Performance comparison of protonic and sodium phosphomolybdovanadate polyoxoanion catholytes within a chemically regenerative redox cathode polymer electrolyte fuel cell

Science.gov (United States)

Ward, David B.; Gunn, Natasha L. O.; Uwigena, Nadine; Davies, Trevor J.

2018-01-01

The direct reduction of oxygen in conventional polymer electrolyte fuel cells (PEFCs) is seen by many researchers as a key challenge in PEFC development. Chemically regenerative redox cathode (CRRC) polymer electrolyte fuel cells offer an alternative approach via the indirect reduction of oxygen, improving durability and reducing cost. These systems substitute gaseous oxygen for a liquid catalyst that is reduced at the cathode then oxidised in a regeneration vessel via air bubbling. A key component of a CRRC system is the liquid catalyst or catholyte. To date, phosphomolybdovanadium polyoxometalates with empirical formula H3+nPVnMo12-nO40 have shown the most promise for CRRC PEFC systems. In this work, four catholyte formulations are studied and compared against each other. The catholytes vary in vanadium content, pH and counter ion, with empirical formulas H6PV3Mo9O40, H7PV4Mo8O40, Na3H3PV3Mo9O40 and Na4H3PV4Mo8O40. Thermodynamic properties, cell performance and regeneration rates are measured, generating new insights into how formulation chemistry affects the components of a CRRC system. The results include the best CRRC PEFC performance reported to date, with noticeable advantages over conventional PEFCs. The optimum catholyte formulation is then determined via steady state tests, the results of which will guide further optimization of the catholyte formulation.

A highly reversible anthraquinone-based anolyte for alkaline aqueous redox flow batteries

Science.gov (United States)

Cao, Jianyu; Tao, Meng; Chen, Hongping; Xu, Juan; Chen, Zhidong

2018-05-01

The development of electroactive organic materials for use in aqueous redox flow battery (RFB) electrolytes is highly attractive because of their structural flexibility, low cost and sustainability. Here, we report on a highly reversible anthraquinone-based anolyte (1,8-dihydroxyanthraquinone, 1,8-DHAQ) for alkaline aqueous RFB applications. Electrochemical measurements reveal the substituent position of hydroxyl groups for DHAQ isomers has a significant impact on the redox potential, electrochemical reversibility and water-solubility. 1,8-DHAQ shows the highest redox reversibility and rapidest mass diffusion among five isomeric DHAQs. The alkaline aqueous RFB using 1,8-DHAQ as the anolyte and potassium ferrocyanide as the catholyte yields open-circuit voltage approaching 1.1 V and current efficiency and capacity retention exceeding 99.3% and 99.88% per cycle, respectively. This aqueous RFB produces a maximum power density of 152 mW cm-2 at 100% SOC and 45 °C. Choline hydroxide was used as a hydrotropic agent to enhance the water-solubility of 1,8-DHAQ. 1,8-DHAQ has a maximum solubility of 3 M in 1 M KOH with 4 M choline hydroxide.

A fuel-cell reactor for the direct synthesis of hydrogen peroxide alkaline solutions from H(2) and O(2).

Science.gov (United States)

Yamanaka, Ichiro; Onisawa, Takeshi; Hashimoto, Toshikazu; Murayama, Toru

2011-04-18

The effects of the type of fuel-cell reactors (undivided or divided by cation- and anion-exchange membranes), alkaline electrolytes (LiOH, NaOH, KOH), vapor-grown carbon fiber (VGCF) cathode components (additives: none, activated carbon, Valcan XC72, Black Pearls 2000, Seast-6, and Ketjen Black), and the flow rates of anolyte (0, 1.5, 12 mL h(-1)) and catholyte (0, 12 mL h(-1)) on the formation of hydrogen peroxide were studied. A divided fuel-cell system, O(2) (g)|VGCF-XC72 cathode|2 M NaOH catholyte|cation-exchange membrane (Nafion-117)|Pt/XC72-VGCF anode|2 M NaOH anolyte at 12 mL h(-1) flow|H(2) (g), was effective for the selective formation of hydrogen peroxide, with 130 mA cm(-2) , a 2 M aqueous solution of H(2)O(2)/NaOH, and a current efficiency of 95 % at atmospheric pressure and 298 K. The current and formation rate gradually decreased over a long period of time. The cause of the slow decrease in electrocatalytic performance was revealed and the decrease was stopped by a flow of catholyte. Cyclic voltammetry studies at the VGCF-XC72 electrode indicated that fast diffusion of O(2) from the gas phase to the electrode, and quick desorption of hydrogen peroxide from the electrode to the electrolyte were essential for the efficient formation of solutions of H(2)O(2)/NaOH. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electricity and catholyte production from ceramic MFCs treating urine.

Science.gov (United States)

Merino Jimenez, Irene; Greenman, John; Ieropoulos, Ioannis

2017-01-19

The use of ceramics as low cost membrane materials for Microbial Fuel Cells (MFCs) has gained increasing interest, due to improved performance levels in terms of power and catholyte production. The catholyte production in ceramic MFCs can be attributed to a combination of water or hydrogen peroxide formation from the oxygen reduction reaction in the cathode, water diffusion and electroosmotic drag through the ion exchange membrane. This study aims to evaluate, for the first time, the effect of ceramic wall/membrane thickness, in terms of power, as well as catholyte production from MFCs using urine as a feedstock. Cylindrical MFCs were assembled with fine fire clay of different thicknesses (2.5, 5 and 10 mm) as structural and membrane materials. The power generated increased when the membrane thickness decreased, reaching 2.1 ± 0.19 mW per single MFC (2.5 mm), which was 50% higher than that from the MFCs with the thickest membrane (10 mm). The amount of catholyte collected also decreased with the wall thickness, whereas the pH increased. Evidence shows that the catholyte composition varies with the wall thickness of the ceramic membrane. The possibility of producing different quality of catholyte from urine opens a new field of study in water reuse and resource recovery for practical implementation.

Distribution of electrolytes in a flow battery

Science.gov (United States)

Darling, Robert Mason; Smeltz, Andrew; Junker, Sven Tobias; Perry, Michael L.

2017-12-26

A method of determining a distribution of electrolytes in a flow battery includes providing a flow battery with a fixed amount of fluid electrolyte having a common electrochemically active specie, a portion of the fluid electrolyte serving as an anolyte and a remainder of the fluid electrolyte serving as a catholyte. An average oxidation state of the common electrochemically active specie is determined in the anolyte and the catholyte and, responsive to the determined average oxidation state, a molar ratio of the common electrochemically active specie between the anolyte and the catholyte is adjusted to increase an energy discharge capacity of the flow battery for the determined average oxidation state.

Electrolytic method to make alkali alcoholates using ion conducting alkali electrolyte/separator

Science.gov (United States)

Joshi, Ashok V [Salt Lake City, UT; Balagopal, Shekar [Sandy, UT; Pendelton, Justin [Salt Lake City, UT

2011-12-13

Alkali alcoholates, also called alkali alkoxides, are produced from alkali metal salt solutions and alcohol using a three-compartment electrolytic cell. The electrolytic cell includes an anolyte compartment configured with an anode, a buffer compartment, and a catholyte compartment configured with a cathode. An alkali ion conducting solid electrolyte configured to selectively transport alkali ions is positioned between the anolyte compartment and the buffer compartment. An alkali ion permeable separator is positioned between the buffer compartment and the catholyte compartment. The catholyte solution may include an alkali alcoholate and alcohol. The anolyte solution may include at least one alkali salt. The buffer compartment solution may include a soluble alkali salt and an alkali alcoholate in alcohol.

Understanding Ammonium Transport in Bioelectrochemical Systems towards its Recovery

Science.gov (United States)

Liu, Ying; Qin, Mohan; Luo, Shuai; He, Zhen; Qiao, Rui

2016-03-01

We report an integrated experimental and simulation study of ammonia recovery using microbial electrolysis cells (MECs). The transport of various species during the batch-mode operation of an MEC was examined experimentally and the results were used to validate the mathematical model for such an operation. It was found that, while the generated electrical current through the system tends to acidify (or basify) the anolyte (or catholyte), their effects are buffered by a cascade of chemical groups such as the NH3/NH4+ group, leading to relatively stable pH values in both anolyte and catholyte. The transport of NH4+ ions accounts for ~90% of the total current, thus quantitatively confirming that the NH4+ ions serve as effective proton shuttles during MEC operations. Analysis further indicated that, because of the Donnan equilibrium at cation exchange membrane-anolyte/catholyte interfaces, the Na+ ion in the anolyte actually facilitates the transport of NH4+ ions during the early stage of a batch cycle and they compete with the NH4+ ions weakly at later time. These insights, along with a new and simple method for predicting the strength of ammonia diffusion from the catholyte toward the anolyte, will help effective design and operation of bioeletrochemical system-based ammonia recovery systems.

The importance of OH − transport through anion exchange membrane in microbial electrolysis cells

KAUST Repository

Ye, Yaoli

2018-01-11

In two-chamber microbial electrolysis cells (MECs) with anion exchange membranes (AEMs), a phosphate buffer solution (PBS) is typically used to avoid increases in catholyte pH as Nernst equation calculations indicate that high pHs adversely impact electrochemical performance. However, ion transport between the chambers will also impact performance, which is a factor not included in those calculations. To separate the impacts of pH and ion transport on MEC performance, a high molecular weight polymer buffer (PoB), which was retained in the catholyte due to its low AEM transport and cationic charge, was compared to PBS in MECs and abiotic electrochemical half cells (EHCs). In MECs, catholyte pH control was less important than ion transport. MEC tests using the PoB catholyte, which had a higher buffer capacity and thus maintained a lower catholye pH (<8), resulted in a 50% lower hydrogen production rate (HPR) than that obtained using PBS (HPR = 0.7 m3-H2 m−3 d−1) where the catholyte rapidly increased to pH = 12. The main reason for the decreased performance using PoB was a lack of hydroxide ion transfer into the anolyte to balance pH. The anolyte pH in MECs rapidly decreased to 5.8 due to a lack of hydroxide ion transport, which inhibited current generation by the anode, whereas the pH was maintained at 6.8 using PBS. In abiotic tests in ECHs, where the cathode potential was set at −1.2 V, the HPR was 133% higher using PoB than PBS due to catholyte pH control, as the anolyte pH was not a factor in the performance. These results show that maintaining charge transfer to control anolyte pH is more important than obtaining a more neutral pH catholyte.

A π-Conjugation Extended Viologen as a Two-Electron Storage Anolyte for Total Organic Aqueous Redox Flow Batteries.

Science.gov (United States)

Luo, Jian; Hu, Bo; Debruler, Camden; Liu, Tianbiao Leo

2018-01-02

Extending the conjugation of viologen by a planar thiazolo[5,4-d]thiazole (TTz) framework and functionalizing the pyridinium with hydrophilic ammonium groups yielded a highly water-soluble π-conjugation extended viologen, 4,4'-(thiazolo[5,4-d]thiazole-2,5-diyl)bis(1-(3-(trimethylammonio)propyl)pyridin-1-ium) tetrachloride, [(NPr) 2 TTz]Cl 4  , as a novel two-electron storage anolyte for aqueous organic redox flow battery (AORFB) applications. Its physical and electrochemical properties were systematically investigated. Paired with 4-trimethylammonium-TEMPO (N Me -TEMPO) as catholyte, [(NPr) 2 TTz]Cl 4 enables a 1.44 V AORFB with a theoretical energy density of 53.7 Wh L -1 . A demonstrated [(NPr) 2 TTz]Cl 4 /N Me -TEMPO AORFB delivered an energy efficiency of 70 % and 99.97 % capacity retention per cycle. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrochemical characteristics of vanadium redox reactions on porous carbon electrodes for microfluidic fuel cell applications

International Nuclear Information System (INIS)

Lee, Jin Wook; Hong, Jun Ki; Kjeang, Erik

2012-01-01

Microfluidic vanadium redox fuel cells are membraneless and catalyst-free fuel cells comprising a microfluidic channel network with two porous carbon electrodes. The anolyte and catholyte for fuel cell operation are V(II) and V(V) in sulfuric acid based aqueous solution. In the present work, the electrochemical characteristics of the vanadium redox reactions are investigated on commonly used porous carbon paper electrodes and compared to a standard solid graphite electrode as baseline. Half-cell electrochemical impedance spectroscopy is applied to measure the overall ohmic resistance and resistivity of the electrodes. Kinetic parameters for both V(II) and V(V) discharging reactions are extracted from Tafel plots and compared for the different electrodes. Cyclic voltammetry techniques reveal that the redox reactions are irreversible and that the magnitudes of peak current density vary significantly for each electrode. The obtained kinetic parameters for the carbon paper are implemented into a numerical simulation and the results show a good agreement with measured polarization curves from operation of a microfluidic vanadium redox fuel cell employing the same material as flow-through porous electrodes. Recommendations for microfluidic fuel cell design and operation are provided based on the measured trends.

Water SA - Vol 32, No 2 (2006)

African Journals Online (AJOL)

The effect of sodium chloride and sodium bicarbonate derived anolytes, and anolyte-catholyte combination on biofilms · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. MS Thantsha, TE Cloete, 237-242. http://dx.doi.org/10.4314/wsa.v32i2.5248 ...

Effect of selected factors on the current flow and voltage loss at ...

African Journals Online (AJOL)

In this paper, laboratory scale study was conducted to investigate the current flow and voltage loss at the electrodes in the electrochemical treatment of a tropical laterite. Three different tests using calcium chloride (CC) as anolyte and sodium chloride (SC) as catholyte (NC); SC as anolyte and Phosphoric acid (PA) as ...

A comparison of the influence of catholyte vs phosphate detergent ...

African Journals Online (AJOL)

The electro-chemical activation of aqueous media is a relatively new technology. The alkaline part of the activated media (catholyte) has outstanding detergency properties. Catholyte provides an environmentally friendly alternative to conventional phosphate based detergents. Little is, however, known about the effect of ...

Redox flow batteries based on supporting solutions containing chloride

Science.gov (United States)

Li, Liyu; Kim, Soowhan; Yang, Zhenguo; Wang, Wei; Zhang, Jianlu; Chen, Baowei; Nie, Zimin; Xia, Guanguang

2014-01-14

Redox flow battery systems having a supporting solution that contains Cl.sup.- ions can exhibit improved performance and characteristics. Furthermore, a supporting solution having mixed SO.sub.4.sup.2- and Cl.sup.- ions can provide increased energy density and improved stability and solubility of one or more of the ionic species in the catholyte and/or anolyte. According to one example, a vanadium-based redox flow battery system is characterized by an anolyte having V.sup.2+ and V.sup.3+ in a supporting solution and a catholyte having V.sup.4+ and V.sup.5+ in a supporting solution. The supporting solution can contain Cl.sup.- ions or a mixture of SO.sub.4.sup.2- and Cl.sup.- ions.

Redox flow batteries based on supporting solutions containing chloride

Energy Technology Data Exchange (ETDEWEB)

Li, Liyu; Kim, Soowhan; Yang, Zhenguo; Wang, Wei; Nie, Zimin; Chen, Baowei; Zhang, Jianlu; Xia, Guanguang

2017-11-14

Redox flow battery systems having a supporting solution that contains Cl.sup.- ions can exhibit improved performance and characteristics. Furthermore, a supporting solution having mixed SO.sub.4.sup.2- and Cl.sup.- ions can provide increased energy density and improved stability and solubility of one or more of the ionic species in the catholyte and/or anolyte. According to one example, a vanadium-based redox flow battery system is characterized by an anolyte having V.sup.2+ and V.sup.3+ in a supporting solution and a catholyte having V.sup.4+ and V.sup.5+ in a supporting solution. The supporting solution can contain Cl.sup.- ions or a mixture of SO.sub.4.sup.2- and Cl.sup.- ions.

Zinc-based electrolyte compositions, and related electrochemical processes and articles

Science.gov (United States)

Kniajanski, Sergei; Soloveichik, Grigorii Lev

2018-02-20

An aqueous electrolyte composition is described, including a zinc salt based on zinc acetate or zinc glocolate. The saturation concentration of zinc in the electrolyte composition is in the range of about 2.5M to about 3.5M. The composition also contains at least one salt of a monovalent cation. The molar ratio of zinc to the monovalent cation is about 1:2. An aqueous zinc electroplating bath, containing the aqueous electrolyte composition, is also disclosed, along with a method for the electrochemical deposition of zinc onto a substrate surface, using the electroplating bath. Related flow batteries are also described, including a catholyte, as well as an anolyte based on the aqueous electrolyte composition, with a membrane between the catholyte and the anolyte.

The modeling of gold recovery from tetrachloroaurate wastewater using a microbial fuel cell.

Science.gov (United States)

Choi, Chansoo; Hu, Naixu

2013-04-01

In this study, tetrachloroaurate as an electron acceptor of a microbial fuel cell (MFC) has been studied to discover the parameters that affect the cost-effective recovery of gold. The modeling and equations for calculating the maximum actual efficiency and electrochemical impedance spectroscopic internal resistance of the MFC were also developed. The maximum power density (Pmax) of 6.58 W/m(2) with a fill factor of 0.717 was achieved for 60 mL volumes of 2000 ppm Au(III) catholyte and 12.2 mM acetate anolyte, respectively. The Pmax can also be predicted simply by measuring Rint by EIS. Additionally, the maximum actual MFC efficiency of about 57% was achieved, and the recovery efficiency of Au and the remaining concentration reached 99.89±0.00% and 0.22±0.00 ppm, respectively, for an Au(III) concentration of 200 ppm. The anodic concentration polarization quenching of the MFC strongly supports a mediator mechanism for the electron transfer from the microorganism to the anode. Copyright © 2013 Elsevier Ltd. All rights reserved.

Paper-based enzymatic microfluidic fuel cell: From a two-stream flow device to a single-stream lateral flow strip

Science.gov (United States)

González-Guerrero, Maria José; del Campo, F. Javier; Esquivel, Juan Pablo; Giroud, Fabien; Minteer, Shelley D.; Sabaté, Neus

2016-09-01

This work presents a first approach towards the development of a cost-effective enzymatic paper-based glucose/O2 microfluidic fuel cell in which fluid transport is based on capillary action. A first fuel cell configuration consists of a Y-shaped paper device with the fuel and the oxidant flowing in parallel over carbon paper electrodes modified with bioelectrocatalytic enzymes. The anode consists of a ferrocenium-based polyethyleneimine polymer linked to glucose oxidase (GOx/Fc-C6-LPEI), while the cathode contains a mixture of laccase, anthracene-modified multiwall carbon nanotubes, and tetrabutylammonium bromide-modified Nafion (MWCNTs/laccase/TBAB-Nafion). Subsequently, the Y-shaped configuration is improved to use a single solution containing both, the anolyte and the catholyte. Thus, the electrolytes pHs of the fuel and the oxidant solutions are adapted to an intermediate pH of 5.5. Finally, the fuel cell is run with this single solution obtaining a maximum open circuit of 0.55 ± 0.04 V and a maximum current and power density of 225 ± 17 μA cm-2 and 24 ± 5 μW cm-2, respectively. Hence, a power source closer to a commercial application (similar to conventional lateral flow test strips) is developed and successfully operated. This system can be used to supply the energy required to power microelectronics demanding low power consumption.

A floating water bridge produces water with excess charge

Science.gov (United States)

Fuchs, Elmar C.; Sammer, Martina; Wexler, Adam D.; Kuntke, Philipp; Woisetschläger, Jakob

2016-03-01

Excess positive and negative Bjerrum-defect like charge (protonic and ‘aterprotonic’, from ancient Greek ἄ'τɛρ, ‘without’) in anolyte and catholyte of high voltage electrolysis of highly pure water was found during the so-called ‘floating water bridge’ experiment. The floating water bridge is a special case of an electrohydrodynamic liquid bridge and constitutes an intriguing phenomenon that occurs when a high potential difference (~kV cm-1) is applied between two beakers of water. To obtain such results impedance spectroscopy was used. This measurement technique allows the depiction and simulation of complex aqueous systems as simple electric circuits. In the present work we show that there is an additional small contribution from the difference in conductivity between anolyte and catholyte which cannot be measured with a conductivity meter, but is clearly visible in an impedance spectrum.

anolyte as an alternative bleach for stained cotton fabrics

African Journals Online (AJOL)

user

ISSN 0378-5254 Journal of Consumer Sciences, Special Edition. Diversifying .... detergent effect, while Anolyte is antimicrobial. Steponavičius and ..... set and the longer exposure and higher temperature are .... Mere washing with detergent ...

A floating water bridge produces water with excess charge

International Nuclear Information System (INIS)

Fuchs, Elmar C; Sammer, Martina; Wexler, Adam D; Kuntke, Philipp; Woisetschläger, Jakob

2016-01-01

Excess positive and negative Bjerrum-defect like charge (protonic and ‘aterprotonic’, from ancient Greek ατερ, ‘without’) in anolyte and catholyte of high voltage electrolysis of highly pure water was found during the so-called ‘floating water bridge’ experiment. The floating water bridge is a special case of an electrohydrodynamic liquid bridge and constitutes an intriguing phenomenon that occurs when a high potential difference (∼kV cm −1 ) is applied between two beakers of water. To obtain such results impedance spectroscopy was used. This measurement technique allows the depiction and simulation of complex aqueous systems as simple electric circuits. In the present work we show that there is an additional small contribution from the difference in conductivity between anolyte and catholyte which cannot be measured with a conductivity meter, but is clearly visible in an impedance spectrum. (paper)

Enhanced hydrogen generation using a saline catholyte in a two chamber microbial electrolysis cell

KAUST Repository

Nam, Joo-Youn

2011-11-01

High rates of hydrogen gas production were achieved in a two chamber microbial electrolysis cell (MEC) without a catholyte phosphate buffer by using a saline catholyte solution and a cathode constructed around a stainless steel mesh current collector. Using the non-buffered salt solution (68 mM NaCl) produced the highest current density of 131 ± 12 A/m3, hydrogen yield of 3.2 ± 0.3 mol H2/mol acetate, and gas production rate of 1.6 ± 0.2 m3 H2/m 3·d, compared to MECs with catholytes externally sparged with CO2 or containing a phosphate buffer. The salinity of the catholyte achieved a high solution conductivity, and therefore the electrode spacing did not appreciably affect performance. The coulombic efficiency with the cathode placed near the membrane separating the chambers was 83 ± 4%, similar to that obtained with the cathode placed more distant from the membrane (84 ± 4%). Using a carbon cloth cathode instead of the stainless steel mesh cathode did not significantly affect performance, with all reactor configurations producing similar performance in terms of total gas volume, COD removal, rcat and overall energy recovery. These results show MEC performance can be improved by using a saline catholyte without pH control. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Electrochemical membrane reactor: In situ separation and recovery of chromic acid and metal ions

International Nuclear Information System (INIS)

Khan, Jeeshan; Tripathi, Bijay P.; Saxena, Arunima; Shahi, Vinod K.

2007-01-01

An electrochemical membrane reactor with three compartments (anolyte, catholyte and central compartment) based on in-house-prepared cation- and anion-exchange membrane was developed to achieve in situ separation and recovery of chromic acid and metal ions. The physicochemical and electrochemical properties of the ion-exchange membrane under standard operating conditions reveal its suitability for the proposed reactor. Experiments using synthetic solutions of chromate and dichromate of different concentrations were carried out to study the feasibility of the process. Electrochemical reactions occurring at the cathode and anode under operating conditions are proposed. It was observed that metal ion migrated through the cation-exchange membrane from central compartment to catholyte and OH - formation at the cathode leads to the formation of metal hydroxide. Simultaneously, chromate ion migrated through the anion-exchange membrane from central compartment to the anolyte and formed chromic acid by combining H + produced their by oxidative water splitting. Thus a continuous decay in the concentration of chromate and metal ion was observed in the central compartment, which was recovered separately in the anolyte and catholyte, respectively, from their mixed solution. This process was completely optimized in terms of operating conditions such as initial concentration of chromate and metal ions in the central compartment, the applied cell voltage, chromate and metal ion flux, recovery percentage, energy consumption, and current efficiency. It was concluded that chromic acid and metal ions can be recovered efficiently from their mixed solution leaving behind the uncharged organics and can be reused as their corresponding acid and base apart from the purifying water for further applications

On performance capabilities of alkaline anolyte in wastewater management

International Nuclear Information System (INIS)

Shimkevich, Alexander

2014-01-01

A concept for electric converting a saline wastewater into basic solution (pH > 7) with a positive RedOx potential (alkaline anolyte) is considered. Such the medium can be obtained in situ at flowing wastewater via a special electrochemical cell with strongly polarized cathode (generating hydroxide anions) and quasi-equilibrium anode which intensively discharges hydroxide ions to hydroxyl radicals into the wastewater. The radicals will oxidize anions of strong acid and convert them into weak-acid micro precipitates in the flowing basic solution. These renewable nano-sorbents will uninterruptedly co-precipitate radioactive contamination from wastewater and be agglomerated as corrosion by-products in the felt-like anode. The consideration of liquid water as a chemical compound with a wide band gap shows that the anolyte (as a hyper-stoichiometric water, H 2 O 1+|x| ) is a simple and effective tool for varying physical and chemical properties of the aqueous solution due to forced changing its RedOx potential as one needs. This potential as Fermi level in the band gap of liquid water is the most convenient parameter for monitoring and managing the electrochemical potential of the aqueous medium. Its hyper-stoichiometric state is realized when Fermi level is shifted to the top of a valence band. This electro-oxidized state as the alkaline anolyte is characterized by an acceptor level, OH/OH - , partially occupied by electrons. Then, the hydroxyl radical (OH • ) as the strongest oxidizer will oxidize intensively the metal anode and renew its surface for great removal of radio-nuclides from the wastewater due to their large specific area of renewable surface of hydroxide absorber on the felt-like anode. (author)

Electrochemical Oscillation of Vanadium Ions in Anolyte

Directory of Open Access Journals (Sweden)

Hao Peng

2017-08-01

Full Text Available Periodic electrochemical oscillation of the anolyte was reported for the first time in a simulated charging process of the vanadium redox flow batteries. The electrochemical oscillation could be explained in terms of the competition between the growth and the chemical dissolution of V2O5 film. Also, the oscillation phenomenon was possible to regular extra power consumption. The results of this paper might enable new methods to improve the charge efficiency and energy saving for vanadium redox flow batteries.

Development of a membraneless ethanol/oxygen biofuel cell

International Nuclear Information System (INIS)

Topcagic, Sabina; Minteer, Shelley D.

2006-01-01

Biofuel cells are similar to traditional fuel cells, except the metallic electrocatalyst is replaced with a biological electrocatalyst. This paper details the development of an enzymatic biofuel cell, which employs alcohol dehydrogenase to oxidize ethanol at the anode and bilirubin oxidase to reduce oxygen at the cathode. This ethanol/oxygen biofuel cell has an active lifetime of about 30 days and shows power densities of up to 0.46 mW/cm 2 . The biocathode described in this paper is unique in that bilirubin oxidase is immobilized within a modified Nafion polymer that acts both to entrap and stabilize the enzyme, while also containing the redox mediator in concentrations large enough for self-exchange based conduction of electrons between the enzyme and the electrode. This biocathode is fuel tolerant, which leads to a unique fuel cell that employs both renewable catalysts and fuel, but does not require a separator membrane to separate anolyte from catholyte

Elimination of biofilm and microbial contamination reservoirs in hospital washbasin U-bends by automated cleaning and disinfection with electrochemically activated solutions.

Science.gov (United States)

Swan, J S; Deasy, E C; Boyle, M A; Russell, R J; O'Donnell, M J; Coleman, D C

2016-10-01

Washbasin U-bends are reservoirs of microbial contamination in healthcare environments. U-Bends are constantly full of water and harbour microbial biofilm. To develop an effective automated cleaning and disinfection system for U-bends using two solutions generated by electrochemical activation of brine including the disinfectant anolyte (predominantly hypochlorous acid) and catholyte (predominantly sodium hydroxide) with detergent properties. Initially three washbasin U-bends were manually filled with catholyte followed by anolyte for 5min each once weekly for five weeks. A programmable system was then developed with one washbasin that automated this process. This U-bend had three cycles of 5min catholyte followed by 5min anolyte treatment per week for three months. Quantitative bacterial counts from treated and control U-bends were determined on blood agar (CBA), R2A, PAS, and PA agars following automated treatment and on CBA and R2A following manual treatment. The average bacterial density from untreated U-bends throughout the study was >1×10(5) cfu/swab on all media with Pseudomonas aeruginosa accounting for ∼50% of counts. Manual U-bend electrochemically activated (ECA) solution treatment reduced counts significantly (<100cfu/swab) (P<0.01 for CBA; P<0.005 for R2A). Similarly, counts from the automated ECA-treatment U-bend were significantly reduced with average counts for 35 cycles on CBA, R2A, PAS, and PA of 2.1±4.5 (P<0.0001), 13.1±30.1 (P<0.05), 0.7±2.8 (P<0.001), and 0 (P<0.05) cfu/swab, respectively. P. aeruginosa was eliminated from all treated U-bends. Automated ECA treatment of washbasin U-bends consistently minimizes microbial contamination. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Geochemical effects of electro-osmosis in clays

KAUST Repository

Loch, J. P. Gustav

2010-02-13

Geochemical effects of electro-osmosis in bentonite clay are studied in the laboratory, where a 6 mm thick bentonite layer is subjected to direct current. Acidification and alkalization near anode and cathode are expected, possibly causing mineral deterioration, ion mobilization and precipitation of new solids. Afterwards the clay is analysed by XRF and anolyte and catholyte are analysed by ICP-MS. In addition, as a preliminary experiment treated bentonite is analysed by high resolution μ-XRF. Electro-osmotic flow is observed. Due to its carbonate content the bentonite is pH-buffering. Alkalization in the catholyte is substantial. Ca, Na and Sr are significantly removed from the clay and accumulate in the catholyte. Recovery in the catholyte accounts for a small fraction of the element-loss from the clay. The rest will have precipitated in undetected solid phases. μ-XRF indicates the loss of Ca-content throughout the bentonite layer. © The Author(s) 2010.

Effect of electrolytes concentration on recovery of cesium from AMP-PAN by Electrodialysis-Ion Exchange (EDIX)

International Nuclear Information System (INIS)

Mahendra, Ch.; Rajan, K.K.; SatyaSai, P.M.; Anand Babu, C.

2014-01-01

Cesium from the simulated acidic waste solution was separated using Ammonium Molybdophosphate (AMP) - Polyacrylonitrile (PAN) ion exchange resin in column operations. Electrodialysis - Ion exchange (EDIX) has been tried for the recovery of cesium from the AMP-PAN which was saturated with cesium. The electrodialysis setup consists of three compartments; cesium loaded AMP-PAN is placed in the middle compartment and is separated from the anode and cathode compartments by cation exchange membranes. Ammonium sulphate was used as anolyte and HNO 3 as catholyte. 0.1N HNO 3 was circulated in the middle compartment containing AMP-PAN to keep the resin in acidic form. On application of potential, the ammonium ions from the anode compartment migrate towards cathode through the middle compartment where they exchange with cesium ions on the resin and the exchanged cesium ions migrate towards cathode to get concentrated. Some part of cesium is recovered in the middle compartment due to convection. Cesium recovery from the AMP-PAN in the electrodialysis setup was studied at different anolyte and catholyte concentrations. All the experiments were carried out at constant current density of 40 mA/cm 2 for 15h. It was found that more than 50% of cesium recovery was observed for all the experiments studied and recovery percentage increased with increasing the anolyte concentration. It was observed that the electrolytes concentration affects the voltage drop across the cell

[Study of cytogenetic and cytotoxic effect of non-contact electrochemically-activated waters in the five organs of rats].

Science.gov (United States)

Sycheva, L P; Mikhaĭlova, R I; Beliaeva, N N; Zhurkov, V S; Iurchenko, V V; Savostikova, O N; Alekseeva, A V; Kribtsova, E K; Kovalenko, M A; Akhal'tseva, L V; Sheremet'eva, S M; Iurtseva, N A; Murav'eva, L V; Kamenetskaia, D B

2014-01-01

For the first time the multiorgan karyological analysis of five organs of rats was applied for the study of the cytogenetic and cytotoxic action of the four types of non-contact electrochemically activated water in the 30-days in vivo experiment. The effects of investigated waters were not detected in bone marrow polychromatic erythrocytes. "Anolyte" (ORP = -362 mV) did not have a negative effect on rats. "Catholyte-5" (ORP = +22 mV) and "Catholyte-25" (ORP = -60 mV) induced cytogenetic abnormalities in the bladder and fore stomach. The same catholytes and "Catholyte-40" (ORP = -10 mV) changed the proliferation indices: increased the mitotic index in the fore stomach epithelium and reduced the frequency of binucleated cells in the fore stomach, bladder and lungs. The increase in the rate of cells with cytogenetic abnormalities on the background of the promotion of mitotic activity can be considered as a manifestation of the negative effect, typical for catolytes, but the effect of each out of them has its own features.

Fundamentally Addressing Bromine Storage through Reversible Solid-State Confinement in Porous Carbon Electrodes: Design of a High-Performance Dual-Redox Electrochemical Capacitor.

Science.gov (United States)

Yoo, Seung Joon; Evanko, Brian; Wang, Xingfeng; Romelczyk, Monica; Taylor, Aidan; Ji, Xiulei; Boettcher, Shannon W; Stucky, Galen D

2017-07-26

Research in electric double-layer capacitors (EDLCs) and rechargeable batteries is converging to target systems that have battery-level energy density and capacitor-level cycling stability and power density. This research direction has been facilitated by the use of redox-active electrolytes that add faradaic charge storage to increase energy density of the EDLCs. Aqueous redox-enhanced electrochemical capacitors (redox ECs) have, however, performed poorly due to cross-diffusion of soluble redox couples, reduced cycle life, and low operating voltages. In this manuscript, we propose that these challenges can be simultaneously met by mechanistically designing a liquid-to-solid phase transition of oxidized catholyte (or reduced anolyte) with confinement in the pores of electrodes. Here we demonstrate the realization of this approach with the use of bromide catholyte and tetrabutylammonium cation that induces reversible solid-state complexation of Br 2 /Br 3 - . This mechanism solves the inherent cross-diffusion issue of redox ECs and has the added benefit of greatly stabilizing the reactive bromine generated during charging. Based on this new mechanistic insight on the utilization of solid-state bromine storage in redox ECs, we developed a dual-redox EC consisting of a bromide catholyte and an ethyl viologen anolyte with the addition of tetrabutylammonium bromide. In comparison to aqueous and organic electric double-layer capacitors, this system enhances energy by factors of ca. 11 and 3.5, respectively, with a specific energy of ∼64 W·h/kg at 1 A/g, a maximum power density >3 kW/kg, and cycling stability over 7000 cycles.

Enhanced hydrogen generation using a saline catholyte in a two chamber microbial electrolysis cell

KAUST Repository

Nam, Joo-Youn; Logan, Bruce E.

2011-01-01

sparged with CO2 or containing a phosphate buffer. The salinity of the catholyte achieved a high solution conductivity, and therefore the electrode spacing did not appreciably affect performance. The coulombic efficiency with the cathode placed near

Simultaneous Extraction of Lithium and Hydrogen from Seawater

Science.gov (United States)

2011-01-26

P2S5 glass ceramic membrane . The potential was scanned to 4V at the rate of 50mV/sec. Operating Conditions: Anode: carbon felt (0.5mm) Anolyte...significantly. Further, the ceramic membrane only allows diffusion of ions but prevents transport of bulk solution. Figure 8 shows the IC chromatogram...electrochemical process employing solid electrolytes. Li ion conducting ceramic membrane produces high selectivity to lithium ion in the catholyte. Cell

High Efficiency Semi-Fuel Cell Incorporating an Ion Exchange Membrane

National Research Council Canada - National Science Library

Medeiros, Maria G; Dow, Eric G; Bessette, Russell R; Yan, Susan G; Dischert, Dwayne W

2004-01-01

It is a general purpose and object of the present invention to eliminate the parasitic direct reaction of the catholyte with the metal anode in a semi-fuel cell, thereby improving the overall energy...

TEMPO-based catholyte for high-energy density nonaqueous redox flow batteries.

Science.gov (United States)

Wei, Xiaoliang; Xu, Wu; Vijayakumar, Murugesan; Cosimbescu, Lelia; Liu, Tianbiao; Sprenkle, Vincent; Wang, Wei

2014-12-03

A TEMPO-based non-aqueous electrolyte with the TEMPO concentration as high as 2.0 m is demonstrated as a high-energy-density catholyte for redox flow battery applications. With a hybrid anode, Li|TEMPO flow cells using this electrolyte deliver an energy efficiency of ca. 70% and an impressively high energy density of 126 W h L(-1) . © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A thermally regenerative ammonia-based battery for efficient harvesting of low-grade thermal energy as electrical power

KAUST Repository

Zhang, Fang

2015-01-01

© 2015 The Royal Society of Chemistry. Thermal energy was shown to be efficiently converted into electrical power in a thermally regenerative ammonia-based battery (TRAB) using copper-based redox couples [Cu(NH3)4 2+/Cu and Cu(ii)/Cu]. Ammonia addition to the anolyte (2 M ammonia in a copper-nitrate electrolyte) of a single TRAB cell produced a maximum power density of 115 ± 1 W m-2 (based on projected area of a single copper mesh electrode), with an energy density of 453 W h m-3 (normalized to the total electrolyte volume, under maximum power production conditions). Adding a second cell doubled both the voltage and maximum power. Increasing the anolyte ammonia concentration to 3 M further improved the maximum power density to 136 ± 3 W m-2. Volatilization of ammonia from the spent anolyte by heating (simulating distillation), and re-addition of this ammonia to the spent catholyte chamber with subsequent operation of this chamber as the anode (to regenerate copper on the other electrode), produced a maximum power density of 60 ± 3 W m-2, with an average discharge energy efficiency of ∼29% (electrical energy captured versus chemical energy in the starting solutions). Power was restored to 126 ± 5 W m-2 through acid addition to the regenerated catholyte to decrease pH and dissolve Cu(OH)2 precipitates, suggesting that an inexpensive acid or a waste acid could be used to improve performance. These results demonstrated that TRABs using ammonia-based electrolytes and inexpensive copper electrodes can provide a practical method for efficient conversion of low-grade thermal energy into electricity.

Retrieval of Au, Ag, Cu precious metals coupled with electric energy production via an unconventional coupled redox fuel cell reactor.

Science.gov (United States)

Zhang, Hui-Min; Fan, Zheng; Xu, Wei; Feng, Xiao; Wu, Zu-Cheng

2017-09-15

The recovery of heavy metals from aqueous solutions or e-wastes is of upmost importance. Retrieval of Au, Ag, and Cu with electricity generation through building an ethanol-metal coupled redox fuel cells (CRFCs) is demonstrated. The cell was uniquely assembled on PdNi/C anode the electro-oxidation of ethanol takes place to give electrons and then go through the external circuit reducing metal ions to metallic on the cathode, metals are recovered. Taking an example of removal of 100mgL -1 gold in 0.5M HAc-NaAc buffer solution as the catholyte, 2.0M ethanol in 1.0M alkaline solution as the anolyte, an open circuit voltage of 1.4V, more than 96% of gold removal efficiency in 20h, and equivalent energy production of 2.0kWhkg -1 of gold can be readily achieved in this system. When gold and copper ions coexist, it was confirmed that metallic Cu is formed on the cathodic electrode later than metallic Au formation by XPS analysis. Thus, this system can achieve step by step electrodeposition of gold and copper while the two metal ions coexisting. This work develops a new approach to retrieve valuable metals from aqueous solution or e-wastes. Copyright © 2017 Elsevier B.V. All rights reserved.

Simulation and resolution of voltage reversal in microbial fuel cell stack.

Science.gov (United States)

Sugnaux, Marc; Savy, Cyrille; Cachelin, Christian Pierre; Hugenin, Gérald; Fischer, Fabian

2017-08-01

To understand the biotic and non-biotic contributions of voltage reversals in microbial fuel cell stacks (MFC) they were simulated with an electronic MFC-Stack mimic. The simulation was then compared with results from a real 3L triple MFC-Stack with shared anolyte. It showed that voltage reversals originate from the variability of biofilms, but also the external load plays a role. When similar biofilm properties were created on all anodes the likelihood of voltage reversals was largely reduced. Homogenous biofilms on all anodes were created by electrical circuit alternation and electrostimulation. Conversely, anolyte recirculation, or increased nutriment supply, postponed reversals and unfavourable voltage asymmetries on anodes persisted. In conclusion, voltage reversals are often a negative event but occur also in close to best MFC-Stack performance. They were manageable and this with a simplified MFC architecture in which multiple anodes share the same anolyte. Copyright © 2017 Elsevier Ltd. All rights reserved.

In situ X-ray near-edge absorption spectroscopy investigation of the state of charge of all-vanadium redox flow batteries.

Science.gov (United States)

Jia, Chuankun; Liu, Qi; Sun, Cheng-Jun; Yang, Fan; Ren, Yang; Heald, Steve M; Liu, Yadong; Li, Zhe-Fei; Lu, Wenquan; Xie, Jian

2014-10-22

Synchrotron-based in situ X-ray near-edge absorption spectroscopy (XANES) has been used to study the valence state evolution of the vanadium ion for both the catholyte and anolyte in all-vanadium redox flow batteries (VRB) under realistic cycling conditions. The results indicate that, when using the widely used charge-discharge profile during the first charge process (charging the VRB cell to 1.65 V under a constant current mode), the vanadium ion valence did not reach V(V) in the catholyte and did not reach V(II) in the anolyte. Consequently, the state of charge (SOC) for the VRB cell was only 82%, far below the desired 100% SOC. Thus, such incompletely charged mix electrolytes results in not only wasting the electrolytes but also decreasing the cell performance in the following cycles. On the basis of our study, we proposed a new charge-discharge profile (first charged at a constant current mode up to 1.65 V and then continuously charged at a constant voltage mode until the capacity was close to the theoretical value) for the first charge process that achieved 100% SOC after the initial charge process. Utilizing this new charge-discharge profile, the theoretical charge capacity and the full utilization of electrolytes has been achieved, thus having a significant impact on the cost reduction of the electrolytes in VRB.

Simultaneous Recovery of Hydrogen and Chlorine from Industrial Waste Dilute Hydrochloric Acid

Directory of Open Access Journals (Sweden)

N. Paidimarri

2016-01-01

Full Text Available Recovery of chlorine from byproduct HCl has inevitable commercial importance in industries lately because of insufficient purity or too low concentration to recycle it. Instead it is being neutralized in industries before disposing to meet stringent environmental conditions. Although recovery through catalytic oxidation processes is studied since the 19th century, their high operating conditions combined with sluggish reaction kinetics and low single pass conversions make electrolysis a better alternative. The present motive of this work is to develop a novel electrolysis process which in contrast to traditional processes effectively recovers both hydrogen and chlorine from dilute HCl. For this, an electrolytic cell with an Anionic Exchange Membrane has been designed which only allows the passage of chlorine anions from catholyte to anolyte separating the gasses in a single step. The catholyte can be as low as 3.59 wt% because of fixed anolyte concentration of 1.99 wt% which minimizes oxygen formation. Preliminary results show that the simultaneous recovery of hydrogen and chlorine is possible with high conversion up to 98%. The maximum current density value for 4.96 cm2 membrane surface area (70% active surface area is 2.54 kAm−2, which is comparable with reported commercial processes. This study is expected to be useful for process intensification of the same in a continuous process environment.

Use of electrochemically activated aqueous solutions in the manufacture of fur materials.

Science.gov (United States)

Danylkovych, Anatoliy G; Lishchuk, Viktor I; Romaniuk, Oksana O

2016-01-01

The influence of characteristics of electrochemically activated aqueous processing mediums in the treatment of fur skins with different contents of fatty substances was investigated. The use of electroactive water, namely anolytes and catholytes, forgoing antiseptics or surface-active materials, helped to restore the hydration of fur skins and to remove from them soluble proteins, carbohydrates and fatty substances. The activating effect of anolyte and catholyte in solutions of water on the processes of treating raw furs is explained by their special physical and chemical properties, namely the presence of free radicals, ions and molecules of water which easily penetrate cells' membranes and into the structure of non-collagen components and microfiber structure of dermic collagen. The stage of lengthy acid and salt treatment is excluded from the technical treatment as a result of using electroactivated water with high oxidizing power. A low-cost technology of processing different kinds of fur with the use of electroactivated water provides for substantial economy of water and chemical reagents, a two to threefold acceleration of the soaking and tanning processes and creation of highly elastic fur materials with a specified set of physical and chemical properties. At the same time the technology of preparatory processes of fur treatment excludes the use of such toxic antiseptics as formalin and sodium silicofluoride, which gives grounds to regard it as ecologically safe.

Use of carbon filaments in place of carbon black as the current collector of a lithium cell with a thionyl chloride bromine chloride catholyte

Science.gov (United States)

Frysz, Christine A.; Shui, Xiaoping; Chung, D. D. L.

Submicron carbon filaments (ADNH, Applied Sciences Inc.) used in place of carbon black as porous reduction electrodes (i.e., current collectors) in plate and jellyroll configurations in carbon limited lithium batteries with the BCX (bromine chloride in thionyl chloride) catholyte gave a specific capacity (at 2 V cut-off) of up to 8700 mAh/g of carbon, compared with a value of up to 2900 mAh/g of carbon for carbon black. The high specific capacity for the filament electrode is partly due to the filaments' processability into sheets as thin as 0.2 mm with good porosity, acceptable mechanical properties and without binder, and partly due to the high catholyte absorptivity and high rate of catholyte absorption of the filament electrode. Use of solvent-cleansed filaments in place of as-received filaments in making electrodes increased the packing density, thus decreasing capacity per g of carbon. The BCX catholyte acted as a cleanser anyway, due to the thionyl chloride in it. The specific capacity per cm 3 of carbon and that per unit density of carbon were also increased by using carbon filaments in place of carbon black, provided that the filament electrode was not pressed after forming by slurry filtration. Though no binder was needed for the filament plate electrode, it was needed for the filament jellyroll electrode. The Teflon™ binder increased the tensile strength and modulus, but decreased the catholyte absorption and rate of absorption. The filament electrode exhibited 405 less volume electrical resistivity than the carbon black electrode, both without a binder.

Use of carbon filaments in place of carbon black as the current collector of a lithium cell with a thionyl chloride bromine chloride catholyte

Energy Technology Data Exchange (ETDEWEB)

Frysz, C.A. [Technology Div., Wilson Greatbatch Ltd., Clarence, NY (United States); Shui Xiaoping [Composite Materials Research Lab., State Univ. of New York, Buffalo, NY (United States); Chung, D.D.L. [Composite Materials Research Lab., State Univ. of New York, Buffalo, NY (United States)

1996-01-01

Submicron carbon filaments (ADNH, Applied Sciences Inc.) used in place of carbon black as porous reduction electrodes (i.e., current collectors) in plate and jellyroll configurations in carbon limited lithium batteries with the BCX (bromine chloride in thionyl chloride) catholyte gave a specific capacity (at 2 V cut-off) of up to 8700 mAh/g of carbon, compared with a value of up to 2900 mAh/g of carbon for carbon black. The high specific capacity for the filament electrode is partly due to the filaments` processability into sheets as thin as 0.2 mm with good porosity, acceptable mechanical properties and without binder, and partly due to the high catholyte absorptivity and high rate of catholyte absorption of the filament electrode. Use of solvent-cleansed filaments in place of as-received filaments in making electrodes increased the packing density, thus decreasing capacity per g of carbon. The BCX catholyte acted as a cleanser anyway, due to the thionyl chloride in it. The specific capacity per cm{sup 3} of carbon and that per unit density of carbon were also increased by using carbon filaments in place of carbon black, provided that the filament electrode was not pressed after forming by slurry filtration. Though no binder was needed for the filament plate electrode, it was needed for the filament jellyroll electrode. The Teflon{sup TM} binder increased the tensile strength and modulus, but decreased the catholyte absorption and rate of absorption. The filament electrode exhibited 40% less volume electrical resistivity than the carbon black electrode, both without a binder. (orig.)

Measurements of non-reacting and reacting flow fields of a liquid swirl flame burner

Science.gov (United States)

Chong, Cheng Tung; Hochgreb, Simone

2015-03-01

The understanding of the liquid fuel spray and flow field characteristics inside a combustor is crucial for designing a fuel efficient and low emission device. Characterisation of the flow field of a model gas turbine liquid swirl burner is performed by using a 2-D particle imaging velocimetry(PIV) system. The flow field pattern of an axial flow burner with a fixed swirl intensity is compared under confined and unconfined conditions, i.e., with and without the combustor wall. The effect of temperature on the main swirling air flow is investigated under open and non-reacting conditions. The result shows that axial and radial velocities increase as a result of decreased flow density and increased flow volume. The flow field of the main swirling flow with liquid fuel spray injection is compared to non-spray swirling flow. Introduction of liquid fuel spray changes the swirl air flow field at the burner outlet, where the radial velocity components increase for both open and confined environment. Under reacting condition, the enclosure generates a corner recirculation zone that intensifies the strength of radial velocity. The reverse flow and corner recirculation zone assists in stabilizing the flame by preheating the reactants. The flow field data can be used as validation target for swirl combustion modelling.

Mathematical modeling based evaluation and simulation of boron removal in bioelectrochemical systems

Energy Technology Data Exchange (ETDEWEB)

Ping, Qingyun [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Abu-Reesh, Ibrahim M. [Department of Chemical Engineering, College of Engineering, Qatar University, P.O. Box 2713, Doha (Qatar); He, Zhen, E-mail: zhenhe@vt.edu [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

2016-11-01

Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level < 2 mg L{sup −} {sup 1}. The ratio between the anolyte and the catholyte flow rates should be kept > 22.2 in order to avoid boron accumulation in the anolyte effluent. - Highlights: • Mathematical models are developed to understand boron removal in BES. • Boron removal can be driven by electromigration induced by current generation. • Diffusion induced by a salt concentration gradient also contributes to boron removal. • Osmosis and current driven convection transport play diverse roles in different BES.

Annulated Dialkoxybenzenes as Catholyte Materials for Non-aqueous Redox Flow Batteries: Achieving High Chemical Stability through Bicyclic Substitution

International Nuclear Information System (INIS)

Zhang, Jingjing; Yang, Zheng; Shkrob, Ilya A.; Assary, Rajeev S.

2017-01-01

1,4-Dimethoxybenzene derivatives are materials of choice for use as catholytes in nonaqueous redox flow batteries, as they exhibit high open-circuit potentials and excellent electrochemical reversibility. However, chemical stability of these materials in their oxidized form needs to be improved. Disubstitution in the arene ring is used to suppress parasitic reactions of their radical cations, but this does not fully prevent ring-addition reactions. By incorporating bicyclic substitutions and ether chains into the dialkoxybenzenes, a novel catholyte molecule, 9,10-bis(2-methoxyethoxy)-1,2,3,4,5,6,7,8-octahydro-1,4:5, 8-dimethanenoanthracene (BODMA), is obtained and exhibits greater solubility and superior chemical stability in the charged state. As a result, a hybrid flow cell containing BODMA is operated for 150 charge–discharge cycles with minimal loss of capacity.

Use of submicron carbon filaments in place of carbon black as a porous reduction electrode in lithium batteries with a catholyte comprising bromine chloride in thionyl chloride

Energy Technology Data Exchange (ETDEWEB)

Frysz, C.A. [Wilson Greatbatch, Ltd., Clarence, NY (United States); Shui, X.; Chung, D.D.L. [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.

1995-12-31

Submicron carbon filaments used in place of carbon black as porous reduction electrodes in carbon limited lithium batteries in plate and jellyroll configurations with the BCX (bromine chloride in thionyl chloride) catholyte gave a specific capacity (at 2 V cut-off) of up to 8,700 mAh/g carbon, compared to a value of up to 2,900 mAh/g carbon for carbon black. The high specific capacity per g carbon (demonstrating superior carbon efficiency) for the filament electrode is partly due to the filaments` processability into sheets as thin as 0.2 mm with good porosity and without a binder, and partly due to the high catholyte absorptivity and high rate of catholyte absorption of the filament electrode.

Phosphorous recovery from sewage sludge ash suspended in water in a two-compartment electrodialytic cell

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Jensen, Pernille Erland; Kirkelund, Gunvor Marie

2016-01-01

was suspended in water in the anolyte, which was separated from the catholyte by a cation exchange membrane. Electrolysis at the anode acidified the SSA suspension, and hereby P, Cu, Pb, Cd and Zn were extracted. The heavy metal ions electromigrated into the catholyte and were thus separated from the filtrate......Phosphorus (P) is indispensable for all forms of life on Earth and as P is a finite resource, it is highly important to increase recovery of P from secondary resources. This investigation is focused on P recovery from sewage sludge ash (SSA) by a two-compartment electrodialytic separation (EDS......) technique. Two SSAs are included in the investigation and they contained slightly less P than phosphate rock used in commercial fertilizer production and more heavy metals. The two-compartment electrodialytic technique enabled simultaneous recovery of P and separation of heavy metals. During EDS the SSA...

The effect of soil type on the electrodialytic remediation of lead-contaminated soil

DEFF Research Database (Denmark)

Jensen, Pernille Erland; Ottosen, Lisbeth M.; Harmon, Thomas C.

2007-01-01

experiments with ten representative industrially Pb-contaminated surface soils. Results indicate that Pb-speciation is of primary importance. Specifically, organic matter and stable compounds like PbCrO4 can impede and possibly even preclude soil remediation. In soils rich in carbonate, where the acidic front...... to the catholyte. Thus, the presence of carbonate negatively influences the remediation time. Pb bound to soluble organic matter is also transported towards the anolyte during EDR. The primary effect of the mainly insoluble organic matter commonly present in surface soil is however to immobilize Pb and impede...

Series Assembly of Microbial Desalination Cells Containing Stacked Electrodialysis Cells for Partial or Complete Seawater Desalination

KAUST Repository

Kim, Younggy

2011-07-01

A microbial desalination cell (MDC) is a new approach for desalinating water based on using the electrical current generated by exoelectrogenic bacteria. Previously developed MDCs have used only one or two desalination chambers with substantial internal resistance, and used low salinity catholytes containing a buffered or acid solution. Here we show that substantially improved MDC performance can be obtained even with a nonbuffered, saline catholyte, by using an electrodialysis stack consisting of 5 pairs of desalting and concentrating cells. When 4 stacked MDCs were used in series (20 total pairs of desalination chambers), the salinity of 0.06 L of synthetic seawater (35 g/L NaCl) was reduced by 44% using 0.12 L of anode solution (2:1). The resistive loss in the electrodialysis stack was negligible due to minimization of the intermembrane distances, and therefore the power densities produced by the MDC were similar to those produced by single chamber microbial fuel cells (MFCs) lacking desalination chambers. The observed current efficiency was 86%, indicating separation of 4.3 pairs of sodium and chloride ions for every electron transferred through the circuit. With two additional stages (total of 3.8 L of anolyte), desalination was increased to 98% salt removal, producing 0.3 L of fresh water (12.6:1). These results demonstrate that stacked MDCs can be used for efficient desalination of seawater while at the same time achieving power densities comparable to those obtained in MFCs. © 2011 American Chemical Society.

All-Fullerene-Based Cells for Nonaqueous Redox Flow Batteries.

Science.gov (United States)

Friedl, Jochen; Lebedeva, Maria A; Porfyrakis, Kyriakos; Stimming, Ulrich; Chamberlain, Thomas W

2018-01-10

Redox flow batteries have the potential to revolutionize our use of intermittent sustainable energy sources such as solar and wind power by storing the energy in liquid electrolytes. Our concept study utilizes a novel electrolyte system, exploiting derivatized fullerenes as both anolyte and catholyte species in a series of battery cells, including a symmetric, single species system which alleviates the common problem of membrane crossover. The prototype multielectron system, utilizing molecular based charge carriers, made from inexpensive, abundant, and sustainable materials, principally, C and Fe, demonstrates remarkable current and energy densities and promising long-term cycling stability.

Photosynthetic microbial fuel cell with polybenzimidazole membrane: synergy between bacteria and algae for wastewater removal and biorefinery

Directory of Open Access Journals (Sweden)

S. Angioni

2018-03-01

Full Text Available Here, we demonstrate a very efficient simultaneous approach of bioenergy generation from wastewater and added-value compounds production by using a photosynthetic microalgae microbial fuel cells (PMFC, based on polybenzimidazole (PBI composite membrane as separator. The use of PBI was proved to be very promising, even more convenient than Nafion™ in terms of energy performances as well as cost and sustainability. This polymer is also easily autoclavable, so allowing a re-use of the separator with a consequent beneficial cost effect. Two PMFCs were investigated: 1 Pt electrocatalysed and 2 Pt-free. They were operated as microbial carbon capture (MCC device under continuous illumination, by using a domestic wastewater as anolyte and Scenedesmus acutus strain in the catholyte. The Pt-based cell allowed to generate higher volumetric power density (∼400 mW m−3 after more than 100 operating days. This resulted in an improved wastewater treatment efficiency, determined in terms of normalised energy recovery (NER > 0.19 kWh kgCOD−1 in case of Pt. The CO2 fixation of the PMFC-grown microalgae leaded to a high accumulation of added-value products, namely pigments and fatty acids. A significant quantity of lutein was observed as well as a relevant amount of other valuable carotenoids, as violaxanthin, astaxanthin and cantaxanthin. The lipids were even excellently accumulated (49%dw. Their profile was mainly composed by fatty acids in the range C16-18, which are particularly indicated for the biofuel production. These results demonstrate the feasibility and the implemented sustainability of such PMFCs as a great potential technology for the wastewater treatment and the simultaneous production of valuable products. Keyword: Energy

A vapor feed methanol microfluidic fuel cell with high fuel and energy efficiency

International Nuclear Information System (INIS)

Wang, Yifei; Leung, Dennis Y.C.; Xuan, Jin; Wang, Huizhi

2015-01-01

Highlights: • A microfluidic fuel cell with a vapor feed anode is investigated. • Its advantages include simpler design, direct usage of methanol and better performance. • The prototype achieves a peak power density of 55.4 mW cm −2 under room temperature. • The energy efficiency of 9.4% is much higher than its liquid feed counterpart. - Abstract: In this paper, a prototype of methanol microfluidic fuel cell with vapor feed anode configuration is proposed to improve the fuel and energy efficiency of the conventional liquid feed methanol microfluidic fuel cells. Peak power density of 55.4 mW cm −2 can be achieved with this prototype under room temperature, which is 30% higher than its conventional liquid feed counterpart. Moreover, an energy efficiency of 9.4% is achieved, which is 27.5 times higher than its liquid feed counterpart. This superiority on both cell performance and energy efficiency is directly benefitted from its vapor feed anode configuration, which alleviates the fuel crossover, eliminates the fuel depletion boundary layer, and avoids the bulk anolyte wastage. The tradeoff between cell performance and fuel utilization for conventional liquid feed microfluidic fuel cells is also evaded

Effect of short-term alkaline intervention on the performance of buffer-free single-chamber microbial fuel cell.

Science.gov (United States)

Yang, Na; Ren, Yueping; Li, Xiufen; Wang, Xinhua

2017-06-01

Anolyte acidification is a drawback restricting the electricity generation performance of the buffer-free microbial fuel cells (MFC). In this paper, a small amount of alkali-treated anion exchange resin (AER) was placed in front of the anode in the KCl mediated single-chamber MFC to slowly release hydroxyl ions (OH - ) and neutralize the H + ions that are generated by the anodic reaction in two running cycles. This short-term alkaline intervention to the KCl anolyte has promoted the proliferation of electroactive Geobacter sp. and enhanced the self-buffering capacity of the KCl-AER-MFC. The pH of the KCl anolyte in the KCl-AER-MFC increased and became more stable in each running cycle compared with that of the KCl-MFC after the short-term alkaline intervention. The maximum power density (P max ) of the KCl-AER-MFC increased from 307.5mW·m -2 to 542.8mW·m -2 , slightly lower than that of the PBS-MFC (640.7mW·m -2 ). The coulombic efficiency (CE) of the KCl-AER-MFC increased from 54.1% to 61.2% which is already very close to that of the PBS-MFC (61.9%). The results in this paper indicate that short-term alkaline intervention to the anolyte is an effective strategy to further promote the performance of buffer-free MFCs. Copyright © 2017 Elsevier B.V. All rights reserved.

Catholyte-Free Electrocatalytic CO2 Reduction to Formate.

Science.gov (United States)

Lee, Wonhee; Kim, Young Eun; Youn, Min Hye; Jeong, Soon Kwan; Park, Ki Tae

2018-04-16

Electrochemical reduction of carbon dioxide (CO 2 ) into value-added chemicals is a promising strategy to reduce CO 2 emission and mitigate climate change. One of the most serious problems in electrocatalytic CO 2 reduction (CO 2 R) is the low solubility of CO 2 in an aqueous electrolyte, which significantly limits the cathodic reaction rate. This paper proposes a facile method of catholyte-free electrocatalytic CO 2 reduction to avoid the solubility limitation using commercial tin nanoparticles as a cathode catalyst. Interestingly, as the reaction temperature rises from 303 K to 363 K, the partial current density (PCD) of formate improves more than two times with 52.9 mA cm -2 , despite the decrease in CO 2 solubility. Furthermore, a significantly high formate concentration of 41.5 g L -1 is obtained as a one-path product at 343 K with high PCD (51.7 mA cm -2 ) and high Faradaic efficiency (93.3 %) via continuous operation in a full flow cell at a low cell voltage of 2.2 V. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improving bioelectricity generation and COD removal of sewage sludge in microbial desalination cell.

Science.gov (United States)

Ebrahimi, Atieh; Yousefi Kebria, Daryoush; Darzi, Ghasem Najafpour

2018-05-01

Improving wastewater treatment process and water desalination are two important solutions for increasing the available supply of fresh water. Microbial desalination cells (MDCs) with common electrolytes display relatively low organic matter removal and high cost. In this study, sewage sludge was used as the substrate in the Microbial desalination cell (MDC) under three different initial salt concentrations (5, 20 and 35 g.L -1 ) and the maximum salt removal rates of 50.6%, 64% and 69.6% were obtained under batch condition, respectively. The MDC also produced the maximum power density of 47.1 W m -3 and the averaged chemical oxygen demand (COD) removal of 58.2 ± 0.89% when the initial COD was 6610 ± 83 mg L -1 . Employing treated sludge as catholyte enhanced COD removal and power density to 87.3% and 54.4 W m -3 , respectively, with counterbalancing pH variation in treated effluent. These promising results showed, for the first time, that the excess sewage sludge obtained from biological wastewater treatment plants could be successfully used as anolyte and catholyte in MDC, achieving organic matter biodegradation along with salt removal and energy production. In addition, using treated sludge as catholyte will improve the performance of MDC and introduce a more effective method for both sludge treatment and desalination.

Control of electrode processes in electrokinetic soil remediation

Energy Technology Data Exchange (ETDEWEB)

Schmid, M.; Marb, C. [Bavarian State Office for Environmental Protection, Waste Technology Centre, Augsburg (Germany)

2001-07-01

Technical control of electrode processes induced by water electrolysis is crucial for the effectiveness of electrokinetic soil remediation. A calculation method for the quantification of electrolysis products is derived and its validity by the consumption of neutralizing agents verified. Steel rods used as sacrificial anodes instead of inert materials cannot counteract the acidification of the anolyte due to the acidic property of Fe-cations released as oxidation products. An an alternative to ordinary porous well materials a tubular cation exchange membrane was used as a cathode well. Thereby the migration of anions stemming from the catholyte neutralisation was hampered and no loss in the electric field strength occured. (orig.)

Redox non-innocent bis(2,6-diimine-pyridine) ligand-iron complexes as anolytes for flow battery applications.

Science.gov (United States)

Duarte, Gabriel M; Braun, Jason D; Giesbrecht, Patrick K; Herbert, David E

2017-12-21

Diiminepyridines are a well-known class of "non-innocent" ligands that confer additional redox activity to coordination complexes beyond metal-centred oxidation/reduction. Here, we demonstrate that metal coordination complexes (MCCs) of diiminepyridine (DIP) ligands with iron are suitable anolytes for redox-flow battery applications, with enhanced capacitance and stability compared with bipyridine analogs, and access to storage of up to 1.6 electron equivalents. Substitution of the ligand is shown to be a key factor in the cycling stability and performance of MCCs based on DIP ligands, opening the door to further optimization.

Simultaneous Hydrogen Generation and Waste Acid Neutralization in a Reverse Electrodialysis System

KAUST Repository

Hatzell, Marta C.

2014-09-02

Waste acid streams produced at industrial sites are often co-located with large sources of waste heat (e.g., industrial exhaust gases, cooling water, and heated equipment). Reverse electrodialysis (RED) systems can be used to generate electrical power and hydrogen gas using waste heat-derived solutions, but high electrode overpotentials limit system performance. We show here that an ammonium bicarbonate (AmB) RED system can achieve simultaneous waste acid neutralization and in situ hydrogen production, while capturing energy from excess waste heat. The rate of acid neutralization was dependent on stack flow rate and increased 50× (from 0.06 ± 0.04 to 3.0 ± 0.32 pH units min -1 m-2 membrane), as the flow rate increased 6× (from 100 to 600 mL min-1). Acid neutralization primarily took place due to ammonium electromigration (37 ± 4%) and proton diffusion (60 ± 5%). The use of a synthetic waste acid stream as a catholyte (pH ≈ 2) also increased hydrogen production rates by 65% (from 5.3 ± 0.5 to 8.7 ± 0.1 m3 H2 m-3 catholyte day -1) compared to an AmB electrolyte (pH ≈ 8.5). These findings highlight the potential use of dissimilar electrolytes (e.g., basic anolyte and acidic catholyte) for enhanced power and hydrogen production in RED stacks. © 2014 American Chemical Society.

