-like structure as anode material for alkaline secondary batteries
NASA Astrophysics Data System (ADS)
Zhao, W.; Liao, Y. L.; Qiu, S. J.; Chu, H. L.; Zou, Y. J.; Xiang, C. L.; Zhang, H. Z.; Xu, F.; Sun, L. X.
2018-01-01
The cotton-like Co(OH)2 (S-Co(OH)2) was successfully synthesized and its electrochemical performance was systematically investigated. S-Co(OH)2 was prepared through the “destruction” of the newly formed colloid Co(OH)2 by the reduction using sodium borohydride. The crystal structure and surface morphology were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). Used as an anode material for alkaline secondary batteries, S-Co(OH)2 sample exhibited better cycle stability, higher electrochemical capacity, and higher rate performance than those of conventional β-Co(OH)2. At a discharge current density of 100 mA/g, the initial discharge capacity of S-Co(OH)2 is 549.3 mAh/g and the discharge capacity is still sustained to be 329.2 mAh/g after 100 charge-discharge cycles with a capacity retention of 59.9%.
Charging and Discharging of Lichtenberg Electrets
NASA Astrophysics Data System (ADS)
Wood, Monika
The research presented here describes a unique way to deposit a large amount of charge onto the surface of a thin dielectric sheet to create a Lichtenberg electret that can be discharged elsewhere to form spectacular Lichtenberg figures. This study examines how the amount of charge deposited onto the surface, the geometry of the probes, and the type of material used can all impact the formation of the Lichtenberg figures. Photographs of the Lichtenberg figures were taken and used to determine the voltage, current, and energy released during each discharge. It was found that a single discharge can release 0.49 J of energy in 1.24 micros for a Lichtenberg figure that covers approximately 500 cm. 2. Lichtenberg figures can be used to characterize high-voltage surgeson power lines, to diagnose lightning strike victims, to analyze electrical breakdown of insulating materials, for artistic purposes, and for similar applications where pulsed capacitors are commonly used.
Code of Federal Regulations, 2012 CFR
2012-07-01
... Species Act. Existing Great Lakes discharger is any building, structure, facility, or installation from... discharger is any building, structure, facility, or installation from which there is or may be a “discharge... monitoring of the contaminant. Quantitative structure activity relationship (QSAR) or structure activity...
Ge, Hui; Yan, Ling; Mi, Dong; Zhu, Yi-min; Zhang, Lu
2012-04-01
The emission spectra of O(3p 5 P --> 3s 5 S2(0) 777.4 nm) produced by multi-needle-to-plate negative corona discharge and positive streamer discharge in air were successfully recorded at one atmosphere. The influences of discharge power, electrode gap, content of N2 and relative humidity on the excited O atom production were investigated in negative corona discharge. Meanwhile, the distribution of relative density of excited O atom in discharge space was also studied in positive streamer discharge. The results indicate that, for negative corona discharge, the amount of O active atom increases with the increase in power, decreases with increased discharge gap. And with the increase in relative humidity and N2 content, its amount firstly increases and then decreases; whereas for positive corona discharge, the relative density of O active atom from needlepoint to plate firstly increases and then decreases.
Black pepper powder microbiological quality improvement using DBD systems in atmospheric pressure
NASA Astrophysics Data System (ADS)
Grabowski, Maciej; Hołub, Marcin; Balcerak, Michał; Kalisiak, Stanisław; Dąbrowski, Waldemar
2015-07-01
Preliminary results are given regarding black pepper powder decontamination using dielectric barrier discharge (DBD) plasma in atmospheric pressure. Three different DBD reactor constructions were investigated, both packaged and unpackaged material was treated. Due to potential, industrial applications, in addition to microbiological results, water activity, loss of mass and the properties of packaging material, regarding barrier properties were investigated. Argon based treatment of packed pepper with DBD reactor configuration is proposed and satisfactory results are presented for treatment time of 5 min or less. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark
Related Studies in Long Term Lithium Battery Stability
NASA Technical Reports Server (NTRS)
Horning, R. J.; Chua, D. L.
1984-01-01
The continuing growth of the use of lithium electrochemical systems in a wide variety of both military and industrial applications is primarily a result of the significant benefits associated with the technology such as high energy density, wide temperature operation and long term stability. The stability or long term storage capability of a battery is a function of several factors, each important to the overall storage life and, therefore, each potentially a problem area if not addressed during the design, development and evaluation phases of the product cycle. Design (e.g., reserve vs active), inherent material thermal stability, material compatibility and self-discharge characteristics are examples of factors key to the storability of a power source.
Evaluation of lithium alloy anode materials for Li-TiS2 cells
NASA Technical Reports Server (NTRS)
Huang, C.-K.; Subbarao, S.; Shen, D. H.; Deligiannis, F.; Attia, A.; Halpert, G.
1991-01-01
A study was performed to select candidate lithium alloy anode materials and establish selection criteria. Some of the selected alloy materials were evaluated for their electrochemical properties and performance. This paper describes the criteria for the selection of alloys and the findings of the studies. Li-Si and Li-Cd alloys have been found to be unstable in the EC+2-MeTHF-based electrolyte. The Li-Al alloy system was found to be promising among the alloy systems studied in view of its stability and reversibility. Unfortunately, the large volume changes of LiAl alloys during charge/discharge cycling cause considerable 'exfoliation' of its active mass. This paper also describes ways how to address this problem. The rate of disintegration of this anode would probably be surpressed by the presence of an inert solid solution or a uniform distribution of precipitates within the grains of the active mass. It was discovered that the addition of a small quantity of Mn may improve the mechanical properties of LiAl. In an attempt to reduce the Li-Al alloy vs. Li voltage, it was observed that LiAlPb(0.1)Cd(0.3) material can be cycled at 1.5 mA/sq cm without exfoliation of the active mass.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Twu, Nancy; Metzger, Michael; Balasubramanian, Mahalingam
Here, the lithium-excess Li xNi 2-4x/3Sb x/3O 2 (LNSO) materials were previously shown to demonstrate higher capacities and improved cyclability with increasing lithium content. While the performance trend is promising, observed capacities are much lower than theoretical capacities, pointing to a need for further understanding of active redox processes in these materials. In this work, we study the electrochemical behavior of the LNSO materials as a function of lithium content and at slow and fast rates. Surprisingly, Li 1.15Ni 0.47Sb 0.38O 2 (LNSO-15) exhibits higher discharge capacities at faster rates and traverses distinct voltage curves at slow and fast rates.more » To understand these two peculiarities, we characterize the redox activity of nickel, antimony, and oxygen at different rates. While experiments confirm some nickel redox activity and oxygen loss, these two mechanisms cannot account for all observed capacity. We propose that the balance of the observed capacity may be due reversible oxygen redox and that the rate-dependent voltage curve features may derive from irreversible nickel migration occurring on slow charge. As future high energy density cathodes are likely to contain both lithium excess and high nickel content, both of these findings have important implications for the development of novel high capacity cathode materials.« less
Effect of KOH Concentration and Anions on the Performance of a Ni-H2 Battery Positive Plate
NASA Technical Reports Server (NTRS)
Vaidyanathan, Hari; Robbins, Kathleen; Gopalakrishna, M. Rao
1996-01-01
The capacity and voltage behavior of electrochemically impregnated sintered nickel positive plates was examined by galvanostatic charging and discharging in a flooded electrolyte cell. Three different concentrations of potassium hydroxide (KOH) (40, 31, and 26 percent) and 31 percent KOH containing dissolved nitrate, sulfate, or silicate were investigated. The end-of-charge voltage at C/10 charge and at 10 degrees C showed the following order: 40 percent KOH greater than 31 percent KOH alone and in the presence of the anions greater than 26 percent KOH. The mid discharge voltage at C/2 discharge was higher in 26 percent KOH, almost the same for 31 percent KOH with and without added contaminants, and much lower for 40 percent KOH. The plate capacity was marginally affected by cycling in all cases except for 40 percent KOH, where the capacity declined after 1,000 cycles at 80 percent depth of discharge (DOD). At the end of cycling, all the plates tested experienced a weight loss, except in the case of 31 percent KOH, as a result of active material extrusion. Cyclic voltammetry of miniature electrodes in 31 percent KOH showed that the cathodic peak potentials are less polarized in the presence and absence of silicate at -5 degrees C compared to 25 degrees C indicating a slightly higher voltage during discharge in a Ni-H2 battery. Futhermore, the features of the current-potential profile were practically unchanged in the presence of silicate.
NASA Astrophysics Data System (ADS)
Zhao, Luxiang; Liu, Wenzheng; Li, Zhiyi; Ma, Chuanlong
2018-05-01
A method to generate large-area surface plasma in air by micro-discharge is proposed. Two ultrathin laminated electrode structures of non-insulating and insulating types were formed by using the nanoscale ITO conductive layer. The surface glow discharge in atmospheric air is realized in low discharge voltage by constructing the special electric field of two-dimensional unidirectional attenuation. In particular, the insulating electrode structure can avoid the loss of ITO electrodes so that the discharge stability can be increased, and the treated objects can be prevented from metal ion pollution caused by the electrode in the discharge. It has broad application prospects in the fields of aerodynamics and material surface treatment.
Qiu, Bao; Zhang, Minghao; Wu, Lijun; Wang, Jun; Xia, Yonggao; Qian, Danna; Liu, Haodong; Hy, Sunny; Chen, Yan; An, Ke; Zhu, Yimei; Liu, Zhaoping; Meng, Ying Shirley
2016-07-01
Lattice oxygen can play an intriguing role in electrochemical processes, not only maintaining structural stability, but also influencing electron and ion transport properties in high-capacity oxide cathode materials for Li-ion batteries. Here, we report the design of a gas-solid interface reaction to achieve delicate control of oxygen activity through uniformly creating oxygen vacancies without affecting structural integrity of Li-rich layered oxides. Theoretical calculations and experimental characterizations demonstrate that oxygen vacancies provide a favourable ionic diffusion environment in the bulk and significantly suppress gas release from the surface. The target material is achievable in delivering a discharge capacity as high as 301 mAh g(-1) with initial Coulombic efficiency of 93.2%. After 100 cycles, a reversible capacity of 300 mAh g(-1) still remains without any obvious decay in voltage. This study sheds light on the comprehensive design and control of oxygen activity in transition-metal-oxide systems for next-generation Li-ion batteries.
Qiu, Bao; Zhang, Minghao; Wu, Lijun; Wang, Jun; Xia, Yonggao; Qian, Danna; Liu, Haodong; Hy, Sunny; Chen, Yan; An, Ke; Zhu, Yimei; Liu, Zhaoping; Meng, Ying Shirley
2016-01-01
Lattice oxygen can play an intriguing role in electrochemical processes, not only maintaining structural stability, but also influencing electron and ion transport properties in high-capacity oxide cathode materials for Li-ion batteries. Here, we report the design of a gas–solid interface reaction to achieve delicate control of oxygen activity through uniformly creating oxygen vacancies without affecting structural integrity of Li-rich layered oxides. Theoretical calculations and experimental characterizations demonstrate that oxygen vacancies provide a favourable ionic diffusion environment in the bulk and significantly suppress gas release from the surface. The target material is achievable in delivering a discharge capacity as high as 301 mAh g−1 with initial Coulombic efficiency of 93.2%. After 100 cycles, a reversible capacity of 300 mAh g−1 still remains without any obvious decay in voltage. This study sheds light on the comprehensive design and control of oxygen activity in transition-metal-oxide systems for next-generation Li-ion batteries. PMID:27363944
Qiu, Bao; Zhang, Minghao; Wu, Lijun; ...
2016-07-01
Lattice oxygen can play an intriguing role in electrochemical processes, not only maintaining structural stability, but also influencing electron and ion transport properties in high-capacity oxide cathode materials for Li-ion batteries. Here, we report the design of a gas–solid interface reaction to achieve delicate control of oxygen activity through uniformly creating oxygen vacancies without affecting structural integrity of Li-rich layered oxides. Theoretical calculations and experimental characterizations demonstrate that oxygen vacancies provide a favourable ionic diffusion environment in the bulk and significantly suppress gas release from the surface. The target material is achievable in delivering a discharge capacity as high asmore » 301 mAh g –1 with initial Coulombic efficiency of 93.2%. After 100 cycles, a reversible capacity of 300 mAh g –1 still remains without any obvious decay in voltage. Lastly, this study sheds light on the comprehensive design and control of oxygen activity in transition-metal-oxide systems for next-generation Li-ion batteries.« less
Capacity loss on storage and possible capacity recovery for HST nickel-hydrogen cells
NASA Technical Reports Server (NTRS)
Lowery, John E.
1992-01-01
Negatively precharged nickel hydrogen cells will experience a useable capacity loss during extended open circuit storage periods. Some of the lost capacity can be recovered through cycling. Capacity recovery through cycling can be enhanced by cycling at high depths of discharge (DOD). The most timely procedure for recovering the faded capacity is to charge the cell fully and allow the cell to sit open-circuit at room temperature. This procedure seems to be effective in part because of the enlarged structure of the active materials. The compounds that formed during storage at the low electrode potentials can more easily dissolve and redistribute. All of the original capacity cannot be recovered because the lattice structure of the active material is irreversibly altered during storage. The recommendation is to use positively precharged cells activated with 26 percent KOH if possible. In aerospace applications, the benefits of negative precharge are offset by the possibility of delays and storage periods.
RECENT DEVELOPMENTS IN HYDROLOGIC INSTRUMENTATION.
Latkovich, Vito J.
1985-01-01
The availability of space-age materials and implementation of state-of-the-art electronics is making possible the recent developments of hydrologic instrumentation. Material developments include: Synthetic-fiber sounding and tag lines; fiberglass wading rod; polymer (plastic) sheaves, pulleys and sampler components; and polymer (plastic) bucket wheels for current meters. These materials are very cost effective and efficient. Electromechanical and electronic developments and applications include: adaptable data acquisition system; downhole sampler for hazardous substances; current-meter digitizer; hydraulic power/drive system for discharge measurements and water-quality sampling; non-contact water-level sensors; minimum data recorder; acoustic velocity meters, and automated current meter discharge-measurement system.
Fei, Hailong; Feng, Wenjing; Xu, Tan
2017-02-15
It is important to discover new, cheap and environmental friendly electrode materials with high capacity and good cycling stability for lithium and sodium-ion batteries. Zinc 1,4-naphthalenedicarboxylate was firstly found to be stable anode materials for lithium and sodium-ion batteries. The discharge capacity can be up to 468.9mAhg -1 after 100 cycles at a current density of 100mAg -1 for lithium-ion batteries, while the second discharge capacity of 320.7mAhg -1 was achieved as anode materials for sodium-ion batteries. A possible electrochemical reaction mechanism was discussed. Copyright © 2016 Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cundy, A.B.; Croudace, I.W.; Warwick, P.E.
1999-09-01
Radioactive discharges from nuclear facilities are frequently made into the marine environment and their fate during and after cessation of discharges is a matter of interest and concern. This study examines the decline of the radionuclides {sup 60} and {sup 65}Zn along the southern UK. coast, over the per 1988--1998, following the closure of the steam-generating heavy water (SGHW) reactor at AEA Winfrith, Dorset, UK. {sup 60}Co and {sup 65}Zn (and other activation products such as {sup 63}Ni and {sup 55}Fe) were widely dispersed in the marine environment off the central south coast of England, due to authorized releases frommore » AEA Winfrith. Significant interaction occurred with clay-rich sediments and biota. A general exponential decline in {sup 60}Co activities (and in {sup 65}Zn activity) is found in intertidal mudflat sediments, seaweed and marine fauna in different areas along the south coast following closure of the reactor in 1990. Effective half-lives are determined which vary from 1 to 4 years in surface sediments ({sup 60}Co only), 1--4 years in seaweed and 0.5--2.5 years in crustaceans, bivalves and molluscs. Physical mixing and bioturbation largely control the rate at which {sup 60}Co declines in surface sediments. Both {sup 60}Co and {sup 65}Zn show a relatively slow rate of decline in seaweed and in marine fauna, showing that even after the virtual cessation of discharge from nuclear facilities, contamination of these organisms may persist for a number of years, albeit at reduced activities. Reasons for this persistence are likely to include absorption of radionuclides from sediment, and release and recycling of radionuclides via breakdown of contaminated organic material.« less
2011-12-01
Figure 2. Picture of the spark discharge with Ga electrodes. dgap superconducting transition temperature would cause a jump in the AEM current ...failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE...materials such as gold, sodium, and aluminum will not form a sufficiently concentrated vapor cloud from a current -carrying wire to form aerosol
Atmospheric electricity criteria guidelines for use in aerospace vehicle development
NASA Technical Reports Server (NTRS)
Daniels, G. E.
1972-01-01
Lightning has always been of concern for aerospace vehicle ground activities. The unexpected triggering of lightning discharges by the Apollo 12 space vehicle shortly after launch and the more recent repeated lightning strikes to the launch umbilical tower while the Apollo 15 space vehicle was being readied for launch have renewed interest in studies of atmospheric electricity as it relates to space vehicle missions. The material presented reflects some of the results of these studies with regard to updating the current criteria guidelines.
Enhancement of discharge performance of Li/CF x cell by thermal treatment of CF x cathode material
NASA Astrophysics Data System (ADS)
Zhang, Sheng S.; Foster, Donald; Read, Jeffrey
In this work we demonstrate that the thermal treatment of CF x cathode material just below the decomposition temperature can enhance discharge performance of Li/CF x cells. The performance enhancement becomes more effective when heating a mixture of CF x and citric acid (CA) since CA serves as an extra carbon source. Discharge experiments show that the thermal treatment not only reduces initial voltage delay, but also raises discharge voltage. Whereas the measurement of powder impedance indicates the thermal treatment does not increase electronic conductivity of CF x material. Based on these facts, we propose that the thermal treatment results in a limited decomposition of CF x, which yields a subfluorinated carbon (CF x- δ), instead of a highly conductive carbon. In the case of CF x/AC mixture, the AC provides extra carbon that reacts with F 2 and fluorocarbon radicals generated by the thermal decomposition of CF x to form subfluorinated carbon. The process of thermal treatment is studied by thermogravimetric analysis and X-ray diffraction, and the effect of treatment conditions such as heating temperature, heating time and CF x/CA ratio on the discharge performance of CF x cathode is discussed. As an example, a Li/CF x cell using CF x treated with CA at 500 °C under nitrogen for 2 h achieved theretical specific capacity when being discharged at C/5. Impedance analysis indicates that the enhanced performance is attributed to a significant reduction in the cell reaction resistance.
Long life nickel electrodes for a nickel-hydrogen cell: Cycle life tests
NASA Technical Reports Server (NTRS)
Lim, H. S.; Verzwyvelt, S. A.
1985-01-01
In order to develop a long life nickel electrode for a Ni/H2 cell, the cycle life of nickel electrodes was tested in Ni/H2 boiler plate cells. A 19 test cell matrix was made of various nickel electrode designs including three levels each of plaque mechanical strength, median pore size of the plaque, and active material loading. Test cells were cycled to the end of their life (0.5v) in a 45 minute low Earth orbit cycle regime at 80% depth-of-discharge. It is shown that the active material loading level affects the cycle life the most with the optimum loading at 1.6 g/cc void. Mechanical strength does not affect the cycle life noticeably in the bend strength range of 400 to 700 psi. It is found that the best plaque is made of INCO nickel powder type 287 and has median pore size of 13 micron.
Lithium-aluminum-magnesium electrode composition
Melendres, Carlos A.; Siegel, Stanley
1978-01-01
A negative electrode composition is presented for use in a secondary, high-temperature electrochemical cell. The cell also includes a molten salt electrolyte of alkali metal halides or alkaline earth metal halides and a positive electrode including a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent and a magnesium-aluminum alloy as a structural matrix. Various binary and ternary intermetallic phases of lithium, magnesium, and aluminum are formed but the electrode composition in both its charged and discharged state remains substantially free of the alpha lithium-aluminum phase and exhibits good structural integrity.
TESTING OF TMR SAND MANTIS FINAL REPORT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krementz, D; William Daugherty, W
2007-06-12
Screening tests of Sand Mantis candidate materials selected for erosion resistance have been completed. The results of this testing identified that over a relatively short period of operation (<1 hour), measurable erosion will occur in each of the candidate zoom tube materials given equal operating exposure. Additionally, this testing has shown that erosion of the rubber discharge hose directly downstream of the vehicle could be expected to limit the service life of the discharge hose. On the basis of these test results, SRNL recommends the following; {lg_bullet} redesign of critical system components (e.g., zoom tube, discharge hose) should be conductedmore » to improve system characteristics relative to erosion and capitalize on the results of this testing, {lg_bullet} continued efforts to deploy the Sand Mantis should include testing to better define and optimize operating parameters, and gain an understanding of system dynamics, {lg_bullet} discontinue wear testing with the selected materials pending redesign of critical system components (1st recommendation) and inclusion of other candidate materials. The final selection of additional candidate materials should be made following design changes, but might include a Stellite alloy or zirconia.« less
Parts, Materials, and Processes Control Program for Expendable Launch Vehicles
2015-07-31
burn-in, electrical tests (DWV, room and hot IR, partial discharge when in corona region); perform DPA with SEM/EDX analysis of dielectric...life test; x-ray and vicinal illumination inspection; electrical tests (DWV, room and hot IR, partial discharge when in corona region) Termination...defects; proper voltage derating. Partial discharge testing, corona inception testing up to 60% of rated voltage; CSAM screening; voltage burn
NASA Astrophysics Data System (ADS)
Joye, S. B.
2016-02-01
The fate of oil derived from natural seepage in the marine environment is poorly constrained. In the aftermath of the 2010 BP/Macondo oil well blowout, sedimentation of oil-containing material to the seafloor was an important fate for discharged oil. Though the amount of oil accounted for by sedimentation processes remains poorly constrained, sedimentation is now considered an important fate of oil during large open water spills that generate extensive surface slicks. In the Gulf of Mexico, vigorous natural oil seeps generate extensive, sometimes thick, surface slicks. In the case of highly active seeps, these surface oil slicks persist at the sea surface over the seep site a majority of the time. We investigated the fate of oil released through natural seepage and the potential for the sedimentation of surface-slick derived oil at two vigorous hydrocarbon seeps in the Gulf of Mexico, Green Canyon block 600 and block 767. Hydrocarbon analyses were performed on samples collected from oil vents at the seafloor, in surface slicks, and in sediments cores apparently containing sedimented oil. Sediment cores collected from both of these active seep sites away from known oil vents contained distinct (1-3 cm thick) layers that were brown in coloration and which displayed distinct sedimentology compared to deeper strata. The oil fingerprint was also different, suggesting this material was not the result of weathering during transit through the sediment column. Available data suggest that sedimentation of weathered oil also occurs at vigorous natural seeps. Detailed studies of the weathered oil sedimentation process at natural seeps will help reveal the mechanisms driving this phenomena and are important for understanding the fate of oil released during accidental discharges and spills.
Hu, Enyuan; Wang, Xuelong; Yu, Xiqian; ...
2018-01-19
The rechargeable lithium-ion battery (LIB) is the most promising energy storage system to power electric vehicles with high energy density and long cycling life. However, in order to meet customers’ demands for fast charging, the power performances of current LIBs need to be improved. From the cathode aspect, layer-structured cathode materials are widely used in today’s market and will continue to play important roles in the near future. The high rate capability of layered cathode materials during charging and discharging is critical to the power performance of the whole cell and the thermal stability is closely related to the safetymore » issues. Therefore, the in-depth understanding of structural changes of layered cathode materials during high rate charging/discharging and the thermal stability during heating are essential in developing new materials and improving current materials. Since structural changes take place from the atomic level to the whole electrode level, combination of characterization techniques covering multilength scales is quite important. Finally, in many cases, this means using comprehensive tools involving diffraction, spectroscopy, and imaging to differentiate the surface from the bulk and to obtain structural/chemical information with different levels of spatial resolution.« less
30 CFR 817.47 - Hydrologic balance: Discharge structures.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Hydrologic balance: Discharge structures. 817...-UNDERGROUND MINING ACTIVITIES § 817.47 Hydrologic balance: Discharge structures. Discharge from sedimentation... the hydrologic balance. Discharge structures shall be designed according to standard engineering...
30 CFR 817.47 - Hydrologic balance: Discharge structures.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Hydrologic balance: Discharge structures. 817...-UNDERGROUND MINING ACTIVITIES § 817.47 Hydrologic balance: Discharge structures. Discharge from sedimentation... the hydrologic balance. Discharge structures shall be designed according to standard engineering...
30 CFR 816.47 - Hydrologic balance: Discharge structures.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Hydrologic balance: Discharge structures. 816...-SURFACE MINING ACTIVITIES § 816.47 Hydrologic balance: Discharge structures. Discharge from sedimentation... the hydrologic balance. Discharge structures shall be designed according to standard engineering...
30 CFR 816.47 - Hydrologic balance: Discharge structures.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Hydrologic balance: Discharge structures. 816...-SURFACE MINING ACTIVITIES § 816.47 Hydrologic balance: Discharge structures. Discharge from sedimentation... the hydrologic balance. Discharge structures shall be designed according to standard engineering...
NASA Astrophysics Data System (ADS)
Saravanan, M.; Ganesan, M.; Ambalavanan, S.
2014-04-01
In this work, we report an in situ generated carbon from sugar as additive in the Negative Active Mass (NAM) which enhances the charge-discharge characteristics of the lead-acid cells. In situ formed sugar derived carbon (SDC) with leady oxide (LO) provides a conductive network and excellent protection against NAM irreversible lead sulfation. The effect of SDC and carbon black (CB) added negative plates are characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), galvanostatic charge-discharge, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. The results show that subtle changes in the addition of carbon to NAM led to subsequent changes on the performance during partial-state-of-charge (PSoC) operations in lead-acid cells. Furthermore, SDC added cells exhibit remarkable improvement in the rate capability, active material utilization, cycle performance and charge acceptance compared to that of the conventional CB added cells. The impact of SDC with LO at various synthesis conditions on the electrochemical performance of the negative plate is studied systematically.
Computational study of sheath structure in oxygen containing plasmas at medium pressures
NASA Astrophysics Data System (ADS)
Hrach, Rudolf; Novak, Stanislav; Ibehej, Tomas; Hrachova, Vera
2016-09-01
Plasma mixtures containing active species are used in many plasma-assisted material treatment technologies. The analysis of such systems is rather difficult, as both physical and chemical processes affect plasma properties. A combination of experimental and computational approaches is the best suited, especially at higher pressures and/or in chemically active plasmas. The first part of our study of argon-oxygen mixtures was based on experimental results obtained in the positive column of DC glow discharge. The plasma was analysed by the macroscopic kinetic approach which is based on the set of chemical reactions in the discharge. The result of this model is a time evolution of the number densities of each species. In the second part of contribution the detailed analysis of processes taking place during the interaction of oxygen containing plasma with immersed substrates was performed, the results of the first model being the input parameters. The used method was the particle simulation technique applied to multicomponent plasma. The sheath structure and fluxes of charged particles to substrates were analysed in the dependence on plasma pressure, plasma composition and surface geometry.
NASA Astrophysics Data System (ADS)
Duan, Zhengchao; He, Feng; Si, Xinlu; Bradley, James W.; Ouyang, Jiting
2018-02-01
Conductive solid material sampling by micro-plasma under ambient atmosphere was studied experimentally. A high-voltage pulse generator was utilized to drive discharge between a tungsten needle and metal samples. The effects of pulse width on discharge, micro-plasma and sampling were investigated. The electrical results show that two discharge current pulses can be formed in one voltage pulse. The duration of the first current pulse is of the order of 100 ns. The duration of the second current pulse depends on the width of the voltage pulse. The electrical results also show that arc micro-plasma was generated during both current pulses. The results of the emission spectra of different sampled materials indicate that the relative emission intensity of elemental metal ions will increase with pulse width. The excitation temperature and electron density of the arc micro-plasmas increase with the voltage pulse width, which contributes to the increase of relative emission intensity of metal ions. The optical images and energy dispersive spectroscopy results of the sampling spots on metal surfaces indicate that discharge with a short voltage pulse can generate a small sputtering crater.
Measurement of the Electron Density and the Attachment Rate Coefficient in Silane/Helium Discharges.
1986-09-01
materials -- in this case hydrogenated amorphous silicon . One of the biggest problems in such a task is the fact that the discharge creates complex radicals...electron density is enhanced -- even on a time-averaged basis, and the silicon deposition rate is also increased. The physical process for the density...etching and deposition of semiconductor materials. Plasma etching (also known as dry etching) Of silicon using flourine bearing gases has made it possible
First-principles study of the electronic properties and discharge profile of AgNa(VO2F2)2
NASA Astrophysics Data System (ADS)
Onoue, Masatoshi; Trimarchi, Giancarlo; Freeman, Arthur J.
2014-03-01
Implantable cardiac defibrillators (ICDs) require batteries with high capacities and high discharge rates to ensure the optimal operation of the device over several years. Ag2V4O11 has been a cathode material of choice for the ICDs owing to its high capacity and fast rate of electronic discharge. To reduce ICD size and improve ICD performance, a new cathode material would need to display a higher volumetric capacity and redox potential. Recently, the new cathode compound AgNa(VO2F2)2 (SSVOF) was synthesized and displayed favorable voltage for sodium-ion batteries. However, the discharge reaction has been unclear. In this presentation, we study the discharge reaction of SSVOF through DFT calculations. All calculations are performed within the PAW method using the GGA and GGA + U functionals. Among several possible reactions, we focus on the reaction Ag X + A --> AX + Ag, where X is Na(VO2F2)2 and A is Li or Na. In this reaction, the discharge occurs by replacing Ag with A. The calculated discharge potential for Li is 3.3 V in GGA and 2.9 V in GGA + U and that for Na is 3.1 V in GGA and 2.8 V in GGA + U . These values are consistent with the experimental ones. Supported by the DOE ER46536 Program.
A novel carbon electrode material for highly improved EDLC performance.
Fang, Baizeng; Binder, Leo
2006-04-20
Porous materials, developed by grafting functional groups through chemical surface modification with a surfactant, represent an innovative concept in energy storage. This work reports, in detail, the first practical realization of a novel carbon electrode based on grafting of vinyltrimethoxysilane (vtmos) functional group for energy storage in electric double layer capacitor (EDLC). Surface modification with surfactant vtmos enhances the hydrophobisation of activated carbon and the affinity toward propylene carbonate (PC) solvent, which improves the wettability of activated carbon in the electrolyte solution based on PC solvent, resulting in not only a lower resistance to the transport of electrolyte ions within micropores of activated carbon but also more usable surface area for the formation of electric double layer, and accordingly, higher specific capacitance, energy density, and power capability available from the capacitor based on modified carbon. Especially, the effects from surface modification become superior at higher discharge rate, at which much better EDLC performance (i.e., much higher energy density and power capability) has been achieved by the modified carbon, suggesting that the modified carbon is a novel and very promising electrode material of EDLC for large current applications where both high energy density and power capability are required.
Ngandjong, Alain C; Rucci, Alexis; Maiza, Mariem; Shukla, Garima; Vazquez-Arenas, Jorge; Franco, Alejandro A
2017-12-07
A novel multiscale modeling platform is proposed to demonstrate the importance of particle assembly during battery electrode fabrication by showing its effect on battery performance. For the first time, a discretized three-dimensional (3D) electrode resulting from the simulation of its fabrication has been incorporated within a 3D continuum performance model. The study used LiNi 0.5 Co 0.2 Mn 0.3 O 2 as active material, and the effect of changes of electrode formulation is explored for three cases, namely 85:15, 90:10, and 95:5 ratios between active material and carbon-binder domains. Coarse-grained molecular dynamics is used to simulate the electrode fabrication. The resulting electrode mesostructure is characterized in terms of active material surface coverage by the carbon-binder domains and porosity. The trends observed are nonintuitive, indicating a high degree of complexity of the system. These structures are subsequently implemented into a 3D continuum model which displays distinct discharge behaviors for the three cases. The study offers a method for developing a coherent theoretical understanding of electrode fabrication that can help optimize battery performance.
NASA Astrophysics Data System (ADS)
Xu, XiaoLong; Qi, CongYu; Hao, ZhenDong; Wang, Hao; Jiu, JinTing; Liu, JingBing; Yan, Hui; Suganuma, Katsuaki
2018-03-01
The requirement of energy-storage equipment needs to develop the lithium ion battery (LIB) with high electrochemical performance. The surface modification of commercial LiFePO4 (LFP) by utilizing zeolitic imidazolate frameworks-8 (ZIF-8) offers new possibilities for commercial LFP with high electrochemical performances. In this work, the carbonized ZIF-8 (CZIF-8) was coated on the surface of LFP particles by the in situ growth and carbonization of ZIF-8. Transmission electron microscopy indicates that there is an approximate 10 nm coating layer with metal zinc and graphite-like carbon on the surface of LFP/CZIF-8 sample. The N2 adsorption and desorption isotherm suggests that the coating layer has uniform and simple connecting mesopores. As cathode material, LFP/CZIF-8 cathode-active material delivers a discharge specific capacity of 159.3 mAh g-1 at 0.1C and a discharge specific energy of 141.7 mWh g-1 after 200 cycles at 5.0C (the retention rate is approximate 99%). These results are attributed to the synergy improvement of the conductivity, the lithium ion diffusion coefficient, and the degree of freedom for volume change of LFP/CZIF-8 cathode. This work will contribute to the improvement of the cathode materials of commercial LIB.[Figure not available: see fulltext.
Recent Progress on Flexible and Wearable Supercapacitors.
Xue, Qi; Sun, Jinfeng; Huang, Yan; Zhu, Minshen; Pei, Zengxia; Li, Hongfei; Wang, Yukun; Li, Na; Zhang, Haiyan; Zhi, Chunyi
2017-12-01
Recently, wearable electronic devices including electrical sensors, flexible displays, and health monitors have received considerable attention and experienced rapid progress. Wearable supercapacitors attract tremendous attention mainly due to their high stability, low cost, fast charging/discharging, and high efficiency; properties that render them value for developing fully flexible devices. In this Concept, the recent achievements and advances made in flexible and wearable supercapacitors are presented, especially highlighting the promising performances of yarn/fiber-shaped and planar supercapacitors. On the basis of their working mechanism, electrode materials including carbon-based materials, metal oxide-based materials, and conductive polymers with an emphasis on the performance-optimization method are introduced. The latest representative techniques and active materials of recently developed supercapacitors with superior performance are summarized. Furthermore, the designs of 1D and 2D electrodes are discussed according to their electrically conductive supporting materials. Finally, conclusions, challenges, and perspective in optimizing and developing the electrochemical performance and function of wearable supercapacitors for their practical utility are addressed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Geomorphic impacts of flash flooding in a forested headwater basin
NASA Astrophysics Data System (ADS)
Phillips, Jonathan D.