A biomimetic high-capacity phenazine-based anolyte for aqueous organic redox flow batteries

Science.gov (United States)

Hollas, Aaron; Wei, Xiaoliang; Murugesan, Vijayakumar; Nie, Zimin; Li, Bin; Reed, David; Liu, Jun; Sprenkle, Vincent; Wang, Wei

2018-06-01

Aqueous soluble organic (ASO) redox-active materials have recently attracted significant attention as alternatives to traditional transition metal ions in redox flow batteries (RFB). However, reported reversible capacities of ASO are often substantially lower than their theoretical values based on the reported maximum solubilities. Here, we describe a phenazine-based ASO compound with an exceptionally high reversible capacity that exceeds 90% of its theoretical value. By strategically modifying the phenazine molecular structure, we demonstrate an increased solubility from near-zero with pristine phenazine to as much as 1.8 M while also shifting its redox potential by more than 400 mV. An RFB based on a phenazine derivative (7,8-dihydroxyphenazine-2-sulfonic acid) at its near-saturation concentration exhibits an operating voltage of 1.4 V with a reversible anolyte capacity of 67 Ah l-1 and a capacity retention of 99.98% per cycle over 500 cycles.

Direct numerical simulation of turbulent, chemically reacting flows

Science.gov (United States)

Doom, Jeffrey Joseph

This dissertation: (i) develops a novel numerical method for DNS/LES of compressible, turbulent reacting flows, (ii) performs several validation simulations, (iii) studies auto-ignition of a hydrogen vortex ring in air and (iv) studies a hydrogen/air turbulent diffusion flame. The numerical method is spatially non-dissipative, implicit and applicable over a range of Mach numbers. The compressible Navier-Stokes equations are rescaled so that the zero Mach number equations are discretely recovered in the limit of zero Mach number. The dependent variables are co--located in space, and thermodynamic variables are staggered from velocity in time. The algorithm discretely conserves kinetic energy in the incompressible, inviscid, non--reacting limit. The chemical source terms are implicit in time to allow for stiff chemical mechanisms. The algorithm is readily applicable to complex chemical mechanisms. Good results are obtained for validation simulations. The algorithm is used to study auto-ignition in laminar vortex rings. A nine species, nineteen reaction mechanism for H2/air combustion proposed by Mueller et al. [37] is used. Diluted H 2 at ambient temperature (300 K) is injected into hot air. The simulations study the effect of fuel/air ratio, oxidizer temperature, Lewis number and stroke ratio (ratio of piston stroke length to diameter). Results show that auto--ignition occurs in fuel lean, high temperature regions with low scalar dissipation at a 'most reactive' mixture fraction, zeta MR (Mastorakos et al. [32]). Subsequent evolution of the flame is not predicted by zetaMR; a most reactive temperature TMR is defined and shown to predict both the initial auto-ignition as well as subsequent evolution. For stroke ratios less than the formation number, ignition in general occurs behind the vortex ring and propagates into the core. At higher oxidizer temperatures, ignition is almost instantaneous and occurs along the entire interface between fuel and oxidizer. For stroke

An experimental and numerical study of confined non-reacting and reacting turbulent jets to facilitate homogeneous combustion in industrial furnaces

Science.gov (United States)

Lee, Insu

Confined non-reacting turbulent jets are ideal for recirculating the hot flue gas back into the furnace from an external exhaust duct. Such jets are also used inside the furnace to internally entrain and recirculate the hot flue gas to preheat and dilute the reactants. Both internal and external implementation of confined turbulent jets increase the furnace thermal efficiency. For external implementation, depending on the circumstances, the exhaust gas flow may be co- or counter-flow relative to the jet flow. Inside the furnaces, fuel and air jets are injected separately. To create a condition which can facilitate near homogeneous combustion, these jets have to first mix with the burned gas inside the furnace and simultaneously being heated and diluted prior to combustion. Clearly, the combustion pattern and emissions from reacting confined turbulent jets are affected by jet interactions, mixing and entrainment of hot flue gas. In this work, the flow and mixing characteristics of a non-reacting and reacting confined turbulent jet are investigated experimentally and numerically. This work consists of two parts: (i) A study of flow and mixing characteristics of non-reacting confined turbulent jets with co- or counter-flowing exhaust/flue gas. Here the axial and radial distributions of temperature, velocity and NO concentration (used as a tracer gas) were measured. FLUENT was used to numerically simulate the experimental results. This work provides the basic understanding of the flow and mixing characteristics of confined turbulent jets and develops some design considerations for recirculating flue gas back into the furnace as expressed by the recirculation zone and the stagnation locations. (ii) Numerical calculations of near homogeneous combustion are performed for the existing furnace. The exact geometry of the furnace in the lab is used and the real dimensional boundary conditions are considered. The parameters such as air nozzle diameter (dair), fuel nozzle

Thermodynamics and Efficiency of a CuCl(aq)/HCl(aq) Electrolyzer

International Nuclear Information System (INIS)

Hall, Derek M.; Akinfiev, Nikolay N.; LaRow, Eric G.; Schatz, Richard S.; Lvov, Serguei N.

2014-01-01

The high ionic strength and complex speciation of the anolyte solution within the CuCl(aq)/HCl(aq) electrolytic cell have impeded predictions of the energy requirements for the cell's electrolytic reaction at 25 °C and 1 bar. After collecting experimental open circuit potential (OCP) data and comparing the values obtained with predictions from prospective thermodynamic models, an approach to predict thermodynamic values and the overall efficiency was formulated. The compositions of the experimental measurements ranged from 2-2.5 mol of CuCl(aq) with 8-9 mol of HCl(aq) per kilogram of water in anolyte solution and 8-9 mol of HCl(aq) per kilogram of water in catholyte solution. From the OCP data, it was found that activity coefficient and speciation effects were critical in predicting the Gibbs energy, entropy and thermodynamic (intrinsic maximum) efficiency of the electrolytic cell. At equilibrium, all thermodynamic functions of the anolyte redox reactions were the same after activity coefficients and speciation effects were taken into account. The electrochemical reactions’ Gibbs energy and entropy were found to be 9700 J/mol and 2.18 J/(mol K) at 25 °C and 1 bar, which indicated that the reactions required a small amount of electrical and thermal energy to proceed. With thermodynamic values for the electrolytic reaction and experimental data from a CuCl(aq)/HCl(aq) electrolytic cell, the voltage, current, thermodynamic and overall efficiency were calculated. The overall efficiency ranged from 15 to 95% depending on the current density

One-Step Cationic Grafting of 4-Hydroxy-TEMPO and its Application in a Hybrid Redox Flow Battery with a Crosslinked PBI Membrane.

Science.gov (United States)

Chang, Zhenjun; Henkensmeier, Dirk; Chen, Ruiyong

2017-08-24

By using a one-step epoxide ring-opening reaction between 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (4-hydroxy-TEMPO) and glycidyltrimethylammonium cation (GTMA + ), we synthesized a cation-grafted TEMPO (g + -TEMPO) and studied its electrochemical performance against a Zn 2+ /Zn anode in a hybrid redox flow battery. To conduct Cl - counter anions, a crosslinked methylated polybenzimidazole (PBI) membrane was prepared and placed between the catholyte and anolyte. Compared to 4-hydroxy-TEMPO, the positively charged g + - TEMPO exhibits enhanced reaction kinetics. Moreover, flow battery tests with g + -TEMPO show improved Coulombic, voltage, and energy efficiencies and cycling stability over 140 cycles. Crossover of active species through the membrane was not detected. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of Mixing Calculations for Reacting and Non-Reacting Flows in a Cylindrical Duct

Science.gov (United States)

Oechsle, V. L.; Mongia, H. C.; Holdeman, J. D.

1994-01-01

A production 3-D elliptic flow code has been used to calculate non-reacting and reacting flow fields in an experimental mixing section relevant to a rich burn/quick mix/lean burn (RQL) combustion system. A number of test cases have been run to assess the effects of the variation in the number of orifices, mass flow ratio, and rich-zone equivalence ratio on the flow field and mixing rates. The calculated normalized temperature profiles for the non-reacting flow field agree qualitatively well with the normalized conserved variable isopleths for the reacting flow field indicating that non-reacting mixing experiments are appropriate for screening and ranking potential rapid mixing concepts. For a given set of jet momentum-flux ratio, mass flow ratio, and density ratio (J, MR, and DR), the reacting flow calculations show a reduced level of mixing compared to the non-reacting cases. In addition, the rich-zone equivalence ratio has noticeable effect on the mixing flow characteristics for reacting flows.

Thermal-hydraulic characteristics of reacting zone for TWR bundles based on CFD method

International Nuclear Information System (INIS)

Lu Chuan; Yan Mingyu; Lu Jianchao

2013-01-01

Thermal-hydraulic characteristics of reacting zone for TWR (travelling wave reactor) bundles were analysed by CFD method. The calculation results of 7, 19 and 37 fuel pin bundles show the similar characteristics. The hot coolant seems to congregate into the centre as flowing to the downstream area. The high temperature coolant always distributes in the inner area while the temperature shows distinct gradation in the outer area. The temperature difference is more than 100 ℃ for the bundle whose diameter is about 26 cm. The major temperature gradations mainly locate in the outermost fuel rods of two circles while other circles show much smaller temperature gradients. This conclusion is estimated to be true for more fuel pin bundles such as 217 fuel pin bundles. The fuel assembly structure of the existing TWR design should be optimized in future. (authors)

A Lithium/Polysulfide Battery with Dual-Working Mode Enabled by Liquid Fuel and Acrylate-Based Gel Polymer Electrolyte.

Science.gov (United States)

Liu, Ming; Ren, Yuxun; Zhou, Dong; Jiang, Haoran; Kang, Feiyu; Zhao, Tianshou

2017-01-25

The low density associated with low sulfur areal loading in the solid-state sulfur cathode of current Li-S batteries is an issue hindering the development of this type of battery. Polysulfide catholyte as a recyclable liquid fuel was proven to enhance both the energy density and power density of the battery. However, a critical barrier with this lithium (Li)/polysulfide battery is that the shuttle effect, which is the crossover of polysulfides and side deposition on the Li anode, becomes much more severe than that in conventional Li-S batteries with a solid-state sulfur cathode. In this work, we successfully applied an acrylate-based gel polymer electrolyte (GPE) to the Li/polysulfide system. The GPE layer can effectively block the detrimental diffusion of polysulfides and protect the Li metal from the side passivation reaction. Cathode-static batteries utilizing 2 M catholyte (areal sulfur loading of 6.4 mg cm -2 ) present superior cycling stability (727.4 mAh g -1 after 500 cycles at 0.2 C) and high rate capability (814 mAh g -1 at 2 C) and power density (∼10 mW cm -2 ), which also possess replaceable and encapsulated merits for mobile devices. In the cathode-flow mode, the Li/polysulfide system with catholyte supplied from an external tank demonstrates further improved power density (∼69 mW cm -2 ) and stable cycling performance. This novel and simple Li/polysulfide system represents a significant advancement of high energy density sulfur-based batteries for future power sources.

Hydrogen anode for nitrate waste destruction. Revision 2

International Nuclear Information System (INIS)

Hobbs, D.T.; Kalu, E.E.; White, R.E.

1996-01-01

Large quantities of radioactive and hazardous wastes have been generated from nuclear materials production during the past fifty years. Processes are under evaluation to separate the high level radioactive species from the waste and store them permanently in the form of durable solids. The schemes proposed will separate the high level radioactive components, cesium-137 and strontium-90, into a small volume for incorporation into a glass wasteform. The remaining low-level radioactive waste contain species such as nitrites and nitrates that are capable of contaminating ground water. Electrochemical destruction of the nitrate and nitrite before permanent storage has been proposed. Not only will the electrochemical processing destroy these species, the volume of the waste could also be reduced. The use of a hydrogen gas-fed anode and an acid anolyte in an electrochemical cell used to destroy nitrate was demonstrated. A mixed Na 2 SO 4 /H 2 SO 4 anolyte was shown to favor the nitrate cell performance, and the generation of a higher hydroxide ion concentration in the catholyte. The suggested scheme is an apparent method of sodium sulfate disposal and a possible means through which ammonia (to ammonium sulfate, fertilizer) and hydrogen gas could be recycled through the anode side of the reactor. This could result in a substantial savings in the operation of a nitrate destruction cell

Three-dimensional anode engineering for the direct methanol fuel cell

Energy Technology Data Exchange (ETDEWEB)

Bauer, A.; Oloman, C.W.; Gyenge, E.L. [Department of Chemical and Biological Engineering, The University of British Columbia, 2360 East Mall, Vancouver, BC (Canada)

2009-09-05

Catalyzed graphite felt three-dimensional anodes were investigated in direct methanol fuel cells (DMFCs) operated with sulfuric acid supporting electrolyte. With a conventional serpentine channel flow field the preferred anode thickness was 100 {mu}m, while a novel flow-by anode showed the best performance with a thickness of 200-300 {mu}m. The effects of altering the methanol concentration, anolyte flow rate and operating temperature on the fuel cell superficial power density were studied by full (2{sup 3} + 1) factorial experiments on a cell with anode area of 5 cm{sup 2} and excess oxidant O{sub 2} at 200 kPa(abs). For operation in the flow-by mode with 2 M methanol at 2 cm{sup 3} min{sup -1} and 353 K the peak power density was 2380 W m{sup -2} with a PtRuMo anode catalyst, while a PtRu catalyst yielded 2240 W m{sup -2} under the same conditions. (author)

Three-dimensional anode engineering for the direct methanol fuel cell

Science.gov (United States)

Bauer, A.; Oloman, C. W.; Gyenge, E. L.

Catalyzed graphite felt three-dimensional anodes were investigated in direct methanol fuel cells (DMFCs) operated with sulfuric acid supporting electrolyte. With a conventional serpentine channel flow field the preferred anode thickness was 100 μm, while a novel flow-by anode showed the best performance with a thickness of 200-300 μm. The effects of altering the methanol concentration, anolyte flow rate and operating temperature on the fuel cell superficial power density were studied by full (2 3 + 1) factorial experiments on a cell with anode area of 5 cm 2 and excess oxidant O 2 at 200 kPa(abs). For operation in the flow-by mode with 2 M methanol at 2 cm 3 min -1 and 353 K the peak power density was 2380 W m -2 with a PtRuMo anode catalyst, while a PtRu catalyst yielded 2240 W m -2 under the same conditions.

A miniature microbial fuel cell with conducting nanofibers-based 3D porous biofilm

International Nuclear Information System (INIS)

Jiang, Huawei; Dong, Liang; Halverson, Larry J

2015-01-01

Miniature microbial fuel cell (MFC) technology has received growing interest due to its potential applications in high-throughput screening of bacteria and mutants to elucidate mechanisms of electricity generation. This paper reports a novel miniature MFC with an improved output power density and short startup time, utilizing electrospun conducting poly(3,4-ethylenedioxythiophene) (PEDOT) nanofibers as a 3D porous anode within a 12 μl anolyte chamber. This device results in 423 μW cm −3 power density based on the volume of the anolyte chamber, using Shewanella oneidensis MR-1 as a model biocatalyst without any optimization of bacterial culture. The device also excels in a startup time of only 1hr. The high conductivity of the electrospun nanofibers makes them suitable for efficient electron transfer. The mean pore size of the conducting nanofibers is several micrometers, which is favorable for bacterial penetration and colonization of surfaces of the nanofibers. We demonstrate that S. oneidensis can fully colonize the interior region of this nanofibers-based porous anode. This work represents a new attempt to explore the use of electrospun PEDOT nanofibers as a 3D anode material for MFCs. The presented miniature MFC potentially will provide a high-sensitivity, high-throughput tool to screen suitable bacterial species and mutant strains for use in large-size MFCs. (paper)

Electricity generation coupled with wastewater treatment using a microbial fuel cell composed of a modified cathode with a ceramic membrane and cellulose acetate film.

Science.gov (United States)

Seo, Ha Na; Lee, Woo Jin; Hwang, Tae Sik; Park, Doo Hyun

2009-09-01

A noncompartmented microbial fuel cell (NCMFC) composed of a Mn(IV)-carbon plate and a Fe(III)-carbon plate was used for electricity generation from organic wastewater without consumption of external energy. The Fe(III)-carbon plate, coated with a porous ceramic membrane and a semipermeable cellulose acetate film, was used as a cathode, which substituted for the catholyte and cathode. The Mn(IV)-carbon plate was used as an anode without a membrane or film coating. A solar cell connected to the NCMFC activated electricity generation and bacterial consumption of organic matter contained in the wastewater. More than 99 degrees of the organic matter was biochemically oxidized during wastewater flow through the four NCMFC units. A predominant bacterium isolated from the anode surface in both the conventional and the solar cell-linked NCMFC was found to be more than 99 degrees similar to a Mn(II)-oxidizing bacterium and Burkeholderia sp., based on 16S rDNA sequence analysis. The isolate reacted electrochemically with the Mn(IV)-modified anode and produced electricity in the NCMFC. After 90 days of incubation, a bacterial species that was enriched on the Mn(IV)-modified anode surface in all of the NCMFC units was found to be very similar to the initially isolated predominant species by comparing 16S rDNA sequences.

Proton production, neutralisation and reduction in a floating water bridge

International Nuclear Information System (INIS)

Sammer, Martina; Wexler, Adam D; Kuntke, Philipp; Stanulewicz, Natalia; Lankmayr, Ernst; Woisetschläger, Jakob; Fuchs, Elmar C; Wiltsche, Helmar

2015-01-01

This work reports on proton production, transport, reduction and neutralization in floating aqueous bridges under the application of a high dc voltage (‘floating water bridge’). Recently possible mechanisms for proton transfer through the bridge were suggested. In this work we visualize and describe the production of protons in the anolyte and their neutralization in the catholyte. Apart from that, protons are reduced to hydrogen due to electrolysis. Microbubbles are detached instantly, due to the electrohydrodynamic flow at the electrode surface. No larger, visible bubbles are formed and the system degasses through the bridge due to its higher local temperature. A detailed analysis of trace elements originating from beaker material, anode or the atmosphere is presented, showing that their influence on the overall conduction compared to the contribution of protons is negligible. Finally, an electrochemical rationale of high voltage electrolysis of low ionic strength solutions is presented. (paper)

Proton production, neutralisation and reduction in a floating water bridge

Science.gov (United States)

Sammer, Martina; Wexler, Adam D.; Kuntke, Philipp; Wiltsche, Helmar; Stanulewicz, Natalia; Lankmayr, Ernst; Woisetschläger, Jakob; Fuchs, Elmar C.

2015-10-01

This work reports on proton production, transport, reduction and neutralization in floating aqueous bridges under the application of a high dc voltage (‘floating water bridge’). Recently possible mechanisms for proton transfer through the bridge were suggested. In this work we visualize and describe the production of protons in the anolyte and their neutralization in the catholyte. Apart from that, protons are reduced to hydrogen due to electrolysis. Microbubbles are detached instantly, due to the electrohydrodynamic flow at the electrode surface. No larger, visible bubbles are formed and the system degasses through the bridge due to its higher local temperature. A detailed analysis of trace elements originating from beaker material, anode or the atmosphere is presented, showing that their influence on the overall conduction compared to the contribution of protons is negligible. Finally, an electrochemical rationale of high voltage electrolysis of low ionic strength solutions is presented.

“Wine-Dark Sea” in an Organic Flow Battery: Storing Negative Charge in 2,1,3-Benzothiadiazole Radicals Leads to Improved Cyclability

Energy Technology Data Exchange (ETDEWEB)

Duan, Wentao [Joint Center for Energy Storage Research, Argonne, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Huang, Jinhua [Joint Center for Energy Storage Research, Argonne, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Kowalski, Jeffrey A. [Joint Center for Energy Storage Research, Argonne, IL (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Shkrob, Ilya A. [Joint Center for Energy Storage Research, Argonne, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Vijayakumar, M. [Joint Center for Energy Storage Research, Argonne, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Walter, Eric [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pan, Baofei [Joint Center for Energy Storage Research, Argonne, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Yang, Zheng [Joint Center for Energy Storage Research, Argonne, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Milshtein, Jarrod D. [Joint Center for Energy Storage Research, Argonne, IL (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Li, Bin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liao, Chen [Joint Center for Energy Storage Research, Argonne, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Zhang, Zhengcheng [Joint Center for Energy Storage Research, Argonne, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Wang, Wei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Jun [Joint Center for Energy Storage Research, Argonne, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moore, Jeffery S. [Joint Center for Energy Storage Research, Argonne, IL (United States); Univ. of Illinois Urbana-Champaign, Urbana, IL (United States); Brushett, Fikile R. [Joint Center for Energy Storage Research, Argonne, IL (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Zhang, Lu [Joint Center for Energy Storage Research, Argonne, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Wei, Xiaoliang [Joint Center for Energy Storage Research, Argonne, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-04-24

Redox-active organic materials (ROMs) have shown great promise for redox flow battery applications but generally encounter limited cycling efficiency and stability at relevant redox material concentrations in nonaqueous systems. Here we report a new heterocyclic organic anolyte molecule, 2,1,3-benzothiadiazole, that has high solubility, a low redox potential, and fast electrochemical kinetics. Coupling it with a benchmark catholyte ROM, the nonaqueous organic flow battery demonstrated significant improvement in cyclable redox material concentrations and cell efficiencies compared to the state-of-the-art nonaqueous systems. Especially, this system produced exceeding cyclability with relatively stable efficiencies and capacities at high ROM concentrations (>0.5 M), which is ascribed to the highly delocalized charge densities in the radical anions of 2,1,3-benzothiadiazole, leading to good chemical stability. As a result, this material development represents significant progress toward promising next-generation energy storage.

A paper-based microbial fuel cell: instant battery for disposable diagnostic devices.

Science.gov (United States)

Fraiwan, Arwa; Mukherjee, Sayantika; Sundermier, Steven; Lee, Hyung-Sool; Choi, Seokheun

2013-11-15

We present a microfabricated paper-based microbial fuel cell (MFC) generating a maximum power of 5.5 μW/cm(2). The MFC features (1) a paper-based proton exchange membrane by infiltrating sulfonated sodium polystyrene sulfonate and (2) micro-fabricated paper chambers by patterning hydrophobic barriers of photoresist. Once inoculum and catholyte were added to the MFC, a current of 74 μA was generated immediately. This paper-based MFC has the advantages of ease of use, low production cost, and high portability. The voltage produced was increased by 1.9 × when two MFC devices were stacked in series, while operating lifetime was significantly enhanced in parallel. Copyright © 2013 Elsevier B.V. All rights reserved.

Thermochemical aspects of fuel-cladding and fuel-coolant interactions in LMFBR oxide fuel pins

International Nuclear Information System (INIS)

Adamson, M.G.; Aitken, E.A.; Caputi, R.W.; Potter, P.E.; Mignanelli, M.A.

1979-01-01

This paper examines several thermochemical aspects of the fuel-cladding, fuel-coolant and fuel-fission product interactions that occur in LMFBR austenitic stainless steel-clad mixed (U,Pu)-oxide fuel pins during irradiation under normal operating conditions. Results are reported from a variety of high temperature EMF cell experiments in which continuous oxygen activity measurements on reacting and equilibrium mixtures of metal oxides and (excess) liquid alkali metal (Na, K, Cs) were performed. Oxygen potential and 0:M thresholds for Na-fuel reactions are re-evaluated in the light of new measurements and newly-assessed thermochemical data, and the influence on oxygen potential of possible U-Pu segregation between oxide and urano-plutonate (equilibrium) phases has been analyzed. (orig./RW) [de

Effects of sodium hypochlorite and high pH buffer solution in electrokinetic soil treatment on soil chromium removal and the functional diversity of soil microbial community

International Nuclear Information System (INIS)

Cang Long; Zhou Dongmei; Alshawabkeh, Akram N.; Chen Haifeng

2007-01-01

Effects of sodium hypochlorite (NaClO), applied as an oxidant in catholyte, and high pH buffer solution on soil Cr removal and the functional diversity of soil microbial community during enhanced electrokinetic treatments of a chromium (Cr) contaminated red soil are evaluated. Using pH control system to maintain high alkalinity of soil together with the use of NaClO increased the electrical conductivities of soil pore liquid and electroosmotic flux compared with the control (Exp-01). The pH control and NaClO improved the removal of Cr(VI) and total Cr from the soil. The highest removal percentages of soil Cr(VI) and total Cr were 96 and 72%, respectively, in Exp-04 when the pH value of the anolyte was controlled at 10 and NaClO was added in the catholyte. The alkaline soil environment and introduction of NaClO in the soil enhanced the desorption of Cr(VI) from the soil and promoted Cr(III) oxidation to mobile Cr(VI), respectively. However, the elevated pH and introduction of NaClO in the soil, which are necessary for improving the removal efficiency of soil Cr, resulted in a significantly adverse impact on the functional diversity of soil microbial community. It suggests that to assess the negative impact of extreme conditions for enhancing the extraction efficiencies of Cr on the soil properties and function is necessary

Generation of Electricity from Abattoir Waste Water with the Aid of a ...

African Journals Online (AJOL)

Michael Horsfall

Generation of Electricity from Abattoir Waste Water with the Aid of a Relatively Cheap. Source of Catholyte ... in recent times is the microbial fuel cell technology. This technology ..... fuel cell in the presence and absence of a proton exchange.

Evaluation of catalytic properties of tungsten carbide for the anode of microbial fuel cells

Energy Technology Data Exchange (ETDEWEB)

Rosenbaum, Miriam; Zhao, Feng; Quaas, Marion; Wulff, Harm; Schroeder, Uwe; Scholz, Fritz [Universitaet Greifswald, Institut fuer Biochemie, Felix-Hausdorff-Strasse 4, 17487 Greifswald (Germany)

2007-07-31

In this communication we discuss the properties of tungsten carbide, WC, as anodic electrocatalyst for microbial fuel cell application. The electrocatalytic activity of tungsten carbide is evaluated in the light of its preparation procedure, its structural properties as well as the pH and the composition of the anolyte solution and the catalyst load. The activity of the noble-metal-free electrocatalyst towards the oxidation of several common microbial fermentation products (hydrogen, formate, lactate, ethanol) is studied for microbial fuel cell conditions (e.g., pH 5, room temperature and ambient pressure). Current densities of up to 8.8 mA cm{sup -2} are achieved for hydrogen (hydrogen saturated electrolyte solution), and up to 2 mA cm{sup -2} for formate and lactate, respectively. No activity was observed for ethanol electrooxidation. The electrocatalytic activity and chemical stability of tungsten carbide is excellent in acidic to pH neutral potassium chloride electrolyte solutions, whereas higher phosphate concentrations at neutral pH support an oxidative degradation. (author)

Nuclear fuel element

International Nuclear Information System (INIS)

Grossman, L.N.; Levin, H.A.

1975-01-01

A nuclear fuel element has disposed therein an alloy having the essential components of nickel, titanium and zirconium, and the alloy reacts with water, water vapor and reactive gases at reactor ambient temperatures. The alloy is disposed in the plenum of the fuel element in the form of particles in a hollow gas permeable container having a multiplicity of openings of size smallr than the size of the particles. The container is preferably held in the spring in the plenum of the fuel element. (E.C.B.)

Fuel temperature influence on diesel sprays in inert and reacting conditions

International Nuclear Information System (INIS)

Payri, Raul; García-Oliver, Jose M.; Bardi, Michele; Manin, Julien

2012-01-01

The detailed knowledge of the evaporation–combustion process of the Diesel spray is a key factor for the development of robust injection strategies able to reduce the pollutant emissions and keep or increase the combustion efficiency. In this work several typical measurement applied to the diesel spray diagnostic (liquid length, lift-off length and ignition delay) have been employed in a novel continuous flow test chamber that allows an accurate control on a wide range of thermodynamic test conditions (up to 1000 K and 15 MPa). A step forward in the control of the test boundary conditions has been done employing a special system to study the fuel temperature effect on the evaporation and combustion of the spray. The temperature of the injector body has been controlled with a thermostatic system and the relationship between injector body and fuel temperature has been observed experimentally. Imaging diagnostics have been employed to visualize the liquid phase penetration in evaporative/inert conditions and, lift-off length and ignition delay in reactive condition. The results underline a clear influence of the injector body temperature on both conditions, evaporative and, in a lesser degree, reactive; finally the physical models found in the literature have been compared with the results obtained experimentally. - Highlights: ► The effect of the fuel temperature is substantial on liquid length (up to 15%). ► Fuel temperature has low effect but still appreciable on LOL and ignition delay. ► Theoretical one dimensional spray models are able to reproduce the experimental results with good accuracy.

Enhancing power density of biophotovoltaics by decoupling storage and power delivery

Science.gov (United States)

Saar, Kadi L.; Bombelli, Paolo; Lea-Smith, David J.; Call, Toby; Aro, Eva-Mari; Müller, Thomas; Howe, Christopher J.; Knowles, Tuomas P. J.

2018-01-01

Biophotovoltaic devices (BPVs), which use photosynthetic organisms as active materials to harvest light, have a range of attractive features relative to synthetic and non-biological photovoltaics, including their environmentally friendly nature and ability to self-repair. However, efficiencies of BPVs are currently lower than those of synthetic analogues. Here, we demonstrate BPVs delivering anodic power densities of over 0.5 W m-2, a value five times that for previously described BPVs. We achieved this through the use of cyanobacterial mutants with increased electron export characteristics together with a microscale flow-based design that allowed independent optimization of the charging and power delivery processes, as well as membrane-free operation by exploiting laminar flow to separate the catholyte and anolyte streams. These results suggest that miniaturization of active elements and flow control for decoupled operation and independent optimization of the core processes involved in BPV design are effective strategies for enhancing power output and thus the potential of BPVs as viable systems for sustainable energy generation.

Some laws governing the electrosynthesis of organic compounds with a solid polymetric electrolyte

Energy Technology Data Exchange (ETDEWEB)

Rodionova, N.A.; Avrutskaya, I.A.; Fioshin, M. Ya.; Khrizolitova, M.A.

1986-01-01

The electrosynthesis of organic compounds with a solid polymetric electrolyte (SPE) makes it possible to carry out the process in the absence of a supporting electrolyte. This facilitates the recovery of the desired product, eliminates the inorganic waste products, and allows a small interelectrode distance, and the absence of the accumulation of gases lowers the voltage in the cell. Some laws governing syntheses of SPE were studied in the example cases of the electrochemical reduction of 2,2,6,6-tetramethyl-4-oxopiperidine to 2,2,6,6-tetramethyl-4-hydroxy-piperidine, the reduction of triacetonamine oxime and triacetonamine azine to 2,2,6,6-tetramethyl-4- aminopiperidine and the oxidation of isobutanol to isobutyric acid. The electrolysis with an SPE was carried out under galvanostatic conditions in an electrolyzer of the filter-press type with forced circulation of the catholyte and anolyte. Low reaction rates are found to be characteristic of all the compounds investigated when the electrolysis is carried out with an SPE.

Electricity generation by Enterobacter cloacae SU-1 in mediator less microbial fuel cell

Energy Technology Data Exchange (ETDEWEB)

Samrot, Antony V.; Senthilkumar, P.; Pavankumar, K.; Akilandeswari, G.C. [Department of Biotechnology, Sathyabama University, Rajiv Gandhi Salai, Chennai, Tamilnadu (India); Rajalakshmi, N.; Dhathathreyan, K.S. [Center for Fuel Cell Technology ARCI, IITM Research Park, Phase I, 2nd Floor, 6 Kanagam Road, Tharamani, Chennai 600 113, Tamilnadu (India)

2010-08-15

We have investigated a Enterobacter cloacae SU-1, bacteria for mediator less microbial fuel cell with different carbon sources and is found to be more effective as the microorganism is able to transfer electrons directly (exo-electrogenic organism) via the cytochromes or the ubiquinone. These carriers of electrons are in form of stable reversible redox couples, not biologically degraded and not toxic to cell. The major advantage of mediator less microbial fuel cells emphasize that additives in the anolyte is not compatible with the purpose of water purification. The anode chamber with the bacteria is maintained under anaerobic conditions so that the bacteria will undergo anaerobic biochemical pathways like Glycolysis, TCA cycle, Electron Transport Chain (ETC) where electrons and protons are released. Here protons are released in TCA cycle and whereas electrons are released from ETC. The mediator less microbial fuel cell delivered an open circuit potential (OCP) of 0.93 V and power of 3 mW/sq cm. During power generation from the microbes, there was a drop in coulombic efficiency in terms of fluctuations during drawing power, as the carbon source is being utilized for the cell growth. (author)

Numerical Investigation into CO Emission, O Depletion, and Thermal Decomposition in a Reacting Slab

Directory of Open Access Journals (Sweden)

O. D. Makinde

2011-01-01

Full Text Available The emission of carbon dioxide (CO2 is closely associated with oxygen (O2 depletion, and thermal decomposition in a reacting stockpile of combustible materials like fossil fuels (e.g., coal, oil, and natural gas. Moreover, it is understood that proper assessment of the emission levels provides a crucial reference point for other assessment tools like climate change indicators and mitigation strategies. In this paper, a nonlinear mathematical model for estimating the CO2 emission, O2 depletion, and thermal stability of a reacting slab is presented and tackled numerically using a semi-implicit finite-difference scheme. It is assumed that the slab surface is subjected to a symmetrical convective heat and mass exchange with the ambient. Both numerical and graphical results are presented and discussed quantitatively with respect to various parameters embedded in the problem.

Study on flow characteristics of chemically reacting liquid jet

International Nuclear Information System (INIS)

Hong Seon Dae; Okamoto, Koji; Takata, Takashi; Yamaguchi, Akira

2004-07-01

Tube rupture accidents in steam generators of sodium-cooled fast breeder reactors are important for safety because the rupture may propagates to neighboring tubes due to sodium-water reaction. In order to clarify the thermal-hydraulic phenomena in the accidents, the flow pattern and the interface in multi-phase flow must be investigated. The JNC cooperative research scheme on the nuclear fuel cycle with the University of Tokyo has been carried to develop a simultaneous measurement system of concentration and velocity profiles and to evaluate influence of chemical reaction on mixing phenomena. In the experiments, aqueous liquor of acetic acid and ammonium hydroxide are selected as a simulant fluid instead of liquid sodium and water vapor. The following conclusions are obtained in this research. Laser Induced Fluorescence (LIF) technique was adopted to measure reacting zone and pH distribution in chemically reacting liquid round free jet. As a result, it was found that the chemical reaction, which took place at the interface between the jet and outer flow, suppressed the mixing phenomenon (in 2001 research). Dynamic Particle Image Velocimetry (PIV) method was developed to measure instantaneous velocity profile with high temporal resolution. In the Dynamic PIV, a high-speed video camera coupled with a high-speed laser pulse generator was implemented. A time-line trend of interfacial area in the free jet was investigated with the Dynamic PIV. This technique was also applied to a complicated geometry (in 2002 research). A new algorithms for image analysis was developed to evaluated the Dynamic PIV data in detail. The characteristics of the mixing phenomenon with reacting jet such as the turbulent kinetic energy and the Reynolds stress were estimated in a spatial and temporal spectrum (in 2003 research). (author)

Motivation, procedures and aims of reacting plasma experiments

International Nuclear Information System (INIS)

Miyahara, Akira

1982-01-01

A project of reacting plasma experiment (R-project) was proposed at the Institute of Plasma Physics (IPP), Nagoya University. It is necessary to bridge plasma physics and fusion engineering by means of a messenger wire like burning plasma experiment. This is a motivation of the R-project. The university linkage organization of Japan for fusion engineering category carried out a lot of contribution to R-tokamak design. The project consists of four items, namely, R-tokamak design, research and development (R and D), site and facilities, and international collaboration. The phase 1 experiment (R 1 - phase) corresponds to burning plasma experiment without D + T fuel, while the phase-2 experiment (R 2 -phase) with D + T fuel. One reference design was finished. Intensive efforts have been carried out by the R and D team on the following items, wall material, vacuum system, tritium system, neutronics, remote control system, pulsed superconducting magnet development, negative ion source, and alpha-particle diagnostics. The problems concerning site and major facilities are also important, because tritium handling, neutron and gamma-ray sky shines and the activation of devices cause impact to surrounding area. The aims of burning plasma experiment are to enter tritium into the fusion device, and to study burning plasma physics. (Kato, T.)

Sulphur release from alternative fuel firing

DEFF Research Database (Denmark)

Cortada Mut, Maria del Mar; Nørskov, Linda Kaare; Glarborg, Peter

2014-01-01

The cement industry has long been dependent on the use of fossil fuels, although a recent trend in replacing fossil fuels with alternative fuels has arisen. 1, 2 However, when unconverted or partly converted alternative fuels are admitted directly in the rotary kiln inlet, the volatiles released...... from the fuels may react with sulphates present in the hot meal to form SO 2 . Here Maria del Mar Cortada Mut and associates describe pilot and industrial scale experiments focusing on the factors that affect SO 2 release in the cement kiln inlet....

Stochastic models for turbulent reacting flows

Energy Technology Data Exchange (ETDEWEB)

Kerstein, A. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01

The goal of this program is to develop and apply stochastic models of various processes occurring within turbulent reacting flows in order to identify the fundamental mechanisms governing these flows, to support experimental studies of these flows, and to further the development of comprehensive turbulent reacting flow models.

Internal fuel pin oxidizer

International Nuclear Information System (INIS)

Andrews, M.G.

1978-01-01

A nuclear fuel pin has positioned within it material which will decompose to release an oxidizing agent which will react with the cladding of the pin and form a protective oxide film on the internal surface of the cladding

Cobalt and Vanadium Trimetaphosphate Polyanions: Synthesis, Characterization, and Electrochemical Evaluation for Non-aqueous Redox-Flow Battery Applications.

Science.gov (United States)

Stauber, Julia M; Zhang, Shiyu; Gvozdik, Nataliya; Jiang, Yanfeng; Avena, Laura; Stevenson, Keith J; Cummins, Christopher C

2018-01-17

An electrochemical cell consisting of cobalt ([Co II/III (P 3 O 9 ) 2 ] 4-/3- ) and vanadium ([V III/II (P 3 O 9 ) 2 ] 3-/4- ) bistrimetaphosphate complexes as catholyte and anolyte species, respectively, was constructed with a cell voltage of 2.4 V and Coulombic efficiencies >90% for up to 100 total cycles. The [Co(P 3 O 9 ) 2 ] 4- (1) and [V(P 3 O 9 ) 2 ] 3- (2) complexes have favorable properties for flow-battery applications, including reversible redox chemistry, high stability toward electrochemical cycling, and high solubility in MeCN (1.09 ± 0.02 M, [PPN] 4 [1]·2MeCN; 0.77 ± 0.06 M, [PPN] 3 [2]·DME). The [PPN] 4 [1]·2MeCN and [PPN] 3 [2]·DME salts were isolated as crystalline solids in 82 and 68% yields, respectively, and characterized by 31 P NMR, UV/vis, ESI-MS(-), and IR spectroscopy. The [PPN] 4 [1]·2MeCN salt was also structurally characterized, crystallizing in the monoclinic P2 1 /c space group. Treatment of 1 with [(p-BrC 6 H 4 ) 3 N] + allowed for isolation of the one-electron-oxidized spin-crossover (SCO) complex, [Co(P 3 O 9 ) 2 ] 3- (3), which is the active catholyte species generated during cell charging. The success of the 1-2 cell provides a promising entry point to a potential future class of transition-metal metaphosphate-based all-inorganic non-aqueous redox-flow battery electrolytes.

Impact of fuel fabrication and fuel management technologies on uranium management

International Nuclear Information System (INIS)

Arnsberger, P.L.; Stucker, D.L.

1994-01-01

Uranium utilization in commercial pressurized water reactors is a complex function of original NSSS design, utility energy requirements, fuel assembly design, fuel fabrication materials and fuel fabrication materials and fuel management optimization. Fuel design and fabrication technologies have reacted to the resulting market forcing functions with a combination of design and material changes. The technologies employed have included ever-increasing fuel discharge burnup, non-parasitic structural materials, burnable absorbers, and fissile material core zoning schemes (both in the axial and radial direction). The result of these technological advances has improved uranium utilization by roughly sixty percent from the infancy days of nuclear power to present fuel management. Fuel management optimization technologies have also been developed in recent years which provide fuel utilization improvements due to core loading pattern optimization. This paper describes the development and impact of technology advances upon uranium utilization in modern pressurized water reactors. 10 refs., 3 tabs., 10 figs

Using of cotton oil soapstock biodiesel-diesel fuel blends as an alternative diesel fuel

Energy Technology Data Exchange (ETDEWEB)

Keskin, Ali [Technical Education Faculty, Mersin University, 33500 Mersin (Turkey); Guerue, Metin [Engineering and Architectural Faculty, Gazi University, 06570 Maltepe, Ankara (Turkey); Altiparmak, Duran [Technical Education Faculty, Gazi University, 06500 Ankara (Turkey); Aydin, Kadir [Engineering and Architectural Faculty, Cukurova University, 01330 Adana (Turkey)

2008-04-15

In this study, usability of cotton oil soapstock biodiesel-diesel fuel blends as an alternative fuel for diesel engines were studied. Biodiesel was produced by reacting cotton oil soapstock with methyl alcohol at determined optimum condition. The cotton oil biodiesel-diesel fuel blends were tested in a single cylinder direct injection diesel engine. Engine performances and smoke value were measured at full load condition. Torque and power output of the engine with cotton oil soapstock biodiesel-diesel fuel blends decreased by 5.8% and 6.2%, respectively. Specific fuel consumption of engine with cotton oil soapstock-diesel fuel blends increased up to 10.5%. At maximum torque speeds, smoke level of engine with blend fuels decreased up to 46.6%, depending on the amount of biodiesel. These results were compared with diesel fuel values. (author)

Using of cotton oil soapstock biodiesel-diesel fuel blends as an alternative diesel fuel

International Nuclear Information System (INIS)

Keskin, Ali; Guerue, Metin; Altiparmak, Duran; Aydin, Kadir

2008-01-01

In this study, usability of cotton oil soapstock biodiesel-diesel fuel blends as an alternative fuel for diesel engines were studied. Biodiesel was produced by reacting cotton oil soapstock with methyl alcohol at determined optimum condition. The cotton oil biodiesel-diesel fuel blends were tested in a single cylinder direct injection diesel engine. Engine performances and smoke value were measured at full load condition. Torque and power output of the engine with cotton oil soapstock biodiesel-diesel fuel blends decreased by 5.8% and 6.2%, respectively. Specific fuel consumption of engine with cotton oil soapstock-diesel fuel blends increased up to 10.5%. At maximum torque speeds, smoke level of engine with blend fuels decreased up to 46.6%, depending on the amount of biodiesel. These results were compared with diesel fuel values. (author)

Simultaneous energy generation and UV quencher removal from landfill leachate using a microbial fuel cell.

Science.gov (United States)

Iskander, Syeed Md; Novak, John T; Brazil, Brian; He, Zhen

2017-11-01

The presence of UV quenching compounds in landfill leachate can negatively affect UV disinfection in a wastewater treatment plant when leachate is co-treated. Herein, a microbial fuel cell (MFC) was investigated to remove UV quenchers from a landfill leachate with simultaneous bioelectricity generation. The key operating parameters including hydraulic retention time (HRT), anolyte recirculation rate, and external resistance were systematically studied to maximize energy recovery and UV absorbance reduction. It was found that nearly 50% UV absorbance was reduced under a condition of HRT 40 days, continuous anolyte recirculation, and 10 Ω external resistance. Further analysis showed a total reduction of organics by 75.3%, including the reduction of humic acids, fulvic acids, and hydrophilic fraction concentration as TOC. The MFC consumed 0.056 kWh m -3 by its pump system for recirculation and oxygen supply. A reduced HRT of 20 days with periodical anode recirculation (1 hour in every 24 hours) and 39 Ω external resistance (equal to the internal resistance of the MFC) resulted in the highest net energy of 0.123 kWh m -3 . Granular activated carbon (GAC) was used as an effective post-treatment step and could achieve 89.1% UV absorbance reduction with 40 g L -1 . The combined MFC and GAC treatment could reduce 92.9% of the UV absorbance and remove 89.7% of the UV quenchers. The results of this study would encourage further exploration of using MFCs as an energy-efficient method for removing UV quenchers from landfill leachate.

Mechanism for Self-Reacted Friction Stir Welding

Science.gov (United States)

Venable, Richard; Bucher, Joseph

2004-01-01

A mechanism has been designed to apply the loads (the stirring and the resection forces and torques) in self-reacted friction stir welding. This mechanism differs somewhat from mechanisms used in conventional friction stir welding, as described below. The tooling needed to apply the large reaction loads in conventional friction stir welding can be complex. Self-reacted friction stir welding has become popular in the solid-state welding community as a means of reducing the complexity of tooling and to reduce costs. The main problems inherent in self-reacted friction stir welding originate in the high stresses encountered by the pin-and-shoulder assembly that produces the weld. The design of the present mechanism solves the problems. The mechanism includes a redesigned pin-and-shoulder assembly. The welding torque is transmitted into the welding pin by a square pin that fits into a square bushing with set-screws. The opposite or back shoulder is held in place by a Woodruff key and high-strength nut on a threaded shaft. The Woodruff key reacts the torque, while the nut reacts the tensile load on the shaft.

Alternative fuel properties of tall oil fatty acid methyl ester-diesel fuel blends

Energy Technology Data Exchange (ETDEWEB)

Altiparmak, D.; Keskin, A.; Koca, A. [Gazi University, Ankara (Turkey). Technical Education Faculty; Guru, M. [Gazi University, Ankara (Turkey). Engineering and Architectural Faculty

2007-01-15

In this experimental work, tall oil methyl ester-diesel fuel blends as alternative fuels for diesel engines were studied. Tall oil methyl ester was produced by reacting tall oil fatty acids with methyl alcohol under optimum conditions. The blends of tall oil methyl ester-diesel fuel were tested in a direct injection diesel engine at full load conditions. The effects of the new fuel blends on the engine performance and exhaust emission were tested. It was observed that the engine torque and power output with tall oil methyl ester-diesel fuel blends increased up to 6.1% and 5.9%, respectively. It was also seen that CO emissions decreased to 38.9% and NO{sub x} emissions increased up to 30% with the new fuel blends. The smoke capacity did not vary significantly. (author)

Alternative fuel properties of tall oil fatty acid methyl ester-diesel fuel blends.

Science.gov (United States)

Altiparmak, Duran; Keskin, Ali; Koca, Atilla; Gürü, Metin

2007-01-01

In this experimental work, tall oil methyl ester-diesel fuel blends as alternative fuels for diesel engines were studied. Tall oil methyl ester was produced by reacting tall oil fatty acids with methyl alcohol under optimum conditions. The blends of tall oil methyl ester-diesel fuel were tested in a direct injection diesel engine at full load condition. The effects of the new fuel blends on the engine performance and exhaust emission were tested. It was observed that the engine torque and power output with tall oil methyl ester-diesel fuel blends increased up to 6.1% and 5.9%, respectively. It was also seen that CO emissions decreased to 38.9% and NO(x) emissions increased up to 30% with the new fuel blends. The smoke opacity did not vary significantly.

Calorimetry of non-reacting systems

CERN Document Server

McCullough, John P

2013-01-01

Experimental Thermodynamics, Volume 1: Calorimetry of Non-Reacting Systems covers the heat capacity determinations for chemical substances in the solid, liquid, solution, and vapor states, at temperatures ranging from near the absolute zero to the highest at which calorimetry is feasible.This book is divided into 14 chapters. The first four chapters provide background information and general principles applicable to all types of calorimetry of non-reacting systems. The remaining 10 chapters deal with specific types of calorimetry. Most of the types of calorimetry treated are developed over a c

Sodium borohydride as an additive to enhance the performance of direct ethanol fuel cells

Energy Technology Data Exchange (ETDEWEB)

Wang, Lianqin; Fang, Xiang; Shen, Pei Kang [The Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, The State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275 (China); Bambagioni, Valentina; Bevilacqua, Manuela; Bianchini, Claudio; Filippi, Jonathan; Lavacchi, Alessandro; Marchionni, Andrea; Vizza, Francesco [Istituto di Chimica dei Composti Organometallici (ICCOM-CNR), via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence (Italy)

2010-12-15

The effect of adding small quantities (0.1-1 wt.%) of sodium borohydride (NaBH{sub 4}) to the anolyte solution of direct ethanol fuel cells (DEFCs) with membrane-electrode assemblies constituted by nanosized Pd/C anode, Fe-Co cathode and anion-exchange membrane (Tokuyama A006) was investigated by means of various techniques. These include cyclic voltammetry, in situ FTIR spectroelectrochemistry, a study of the performance of monoplanar fuel cells and an analysis of the ethanol oxidation products. A comparison with fuel cells fed with aqueous solutions of ethanol proved unambiguously the existence of a promoting effect of NaBH{sub 4} on the ethanol oxidation. Indeed, the potentiodynamic curves of the ethanol-NaBH{sub 4} mixtures showed higher power and current densities, accompanied by a remarkable increase in the fuel consumption at comparable working time of the cell. A {sup 13}C and {sup 11}B {l_brace}{sup 1}H{r_brace}NMR analysis of the cell exhausts and an in situ FTIR spectroelectrochemical study showed that ethanol is converted selectively to acetate while the oxidation product of NaBH{sub 4} is sodium metaborate (NaBO{sub 2}). The enhancement of the overall cell performance has been explained in terms of the ability of NaBH{sub 4} to reduce the PdO layer on the catalyst surface. (author)

Mathematical modeling based evaluation and simulation of boron removal in bioelectrochemical systems.

Science.gov (United States)

Ping, Qingyun; Abu-Reesh, Ibrahim M; He, Zhen

2016-11-01

Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level 22.2 in order to avoid boron accumulation in the anolyte effluent. Copyright © 2016 Elsevier B.V. All rights reserved.

Nuclear fuel element containing strips of an alloyed Zr, Ti, and Ni getter material

International Nuclear Information System (INIS)

Grossman, L.N.; Packard, D.R.

1975-01-01

A nuclear fuel element for use in the core of a nuclear reactor is disclosed. The nuclear fuel element has disposed therein an alloy having the essential components of nickel, titanium and zirconium, and the alloy reacts with water, water vapor and reactive gases at reactor ambient temperatures. The alloy is disposed in the plenum of the fuel element in the form of strips and preferably the strips are positioned inside a helical member in the plenum. The position of the alloy strips permits gases and liquids entering the plenum to contact and react with the alloy strips. (U.S.)

Fuel-cladding chemical interaction

International Nuclear Information System (INIS)

Gueneau, C.; Piron, J.P.; Dumas, J.C.; Bouineau, V.; Iglesias, F.C.; Lewis, B.J.

2015-01-01

The chemistry of the nuclear fuel is very complex. Its chemical composition changes with time due to the formation of fission products and depends on the temperature level history within the fuel pellet and the clad during operation. Firstly, in thermal reactors, zircaloy oxidation from reaction with UO 2 fuel under high-temperature conditions will be addressed. Then other fuel-cladding interaction phenomena occurring in fast reactors will be described. Large thermal gradients existing between the centre and the periphery of the pellet induce the radial redistribution of the fuel constituents. The fuel pellet can react with the clad by different corrosion processes which can involve actinide and/or fission product transport via gas, liquid or/and solid phases. All these phenomena are briefly described in the case of different kinds of fuels (oxide, carbide, nitride, metallic) to be used in fast reactors. The way these phenomena are taken into account in fuel performance codes is presented. (authors)

Chelating agent-assisted electrokinetic removal of cadmium, lead and copper from contaminated soils

International Nuclear Information System (INIS)

Giannis, Apostolos; Nikolaou, Aris; Pentari, Despina; Gidarakos, Evangelos

2009-01-01

An integrated experimental program was conducted to remove Cd, Pb and Cu from contaminated soil. The chelate agents nitrilotriacetic acid (NTA), diethylenetriamine pentaacetic acid (DTPA) and ethyleneglycol tetraacetic acid (EGTA) were used as washing solutions under different pH conditions and concentrations. Results showed that the extraction efficiency for Cd in decreasing order was NTA > EGTA > DTPA, while for Pb and Cu it was DTPA > NTA > EGTA. The use of higher chelate concentrations did not necessarily result in greater extraction efficiency. Electrokinetic remediation was applied by conditioning anolyte-catholyte pH to neutral values in order to avoid any potential alterations to the physicochemical soil properties. The removal efficiency for Cd was 65-95%, for Cu 15-60%, but for Pb was less than 20%. The phytotoxicity of the treated soil showed that the soil samples from the anode section were less phytotoxic than the untreated soil, but the phytotoxicity was increased in the samples from the cathode section. - Cadmium, lead and copper were extracted from contaminated soil by integrated electrokinetic and soil washing studies.

Chelating agent-assisted electrokinetic removal of cadmium, lead and copper from contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Giannis, Apostolos, E-mail: apostolos.giannis@enveng.tuc.g [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Nikolaou, Aris [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Pentari, Despina [Laboratory of Inorganic and Organic Geochemistry and Organic Petrography, Department of Mineral Resources Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Gidarakos, Evangelos, E-mail: gidarako@mred.tuc.g [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece)

2009-12-15

An integrated experimental program was conducted to remove Cd, Pb and Cu from contaminated soil. The chelate agents nitrilotriacetic acid (NTA), diethylenetriamine pentaacetic acid (DTPA) and ethyleneglycol tetraacetic acid (EGTA) were used as washing solutions under different pH conditions and concentrations. Results showed that the extraction efficiency for Cd in decreasing order was NTA > EGTA > DTPA, while for Pb and Cu it was DTPA > NTA > EGTA. The use of higher chelate concentrations did not necessarily result in greater extraction efficiency. Electrokinetic remediation was applied by conditioning anolyte-catholyte pH to neutral values in order to avoid any potential alterations to the physicochemical soil properties. The removal efficiency for Cd was 65-95%, for Cu 15-60%, but for Pb was less than 20%. The phytotoxicity of the treated soil showed that the soil samples from the anode section were less phytotoxic than the untreated soil, but the phytotoxicity was increased in the samples from the cathode section. - Cadmium, lead and copper were extracted from contaminated soil by integrated electrokinetic and soil washing studies.

Carrier ampholyte-free isoelectric focusing on a paper-based analytical device for the fractionation of proteins.

Science.gov (United States)

Xie, Song-Fang; Gao, Han; Niu, Li-Li; Xie, Zhen-Sheng; Fang, Fang; Wu, Zhi-Yong; Yang, Fu-Quan

2018-01-25

Isoelectric focusing plays a critical role in the analysis of complex protein samples. Conventionally, isoelectric focusing is implemented with carrier ampholytes in capillary or immobilized pH gradient gel. In this study, we successfully exhibited a carrier ampholyte-free isoelectric focusing on paper-based analytical device. Proof of the concept was visually demonstrated with color model proteins. Experimental results showed that not only a pH gradient was well established along the open paper fluidic channel as confirmed by pH indicator strip, the pH gradient range could also be tuned by the catholyte or anolyte. Furthermore, the isoelectric focusing fractions from the paper channel can be directly cut and recovered into solutions for post analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. This paper-based isoelectric focusing method is fast, cheap, simple and easy to operate, and could potentially be used as a cost-effective protein sample clean-up method for target protein analysis with mass spectrometry. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly enhanced electrochemical activity of Ni foam electrodes decorated with nitrogen-doped carbon nanotubes for non-aqueous redox flow batteries

Science.gov (United States)

Lee, Jungkuk; Park, Min-Sik; Kim, Ki Jae

2017-02-01

Nitrogen-doped carbon nanotubes (NCNTs) are directly grown on the surface of a three-dimensional (3D) Ni foam substrate by floating catalytic chemical vapor deposition (FCCVD). The electrochemical properties of the 3D NCNT-Ni foam are thoroughly examined as a potential electrode for non-aqueous redox flow batteries (RFBs). During synthesis, nitrogen atoms can be successfully doped onto the carbon nanotube (CNT) lattices by forming an abundance of nitrogen-based functional groups. The 3D NCNT-Ni foam electrode exhibits excellent electrochemical activities toward the redox reactions of [Fe (bpy)3]2+/3+ (in anolyte) and [Co(bpy)3]+/2+ (in catholyte), which are mainly attributed to the hierarchical 3D structure of the NCNT-Ni foam electrode and the catalytic effect of nitrogen atoms doped onto the CNTs; this leads to faster mass transfer and charge transfer during operation. As a result, the RFB cell assembled with 3D NCNT-Ni foam electrodes exhibits a high energy efficiency of 80.4% in the first cycle; this performance is maintained up to the 50th cycle without efficiency loss.

Large-Eddy Simulations of Reacting Liquid Spray

Science.gov (United States)

Lederlin, Thomas; Sanjose, Marlene; Gicquel, Laurent; Cuenot, Benedicte; Pitsch, Heinz; Poinsot, Thierry

2008-11-01

Numerical simulation, which is commonly used in many stages of aero-engine design, still has to demonstrate its predictive capability for two-phase reacting flows. This study is a collaboration between Stanford University and CERFACS to perform LES of a realistic spray combustor installed at ONERA, Toulouse. The experimental configuration is computed on the same unstructured mesh with two different solvers: Stanford's CDP code and CERFACS's AVBP code. CDP uses a low-Mach, variable-density solver with implicit time advancement. Droplets are tracked in a Lagrangian point-particle framework. The combustion model uses a flamelet approach, based on two transported scalars, mixture fraction and reaction progress variable. AVBP is a fully compressible solver with explicit time advancement. The liquid phase is described with an Eulerian method. The flame-turbulence interaction is modeled using a dynamically-thickened flame. Results are compared with experimental data for three regimes: purely gaseous non-reacting flow, non-reacting flow with evaporating droplets, reacting flow with droplets. Both simulations show a good agreement with experimental data and also stress the difference and relative advantages of the numerical methods.

A Hybrid Mineral Battery: Energy Storage and Dissolution Behavior of CuFeS2 in a Fixed Bed Flow Cell.

Science.gov (United States)

Deen, Kashif Mairaj; Asselin, Edouard

2018-05-09

The development of a hybrid system capable of storing energy and the additional benefit of Cu extraction is discussed in this work. A fixed bed flow cell (FBFC) was used in which a composite negative electrode containing CuFeS 2 (80 wt %) and carbon black (20 wt %) in graphite felt was separated from a positive (graphite felt) electrode by a proton-exchange membrane. The anolyte (0.2 m H 2 SO 4 ) and catholyte (0.5 m Fe 2+ in 0.2 m H 2 SO 4 with or without 0.1 m Cu 2+ ) were circulated in the cell. The electrochemical activity of the Fe 2+ /Fe 3+ redox couple over graphite felt significantly improved after the addition of Cu 2+ in the catholyte. Ultimately, in the CuFeS 2 ∥Fe 2+ /Cu 2+ (CFeCu) FBFC system, the specific capacity increased continuously to 26.4 mAh g -1 in 500 galvanostatic charge-discharge (GCD) cycles, compared to the CuFeS 2 ∥Fe 2+ (CFe) system (13.9 mAh g -1 ). Interestingly, the specific discharge energy gradually increased to 3.6 Wh kg -1 in 500 GCD cycles for the CFeCu system compared to 3.29 Wh kg -1 for the CFe system in 150 cycles. In addition to energy storage, 10.75 % Cu was also extracted from the mineral, which is an important feature of the CFeCu system as it would allow Cu extraction and recovery through hydrometallurgical methods. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Direct numerical simulation of an isothermal reacting turbulent wall-jet

Science.gov (United States)

Pouransari, Zeinab; Brethouwer, Geert; Johansson, Arne V.

2011-08-01

In the present investigation, Direct Numerical Simulation (DNS) is used to study a binary irreversible and isothermal reaction in a plane turbulent wall-jet. The flow is compressible and a single-step global reaction between an oxidizer and a fuel species is solved. The inlet based Reynolds, Schmidt, and Mach numbers of the wall-jet are Re = 2000, Sc = 0.72, and M = 0.5, respectively, and a constant coflow velocity is applied above the jet. At the inlet, fuel and oxidizer enter the domain separately in a non-premixed manner. The turbulent structures of the velocity field show the common streaky patterns near the wall, while a somewhat patchy or spotty pattern is observed for the scalars and the reaction rate fluctuations in the near-wall region. The reaction mainly occurs in the upper shear layer in thin highly convoluted reaction zones, but it also takes place close to the wall. Analysis of turbulence and reaction statistics confirms the observations in the instantaneous snapshots, regarding the intermittent character of the reaction rate near the wall. A detailed study of the probability density functions of the reacting scalars and comparison to that of the passive scalar throughout the domain reveals the significance of the reaction influence as well as the wall effects on the scalar distributions. The higher order moments of both the velocities and the scalar concentrations are analyzed and show a satisfactory agreement with experiments. The simulations show that the reaction can both enhance and reduce the dissipation of fuel scalar, since there are two competing effects; on the one hand, the reaction causes sharper scalar gradients and thus a higher dissipation rate, on the other hand, the reaction consumes the fuel scalar thereby reducing the scalar dissipation.

Proceedings of fuel strategies for conventional and unconventional fuels

International Nuclear Information System (INIS)

Mahr, D.; Nechvatal, T.T.

1991-01-01

Fuel selection is a major decision for a power engineer. It is the single largest item in the power plant operating budget and has a major effect on power plant economics. Fuel determines plant design requirements and the types of systems that are provided. As a result, it affects capital budgets and financing requirements. In the last few decades, we have seen different fuels of choice at any one time. Coal has always been a staple for power generation. During the 1950s and 1960s, oil became an attractive alternative. Nuclear fuel became a popular choice due to its very low energy cost. After Three-Mile-Island, however, capital budgets went through the roof, resulting in severe financial constraints. Natural gas, which was rationed in some regions a few years ago, is now a popular choice. Some sources predict that its cost will increase faster than other fuels. To mitigate the relative variations in energy cost for different fuels, a balanced energy plan is required. A balanced power generation plan with fuel options provides the flexibility to react to unpredictable changes. The papers in this book are a continuation of the Fuel Strategies theme. Three technical topics are covered: Converting to Orimulsion, A Replacement Fuel for Heavy Oil; Innovations in Handling Conventional and Unconventional Fuels for Power Plants; and Pacific Rim Experience With Coal

Planar Solid-Oxide Fuel Cell System Demonstration at UT SimCenter

Science.gov (United States)

2015-12-09

Optimization of Chemically Reacting Flows in Catalytic Monoliths", PhD Thesis, University of Heidelberg, 2005. [55] David G. Goodwin, Harry K. Moffat...Berry. Fuel Cells: Technologies for Fuel Processing. Oxford: Elsevier, 2011 [114] J. Pasel, J. Meissner, Z. Pors, C. Palm, P. Cremer , R. Peters, D

The Synthesis and Characterization of Ionic Liquids for Alkali-Metal Batteries and a Novel Electrolyte for Non-Humidified Fuel Cells

Science.gov (United States)

Tucker, Telpriore G.

This thesis focused on physicochemical and electrochemical projects directed towards two electrolyte types: 1) class of ionic liquids serving as electrolytes in the catholyte for alkali-metal ion conduction in batteries and 2) gel membrane for proton conduction in fuel cells; where overall aims were encouraged by the U.S. Department of Energy. Large-scale, sodium-ion batteries are seen as global solutions to providing undisrupted electricity from sustainable, but power-fluctuating, energy production in the near future. Foreseen ideal advantages are lower cost without sacrifice of desired high-energy densities relative to present lithium-ion and lead-acid battery systems. Na/NiCl2 (ZEBRA) and Na/S battery chemistries, suffer from high operation temperature (>300ºC) and safety concerns following major fires consequent of fuel mixing after cell-separator rupturing. Initial interest was utilizing low-melting organic ionic liquid, [EMI+][AlCl 4-], with well-known molten salt, NaAlCl4, to create a low-to-moderate operating temperature version of ZEBRA batteries; which have been subject of prior sodium battery research spanning decades. Isothermal conductivities of these electrolytes revealed a fundamental kinetic problem arisen from "alkali cation-trapping effect" yet relived by heat-ramping >140ºC. Battery testing based on [EMI+][FeCl4 -] with NaAlCl4 functioned exceptional (range 150-180ºC) at an impressive energy efficiency >96%. Newly prepared inorganic ionic liquid, [PBr4+][Al2Br7-]:NaAl2Br 7, melted at 94ºC. NaAl2Br7 exhibited super-ionic conductivity 10-1.75 Scm-1 at 62ºC ensued by solid-state rotator phase transition. Also improved thermal stability when tested to 265ºC and less expensive chemical synthesis. [PBr4 +][Al2Br7-] demonstrated remarkable, ionic decoupling in the liquid-state due to incomplete bromide-ion transfer depicted in NMR measurements. Fuel cells are electrochemical devices generating electrical energy reacting hydrogen/oxygen gases

Experimental investigation of a reacting transverse jet in a high pressure oscillating vitiated crossflow

Science.gov (United States)

Fugger, Christopher A.

Staged combustion is one design approach in a gas turbine engine to reduce pollutant emission levels. In axially staged combustion, portions of the air and fuel are injected downstream of a lean premixed low NOx primary combustion zone. The gas residence time at elevated temperatures is decreased resulting in lower thermal NOx, and the reduced oxygen and high temperature vitiated primary zone flow further help to reduce pollutant emissions and quickly complete combustion. One implementation of axially staged combustion is transverse fuel jet injection. An important consideration for staged combustion systems, though, is how the primary and secondary combustion zones can couple through the acoustic resonances of the chamber. These couplings can lead to additional source terms that pump energy into the resonant acoustic field and help sustain the high-amplitude combustor pressure oscillations. An understanding of these couplings is important so that it may be possible to design a secondary combustion system that provides inherent damping to the combustor system. To systematically characterize the coupling of a reacting jet in unsteady crossflow in detail, the effects of an an unsteady pressure flowfield and an unsteady velocity flowfield are separately investigated. An optically accessible resonant combustion chamber was designed and built as part of this work to generate a standing wave unsteady vitiated crossflow at a chamber pressure of 0.9 MPa. The location of transverse jet injection corresponds to one of two locations, where one location is the pressure node and the other location the pressure anti-node of the resonant chamber acoustic mode. The injection location is optically accessible, and the dynamic interactions between the transverse jet flow and the 1st and 2nd axial combustor modes are measured using 10 kHz OH-PLIF and 2D PIV. This document analyzes five test cases: two non-reacting jets and three reacting jets. All cases correspond to jet injection

High performance liquid chromatographic hydrocarbon group-type analyses of mid-distillates employing fuel-derived fractions as standards

Science.gov (United States)

Seng, G. T.; Otterson, D. A.

1983-01-01

Two high performance liquid chromatographic (HPLC) methods have been developed for the determination of saturates, olefins and aromatics in petroleum and shale derived mid-distillate fuels. In one method the fuel to be analyzed is reacted with sulfuric acid, to remove a substantial portion of the aromatics, which provides a reacted fuel fraction for use in group type quantitation. The second involves the removal of a substantial portion of the saturates fraction from the HPLC system to permit the determination of olefin concentrations as low as 0.3 volume percent, and to improve the accuracy and precision of olefins determinations. Each method was evaluated using model compound mixtures and real fuel samples.

Storage of LWR spent fuel in air. Volume 3, Results from exposure of spent fuel to fluorine-contaminated air

Energy Technology Data Exchange (ETDEWEB)

Cunningham, M.E.; Thomas, L.E.

1995-06-01

The Behavior of Spent Fuel in Storage (BSFS) Project has conducted research to develop data on spent nuclear fuel (irradiated U0{sub 2}) that could be used to support design, licensing, and operation of dry storage installations. Test Series B conducted by the BSFS Project was designed as a long-term study of the oxidation of spent fuel exposed to air. It was discovered after the exposures were completed in September 1990 that the test specimens had been exposed to an atmosphere of bottled air contaminated with an unknown quantity of fluorine. This exposure resulted in the test specimens reacting with both the oxygen and the fluorine in the oven atmospheres. The apparent source of the fluorine was gamma radiation-induced chemical decomposition of the fluoro-elastomer gaskets used to seal the oven doors. This chemical decomposition apparently released hydrofluoric acid (HF) vapor into the oven atmospheres. Because the Test Series B specimens were exposed to a fluorine-contaminated oven atmosphere and reacted with the fluorine, it is recommended that the Test Series B data not be used to develop time-temperature limits for exposure of spent nuclear fuel to air. This report has been prepared to document Test Series B and present the collected data and observations.

Storage of LWR spent fuel in air. Volume 3, Results from exposure of spent fuel to fluorine-contaminated air

International Nuclear Information System (INIS)

Cunningham, M.E.; Thomas, L.E.

1995-06-01

The Behavior of Spent Fuel in Storage (BSFS) Project has conducted research to develop data on spent nuclear fuel (irradiated U0 2 ) that could be used to support design, licensing, and operation of dry storage installations. Test Series B conducted by the BSFS Project was designed as a long-term study of the oxidation of spent fuel exposed to air. It was discovered after the exposures were completed in September 1990 that the test specimens had been exposed to an atmosphere of bottled air contaminated with an unknown quantity of fluorine. This exposure resulted in the test specimens reacting with both the oxygen and the fluorine in the oven atmospheres. The apparent source of the fluorine was gamma radiation-induced chemical decomposition of the fluoro-elastomer gaskets used to seal the oven doors. This chemical decomposition apparently released hydrofluoric acid (HF) vapor into the oven atmospheres. Because the Test Series B specimens were exposed to a fluorine-contaminated oven atmosphere and reacted with the fluorine, it is recommended that the Test Series B data not be used to develop time-temperature limits for exposure of spent nuclear fuel to air. This report has been prepared to document Test Series B and present the collected data and observations

Evolving Microbial Communities in Cellulose-Fed Microbial Fuel Cell

Directory of Open Access Journals (Sweden)

Renata Toczyłowska-Mamińska

2018-01-01

Full Text Available The abundance of cellulosic wastes make them attractive source of energy for producing electricity in microbial fuel cells (MFCs. However, electricity production from cellulose requires obligate anaerobes that can degrade cellulose and transfer electrons to the electrode (exoelectrogens, and thus most previous MFC studies have been conducted using two-chamber systems to avoid oxygen contamination of the anode. Single-chamber, air-cathode MFCs typically produce higher power densities than aqueous catholyte MFCs and avoid energy input for the cathodic reaction. To better understand the bacterial communities that evolve in single-chamber air-cathode MFCs fed cellulose, we examined the changes in the bacterial consortium in an MFC fed cellulose over time. The most predominant bacteria shown to be capable electron generation was Firmicutes, with the fermenters decomposing cellulose Bacteroidetes. The main genera developed after extended operation of the cellulose-fed MFC were cellulolytic strains, fermenters and electrogens that included: Parabacteroides, Proteiniphilum, Catonella and Clostridium. These results demonstrate that different communities evolve in air-cathode MFCs fed cellulose than the previous two-chamber reactors.

Sensitivity Analysis of Heavy Fuel Oil Spray and Combustion under Low-Speed Marine Engine-Like Conditions

Directory of Open Access Journals (Sweden)

Lei Zhou

2017-08-01

Full Text Available On account of their high power, thermal efficiency, good reliability, safety, and durability, low-speed two-stroke marine diesel engines are used as the main drive devices for large fuel and cargo ships. Most marine engines use heavy fuel oil (HFO as the primary fuel, however, the physical and chemical characteristics of HFO are not clear because of its complex thermophysical properties. The present study was conducted to investigate the effects of fuel properties on the spray and combustion characteristics under two-stroke marine engine-like conditions via a sensitivity analysis. The sensitivity analysis of fuel properties for non-reacting and reacting simulations are conducted by comparing two fuels having different physical properties, such as fuel density, dynamic viscosity, critical temperature, and surface tension. The performances of the fuels are comprehensively studied under different ambient pressures, ambient temperatures, fuel temperatures, and swirl flow conditions. From the results of non-reacting simulations of HFO and diesel fuel properties in a constant volume combustion chamber, it can be found that the increase of the ambient pressure promotes fuel evaporation, resulting in a reduction in the steady liquid penetration of both diesel and HFO; however, the difference in the vapor penetrations of HFO and diesel reduces. Increasing the swirl flow significantly influences the atomization of both HFO and diesel, especially the liquid distribution of diesel. It is also found that the ambient temperature and fuel temperature have the negative effects on Sauter mean diameter (SMD distribution. For low-speed marine engines, the combustion performance of HFO is not sensitive to activation energy in a certain range of activation energy. At higher engine speed, the difference in the effects of different activation energies on the in-cylinder pressure increases. The swirl flow in the cylinder can significantly promote fuel evaporation and

Study of transport and micro-structural properties of magnesium di-boride strand under react and bend mode and bend and react mode

International Nuclear Information System (INIS)

Kundu, Ananya; Das, Subrat Kumar; Bano, Anees; Pradhan, Subrata

2015-01-01

I-V characterization of commercial multi-filamentary Magnesium Di-Boride (MgB 2 ) wire of diameter 0.83 mm were studied in cryocooler based self-field characterization system under both react and bent mode and bent and react mode for a range of temperature 6 K - 25 K. This study is of practical technical relevance where the heat treatment of the superconducting wire makes the sample less flexible for winding in magnet and in other applications. There are limited reported data, available on degradation of MgB 2 wire with bending induced strain in react and wind and wind and react method. In the present work the bending diameter were varied from 80 mm to 20 mm in the interval of 10 mm change of bending diameter and for each case critical current (Ic) of the strand is measured for the above range of temperature. An ETP copper made customized sample holder for mounting the MgB 2 strand was fabricated and is thermally anchored to the cooling stage of the cryocooler. It is seen from the experimental data that in react and bent mode the critical current degrades from 105 A to 87 A corresponding to bending diameter of 80 mm and 20 mm respectively. The corresponding bending strain was analytically estimated and compared with the simulation result. It is also observed that in react and bent mode, the degradation of the transport property of the strand is less as compared to react and bent mode. For bent and react mode in the same sample, the critical current (Ic) was measured to be ∼145 A at 15 K for bending diameter of 20 mm. Apart from studying the bending induced strain on MgB 2 strand, the tensile test of the strand at RT was carried out. The electrical characterizations of the samples were accompanied by the microstructure analyses of the bent strand to examine the bending induced degradation in the grain structure of the strand. All these experimental findings are expected to be used as input to fabricate prototype MgB 2 based magnet. (author)

Fabrication of a Combustion-Reacted High-Performance ZnO Electron Transport Layer with Silver Nanowire Electrodes for Organic Solar Cells.

Science.gov (United States)

Park, Minkyu; Lee, Sang-Hoon; Kim, Donghyuk; Kang, Juhoon; Lee, Jung-Yong; Han, Seung Min

2018-02-28

Herein, a new methodology for solution-processed ZnO fabrication on Ag nanowire network electrode via combustion reaction is reported, where the amount of heat emitted during combustion was minimized by controlling the reaction temperature to avoid damaging the underlying Ag nanowires. The degree of participation of acetylacetones, which are volatile fuels in the combustion reaction, was found to vary with the reaction temperature, as revealed by thermogravimetric and compositional analyses. An optimized processing temperature of 180 °C was chosen to successfully fabricate a combustion-reacted ZnO and Ag nanowire hybrid electrode with a sheet resistance of 30 Ω/sq and transmittance of 87%. A combustion-reacted ZnO on Ag nanowire hybrid structure was demonstrated as an efficient transparent electrode and electron transport layer for the PTB7-Th-based polymer solar cells. The superior electrical conductivity of combustion-reacted ZnO, compared to that of conventional sol-gel ZnO, increased the external quantum efficiency over the entire absorption range, whereas a unique light scattering effect due to the presence of nanopores in the combustion-derived ZnO further enhanced the external quantum efficiency in the 450-550 nm wavelength range. A power conversion efficiency of 8.48% was demonstrated for the PTB7-Th-based polymer solar cell with the use of a combustion-reacted ZnO/Ag NW hybrid transparent electrode.

In situ characterization of Hanford K Basins fuel

Energy Technology Data Exchange (ETDEWEB)

Pitner, A.L.

1998-01-06

Irradiated N Reactor uranium metal fuel is stored underwater in the Hanford K East and K West Basins. In K East Basin, fuel is stored in open canisters and defected fuel is free to react with the basin water. In K West Basin, the fuel is stored in sealed canisters filled with water containing a corrosion inhibitor (potassium nitrite). To gain a better understanding of the physical condition of the fuel in these basins, visual surveys using high resolution underwater cameras were conducted. The inspections included detailed lift and look examinations of a number of fuel assemblies from selected canisters in each basin. These examinations formed the bases for selecting specific fuel elements for laboratory testing and analyses as prescribed in the characterization plan for Hanford K Basin Spent Nuclear Fuel.

Reacting plasma project at IPP Japan

International Nuclear Information System (INIS)

Miyahara, A.; Momota, H.; Hamada, Y.; Kawamura, K.; Akimune, H.

1981-01-01

Contributed papers of the seminar on burning plasma held at UCLA are collected. Paper on ''overview of reacting plasma project'' described aim and philosophy of R-Project in Japan. Paper on ''Burning plasma and requirements for design'' gave theoretical aspect of reacting plasma physics while paper on ''plasma container, heating and diagnostics'' treated experimental aspect. Tritium handling is essential for the next step experiment; therefore, paper on ''Tritium problems in burning plasma experiments'' took an important part of this seminar. As appendix, paper on ''a new type of D - ion source using Si-semiconductor'' was added because such an advanced R and D work is essential for R-Project. (author)

Recent advances in ultrafast-laser-based spectroscopy and imaging for reacting plasmas and flames

Science.gov (United States)

Patnaik, Anil K.; Adamovich, Igor; Gord, James R.; Roy, Sukesh

2017-10-01

Reacting flows and plasmas are prevalent in a wide array of systems involving defense, commercial, space, energy, medical, and consumer products. Understanding the complex physical and chemical processes involving reacting flows and plasmas requires measurements of key parameters, such as temperature, pressure, electric field, velocity, and number densities of chemical species. Time-resolved measurements of key chemical species and temperature are required to determine kinetics related to the chemical reactions and transient phenomena. Laser-based, noninvasive linear and nonlinear spectroscopic approaches have proved to be very valuable in providing key insights into the physico-chemical processes governing reacting flows and plasmas as well as validating numerical models. The advent of kilohertz rate amplified femtosecond lasers has expanded the multidimensional imaging of key atomic species such as H, O, and N in a significant way, providing unprecedented insight into preferential diffusion and production of these species under chemical reactions or electric-field driven processes. These lasers not only provide 2D imaging of chemical species but have the ability to perform measurements free of various interferences. Moreover, these lasers allow 1D and 2D temperature-field measurements, which were quite unimaginable only a few years ago. The rapid growth of the ultrafast-laser-based spectroscopic measurements has been fueled by the need to achieve the following when measurements are performed in reacting flows and plasmas. They are: (1) interference-free measurements (collision broadening, photolytic dissociation, Stark broadening, etc), (2) time-resolved single-shot measurements at a rate of 1-10 kHz, (3) spatially-resolved measurements, (4) higher dimensionality (line, planar, or volumetric), and (5) simultaneous detection of multiple species. The overarching goal of this article is to review the current state-of-the-art ultrafast-laser-based spectroscopic

Analytical investigation of AlCl[3]/SO[2]Cl[2] catholyte materials for secondary fuze reserve batteries.

Energy Technology Data Exchange (ETDEWEB)

Butler, Paul Charles; Rodriguez, Mark Andrew; Segall, Judith M.; Malizia, Louis A., Jr.; Cherry, Brian Ray; Andrews, Nicholas L.; Clark, Nancy H.; Alam, Todd Michael; Ingersoll, David T.; Tallant, David Robert; Simpson, Regina Lynn; Boyle, Timothy J.; Garcia, Manuel Joseph

2004-05-01

Exploration of the fundamental chemical behavior of the AlCl{sub 3}/SO{sub 2}Cl{sub 2} catholyte system for the ARDEC Self-Destruct Fuze Reserve Battery Project under accelerated aging conditions was completed using a variety of analytical tools. Four different molecular species were identified in this solution, three of which are major. The relative concentrations of the molecular species formed were found to depend on aging time, initial concentrations, and storage temperature, with each variable affecting the kinetics and thermodynamics of this complex reaction system. We also evaluated the effect of water on the system, and determined that it does not play a role in dictating the observed molecular species present in solution. The first Al-containing species formed was identified as the dimer [Al({mu}-Cl)Cl{sub 2}]{sub 2}, and was found to be in equilibrium with the monomer, AlCl{sub 3}. The second species formed in the reaction scheme was identified by single crystal X-ray diffraction studies as [Cl{sub 2}Al({mu}-O{sub 2}SCl)]{sub 2} (I), a scrambled AlCl{sub 3}{center_dot}SO{sub 2} adduct. The SO{sub 2}(g) present, as well as CL{sub 2}(g), was formed through decomposition of SO{sub 2}CL{sub 2}. The SO{sub 2}(g) generated was readily consumed by AlCl{sub 3} to form the adduct 1 which was experimentally verified when 1 was also isolated from the reaction of SO{sub 2}(g) and AlCl {sub 3}. The third species found was tentatively identified as a compound having the general formula {l_brace}[Al(O)Cl{sub 2}][OSCl{sub 2}]{r_brace}{sub n}. This was based on {sup 27}Al NMR data that revealed a species with tetrahedrally coordinated Al metal centers with increased oxygen coordination and the fact that the precipitate, or gel, that forms over time was shown by Raman spectroscopic studies to possess a component that is consistent with SOCl{sub 2}. The precursor to the precipitate should have similar constituents, thus the assignment of {l_brace}[Al(O)Cl{sub 2}][OSCl{sub 2

Environmental Life Cycle Assessment of Coal-Biomass to Liquid Jet Fuel Compared to Petroleum-Derived JP-8 Jet Fuel

Science.gov (United States)

2010-03-01

is a Metal Deactivator Additive (MDA) to prevent fuel oxidation with trace metals such as copper or zinc that may be in the jet fuel (MIL- HDBK-510-1...react in the FT synthesis process). The gasifier is of the slagging type and a direct contact water quench spray system is used to cool the syngas...exiting the gasifier. The quench also removes particulate matter and contaminants not removed in the slag . However, because the ash from biomass is

Cross-reacting and heterospecific monoclonal antibodies produced against arabis mosaic nepovirus.

Science.gov (United States)

Frison, E A; Stace-Smith, R

1992-10-01

Monoclonal antibodies (MAbs) were produced against arabis mosaic nepovirus (AMV). A hybridoma screening procedure was applied which involved the testing of culture supernatants, before the hybridomas were cloned to single cell lines, for their reaction with eight nepoviruses [AMV, cherry leafroll virus (CLRV), grapevine fanleaf virus (GFLV), peach rosette mosaic virus, raspberry ringspot virus (RRSV), tobacco ringspot virus, tomato black ring virus (TBRV) and tomato ringspot virus]. In addition to AMV-specific MAbs, this screening technique has allowed the selection of two cross-reacting MAbs: one reacting with AMV and GFLV, and one reacting with AMV and RRSV. This is the first report of MAbs cross-reacting with these nepoviruses. In addition, five heterospecific MAbs (HS-MAbs) could be selected: two reacting with RRSV, two with CLRV and one with TBRV. The usefulness of the screening technique that was applied for the selection of cross-reacting MAbs and HS-MAbs, and the potential use of such antibodies are discussed.

Reaction of unirradiated high-density fuel with aluminum

International Nuclear Information System (INIS)

Wiencek, T.C.; Meyer, M.K.; Prokofiev, I.G.; Keiser, D.D.

1997-01-01

Excellent dispersion fuel performance requires that fuel particles remain stable and do not react significantly with the surrounding aluminum matrix. A series of high-density fuels, which contain uranium densities >12 g/cm 3 , have been fabricated into plates. As part of standard processing, all of these fuels were subjected to a blister anneal of 1 h at 485 deg. C. Changes in plate thickness were measured and evaluated. From these results, suppositions about the probable irradiation properties of these fuels have been proposed. In addition, two fuels, U-10 wt% Mo and U 2 Mo, were subjected to various heat treatments and were found to be very stable in an aluminum matrix. On the basis of the experimental data, hypotheses of the irradiation behavior of these fuels are presented. (author)

Fungal decay resistance of wood reacted with phosphorus pentoxide-amine system

Science.gov (United States)

Hong-Lin Lee; George C. Chen; Roger M. Rowell

2004-01-01

Resistance of wood reacted in situ with phosphorus pentoxide-amine to the brown-rot fungus Gloeophyllum trabeum and white-rot fungus Trametes versicolor was examined. Wood reacted with either octyl, tribromo, or nitro derivatives were more resistant to both fungi. Threshold retention values of phosphoramide-reacted wood to white-rot fungus T. versicolor ranged from 2.9...

One-step catalytic conversion of biomass-derived carbohydrates to liquid fuels

Science.gov (United States)

Sen, Ayusman; Yang, Weiran

2014-03-18

The invention relates to a method for manufacture of hydrocarbon fuels and oxygenated hydrocarbon fuels such as alkyl substituted tetrahydrofurans such as 2,5-dimethyltetrahydrofuran, 2-methyltetrahydrofuran, 5-methylfurfural and mixtures thereof. The method generally entails forming a mixture of reactants that includes carbonaceous material, water, a metal catalyst and an acid reacting that mixture in the presence of hydrogen. The reaction is performed at a temperature and for a time sufficient to produce a furan type hydrocarbon fuel. The process may be adapted to provide continuous manufacture of hydrocarbon fuels such as a furan type fuel.

Combustion characteristics and turbulence modeling of swirling reacting flow in solid fuel ramjet

Science.gov (United States)

Musa, Omer; Xiong, Chen; Changsheng, Zhou

2017-10-01

This paper reviews the historical studies have been done on the solid-fuel ramjet engine and difficulties associated with numerical modeling of swirling flow with combustible gases. A literature survey about works related to numerical and experimental investigations on solid-fuel ramjet as well as using swirling flow and different numerical approaches has been provided. An overview of turbulence modeling of swirling flow and the behavior of turbulence at streamline curvature and system rotation are presented. A new and simple curvature/correction factor is proposed in order to reduce the programming complexity of SST-CC turbulence model. Finally, numerical and experimental investigations on the impact of swirling flow on SFRJ have been carried out. For that regard, a multi-physics coupling code is developed to solve the problems of multi-physics coupling of fluid mechanics, solid pyrolysis, heat transfer, thermodynamics, and chemical kinetics. The connected-pipe test facility is used to carry out the experiments. The results showed a positive impact of swirling flow on SFRJ along with, three correlations are proposed.

Composite Nafion 117-TMSP membrane for Fe-Cr redox flow battery applications

Energy Technology Data Exchange (ETDEWEB)

Haryadi, E-mail: haryadi@polban.ac.id [Department of Chemical Engineering, PoliteknikNegeri Bandung Indonesia (Indonesia); Gunawan, Y. B.; Harjogi, D. [Department of Electronic Engineering, PoliteknikNegeri Bandung Indonesia (Indonesia); Mursid, S. P. [Department of Energy Engineering, PoliteknikNegeri Bandung. Jl. GegerkalongHilir, Ds, Ciwaruga, Bandung, West Java Indonesia (Indonesia)

2016-04-19

The modification of Nafion 117 - TMSP (trimethoxysylilprophanthiol) composite membrane has been conducted by in-situ sol-gel method followed by characterization of structural and properties of material using spectroscopic techniques. The performance of composite membrane has then been examined in the single stack module of Fe-Cr Redox Flow Battery. It was found that the introduction of silica from TMSP through sol-gel process within the Nafion 117 membrane produced composite membrane that has slightly higher proton conductivity values as compared to the pristine of Nafion 117 membrane observed by electrochemical impedance spectroscopy. The degree of swelling of water in the composite membrane demonstrated greatly reduced than a pristine Nafion 117 signifying low water cross over. The SEM-EDX measurements indicated that there was no phase separation occurred suggesting that silica nanoparticles are distributed homogeneously within the composite membrane. The composite membrane used as separator in the system of Fe-Cr Redox Flow Battery revealed no cross mixing (crossover) occurred between anolyte and catholyte in the system as observed from the total voltage measurements that closed to the theoretical value. The battery efficiency generally increased as the volume of the electrolytes enlarged.

Composite Nafion 117-TMSP membrane for Fe-Cr redox flow battery applications

International Nuclear Information System (INIS)

Haryadi; Gunawan, Y. B.; Harjogi, D.; Mursid, S. P.

2016-01-01

The modification of Nafion 117 - TMSP (trimethoxysylilprophanthiol) composite membrane has been conducted by in-situ sol-gel method followed by characterization of structural and properties of material using spectroscopic techniques. The performance of composite membrane has then been examined in the single stack module of Fe-Cr Redox Flow Battery. It was found that the introduction of silica from TMSP through sol-gel process within the Nafion 117 membrane produced composite membrane that has slightly higher proton conductivity values as compared to the pristine of Nafion 117 membrane observed by electrochemical impedance spectroscopy. The degree of swelling of water in the composite membrane demonstrated greatly reduced than a pristine Nafion 117 signifying low water cross over. The SEM-EDX measurements indicated that there was no phase separation occurred suggesting that silica nanoparticles are distributed homogeneously within the composite membrane. The composite membrane used as separator in the system of Fe-Cr Redox Flow Battery revealed no cross mixing (crossover) occurred between anolyte and catholyte in the system as observed from the total voltage measurements that closed to the theoretical value. The battery efficiency generally increased as the volume of the electrolytes enlarged.

Fuel behaviour in the case of severe accidents and potential ATF designs. Fuel Behavior in Severe Accidents and Potential Accident Tolerance Fuel Designs

International Nuclear Information System (INIS)

Cheng, Bo

2013-01-01

This presentation reviews the conditions of fuel rods under severe loss of coolant conditions, approaches that may increase coping time for plant operators to recover, requirements of advanced fuel cladding to increase tolerance in accident conditions, potential candidate alloys for accident-tolerant fuel cladding and a novel design of molybdenum (Mo) -based fuel cladding. The current Zr-alloy fuel cladding will lose all its mechanical strength at 750-800 deg. C, and will react rapidly with high-pressure steam, producing significant hydrogen and exothermic heat at 700-1000 deg. C. The metallurgical properties of Zr make it unlikely that modifications of the Zr-alloy will improve the behaviour of Zr-alloys at temperatures relevant to severe accidents. The Mo-based fuel cladding is designed to (1) maintain fuel rod integrity, and reduce the release rate of hydrogen and exothermic heat in accident conditions at 1200-1500 deg. C. The EPRI research has thus far completed the design concepts, demonstration of feasibility of producing very thin wall (0.2 mm) Mo tubes. The feasibility of depositing a protective coating using various techniques has also been demonstrated. Demonstration of forming composite Mo-based cladding via mechanical reduction has been planned

The REACT Project

DEFF Research Database (Denmark)

Bloch, Paul; Blystad, Astrid; Byskov, Jens

decisions; and the provision of leadership and the enforcement of conditions. REACT - "REsponse to ACcountable priority setting for Trust in health systems" is an EU-funded five-year intervention study, which started in 2006 testing the application and effects of the AFR approach in one district each...... selected disease and programme interventions and services, within general care and on health systems management. Efforts to improve health sector performance have not yet been satisfactory, and adequate and sustainable improvements in health outcomes have not been shown. Priority setting in health systems...... improvements to health systems performance discussed....

Behavior of molybdenum in mixed-oxide fuel

International Nuclear Information System (INIS)

Giacchetti, G.; Sari, C.

1976-01-01

Metallic molybdenum, Mo--Ru--Rh--Pd alloys, barium, zirconium, and tungsten were added to uranium and uranium--plutonium oxides by coprecipitation and mechanical mixture techniques. This material was treated in a thermal gradient similar to that existing in fuel during irradiation to study the behavior of molybdenum in an oxide matrix as a function of the O/(U + Pu) ratio and some added elements. Result of ceramographic and microprobe analysis shows that when the overall O/(U + Pu) ratio is less than 2, molybdenum and Mo--Ru--Rh--Pd alloy inclusions are present in the uranium--plutonium oxide matrix. If the O/(U + Pu) ratio is greater than 2, molybdenum oxidizes to MoO 2 , which is gaseous at a temperature approximately 1000 0 C. Molybdenum oxide vapor reacts with barium oxide and forms a compound that exists as a liquid phase in the columnar grain region. Molybdenum oxide also reacts with tungsten oxide (tungsten is often present as an impurity in the fuel) and forms a compound that contains approximately 40 wt percent of actinide metals. The apparent solubility of molybdenum in uranium and uranium--plutonium oxides, determined by electron microprobe, was found to be less than 250 ppM both for hypo- and hyperstoichiometric fuels

A constitutive theory of reacting electrolyte mixtures

Science.gov (United States)

Costa Reis, Martina; Wang, Yongqi; Bono Maurizio Sacchi Bassi, Adalberto

2013-11-01

A constitutive theory of reacting electrolyte mixtures is formulated. The intermolecular interactions among the constituents of the mixture are accounted for through additional freedom degrees to each constituent of the mixture. Balance equations for polar reacting continuum mixtures are accordingly formulated and a proper set of constitutive equations is derived with basis in the Müller-Liu formulation of the second law of thermodynamics. Moreover, the non-equilibrium and equilibrium responses of the reacting mixture are investigated in detail by emphasizing the inner and reactive structures of the medium. From the balance laws and constitutive relations, the effects of molecular structure of constituents upon the fluid flow are studied. It is also demonstrated that the local thermodynamic equilibrium state can be reached without imposing that the set of independent constitutive variables is time independent, neither spatially homogeneous nor null. The resulting constitutive relations presented throughout this work are of relevance to many practical applications, such as swelling of clays, developing of bio and polymeric membranes, and use of electrorheological fluids in industrial processes. The first author acknowledges financial support from National Counsel of Technological and Scientific Development (CNPq) and German Academic Exchange Service (DAAD).

Three-dimensional reacting shock–bubble interaction

NARCIS (Netherlands)

Diegelmann, Felix; Hickel, S.; Adams, Nikolaus A.

2017-01-01

We investigate a reacting shock–bubble interaction through three-dimensional numerical simulations with detailed chemistry. The convex shape of the bubble focuses the shock and generates regions of high pressure and temperature, which are sufficient to ignite the diluted stoichiometric

Atomization of JP-10/B4C gelled slurry fuel

OpenAIRE

Guglielmi, John David

1992-01-01

The atomization of a gelled boron slurry fuel using two commercially available airblast atomizers was studied at atmospheric pressure in non-reacting flow. The atomization of water was also characterized for comparison. Each atomizer was operated at two different liquid mass flow rates and several air/ fuel ratios. Drop size distribution was measured using a Malvern 2600 HSD Laser Diffraction Particle Sizer, Drop sizes acceptable for use in ramjet combustors could be obtained f...

Fuel Flexible, Low Emission Catalytic Combustor for Opportunity Fuel Applications

Energy Technology Data Exchange (ETDEWEB)

Eteman, Shahrokh

2013-06-30

Limited fuel resources, increasing energy demand and stringent emission regulations are drivers to evaluate process off-gases or process waste streams as fuels for power generation. Often these process waste streams have low energy content and/or highly reactive components. Operability of low energy content fuels in gas turbines leads to issues such as unstable and incomplete combustion. On the other hand, fuels containing higher-order hydrocarbons lead to flashback and auto-ignition issues. Due to above reasons, these fuels cannot be used directly without modifications or efficiency penalties in gas turbine engines. To enable the use of these wide variety of fuels in gas turbine engines a rich catalytic lean burn (RCL®) combustion system was developed and tested in a subscale high pressure (10 atm.) rig. The RCL® injector provided stability and extended turndown to low Btu fuels due to catalytic pre-reaction. Previous work has shown promise with fuels such as blast furnace gas (BFG) with LHV of 85 Btu/ft3 successfully combusted. This program extends on this work by further modifying the combustor to achieve greater catalytic stability enhancement. Fuels containing low energy content such as weak natural gas with a Lower Heating Value (LHV) of 6.5 MJ/m3 (180 Btu/ft3 to natural gas fuels containing higher hydrocarbon (e.g ethane) with LHV of 37.6 MJ/m3 (1010 Btu/ft3) were demonstrated with improved combustion stability; an extended turndown (defined as the difference between catalytic and non-catalytic lean blow out) of greater than 250oF was achieved with CO and NOx emissions lower than 5 ppm corrected to 15% O2. In addition, for highly reactive fuels the catalytic region preferentially pre-reacted the higher order hydrocarbons with no events of flashback or auto-ignition allowing a stable and safe operation with low NOx and CO emissions.

Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

Science.gov (United States)

Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

2018-04-17

The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

Science.gov (United States)

Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

2017-05-23

The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

Characterization of forced response of density stratified reacting wake

Science.gov (United States)

Pawar, Samadhan A.; Sujith, Raman I.; Emerson, Benjamin; Lieuwen, Tim

2018-02-01

The hydrodynamic stability of a reacting wake depends primarily on the density ratio [i.e., ratio of unburnt gas density (ρu) to burnt gas density (ρb)] of the flow across the wake. The variation of the density ratio from high to low value, keeping ρ u / ρ b > 1 , transitions dynamical characteristics of the reacting wake from a linearly globally stable (or convectively unstable) to a globally unstable mode. In this paper, we propose a framework to analyze the effect of harmonic forcing on the deterministic and synchronization characteristics of reacting wakes. Using the recurrence quantification analysis of the forced wake response, we show that the deterministic behaviour of the reacting wake increases as the amplitude of forcing is increased. Furthermore, for different density ratios, we found that the synchronization of the top and bottom branches of the wake with the forcing signal is dependent on whether the mean frequency of the natural oscillations of the wake (fn) is lesser or greater than the frequency of external forcing (ff). We notice that the response of both branches (top and bottom) of the reacting wake to the external forcing is asymmetric and symmetric for the low and high density ratios, respectively. Furthermore, we characterize the phase-locking behaviour between the top and bottom branches of the wake for different values of density ratios. We observe that an increase in the density ratio results in a gradual decrease in the relative phase angle between the top and bottom branches of the wake, which leads to a change in the vortex shedding pattern from a sinuous (anti-phase) to a varicose (in-phase) mode of the oscillations.

Combining discrete equations method and upwind downwind-controlled splitting for non-reacting and reacting two-fluid computations

International Nuclear Information System (INIS)

Tang, K.

2012-01-01

When numerically investigating multiphase phenomena during severe accidents in a reactor system, characteristic lengths of the multi-fluid zone (non-reactive and reactive) are found to be much smaller than the volume of the reactor containment, which makes the direct modeling of the configuration hardly achievable. Alternatively, we propose to consider the physical multiphase mixture zone as an infinitely thin interface. Then, the reactive Riemann solver is inserted into the Reactive Discrete Equations Method (RDEM) to compute high speed combustion waves represented by discontinuous interfaces. An anti-diffusive approach is also coupled with RDEM to accurately simulate reactive interfaces. Increased robustness and efficiency when computing both multiphase interfaces and reacting flows are achieved thanks to an original upwind downwind-controlled splitting method (UDCS). UDCS is capable of accurately solving interfaces on multi-dimensional unstructured meshes, including reacting fronts for both deflagration and detonation configurations. (author)

Sentinel Gap basalt reacted in a temperature gradient

International Nuclear Information System (INIS)

Charles, R.W.; Bayhurst, G.K.

1983-01-01

Six basalt prisms were reacted in a controlled temperature gradient hydrothermal circulation system for two months. The prisms were centered at 72, 119, 161, 209, 270, and 310 0 C. Total pressure was 1/3 kbar. All prisms showed large weight loss: 5.5% to 14.9%. The matrix micropegmatite and natural nontronitic alteration reacted readily to clays at all temperatures. The first four prisms were coated with a calcium smectite, and the last two prisms were covered with discrete patches of potassium-rich phengite and alkali feldspar. The results indicated that clays may act as adsorbers of various ions

Sentinel Gap basalt reacted in a temperature gradient

International Nuclear Information System (INIS)

Charles, R.W.; Bayhurst, G.K.

1982-01-01

Six basalt prisms were reacted in a controlled temperature gradient hydrothermal circulation system for two months. The prisms are centered at 72, 119, 161, 209, 270, and 310 0 C. Total pressure is 1/3 kbar. All prisms show large weight loss: 5.5% to 14.9%. The matrix micropegmatite and natural nontronitic alteration readily reacts to clays at all temperatures. The first four prisms are coated with a Ca-smectite while the last two prisms are covered with discrete patches of K rich phengite and alkali feldspar. The clays may act as adsorbers of various ions

Bioelectricity Generation in a Microbial Fuel Cell with a Self-Sustainable Photocathode

Directory of Open Access Journals (Sweden)

Ting Liu

2015-01-01

Full Text Available This study aims to construct an MFC with a photosynthetic algae cathode, which is maintained by self-capturing CO2 released from the anode and utilizing solar energy as energy input. With this system, a maximum power density of 187 mW/m2 is generated when the anode off gas is piped into the catholyte under light illumination, which is higher than that of 21 mW/m2 in the dark, demonstrating the vital contribution of the algal photosynthesis. However, an unexpected maximum power density of 146 mW/m2 is achieved when the anode off gas is not piped into the catholyte. Measurements of cathodic microenvironments reveal that algal photosynthesis still takes place for oxygen production under this condition, suggesting the occurrence of CO2 crossover from anode to cathode through the Nafion membrane. The results of this study provide further understanding of the algae-based microbial carbon capture cell (MCC and are helpful in improving MCC performance.

Degradation of EBR-II driver fuel during wet storage

International Nuclear Information System (INIS)

Pahl, R. G.

2000-01-01

Characterization data are reported for sodium bonded EBR-II reactor fuel which had been stored underwater in containers since the 1981--1982 timeframe. Ten stainless steel storage containers, which had leaked water during storage due to improper sealing, were retrieved from the ICPP-603 storage basin at the Idaho National Engineering and Environmental Laboratory (INEEL) in Idaho. In the container chosen for detailed destructive analysis, the stainless steel cladding on the uranium alloy fuel had ruptured and fuel oxide sludge filled the bottom of the container. Headspace gas sampling determined that greater than 99% hydrogen was present. Cesium 137, which had leached out of the fuel during the aqueous corrosion process, dominated the radionuclide source term of the water. The metallic sodium from the fuel element bond had reacted with the water, forming a concentrated caustic solution of NaOH

Enhancing instruction in Fuels and Combustion Laboratory via a developed computer-assisted program for establishing efficient coal-diesel oil mixture (CDOM) fuel proportions

Energy Technology Data Exchange (ETDEWEB)

Maglaya, A.B. [La Salle University, Manila (Philippines). Dept. of Mechanical Engineering

2004-07-01

This paper discusses the relevance of digital computation in Fuels and Combustion Laboratory experiments used by the senior students of the Department of Mechanical Engineering, De La Salle University-Manila, Philippines. One of the students' experiments involved the determination of the most efficient CDOM fuel proportion as alternative fuel to diesel oil for steam generators and other industrial applications. Theoretical calculations show that it requires tedious and repetitive computations. A computer-assisted program was developed to lessen the time-consuming activities. The formulation of algorithms were based on the system of equations of the heat interaction between the CDOM fuel, combustion air and products of combustion and by applying the principles of mass and energy equations (or the First Law of Thermodynamics) for reacting systems were utilized. The developed computer-assisted program output verified alternative fuel selected through actual experimentation.

ReACT!: An Interactive Educational Tool for AI Planning for Robotics

Science.gov (United States)

Dogmus, Zeynep; Erdem, Esra; Patogulu, Volkan

2015-01-01

This paper presents ReAct!, an interactive educational tool for artificial intelligence (AI) planning for robotics. ReAct! enables students to describe robots' actions and change in dynamic domains without first having to know about the syntactic and semantic details of the underlying formalism, and to solve planning problems using…

Method of Generating Hydrocarbon Reagents from Diesel, Natural Gas and Other Logistical Fuels

Science.gov (United States)

Herling, Darrell R [Richland, WA; Aardahl, Chris L [Richland, WA; Rozmiarek, Robert T [Middleton, WI; Rappe, Kenneth G [Richland, WA; Wang, Yong [Richland, WA; Holladay, Jamelyn D [Kennewick, WA

2008-10-14

The present invention provides a process for producing reagents for a chemical reaction by introducing a fuel containing hydrocarbons into a flash distillation process wherein the fuel is separated into a first component having a lower average molecular weight and a second component having a higher average molecular weight. The first component is then reformed to produce synthesis gas wherein the synthesis gas is reacted catalytically to produce the desire reagent.

Firing the furnace? An econometric analysis of utilities' fuel choice

International Nuclear Information System (INIS)

Tauchmann, H.

2006-01-01

This paper attempts to estimate how the fuel mix of German electricity producers does react to fuel price changes. The empirical analysis is based on panel data (1968-1998) of major utilities. Two different aspects of fuel choice are distinguished: at the one hand, the construction of usually fuel-specific capacities for electric power generation, i.e. investment decisions that determine the fuel mix in the long run; at the other, fuel use conditional on existing generation capacities, i.e. short-run inter-fuel substitution. According to the results from panel unit root tests, both the econometric models which describe these two aspects are specified in changes rather than levels. The partly discrete nature of investment decisions is taken into account, by constructing a discrete model of capacity adjustment. Our estimation results suggest that the fuel mix of electric utilities is price inelastic either if long-term investment or short-term inter-fuel substitution is considered. Finally, the empirical results are used to predict the potential impacts of CO 2 emissions trading on fuel choice in the German electric power industry

Firing the furnace? An econometric analysis of utilities' fuel choice

International Nuclear Information System (INIS)

Tauchmann, H.

2006-01-01

This paper attempts to estimate how the fuel mix of German electricity producers does react to fuel price changes. The empirical analysis is based on panel data (1968-1998) of major utilities. Two different aspects of fuel choice are distinguished: at the one hand, the construction of usually fuel-specific capacities for electric power generation, i.e. investment decisions that determine the fuel mix in the long run; at the other, fuel use conditional on existing generation capacities, i.e. short-run inter-fuel substitution. According to the results from panel unit root tests, both the econometric models which describe these two aspects are specified in changes rather than levels. The partly discrete nature of investment decisions is taken into account, by constructing a discrete model of capacity adjustment. Our estimation results suggest that the fuel mix of electric utilities is price inelastic either if long-term investment or short-term inter-fuel substitution is considered. Finally, the empirical results are used to predict the potential impacts of CO 2 emissions trading on fuel choice in the German electric power industry. (Author)

Continuum-Kinetic Hybrid Framework for Chemically Reacting Flows

Data.gov (United States)

National Aeronautics and Space Administration — Predictive modeling of chemically reacting flows is essential for the design and optimization of future hypersonic vehicles. During atmospheric re-entry, complex...

The effect of the fuel rod friction force to the fuel assembly lateral mechanical characteristics

International Nuclear Information System (INIS)

Ha, Dong Geun; Jeon, Sang Youn; Suh, Jung Min

2012-01-01

The Fuel Assembly (FA) for light water reactor consists of hundreds of fuel rods, guide tubes, spacer grids, top/bottom nozzles. The guide tubes transmit vertical loads between the top and bottom nozzles, position the fuel rod support grids vertically, react the loads from the fuel rods that are applied to the grids, and provide some of the lateral load capability for the overall fuel assembly. The guide tubes are the structural members of the skeleton assembly. And the spacer grids maintain the fuel rod array by providing positive lateral restraint to the fuel rod but only frictional restraint in the axial direction. Figure 1 shows the outline of skeleton, FA and the location of guide tubes in the view of cross section. 17x17 FA has 24 guide tubes and one instrumentation tube. When the FA is in reactor, the lateral stiffness is one of very important factors from the view point of in reactor integrity of fuel assembly such as guarantee of the cool able geometry, the control rod insertion etc. The lateral stiffness of FA is mainly determined by skeleton lateral stiffness. And the fuel rods loaded in the spacer grids reinforce the FA lateral stiffness. Generally, fuel rods and spacer grids create the nonlinear friction force between fuel rod tube and grid spring/dimple against external lateral force of FA. Thus, it is necessary to study the contribution of the fuel rods friction force to the FA lateral stiffness. So, this paper is to show how much amount of the fuel rod grid interaction contributes to the FA lateral stiffness based on the test results

3D Graphene-Ni Foam as an Advanced Electrode for High-Performance Nonaqueous Redox Flow Batteries.

Science.gov (United States)

Lee, Kyubin; Lee, Jungkuk; Kwon, Kyoung Woo; Park, Min-Sik; Hwang, Jin-Ha; Kim, Ki Jae

2017-07-12

Electrodes composed of multilayered graphene grown on a metal foam (GMF) were prepared by directly growing multilayer graphene sheets on a three-dimensional (3D) Ni-foam substrate via a self-catalyzing chemical vapor deposition process. The multilayer graphene sheets are successfully grown on the Ni-foam substrate surface, maintaining the unique 3D macroporous structure of the Ni foam. The potential use of GMF electrodes in nonaqueous redox flow batteries (RFBs) is carefully examined using [Co(bpy) 3 ] +/2+ and [Fe(bpy) 3 ] 2+/3+ redox couples. The GMF electrodes display a much improved electrochemical activity and enhanced kinetics toward the [Co(bpy) 3 ] +/2+ (anolyte) and [Fe(bpy) 3 ] 2+/3+ (catholyte) redox couples, compared with the bare Ni metal foam electrodes, suggesting that the 2D graphene sheets having lots of interdomain defects provide sufficient reaction sites and secure electric-conduction pathways. Consequently, a nonaqueous RFB cell assembled with GMF electrodes exhibits high Coulombic and voltage efficiencies of 87.2 and 90.9%, respectively, at the first cycle. This performance can be maintained up to the 50th cycle without significant efficiency loss. Moreover, the importance of a rational electrode design for improving electrochemical performance is addressed.

Micro-Solid Oxide Fuel Cell: A multi-fuel approach for portable applications

International Nuclear Information System (INIS)

Patil, Tarkeshwar C.; Duttagupta, Siddhartha P.

2016-01-01

Highlights: • We report the oxygen ion transport properties at the electrode–electrolyte interface (EEI) of the SOFC for the first time. • This ion transport plays a key role in the overall performance of SOFCs with different fuels. • The GIIB mechanism is also studied for the first time. • GIIB is assumed to be the prime reason for low power density and ion conductivity at the EEI when using hydrocarbon fuels. • Due to its scalability, a fuel cell can serve as a power source for on-chip applications and all portable equipment. - Abstract: The impact of oxygen ion transport at the electrolyte–electrode interface of a micro-solid oxide fuel cell using different fuels is investigated. Model validation is performed to verify the results versus the reported values. Furthermore, as the hydrogen-to-carbon ratio decreases, the diffusivity of the oxygen ion increases. This increase in diffusivity is observed because the number of hydrogen atoms available as the reacting species increases in fuels with lower hydrogen-to-carbon ratios. The oxygen ion conductivity and output power density decrease as the hydrogen-to-carbon ratio of the fuels decreases. The reason behind this impact is the formation of a gas-induced ion barrier at the electrode–electrolyte interface by the CO_2 molecules formed during the reaction at the interface, thus blocking the flow of oxygen ions. As the oxygen ions become blocked, the output current contribution from the reaction also decreases and thereby affects the overall performance of the micro-solid oxide fuel cell. The experimental verification confirms this because of a significant decrease in the output power density. Furthermore, as per the application in portable devices, the appropriate choice of fuel can be chosen so that the micro-solid oxide fuel cell operates at the maximum power density.

Modeling reacting gases and aftertreatment devices for internal combustion engines

Science.gov (United States)

Depcik, Christopher David

As more emphasis is placed worldwide on reducing greenhouse gas emissions, automobile manufacturers have to create more efficient engines. Simultaneously, legislative agencies want these engines to produce fewer problematic emissions such as nitrogen oxides and particulate matter. In response, newer combustion methods, like homogeneous charge compression ignition and fuel cells, are being researched alongside the old standard of efficiency, the compression ignition or diesel engine. These newer technologies present a number of benefits but still have significant challenges to overcome. As a result, renewed interest has risen in making diesel engines cleaner. The key to cleaning up the diesel engine is the placement of aftertreatment devices in the exhaust. These devices have shown great potential in reducing emission levels below regulatory levels while still allowing for increased fuel economy versus a gasoline engine. However, these devices are subject to many flow control issues. While experimental evaluation of these devices helps to understand these issues better, it is impossible to solve the problem through experimentation alone because of time and cost constraints. Because of this, accurate models are needed in conjunction with the experimental work. In this dissertation, the author examines the entire exhaust system including reacting gas dynamics and aftertreatment devices, and develops a complete numerical model for it. The author begins by analyzing the current one-dimensional gas-dynamics simulation models used for internal combustion engine simulations. It appears that more accurate and faster numerical method is available, in particular, those developed in aeronautical engineering, and the author successfully implements one for the exhaust system. The author then develops a comprehensive literature search to better understand the aftertreatment devices. A number of these devices require a secondary injection of fuel or reductant in the exhaust stream

Study of Transport and Micro-structural properties of Magnesium Di-Boride Strand under react and bend mode and bend and react mode

International Nuclear Information System (INIS)

Kundu, Ananya; Kumar Das, Subrat; Bano, Anees; Pradhan, Subrata

2017-01-01

I-V characterization of commercial multi-filamentary Magnesium Di-Boride (MgB 2 ) wire of diameter 0.83 mm were studied in Cryocooler at self-field I-V characterization system under both react and bend mode and bend and react mode for a range of temperature 6 K - 25 K. This study is of practical technical relevance where the heat treatment of the superconducting wire makes the wire less flexible for winding in magnet and in other applications. In the present work the bending diameter was varied from 40 mm to 20 mm and for each case critical current (I c ) of the strand is measured for above range of temperature. A customized sample holder is fabricated and thermally anchored with the 2 nd cold stage of Cryocooler. It is observed from the measurement that the strand is more susceptible to degradation for react and bend cases. The transport measurement of the strand was accompanied by SEM analyses of bend samples. Also the tensile strength of the raw strands and the heat treated strands were carried out at room temperature in Universal Testing Machine (UTM) to have an estimate about the limiting winding tension value during magnet fabrication. (paper)

Demonstration of Hybrid DSMC-CFD Capability for Nonequilibrium Reacting Flow

Science.gov (United States)

2018-02-09

AFRL-RV-PS- TR-2018-0056 AFRL-RV-PS- TR-2018-0056 DEMONSTRATION OF HYBRID DSMC-CFD CAPABILITY FOR NONEQUILIBRIUM REACTING FLOW Thomas E...4. TITLE AND SUBTITLE Demonstration of Hybrid DSMC-CFD Capability for Nonequilibrium Reacting Flow 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9453-17-1...simulation codes. The models are based on new ab-intio rate data obtained using state -of-the-art potential energy surfaces for air species. A probability

Studies of irradiated zircaloy fuel sheathing using XPS

Energy Technology Data Exchange (ETDEWEB)

Chan, P K; Irving, K G [Atomic Energy of Canada Ltd., Chalk River, ON (Canada); Hocking, W H; Duclos, A M; Gerwing, A F [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

1996-12-31

The preliminary results reported here support the hypothesis that CANLUB graphite coating reduces the rate at which oxygen can react with fuel sheathing. X-ray photoelectron spectroscopic (XPS) characterization of Zircaloy sheathing obtained from extended-burnup Bruce-type elements (BDL-406-XY (555 MW.h/kgU) and BDL-406-AAH (731 MW.h/kgU)) irradiated in NRU indicates that CANLUB may reduce fuel sheath oxidation, and hence that fission-liberated oxygen may remain in the fuel. Chemical shifts in the Zr 3d spectra suggest that a stoichiometric (ZrO{sub 2}) oxide film was formed only on Zircaloy in direct contact with fuel. Particulate fuel adhering to the sheath was also determined to be systematically more oxidized on surfaces with CANLUB than on those without it. The unique association of tin on sheathing specimens with the non-CANLUB-coated specimens might also suggest that the tin had segregated from the sheathing. It must be emphasized that further experiments are required to better define the effect of CANLUB on fuel oxidation. (author). 14 refs., 1 tab., 3 figs.

Studies of irradiated zircaloy fuel sheathing using XPS

International Nuclear Information System (INIS)

Chan, P.K.; Irving, K.G.; Hocking, W.H.; Duclos, A.M.; Gerwing, A.F.

1995-01-01

The preliminary results reported here support the hypothesis that CANLUB graphite coating reduces the rate at which oxygen can react with fuel sheathing. X-ray photoelectron spectroscopic (XPS) characterization of Zircaloy sheathing obtained from extended-burnup Bruce-type elements (BDL-406-XY (555 MW.h/kgU) and BDL-406-AAH (731 MW.h/kgU)) irradiated in NRU indicates that CANLUB may reduce fuel sheath oxidation, and hence that fission-liberated oxygen may remain in the fuel. Chemical shifts in the Zr 3d spectra suggest that a stoichiometric (ZrO 2 ) oxide film was formed only on Zircaloy in direct contact with fuel. Particulate fuel adhering to the sheath was also determined to be systematically more oxidized on surfaces with CANLUB than on those without it. The unique association of tin on sheathing specimens with the non-CANLUB-coated specimens might also suggest that the tin had segregated from the sheathing. It must be emphasized that further experiments are required to better define the effect of CANLUB on fuel oxidation. (author). 14 refs., 1 tab., 3 figs

PENGARUH JENIS ANODA PADA PROSES PEMULIHAN LOGAM NIKEL DARI TIRUAN AIR LIMBAH ELECTROPLATING MENGGUNAKAN SEL ELEKTRODEPOSISI

Directory of Open Access Journals (Sweden)

Djaenudin Dhaenudin

2013-11-01

Full Text Available EFFECT OF ANODES TYPES ON NICKEL RECOVERY FROM SYNTHETIC ELECTROPLATING WASTE ELECTRODEPOSITION CELLS. A study concerning the recovery of nickel from electroplating wastewater artificial solution. The study was conducted with a batch system using electrodeposition cell consisting of two spaces separated by water hyacinth leaf, copper cathode plate, H2SO4 solution anolyte, catholyte solution of NiSO4 plus NaCl supporting electrolyte and anode varied. Electrodeposition performed at the direct current of 5V power for 4 hours each run. The research objective was to obtain the best anode in nickel electrodeposition process of electroplating waste artificial solution. Graphite, stainless steel type AISI 316 and the lead were used as a variation of the anode. Concentration of nickel in the catholyte at baseline 2200 mg/L. The results showed that the anode was a graphite anode with best value decreased by 72.44% nickel concentration, deposition of nickel on the cathode of 0.188 grams and specific energy values ​​of 6.1625 kWh/kg.nickel.   Telah dilakukan penelitian tentang pemulihan logam nikel dari larutan tiruan air limbah electroplating. Penelitian dilakukan dengan sistem batch menggunakan sel elektrodeposisi yang terdiri dari dua ruang yang dipisahkan dengan daun eceng gondok, katoda pelat tembaga, anolit larutan H2SO4, katolit larutan NiSO4 ditambah elektrolit pendukung larutan NaCl dan anoda divariasikan. Elektrodeposisi dilakukan pada listrik searah sebesar 5V selama 4 jam setiap tempuhan. Tujuan penelitian adalah memperoleh anoda terbaik pada proses elektrodeposisi nikel dari larutan tiruan limbah electroplating. Grafit, Stainless Steel  tipe AISI 316 dan timbal digunakan sebagai variasi jenis anoda. Konsentrasi nikel dalam katolit pada awal penelitian 2200 mg/L. Hasil penelitian menunjukkan bahwa anoda grafit merupakan anoda yang paling baik dengan nilai penurunan konsentrasi nikel sebesar 72,44%, deposisi nikel di katoda sebesar 0

An experimental study on downstream of the transition of the chemically reacting liquid round free jet

International Nuclear Information System (INIS)

Hong, S.D.; Sugii, Y.; Okamoto, K.; Madarame, H.

2002-01-01

An experimental study was conducted on the chemically reacting liquid round free jet, Laser Induced Fluorescence (LIF) technique was adopted to evaluate the diffusion width of the jet into liquid streams. In the fluid engineering, it is very important to evaluate the characteristics of reacting jet for the safety of the nuclear reactor. In this study, the jet profile of downstream region far away from the transition point was evaluated, providing comparisons between reacting and non-reacting jet case. The concentration of the jet solution was varied from 0.01 mol/L to 0.5 mol/L in reacting cases. In the downstream far away from the transition point, the jet profiles between reacting cases and non-reacting cases were visualized quite different. It was concluded that the chemical reaction affects the momentum diffusion of the jet in the downstream region. (author)

Energy conversion using hydrogen PEM fuel cells

International Nuclear Information System (INIS)

Stoenescu, D.; Patularu, L.; Culcer, M.; Lazar, R.; Mirica, D.; Varlam, M.; Carcadea, E.; Stefanescu, I.

2004-01-01

It is well known that hydrogen is the most promising solution of future energy, both for long and medium term strategies. Hydrogen can be produced using many primary sources (naphthalene, natural gas, methanol, coal, biomass), solar cells power, etc. It can be burned or chemically reacted having a high yield of energy conversion and is a non-polluted fuel. This paper presents the results obtained by ICSI Rm. Valcea in an experimental-demonstrative conversion energy system consisting in a catalytic methane reforming plant for hydrogen production and three synthesis gas purification units in order to get pure hydrogen with a CO level lower than 10 ppm that finally feeds a hydrogen fuel stock. (authors)

Improving Resilience to Emergencies through Advanced Cyber Technologies: the I-REACT project

Directory of Open Access Journals (Sweden)

Claudia Maltoni

2017-08-01

be equipped with essential tools for early warning and response. At the same time, private companies could leverage specific set of I-REACT components to improve their business, when linked to disaster management. Overall, I-REACT aims to be a European-wide contribution to build more secure and resilient societies to disasters.

KEEFEKTIFAN STRATEGI REACT DITINJAU DARI PRESTASI BELAJAR, KEMAMPUAN PENYELESAIAN MASALAH, KONEKSI MATEMATIS, SELF EFFICACY

Directory of Open Access Journals (Sweden)

Runtyani Irjayanti Putri

2015-11-01

Full Text Available Penelitian ini bertujuan untuk: (1 mendeskripsikan keefektifan strategi pembelajaran REACT pada pembelajaran turunan fungsi ditinjau dari prestasi belajar matematika, kemampuan penyelesaian masalah matematis, kemampuan koneksi matematis, dan Self efficacy siswa SMA Negeri 4 Magelang, (2 menentukan strategi pembelajaran yang lebih efektif diantara strategi REACT dan pembelajaran konvensional pada pembelajaran turunan fungsi ditinjau dari aspek prestasi belajar matematika, kemampuan penyelesaian masalah matematis, kemampuan koneksi matematis, dan Self efficacy siswa SMA Negeri 4 Magelang. Penelitian ini adalah penelitian quasi experiment. Teknik pengumpulan data yang digunakan adalah teknik tes dan nontes. Teknik analisis data yang digunakan adalah uji one sample t-test, uji T2 Hotelling’s, dan uji t-Bonferroni. Hasil penelitian menunjukkan bahwa: (1 strategi pembelajaran REACT efektif pada pembelajaran turunan fungsi ditinjau dari prestasi belajar matematika, kemampuan penyelesaian masalah matematis, kemampuan koneksi matematis, dan Self efficacy siswa SMA Negeri 4 Magelang, dan (2 strategi pembelajaran REACT lebih efektif daripada pembelajaran konvensional pada pembelajaran turunan fungsi ditinjau dari aspek prestasi belajar matematika, kemampuan penyelesaian masalah matematis, kemampuan koneksi matematis, dan Self efficacy siswa SMA Negeri 4 Magelang. Kata Kunci: strategi REACT, prestasi belajar, kemampuan penyelesaian masalah matematis, kemampuan koneksi matematis, dan Self efficacy siswa SMA   THE EFFECTIVENESS OF REACT STRATEGY VIEWED FROM LEARNING ACHIEVEMENT, PROBLEM SOLVING ABILITY, MATHEMATICAL CONNECTION, SELF EFFICACY Abstract The aims of this study are to: (1 to describe the effectiveness of the REACT strategy viewed from Mathematics Learning Achievement, Mathematics Problem Solving Ability, Mathematics Connection Ability, and Student Self efficacy of State Senior High School 4 Magelang Students, and (2 determine a more effective

Process to separate alkali metal salts from alkali metal reacted hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Gordon, John Howard; Alvare, Javier; Larsen, Dennis; Killpack, Jeff

2017-06-27

A process to facilitate gravimetric separation of alkali metal salts, such as alkali metal sulfides and polysulfides, from alkali metal reacted hydrocarbons. The disclosed process is part of a method of upgrading a hydrocarbon feedstock by removing heteroatoms and/or one or more heavy metals from the hydrocarbon feedstock composition. This method reacts the oil feedstock with an alkali metal and an upgradant hydrocarbon. The alkali metal reacts with a portion of the heteroatoms and/or one or more heavy metals to form an inorganic phase containing alkali metal salts and reduced heavy metals, and an upgraded hydrocarbon feedstock. The inorganic phase may be gravimetrically separated from the upgraded hydrocarbon feedstock after mixing at a temperature between about 350.degree. C. to 400.degree. C. for a time period between about 15 minutes and 2 hours.

Prediction of reacting atoms for the major biotransformation reactions of organic xenobiotics.

Science.gov (United States)

Rudik, Anastasia V; Dmitriev, Alexander V; Lagunin, Alexey A; Filimonov, Dmitry A; Poroikov, Vladimir V

2016-01-01

The knowledge of drug metabolite structures is essential at the early stage of drug discovery to understand the potential liabilities and risks connected with biotransformation. The determination of the site of a molecule at which a particular metabolic reaction occurs could be used as a starting point for metabolite identification. The prediction of the site of metabolism does not always correspond to the particular atom that is modified by the enzyme but rather is often associated with a group of atoms. To overcome this problem, we propose to operate with the term "reacting atom", corresponding to a single atom in the substrate that is modified during the biotransformation reaction. The prediction of the reacting atom(s) in a molecule for the major classes of biotransformation reactions is necessary to generate drug metabolites. Substrates of the major human cytochromes P450 and UDP-glucuronosyltransferases from the Biovia Metabolite database were divided into nine groups according to their reaction classes, which are aliphatic and aromatic hydroxylation, N- and O-glucuronidation, N-, S- and C-oxidation, and N- and O-dealkylation. Each training set consists of positive and negative examples of structures with one labelled atom. In the positive examples, the labelled atom is the reacting atom of a particular reaction that changed adjacency. Negative examples represent non-reacting atoms of a particular reaction. We used Labelled Multilevel Neighbourhoods of Atoms descriptors for the designation of reacting atoms. A Bayesian-like algorithm was applied to estimate the structure-activity relationships. The average invariant accuracy of prediction obtained in leave-one-out and 20-fold cross-validation procedures for five human isoforms of cytochrome P450 and all isoforms of UDP-glucuronosyltransferase varies from 0.86 to 0.99 (0.96 on average). We report that reacting atoms may be predicted with reasonable accuracy for the major classes of metabolic reactions

Numerical simulation of reacting and non-reacting flow in a combustion chamber; Numerisk simulering av reagerande och icke-reagerande stroemning i en braennkammare

Energy Technology Data Exchange (ETDEWEB)

Borg, A.; Revstedt, J.

1996-04-01

The purpose of this work has been to do a preliminary study of how well numerical calculations with different turbulence models can predict the flow and temperature fields of a strongly swirling and combusting flow in an experimental combustion chamber and to see which parameters in the mathematical model are the most important. The combustion chamber on which we have done the calculations is called Validation Rig II and was designed by Volvo Aero Corporation. The main part of the study has been carried out on a non-reacting flow but some work has also been done on reacting flow. In most cases it has not been meaningful to compare the calculations with the measurements because they differ quite a lot from each other. For the non-reacting case the following investigations have been made: * How the solution differs for different turbulence models, * The solutions sensitivity to inlet boundary conditions, * How different types of leakage disturb the flow, and * The difference in results between two different CFD-codes, the commercial code CFDS-Flow3D and a code developed at the department of fluid mechanics. For the reacting cases we have studied the influence of: * one or two reaction steps, * the effects of a change in reaction rate, * the influence of thermal radiation, and * the effects of changing the boundary conditions for temperature on the walls. The results from these calculations show that the inlet turbulence intensity has very little effect on the values of the turbulent quantities as well as the velocity profiles at the outlet. Changing the turbulence model or the outlet boundary conditions gives some change in velocity profiles at the outlet but only marginal effects on the swirl number. 21 refs, 54 figs, 19 tabs

The training for nuclear fuel handling at EDF

International Nuclear Information System (INIS)

Marion, J.P.

1999-01-01

The handling of fuel assemblies in a nuclear power plant presents 3 types of work: the taking delivery of fresh fuel, the refueling and the disposal of spent fuel. These operations are realized by teams made up of 3 handling operators and a supervisor. The refueling is made by 3*8-hour teams. These handling operations are important for the nuclear safety, a mishandling can damage the fuel cladding which is the first containment barrier, so a training center (CETIC) has been created. This center was founded in 1986 by EDF and Framatome, the purpose was to validate maintenance procedures, to test handling equipment and to train the teams which work on site. Various training programmes have been set up and a system of qualification degrees has been organized. The CETIC is fitted up with equipment that are full-sized mockups of real installations. Fuel assemblies don't react in a similar way to the different mechanical and neutronic stresses they undergo while they are in the core, they get deformed and the handling operations become more delicate. The mockup fuel assemblies are quite deformed to train the teams and prepare them to face any real situation. (A.C.)

Three-Dimensional Carbon Nanotube−Textile Anode for High-Performance Microbial Fuel Cells

KAUST Repository

Xie, Xing; Hu, Liangbing; Pasta, Mauro; Wells, George F.; Kong, Desheng; Criddle, Craig S.; Cui, Yi

2011-01-01

Microbial fuel cells (MFCs) harness the metabolism of microorganisms, converting chemical energy into electrical energy. Anode performance is an important factor limiting the power density of MFCs for practical application. Improving the anode design is thus important for enhancing the MFC performance, but only a little development has been reported. Here, we describe a biocompatible, highly conductive, two-scale porous anode fabricated from a carbon nanotube-textile (CNT-textile) composite for high-performance MFCs. The macroscale porous structure of the intertwined CNT-textile fibers creates an open 3D space for efficient substrate transport and internal colonization by a diverse microflora, resulting in a 10-fold-larger anolyte-biofilm-anode interfacial area than the projective surface area of the CNT-textile. The conformally coated microscale porous CNT layer displays strong interaction with the microbial biofilm, facilitating electron transfer from exoelectrogens to the CNT-textile anode. An MFC equipped with a CNT-textile anode has a 10-fold-lower charge-transfer resistance and achieves considerably better performance than one equipped with a traditional carbon cloth anode: the maximum current density is 157% higher, the maximum power density is 68% higher, and the energy recovery is 141% greater. © 2011 American Chemical Society.