2002-12-01
Geomorphic impacts of a July 2001 flood in the Hungry Mother basin near Marion, Virginia, were examined to shed light on the relationships between channel characteristics and the frequency of channel-modifying discharges. Creeks in the study area have been observed for many years, with no significant channel changes since at least 1985. The 2001 flood had a recurrence interval of >200 years, and caused the only channel change, bank erosion, and transport of coarse channel material observed in recent decades. The paucity of fines in channels before or after the flood, and the absence of sub-sand sized material in the flood deposits, indicates that normal, frequent, well-below-bankfull flows are sufficient to transport the (apparently limited) supply of fines. The large particles transported during the 2001 flood after years of inactivity indicate that relatively rare floods are necessary to mobilize this material. This suggests the notion of a bimodal 'dominant' discharge. On the one hand frequent flows considerably below bankfull levels are sufficient to maintain the channel and prevent significant accumulation of fine sediments and organic matter. On the other hand, rare floods are necessary to transport the coarser bed material and erode channel banks. In the Hungry Mother area, bed material has no relationship to normal flows, or to flows with recurrence intervals on the order of 1-3 years. Bankfull discharge is apparently not related to either the maintenance or channel-changing dominant discharges. These results suggest that the use of channel dimensions and/or bed material as surrogate indicators of hydrologic regimes can be quite complicated, and that in some streams bankfull flow has no particular significance in terms of sediment transport and channel modifications.
NASA Astrophysics Data System (ADS)
Hamdan, A.; Noel, C.; Kosior, F.; Henrion, G.; Belmonte, T.
2013-01-01
Modes of energy dissipation in impacts made on various materials (Al, Cu, Fe, and Si) by discharges in heptane are investigated for micro-gap conditions. Bulk metals and thin films of 300 nm in thickness deposited on silicon wafers are used as samples. Positive high voltage pulses with nanosecond rise times make it possible to isolate a single discharge and to study the way the charge delivered by the power supply is transferred to the larger electrode (the sample) in a pin-to-plate configuration. The diameter of the impacts created by the plasma varies linearly versus the charge raised at a power close to 0.5. However, the exact value of the power depends on the material. We also show how the impact morphologies change with the applied charge. At high charges, the diameters of impacts on thin films behave as those made on silicon. At low charges, they behave as the bulk material. Finally, we show that the energy dissipated in impacts is below a few percent.
Control of three different continuous pharmaceutical manufacturing processes: Use of soft sensors.
Rehrl, Jakob; Karttunen, Anssi-Pekka; Nicolaï, Niels; Hörmann, Theresa; Horn, Martin; Korhonen, Ossi; Nopens, Ingmar; De Beer, Thomas; Khinast, Johannes G
2018-05-30
One major advantage of continuous pharmaceutical manufacturing over traditional batch manufacturing is the possibility of enhanced in-process control, reducing out-of-specification and waste material by appropriate discharge strategies. The decision on material discharge can be based on the measurement of active pharmaceutical ingredient (API) concentration at specific locations in the production line via process analytic technology (PAT), e.g. near-infrared (NIR) spectrometers. The implementation of the PAT instruments is associated with monetary investment and the long term operation requires techniques avoiding sensor drifts. Therefore, our paper proposes a soft sensor approach for predicting the API concentration from the feeder data. In addition, this information can be used to detect sensor drift, or serve as a replacement/supplement of specific PAT equipment. The paper presents the experimental determination of the residence time distribution of selected unit operations in three different continuous processing lines (hot melt extrusion, direct compaction, wet granulation). The mathematical models describing the soft sensor are developed and parameterized. Finally, the suggested soft sensor approach is validated on the three mentioned, different continuous processing lines, demonstrating its versatility. Copyright © 2018 Elsevier B.V. All rights reserved.
Microalgae and wastewater treatment
Abdel-Raouf, N.; Al-Homaidan, A.A.; Ibraheem, I.B.M.
2012-01-01
Organic and inorganic substances which were released into the environment as a result of domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The normal primary and secondary treatment processes of these wastewaters have been introduced in a growing number of places, in order to eliminate the easily settled materials and to oxidize the organic material present in wastewater. The final result is a clear, apparently clean effluent which is discharged into natural water bodies. This secondary effluent is, however, loaded with inorganic nitrogen and phosphorus and causes eutrophication and more long-term problems because of refractory organics and heavy metals that are discharged. Microalgae culture offers an interesting step for wastewater treatments, because they provide a tertiary biotreatment coupled with the production of potentially valuable biomass, which can be used for several purposes. Microalgae cultures offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae to use inorganic nitrogen and phosphorus for their growth. And also, for their capacity to remove heavy metals, as well as some toxic organic compounds, therefore, it does not lead to secondary pollution. In the current review we will highlight on the role of micro-algae in the treatment of wastewater. PMID:24936135
Lithium-manganese dioxide cells for implantable defibrillator devices-Discharge voltage models
NASA Astrophysics Data System (ADS)
Root, Michael J.
The discharge potential behavior of lithium-manganese dioxide cells designed for implantable cardiac defibrillators was characterized as a function of extent of cell depletion for tests designed to discharge the cells for times between 1 and 7 years. The discharge potential curves may be separated into two segments from 0 ≤ x ≤ ∼0.51 and ∼0.51 ≤ x ≤ 1.00, where x is the dimensionless extent of discharge referenced to the rated cell capacity. The discharge potentials conform to Tafel kinetics in each segment. This behavior allows the discharge potential curves to be predicted for an arbitrary discharge load and long term discharge performance may be predicted from short term test results. The discharge potentials may subsequently be modeled by fitting the discharge curves to empirical functions like polynomials and Padé approximants. A function based on the Nernst equation that includes a term accounting for nonideal interactions between lithium ions and the cathode host material, such as the Redlich-Kister relationship, also may be used to predict discharge behavior.
Changes in Meeting Physical Activity Guidelines After Discharge From the Military.
Littman, Alyson J; Jacobson, Isobel G; Boyko, Edward J; Smith, Tyler C
2015-05-01
Understanding physical activity (PA) after discharge from the military can inform theory on the role of habit and reinforcement in behavior maintenance and has implications for this population's future health. Using data from 28,866 Millennium Cohort Study participants (n = 3782 of whom were discharged during the years between assessments), we 1) investigated changes in meeting federal PA guidelines for moderate-to-vigorous activity (MVPA) following military discharge and 2) determined predictors of meeting these guidelines after discharge. MVPA declined more in those who were discharged than in those who were not (-17.8 percentage points vs. -2.7 percentage points), with greater declines in former active-duty personnel, those who had deployed with combat exposures, had 14 to 25 years of service, and had been discharged more recently (>2 years prior). In those who were discharged, being normal or overweight (vs. obese), and a nonsmoker or former smoker (vs. current smoker) were positively associated with meeting MVPA Guidelines at follow-up, while meeting MVPA Guidelines at baseline and depression were inversely associated. Reductions in MVPA were substantial and unexpected. Increased understanding of transitional periods that may benefit from interventions to mitigate declines in PA will help prevent excess weight gain and physical inactivity-associated health consequences.
Machinability of nickel based alloys using electrical discharge machining process
NASA Astrophysics Data System (ADS)
Khan, M. Adam; Gokul, A. K.; Bharani Dharan, M. P.; Jeevakarthikeyan, R. V. S.; Uthayakumar, M.; Thirumalai Kumaran, S.; Duraiselvam, M.
2018-04-01
The high temperature materials such as nickel based alloys and austenitic steel are frequently used for manufacturing critical aero engine turbine components. Literature on conventional and unconventional machining of steel materials is abundant over the past three decades. However the machining studies on superalloy is still a challenging task due to its inherent property and quality. Thus this material is difficult to be cut in conventional processes. Study on unconventional machining process for nickel alloys is focused in this proposed research. Inconel718 and Monel 400 are the two different candidate materials used for electrical discharge machining (EDM) process. Investigation is to prepare a blind hole using copper electrode of 6mm diameter. Electrical parameters are varied to produce plasma spark for diffusion process and machining time is made constant to calculate the experimental results of both the material. Influence of process parameters on tool wear mechanism and material removal are considered from the proposed experimental design. While machining the tool has prone to discharge more materials due to production of high energy plasma spark and eddy current effect. The surface morphology of the machined surface were observed with high resolution FE SEM. Fused electrode found to be a spherical structure over the machined surface as clumps. Surface roughness were also measured with surface profile using profilometer. It is confirmed that there is no deviation and precise roundness of drilling is maintained.
NASA Astrophysics Data System (ADS)
Wu, Hao; Wang, Xianyou; Jiang, Lanlan; Wu, Chun; Zhao, Qinglan; Liu, Xue; Hu, Ben'an; Yi, Lanhua
2013-03-01
Porous calcium carbide-derived carbon (CCDC) has been prepared by one-step route from CaC2 in a freshly prepared chlorine environment at lower temperature, and following activated by ZnCl2 to get activated CCDC. The performances of the supercapacitors based on activated CCDC as electrode active material in aqueous KOH, K2SO4, KCl and KNO3 electrolytes are studied by cyclic voltammetry, constant current charged/discharged, cyclic life and electrochemical impedance spectroscopy. It has been found that the supercapacitor using 6 M KOH as electrolyte shows an energy density of 8.3 Wh kg-1 and a power density of 1992 W kg-1 based on the total weight of the electrode active materials with a voltage range 0 V-1 V. Meanwhile, the specific capacitance of the supercapacitor in 6 M KOH electrolyte is 68 F g-1 at the scan rate of 1 mV s-1 in the voltage range of 0 V-1 V, the charge-transfer resistance is extremely low and the relaxation time is the least of all. The supercapacitor also exhibits a good cycling performance and keeps 95% of initial capacity over 5000 cycles.
Auble, Gregor T.; Andrews, Austin K.; Ellison, Richard A.; Hamilton, David B.; Johnson, Richard A.; Roelle, James E.; Marmorek, David R.
1983-01-01
Drilling fluids or "muds" are essential components of modern drilling operations. They provide integrity for the well bore, a medium for removal of formation cuttings, and lubrication and cooling of the drill bit and pipe. The modeling workshop described in this report was conducted September 14-18, 1981 in Gulf Breeze, Florida to consider potential impacts of discharged drilling muds and cuttings on the marine environment. The broad goals of the workshop were synthesis of information on fate and effects, identification of general relationships between drilling fluids and the marine environment, and identification of site-specific variables likely to determine impacts of drilling muds and cuttings in various marine sites. The workshop was structured around construction of a model simulating fate and effects of discharges from a single rig into open water areas of the Gulf of Mexico, and discussion of factors that might produce different fate and effects in enclosed areas such as bays and estuaries. The simulation model was composed of four connected submodels. A Discharge/Fate submodel dealt with the discharge characteristics of the rig and the subsequent fate of discharged material. Three effects submodels then calculated biological responses at distances away from the rig for the water column, soft bottom benthos (assuming the rig was located over a soft bottom environment), and hard bottom benthos (assuming the rig was located over a hard bottom environment). The model focused on direct linkages between the discharge and various organisms rather than on how the marine ecosystem itself is interconnected. Behavior of the simulation model indicated relatively localized effects of drilling muds and cuttings discharged from a single platform into open water areas. Water column fate and effects were dominated by rapid dilution. Effects from deposition of spent mud and cuttings were spatially limited with relatively rapid recovery, especially in soft bottom benthic communities which were conceptualized as being adapted to frequent storms. This behavior was generated by the set of assumptions about linkages and functional relationships used to construct the model. Areas of uncertainty included methods for extrapolating 96-hr LC50 so results to exposures of varying lengths and concentrations; recovery rates of benthic communities; responses to various depths and rates of burial; fate and effects of the plume in relationship to stratification layers; and long-term and sub-lethal effects of slightly elevated concentrations of discharged materials. Evaluation of the assumptions of the Soft Bottom Submodel suggest that the assumptions used may have been relatively liberal estimates of resiliency of these communities. Discussion of "closed" water bodies such as bays and estuaries indicated several reasons to expect different and more complex fate and effects behavior in these areas. These factors included different species and communities (such as aquatic macrophytes and oyster beds), more complex circulation and stratification patterns, and potentially more active resuspension processes. Much of the possible difference in behavior in these areas centers around the extent to which they are “closed” or in the relative residence times of water and sediments in these areas as they determine the long-term dispersion of discharged material. Despite the complexity and variability of these areas, a large body of knowledge (such as that concerning fate and physical effects of dredge spoil) that could be effectively employed in analysis of potential fate and physical effects in enclosed areas was identified.
NASA Technical Reports Server (NTRS)
Koontz, Steve L.; Leger, Lubert J.; Wu, Corina; Cross, Jon B.; Jurgensen, Charles W.
1994-01-01
Neutral atomic oxygen is the most abundant component of the ionospheric plasma in the low Earth orbit environment (LEO; 200 to 700 kilometers altitude) and can produce significant degradation of some spacecraft materials. In order to produce a more complete understanding of the materials chemistry of atomic oxygen, the chemistry and physics of O-atom interactions with materials were determined in three radically different environments: (1) The Space Shuttle cargo bay in low Earth orbit (the EOIM-3 space flight experiment), (2) a high-velocity neutral atom beam system (HVAB) at Los Alamos National Laboratory (LANL), and (3) a microwave-plasma flowing-discharge system at JSC. The Space Shuttle and the high velocity atom beam systems produce atom-surface collision energies ranging from 0.1 to 7 eV (hyperthermal atoms) under high-vacuum conditions, while the flowing discharge system produces a 0.065 eV surface collision energy at a total pressure of 2 Torr. Data obtained in the three different O-atom environments referred to above show that the rate of O-atom reaction with polymeric materials is strongly dependent on atom kinetic energy, obeying a reactive scattering law which suggests that atom kinetic energy is directly available for overcoming activation barriers in the reaction. General relationships between polymer reactivity with O atoms and polymer composition and molecular structure have been determined. In addition, vacuum ultraviolet photochemical effects have been shown to dominate the reaction of O atoms with fluorocarbon polymers. Finally, studies of the materials chemistry of O atoms have produced results which may be of interest to technologists outside the aerospace industry. Atomic oxygen 'spin-off' or 'dual use' technologies in the areas of anisotropic etching in microelectronic materials and device processing, as well as surface chemistry engineering of porous solid materials are described.
Lightning and middle atmospheric discharges in the atmosphere
NASA Astrophysics Data System (ADS)
Siingh, Devendraa; Singh, R. P.; Kumar, Sarvan; Dharmaraj, T.; Singh, Abhay K.; Singh, Ashok K.; Patil, M. N.; Singh, Shubha
2015-11-01
Recent development in lightning discharges including transient luminous events (TLEs) and global electric circuit are discussed. Role of solar activity, convective available potential energy, surface temperature and difference of land-ocean surfaces on convection process are discussed. Different processes of discharge initiation are discussed. Events like sprites and halos are caused by the upward quasi-electrostatic fields associated with intense cloud-to-ground discharges while jets (blue starter, blue jet, gigantic jet) are caused by charge imbalance in thunderstorm during lightning discharges but they are not associated with a particular discharge flash. Elves are generated by the electromagnetic pulse radiated during lightning discharges. The present understanding of global electric circuit is also reviewed. Relation between lightning activity/global electric circuit and climate is discussed.
Backwater development by woody debris
NASA Astrophysics Data System (ADS)
Geertsema, Tjitske; Torfs, Paul; Teuling, Ryan; Hoitink, Ton
2017-04-01
Placement of woody debris is a common method for increasing ecological values in river and stream restoration, and is thus widely used in natural environments. Water managers, however, are afraid to introduce wood in channels draining agricultural and urban areas. Upstream, it may create backwater, depending on hydrodynamic characteristics including the obstruction ratio, the Froude number and the surface level gradient. Patches of wood may trigger or counter morphological activity, both laterally, through bank erosion and protection, and vertically, with pool and riffle formation. Also, a permeable construction composed of wood will weather over time. Both morphodynamic activity and weathering cause backwater effects to change in time. The purpose of this study is to quantify the time development of backwater effects caused by woody debris. Hourly water levels gauged upstream and downstream of patches and discharge are collected for five streams in the Netherlands. The water level drop over the woody debris patch relates to discharge in the streams. This relation is characterized by an increasing water level difference for an increasing discharge, up to a maximum. If the discharge increases beyond this level, the water level difference reduces to the value that may represent the situation without woody debris. This reduction depends primarily on the obstruction ratio of the woody debris in the channel cross-section. Morphologic adjustments in the stream and reorientation of the woody material reduce the water level drop over the patches in time. Our results demonstrate that backwater effects can be reduced by optimizing the location where woody debris is placed and manipulating the obstruction ratio. Current efforts are focussed on representing woody debris in a one-dimensional numerical model, aiming to obtain a generic tool to achieve a stream design with woody debris that minimizes backwater.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hu, Wen; State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, CAS, Changchun 130022, Jilin; Yi, Jianhong
2013-06-01
Thanks to the revolutionary discovery of 5-fold symmetry contributed by Shechtman, quasicrystal is now recognized as another solid-state existing form. As the second largest class of quasicrystals, titanium-based icosahedral quasicrystals are very promising for hydrogen storage applications owing to their inherent abundant interstitial sites and favorable hydrogen-metal chemistry. In this context, (Ti₁.₆V₀.₄Ni)₁₀₀₋xScx (x=0.5–6) quaternary icosahedral quasicrystals have been successfully synthesized via arc-melting and subsequent melt-spinning techniques, and then their electrochemical performance toward hydrogen is explored. When the molar ratio of Sc addition is under 1%, a maximum discharge capacity of about 270 mA h g⁻¹ can be delivered. With furthermore » increasing Sc amount to 6%, good cycling stability as well as significantly retarded self-discharge rate (capacity retention 94% after 24 h relaxation) is observed. But meanwhile, the discharge capacities fall into 250-240 mA h g⁻¹, and the electrocatalytic activity improvement is highly demanded. - Graphical abstract: Quasicrystalline Ti–V–Ni–Sc hydrogen storage materials: Sc addition into Ti₁.₆V₀.₄Ni alloy forms the icosahedral phase (see picture). With optimal Sc dosage, the anodic cycling stability and self-discharge property are greatly enhanced. - Highlights: • Crystalline disallowed 5-fold symmetry is present in (Ti₁.₆V₀.₄Ni)₁₀₀₋xScx alloys. • Ti-based metastable quasicrystalline alloys can store hydrogen electrochemically. • A maximum discharge capacity of 270 mA h g⁻¹ can be delivered. • Advantageous cycle stability and self-discharge property benefit from Sc addition. • Ti and V dissolution is suppressed by an oxide layer resulting from Sc corrosion.« less
NASA Astrophysics Data System (ADS)
Sahu, Anshuman Kumar; Chatterjee, Suman; Nayak, Praveen Kumar; Sankar Mahapatra, Siba
2018-03-01
Electrical discharge machining (EDM) is a non-traditional machining process which is widely used in machining of difficult-to-machine materials. EDM process can produce complex and intrinsic shaped component made of difficult-to-machine materials, largely applied in aerospace, biomedical, die and mold making industries. To meet the required applications, the EDMed components need to possess high accuracy and excellent surface finish. In this work, EDM process is performed using Nitinol as work piece material and AlSiMg prepared by selective laser sintering (SLS) as tool electrode along with conventional copper and graphite electrodes. The SLS is a rapid prototyping (RP) method to produce complex metallic parts by additive manufacturing (AM) process. Experiments have been carried out varying different process parameters like open circuit voltage (V), discharge current (Ip), duty cycle (τ), pulse-on-time (Ton) and tool material. The surface roughness parameter like average roughness (Ra), maximum height of the profile (Rt) and average height of the profile (Rz) are measured using surface roughness measuring instrument (Talysurf). To reduce the number of experiments, design of experiment (DOE) approach like Taguchi’s L27 orthogonal array has been chosen. The surface properties of the EDM specimen are optimized by desirability function approach and the best parametric setting is reported for the EDM process. Type of tool happens to be the most significant parameter followed by interaction of tool type and duty cycle, duty cycle, discharge current and voltage. Better surface finish of EDMed specimen can be obtained with low value of voltage (V), discharge current (Ip), duty cycle (τ) and pulse on time (Ton) along with the use of AlSiMg RP electrode.
Using Volcanic Lightning Measurements to Discern Variations in Explosive Volcanic Activity
NASA Astrophysics Data System (ADS)
Behnke, S. A.; Thomas, R. J.; McNutt, S. R.; Edens, H. E.; Krehbiel, P. R.; Rison, W.
2013-12-01
VHF observations of volcanic lightning have been made during the recent eruptions of Augustine Volcano (2006, Alaska, USA), Redoubt Volcano (2009, Alaska, USA), and Eyjafjallajökull (2010, Iceland). These show that electrical activity occurs both on small scales at the vent of the volcano, concurrent with an eruptive event and on large scales throughout the eruption column during and subsequent to an eruptive event. The small-scale discharges at the vent of the volcano are often referred to as 'vent discharges' and are on the order of 10-100 meters in length and occur at rates on the order of 1000 per second. The high rate of vent discharges produces a distinct VHF signature that is sometimes referred to as 'continuous RF' radiation. VHF radiation from vent discharges has been observed at sensors placed as far as 100 km from the volcano. VHF and infrasound measurements have shown that vent discharges occur simultaneously with the onset of eruption, making their detection an unambiguous indicator of explosive volcanic activity. The fact that vent discharges are observed concurrent with explosive volcanic activity indicates that volcanic ejecta are charged upon eruption. VHF observations have shown that the intensity of vent discharges varies between eruptive events, suggesting that fluctuations in eruptive processes affect the electrification processes giving rise to vent discharges. These fluctuations may be variations in eruptive vigor or variations in the type of eruption; however, the data obtained so far do not show a clear relationship between eruption parameters and the intensity or occurrence of vent discharges. Further study is needed to clarify the link between vent discharges and eruptive behavior, such as more detailed lightning observations concurrent with tephra measurements and other measures of eruptive strength. Observations of vent discharges, and volcanic lightning observations in general, are a valuable tool for volcano monitoring, providing a method for rapid detection of volcanic activity in real-time.
Parts, Materials, and Processes Control Program for Expendable Launch Vehicles
2015-05-21
CSAM, thermal shock, voltage burn-in, electrical tests (DWV, room and hot IR, partial discharge when in corona region); perform DPA with SEM/EDX...controls to eliminate dielectric defects; proper voltage derating. Partial discharge testing, corona inception testing up to 60% of rated voltage...voltage burn-in; DWV; room and hot IR; life test; partial discharge when in corona region B-7 Table B-5. Metallized Plastic Capacitors
Hollow - cathode electrode for high-power, high-pressure discharge devices
Chang, Jim J.; Alger, Terry W.
1995-01-01
Several different cold cathode configurations for a gas discharge device each having a plurality of grooves of selected spacing, depth and width to improve the emission of electrons in a gas discharge device. Each of the cold cathode configurations can be machined from a single piece of a selected material. Several of the configurations can be assembled with individual elements which is easily seen from the various figures.
NASA Astrophysics Data System (ADS)
Antonsen, Erik L.; Burton, Rodney L.; Reed, Garrett A.; Spanjers, Gregory G.
2006-10-01
High-speed mercury cadmium telluride photovoltaic detectors, sensitive to infrared emission, are investigated as a means of measuring surface temperature on a microsecond time frame during pulsed ablative discharges with Teflon™ as the ablated material. Analysis is used to derive a governing equation for detector output voltage for materials with wavelength dependent emissivity. The detector output voltage is experimentally calibrated against thermocouples embedded in heated Teflon. Experimental calibration is performed with Teflon that has been exposed to ˜200 pulsed discharges and non-plasma-exposed Teflon and is compared to theoretical predictions to analyze emissivity differences. The diagnostic capability is evaluated with measurements of surface temperature from the Teflon propellant of electric micropulsed plasma thrusters. During the pulsed current discharge, there is insufficient information to claim that the surface temperature is accurately measured. However, immediately following the discharge, the postpulse cooling curve is measured. The statistical spread of postpulse surface temperature from shot to shot, most likely due to arc constriction and localization, is investigated to determine an operational envelope for postpulse temperature and mass ablation. This information is useful for determining postpulse ablation contributions to mass loss as well as evaluation of theoretical discharge models currently under development.
Electrochemical properties of new organic radical materials for lithium secondary batteries
NASA Astrophysics Data System (ADS)
Lee, Seo Hwan; Kim, Jae-Kwang; Cheruvally, Gouri; Choi, Jae-Won; Ahn, Jou-Hyeon; Chauhan, Ghanshyam S.; Song, Choong Eui
The use of ionic liquid (IL)-supported organic radicals as cathode-active materials in lithium secondary batteries is reported in this article. Two different types of IL-supported organic radicals based on the 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) radical and imidazolium hexafluorophosphate IL were synthesized. The first type is a mono-radical with one unit of TEMPO and the second is a symmetrical di-radical with 2 U of TEMPO; both are viscous liquids at 25 °C. The radicals exhibit electrochemical activity at ∼3.5 V versus Li/Li + as revealed in the cyclic voltammetry tests. The organic radical batteries (ORBs) with these materials as the cathode, a lithium metal anode and 1 M LiPF 6 in EC/DMC electrolyte exhibited good performance at room temperature during the charge-discharge and cycling tests. The batteries exhibited specific capacities of 59 and 80 mAh g -1 at 1 C-rate with the mono- and di-radicals as the cathodes, respectively, resulting in 100% utilization of the materials. The performance degradation with increasing C-rate is very minimal for the ORBs, thus demonstrating good rate capability.
NASA Astrophysics Data System (ADS)
Kizilel, R.; Lateef, A.; Sabbah, R.; Farid, M. M.; Selman, J. R.; Al-Hallaj, S.
A strategy for portable high-power applications with a controlled thermal environment has been developed and has demonstrated the advantage of using the novel phase change material (PCM) thermal management systems over conventional active cooling systems. A passive thermal management system using PCM for Li-ion batteries is tested for extreme conditions, such as ambient temperature of 45 °C and discharge rate of 2.08 C-rate (10 A). Contrary to Li-ion packs without thermal management system, high-energy packs with PCM are discharged safely at high currents and degrading rate of capacity of the Li-ion packs lowered by half. Moreover, the compactness of the packs not only decreases the volume occupied by the packs and its associated complex cooling system, but also decreases the total weight for large power application.
Development and testing of a high cycle life 30 A-h sealed AgO-Zn battery
NASA Technical Reports Server (NTRS)
Bogner, R. S.
1972-01-01
A two-phase program was initiated to investigate design parameters and technology to develop an improved AgO-Zn battery. The basic performance goal was 100 charge/discharge cycles (22 h/2 h) at 50 percent depth of discharge following a six-month period of charged stand at room temperature. Phase 1, cell evaluation, involved testing 70 cells in five-cell groups. The major design variables were active material ratios, electrolyte concentrations, separator systems, and negative plate shape. Phase 1 testing showed that cycle life could be improved 10 percent to 20 percent by using greater ratios of zinc to silver oxide and higher electrolyte concentrations. Wedge-shaped negatives increased cycle life by nearly 100 percent. Phase 2 battery evaluation, which was initiated before the Phase 1 results were known completely, involved evaluation of six designs as 19-cell batteries. Only one battery exceeded 100 cycles following nine months charged stand.
Wang, Chao; Li, Shiheng; Han, Yuyao; Lu, Zhenda
2017-08-23
A novel structure of a carbon-coated LiMnPO 4 microcluster through emulsion-based self-assembly has been fabricated to yield a high-performance battery cathode. In this rational design, nanosized LiMnPO 4 plates are assembled into microclusters to achieve a dense packing and robust interparticle contact. In addition, the conductive carbon framework wrapping around these clusters functions as a fast electron highway, ensuring the high utilization of the active materials. The designed structure demonstrates enhanced specific capacity and cycling stability in lithium-ion batteries, delivering a discharge capacity of 120 mAh g -1 after 200 cycles at 0.2 C. It also shows a superior rate capability with discharge capacities of 139.7 mAh g -1 at 0.05 C, 131.7 mAh g -1 at 0.1 C, and 99.2 mAh g -1 at 1 C at room temperature.
Zhong, Taiyang; Chen, Dongmei; Zhang, Xiuying
2016-01-01
Identification of the sources of soil mercury (Hg) on the provincial scale is helpful for enacting effective policies to prevent further contamination and take reclamation measurements. The natural and anthropogenic sources and their contributions of Hg in Chinese farmland soil were identified based on a decision tree method. The results showed that the concentrations of Hg in parent materials were most strongly associated with the general spatial distribution pattern of Hg concentration on a provincial scale. The decision tree analysis gained an 89.70% total accuracy in simulating the influence of human activities on the additions of Hg in farmland soil. Human activities—for example, the production of coke, application of fertilizers, discharge of wastewater, discharge of solid waste, and the production of non-ferrous metals—were the main external sources of a large amount of Hg in the farmland soil. PMID:27834884
Searching for order in atmospheric pressure plasma jets
NASA Astrophysics Data System (ADS)
Schäfer, Jan; Sigeneger, Florian; Šperka, Jiří; Rodenburg, Cornelia; Foest, Rüdiger
2018-01-01
The self-organized discharge behaviour occurring in a non-thermal radio-frequency plasma jet in rare gases at atmospheric pressure was investigated. The frequency of the azimuthal rotation of filaments in the active plasma volume and their inclination were measured along with the gas temperature under varying discharge conditions. The gas flow and heating were described theoretically by a three-dimensional hydrodynamic model. The rotation frequencies obtained by both methods qualitatively agree. The results demonstrate that the plasma filaments forming an inclination angle α with the axial gas velocity u z are forced to a transversal movement with the velocity {u}φ =\\tan (α )\\cdot {u}z, which is oriented in the inclination direction. Variations of {u}φ in the model reveal that the observed dynamics minimizes the energy loss due to convective heat transfer by the gas flow. The control of the self-organization regime motivates the application of the plasma jet for precise and reproducible material processing.
Heterogeneous neuronal firing patterns during interictal epileptiform discharges in the human cortex
Keller, Corey J.; Truccolo, Wilson; Gale, John T.; Eskandar, Emad; Thesen, Thomas; Carlson, Chad; Devinsky, Orrin; Kuzniecky, Ruben; Doyle, Werner K.; Madsen, Joseph R.; Schomer, Donald L.; Mehta, Ashesh D.; Brown, Emery N.; Hochberg, Leigh R.; Ulbert, István; Halgren, Eric
2010-01-01
Epileptic cortex is characterized by paroxysmal electrical discharges. Analysis of these interictal discharges typically manifests as spike–wave complexes on electroencephalography, and plays a critical role in diagnosing and treating epilepsy. Despite their fundamental importance, little is known about the neurophysiological mechanisms generating these events in human focal epilepsy. Using three different systems of microelectrodes, we recorded local field potentials and single-unit action potentials during interictal discharges in patients with medically intractable focal epilepsy undergoing diagnostic workup for localization of seizure foci. We studied 336 single units in 20 patients. Ten different cortical areas and the hippocampus, including regions both inside and outside the seizure focus, were sampled. In three of these patients, high density microelectrode arrays simultaneously recorded between 43 and 166 single units from a small (4 mm × 4 mm) patch of cortex. We examined how the firing rates of individual neurons changed during interictal discharges by determining whether the firing rate during the event was the same, above or below a median baseline firing rate estimated from interictal discharge-free periods (Kruskal–Wallis one-way analysis, P<0.05). Only 48% of the recorded units showed such a modulation in firing rate within 500 ms of the discharge. Units modulated during the discharge exhibited significantly higher baseline firing and bursting rates than unmodulated units. As expected, many units (27% of the modulated population) showed an increase in firing rate during the fast segment of the discharge (±35 ms from the peak of the discharge), while 50% showed a decrease during the slow wave. Notably, in direct contrast to predictions based on models of a pure paroxysmal depolarizing shift, 7.7% of modulated units recorded in or near the seizure focus showed a decrease in activity well ahead (0–300 ms) of the discharge onset, while 12.2% of units increased in activity in this period. No such pre-discharge changes were seen in regions well outside the seizure focus. In many recordings there was also a decrease in broadband field potential activity during this same pre-discharge period. The different patterns of interictal discharge-modulated firing were classified into more than 15 different categories. This heterogeneity in single unit activity was present within small cortical regions as well as inside and outside the seizure onset zone, suggesting that interictal epileptiform activity in patients with epilepsy is not a simple paroxysm of hypersynchronous excitatory activity, but rather represents an interplay of multiple distinct neuronal types within complex neuronal networks. PMID:20511283
Effects of Electrical Insulation Breakdown Voltage And Partial Discharge
NASA Astrophysics Data System (ADS)
Bahrim, F. S.; Rahman, N. F. A.; Haris, H. C. M.; Salim, N. A.
2018-03-01
During the last few decades, development of new materials using composite materials has been of much interest. The Cross-linked Polyethylene (XLPE) which is insulated power cables has been widely used. This paper describes the theoretical analysis, fundamental experiments and application experiments for the XLPE cable insulation. The composite that has been tested is a commercial XLPE and Polypropylene with 30% fiber glass. The results of breakdown strength and partial discharge (PD) behavior described the insulating performance of the composite.
NASA Astrophysics Data System (ADS)
Li, Zhenwei; Xu, Xianli; Yu, Bofu; Xu, Chaohao; Liu, Meixian; Wang, Kelin
2016-11-01
Quantifying the impacts of climate and human activities on water and sediment discharge has become a central topic in climate and hydrologic research. This issue, however, has so far received little attention in karst regions around the world. Seven karst catchments located in southwest China were chosen to explore water and sediment discharge responses to different driving factors during the period from the 1950s to 2011. The non-parametric Mann-Kendall test was used to detect both the trends and abrupt changes in water and sediment discharge. The double mass curve method was used to quantify the effects of climate and human activities on water and sediment discharge. Results indicated that the annual water discharge showed a decreasing trend in all catchments (-0.21 to -3.68 × 108 m3 yr-1), and the sediment discharge exhibited a significant decreasing trend (-7 to -101 × 104 t yr-1) for six out of the seven catchments. A rapid decline (abrupt change) in sediment discharge occurred since 2000 for all except Liujiang catchment where the sediment discharge has a slight increase since 1983 as no large dams were constructed in this catchment. Specifically, the magnitude of reduction in sediment discharge (%) significantly increases with the extent of flow regulation as measured by the ratio of the area upstream the dam to the total catchment area for the seven catchments (R2 = 0.98, P < 0.01). This study demonstrated that water discharge was mainly influenced by precipitation, while sediment discharge was mainly influenced by human activities (relative contribution 70-111%, regardless of whether the effect is negative or positive). Ecological restoration played somehow important roles in the decrease in sediment discharge (negative relationships of sediment discharge with the Normalized Differential Vegetation Index (NDVI)), but dam construction was likely to be the principal cause of the significant decrease in sediment discharge. This study is of use for better catchment management in karst regions in southwest of China.