Three-Dimensional Carbon Nanotube−Textile Anode for High-Performance Microbial Fuel Cells

KAUST Repository

Xie, Xing

2011-01-12

Microbial fuel cells (MFCs) harness the metabolism of microorganisms, converting chemical energy into electrical energy. Anode performance is an important factor limiting the power density of MFCs for practical application. Improving the anode design is thus important for enhancing the MFC performance, but only a little development has been reported. Here, we describe a biocompatible, highly conductive, two-scale porous anode fabricated from a carbon nanotube-textile (CNT-textile) composite for high-performance MFCs. The macroscale porous structure of the intertwined CNT-textile fibers creates an open 3D space for efficient substrate transport and internal colonization by a diverse microflora, resulting in a 10-fold-larger anolyte-biofilm-anode interfacial area than the projective surface area of the CNT-textile. The conformally coated microscale porous CNT layer displays strong interaction with the microbial biofilm, facilitating electron transfer from exoelectrogens to the CNT-textile anode. An MFC equipped with a CNT-textile anode has a 10-fold-lower charge-transfer resistance and achieves considerably better performance than one equipped with a traditional carbon cloth anode: the maximum current density is 157% higher, the maximum power density is 68% higher, and the energy recovery is 141% greater. © 2011 American Chemical Society.

Nuclear Energy and Synthetic Liquid Transportation Fuels

Science.gov (United States)

McDonald, Richard

2012-10-01

This talk will propose a plan to combine nuclear reactors with the Fischer-Tropsch (F-T) process to produce synthetic carbon-neutral liquid transportation fuels from sea water. These fuels can be formed from the hydrogen and carbon dioxide in sea water and will burn to water and carbon dioxide in a cycle powered by nuclear reactors. The F-T process was developed nearly 100 years ago as a method of synthesizing liquid fuels from coal. This process presently provides commercial liquid fuels in South Africa, Malaysia, and Qatar, mainly using natural gas as a feedstock. Nuclear energy can be used to separate water into hydrogen and oxygen as well as to extract carbon dioxide from sea water using ion exchange technology. The carbon dioxide and hydrogen react to form synthesis gas, the mixture needed at the beginning of the F-T process. Following further refining, the products, typically diesel and Jet-A, can use existing infrastructure and can power conventional engines with little or no modification. We can then use these carbon-neutral liquid fuels conveniently long into the future with few adverse environmental impacts.

Geochemical effects of electro-osmosis in clays

KAUST Repository

Loch, J. P. Gustav; Lima, Ana Teresa; Kleingeld, Pieter J.

2010-01-01

-osmotic flow is observed. Due to its carbonate content the bentonite is pH-buffering. Alkalization in the catholyte is substantial. Ca, Na and Sr are significantly removed from the clay and accumulate in the catholyte. Recovery in the catholyte accounts for a

Experimental investigation of nitrogen based emissions from an ammonia fueled SI-engine

DEFF Research Database (Denmark)

Westlye, Fredrik Ree; Ivarsson, Anders; Schramm, Jesper

2013-01-01

. This causes the NO emissions to peak around 35% rather than 10% excess air, as is typical in HC fueled SI-engines. However the magnitude of NO emissions are comparable to that of measurements conducted with gasoline due to lower flame temperatures. Nitrogen dioxide levels are higher when comparing...... with gasoline, but has a relatively low share of the total NOx emissions (3-4%). Nitrous oxide is a product of NH2 reacting with NO 2 and NH reacting with NO. The magnitude is largely affected by ignition timing due to the temperature development during expansion and the amount of excess air, as increased...

Dual fuel injection piggyback controller system

Science.gov (United States)

Muji, Siti Zarina Mohd.; Hassanal, Muhammad Amirul Hafeez; Lee, Chua King; Fawzi, Mas; Zulkifli, Fathul Hakim

2017-09-01

Dual-fuel injection is an effort to reduce the dependency on diesel and gasoline fuel. Generally, there are two approaches to implement the dual-fuel injection in car system. The first approach is changing the whole injector of the car engine, the consequence is excessive high cost. Alternatively, it also can be achieved by manipulating the system's control signal especially the Electronic Control Unit (ECU) signal. Hence, the study focuses to develop a dual injection timing controller system that likely adopted to control injection time and quantity of compressed natural gas (CNG) and diesel fuel. In this system, Raspberry Pi 3 reacts as main controller unit to receive ECU signal, analyze it and then manipulate its duty cycle to be fed into the Electronic Driver Unit (EDU). The manipulation has changed the duty cycle to two pulses instead of single pulse. A particular pulse mainly used to control injection of diesel fuel and another pulse controls injection of Compressed Natural Gas (CNG). The test indicated promising results that the system can be implemented in the car as piggyback system. This article, which was originally published online on 14 September 2017, contained an error in the acknowledgment section. The corrected acknowledgment appears in the Corrigendum attached to the pdf.

The history, genotoxicity, and carcinogenicity of carbon-based fuels and their emissions. Part 2: solid fuels.

Science.gov (United States)

Claxton, Larry D

2014-01-01

The combustion of solid fuels (like wood, animal dung, and coal) usually involves elevated temperatures and altered pressures and genotoxicants (e.g., PAHs) are likely to form. These substances are carcinogenic in experimental animals, and epidemiological studies implicate these fuels (especially their emissions) as carcinogens in man. Globally, ∼50% of all households and ∼90% of all rural households use solid fuels for cooking or heating and these fuels often are burnt in simple stoves with very incomplete combustion. Exposed women and children often exhibit low birth weight, increased infant and perinatal mortality, head and neck cancer, and lung cancer although few studies have measured exposure directly. Today, households that cannot meet the expense of fuels like kerosene, liquefied petroleum gas, and electricity resort to collecting wood, agricultural residue, and animal dung to use as household fuels. In the more developed countries, solid fuels are often used for electric power generation providing more than half of the electricity generated in the United States. The world's coal reserves, which equal approximately one exagram, equal ∼1 trillion barrels of crude oil (comparable to all the world's known oil reserves) and could last for 600 years. Studies show that the PAHs that are identified in solid fuel emissions react with NO2 to form direct-acting mutagens. In summary, many of the measured genotoxicants found in both the indoor and electricity-generating combustors are the same; therefore, the severity of the health effects vary with exposure and with the health status of the exposed population. Copyright © 2014. Published by Elsevier B.V.

Electrolyte creepage barrier for liquid electrolyte fuel cells

Science.gov (United States)

Li, Jian [Alberta, CA; Farooque, Mohammad [Danbury, CT; Yuh, Chao-Yi [New Milford, CT

2008-01-22

A dielectric assembly for electrically insulating a manifold or other component from a liquid electrolyte fuel cell stack wherein the dielectric assembly includes a substantially impermeable dielectric member over which electrolyte is able to flow and a barrier adjacent the dielectric member and having a porosity of less than 50% and greater than 10% so that the barrier is able to measurably absorb and chemically react with the liquid electrolyte flowing on the dielectric member to form solid products which are stable in the liquid electrolyte. In this way, the barrier inhibits flow or creepage of electrolyte from the dielectric member to the manifold or component to be electrically insulated from the fuel cell stack by the dielectric assembly.

Wastewater treatment, energy recovery and desalination using a forward osmosis membrane in an air-cathode microbial osmotic fuel cell

KAUST Repository

Werner, Craig M.

2013-02-01

A microbial osmotic fuel cell (MOFC) has a forward osmosis (FO) membrane situated between the electrodes that enable desalinated water recovery along with power generation. Previous designs have required aerating the cathode chamber water, offsetting the benefits of power generation by power consumption for aeration. An air-cathode MOFC design was developed here to improve energy recovery, and the performance of this new design was compared to conventional microbial fuel cells containing a cation (CEM) or anion exchange membrane (AEM). Internal resistance of the MOFC was reduced with the FO membrane compared to the ion exchange membranes, resulting in a higher maximum power production (43W/m3) than that obtained with an AEM (40W/m3) or CEM (23W/m3). Acetate (carbon source) removal reached 90% in the MOFC; however, a small amount of acetate crossed the membrane to the catholyte. The initial water flux declined by 28% from cycle 1 to cycle 3 of operation but stabilized at 4.1L/m2/h over the final three batch cycles. This decline in water flux was due to membrane fouling. Overall desalination of the draw (synthetic seawater) solution was 35%. These results substantially improve the prospects for simultaneous wastewater treatment and seawater desalination in the same reactor. © 2012 Elsevier B.V.

Nuclear fuel element containing particles of an alloyed Zr, Ti, and Ni getter material

International Nuclear Information System (INIS)

Grossman, L.N.; Levin, H.A.

1975-01-01

A nuclear fuel element for use in the core of a nuclear reactor is disclosed. The nuclear fuel element has disposed therein an alloy having the essential components of nickel, titanium and zirconium, and the alloy reacts with water, water vapor and reactive gases at reactor ambient temperatures. The alloy is disposed in the plenum of the fuel element in the form of particles in a hollow gas permeable container having a multiplicity of openings of size smaller than the size of the particles. The openings permit gases and liquids entering the plenum to contact the particles of alloy. The container is preferably held in the spring in the plenum of the fuel element. (Official Gazette)

LES and experimental studies of cold and reacting flow in a swirled partially remixed burner with and without fuel modulation

NARCIS (Netherlands)

Sengissen, A.X.; van Kampen, J.F.; Huls, R.A.; Stoffels, Genie G.M.; Kok, Jacobus B.W.; Poinsot, T.J.

2007-01-01

In devices where air and fuel are injected separately, combustion processes are influenced by oscillations of the air flow rate but may also be sensitive to fluctuations of the fuel flow rate entering the chamber. This paper describes a joint experimental and numerical study of the mechanisms

Polymer coatings as separator layers for microbial fuel cell cathodes

KAUST Repository

Watson, Valerie J.

2011-03-01

Membrane separators reduce oxygen flux from the cathode into the anolyte in microbial fuel cells (MFCs), but water accumulation and pH gradients between the separator and cathode reduces performance. Air cathodes were spray-coated (water-facing side) with anion exchange, cation exchange, and neutral polymer coatings of different thicknesses to incorporate the separator into the cathode. The anion exchange polymer coating resulted in greater power density (1167 ± 135 mW m-2) than a cation exchange coating (439 ± 2 mW m-2). This power output was similar to that produced by a Nafion-coated cathode (1114 ± 174 mW m-2), and slightly lower than the uncoated cathode (1384 ± 82 mW m-2). Thicker coatings reduced oxygen diffusion into the electrolyte and increased coulombic efficiency (CE = 56-64%) relative to an uncoated cathode (29 ± 8%), but decreased power production (255-574 mW m-2). Electrochemical characterization of the cathodes ex situ to the MFC showed that the cathodes with the lowest charge transfer resistance and the highest oxygen reduction activity produced the most power in MFC tests. The results on hydrophilic cathode separator layers revealed a trade off between power and CE. Cathodes coated with a thin coating of anion exchange polymer show promise for controlling oxygen transfer while minimally affecting power production. © 2010 Elsevier B.V. All rights reserved.

Comparison of improved finite-difference WENO schemes for the implicit large eddy simulation of turbulent non-reacting and reacting high-speed shear flows

International Nuclear Information System (INIS)

Zhao, S.; Lardjane, N.; Fedioun, I.

2014-01-01

Improved WENO schemes, Z, M, and their combination MZ, originally designed to capture sharper discontinuities than the classical fifth order Jiang-Shu scheme does, are evaluated for the purpose of implicit large eddy simulation of free shear flows. 1D Fourier analysis of errors reveals the built-in filter and dissipative properties of the schemes, which are subsequently applied to the canonical Rayleigh-Taylor and Taylor-Green flows. Large eddy simulations of a transonic non-reacting and a supersonic reacting air/H2 jets are then performed at resolution 128 * 128 * 512, showing no significant difference in the flow statistics. However, the computational time varies from one scheme to the other, the Z scheme providing the smaller wall-time due to larger allowed time steps. (authors)

Computation of turbulent reacting flow in a solid-propellant ducted rocket

Science.gov (United States)

Chao, Yei-Chin; Chou, Wen-Fuh; Liu, Sheng-Shyang

1995-05-01

A mathematical model for computation of turbulent reacting flows is developed under general curvilinear coordinate systems. An adaptive, streamline grid system is generated to deal with the complex flow structures in a multiple-inlet solid-propellant ducted rocket (SDR) combustor. General tensor representations of the k-epsilon and algebraic stress (ASM) turbulence models are derived in terms of contravariant velocity components, and modification caused by the effects of compressible turbulence is also included in the modeling. The clipped Gaussian probability density function is incorporated in the combustion model to account for fluctuations of properties. Validation of the above modeling is first examined by studying mixing and reacting characteristics in a confined coaxial-jet problem. This is followed by study of nonreacting and reacting SDR combustor flows. The results show that Gibson and Launder's ASM incorporated with Sarkar's modification for compressible turbulence effects based on the general curvilinear coordinate systems yields the most satisfactory prediction for this complicated SDR flowfield.

Nb3Sn dipole magnet reacted after winding

International Nuclear Information System (INIS)

Taylor, C.; Scanlan, R.; Peters, C.; Wolgast, R.; Gilbert, W.; Hassenzahl, W.; Meuser, R.; Rechen, J.

1984-09-01

A 5 cm bore dia., 1-m-long dipole model magnet was constructed by winding un-reacted cable, followed by reaction and epoxy-impregnation. Experience and test results are described on the 1.7 mm dia. internal-tin wire, the eleven-strand flattened cable, fiberglass insulation, and construction of the magnet. Each half of the magnet has two double-pancake-type windings that were reacted in a single operation. The two double-pancakes were then separately vacuum impregnated after soldering the flexible Nb-Ti leads to the Nb 3 Sn conductors. No iron flux return yoke was used. In initial tests a central field of 8.0 T was reached at 4.4 K. However, evidence from training behavior, and 1.8 K tests indicate that premature quenching, rather than critical current of the cable, limited the field intensity. The magnet was reassembled and more rigidly clamped; additional test results are reported

Development of oxygen scavenger additives for jet fuels

Energy Technology Data Exchange (ETDEWEB)

Beaver, B.D.; Demunshi, R.; Sharief, V.; Tian, D.; Teng, Y. [Duquesne Univ., Pittsburgh, PA (United States)

1995-05-01

Our current research program is in response to the US Air Force`s FY93 New Initiative entitled {open_quotes}Advanced Fuel Composition and Use.{close_quotes} The critical goal of this initiative is to develop aircraft fuels which can operate at supercritical conditions. This is a vital objective since future aircraft designs will transfer much higher heat loads into the fuel as compared with current heat loads. In this paper it is argued that the thermal stability of most jet fuels would be dramatically improved by the efficient in flight-removal of a fuel`s dissolved oxygen. It is proposed herein to stabilize the bulk fuel by the addition of an additive which will be judiciously designed and programmed to react with oxygen and produce an innocuous product. It is envisioned that a thermally activated reaction will occur, between the oxygen scavenging additive and dissolved oxygen, in a controlled and directed manner. Consequently formation of insoluble thermal degradation products will be limited. It is believed that successful completion of this project will result in the development of a new type of jet fuel additive which will enable current conventional jet fuels to obtain sufficient thermal stability to function in significantly higher temperature regimes. In addition, it is postulated that the successful development of thermally activated oxygen scavengers will also provide the sub-critical thermal stability necessary for future development of endothermic fuels.

Investigation of High Pressure, Multi-Hole Diesel Fuel Injection Using High Speed Imaging

Science.gov (United States)

Morris, Steven; Eagle, Ethan; Wooldridge, Margaret

2012-10-01

Research to experimentally capture and understand transient fuel spray behavior of modern fuel injection systems remains underdeveloped. To this end, a high-pressure diesel common-rail fuel injector was instrumented in a spherical, constant volume combustion chamber to image the early time history of injection of diesel fuel. The research-geometry fuel injector has four holes aligned on a radial plane of the nozzle with hole sizes of 90, 110, 130 and 150 μm in diameter. Fuel was injected into a non-reacting environment with ambient densities of 17.4, 24.0, and 31.8 kg/m3 at fuel rail pressures of 1000, 1500, and 2000 bar. High speed images of fuel injection were taken using backlighting at 100,000 frames per second (100 kfps) and an image processing algorithm. The experimental results are compared with a one-dimensional fuel-spray model that was historically developed and applied to fuel sprays from single-hole fuel injectors. Fuel spray penetration distance was evaluated as a function of time for the different injector hole diameters, fuel injection pressures and ambient densities. The results show the differences in model predictions and experimental data at early times in the spray development.

Dynamic behavior of gasoline fuel cell electric vehicles

Science.gov (United States)

Mitchell, William; Bowers, Brian J.; Garnier, Christophe; Boudjemaa, Fabien

As we begin the 21st century, society is continuing efforts towards finding clean power sources and alternative forms of energy. In the automotive sector, reduction of pollutants and greenhouse gas emissions from the power plant is one of the main objectives of car manufacturers and innovative technologies are under active consideration to achieve this goal. One technology that has been proposed and vigorously pursued in the past decade is the proton exchange membrane (PEM) fuel cell, an electrochemical device that reacts hydrogen with oxygen to produce water, electricity and heat. Since today there is no existing extensive hydrogen infrastructure and no commercially viable hydrogen storage technology for vehicles, there is a continuing debate as to how the hydrogen for these advanced vehicles will be supplied. In order to circumvent the above issues, power systems based on PEM fuel cells can employ an on-board fuel processor that has the ability to convert conventional fuels such as gasoline into hydrogen for the fuel cell. This option could thereby remove the fuel infrastructure and storage issues. However, for these fuel processor/fuel cell vehicles to be commercially successful, issues such as start time and transient response must be addressed. This paper discusses the role of transient response of the fuel processor power plant and how it relates to the battery sizing for a gasoline fuel cell vehicle. In addition, results of fuel processor testing from a current Renault/Nuvera Fuel Cells project are presented to show the progress in transient performance.

Elimination of pyraclostrobin by simultaneous microbial degradation coupled with the Fenton process in microbial fuel cells and the microbial community.

Science.gov (United States)

Zhao, Huanhuan; Kong, Chui-Hua

2018-06-01

The elimination of pyraclostrobin by simultaneous microbial degradation and Fenton oxidation was achieved in a microbial fuel cell (MFC) system. After 12 h of incubation, the removal rate of pyraclostrobin was 1.4 mg/L/h at the anode and 1.7 mg/L/h at the cathode. The pyraclostrobin concentration was less than the detection limit (0.1 mg/L) after 72 h at the anode and 24 h at the cathode. The air flow rate, temperature, and pH of the catholyte had significant effects on the generation of H 2 O 2 . The maximum production of H 2 O 2 was 1.2 mg/L after reaction for 20 h during the Fenton process. Microbial community analysis indicated that functional bacteria in the genera Chryseobacterium, Stenotrophomonas, Arcobacter, and Comamonas were predominant in the anodic biofilm. In conclusion, the MFC-Fenton system provides an effective approach for treating environmental contaminants. Copyright © 2018 Elsevier Ltd. All rights reserved.

REAC/TS radiation accident registry. Update of accidents in the United States

International Nuclear Information System (INIS)

Ricks, R.C.; Berger, M.E.; Holloway, E.C.; Goans, R.E.

2000-01-01

Serious injury due to ionizing radiation is a rare occurrence. From 1944 to the present, 243 US accidents meeting dose criteria for classification as serious are documented in the REAC/TS Registry. Thirty individuals have lost their lives in radiation accidents in the United States. The Registry is part of the overall REAC/TS program providing 24-hour direct or consultative assistance regarding medical and heath physics problems associated with radiation accidents in local, national, and international incidents. The REAC/TS Registry serves as a repository of medically important information documenting the consequences of these accidents. Registry data are gathered from various sources. These include reports from the World Heath Organization (WHO), International Atomic Energy Agency (IAEA), US Nuclear Regulatory Commission (US NRC), state radiological health departments, medical/health physics literature, personal communication, the Internet, and most frequently, from calls for medical assistance to REAC/TS, as part of our 24-hour medical assistance program. The REAC/TS Registry for documentation of radiation accidents serves several useful purposes: 1) weaknesses in design, safety practices, training or control can be identified, and trends noted; 2) information regarding the medical consequences of injuries and the efficacy of treatment protocols is available to the treating physician; and 3) Registry case studies serve as valuable teaching tools. This presentation will review and summarize data on the US radiation accidents including their classification by device, accident circumstances, and frequency by respective states. Data regarding accidents with fatal outcomes will be reviewed. The inclusion of Registry data in the IAEA's International Reporting System of Radiation Events (RADEV) will also be discussed. (author)

Modified hydrogenated PBLH copolymer synthesis with styrene for proton exchange membranes fuel cell application

International Nuclear Information System (INIS)

Ferraz, Fernando A.; Oliveira, Angelo R.S.; Rodrigues, Maraiza F.; Groetzner, Mariana B.; Cesar-Oliveira, Maria Aparecida F.; Cantao, Mauricio P.

2005-01-01

Polymers used as electrolyte in fuel cells are expected to have functional groups in their structure which are responsible for proton conductivity. Since the use of hydroxylated liquid polybutadiene (PBLH) has not been mentioned in the literature as an ion exchange membrane for fuel cell application (PEMFC), and its structure can be modified for a later sulfonation, it has been studied. In this work, PBLH was modified through a hydrogenation reaction. Furthermore, hydrogenated polymeric esters were obtained by esterification and transesterification reactions (PBLH- estearate and PBLH- methacrylate). Reacting the PBLH methacrylate with styrene, it was generated a copolymer with appropriated structure for sulfonation, justifying researches for fuel cell. (author)

Tip-to-tail numerical simulation of a hypersonic air-breathing engine with ethylene fuel

Science.gov (United States)

Dharavath, Malsur; Manna, P.; Chakraborty, Debasis

2016-11-01

End to end CFD simulations of external and internal flow paths of an ethylene fueled hypersonic airbreathing vehicle with including forebody, horizontal fins, vertical fins, intake, combustor, single expansion ramp nozzle are carried out. The performance of the scramjet combustor and vehicle net thrust-drag is calculated for hypersonic cruise condition. Three-dimensional Navier-Stokes equations are solved along with SST-k-ω turbulence model using the commercial CFD software CFX-14. Single step chemical reaction based on fast chemistry assumption is used for combustion of gaseous ethylene fuel. Simulations captured complex shock structures including the shocks generated from the vehicle nose and compression ramps, impingement of cowl-shock on vehicle undersurface and its reflection in the intake and combustor etc. Various thermochemical parameters are analyzed and performance parameters are evaluated for nonreacting and reacting cases. Very good mixing ( 98%) of fuel with incoming air stream is observed. Positive thrust-drag margins are obtained for fuel equivalence ratio of 0.6 and computed combustion efficiency is observed to be 94 %. Effect of equivalence ratio on the vehicle performance is studied parametrically. Though the combustion efficiency has come down by 8% for fuel equivalence ratio of 0.8, net vehicle thrust is increased by 44%. Heat flux distribution on the various walls of the whole vehicle including combustor is estimated for the isothermal wall condition of 1000 K in reacting flow. Higher local heat flux values are observed at all the leading edges of the vehicle (i.e., nose, wing, fin and cowl leading edges) and strut regions of the combustor.

High temperature reactor: Driving force to convert CO2 to fuel - HTR2008-58132

International Nuclear Information System (INIS)

McCormick, J. L.

2008-01-01

The rapidly increasing cost of petroleum products and uncertainty of long-term supply have prompted the U.S. military to aggressively pursue production of alternative fuels (synfuels) such as coal-to-liquids (CTL). U.S. Air Force is particularly active in this effort while the entire military is involved in simultaneously developing fuel specifications for alternative fuels that enable a single fuel for the entire battle space; all ground vehicles, aircraft and fuel cells. By limiting its focus on coal, tar sands and oil shale resources, the military risks violating federal law which requires the use of synfuels that have life cycle greenhouse gas emissions less than or equal to emissions from conventional petroleum fuels. A climate-friendly option would use a high temperature nuclear reactor to split water. The hydrogen (H 2 ) would be used in the reverse water gas shift (RWGS) to react with carbon dioxide (CO 2 ) to produce carbon monoxide (CO) and water. The oxygen (O 2 ) would be fed into a supercritical (SC) coal furnace. The flue gas CO 2 emissions would be stripped of impurities before reacting with H 2 in a RWGS process. Resultant carbon monoxide (CO) is fed, with additional H2, (extra H 2 needed to adjust the stoichiometry: 2 moles H 2 to one mole CO) into a conventional Fischer-Tropsch synthesis (FTS) to produce a heavy wax which is cracked and isomerized and refined to Jet Propulsion 8 (JP-8) and Jet Propulsion 5 (JP-5) fuels. The entire process offers valuable carbon-offsets and multiple products that contribute to lower syn-fuel costs and to comply with the federal limitation imposed on syn-fuel purchases. While the entire process is not commercially available, component parts are being researched; their physical and chemical properties understood and some are state-of-the-art technologies. An international consortium should complete physical, chemical and economic flow sheets to determine the feasibility of this concept that, if pursued, has broad

A stochastic model of particle dispersion in turbulent reacting gaseous environments

Science.gov (United States)

Sun, Guangyuan; Lignell, David; Hewson, John

2012-11-01

We are performing fundamental studies of dispersive transport and time-temperature histories of Lagrangian particles in turbulent reacting flows. The particle-flow statistics including the full particle temperature PDF are of interest. A challenge in modeling particle motions is the accurate prediction of fine-scale aerosol-fluid interactions. A computationally affordable stochastic modeling approach, one-dimensional turbulence (ODT), is a proven method that captures the full range of length and time scales, and provides detailed statistics of fine-scale turbulent-particle mixing and transport. Limited results of particle transport in ODT have been reported in non-reacting flow. Here, we extend ODT to particle transport in reacting flow. The results of particle transport in three flow configurations are presented: channel flow, homogeneous isotropic turbulence, and jet flames. We investigate the functional dependence of the statistics of particle-flow interactions including (1) parametric study with varying temperatures, Reynolds numbers, and particle Stokes numbers; (2) particle temperature histories and PDFs; (3) time scale and the sensitivity of initial and boundary conditions. Flow statistics are compared to both experimental measurements and DNS data.

Electrochemical migration technique to accelerate ageing of cementitious materials

Directory of Open Access Journals (Sweden)

Abbas Z.

2013-07-01

Full Text Available Durability assessment of concrete structures for constructions in nuclear waste repositories requires long term service life predictions. As deposition of low and intermediate level radioactive waste (LILW takes up to 100 000 years, it is necessary to analyze the service life of cementitious materials in this time perspective. Using acceleration methods producing aged specimens would decrease the need of extrapolating short term data sets. Laboratory methods are therefore, needed for accelerating the ageing process without making any influencing distortion in the properties of the materials. This paper presents an electro-chemical migration method to increase the rate of calcium leaching from cementitious specimens. This method is developed based on the fact that major long term deterioration process of hardened cement paste in concrete structures for deposition of LILW is due to slow diffusion of calcium ions. In this method the cementitious specimen is placed in an electrochemical cell as a porous path way through which ions can migrate at a rate far higher than diffusion process. The electrical field is applied to the cell in a way to accelerate the ion migration without making destructions in the specimen’s micro and macroscopic properties. The anolyte and catholyte solutions are designed favoring dissolution of calcium hydroxide and compensating for the leached calcium ions with another ion like lithium.

Electrochemical migration technique to accelerate ageing of cementitious materials

Science.gov (United States)

Babaahmadi, A.; Tang, L.; Abbas, Z.

2013-07-01

Durability assessment of concrete structures for constructions in nuclear waste repositories requires long term service life predictions. As deposition of low and intermediate level radioactive waste (LILW) takes up to 100 000 years, it is necessary to analyze the service life of cementitious materials in this time perspective. Using acceleration methods producing aged specimens would decrease the need of extrapolating short term data sets. Laboratory methods are therefore, needed for accelerating the ageing process without making any influencing distortion in the properties of the materials. This paper presents an electro-chemical migration method to increase the rate of calcium leaching from cementitious specimens. This method is developed based on the fact that major long term deterioration process of hardened cement paste in concrete structures for deposition of LILW is due to slow diffusion of calcium ions. In this method the cementitious specimen is placed in an electrochemical cell as a porous path way through which ions can migrate at a rate far higher than diffusion process. The electrical field is applied to the cell in a way to accelerate the ion migration without making destructions in the specimen's micro and macroscopic properties. The anolyte and catholyte solutions are designed favoring dissolution of calcium hydroxide and compensating for the leached calcium ions with another ion like lithium.

Linear models for sound from supersonic reacting mixing layers

Science.gov (United States)

Chary, P. Shivakanth; Samanta, Arnab

2016-12-01

We perform a linearized reduced-order modeling of the aeroacoustic sound sources in supersonic reacting mixing layers to explore their sensitivities to some of the flow parameters in radiating sound. Specifically, we investigate the role of outer modes as the effective flow compressibility is raised, when some of these are expected to dominate over the traditional Kelvin-Helmholtz (K-H) -type central mode. Although the outer modes are known to be of lesser importance in the near-field mixing, how these radiate to the far-field is uncertain, on which we focus. On keeping the flow compressibility fixed, the outer modes are realized via biasing the respective mean densities of the fast (oxidizer) or slow (fuel) side. Here the mean flows are laminar solutions of two-dimensional compressible boundary layers with an imposed composite (turbulent) spreading rate, which we show to significantly alter the growth of instability waves by saturating them earlier, similar to in nonlinear calculations, achieved here via solving the linear parabolized stability equations. As the flow parameters are varied, instability of the slow modes is shown to be more sensitive to heat release, potentially exceeding equivalent central modes, as these modes yield relatively compact sound sources with lesser spreading of the mixing layer, when compared to the corresponding fast modes. In contrast, the radiated sound seems to be relatively unaffected when the mixture equivalence ratio is varied, except for a lean mixture which is shown to yield a pronounced effect on the slow mode radiation by reducing its modal growth.

Greater use of wood residue fuels through improved financial planning: a case study in Alabama

Energy Technology Data Exchange (ETDEWEB)

Billings, C.D.; Ziemke, M.C. (Alabama Univ., Huntsville, AL (United States). Coll. of Administrative Science); Stanford, R. (Alabama Dept. of Economic and Community Affairs, Montgomery, AL (United States))

1993-01-01

As the world reacts to environmental concerns relating to fossil energy usage, emphasis is again placed on greater use of renewable fuels such as wood residues. Realistically, however, decisions to utilize such fuels are based on economic factors, rather than desires to improve US energy independence and/or protect the environment. Because Alabama has a large forest products industry, state authorities have long sought to assist potential users of wood residue fuels to better use biomass fuels instead of the usual alternative: natural gas. State agency experience in promoting commercial and industrial use of wood residue fuels has shown that inadequate financial planning has often resulted in rejection of viable projects or acceptance of non-optimum projects. This paper discusses the reasons for this situation and suggests remedies for its improvement. (author)

Keefektifan Strategi Pembelajaran React Pada Kemampuan Siswa Kelas VII Aspek Komunikasi Matematis

Directory of Open Access Journals (Sweden)

A.T. Arifin

2014-06-01

Full Text Available AbstrakTujuan penelitian ini adalah mengetahui pembelajaran dengan strategi REACT efektif ter-hadap kemampuan komunikasi matematis siswa. Metode pengumpulan data dilakukan de-ngan metode dokumentasi, tes, dan observasi. Hasil uji proporsi menunjukkan bahwa hasil belajar siswa kelas eksperimen pada aspek kemampuan komunikasi matematis telah men-capai ketuntasan klasikal, mencapai lebih dari 80 % yaitu sebesar 96,7%. Dilihat dari nilai rata-rata tes kemampuan komunikasi matematis kelas eksperimen  adalah 83,61 sedangkan kelas kontrol adalah 73,79 dapat disimpulkan bahwa kemampuan komunikasi matematis siswa kelas eksperimen lebih baik daripada kemampuan komunikasi matematis siswa kon-trol. Hasil penelitian menunjukkan bahwa penerapan strategi pembelajaran REACT efektif terhadap kemampuan komunikasi matematis siswa materi segiempat kelas VII SMP Negeri 1 Gembong. Kata kunci:      keefektifan, kemampuan komunikasi matematis, Relating Experiencing Applying Cooperating Transferring (REACT  AbstractThe purpose of this study was to determine the effectiveness of the application of REACT learning strategy approach to mathematic communication ability of students. Methods of data collection is done by the method of documentation, testing, and observation. The test results showed that the proportion of student learning outcomes in the experimental class with the aspects of mathematic communication ability has reached the classical completeness, reached more than 80% is equal to 96.7%. Judging from the value of the average test learners' ability to mathematic communication experimental class was 83.61 while the control class is 73.79 it can be concluded that the mathematic communication skills of learners experimental classes are better than mathematic communication abilities of learners control class. The results showed that the application of REACT learning strategy approach effective to mathematic communication abilities of students of class VII

Impact of Flight Enthalpy, Fuel Simulant, and Chemical Reactions on the Mixing Characteristics of Several Injectors at Hypervelocity Flow Conditions

Science.gov (United States)

Drozda, Tomasz G.; Baurle, Robert A.; Drummond, J. Philip

2016-01-01

The high total temperatures or total enthalpies required to duplicate the high-speed flight conditions in ground experiments often place stringent requirements on the material selection and cooling needs for the test articles and intrusive flow diagnostic equipment. Furthermore, for internal flows, these conditions often complicate the use of nonintrusive diagnostics that need optical access to the test section and interior portions of the flowpath. Because of the technical challenges and increased costs associated with experimentation at high values of total enthalpy, an attempt is often made to reduce it. This is the case for the Enhanced Injection and Mixing Project (EIMP) currently underway in the Arc-Heated Scramjet Test Facility at the NASA Langley Research Center. The EIMP aims to investigate supersonic combustion ramjet (scramjet) fuel injection and mixing physics, improve the understanding of underlying physical processes, and develop enhancement strategies and functional relationships between mixing performance and losses relevant to flight Mach numbers greater than 8. The experiments will consider a "direct-connect" approach and utilize a Mach 6 nozzle to simulate the combustor entrance flow of a scramjet engine. However, while the value of the Mach number is matched to that expected at the combustor entrance in flight, the maximum value of the total enthalpy for these experiments is limited by the thermal-structural limits of the uncooled experimental hardware. Furthermore, the fuel simulant is helium, not hydrogen. The use of "cold" flows and non-reacting mixtures of fuel simulants for mixing experiments is not new and has been extensively utilized as a screening technique for scramjet fuel injectors. In this study, Reynolds-averaged simulations are utilized (RAS) to systematically verify the implicit assumptions used by the EIMP. This is accomplished by first performing RAS of mixing for two injector configurations at planned nominal experimental

Experimental-demonstrative system for energy conversion using hydrogen fuel cell - preliminary results

International Nuclear Information System (INIS)

Stoenescu, D.; Stefanescu, I.; Patularu, I.; Culcer, M.; Lazar, R.E.; Carcadea, E.; Mirica, D. . E-mail address of corresponding author: daniela@icsi.ro; Stoenescu, D.)

2005-01-01

It is well known that hydrogen is the most promising solution of future energy, both for long and medium term strategies. Hydrogen can be produced using many primary sources (natural gas, methane, biomass, etc.), it can be burned or chemically react having a high yield of energy conversion, being a non-polluted fuel. This paper presents the preliminary results obtained by ICSI Rm. Valcea in an experimental-demonstrative conversion energy system made by a sequence of hydrogen purification units and a CO removing reactors until a CO level lower than 10ppm, that finally feeds a hydrogen fuel stack. (author)

Simultaneous Temperature and Velocity Diagnostic for Reacting Flows, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — A diagnostic technique is proposed for measuring temperature and velocity simultaneously in a high temperature reacting flow for aiding research in propulsion. The...

Corrosion mechanisms of spent fuel under oxidizing conditions

International Nuclear Information System (INIS)

Finn, P.A.; Finch, R.; Buck, E.; Bates, J.

1997-01-01

The release of 99 Tc can be used as a reliable marker for the extent of spent oxide fuel reaction under unsaturated high-drip-rate conditions at 90 degrees C. Evidence from leachate data and from scanning and transmission electron microscopy (SEM and TEM) examination of reacted fuel samples is presented for radionuclide release, potential reaction pathways, and the formation of alteration products. In the ATM-103 fuel, 0.03 of the total inventory of 99 Tc is released in 3.7 years under unsaturated and oxidizing conditions. Two reaction pathways that have been identified from SEM are (1) through-grain dissolution with subsequent formation of uranyl alteration products, and (2) grain-boundary dissolution. The major alteration product identified by x-ray diffraction (XRD) and SEM, is Na-boltwoodite, Na[(UO 2 )(SiO 3 OH)]lg-bullet H 2 O, which is formed from sodium and silicon in the water leachant

Developing Dynamic Single Page Web Applications Using Meteor : Comparing JavaScript Frameworks: Blaze and React

OpenAIRE

Yetayeh, Asabeneh

2017-01-01

This paper studies Meteor which is a JavaScript full-stack framework to develop interactive single page web applications. Meteor allows building web applications entirely in JavaScript. Meteor uses Blaze, React or AngularJS as a view layer and Node.js and MongoDB as a back-end. The main purpose of this study is to compare the performance of Blaze and React. A multi-user Blaze and React web applications with similar HTML and CSS were developed. Both applications were deployed on Heroku’s w...

Assessment of four different cathode materials at different initial pHs using unbuffered catholytes in microbial electrolysis cells

KAUST Repository

Ribot-Llobet, Edgar; Nam, Joo-Youn; Tokash, Justin C.; Guisasola, Albert; Logan, Bruce E.

2013-01-01

Nickel foam (NF), stainless steel wool (SSW), platinum coated stainless steel mesh (Pt), and molybdenum disulfide coated stainless steel mesh (MoS 2) electrodes have been proposed as catalysts for hydrogen gas production, but previous tests have primarily examined their performance in well buffered solutions. These materials were compared using two-chamber microbial electrolysis cells (MECs), and linear sweep voltammetry (LSV) in unbuffered saline solutions at two different initial pHs (7 and 12). There was generally no appreciable effect of initial pH on production rates or total gas production. NF produced hydrogen gas at a rate of 1.1 m3 H2/m 3·d, which was only slightly less than that using Pt (1.4 m3 H2/m3·d), but larger than that obtained with SSW (0.52 m3 H2/m3·d) or MoS2 (0.67 m3 H2/m3·d). Overall hydrogen gas recoveries with SSW (29.7 ± 0.5 mL), MoS2 (28.6 ± 1.3 mL) and NF (32.4 ± 2 mL) were only slightly less than that of Pt (37.9 ± 0.5 mL). Total energy recoveries, based on the gas produced versus electrical energy input, ranged from 0.75 ± 0.02 for Pt, to 0.55 ± 0.02 for SSW. An LSV analysis showed no effect of pH for NF and Pt, but overpotentials were reduced for MoS2 and SSW by using an initial lower pH. At cathode potentials more negative than -0.85 V (vs Ag/AgCl), NF had lower overpotentials than the MoS2. These results provide the first assessment of these materials under practical conditions of high pH in unbuffered saline catholytes, and position NF as the most promising inexpensive alternative to Pt.

Assessment of four different cathode materials at different initial pHs using unbuffered catholytes in microbial electrolysis cells

KAUST Repository

Ribot-Llobet, Edgar

2013-03-01

Nickel foam (NF), stainless steel wool (SSW), platinum coated stainless steel mesh (Pt), and molybdenum disulfide coated stainless steel mesh (MoS 2) electrodes have been proposed as catalysts for hydrogen gas production, but previous tests have primarily examined their performance in well buffered solutions. These materials were compared using two-chamber microbial electrolysis cells (MECs), and linear sweep voltammetry (LSV) in unbuffered saline solutions at two different initial pHs (7 and 12). There was generally no appreciable effect of initial pH on production rates or total gas production. NF produced hydrogen gas at a rate of 1.1 m3 H2/m 3·d, which was only slightly less than that using Pt (1.4 m3 H2/m3·d), but larger than that obtained with SSW (0.52 m3 H2/m3·d) or MoS2 (0.67 m3 H2/m3·d). Overall hydrogen gas recoveries with SSW (29.7 ± 0.5 mL), MoS2 (28.6 ± 1.3 mL) and NF (32.4 ± 2 mL) were only slightly less than that of Pt (37.9 ± 0.5 mL). Total energy recoveries, based on the gas produced versus electrical energy input, ranged from 0.75 ± 0.02 for Pt, to 0.55 ± 0.02 for SSW. An LSV analysis showed no effect of pH for NF and Pt, but overpotentials were reduced for MoS2 and SSW by using an initial lower pH. At cathode potentials more negative than -0.85 V (vs Ag/AgCl), NF had lower overpotentials than the MoS2. These results provide the first assessment of these materials under practical conditions of high pH in unbuffered saline catholytes, and position NF as the most promising inexpensive alternative to Pt.

A model for reaction rates in turbulent reacting flows

Science.gov (United States)

Chinitz, W.; Evans, J. S.

1984-01-01

To account for the turbulent temperature and species-concentration fluctuations, a model is presented on the effects of chemical reaction rates in computer analyses of turbulent reacting flows. The model results in two parameters which multiply the terms in the reaction-rate equations. For these two parameters, graphs are presented as functions of the mean values and intensity of the turbulent fluctuations of the temperature and species concentrations. These graphs will facilitate incorporation of the model into existing computer programs which describe turbulent reacting flows. When the model was used in a two-dimensional parabolic-flow computer code to predict the behavior of an experimental, supersonic hydrogen jet burning in air, some improvement in agreement with the experimental data was obtained in the far field in the region near the jet centerline. Recommendations are included for further improvement of the model and for additional comparisons with experimental data.

Method for the protection of the cladding tubes of fuel rods

International Nuclear Information System (INIS)

Steinberg, E.

1978-01-01

To present stress crack corrosion and to protect the cladding tubes of the fuel rods made of a circonium alloy from attack by iodine, the inward surfaces are provided with protective coatings. Therefore the casting tubes already filled with fuel element pellets are put under over-pressure at a temperature range between 300 and 500 0 C, until almost yield-point is reached. A small amount of H 2 O or H 2 O 2 , filled in, reacts with the cladding tube material to form the Zr-O 2 protective coating. Afterwards comes a pressure relief, and the cladding tube reaches its original dimensions. (DG) [de

Different event-related patterns of gamma-band power in brain waves of fast- and slow-reacting subjects.

Science.gov (United States)

Jokeit, H; Makeig, S

1994-01-01

Fast- and slow-reacting subjects exhibit different patterns of gamma-band electroencephalogram (EEG) activity when responding as quickly as possible to auditory stimuli. This result appears to confirm long-standing speculations of Wundt that fast- and slow-reacting subjects produce speeded reactions in different ways and demonstrates that analysis of event-related changes in the amplitude of EEG activity recorded from the human scalp can reveal information about event-related brain processes unavailable using event-related potential measures. Time-varying spectral power in a selected (35- to 43-Hz) gamma frequency band was averaged across trials in two experimental conditions: passive listening and speeded reacting to binaural clicks, forming 40-Hz event-related spectral responses. Factor analysis of between-subject event-related spectral response differences split subjects into two near-equal groups composed of faster- and slower-reacting subjects. In faster-reacting subjects, 40-Hz power peaked near 200 ms and 400 ms poststimulus in the react condition, whereas in slower-reacting subjects, 40-Hz power just before stimulus delivery was larger in the react condition. These group differences were preserved in separate averages of relatively long and short reaction-time epochs for each group. gamma-band (20-60 Hz)-filtered event-related potential response averages did not differ between the two groups or conditions. Because of this and because gamma-band power in the auditory event-related potential is small compared with the EEG, the observed event-related spectral response features must represent gamma-band EEG activity reliably induced by, but not phase-locked to, experimental stimuli or events. PMID:8022783

Study of subgrid-scale velocity models for reacting and nonreacting flows

Science.gov (United States)

Langella, I.; Doan, N. A. K.; Swaminathan, N.; Pope, S. B.

2018-05-01

A study is conducted to identify advantages and limitations of existing large-eddy simulation (LES) closures for the subgrid-scale (SGS) kinetic energy using a database of direct numerical simulations (DNS). The analysis is conducted for both reacting and nonreacting flows, different turbulence conditions, and various filter sizes. A model, based on dissipation and diffusion of momentum (LD-D model), is proposed in this paper based on the observed behavior of four existing models. Our model shows the best overall agreements with DNS statistics. Two main investigations are conducted for both reacting and nonreacting flows: (i) an investigation on the robustness of the model constants, showing that commonly used constants lead to a severe underestimation of the SGS kinetic energy and enlightening their dependence on Reynolds number and filter size; and (ii) an investigation on the statistical behavior of the SGS closures, which suggests that the dissipation of momentum is the key parameter to be considered in such closures and that dilatation effect is important and must be captured correctly in reacting flows. Additional properties of SGS kinetic energy modeling are identified and discussed.

Electricity generation from cattle dung using microbial fuel cell technology during anaerobic acidogenesis and the development of microbial populations.

Science.gov (United States)

Zhao, Guang; Ma, Fang; Wei, Li; Chua, Hong; Chang, Chein-Chi; Zhang, Xiao-Jun

2012-09-01

A microbial fuel cell (MFC) was constructed to investigate the possible generation of electricity using cattle dung as a substrate. After 30 days of operation, stable electricity was generated, and the maximum volumetric power density was 0.220 W/m(3). The total chemical oxygen demand (TCOD) removal and coulombic efficiency (CE) of the MFC reached 73.9±1.8% and 2.79±0.6%, respectively, after 120 days of operation. Acetate was the main metabolite in the anolyte, and other volatile fatty acids (VFAs) (propionate and butyrate) were present in minor amounts. The PCR-DGGE analysis indicated that the following five groups of microbes were present: Proteobacteria, Bacteroides, Chloroflexi, Actinobacteria and Firmicutes. Proteobacteria and Firmicutes were the dominant phyla in the sample; specifically, 36.3% and 24.2% of the sequences obtained were Proteobacteria and Firmicutes, respectively. Clostridium sp., Pseudomonas luteola and Ochrobactrum pseudogrignonense were the most dominant groups during the electricity generation process. The diversity of archaea dramatically decreased after 20 days of operation. The detected archaea were hydrogenotrophic methanogens, and the Methanobacterium genus disappeared during the periods of stable electricity generation via acidogenesis. Copyright © 2012 Elsevier Ltd. All rights reserved.

DGMK 729. Application characteristics of fuels with biogenic components

Energy Technology Data Exchange (ETDEWEB)

Neulen, Martin; Hoffmann, Hajo [OWI - Oel-Waerme-Institut GmbH, Herzogenrath (Germany)

2013-06-01

Using the test rig developed within a project funded by the DGMK (project 729), fuel can be aged semi-realistically in a short time. The test rig was designed to age a fuel within less than 1,000 hours of operation. Another aspect was to investigate the influence of the different aging mechanisms on the fuel, such as light, ambient air, high temperatures and mechanical stress. By defining these parameters and intensifying them, the goal of 1,000 hours of operation has already been achieved in the first test run. A high repeatability and the possibility to vary the parameters of the test runs for all four nearly identical apparatuses are the main characteristics of this test rig. With this test rig it can be tried out how additives react when the fuel ages and how a fuel behaves during its storage. The test runs are supervised by pressure transducer and thermocouples, so that the test rig can be operated unattendedly when started. During the test run every 300 hours of operation fuel samples are taken. These samples are analyzed according to an analysis matrix. Furthermore, the deposits sedimented in the filters or other components can be analyzed. By this, the aging can be understood and monitored. (orig.)

Effects of Fusion Tack Welds on Self-Reacting Friction Stir Welds

Science.gov (United States)

Nunes, A. C., Jr.; Pendleton, M. L.; Brooke, S. A.; Russell, C. K.

2012-01-01

In order to know whether fusion tack welds would affect the strength of self-reacting friction stir seam welds in 2195-T87 aluminum alloy, the fracture stresses of 144 tensile test coupons cut from 24 welded panels containing segments of friction stir welds were measured. Each of the panels was welded under unique processing conditions. A measure of the effect of the tack welds for each panel was devised. An analysis of the measures of the tack weld effect supported the hypothesis that fusion tack welds do not affect the strength of self-reacting friction stir welds to a 5% level of confidence.

Evaluation of cover gas impurities and their effects on the dry storage of LWR [light-water reactor] spent fuel

International Nuclear Information System (INIS)

Knoll, R.W.; Gilbert, E.R.

1987-11-01

The purposes of this report are to (1) identify the sources of impurity gases in spent fuel storage casks; (2) identify the expected concentrations and types of reactive impurity gases from these sources over an operating lifetime of 40 years; and (3) determine whether these impurities could significantly degrade cladding or exposed fuel during this period. Four potential sources of impurity gases in the helium cover gas in operating casks were identified and evaluated. Several different bounding cases have been considered, where the reactive gas inventory is either assumed to be completely gettered by the cladding or where all oxygen is assumed to react completely with the exposed fuel. It is concluded that the reactive gas inventory will have no significant effect on the cladding unless all available oxygen reacts with the UO 2 fuel to produce U 3 O 8 at one or two cladding breaches. Based on Zircaloy oxidation data, the oxygen inventory in a fully loaded pressurized water reactor cask such as the Castor-V/21 will be gettered by the Zircaloy cladding in about 1 year if the peak cladding temperature within the task is ≥300 0 C. Only a negligible decrease in the thickness of the cladding would result. 24 refs., 4 tabs

Direct numerical simulations of reacting flows with detailed chemistry using many-core/GPU acceleration

KAUST Repository

Herná ndez Pé rez, Francisco E.; Mukhadiyev, Nurzhan; Xu, Xiao; Sow, Aliou; Lee, Bok Jik; Sankaran, Ramanan; Im, Hong G.

2018-01-01

A new direct numerical simulation (DNS) code for multi-component gaseous reacting flows has been developed at KAUST, with the state-of-the-art programming model for next generation high performance computing platforms. The code, named KAUST Adaptive Reacting Flows Solver (KARFS), employs the MPI+X programming, and relies on Kokkos for “X” for performance portability to multi-core, many-core and GPUs, providing innovative software development while maintaining backward compatibility with established parallel models and legacy code. The capability and potential of KARFS to perform DNS of reacting flows with large, detailed reaction mechanisms is demonstrated with various model problems involving ignition and turbulent flame propagations with varying degrees of chemical complexities.

Direct numerical simulations of reacting flows with detailed chemistry using many-core/GPU acceleration

KAUST Repository

Hernández Pérez, Francisco E.

2018-03-29

A new direct numerical simulation (DNS) code for multi-component gaseous reacting flows has been developed at KAUST, with the state-of-the-art programming model for next generation high performance computing platforms. The code, named KAUST Adaptive Reacting Flows Solver (KARFS), employs the MPI+X programming, and relies on Kokkos for “X” for performance portability to multi-core, many-core and GPUs, providing innovative software development while maintaining backward compatibility with established parallel models and legacy code. The capability and potential of KARFS to perform DNS of reacting flows with large, detailed reaction mechanisms is demonstrated with various model problems involving ignition and turbulent flame propagations with varying degrees of chemical complexities.

Birefringence characteristics in sperm heads allow for the selection of reacted spermatozoa for intracytoplasmic sperm injection.

Science.gov (United States)

Gianaroli, Luca; Magli, M Cristina; Ferraretti, Anna P; Crippa, Andor; Lappi, Michela; Capitani, Serena; Baccetti, Baccio

2010-02-01

To verify clinical outcome after injection of spermatozoa that have undergone the acrosome reaction (reacted spermatozoa) vs. those still having an intact acrosome (nonreacted spermatozoa). Prospective, randomized study. Reproductive Medicine Unit, Italian Society for the Study of Reproductive Medicine, Bologna, Italy. According to a prospective randomization including 71 couples with severe male factor infertility, intracytoplasmic sperm injection (ICSI) was performed under polarized light that permitted analysis of the pattern of birefringence in the sperm head. Twenty-three patients had their oocytes injected with reacted spermatozoa, 26 patient's oocytes were injected with nonreacted spermatozoa, and in 22 patients both reacted and nonreacted spermatozoa were injected. Intracytoplasmic sperm injection was performed under polarized light to selectively inject acrosome-reacted and acrosome-nonreacted spermatozoa. Rates of fertilization, cleavage, pregnancy, implantation, and ongoing implantation. There was no effect on the fertilizing capacity and embryo development of either type of sperm, whereas the implantation rate was higher in oocytes injected with reacted spermatozoa (39.0%) vs. those injected with nonreacted spermatozoa (8.6%). The implantation rate was 24.4% in the group injected with both reacted and nonreacted spermatozoa. The delivery rate per cycle followed the same trend. Spermatozoa that have undergone the acrosome reaction seem to be more prone to supporting the development of viable ICSI embryos. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Second law analysis of a reacting temperature dependent viscous ...

African Journals Online (AJOL)

In this paper, entropy generation during the flow of a reacting viscous fluid through an inclined Channel with isothermal walls are investigated. The coupled energy and momentum equations were solved numerically. Previous results in literature (Adesanya et al 2006 [[17]) showed both velocity and temperature have two ...

Aerodynamic characteristics and thermal structure of nonpremixed reacting swirling wakes at low Reynolds numbers

Energy Technology Data Exchange (ETDEWEB)

Huang, Rong F. [Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei (China); Yen, Shun C. [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung (China)

2008-12-15

The aerodynamic characteristics and thermal structure of uncontrolled and controlled swirling double-concentric jet flames at low Reynolds numbers are experimentally studied. The swirl and Reynolds numbers are lower than 0.6 and 2000, respectively. The flow characteristics are diagnosed by the laser-light-sheet-assisted Mie scattering flow visualization method and particle image velocimetry (PIV). The thermal structure is measured by a fine-wire thermocouple. The flame shapes, combined images of flame and flow, velocity vector maps, streamline patterns, velocity and turbulence distributions, flame lengths, and temperature distributions are discussed. The flow patterns of the no-control case exhibit an open-top, single-ring vortex sitting on the blockage disc with a jetlike swirling flow evolving from the central disc face toward the downstream area. The rotation direction and size of the near-disc vortex, as well as the flow properties, change in different ranges of annulus swirl number and therefore induce three characteristic flame modes: weak swirling flame, lifted flame, and turbulent reattached flame. Because the near-disc vortex is open-top, the radial dispersion of the fuel-jet fluids is not significantly enhanced by the annulus swirling flow. The flows of the reacting swirling double-concentric jets at such low swirl and Reynolds numbers therefore present characteristics of diffusion jet flames. In the controlled case, the axial momentum of the central fuel jet is deflected radially by a control disc placed above the blockage disc. This arrangement can induce a large near-disc recirculation bubble and high turbulence intensities. The enhanced mixing hence tremendously shortens the flame length and enlarges the flame width. (author)

Characterization of Regional Marginal Abatement Cost Curves for NOx that Incorporate Control Measures, Renewable Energy, Energy Efficiency and Fuel Switching

Science.gov (United States)

Anthropogenic nitrogen oxides (NOx) are emitted when fossil fuels are combusted. In the atmosphere, NOx reacts with volatile organic compounds (VOCs) to produce tropospheric ozone, a component of photochemical smog. In most parts of the country, strategies for reducing ozone gene...

Fuel performance computer code simulation of steady-state and transient regimes of the stainless steel fuel rods

International Nuclear Information System (INIS)

Gomes, Daniel de Souza

2014-01-01

The immediate cause of the accident at the Fukushima Daiichi nuclear plant in March 2011 was the meltdown of the reactor core. During this process, the zirconium cladding of the fuel reacts with water, producing a large amount of hydrogen. This hydrogen, combined with volatile radioactive materials leaked from the containment vessel and entered the building of the reactor, resulting in explosions. In the past, stainless steel was used as the coating in many pressurized water reactors (PWR) under irradiation and their performance was excellent, however, the stainless steel was replaced by a zirconium-based alloy as a coating material mainly due to its lower section shock-absorbing neutrons. Today, the stainless steel finish appears again as a possible solution for security issues related to the explosion and hydrogen production. The objective of this thesis is to discuss the performance under irradiation of fuel rods using stainless steel as a coating material. The results showed that stainless steel rods exhibit lower temperatures and higher fuel pellet width of the gap - coating the coated rods Zircaloy and this gap does not close during the irradiation. The thermal performance of the two fuel rods is very similar, and the penalty of increased absorption of neutrons due to the use of stainless steel can be offset by the combination of a small increase in the enrichment of U- 235 and changes in the size of the spacing between the fuel rods. (author)

Chlorine in solid fuels fired in pulverized fuel boilers sources, forms, reactions, and consequences: a literature review

Energy Technology Data Exchange (ETDEWEB)

David A. Tillman; Dao Duong; Bruce Miller [Foster Wheeler North America Corp. (United States)

2009-07-15

Chlorine is a significant source of corrosion and deposition, both from coal and from biomass, and in PF boilers. This investigation was designed to highlight the potential for corrosion risks associated with once-through units and advanced cycles. The research took the form of a detailed literature investigation to evaluate chlorine in solid fuels: coals of various ranks and origins, biomass fuels of a variety of types, petroleum cokes, and blends of the above. The investigation focused upon an extensive literature review of documents dating back to 1991. The focus is strictly corrosion and deposition. To address the deposition and corrosion issues, this review evaluates the following considerations: concentrations of chlorine in available solid fuels including various coals and biomass fuels, forms of chlorine in those fuels, and reactions - including reactivities - of chlorine in such fuels. The assessment includes consideration of alkali metals and alkali earth elements as they react with, and to, the chlorine and other elements (e.g., sulfur) in the fuel and in the gaseous products of combustion. The assessment also includes other factors of combustion: for example, combustion conditions including excess O{sub 2} and combustion temperatures. It also considers analyses conducted at all levels: theoretical calculations, bench scale laboratory data and experiments, pilot plant experiments, and full scale plant experience. Case studies and plant surveys form a significant consideration in this review. The result of this investigation focuses upon the concentrations of chlorine acceptable in coals burned exclusively, in coals burned with biomass, and in biomass cofired with coal. Values are posited based upon type of fuel and combustion technology. Values are also posited based upon both first principles and field experience. 86 refs., 8 figs., 7 tabs.

Numerical Simulations of Two-Phase Reacting Flow in a Single-Element Lean Direct Injection (LDI) Combustor Using NCC

Science.gov (United States)

Liu, Nan-Suey; Shih, Tsan-Hsing; Wey, C. Thomas

2011-01-01

A series of numerical simulations of Jet-A spray reacting flow in a single-element lean direct injection (LDI) combustor have been conducted by using the National Combustion Code (NCC). The simulations have been carried out using the time filtered Navier-Stokes (TFNS) approach ranging from the steady Reynolds-averaged Navier-Stokes (RANS), unsteady RANS (URANS), to the dynamic flow structure simulation (DFS). The sub-grid model employed for turbulent mixing and combustion includes the well-mixed model, the linear eddy mixing (LEM) model, and the filtered mass density function (FDF/PDF) model. The starting condition of the injected liquid spray is specified via empirical droplet size correlation, and a five-species single-step global reduced mechanism is employed for fuel chemistry. All the calculations use the same grid whose resolution is of the RANS type. Comparisons of results from various models are presented.

Differing Event-Related Patterns of Gamma-Band Power in Brain Waves of Fast- and Slow-Reacting Subjects

Science.gov (United States)

1994-05-01

Wilhelm Wundt proposed that there are two types of subjects in sim- ple RT experiments: fast-reacting subjects, who respond before they fully...quickly as possible to auditory stimuli. This result appears to confirm long-standing speculations of Wundt that fast- and slow-reacting subjects...accord with the hypothesis of Wundt and others that slower ("sensorial") responders wait to fully perceive a stimulus and then react to their perception

Nitrogen-doped fullerene as a potential catalyst for hydrogen fuel cells.

Science.gov (United States)

Gao, Feng; Zhao, Guang-Lin; Yang, Shizhong; Spivey, James J

2013-03-06

We examine the possibility of nitrogen-doped C60 fullerene (N-C60) as a cathode catalyst for hydrogen fuel cells. We use first-principles spin-polarized density functional theory calculations to simulate the electrocatalytic reactions on N-C60. The first-principles results show that an O2 molecule can be adsorbed and partially reduced on the N-C complex sites (Pauling sites) of N-C60 without any activation barrier. Through a direct pathway, the partially reduced O2 can further react with H(+) and additional electrons and complete the water formation reaction (WFR) with no activation energy barrier. In the indirect pathway, reduced O2 reacts with H(+) and additional electrons to form H2O molecules through a transition state (TS) with a small activation barrier (0.22-0.37 eV). From an intermediate state to a TS, H(+) can obtain a kinetic energy of ∼0.95-3.68 eV, due to the Coulomb electric interaction, and easily overcome the activation energy barrier during the WFR. The full catalytic reaction cycles can be completed energetically, and N-C60 fullerene recovers to its original structure for the next catalytic reaction cycle. N-C60 fullerene is a potential cathode catalyst for hydrogen fuel cells.

Aircraft Fuel Cell Power Systems

Science.gov (United States)

Needham, Robert

2004-01-01

In recent years, fuel cells have been explored for use in aircraft. While the weight and size of fuel cells allows only the smallest of aircraft to use fuel cells for their primary engines, fuel cells have showed promise for use as auxiliary power units (APUs), which power aircraft accessories and serve as an electrical backup in case of an engine failure. Fuel cell MUS are both more efficient and emit fewer pollutants. However, sea-level fuel cells need modifications to be properly used in aircraft applications. At high altitudes, the ambient air has a much lower pressure than at sea level, which makes it much more difficult to get air into the fuel cell to react and produce electricity. Compressors can be used to pressurize the air, but this leads to added weight, volume, and power usage, all of which are undesirable things. Another problem is that fuel cells require hydrogen to create electricity, and ever since the Hindenburg burst into flames, aircraft carrying large quantities of hydrogen have not been in high demand. However, jet fuel is a hydrocarbon, so it is possible to reform it into hydrogen. Since jet fuel is already used to power conventional APUs, it is very convenient to use this to generate the hydrogen for fuel-cell-based APUs. Fuel cells also tend to get large and heavy when used for applications that require a large amount of power. Reducing the size and weight becomes especially beneficial when it comes to fuel cells for aircraft. My goal this summer is to work on several aspects of Aircraft Fuel Cell Power System project. My first goal is to perform checks on a newly built injector rig designed to test different catalysts to determine the best setup for reforming Jet-A fuel into hydrogen. These checks include testing various thermocouples, transmitters, and transducers, as well making sure that the rig was actually built to the design specifications. These checks will help to ensure that the rig will operate properly and give correct results

Coated U(Mo) Fuel: As-Fabricated Microstructures

Energy Technology Data Exchange (ETDEWEB)

Emmanuel Perez; Dennis D. Keiser, Jr.; Ann Leenaers; Sven Van den Berghe; Tom Wiencek

2014-04-01

As part of the development of low-enriched uranium fuels, fuel plates have recently been tested in the BR-2 reactor as part of the SELENIUM experiment. These fuel plates contained fuel particles with either Si or ZrN thin film coating (up to 1 µm thickness) around the U-7Mo fuel particles. In order to best understand irradiation performance, it is important to determine the starting microstructure that can be observed in as-fabricated fuel plates. To this end, detailed microstructural characterization was performed on ZrN and Si-coated U-7Mo powder in samples taken from AA6061-clad fuel plates fabricated at 500°C. Of interest was the condition of the thin film coatings after fabrication at a relatively high temperature. Both scanning electron microscopy and transmission electron microscopy were employed. The ZrN thin film coating was observed to consist of columns comprised of very fine ZrN grains. Relatively large amounts of porosity could be found in some areas of the thin film, along with an enrichment of oxygen around each of the the ZrN columns. In the case of the pure Si thin film coating sample, a (U,Mo,Al,Si) interaction layer was observed around the U-7Mo particles. Apparently, the Si reacted with the U-7Mo and Al matrix during fuel plate fabrication at 500°C to form this layer. The microstructure of the formed layer is very similar to those that form in U-7Mo versus Al-Si alloy diffusion couples annealed at higher temperatures and as-fabricated U-7Mo dispersion fuel plates with Al-Si alloy matrix fabricated at 500°C.

The impact of new cathode materials relative to baseline performance of microbial fuel cells all with the same architecture and solution chemistry

KAUST Repository

Yang, Wulin

2017-04-21

Differences in microbial fuel cell (MFC) architectures, materials, and solution chemistries, have previously hindered direct comparisons of improvements in power production due to new cathode materials. However, one common reactor design has now been used in many different laboratories around the world under similar operating conditions based on using: a graphite fiber brush anode, a platinum cathode catalyst, a single-chamber cube-shaped (4-cm) MFC with a 3-cm diameter anolyte chamber, 50 mM phosphate buffer, and an acetate fuel. Analysis of several publications over 10 years from a single laboratory showed that even under such identical operational conditions, maximum power densities varied by 15%, with an average of 1.36 ± 0.20 W m–2 (n=24), normalized to cathode projected area (34 W m–3 liquid volume). In other laboratories, maximum power was significantly less, with an average of 1.03 ± 0.46 W m–2 (n=11), despite identical conditions. One likely reason for the differences in power is cathode age. Power production with Pt catalyst cathodes significantly declined after one month of operation or more to 0.87 ± 0.31 W m–2 (n=18) based on studies where cathode aging was examined, while in many studies the age of the cathode was not reported. Using these studies as a performance baseline, we review the claims of improvements in power generation due to new anode or cathode materials, or changes in solution conductivities and substrates.