El-Eskandarany, M. Sherif
2016-01-01
Because of its low density, storage of hydrogen in the gaseous and liquids states possess technical and economic challenges. One practical solution for utilizing hydrogen in vehicles with proton-exchange fuel cells membranes is storing hydrogen in metal hydrides. Magnesium hydride (MgH2) remains the best hydrogen storage material due to its high hydrogen capacity and low cost of production. Due to its high activation energy and poor hydrogen sorption/desorption kinetics at moderate temperatures, the pure form of MgH2 is usually mechanically treated by high-energy ball mills and catalyzed with different types of catalysts. These steps are necessary for destabilizing MgH2 to enhance its kinetics behaviors. In the present work, we used a small mole fractions (5 wt.%) of metallic glassy of Zr70Ni20Pd10 powders as a new enhancement agent to improve its hydrogenation/dehydrogenation behaviors of MgH2. This short-range ordered material led to lower the decomposition temperature of MgH2 and its activation energy by about 121 °C and 51 kJ/mol, respectively. Complete hydrogenation/dehydrogenation processes were successfully achieved to charge/discharge about 6 wt.%H2 at 100 °C/200 °C within 1.18 min/3.8 min, respectively. In addition, this new nanocomposite system shows high performance of achieving continuous 100 hydrogen charging/discharging cycles without degradation. PMID:27220994
Electric fish as natural models for technical sensor systems
NASA Astrophysics Data System (ADS)
von der Emde, Gerhard; Bousack, Herbert; Huck, Christina; Mayekar, Kavita; Pabst, Michael; Zhang, Yi
2009-05-01
Instead of vision, many animals use alternative senses for object detection. Weakly electric fish employ "active electrolocation", during which they discharge an electric organ emitting electrical current pulses (electric organ discharges, EOD). Local EODs are sensed by electroreceptors in the fish's skin, which respond to changes of the signal caused by nearby objects. Fish can gain information about attributes of an object, such as size, shape, distance, and complex impedance. When close to the fish, each object projects an 'electric image' onto the fish's skin. In order to get information about an object, the fish has to analyze the object's electric image by sampling its voltage distribution with the electroreceptors. We now know a great deal about the mechanisms the fish use to gain information about objects in their environment. Inspired by the remarkable capabilities of weakly electric fish in detecting and recognizing objects with their electric sense, we are designing technical sensor systems that can solve similar sensing problems. We applied the principles of active electrolocation to devices that produce electrical current pulses in water and simultaneously sense local current densities. Depending on the specific task, sensors can be designed which detect an object, localize it in space, determine its distance, and measure certain object properties such as material properties, thickness, or material faults. We present first experiments and FEM simulations on the optimal sensor arrangement regarding the sensor requirements e. g. localization of objects or distance measurements. Different methods of the sensor read-out and signal processing are compared.
Device for providing high-intensity ion or electron beam
McClanahan, Edwin D.; Moss, Ronald W.
1977-01-01
A thin film of a low-thermionic-work-function material is maintained on the cathode of a device for producing a high-current, low-pressure gas discharge by means of sputter deposition from an auxiliary electrode. The auxiliary electrode includes a surface with a low-work-function material, such as thorium, uranium, plutonium or one of the rare earth elements, facing the cathode but at a disposition and electrical potential so as to extract ions from the gas discharge and sputter the low-work-function material onto the cathode. By continuously replenishing the cathode film, high thermionic emissions and ion plasmas can be realized and maintained over extended operating periods.
Electrode erosion in arc discharges at atmospheric pressure
NASA Technical Reports Server (NTRS)
Hardy, T. L.
1985-01-01
An experimental investigation was performed in an effort to measure and increase lifetime of electrodes in an arcjet thruster. The electrode erosion of various anode and cathode materials was measured after tests in an atmospheric pressure nitrogen arc discharge at powers less than 1 kW. A free-burning arc configuration and a constricted arc configuration were used to test the materials. Lanthanum hexboride and thoriated tungsten had low cathode erosion rates while thoriated tungsten and pure tungsten had the lowest anode erosion rates of the materials tested. Anode cooling, reverse gas flow, an external magnetic fields were all found to reduce electrode mass loss.
Feedback model of secondary electron emission in DC gas discharge plasmas
NASA Astrophysics Data System (ADS)
Saravanan, ARUMUGAM; Prince, ALEX; Suraj, Kumar SINHA
2018-01-01
Feedback is said to exist in any amplifier when the fraction of output power in fed back as an input. Similarly, in gaseous discharge ions that incident on the cathode act as a natural feedback element to stabilize and self sustain the discharge. The present investigation is intended to emphasize the feedback nature of ions that emits secondary electrons (SEs) from the cathode surface in DC gas discharges. The average number of SEs emitted per incident ion and non ionic species (energetic neutrals, metastables and photons) which results from ion is defined as effective secondary electron emission coefficient (ESEEC,{γ }{{E}}). In this study, we derive an analytic expression that corroborates the relation between {γ }{{E}} and power influx by ion to the cathode based on the feedback theory of an amplifier. In addition, experimentally, we confirmed the typical positive feedback nature of SEE from the cathode in argon DC glow discharges. The experiment is done for three different cathode material of same dimension (tungsten (W), copper (Cu) and brass) under identical discharge conditions (pressure: 0.45 mbar, cathode bias: -600 V, discharge gab: 15 cm and operating gas: argon). Further, we found that the {γ }{{E}} value of these cathode material controls the amount of feedback power given by ions. The difference in feedback leads different final output i.e the power carried by ion at cathode ({P}{{i}}{\\prime }{| }{{C}}). The experimentally obtained value of {P}{{i}}{\\prime }{| }{{C}} is 4.28 W, 6.87 W and 9.26 W respectively for W, Cu and brass. In addition, the present investigation reveals that the amount of feedback power in a DC gas discharges not only affect the fraction of power fed back to the cathode but also the entire characteristics of the discharge.
NASA Technical Reports Server (NTRS)
Kamhawi, Hani; Huang, Wensheng; Gilland, James H.; Haag, Thomas W.; Mackey, Jonathan; Yim, John; Pinero, Luis; Williams, George; Peterson, Peter; Herman, Daniel
2017-01-01
NASA's Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5kW Technology Demonstration Unit-3 (TDU-3) has been the subject of extensive technology maturation in preparation for flight system development. Detailed performance, stability, and plume characterization tests of the thruster were performed at NASA GRC's Vacuum Facility 5 (VF-5). The TDU-3 thruster implements a magnetic topology that is identical to TDU-1. The TDU-3 boron nitride silica composite discharge channel material is different than the TDU-1 heritage boron nitride discharge channel material. Performance and stability characterization of the TDU-3 thruster was performed at discharge voltages between 300V and 600V and at discharge currents between 5A and 21.8A. The thruster performance and stability were assessed for varying magnetic field strength, cathode flow fractions between 5% and 9%, varying harness inductance, and for reverse magnet polarity. Performance characterization test results indicate that the TDU-3 thruster performance is in family with the TDU-1 levels. TDU-3's thrust efficiency of 65% and specific impulse of 2,800sec at 600V and 12.5kW exceed performance levels of SOA Hall thrusters. Thruster stability regimes were characterized with respect to the thruster discharge current oscillations (discharge current peak-to-peak and root mean square magnitudes), discharge current waveform power spectral density analysis, and maps of the current-voltage-magnetic field. Stability characterization test results indicate a stability profile similar to TDU-1. Finally, comparison of the TDU-1 and TDU-3 plume profiles found that there were negligible differences in the plasma plume characteristics between the TDU with heritage boron nitride versus the boron nitride silica composite discharge channel.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Veda Prakash, G.; Kumar, R.; Saurabh, K.
A comparative study of electrical breakdown properties of deionized water (H{sub 2}O) and heavy water (D{sub 2}O) is presented with two different electrode materials (stainless steel (SS) and brass) and polarity (positive and negative) combinations. The pulsed (∼a few tens of nanoseconds) discharges are conducted by applying high voltage (∼a few hundred kV) pulse between two hemisphere electrodes of the same material, spaced 3 mm apart, at room temperature (∼26-28 °C) with the help of Tesla based pulse generator. It is observed that breakdown occurred in heavy water at lesser voltage and in short duration compared to deionized water irrespective ofmore » the electrode material and applied voltage polarity chosen. SS electrodes are seen to perform better in terms of the voltage withstanding capacity of the liquid dielectric as compared to brass electrodes. Further, discharges with negative polarity are found to give slightly enhanced discharge breakdown voltage when compared with those with positive polarity. The observations corroborate well with conductivity measurements carried out on original and post-treated liquid samples. An interpretation of the observations is attempted using Fourier transform infrared measurements on original and post-treated liquids as well as in situ emission spectra studies. A yet another important observation from the emission spectra has been that even short (nanosecond) duration discharges result in the formation of a considerable amount of ions injected into the liquid from the electrodes in a similar manner as reported for long (microseconds) discharges. The experimental observations show that deionised water is better suited for high voltage applications and also offer a comparison of the discharge behaviour with different electrodes and polarities.« less
NASA Astrophysics Data System (ADS)
Li, Jing; Zhang, Yining; Zhou, Wei; Nie, Hongjiao; Zhang, Huamin
2014-09-01
Li-O2 batteries have attracted considerable attention due to their high energy density. The critical challenges that limit the practical applications include effective utilization of electrode space for solid products deposition and acceptable cycling performance. In the present work, a nitrogen-doped micron-sized honeycomb-like carbon is developed for use as a cathode material for Li-O2 batteries. This novel material is obtained by using nano-CaCO3 particles as hard template and sucrose as the carbon source, followed by thermal annealing at 800 °C in ammonia. With one-step ammonia activation, surface nitrogenation and further pore structure optimization are realized simultaneously. The material exhibits enhanced activity for oxygen reduction reaction and oxygen transfer ability. Surprisingly, an improved cycling stability is also obtained. As a result, a superior discharge capacity up to 12,600 mAh g-1 is achieved, about 4 times that of commercial Ketjenblack carbon. The results provide a novel route to construct effective non-metal carbon-based cathodes for high performance of Li-O2 batteries.
Cost efficient environmental survey paths for detecting continuous tracer discharges
NASA Astrophysics Data System (ADS)
Alendal, G.
2017-07-01
Designing monitoring programs for detecting potential tracer discharges from unknown locations is challenging. The high variability of the environment may camouflage the anticipated anisotropic signal from a discharge, and there are a number of discharge scenarios. Monitoring operations may also be costly, constraining the number of measurements taken. By assuming that a discharge is active, and a prior belief on the most likely seep location, a method that uses Bayes' theorem combined with discharge footprint predictions is used to update the probability map. Measurement locations with highest reduction in the overall probability of a discharge to be active can be identified. The relative cost between reallocating and measurements can be taken into account. Three different strategies are suggested to enable cost efficient paths for autonomous vessels.
Characteristics of the high-rate discharge capability of a nickel/metal hydride battery electrode
DOE Office of Scientific and Technical Information (OSTI.GOV)
Geng, M.; Han, J.; Feng, F.
1999-10-01
The high rate discharge capability of the negative electrode in a Ni/MH battery is mainly determined by the charge transfer process at the interface between the metal hydride (MH) alloy powder and the electrolyte, and the mass transfer process in the bulk MH alloy powder. In this study, the anodic polarization curves of a MH electrode were measured and analyzed. An alloy of nominal composition Mm{sub 0.95}Ti{sub 0.05}Ni{sub 3.85}Co{sub 0.45}Mn{sub 0.35}Al{sub 0.35} was used as the negative electrode material. With increasing number of charge/discharge cycles, the MH alloy powders microcrack into particles several micrometers in diameter. The decrease in themore » MH alloy particle size results in an increase in both the activation surface area and the exchange current density of the MH alloy electrode. The electrode overpotentials of the MH electrode decreases with increasing number of cycles at a large value of anodic polarization current. The decrease in electrode overpotential leads to an increase in the high rate discharge capability of the MH electrode. By using the limiting current, the hydrogen diffusion coefficient in the MH alloy was estimated to be 1.2 x 10{sup {minus}11}cm{sup 2}s{sup {minus}1} assuming an average particle radius of 5 {micro}m.« less
Collective Phenomena In Volume And Surface Barrier Discharges
NASA Astrophysics Data System (ADS)
Kogelschatz, U.
2010-07-01
Barrier discharges are increasingly used as a cost-effective means to produce non-equilibrium plasmas at atmospheric pressure. This way, copious amounts of electrons, ions, free radicals and excited species can be generated without appreciable gas heating. In most applications the barrier is made of dielectric material. In laboratory experiments also the use of resistive, ferroelectric and semiconducting materials has been investigated, also porous ceramic layers and dielectric barriers with controlled surface conductivity. Major applications utilizing mainly dielectric barriers include ozone generation, surface cleaning and modification, polymer and textile treatment, sterilization, pollution control, CO2 lasers, excimer lamps, plasma display panels (flat TV screens). More recent research efforts are also devoted to biomedical applications and to plasma actuators for flow control. Sinu- soidal feeding voltages at various frequencies as well as pulsed excitation schemes are used. Volume as well as surface barrier discharges can exist in the form of filamentary, regularly patterned or laterally homogeneous discharges. Reviews of the subject and the older literature on barrier discharges were published by Kogelschatz (2002, 2003), by Wagner et al. (2003) and by Fridman et al. (2005). A detailed discussion of various properties of barrier discharges can also be found in the recent book "Non-Equilibrium Air Plasmas at Atmospheric Pressure" by Becker et al. (2005). The physical effects leading to collective phenomena in volume and surface barrier discharges will be discussed in detail. Special attention will be given to self-organization of current filaments. Main similarities and differences of the two types of barrier discharges will be elaborated.
Sediment source fingerprinting to quantify fine sediment sources in forested catchments, Chile.
NASA Astrophysics Data System (ADS)
Schuller, P.; Walling, D. E.; Iroume, A.; Castillo, A.; Quilodran, C.
2012-04-01
A study to improve the understanding of the primary sediment sources and transfer pathways in catchments disturbed following forest plantation harvesting is being undertaken in South-Central Chile. The study focuses on two sets of paired experimental catchments (treatment and control), located about 400 km apart, with similar soil type but contrasting mean annual rainfall: Nacimiento (1,200 mm year-1) and Los Ulmos (2,500 mm year-1). Sediment source fingerprinting techniques are being used to document the primary fine sediment sources. In each catchment, three potential sediment sources were defined: clearcut slopes (Z1), forest roads (Z2) and the stream channel (Z3). In each catchment, multiple representative composite samples of the different potential source materials were collected before harvest operations from the upper 1 cm layer in Z1, Z2, and from the channel bank and bed for Z3. A time-integrating trap sampler installed in the discharge monitoring station constructed at the outlet of each catchment has been used to collect samples of the suspended sediment and these have been supplemented by sediment collected from the weir pools. Total suspended sediment load is been quantified in the monitoring stations using discharge records and integrated water sampling. Caesium-137 (137Cs), excess lead-210 (210Pbex) and other sediment properties are being used as fingerprints. After air-drying, oven-drying at 40°C and disaggregation, both the source material samples and the sediment samples collected in the discharge monitoring stations were sieved through a 63-μm sieve and the <63-μm fractions were used for subsequent analyses. For radionuclide assay, the samples were sealed in Petri dishes and after 4 weeks the mass activity density (activity concentration) of 137Cs and 210Pbex was determined by gamma analysis, using an ORTEC extended range Ge detector of 53% relative efficiency. The 137Cs and 210Pbex activity and organic carbon (Corg) concentration associated with potential source materials and the target sediment show that the two radionuclides used in combination with the Corg property provide effective source fingerprints. Additional work using a mixing model taking account of particle size effects is required to establish the relative contributions of the three sources to the fine sediment loads of the study catchments. This research is supported by the Chilean Government through FONDECYT Project 1090574 and by the IAEA through CRP D1.20.11 (Contract CHI-15531 and Technical Contract 15478) and the RLA 05/051 Project.
Adhesive Leaf Created by a Corona Discharge.
Lee, Wonseok; Son, Jongsang; Kim, Seonghyun; Yang, Dongmin; Choi, Seungyeop; Watanabe, Rodrigo Akira; Hwang, Kyo Seon; Lee, Sang Woo; Lee, Gyudo; Yoon, Dae Sung
2018-01-29
Here, we report a new concept of both the adhesive manner and material, named "adhesive leaf (AL)," based on the leaf of the plant Heteropanax fragrans. The treatment of the corona discharge on the leaf surface can cause the nano-/microdestruction of the leaf epidermis, resulting in an outward release of sap. The glucose-containing sap provided the AL with a unique ability to stick to various substrates such as steel, polypropylene, and glass. Moreover, we reveal that the AL adhesion strength depends on the AL size, as well as the corona-discharge intensity. Conventional adhesives, such as glue and bond, lose their adhesive property and leave dirty residues upon the removal of the attached material. Unlike the conventional methods, the AL is advantageous as it can be repeatedly attached and detached thoroughly until the sap liquid is exhausted; its adhesive ability is maintained for at least three weeks at room temperature. Our findings shed light on a new concept of a biodegradable adhesive material that is created by a simple surface treatment.
Lai, Feili; Miao, Yue-E; Zuo, Lizeng; Lu, Hengyi; Huang, Yunpeng; Liu, Tianxi
2016-06-01
The development of biomass-based energy storage devices is an emerging trend to reduce the ever-increasing consumption of non-renewable resources. Here, nitrogen-doped carbonized bacterial cellulose (CBC-N) nanofibers are obtained by one-step carbonization of polyaniline coated bacterial cellulose (BC) nanofibers, which not only display excellent capacitive performance as the supercapacitor electrode, but also act as 3D bio-template for further deposition of ultrathin nickel-cobalt layered double hydroxide (Ni-Co LDH) nanosheets. The as-obtained CBC-N@LDH composite electrodes exhibit significantly enhanced specific capacitance (1949.5 F g(-1) at a discharge current density of 1 A g(-1) , based on active materials), high capacitance retention of 54.7% even at a high discharge current density of 10 A g(-1) and excellent cycling stability of 74.4% retention after 5000 cycles. Furthermore, asymmetric supercapacitors (ASCs) are constructed using CBC-N@LDH composites as positive electrode materials and CBC-N nanofibers as negative electrode materials. By virtue of the intrinsic pseudocapacitive characteristics of CBC-N@LDH composites and 3D nitrogen-doped carbon nanofiber networks, the developed ASC exhibits high energy density of 36.3 Wh kg(-1) at the power density of 800.2 W kg(-1) . Therefore, this work presents a novel protocol for the large-scale production of biomass-derived high-performance electrode materials in practical supercapacitor applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
46 CFR 153.964 - Discharge by gas pressurization.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Discharge by gas pressurization. 153.964 Section 153.964 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer...
46 CFR 153.964 - Discharge by gas pressurization.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 5 2013-10-01 2013-10-01 false Discharge by gas pressurization. 153.964 Section 153.964 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer...
46 CFR 153.964 - Discharge by gas pressurization.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 5 2012-10-01 2012-10-01 false Discharge by gas pressurization. 153.964 Section 153.964 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer...
46 CFR 153.964 - Discharge by gas pressurization.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 5 2014-10-01 2014-10-01 false Discharge by gas pressurization. 153.964 Section 153.964 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer...
46 CFR 153.964 - Discharge by gas pressurization.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Discharge by gas pressurization. 153.964 Section 153.964 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer...
Yan, Dickson Y S; Liu, Tongzhou; Lo, Irene M C
2015-01-01
The technical feasibility, environmental discharges and cost-performance of urban river contaminated sediment treatment with ex situ advanced oxidation processes were evaluated for the purpose of achieving an ideal treatment goal (for marine disposal) and a cost-performance treatment goal (for beneficially reusing as a filling material). Sediment samples were collected from a river located in southern China. To achieve the ideal treatment goal, sequential treatments (Fenton's reaction+activated persulphate oxidation) were carried out. One-step Fenton's reaction was applied to achieve the cost-performance treatment goal. The resulting effluent was treated and discharged, and sludge generated in wastewater treatment was characterized. The resources input throughout the treatment processes were recorded for cost estimation. After the treatment designed for achieving the ideal treatment goal, most pollutants fulfilled the treatment goal except Pb, Cd, Hg and Ag, probably because these four metals were present mainly in stable fractions of the sediment. The cost-performance treatment goal was achieved in view of low pollutant contents in the toxicity characteristic leaching procedure leachate of treated sediment. The cost for achieving the cost-performance treatment goal is much less than that for achieving the ideal treatment goal. The major cost difference is attributed to chemical cost. Stringent sediment treatment goals based on existing standards would lead to massive chemical use, complex treatment and hence huge cost. A simpler treatment with fewer chemicals is adequate for sediment beneficially reused as a filling material, and is economically more advantageous than handling sediment for marine disposal.
Characterization of real objects by an active electrolocation sensor
NASA Astrophysics Data System (ADS)
Metzen, Michael G.; Al Ghouz, Imène; Krueger, Sandra; Bousack, Herbert; von der Emde, Gerhard
2012-04-01
Weakly electric fish use a process called 'active electrolocation' to orientate in their environment and to localize objects based on their electrical properties. To do so, the fish discharge an electric organ which emits brief electrical current pulses (electric organ discharge, EOD) and in return sense the generated electric field which builds up surrounding the animal. Caused by the electrical properties of nearby objects, fish measure characteristic signal modulations with an array of electroreceptors in their skin. The fish are able to gain important information about the geometrical properties of an object as well as its complex impedance and its distance. Thus, active electrolocation is an interesting feature to be used in biomimetic approaches. We used this sensory principle to identify different insertions in the walls of Plexiglas tubes. The insertions tested were composed of aluminum, brass and graphite in sizes between 3 and 20 mm. A carrier signal was emitted and perceived with the poles of a commercial catheter for medical diagnostics. Measurements were performed with the poles separated by 6.3 to 55.3 mm. Depending on the length of the insertion in relation to the sender-receiver distance, we observed up to three peaks in the measured electric images. The first peak was affected by the material of the insertion, while the distance between the second and third peak strongly correlated with the length of the insertion. In a second experiment we tested whether various materials could be detected by using signals of different frequency compositions. Based on their electric images we were able to discriminate between objects having different resistive properties, but not between objects of complex impedances.
Hollow-cathode electrode for high-power, high-pressure discharge devices
Chang, J.J.; Alger, T.W.
1995-08-22
Several different cold cathode configurations are disclosed for a gas discharge device each having a plurality of grooves of selected spacing, depth and width to improve the emission of electrons in a gas discharge device. Each of the cold cathode configurations can be machined from a single piece of a selected material. Several of the configurations can be assembled with individual elements which is easily seen from the various figures. 8 figs.
Macrides, F; Clancy, A N; Singer, A G; Agosta, W C
1984-10-01
Hamster vaginal discharge elicits intense genital investigation and facilitates overt copulatory behavior toward anesthetized males (female surrogates) whose hindquarters have been scented with this material. The ability of an arbitrary chemosensory stimulus to acquire behavioral activity like that of vaginal discharge through association with maternal stimuli and/or adult sexual experience was examined in male hamsters. Vanillin was used as the arbitrary stimulus because it is attractive to hamsters, is not likely to be a natural constituent of hamster scents, is not known to exert any adverse physiological effects, and is a subliming solid with an extremely long persistence when used as an artificial scent. The males were reared by vanillin-scented or control solvent (water)-scented foster mothers, and in adulthood were paired repeatedly with vanillin- or solvent-scented receptive females. Behavioral testing with scented surrogates was performed one week preceding, and again following, the sexual pairings. Rearing by vanillin-scented mothers modestly but significantly increased the amount of time sexually naive males spent investigating the hindquarters as compared to other body regions of vanillin-scented surrogates. However, neither neonatal nor adult interactions with vanillin-scented females imparted to this stimulus the capacity to facilitate overt copulatory behavior. Also, regardless of the males' exposure history, only vaginal discharge caused the males to direct their investigatory behavior predominantly toward the hindquarters. The characteristic investigatory and copulatory responses exhibited by male hamsters toward vaginal discharge thus do not appear to be readily developed toward arbitrary chemosensory stimuli associated with particular females to which the males have been exposed.
Wu, M-F; John, J; Boehmer, L N; Yau, D; Nguyen, G B; Siegel, J M
2004-01-01
Cataplexy, a symptom associated with narcolepsy, represents a unique dissociation of behavioural states. During cataplectic attacks, awareness of the environment is maintained, as in waking, but muscle tone is lost, as in REM sleep. We have previously reported that, in the narcoleptic dog, noradrenergic cells of the locus coeruleus cease discharge during cataplexy. In the current study, we report on the activity of serotonergic cells of the dorsal raphe nucleus. The discharge patterns of serotonergic dorsal raphe cells across sleep–waking states did not differ from those of dorsal raphe and locus coeruleus cells recorded in normal rats, cats and monkeys, with tonic discharge in waking, reduced activity in non-REM sleep and cessation of activity in REM sleep. However, in contrast with locus coeruleus cells, dorsal raphe REM sleep-off neurones did not cease discharge during cataplexy. Instead, discharge continued at a level significantly higher than that seen in REM sleep and comparable to that seen in non-REM sleep. We also identified several cells in the dorsal raphe whose pattern of activity was the opposite of that of the presumed serotonergic cells. These cells were maximally active in REM sleep and minimally active in waking and increased activity during cataplexy. The difference between noradrenergic and serotonergic cell discharge profiles in cataplexy suggests different roles for these cell groups in the normal regulation of environmental awareness and muscle tone and in the pathophysiology of narcolepsy. PMID:14678502
DOE Office of Scientific and Technical Information (OSTI.GOV)
Voitenko, N. V., E-mail: tevn@hvd.tpu.ru; Yudin, A. S.; Kuznetsova, N. S.
The paper deals with the relevance of using electrical discharge technology for construction works in the city. The technical capabilities of the installation for the multi-borehole electro-discharge splitting off and destruction of rocks and concrete are described. The ways to increase the efficiency of the electrical discharge method for the destruction of solids are proposed. In order to augment the discharge circuit energy, the energy storage is separated into two individual capacitor batteries. The throttle with the inductance of 28.6 μH is installed in one of the batteries, which increases the duration of the channel energy release to 400 μsmore » and the efficiency of electrical discharge splitting off of concrete.« less
NASA Astrophysics Data System (ADS)
Orlovskii, V. M.; Panarin, V. A.; Shulepov, M. A.
2014-07-01
The dynamics of diffuse discharge formation under the action of nanosecond voltage pulses with short fronts (below 1 ns) in the absence of a source of additional preionization and the influence of a dielectric film on this process have been studied. It is established that the diffuse discharge is induced by the avalanche multiplication of charge initiated by high-energy electrons and then maintained due to secondary breakdowns propagating via ionized gas channels. If a dielectric film (polyethylene, Lavsan, etc.) is placed on the anode, then multiply repeated discharge will lead to surface and bulk modification of the film material. Discharge-treated polyethylene film exhibits a change in the optical absorption spectrum in the near-IR range.
Riparian vegetation controls on channels formed in non-cohesive sediment
NASA Astrophysics Data System (ADS)
Gran, K.; Tal, M.; Paola, C.
2002-05-01
Riparian vegetation can significantly influence the morphology of a river, affecting channel geometry and flow dynamics. In channels formed in non-cohesive material, vegetation is the main source of bank cohesion and could affect the overall behavior of the river, potentially constraining the flow from a multi-thread channel to a single-thread channel. To examine the effects of riparian vegetation on streams formed in non-cohesive material, we conducted a series of physical experiments at the St. Anthony Falls Laboratory. The first set of experiments examines the effects of varying densities of vegetation on braided stream dynamics. Water discharge, sediment discharge, and grain size were held constant. For each run, we allowed a braided system to develop, then halved the discharge, and seeded the flume with alfalfa (Medicago sativa). After ten to fourteen days of growth, we returned the discharge to its original value and continued the run for 30-36 hours. Our results show that the influence of vegetation on the overall river pattern varied systematically with the spatial density of plant stems. The vegetation reduced the number of active channels and increased bank stability, leading to lower lateral migration rates, narrower and deeper channels, and an increase in channel relief. All these effects increased with vegetation density. Vegetation also influenced flow dynamics, increasing the variance of flow direction in the vegetated runs, and increasing scour depths through strong downwelling where the flow collided with relatively resistant banks. This oblique bank collision provides a new mechanism for producing secondary flows. We found these bank collision driven secondary flows to be more important than the classical curvature-driven mechanism in the vegetated runs. The next set of experiments examines more closely how the channel pattern evolves through time, allowing for both channel migration and successive vegetation growth. In these on-going experiments, vegetation is reseeded following repeat high flow events, simulating the natural process of vegetation encroachment on the floodplain and channel.
NASA Astrophysics Data System (ADS)
Park, Jin-Sung; Cho, Jung Sang; Kang, Yun Chan
2018-03-01
Closely in line with advances in next-generation energy storage materials, anode materials for lithium-ion batteries (LIBs) with high capacity and long cycle life have been widely explored. As part of the current effort, nickel molybdate (NiMoO4) microspheres with empty nanovoids are synthesized via spray drying process and subsequent one-step calcination in air. Dextrin in the atomized droplet is phase segregated during the spray drying process and calcined in air atmosphere, resulting in numerous empty nanovoids well-distributed within a microsphere. The empty nanovoids alleviate volume expansion during cycling, shorten lithium-ion diffusion length, and facilitate contact between electrode and electrolyte materials. Along with the high discharge capacity of NiMoO4 material, as high as 1240 mA h g-1 for the 2nd cycle at a high current density of 1 A g-1, uniquity of the structure enables longer cycle life and higher quality performances. The discharge capacity corresponding to the 500th cycle is 1020 mA h g-1 and the capacity retention calculated from the 2nd cycle is 82%. In addition, a discharge capacity of 413 mA g-1 is obtained at an extremely high current density of 10 A g-1.
NASA Astrophysics Data System (ADS)
Wang, Zhaomin; Cheng, Yong; Li, Qian; Chang, Limin; Wang, Limin
2018-06-01
Metallic Sb is deemed as a promising anode material for lithium ion batteries (LIBs) due to its flat voltage platform and high security. Nevertheless, the limited capacity restricts its large-scale application. Therefore, a simple and effective method to explore novel antimony trioxide with high capacity used as anode material for LIBs is imperative. In this work, we report a facile and efficient strategy to fabricate 1D hollow Sb2O3@TiO2 composites by using the Kirkendall effect. When used as an anode material for LIBs, the optimal Sb2O3@TiO2 composite displays a high reversible discharge capacity of 593 mAh g-1 at a current density of 100 mA g-1 after 100 cycles and a relatively superior discharge capacity of 439 mAh g-1 at a current density of 500 mA g-1 even after 600 cycles. In addition, a reversible discharge capacity of 334 mAh g-1 can also be obtained even at a current density of 2000 mA g-1. The excellent cycling stability and rate performance of the Sb2O3@TiO2 composite can be attributed to the synergistic effect of TiO2 shell and hollow structure of Sb2O3, both of which can effectively buffer the volume expansion and maintain the integrity of the electrode during the repeated charge-discharge cycles.
NASA Astrophysics Data System (ADS)
Zhang, J. W.; Zhou, T. C.; Wang, J. X.; Yang, X. F.; Zhu, F.; Tian, L. M.; Liu, R. T.
2017-10-01
As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC). In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.
Izzati, Wan Akmal; Arief, Yanuar Z; Adzis, Zuraimy; Shafanizam, Mohd
2014-01-01
Polymer nanocomposites have recently been attracting attention among researchers in electrical insulating applications from energy storage to power delivery. However, partial discharge has always been a predecessor to major faults and problems in this field. In addition, there is a lot more to explore, as neither the partial discharge characteristic in nanocomposites nor their electrical properties are clearly understood. By adding a small amount of weight percentage (wt%) of nanofillers, the physical, mechanical, and electrical properties of polymers can be greatly enhanced. For instance, nanofillers in nanocomposites such as silica (SiO2), alumina (Al2O3) and titania (TiO2) play a big role in providing a good approach to increasing the dielectric breakdown strength and partial discharge resistance of nanocomposites. Such polymer nanocomposites will be reviewed thoroughly in this paper, with the different experimental and analytical techniques used in previous studies. This paper also provides an academic review about partial discharge in polymer nanocomposites used as electrical insulating material from previous research, covering aspects of preparation, characteristics of the nanocomposite based on experimental works, application in power systems, methods and techniques of experiment and analysis, and future trends.
Assessing the relationship between Section 404 and wetland losses: a feasibility study
Gladwin, Douglas N.; Roelle, James E.; Asherin, Duane A.
1989-01-01
The primary objective of the Clean Water Act of 1977 (33 U.S.C. 1251) is to restore and maintain the physical, chemical, and biological integrity of the Nation's waters. Section 404 of the Act regulates the discharge of dredged or fill materials into wetlands and represents the primary Federal authority for regulation of wetland alterations. Since its inception, the Section 404 program has been controversial in regard to the extent to which it was intended to provide wetlands regulation. Section 404 requires those who wish to discharge dredged or fill material into waters of the United States, which include many wetlands, to first obtain a Federal permit. The Environmental Protection Agency (EPA) has overall responsibility for administration of the Section 404 program and promulgates guidelines that must be followed in issuing permits. In addition, EPA has the final authority to prohibit specific discharges if the environmental impacts are unacceptable. The U.S. Army Corps of Engineers (Corps) issues Section 404 permits, which can be of two types. Individual Permits are issued following case-by-case reviews of proposed discharges. General Permits, which can be either nationwide or regional in scope, are authorized by the Corps for categories of activities that are similar in nature and that have only minimal individual and cumulative adverse environmental impacts. EPA, the National Marine Fisheries Service (NMFS), the Fish and Wildlife Service (Service), and State natural resource agencies review and comment on permit applications and offer recommendations on appropriate mitigation measures. Although comments from the Service and other natural resource agencies are advisory in nature (EPA's veto authority excepted), they can serve as the basis for modifying, conditioning, or denying a Section 404 permit. In 1986, in a survey conducted by the National Ecology Research Center, Service personnel indicated interest in additional information concerning both wetland trends and the impacts of activities authorized by the Corps under Section 404 (Roelle 1986). Although there is some information concerning wetland losses for certain geographic areas and for the Nation as a whole (Frayer et al. 1983; Tiner 1984), there appears to be little information on how these losses relate to the Section 404 permitting process. The primary objective of this study was to determine the feasibility of estimating wetland losses in relationship to Individual and General Permits issued under Section 404. A secondary objective was to assemble data on acceptance and implementation of specific mitigation recommendations offered by the Service and other natural resource agencies in connection with development activities on wetlands examined. At present, 26 categories of Nationwide permits have been authorized by the Corps. Nationwide permit 26 was of particular interest in this study because it specifically authorizes discharges into wetlands under certain circumstances (see Figure 1 and related text for a more complete discussion of circumstances under which Nationwide Permit 26 is applicable). All subsequent references to Nationwide or General permits pertain to Nationwide Permit 26.