Computational Investigation of Soot and Radiation in Turbulent Reacting Flows

Science.gov (United States)

Lalit, Harshad

This study delves into computational modeling of soot and infrared radiation for turbulent reacting flows, detailed understanding of both of which is paramount in the design of cleaner engines and pollution control. In the first part of the study, the concept of Stochastic Time and Space Series Analysis (STASS) as a numerical tool to compute time dependent statistics of radiation intensity is introduced for a turbulent premixed flame. In the absence of high fidelity codes for large eddy simulation or direct numerical simulation of turbulent flames, the utility of STASS for radiation imaging of reacting flows to understand the flame structure is assessed by generating images of infrared radiation in spectral bands dominated by radiation from gas phase carbon dioxide and water vapor using an assumed PDF method. The study elucidates the need for time dependent computation of radiation intensity for validation with experiments and the need for accounting for turbulence radiation interactions for correctly predicting radiation intensity and consequently the flame temperature and NOx in a reacting fluid flow. Comparison of single point statistics of infrared radiation intensity with measurements show that STASS can not only predict the flame structure but also estimate the dynamics of thermochemical scalars in the flame with reasonable accuracy. While a time series is used to generate realizations of thermochemical scalars in the first part of the study, in the second part, instantaneous realizations of resolved scale temperature, CO2 and H2O mole fractions and soot volume fractions are extracted from a large eddy simulation (LES) to carry out quantitative imaging of radiation intensity (QIRI) for a turbulent soot generating ethylene diffusion flame. A primary motivation of the study is to establish QIRI as a computational tool for validation of soot models, especially in the absence of conventional flow field and measured scalar data for sooting flames. Realizations of

Room Temperature, Hybrid Sodium-Based Flow Batteries with Multi-Electron Transfer Redox Reactions

Science.gov (United States)

Shamie, Jack S.; Liu, Caihong; Shaw, Leon L.; Sprenkle, Vincent L.

2015-01-01

We introduce a new concept of hybrid Na-based flow batteries (HNFBs) with a molten Na alloy anode in conjunction with a flowing catholyte separated by a solid Na-ion exchange membrane for grid-scale energy storage. Such HNFBs can operate at ambient temperature, allow catholytes to have multiple electron transfer redox reactions per active ion, offer wide selection of catholyte chemistries with multiple active ions to couple with the highly negative Na alloy anode, and enable the use of both aqueous and non-aqueous catholytes. Further, the molten Na alloy anode permits the decoupled design of power and energy since a large volume of the molten Na alloy can be used with a limited ion-exchange membrane size. In this proof-of-concept study, the feasibility of multi-electron transfer redox reactions per active ion and multiple active ions for catholytes has been demonstrated. The critical barriers to mature this new HNFBs have also been explored. PMID:26063629

Improving Accident Tolerance of Nuclear Fuel with Coated Mo-alloy Cladding

OpenAIRE

Bo Cheng; Young-Jin Kim; Peter Chou

2016-01-01

In severe loss of coolant accidents (LOCA), similar to those experienced at Fukushima Daiichi and Three Mile Island Unit 1, the zirconium alloy fuel cladding materials are rapidly heated due to nuclear decay heating and rapid exothermic oxidation of zirconium with steam. This heating causes the cladding to rapidly react with steam, lose strength, burst or collapse, and generate large quantities of hydrogen gas. Although maintaining core cooling remains the highest priority in accident managem...

A Fuel-Sensitive Reduced-Order Model (ROM) for Piston Engine Scaling Analysis

Science.gov (United States)

2017-09-29

of high Reynolds number nonreacting and reacting JP-8 sprays in a constant pressure flow vessel with a detailed chemistry approach . J Energy Resour...for rapid grid generation applied to in-cylinder diesel engine simulations. Society of Automotive Engineers ; 2007 Apr. SAE Technical Paper No.: 2007...ARL-TR-8172 ● Sep 2017 US Army Research Laboratory A Fuel-Sensitive Reduced-Order Model (ROM) for Piston Engine Scaling Analysis

[A surface reacted layer study of titanium-zirconium alloy after dental casting].

Science.gov (United States)

Zhang, Y; Guo, T; Li, Z; Li, C

2000-10-01

To investigate the influence of the mold temperature on the surface reacted layer of Ti-Zr alloy castings. Ti-Zr alloy was casted into a mold which was made of a zircon (ZrO2.SiO2) for inner coating and a phosphate-bonded material for outer investing with a casting machine (China) designed as vacuum, pressure and centrifuge. At three mold temperatures (room temperature, 300 degrees C, 600 degrees C) the Ti-Zr alloy was casted separately. The surface roughness of the castings was calculated by instrument of smooth finish (China). From the surface to the inner part the Knoop hardness and thickness in reacted layer of Ti-Zr alloy casting was measured. The structure of the surface reacted layer was analysed by SEM. Elemental analyses of the interfacial zone of the casting was made by element line scanning observation. The surface roughness of the castings was increased significantly with the mold temperature increasing. At a higher mold temperature the Knoop hardness of the reactive layer was increased. At the three mold temperature the outmost surface was very hard, and microhardness data decreased rapidly where they reached constant values. The thickness was about 85 microns for castings at room temperature and 300 degrees C, 105 microns for castings at 600 degrees C. From the SEM micrograph of the Ti-Zr alloy casting, the surface reacted layer could be divided into three different layers. The first layer was called non-structure layer, which thickness was about 10 microns for room temperature group, 20 microns for 300 degrees C and 25 microns for 600 degrees C. The second layer was characterized by coarse-grained acicular crystal, which thickness was about 50 microns for three mold temperatures. The third layer was Ti-Zr alloy. The element line scanning showed non-structure layer with higher level of element of O, Al, Si and Zr, The higher the mold temperature during casting, the deeper the Si permeating and in the second layer the element Si could also be found

A novel H2S/H2O2 fuel cell operating at the room temperature

Energy Technology Data Exchange (ETDEWEB)

Sanli, Ayse Elif [Gazi University (Turkey)], email: aecsanli@gmail.com; Aytac, Aylin [Department of Chemistry, Faculty of Science, Gazi University, Teknikokullar (Turkey)], email: aytaca@gazi.edu.tr

2011-07-01

This study concerns the oxidation mechanism of hydrogen sulfide and a fuel cell; acidic peroxide is used as the oxidant and basic hydrogen sulfide is the fuel. A solid state H2S/H2O2 stable fuel cell was produced at room temperature. A cell potential of 0.85 V was reached; this is quite remarkable in comparison to the H2S/O2 fuel cell potential of 0.85 V obtained at 850-1000 degree celsius. The hydrogen sulfide goes through an oxidation reaction in the alkaline fuel cell (H2S/H2O2 fuel cell) which opens up the possibility of using the cheaper nickel as a catalyst. As a result, the fuel cell becomes a potentially low cost technology. A further benefit from using H2S as the alkaline liquid H2S/H2O2 fuel cell, is that sulfide ions are oxidized at the anode, releasing electrons. Sulfur produced reacts with the other sulfide ions and forms disulfide and polysulfide ions in basic electrolytes (such as Black Sea water).

Experimental thermodynamics experimental thermodynamics of non-reacting fluids

CERN Document Server

Neindre, B Le

2013-01-01

Experimental Thermodynamics, Volume II: Experimental Thermodynamics of Non-reacting Fluids focuses on experimental methods and procedures in the study of thermophysical properties of fluids. The selection first offers information on methods used in measuring thermodynamic properties and tests, including physical quantities and symbols for physical quantities, thermodynamic definitions, and definition of activities and related quantities. The text also describes reference materials for thermometric fixed points, temperature measurement under pressures, and pressure measurements. The publicatio

Numerical exploration of mixing and combustion in ethylene fueled scramjet combustor

Science.gov (United States)

Dharavath, Malsur; Manna, P.; Chakraborty, Debasis

2015-12-01

Numerical simulations are performed for full scale scramjet combustor of a hypersonic airbreathing vehicle with ethylene fuel at ground test conditions corresponding to flight Mach number, altitude and stagnation enthalpy of 6.0, 30 km and 1.61 MJ/kg respectively. Three dimensional RANS equations are solved along with species transport equations and SST-kω turbulence model using Commercial CFD software CFX-11. Both nonreacting (with fuel injection) and reacting flow simulations [using a single step global reaction of ethylene-air with combined combustion model (CCM)] are carried out. The computational methodology is first validated against experimental results available in the literature and the performance parameters of full scale combustor in terms of thrust, combustion efficiency and total pressure loss are estimated from the simulation results. Parametric studies are conducted to study the effect of fuel equivalence ratio on the mixing and combustion behavior of the combustor.

Does the StartReact Effect Apply to First-Trial Reactive Movements?

Directory of Open Access Journals (Sweden)

Katrin Sutter

Full Text Available StartReact is the acceleration of reaction time by a startling acoustic stimulus (SAS. The SAS is thought to release a pre-prepared motor program. Here, we investigated whether the StartReact effect is applicable to the very first trial in a series of repeated unpractised single-joint movements.Twenty healthy young subjects were instructed to perform a rapid ankle dorsiflexion movement in response to an imperative stimulus. Participants were divided in two groups of ten. Both groups performed 17 trials. In one group a SAS (116 dB was given in the first trial, whereas the other group received a non-startling sound (70 dB as the first imperative stimulus. In the remaining 16 trials, the SAS was given as the imperative stimulus in 25% of the trials in both groups. The same measurement was repeated one week later, but with the first-trial stimuli counterbalanced between groups.When a SAS was given in the very first trial, participants had significantly shorter onset latencies compared to first-trial responses to a non-startling stimulus. Succeeding trials were significantly faster compared to the first trial, both for trials with and without a SAS. However, the difference between the first and succeeding trials was significantly larger for responses to a non-startling stimulus compared to responses triggered by a SAS. SAS-induced acceleration in the first trial of the second session was similar to that in succeeding trials of session 1.The present results confirm that the StartReact phenomenon also applies to movements that have not yet been practiced in the experimental context. The excessive SAS-induced acceleration in the very first trial may be due to the absence of integration of novel context-specific information with the existing motor memory for movement execution. Our findings demonstrate that StartReact enables a rapid release of motor programs in the very first trial also without previous practice, which might provide a behavioural

Determining Bond Sodium Remaining in Plenum Region of Spent Nuclear Driver Fuel

International Nuclear Information System (INIS)

Vaden, D.; Li, S.X.

2008-01-01

The Fuel Conditioning Facility (FCF) at the Idaho National Laboratory (INL) treats spent nuclear fuel using an electro-chemical process that separates the uranium from the fission products, sodium thermal bond, and cladding materials (REF 1). Upon immersion into the ER electrolyte, the sodium used to thermally bond the fuel to the clad jacket chemically reacts with the UCl3 in the electrolyte producing NaCl and uranium metal. The uranium in the spent fuel is separated from the cladding and fission products by taking advantage of the electro-chemical potential differences between uranium and the other fuel components. Assuming all the sodium in the thermal bond is converted to NaCl in the ER, the difference between the cumulative bond sodium mass in the fuel elements and the cumulative sodium mass found in the driver ER electrolyte inventory provides an upper mass limit for the sodium that migrated to the upper gas region, or plenum section, of the fuel element during irradiation in the reactor. The plenums are to be processed as metal waste via melting and metal consolidation operations. However, depending on the amount of sodium in the plenums, additional processing may be required to remove the sodium before metal waste processing

Direct numerical simulation of turbulent reacting flows

Energy Technology Data Exchange (ETDEWEB)

Chen, J.H. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01

The development of turbulent combustion models that reflect some of the most important characteristics of turbulent reacting flows requires knowledge about the behavior of key quantities in well defined combustion regimes. In turbulent flames, the coupling between the turbulence and the chemistry is so strong in certain regimes that is is very difficult to isolate the role played by one individual phenomenon. Direct numerical simulation (DNS) is an extremely useful tool to study in detail the turbulence-chemistry interactions in certain well defined regimes. Globally, non-premixed flames are controlled by two limiting cases: the fast chemistry limit, where the turbulent fluctuations. In between these two limits, finite-rate chemical effects are important and the turbulence interacts strongly with the chemical processes. This regime is important because industrial burners operate in regimes in which, locally the flame undergoes extinction, or is at least in some nonequilibrium condition. Furthermore, these nonequilibrium conditions strongly influence the production of pollutants. To quantify the finite-rate chemistry effect, direct numerical simulations are performed to study the interaction between an initially laminar non-premixed flame and a three-dimensional field of homogeneous isotropic decaying turbulence. Emphasis is placed on the dynamics of extinction and on transient effects on the fine scale mixing process. Differential molecular diffusion among species is also examined with this approach, both for nonreacting and reacting situations. To address the problem of large-scale mixing and to examine the effects of mean shear, efforts are underway to perform large eddy simulations of round three-dimensional jets.

Low Mach number asymptotics for reacting compressible fluid flows

Czech Academy of Sciences Publication Activity Database

Feireisl, Eduard; Petzeltová, Hana

2010-01-01

Roč. 26, č. 2 (2010), s. 455-480 ISSN 1078-0947 R&D Projects: GA ČR GA201/05/0164 Institutional research plan: CEZ:AV0Z10190503 Keywords : low Mach number * Navier-Stokes-Fourier system * reacting fluids Subject RIV: BA - General Mathematics Impact factor: 0.986, year: 2010 http://www.aimsciences.org/journals/displayArticles.jsp?paperID=4660

Fission-product SiC reaction in HTGR fuel

International Nuclear Information System (INIS)

Montgomery, F.

1981-01-01

The primary barrier to release of fission product from any of the fuel types into the primary circuit of the HTGR are the coatings on the fuel particles. Both pyrolytic carbon and silicon carbide coatings are very effective in retaining fission gases under normal operating conditions. One of the possible performance limitations which has been observed in irradiation tests of TRISO fuel is chemical interaction of the SiC layer with fission products. This reaction reduces the thickness of the SiC layer in TRISO particles and can lead to release of fission products from the particles if the SiC layer is completely penetrated. The experimental section of this report describes the results of work at General Atomic concerning the reaction of fission products with silicon carbide. The discussion section describes data obtained by various laboratories and includes (1) a description of the fission products which have been found to react with SiC; (2) a description of the kinetics of silicon carbide thinning caused by fission product reaction during out-of-pile thermal gradient heating and the application of these kinetics to in-pile irradiation; and (3) a comparison of silicon carbide thinning in LEU and HEU fuels

Assessment of environmentally friendly fuel emissions from in-use vehicle exhaust: low-blend iso-stoichiometric GEM mixture as example.

Science.gov (United States)

Schifter, Isaac; Díaz-Gutiérrez, Luis; Rodríguez-Lara, René; González-Macías, Carmen; González-Macías, Uriel

2017-05-01

Gasoline-ethanol-methanol fuel blends were formulated with the same stoichiometric air-to-fuel ratio and volumetric energy concentration as any binary ethanol-gasoline blend. When the stoichiometric blends operated in a vehicle, the time period, injector voltage, and pressure for each fuel injection event in the engine corresponded to a given stoichiometric air-to-fuel ratio, and the load was essentially constant. Three low oxygen content iso-stoichiometric ternary gasoline-ethanol-methanol fuel blends were prepared, and the properties were compared with regular-type fuel without added oxygen. One of the ternary fuels was tested using a fleet of in-use vehicles for15 weeks and compared to neat gasoline without oxygenated compounds as a reference. Only a small number of publications have compared these ternary fuels in the same engine, and little data exist on the performance and emissions of in-use spark-ignition engines. The total hydrocarbon emissions observed was similar in both fuels, in addition to the calculated ozone forming potential of the tailpipe and evaporative emissions. In ozone non-attainment areas, the original purpose for oxygenate gasolines was to decrease carbon monoxide emissions. The results suggest that the strategy is less effective than expected because there still exist a great number of vehicles that have suffered the progressive deterioration of emissions and do not react to oxygenation, while new vehicles are equipped with sophisticated air/fuel control systems, and oxygenation does not improve combustion because the systems adjust the stoichiometric point, making it insensitive to the origin of the added excess oxygen (fuel or excess air). Graphical abstract Low level ternary blend of gasoline-ethanol-methanol were prepared with the same stoichiometric air-fuel ratio and volumetric energy concentration, based on the volumetric energy density of the pre-blended components. Exhaust and evaporative emissions was compared with a blend

Molecular Simulation of Reacting Systems; TOPICAL

International Nuclear Information System (INIS)

THOMPSON, AIDAN P.

2002-01-01

The final report for a Laboratory Directed Research and Development project entitled, Molecular Simulation of Reacting Systems is presented. It describes efforts to incorporate chemical reaction events into the LAMMPS massively parallel molecular dynamics code. This was accomplished using a scheme in which several classes of reactions are allowed to occur in a probabilistic fashion at specified times during the MD simulation. Three classes of reaction were implemented: addition, chain transfer and scission. A fully parallel implementation was achieved using a checkerboarding scheme, which avoids conflicts due to reactions occurring on neighboring processors. The observed chemical evolution is independent of the number of processors used. The code was applied to two test applications: irreversible linear polymerization and thermal degradation chemistry

Computer program for obtaining thermodynamic and transport properties of air and products of combustion of ASTM-A-1 fuel and air

Science.gov (United States)

Hippensteele, S. A.; Colladay, R. S.

1978-01-01

A computer program for determining desired thermodynamic and transport property values by means of a three-dimensional (pressure, fuel-air ratio, and either enthalpy or temperature) interpolation routine was developed. The program calculates temperature (or enthalpy), molecular weight, viscosity, specific heat at constant pressure, thermal conductivity, isentropic exponent (equal to the specific heat ratio at conditions where gases do not react), Prandtl number, and entropy for air and a combustion gas mixture of ASTM-A-1 fuel and air over fuel-air ratios from zero to stoichiometric, pressures from 1 to 40 atm, and temperatures from 250 to 2800 K.

Numerical Simulations of High Reactivity Gasoline Fuel Sprays under Vaporizing and Reactive Conditions

KAUST Repository

Mohan, Balaji; Jaasim, Mohammed; Ahmed, Ahfaz; Hernandez Perez, Francisco; Sim, Jaeheon; Roberts, William L.; Sarathy, Mani; Im, Hong G.

2018-01-01

Gasoline compression ignition (GCI) engines are becoming more popular alternative for conventional spark engines to harvest the advantage of high volatility. Recent experimental study demonstrated that high reactivity gasoline fuel can be operated in a conventional mixing controlled combustion mode producing lower soot emissions than that of diesel fuel under similar efficiency and NOx level [1]. Therefore, there is much interest in using gasoline-like fuels in compression ignition engines. In order to improve the fidelity of simulation-based GCI combustion system development, it is mandatory to enhance the prediction of spray combustion of gasoline-like fuels. The purpose of this study is to model the spray characteristics of high reactivity gasoline fuels and validate the models with experimental results obtained through an optically accessible constant volume vessel under vaporizing [2] and reactive conditions [3]. For reacting cases, a comparison of PRF and KAUST multi-component surrogate (KMCS) mechanism was done to obtain good agreement with the experimental ignition delay. From this study, some recommendations were proposed for GCI combustion modelling framework using gasoline like fuels.

Numerical Simulations of High Reactivity Gasoline Fuel Sprays under Vaporizing and Reactive Conditions

KAUST Repository

Mohan, Balaji

2018-04-03

Gasoline compression ignition (GCI) engines are becoming more popular alternative for conventional spark engines to harvest the advantage of high volatility. Recent experimental study demonstrated that high reactivity gasoline fuel can be operated in a conventional mixing controlled combustion mode producing lower soot emissions than that of diesel fuel under similar efficiency and NOx level [1]. Therefore, there is much interest in using gasoline-like fuels in compression ignition engines. In order to improve the fidelity of simulation-based GCI combustion system development, it is mandatory to enhance the prediction of spray combustion of gasoline-like fuels. The purpose of this study is to model the spray characteristics of high reactivity gasoline fuels and validate the models with experimental results obtained through an optically accessible constant volume vessel under vaporizing [2] and reactive conditions [3]. For reacting cases, a comparison of PRF and KAUST multi-component surrogate (KMCS) mechanism was done to obtain good agreement with the experimental ignition delay. From this study, some recommendations were proposed for GCI combustion modelling framework using gasoline like fuels.

Rule-Based Multidisciplinary Tool for Unsteady Reacting Real-Fluid Flows, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — A design and analysis computational tool is proposed for simulating unsteady reacting flows in combustor devices used in reusable launch vehicles. Key aspects...

Numerical modelling of fuel sprays

Energy Technology Data Exchange (ETDEWEB)

Bergstroem, C.

1999-06-01

The way the fuel is introduced into the combustion chamber is one of the most important parameters for the power output and the generation of emissions in the combustion of liquid fuels. The interaction between the turbulent gas flow field and the liquid fuel droplets, the vaporisation of them and the mixing of the gaseous fuel with the ambient air that are vital parameters in the combustion process. The use of numerical calculations is an important tool to better understand these complex interacting phenomena. This thesis reports on the numerical modelling of fuel sprays in non-reacting cases using an own developed spray module. The spray module uses the stochastic parcel method to represent the spray. The module was made in such manner that it could by coupled with different gas flow solver. Results obtained from four different gas flow solvers are presented in the thesis, including the use of two different kinds of turbulence models. In the first part the spray module is coupled with a k-{eta} based 2-D cylindrical gas flow solver. A thorough sensitivity analysis was performed on the spray and gas flow solver parameters, such as grid size dependence and sensitivity to initial values of k-{eta}. The results of the spray module were also compared to results from other spray codes, e.g. the well known KIVA code. In the second part of this thesis the spray was injected into a turbulent and fully developed crossflow studied. The spray module was attached to a LES (Large Eddy Simulation) based flow solvers enabling the study of the complex structures and time dependent phenomena involved in spray in crossflows. It was found that the spray performs an oscillatory motion and that the Strouhal number in the wake was about 0.1. Different spray breakup models were evaluated by comparing with experimental results 66 refs, 56 figs

Double shock experiments and reactive flow modeling on LX-17 to understand the reacted equation of state

International Nuclear Information System (INIS)

Vandersall, Kevin S; Garcia, Frank; Fried, Laurence E; Tarver, Craig M

2014-01-01

Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as detail on possible future experiments.

Oxygen-Reducing Biocathodes Operating with Passive Oxygen Transfer in Microbial Fuel Cells

KAUST Repository

Xia, Xue

2013-02-19

Oxygen-reducing biocathodes previously developed for microbial fuel cells (MFCs) have required energy-intensive aeration of the catholyte. To avoid the need for aeration, the ability of biocathodes to function with passive oxygen transfer was examined here using air cathode MFCs. Two-chamber, air cathode MFCs with biocathodes produced a maximum power density of 554 ± 0 mW/m 2, which was comparable to that obtained with a Pt cathode (576 ± 16 mW/m2), and 38 times higher than that produced without a catalyst (14 ± 3 mW/m2). The maximum current density with biocathodes in this air-cathode MFC was 1.0 A/m2, compared to 0.49 A/m2 originally produced in a two-chamber MFC with an aqueous cathode (with cathode chamber aeration). Single-chamber, air-cathode MFCs with the same biocathodes initially produced higher voltages than those with Pt cathodes, but after several cycles the catalytic activity of the biocathodes was lost. This change in cathode performance resulted from direct exposure of the cathodes to solutions containing high concentrations of organic matter in the single-chamber configuration. Biocathode performance was not impaired in two-chamber designs where the cathode was kept separated from the anode solution. These results demonstrate that direct-air biocathodes can work very well, but only under conditions that minimize heterotrophic growth of microorganisms on the cathodes. © 2013 American Chemical Society.

Numerical simulation of low Mach number reacting flows

International Nuclear Information System (INIS)

Bell, J B; Aspden, A J; Day, M S; Lijewski, M J

2007-01-01

Using examples from active research areas in combustion and astrophysics, we demonstrate a computationally efficient numerical approach for simulating multiscale low Mach number reacting flows. The method enables simulations that incorporate an unprecedented range of temporal and spatial scales, while at the same time, allows an extremely high degree of reaction fidelity. Sample applications demonstrate the efficiency of the approach with respect to a traditional time-explicit integration method, and the utility of the methodology for studying the interaction of turbulence with terrestrial and astrophysical flame structures

REAC/TS Radiation Accident Registry: An Overview

Energy Technology Data Exchange (ETDEWEB)

Doran M. Christensen, DO, REAC/TS Associate Director and Staff Physician Becky Murdock, REAC/TS Registry and Health Physics Technician

2012-12-12

Over the past four years, REAC/TS has presented a number of case reports from its Radiation Accident Registry. Victims of radiological or nuclear incidents must meet certain dose criteria for an incident to be categorized as an “accident” and be included in the registry. Although the greatest numbers of “accidents” in the United States that have been entered into the registry involve radiation devices, the greater percentage of serious accidents have involved sealed sources of one kind or another. But if one looks at the kinds of accident scenarios that have resulted in extreme consequence, i.e., death, the greater share of deaths has occurred in medical settings.

Method of dry distillation of solid and liquid fuels. [below 500/sup 0/C

Energy Technology Data Exchange (ETDEWEB)

Michot-Dupont, G F

1932-07-29

A method of manufacture is given of liquid fuels with a low boiling temperature by means of dry distillation of coals, lignites, peat, and similar materials at temperatures below 500/sup 0/C in the presence of fatty acids (such as acetates). It is characterized by carrying out the distillation after adding at least one more basic reacting salt in such quantity that the reaction takes place under highly basic conditions.

Experimental program to determine maximum temperatures for dry storage of spent fuel

International Nuclear Information System (INIS)

Knox, C.A.; Gilbert, E.R.; White, G.D.

1985-02-01

Although air is used as a cover gas in some dry storage facilities, other facilities use inert cover gases which must be monitored to assure inertness of the atmosphere. Thus qualifying air as a cover gas is attractive for the dry storage of spent fuels. At sufficiently high temperatures, air can react with spent fuel (UO 2 ) at the site of cladding breaches that formed during reactor irradiation or during dry storage. The reaction rate is temperature dependent; hence the rates can be maintained at acceptable levels if temperatures are low. Tests with spent fuel are being conducted at Pacific Northwest Laboratory (PNL) to determine the allowable temperatures for storage of spent fuel in air. Tests performed with nonirradiated UO 2 pellets indicated that moisture, surface condition, gamma radiation, gadolinia content of the fuel pellet, and temperature are important variables. Tests were then initiated on spent fuel to develop design data under simulated dry storage conditions. Tests have been conducted at 200 and 230 0 C on spent fuel in air and 275 0 C in moist nitrogen. The results for nonirradiated UO 2 and published data for irradiated fuel indicate that above 230 0 C, oxidation rates are unacceptably high for extended storage in air. The tests with spent fuel will be continued for approximately three years to enable reliable extrapolations to be made for extended storage in air and inert gases with oxidizing constituents. 6 refs., 6 figs., 3 tabs

Comparing Spray Characteristics from Reynolds Averaged Navier-Stokes (RANS) National Combustion Code (NCC) Calculations Against Experimental Data for a Turbulent Reacting Flow

Science.gov (United States)

Iannetti, Anthony C.; Moder, Jeffery P.

2010-01-01

Developing physics-based tools to aid in reducing harmful combustion emissions, like Nitrogen Oxides (NOx), Carbon Monoxide (CO), Unburnt Hydrocarbons (UHC s), and Sulfur Dioxides (SOx), is an important goal of aeronautics research at NASA. As part of that effort, NASA Glenn Research Center is performing a detailed assessment and validation of an in-house combustion CFD code known as the National Combustion Code (NCC) for turbulent reacting flows. To assess the current capabilities of NCC for simulating turbulent reacting flows with liquid jet fuel injection, a set of Single Swirler Lean Direct Injection (LDI) experiments performed at the University of Cincinnati was chosen as an initial validation data set. This Jet-A/air combustion experiment operates at a lean equivalence ratio of 0.75 at atmospheric pressure and has a 4 percent static pressure drop across the swirler. Detailed comparisons of NCC predictions for gas temperature and gaseous emissions (CO and NOx) against this experiment are considered in a previous work. The current paper is focused on detailed comparisons of the spray characteristics (radial profiles of drop size distribution and at several radial rakes) from NCC simulations against the experimental data. Comparisons against experimental data show that the use of the correlation for primary spray break-up implemented by Raju in the NCC produces most realistic results, but this result needs to be improved. Given the single or ten step chemical kinetics models, use of a spray size correlation gives similar, acceptable results

Research and development into power reactor fuel performance

International Nuclear Information System (INIS)

Notley, M.J.F.

1983-07-01

The nuclear fuel in a power reactor must perform reliably during normal operation, and the consequences of abnormal events must be researched and assessed. The present highly reliable operation of the natural UO 2 in the CANDU power reactors has reduced the need for further work in this area; however a core of expertise must be retained for purposes such as training of new staff, retaining the capability of reacting to unforeseen circumstances, and participating in the commercial development of new ideas. The assessment of fuel performance during accidents requires research into many aspects of materials, fuel and fission product behaviour, and the consolidation of that knowledge into computer codes used to evaluate the consequences of any particular accident. This work is growing in scope, much is known from out-reactor work at temperatures up to about 1500 degreesC, but the need for in-reactor verification and investigation of higher-temperature accidents has necessitated the construction of a major new in-reactor test loop and the initiation of the associated out-reactor support programs. Since many of the programs on normal and accident-related performance are generic in nature, they will be applicable to advanced fuel cycles. Work will therefore be gradually transferred from the present, committed power reactor system to support the next generation of thorium-based reactor cycles

Quantitative imaging of turbulent and reacting flows

Energy Technology Data Exchange (ETDEWEB)

Paul, P.H. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01

Quantitative digital imaging, using planar laser light scattering techniques is being developed for the analysis of turbulent and reacting flows. Quantitative image data, implying both a direct relation to flowfield variables as well as sufficient signal and spatial dynamic range, can be readily processed to yield two-dimensional distributions of flowfield scalars and in turn two-dimensional images of gradients and turbulence scales. Much of the development of imaging techniques to date has concentrated on understanding the requisite molecular spectroscopy and collision dynamics to be able to determine how flowfield variable information is encoded into the measured signal. From this standpoint the image is seen as a collection of single point measurements. The present effort aims at realizing necessary improvements in signal and spatial dynamic range, signal-to-noise ratio and spatial resolution in the imaging system as well as developing excitation/detection strategies which provide for a quantitative measure of particular flowfield scalars. The standard camera used for the study is an intensified CCD array operated in a conventional video format. The design of the system was based on detailed modeling of signal and image transfer properties of fast UV imaging lenses, image intensifiers and CCD detector arrays. While this system is suitable for direct scalar imaging, derived quantities (e.g. temperature or velocity images) require an exceptionally wide dynamic range imaging detector. To apply these diagnostics to reacting flows also requires a very fast shuttered camera. The authors have developed and successfully tested a new type of gated low-light level detector. This system relies on fast switching of proximity focused image-diode which is direct fiber-optic coupled to a cooled CCD array. Tests on this new detector show significant improvements in detection limit, dynamic range and spatial resolution as compared to microchannel plate intensified arrays.

Investigation on fuel-cladding chemical interaction in metal fuel for FBR

International Nuclear Information System (INIS)

Inagaki, Kenta; Nakamura, Kinya; Ogata, Takanari; Uwaba, Tomoyuki

2013-01-01

During steady-state irradiation of metallic fuel in fast reactors, rare-earth fission products can react with stainless steel cladding at the fuel-cladding interface. The authors conducted isothermal annealing tests with some diffusion couples to investigate the structure of the wastage layer formed at the interface. Candidate cladding alloys, ferritic-martensitic steel (PNC-FMS) and oxide-dispersion-strengthened (ODS) steel were assembled with rare-earth alloys, RE5 : La-Ce-Pr-Nd-Sm, which simulate the fission yield of rare-earth fission products. The diffusion couples were isothermally annealed in the temperature range of 500-650°C for up to 170 h. In both RE5/ODS-steel and RE5/PNC-FMS couples, the wastage layer of the two-phase region of the (Fe, Cr) 17 RE 2 matrix phase with the precipitation of the (Fe, RE, Cr) phase was formed. The structure was similar to that formed in RE5/Fe-12Cr and RE5/HT9 couples, which implies that the reaction between REs and steel is not significantly influenced by the minor alloying elements within the candidate cladding materials. It was also clarified that the increase in the wastage layer thickness was diffusion-controlled. The temperature dependence of the reaction rate constants were formulated, which can be the basis for the quantification of the wastage layer growth. (author)

Characterization of Horizontally-Issuing Reacting Buoyant Jets

Science.gov (United States)

2011-03-01

with unparalleled support. I would like to especially thank Mr. John Hixenbaugh whose comical nature and upbeat personality always brightened my day...as the air and fuel mixture navigate circumferentially around the engine. When fuel and air are injected into the UCC, a swirling motion is created...are dominant. As a result, the flow is laminar, characterized by smooth constant motions . Conversely, at high Reynolds numbers, inertial or momentum

Retail fuel price adjustment in Germany: A threshold cointegration approach

International Nuclear Information System (INIS)

Asane-Otoo, Emmanuel; Schneider, Jan

2015-01-01

Consumers in Germany often complain that retail fuel prices usually adjust quickly to crude oil price increases than decreases and characterize this pricing pattern as market power exploitation. In this paper, we use both weekly national and daily city-specific (Berlin, Hamburg, Munich and Cologne) data to investigate the extent to which retail fuel prices in Germany adjust to changes in the international crude oil price. At the national level with weekly prices, we find positive asymmetries for both gasoline and diesel within the period 2003–2007, reflecting that retail prices react more swiftly to crude oil price increases than decreases. In contrast, for 2009–2013, we observe symmetric adjustment and negative asymmetry for retail diesel and gasoline prices, respectively. The city level analysis supports our findings in the latter time period. Thus, regulatory measures aimed at the retail fuel market over recent years seem to have been effective, and, contrary to consumers' perception, we find no evidence for excessive market power or collusion. - Highlights: • The paper examines the adjustment of German retail fuel (gasoline and diesel) prices to international crude oil price changes. • An error correction model with threshold cointegration is used to investigate the price dynamics. • The findings generally point to a competitive retail fuel pricing, notwithstanding the oligopolistic market structure

Effects of continuum breakdown on hypersonic aerothermodynamics for reacting flow

Science.gov (United States)

Holman, Timothy D.; Boyd, Iain D.

2011-02-01

This study investigates the effects of continuum breakdown on the surface aerothermodynamic properties (pressure, stress, and heat transfer rate) of a sphere in a Mach 25 flow of reacting air in regimes varying from continuum to a rarefied gas. Results are generated using both continuum [computational fluid dynamics (CFD)] and particle [direct simulation Monte Carlo (DSMC)] approaches. The DSMC method utilizes a chemistry model that calculates the backward rates from an equilibrium constant. A preferential dissociation model is modified in the CFD method to better compare with the vibrationally favored dissociation model that is utilized in the DSMC method. Tests of these models are performed to confirm their validity and to compare the chemistry models in both numerical methods. This study examines the effect of reacting air flow on continuum breakdown and the surface properties of the sphere. As the global Knudsen number increases, the amount of continuum breakdown in the flow and on the surface increases. This increase in continuum breakdown significantly affects the surface properties, causing an increase in the differences between CFD and DSMC. Explanations are provided for the trends observed.

Porous membrane electrochemical cell for uranium and transuranic recovery from molten salt electrolyte

Science.gov (United States)

Willit, James L [Batavia, IL

2010-09-21

An improved process and device for the recovery of the minor actinides and the transuranic elements (TRU's) from a molten salt electrolyte. The process involves placing the device, an electrically non-conducting barrier between an anode salt and a cathode salt. The porous barrier allows uranium to diffuse between the anode and cathode, yet slows the diffusion of uranium ions so as to cause depletion of uranium ions in the catholyte. This allows for the eventual preferential deposition of transuranics present in spent nuclear fuel such as Np, Pu, Am, Cm. The device also comprises an uranium oxidation anode. The oxidation anode is solid uranium metal in the form of spent nuclear fuel. The spent fuel is placed in a ferric metal anode basket which serves as the electrical lead or contact between the molten electrolyte and the anodic uranium metal.

Porous membrane electrochemical cell for uranium and transuranic recovery from molten salt electrolyte

Science.gov (United States)

Willit, James L.

2007-09-11

An improved process and device for the recovery of the minor actinides and the transuranic elements (TRU's) from a molten salt electrolyte. The process involves placing the device, an electrically non-conducting barrier between an anode salt and a cathode salt. The porous barrier allows uranium to diffuse between the anode and cathode, yet slows the diffusion of uranium ions so as to cause depletion of uranium ions in the catholyte. This allows for the eventual preferential deposition of transuranics present in spent nuclear fuel such as Np, Pu, Am, Cm. The device also comprises an uranium oxidation anode. The oxidation anode is solid uranium metal in the form of spent nuclear fuel. The spent fuel is placed in a ferric metal anode basket which serves as the electrical lead or contact between the molten electrolyte and the anodic uranium metal.

Preparation of Uranium Dioxide by Electrochemical Reduction in Ammonium Carbonate Solutions and Subsequent Precipitation; Preparation de bioxyde d'uranium par reduction electrochimique dans des solutions de carbonate d'ammonium et precipitation; Prigotovlenie dvuokisi urana metodom ehlektrokhimicheskogo vosstanovleniya v rastvore karbonata ammoniya s posleduyushchim osazhdeniem; Preparacion de dioxido de uranio por reduccion electroquimica en soluciones de carbonato amonico u precipitacion subsiguiente

Energy Technology Data Exchange (ETDEWEB)

Pravdic, V.; Branica, M.; Pucar, Z. [Department of Physical Chemistry, Rudjer Boskovic Institute, Zagreb, Yugoslavia (Serbia)

1963-11-15

Experiments in a small scale electrolysis cell on cathodic reduction of uranium (VI) to uranium (IV) show the possibility of an efficient way to obtain uranium (IV) in carbonate solutions. From this solution uranium (IV) hydrous oxide precipitates by merely raising the temperature. To obtain larger quantities of material needed for technological testing, a scale-up of the process was attempted. An electrolysis cell of hard PVC (polyvinylchloride) was constructed with a mercury pool cathode of approximately 2.5 dm{sup 2} and platinum anodes. The catholyte was separated from the anolyte by cationexchange membranes. The catholyte was circulated between two 50-1 reservoirs and streamed toward the vigorously stirred mercury cathode. The working potential of mercury was controlled against an Ag/AgCl/KC1 (sat.) reference electrode, the potential being held constant at -1.5 V. The current efficiency is approximately 90%; the power consumed for the reduction process is about 0.8 kWh/kg of uranium dioxide. After the electrolysis was completed the precipitation was initiated only by heating the deeply green clear solution up to 70 deg. C in a separate all-glass vessel of 60-1 volume. From 50, 1 of the catholyte solution 1 kg of a centrifuged product (containing about 20% of water) was obtained. The coulometric analysis of the oxygen-uranium ratio always gave results in the range of 2.04 to 2.09. By the procedure described uranium (IV) hydrous oxide is selectively precipitated, and the oxygen-uranium ratio in the precipitate was found to be independent of the degree of completion of the reduction. The product was identified as the alpha phase of uranium dioxide by the X-ray powder diffraction. Experiments in sintering and characterization of uranium dioxide thus obtained for the ceramic nuclear fuel requirements are under way. (author) [French] Des experiences faites dans une petite cellule d'electrolyse sur la reduction cathodique d'uranium (VI) en uranium (IV) montrent qu

Multiphase reacting flows modelling and simulation

CERN Document Server

Marchisio, Daniele L

2007-01-01

The papers in this book describe the most widely applicable modeling approaches and are organized in six groups covering from fundamentals to relevant applications. In the first part, some fundamentals of multiphase turbulent reacting flows are covered. In particular the introduction focuses on basic notions of turbulence theory in single-phase and multi-phase systems as well as on the interaction between turbulence and chemistry. In the second part, models for the physical and chemical processes involved are discussed. Among other things, particular emphasis is given to turbulence modeling strategies for multiphase flows based on the kinetic theory for granular flows. Next, the different numerical methods based on Lagrangian and/or Eulerian schemes are presented. In particular the most popular numerical approaches of computational fluid dynamics codes are described (i.e., Direct Numerical Simulation, Large Eddy Simulation, and Reynolds-Averaged Navier-Stokes approach). The book will cover particle-based meth...

Electricity generation from tetrathionate in microbial fuel cells by acidophiles

International Nuclear Information System (INIS)

Sulonen, Mira L.K.; Kokko, Marika E.; Lakaniemi, Aino-Maija; Puhakka, Jaakko A.

2015-01-01

Highlights: • Electricity can be generated from tetrathionate in MFCs at pH below 2.5. • Tetrathionate disproportionated to sulfate and elemental sulfur. • Biohydrometallurgical process waters contained electrochemically active bacteria. • Acidithiobacillus spp. and Ferroplasma spp. were identified from the MFCs. - Abstract: Inorganic sulfur compounds, such as tetrathionate, are often present in mining process and waste waters. The biodegradation of tetrathionate was studied under acidic conditions in aerobic batch cultivations and in anaerobic anodes of two-chamber flow-through microbial fuel cells (MFCs). All four cultures originating from biohydrometallurgical process waters from multimetal ore heap bioleaching oxidized tetrathionate aerobically at pH below 3 with sulfate as the main soluble metabolite. In addition, all cultures generated electricity from tetrathionate in MFCs at pH below 2.5 with ferric iron as the terminal cathodic electron acceptor. The maximum current and power densities during MFC operation and in the performance analysis were 79.6 mA m −2 and 13.9 mW m −2 and 433 mA m −2 and 17.6 mW m −2 , respectively. However, the low coulombic efficiency (below 5%) indicates that most of the electrons were directed to other processes, such as aerobic oxidation of tetrathionate and unmeasured intermediates. The microbial community analysis revealed that the dominant species both in the anolyte and on the anode electrode surface of the MFCs were Acidithiobacillus spp. and Ferroplasma spp. This study provides a proof of concept that tetrathionate serves as electron donor for biological electricity production in the pH range of 1.2–2.5

Electricity generation from tetrathionate in microbial fuel cells by acidophiles

Energy Technology Data Exchange (ETDEWEB)

Sulonen, Mira L.K., E-mail: mira.sulonen@tut.fi; Kokko, Marika E.; Lakaniemi, Aino-Maija; Puhakka, Jaakko A.

2015-03-02

Highlights: • Electricity can be generated from tetrathionate in MFCs at pH below 2.5. • Tetrathionate disproportionated to sulfate and elemental sulfur. • Biohydrometallurgical process waters contained electrochemically active bacteria. • Acidithiobacillus spp. and Ferroplasma spp. were identified from the MFCs. - Abstract: Inorganic sulfur compounds, such as tetrathionate, are often present in mining process and waste waters. The biodegradation of tetrathionate was studied under acidic conditions in aerobic batch cultivations and in anaerobic anodes of two-chamber flow-through microbial fuel cells (MFCs). All four cultures originating from biohydrometallurgical process waters from multimetal ore heap bioleaching oxidized tetrathionate aerobically at pH below 3 with sulfate as the main soluble metabolite. In addition, all cultures generated electricity from tetrathionate in MFCs at pH below 2.5 with ferric iron as the terminal cathodic electron acceptor. The maximum current and power densities during MFC operation and in the performance analysis were 79.6 mA m{sup −2} and 13.9 mW m{sup −2} and 433 mA m{sup −2} and 17.6 mW m{sup −2}, respectively. However, the low coulombic efficiency (below 5%) indicates that most of the electrons were directed to other processes, such as aerobic oxidation of tetrathionate and unmeasured intermediates. The microbial community analysis revealed that the dominant species both in the anolyte and on the anode electrode surface of the MFCs were Acidithiobacillus spp. and Ferroplasma spp. This study provides a proof of concept that tetrathionate serves as electron donor for biological electricity production in the pH range of 1.2–2.5.

Non-equilibrium reacting gas flows kinetic theory of transport and relaxation processes

CERN Document Server

Nagnibeda, Ekaterina; Nagnibeda, Ekaterina

2009-01-01

This volume develops the kinetic theory of transport phenomena and relaxation processes in the flows of reacting gas mixtures. The theory is applied to the modeling of non-equilibrium flows behind strong shock waves, in the boundary layer, and in nozzles.

'REACTS'. A pragmatic approach for providing medical care and physician education for radiation emergencies

International Nuclear Information System (INIS)

Lushbaugh, C.C.; Andrews, G.A.; Huebner, K.F.; Cloutier, R.J.; Beck, W.L.; Berger, J.D.

1976-01-01

Because serious radiation incidents have been rare, few medical personnel (notably only some in France, Russia, Belgium, Canada, Yugoslavia, Japan, Great Britain and the United States) have first-hand experience in radiation-accident management. The generation of physicians who participated in those accidents now needs to pass on the bits of knowledge that were gleaned from them. These case histories are difficult for the local, non-radiology physician to obtain when he is called upon to help formulate the medical-emergency response plan required everywhere for licensing power reactors. The Radiation Emergency Assistance Center and Training Site (REACTS) in Oak Ridge, Tennessee, supported by the US Energy Research and Development Administration, is designed to meet these medical and educational needs. REACTS, located in the Oak Ridge Hospital of the Methodist Church, is not involved in the hospital's daily community functions except insofar as REACTS is the radiation emergency arm of the area's major disaster plan. Its dual mission is training physicians, nurses, and paramedical emergency personnel in radiation-accident management, and treating irradiated and contaminated persons. Its training activities are carried out by the Special Training Division of Oak Ridge Associated Universities. Formal courses in radiation medicine and health physics and practical laboratory experience are now conducted twice a year for physicians. They will be expanded in the future to include training of paramedical personnel. Follow-up studies of radiation-accident survivors are carried out in REACTS to ensure the preservation of valuable human data and radiation-accident experiences. This unique facility and its staff are dedicated to meet the needs of the far-flung public and private medical domains in the United States for nuclear-production energy

Tax havens under international pressure: How do they react?

OpenAIRE

Patrice Pieretti; Giuseppe Pulina

2015-01-01

This paper contributes to the literature about tax havens by providing a more comprehensive analysis of their role. The aim is to analyze how low-tax jurisdictions can react to growing international pressure exerted, by high-tax countries, to enforce compliance with anti aggressive tax planning standards. To this end, we model how a small tax haven tries to be attractive to multinationals located in a high-tax region by providing aggressive tax planning services and/or a favorable environment...

Testing of low pressure proton exchange membrane fuel cells

Energy Technology Data Exchange (ETDEWEB)

Bettoni, M; Naso, V; Lucentini, M; Rubini, L

1998-07-01

One of the main issues concerning PEMFC is the choice of operating pressure, for both stationary and automotive applications. This is because the air compressor may absorb a significant amount--up to 25%--of the power output of the fuel cells stack. A comparison has been made between the performance of various stacks of different dimensions, tested in the De Nora Laboratories operated at high (4 bar) and low (1.5 bar) pressures, considering power output reduced by the compressor power absorption. Differences of performance and efficiency between high and low pressure stacks have been noticed in the range of 10%. In operating at low pressure, higher efficiency is obtainable, but the maximum power of the stack is less; this means less fuel consumption, but requires a greater reacting surface and larger dimension of the stack. Consequently low pressures make the system simpler (a blower can be used instead of a compressor), and safer (there is practically no risk of breaking the membrane).

Prospect of Uranium Silicide fuel element with hypostoichiometric (Si ≤3.7%)

International Nuclear Information System (INIS)

Suripto, A.; Sardjono; Martoyo

1996-01-01

An attempt to obtain high uranium-loading in silicide dispersion fuel element using the fabrication technology applicable nowadays can reach Uranium-loading slightly above 5 gU/cm 3 . It is difficult to achieve a higher uranium-loading than that because of fabricability constraints. To overcome those difficulties, the use of uranium silicide U 3 Si based is considered. The excess of U is obtained by synthesising U 3 Si 2 in Si-hypostoichiometric stage, without applying heat treatment to the ingot as it can generate undesired U 3 Si. The U U will react with the matrix to form U al x compound, that its pressure is tolerable. This experiment is to consider possibilities of employing the U 3 Si 2 as nuclear fuel element which have been performed by synthesising U 3 Si 2 -U with the composition of 3.7 % weigh and 3 % weigh U. The ingot was obtained and converted into powder form which then was fabricated into experimental plate nuclear fuel element. The interaction between free U and Al-matrix during heat-treatment is the rolling phase of the fuel element was observed. The study of the next phase will be conducted later

Responding to excessive alcohol consumption in third-level (REACT): a study protocol.

Science.gov (United States)

Davoren, Martin P; Calnan, Susan; Mulcahy, Judith; Lynch, Emily; Perry, Ivan J; Byrne, Michael

2018-05-11

Problem alcohol use is an ongoing, worldwide phenomenon of considerable concern. Throughout the past 20 years, national policies have noted the importance of students when tackling alcohol consumption. Considering alcohol is a multifaceted issue, a multi-component response is required to combat its excessive use. This protocol sets out the approach used for developing, implementing and evaluating the REACT (Responding to Excessive Alcohol Consumption in Third-level) Programme. This evaluation will provide the evidence base for programme development, implementation and improvement. Stage one involved defining the multi-component intervention. This was developed following a systematic review of existing literature and a Delphi-consensus workshop involving university students, staff and relevant stakeholders. Following this, the programme is being implemented across the Higher Education sector in Ireland. A number of Higher Education Institutes have declined the invitation to participate in the programme. These institutions will act as control sites. Each intervention site will have a steering committee whose membership will include a mix of students and academic and student service staff. This steering committee will report to the REACT research team on the implementation of mandatory and optional action points at local sites. An online cross-sectional study at baseline and two-years post intervention will be utilised to determine the impact of the REACT programme. The impact assessment will focus on (1) whether the intervention has reduced alcohol consumption among third-level students (2); whether the programme altered students attitudes toward alcohol and (3) whether the programme has decreased the second-hand effects associated with excessive consumption. Finally, qualitative research will focus on factors influencing the take-up and implementation of this programme as well as students' views on the initiative. Alcohol consumption has remained on the policy

Catalase measurement: A new field procedure for rapidly estimating microbial loads in fuels and water-bottoms

Energy Technology Data Exchange (ETDEWEB)

Passman, F.J. [Biodeterioration Control Associates, Inc., Chicago, IL (United States); Daniels, D.A. [Basic Fuel Services, Dover, NJ (United States); Chesneau, H.F.

1995-05-01

Low-grade microbial infections of fuel and fuel systems generally go undetected until they cause major operational problems. Three interdependent factors contribute to this: mis-diagnosis, incorrect or inadequate sampling procedures and perceived complexity of microbiological testing procedures. After discussing the first two issues, this paper describes a rapid field test for estimating microbial loads in fuels and associated water. The test, adapted from a procedure initially developed to measure microbial loads in metalworking fluids, takes advantage of the nearly universal presence of the enzyme catalase in the microbes that contaminated fuel systems. Samples are reacted with a peroxide-based reagent; liberating oxygen gas. The gas generates a pressure-head in a reaction tube. At fifteen minutes, a patented, electronic pressure-sensing device is used to measure that head-space pressure. The authors present both laboratory and field data from fuels and water-bottoms, demonstrating the excellent correlation between traditional viable test data (acquired after 48-72 hours incubation) and catalase test data (acquired after 15 min.-4 hours). We conclude by recommending procedures for developing a failure analysis data-base to enhance our industry`s understanding of the relationship between uncontrolled microbial contamination and fuel performance problems.

THE STABILITY OF OPTICALLY THIN REACTING PLASMAS: EFFECTS OF THE BULK VISCOSITY

International Nuclear Information System (INIS)

Ibanez S, Miguel H.

2009-01-01

The thermochemical stability of reacting plasmas is analyzed by taking into account the change in the thermodynamical equilibrium values during the fluctuation. This shift in the equilibrium produces two main effects: a change in the four instability criteria for reacting gases resulting when the above effect is neglected and adds a fifth instability criterion due to the fact that the corresponding secular equation becomes a fifth-order polynomial. The above results are applied to several plasma models, in particular, to a photoionized hydrogen plasma for which the bulk viscosity can be more important than the dynamic viscosity and the thermometric conductivity. Therefore, the bulk viscosity may quench thermochemical instabilities were the thermal conduction is unable of stabilizing. This occurs for low values of the photoionizing energy E. The implications of the above results in explaining the formation of clump structures in different regions of the interstellar medium are outlined.

Materials study for reacting plasma machine

International Nuclear Information System (INIS)

Kamada, Kohji; Hamada, Yasuji

1982-01-01

A new reacting plasma machine is designed, and will be constructed at the Institute of Plasma Physics, Nagoya University. It is important to avoid the activation of the materials for the machine, accordingly, aluminum alloy has been considered as the material since the induced activity of aluminum due to 14 MeV neutrons is small. The vacuum chamber of the new machine consists of four modules, and the remote control of each module is considered. However, the cost of the remote control of modules is expensive. To minimize the dependence on the remote control, the use of aluminum alloy is considered as the first step. The low electrical resistivity, over-ageing, weak mechanical strength and eddy current characteristics of aluminum alloy must be improved. The physical and electrical properties of various aluminum alloys have been investigated. Permeability of hydrogen through aluminum, the recycling characteristics and surface coating materials have been also studied. (Kato, T.)

Thermal properties of wood reacted with a phosphorus pentoxide–amine system

Science.gov (United States)

Hong-Lin Lee; George C. Chen; Roger M. Rowell

2004-01-01

The objective of this research was to improve the fire-retardant properties of wood in one treatment using a phosphorus pentoxide–amine system. Phosphorus pentoxide and 16 amines including alkyl, halophenyl, and phenyl amines were compounded in N,N-dimethylformamide and the resulting solutions containing phosphoramides were reacted with wood. The characteristics of...

ReACT Methodology Proof of Concept Final Report

Energy Technology Data Exchange (ETDEWEB)

Bri Rolston; Sarah Freeman

2014-03-01

The Department of Energy’s Office of Electricity Delivery and Energy Reliability (DOE-OE) funded INL Researchers to evaluate a novel process for assessing and mitigating cyber security risks. The proof of concept level of the method was tested in an industry environment. This case study, plus additional case studies will support the further development of the method into a tool to assist industry in securing their critical networks. This report provides an understanding of the process developed in the Response Analysis and Characterization Tool (ReACT) project. This report concludes with lessons learned and a roadmap for final development of these tools for use by industry.

Treatment of Oily Wastewater by the Optimization of Fe2O3 Calcination Temperatures in Innovative Bio-Electron-Fenton Microbial Fuel Cells

Directory of Open Access Journals (Sweden)

Jung-Chen Wu

2018-03-01

Full Text Available Due to the fact that Iron oxide (Fe2O3 is known to have a good effect on the photochemical reaction of catalysts, an investigation in this study into the enhancement of the degradation performance of bio-electro-Fenton microbial fuel cells (Bio-E-Fenton MFCs was carried out using three photocatalytic cathodes. These cathodes were produced at different calcination temperatures of Fe2O3 ranging from 500 °C to 900 °C for realizing their performance as photo catalysts within the cathodic chamber of an MFC, and they were compared for their ability to degrade oily wastewater. Results show that a suitable temperature for the calcination of iron oxide would have a significantly positive effect on the performance of Bio-E-Fenton MFCs. An optimal calcination temperature of 500 °C for Fe2O3 in the electrode material of the cathode was observed to produce a maximum power density of 52.5 mW/m2 and a chemical oxygen demand (COD degradation rate of oily wastewater (catholyte of 99.3% within one hour of operation. These novel findings will be useful for the improvement of the performance and applications of Bio-E-Fenton MFCs and their future applications in the field of wastewater treatment.

Heat and mass transfer for turbulent flow of chemically reacting gas in eccentric annular channels

International Nuclear Information System (INIS)

Besedina, T.V.; Tverkovkin, B.E.; Udot, A.V.; Yakushev, A.P.

1988-01-01

Because of the possibility of using dissociating gases as coolants and working bodies of nuclear power plants, it is necessary to develop computational algorithms for calculating heat and mass transfer processes under conditions of nonequilibrium flow of chemically reacting gases not only in axisymmetric channels, but also in channels with a complex transverse cross section (including also in eccentric annular channels). An algorithm is proposed for calculating the velocity, temperature, and concentration fields under conditions of cooling of a cylindrical heat-releasing rod, placed off-center in a circular casing pipe, by a longitudinal flow of chemically reacting gas [N 2 O 4

Biodiesel production from tall oil with synthesized Mn and Ni based additives: effects of the additives on fuel consumption and emissions

Energy Technology Data Exchange (ETDEWEB)

Ali Keskin; Metin Guru; Duran Altiparmak [Mersin University, Mersin (Turkey). Technical Education Faculty

2007-05-15

In this study, biodiesel fuel and fuel additives were produced from crude tall oil that is a by-product in the pulp manufacturing by craft or sulphate pulping process. Fatty acids and resinic acids were obtained from crude tall oil by distillation method. Tall oil methyl ester (biodiesel) was produced from fatty acids. Resinic acids were reacted with NiO and MnO{sub 2} stoichiometrically for production of metallic fuel additives. Each metallic fuel additive was added at the rate of 8 {mu}mol/l and 12 {mu}mol/l to make mixtures of 60% tall oil methyl ester/40% diesel fuel (TE60) for preparing test fuels. Metallic fuel additives improved properties of biodiesel fuels, such as pour point and viscosity values. Biodiesel fuels were tested in an unmodified direct injection diesel engine at full load condition. Specific fuel consumption of biodiesel fuels increased by 6.00%, however, in comparison with TE60, it showed trend of decreasing with adding of additives. Exhaust emission profile of biodiesel fuels improved. CO emissions and smoke opacity decreased up to 64.28% and 30.91% respectively. Low NOx emission was also observed in general for the biodiesel fuels. 28 refs., 4 figs., 3 tabs.

A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery.

Science.gov (United States)

Duan, Wentao; Vemuri, Rama S; Hu, Dehong; Yang, Zheng; Wei, Xiaoliang

2017-02-13

Redox flow batteries have been considered as one of the most promising stationary energy storage solutions for improving the reliability of the power grid and deployment of renewable energy technologies. Among the many flow battery chemistries, non-aqueous flow batteries have the potential to achieve high energy density because of the broad voltage windows of non-aqueous electrolytes. However, significant technical hurdles exist currently limiting non-aqueous flow batteries to demonstrate their full potential, such as low redox concentrations, low operating currents, under-explored battery status monitoring, etc. In an attempt to address these limitations, we recently reported a non-aqueous flow battery based on a highly soluble, redox-active organic nitronyl nitroxide radical compound, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO). This redox material exhibits an ambipolar electrochemical property, and therefore can serve as both anolyte and catholyte redox materials to form a symmetric flow battery chemistry. Moreover, we demonstrated that Fourier transform infrared (FTIR) spectroscopy could measure the PTIO concentrations during the PTIO flow battery cycling and offer reasonably accurate detection of the battery state of charge (SOC), as cross-validated by electron spin resonance (ESR) measurements. Herein we present a video protocol for the electrochemical evaluation and SOC diagnosis of the PTIO symmetric flow battery. With a detailed description, we experimentally demonstrated the route to achieve such purposes. This protocol aims to spark more interests and insights on the safety and reliability in the field of non-aqueous redox flow batteries.

Investigation on the electrode process of the Mn(II)/Mn(III) couple in redox flow battery

International Nuclear Information System (INIS)

Xue Fangqin; Wang Yongliang; Wang Wenhong; Wang Xindong

2008-01-01

The Mn(II)/Mn(III) couple has been recognized as a potential anode for redox flow batteries to take the place of the V(IV)/V(V) in all-vanadium redox battery (VRB) and the Br 2 /Br - in sodium polysulfide/bromine (PSB) because it has higher standard electrode potential. In this study, the electrochemical behavior of the Mn(II)/Mn(III) couple on carbon felt and spectral pure graphite were investigated by cyclic voltammetry, steady polarization curve, electrochemical impedance spectroscopy, transient potential-step experiment, X-ray diffraction and charge-discharge experiments. Results show that the Mn(III) disproportionation reaction phenomena is obvious on the carbon felt electrode while it is weak on the graphite electrode owing to its fewer active sites. The reaction mechanism on carbon felt was discussed in detail. The reversibility of Mn(II)/Mn(III) is best when the sulfuric acid concentration is 5 M on the graphite electrode. Performance of a RFB employing Mn(II)/Mn(III) couple as anolyte active species and V(III)/V(II) as catholyte ones was evaluated with constant-current charge-discharge tests. The average columbic efficiency is 69.4% and the voltage efficiency is 90.4% at a current density of 20 mA cm -2 . The whole energy efficiency is 62.7% close to that of the all-vanadium battery and the average discharge voltage is about 14% higher than that of an all-vanadium battery. The preliminary exploration shows that the Mn(II)/Mn(III) couple is electrochemically promising for redox flow battery

Molten salt fueled nuclear facility with steam-and gas turbine cycles of heat transformation

International Nuclear Information System (INIS)

Ananich, P.I.; Bunin, E.N.; Kazazyan, V.T.; Nemtsev, V.A.; Sikorin, S.N.

2001-01-01

The molten salt fueled nuclear facilities with fuel circulating in the primary circuit have a series of the potential advantages in comparison with the traditional thermal and fast reactors with solid fuel elements. These advantages are ensured by the possibility to receive effective neutron balance in the core, minimum margin reactivity, more deep fuel burnup, unbroken correctness of the fuel physical and chemical properties and by low prices of the fuel cycle. The neutron and thermal-physical calculations of the various variants of the MSFNF with steam-water and gas turbine power circuits and their technical and economical comparison are carried out in this article. Calculations of molten salt nuclear power plant with gas turbine power circuit have been carried out using chemically reacting working body ''nitrin'' (N304 + 1%NO). The molten salt fueled reactors with the thermal power near of 2300 MW with two fuel compositions have been considered. The base variant has been taken the design of NPP with VVER NP-1000 when comparing the results of the calculations. Its economical performances are presented in prices of 1990. The results of the calculations show that it is difficult to determine the advantages of any one of the variants considered in a unique fashion. But NPP with MSR possesses large reserves in the process of optimization of cycle and energy equipment parameters that can improve its technical and economical performances sufficiently. (author)

Computer Simulations of Composite Electrodes in Solid-Oxide Fuel-Cells

Energy Technology Data Exchange (ETDEWEB)

Sunde, Svein

1999-07-01

Fuel cells are devices for converting the combined chemical (free) energy of fuels and oxygen (air) directly to electrical energy without relying on the dynamic action of steam heated by reacting fuel-oxygen mixtures, like in steam turbines, or of the reacting gas mixtures themselves, like in gas turbines. The basic rationale for fuel cells is their high efficiencies as compared to indirect-conversion methods. Fuel cells are currently being considered for a number of applications, among them de-centralised power supply. Fuel cells come in five basic types and are usually classified according to the type of electrolyte used, which in turn to a significant degree limits the options for anode and cathode materials. The solid-oxide fuel-cell (SOFC) , with which this thesis is concerned, is thus named after its oxide electrolyte, typically the oxide-ion conducting material yttria-stabilised zirconia (YSZ). While the cathode of an SOFC is often uniform in chemical composition (or at least intended to be), various problems of delamination, cracking etc. associated with the use of metallic anode electrocatalysts led to the development of composite SOFC anodes. Porous anodes consisting of Ni and YSZ particles in roughly 50/50 wt-% mixtures are now almost standard with any SOFC-development programme. The designer of composite SOFC electrodes is faced with at least three, interrelated questions: (1) What will be the optimum microstructure and composition of the composite electrode? (2) If the structure changes during operation, as is often observed, what will be the consequences for the internal losses in the cell? (3) How do we interpret electrochemical and conductivity measurements with regard to structure and composition? It is the primary purpose of this thesis to provide a framework for modelling the electrochemical and transport properties of composite electrodes for SOFC, and to arrive at some new insights that cannot be offered by experiment alone. Emphasis is put on

Oxidative corrosion of spent UO2 fuel in vapor and dripping groundwater at 900C

International Nuclear Information System (INIS)

Finch, R. J.

1999-01-01

Corrosion of spent UO 2 fuel has been studied in experiments conducted for nearly six years. Oxidative dissolution in vapor and dripping groundwater at 90 C occurs via general corrosion at fuel-fragment surfaces. Dissolution along fuel-grain boundaries is also evident in samples contacted by the largest volumes of groundwater, and corroded grain boundaries extend at least 20 or 30 grains deep (> 200 microm), possibly throughout millimeter-sized fragments. Apparent dissolution of fuel along defects that intersect grain boundaries has created dissolution pits that are 50 to 200 nm in diameter. Dissolution pits penetrate 1-2 microm into each grain, producing a ''worm-like'' texture along fuel-grain-boundaries. Sub-micrometer-sized fuel shards are common between fuel grains and may contribute to the reactive surface area of fuel exposed to groundwater. Outer surfaces of reacted fuel fragments develop a fine-grained layer of corrosion products adjacent to the fuel (5-15 microm thick). A more coarsely crystalline layer of corrosion products commonly covers the fine-grained layer, the thickness of which varies considerably among samples (from less than 5 microm to greater than 40 microm). The thickest and most porous corrosion layers develop on fuel fragments exposed to the largest volumes of groundwater. Corrosion-layer compositions depend strongly on water flux, with uranyl oxy-hydroxides predominating in vapor experiments, and alkali and alkaline earth uranyl silicates predominating in high drip-rate experiments. Low drip-rate experiments exhibit a complex assemblage of corrosion products, including phases identified in vapor and high drip-rate experiments

IgE antibodies of fish allergic patients cross-react with frog parvalbumin.

Science.gov (United States)

Hilger, C; Thill, L; Grigioni, F; Lehners, C; Falagiani, P; Ferrara, A; Romano, C; Stevens, W; Hentges, F

2004-06-01

The major allergens in fish are parvalbumins. Important immunoglobulin (Ig)E cross-recognition of parvalbumins from different fish species has been shown. Recently frog parvalbumin alpha has been found to be responsible for a case of IgE-mediated anaphylaxis triggered by the ingestion of frog meat. The aim of this study was to investigate whether IgE antibodies of fish allergic persons cross-react with frog parvalbumin and to appreciate its clinical relevance. The sera of 15 fish allergic patients and one fish and frog allergic patient were tested by IgE-immunoblotting against frog muscle extract. Sera were tested against recombinant parvalbumin alpha and beta from Rana esculenta. Skin prick tests were performed in selected patients with recombinant frog parvalbumin. Ca(2+) depletion experiments and inhibition studies with purified cod and frog recombinant parvalbumin were done to characterize the cross-reactive pattern. Fourteen of the sera tested had IgE antibodies recognizing low molecular weight components in frog muscle extract. Calcium depletion experiments or inhibition of patient sera with purified cod parvalbumin led to a significant or complete decrease in IgE binding. When tested against recombinant parvalbumins, three of 13 sera reacted with alpha parvalbumin and 11 of 12 reacted with beta parvalbumin from R. esculenta. Skin prick tests performed with recombinant frog parvalbumin were positive in fish allergic patients. Inhibition studies showed that a fish and frog allergic patient was primarily sensitized to fish parvalbumin. Cod parvalbumin, a major cross-reactive allergen among different fish species, shares IgE binding epitopes with frog parvalbumin. This in vitro cross-reactivity seems to be also clinically relevant. Parvalbumins probably represent a new family of cross-reactive allergens.

Transverse liquid fuel jet breakup, burning, and ignition

Energy Technology Data Exchange (ETDEWEB)

Li, H.

1990-01-01

An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

Development of a Reduced-Order Model for Reacting Gas-Solids Flow using Proper Orthogonal Decomposition

Energy Technology Data Exchange (ETDEWEB)

McDaniel, Dwayne [Florida International Univ., Miami, FL (United States); Dulikravich, George [Florida International Univ., Miami, FL (United States); Cizmas, Paul [Florida International Univ., Miami, FL (United States)

2017-11-27

This report summarizes the objectives, tasks and accomplishments made during the three year duration of this research project. The report presents the results obtained by applying advanced computational techniques to develop reduced-order models (ROMs) in the case of reacting multiphase flows based on high fidelity numerical simulation of gas-solids flow structures in risers and vertical columns obtained by the Multiphase Flow with Interphase eXchanges (MFIX) software. The research includes a numerical investigation of reacting and non-reacting gas-solids flow systems and computational analysis that will involve model development to accelerate the scale-up process for the design of fluidization systems by providing accurate solutions that match the full-scale models. The computational work contributes to the development of a methodology for obtaining ROMs that is applicable to the system of gas-solid flows. Finally, the validity of the developed ROMs is evaluated by comparing the results against those obtained using the MFIX code. Additionally, the robustness of existing POD-based ROMs for multiphase flows is improved by avoiding non-physical solutions of the gas void fraction and ensuring that the reduced kinetics models used for reactive flows in fluidized beds are thermodynamically consistent.

MHD flow and heat transfer of a viscous reacting fluid over a ...

African Journals Online (AJOL)

This paper presents a boundary layer flow analysis for a viscous, incompressible, electrically conducting reacting fluid over a stretching sheet in the presence of a magnetic field. It is shown that the Hartmann, Prandtl and the Eckert numbers have effect on the velocity and temperature fields. Journal of the Nigerian ...

Propel: A Discontinuous-Galerkin Finite Element Code for Solving the Reacting Navier-Stokes Equations

Science.gov (United States)

Johnson, Ryan; Kercher, Andrew; Schwer, Douglas; Corrigan, Andrew; Kailasanath, Kazhikathra

2017-11-01

This presentation focuses on the development of a Discontinuous Galerkin (DG) method for application to chemically reacting flows. The in-house code, called Propel, was developed by the Laboratory of Computational Physics and Fluid Dynamics at the Naval Research Laboratory. It was designed specifically for developing advanced multi-dimensional algorithms to run efficiently on new and innovative architectures such as GPUs. For these results, Propel solves for convection and diffusion simultaneously with detailed transport and thermodynamics. Chemistry is currently solved in a time-split approach using Strang-splitting with finite element DG time integration of chemical source terms. Results presented here show canonical unsteady reacting flow cases, such as co-flow and splitter plate, and we report performance for higher order DG on CPU and GPUs.

Why Targets of Economic Sanctions React Differently: Reference Point Effects on North Korea and Libya

Directory of Open Access Journals (Sweden)

Jiyoun Park

2017-06-01

Full Text Available The international community has frequently introduced economic sanctions to curb the proliferation of weapons of mass destruction, to which each target nation has reacted differently. This paper explores the reasons why each target of economic sanctions reacts differently by specif- ically building a model based on reference point effects, and by analyzing the cases of North Korea and Libya. According to the results, when the reference point level increases, as in the case of North Korea, the target resists more firmly; on the other hand, when the reference point decreases, like in the case of Libya, the target resists more subtly.

The Responsive Environmental Assessment for Classroom Teaching (REACT): the dimensionality of student perceptions of the instructional environment.

Science.gov (United States)

Nelson, Peter M; Demers, Joseph A; Christ, Theodore J

2014-06-01

This study details the initial development of the Responsive Environmental Assessment for Classroom Teachers (REACT). REACT was developed as a questionnaire to evaluate student perceptions of the classroom teaching environment. Researchers engaged in an iterative process to develop, field test, and analyze student responses on 100 rating-scale items. Participants included 1,465 middle school students across 48 classrooms in the Midwest. Item analysis, including exploratory and confirmatory factor analysis, was used to refine a 27-item scale with a second-order factor structure. Results support the interpretation of a single general dimension of the Classroom Teaching Environment with 6 subscale dimensions: Positive Reinforcement, Instructional Presentation, Goal Setting, Differentiated Instruction, Formative Feedback, and Instructional Enjoyment. Applications of REACT in research and practice are discussed along with implications for future research and the development of classroom environment measures. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Trapped in the heat: A post-communist type of fuel poverty

International Nuclear Information System (INIS)

Tirado Herrero, Sergio; Ürge-Vorsatz, Diana

2012-01-01

Fuel poverty is a still insufficiently researched social and energy challenge with significant climate change implications. Based on evidence from Hungarian panel apartment blocks connected to district heating, this paper introduces a new variant of fuel poverty that may not be properly captured by existing fuel poverty indicators. This newly defined variant can be largely attributed to post-communist legacies – though it might also exist in other contexts – and assumes that consumers living in poor-efficiency, district-heated buildings are trapped in dwellings with adequate indoor temperatures but disproportionately high heating costs because (a) changing supplier or fuel is difficult because of the existing technical and institutional constraints, and (b) they do not realistically have the option to reduce individually their heating costs through individual efficiency improvements. This situation often translates into payment arrears, indebtedness, risk of disconnection, or reduced consumption of other basic goods and services. State-supported policy responses to date have favoured symptomatic solutions (direct consumer support) combined with superficial retrofits, though it is argued that only state-of-the-art retrofits such as the passive house-based SOLANOVA pilot project in Dunaújváros can fully eradicate fuel poverty in this consumer group. - Highlights: ► We identify a new variant of fuel poverty. ► We explore this variant in panel apartment blocks connected to DH in Hungary, where dwellings are warm enough in winter but have disproportionately high energy costs. ► Affected households react in ways that harm their welfare and put them at risk. ► Deep retrofits in dwellings such as these can eradicate fuel poverty while also contributing to other goals.

Sticky tunes: how do people react to involuntary musical imagery?

Directory of Open Access Journals (Sweden)

Victoria J Williamson

Full Text Available The vast majority of people experience involuntary musical imagery (INMI or 'earworms'; perceptions of spontaneous, repetitive musical sound in the absence of an external source. The majority of INMI episodes are not bothersome, while some cause disruption ranging from distraction to anxiety and distress. To date, little is known about how the majority of people react to INMI, in particular whether evaluation of the experience impacts on chosen response behaviours or if attempts at controlling INMI are successful or not. The present study classified 1046 reports of how people react to INMI episodes. Two laboratories in Finland and the UK conducted an identical qualitative analysis protocol on reports of INMI reactions and derived visual descriptive models of the outcomes using grounded theory techniques. Combined analysis carried out across the two studies confirmed that many INMI episodes were considered neutral or pleasant, with passive acceptance and enjoyment being among the most popular response behaviours. A significant number of people, however, reported on attempts to cope with unwanted INMI. The most popular and effective behaviours in response to INMI were seeking out the tune in question, and musical or verbal distraction. The outcomes of this study contribute to our understanding of the aetiology of INMI, in particular within the framework of memory theory, and present testable hypotheses for future research on successful INMI coping strategies.

Sticky Tunes: How Do People React to Involuntary Musical Imagery?

Science.gov (United States)

Williamson, Victoria J.; Liikkanen, Lassi A.; Jakubowski, Kelly; Stewart, Lauren

2014-01-01

The vast majority of people experience involuntary musical imagery (INMI) or ‘earworms’; perceptions of spontaneous, repetitive musical sound in the absence of an external source. The majority of INMI episodes are not bothersome, while some cause disruption ranging from distraction to anxiety and distress. To date, little is known about how the majority of people react to INMI, in particular whether evaluation of the experience impacts on chosen response behaviours or if attempts at controlling INMI are successful or not. The present study classified 1046 reports of how people react to INMI episodes. Two laboratories in Finland and the UK conducted an identical qualitative analysis protocol on reports of INMI reactions and derived visual descriptive models of the outcomes using grounded theory techniques. Combined analysis carried out across the two studies confirmed that many INMI episodes were considered neutral or pleasant, with passive acceptance and enjoyment being among the most popular response behaviours. A significant number of people, however, reported on attempts to cope with unwanted INMI. The most popular and effective behaviours in response to INMI were seeking out the tune in question, and musical or verbal distraction. The outcomes of this study contribute to our understanding of the aetiology of INMI, in particular within the framework of memory theory, and present testable hypotheses for future research on successful INMI coping strategies. PMID:24497938

Steam Methane Reformation Testing for Air-Independent Solid Oxide Fuel Cell Systems

Science.gov (United States)

Mwara, Kamwana N.

2015-01-01

Recently, NASA has been looking into utilizing landers that can be propelled by LOX-CH (sub 4), to be used for long duration missions. Using landers that utilize such propellants, also provides the opportunity to use solid oxide fuel cells as a power option, especially since they are able to process methane into a reactant through fuel reformation. One type of reformation, called steam methane reformation, is a process to reform methane into a hydrogen-rich product by reacting methane and steam (fuel cell exhaust) over a catalyst. A steam methane reformation system could potentially use the fuel cell's own exhaust to create a reactant stream that is hydrogen-rich, and requires less internal reforming of the incoming methane. Also, steam reformation may hold some advantages over other types of reforming, such as partial oxidation (PROX) reformation. Steam reformation does not require oxygen, while up to 25 percent can be lost in PROX reformation due to unusable CO (sub 2) reformation. NASA's Johnson Space Center has conducted various phases of steam methane reformation testing, as a viable solution for in-space reformation. This has included using two different types of catalysts, developing a custom reformer, and optimizing the test system to find the optimal performance parameters and operating conditions.

Reoxidation of uranium in electrolytically reduced simulated oxide fuel during residual salt distillation

International Nuclear Information System (INIS)

Eun-Young Choi; Jin-Mok Hur; Min Ku Jeon; University of Science and Technology, Yuseong-gu, Daejeon

2017-01-01

We report that residual salt removal by high-temperature distillation causes partial reoxidation of uranium metal to uranium oxide in electrolytically reduced simulated oxide fuel. Specifically, the content of uranium metal in the above product decreases with increasing distillation temperatures, which can be attributed to reoxidation by Li 2 O contained in residual salt (LiCl). Additionally, we estimate the fractions of Li 2 O reacted with uranium metal under these conditions, showing that they decrease with decreasing temperature, and calculate some thermodynamic parameters of the above reoxidation. (author)

Method to upgrade bio-oils to fuel and bio-crude

Science.gov (United States)

Steele, Philip H; Pittman, Jr., Charles U; Ingram, Jr., Leonard L; Gajjela, Sanjeev; Zhang, Zhijun; Bhattacharya, Priyanka

2013-12-10

This invention relates to a method and device to produce esterified, olefinated/esterified, or thermochemolytic reacted bio-oils as fuels. The olefinated/esterified product may be utilized as a biocrude for input to a refinery, either alone or in combination with petroleum crude oils. The bio-oil esterification reaction is catalyzed by addition of alcohol and acid catalyst. The olefination/esterification reaction is catalyzed by addition of resin acid or other heterogeneous catalyst to catalyze olefins added to previously etherified bio-oil; the olefins and alcohol may also be simultaneously combined and catalyzed by addition of resin acid or other heterogeneous catalyst to produce the olefinated/esterified product.

SQL Triggers Reacting on Time Events: An Extension Proposal

Science.gov (United States)

Behrend, Andreas; Dorau, Christian; Manthey, Rainer

Being able to activate triggers at timepoints reached or after time intervals elapsed has been acknowledged by many authors as a valuable functionality of a DBMS. Recently, the interest in time-based triggers has been renewed in the context of data stream monitoring. However, up till now SQL triggers react to data changes only, even though research proposals and prototypes have been supporting several other event types, in particular time-based ones, since long. We therefore propose a seamless extension of the SQL trigger concept by time-based triggers, focussing on semantic issues arising from such an extension.

Techno-Economic Analysis of Scalable Coal-Based Fuel Cells

Energy Technology Data Exchange (ETDEWEB)

Chuang, Steven S. C. [Univ. of Akron, OH (United States)

2014-08-31

Researchers at The University of Akron (UA) have demonstrated the technical feasibility of a laboratory coal fuel cell that can economically convert high sulfur coal into electricity with near zero negative environmental impact. Scaling up this coal fuel cell technology to the megawatt scale for the nation’s electric power supply requires two key elements: (i) developing the manufacturing technology for the components of the coal-based fuel cell, and (ii) long term testing of a kW scale fuel cell pilot plant. This project was expected to develop a scalable coal fuel cell manufacturing process through testing, demonstrating the feasibility of building a large-scale coal fuel cell power plant. We have developed a reproducible tape casting technique for the mass production of the planner fuel cells. Low cost interconnect and cathode current collector material was identified and current collection was improved. In addition, this study has demonstrated that electrochemical oxidation of carbon can take place on the Ni anode surface and the CO and CO₂ product produced can further react with carbon to initiate the secondary reactions. One important secondary reaction is the reaction of carbon with CO₂ to produce CO. We found CO and carbon can be electrochemically oxidized simultaneously inside of the anode porous structure and on the surface of anode for producing electricity. Since CH₄ produced from coal during high temperature injection of coal into the anode chamber can cause severe deactivation of Ni-anode, we have studied how CH₄ can interact with CO₂ to produce in the anode chamber. CO produced was found able to inhibit coking and allow the rate of anode deactivation to be decreased. An injection system was developed to inject the solid carbon and coal fuels without bringing air into the anode chamber. Five planner fuel cells connected in a series configuration and tested. Extensive studies on the planner fuels

Carbon deposition on 20/25/Nb steel using an electrically heated AGR fuel pin

International Nuclear Information System (INIS)

Blanchard, A.; Campion, P.

1980-01-01

The radiolysis of carbon dioxide in gas-cooled reactors leads to the production of active species capable of reacting with the graphite moderator to form carbon monoxide with a resultant gradual loss of moderator. In the early days of gas-cooled reactor design, the intention was to allow the carbon monoxide concentration to increase and use this reaction product to inhibit the initial radiolysis of the carbon dioxide. Exploratory irradiation experiments using 4 to 7% carbon monoxide revealed that low density deposits ranging in colour from light grey through brown to black were found in the temperature range 470 to 600 K. In view of the fact that this type of deposition could adversely affect heat transfer processes in both fuel channels and heat exchangers, together with the fact that carbon monoxide was not sufficiently powerful as a graphite oxidation inhibitor, methane was selected as the primary inhibitor for the AGR series of power stations. This paper describes some carbon deposition experiments using an electrically heated 'dummy fuel element' linked to a recirculating carbon dioxide irradiation loop in which carbon monoxide concentration, methane concentration, fuel pin temperature and the chemical nature of the fuel pin surface were varied. (author)

Methane reacts with heteropolyacids chemisorbed on silica to produce acetic acid under soft conditions

KAUST Repository

Sun, Miao; Abou-Hamad, Edy; Rossini, Aaron J.; Zhang, Jizhe; Lesage, Anne; Zhu, Haibo; Pelletier, Jeremie; Emsley, Lyndon; Caps, Valerie; Basset, Jean-Marie

2013-01-01

Selective functionalization of methane at moderate temperature is of crucial economic, environmental, and scientific importance. Here, we report that methane reacts with heteropolyacids (HPAs) chemisorbed on silica to produce acetic acid under soft

Post-pulse detail metallographic examinations of low-enriched uranium silicide plate-type miniature fuel

International Nuclear Information System (INIS)

Yanagisawa, Kazuaki

1991-10-01

Pulse irradiation at Nuclear Safety Research Reactor (NSRR) was performed using low-enriched (19.89 w% 235 U) unirradiated silicide plate-type miniature fuel which had a density of 4.8 gU/cm 3 . Experimental aims are to understand the dimensional stability and to clarify the failure threshold of the silicide plate-type miniature fuel under power transient conditions through post-pulse detail metallographic examinations. A silicide plate-type miniature fuel was loaded into an irradiation capsule and irradiated by a single pulse. Deposited energies given in the experiments were 62, 77, 116 and 154 cal/g·fuel, which lead to corresponding peak fuel plate temperatures, 201 ± 28degC, 187 ± 10degC, 418 ± 74degC and 871 ± 74degC, respectively. Below 400degC, reliability and dimensional stability of the silicide plate fuel was sustained, and the silicide plate fuel was intact. Up to 540degC, wall-through intergranular crackings occurred in the Al-3%Mg alloy cladding. With the increase of the temperature, the melting of the aluminum cladding followed by recrystallization, the denudation of fuel core and the plate-through intergranular cracking were observed. With the increase of the temperature beyond 400degC, the bowing of fuel plate became significant. Above the temperature of 640degC molten aluminum partially reacted with the fuel core, partially flowed downward under the influence of surface tension and gravity, and partially formed agglomerations. Judging from these experimental observations, the fuel-plate above 400degC tends to reduce its dimensional stability. Despite of the apparent silicide fuel-plate failure, neither generation of pressure pulse nor that of mechanical energy occurred at all. (J.P.N.)

Effect of secondary fuels and combustor temperature on mercury speciation in pulverized fuel co-combustion: part 1

Energy Technology Data Exchange (ETDEWEB)

Shishir P. Sable; Wiebren de Jong; Ruud Meij; Hartmut Spliethoff [Delft University Technology, Delft (Netherlands). Section Energy Technology, Department of Process and Energy

2007-08-15

The present work mainly involves bench scale studies to investigate partitioning of mercury in pulverized fuel co-combustion at 1000 and 1300{sup o}C. High volatile bituminous coal is used as a reference case and chicken manure, olive residue, and B quality (demolition) wood are used as secondary fuels with 10 and 20% thermal shares. The combustion experiments are carried out in an entrained flow reactor with a fuel input of 7-8 kWth. Elemental and total gaseous mercury concentrations in the flue gas of the reactor are measured on-line, and ash is analyzed for particulate mercury along with other elemental and surface properties. Animal waste like chicken manure behaves very differently from plant waste. The higher chlorine contents of chicken manure cause higher ionic mercury concentrations whereas even with high unburnt carbon, particulate mercury reduces with increase in the chicken manure share. This might be a problem due to coarse fuel particles, low surface area, and iron contents. B-wood and olive residue cofiring reduces the emission of total gaseous mercury and increases particulate mercury capture due to unburnt carbon formed, fine particles, and iron contents of the ash. Calcium in chicken manure does not show any effect on particulate or gaseous mercury. It is probably due to a higher calcium sulfation rate in the presence of high sulfur and chlorine contents. However, in plant waste cofiring, calcium may have reacted with chlorine to reduce ionic mercury to its elemental form. According to thermodynamic predictions, almost 50% of the total ash is melted to form slag at 1300{sup o}C in cofiring because of high calcium, iron, and potassium and hence mercury and other remaining metals are concentrated in small amounts of ash and show an increase at higher temperatures. No slag formation was predicted at 1000{sup o}C. 24 refs., 8 figs., 4 tabs.

Electrodialysis separation of rhenium from silicon

International Nuclear Information System (INIS)

Prasolova, O.D.; Borisova, L.V.; Ermakov, A.N.

1989-01-01

A method of separation of ruthenium from silicon by electrodialysis with heterogenuos ion-exchange membranes is developed. The effeciency of purification of rhenium from silicon depending on the number of dialyzer chambers, temperature and pH value of the dialyzate is studed. It is found that an addditional fourth chamber between the middle and anolytic ones causes the purification coefficient increase 50 times. It is necessary to cool the dialyzate in order to reduce silicon migration into the anolyte and reverse diffusion of perrhenate-ion from the anolyte into the dialyzate. The optimal pH value of diaizate is 5.5-6. The method developed has been used for separating rhenium from industrial solution of lead production with complex composition

Biological fuel-cell converts sugar into electric power; Biologinen polttokenno muuttaa sokerin saehkoeksi

Energy Technology Data Exchange (ETDEWEB)

Kinnunen, L.

1994-12-31

The Automation Technology Laboratory at the Helsinki University of Technology has developed a fuel-cell which produces electric power and water from glucose. The fuel-cell opens new possibilities for utilization of biologically disintegrable matter, e.g. different kinds of carbage, in power generation. The glucose is converted in the reactor by baking yeast into a metabolite, which is feeded into the fuel-cell of volume 55 ml. Graphite, wound into the nickel wire net, is used as anode in the system. Porous graphite is used as cathode. Anode and cathode are separated from each other by ion- exchange membrane, which is penetrable by hydrogen iones, but not by salt solution of the cathode half-cell. The metabolite is oxidized at the anode, donating electrons and hydrogen iones to the ande. The electrones flow through the circuit into the cathode there they react with hydrogen iones and oxygen feeded through the cathode to form water. The fuel-cell, based on direct oxygenation-reduction, has operated without any disturbances for 280 hours. The efficiency, calculated from the heating value of the glucose, is 44 %, which is better than that of the chemical fuel-cells. The disadvantage of the biological reactions is the low speed of them, so the current densities of the cell still remain into the class 2.0 W/m{sup 2}, which is about 1.0 % of that of the developed phosphoric acid fuel-cells

LES-ODT Simulations of Turbulent Reacting Shear Layers

Science.gov (United States)

Hoffie, Andreas; Echekki, Tarek

2012-11-01

Large-eddy simulations (LES) combined with the one-dimensional turbulence (ODT) simulations of a spatially developing turbulent reacting shear layer with heat release and high Reynolds numbers were conducted and compared to results from direct numerical simulations (DNS) of the same configuration. The LES-ODT approach is based on LES solutions for momentum on a coarse grid and solutions for momentum and reactive scalars on a fine ODT grid, which is embedded in the LES computational domain. The shear layer is simulated with a single-step, second-order reaction with an Arrhenius reaction rate. The transport equations are solved using a low Mach number approximation. The LES-ODT simulations yield reasonably accurate predictions of turbulence and passive/reactive scalars' statistics compared to DNS results.

Detecting and Reacting to Change: The Effect of Exposure to Narrow Categorizations

Science.gov (United States)

Chakravarti, Amitav; Fang, Christina; Shapira, Zur

2011-01-01

The ability to detect a change, to accurately assess the magnitude of the change, and to react to that change in a commensurate fashion are of critical importance in many decision domains. Thus, it is important to understand the factors that systematically affect people's reactions to change. In this article we document a novel effect: Decision…

Large Eddy Simulation of Spatially Developing Turbulent Reacting Shear Layers with the One-Dimensional Turbulence Model

Science.gov (United States)

Hoffie, Andreas Frank

Large eddy simulation (LES) combined with the one-dimensional turbulence (ODT) model is used to simulate spatially developing turbulent reacting shear layers with high heat release and high Reynolds numbers. The LES-ODT results are compared to results from direct numerical simulations (DNS), for model development and validation purposes. The LES-ODT approach is based on LES solutions for momentum and pressure on a coarse grid and solutions for momentum and reactive scalars on a fine, one-dimensional, but three-dimensionally coupled ODT subgrid, which is embedded into the LES computational domain. Although one-dimensional, all three velocity components are transported along the ODT domain. The low-dimensional spatial and temporal resolution of the subgrid scales describe a new modeling paradigm, referred to as autonomous microstructure evolution (AME) models, which resolve the multiscale nature of turbulence down to the Kolmogorv scales. While this new concept aims to mimic the turbulent cascade and to reduce the number of input parameters, AME enables also regime-independent combustion modeling, capable to simulate multiphysics problems simultaneously. The LES as well as the one-dimensional transport equations are solved using an incompressible, low Mach number approximation, however the effects of heat release are accounted for through variable density computed by the ideal gas equation of state, based on temperature variations. The computations are carried out on a three-dimensional structured mesh, which is stretched in the transverse direction. While the LES momentum equation is integrated with a third-order Runge-Kutta time-integration, the time integration at the ODT level is accomplished with an explicit Forward-Euler method. Spatial finite-difference schemes of third (LES) and first (ODT) order are utilized and a fully consistent fractional-step method at the LES level is used. Turbulence closure at the LES level is achieved by utilizing the Smagorinsky

Applied patent RFID systems for building reacting HEPA air ventilation system in hospital operation rooms.

Science.gov (United States)

Lin, Jesun; Pai, Jar-Yuan; Chen, Chih-Cheng

2012-12-01

RFID technology, an automatic identification and data capture technology to provide identification, tracing, security and so on, was widely applied to healthcare industry in these years. Employing HEPA ventilation system in hospital is a way to ensure healthful indoor air quality to protect patients and healthcare workers against hospital-acquired infections. However, the system consumes lots of electricity which cost a lot. This study aims to apply the RFID technology to offer a unique medical staff and patient identification, and reacting HEPA air ventilation system in order to reduce the cost, save energy and prevent the prevalence of hospital-acquired infection. The system, reacting HEPA air ventilation system, contains RFID tags (for medical staffs and patients), sensor, and reacting system which receives the information regarding the number of medical staff and the status of the surgery, and controls the air volume of the HEPA air ventilation system accordingly. A pilot program was carried out in a unit of operation rooms of a medical center with 1,500 beds located in central Taiwan from Jan to Aug 2010. The results found the air ventilation system was able to function much more efficiently with less energy consumed. Furthermore, the indoor air quality could still keep qualified and hospital-acquired infection or other occupational diseases could be prevented.

Direct Carbon Fuel Cell System Utilizing Solid Carbonaceous Fuels

Energy Technology Data Exchange (ETDEWEB)

Turgut Gur

2010-04-30

This 1-year project has achieved most of its objective and successfully demonstrated the viability of the fluidized bed direct carbon fuel cell (FB-DCFC) approach under development by Direct Carbon technologies, LLC, that utilizes solid carbonaceous fuels for power generation. This unique electrochemical technology offers high conversion efficiencies, produces proportionately less CO{sub 2} in capture-ready form, and does not consume or require water for gasification. FB-DCFC employs a specialized solid oxide fuel cell (SOFC) arrangement coupled to a Boudouard gasifier where the solid fuel particles are fluidized and reacted by the anode recycle gas CO{sub 2}. The resulting CO is electrochemically oxidized at the anode. Anode supported SOFC structures employed a porous Ni cermet anode layer, a dense yttria stabilized zirconia membrane, and a mixed conducting porous perovskite cathode film. Several kinds of untreated solid fuels (carbon and coal) were tested in bench scale FBDCFC prototypes for electrochemical performance and stability testing. Single cells of tubular geometry with active areas up to 24 cm{sup 2} were fabricated. The cells achieved high power densities up to 450 mW/cm{sup 2} at 850 C using a low sulfur Alaska coal char. This represents the highest power density reported in the open literature for coal based DCFC. Similarly, power densities up to 175 mW/cm{sup 2} at 850 C were demonstrated with carbon. Electrical conversion efficiencies for coal char were experimentally determined to be 48%. Long-term stability of cell performance was measured under galvanostatic conditions for 375 hours in CO with no degradation whatsoever, indicating that carbon deposition (or coking) does not pose any problems. Similar cell stability results were obtained in coal char tested for 24 hours under galvanostatic conditions with no sign of sulfur poisoning. Moreover, a 50-cell planar stack targeted for 1 kW output was fabricated and tested in 95% CO (balance CO{sub 2

Computational fluid dynamics (CFD) analysis of the combustion process of a leather residuals gasification fuel gas: influence of fuel moisture content

Energy Technology Data Exchange (ETDEWEB)

Antonietti, Anderson Jose; Beskow, Arthur Bortolin; Silva, Cristiano Vitorino da [Universidade Regional Integrada do Alto Uruguai e das Missoes (URI), Erechim, RS (Brazil)], E-mails: arthur@uricer.edu.br, mlsperb@unisinos.br; Indrusiak, Maria Luiza Sperb [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil)], E-mail: cristiano@uricer.edu.br

2010-07-01

This work presents a numerical study of the combustion process of leather residuals gasification gas, aiming the improvement of the process efficiency, considering different concentrations of water on the gas. The heating produced in this combustion process can be used to generation of thermal and/or electrical energy, for use at the leather industrial plant. However, the direct burning of this leather-residual-gas into the chambers is not straightforward. The alternative in development consists in processing this leather residuals by gasification or pyrolysis, separating the volatiles and products of incomplete combustion, for after use as fuel in a boiler. At these processes, different quantities of water can be used, resulting at different levels of moisture content in this fuel gas. This humidity can affect significantly the burning of this fuel, producing unburnt gases, as the carbon monoxide, or toxic gases as NOx, which must have their production minimized on the process, with the purpose of reducing the emission of pollutants to the atmosphere. Other environment-harmful-gases, remaining of the chemical treatment employed at leather manufacture, as cyanide, and hydrocarbons as toluene, must burn too, and the moisture content has influence on it. At this way, to increase understanding of the influence of moisture in the combustion process, it was made a numerical investigation study of reacting flow in the furnace, evaluating the temperature field, the chemical species concentration fields, flow mechanics and heat transfer at the process. The commercial CFD code CFX Ansys Inc. was used. Considering different moisture contents in the fuel used on the combustion process, with this study was possible to achieve the most efficient burning operation parameters, with improvement of combustion efficiency, and reduction of environmental harmful gases emissions. It was verified that the different moisture contents in the fuel gas demand different operation conditions

Advanced chemical hydride-based hydrogen generation/storage system for fuel cell vehicles

Energy Technology Data Exchange (ETDEWEB)

Breault, R.W.; Rolfe, J. [Thermo Power Corp., Waltham, MA (United States)

1998-08-01

Because of the inherent advantages of high efficiency, environmental acceptability, and high modularity, fuel cells are potentially attractive power supplies. Worldwide concerns over clean environments have revitalized research efforts on developing fuel cell vehicles (FCV). As a result of intensive research efforts, most of the subsystem technology for FCV`s are currently well established. These include: high power density PEM fuel cells, control systems, thermal management technology, and secondary power sources for hybrid operation. For mobile applications, however, supply of hydrogen or fuel for fuel cell operation poses a significant logistic problem. To supply high purity hydrogen for FCV operation, Thermo Power`s Advanced Technology Group is developing an advanced hydrogen storage technology. In this approach, a metal hydride/organic slurry is used as the hydrogen carrier and storage media. At the point of use, high purity hydrogen will be produced by reacting the metal hydride/organic slurry with water. In addition, Thermo Power has conceived the paths for recovery and regeneration of the spent hydride (practically metal hydroxide). The fluid-like nature of the spent hydride/organic slurry will provide a unique opportunity for pumping, transporting, and storing these materials. The final product of the program will be a user-friendly and relatively high energy storage density hydrogen supply system for fuel cell operation. In addition, the spent hydride can relatively easily be collected at the pumping station and regenerated utilizing renewable sources, such as biomass, natural, or coal, at the central processing plants. Therefore, the entire process will be economically favorable and environmentally friendly.

Conversion of a gasoline internal combustion engine to operate on hydrogen fuel

International Nuclear Information System (INIS)

Bates, M.; Dincer, I.

2009-01-01

This study deals with the conversion of a gasoline spark ignition internal combustion engine to operate on hydrogen fuel while producing similar power, economy and reliability as gasoline. The conversion engine will have the fuel system redesigned and ignition and fuel timing changed. Engine construction material is of great importance due to the low ignition energy of hydrogen, making aluminum a desirable material in the intake manifold and combustion chamber. The engine selected to convert is a 3400 SFI dual over head cam General Motors engine. Hydrogen reacts with metals causing hydrogen embrittlement which leads to failure due to cracking. There are standards published by American Society of Mechanical Engineers (ASME) to avoid such a problem. Tuning of the hydrogen engine proved to be challenging due to the basic tuning tools of a gasoline engine such as a wide band oxygen sensor that could not measure the 34:1 fuel air mixture needed for the hydrogen engine. Once the conversion was complete the engine was tested on a chassis dynamometer to compare the hydrogen horsepower and torque produced to that of a gasoline engine. Results showed that the engine is not operating correctly. The engine is not getting the proper amount of fuel needed for complete combustion when operated in a loaded state over 3000 rpm. The problem was found to be the use of the stock injector driver that could not deliver enough power for the proper operation of the larger CM4980 injectors. (author)

Modeling and design of reacting systems with phase transfer catalysis

DEFF Research Database (Denmark)

Piccolo, Chiara; Hodges, George; Piccione, Patrick M.

2011-01-01

Issues related to the design of biphasic (liquid) catalytic reaction operations are discussed. A chemical system involving the reaction of an organic-phase soluble reactant (A) with an aqueous-phase soluble reactant (B) in the presence of phase transfer catalyst (PTC) is modeled and based on it......, some of the design issues related to improved reaction operation are analyzed. Since the solubility of the different forms of the PTC in the organic solvent affects ultimately the catalyst partition coefficients, therefore, the organic solvent plays an important role in the design of PTC-based reacting...

Mathematical aspects of reacting and diffusing systems

CERN Document Server

Fife, Paul C

1979-01-01

Modeling and analyzing the dynamics of chemical mixtures by means of differ- tial equations is one of the prime concerns of chemical engineering theorists. These equations often take the form of systems of nonlinear parabolic partial d- ferential equations, or reaction-diffusion equations, when there is diffusion of chemical substances involved. A good overview of this endeavor can be had by re- ing the two volumes by R. Aris (1975), who himself was one of the main contributors to the theory. Enthusiasm for the models developed has been shared by parts of the mathematical community, and these models have, in fact, provided motivation for some beautiful mathematical results. There are analogies between chemical reactors and certain biological systems. One such analogy is rather obvious: a single living organism is a dynamic structure built of molecules and ions, many of which react and diffuse. Other analogies are less obvious; for example, the electric potential of a membrane can diffuse like a chemical, and ...

Large eddy simulation and direct numerical simulation of high speed turbulent reacting flows

Science.gov (United States)

Adumitroaie, V.; Frankel, S. H.; Madnia, C. K.; Givi, P.

The objective of this research is to make use of Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) for the computational analyses of high speed reacting flows. Our efforts in the first phase of this research conducted within the past three years have been directed in several issues pertaining to intricate physics of turbulent reacting flows. In our previous 5 semi-annual reports submitted to NASA LaRC, as well as several technical papers in archival journals, the results of our investigations have been fully described. In this progress report which is different in format as compared to our previous documents, we focus only on the issue of LES. The reason for doing so is that LES is the primary issue of interest to our Technical Monitor and that our other findings were needed to support the activities conducted under this prime issue. The outcomes of our related investigations, nevertheless, are included in the appendices accompanying this report. The relevance of the materials in these appendices are, therefore, discussed only briefly within the body of the report. Here, results are presented of a priori and a posterior analyses for validity assessments of assumed Probability Density Function (PDF) methods as potential subgrid scale (SGS) closures for LES of turbulent reacting flows. Simple non-premixed reacting systems involving an isothermal reaction of the type A + B yields Products under both chemical equilibrium and non-equilibrium conditions are considered. A priori analyses are conducted of a homogeneous box flow, and a spatially developing planar mixing layer to investigate the performance of the Pearson Family of PDF's as SGS models. A posteriori analyses are conducted of the mixing layer using a hybrid one-equation Smagorinsky/PDF SGS closure. The Smagorinsky closure augmented by the solution of the subgrid turbulent kinetic energy (TKE) equation is employed to account for hydrodynamic fluctuations, and the PDF is employed for modeling the

Reacting to different types of concept drift: the Accuracy Updated Ensemble algorithm.

Science.gov (United States)

Brzezinski, Dariusz; Stefanowski, Jerzy

2014-01-01

Data stream mining has been receiving increased attention due to its presence in a wide range of applications, such as sensor networks, banking, and telecommunication. One of the most important challenges in learning from data streams is reacting to concept drift, i.e., unforeseen changes of the stream's underlying data distribution. Several classification algorithms that cope with concept drift have been put forward, however, most of them specialize in one type of change. In this paper, we propose a new data stream classifier, called the Accuracy Updated Ensemble (AUE2), which aims at reacting equally well to different types of drift. AUE2 combines accuracy-based weighting mechanisms known from block-based ensembles with the incremental nature of Hoeffding Trees. The proposed algorithm is experimentally compared with 11 state-of-the-art stream methods, including single classifiers, block-based and online ensembles, and hybrid approaches in different drift scenarios. Out of all the compared algorithms, AUE2 provided best average classification accuracy while proving to be less memory consuming than other ensemble approaches. Experimental results show that AUE2 can be considered suitable for scenarios, involving many types of drift as well as static environments.

Alternative Fuel Research in Fischer-Tropsch Synthesis

Science.gov (United States)

Surgenor, Angela D.; Klettlinger, Jennifer L.; Yen, Chia H.; Nakley, Leah M.

2011-01-01

NASA Glenn Research Center has recently constructed an Alternative Fuels Laboratory which is solely being used to perform Fischer-Tropsch (F-T) reactor studies, novel catalyst development and thermal stability experiments. Facility systems have demonstrated reliability and consistency for continuous and safe operations in Fischer-Tropsch synthesis. The purpose of this test facility is to conduct bench scale Fischer-Tropsch (F-T) catalyst screening experiments while focusing on reducing energy inputs, reducing CO2 emissions and increasing product yields within the F-T process. Fischer-Tropsch synthesis is considered a gas to liquid process which reacts syn-gas (a gaseous mixture of hydrogen and carbon monoxide), over the surface of a catalyst material which is then converted into liquids of various hydrocarbon chain length and product distributions1. These hydrocarbons can then be further processed into higher quality liquid fuels such as gasoline and diesel. The experiments performed in this laboratory will enable the investigation of F-T reaction kinetics to focus on newly formulated catalysts, improved process conditions and enhanced catalyst activation methods. Currently the facility has the capability of performing three simultaneous reactor screening tests, along with a fourth fixed-bed reactor used solely for cobalt catalyst activation.

BETWEEN THE RIGHT AND THE COMMON. HOW GROUPS REACT TO SOCIALLY UNDESIRABLE BEHAVIOUR

Directory of Open Access Journals (Sweden)

Komendant-Brodowska Agata

2017-06-01

Full Text Available The aim of the paper is to analyse the relationship between group characteristics and the scope of reaction of the group to socially undesirable behaviour. Sometimes small groups or communities fail to react to undesirable or violent behaviour and their apathy can have devastating consequences. Such a situation can occur among co-workers witnessing workplace mobbing, or neighbours who do not react to a suspicion of domestic violence. Reasons for their inaction are diverse and can include fear, doubts concerning the necessity of such a reaction, and also conformity. In the paper I examine a seemingly favourable situation: I assume that reaction is costless and all the members of the group would like to react (internalised norm, but they also want to conform. In order to analyse the factors that can influence the scope of group reaction, a structurally embedded sequential coordination game was played for different initial conditions. Computer simulations were conducted for networks of a specific type (Erd¨os-R´enyi random graph. The main aim of the analysis was to identify non-structural and structural features of the group that can impede or even block the intervention of the group. There is a positive relationship between the scope of group reaction and the strength of the internalized norm, whereas the level of conformity affects the chances of group intervention in a negative way. Heterogeneity of the group is an important factor - the scope of reaction is higher when members of the group have different levels of norm internalisation and conformity. There is a non-linear relationship between network density and the scope of reaction. Both low and high density can make it harder for people to act.

Water-Free Proton-Conducting Membranes for Fuel Cells

Science.gov (United States)

Narayanan, Sekharipuram; Yen, Shiao-Pin

2007-01-01

Poly-4-vinylpyridinebisulfate (P4VPBS) is a polymeric salt that has shown promise as a water-free proton-conducting material (solid electrolyte) suitable for use in membrane/electrode assemblies in fuel cells. Heretofore, proton-conducting membranes in fuel cells have been made from perfluorinated ionomers that cannot conduct protons in the absence of water and, consequently, cannot function at temperatures >100 C. In addition, the stability of perfluorinated ionomers at temperatures >100 C is questionable. However, the performances of fuel cells of the power systems of which they are parts could be improved if operating temperatures could be raised above 140 C. What is needed to make this possible is a solid-electrolyte material, such as P4VPBS, that can be cast into membranes and that both retains proton conductivity and remains stable in the desired higher operating temperature range. A family of solid-electrolyte materials different from P4VPBS was described in Anhydrous Proton-Conducting Membranes for Fuel Cells (NPO-30493), NASA Tech Briefs, Vol. 29, No. 8 (August 2005), page 48. Those materials notably include polymeric quaternized amine salts. If molecules of such a polymeric salt could be endowed with flexible chain structures, it would be possible to overcome the deficiencies of simple organic amine salts that must melt before being able to conduct protons. However, no polymeric quaternized amine salts have yet shown to be useful in this respect. The present solid electrolyte is made by quaternizing the linear polymer poly- 4-vinylpyridine (P4VP) to obtain P4VPBS. It is important to start with P4VP having a molecular weight of 160,000 daltons because P4VPBS made from lower-molecular-weight P4VP yields brittle membranes. In an experimental synthesis, P4VP was dissolved in methanol and then reacted with an excess of sulfuric acid to precipitate P4VPBS. The precipitate was recovered, washed several times with methanol to remove traces of acid, and dried to a

Efficient removal of sulfur hexafluoride (SF6) through reacting with recycled electroplating sludge.

Science.gov (United States)

Zhang, Jia; Zhou, Ji Zhi; Liu, Qiang; Qian, Guangren; Xu, Zhi Ping

2013-06-18

This paper reports that recycled electroplating sludge is able to efficiently remove greenhouse gas sulfur hexafluoride (SF6). The removal process involves various reactions of SF6 with the recycled sludge. Remarkably, the sludge completely removed SF6 at a capacity of 1.10 mmol/g (SF6/sludge) at 600 °C. More importantly, the evolved gases were SO2, SiF4, and a limited amount of HF, with no toxic SOF4, SO2F2, or SF4 being detected. These generated gases can be readily captured and removed by NaOH solution. The reacted solids were further found to be various metal fluorides, thus revealing that SF6 removal takes place by reacting with various metal oxides and silicate in the sludge. Moreover, the kinetic investigation revealed that the SF6 reaction with the sludge is a first-order chemically controlled process. This research thus demonstrates that the waste electroplating sludge can be potentially used as an effective removal agent for one of the notorious greenhouse gases, SF6.

DESIGN, FABRICATION AND TEST OF THE REACT AND WIND, NB(3)SN, LDX FLOATING COIL CONDUCTOR

International Nuclear Information System (INIS)

SMITH, B.A.; MICHAEL, P.C.; MINERVINI, J.V.; TAKAYASU, M.; SCHULTZ, J.H.; GREGORY, E.; PYON, T.; SAMPSON, W.B.; GHOSH, A.; SCANLAN, R.

2000-01-01

The Levitated Dipole Experiment (LDX) is a novel approach for studying magnetic confinement of a fusion plasma. In this approach, a superconducting ring coil is magnetically levitated for up to 8 hours a day in the center of a 5 meter diameter vacuum vessel. The levitated coil, with on-board helium supply, is called the gloating Coil (F-Coil). Although the maximum field at the coil is only 5.3 tesla, a react-and-wind Nb 3 Sn conductor was selected because the relatively high critical temperature will enable the coil to remain levitated while it warms from 5 K to 10 K. Since pre-reacted Nb 3 Sn tape is no longer commercially available, a composite conductor was designed that contains an 18 strand Nb 3 Sn Rutherford cable. The cable was reacted and then soldered into a structural copper channel that completes the conductor and also provides quench protection. The strain state of the cable was continuously controlled during fabrication steps such as: soldering into the copper channel, spooling, and coil winding, to prevent degradation of the critical current. Measurements of strand and cable critical currents are reported, as well as estimates of the effect of fabrication, winding and operating strains on critical current

Realistic Creativity Training for Innovation Practitioners: The Know-Recognize-React Model

DEFF Research Database (Denmark)

Valgeirsdóttir, Dagný; Onarheim, Balder

2017-01-01

As creativity becomes increasingly recognized as important raw material for innovation, the importance of identifying ways to increase practitioners’ creativity through rigorously designed creativity training programs is highlighted. Therefore we sat out to design a creativity training program...... the transdisciplinary study described in this paper. Co-creation was employed as a method to ensure the three layers of focus would be taken into consideration. The result is a program called Creative Awareness Training which is based on the new Know-Recognize-React model....

Application of fuel cell for pyrite and heavy metal containing mining waste

Science.gov (United States)

Keum, H.; Ju, W. J.; Jho, E. H.; Nam, K.

2015-12-01

Once pyrite and heavy metal containing mining waste reacts with water and air it produces acid mine drainage (AMD) and leads to the other environmental problems such as contamination of surrounding soils. Pyrite is the major source of AMD and it can be controlled using a biological-electrochemical dissolution method. By enhancing the dissolution of pyrite using fuel cell technology, not only mining waste be beneficially utilized but also be treated at the same time by. As pyrite-containing mining waste is oxidized in the anode of the fuel cell, electrons and protons are generated, and electrons moves through an external load to cathode reducing oxygen to water while protons migrate to cathode through a proton exchange membrane. Iron-oxidizing bacteria such as Acidithiobacillus ferrooxidans, which can utilize Fe as an electron donor promotes pyrite dissolution and hence enhances electrochemical dissolution of pyrite from mining waste. In this study mining waste from a zinc mine in Korea containing 17 wt% pyrite and 9% As was utilized as a fuel for the fuel cell inoculated with A. ferrooxidans. Electrochemically dissolved As content and chemically dissolved As content was compared. With the initial pH of 3.5 at 23℃, the dissolved As concentration increased (from 4.0 to 13 mg/L after 20 d) in the fuel cell, while it kept decreased in the chemical reactor (from 12 to 0.43 mg/L after 20 d). The fuel cell produced 0.09 V of open circuit voltage with the maximum power density of 0.84 mW/m2. Dissolution of As from mining waste was enhanced through electrochemical reaction. Application of fuel cell technology is a novel treatment method for pyrite and heavy metals containing mining waste, and this method is beneficial for mining environment as well as local community of mining areas.

Determination of charge transfer resistance and capacitance of microbial fuel cell through a transient response analysis of cell voltage.

Science.gov (United States)

Ha, Phuc Thi; Moon, Hyunsoo; Kim, Byung Hong; Ng, How Yong; Chang, In Seop

2010-03-15

An alternative method for determining the charge transfer resistance and double-layer capacitance of microbial fuel cells (MFCs), easily implemented without a potentiostat, was developed. A dynamic model with two parameters, the charge transfer resistance and double-layer capacitance of electrodes, was derived from a linear differential equation to depict the current generation with respect to activation overvoltage. This model was then used to fit the transient cell voltage response to the current step change during the continuous operation of a flat-plate type MFC fed with acetate. Variations of the charge transfer resistance and the capacitance value with respect to the MFC design conditions (biocatalyst existence and electrode area) and operating parameters (acetate concentration and buffer strength in the catholyte) were then determined to elucidate the validity of the proposed method. This model was able to describe the dynamic behavior of the MFC during current change in the activation loss region; having an R(2) value of over 0.99 in most tests. Variations of the charge transfer resistance value (thousands of Omega) according to the change of the design factors and operational factors were well-correlated with the corresponding MFC performances. However, though the capacitance values (approximately 0.02 F) reflected the expected trend according to the electrode area change and catalyst property, they did not show significant variation with changes in either the acetate concentration or buffer strength. (c) 2009 Elsevier B.V. All rights reserved.

Rotary kiln and batch pyrolysis of waste tire to produce gasoline and diesel like fuels

International Nuclear Information System (INIS)

Ayanoğlu, Abdulkadir; Yumrutaş, Recep

2016-01-01

Highlights: • Waste Tire Oil (WTO) is produced from waste tire at rotary kiln reactor. • Physical and chemical properties of WTO and fuel samples are analyzed. • Gasoline like fuel (GLF) and diesel like fuel (DLF) are produced from the WTO-10 wt% CaO mixture at fixed bed reactor. • Physical and chemical properties of the GLF and DLF are compared with the standard fuels. - Abstract: In this study, waste tire is pyrolyzed in a rotary kiln reactor to obtain more gas, light liquid, heavy liquid, wax products, and less carbon black at their maximum yields as, 20%, 12%, 25%, 8% and 35% of the total weight (4 tones), respectively. Then, the heavy and light oils are reacted with additives such as natural zeolite (NZ) and lime (CaO) at different mass ratio as 2, 6, and 10 wt%, respectively, in the batch reactor to produce liquids similar to standard petroleum fuels. The heavy and light oils mixture samples are distillated to observe their optimum graphics which are similar to gasoline and diesel like fuel. Consequently, the best results are obtained from the CaO sample with 10 wt% in comparison to the ones from the gasoline and diesel fuels. The 10 wt% CaO light liquid mixture resembles to gasoline named as gasoline like fuel (GLF) and the 10 wt% CaO heavy liquid mixture is similar to diesel called as diesel like fuel (DLF). The chemical and physical features of the waste tire, light oil, heavy oil, GLF, and DLF are analyzed by TG (thermogravimetric)/dTG (derivative thermogravimetric), proximate, ultimate, higher heating value (HHV), fourier transform-infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET), sulfur, density, viscosity, gas chromatography–mass spectroscopy (GC–MS), flash point, moisture, and distillation tests. The test results are turned out to be very close to the standard petroleum fuel.

A framework for the design of reacting systems with phase transfer catalysis

DEFF Research Database (Denmark)

Piccolo, Chiara; Shaw, Andrew; Hodges, George

2012-01-01

A generic modelling framework for phase transition catalyst based reacting systems has been developed and converted into a software tool. The modelling framework accommodates models of different types representing different sub-systems of the PTCbased reactive system; databases of model parameters...... and carefully collected and checked (for thermodynamic consistency) experimentally measured data. The models, data and software have been tested on various PTC-based reactive systems. Illustrative examples are provided....

Experimental investigation of hydrous pyrolysis of diesel fuel and the effect of pyrolysis products on performance of the candidate nuclear waste repository at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Jackson, K.J.; Carroll, S.A.

1994-01-01

It is thought that a significant amount of diesel fuel and other hydrocarbon-rich phases may remain inside the candidate nuclear waste repository at Yucca Mountain after construction and subsequent emplacement of radioactive waste. Although the proposed repository horizon is above the water table, the remnant hydrocarbon phases may react with hydrothermal solutions generated by high temperature conditions that will prevail for a period of time in the repository. The preliminary experimental results of this study show that diesel fuel hydrous pyrolysis is minimal at 200 degrees C and 70 bars. The composition of the diesel fuel remained constant throughout the experiment and the concentration of carboxylic acids in the aqueous phases was only slightly above the detection limit (1-2 ppm) of the analytical technique

Effects of radiative heat transfer on the turbulence structure in inert and reacting mixing layers

International Nuclear Information System (INIS)

Ghosh, Somnath; Friedrich, Rainer

2015-01-01

We use large-eddy simulation to study the interaction between turbulence and radiative heat transfer in low-speed inert and reacting plane temporal mixing layers. An explicit filtering scheme based on approximate deconvolution is applied to treat the closure problem arising from quadratic nonlinearities of the filtered transport equations. In the reacting case, the working fluid is a mixture of ideal gases where the low-speed stream consists of hydrogen and nitrogen and the high-speed stream consists of oxygen and nitrogen. Both streams are premixed in a way that the free-stream densities are the same and the stoichiometric mixture fraction is 0.3. The filtered heat release term is modelled using equilibrium chemistry. In the inert case, the low-speed stream consists of nitrogen at a temperature of 1000 K and the highspeed stream is pure water vapour of 2000 K, when radiation is turned off. Simulations assuming the gas mixtures as gray gases with artificially increased Planck mean absorption coefficients are performed in which the large-eddy simulation code and the radiation code PRISSMA are fully coupled. In both cases, radiative heat transfer is found to clearly affect fluctuations of thermodynamic variables, Reynolds stresses, and Reynolds stress budget terms like pressure-strain correlations. Source terms in the transport equation for the variance of temperature are used to explain the decrease of this variance in the reacting case and its increase in the inert case

Identification of streptococcal proteins reacting with sera from Behçet's disease and rheumatic disorders.

Science.gov (United States)

Cho, Sung Bin; Lee, Ju Hee; Ahn, Keun Jae; Cho, Suhyun; Park, Yong-Beom; Lee, Soo-Kon; Bang, Dongsik; Lee, Kwang Hoon

2010-01-01

We evaluated the reactivity of sera from Behçet's disease (BD), systemic lupus erythematosus (SLE), dermatomyositis (DM), rheumatoid arthritis (RA), and Takayasu's arteritis (TA) patients against human α-enolase and streptococcal α-enolase, and identified additional streptococcal antigens. Enzyme-linked immunosorbent assay (ELISA) and immunoblotting were performed using sera from patients with BD, SLE, DM, RA, and TA and healthy volunteers (control) against human α-enolase and streptococcal α-enolase. Immunoblot analysis and matrix-assisted laser desorption ionisation-time-of-flight mass spectrometry were used to identify and recombine other streptococcal antigens. Specific positive signals against recombinant human α-enolase were detected by IgM ELISA of serum samples from 50% of BD, 14.3% of SLE, 57.1% of DM, 42.9% of RA, and 57.1% of TA patients. Specific positive signals against streptococcal α-enolase were detected from 42.9% of BD, 14.3% of DM, and 14.3% of TA patients. No SLE and RA sera reacted against streptococcal α-enolase antigen. Streptococcal proteins reacting with sera were identified as hypothetical protein (HP) for SLE and DM patients, acid phosphatase (AP) for RA patients, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) for TA patients. We observed that RA patients did not present serum reactivity against either HP or GAPDH though BD, SLE, DM, and TA patients did. Also, AP reacted with sera from BD, SLE, DM, RA, and TA patients.

Performance of nickel-based oxygen carrier produced using renewable fuel aloe vera

Science.gov (United States)

Afandi, NF; Devaraj, D.; Manap, A.; Ibrahim, N.

2017-04-01

Consuming and burning of fuel mainly fossil fuel has gradually increased in this upcoming era due to high-energy demand and causes the global warming. One of the most effective ways to reduce the greenhouse gases is by capturing carbon dioxide (CO2) during the combustion process. Chemical looping combustion (CLC) is one of the most effective methods to capture the CO2 without the need of an energy intensive air separation unit. This method uses oxygen carrier to provide O2 that can react with fuel to form CO2 and H2O. This research focuses on synthesizing NiO/NiAl2O4 as an oxygen carrier due to its properties that can withstand high temperature during CLC application. The NiO/NiAl2O4 powder was synthesized using solution combustion method with plant extract renewable fuel, aloe vera as the fuel. In order to optimize the performance of the particles that can be used in CLC application, various calcination temperatures were varied at 600°C, 800°C, 1050°C and 1300°C. The phase and morphology of obtained powders were characterized using X-ray diffraction (XRD) and Field Emission Microscopy (FESEM) respectively together with the powder elements. In CLC application, high reactivity can be achieved by using smaller particle size of oxygen carrier. This research succeeded in producing nano-structured powder with high crystalline structure at temperature 1050°C which is suitable to be used in CLC application.

A mathematical model for chemical reactions with actinide elements in the aqueous nitric acid solution: REACT

International Nuclear Information System (INIS)

Tachimori, Shoichi

1990-02-01

A mathematical model of chemical reactions with actinide elements: REACT code, was developed to simulate change of valency states of U, Pu and Np in the aqueous nitric acid solution. Twenty seven rate equations for the redox reactions involving some reductants, disproportionation reactions, and radiolytic growth and decay reaction of nitrous acid were programmed in the code . Eight numerical solution methods such as Porsing method to solve the rate equations were incorporated parallel as options depending on the characteristics of the reaction systems. The present report gives a description of the REACT code, e.g., chemical reactions and their rate equations, numerical solution methods, and some examples of the calculation results. A manual and a source file of the program was attached to the appendix. (author)

Methods of refining natural oils, and methods of producing fuel compositions

Science.gov (United States)

Firth, Bruce E.; Kirk, Sharon E.

2015-10-27

A method of refining a natural oil includes: (a) providing a feedstock that includes a natural oil; (b) reacting the feedstock in the presence of a metathesis catalyst to form a metathesized product that includes olefins and esters; (c) passivating residual metathesis catalyst with an agent that comprises nitric acid; (d) separating the olefins in the metathesized product from the esters in the metathesized product; and (e) transesterifying the esters in the presence of an alcohol to form a transesterified product and/or hydrogenating the olefins to form a fully or partially saturated hydrogenated product. Methods for suppressing isomerization of olefin metathesis products produced in a metathesis reaction, and methods of producing fuel compositions are described.

PENGARUH MODEL PEMBELAJARAN INKUIRI BERSTRATEGI REACT TERHADAP HASIL BELAJAR KIMIA SISWA SMA KELAS XI

Directory of Open Access Journals (Sweden)

Riva Ismawati

2015-11-01

Full Text Available This study aimed to determine the effect of inquiry learning model with REACT strategy on learning outcomes and to determine the contribution to the learning outcomes. The expected benefits are improvements in learning chemistry subjects in class XI of high school through constructivism learning activities. The population in this study were students of class XI of high school in Semarang. The analysis showed the early stages of the population have the same degree of homogeneity and normal distribution. Average learning outcomes after experimental class treated were better than the control class, which amounted to 75.52 and 67.14. Test the difference between two average results obtained t from calculation (4.85> t from table (1.66, so we can conclude the experimental class learning results are better than the control class. Correlation test resulted biserial correlation coefficient (rb of 0.58 and t from calculation (5.68> t from table (1.99, so the influence was significant. Effect of application of inquiry learning model with REACT strategy shown by the coefficient of determination of 33.64%.The cognitive learning outcomes of experimental class had reached mastery learning classical while control class not yet. The average value of affective and psychomotor experimental classes are better than the control class. Based on these results, it can be concluded that the inquiry learning with REACT strategy have positive effect on learning outcomes chemistry in student class XI of high school in Semarang.

Measurement of properties of sealant materials for solid oxide fuel cell systems

International Nuclear Information System (INIS)

Boersma, R.J.; Sammes, N.M.; Zhang, Y.

1998-01-01

Thermal expansion of ceramic materials, ceramic cements and steels was studied, and their compatibility with materials used in the SOFC system was evaluated. A number of ceramic cements, a glass paste and a glass ceramic were examined to identify their potential as a sealing material in a tubular fuel cell system. Thermal expansion coefficients of these materials were compared for thermal matching with materials employed in the fuel cell construction, such as yttria stabilised with 8 mole% zirconia (8YSZ) and stainless steel. A reasonable match was found for Macor, a glass ceramic, with one of the steel samples studied and with 8YSZ. Candidate sealants were tested for bonding quality, which made it evident that the ceramic cements had to be discarded. Good bonds between Macor and one of the steel samples and Macor and 8YSZ were formed, resulting in a gas tight seal. Uncertainty remains regarding the long term effect of the interface reactions between steel and Macor. Exposure of the Macor and a steel-Macor-8YSZ assembly to the different fuel cell gas atmospheres revealed that the Macor reacts with hydrogen, the long term effect of which is also unknown. Copyright (1998) Australasian Ceramic Society

Errors of Students Learning With React Strategy in Solving the Problems of Mathematical Representation Ability

Directory of Open Access Journals (Sweden)

Delsika Pramata Sari

2017-06-01

Full Text Available The purpose of this study was to investigate the errors experienced by students learning with REACT strategy and traditional learning in solving problems of mathematical representation ability. This study used quasi experimental pattern with static-group comparison design. The subjects of this study were 47 eighth grade students of junior high school in Bandung consisting of two samples. The instrument used was a test to measure students' mathematical representation ability. The reliability coefficient about the mathematical representation ability was 0.56. The most prominent errors of mathematical representation ability of students learning with REACT strategy and traditional learning, was on indicator that solving problem involving arithmetic symbols (symbolic representation. In addition, errors were also experienced by many students with traditional learning on the indicator of making the image of a real world situation to clarify the problem and facilitate its completion (visual representation.

Mediated electrochemical oxidation of organic wastes using a Co(III) mediator in a neutral electrolyte

International Nuclear Information System (INIS)

Balazs, G.B.; Lewis, P.R.

1999-01-01

An electrochemical cell with a Co(III) mediator and neutral pH anolyte provides efficient destruction of organic and mixed wastes. The organic waste is concentrated in the anolyte reservoir, where the cobalt mediator oxidizes the organics and insoluble radioactive species and is regenerated at the anode until all organics are converted to carbon dioxide and destroyed. The neutral electrolyte is non-corrosive, and thus extends the lifetime of the cell and its components. 2 figs

Acute hepatitis due to Epstein–Barr virus with cross-reacting antibodies to cytomegalovirus

Directory of Open Access Journals (Sweden)

Asli Karadeniz

2018-01-01

Full Text Available Epstein–Barr virus (EBV is the cause of systemic infection known as infectious mononucleosis with classic presentation of fever, oropharyngitis and lymphadenitis. EBV rarely causes acute hepatitis. In this report, we present a 19-year-old patient presented with nausea, fatigue and jaundice. Her physical examination and laboratory tests revealed the diagnosis as acute hepatitis due to EBV with cross-reacting antibodies to cytomegalovirus.

Investigation of the properties of fully reacted unstoichiometric polydimethylsiloxane networks and their extracted network fractions

DEFF Research Database (Denmark)

Frankær, Sarah Maria Grundahl; Jensen, Mette Krog; Bejenariu, Anca Gabriela

2012-01-01

We investigated the linear dynamic response of a series of fully reacted unstoichiometric polydimethylsiloxane (PDMS) networks and of the two corresponding network fractions namely the sol and the washed network. The sol and the washed network were separated by a simple extraction process. This way...

A Finite Element Theory for Predicting the Attenuation of Extended-Reacting Liners

Science.gov (United States)

Watson, W. R.; Jones, M. G.

2009-01-01

A non-modal finite element theory for predicting the attenuation of an extended-reacting liner containing a porous facesheet and located in a no-flow duct is presented. The mathematical approach is to solve separate wave equations in the liner and duct airway and to couple these two solutions by invoking kinematic constraints at the facesheet that are consistent with a continuum theory of fluid motion. Given the liner intrinsic properties, a weak Galerkin finite element formulation with cubic polynomial basis functions is used as the basis for generating a discrete system of acoustic equations that are solved to obtain the coupled acoustic field. A state-of-the-art, asymmetric, parallel, sparse equation solver is implemented that allows tens of thousands of grid points to be analyzed. A grid refinement study is presented to show that the predicted attenuation converges. Excellent comparison of the numerically predicted attenuation to that of a mode theory (using a Haynes 25 metal foam liner) is used to validate the computational approach. Simulations are also presented for fifteen porous plate, extended-reacting liners. The construction of some of the porous plate liners suggest that they should behave as resonant liners while the construction of others suggest that they should behave as broadband attenuators. In each case the finite element theory is observed to predict the proper attenuation trend.

A quasi-linear formulation for chemically reacting compressible mixtures of imperfect gases

Science.gov (United States)

Lentini, D.

2008-01-01

A quasi-linear formulation is proposed for high-speed finite-rate chemically reacting mixtures of imperfect gases, i.e., thermally perfect gases with specific heat varying with temperature. It retains the same formalism of a well-tried counterpart formulation for perfect gases, which has been proven to be suited for application of accurate and fast algorithms. Equations for both quasi-monodimensional flows, and for axisymmetric viscous flows are presented. The approach is based on the definition of an appropriate function F of temperature and concentration, which allows to identify Riemann variables for the flow under consideration; the formulation also includes equations for the entropy and the mass fractions of the N chemical species present in the reacting mixture. The key function F must be computed by numerical quadrature, together with its derivatives with respect to the individual species mass fractions. An example of computation of these quantities is reported, with reference to conditions in the combustion chamber of the Vulcain engine powering the first stage of the Ariane 5 launcher. Such a computation is demonstrated to be both economic and accurate, thus proving the workability of the proposed approach. Further, an estimate of the variation of the mixture specific heat ratio with temperature is given, in order to underline the importance of the effect under consideration.

''A Parallel Adaptive Simulation Tool for Two Phase Steady State Reacting Flows in Industrial Boilers and Furnaces''; FINAL

International Nuclear Information System (INIS)

Michael J. Bockelie

2002-01-01

This DOE SBIR Phase II final report summarizes research that has been performed to develop a parallel adaptive tool for modeling steady, two phase turbulent reacting flow. The target applications for the new tool are full scale, fossil-fuel fired boilers and furnaces such as those used in the electric utility industry, chemical process industry and mineral/metal process industry. The type of analyses to be performed on these systems are engineering calculations to evaluate the impact on overall furnace performance due to operational, process or equipment changes. To develop a Computational Fluid Dynamics (CFD) model of an industrial scale furnace requires a carefully designed grid that will capture all of the large and small scale features of the flowfield. Industrial systems are quite large, usually measured in tens of feet, but contain numerous burners, air injection ports, flames and localized behavior with dimensions that are measured in inches or fractions of inches. To create an accurate computational model of such systems requires capturing length scales within the flow field that span several orders of magnitude. In addition, to create an industrially useful model, the grid can not contain too many grid points - the model must be able to execute on an inexpensive desktop PC in a matter of days. An adaptive mesh provides a convenient means to create a grid that can capture both fine flow field detail within a very large domain with a ''reasonable'' number of grid points. However, the use of an adaptive mesh requires the development of a new flow solver. To create the new simulation tool, we have combined existing reacting CFD modeling software with new software based on emerging block structured Adaptive Mesh Refinement (AMR) technologies developed at Lawrence Berkeley National Laboratory (LBNL). Specifically, we combined: -physical models, modeling expertise, and software from existing combustion simulation codes used by Reaction Engineering International

Evaluation of a porcine internal mammary artery (No-React II) as a small-diameter conduit

NARCIS (Netherlands)

Ostapczuk, S; Poniewierski, J; Thiel, A; Knieriem, HJ; Orlowski, T; Rakhorst, G; Krian, A

1998-01-01

Background. The patency of biologic small-diameter vascular grafts in the aortocoronary position is still unsatisfactory. Most of the studies suggest that xeno-grafts are to be avoided as an aortocoronary bypass. Methods. The porcine internal mammary artery treated by the No-React II procedure was

Cross-reacting antibacterial auto-antibodies are produced within coronary atherosclerotic plaques of acute coronary syndrome patients.

Directory of Open Access Journals (Sweden)

Filippo Canducci

Full Text Available Coronary atherosclerosis, the main condition predisposing to acute myocardial infarction, has an inflammatory component caused by stimuli that are yet unknown. We molecularly investigated the nature of the immune response within human coronary lesion in four coronary plaques obtained by endoluminal atherectomy from four patients. We constructed phage-display libraries containing the IgG1/kappa antibody fragments produced by B-lymphocytes present in each plaque. By immunoaffinity, we selected from these libraries a monoclonal antibody, arbitrarily named Fab7816, able to react both with coronary and carotid atherosclerotic tissue samples. We also demonstrated by confocal microscopy that this monoclonal antibody recognized human transgelin type 1, a cytoskeleton protein involved in atherogenesis, and that it co-localized with fibrocyte-like cells transgelin+, CD68+, CD45+ in human sections of coronary and carotid plaques. In vitro fibrocytes obtained by differentiating CD14+ cells isolated from peripheral blood mononuclear cells also interacted with Fab7816, thus supporting the hypothesis of a specific recognition of fibrocytes into the atherosclerotic lesions. Interestingly, the same antibody, cross-reacted with the outer membrane proteins of Proteus mirabilis and Klebsiella pneumoniae (and possibly with homologous proteins of other enterobacteriaceae present in the microbiota. From all the other three libraries, we were able to clone, by immunoaffinity selection, human monoclonal antibodies cross-reacting with bacterial outer membrane proteins and with transgelin. These findings demonstrated that in human atherosclerotic plaques a local cross-reactive immune response takes place.

Competitor's marketing : How banks acquire and react to knowledge about their competitor's marketing.

OpenAIRE

Puelma, Rodrigo; Persson, Annika

2008-01-01

Abstract   Introduction The way banks compete has changed dramatically during recent years, mostly because of international trends such as advances in information technology, globalisation and deregulations. This has made competition harsher meaning that survival and success requires knowledge about the competitors and understanding about the way they act and react. Within marketing there is a need to identify suitable strategies to acquire knowledge about competitor’s marketing and methods t...

Fuel Exhaling Fuel Cell.

Science.gov (United States)

Manzoor Bhat, Zahid; Thimmappa, Ravikumar; Devendrachari, Mruthyunjayachari Chattanahalli; Kottaichamy, Alagar Raja; Shafi, Shahid Pottachola; Varhade, Swapnil; Gautam, Manu; Thotiyl, Musthafa Ottakam

2018-01-18

State-of-the-art proton exchange membrane fuel cells (PEMFCs) anodically inhale H 2 fuel and cathodically expel water molecules. We show an unprecedented fuel cell concept exhibiting cathodic fuel exhalation capability of anodically inhaled fuel, driven by the neutralization energy on decoupling the direct acid-base chemistry. The fuel exhaling fuel cell delivered a peak power density of 70 mW/cm 2 at a peak current density of 160 mA/cm 2 with a cathodic H 2 output of ∼80 mL in 1 h. We illustrate that the energy benefits from the same fuel stream can at least be doubled by directing it through proposed neutralization electrochemical cell prior to PEMFC in a tandem configuration.

Formulation and Testing of Paraffin-Based Solid Fuels Containing Energetic Additives for Hybrid Rockets

Science.gov (United States)

Larson, Daniel B.; Boyer, Eric; Wachs,Trevor; Kuo, Kenneth K.; Story, George

2012-01-01

Many approaches have been considered in an effort to improve the regression rate of solid fuels for hybrid rocket applications. One promising method is to use a fuel with a fast burning rate such as paraffin wax; however, additional performance increases to the fuel regression rate are necessary to make the fuel a viable candidate to replace current launch propulsion systems. The addition of energetic and/or nano-sized particles is one way to increase mass-burning rates of the solid fuels and increase the overall performance of the hybrid rocket motor.1,2 Several paraffin-based fuel grains with various energetic additives (e.g., lithium aluminum hydride (LiAlH4) have been cast in an attempt to improve regression rates. There are two major advantages to introducing LiAlH4 additive into the solid fuel matrix: 1) the increased characteristic velocity, 2) decreased dependency of Isp on oxidizer-to-fuel ratio. The testing and characterization of these solid-fuel grains have shown that continued work is necessary to eliminate unburned/unreacted fuel in downstream sections of the test apparatus.3 Changes to the fuel matrix include higher melting point wax and smaller energetic additive particles. The reduction in particle size through various methods can result in more homogeneous grain structure. The higher melting point wax can serve to reduce the melt-layer thickness, allowing the LiAlH4 particles to react closer to the burning surface, thus increasing the heat feedback rate and fuel regression rate. In addition to the formulation of LiAlH4 and paraffin wax solid-fuel grains, liquid additives of triethylaluminum and diisobutylaluminum hydride will be included in this study. Another promising fuel formulation consideration is to incorporate a small percentage of RDX as an additive to paraffin. A novel casting technique will be used by dissolving RDX in a solvent to crystallize the energetic additive. After dissolving the RDX in a solvent chosen for its compatibility

'Reacting to the unknown': experiencing the first birth at home or in hospital in Australia.

Science.gov (United States)

Dahlen, Hannah G; Barclay, Lesley; Homer, Caroline S E

2010-08-01

to explore the experiences of a small group of first-time mothers giving birth at home or in hospital. a grounded theory methodology was used. Data were generated from in-depth interviews with women in their own homes. Sydney, Australia. 19 women were interviewed. Seven women who gave birth for the first time in a public hospital and seven women who gave birth for the first time at home were interviewed, and their experiences were contrasted with two mothers who gave birth for the first time in a birth centre, one mother who gave birth for the first time in a private hospital and two women who had given birth more than once. these women shared common experiences of giving birth as 'novices'. Regardless of birth setting, they were all 'reacting to the unknown'. As they entered labour, the women chose different levels of responsibility for their birth. They also readjusted their expectations when the reality of labour occurred, reacted to the 'force' of labour, and connected or disconnected from the labour and eventually the baby. knowing that first-time mothers, irrespective of birth setting, are essentially 'reacting to the unknown' as they negotiate the experience of birth, could alter the way in which care is provided and increase the sensitivity of midwives to women's needs. Most importantly, midwives need to be aware of the need to help women adjust their expectations during labour and birth. Identifying the 'novice' status of first-time mothers also better explains previous research that reports unrealistic expectations and fear that may be associated with first-time birthing. Crown Copyright 2008. Published by Elsevier Ltd. All rights reserved.

A Parallel Multiblock Structured Grid Method with Automated Interblocked Unstructured Grids for Chemically Reacting Flows

Science.gov (United States)

Spiegel, Seth Christian

An automated method for using unstructured grids to patch non- C0 interfaces between structured blocks has been developed in conjunction with a finite-volume method for solving chemically reacting flows on unstructured grids. Although the standalone unstructured solver, FVFLO-NCSU, is capable of resolving flows for high-speed aeropropulsion devices with complex geometries, unstructured-mesh algorithms are inherently inefficient when compared to their structured counterparts. However, the advantages of structured algorithms in developing a flow solution in a timely manner can be negated by the amount of time required to develop a mesh for complex geometries. The global domain can be split up into numerous smaller blocks during the grid-generation process to alleviate some of the difficulties in creating these complex meshes. An even greater abatement can be found by allowing the nodes on abutting block interfaces to be nonmatching or non-C 0 continuous. One code capable of solving chemically reacting flows on these multiblock grids is VULCAN, which uses a nonconservative approach for patching non-C0 block interfaces. The developed automated unstructured-grid patching algorithm has been installed within VULCAN to provide it the capability of a fully conservative approach for patching non-C0 block interfaces. Additionally, the FVFLO-NCSU solver algorithms have been deeply intertwined with the VULCAN source code to solve chemically reacting flows on these unstructured patches. Finally, the CGNS software library was added to the VULCAN postprocessor so structured and unstructured data can be stored in a single compact file. This final upgrade to VULCAN has been successfully installed and verified using test cases with particular interest towards those involving grids with non- C0 block interfaces.

"Reacting to the Past" to Be Proactive in the Present: Feminist Roots of High-Impact Practices

Science.gov (United States)

Lidinsky, April

2014-01-01

In this article, the author explains a high-impact role-playing pedagogy developed at Barnard College called "Reacting to the Past," which she uses to introduce first-year and general education students to feminist history, current feminist issues, and feminist pedagogy.

Development of the uranium recovery process from rejected fuel plates in the fabrication of MTR type nuclear fuel

International Nuclear Information System (INIS)

Fleming Rubio, Peter Alex

2010-01-01

The current work was made in Conversion laboratory belonging to Chilean Nuclear Energy Commission, CCHEN. This is constituted by the development of three hydrometallurgical processes, belonging to the recovery of uranium from fuel plates based on uranium silicide (U_3Si_2) process, for nuclear research reactors MTR (Material Testing Reactor) type, those that come from the Fuel Elements Manufacture Plant, PEC. In the manufacturing process some of these plates are subjected to destructive tests by quality requirement or others are rejected for non-compliance with technical specifications, such as: lack of homogenization of the dispersion of uraniferous compound in the meat, as well as the appearance of the defects, such as blisters, so-called "dog bone", "fish tail", "remote islands", among others. Because the uranium used is enriched in 19.75% U_2_3_5 isotope, which explains the high value in the market, it must be recovered for reuse, returning to the production line of fuel elements. The uranium silicide, contained in the plates, is dispersed in an aluminum matrix and covered with plates and frames of ASTM 6061 Aluminum, as a sandwich coating, commonly referred to as 'meat' (sandwich meat). As aluminum is the main impurity, the process begins with this metal dissolution, present in meat and plates, by NaOH reaction, followed by a vacuum filtration, washing and drying, obtaining a powder of uranium silicide, with a small impurities percentage. Then, the crude uranium silicide reacts with a solution of hydrofluoric acid, dissolving the silicon and simultaneously precipitating UF_4 by reaction with HNO_3, obtaining an impure UO_2(NO_3)_2 solution. The experimental work was developed and implemented at laboratory scale for the three stages pertaining to the uranium recovery process, determining for each one the optimum operation conditions: temperature, molarity or concentration, reagent excess, among others (author)

Desarrollo de una aplicación móvil mediante React-Native

OpenAIRE

Raja Lentijo, David

2018-01-01

In this document has been developed an application to share food recipes with social format where the users can interact between them. The goal of this applications is to create a global platform when users wants to find something related with cooking, know where have to go and don't have to use a web browser. All has developed with React-Native that allows to develop native applications for Android and IOS platforms, and reduce the processing time respect to hybrid applications. Also, the co...

Errors of Students Learning with React Strategy in Solving the Problems of Mathematical Representation Ability

Science.gov (United States)

Sari, Delsika Pramata; Darhim; Rosjanuardi, Rizky

2018-01-01

The purpose of this study was to investigate the errors experienced by students learning with REACT strategy and traditional learning in solving problems of mathematical representation ability. This study used quasi experimental pattern with static-group comparison design. The subjects of this study were 47 eighth grade students of junior high…

Use of Crystalline Boron as a Burn Rate Retardant Toward the Development of Green-Colored Handheld Signal Formulations

Science.gov (United States)

2011-01-01

emitter and formed magnesium oxide (MgO) in a highly exothermic process upon reacting with barium nitrate. Although it served as a low-energy fuel...nitric acid under boiling conditions, it fails to react when treated with boiling hydrofluoric and hydrochloric acids [13]. Table 3 Performance of...fuel. It is believed that amorphous boron, when reacted with oxygen, forms metastable boron oxide (BO2) in the excited state, which is responsible for

Development status of irradiation devices and instrumentation for material and nuclear fuel irradiation tests in HANARO

Energy Technology Data Exchange (ETDEWEB)

Kim, Bong Goo; Sohn, Jae Min; Choo, Kee Nam [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-04-15

The High flux Advanced Neutron Application ReactOr (HANARO), an open-tank-in-pool type reactor, is one of the multi-purpose research reactors in the world. Since the commencement of HANARO's operations in 1995, a significant number of experimental facilities have been developed and installed at HANARO, and continued efforts to develop more facilities are in progress. Owing to the stable operation of the reactor and its frequent utilization, more experimental facilities are being continuously added to satisfy various fields of study and diverse applications. The irradiation testing equipment for nuclear fuels and materials at HANARO can be classified into capsules and the Fuel Test Loop (FTL). Capsules for irradiation tests of nuclear fuels in HANARO have been developed for use under the dry conditions of the coolant and materials at HANARO and are now successfully utilized to perform irradiation tests. The FTL can be used to conduct irradiation testing of a nuclear fuel under the operating conditions of commercial nuclear power plants. During irradiation tests conducted using these capsules in HANARO, instruments such as the thermocouple, Linear Variable Differential Transformer (LVDT), small heater, Fluence Monitor (F/M) and Self-Powered Neutron Detector (SPND) are used to measure various characteristics of the nuclear fuel and irradiated material. This paper describes not only the status of HANARO and the status and perspective of irradiation devices and instrumentation for carrying out nuclear fuel and material tests in HANARO but also some results from instrumentation during irradiation tests

Recent Progress in the Development of Diesel Surrogate Fuels

Energy Technology Data Exchange (ETDEWEB)

Pitz, W J; Mueller, C J

2009-12-09

There has been much recent progress in the area of surrogate fuels for diesel. In the last few years, experiments and modeling have been performed on higher molecular weight components of relevance to diesel fuel such as n-hexadecane (n-cetane) and 2,2,4,4,6,8,8-heptamethylnonane (iso-cetane). Chemical kinetic models have been developed for all the n-alkanes up to 16 carbon atoms. Also, there has been much experimental and modeling work on lower molecular weight surrogate components such as n-decane and n-dodecane that are most relevant to jet fuel surrogates, but are also relevant to diesel surrogates where simulation of the full boiling point range is desired. For two-ring compounds, experimental work on decalin and tetralin recently has been published. For multi-component surrogate fuel mixtures, recent work on modeling of these mixtures and comparisons to real diesel fuel is reviewed. Detailed chemical kinetic models for surrogate fuels are very large in size. Significant progress also has been made in improving the mechanism reduction tools that are needed to make these large models practicable in multi-dimensional reacting flow simulations of diesel combustion. Nevertheless, major research gaps remain. In the case of iso-alkanes, there are experiments and modeling work on only one of relevance to diesel: iso-cetane. Also, the iso-alkanes in diesel are lightly branched and no detailed chemical kinetic models or experimental investigations are available for such compounds. More components are needed to fill out the iso-alkane boiling point range. For the aromatic class of compounds, there has been no new work for compounds in the boiling point range of diesel. Most of the new work has been on alkyl aromatics that are of the range C7 to C8, below the C10 to C20 range that is needed. For the chemical class of cycloalkanes, experiments and modeling on higher molecular weight components are warranted. Finally for multi-component surrogates needed to treat real

Combined LAURA-UPS solution procedure for chemically-reacting flows. M.S. Thesis

Science.gov (United States)

Wood, William A.

1994-01-01

A new procedure seeks to combine the thin-layer Navier-Stokes solver LAURA with the parabolized Navier-Stokes solver UPS for the aerothermodynamic solution of chemically-reacting air flowfields. The interface protocol is presented and the method is applied to two slender, blunted shapes. Both axisymmetric and three dimensional solutions are included with surface pressure and heat transfer comparisons between the present method and previously published results. The case of Mach 25 flow over an axisymmetric six degree sphere-cone with a noncatalytic wall is considered to 100 nose radii. A stability bound on the marching step size was observed with this case and is attributed to chemistry effects resulting from the noncatalytic wall boundary condition. A second case with Mach 28 flow over a sphere-cone-cylinder-flare configuration is computed at both two and five degree angles of attack with a fully-catalytic wall. Surface pressures are seen to be within five percent with the present method compared to the baseline LAURA solution and heat transfers are within 10 percent. The effect of grid resolution is investigated and the nonequilibrium results are compared with a perfect gas solution, showing that while the surface pressure is relatively unchanged by the inclusion of reacting chemistry the nonequilibrium heating is 25 percent higher. The procedure demonstrates significant, order of magnitude reductions in solution time and required memory for the three dimensional case over an all thin-layer Navier-Stokes solution.

Turbulent diffusion of chemically reacting flows: Theory and numerical simulations.

Science.gov (United States)

Elperin, T; Kleeorin, N; Liberman, M; Lipatnikov, A N; Rogachevskii, I; Yu, R

2017-11-01

The theory of turbulent diffusion of chemically reacting gaseous admixtures developed previously [T. Elperin et al., Phys. Rev. E 90, 053001 (2014)PLEEE81539-375510.1103/PhysRevE.90.053001] is generalized for large yet finite Reynolds numbers and the dependence of turbulent diffusion coefficient on two parameters, the Reynolds number and Damköhler number (which characterizes a ratio of turbulent and reaction time scales), is obtained. Three-dimensional direct numerical simulations (DNSs) of a finite-thickness reaction wave for the first-order chemical reactions propagating in forced, homogeneous, isotropic, and incompressible turbulence are performed to validate the theoretically predicted effect of chemical reactions on turbulent diffusion. It is shown that the obtained DNS results are in good agreement with the developed theory.

Therapeutic preparations of IVIg contain naturally occurring anti-HLA-E antibodies that react with HLA-Ia (HLA-A/-B/-Cw) alleles.

Science.gov (United States)

Ravindranath, Mepur H; Terasaki, Paul I; Pham, Tho; Jucaud, Vadim; Kawakita, Satoru

2013-03-14

The US Food and Drug Administration approved intravenous immunoglobulin (IVIg), extracted from the plasma of thousands of blood donors, for removing HLA antibodies (Abs) in highly sensitized patients awaiting organ transplants. Since the blood of healthy individuals has HLA Abs, we tested different IVIg preparations for reactivity to HLA single antigen Luminex beads. All preparations showed high levels of HLA-Ia and -Ib reactivity. Since normal nonalloimmunized males have natural antibodies to the heavy chains (HCs) of HLA antigens, the preparations were then tested against iBeads coated only with intact HLA antigens. All IVIg preparations varied in level of antibody reactivity to intact HLA antigens. We raised monoclonal Abs against HLA-E that mimicked IVIg's HLA-Ia and HLA-Ib reactivity but reacted only to HLA-I HCs. Inhibition experiments with synthetic peptides showed that HLA-E shares epitopes with HLA-Ia alleles. Importantly, depleting anti-HLA-E Abs from IVIg totally eliminated the HLA-Ia reactivity of IVIg. Since anti-HLA-E mAbs react with HLA-Ia, they might be useful in suppressing HLA antibody production, similar to the way anti-RhD Abs suppress production. At the same time, anti-HLA-E mAb, which reacts only to HLA-I HCs, is unlikely to produce transfusion-related acute lung injury, in contrast to antibodies reacting to intact-HLA.

Fuel performance computer code simulation of steady-state and transient regimes of the stainless steel fuel rods; Simulacao com programas computacionais de desempenho do combustivel em regimes permanente e transiente de varetas combustiveis de aco inoxidavel austenitico

Energy Technology Data Exchange (ETDEWEB)

Gomes, Daniel de Souza

2014-07-01

The immediate cause of the accident at the Fukushima Daiichi nuclear plant in March 2011 was the meltdown of the reactor core. During this process, the zirconium cladding of the fuel reacts with water, producing a large amount of hydrogen. This hydrogen, combined with volatile radioactive materials leaked from the containment vessel and entered the building of the reactor, resulting in explosions. In the past, stainless steel was used as the coating in many pressurized water reactors (PWR) under irradiation and their performance was excellent, however, the stainless steel was replaced by a zirconium-based alloy as a coating material mainly due to its lower section shock-absorbing neutrons. Today, the stainless steel finish appears again as a possible solution for security issues related to the explosion and hydrogen production. The objective of this thesis is to discuss the performance under irradiation of fuel rods using stainless steel as a coating material. The results showed that stainless steel rods exhibit lower temperatures and higher fuel pellet width of the gap - coating the coated rods Zircaloy and this gap does not close during the irradiation. The thermal performance of the two fuel rods is very similar, and the penalty of increased absorption of neutrons due to the use of stainless steel can be offset by the combination of a small increase in the enrichment of U- 235 and changes in the size of the spacing between the fuel rods. (author)

Lean premixed reacting flows with swirl and wall-separation zones in a contracting chamber

Science.gov (United States)

Zhang, Yuxin; Rusak, Zvi; Wang, Shixiao

2017-11-01

Low Mach number lean premixed reacting swirling flows with wall-separation zones in a contracting circular finite-length open chamber are studied. Assuming a complete reaction with high activation energy and chemical equilibrium behind the reaction zone, a nonlinear partial differential equation is derived for the solution of the flow stream function behind the reaction zone in terms of the inlet total enthalpy for a reacting flow, specific entropy and the circulation functions. Bifurcation diagrams of steady flows are described as the inlet swirl level is increased at fixed chamber contraction and reaction heat release. The approach is applied to an inlet solid-body rotation flow with constant profiles of the axial velocity, temperature and mixture reactant mass fraction. The computed results provide predictions of the critical inlet swirl levels for the first appearance of wall-separation states and for the size of the separation zone as a function of the inlet swirl ratio, Mach number, chamber contraction and heat release of the reaction. The methodology developed in this paper provides a theoretical feasibility for the development of the technology of swirl-assisted combustion where the reaction zone is supported and stabilized by a wall-separation zone.

Approximate solution to the Kolmogorov equation for a fission chain-reacting system

International Nuclear Information System (INIS)

Ruby, L.; McSwine, T.L.

1986-01-01

An approximate solution has been obtained for the Kolmogorov equation describing a fission chain-reacting system. The method considers the population of neutrons, delayed-neutron precursors, and detector counts. The effect of the detector is separated from the statistics of the chain reaction by a weak coupling assumption that predicts that the detector responds to the average rather than to the instantaneous neutron population. An approximate solution to the remaining equation, involving the populations of neutrons and precursors, predicts a negative-binomial behaviour for the neutron probability distribution

Extension of a semi-implicit shock-capturing algorithm for 3-D fully coupled, chemically reacting flows in generalized coordinates

International Nuclear Information System (INIS)

Shinn, J.L.; Yee, H.C.; Uenishi, K.; NASA, Ames Research Center, Moffett Field, CA; Vigyan Research Associates, Inc., Hampton, VA)

1987-01-01

A semiimplicit high-resolution shock-capturing method for multidimensional systems of hyperbolic conservation laws with stiff source terms has been developed by Yee and Shinn (1987). The goal of this work is to extend this method to solve the three-dimensional fully coupled Navier-Stokes equations for a hypersonic chemically reacting flow in generalized coordinates. In this formulation, the global continuity equation was replaced by all the species continuity equations. The shock-capturing technique is a second-order-accurate, symmetric total-variation-diminishing method which accounts fully and directly for the coupling among the fluid and all the species. To verify the current approach, it was implemented into an existing computer code which contained the MacCormack method. Test results for a five-species reacting flow are shown to be oscillation-free around the shock, and the time spent per iteration only doubles when compared to the result using classical way of supplying numerical dissipation. The extra computation is more than justified by the elimination of spurious oscillation and nonlinear instability associated with the classical shock-capturing schemes in computing hypersonic reacting flows. 27 references

Reaction Ensemble Molecular Dynamics: Direct Simulation of the Dynamic Equilibrium Properties of Chemically Reacting Mixtures

Czech Academy of Sciences Publication Activity Database

Brennan, J.K.; Lísal, Martin; Gubbins, K.E.; Rice, B.M.

2004-01-01

Roč. 70, č. 6 (2004), 0611031-0611034 ISSN 1063-651X R&D Projects: GA ČR GA203/03/1588 Grant - others:NSF(US) CTS-0211792 Institutional research plan: CEZ:AV0Z4072921 Keywords : reacting systems * simulation * molecular dynamics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.352, year: 2004

Inert materials for the GFR fuel. Characterizations, chemical interactions and irradiation damage

International Nuclear Information System (INIS)

Audubert, Fabienne; Carlot, Gaoelle; Lechelle, Jacques; David, Laurent; Gomes, Severine

2005-01-01

In the framework of an extensive R and D Program on GFR fuel, studies on inert materials have been performed at the French Atomic Energy Commission (CEA). The inert materials would be associated with the fuel with the aim of featuring an efficient barrier to radiotoxic species with regard to the cooling circuit of the reactor. Potential matrices identified for dispersion fuels or particles fuels are SiC, TiN, ZrN, ZrC, TiC. Physical microstructural and thermal properties have been determined in order to evaluate elaboration process effects. The evolution under irradiation of thermal properties (such as conductivity, diffusivity) of the materials has been studied using heavy ions to simulate fission product irradiation. After irradiation, scanning thermal microscopy is used to investigate the thermal degradation of the materials. Thermal conductivity variations were obtained on TiC irradiated with krypton ion at an energy of 86 MeV and a fluence of 5.10 15 ions.cm -2 . They are quantified at 19 W.m -1 .K -1 . On other materials such as SiC, ZrC, TiN, no thermal conductivity contrast was shown. Reactivity between the inert matrix (SiC or TiN) and the fuel (U, Pu)N have been evaluated on powders and on ceramic samples in contact by a thermal treatment under several atmospheres. It was shown that SiC reacts with (U, Pu)N in various atmospheres making secondary phases as PuSi 2 , USi 2 , U 20 Si 16 C 3 . TiN behaviour seems to be better: the only reactivity which may take place would be a variation of the nitrogen stoichiometry in TiN and (U, Pu)N at the interface. (author)

Fuel cell generator with fuel electrodes that control on-cell fuel reformation

Science.gov (United States)

Ruka, Roswell J [Pittsburgh, PA; Basel, Richard A [Pittsburgh, PA; Zhang, Gong [Murrysville, PA

2011-10-25

A fuel cell for a fuel cell generator including a housing including a gas flow path for receiving a fuel from a fuel source and directing the fuel across the fuel cell. The fuel cell includes an elongate member including opposing first and second ends and defining an interior cathode portion and an exterior anode portion. The interior cathode portion includes an electrode in contact with an oxidant flow path. The exterior anode portion includes an electrode in contact with the fuel in the gas flow path. The anode portion includes a catalyst material for effecting fuel reformation along the fuel cell between the opposing ends. A fuel reformation control layer is applied over the catalyst material for reducing a rate of fuel reformation on the fuel cell. The control layer effects a variable reformation rate along the length of the fuel cell.

Stoichiometric effects on performance of high-temperature gas-cooled reactor fuels from the U--C--O system

International Nuclear Information System (INIS)

Homan, F.J.; Lindemer, T.B.; Long, E.L. Jr.; Tiegs, T.N.; Beatty, R.L.

1977-01-01

Two fuel failure mechanisms were identified for coated particle fuels that are directly related to fuel kernel stoichiometry. These mechanisms are thermal migration of the kernel through the coating layers and chemical interaction between rare-earth fission products and the silicon carbide (SiC) layer leading to failure of the SiC layer. Thermal migration appears to be most severe for oxide fuels, while chemical interaction is most severe with carbide systems. Thermodynamic calculations indicated that oxide-carbide fuel kernels may permit a stoichiometry that reduces both problems to manageable levels for currently planned high-temperature gas-cooled reactors. Such stoichiometry adjustment is possible over the complete spectrum from UO 2 to UC 2 for the present recycle fuel, a weak acid resin (WAR)-derived fissile kernel. Thermodynamic calculations indicate that WAR kernels containing less than 15 percent UC 2 (greater than 85 percent UO 2 ) will develop excessive CO overpressures within the particle during irradiation. In 100 percent UO 2 particles, thermal migration and oxidation of the SiC layer were observed after irradiation. The calculations also indicate that WAR kernels containing greater than 70 percent UC 2 (less than 30 percent UC 2 ) contain insufficient oxygen to oxidize the rare-earth fission products formed in fuel operated to the maximum burnup levels of 75 percent fissions per initial metal atom (75 percent FIMA). Instead, the rare earths are present in part or completely as dicarbides. As such, they were observed to segregate from the kernel and collect at the SiC interface on the cold side of the particle, react with the SiC, and eventually fail this coating

Computer program to solve two-dimensional shock-wave interference problems with an equilibrium chemically reacting air model

Science.gov (United States)

Glass, Christopher E.

1990-08-01

The computer program EASI, an acronym for Equilibrium Air Shock Interference, was developed to calculate the inviscid flowfield, the maximum surface pressure, and the maximum heat flux produced by six shock wave interference patterns on a 2-D, cylindrical configuration. Thermodynamic properties of the inviscid flowfield are determined using either an 11-specie, 7-reaction equilibrium chemically reacting air model or a calorically perfect air model. The inviscid flowfield is solved using the integral form of the conservation equations. Surface heating calculations at the impingement point for the equilibrium chemically reacting air model use variable transport properties and specific heat. However, for the calorically perfect air model, heating rate calculations use a constant Prandtl number. Sample calculations of the six shock wave interference patterns, a listing of the computer program, and flowcharts of the programming logic are included.

Development and testing of bumper limiter of aluminum alloy vacuum vessel for reacting plasma experiment

International Nuclear Information System (INIS)

Uchikawa, T.; Fujiwara, M.; Ioki, K.; Irie, T.; Nayama, R.; Nishikawa, M.; Onozuka, M.; Tomita, M.

1985-01-01

Two types of graphite bumper limiters were designed and trially fabricated for a reacting plasma device, R-tokamak. High heat load tests were conducted to examine thermal behavior and thermal shock resistance of the limiters by using a 100kW electron beam facility. The experimental data were compared with the results of 3-D thermal analysis

Development and testing of bumper limiter of aluminum alloy vacuum vessel for reacting plasma experiment

Energy Technology Data Exchange (ETDEWEB)

Uchikawa, T.; Fujiwara, M.; Ioki, K.; Irie, T.; Nayama, R.; Nishikawa, M.; Onozuka, M.; Tomita, M.

1985-07-01

Two types of graphite bumper limiters were designed and trially fabricated for a reacting plasma device, R-tokamak. High heat load tests were conducted to examine thermal behavior and thermal shock resistance of the limiters by using a 100kW electron beam facility. The experimental data were compared with the results of 3-D thermal analysis.

Statistical analysis of the velocity and scalar fields in reacting turbulent wall-jets

Science.gov (United States)

Pouransari, Z.; Biferale, L.; Johansson, A. V.

2015-02-01

The concept of local isotropy in a chemically reacting turbulent wall-jet flow is addressed using direct numerical simulation (DNS) data. Different DNS databases with isothermal and exothermic reactions are examined. The chemical reaction and heat release effects on the turbulent velocity, passive scalar, and reactive species fields are studied using their probability density functions (PDFs) and higher order moments for velocities and scalar fields, as well as their gradients. With the aid of the anisotropy invariant maps for the Reynolds stress tensor, the heat release effects on the anisotropy level at different wall-normal locations are evaluated and found to be most accentuated in the near-wall region. It is observed that the small-scale anisotropies are persistent both in the near-wall region and inside the jet flame. Two exothermic cases with different Damköhler numbers are examined and the comparison revealed that the Damköhler number effects are most dominant in the near-wall region, where the wall cooling effects are influential. In addition, with the aid of PDFs conditioned on the mixture fraction, the significance of the reactive scalar characteristics in the reaction zone is illustrated. We argue that the combined effects of strong intermittency and strong persistency of anisotropy at the small scales in the entire domain can affect mixing and ultimately the combustion characteristics of the reacting flow.

Development of uranium milling and conversion

International Nuclear Information System (INIS)

Takada, Shingo; Hirono, Shuichiro.

1983-11-01

The development and improvement of uranium milling and refining producing uranium tetrafluoride from ores by the wet process, without producing yellowcake as an intermediate product, have been carried out for over ten years with a small pilot plant (50 t-ore/day). In the past several years, a process for converting uranium tetrafluoride into hexafluoride has been developed successfully. To develop the process further, the construction of an integrated milling and conversion pilot plant (200 t-U/year) started in 1979 and was completed in 1981. This new plant has two systems of solvent extraction using tri-noctylamine: one of the systems treats the pregnant solution (uranyl sulphate) by heap-leaching followed by ion exchange, and the other treats the uranyl sulphate solution by dissolving imported yellowcake. The uranium loading solvents from the two systems are stripped with hydrochloric acid solution to obtain the concentrated uranium solution containing 100 g-U/1. Uranyl sulphate solution from the stripping circuit is reduced to a uranous sulphate solution by the electrolytic method. In a reduction cell, uranyl sulphate solution and dilute sulphuric acid are used respectively as catholyte and anolyte, and a cation exchange membrane is used to prevent re-oxidation of the uranous sulphate. In the following hydrofluorination step, uranium tetrafluoride, UF 4 .1-1.2H 2 O (particle size: 50-100μ), is produced continuously as the precipitate in an improved reaction vessel, and this makes it possible to simplify the procedures of liquid-solid separation, drying and granulation. The uranium tetrafluoride is dehydrated by heating to 350 0 C in an inert gas flow. The complete conversion from UF 4 into UF 6 is achieved by a fluidized-bed reactor and a high value of utilization efficiency of fluorine, over 99.9 percent, is attained at about 400 0 C. (author)

Capillary Isoelectric Focusing-Mass Spectrometry Method for the Separation and Online Characterization of Intact Monoclonal Antibody Charge Variants.

Science.gov (United States)

Dai, Jun; Lamp, Jared; Xia, Qiangwei; Zhang, Yingru

2018-02-06

We report a new online capillary isoelectric focusing-mass spectrometry (CIEF-MS) method for monoclonal antibody (mAb) charge variant analysis using an electrokinetically pumped sheath-flow nanospray ion source and a time-of-flight MS with pressure-assisted chemical mobilization. To develop a successful, reliable CIEF-MS method for mAb, we have selected and optimized many critical, interrelating reagents and parameters that include (1) MS-friendly anolyte and catholyte; (2) a glycerol enhanced sample mixture that reduced non-CIEF electrophoretic mobility and band broadening; (3) ampholyte selected for balancing resolution and MS sensitivity; (4) sheath liquid composition optimized for efficient focusing, mobilization, and electrospray ionization; (5) judiciously selected CIEF running parameters including injection amount, field strength, and applied pressure. The fundamental premise of CIEF was well maintained as verified by the linear correlation (R 2 = 0.99) between pI values and migration time using a mixture of pI markers. In addition, the charge variant profiles of trastuzumab, bevacizumab, infliximab, and cetuximab, obtained using this CIEF-MS method, were corroborated by imaged CIEF-UV (iCIEF-UV) analyses. The relative standard deviations (RSD) of absolute migration time of pI markers were all less than 5% (n = 4). Triplicate analyses of bevacizumab showed RSD less than 1% for relative migration time to an internal standard and RSD of 7% for absolute MS peak area. Moreover, the antibody charge variants were characterized using the online intact MS data. To the best of our knowledge, this is the first time that direct online MS detection and characterization were achieved for mAb charge variants resolved by CIEF as indicated by a well-established linear pH gradient and correlated CIEF-UV charge variant profiles.

A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery

Energy Technology Data Exchange (ETDEWEB)

Duan, Wentao; Vemuri, Rama S.; Hu, Dehong; Yang, Zheng; Wei, Xiaoliang

2017-01-01

Redox flow batteries have been considered as one of the most promising stationary energy storage solutions for improving the reliability of the power grid and deployment of renewable energy technologies. Among the many flow battery chemistries, nonaqueous flow batteries have the potential to achieve high energy density because of the broad voltage windows of nonaqueous electrolytes. However, significant technical hurdles exist currently limiting nonaqueous flow batteries to demonstrate their full potential, such as low redox concentrations, low operating currents, under-explored battery status monitoring, etc. In an attempt to address these limitations, we report a nonaqueous flow battery based on a highly soluble, redox-active organic nitronyl nitroxide radical compound, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO). This redox materials exhibits an ambipolar electrochemical property with two reversible redox pairs that are moderately separated by a voltage gap of ~1.7 V. Therefore, PTIO can serve as both anolyte and catholyte redox materials to form a symmetric flow battery chemistry, which affords the advantages such as high effective redox concentrations and low irreversible redox material crossover. The PTIO flow battery shows decent electrochemical cyclability under cyclic voltammetry and flow cell conditions; an improved redox concentration of 0.5 M PTIO and operational current density of 20 mA cm-2 were achieved in flow cell tests. Moreover, we show that Fourier transform infrared (FTIR) spectroscopy could measure the PTIO concentrations during the PTIO flow battery cycling and offer reasonably accurate detection of the battery state of charge (SOC) as cross-validated by electron spin resonance measurements. This study suggests FTIR can be used as a reliable online SOC sensor to monitor flow battery status and ensure battery operations stringently in a safe SOC range.

Fuel and nuclear fuel cycle

International Nuclear Information System (INIS)

Prunier, C.

1998-01-01

The nuclear fuel is studied in detail, the best choice and why in relation with the type of reactor, the properties of the fuel cans, the choice of fuel materials. An important part is granted to the fuel assembly of PWR type reactor and the performances of nuclear fuels are tackled. The different subjects for research and development are discussed and this article ends with the particular situation of mixed oxide fuels ( materials, behavior, efficiency). (N.C.)

Synthesis and sintering of UN-UO{sub 2} fuel composites

Energy Technology Data Exchange (ETDEWEB)

Jaques, Brian J., E-mail: BrianJaques@BoiseState.edu [Department of Materials Science and Engineering, Boise State University, 1910 University Dr., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Watkins, Jennifer; Croteau, Joseph R.; Alanko, Gordon A. [Department of Materials Science and Engineering, Boise State University, 1910 University Dr., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Tyburska-Püschel, Beata [Department of Engineering Physics, University of Wisconsin–Madison, 1500 Engineering Dr., Madison, WI 53706 (United States); Meyer, Mitch [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Xu, Peng; Lahoda, Edward J. [Westinghouse Electric Company LLC, Pittsburgh, PA 15235 (United States); Butt, Darryl P., E-mail: DarrylButt@BoiseState.edu [Department of Materials Science and Engineering, Boise State University, 1910 University Dr., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States)

2015-11-15

The design and development of an economical, accident tolerant fuel (ATF) for use in the current light water reactor (LWR) fleet is highly desirable for the future of nuclear power. Uranium mononitride has been identified as an alternative fuel with higher uranium density and thermal conductivity when compared to the benchmark, UO{sub 2}, which could also provide significant economic benefits. However, UN by itself reacts with water at reactor operating temperatures. In order to reduce its reactivity, the addition of UO{sub 2} to UN has been suggested. In order to avoid carbon impurities, UN was synthesized from elemental uranium using a hydride-dehydride-nitride thermal synthesis route prior to mixing with up to 10 wt% UO{sub 2} in a planetary ball mill. UN and UN – UO{sub 2} composite pellets were sintered in Ar – (0–1 at%) N{sub 2} to study the effects of nitrogen concentration on the evolved phases and microstructure. UN and UN-UO{sub 2} composite pellets were also sintered in Ar – 100 ppm N{sub 2} to assess the effects of temperature (1700–2000 °C) on the final grain morphology and phase concentration.

North American natural gas outlook : does gas remain a fuel option for oil sands?

International Nuclear Information System (INIS)

George, R.R.

2003-01-01

This paper presents a North America natural gas outlook from Purvin and Gertz, an international energy consulting firm that has 30 years experience in providing strategic, commercial and technical advice to the petroleum industry. In particular, this presentation focuses on natural gas market fundamentals and how they may impact on oil sands development. It includes charts and graphs depicting NYMEX natural gas outlooks to July, 2009 and examines how supply will react to major changes in Canada's supply portfolio. It was noted that oil sands development is a driver for natural gas demand in Alberta. The existing regional gas pipeline infrastructure was presented and the market impact on upgrader options was discussed. The author suggests that if gas prices are too high, there are other fuel options for steam and power generation. These include bitumen, asphalt, coke, coal and nuclear. However, these options have additional costs, uncertainties and environmental issues. A key factor for success would be to have a clear understanding of the benefits and risks between these fuel options. 1 tab., 9 figs

Vorticity Dynamics in Single and Multiple Swirling Reacting Jets

Science.gov (United States)

Smith, Travis; Aguilar, Michael; Emerson, Benjamin; Noble, David; Lieuwen, Tim

2015-11-01

This presentation describes an analysis of the unsteady flow structures in two multinozzle swirling jet configurations. This work is motivated by the problem of combustion instabilities in premixed flames, a major concern in the development of modern low NOx combustors. The objective is to compare the unsteady flow structures in these two configurations for two separate geometries and determine how certain parameters, primarily distance between jets, influence the flow dynamics. The analysis aims to differentiate between the flow dynamics of single nozzle and triple nozzle configurations. This study looks at how the vorticity in the shear layers of one reacting swirling jet can affect the dynamics of a nearby similar jet. The distance between the swirling jets is found to have an effect on the flow field in determining where swirling jets merge and on the dynamics upstream of the merging location. Graduate Student, School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA.

Irradiation of Parts of the X-Gen Nuclear Fuel Assembly made by KNF in HANARO

International Nuclear Information System (INIS)

Choo, K. N.; Cho, M. S.; Shin, Y. T.; Kim, B. G.; Lee, S. H.; Eom, K. B.

2008-01-01

An instrumented capsule has been developed at HANARO (High flux Advanced Neutron Application ReactOr) for the neutron irradiation tests of materials. The capsule system has been actively utilized for the various material irradiation tests requested by users from research institutes, universities, and the industries. As a preliminary test, some specimens made of the parts of a nuclear fuel assembly were inserted in the 05M-07U instrumented capsule and successfully irradiated at HANARO. Based on the results and experience, a new irradiation capsule of 07M-13N was designed, fabricated, and irradiated at HANARO for the evaluation of the neutron irradiation properties of the parts of the X-Gen nuclear fuel assembly made by KNF (Korea Nuclear Fuel). Specimens such as bucking and spring test specimens of spacer grid, microstructure and tensile test specimens of welded parts, tensile, irradiation growth and spring test specimens made of HANA tube, Zirlo, Zircaloy-4 and Inconel-718 were placed in the capsule. The capsule was loaded into the CT test hole of HANARO of a 30MW thermal output and the specimens were irradiated at 295 - 460 .deg. C up to a fast neutron fluence of 1.2x10 21 (n/cm 2 ) (E>1.0MeV)

Catalytic Upgrading of Bio-Oil by Reacting with Olefins and Alcohols over Solid Acids: Reaction Paths via Model Compound Studies

Directory of Open Access Journals (Sweden)

Qingwen Wang

2013-03-01

Full Text Available Catalytic refining of bio-oil by reacting with olefin/alcohol over solid acids can convert bio-oil to oxygen-containing fuels. Reactivities of groups of compounds typically present in bio-oil with 1-octene (or 1-butanol were studied at 120 °C/3 h over Dowex50WX2, Amberlyst15, Amberlyst36, silica sulfuric acid (SSA and Cs2.5H0.5PW12O40 supported on K10 clay (Cs2.5/K10, 30 wt. %. These compounds include phenol, water, acetic acid, acetaldehyde, hydroxyacetone, d-glucose and 2-hydroxymethylfuran. Mechanisms for the overall conversions were proposed. Other olefins (1,7-octadiene, cyclohexene, and 2,4,4-trimethylpentene and alcohols (iso-butanol with different activities were also investigated. All the olefins and alcohols used were effective but produced varying product selectivities. A complex model bio-oil, synthesized by mixing all the above-stated model compounds, was refined under similar conditions to test the catalyst’s activity. SSA shows the highest hydrothermal stability. Cs2.5/K10 lost most of its activity. A global reaction pathway is outlined. Simultaneous and competing esterification, etherfication, acetal formation, hydration, isomerization and other equilibria were involved. Synergistic interactions among reactants and products were determined. Acid-catalyzed olefin hydration removed water and drove the esterification and acetal formation equilibria toward ester and acetal products.

Removal of copper from aqueous solution by electrodeposition in cathode chamber of microbial fuel cell.

Science.gov (United States)

Tao, Hu-Chun; Liang, Min; Li, Wei; Zhang, Li-Juan; Ni, Jin-Ren; Wu, Wei-Min

2011-05-15

Based on energetic analysis, a novel approach for copper electrodeposition via cathodic reduction in microbial fuel cells (MFCs) was proposed for the removal of copper and recovery of copper solids as metal copper and/or Cu(2)O in a cathode with simultaneous electricity generation with organic matter. This was examined by using dual-chamber MFCs (chamber volume, 1L) with different concentrations of CuSO(4) solution (50.3 ± 5.8, 183.3 ± 0.4, 482.4 ± 9.6, 1007.9 ± 52.0 and 6412.5 ± 26.7 mg Cu(2+)/L) as catholyte at pH 4.7, and different resistors (0, 15, 390 and 1000 Ω) as external load. With glucose as a substrate and anaerobic sludge as an inoculum, the maximum power density generated was 339 mW/m(3) at an initial 6412.5 ± 26.7 mg Cu(2+)/L concentration. High Cu(2+) removal efficiency (>99%) and final Cu(2+) concentration below the USA EPA maximum contaminant level (MCL) for drinking water (1.3mg/L) was observed at an initial 196.2 ± 0.4 mg Cu(2+)/L concentration with an external resistor of 15 Ω, or without an external resistor. X-ray diffraction analysis confirmed that Cu(2+) was reduced to cuprous oxide (Cu(2)O) and metal copper (Cu) on the cathodes. Non-reduced brochantite precipitates were observed as major copper precipitates in the MFC with a high initial Cu(2+) concentration (0.1M) but not in the others. The sustainability of high Cu(2+) removal (>96%) by MFC was further examined by fed-batch mode for eight cycles. Copyright © 2011 Elsevier B.V. All rights reserved.

Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows

Science.gov (United States)

Allen, M. G.; Davis, S. J.; Kessler, W. J.; Sonnenfroh, D. M.

1992-01-01

The application of Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows is analyzed. Focussing on fluorescence of the OH molecule in typical H2-air Scramjet flows, the effects of uncharacterized variations in temperature, pressure, and collisional partner composition across the measurement plane are examined. Detailed measurements of the (1,0) band OH lineshape variations in H2-air combustions are used, along with single-pulse and time-averaged measurements of an excimer-pumped dye laser, to predict the performance of a model velocimeter with typical Scramjet flow properties. The analysis demonstrates the need for modification and control of the laser bandshape in order to permit accurate velocity measurements in the presence of multivariant flow properties.

Approximate method of calculation of non-equilibrium flow parameters of chemically reacting nitrogen tetroxide in the variable cross-section channels with energy exchange

International Nuclear Information System (INIS)

Bazhin, M.A.; Fedosenko, G.Eh.; Shiryaeva, N.M.; Mal'ko, M.V.

1986-01-01

It is shown that adiabatic non-equilibrium chemically reacting gas flow with energy exchange in a variable cross-section channel may be subdivided into five possible types: 1) quasi-equilibrium flow; 2) flow in the linear region of deviation from equilibrium state; 3) quasi-frozen flow; 4) flow in the linear region of deviation from frozen state; 5) non-equilibrium flow. Criteria of quasi-equilibrium and quazi-frozen flows, including factors of external action of chemically reacting gas on flow, allow to obtain simple but sufficiently reliable approximate method of calculation of flow parameters. The considered method for solving the problem of chemically reacting nitrogen tetroxide in the variable cross-section channel with energy exchange can be used for evaluation of chemical reaction kinetics on the flow parameter in the stages of axial-flow and radial-flow turbines and in another practical problems

Outcomes in Patients With Metastatic Renal Cell Carcinoma Who Develop Everolimus-Related Hyperglycemia and Hypercholesterolemia: Combined Subgroup Analyses of the RECORD-1 and REACT Trials.

Science.gov (United States)

Bono, Petri; Oudard, Stephane; Bodrogi, Istvan; Hutson, Thomas E; Escudier, Bernard; Machiels, Jean-Pascal; Thompson, John A; Figlin, Robert A; Ravaud, Alain; Basaran, Mert; Porta, Camillo; Bracarda, Sergio; Brechenmacher, Thomas; Lin, Chinjune; Voi, Maurizio; Grunwald, Viktor; Motzer, Robert J

2016-10-01

Hyperglycemia and hypercholesterolemia are class effects of mammalian target of rapamycin inhibitors. The purpose of this study was to characterize safety and efficacy of patients with metastatic renal cell carcinoma (mRCC) treated with everolimus in RECORD-1 (REnal Cell cancer treatment with Oral RAD001 given Daily) and REACT (RAD001 Expanded Access Clinical Trial in RCC) who developed these events. Adults with vascular endothelial growth factor-refractory mRCC received everolimus 10 mg/d in the randomized RECORD-1 (n = 277) and open-label REACT (n = 1367) studies. Outcomes included safety, treatment duration, overall response, and progression-free survival for patients who developed hypercholesterolemia or hyperglycemia. In RECORD-1, 12% (33 of 277) and 20% (55 of 277) of patients developed any grade hyperglycemia or hypercholesterolemia, respectively, with only 6% (78 of 1367) and 1% (14 of 1367) of the same events, respectively, in REACT. Median everolimus treatment duration was similar for patients with hyperglycemia or hypercholesterolemia (RECORD-1, 6.2 and 6.2 months, respectively; REACT, 4.4 and 4.5 months, respectively), but longer than the overall populations (RECORD-1, 4.6 months; REACT, 3.2 months). In RECORD-1/REACT, 82%/68% of patients with hyperglycemia and 75%/71% of patients with hypercholesterolemia achieved partial response or stable disease. The incidence of clinically notable Grade 3 or 4 adverse events, other than anemia and lymphopenia, appeared to be similar across trials and subgroups. Although there was a trend for improved progression-free survival with development of hyperglycemia or hypercholesterolemia, the association was not statistically significant. Hyperglycemia and hypercholesterolemia were observed in low numbers of patients, and although these events might be associated with improved response to everolimus, the differences were not significant. These findings should be validated with prospective biomarker studies. Copyright

HTGR fuel and fuel cycle technology

International Nuclear Information System (INIS)

Lotts, A.L.; Homan, F.J.; Balthesen, E.; Turner, R.F.

1977-01-01

Significant advances have occurred in the development of HTGR fuel and fuel cycle. These accomplishments permit a wide choice of fuel designs, reactor concepts, and fuel cycles. Fuels capable of providing helium outlet temperatures of 750 0 C are available, and fuels capable of 1000 0 C outlet temperatures may be expected from extension of present technology. Fuels have been developed for two basic HTGR designs, one using a spherical (pebble bed) element and the other a prismatic element. Within each concept a number of variations of geometry, fuel composition, and structural materials are permitted. Potential fuel cycles include both low-enriched and high-enriched Th- 235 U, recycle Th- 233 U, and Th-Pu or U-Pu cycles. This flexibility offered by the HTGR is of great practical benefit considering the rapidly changing economics of power production. The inflation of ore prices has increased optimum conversion ratios, and increased the necessity of fuel recycle at an early date. Fuel element makeup is very similar for prismatic and spherical designs. Both use spherical fissile and fertile particles coated with combinations of pyrolytic carbon and silicon carbide. Both use carbonaceous binder materials, and graphite as the structural material. Weak-acid resin (WAR) UO 2 -UC 2 fissile fuels and sol-gel-derived ThO 2 fertile fuels have been selected for the Th- 233 U cycle in the prismatic design. Sol-gel-derived UO 2 UC 2 is the reference fissile fuel for the low-enriched pebble bed design. Both the United States and Federal Republic of Germany are developing technology for fuel cycle operations including fabrication, reprocessing, refabrication, and waste handling. Feasibility of basic processes has been established and designs developed for full-scale equipment. Fuel and fuel cycle technology provide the basis for a broad range of applications of the HTGR. Extension of the fuels to higher operating temperatures and development and commercial demonstration of fuel

Coupling a PEM fuel cell and the hydrogen generation from aluminum waste cans

Energy Technology Data Exchange (ETDEWEB)

Martinez, Susana Silva; Albanil Sanchez, Loyda; Alvarez Gallegos, Alberto A. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Mor. CP 62210 (Mexico); Sebastian, P.J. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico); Cuerpo Academico de Energia y Sustentabilidad, UPCH, Tuxtla Gutierrez, Chiapas (Mexico)

2007-10-15

High purity hydrogen was generated from the chemical reaction of aluminum and sodium hydroxide. The aluminum used in this study was obtained from empty soft drink cans and treated with concentrated sulfuric acid to remove the paint and plastic film. One gram of aluminum was reacted with a solution of 2moldm{sup -3} of sodium hydroxide to produce hydrogen. The hydrogen produced from aluminum cans and oxygen obtained from a proton exchange membrane electrolyzer or air, was fed to a proton exchange membrane (PEM) fuel cell to produce electricity. Yields of 44 mmol of hydrogen contained in a volume of 1.760dm{sup 3} were produced from one gram of aluminum in a time period of 20 min. (author)

Constant strength fuel-fuel cell

International Nuclear Information System (INIS)

Vaseen, V.A.

1980-01-01

A fuel cell is an electrochemical apparatus composed of both a nonconsumable anode and cathode; and electrolyte, fuel oxidant and controls. This invention guarantees the constant transfer of hydrogen atoms and their respective electrons, thus a constant flow of power by submergence of the negative electrode in a constant strength hydrogen furnishing fuel; when said fuel is an aqueous absorbed hydrocarbon, such as and similar to ethanol or methnol. The objective is accomplished by recirculation of the liquid fuel, as depleted in the cell through specific type membranes which pass water molecules and reject the fuel molecules; thus concentrating them for recycle use

Release of UF6 from a ruptured model 48Y cylinder at Sequoyah Fuels Corporation Facility: lessons-learned report

International Nuclear Information System (INIS)

1986-08-01

The uranium hexafluoride (UF 6 ) release of January 4, 1986, at the Sequoyah Fuels Corporation facility has been reviewed by a NRC Lessons-Learned Group. A Model 48Y cylinder containing UF 6 ruptured upon being heated after it was grossly overfilled. The UF 6 released upon rupture of the cylinder reacted with airborne moisture to produce hydrofluoric acid (HF) and uranyl fluoride (UO 2 F 2 ). One individual died from exposure to airborne HF and several others were injured. There were no significant immediate effects from exposure to uranyl fluoride. This supplement report contains NRC's response to the recommendations made in NUREG-1198 by the Lessons Learned Group. In developing a response to each of the recommendations, the staff considered actions that should be taken: (1) for the restart of the Sequoyah Fuels Facility; (2) to make near-term improvement; and (3) to improve the regulatory framework

Interaction between uranium oxide alloyed with Al2O3·SiO2 and pyrocarbon coating during irradiation of micro fuel elements

International Nuclear Information System (INIS)

Chernikov, A.S.; Khromov, Y.F.; Svistunov, D.E.; Chuiko, E.E.

1989-01-01

The thermodynamics of the interaction between uranium oxide and carbon was previously studied in the presence of Al 2 O 3 ·SiO 2 , SiC, and UC 1.86 ; in this case, the quantity of the reacting substances does not have any effect on the attainment of the equilibrium state. Based on the obtained results, it is interesting to study the characteristic features of the interaction between the alloyed UO x cores (kernels) with the PyC-coating under the conditions involving irradiation of the micro fuel elements with thermal neutrons and the formation of solid fission products. The data concerning the characteristics of a micro fuel element (the weight of the core, its composition, etc.) are useful for carrying out a quantitative evaluation of the additives required for fixing the alkali-earth fission products by obtaining stable compounds of aluminosilicates with Ba, Sr, Rb, and Cs at different levels of depletion (burnup) of the oxide fuel. An analysis of the interaction processes in such a complex system as the irradiated alloyed uranium oxide fuel located in a micro fuel element is carried out by comparing the chemical potential of oxygen (RT ln P O 2 ) for the competing constituents of the system

How preschoolers react to norm violations is associated with culture.

Science.gov (United States)

Gampe, Anja; Daum, Moritz M

2018-01-01

Children from the age of 3years understand social norms as such and enforce these norms in interactions with others. Differences in parental and institutional education across cultures make it likely that children receive divergent information about how to act in cases of norm violations. In the current study, we investigated whether cultural values are associated with the ways in which children react to norm violations. We tested 80 bicultural 3-year-olds with a norm enforcement paradigm and analyzed their reactions to norm violations. The reactions were correlated to the children's parental cultural values using the Global Leadership and Organizational Behavior Effectiveness (GLOBE) scales, and these results show that parental culture was associated with children's reactions to norm violations. The three strongest correlations were found for institutional collectivism, performance orientation, and assertiveness. Copyright © 2017 Elsevier Inc. All rights reserved.

Calcination of calcium acetate and calcium magnesium acetate: effect of the reacting atmosphere

Energy Technology Data Exchange (ETDEWEB)

Adanez, J.; Diego, L.F. de; Garcia-Labiano, F. [Instituto de Carboquimica, Zaragoza (Spain). Dept. of Energy and Environment

1999-04-01

The calcination process of the calcium acetate (CA) and calcium magnesium acetate (CMA) was investigated as a previous step for coal gas desulfurisation during sorbent injection at high temperatures because the excellent results demonstrated by these sorbents as sulfur removal agents both in combustion and gasification processes. As pore structure developed during calcination is one of the most important characteristics of the sorbent related with the later reaction with the gaseous pollutants, several calcination tests were conducted in a drop tube reactor at temperatures from 700{degree}C to 1100{degree}C, and residence times from 0.8 to 2.4 s. Four different gas atmospheres were used for comparative purposes: inert, oxidising, reducing, and non-calcining (pure CO{sub 2}). Despite the advantage of the high porous cenospheric structure developed by these sorbents during their injection at high temperature, calcination of the CaCO{sub 3} was not complete even at the longest residence time, 2.4 s, and the highest temperature, 1100{degree}C, tested. An important effect of the reacting atmosphere on the calcination conversion and on the sorbent pore structure was detected. The CO{sub 2} concentration around the particle, both that fed in the reacting gases or that generated by organic material combustion, seems to be responsible for the final calcination conversions obtained in each case, also affecting the sintering suffered by the sorbents. 19 refs., 10 figs.

Eco-friendly synthesis for MCM-41 nanoporous materials using the non-reacted reagents in mother liquor.

Science.gov (United States)

Ng, Eng-Poh; Goh, Jia-Yi; Ling, Tau Chuan; Mukti, Rino R

2013-03-04

Nanoporous materials such as Mobil composite material number 41 (MCM-41) are attractive for applications such as catalysis, adsorption, supports, and carriers. Green synthesis of MCM-41 is particularly appealing because the chemical reagents are useful and valuable. We report on the eco-friendly synthesis of MCM-41 nanoporous materials via multi-cycle approach by re-using the non-reacted reagents in supernatant as mother liquor after separating the solid product. This approach was achieved via minimal requirement of chemical compensation where additional fresh reactants were added into the mother liquor followed by pH adjustment after each cycle of synthesis. The solid product of each successive batch was collected and characterized while the non-reacted reagents in supernatant can be recovered and re-used to produce subsequent cycle of MCM-41. The multi-cycle synthesis is demonstrated up to three times in this research. This approach suggests a low cost and eco-friendly synthesis of nanoporous material since less waste is discarded after the product has been collected, and in addition, product yield can be maintained at the high level.

High-fidelity simulations for clean and efficient combustion of alternative fuels

Energy Technology Data Exchange (ETDEWEB)

Oefelein, J C; Chen, J H [Reacting Flow Research Department, Sandia National Laboratories, Livermore, CA 94550 (United States); Sankaran, R, E-mail: oefelei@sandia.go [National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2009-07-01

There is an urgent and growing demand for high-fidelity simulations that capture complex turbulence-chemistry interactions in propulsion and power systems, and in particular, that capture and discriminate the effects of fuel variability. This project addresses this demand using the Large Eddy Simulation (LES) technique (led by Oefelein) and the Direct Numerical Simulation (DNS) technique (led by Chen). In particular, we are conducting research under the INCITE program that is tightly coupled with funded projects established under the DOE Basic Energy Sciences and Energy Efficiency and Renewable Energy programs that will provide the foundational science required to develop a predictive modeling capability for design of advanced engines for transportation. Application of LES provides the formal ability to treat the full range of multidimensional time and length scales that exist in turbulent reacting flows in a computationally feasible manner and thus provides a way to simulate reacting flow phenomena in complex internal-combustion engine geometries at device relevant conditions. Application of DNS provides a way to study fundamental issues related to small-scale combustion processes in canonical configurations to understand dynamics that occur over a range of reactive-diffusive scales. Here we describe the challenges and present representative examples of the types of simulations each respective tool has been used for as part of the INCITE program. We focus on recent experiences on the Oak Ridge National Laboratory (ORNL) National Center for Computational Sciences (NCCS) Cray-XT Platform (i.e., Jaguar).

Process Developed for Generating Ceramic Interconnects With Low Sintering Temperatures for Solid Oxide Fuel Cells

Science.gov (United States)

Zhong, Zhi-Min; Goldsby, Jon C.

2005-01-01

Solid oxide fuel cells (SOFCs) have been considered as premium future power generation devices because they have demonstrated high energy-conversion efficiency, high power density, and extremely low pollution, and have the flexibility of using hydrocarbon fuel. The Solid-State Energy Conversion Alliance (SECA) initiative, supported by the U.S. Department of Energy and private industries, is leading the development and commercialization of SOFCs for low-cost stationary and automotive markets. The targeted power density for the initiative is rather low, so that the SECA SOFC can be operated at a relatively low temperature (approx. 700 C) and inexpensive metallic interconnects can be utilized in the SOFC stack. As only NASA can, the agency is investigating SOFCs for aerospace applications. Considerable high power density is required for the applications. As a result, the NASA SOFC will be operated at a high temperature (approx. 900 C) and ceramic interconnects will be employed. Lanthanum chromite-based materials have emerged as a leading candidate for the ceramic interconnects. The interconnects are expected to co-sinter with zirconia electrolyte to mitigate the interface electric resistance and to simplify the processing procedure. Lanthanum chromites made by the traditional method are sintered at 1500 C or above. They react with zirconia electrolytes (which typically sinter between 1300 and 1400 C) at the sintering temperature of lanthanum chromites. It has been envisioned that lanthanum chromites with lower sintering temperatures can be co-fired with zirconia electrolyte. Nonstoichiometric lanthanum chromites can be sintered at lower temperatures, but they are unstable and react with zirconia electrolyte during co-sintering. NASA Glenn Research Center s Ceramics Branch investigated a glycine nitrate process to generate fine powder of the lanthanum-chromite-based materials. By simultaneously doping calcium on the lanthanum site, and cobalt and aluminum on the

Fuels processing for transportation fuel cell systems

Science.gov (United States)

Kumar, R.; Ahmed, S.

Fuel cells primarily use hydrogen as the fuel. This hydrogen must be produced from other fuels such as natural gas or methanol. The fuel processor requirements are affected by the fuel to be converted, the type of fuel cell to be supplied, and the fuel cell application. The conventional fuel processing technology has been reexamined to determine how it must be adapted for use in demanding applications such as transportation. The two major fuel conversion processes are steam reforming and partial oxidation reforming. The former is established practice for stationary applications; the latter offers certain advantages for mobile systems and is presently in various stages of development. This paper discusses these fuel processing technologies and the more recent developments for fuel cell systems used in transportation. The need for new materials in fuels processing, particularly in the area of reforming catalysis and hydrogen purification, is discussed.

Realistic Creativity Training for Innovation Practitioners: The Know-Recognize-React Model

DEFF Research Database (Denmark)

Valgeirsdóttir, Dagný; Onarheim, Balder

2017-01-01

As creativity becomes increasingly recognized as important raw material for innovation, the importance of identifying ways to increase practitioners’ creativity through rigorously designed creativity training programs is highlighted. Therefore we sat out to design a creativity training program sp...... the transdisciplinary study described in this paper. Co-creation was employed as a method to ensure the three layers of focus would be taken into consideration. The result is a program called Creative Awareness Training which is based on the new Know-Recognize-React model.......As creativity becomes increasingly recognized as important raw material for innovation, the importance of identifying ways to increase practitioners’ creativity through rigorously designed creativity training programs is highlighted. Therefore we sat out to design a creativity training program...

PERBEDAAN KEMAMPUAN KONEKSI MATEMATIS MELALUI MODEL PEMBELAJARAN REACT DENGAN MODEL PEMBELAJARAN LEARNING CYCLE 5E SISWA SMKN 39 JAKARTA

Directory of Open Access Journals (Sweden)

Aditya Prihandhika

2017-03-01

Full Text Available Hasil analisa TIMSS Tahun 2013 menempatkan Indonesia sebagai salah satu negara dengan peringkat terendah dalam perolehan nilai matematika. Model pembelajaran yang dapat digunakan untuk meningkatkan kemampuan koneksi matematis diantaranya adalah model pembelajaran REACT dan Learning Cycle 5E. Penelitian ini bertujuan untuk mengetahui terdapat atau tidaknya perbedaan kemampuan koneksi matematis peserta didik yang diajarkan dengan kedua model tersebut. Penelitian dilaksanakan di SMKN 39 Jakarta dengan populasi kelas X semester ganjil tahun pelajaran 2015-2016. Sampel yang diteliti sebanyak 61 orang dengan menggunakan design penelitian quasi experimental. Variabel bebas : model pembelajaran REACT dan model pembelajaran Learning Cycle 5E. Variabel terikat : kemampuan koneksi matematis. Uji instrumen dengan uji validitas dan uji reliabilitas. Uji validitas dengan rumus korelasi Product Moment didapat 7 soal yang valid. Uji reliabilitas dengan rumus Alpha menunjukan bahwa soal tersebut reliabel. Uji normalitas dengan uji Lilliefors menunjukan kedua sampel dari populasi yang berdistribusi normal. Uji homogenitas dengan uji Fisher menunjukan kedua sampel memiliki varians yang homogen. Uji hipotesis dengan uji-t  didapat  dengan alpha sebesar 0,05, maka  di tolak. Dengan demikian terdapat perbedaan kemampuan koneksi matematis peserta didik yang diajarkan dengan model pembelajaran REACT dan model pembelajaran Learning Cycle 5E di SMKN 39 Jakarta.   Kata Kunci: Kemampuan Koneksi Matematis, Model Pembelajaran REACT      Model Pembelajaran Learning Cycle 5E.

Molecular Characterization of Thiols in Fossil Fuels by Michael Addition Reaction Derivatization and Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

Science.gov (United States)

Wang, Meng; Zhao, Suoqi; Liu, Xuxia; Shi, Quan

2016-10-04

Thiols widely occur in sediments and fossil fuels. However, the molecular composition of these compounds is unclear due to the lack of appropriate analytical methods. In this work, a characterization method for thiols in fossil fuels was developed on the basis of Michael addition reaction derivatization followed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). Model thiol compound studies showed that thiols were selectively reacted with phenylvinylsulfone and transformed to sulfones with greater than 98% conversions. This method was applied to a coker naphtha, light and heavy gas oils, and crude oils from various geological sources. The results showed that long alkyl chain thiols are readily present in petroleum, which have up to 30 carbon atoms. Large DBE dispersity of thiols indicates that naphthenic and aromatic thiols are also present in the petroleum. This method is capable of detecting thiol compounds in the part per million range by weight. This method allows characterization of thiols in a complex hydrocarbon matrix, which is complementary to the comprehensive analysis of sulfur compounds in fossil fuels.

Review of consequences of uranium hydride formation in N-Reactor fuel elements stored in the K-Basins

Energy Technology Data Exchange (ETDEWEB)

Weber, J.W.

1994-09-28

The 105-K Basins on the Hanford site are used to store uranium fuel elements and assemblies irradiated in and discharged from N Reactor. The storage cylinders in KW Basin are known to have some broken N reactor fuel elements in which the exposed uranium is slowly reacting chemically with water in the cylinder. The products of these reactions are uranium oxide, hydrogen, and potentially some uranium hydride. The purpose of this report is to document the results f the latest review of potential, but highly unlikely accidents postulated to occur as closed cylinders containing N reactor fuel assemblies are opened under water in the KW basin and as a fuel assembly is raised from the basin in a shipping cask for transportation to the 327 Building for examination as part of the SNF Characterization Program. The postulated accidents reviews in this report are considered to bound all potential releases of radioactivity and hydrogen. These postulated accidents are: (1) opening and refill of a cylinder containing significant amounts of hydrogen and uranium hydride; and (2) draining of the single element can be used to keep the fuel element submerged in water after the cask containing the can and element is lifted from the KW Basin. Analysis shows the release of radioactivity to the site boundary is significantly less than that allowed by the K Basin Safety Evaluation. Analysis further shows there would be no damage to the K Basin structure nor would there be injury to personnel for credible events.

Effect of L-glutamic acid on the positive electrolyte for all-vanadium redox flow battery

International Nuclear Information System (INIS)

Liang, Xinxing; Peng, Sui; Lei, Ying; Gao, Chao; Wang, Nanfang; Liu, Suqin; Fang, Dong

2013-01-01

Highlights: ► Amino acid is used as additive for all-vanadium redox flow battery. ► The additive can significantly improve performance of positive electrolyte. ► Mechanism for the improvement is investigated. -- Abstract: L-Glutamic acid is used as an additive for the positive electrolyte of all-vanadium redox flow battery (VRFB), and its effect on the thermal stability and electrochemical activity is investigated. It is found that the addition of L-glutamic can significantly alleviate the precipitation of V 2 O 5 from positive electrolyte. The conservation rate of V(V) ion can be as high as 58% after 2 M V(V) solution being kept in 40 °C for 89 h. Besides, L-glutamic can also improve the mass transport and electrochemical performance of anolyte. A high coulombic efficiency of over 95% and energy efficiency of 74% are obtained. XPS spectra illustrate that L-glutamic can react with the surface of carbon felt electrode and introduce more oxygen-containing and nitrogen-containing groups, which should be responsible for the improvement of electrochemical performance

Optimal stretching in the reacting wake of a bluff body.

Science.gov (United States)

Wang, Jinge; Tithof, Jeffrey; Nevins, Thomas D; Colón, Rony O; Kelley, Douglas H

2017-12-01

We experimentally study spreading of the Belousov-Zhabotinsky reaction behind a bluff body in a laminar flow. Locations of reacted regions (i.e., regions with high product concentration) correlate with a moderate range of Lagrangian stretching and that range is close to the range of optimal stretching previously observed in topologically different flows [T. D. Nevins and D. H. Kelley, Phys. Rev. Lett. 117, 164502 (2016)]. The previous work found optimal stretching in a closed, vortex dominated flow, but this article uses an open flow and only a small area of appreciable vorticity. We hypothesize that optimal stretching is common in advection-reaction-diffusion systems with an excitation threshold, including excitable and bistable systems, and that the optimal range depends on reaction chemistry and not on flow shape or characteristic speed. Our results may also give insight into plankton blooms behind islands in ocean currents.

Simulation of moving boundaries interacting with compressible reacting flows using a second-order adaptive Cartesian cut-cell method

Science.gov (United States)

Muralidharan, Balaji; Menon, Suresh

2018-03-01

A high-order adaptive Cartesian cut-cell method, developed in the past by the authors [1] for simulation of compressible viscous flow over static embedded boundaries, is now extended for reacting flow simulations over moving interfaces. The main difficulty related to simulation of moving boundary problems using immersed boundary techniques is the loss of conservation of mass, momentum and energy during the transition of numerical grid cells from solid to fluid and vice versa. Gas phase reactions near solid boundaries can produce huge source terms to the governing equations, which if not properly treated for moving boundaries, can result in inaccuracies in numerical predictions. The small cell clustering algorithm proposed in our previous work is now extended to handle moving boundaries enforcing strict conservation. In addition, the cell clustering algorithm also preserves the smoothness of solution near moving surfaces. A second order Runge-Kutta scheme where the boundaries are allowed to change during the sub-time steps is employed. This scheme improves the time accuracy of the calculations when the body motion is driven by hydrodynamic forces. Simple one dimensional reacting and non-reacting studies of moving piston are first performed in order to demonstrate the accuracy of the proposed method. Results are then reported for flow past moving cylinders at subsonic and supersonic velocities in a viscous compressible flow and are compared with theoretical and previously available experimental data. The ability of the scheme to handle deforming boundaries and interaction of hydrodynamic forces with rigid body motion is demonstrated using different test cases. Finally, the method is applied to investigate the detonation initiation and stabilization mechanisms on a cylinder and a sphere, when they are launched into a detonable mixture. The effect of the filling pressure on the detonation stabilization mechanisms over a hyper-velocity sphere launched into a hydrogen

Insulation and Heat Treatment of Bi-2212 Wire for Wind-and-React Coils

Energy Technology Data Exchange (ETDEWEB)

Peter K. F. Hwang

2007-10-22

Higher Field Magnets demand higher field materials such as Bi-2212 round superconducting wire. The Bi-2212 wire manufacture process depends on the coil fabrication method and wire insulation material. Considering the wind-and-react method, the coil must unifirmly heated to the melt temperature and uniformly cooled to the solidification temperature. During heat treat cycle for tightly wound coils, the leakage melt from conductor can chemically react with insulation on the conductor and creat short turns in the coils. In this research project, conductor, insulation, and coils are made to systemically study the suitable insulation materials, coil fabrication method, and heat treatment cycles. In this phase I study, 800 meters Bi-2212 wire with 3 different insulation materials have been produced. Best insulation material has been identified after testing six small coils for insulation integrity and critical current at 4.2 K. Four larger coils (2" dia) have been also made with Bi-2212 wrapped with best insulation and with different heattreatment cycle. These coils were tested for Ic in a 6T background field and at 4.2 K. The test result shows that Ic from 4 coils are very close to short samples (1 meter) result. It demonstrates that HTS coils can be made with Bi-2212 wire with best insulation consistently. Better wire insulation, improving coil winding technique, and wire manufacture process can be used for a wide range of high field magnet application including acclerators such as Muon Collider, fusion energy research, NMR spectroscopy, MRI, and other industrial magnets.

Insulation and Heat Treatment of Bi-2212 Wires for Wind-and-React Coils

International Nuclear Information System (INIS)

Hwang, Peter K.F.

2007-01-01

Higher Field Magnets demand higher field materials such as Bi-2212 round superconducting wire. The Bi-2212 wire manufacture process depends on the coil fabrication method and wire insulation material. Considering the wind-and-react method, the coil must unifirmly heated to the melt temperature and uniformly cooled to the solidification temperature. During heat treat cycle for tightly wound coils, the leakage melt from conductor can chemically react with insulation on the conductor and creat short turns in the coils. In this research project, conductor, insulation, and coils are made to systemically study the suitable insulation materials, coil fabrication method, and heat treatment cycles. In this phase I study, 800 meters Bi-2212 wire with 3 different insulation materials have been produced. Best insulation material has been identified after testing six small coils for insulation integrity and critical current at 4.2 K. Four larger coils (2-inch dia) have been also made with Bi-2212 wrapped with best insulation and with different heattreatment cycle. These coils were tested for Ic in a 6T background field and at 4.2 K. The test result shows that Ic from 4 coils are very close to short samples (1 meter) result. It demonstrates that HTS coils can be made with Bi-2212 wire with best insulation consistently. Better wire insulation, improving coil winding technique, and wire manufacture process can be used for a wide range of high field magnet application including acclerators such as Muon Collider, fusion energy research, NMR spectroscopy, MRI, and other industrial magnets.

Development and Validation of Chemical Kinetic Mechanism Reduction Scheme for Large-Scale Mechanisms

DEFF Research Database (Denmark)

Poon, Hiew Mun; Ng, Hoon Kiat; Gan, Suyin

2014-01-01

This work is an extension to a previously reported work on chemical kinetic mechanism reduction scheme for large-scale mechanisms. Here, Perfectly Stirred Reactor (PSR) was added as a criterion of data source for mechanism reduction instead of using only auto-ignition condition. As a result......) simulations were performed to study the spray combustion phenomena within a constant volume bomb. Both non-reacting and reacting conditions were applied in this study. Liquid and vapor penetration lengths were replicated for non-reacting diesel spray. For reacting diesel spray, both ignition delay and lift......-off length were simulated. The simulation results were then compared to the experimental data of Sandia National Laboratories and No. 2 Diesel Fuel (D2) was designated as the reference fuel. Both liquid and vapor penetrations for non-reacting condition were well-matched, while ignition delay was advanced...

Fuel performance and operation experience of WWER-440 fuel in improved fuel cycle

International Nuclear Information System (INIS)

Gagarinski, A.; Proselkov, V.; Semchenkov, Yu.

2007-01-01

The paper summarizes WWER-440 second-generation fuel operation experience in improved fuel cycles using the example of Kola NPP units 3 and 4. Basic parameters of fuel assemblies, fuel rods and uranium-gadolinium fuel rods, as well as the principal neutronic parameters and burn-up achieved in fuel assemblies are presented. The paper also contains some data concerning the activity of coolant during operation (Authors)

Advanced fuel development at AECL: What does the future hold for CANDU fuels/fuel cycles?

Energy Technology Data Exchange (ETDEWEB)

Kupferschmidt, W.C.H. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

2013-07-01

This paper outlines advanced fuel development at AECL. It discusses expanding the limits of fuel utilization, deploy alternate fuel cycles, increase fuel flexibility, employ recycled fuels; increase safety and reliability, decrease environmental impact and develop proliferation resistant fuel and fuel cycle.

HTGR fuel and fuel cycle technology

International Nuclear Information System (INIS)

Lotts, A.L.; Coobs, J.H.

1976-08-01

The status of fuel and fuel cycle technology for high-temperature gas-cooled reactors (HTGRs) is reviewed. The all-ceramic core of the HTGRs permits high temperatures compared with other reactors. Core outlet temperatures of 740 0 C are now available for the steam cycle. For advanced HTGRs such as are required for direct-cycle power generation and for high-temperature process heat, coolant temperatures as high as 1000 0 C may be expected. The paper discusses the variations of HTGR fuel designs that meet the performance requirements and the requirements of the isotopes to be used in the fuel cycle. Also discussed are the fuel cycle possibilities, which include the low-enrichment cycle, the Th- 233 U cycle, and plutonium utilization in either cycle. The status of fuel and fuel cycle development is summarized

Hydrogen production and purification for fuel cell applications

Science.gov (United States)

Chin, Soo Yin

The increased utilization of proton-exchange membrane (PEM) fuel cells as an alternative to internal combustion engines is expected to increase the demand for hydrogen, which is used as the energy source in these systems. Currently, production of hydrogen for fuel cells is primarily achieved via steam reforming, partial oxidation or autothermal reforming of natural gas, or steam reforming of methanol. However, in all of these processes CO is a by-product that must be subsequently removed due to its adverse effects on the Pt-based electrocatalysts of the PEM fuel cell. Our efforts have focused on production of CO-free hydrogen via catalytic decomposition of hydrocarbons and purification of H2 via the preferential oxidation of CO. The catalytic decomposition of hydrocarbons is an attractive alternative for the production of H2. Previous studies utilizing methane have shown that this approach can indeed produce CO-free hydrogen, with filamentous carbon formed as the by-product and deposited on the catalyst. We have further extended this approach to the decomposition of ethane. In addition to hydrogen and filamentous carbon however, methane is also formed in this case as a by-product. Studies conducted at different temperatures and space velocities suggest that hydrogen is the primary product while methane is formed in a secondary step. Ni/SiO2 catalysts are active for ethane decomposition at temperatures above 500°C. Although the yield of hydrogen increases with temperature, the catalyst deactivation rate also accelerates at higher temperatures. The preferential oxidation of CO is currently used for the purification of CO-contaminated hydrogen streams due to its efficiency and simplicity. Conventional Pt catalysts used for this reaction have been shown to effectively remove CO, but have limited selectivity (i.e., substantial amounts of H 2 also react with O2). Our work focused on alternative catalytic materials, such as Ru and bimetallic Ru-based catalysts (Pt-Ru, Ru

76 FR 37703 - Regulation of Fuels and Fuel Additives: 2012 Renewable Fuel Standards; Public Hearing

Science.gov (United States)

2011-06-28

... Regulation of Fuels and Fuel Additives: 2012 Renewable Fuel Standards; Public Hearing AGENCY: Environmental... hearing to be held for the proposed rule ``Regulation of Fuels and Fuel Additives: 2012 Renewable Fuel... be proposing amendments to the renewable fuel standard program regulations to establish annual...

Multi-fuel reformers for fuel cells used in transportation. Phase 1: Multi-fuel reformers

Science.gov (United States)

1994-05-01

DOE has established the goal, through the Fuel Cells in Transportation Program, of fostering the rapid development and commercialization of fuel cells as economic competitors for the internal combustion engine. Central to this goal is a safe feasible means of supplying hydrogen of the required purity to the vehicular fuel cell system. Two basic strategies are being considered: (1) on-board fuel processing whereby alternative fuels such as methanol, ethanol or natural gas stored on the vehicle undergo reformation and subsequent processing to produce hydrogen, and (2) on-board storage of pure hydrogen provided by stationary fuel processing plants. This report analyzes fuel processor technologies, types of fuel and fuel cell options for on-board reformation. As the Phase 1 of a multi-phased program to develop a prototype multi-fuel reformer system for a fuel cell powered vehicle, the objective of this program was to evaluate the feasibility of a multi-fuel reformer concept and to select a reforming technology for further development in the Phase 2 program, with the ultimate goal of integration with a DOE-designated fuel cell and vehicle configuration. The basic reformer processes examined in this study included catalytic steam reforming (SR), non-catalytic partial oxidation (POX) and catalytic partial oxidation (also known as Autothermal Reforming, or ATR). Fuels under consideration in this study included methanol, ethanol, and natural gas. A systematic evaluation of reforming technologies, fuels, and transportation fuel cell applications was conducted for the purpose of selecting a suitable multi-fuel processor for further development and demonstration in a transportation application.

Fuel assembly

International Nuclear Information System (INIS)

Chaki, Masao; Nishida, Koji; Karasawa, Hidetoshi; Kanazawa, Toru; Orii, Akihito; Nagayoshi, Takuji; Kashiwai, Shin-ichi; Masuhara, Yasuhiro

1998-01-01

The present invention concerns a fuel assembly, for a BWR type nuclear reactor, comprising fuel rods in 9 x 9 matrix. The inner width of the channel box is about 132mm and the length of the fuel rods which are not short fuel rods is about 4m. Two water rods having a circular cross section are arranged on a diagonal line in a portion of 3 x 3 matrix at the center of the fuel assembly, and two fuel rods are disposed at vacant spaces, and the number of fuel rods is 74. Eight fuel rods are determined as short fuel rods among 74 fuel rods. Assuming the fuel inventory in the short fuel rod as X(kg), and the fuel inventory in the fuel rods other than the short fuel rods as Y(kg), X and Y satisfy the relation: X + Y ≥ 173m, Y ≤ - 9.7X + 292, Y ≤ - 0.3X + 203 and X > 0. Then, even when the short fuel rods are used, the fuel inventory is increased and fuel economy can be improved. (I.N.)

Fuel assemblies

International Nuclear Information System (INIS)

Mukai, Hideyuki

1987-01-01

Purpose: To prevent bending of fuel rods caused by the difference of irradiation growth between coupling fuel rods and standards fuel rods thereby maintain the fuel rod integrity. Constitution: The f value for a fuel can (the ratio of pole of zirconium crystals in the entire crystals along the axial direction of the fuel can) of a coupling fuel rod secured by upper and lower tie plates is made smaller than the f value for the fuel can of a standard fuel rod not secured by the upper and the lower tie plates. This can make the irradiation growth of the fuel can of the coupling fuel rod greater than the irradiation growth of the fuel can of the standard fuel rod and, accordingly, since the elongation of the standard fuel rod can always by made greater, bending of the standard fuel rod can be prevented. (Yoshihara, M.)

Features of fuel performance at high fuel burnups

International Nuclear Information System (INIS)

Proselkov, V.N.; Scheglov, A.S.; Smirnov, A.V.; Smirnov, V.P.

2001-01-01

Some features of fuel behavior at high fuel burnups, in particular, initiation and development of rim-layer, increase in the rate of fission gas release from the fuel and increase in the inner gas pressure in the fuel rod are briefly described. Basing on the analysis of the data of post-irradiation examinations of fuel rods of WWER-440 working FA and CR fuel followers, that have been operated for five fuel cycles and got the average fuel burnup or varies as 50MW-day/kgU, a conclusion is made that the WWER-440 fuel burnup can be increased at least to average burnups of 55-58 MW-day/kgU per fuel assembly (Authors)

Possible effects of small-scale intermittency in turbulent reacting flows

International Nuclear Information System (INIS)

Sreenivasan, K.R.

2006-12-01

It is now well established that quantities such as energy dissipation, scalar dissipation and enstrophy possess huge fluctuations in turbulent flows, and that the fluctuations become increasingly stronger with increasing Reynolds number of the flow. The effects of this small-scale 'intermittency' on various aspects of reacting flows have not been addressed fully. This paper draws brief attention to a few possible effects on reaction rates, flame extinction, flamelet approximation, conditional moment closure methods, and so forth, besides commenting on possible effects on the resolution requirements of direct numerical simulations of turbulence. We also discuss the likelihood that large-amplitude events in a given class of shear flows are characteristic of that class, and that, plausible estimates of such quantities cannot be made, in general, on the hypothesis that large and small scales are independent. Finally, we briefly describe some ideas from multifractals as a potentially useful tool for an economical handling of a few of the problems touched upon here. (author)

Wildfire simulation using a chemically-reacting plume in a crossflow

Science.gov (United States)

Breidenthal, Robert; Alvarado, Travis; Potter, Brian

2010-11-01

Water tunnel experiments reveal the flame length of a chemically-reacting plume in a crossflow. Salt water containing a pH indicator and a base is slowly injected from above into the test section of a water tunnel containing an acidic solution. The flame length is measured optically as a function of the buoyancy flux, crossflow speed, and volume equivalence ratio of the chemical reaction. Based on earlier work of Broadwell with the transverse jet, a simple dilution model predicts the flame length of the transverse plume. The plume observations are in accord with the model. As with the jet, there is a minimum in the flame length of the plume at a transition between two self-similar regimes, corresponding to the formation of a pair of counter-rotating vortices at a certain crossflow speed. At the transition, there is a maximum in the entrainment and mixing rates. In an actual wildfire with variable winds, this transition may correspond to a dangerous condition for firefighters.

CERN reacts to increased costs to completion of the LHC

CERN Multimedia

2002-01-01

Aspects of LHC construction. The CERN Council, where the representatives of the 20 Member States of the Organization decide on scientific programmes and financial resources, held its 120th session on 14 December under the chairmanship of Prof. Maurice Bourquin (CH). CERN adjusts to the LHC Director-General, Luciano Maiani, stressed that CERN was now fully engaged in the LHC and outlined the first moves to react to the increased cost to completion of the LHC. The new accelerator is an extremely complex, high-tech project which CERN is building under very severe conditions. However, the technical challenges are solved and industrial production of accelerator elements, and installation are starting. Professor Maiani said that 2001 had been a very hard but decisive year for CERN. An important milestone had been passed during this meeting with the approval of the LHC dipole magnets contract, the last major contract for the accelerator. The new costs to completion of the LHC project are now clear. A first propos...

Studies on the different forms of material reacting with antiinsulin antibodies in the fetal and adult rat

International Nuclear Information System (INIS)

Felix, J.M.; Sutter-Dub, M.T.; Legrele, C.; Reims Univ., 51

1975-01-01

The nature of peak B (MW = 10-12,000, proinsulin) and peak C (MW = 50-100,000, 'big big' insulin) materials detected by the double antibody (DA) procedure in elution profiles of rat sera after Sephadex G 50 or G 100 chromatography (cf. preceding companion paper) is further investigated. Peak B is converted by mild tryptic digestion in an immunoreactive material behaving in rechromatography exactly like insulin monomer. Peak C is less easily detected by the dextran coated charcoal (DCC) method; it resists 8 M urea 37 0 C for 1 hr, is not an artifact due to the complement system; its relative importance is very much reduced in pancreatic extracts or perifusates. Incubation of biologically active 125 I labelled insulin in rat sera results in appearance of labelled material behaving on chromatography like peak C natural material, having the electrophoretic mobility of rat α 1 globulins and albumin, and resisting 8 M urea, acidic pHs and 0.5 M NaCl. Similar incubation in buffer supplemented with bovine albumin results in appearance of a labelled material having the electrophoretic mobility of beef albumin; N-ethyl-maleimide provides against this binding, which might result from (S-S)-(SH) interchanges. Rat α globulins and albumin (but not beef albumin) cross-react with the DA procedure; they do not react with the DCC method. Insulin bound to plasma proteins react with both methods. It is suggested that peak C material, as detected by the DA method in rat serum, consists both of insulin covalently bound to plasma proteins and of certain plasma proteins; the DCC method detects only bound insulin. In streptozotocin treated rats, peak C material persists after the complete disappearance of insulin and proinsulin when detected by the (DA) procedure, but disappears when detected by the DCC procedure. (orig.) [de

Studies on the different forms of material reacting with antiinsulin antibodies in the fetal and adult rat

Energy Technology Data Exchange (ETDEWEB)

Felix, J M; Sutter-Dub, M T; Legrele, C [Reims Univ., 51 (France). Lab. de Physiologie Animale; Reims Univ., 51 (France). Centre de Biologie et de Biochimie du Developpement)

1975-09-01

The nature of peak B (MW = 10-12,000, proinsulin) and peak C (MW = 50-100,000, 'big big' insulin) materials detected by the double antibody (DA) procedure in elution profiles of rat sera after Sephadex G 50 or G 100 chromatography (cf. preceding companion paper) is further investigated. Peak B is converted by mild tryptic digestion in an immunoreactive material behaving in rechromatography exactly like insulin monomer. Peak C is less easily detected by the dextran coated charcoal (DCC) method; it resists 8 M urea 37/sup 0/C for 1 hr, is not an artifact due to the complement system; its relative importance is very much reduced in pancreatic extracts or perifusates. Incubation of biologically active /sup 125/I labelled insulin in rat sera results in appearance of labelled material behaving on chromatography like peak C natural material, having the electrophoretic mobility of rat ..cap alpha../sub 1/ globulins and albumin, and resisting 8 M urea, acidic pHs and 0.5 M NaCl. Similar incubation in buffer supplemented with bovine albumin results in appearance of a labelled material having the electrophoretic mobility of beef albumin; N-ethyl-maleimide provides against this binding, which might result from (S-S)-(SH) interchanges. Rat ..cap alpha.. globulins and albumin (but not beef albumin) cross-react with the DA procedure; they do not react with the DCC method. Insulin bound to plasma proteins react with both methods. It is suggested that peak C material, as detected by the DA method in rat serum, consists both of insulin covalently bound to plasma proteins and of certain plasma proteins; the DCC method detects only bound insulin. In streptozotocin treated rats, peak C material persists after the complete disappearance of insulin and proinsulin when detected by the (DA) procedure, but disappears when detected by the DCC procedure.

Fuel Handbook[Wood and other renewable fuels

Energy Technology Data Exchange (ETDEWEB)

Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (SE)] (ed.)

2006-03-15

This handbook on renewable fuels is intended for power and heat producers in Sweden. This fuel handbook provides, from a plant owner's perspective, a method to evaluate different fuels on the market. The fuel handbook concerns renewable fuels (but does not include household waste) that are available on the Swedish market today or fuels that have potential to be available within the next ten years. The handbook covers 26 different fuels. Analysis data, special properties, operating experiences and literature references are outlined for each fuel. [Special properties, operating experiences and literature references are not included in this English version] The handbook also contains: A proposed methodology for introduction of new fuels. A recommendation of analyses and tests to perform in order to reduce the risk of problems is presented. [The recommendation of analyses and tests is not included in the English version] A summary of relevant laws and taxes for energy production, with references to relevant documentation. [Only laws and taxes regarding EU are included] Theory and background to evaluate a fuel with respect to combustion, ash and corrosion properties and methods that can be used for such evaluations. Summary of standards, databases and handbooks on biomass fuels and other solid fuels, and links to web sites where further information about the fuels can be found. The appendices includes: A methodology for trial firing of fuels. Calculations procedures for, amongst others, heating value, flue gas composition, key number and free fall velocity [Free fall velocity is not included in the English version]. In addition, conversion routines between different units for a number of different applications are provided. Fuel analyses are presented in the appendix. (The report is a translation of parts of the report VARMEFORSK--911 published in 2005)

Benefits of barrier fuel on fuel cycle economics

International Nuclear Information System (INIS)

Crowther, R.L.; Kunz, C.L.

1988-01-01

Barrier fuel rod cladding was developed to eliminate fuel rod failures from pellet/cladding stress/corrosion interaction and to eliminate the associated need to restrict the rate at which fuel rod power can be increased. The performance of barrier cladding has been demonstrated through extensive testing and through production application to many boiling water reactors (BWRs). Power reactor data have shown that barrier fuel rod cladding has a significant beneficial effect on plant capacity factor and plant operating costs and significantly increases fuel reliability. Independent of the fuel reliability benefit, it is less obvious that barrier fuel has a beneficial effect of fuel cycle costs, since barrier cladding is more costly to fabricate. Evaluations, measurements, and development activities, however, have shown that the fuel cycle cost benefits of barrier fuel are large. This paper is a summary of development activities that have shown that application of barrier fuel significantly reduces BWR fuel cycle costs

Fuel assembly

International Nuclear Information System (INIS)

Yamazaki, Hajime.

1995-01-01

In a fuel assembly having fuel rods of different length, fuel pellets of mixed oxides of uranium and plutonium are loaded to a short fuel rod. The volume ratio of a pellet-loaded portion to a plenum portion of the short fuel rod is made greater than the volume ratio of a fuel rod to which uranium fuel pellets are loaded. In addition, the volume of the plenum portion of the short fuel rod is set greater depending on the plutonium content in the loaded fuel pellets. MOX fuel pellets are loaded on the short fuel rods having a greater degree of freedom relevant to the setting for the volume of the plenum portion compared with that of a long rod fuel, and the volume of the plenum portion is ensured greater depending on the plutonium content. Even if a large amount of FP gas and He gas are discharged from the MOX fuels compared with that from the uranium fuels, the internal pressure of the MOX fuel rod during operation is maintained substantially identical with that of the uranium fuel rod, so that a risk of generating excess stresses applied to the fuel cladding tubes and rupture of fuels are greatly reduced. (N.H.)

Framing car fuel efficiency : linearity heuristic for fuel consumption and fuel-efficiency ratings

NARCIS (Netherlands)

Schouten, T.M.; Bolderdijk, J.W.; Steg, L.

2014-01-01

People are sensitive to the way information on fuel efficiency is conveyed. When the fuel efficiency of cars is framed in terms of fuel per distance (FPD; e.g. l/100 km), instead of distance per units of fuel (DPF; e.g. km/l), people have a more accurate perception of potential fuel savings. People

Used fuel packing plant for CANDU fuel

Energy Technology Data Exchange (ETDEWEB)

Menzies, I.; Thayer, B.; Bains, N., E-mail: imenzies@atsautomation.com [ATS Automation, Cambridge, ON (Canada); Murchison, A., E-mail: amurchison@nwmo.ca [NWMO, Toronto, ON (Canada)

2015-07-01

Large forgings have been selected to containerize Light Water Reactor used nuclear fuel. CANDU fuel, which is significantly smaller in size, allows novel approaches for containerization. For example, by utilizing commercially available extruded ASME pipe a conceptual design of a Used Fuel Packing Plant for containerization of used CANDU fuel in a long lived metallic container has been developed. The design adopts a modular approach with multiple independent work cells to transfer and containerize the used fuel. Based on current technologies and concepts from proven industrial systems, the Used Fuel Packing Plant can assemble twelve used fuel containers per day considering conservative levels of process availability. (author)

Fuel assembly

International Nuclear Information System (INIS)

Sakuyama, Tadashi; Mukai, Hideyuki.

1988-01-01

Purpose: To prevent the bending of a fuel rod caused by the difference in the elongation between a joined fuel rod and a standard fuel rod thereby maintain the fuel rod integrity. Constitution: A joined fuel rod is in a thread engagement at its lower end plug thereof with a lower plate, while passed through at its upper end plug into an upper tie plate and secured with a nut. Further, a standard fuel rod is engaged at its upper end plug and lower end plug with the upper tie plate and the lower tie plate respectively. Expansion springs are mounted to the upper end plugs of these bonded fuel rods and the standard fuel rods for preventing this lifting. Each of the fuel rods comprises a plurality of sintered pellets of nuclear fuel materials laminated in a zircaloy fuel can. The content of the alloy ingredient in the fuel can of the bonded fuel rod is made greater than that of the alloy ingredient of the standard fuel rod. this can increase the elongation for the bonded fuel rod, and the spring of the standard fuel rod is tightly bonded to prevent the bending. (Yoshino, Y.)

Fuel performance of DOE fuels in water storage

International Nuclear Information System (INIS)

Hoskins, A.P.; Scott, J.G.; Shelton-Davis, C.V.; McDannel, G.E.

1993-01-01

Westinghouse Idaho Nuclear Company operates the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory. In April of 1992, the U.S. Department of Energy (DOE) decided to end the fuel reprocessing mission at ICPP. Fuel performance in storage received increased emphasis as the fuel now needs to be stored until final dispositioning is defined and implemented. Fuels are stored in four main areas: an original underwater storage facility, a modern underwater storage facility, and two dry fuel storage facilities. As a result of the reactor research mission of the DOE and predecessor agencies, the Energy Research and Development Administration and the Atomic Energy Commission, many types of nuclear fuel have been developed, used, and assigned to storage at the ICPP. Fuel clad with stainless steel, zirconium, aluminum, and graphite are represented. Fuel matrices include uranium oxide, hydride, carbide, metal, and alloy fuels, resulting in 55 different fuel types in storage. Also included in the fuel storage inventory is canned scrap material

Comparison of Numerical and Experimental Studies for Flow-Field Optimization Based on Under-Rib Convection in Polymer Electrolyte Membrane Fuel Cells

Directory of Open Access Journals (Sweden)

Nguyen Duy Vinh

2016-10-01

Full Text Available The flow-field design based on under-rib convection plays an important role in enhancing the performance of polymer electrolyte membrane fuel cells (PEMFCs because it ensures the uniform distribution of the reacting gas and the facilitation of water. This research focused on developing suitable configurations of the anode and cathode bipolar plates to enhance the fuel cell performance based on under-rib convection. The work here evaluated the effects of flow-field designs, including a serpentine flow field with sub channel and by pass and a conventional serpentine flow-field on single-cell performance. Both the experiment and computer simulation indicated that the serpentine flow field with sub channel and by pass (SFFSB configuration enables more effective utilization of the electrocatalysts since it improves reactant transformation rate from the channel to the catalyst layer, thereby dramatically improving the fuel cell performance. The simulation and experimental results indicated that the power densities are increased by up to 16.74% and 18.21%, respectively, when applying suitable flow-field configurations to the anode and cathode bipolar plates. The findings in this are the foundation for enhancing efficient PEMFCs based on flow field design.

Studies on sulfur poisoning and development of advanced anodic materials for waste-to-energy fuel cells applications

Science.gov (United States)

Zaza, Fabio; Paoletti, Claudia; LoPresti, Roberto; Simonetti, Elisabetta; Pasquali, Mauro

Biomass is the renewable energy source with the most potential penetration in energy market for its positive environmental and socio-economic consequences: biomass live cycles for energy production is carbon neutral; energy crops promote alternative and productive utilizations of rural sites creating new economic opportunities; bioenergy productions promote local energy independence and global energy security defined as availability of energy resource supply. Different technologies are currently available for energy production from biomass, but a key role is played by fuel cells which have both low environmental impacts and high efficiencies. High temperature fuel cells, such as molten carbonate fuel cells (MCFC), are particularly suitable for bioenergy production because it can be directly fed with biogas: in fact, among its principal constituents, methane can be transformed to hydrogen by internal reforming; carbon dioxide is a safe diluent; carbon monoxide is not a poison, but both a fuel, because it can be discharged at the anode, and a hydrogen supplier, because it can produce hydrogen via the water-gas shift reaction. However, the utilization of biomass derived fuels in MCFC presents different problems not yet solved, such as the poisoning of the anode due to byproducts of biofuel chemical processing. The chemical compound with the major negative effects on cell performances is hydrogen sulfide. It reacts with nickel, the main anodic constituent, forming sulfides and blocking catalytic sites for electrode reactions. The aim of this work is to study the hydrogen sulfide effects on MCFC performances for defining the poisoning mechanisms of conventional nickel-based anode, recommending selection criteria of sulfur-tolerant materials, and selecting advanced anodes for MCFC fed with biogas.

Fuel Supply Defaults for Regional Fuels and Fuel Wizard Tool in MOVES201X

Science.gov (United States)

The fuel supply report documents the data and methodology used to derive the default gasoline, diesel and fuel-blend fuel properties, and their respective fuel market share in MOVES. The default market share of the individual fuels varies by calendar year, seasons, and several do...

Nonlinear Stability and Structure of Compressible Reacting Mixing Layers

Science.gov (United States)

Day, M. J.; Mansour, N. N.; Reynolds, W. C.

2000-01-01

The parabolized stability equations (PSE) are used to investigate issues of nonlinear flow development and mixing in compressible reacting shear layers. Particular interest is placed on investigating the change in flow structure that occurs when compressibility and heat release are added to the flow. These conditions allow the 'outer' instability modes- one associated with each of the fast and slow streams-to dominate over the 'central', Kelvin-Helmholtz mode that unaccompanied in incompressible nonreacting mixing layers. Analysis of scalar probability density functions in flows with dominant outer modes demonstrates the ineffective, one-sided nature of mixing that accompany these flow structures. Colayer conditions, where two modes have equal growth rate and the mixing layer is formed by two sets of vortices, offer some opportunity for mixing enhancement. Their extent, however, is found to be limited in the mixing layer's parameter space. Extensive validation of the PSE technique also provides a unique perspective on central- mode vortex pairing, further supporting the view that pairing is primarily governed perspective sheds insight on how linear stability theory is able to provide such an accurate prediction of experimentally-observed, fully nonlinear flow phenomenon.

78 FR 12005 - Regulation of Fuels and Fuel Additives: 2013 Renewable Fuel Standards; Public Hearing

Science.gov (United States)

2013-02-21

... Regulation of Fuels and Fuel Additives: 2013 Renewable Fuel Standards; Public Hearing AGENCY: Environmental... EPA is announcing a public hearing to be held for the proposed rule ``Regulation of Fuels and Fuel Additives: 2013 Renewable Fuel Standards,'' which was published separately in the Federal Register on...

Solid TRU fuels and fuel cycle technology

International Nuclear Information System (INIS)

Ogawa, Toru; Suzuki, Yasufumi

1997-01-01

Alloys and nitrides are candidate solid fuels for transmutation. However, the nitride fuels are preferred to the alloys because they have more favorable thermal properties which allows to apply a cold-fuel concept. The nitride fuel cycle technology is briefly presented

Nuclear fuels

International Nuclear Information System (INIS)

Beauvy, M.; Berthoud, G.; Defranceschi, M.; Ducros, G.; Guerin, Y.; Limoge, Y.; Madic, Ch.; Santarini, G.; Seiler, J.M.; Sollogoub, P.; Vernaz, E.; Guillet, J.L.; Ballagny, A.; Bechade, J.L.; Bonin, B.; Brachet, J.Ch.; Delpech, M.; Dubois, S.; Ferry, C.; Freyss, M.; Gilbon, D.; Grouiller, J.P.; Iracane, D.; Lansiart, S.; Lemoine, P.; Lenain, R.; Marsault, Ph.; Michel, B.; Noirot, J.; Parrat, D.; Pelletier, M.; Perrais, Ch.; Phelip, M.; Pillon, S.; Poinssot, Ch.; Vallory, J.; Valot, C.; Pradel, Ph.; Bonin, B.; Bouquin, B.; Dozol, M.; Lecomte, M.; Vallee, A.; Bazile, F.; Parisot, J.F.; Finot, P.; Roberts, J.F.

2009-01-01

Fuel is one of the essential components in a reactor. It is within that fuel that nuclear reactions take place, i.e. fission of heavy atoms, uranium and plutonium. Fuel is at the core of the reactor, but equally at the core of the nuclear system as a whole. Fuel design and properties influence reactor behavior, performance, and safety. Even though it only accounts for a small part of the cost per kilowatt-hour of power provided by current nuclear power plants, good utilization of fuel is a major economic issue. Major advances have yet to be achieved, to ensure longer in-reactor dwell-time, thus enabling fuel to yield more energy; and improve ruggedness. Aside from economics, and safety, such strategic issues as use of plutonium, conservation of resources, and nuclear waste management have to be addressed, and true technological challenges arise. This Monograph surveys current knowledge regarding in-reactor behavior, operating limits, and avenues for R and D. It also provides illustrations of ongoing research work, setting out a few noteworthy results recently achieved. Content: 1 - Introduction; 2 - Water reactor fuel: What are the features of water reactor fuel? 9 (What is the purpose of a nuclear fuel?, Ceramic fuel, Fuel rods, PWR fuel assemblies, BWR fuel assemblies); Fabrication of water reactor fuels (Fabrication of UO 2 pellets, Fabrication of MOX (mixed uranium-plutonium oxide) pellets, Fabrication of claddings); In-reactor behavior of UO 2 and MOX fuels (Irradiation conditions during nominal operation, Heat generation, and removal, The processes involved at the start of irradiation, Fission gas behavior, Microstructural changes); Water reactor fuel behavior in loss of tightness conditions (Cladding, the first containment barrier, Causes of failure, Consequences of a failure); Microscopic morphology of fuel ceramic and its evolution under irradiation; Migration and localization of fission products in UOX and MOX matrices (The ceramic under irradiation

Nuclear fuels

Energy Technology Data Exchange (ETDEWEB)

Beauvy, M.; Berthoud, G.; Defranceschi, M.; Ducros, G.; Guerin, Y.; Limoge, Y.; Madic, Ch.; Santarini, G.; Seiler, J.M.; Sollogoub, P.; Vernaz, E.; Guillet, J.L.; Ballagny, A.; Bechade, J.L.; Bonin, B.; Brachet, J.Ch.; Delpech, M.; Dubois, S.; Ferry, C.; Freyss, M.; Gilbon, D.; Grouiller, J.P.; Iracane, D.; Lansiart, S.; Lemoine, P.; Lenain, R.; Marsault, Ph.; Michel, B.; Noirot, J.; Parrat, D.; Pelletier, M.; Perrais, Ch.; Phelip, M.; Pillon, S.; Poinssot, Ch.; Vallory, J.; Valot, C.; Pradel, Ph.; Bonin, B.; Bouquin, B.; Dozol, M.; Lecomte, M.; Vallee, A.; Bazile, F.; Parisot, J.F.; Finot, P.; Roberts, J.F

2009-07-01

Fuel is one of the essential components in a reactor. It is within that fuel that nuclear reactions take place, i.e. fission of heavy atoms, uranium and plutonium. Fuel is at the core of the reactor, but equally at the core of the nuclear system as a whole. Fuel design and properties influence reactor behavior, performance, and safety. Even though it only accounts for a small part of the cost per kilowatt-hour of power provided by current nuclear power plants, good utilization of fuel is a major economic issue. Major advances have yet to be achieved, to ensure longer in-reactor dwell-time, thus enabling fuel to yield more energy; and improve ruggedness. Aside from economics, and safety, such strategic issues as use of plutonium, conservation of resources, and nuclear waste management have to be addressed, and true technological challenges arise. This Monograph surveys current knowledge regarding in-reactor behavior, operating limits, and avenues for R and D. It also provides illustrations of ongoing research work, setting out a few noteworthy results recently achieved. Content: 1 - Introduction; 2 - Water reactor fuel: What are the features of water reactor fuel? 9 (What is the purpose of a nuclear fuel?, Ceramic fuel, Fuel rods, PWR fuel assemblies, BWR fuel assemblies); Fabrication of water reactor fuels (Fabrication of UO{sub 2} pellets, Fabrication of MOX (mixed uranium-plutonium oxide) pellets, Fabrication of claddings); In-reactor behavior of UO{sub 2} and MOX fuels (Irradiation conditions during nominal operation, Heat generation, and removal, The processes involved at the start of irradiation, Fission gas behavior, Microstructural changes); Water reactor fuel behavior in loss of tightness conditions (Cladding, the first containment barrier, Causes of failure, Consequences of a failure); Microscopic morphology of fuel ceramic and its evolution under irradiation; Migration and localization of fission products in UOX and MOX matrices (The ceramic under

Fuel economy of hybrid fuel-cell vehicles

Science.gov (United States)

Ahluwalia, Rajesh K.; Wang, X.; Rousseau, A.

The potential improvement in fuel economy of a mid-size fuel-cell vehicle by combining it with an energy storage system has been assessed. An energy management strategy is developed and used to operate the direct hydrogen, pressurized fuel-cell system in a load-following mode and the energy storage system in a charge-sustaining mode. The strategy places highest priority on maintaining the energy storage system in a state where it can supply unanticipated boost power when the fuel-cell system alone cannot meet the power demand. It is found that downsizing a fuel-cell system decreases its efficiency on a drive cycle which is compensated by partial regenerative capture of braking energy. On a highway cycle with limited braking energy the increase in fuel economy with hybridization is small but on the stop-and-go urban cycle the fuel economy can improve by 27%. On the combined highway and urban drive cycles the fuel economy of the fuel-cell vehicle is estimated to increase by up to 15% by hybridizing it with an energy storage system.

[Complex technology for water and wastewater disinfection and its industrial realization in prototype unit].

Science.gov (United States)

Arakcheev, E N; Brunman, V E; Brunman, M V; Konyashin, A V; Dyachenko, V A; Petkova, A P

Usage of complex automated electrolysis unit for drinking water disinfection and wastewater oxidation and coagulation is scoped, its ecological and energy efficiency is shown. Properties of technological process of anolyte production using membrane electrolysis of brine for water disinfection in municipal pipelines and potassium ferrate production using electrochemical dissolution of iron anode in NaOH solution for usage in purification plants are listed. Construction of modules of industrial prototype for anolyte and ferrate production and applied aspects of automation of complex electrolysis unit are proved. Results of approbation of electrolytic potassium ferrate for drinking water disinfection and wastewater, rain water and environmental water oxidation and coagulation are shown.

Ammonia as a Suitable Fuel for Fuel Cells

International Nuclear Information System (INIS)

Lan, Rong; Tao, Shanwen

2014-01-01

Ammonia, an important basic chemical, is produced at a scale of 150 million tons per year. Half of hydrogen produced in chemical industry is used for ammonia production. Ammonia containing 17.5 wt% hydrogen is an ideal carbon-free fuel for fuel cells. Compared to hydrogen, ammonia has many advantages. In this mini-review, the suitability of ammonia as fuel for fuel cells, the development of different types of fuel cells using ammonia as the fuel and the potential applications of ammonia fuel cells are briefly reviewed.

Ammonia as a suitable fuel for fuel cells

Directory of Open Access Journals (Sweden)

Rong eLan

2014-08-01

Full Text Available Ammonia, an important basic chemical, is produced at a scale of 150 million tons per year. Half of hydrogen produced in chemical industry is used for ammonia production. Ammonia containing 17.5wt% hydrogen is an ideal carbon-free fuel for fuel cells. Compared to hydrogen, ammonia has many advantages. In this mini-review, the suitability of ammonia as fuel for fuel cells, the development of different types of fuel cells using ammonia as the fuel and the potential applications of ammonia fuel cells are briefly reviewed.

Safety analysis of MOX fuels by fuel performance code

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Motoe [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2002-12-01

Performance of plutonium rick mixed oxide fuels specified for the Reduced-Moderation Water Reactor (RMWR) has been analysed by modified fuel performance code. Thermodynamic properties of these fuels up to 120 GWd/t burnup have not been measured and estimated using existing uranium fuel models. Fission product release, pressure rise inside fuel rods and mechanical loads of fuel cans due to internal pressure have been preliminarily assessed based on assumed axial power distribution history, which show the integrity of fuel performance. Detailed evaluation of fuel-cladding interactions due to thermal expansion or swelling of fuel pellets due to high burnup will be required for safety analysis of mixed oxide fuels. Thermal conductivity and swelling of plutonium rich mixed oxide fuels shall be taken into consideration. (T. Tanaka)

How Did the Asian Stock Markets React to Bank Mergera after the 1997 Financial Crisis?

OpenAIRE

Meslier-Crouzille , Céline; Lepetit , Laetitia; Bautista , Carlos C.

2008-01-01

International audience; The objective of this paper is to empirically assess the stock market reaction to the announcement of bank mergers and acquisitions (M&As) in eight East Asian countries over the 1997-2003 period. M&As are classified according to the status of entity, the time period of the deal and the maturity of the banking system. A bivariate GARCH model is used to estimate abnormal returns taking beta conditional variability into account. We find that the market reacted negatively ...

Reactor fuel element and fuel assembly

International Nuclear Information System (INIS)

Okada, Seiji; Ishida, Tsuyoshi; Ikeda, Atsuko.

1997-01-01

A mixture of fission products and burnable poisons is disposed at least to a portion between MOX pellets to form a burnable poison-incorporated fuel element without mixing burnable poisons to the MOX pellets. Alternatively, a mixture of materials other than the fission products and burnable poisons is formed into disks, a fuel lamination portion is divided into at least to two regions, and the ratio of number of the disks of the mixture relative to the volume of the region is increased toward the lower portion of the fuel lamination portion. With such a constitution, the axial power distribution of fuels can be made flat easily. Alternatively, the thickness of the disk of the mixture is increased toward the lower region of the fuel lamination portion to flatten the axial power distribution of the fuels in the same manner easily. The time and the cost required for the manufacture are reduced, and MOX fuels filled with burnable poisons with easy maintenance and control can be realized. (N.H.)

Emergency fuels utilization guidebook. Alternative Fuels Utilization Program

Energy Technology Data Exchange (ETDEWEB)

1980-08-01

The basic concept of an emergency fuel is to safely and effectively use blends of specification fuels and hydrocarbon liquids which are free in the sense that they have been commandeered or volunteered from lower priority uses to provide critical transportation services for short-duration emergencies on the order of weeks, or perhaps months. A wide variety of liquid hydrocarbons not normally used as fuels for internal combustion engines have been categorized generically, including limited information on physical characteristics and chemical composition which might prove useful and instructive to fleet operators. Fuels covered are: gasoline and diesel fuel; alcohols; solvents; jet fuels; kerosene; heating oils; residual fuels; crude oils; vegetable oils; gaseous fuels.

Assessment of the Effects on PCT Evaluation of Enhanced Fuel Model Facilitated by Coupling the MARS Code with the FRAPTRAN Code

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyong Chol; Lee, Young Jin; Han, Sam Hee [NSE Technology Inc., Daejeon (Korea, Republic of)

2016-10-15

The principal objectives of the two safety criteria, peak cladding temperature (PCT) and total oxidation limits, are to ensure that the fuel rod claddings remain sufficiently ductile so that they do not crack and fragment during a LOCA. Another important purpose of the PCT limit is to ensure that the fuel cladding does not enter the regime of runaway oxidation and uncontrollable heat-up. However, even when the PCT limit is satisfied, it is known that cladding failures may still occur in a certain percentage of the fuel rods during a LOCA. This is largely because a 100% fuel failure is assumed for the radiological consequence analysis in the US regulatory practices. In this study, we analyze the effects of cladding failure and other fuel model features on PCT during a LOCA using the MARS-FRAPTRAN coupled code. MARS code has been coupled with FRAPTRAN code to extend fuel modeling capability. The coupling allows feedback of FRAPTRAN results in real time. Because of the significant impact of fuel models on key safety parameters such as PCT, detailed and accurate fuel models should be employed when evaluating PCT in LOCA analysis. It is noteworthy that the ECCS evaluation models laid out in the Appendix K to 10CFR50 require a provision for predicting cladding swelling and rupture and require to assume that the inside of the cladding react with steam after the rupture. The metal-water reaction energy can have significantly large effect on the reflood PCT, especially when fuel failure occurs. Effects of applying an advanced fuel model on the PCT evaluation can be clearly seen when comparing the MARS and the FRAPTRAN results in both the one-way calculation and the feedback calculation. As long as MARS and FRAPTRAN are used respectively in the ranges where they have been validated, the coupled calculation results are expected to be valid and to reveal various aspects of phenomena which have not been discovered in previous uncoupled calculations by MARS or FRAPTRAN.

77 FR 13009 - Regulation of Fuels and Fuel Additives: Identification of Additional Qualifying Renewable Fuel...

Science.gov (United States)

2012-03-05

... Regulation of Fuels and Fuel Additives: Identification of Additional Qualifying Renewable Fuel Pathways Under the Renewable Fuel Standard Program AGENCY: Environmental Protection Agency (EPA). ACTION: Withdrawal... Renewable Fuel Standard program regulations. Because EPA received adverse comment, we are withdrawing the...

Nuclear fuels

International Nuclear Information System (INIS)

2008-01-01

The nuclear fuel is one of the key component of a nuclear reactor. Inside it, the fission reactions of heavy atoms, uranium and plutonium, take place. It is located in the core of the reactor, but also in the core of the whole nuclear system. Its design and properties influence the behaviour, the efficiency and the safety of the reactor. Even if it represents a weak share of the generated electricity cost, its proper use represents an important economic stake. Important improvements remain to be made to increase its residence time inside the reactor, to supply more energy, and to improve its robustness. Beyond the economical and safety considerations, strategical questions have to find an answer, like the use of plutonium, the management of resources and the management of nuclear wastes and real technological challenges have to be taken up. This monograph summarizes the existing knowledge about the nuclear fuel, its behaviour inside the reactor, its limits of use, and its R and D tracks. It illustrates also the researches in progress and presents some key results obtained recently. Content: 1 - Introduction; 2 - The fuel of water-cooled reactors: aspect, fabrication, behaviour of UO 2 and MOX fuels inside the reactor, behaviour in loss of tightness situation, microscopic morphology of fuel ceramics and evolution under irradiation - migration and localisation of fission products in UOX and MOX matrices, modeling of fuels behaviour - modeling of defects and fission products in the UO 2 ceramics by ab initio calculations, cladding and assembly materials, pellet-cladding interaction, advanced UO 2 and MOX ceramics, mechanical behaviour of the fuel assembly, fuel during a loss of coolant accident, fuel during a reactivity accident, fuel during a serious accident, fuel management inside reactor cores, fuel cycle materials balance, long-term behaviour of the spent fuel, fuel of boiling water reactors; 3 - the fuel of liquid metal fast reactors: fast neutrons radiation

Apparatus for loading fuel pellets in fuel rods

International Nuclear Information System (INIS)

Tedesco, R.J.

1976-01-01

An apparatus is disclosed for loading fuel pellets into fuel rods for a nuclear reactor including a base supporting a table having grooves therein for holding a multiplicity of pellets. Multiple fuel rods are placed in alignment with grooves in the pellet table and a guide member channels pellets from the table into the corresponding fuel rods. To effect movement of pellets inside the fuel rods without jamming, a number of electromechanical devices mounted on the base have arms connected to the lower surface of the fuel rod table which cyclically imparts a reciprocating arc motion to the table for moving the fuel pellets longitudinally of and inside the fuel rods. These electromechanical devices include a solenoid having a plunger therein connected to a leaf type spring, the arrangement being such that upon energization of the solenoid coil, the leaf spring moves the fuel rod table rearwardly and downwardly, and upon deenergization of the coil, the spring imparts an upward-forward movement to the table which results in physical displacement of fuel pellets in the fuel rods clamped to the table surface. 8 claims, 6 drawing figures

Hardened over-coating fuel particle and manufacture of nuclear fuel using its fuel particle

International Nuclear Information System (INIS)

Yoshimuda, Hideharu.

1990-01-01

Coated-fuel particles comprise a coating layer formed by coating ceramics such as silicon carbide or zirconium carbide and carbons, etc. to a fuel core made of nuclear fuel materials. The fuel core generally includes oxide particles such as uranium, thorium and plutonium, having 400 to 600 μm of average grain size. The average grain size of the coated-fuel particle is usually from 800 to 900 μm. The thickness of the coating layer is usually from 150 to 250 μm. Matrix material comprising a powdery graphite and a thermosetting resin such as phenol resin, etc. is overcoated to the surface of the coated-fuel particle and hardened under heating to form a hardened overcoating layer to the coated-fuel particle. If such coated-fuel particles are used, cracks, etc. are less caused to the coating layer of the coated-fuel particles upon production, thereby enabling to prevent the damages to the coating layer. (T.M.)

Fuel and fuel cycles with high burnup for WWER reactors

International Nuclear Information System (INIS)

Chernushev, V.; Sokolov, F.

2002-01-01

The paper discusses the status and trends in development of nuclear fuel and fuel cycles for WWER reactors. Parameters and main stages of implementation of new fuel cycles will be presented. At present, these new fuel cycles are offered to NPPs. Development of new fuel and fuel cycles based on the following principles: profiling fuel enrichment in a cross section of fuel assemblies; increase of average fuel enrichment in fuel assemblies; use of refuelling schemes with lower neutron leakage ('in-in-out'); use of integrated fuel gadolinium-based burnable absorber (for a five-year fuel cycle); increase of fuel burnup in fuel assemblies; improving the neutron balance by using structural materials with low neutron absorption; use of zirconium alloy claddings which are highly resistant to irradiation and corrosion. The paper also presents the results of fuel operation. (author)

Fuel Cell Power Plants Renewable and Waste Fuels

Science.gov (United States)

2011-01-13

logo, Direct FuelCell and “DFC” are all registered trademarks (®) of FuelCell Energy, Inc. Applications •On-site self generation of combined heat... of FuelCell Energy, Inc. Fuels Resources for DFC • Natural Gas and LNG • Propane • Biogas (by Anaerobicnaerobic Digestion) - Municipal Waste...FUEL RESOURCES z NATURAL GAS z PROPANE z DFC H2 (50-60%) z ETHANOL zWASTE METHANE z BIOGAS z COAL GAS Diversity of Fuels plus High Efficiency

Fuel-cycle cost comparisons with oxide and silicide fuels

International Nuclear Information System (INIS)

Matos, J.E.; Freese, K.E.

1982-01-01

This paper addresses fuel cycle cost comparisons for a generic 10 MW reactor with HEU aluminide fuel and with LEU oxide and silicide fuels in several fuel element geometries. The intention of this study is to provide a consistent assessment of various design options from a cost point of view. Fuel cycle cost benefits could result if a number of reactors were to utilize fuel elements with the same number or different numbers of the same standard fuel plate. Data are presented to quantify these potential cost benefits. This analysis shows that there are a number of fuel element designs using LEU oxide or silicide fuels that have either the same or lower total fuel cycle costs than the HEU design. Use of these fuels with the uranium densities considered requires that they are successfully demonstrated and licensed

Improving Accident Tolerance of Nuclear Fuel with Coated Mo-alloy Cladding

Directory of Open Access Journals (Sweden)

Bo Cheng

2016-02-01

Full Text Available In severe loss of coolant accidents (LOCA, similar to those experienced at Fukushima Daiichi and Three Mile Island Unit 1, the zirconium alloy fuel cladding materials are rapidly heated due to nuclear decay heating and rapid exothermic oxidation of zirconium with steam. This heating causes the cladding to rapidly react with steam, lose strength, burst or collapse, and generate large quantities of hydrogen gas. Although maintaining core cooling remains the highest priority in accident management, an accident tolerant fuel (ATF design may extend coping and recovery time for operators to restore emergency power, and cooling, and achieve safe shutdown. An ATF is required to possess high resistance to steam oxidation to reduce hydrogen generation and sufficient mechanical strength to maintain fuel rod integrity and core coolability. The initiative undertaken by Electric Power Research Institute (EPRI is to demonstrate the feasibility of developing an ATF cladding with capability to maintain its integrity in 1,200–1,500°C steam for at least 24 hours. This ATF cladding utilizes thin-walled Mo-alloys coated with oxidation-resistant surface layers. The basic design consists of a thin-walled Mo alloy structural tube with a metallurgically bonded, oxidation-resistant outer layer. Two options are being investigated: a commercially available iron, chromium, and aluminum alloy with excellent high temperature oxidation resistance, and a Zr alloy with demonstrated corrosion resistance. As these composite claddings will incorporate either no Zr, or thin Zr outer layers, hydrogen generation under severe LOCA conditions will be greatly reduced. Key technical challenges and uncertainties specific to Mo alloy fuel cladding include: economic core design, industrial scale fabricability, radiation embrittlement, and corrosion and oxidation resistance during normal operation, transients, and severe accidents. Progress in each aspect has been made and key results are

Fuel temperature characteristics of the 37-element and CANFLEX fuel bundle

International Nuclear Information System (INIS)

Bae, Jun Ho; Rho, Gyu Hong; Park, Joo Hwan

2009-10-01

This report describes the fuel temperature characteristics of CANFLEX fuel bundles and 37-element fuel bundles for a different burnup of fuel. The program was consisted for seeking the fuel temperature of fuel bundles of CANFLEX fuel bundles and 37-element fuel bundles by using the method in NUCIRC. Fuel temperature has an increasing pattern with the burnup of fuel for CANFLEX fuel bundles and 37-element fuel bundles. For all the case of burnup, the fuel temperature of CANFLEX fuel bundles has a lower value than that of 37-element fuel bundles. Especially, for the high power channel, the CANFLEX fuel bundles show a lower fuel temperature as much as about 75 degree, and the core averaged fuel temperature has a lower fuel temperature of about 50 degree than that of 37-element fuel bundles. The lower fuel temperature of CANFLEX fuel bundles is expected to enhance the safety by reducing the fuel temperature coefficient. Finally, for each burnup of CANFLEX fuel bundles and 37-element fuel bundles, the equation was present for predicting the fuel temperature of a bundle in terms of a coolant temperature and bundle power

Nuclear fuels

International Nuclear Information System (INIS)

Gangwani, Saloni; Chakrabortty, Sumita

2011-01-01

Nuclear fuel is a material that can be consumed to derive nuclear energy, by analogy to chemical fuel that is burned for energy. Nuclear fuels are the most dense sources of energy available. Nuclear fuel in a nuclear fuel cycle can refer to the fuel itself, or to physical objects (for example bundles composed of fuel rods) composed of the fuel material, mixed with structural, neutron moderating, or neutron reflecting materials. Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for SNF. When looking at long-term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different. The following paper will also include the uses. advancements, advantages, disadvantages, various processes and behavior of nuclear fuels

Checklist for transition to new highway fuel(s).

Energy Technology Data Exchange (ETDEWEB)

Risch, C.; Santini, D.J. (Energy Systems)

2011-12-15

Transportation is vital to the U.S. economy and society. As such, U.S. Presidents have repeatedly stated that the nation needs to reduce dependence on petroleum, especially for the highway transportation sector. Throughout history, highway transportation fuel transitions have been completed successfully both in United States and abroad. Other attempts have failed, as described in Appendix A: Historical Highway Fuel Transitions. Planning for a transition is critical because the changes can affect our nation's ability to compete in the world market. A transition will take many years to complete. While it is tempting to make quick decisions about the new fuel(s) of choice, it is preferable and necessary to analyze all the pertinent criteria to ensure that correct decisions are made. Doing so will reduce the number of changes in highway fuel(s). Obviously, changes may become necessary because of occurrences such as significant technology breakthroughs or major world events. With any and all of the possible transitions to new fuel(s), the total replacement of gasoline and diesel fuels is not expected. These conventional fuels are envisioned to coexist with the new fuel(s) for decades, while the revised fuel and vehicle infrastructures are implemented. The transition process must analyze the needs of the primary 'players,' which consist of the customers, the government, the fuel industry, and the automotive industry. To maximize the probability of future successes, the prime considerations of these groups must be addressed. Section 2 presents a succinct outline of the Checklist. Section 3 provides a brief discussion about the groupings on the Checklist.

75 FR 37733 - Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard Program

Science.gov (United States)

2010-06-30

... Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard Program AGENCY... direct final rule to amend the Renewable Fuel Standard program requirements on May 10, 2010. Because EPA... Fuel Standard program requirements, published on May 10, 2010. We stated in that direct final rule that...

77 FR 72746 - Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard and Diesel...

Science.gov (United States)

2012-12-06

... Fuels and Fuel Additives: Modifications to Renewable Fuel Standard and Diesel Sulfur Programs AGENCY... Fuel Standard (``RFS'') program under section 211(o) of the Clean Air Act. The direct final rule also... marine diesel fuel produced by transmix processors, and the fuel marker requirements for 500 ppm sulfur...