Surface structuring of boron doped CVD diamond by micro electrical discharge machining
NASA Astrophysics Data System (ADS)
Schubert, A.; Berger, T.; Martin, A.; Hackert-Oschätzchen, M.; Treffkorn, N.; Kühn, R.
2018-05-01
Boron doped diamond materials, which are generated by Chemical Vapor Deposition (CVD), offer a great potential for the application on highly stressed tools, e. g. in cutting or forming processes. As a result of the CVD process rough surfaces arise, which require a finishing treatment in particular for the application in forming tools. Cutting techniques such as milling and grinding are hardly applicable for the finish machining because of the high strength of diamond. Due to its process principle of ablating material by melting and evaporating, Electrical Discharge Machining (EDM) is independent of hardness, brittleness or toughness of the workpiece material. EDM is a suitable technology for machining and structuring CVD diamond, since boron doped CVD diamond is electrically conductive. In this study the ablation characteristics of boron doped CVD diamond by micro electrical discharge machining are investigated. Experiments were carried out to investigate the influence of different process parameters on the machining result. The impact of tool-polarity, voltage and discharge energy on the resulting erosion geometry and the tool wear was analyzed. A variation in path overlapping during the erosion of planar areas leads to different microstructures. The results show that micro EDM is a suitable technology for finishing of boron doped CVD diamond.
Brovold, Therese; Skelton, Dawn A; Sylliaas, Hilde; Mowe, Morten; Bergland, Astrid
2014-07-01
The purpose of this study was to determine the relationship among health-related quality of life (HRQOL), physical fitness, and physical activity in older patients after recent discharge from hospital. One hundred fifteen independent-living older adults (ages 70-92 years) were included. HRQOL (Medical Outcomes Study 36-item Short Form Health Survey), physical activity (Physical Activity Scale for the Elderly), and physical fitness (Senior Fitness Test) were measured 2-4 weeks after discharge. Higher levels of physical activity and physical fitness were correlated with higher self-reported HRQOL. Although cause and effect cannot be determined from this study, the results suggest that a particular focus on the value of physical activity and physical fitness while in hospital and when discharged from hospital may be important to encourage patients to actively preserve independence and HRQOL. It may be especially important to target those with lower levels of physical activity, poorer physical fitness, and multiple comorbidities.
Amorphous Metal Polysulfides: Electrode Materials with Unique Insertion/Extraction Reactions.
Sakuda, Atsushi; Ohara, Koji; Fukuda, Katsutoshi; Nakanishi, Koji; Kawaguchi, Tomoya; Arai, Hajime; Uchimoto, Yoshiharu; Ohta, Toshiaki; Matsubara, Eiichiro; Ogumi, Zempachi; Okumura, Toyoki; Kobayashi, Hironori; Kageyama, Hiroyuki; Shikano, Masahiro; Sakaebe, Hikari; Takeuchi, Tomonari
2017-07-05
A unique charge/discharge mechanism of amorphous TiS 4 is reported. Amorphous transition metal polysulfide electrodes exhibit anomalous charge/discharge performance and should have a unique charge/discharge mechanism: neither the typical intercalation/deintercalation mechanism nor the conversion-type one, but a mixture of the two. Analyzing the mechanism of such electrodes has been a challenge because fewer tools are available to examine the "amorphous" structure. It is revealed that the electrode undergoes two distinct structural changes: (i) the deformation and formation of S-S disulfide bonds and (ii) changes in the coordination number of titanium. These structural changes proceed continuously and concertedly for Li insertion/extraction. The results of this study provide a novel and unique model of amorphous electrode materials with significantly larger capacities.
Cross, Jon B.; Cremers, David A.
1988-01-01
Laser sustained discharge apparatus for the production of intense beams of high kinetic energy atomic species. A portion of the plasma resulting from a laser sustained continuous optical discharge which generates energetic atomic species from a gaseous source thereof is expanded through a nozzle into a region of low pressure. The expanded plasma contains a significant concentration of the high kinetic energy atomic species which may be used to investigate the interaction of surfaces therewith. In particular, O-atoms having velocities in excess of 3.5 km/s can be generated for the purpose of studying their interaction with materials in order to develop protective materials for spacecraft which are exposed to such energetic O-atoms during operation in low earth orbit.
Cross, J.B.; Cremers, D.A.
1986-01-10
Laser sustained discharge apparatus for the production of intense beams of high kinetic energy atomic species is described. A portion of the plasma resulting from a laser sustained continuous optical discharge which generates energetic atomic species from a gaseous source thereof is expanded through a nozzle into a region of low pressure. The expanded plasma contains a significant concentration of the high kinetic energy atomic species which may be used to investigate the interaction of surfaces therewith. In particular, O-atoms having velocities in excess of 3.5 km/s can be generated for the purpose of studying their interaction with materials in order to develop protective materials for spacecraft which are exposed to such energetic O-atoms during operation in low earth orbit.
NASA Astrophysics Data System (ADS)
Soeda, Kazunari; Yamagata, Masaki; Ishikawa, Masashi
2015-04-01
An alginate-based gel electrolyte with an ionic liquid (Alg/IL) is investigated for electric double-layer capacitors (EDLCs) by using physicochemical and electrochemical measurements. The Alg/EMImBF4 (EMImBF4 = 1-ethyl-3-methylimidazolium tetrafluoroborate) gel electrolyte is thermally stable up to 280 °C, where EMImBF4 decomposes. Furthermore, the EDLC with the gel electrolyte can be operated even at high temperature. The cell containing Alg/EMImBF4 is also electrochemically stable even under high voltage (∼3.5 V) operation. Thus, the alginate is a suitable host polymer for the gel electrolyte for EDLCs. According to the result of charge-discharge characteristics, the voltage drop in the charge-discharge curve for the cell with Alg/EMImBF4 gel electrolyte is considerably smaller than that with liquid-phase EMImBF4 electrolyte. To clarify the effect of Alg in contact with the activated carbon electrode, we also prepared an Alg-containing ACFC electrode (Alg + ACFC), and evaluated its EDLC characteristics in liquid EMImBF4. The results prove that the presence of Alg close to the active materials significantly reduces the internal resistance of the EDLC cell, which may be attributed to the high affinity of Alg to activated carbon.
The National Pollutant Discharge Elimination System (NPDES) stormwater program regulates some stormwater discharges from three potential sources: municipal separate storm sewer systems (MS4s), construction activities, and industrial activities.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guo, Shaohua; Yu, Haijun; Liu, Pan
2015-01-01
Based on low-cost and rich resources, sodium-ion batteries have been regarded as a promising candidate for next-generation energy storage batteries in the large-scale energy applications of renewable energy and smart grids. However, there are some critical drawbacks limiting its application, such as safety and stability problems. In this work, a stable symmetric sodium-ion battery based on the bipolar, active O3-type material, Na0.8Ni0.4Ti0.6O2, is developed. This bipolar material shows a typical O3-type layered structure, containing two electrochemically active transition metals with redox couples of Ni4+/Ni2+ and Ti4+/Ti3+, respectively. This Na0.8Ni0.4Ti0.6O2-based symmetric cell exhibits a high average voltage of 2.8 V, amore » reversible discharge capacity of 85 mA h g(-1), 75% capacity retention after 150 cycles and good rate capability. This full symmetric cell will greatly contribute to the development of room-temperature sodium-ion batteries with a view towards safety, low cost and long life, and it will stimulate further research on symmetric cells using the same active materials as both cathode and anode.« less
High-Rate Capable Floating Strip Micromegas
NASA Astrophysics Data System (ADS)
Bortfeldt, Jonathan; Bender, Michael; Biebel, Otmar; Danger, Helge; Flierl, Bernhard; Hertenberger, Ralf; Lösel, Philipp; Moll, Samuel; Parodi, Katia; Rinaldi, Ilaria; Ruschke, Alexander; Zibell, André
2016-04-01
We report on the optimization of discharge insensitive floating strip Micromegas (MICRO-MEsh GASeous) detectors, fit for use in high-energy muon spectrometers. The suitability of these detectors for particle tracking is shown in high-background environments and at very high particle fluxes up to 60 MHz/cm2. Measurement and simulation of the microscopic discharge behavior have demonstrated the excellent discharge tolerance. A floating strip Micromegas with an active area of 48 cm × 50 cm with 1920 copper anode strips exhibits in 120 GeV pion beams a spatial resolution of 50 μm at detection efficiencies above 95%. Pulse height, spatial resolution and detection efficiency are homogeneous over the detector. Reconstruction of particle track inclination in a single detector plane is discussed, optimum angular resolutions below 5° are observed. Systematic deviations of this μTPC-method are fully understood. The reconstruction capabilities for minimum ionizing muons are investigated in a 6.4 cm × 6.4 cm floating strip Micromegas under intense background irradiation of the whole active area with 20 MeV protons at a rate of 550 kHz. The spatial resolution for muons is not distorted by space charge effects. A 6.4 cm × 6.4 cm floating strip Micromegas doublet with low material budget is investigated in highly ionizing proton and carbon ion beams at particle rates between 2 MHz and 2 GHz. Stable operation up to the highest rates is observed, spatial resolution, detection efficiencies, the multi-hit and high-rate capability are discussed.
Microanalysis of extended-test xenon hollow cathodes
NASA Technical Reports Server (NTRS)
Verhey, Timothy R.; Patterson, Michael J.
1991-01-01
Four hollow cathode electron sources were analyzed via boroscopy, scanning electron microscopy, energy dispersive x ray analysis, and x ray diffraction analysis. These techniques were used to develop a preliminary understanding of the chemistry of the devices that arise from contamination due to inadequate feed-system integrity and improper insert activation. Two hollow cathodes were operated in an ion thruster simulator at an emission current of 23.0 A for approximately 500 hrs. The two tests differed in propellant-feed systems, discharge power supplies, and activation procedures. Tungsten deposition and barium tungstate formation on the internal cathode surfaces occurred during the first test, which were believed to result from oxygen contamination of the propellant feed-system. Consequently, the test facility was upgraded to reduce contamination, and the test was repeated. The second hollow cathode was found to have experienced significantly less tungsten deposition. A second pair of cathodes examined were the discharge and the neutralizer hollow cathodes used in a life-test of a 30-cm ring-cusp ion thruster at a 5.5 kW power level. The cathodes' test history was documented and the post-test microanalyses are described. The most significant change resulting from the life-test was substantial tungsten deposition on the internal cathode surfaces, as well as removal of material from the insert surface. In addition, barium tungstate and molybdate were found on insert surfaces. As a result of the cathode examinations, procedures and approaches were proposed for improved discharge ignition and cathode longevity.
Critical analysis of partial discharge dynamics in air filled spherical voids
NASA Astrophysics Data System (ADS)
Callender, G.; Golosnoy, I. O.; Rapisarda, P.; Lewin, P. L.
2018-03-01
In this paper partial discharge (PD) is investigated inside a spherical air filled void at atmospheric pressure using a drift diffusion model. Discharge dynamics consisted of an electron avalanche transitioning into positive streamer, in agreement with earlier work on dielectric barrier discharges. Different model configurations were utilised to test many of the concepts employed in semi-analytical PD activity models, which use simplistic descriptions of the discharge dynamics. The results showed that many of these concepts may be erroneous, with significant discrepancies between the canonical reasoning and the simulation results. For example, the residual electric field, the electric field after a discharge, is significantly lower than the estimates used by classical PD activity models in the literature.
Tissue response to surface-treated tantalum implants: preliminary observations in primates.
Meenaghan, M A; Natiella, J R; Moresi, J L; Flynn, H E; Wirth, J E; Baier, R E
1979-07-01
Samples of capacitor grade tantalum were surface-treated by a variety of methods. These surface treatments allowed testing of the same basic material which was mill-finished, metallurgically polished, electrochemically oxidized, sintered with a porous surface, and glow-discharged. Surface characterization was accomplished by contact angle measurements, Scanning Electron Microscopy, energy-dispensed x-ray analysis, and internal reflection spectroscopy. Subsequent to characterization, the material was surgically implanted in the subperiosteal region of the mandible, the buccal mucosa, and the subcutaneous paravertebral region of the back of Macaca speciosa (stumptail monkey). The tissue reaction at intervals of up to three weeks was evaluated morphologically and ultrastructurally. Significant differences in tissue response were noted at the interfaces with glow-discharge-treated versus lower surface energy samples. Adjacent to the glow-discharge-treated implants, two distinct tissue zones were identified. Zone No. 1, nearest the implant, exhibited an increased cellularity. This consisted of 4-5 layers of highly active mesenchymal cells or fibroblast-like cells with spindle-shaped nuclei and prominent cytoplasmic features. At various foci along the interface, hyperchromatic nuclear forms were noted to project into the space left by removal of the implant. These observations, coupled with a predominance of intercellular ground-substance material and less collagen at the interface, may indicate some form of bioadhesion. The deeper Zone No. 2 was 2-3 times as thick consisted of typical fibroblastic cells with a lamellar configuration, bordered by an occasional delicate-lined space. Independent of implantation site or surface texture, all other implants showed occasional multinucleated giant cells and a decrease in the cellular character of Zone No. 1. Both zones were reduced in thickness and composed of more mature fibroblasts. Some specimens exhibited intracytoplasmic vacuolization. It may be concluded, therefore, that surface-free energy of the implanted specimens played a significant role in inducing differential tissue response to otherwise similar pure metal samples.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-09
... MAG910000 and NHG910000 for Discharges From Remediation Activities in the Commonwealth of Massachusetts (Including Both Commonwealth and Indian Country Lands) and the State of New Hampshire: The Remediation... Elimination System (NPDES) general permits for discharges from remediation activities to certain waters of the...
Method and apparatus for measuring reactivity of fissile material
Lee, David M.; Lindquist, Lloyd O.
1985-01-01
Given are a method and apparatus for measuring nondestructively and non-invasively (i.e., using no internal probing) the burnup, reactivity, or fissile content of any material which emits neutrons and which has fissionable components. No external neutron-emitting interrogation source or fissile material is used and no scanning is required, although if a profile is desired scanning can be used. As in active assays, here both reactivity and content of fissionable material can be measured. The assay is accomplished by altering the return flux of neutrons into the fuel assembly. The return flux is altered by changing the reflecting material. The existing passive neutron emissions in the material being assayed are used as the source of interrogating neutrons. Two measurements of either emitted neutron or emitted gamma-ray count rates are made and are then correlated to either reactivity, burnup, or fissionable content of the material being assayed, thus providing a measurement of either reactivity, burnup, or fissionable content of the material being assayed. Spent fuel which has been freshly discharged from a reactor can be assayed using this method and apparatus. Precisions of 1000 MWd/tU appear to be feasible.
NASA Astrophysics Data System (ADS)
Tao, Jiayou; Liu, Nishuang; Ma, Wenzhen; Ding, Longwei; Li, Luying; Su, Jun; Gao, Yihua
2013-07-01
A solid-state flexible supercapacitor (SC) based on organic-inorganic composite structure was fabricated through an ``in situ growth for conductive wrapping'' and an electrode material of polypyrrole (PPy)-MnO2 nanoflakes-carbon fiber (CF) hybrid structure was obtained. The conductive organic material of PPy greatly improved the electrochemical performance of the device. With a high specific capacitance of 69.3 F cm-3 at a discharge current density of 0.1 A cm-3 and an energy density of 6.16 × 10-3 Wh cm-3 at a power density of 0.04 W cm-3, the device can drive a commercial liquid crystal display (LCD) after being charged. The organic-inorganic composite active materials have enormous potential in energy management and the ``in situ growth for conductive wrapping'' method might be generalized to open up new strategies for designing next-generation energy storage devices.
A polyoxovanadate as an advanced electrode material for supercapacitors.
Chen, Han-Yi; Wee, Grace; Al-Oweini, Rami; Friedl, Jochen; Tan, Kim Soon; Wang, Yuxi; Wong, Chui Ling; Kortz, Ulrich; Stimming, Ulrich; Srinivasan, Madhavi
2014-07-21
Polyoxovanadate Na(6)V(10)O(28) is investigated for the first time as electrode material for supercapacitors (SCs). The electrochemical properties of Na(6)V(10)O(28) electrodes are studied in Li(+) -containing organic electrolyte (1 M LiClO(4) in propylene carbonate) by galvanostatic charge/discharge and cyclic voltammetry in a three-electrode configuration. Na(6)V(10)O(28) electrodes exhibit high specific capacitances of up to 354 F g(-1). An asymmetric SC with activated carbon as positive electrode and Na(6)V(10)O(28) as negative electrode is fabricated and exhibits a high energy density of 73 Wh kg(-1) with a power density of 312 W kg(-1), which successfully demonstrates that Na(6)V(10)O(28) is a promising electrode material for high-energy SC applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Astrophysics Data System (ADS)
Kim, D.; Lee, C.; Jeong, S.
2018-01-01
In this study, a concentrated electrolyte was applied in an aqueous rechargeable zinc-ion battery system with a zinc hexacyanoferrate (ZnHCF) electrode to improve the electrochemical performance by changing the hydration number of the zinc ions. To optimize the active material, ZnHCF was synthesized using aqueous solutions of zinc nitrate with three different concentrations. The synthesized materials exhibited some differences in structure, crystallinity, and particle size, as observed by X-ray diffraction and scanning electron microscopy. Subsequently, these well-structured materials were applied in electrochemical tests. A more than two-fold improvement in the charge/discharge capacities was observed when the concentrated electrolyte was used instead of the dilute electrolyte. Additionally, the cycling performance observed in the concentrated electrolyte was superior to that in the dilute electrolyte. This improvement in the electrochemical performance may result from a decrease in the hydration number of the zinc ions in the concentrated electrolyte.
Asymmetric Supercapacitor for Long-Duration Power Storage
NASA Technical Reports Server (NTRS)
Rangan, Krishnaswamy K.; Sudarshan, Tirumalai S.
2012-01-01
A document discusses a project in which a series of novel hybrid positive electrode materials was developed and tested in asymmetric capacitors with carbon negative electrodes. The electrochemical performance of the hybrid capacitors was characterized by cyclic voltammetry and a DC charge/discharge test. The hybrid capacitor exhibited ideal capacitor behavior with an extended operating voltage of 1.6 V in aqueous electrolyte, and energy density higher than activated carbon-based supercapacitors. Nanostructured MnO2 is a promising material for electrochemical capacitors (ECS) because of its low cost, environmentally friendly nature, and reasonably high specific capacitance. The charge capacity of the capacitors can be further improved by increasing the specific surface area of the MnO2 electrode material. The power density and space radiation stability of the capacitors can be enhanced by coating the MnO2 nanoparticles with conducting polymers. The conducting polymer coating also helps in radiation-hardening the ECS.
Synthesis of V2O5 microspheres by spray pyrolysis as cathode material for supercapacitors
NASA Astrophysics Data System (ADS)
Yin, Zhendong; Xu, Jie; Ge, Yali; Jiang, Qiaoya; Zhang, Yaling; Yang, Yawei; Sun, Yuping; Hou, Siyu; Shang, Yuanyuan; Zhang, Yingjiu
2018-03-01
Vanadium oxide (V2O5) microspheres have attracted considerable attention in the energy field due to their unique properties such as high stability and electrochemical activity. Here, massive V2O5 microspheres with smooth surface, hollow cavity and uniform particle sizes (0.4–1.5 μm), were synthesized by a facile spray pyrolysis process. Post-treatment at predefined temperatures effectively turned the microsphere shell into stacked nanorods with widths of 100 nm and lengths of 500 nm when processed at 500 °C for 3 h under nitrogen atmosphere, with enhanced crystallinity. When applied as cathode materials for supercapacitors, the post-treated V2O5 microspheres at 500 °C exhibited improved specific capacitance and longer discharge time. This is an effective method to manufacture massive V2O5 microspheres with tailored structure and potential applications in high-performance energy storage materials.
(PECASE 08) - ION-Conducting Network Membranes Using Tapered Block Copolymers
2015-07-08
iron phosphate ( LiFePO4 ) as an active material for the cathode. The composite cathode was prepared by mixing P(S-EO) with carbon black and LiFePO4 ...salt- doping ratio of [EO]:[Li] = 12:1. Example cycle-life data for the Li/P(S-EO)/ LiFePO4 cell is shown in Figure 1. The specific discharge...rates, indicating good cycling stability. This investigation currently is in progress. 1 Figure 1: Cycle-life data for the Li/P(S-EO)/ LiFePO4 cell
Yi, Ting-Feng; Li, Yan-Mei; Yang, Shuang-Yuan; Zhu, Yan-Rong; Xie, Ying
2016-11-30
Layered Li-rich, Co-free, and Mn-based cathode material, Li 1.17 Ni 0.25-x Mn 0.58 Mg x O 2 (0 ≤ x ≤ 0.05), was successfully synthesized by a coprecipitation method. All prepared samples have typical Li-rich layered structure, and Mg has been doped in the Li 1.17 Ni 0.25 Mn 0.58 O 2 material successfully and homogeneously. The morphology and the grain size of all material are not changed by Mg doping. All materials have a estimated size of about 200 nm with a narrow particle size distribution. The electrochemical property results show that Li 1.17 Ni 0.25-x Mn 0.58 Mg x O 2 (x = 0.01 and 0.02) electrodes exhibit higher rate capability than that of the pristine one. Li 1.17 Ni 0.25-x Mn 0.58 Mg x O 2 (x = 0.02) indicates the largest reversible capacity of 148.3 mAh g -1 and best cycling stability (capacity retention of 95.1%) after 100 cycles at 2C charge-discharge rate. Li 1.17 Ni 0.25-x Mn 0.58 Mg x O 2 (x = 0.02) also shows the largest discharge capacity of 149.2 mAh g -1 discharged at 1C rate at elevated temperature (55 °C) after 50 cycles. The improved electrochemical performances may be attributed to the decreased polarization, reduced charge transfer resistance, enhanced the reversibility of Li + ion insertion/extraction, and increased lithium ion diffusion coefficient. This promising result gives a new understanding for designing the structure and improving the electrochemical performance of Li-rich cathode materials for the next-generation lithium-ion battery with high rate cycling performance.
ElBasiouny, Sherif M.; Rymer, W. Zev; Heckman, C. J.
2012-01-01
Motoneuron discharge patterns reflect the interaction of synaptic inputs with intrinsic conductances. Recent work has focused on the contribution of conductances mediating persistent inward currents (PICs), which amplify and prolong the effects of synaptic inputs on motoneuron discharge. Certain features of human motor unit discharge are thought to reflect a relatively stereotyped activation of PICs by excitatory synaptic inputs; these features include rate saturation and de-recruitment at a lower level of net excitation than that required for recruitment. However, PIC activation is also influenced by the pattern and spatial distribution of inhibitory inputs that are activated concurrently with excitatory inputs. To estimate the potential contributions of PIC activation and synaptic input patterns to motor unit discharge patterns, we examined the responses of a set of cable motoneuron models to different patterns of excitatory and inhibitory inputs. The models were first tuned to approximate the current- and voltage-clamp responses of low- and medium-threshold spinal motoneurons studied in decerebrate cats and then driven with different patterns of excitatory and inhibitory inputs. The responses of the models to excitatory inputs reproduced a number of features of human motor unit discharge. However, the pattern of rate modulation was strongly influenced by the temporal and spatial pattern of concurrent inhibitory inputs. Thus, even though PIC activation is likely to exert a strong influence on firing rate modulation, PIC activation in combination with different patterns of excitatory and inhibitory synaptic inputs can produce a wide variety of motor unit discharge patterns. PMID:22031773
A 50 AH nickel cadmium battery activation and charge retention parametric study for LANDSAT-D
NASA Technical Reports Server (NTRS)
Tasevoli, M.
1982-01-01
An alternate nickel-cadmium cell activation scheme was developed which significantly reduces battery dissipation while maintaining the cell active material in the proper electrochemical state. The new procedure of charging at C/20 for 8 hours, C/10 for 6 hours and followed by C/5 to a voltage limit of 1.430 volt/cell significantly reduces the heat dissipation and charge period when compared to the standard activation practice of charging at C/20 for 48 hours. In addition, subsequent discharge voltage profiles using the new scheme are higher when compared to the standard practice. The effects of extended open-circuit periods on nickel-cadmium cell results in a capacity loss of approximately 0.7 percent and 1.4 percent per day at 23 and 35 degrees Celsius, respectively.
NASA Astrophysics Data System (ADS)
Balasubramaniam, M.; Balakumar, S.
2018-04-01
Tin (Sn) doped ZnSb2O6 nanostructures was synthesized by chemical precipitation method and was used as an electrode material for supercapacitors to explore its electrochemical stability and potentiality as energy storage materials. Their characteristic structural, morphological and compositional features were investigated through XRD, FESEM and XPS analysis. Results showed that the nanostructures have well ordered crystalline features with spherical particle morphology. As the size and morphology are the vital parameters in exhibiting better electrochemical properties, the prepared nanostructures exhibited a significant specific capacitance of 222 F/g at a current density of 0.5 A/g respectively. While charging and discharging for 1000 cycles, the capacitance retention was enhanced to 105.0% which depicts the stability and activeness of electrochemical sites present in the Sn doped ZnSb2O6 nanostructures even after cycling. Hence, the inclusion of Sn into ZnSb2O6 has contributed in improving the electrochemical properties thereby it represents itself as a potential electrode material for supercapacitors.
Modeling of Floating Time Domain Electromagnetic Method to Detect Dissolved Sediment
NASA Astrophysics Data System (ADS)
Nurjanah, Siti; Widodo
2017-04-01
In hydrology context, sediment can be interpreted as inorganic and organic material that is transported by, suspended in, or deposited by streams. It is important to know the function of soil, stream discharge, land-cover features, weather conditions and land-use activities. Sediment load carried by streams and rivers can be composed either of fine materials, mostly silts, and clays, or coarse materials such as sand. One product of sediment is dissolved load consists of indistinct material in solution moving downstream. It is produced by chemical weathering processes and does not move out of the water. To investigate the dissolved sediment, we have applied the floating of Time Domain Electromagnetic (TDEM) method. The acquisition of TDEM data has been performed use tires and small ship as innovation measurements. The calculated data model using Occam and Marquardt Algorithms. The responses of data show the sedimentation has less resistive compare the surrounding structures. This innovation is very helpful to know the environmental condition, especially in the water.
Emergency Unemployment Compensation Extension Act of 2013
Rep. Levin, Sander M. [D-MI-9
2013-11-20
House - 11/21/2013 Referred to the Subcommittee on Railroads, Pipelines, and Hazardous Materials. (All Actions) Notes: On 3/12/2014, a motion was filed to discharge the Committee on Rules from the consideration of H.Res.490 a resolution providing for the consideration of H.R.3546. A discharge petition requires 218 signatures for further action. (Discharge Petition No. 113-8: text with signatures.) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:
NASA Astrophysics Data System (ADS)
Lin, Chunjing; Xu, Sichuan; Chang, Guofeng; Liu, Jinling
2015-02-01
A passive thermal management system (TMS) for LiFePO4 battery modules using phase change material (PCM) as the heat dissipation source to control battery temperature rise is developed. Expanded graphite matrix and graphite sheets are applied to compensate low thermal conductivity of PCM and improve temperature uniformity of the batteries. Constant current discharge and mixed charge-discharge duties were applied on battery modules with and without PCM on a battery thermal characteristics test platform. Experimental results show that PCM cooling significantly reduces the battery temperature rise during short-time intense use. It is also found that temperature uniformity across the module deteriorates with the increasing of both discharge time and current rates. The maximum temperature differences at the end of 1C and 2C-rate discharges are both less than 5 °C, indicating a good performance in battery thermal uniformity of the passive TMS. Experiments on warm-keeping performance show that the passive TMS can effectively keep the battery within its optimum operating temperature for a long time during cold weather uses. A three dimensional numerical model of the battery pack with the passive TMS was conducted using ANSYS Fluent. Temperature profiles with respect to discharging time reveal that simulation shows good agreement with experiment at 1C-discharge rate.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davis, W Jr
1981-07-01
This report describes results of a parametric study of quantities of radioactive materials that might be discharged by a tornado-generated depressurization on contaminated process cells within the presently inoperative Nuclear Fuel Services' (NFS) fuel reprocessing facility near West Valley, New York. The study involved the following tasks: determining approximate quantities of radioactive materials in the cells and characterizing particle-size distribution; estimating the degree of mass reentrainment from particle-size distribution and from air speed data presented in Part 1; and estimating the quantities of radioactive material (source term) released from the cells to the atmosphere. The study has shown that improperlymore » sealed manipulator ports in the Process Mechanical Cell (PMC) present the most likely pathway for release of substantial quantities of radioactive material in the atmosphere under tornado accident conditions at the facility.« less
Effect of Width of Kerf on Machining Accuracy and Subsurface Layer After WEDM
NASA Astrophysics Data System (ADS)
Mouralova, K.; Kovar, J.; Klakurkova, L.; Prokes, T.
2018-02-01
Wire electrical discharge machining is an unconventional machining technology that applies physical principles to material removal. The material is removed by a series of recurring current discharges between the workpiece and the tool electrode, and a `kerf' is created between the wire and the material being machined. The width of the kerf is directly dependent not only on the diameter of the wire used, but also on the machine parameter settings and, in particular, on the set of mechanical and physical properties of the material being machined. To ensure precise machining, it is important to have the width of the kerf as small as possible. The present study deals with the evaluation of the width of the kerf for four different metallic materials (some of which were subsequently heat treated using several methods) with different machine parameter settings. The kerf is investigated on metallographic cross sections using light and electron microscopy.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fu, Fang; Yao, Yuze; Wang, Haiyan
Rational and precise control of the structure and dimension of electrode materials is an efficient way to improve their electrochemical performance. In this work, solvothermal or co-precipitation method is used to synthesize lithium-rich layered oxide materials of Li1.2Mn0.56Co0.12Ni0.12O2 (LLO) with various morphologies and structures, including microspheres, microrods, nanoplates, and irregular nanoparticles. These materials exhibit strong structure- dependent electrochemical properties. The porous hierarchical structured LLO microrods exhibit the best performance, delivering a discharge capacity of 264.6 mAh g(-1) at 0.5 C with over 91% retention after 100 cycles. At a high rate of 5 C, a high discharge capacity of 173.6more » mAh g(-1) can be achieved. This work reveals the relationship between the morphologies and electrochemical properties of LLO cathode materials, and provides a feasible approach to fabricating robust and high-performance electrode materials for lithium-ion batteries.« less
Rock-salt-type lithium metal sulphides as novel positive-electrode materials
Sakuda, Atsushi; Takeuchi, Tomonari; Okamura, Kazuhiro; Kobayashi, Hironori; Sakaebe, Hikari; Tatsumi, Kuniaki; Ogumi, Zempachi
2014-01-01
One way of increasing the energy density of lithium-ion batteries is to use electrode materials that exhibit high capacities owing to multielectron processes. Here, we report two novel materials, Li2TiS3 and Li3NbS4, which were mechanochemically synthesised at room temperature. When used as positive-electrode materials, Li2TiS3 and Li3NbS4 charged and discharged with high capacities of 425 mA h g−1 and 386 mA h g−1, respectively. These capacities correspond to those resulting from 2.5- and 3.5-electron processes. The average discharge voltage was approximately 2.2 V. It should be possible to prepare a number of high-capacity materials on the basis of the concept used to prepare Li2TiS3 and Li3NbS4. PMID:24811191
Fei, Hailong; Wu, Xiaomin; Li, Huan; Wei, Mingdeng
2014-02-01
A simple and versatile method for preparation of novel sodium intercalated (NH4)2V6O16 is developed via a simple hydrothermal route. It is found that ammonium sodium vanadium bronze displays higher discharge capacity and better rate cyclic stability than ammonium vanadium bronze as lithium-ion battery cathode material because of smaller charge transfer resistance, which would favor superior discharge capacity and rate performance. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.
Minimizing radiation damage in nonlinear optical crystals
Cooke, D.W.; Bennett, B.L.; Cockroft, N.J.
1998-09-08
Methods are disclosed for minimizing laser induced damage to nonlinear crystals, such as KTP crystals, involving various means for electrically grounding the crystals in order to diffuse electrical discharges within the crystals caused by the incident laser beam. In certain embodiments, electrically conductive material is deposited onto or into surfaces of the nonlinear crystals and the electrically conductive surfaces are connected to an electrical ground. To minimize electrical discharges on crystal surfaces that are not covered by the grounded electrically conductive material, a vacuum may be created around the nonlinear crystal. 5 figs.
48 CFR 1252.217-78 - Discharge of liens.
Code of Federal Regulations, 2010 CFR
2010-10-01
... lien or right in rem of any kind, other than in favor of the Government, that exists or arises in connection with work done or materials furnished under this contract. (b) If any such lien or right in rem is... to be discharged, the lien or right. (End of clause) ...
Code of Federal Regulations, 2012 CFR
2012-07-01
... of durable material fixed in a conspicuous place in each machinery space, or at the bilge and ballast pump control station, stating the following: Discharge of Oil Prohibited The Federal Water Pollution Control Act prohibits the discharge of oil or oily waste into or upon the navigable waters of the United...
Code of Federal Regulations, 2014 CFR
2014-07-01
... of durable material fixed in a conspicuous place in each machinery space, or at the bilge and ballast pump control station, stating the following: Discharge of Oil Prohibited The Federal Water Pollution Control Act prohibits the discharge of oil or oily waste into or upon the navigable waters of the United...
Code of Federal Regulations, 2011 CFR
2011-07-01
... of durable material fixed in a conspicuous place in each machinery space, or at the bilge and ballast pump control station, stating the following: Discharge of Oil Prohibited The Federal Water Pollution Control Act prohibits the discharge of oil or oily waste into or upon the navigable waters of the United...
Code of Federal Regulations, 2013 CFR
2013-07-01
... of durable material fixed in a conspicuous place in each machinery space, or at the bilge and ballast pump control station, stating the following: Discharge of Oil Prohibited The Federal Water Pollution Control Act prohibits the discharge of oil or oily waste into or upon the navigable waters of the United...
33 CFR 155.215 - Discharge removal equipment for inland oil barges.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Discharge removal equipment for inland oil barges. 155.215 Section 155.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR...
33 CFR 155.320 - Fuel oil and bulk lubricating oil discharge containment.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fuel oil and bulk lubricating oil discharge containment. 155.320 Section 155.320 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR...
33 CFR 155.220 - Discharge removal equipment for vessels carrying oil as secondary cargo.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Discharge removal equipment for vessels carrying oil as secondary cargo. 155.220 Section 155.220 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION...