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1

Composite polymer electrolytes using fumed silica fillers: synthesis, rheology and electrochemistry  

Energy Technology Data Exchange (ETDEWEB)

The goal of the synthesis research was to devise routes to PEG/fumed silica/lithium salt composites that can be processed and then photochemically cross-linked to form mechanically stable electrolytes. An essential feature of the system is that the ionic conductivity and the mechanical properties must be de-coupled from each other, i.e., cross-linking of the fumed silica matrix must not cause a significant deterioration of the conductivity of the composite. As shown in Figure 2, we prepared a range of surface-modified fumed silicas and investigated their ability to form mechanically stable composite electrolytes. The groups used to modify the surface properties of the silica ranged from simple linear alkyls that render the silica hydrophobia to polyethers that promote compatibility with the electrolyte. From these materials we developed a cross-linkable system that satisfies the criteria of processibility and high-conductivity. The key material needed for the cross-linking reaction are silicas that bear surface-attached monomers. As shown schematically in Figure 3a, we prepared fumed silicas with a combination of surface groups, for example, an octyl chain with different coverages of tethered methacrylates. The length of the tether was varied, and we found that both C{sub 3} and C{sub 8} tethers gave useful composites. The functionalized silicas were combined with PEG-DM, AIBN or benzophenone (free radical initiators), LiClO{sub 4} or Li imide, and either methyl, butyl, or octyl, methacrylate to form stable clear gels. Upon irradiation with UV light, polymerization of both the tethered methacrylate and the added methacrylate took place, yielding a cross-linked rubbery composite material. Ionic conductivity measurements before and after cross-linking showed only a slight decrease (see Figure 9 later), thereby offering strong experimental evidence that the mechanical properties conferred by the silica matrix are de-coupled from the ionic conductivity of the PEG-DM matrix.

Khan, Saad A.; Fedkiw, Peter S.; Baker, Gregory L.

1999-06-28

2

Synthesis of Magneto Rheological Fluid  

Directory of Open Access Journals (Sweden)

Full Text Available Simplicity and more intelligence in its functionality are key features of the Magneto Rheological Fluid (MRF) technology. This technology is an old “newcomers” coming up rapidly on the research and commercial front. In this paper, Magneto Rheological fluid samples are prepared. In this, silicone oil is used as a carrier fluid and is mixed with micron sized iron particles. In order to reduce the sedimentation, white lithium grease is also mixed as an additive in the fluid sample. An experimental setup consisting of an electrical stirrer with speed control unit is designed and developed and fabricated for preparation of the fluid samples. The observations of the surface morphology of iron particles were carried out using digital scanning electron microscope (SEM). The sedimentation properties are studied by visual inspection. The off-state rheological properties e.g. viscosity and shear stress variation with respect to shear rate of the fluid samples are investigated and are measured with a rotational rheometer.

S. K. Mangal,; Mukul Kataria,; Ashwani Kumar

2013-01-01

3

Morphological, rheological and electrochemical studies ofpoly(ethylene oxide) electrolytes containing fumed silicananoparticles  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the rheology and crystallization of composite Poly(Ethylene Oxide) (PEO) electrolytes were studied by dynamic mechanical analysis, DSC and polarized light microscopy. The effects of fumed silica nanoparticles on the conductivities of the polymer electrolytes at temperatures above and below their melting point were measured and related to their rheology and crystallization behavior, respectively. The electrolyte/electrode interfacial properties and cycling performances of the composite polymer electrolytes in Li/Li cells are also discussed. The measured electrochemical properties were found to depend heavily on the operational environments and sample processing history.

Xie, Jiangbing; Kerr, John B.; Duan, Robert G.; Han, Yongbong

2003-06-01

4

Electrolytic Synthesis and Characterizations of Silver Nanopowder  

CERN Document Server

This work reports a simple, novel, cost effective and eco-friendly electrolytic synthesis of silver nanoparticles using AgNO3 as metal precursor. The synthesis rate is much faster than other methods and this approach is suitable for large scale production. They are characterized by XRD, SEM and FT-IR techniques to analyze size, morphology and functional groups. XRD studies reveal a high degree of crystallinity and monophasic Ag nanoparticles. Their particle size is found to be 24 nm and specific surface area (SSA) is 24 m2/g. Analysis of Ag nanoparticles SSA reports that increasing their SSA improves their antibacterial actions. Microbiology assay founds that Ag nanoparticles are effective against E.coli and B.megaterium bacteria. SSA of bacteria analysis reveals that it plays a major role while reacting with antimicrobial agents.

Theivasanthi, T

2011-01-01

5

The rheology of oxide dispersions and the role of concentrated electrolyte solutions  

International Nuclear Information System (INIS)

[en] Stability control of particulate dispersions is critical to a wide range of industrial processes. In the UK nuclear industry, significant volumes of waste materials arising from the corrosion products of Magnox fuel rods currently require treatment and storage. The majority of this waste is present as aqueous dispersions of oxide particulates. Treatment of these dispersions will require a variety of unit operations including mobilisation, transport and solid- liquid separation. Typically these processes must operate across a narrow optimal range of pH and the dispersions are, almost without exception, found in complex electrolyte conditions of high overall concentration. Knowledge of the behaviour of oxides in various electrolyte conditions and over a large pH range is essential for the efficient design and control of any waste processing approach. The transport properties of particle dispersions are characterised by the rheological properties. It is well known that particle dispersion rheology is strongly influenced by particle-particle interaction forces, and that particle-particle interactions are strongly influenced by adsorbed ions on the particle surfaces. Here we correlate measurements of the shear yield stress and the particle zeta potentials to provide insight as to the role of ions in moderating particle interactions. The zeta potential of model TiO2 suspensions were determined (Colloidal Dynamics Zeta Probe) over a range of pH for a series of alkali metal halides and quaternary ammonium halides at a range of solution concentrations (0.001 M - 1 M). The results show some surprising co-ion effects at high electrolyte concentrations (>0.5 M) and indicate that even ions generally considered to be indifferent induce a shift in iso-electric point (i.e.p.) which is inferred as being due to specific adsorption of ions. The shear yield stress values of concentrated titania dispersions were measured using a Bohlin C-VOR stress controlled rheometer. The shear yield stress of a material is defined as the minimum applied shear stress required to induce flow. The yield stress vs. pH curves obtained reflected the shifts in i.e.p. seen in the zeta potential results. Interestingly, specific ion adsorption results in an unexplained increase in the value of the yield stress over that expected for simple systems with no such interfacial ion adsorption. Possible reasons for this effect such as ion-ion correlation effects are discussed. The importance of this increased attraction for the mobilisation of settled solids in an aqueous environment and especially the likely effects on the treatment of Magnox fuel waste materials is discussed. (authors)

2007-01-01

6

SOFC electrolytes synthesis by induction plasma spraying  

Energy Technology Data Exchange (ETDEWEB)

In the continuing progress of fuel cell technology, the use of CeO{sub 2} double doped electrolytes appears to be promising for the lowering of SOFC working temperatures. Ceria electrolytes have better ionic conductivities than YSZ. On the other hand, at low oxygen partial pressures, ceria is chemically reduced, leading to the increase of its electronic conduction. Double doping of the ceria increases the electrolytic conduction range without changing its conductivity. Ceria electrolytes of various compositions and dopant concentrations are synthesised using a combinatorial chemistry approach. New electrolytes are synthesised by suspension plasma spraying with oxide precursor and by solution plasma spraying with nitrate and chlorate salt precursors. Comparative studies of alternate plasma spraying techniques, with YSZ powder plasma spraying as electrolyte reference, are made. (authors)

Bonneau, M.E.; Gitzhofer, F.; Boulos, M.I. [Sherbrooke Univ., Dept. of Chemical Engineering, Plasma Technology Research Center, CRTP, PQ (Canada)

2001-07-01

7

Synthesis and Rheology of Model Comb Polymer Architectures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

For a better understanding of the extent of branching and its influence on the rheological properties of commercial branched polymers, well-defined linear and branched (comb) model polymers were synthesized. The correlation between the melt rheological properties and the polymer topology was investi...

Kempf, Michael

8

Synthesis and characterization of solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The emphasis of this project has been on basic research in the rapidly growing field of solid electrolytes. Studies were focused on 60 different lithium, sodium, potassium and fluorine ion conductors. Materials with technological interest, model compounds, and new systems were studied with neutron scattering,impedance measurements and DSC. The project has resulted in the i) identification of new crystalstructures, which favor ion transport; ii) forwarding of models for a better discription of structural and dynamical properties of solid electrolytes; iii) improvements in measuring/handling techniques. All published results are given in this volume.

Andersen, N.H.; Kjems, J.K.; Poulsen, F.W.

1985-05-01

9

Rheology of concentrated, heterogeneous slurries containing >1M electrolyte - a case study in nuclear waste suspensions  

International Nuclear Information System (INIS)

[en] Neutralized current acid waste (NCAW) simulant was produced to chemically simulate the properties of the washed solids of a high-level waste stream generated from the reprocessing of irradiated nuclear fuel. The NCAW simulant was evaluated by viscosity, yield stress, solid loading, particle size, and anion and cation solubility. For similar solid loadings and pH, the NCAW simulant had higher yield stresses and viscosities than NCAW. The differences in the rheological behavior between NCAW and the simulant were attributed to differences in the suspension microstructure. The effects of formic and nitric acid additions to the NCAW simulant on yield stress and viscosity were measured as a function of solids loading and pH for both acids. In addition, anion and cation solubilities were evaluated. Viscosity and yield stress decreased as pH was lowered. The change in rheological properties was attributed to floc breakdown and particle dissolution, which were initiated by the solubilization of the waste constituents. These results show that the effectiveness of the simulant studied here is unproven rheologically. (orig.)

1996-01-01

10

Rheology of concentrated, heterogeneous slurries containing >1M electrolyte - a case study in nuclear waste suspensions  

Energy Technology Data Exchange (ETDEWEB)

Neutralized current acid waste (NCAW) simulant was produced to chemically simulate the properties of the washed solids of a high-level waste stream generated from the reprocessing of irradiated nuclear fuel. The NCAW simulant was evaluated by viscosity, yield stress, solid loading, particle size, and anion and cation solubility. For similar solid loadings and pH, the NCAW simulant had higher yield stresses and viscosities than NCAW. The differences in the rheological behavior between NCAW and the simulant were attributed to differences in the suspension microstructure. The effects of formic and nitric acid additions to the NCAW simulant on yield stress and viscosity were measured as a function of solids loading and pH for both acids. In addition, anion and cation solubilities were evaluated. Viscosity and yield stress decreased as pH was lowered. The change in rheological properties was attributed to floc breakdown and particle dissolution, which were initiated by the solubilization of the waste constituents. These results show that the effectiveness of the simulant studied here is unproven rheologically. (orig.).

Tracey, E.M. [Pacific Northwest Nat. Lab., Richland, WA (United States); Smith, P.A. [Pacific Northwest Nat. Lab., Richland, WA (United States); Morrey, E.V. [Pacific Northwest Nat. Lab., Richland, WA (United States)

1996-05-01

11

Influences of pH and electrolyte on the rheological properties of aqueous solution of exopolysaccharide secreted by a deep-sea mesophilic bacterium  

UK PubMed Central (United Kingdom)

The effects of pH and electrolytes (NaCl and CaCl?) on the viscosity, dynamic modulus (storage modulus G? and loss modulus G?) and thixotropy of aqueous solution of new exopolysaccharide (SM-A87 EPS) secreted by a deep-sea mesophilic bacterium Wangia profunda SM-A87 were investigated. It was found that at pH 3-12 and the electrolyte concentration of 0.1-80 g/L, the SM-A87 EPS solution showed very weakly pH-dependent and salt-dependent rheological properties and dominant elastic behavior. These properties were considered to arise from the hyper-branched structure of the SM-A87 EPS molecules through the comparison of rheological properties of SM-A87 EPS solutions with those of partially hydrolyzed polyacrylamide ones at different electrolyte concentrations. Such good pH stability and salt resistance of the SM-A87 EPS solution indicate that SM-A87 EPS has great potential for application as food additive, thickener, stabilizer and enhanced oil recovery system. In the studied conditions, 2 g/L SM-A87 EPS solution showed positive thixotropy. The relative thixotropic recovery decreased with pH increasing and the electrolyte concentration decreasing.

Li H; Hou W

2011-08-01

12

Synthesis and rheological properties of cation-exchanged Laponite suspensions  

Energy Technology Data Exchange (ETDEWEB)

In this paper we report our new approach to synthesize cation-exchanged Laponite suspensions. General observations of the prepared samples indicated that an aqueous suspension of 1 wt% Laponite retained its free flowing liquid phase characteristics even after aging for several weeks. When bivalent cationic metals (Cu, Co, Ni) were ablated into the suspension, the strong charge of the crystal face was reduced and, on standing, the suspension gelled becoming highly viscous. This sol-gel transition was induced by the formation of a space-filled structure due to both van derWaals and electrostatic bonds between the positively charged rims and negatively charged faces. Rheological properties of such prepared suspensions were measured using a Brookfield DV-H Pro Viscometer with a small sample adapter{SSA18/13RPY). The yield strengths of2.2 N/m2, 3.2 N/m2, and 1.7 N/m2 were measured for Ni-, Co-, and Cu-modified Laponite suspensions, respectively. These yield strengths are sufficiently high for suspending weighting materials such as barite which requires the gel strength of about 0.5 N/m2.

Tran, X.P.; Howard, B.; Chyu, M.K.

2009-01-01

13

Synthesis and rheological properties of poly(vinyl alcohol)  

International Nuclear Information System (INIS)

Vinyl acetate usually used in PVA resin preparation was converted to PVAc by bulk poly-merization using AIBN as a initiator and PVA was synthesized by changing the concentration of NaOH added for saponification subsequently. As a result of estimating molecular weight using GPC, molecular weight increased as the NaOH concentration increased to 2.5 N, 5.0 N, 7.5 N and 10.0 N and polydispersity had similar values of 2.1?2.3, however, showed slightly decreasing tendency. In addition, PVA saponificated by 10.0 N-NaOH showed high syndiotacticity in observation of tacticity using NMR spectroscopy. From this fact, the degree of tacticity was predicted to be high and it was in good agreement with the tendency of polydisperisity by GPC. Also, from the result of FT-IR spectroscopy, it might be known that hydrolysis was more promoted in the PVA with 10.0 N-NaOH than other NaOH concentration. Intrinsic viscosity measured using Ubbelohde viscometer, which increased as the concentration of NaOH added for saponification increased. The change of shear strength with the change of shear rate was investigated using Brookfield viscometer, in consequence, viscosity of PVA synthesized decreased as shear rate increased. PVA solution confirmed to show the shear thinning behavior by Casson plot and PVA with 10.0 N-NaOH had the largest yield value. DSC measurement was performed to know the thermal properties of PVA. Tp had nearly constant value of 214 .deg. C in all cases except for adding 2.5 N-NaOH and ?H was increased as the concentration of NaOH increased. From this properties, it was concluded that the degree of hydrogen bonding was proportional to the added concentration of NaOH and the increase of the degree of hydrogen bonding and hydrophobic interaction could affect the rheological and thermal properties of title compound.

2001-01-01

14

Synthesis and electric conductivity of solid electrolyte of NASICON type  

International Nuclear Information System (INIS)

[en] The sequences of solid-phase reactions during synthesis of solid electrolyte corresponding to Na3Zr2Si2PO12 stoichiometric composition are studied. It is shown that solid-phase reaction of ZrO(NO3)2x2H2O, Na2CO3, NH4H2PO4 and amorphous SiO2 proceeds through stages of nitrate-zirconium oxide dehydration, ammonium dihydrophosphate decomposition, formation and decomposition of ammonium and sodium. Intermediate reaction products are sodium and zirconium phosphates, and some of ZrO2 takes part in the reaction in the form of amorphous or metastable tetragonal modification and another part transforms into a stable monoclinic one. NASICON formation starts at 1000 deg C, only at this stage silicon dioxide begins to react, which is already transformed from amorphous phase into a mixture of tridymite and ?-crystobalyte. After annealing at 1230 deg C a single-phase solid electrolyte Na3Zr2Si2PO12 having conductivity 0.14 S/cm at 300 deg C and 0.00028 S/cm at 25 deg C

1988-01-01

15

Synthesis of a Magneto-Rheological vehicle suspension system built on the variable structure control approach  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The synthesis of a magneto-rheological vehicle suspension system built on the variable structure control approach is considered in the present work. The suspension is synthesized in order to improve the ride comfort obtained by a standard passive suspension. Although a nominal half-vehicle model with rigid body is considered in the synthesis of the suspension, phenomenological models for the MR dampers and for the seat-driver subsystem, along with the flexibility of the v (more) ehicle body, are considered in the performance assessment. For comparison purposes, active and magneto-rheological suspensions built on the optimal control approach and an active suspension built on the variable structure control approach are also considered. The numerical results show that the proposed suspension outperforms the passive suspension and presents a performance comparable to that of the active ones when the vehicle body may be assumed as rigid. Besides, when its flexibility is an important issue, a great performance drop may be observed, depending on the road quality, the damper characteristics and the adopted control strategy.

Stutz, Leonardo Tavares; Rochinha, Fernando Alves

2011-12-01

16

Synthesis, rheology and forming of Y-Ba-Cu-O ceramics  

Energy Technology Data Exchange (ETDEWEB)

A chemical synthesis route is discussed which results in a low- temperature precursor to Y-Ba-Cu-O ceramics; it is based on use of molten Ba(OH){sub 2}{center_dot}8H{sub 2}O flux. Two different chemical systems have been examined; the first one, based on nitrate salts, has been demonstrated to be a viable precursor material for tape casting and extrusion; the second, made from acetate salts, has been used for powder synthesis and extrusion. Rheology of pastes shows that their flow may be fit to either Bingham Plastic or Hershel- Bulkley models. Yield stress is controlled in both pastes by volume fraction solids. Viscosity also follows solids loading in the paste. Shear thinning is controlled by colloidal nature of precursor. The paste has colloidal microstructure. Comparison of concentric cylinder rheometry and piston extrusion rheometry shows order of magnitude differences in yield stress, resulting from the test method and paste dilation.

Green, T.M.

1993-07-01

17

Synthesis, rheology and forming of Y-Ba-Cu-O ceramics  

International Nuclear Information System (INIS)

A chemical synthesis route is discussed which results in a low- temperature precursor to Y-Ba-Cu-O ceramics; it is based on use of molten Ba(OH)2·8H2O flux. Two different chemical systems have been examined; the first one, based on nitrate salts, has been demonstrated to be a viable precursor material for tape casting and extrusion; the second, made from acetate salts, has been used for powder synthesis and extrusion. Rheology of pastes shows that their flow may be fit to either Bingham Plastic or Hershel- Bulkley models. Yield stress is controlled in both pastes by volume fraction solids. Viscosity also follows solids loading in the paste. Shear thinning is controlled by colloidal nature of precursor. The paste has colloidal microstructure. Comparison of concentric cylinder rheometry and piston extrusion rheometry shows order of magnitude differences in yield stress, resulting from the test method and paste dilation

1993-01-01

18

Synthesis and ionic conductivity of lithium-conducting titanium phosphate solid electrolytes  

International Nuclear Information System (INIS)

Solid electrolytes in the systems Li2O-Al2O3-TiO2-P2O5 and Li2O-Al2O3-TiO2-P2O5-H2O-H2O2 were prepared by the methods of solid phase synthesis and sol-gel process and their lithium-ionic conductivity, depending on electrolyte composition and synthesis conditions, was studied. It was ascertained that partial substitution of Al3+ ions for Li+ ions in Li2Ti(PO4)2 results in preparation of solid electrolyte Li1.4Al0.2Ti(PO2)2, featuring ionic conductivity ?25 = 5.4 x 10-4 Sm cm-1. It is shown that ionic conductivity of solid electrolytes prepared from aqueous-peroxide solutions is no worse than conductivity of electrolytes synthesized by solid phase method

2004-01-01

19

Design and synthesis of a crystalline LiPON electrolyte  

Science.gov (United States)

In the course of a computation study of the broad class of lithium phosphorus oxy-nitride materials of interest for solid electrolyte applications, Du and Holzwarth,footnotetextY. A. Du and N. A. W. Holzwarth, Phys. Rev. B 81 184106 (2010) recently predicted a stable crystalline material with the stoichiometry Li2PO2N. The present paper reports the experimental preparation of the material using high temperature solid state synthesis and reports the results of experimental and calculational characterization studies. The so-named SD-Li2PO2N crystal structure has the orthorhombic space group Cmc21 with lattice constants a=9.0692(4) ,=5.3999(2) ,nd c=4.6856(2) å. The structure is similar but not identical to the predicted structure, characterized by parallel arrangements of anionic phosphorus oxy-nitride chains having planar P-N-P-N backbones. Nitrogen 2p? states contribute to the strong bonding and to the chemical and thermal stablility of the material in air up to 600^o C and in vacuum up to 1050^o C. The measured Arrhenius activation energy for ionic conductivity is 0.6 eV which is comparable to computed vacancy migration energies in the presence of a significant population of Li^+ ion vacancies.

Holzwarth, N. A. W.; Senevirathne, Keerthi; Day, Cynthia S.; Lachgar, Abdessadek; Gross, Michael D.

2013-03-01

20

Polymer electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Polymer electrolytes are defined as solid ionic conductors formed by the dissolution of salts in suitable high molecular weight polymers. Such materials should be distinguished from 'polyelectrolytes'and 'gel electrolytes'. The potential of polymer electrolytes as practical solid electrolytes for high energy density batteries and other devices is discussed. Recent work on understanding the interactions involved in the formation of polymer electrolyte phases, and the detailed mechanism of ions transport, the synthesis of new polymer electrolytes with optimised electrical, chemical and mechanical properties; and the study of the behaviour of these materials when incorporated as a component of an electrochemical cell is outlined.

Vincent, C.A.

1987-01-01

 
 
 
 
21

Proton-conducting polymer electrolyte membranes based on fluoropolymers incorporating perfluorovinyl ether sulfonic acids and fluoroalkenes Synthesis and characterizations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the synthesis of new polymer electrolyte membranes based on fluoropolymers incorporating aromatic perfluorovinyl ether sulfonic acids. A novel synthetic route describing the preparation of perfluorovinyl ether monomer containing sulfonic functionalities, 4-[(alpha,beta,beta-trifl...

Souzy, R.; Ameduri, Bruno; Boutevin, Bernard; Capron, P.; Marsacq, D.; Gebel, G.

22

Towards the synthesis of hydroxyapatite/protein scaffolds with controlled porosities: Bulk and interfacial shear rheology of a hydroxyapatite suspension with protein additives.  

Science.gov (United States)

The synthesis of porous hydroxyapatite scaffolds is essential for biomedical applications such as bone tissue engineering and replacement. One way to induce macroporosity, which is needed to support bone in-growth, is to use protein additives as foaming agents. Another reason to use protein additives is the potential to introduce a specific biofunctionality to the synthesized scaffolds. In this work, we study the rheological properties of a hydroxyapatite suspension system with additions of the proteins bovine serum albumin (BSA), lysozyme (LSZ) and fibrinogen (FIB). Both the rheology of the bulk phase as well as the interfacial shear rheology are studied. The bulk rheological data provides important information on the setting behavior of the thixotropic suspension, which we find to be faster with the addition of FIB and LSZ and much slower with BSA. Foam bubble stabilization mechanisms can be rationalized via interfacial shear rheology and we show that it depends on the growth of interfacial films at the suspension/air interface. These interfacial films support the stabilization of bubbles within the ceramic matrix and thereby introduce macropores. Due to the weak interaction of the protein molecules with the hydroxyapatite particles of the suspension, we find that BSA forms the most stable interfacial films, followed by FIB. LSZ strongly interacts with the hydroxyapatite particles and thus only forms thin films with very low elastic moduli. In summary, our study provides fundamental rheological insights which are essential for tailoring hydroxyapatite/protein suspensions in order to synthesize scaffolds with controlled porosities. PMID:23859812

Maas, Michael; Bodnar, Pedro Marcus; Hess, Ulrike; Treccani, Laura; Rezwan, Kurosch

2013-06-28

23

Towards the synthesis of hydroxyapatite/protein scaffolds with controlled porosities: bulk and interfacial shear rheology of a hydroxyapatite suspension with protein additives.  

UK PubMed Central (United Kingdom)

The synthesis of porous hydroxyapatite scaffolds is essential for biomedical applications such as bone tissue engineering and replacement. One way to induce macroporosity, which is needed to support bone in-growth, is to use protein additives as foaming agents. Another reason to use protein additives is the potential to introduce a specific biofunctionality to the synthesized scaffolds. In this work, we study the rheological properties of a hydroxyapatite suspension system with additions of the proteins bovine serum albumin (BSA), lysozyme (LSZ) and fibrinogen (FIB). Both the rheology of the bulk phase as well as the interfacial shear rheology are studied. The bulk rheological data provides important information on the setting behavior of the thixotropic suspension, which we find to be faster with the addition of FIB and LSZ and much slower with BSA. Foam bubble stabilization mechanisms can be rationalized via interfacial shear rheology and we show that it depends on the growth of interfacial films at the suspension/air interface. These interfacial films support the stabilization of bubbles within the ceramic matrix and thereby introduce macropores. Due to the weak interaction of the protein molecules with the hydroxyapatite particles of the suspension, we find that BSA forms the most stable interfacial films, followed by FIB. LSZ strongly interacts with the hydroxyapatite particles and thus only forms thin films with very low elastic moduli. In summary, our study provides fundamental rheological insights which are essential for tailoring hydroxyapatite/protein suspensions in order to synthesize scaffolds with controlled porosities.

Maas M; Bodnar PM; Hess U; Treccani L; Rezwan K

2013-10-01

24

Synthesis and characterization of Ag+ ion conducting glassy electrolytes  

Science.gov (United States)

Synthesis and characterization of new Ag+ ion conducting glassy systems: x[0.75AgI:0.25AgC1]: (1 - x)[Ag2O:P2O5], where 0.1 OCC). The some basic ion transport parameters viz. ionic conductivity (?), ionic mobility (?), mobile ion concentration (n), ionic drift velocity (vd), ion transference number (tion) and activation energy (Ea) values have been characterized with the help of various experimental techniques. A solid state battery was fabricated and its basic cell parameters calculated.

Chandra, Angesh; Bhatt, Alok; Chandra, Archana

2013-07-01

25

Hydrothermal synthesis and properties of ceria solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The structure, thermal expansion coefficients and ionic/electronic conductivity of (Ce{sub 1{minus}x}Sm{sub x}){sub 1{minus}y}(Tb/Pr){sub y}O{sub (2{minus}x/2)+{delta}} (x = 0--0.30; y = 0--0.10) and Ce{sub 1{minus}x}Ca{sub x}O{sub 2{minus}x} (x = 0--0.17) solid electrolytes prepared hydrothermally were investigated. The uniformly small particle size (7--68 nm) of the hydrothermally prepared materials allows sintering of the samples into highly dense ceramic pellets at 1400 C, a significantly lower temperature, compared to that at 1600--1650 C required for samples prepared by solid state techniques. The maximum ionic conductivity in Ce{sub 1{minus}x}(Sm/Ca){sub x}O{sub 2{minus}{delta}} was found at x = 0.17 for the Sm ({sigma}{sub 600 C} = 5.7 x 10{sup {minus}3} S/cm). In (Ce{sub 0.83}Sm{sub 0.17}){sub 1{minus}y}(Tb/Pr){sub y}O{sub 1.815+{delta}} the maximum conductivity was found at y = 0.10 for the Pr and Tb substituted ceria ({sigma}{sub 600 C} = 7.6 x 10{sup {minus}3} S/cm, E{sub a} = 0.55 eV and {sigma}{sub 600 C} = 10{sup {minus}2} S/cm, E{sub a} = 0.72 eV respectively) with electronic contribution to total conductivity around 20--30%. When the Tb or Pr substitution in Ce{sub 0.83}Sm{sub 0.17}O{sub 1.915} is reduced, the conductivity becomes more ionic, and is purely ionic at 2%. However the conductivity at this lower level doping is not significantly lower.

Greenblatt, M.; Huang, W.; Shuk, P.

1998-07-01

26

Synthesis of One-Dimensional and Hyperbranched Nanomaterials for Lithium-Ion Battery Solid Electrolytes  

Science.gov (United States)

Lithium-ion batteries can fail and catch fire when overcharged, exposed to high temperatures or short-circuited due to the highly flammable organic liquid used in the electrolyte. Using inorganic solid electrolyte materials can potentially improve the safety factor. Additionally, nanostructured electrolyte materials may further enhanced performance by taking advantage of their large aspect ratio. In this work, the synthesis of two promising nanostructured solid electrolyte materials was explored. Amorphous lithium niobate nanowires were synthesized through the decomposition of a niobium-containing complex in a structure-directing solvent using a reflux method. Lithium lanthanum titanate was obtained via solid state reaction with titanium oxide nanowires as the titanium precursor, but the nanowire morphology could not be preserved due to high temperature sintering. Hyperbranched potassium lanthanum titanate was synthesized through hydrothermal route. This was the first time that hyperbranched nanowires with perovskite structure were made without any catalyst or substrate. This result has the potential to be applied to other perovskite materials.

Yang, Ting

27

On the synthesis of oil-containing microcapsules and their electrolytic codeposition  

Energy Technology Data Exchange (ETDEWEB)

Composite coatings consisting of a metal matrix in which ceramic particles are embedded have recently been developed and used in industry as wear-resistant coatings. The present paper deals with the development of oil-containing self-lubricating metallic coatings. These have been produced by electrolytic codeposition of oil-containing microcapsules from Watts nickel plating baths. For this purpose, oil-containing polyterephthalamide microcapsules were synthesized based on the interfacial polymerization of an oil-soluble monomer (terephthaloyl dichloride) and a mixture of two water-soluble monomers (diethylenetriamine and 1,6-hexamethylenediamine). The influence of several synthesis parameters (e.g. type of encapsulated organic phase, monomer concentration(s) and concentration ratio of the two amine monomers) on the size distribution and morphology of the oil-containing polyamide microcapsules as well as on their electrolytic codeposition behaviour is discussed. As revealed by scanning electron microscopy analysis, the morphological characteristics of the microcapsules were affected to a great extent by the functionality of the water-soluble amine monomer. Furthermore, the composition of the core material of the microcapsules showed a marked influence on their stability upon aging in the Watts nickel plating bath. Finally, codeposition experiments using a laboratory rotating electrode showed that the level of codeposition was influenced by the presence of additives in the nickel electrolyte and was strongly dependent on the polymerization conditions employed in the microcapsule synthesis. ((orig.))

Alexandridou, S. [Aristotle Univ. of Thessaloniki (Greece). Dept. of Chem. Eng. and Chem. Process. Eng. Res. Inst.; Kiparissides, C. [Aristotle Univ. of Thessaloniki (Greece). Dept. of Chem. Eng. and Chem. Process. Eng. Res. Inst.; Fransaer, J. [Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, de Croylaan 2, B-3001 Leuven (Belgium); Celis, J.P. [Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, de Croylaan 2, B-3001 Leuven (Belgium)

1995-04-01

28

RHEOLOGICAL PHASE SYNTHESIS AND CHARACTERIZATION OF MICRO-SIZED Li4Ti5O12  

Directory of Open Access Journals (Sweden)

Full Text Available Zero-strain anode material of Li4Ti5O12 for lithium ion battery was successfully synthesized via the rheological phase reaction (RPR) method. The as-prepared powders were characterized by means of powder X-ray diffraction (XRD), scanning electron microscope (SEM) and particle size distribution analysis (PSD), and the electrochemical properties of the powders were evaluated by the galvanostatic discharge test and cyclic voltammetry (CV). The results revealed that well-crystallized uniform micro-sized Li4Ti5O12 powders were obtained at 800°C for different calcination times via the simple template-free rheological phase route. Among these RPR-derived Li4Ti5O12 powders, one synthesized at 800°C for 22 h displays the initial discharge capacity of 184.3 mAh/g and excellent characteristic of cyclic voltammetry.

LINGLING XIE; XIAOYU CAO; CHANGWEI LIU; CHIWEI WANG

2010-01-01

29

Synthesis and investigation of electric conductivity of solid electrolytes in the LaF3-La2O3 system  

International Nuclear Information System (INIS)

Synthesis and investigation of electroconductivity of solid electrolytes in the system LaF3-La2O3 have been carried out. Electronic conductivity has been estimated. The conclusion about pure ionic character of electroconductivity in the investigated solid electrolytes LaF3-La2O3 has been made. The range existence and temperatures of polymorphous phase transition of LaOnF3-2n have been found. 11 refs., 2 figs., 1 tab.

1994-01-01

30

Synthesis of Single Phase Hg-1223 High Tc Superconducting Films With Multistep Electrolytic Process  

CERN Document Server

We report the multistep electrolytic process for the synthesis of high Tc single phase HgBa2Ca2Cu3O8+? (Hg-1223) superconducting films. The process includes : i) deposition of BaCaCu precursor alloy, ii) oxidation of BaCaCu films, iii) electrolytic intercalation of Hg in precursor BaCaCuO films and iv) electrochemical oxidation and annealing of Hg-intercalated BaCaCuO films to convert into Hg1Ba2Ca2Cu3O8+? (Hg-1223). Films were characterized by thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrolytic intercalation of Hg in BaCaCuO precursor is proved to be a novel alternative to high temperature-high pressure mercuration process. The films are single phase Hg-1223 with Tc = 121.5 K and Jc = 4.3 x 104 A/cm2.

Shivagan, D D; Ekal, L A; Pawar, S H

2003-01-01

31

Synthesis and electrochemical properties of tin oxide-based composite by rheological technique  

Energy Technology Data Exchange (ETDEWEB)

Novel rheological technique was developed to synthesize tin oxide-based composites. The microstructure, morphology, and electrochemical performance of the materials were investigated by X-ray diffraction, scanning electron microscopy and electrochemical methods. The particles of tin oxide-based materials form an inactive matrix. The average size of the particles is about 150 nm. The material delivers a charge capacity of more than 570 mAh g{sup -1}. The capacity loss per cycle is about 0.15% after being cycled 30 times. The good electrochemical performance indicates that this kind of tin oxide-based material is promising anode for lithium-ion battery.

He Zeqiang [College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000 (China) and School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)]. E-mail: zeqianghe74@hotmail.com; Li Xinhai [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Xiong Lizhi [College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000 (China); Wu Xianming [College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000 (China); Xiao Zhuobing [College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000 (China); Ma Mingyou [College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000 (China)

2005-10-15

32

Design and synthesis of new electrolyte systems for lithium-ion batteries  

Science.gov (United States)

Rechargeable lithium-ion batteries are extensively used in consumer electronic products, including laptop computers, cellular phones, cameras, camcorders, and medical devices. They have great potential for application in electric and hybrid electric vehicles by virtue of their high energy and power density. Research and development in this direction have been focused all around the globe. The major challenges include the higher cost, safety issues related to the solvents, and conductivities at lower ambient temperature of the solvent-free solid polymer electrolyte (SPE) systems. In this dissertation, three different approaches are presented to achieve an improved electrolyte system for lithium-ion batteries. A plasticizer was synthesized and incorporated into a conventional poly(ethylene oxide) (PEO)-based solid polymer electrolyte system. The ambient temperature ionic conductivity observed at room temperature was noteworthy, due to the decrease of the glass transition temperature of the polymer. Secondly, a branched polymer was synthesized and used as the base matrix in SPEs. Polymers with a higher order of branching remained undissolved in common organic solvents, thereby limiting the scope of their use for making films for the study. The ones with a lower order of branching exhibited ionic conductivities comparable to regular PEO-based electrolytes. The third and most successful approach involved the strategic design and synthesis of a series of low lattice energy lithium salts and their chemical, thermal and electrochemical characterization. In this methodology, the two-to-three step synthetic strategy involved chlorosulfonation of an activated aromatic ring, reaction of the corresponding sulfonyl chloride with trifluoromethanesulfonamide in the presence of triethylamine as a base, followed by lithiation of the resulting triethylammonium salt to generate monolithium, dilithium and scaffolded polylithium salts. The mono- and dilithium salts were tested in electrolyte systems for SPEs, whereas the polylithium salts were characterized as potential candidates for liquid electrolyte systems. The tri-lithium salt based on triptycene proved to be the best of the lot. While all of them showed excellent thermal and electrochemical stability, the salt based on triptycene also demonstrated very good ambient temperature conductivity at low concentrations. The cycling characteristics observed, as well as lithium ion transference number measured with this salt, were impressive and equal to or exceed those for the currently best salt, lithium trifluromethanesulfonimide (LiTFSI).

Chakrabarti, Amartya

33

Interfacial Rheology  

CERN Document Server

This is the first book on interfacial rheology and aims to describe both its history as well as the current, most frequently used experimental techniques for studying dilational and shear rheology of layers at liquid/gas and liquid/liquid interfaces. The book opens with a chapter on the fundamentals of interfacial rheology. All (16) contributions include the theoretical basis for the presented methodologies and experimental examples are given.

Miller, R

2009-01-01

34

Synthesis of yttria-doped zirconia anodes and calcium-doped ceria electrolyte to fuel cell  

International Nuclear Information System (INIS)

From the pursuit of lower operating temperature of fuel cells solid oxide was used polymeric precursor for the synthesis of reactive powder compositions Zr0,92Y0,08O2 for the anode and Ce0,88Ca0,12O2 for the electrolyte. The solutions were prepared using the metal in much of the composition and citric acid molar ratio of 1:3, under stirring at 60 deg C/1 h. The mixture of metallic citrates was subjected to agitation at a temperature of 80 deg C which was added ethylene glycol in the ratio 60:40 by weight citric acid / ethylene glycol, to form a resin that was pre-calcined at 300 deg C/3 h for to form the expanded resin. The powders were disaggregated in a mortar, screened and calcined at 400, 600 and 800 deg C/2 h. The powders were characterized by standard X-ray diffraction. (author)

2010-01-01

35

Synthesis and Rheological Properties of an Associative Star Polymer in Aqueous Solutions  

DEFF Research Database (Denmark)

Rheological properties of aqueous solutions and hydrogels fonned by an amphiphiIic star block copolymer poly(acrylic acid)-blockpolystyrene (PAAS4-b-PS6)4. were investigated as a function of the polymer concentration (Cp), temperature, and added saIt concentration. The water-soluble polymer synthesised by atom transfer radical. polymerization (ATRP) was found to fonn hydrogels at room temperature at polymer concentrations. Cp, over 22 gIL due to the interpolymer drophobic association of the PS blocks. Increasing Cp leads to stronger elastic networks at room temperature that show a gel-to-solution transition with increasing temperature. Increase of ionic strength decreases the moduli compared with the pure hydrogel but did not affect the gel-sol transition temperature significantly. Small-angle X-ray experiments showed two distinct scattering correlation peaks for samples above the gelling Cp, which indicates the aggregates fonmed due to hydrophobic association. Upon heating the intensity of the scattering correlation peaks was found to decrease indicating the loss of the network structure due to thermal motion.

Hietala, Sami; Mononen, Pekka

2007-01-01

36

Synthesis, cure behavior, and rheological properties of fluorine-containing epoxy resins  

Energy Technology Data Exchange (ETDEWEB)

The fluorine-containing epoxy resin, 2-trifluorotoluene diglycidylether (FER) was prepared by reaction of 2-chloro-{alpha},{alpha},{alpha}-trifluorotoluene with glycerol diglycidylether in the presence of pyridine catalyst. Curing behavior of FER/DDM system was investigated using dynamic and isothermal DSC. Cure activation energy (E{sub a}) was determined by Flynn-Wall-Ozawa's equation. The rheological properties of FER/DDM system were studied under isothermal condition using a rheometer. Cross-linking activation energy (E{sub c}) was determined from the Arrhenius equation based on gel time and curing temperature. As a result, the chemical structure of FER was confirmed by FT-IR, {sup 13}C NMR, and {sup 19}F NMR spectroscopy. The cure activation energy of FER/DDM system was 53.4 kJ/mol and conversion rate were increased with the curing temperature. The cross-linking activation energy of FER/DDM system was 41.6 kJ/mol and gel time was decreased with the curing temperature. (author). 22 refs., 4 tabs., 9 figs.

Park, S.J.; Jin, F.L.; Lee, J.R. [Korea Research Institute of Chemical Technology, Taejeon (Korea); Shin, J.S. [Chungbuk National University, Chongju (Korea)

2002-05-01

37

Synthesis, extrusion and rheological behaviour of PU/HA composites for biomedical applications.  

UK PubMed Central (United Kingdom)

Biostable polyurethane/hydroxyapatite (PU/HA) composites with potential application as bone replacement materials were synthesized in bulk and processed in a screw extruder. The polyurethanes (PU) were prepared by reacting an aliphatic diisocyanate, 4-methylene-bis-diisocyanate (MDI), with poly-(epsilon-caprolactone) (PCL) diols and polytetramethylene oxide (PTMO) of different molecular weights, extended with 1, 4-butanediol (BDO). Glass-transition temperatures were measured by differential scanning calorimetry (DSC). The specific PU groups were assessed by total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The effects of polymer chemistry and filler content on the rheological behaviour were studied by oscillatory rheometry. Polymers with larger chain lengths showed higher viscosity and, for identical chain lengths, polyether urethanes seem to have higher viscosities than polyester based urethanes. A lubricating effect was found for composites containing 50% weight of filler, whereas at higher filler contents a solid-like behaviour was measured. Polymer chemistry seems to be affected by ageing but not so by the presence of filler. Ageing is characterized by a decrease in the concentration of hydrogen bonds involving between urethane linkages.

Machado HB; Correia RN; Covas JA

2010-07-01

38

Synthesis, extrusion and rheological behaviour of PU/HA composites for biomedical applications.  

Science.gov (United States)

Biostable polyurethane/hydroxyapatite (PU/HA) composites with potential application as bone replacement materials were synthesized in bulk and processed in a screw extruder. The polyurethanes (PU) were prepared by reacting an aliphatic diisocyanate, 4-methylene-bis-diisocyanate (MDI), with poly-(epsilon-caprolactone) (PCL) diols and polytetramethylene oxide (PTMO) of different molecular weights, extended with 1, 4-butanediol (BDO). Glass-transition temperatures were measured by differential scanning calorimetry (DSC). The specific PU groups were assessed by total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The effects of polymer chemistry and filler content on the rheological behaviour were studied by oscillatory rheometry. Polymers with larger chain lengths showed higher viscosity and, for identical chain lengths, polyether urethanes seem to have higher viscosities than polyester based urethanes. A lubricating effect was found for composites containing 50% weight of filler, whereas at higher filler contents a solid-like behaviour was measured. Polymer chemistry seems to be affected by ageing but not so by the presence of filler. Ageing is characterized by a decrease in the concentration of hydrogen bonds involving between urethane linkages. PMID:20405172

Machado, H B; Correia, Rui N; Covas, J A

2010-04-20

39

Synthesis, morphology and rheology of core-shell silicone acrylic emulsion stabilized with polymerisable surfactant  

Directory of Open Access Journals (Sweden)

Full Text Available Core-shell silicone acrylic emulsions with 3-methacryloxypropyl trimethoxysilane (MPTS) in the shell were prepared by seeded polymerization with the assistance of polymerisable maleate surfactant (MT). Fourier transform infrared (FT-IR) demonstrated the incorporation of polymerisable surfactant in copolymer. It was found that small amount of octadecyl acrylate was beneficial to emulsion stability with decreasing the particle size from 194.6 to 165.7 nm. It was also found that the particle size increased from 165.7 to 242.9 nm with the increase of MPTS concentration. Furthermore, rheological measurement indicated that the emulsion was endowed with pseudoplasticity. At low shear rate, marginal reduction in viscosity was detected when MPTS concentration increased to 2%, while great increase in viscosity was observed with higher MPTS concentration, the interaction force among emulsion particles became the predominant factor instead of particle size. In addition, better water resistance was observed when MT concentration was lower than 1.5%, and MPTS concentration higher than 2%. Moreover, surface roughness was increased with MPTS addition, the crosslinking among core and shell reconstructed the surface morphology of film.

2010-01-01

40

Influence of a singly-charged electrolyte on the efficiency of solubilization compositions for the template synthesis of silica nanoadsorbents  

Science.gov (United States)

Silica mesoporous materials of the MSM-41 type were obtained by bitemplate (solubilization) synthesis in an aqueous electrolyte solution (sodium chloride) using sodium metasilicate as the source of silica, alkylpyridinium halogenides as the micelle-forming surfactants, and monoethanoamides of n-aliphatic acids or trialkylphosphine oxides as the solubilizers. The influence of a singly-charged electrolyte and a solution of bitemplate composition on the X-ray structure and structure adsorption characteristics of the synthesized materials was analyzed. It was shown that mesoporous silica with better spatial structure and high specific surface values ( S sp = 1170-1200 m2/g, ? V = 0.80-1.10 cm3/g, D meso = 3.5-4.1 nm) are formed under the investigated conditions of synthesis when alkylpyridinium halogenides with a length of a hydrocarbon radical consisting of 10, 12, or 14 carbon atoms are used.

Yaroshenko, N. A.; Trofimenko, S. I.; Govorek, Ya.; Zub, Yu. L.

2010-08-01

 
 
 
 
41

Computational rheology  

CERN Multimedia

Modern day high-performance computers are making available to 21st-century scientists solutions to rheological flow problems of ever-increasing complexity. Computational rheology is a fast-moving subject - problems which only 10 years ago were intractable, such as 3D transient flows of polymeric liquids, non-isothermal non-Newtonian flows or flows of highly elastic liquids through complex geometries, are now being tackled owing to the availability of parallel computers, adaptive methods and advances in constitutive modelling.Computational Rheology traces the development of numerical methods fo

Owens, RG

2002-01-01

42

Reactions with ZrO(NO3)2 in the synthesis of solid electrolytes of the NASICON type  

International Nuclear Information System (INIS)

[en] The process of NASICON solid phase synthesis is studied in detail. Solid phase reactions during the synthesis of solid electrolytes of the NASICON type taking place with zirconium dinitrate-oxide end at 300-400 deg C,i.e.before the teransition of appearing zirconium dioxide into the stable monoclinic modification The presense of the nitrate group brings about the decrease in the temperature of intensive decomposition of sodium carbonate and nitrate and sodium zirconate formation close to 180 deg C

1987-01-01

43

Synthesis of Bismuth Oxide Based Material for Sofc Electrolyte with Yttria addictive and their Characterization  

International Nuclear Information System (INIS)

Research on synthesis of solid electrolyte SOFC based on bismuth oxide and yttrium oxide as dopant has been done through pressing technique process, where bismuth oxide and yttrium oxide chloride are as its raw materials. Both of materials are dissolved and then co-precipitated to get a mixture material which has very small grain size (nm), continued with sintering process with temperature variation of 1000 oC, 1050 oC, 1100oC and holding time of 1 hour. The result of this process is analyzed by dilatometer at room temperature until 1000 oC, which gave the coefficient of thermal expansion of 11.9 x 10-6/ oC to 13.4 x 10-6/ oC. The measurement of density by Archimedes method (ASTM D 792), gave the value of density of 6.2 g/cm3 until 7.6 g/cm3. Using ASTM C20 procedure, the porosity measured are 18.3 % until 0.2 %. The Impedance complex spectroscopy and Frequency Response Analyzer (FRA) Solartron 1260 is used for measuring ionic conductivity. The ionic conductivity are increasing on temperature range 500 oC until 800 oC, which are 5 x 10-3/ ?.cm to 1.8 x I0-1/ ?.cm. The yttrium oxide dopant increased bismuth oxide ionic conductivity for 10 times until 1000 times. (author)

2008-01-01

44

Synthesis and electrochemical characterization of PEO-based polymer electrolytes with room temperature ionic liquids  

International Nuclear Information System (INIS)

New gel polymer electrolytes containing 1-butyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide (BMPyTFSI) ionic liquid are prepared by solution casting method. Thermal and electrochemical properties have been determined for these gel polymer electrolytes. The addition of BMPyTFSI to the P(EO)20LiTFSI electrolyte results in an increase of the ionic conductivity, and at high BMPyTFSI concentration (BMPy+/Li+ = 1.0), the ionic conductivity reaches the value of 6.9 x 10-4 S/cm at 40 oC. The lithium ion transference numbers obtained from polarization measurements at 40 oC were found to decrease as the amount of BMPyTFSI increased. However, the lithium ionic conductivity increased with the content of BMPyTFSI. The electrochemical stability and interfacial stability for these gel polymer electrolytes were significantly improved due to the incorporation of BMPyTFSI.

2007-05-25

45

Synthesis and Characterization of Triazolium Iodide Ionic Liquid Electrolyte for Dye Sensitized Solar Cells  

Energy Technology Data Exchange (ETDEWEB)

Imidazolium iodide compounds have been utilized in the electrolytes for dye sensitized solar cells (DSSC). Most of the investigations with these compounds focus on the formulation of eutectic mixtures that promote efficient dissociation and diffusion of the iodide and triiodide species. Facile alternative synthetic approaches such as click chemistry (Huisgen 3+2 dipolar cycloaddition reaction) can be utilized to broaden the scope of electrochemically stable promising materials for novel electrolyte systems. Here, we report the first example of a triazolium functionalized cyclic siloxane that can be used as an electrolyte component in solvent-based DSSCs. The devices fabricated with this new triazolium salt in the electrolyte yielded short circuit current densities (26 mA/cm{sup 2}), as well as power conversion efficiencies of 8%, these values are comparable to those obtained for imidazolium salt analogues.

Kokil, Akshay; Renna, A.; Kumar, Jayant; Granados-Focil, S.

2011-01-01

46

Synthesis and electrochemical properties of lithium methacrylate-based self-doped gel polymer electrolytes  

International Nuclear Information System (INIS)

In this study, a strategy for synthesizing lithium methacrylate (LiMA)-based self-doped gel polymer electrolytes was described and the electrochemical properties were investigated by impedance spectroscopy and linear sweep voltammetry. LiMA was found to dissolve in ethylene carbonate (EC)/diethyl carbonate (DEC) (3/7, v/v) solvent after complexing with boron trifluoride (BF3). This was achieved by lowering the ionic interactions between the methacrylic anion and lithium cation. As a result, gel polymer electrolytes consisting of BF3-LiMA complexes and poly(ethylene glycol) diacrylate were successfully synthesized by radical polymerization in an EC/DEC liquid electrolyte. The FT-IR and AC impedance measurements revealed that the incorporation of BF3 into the gel polymer electrolytes increases the solubility of LiMA and the ionic conductivity by enhancing the ion disassociations. Despite the self-doped nature of the LiMA salt, an ionic conductivity value of 3.0 x 10-5 S cm-1 was achieved at 25 deg. C in the gel polymer electrolyte with 49 wt% of polymer content. Furthermore, linear sweep voltammetry measurements showed that the electrochemical stability of the gel polymer electrolyte was around 5.0 V at 25 deg. C.

2009-07-30

47

Synthesis of polymer gel electrolyte with high molecular weight poly(methyl methacrylate)-clay nanocomposite  

International Nuclear Information System (INIS)

Polymer nanocomposite gel electrolytes consisting of high molecular weight poly(methyl methacrylate) PMMA-clay nanocomposite, ethylene carbonate (EC)/propylene carbonate (PC) as plasticizer, and LiClO4 electrolyte are reported. Montmorillonite clay was ion exchanged with a zwitterionic surfactant (octadecyl dimethyl betaine) and dispersed in methyl methacrylate, which was then polymerized to synthesize PMMA-clay nanocomposites. The nanocomposite was dissolved in a mixture of EC/PC with LiClO4, heated and pressed to obtain polymer gel electrolyte. X-ray diffraction (XRD) of the gels indicated intercalated clay structure with d-spacings of 2.85 and 1.40 nm. In the gel containing plasticizer, the clay galleries shrink suggesting intercalation rather than partial exfoliation observed in the PMMA-clay nanocomposite. Ionic conductivity varied slightly and exhibited a maximum value of 8 x 10-4 S/cm at clay content of 1.5 wt.%. The activation energy was determined by modeling the conductivity with a Vogel-Tamman-Fulcher expression. The clay layers are primarily trapped inside the polymer matrix. Consequently, the polymer does not interact significantly with LiClO4 electrolyte as shown by FTIR. The presence of the clay increased the glass transition temperature (Tg) of the gel as determined by differential scanning calorimetry. The PMMA nanocomposite gel electrolyte shows a stable lithium interfacial resistance over time, which is a key factor for use in electrochemical applications.

2004-10-30

48

SYNTHESIS OF A NEW FAMILY OF FLUORINATED BORONATE COMPOUNDS AS ANION RECEPTORS AND STUDIES OF THEIR USE AS ADDITIVES IN LITHIUM BATTERY ELECTROLYTES.  

Energy Technology Data Exchange (ETDEWEB)

Numerous studies have been done on developing new electrolytes for lithium batteries with high ionic conductivity, and good chemical and electrochemical stability. In addition to the research on new salts and solvents, the use of cation receptors to reduce ion pairing in non-aqueous electrolytes has been considered as an approach to improve the properties of electrolytes. Although both cation and anion receptors enhance the dissociation of ion pairs and increase the conductivity of electrolytes, the use of anion receptors is more attractive for a lithium battery electrolyte because anion receptors increase the lithium transference number in the electrolyte. However, most available neutral anion receptors complex with anions through hydrogen binding and cannot be used in lithium batteries. Recently, we have reported on synthesis of a series of new neutral boron compounds as anion receptors based on the idea that electron-deficient boron would complex the anion of the ion pair. The anion complexation effect of these boron compounds was further enhanced by attaching electron-withdrawing groups. Here we report synthesis of another new family of boronate compounds. The effect of these new compounds on conductivity of lithium salts in non-aqueous solution was studied. The molecular weights of these new boronate compounds are lower than our previously reported boron compounds. Therefore, their effects on conductivity enhancement are superior. They also display high electrochemical stability up to 5 V.

MCBREEN,J.; LEE,H.S.; YANG,X.Q.

2001-06-08

49

Synthesis of a Lewis-acidic boric acid ester monomer and effect of its addition to electrolyte solutions and polymer gel electrolytes on their ion transport properties  

International Nuclear Information System (INIS)

A polymerizable anion receptor based on a boric acid ester was synthesized. When the anion receptor was added to different electrolyte solutions consisting of an aprotic solvent and a lithium salt, the ionic conductivity of certain electrolyte solutions, composed of low polar solvents or salts with low dissociation abilities, was enhanced appreciably. Viscosity measurements for the electrolyte solutions, with and without the added anion receptor, indicated that the conductivity enhancement was caused by an increase in the ionic dissociation due to the addition of the anion receptor. Pulse-field-gradient spin-echo (PGSE) NMR and 11B-NMR spectra supported that the ionic dissociation was facilitated by interaction between the Lewis-acidic anion receptor and Lewis-basic anions. The polymerizable anion receptor was crosslinked with a polyether macromonomer in different electrolyte solutions. Ionic conductivity of the resulting polymer gel electrolytes was also altered like that of the electrolyte solutions containing the anion receptor monomer.

2003-06-30

50

Synthesis of nano-sized electrolyte materials of SOFC by gel combustion route  

International Nuclear Information System (INIS)

A typical SOFC operating at high temperature utilizes cubic yttria-stabilized zirconia (YSZ) as the electrolyte because it fulfils several desired criteria (high ionic conductivity, low or nearly zero electronic conductivity and rational strength to stand the mechanical and thermal stresses). High-temperature operation (about 1000 deg C) causes many serious problems, i.e. degradation of the cell performance and a limited choice of materials and so on, hence it is desirable to operate SOFCs at a moderate temperature around 800 deg C. In order to explore alternate electrolytes, other rare earth (La, Nd and Gd) substituted zirconia were prepared by gel combustion and co-precipitation route to produce homogeneous, very fine, crystalline and unagglomerated powders, without the intermediate decomposition step. Most of these electrolyte materials are synthesized using traditional solid state techniques with sintering at 1600-1650 deg C leading to densities of less than 95% which normally reduces ionic conductivity of the electrolytes. The structural characterizations of prepared sample were done by powder XRD and thermal expansion data was generated by dilatometric studies

2008-01-01

51

Proton-conducting polymer electrolyte membranes based on fluoropolymers incorporating perfluorovinyl ether sulfonic acids and fluoroalkenes: synthesis and characterization  

Energy Technology Data Exchange (ETDEWEB)

This paper presents the synthesis of new polymer electrolyte membranes based on fluoropolymers incorporating aromatic perfluorovinyl ether sulfonic acids. A novel synthetic route describing the preparation of perfluorovinyl ether monomer containing sulfonic functionalities, 4-[({alpha},{beta},{beta}-trifluorovinyl)-oxy]benzene sulfonic acid (TFVOBSA), is reported. The radical (co) and terpolymerisation of 4-[({alpha},{beta},{beta}-trifluorovinyl)oxy]benzene sulfonyl chloride (TFVOBSC) with 1,1-difluoroethylene (or vinylidene fluoride, VDF), hexafluoropropene (HFP), and perfluoromethyl vinyl ether (PMVE) is described. The terpolymers of TFVOBSC with VDF and HFP, or VDF and PMVE, were hydrolysed and also led to new fluorinated terpolymers bearing sulfonic acid aromatic side-groups. The terpolymers were characterized by {sup 1}H and {sup 19}F NMR spectroscopies, SEC, DSC, and TGA. Membranes incorporating these functional fluoropolymers were prepared and the electrochemical properties (IEC, proton conductivity, swelling rates) were studied and discussed. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

Souzy, R.; Ameduri, B.; Boutevin, B. [Laboratory of Macromolecular Chemistry, UMR (CNRS) 5076, Ecole Nationale Superieure de Chimie de Montpellier, 8 Rue Ecole Normale, 34296 Montpellier Cedex 5 (France); Capron, P.; Marsacq, D. [CEA, DTEN/SCSE/LSME, 17 rue des Martyrs, 38054 Grenoble Cedex (France); Gebel, G. [CEA, DRFMC/SI3M, 17 rue des Martyrs, 38054 Grenoble Cedex (France)

2005-08-01

52

Synthesis of polymeric pour point depressants for Nada crude oil (Gujarat, India) and its impact on oil rheology  

Energy Technology Data Exchange (ETDEWEB)

Five flow improvers have been synthesized to study rheological properties of Nada crude oil (Gujarat, India). Anhydride copolymers were prepared making use of the copolymerization of acrylates of different alkyls with maleic anhydride and the Poly (n-alkyl acrylates-co-N-hexadecylmaleimide) were prepared by the reaction of copolymer with hexadecylamine. The additives were purified and characterized by FTIR, GPC. The prepared polymeric additives shows dual function both as wax dispersants and flow improvers and all of them acts as good pour point depressants. Yield stress and the viscosity of the crude oil at different temperatures and concentrations of additives were evaluated by zero friction advanced rheometer AR-500 of TA instrument. Comparison of morphologies and structures of wax crystals or aggregates in waxy crude oils beneficiated with and without a PPD was also done by micro photographic studies which show the modification in wax crystal morphology due to additives. (author)

Deshmukh, Srushti; Bharambe, D.P. [Department of Applied Chemistry, Faculty of Technology and Engineering, The Maharaja Sayajirao University of Baroda, Kalabhavan, VADODARA-390 001, Gujarat (India)

2008-03-15

53

Facile synthesis of supramolecular ionic polymers that combine unique rheological, ionic conductivity, and self-healing properties.  

UK PubMed Central (United Kingdom)

A new family of supramolecular ionic polymers is synthesized by a simple method using (di-/tri-)carboxylic acids and (di-/tri-)alkyl amines. These polymers are formed by carboxylate and ammonium molecules that are weakly bonded together by a combination of ionic and hydrogen bonds, becoming solid at room temperature. The supramolecular ionic polymers show a sharp rheological transition from a viscoelastic gel to a viscous liquid between 30 and 80 °C. This sharp viscosity decrease is responsible for an unprecedented jump in ionic conductivity of four orders of magnitude in that temperature range. As a potential application, this chemistry can be used to develop polymeric materials with self-healing properties, since it combines properties from supramolecular polymers and ionomers into the same material.

Aboudzadeh MA; Muñoz ME; Santamaría A; Marcilla R; Mecerreyes D

2012-02-01

54

Synthesis and rheological investigation of a magnetic fluid using olivary silica-coated iron particles as a precursor  

International Nuclear Information System (INIS)

[en] A new type of magnetic fluid was prepared by dispersing monodispersed iron-silica (Fe-SiO2) composite particles in polyethylene glycol (PEG) 400. The composite particles Fe-SiO2 were synthesized by hydrogen reduction from ?-Fe2O3-SiO2 spheres. Their microstructures were observed by a high-resolution transmission electron microscope (HRTEM) and the magnetism was characterized with a superconducting quantum interference device (SQUID) magnetometer. Both steady-state and dynamic rheological properties of the magnetic fluid under different magnetic fields were studied by using a rheometer. Experimental results show that this magnetic fluid has a relatively high magnetoviscous effect at low shear rates. The yield stress of this material shows an increasing trend with a magnetic flux density. Also, viscoealstic properties of such materials are different from conventional ones

2008-01-01

55

Synthesis and characterisation of poly(methylalkoxysiloxane) solid polymer electrolytes incorporating different lithium salts  

Energy Technology Data Exchange (ETDEWEB)

Two comb polymers with oligo-oxyethylene side chains of the type -O-(CH{sub 2}-CH{sub 2}-O){sub n}-CH{sub 3} were prepared from poly(methylhydrosiloxane) (PMHS). Homogeneous polymer electrolytes were made from the two synthesised polymers and four lithium salts having different chemical structures, such as lithium perchlorate (LiClO{sub 4}), lithium trifluoromethanesulfonate (LiCF{sub 3}SO{sub 3}), lithium hexafluorophosphate (LIPF{sub 6}) and lithium bis (trifluoromethane sulfonylimide) (LiN(SO{sub 2}CF{sub 3}){sub 2}) by solvent casting method, and their thermal, electrical and electrochemical properties measured as a function of temperature. Results indicate that polymer electrolyte complexes are amorphous materials, and that its properties depend on the oligo-oxyethylene chain length as well as on the chemical nature of the lithium salt. (author)

Morales, E.; Acosta, J.L. [Instituto de Ciencia y Tecnologia de Polimeros, Madrid (Spain)

2000-07-01

56

Studies on synthesis and characterizations of gadolinium doped ceria as solid electrolyte  

International Nuclear Information System (INIS)

Due to need of pollution-free and efficient-power-generation devices, in past few years, pace of research has been rapidly driven by fuel cell technology. The thesis contributes in the same regard, in which conventional solid electrolyte of solid oxide fuel cell is replaced by alternate material (Gd-doped-Ceria-GDC) and its performance has been tested. The process parameters of ceramic route and spray-pyrolysis-technique were optimized to obtain dense 'electrolyte-grade' GDC-bulk and thin-film samples, respectively. In symmetrical cell configuration, GDC-bulk sample showed open-circuit-voltage of 0.84 volts at 500 deg C. The grain interior conductivity of 13 ?m GDC-film deposited onto electrode-grade NiO-GDC substrate is ?0.1S/cm at 500 deg C. (author)

2009-01-01

57

Synthesis and characterization of an electrolyte system based on a biodegradable polymer  

Directory of Open Access Journals (Sweden)

Full Text Available A polymer electrolyte system has been developed using a biodegradable polymer namely poly-?-caprolactone (PCL) in combination with zinc triflate [Zn(CF3SO3)2] in different weight percentages and characterized during this investigation. Free-standing thin films of varying compositions were prepared by solution casting technique. The successful doping of the polymer has been confirmed by means of Fourier transform infrared spectroscopy (FTIR) by analyzing the carbonyl (C=O) stretching region of the polymer. The maximum ionic conductivity obtained at room temperature (25°C) was found to be 8.8x10–6 S/cm in the case of PCL complexed with 25 wt% Zn(CF3SO3)2 which is five orders of magnitude higher than that of the pure polymer host material. The increase in amorphous phase with an increase in salt concentration of the prepared polymer electrolyte has also been confirmed from the concordant results obtained from X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopic (SEM) analyses. Furthermore, the electrochemical stability window of the prepared polymer electrolyte was found to be 3.7 V. An electrochemical cell has been fabricated based on Zn/MnO2 electrode couple as an application area and its discharge characteristics were evaluated.

K. Sownthari; S. A. Suthanthiraraj

2013-01-01

58

Synthesis and microstructural characterization of Sr- and Mg-substituted LaGaO3 solid electrolyte  

International Nuclear Information System (INIS)

Sr and Mg substituted LaGaO3 is a solid electrolyte for intermediate temperature solid oxide fuel cell. Phase purity of this material is a concern for the researchers for a long time. In this contribution the secondary phases that are evolved during the synthesis of Sr and Mg doped LaGaO3 are reported. For that purpose, a series of La1-xSr xGa1-yMgyO3-? (LSGM) was prepared by solid state synthesis route. Scanning electron microscopic photographs showed secondary phases namely La4Ga2O9, LaSrGa3O7, LaSrGaO4 along with the parent perovskite LSGM depending upon the amount of dopant. Amount of secondary phases was estimated from the peak positions of room temperature X-ray diffraction. It was observed that for a fixed amount of Mg dopant increasing the amount of Sr content also increased the amount of secondary phases whereas the reverse was found to be true when Sr content was fixed and Mg content was increased. This behaviour was attributed to the increase in solid solubility of Sr in presence of Mg

2007-04-15

59

Synthesis, rheological behavior and swelling properties of copolymer hydrogels based on poly(N-isopropylacrylamide) with hydrophilic monomers  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, hydrogels of poly(N-isopropylacrylamide-co-acrylamide) and poly(N-isopropylacrylamide-co-acrylic acid) having a thermoresponsive character were prepared by aqueous free-radical co-polymerization using the ammonium persulfate/N,N,N',N'-tetramethylethylenediamine (APS/TEMED) redox-pair initiator system in the presence of N,N'-methylenebisacrylamide (MBAAm) crosslinker. (NIPAAm-co-AAm) and (NIPAAm-co-AAc) hydrogels with different thermoresponsive properties were obtained by fixing the initial NIPAAm/AAm mole ratio and and (NIPAAm-co-AAc) mole ratio to 80/20 and changing the crosslinker concentration. The copolymers were characterized with infrared spectroscopy (IR) and differential scanning calorimetry (DSC) techniques. The swelling response of the copolymers networks as a function of time, temperature and swelling environment has been observed to be dependent on both structural aspects of the polymers and swelling environment. The swelling has been observed to be decrease with increase in MBAAm in the copolypolymers networks. Rheological behavior was studies in oscillatory module. All copolymers have a viscoelastic behaviour. We note that the elastic modulus G' increases with increasing hydrophilic monomers.DOI: http://dx.doi.org/10.4314/bcse.v27i3.14

N. Seddiki; D. Aliouche

2013-01-01

60

Synthesis and conductivity of proton-electrolyte membranes based on hybrid inorganic-organic copolymers  

International Nuclear Information System (INIS)

A class of new proton-electrolyte membranes (PEM) based on inorganic-organic copolymers were synthesized from 3-glycidoxypropyltrimethoxysilane (GPTS), sulfonated phenyltriethoxysilane (SPS), tetraethoxysilane (TEOS) and H3PO4. Their thermal stability, microstructure, and proton conductivity were investigated under the conditions for PEM fuel cell operation. TGA-DSC analysis indicated that these membranes are thermally stable up to 180 deg. C. Scanning electron microscope (SEM) micrographs show that the membranes are dense. A proton conductivity of 1.6x10-3 S/cm was observed at 100 deg. C in a dry atmosphere for a sample with 0.5 mol GPTS and 1 mol H3PO4 in 1 mol Si, representing the highest proton conductivity in anhydrous state among PEMs ever reported. In an environment with 15% relative humidity (RH), the proton conductivity increased to 3.6x10-2 S/cm at 120 deg. C. The proton conductivity increases with H3PO4 contents and relative humidity. The hybrid inorganic-organic materials can be readily fabricated in membrane form with thickness as thin as 20 ?m on porous electrodes; they have great potential to be used as the electrolytes for high-temperature PEM fuel cells.

2003-12-15

 
 
 
 
61

Synthesis of yttria-doped bismuth oxide powder by carbonate coprecipitation for IT-SOFC electrolyte.  

UK PubMed Central (United Kingdom)

Yttria-doped bismuth oxide (YBO) powders were synthesized by ammonium carbonate coprecipitation for the preparation of electrolytes of an intermediate temperature solid oxide fuel cell (IT-SOFC). The starting salts were yttrium and bismuth nitrate. The crystal structures and the morphological characteristics of the particles were analyzed by XRD and SEM, respectively. The ionic conductivity of the sintered pellet was measured by an electrochemical impedance analyzer. The size of the calcined YBO powders were in the range of 20-100 nm as measured by SEM images. The YBO pellets had a face-centered cubic structure, and their crystallite size was about 54-88 nm. The ionic conductivity of the YBO pellets sintered at 800 degrees C was observed to be 2.7 x 10(-1) Scm-(-1) at 700 degrees C. The ball-milling of the YBO powder before it was pelletized was found to have been unrequired probably because of a good sinterability of the YBO powders that was prepared via the ammonium carbonate coprecipitation method. The results showed that the ammonium carbonate coprecipitation process could be used as the cost-efficient method of producing YBO electrolytes for IT-SOFC.

Lee JG; Kim SH; Yoon HH

2011-01-01

62

Synthesis of yttria-doped bismuth oxide powder by carbonate coprecipitation for IT-SOFC electrolyte.  

Science.gov (United States)

Yttria-doped bismuth oxide (YBO) powders were synthesized by ammonium carbonate coprecipitation for the preparation of electrolytes of an intermediate temperature solid oxide fuel cell (IT-SOFC). The starting salts were yttrium and bismuth nitrate. The crystal structures and the morphological characteristics of the particles were analyzed by XRD and SEM, respectively. The ionic conductivity of the sintered pellet was measured by an electrochemical impedance analyzer. The size of the calcined YBO powders were in the range of 20-100 nm as measured by SEM images. The YBO pellets had a face-centered cubic structure, and their crystallite size was about 54-88 nm. The ionic conductivity of the YBO pellets sintered at 800 degrees C was observed to be 2.7 x 10(-1) Scm-(-1) at 700 degrees C. The ball-milling of the YBO powder before it was pelletized was found to have been unrequired probably because of a good sinterability of the YBO powders that was prepared via the ammonium carbonate coprecipitation method. The results showed that the ammonium carbonate coprecipitation process could be used as the cost-efficient method of producing YBO electrolytes for IT-SOFC. PMID:21446553

Lee, J G; Kim, S H; Yoon, H H

2011-01-01

63

Microwave-assisted synthesis of PTFE/C nanocomposite for polymer electrolyte fuel cells  

Energy Technology Data Exchange (ETDEWEB)

Carbon black supported polytetrafluoroethylene (PTFE/C) nanocomposite is synthesized by an intermittent microwave irradiation (IMI) method for polymer electrolyte fuel cells (PEFC), using PTFE emulsion as the precursor. The synthesized PTFE/C composite is characterized by uniformly distributed and nano-sized PTFE/C particles without additional high temperature treatment and mechanical milling under liquid nitrogen frozen conditions. Incorporation of the PTFE/C nanocomposite into a Pt/C/Nafion catalyst significantly enhances the mass transportation of the catalyst layer without any adverse effect on the electrocatalytic activity of the Pt catalysts. The power output of the cell with a Pt/C/Nafion-PTFE/C composite cathode is 0.66Wcm{sup -2}, which is 32% higher than that of the cell with a Pt/C/Nafion cathode without the incorporation of the PTFE/C nanocomposite. (author)

Tian, Zhi Qun; Jiang, San Ping [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Wang, Xiao Li; Zhang, Hua Min; Yi, Bao Lian [Fuel Cell Engineering Centre, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 113023 (China)

2006-07-15

64

Synthesis and Properties of Acyclic Ammonium-based Ionic Liquids with Allyl Substituents as Electrolytes  

Directory of Open Access Journals (Sweden)

Full Text Available Several new acyclic ammonium-TFSI ionic liquids with an allyl substituent(s) were synthesized and their physicochemical and electrochemical properties were characterized. [AAMM]Am-TFSI (3) with two allyl groups showed the widest electrochemical stability window (5.9 V) among the ammonium-based ILs reported to date because of the increment of both the anodic and cathodic limits. The charge-discharge performance of a LiCoO2-based half-cell containing [AAMM]Am-TFSI as an electrolyte was better in cycleability (the capacity retention ratio: 99% after 20 cycles) than that of the cell with the corresponding partially saturated analogue, [AMMP]Am-TFSI (2) (the capacity retention ratio: 92% after 20 cycles).

Taeeun Yim; Chang Young Choi; Junyoung Mun; Seung M. Oh; Young Gyu Kim

2009-01-01

65

Alkali Influence on Synthesis of Solid Electrolyte Based on Alkali Nitrate-Alumina  

International Nuclear Information System (INIS)

Research of solid electrolyte based on alumina with addition of alkali materials of barium nitrate, calcium nitrate, sodium nitrate and lithium nitrate has been done. Aluminium hydroxide and alkali nitrate were mixed in mole ratio of 1 : 1 in water media and pyrolyzed at 300oC for 1 hour Pyrolysis result were then mixed with alumina in mole ratio of 1 : 1, compacted and heated at 600oC for 3 hours. To characterize the sample, XRD (X-Ray Diffractometers) and LCR meter (impedance, capacitance, and resistance) were used for analysis the phase and conductivity properties. The result showed formation of alkali-aluminate in which Li-base have the highest room temperature conductivity of 3.1290 x 10-5 S.cm-1, while Ba-base have the lowest conductivity of 5.7266 x 10-8 S.cm-1. (author)

2008-01-01

66

Advances in rheology  

Energy Technology Data Exchange (ETDEWEB)

Over 380 papers are presented collected in four volumes: Theory, Fluids, Polymers, and Applications. The papers are further divided into sections on: general theory, numerical analysis, fluids, suspensions, solids, melts, polymer processing, composites, rheometry, bio-rheology, food rheology, and petroleum rheology. All relevant papers have been abstracted separately.

Mena, B.; Garcia-Rejon, A.; Rangel-Nafaile, C. (eds.)

1984-01-01

67

Paint rheology. Toryo no rheology  

Energy Technology Data Exchange (ETDEWEB)

This paper summarizes paint compositions (resins, pigments, additives, and solvents), and their different coating and painting methods. The paper then describes the following matters on rheological measurement of paints: Because a paint goes through a wide shear velocity region during a coating process, its viscosity behavior changes largely through change in the state of dispersion as a dispersion system. Measurement of paint aqueous solutions is divided into measurements in low, medium, and high shear velocity regions, each region being measured with measuring methods and devices suitable for a particular region. Measurement of a paint during its film forming process is difficult because of increase in non-volatile matters due to evaporation of solvents, and effects of the hardening reaction, hence dynamic visco-elasticity measurement is carried out mainly. Paint films are measured generally by tensile tests and dynamic visco-elasticity measurements. The paper introduces a low shear viscometer, an improved viscometer for low shear regions, and an FT-Rm, an improved rheometer for dynamic visco-elasticity measurement. 4 refs., 7 figs.

Ueda, T. (Nippon Paint Co. Ltd., Tokyo (Japan))

1993-11-01

68

Electrolytes for electrolytic decontamination  

International Nuclear Information System (INIS)

Purpose: To improve the current efficiency and the mirror smoothness at the electrolyzed surface in the case of electrolytically decontaminating radioactive metal wastes. Constitution: In electrolytes for use in electrolytic decontamination upon electrolytically decontaminating radioactive metal wastes generated from nuclear facilities, sodium fluoride at a concentration between 1 wt% and its solubility limit is added to an aqueous 5 % sulfuric acid solution. This can provide the following advantageous effects: (1) high current efficiency can be obtained for the electrolysis even at ambient temperature to eliminate the requirement for the heating facility. (2) The mirror smoothness that facilitates the use after the decontamination can be improved. (3) After the use, the liquid wastes can be processed as they are in existent waste processing facilities. (4) Since the operation is conducted at an ambient temperature, objects can easily be recovered from the electrolysis vessel. (Takahashi, M.).

1986-12-15

69

Synthesis of coral-like tantalum oxide films via anodization in mixed organic-inorganic electrolytes.  

UK PubMed Central (United Kingdom)

We report a simple method to fabricate nano-porous tantalum oxide films via anodization with Ta foils as the anode at room temperature. A mixture of ethylene glycol, phosphoric acid, NH4F and H2O was used as the electrolyte where the nano-porous tantalum oxide could be synthesized by anodizing a tantalum foil for 1 h at 20 V in a two-electrode configuration. The as-prepared porous film exhibited a continuous, uniform and coral-like morphology. The diameters of pores ranged from 30 nm to 50 nm. The pores interlaced each other and the depth was about 150 nm. After calcination, the as-synthesized amorphous tantalum oxide could be crystallized to the orthorhombic crystal system. As observed in photocatalytic experiments, the coral-like tantalum oxide exhibited a higher photocatalytic activity for the degradation of phenol than that with a compact surface morphology, and the elimination rate of phenol increased by 66.7%.

Yu H; Zhu S; Yang X; Wang X; Sun H; Huo M

2013-01-01

70

Synthesis, processing and characterization of calcia-stabilized zirconia solid electrolytes for oxygen sensing applications  

International Nuclear Information System (INIS)

Precursor powders of calcia-stabilized zirconia (CSZ) solid electrolytes have been synthesized by a sol-gel method. The phase evolution of the precursor powders after thermal treatments at different temperatures were analysized by X-ray diffraction technique. Disc-shaped sensor elements were fabricated via uniaxial pressing of the calcined powders and subsequently sintered at 1650 deg. C. Scanning electron microscopy (SEM) was used to analyze the microstructure of the sintered pellets. Platinum electrodes were applied to the sintered elements to produce potentiometric/electrochemical gas sensors. The electrical response of the gas sensors to oxygen and the complex impedance of the sensors in air were measured at various temperatures. Impedance analyses indicate that the sensor cell with 15 mol% CaO has much lower resistance (the sum of bulk and grain-boundary resistance) than the sensor cell with 22 mol% CaO. This is also reflected by the EMF responses of both sensor cells to various oxygen concentrations in the testing gas. The EMF deviation from the theoretical value of the CSZ sensor cell with 22 mol% CaO was larger than that of the CSZ sensor cell with 15 mol% CaO. The corrrelations between material compositions, microstructures of the sintered pellets and the electrical properties of the sensors are discussed.

2006-04-13

71

Synthesis of coral-like tantalum oxide films via anodization in mixed organic-inorganic electrolytes.  

Science.gov (United States)

We report a simple method to fabricate nano-porous tantalum oxide films via anodization with Ta foils as the anode at room temperature. A mixture of ethylene glycol, phosphoric acid, NH4F and H2O was used as the electrolyte where the nano-porous tantalum oxide could be synthesized by anodizing a tantalum foil for 1 h at 20 V in a two-electrode configuration. The as-prepared porous film exhibited a continuous, uniform and coral-like morphology. The diameters of pores ranged from 30 nm to 50 nm. The pores interlaced each other and the depth was about 150 nm. After calcination, the as-synthesized amorphous tantalum oxide could be crystallized to the orthorhombic crystal system. As observed in photocatalytic experiments, the coral-like tantalum oxide exhibited a higher photocatalytic activity for the degradation of phenol than that with a compact surface morphology, and the elimination rate of phenol increased by 66.7%. PMID:23799106

Yu, Hongbin; Zhu, Suiyi; Yang, Xia; Wang, Xinhong; Sun, Hongwei; Huo, Mingxin

2013-06-14

72

Synthesis and proton conductivity studies of doped azole functional polymer electrolyte membranes  

International Nuclear Information System (INIS)

The development of anhydrous proton-conducting membranes is important for the operation of polymer electrolyte membrane fuel cell (PEMFC) at intermediate temperature (100-200 oC). In this work, poly(vinylbenzylchloride), PVBC was produced by free radical polymerization of 4-vinylbenzylchloride and then it was modified with 5-aminotetrazole (ATET) to obtain poly(vinylbenzylaminotetrazole), PVBC-ATET. The composition of the polymer was verified by elemental analysis (EA) and the structure was characterized by FT-IR and 13C NMR spectra. According to the elemental analysis result, PVBC was modified by ATET with 80% yield. The polymer was doped with trifluoromethanesulfonic acid (TA) at various molar ratios, x = 1.25, 2.5, 3.75 with respect to tetrazole unit. The proton transfer from TA to the tetrazole rings was proved with FT-IR spectroscopy. Thermogravimetry (TG) analysis showed that the samples are thermally stable up to approximately 200 oC. Differential scanning calorimetry (DSC) results illustrated the homogeneity of the materials. Cyclic voltammetry (CV) study illustrated that the electrochemical stability domain for PVBC-ATET-TA2.5 extends over 3.0 V. The proton conductivity of these materials increased with dopant concentration and the temperature. Maximum proton conductivity of PVBC-ATET-TA2.5 was found to be 0.01 S/cm at 150 oC in the anhydrous state.

2010-12-01

73

Synthesis and characterization of Nafion-stabilized Pt nanoparticles for polymer electrolyte fuel cells  

Energy Technology Data Exchange (ETDEWEB)

Platinum nanoparticles are synthesized by alcohol reduction method using Nafion as a stabilizer under various conditions such as the Nafion/Pt molar ratio and reflux temperature. Nafion-Pt nanoparticles are characterized by agglomeration and the particle size is typically in the range of 2-4nm. The electrocatalytic activity of Nafion-Pt nanoparticles for polymer electrolyte and direct methanol fuel cells (PEFCs and DMFCs) is investigated in comparison to that of unsupported Pt black and carbon-supported Pt/C electrocatalysts. Nafion-Pt nanoparticles prepared with low Nafion/Pt ratios show higher and/or comparable activities towards O{sub 2} reduction reaction in the absence and presence of methanol in comparison to that of Pt black and Pt/C electrocatalysts. In contrast, the electrocatalytic activity of the Nafion-Pt nanoparticles for the methanol oxidation reaction is very low. The results indicate that Pt nanoparticles embedded in Nafion polyelectrolyte are potential methanol tolerant electrocatalysts for the O{sub 2} reduction reaction in DMFCs. (author)

Liu, Zengcai; Tian, Zhi Qun; Jiang, San Ping [Nanyang Technological University, (Singapore). School of Mechanical and Aerospace Engineering

2006-11-12

74

Synthesis of novel acid electrolytes for phosphoric acid fuel cells. Final report, May 1985-October 1988  

Energy Technology Data Exchange (ETDEWEB)

Construction of a 40-millimole-per-hour-scale aerosol direct-fluorination reactor was completed June 26, 1986. F-Methyl F-4-methoxybutanoate and F-4-methoxybutanoyl fluoride were synthesized by aerosol direct fluorination of methyl 4-methoxybutanoate. Basic hydrolysis of the perfluorinated derivatives produce sodium F-4-methoxybutanoate which was pyrolyzed to F-3-methoxy-1-propene. Purification and shipment of 33 grams of F-3-methoxy-1-propene followed. Syntheses by analogous methods allowed production and shipment of 5 grams of F-3-ethoxy-1-propene, 18 grams of F-3-(2-methoxy.ethoxy)-1-propene, and 37 grams of F-3,3-dimethyl-1-butene. Eighteen grams of F-2,2-dimethyl-1-chloropropane was produced directly and shipped. As suggested by other contractors, 5 grams of F-3-methoxy-1-iodopropane, and 5 grams of F-3-(2-methoxy.ethoxy)-1-iodopropane were produced by converting the respective precursor acid sodium salts produced for olefin synthesis to the silver salts and pyrolyzing them with iodine. Each of these compounds was prepared for the first time by the aerosol fluorination process during the course of the contract. These samples were provided to other GRI contractors for synthesis of perfluorinated sulfur(VI) and phosphorous(V) acids.

Adcock, J.L.

1988-11-01

75

Self-propagating high-temperature synthesis of La(Sr)Ga(Mg)O3-? for electrolyte of solid oxide fuel cells  

International Nuclear Information System (INIS)

This paper describes self-propagating high-temperature synthesis (SHS) of an electrolyte for solid oxide fuel (SOFC), in comparison to a conventional solid-state reaction method (SRM). Doped-lanthanum gallate: La0.9Sr0.1Ga0.8Mg0.2O3-? (LSGM9182) and LSGM9173 as the SOFC electrolyte, was prepared by the SHS and sintered at different temperatures, for measuring the electrical conductivity of the sintered LSGM and the power generating performance at 1073 K, in comparison to the SRM. In the SHS, the LSGM powders with smaller size were obtained and easily sintered at the 100 K-lower temperature, 1673 K, than in the SRM. Most significantly, the electrical conductivity of the sintered LSGM9182 was as high as 0.11 S cm-1 and its maximum power density was a value of 245 mW cm-2 in the cell configuration of Ni/LSGM9182 (0.501 mm in thickness)/Sm0.5Sr0.5CoO3. The conclusion was that the proposed SHS-sintering method with many benefits of minimizing the energy requirement and the processing time in the production, easing temperature restriction for the sintering, and improving the electrolyte performance up to a conventional level is practicable for producing the LSGM-electrolyte of SOFC at an intermediate-temperature application.

2007-03-14

76

Synthesis of Solid Electrolyte Based on Lithium Glass (Ag2S)x(LiPO3)1-x  

International Nuclear Information System (INIS)

Synthesis of solid electrolyte based on lithium glass (Ag2S)x(LiPO3)1-x has been developed. Melt quenching method was used to synthesize the superionic conducting glasses (Ag2S)x(LiPO3)1-x with x 0; 0.3; and 0.5 by using LiPO3 and Ag2S. X-ray diffraction showed that LiPO3 (x =0, LSX 00) (Ag2S)0.3(LiPO3)0.7, (LSX 03) and (Ag2S)0.5(LiPO3)0.5 (LSX 05) have amorphous structure. Thermal data measured by DSC showed that the glass transition temperature decreases from 149 oC for x = 0 (LSX 00) to 147 oC for x = 0.5 (LSX 05). SEM photo of LiPO3 showed smooth surface without grain, while for (Ag2S)0.3(LiPO3)0.7-C (LSX 03 C) and (Ag2S)0.5-C(LiPO3)0.5-C(LSX 05 C), the Ag2S grain that dissolved in LiPO3 matrix is shown. Increasing of Ag2S in LiPO3 glass consistently increased the conductivity of (Ag2S)x(LiPO3)1-x superionic. The milling of Ag2S could also increase the conductivity of (Ag2S)x(LiPO3)1-x superionic, in which the conductivity of (Ag2S)0.5(LiPO3)0.5 superionic increased from 2.5 x 10-3 S/cm to 1.143 S/cm. (author)

2008-01-01

77

Synthesis and electrochemical characterization of hybrid membrane Nafion-SiO2 for application as polymer electrolyte in PEM fuel cell  

International Nuclear Information System (INIS)

In this work, the effect of sol-gel synthesis parameters on the preparation and polarization response of Nafion-SiO2 hybrids as electrolytes for proton exchange membrane fuel cells (PEMFC) operating at high temperatures (130 degree C) was evaluated. The inorganic phase was incorporated in a Nafion matrix with the following purposes: to improve the Nafion water uptake at high temperatures (> 100 degree C); to increase the mechanical strength of Nafion and; to accelerate the electrode reactions. The hybrids were prepared by an in-situ incorporation of silica into commercial Nafion membranes using an acid-catalyzed sol-gel route. The effects of synthesis parameters, such as catalyst concentration, sol-gel solvent, temperature and time of both hydrolysis and condensation reactions, and silicon precursor concentration (Tetraethyl orthosilicate - TEOS), were evaluated as a function on the incorporation degree and polarization response. Nafion-SiO2 hybrids were characterized by gravimetry, thermogravimetric analysis (TGA), scanning electron microscopy and X-ray dispersive energy (SEM-EDS), electrochemical impedance spectroscopy (EIS), and X-ray small angle scattering (SAXS). The hybrids were tested as electrolyte in single H2/O2 fuel cells in the temperature range of 80 - 130 degree C and at 130 degree C and reduced relative humidity (75% and 50%). Summarily, the hybrid performance showed to be strongly dependent on the synthesis parameters, mainly, the type of alcohol and the TEOS concentration. (author)

2009-01-01

78

Synthesis and characterization of zirconia electrolytes for potential use in energy conversion  

International Nuclear Information System (INIS)

[en] The present work is part of a program to develop ionically conducting materials for potential use in energy storage and conversion systems. With applications in high energy-density batteries, magneto-hydrodynamic (MHD) generators, fuel cells and sensors, they ae playing an increasinly important role in developing more efficient energy storage and conversion devices. Using a wet-chemical procedure, a series of compostions having between 0 and 22.2 mol percent CaO in zirconia, was prepared and subsequently formed into sintered samples having a relative density from 95 to 98 percent. Sintered samples were prepared of each composition with a geometry appropriate for determining the thermal, electrical or microstructural characteristics. This report covers only the microstructural aspects of powder synthesis and the development of sintered materials. Using the reactive, homogeneous, chemically prepared powders, it has been shown that cubic and monoclinic zirconia can coexist in compositions containing up to 10 mol percent CaO. From 10 to 20 mol percent CaO, only the cubic phase is formed, whereas at higher CaO concentrations the cubic phase coexits with CaZro3. The change from a two-phase to single-phase system as the CaO concentration is increased above 10 mol percent, increases the grain size nearly an order of magnitude. It has been found that 5 and 7.6 mol percent CaO materials develop considerable stress during the cooling stage of the firing cycle. As a result, they undergo a progressive and irreversible expansion with each thermal shock cycle: the magnitude of the expansion is proportional to the severity of the thermal shock. The microstructural texture of these partially stablilized materials was also shown to be dependent on the thermal history and hence a strong dependence of the electrical and thermal properties can be anticipated. (auth)

1978-01-01

79

Synthesis and characterization of novel electrocatalysts and supports for use in polymer electrolyte membrane fuel cells  

Science.gov (United States)

The direct methanol fuel cell (DMFC) is a very promising power source for low power applications. High power and energy density, low emissions, operation at or near ambient conditions, fast and convenient refueling and a potentially renewable fuel source are some of the features that make the fuel cell very promising. However, there are a few problems that have to be overcome if we are to see DMFCs in our everyday life. Two drawbacks that cause problems with the DMFC are expensive anode catalysts and poor cathode catalyst supports. For the anode catalyst, the currently used PtRu bimetallic catalyst is simply too expensive and the loading required for adequate methanol reaction kinetics is simply too high. For the cathode support, the currently used high surface area carbon has the tendency to corrode and dissolve under high voltage corrosive conditions seen at the cathode. Novel, alternative anode catalysts and cathode supports must be developed to overcome the cost and limitations of each. The aim of this thesis is develop alternative anode catalysts and cathode support materials that will show some insight of how these problems may be begun to be solved. In order to achieve these aims, several synthesis methods were utilized in order to create the best possible materials. A fully alloyed quaternary alloy system with a high surface area is desired for the anode catalyst with reduce noble metal loading. The materials investigated for this purpose centered on PtRu based systems that incorporated materials that have shown promise in literature, namely, Ni, Ti, Sn, Co, Os. A high surface area, corrosion resistance, electronically conducting support materials is desired for the cathode support material. The materials chosen for this investigation centered on mixed metal oxides of SnTa and SnNb, based upon theoretical calculations done in our group. The results in this thesis have shown that a SnNb2O6 foordite structure exhibits promising specific surface areas (71.5 m2/g) with an excellent corrosion resistance and a trend toward the lowest resistivity of all the support materials synthesized. A Pt 40Ru40Ni10Sn10 quaternary alloy system exhibits promising current response with an onset voltage nearly comparable to that of PtRu at 20 at% less noble metal in the alloy system. Keywords: direct methanol fuel cell, pyrochlore, DMFC, anode, support, cathode, quaternary alloy, mixed metal oxide.

Rock, Nicolaus L.

80

Role of interfacial rheological properties in oil field chemistry  

Energy Technology Data Exchange (ETDEWEB)

Interfacial rheological properties of different Hungarian crude oil/water systems were determined in wide temperature and shear rate range and in presence of inorganic electrolytes, tensides, alkaline materials and polymers. The detailed laboratory study definitely proved that the interfacial rheological properties are extremely sensitive parameters towards the chemical composition of inmiscible formation liquids. Comparison and interpretation of the interfacial rheological properties may contribute significantly to extension of the weaponry of the reservoir characterization, better understanding of the displacement mechanism, development of the more profitable EOR/IOR methods, intensification of the surface technologies, optimization of the pipeline transportation and improvement of the refinery operations. It was evidenced that the interfacial rheology is an efficient and powerful detection technique, which may enhance the knowledge on formation, structure, properties and behaviour of interfacial layers. 17 refs., 18 figs., 2 tabs.

Lakatos-Szabo, J.; Lakatos, I.; Kosztin, B.

1996-12-31

 
 
 
 
81

Synthesis of novel fluorinated phosphonic and phosphinic acid electrolytes for phosphoric acid fuel cells. Final report, May 1985-December 1988  

Energy Technology Data Exchange (ETDEWEB)

New methodology has been developed for the preparation of difluoromethylene phosponate derivatives, perfluorinated bis-phosphonates, and mixed phosphonate-sulfonates. The phosphonates were converted to the respective difluoromethylene phosphonic acids, perfluorinated bis-phosphonic acids, and a mixed fluorinated phosphonic-sulfonic acid. The acids were evaluated as a fuel cell electrolyte. The mono phosphonic acids wetted the Teflon electrode and were found to be unsuitable electrolyte candidates. The bis-phosphonic acids and the mixed phosphonic-sulfonic acid did not wet the Teflon electrode, dissolved more oxygen than phosphonic acid, exhibited excellent thermal stability, and were found to warrant additional study as fuel cell electrolytes.

Burton, D.J.

1989-02-01

82

Synthesis of single-phase HgBa2Ca2Cu3O8+? high-Tc superconducting films using the multistep electrolytic process  

International Nuclear Information System (INIS)

We report on the use of the multistep electrolytic process for the synthesis of high-Tc single-phase HgBa2Ca2Cu3O8+? (Hg-1223) superconducting films. The process includes: (i) deposition of BaCaCu precursor alloy; (ii) oxidation of BaCaCu films; (iii) electrolytic intercalation of Hg in precursor Ba2Ca2Cu3Ox films; (iv) electrochemical oxidation and annealing of Hg-intercalated Ba2Ca2Cu3Ox films to convert into Hg-1223. Films were characterized by thermo-gravimetric analysis and differential thermal analysis, x-ray diffraction and scanning electron microscopy. The electrolytic intercalation of Hg in Ba2Ca2Cu3Ox precursor proves to be a novel alternative to the high-temperature-high-pressure mercuration process. The films are single-phase Hg-1223 with Tc = 121.5 K and Jc = 4.3 x 104 A cm-2 at 77 K.

2004-01-01

83

Electrolytes Test  

Science.gov (United States)

... of this website will be limited. Search Help? Electrolytes Share this page: Was this page helpful? Also known as: Lytes Formal name: Electrolyte Panel Related tests: Sodium , Potassium , Chloride , Bicarbonate (or ...

84

Rheology and deep tectonics  

Directory of Open Access Journals (Sweden)

Full Text Available The distribution of the rheological properties of the lithosphere in space, and their variations in time, have a profound effect on the resulting tectonic deformation. A classical way of estimating these properties makes use of rheological profiles (strength envelopes). Although rheological profiles are based on assumptions and approximations which limit their resolving power, they are an efficient first-order tool for the study of lithosphere rheology, and their application clarifies the dynamics of tectonic processes. Two examples of the interaction of rheology and tectonics are discussed, namely, the post-orogenic relaxation of Moho topography (which is an additional factor to be considered in tectonic inversion), and the strength control on the level of necking in extension (which may lead to apparent local isostasy at passive continental margins and in sedimentary basins).

G. Ranalli

1997-01-01

85

Development of a model colloidal system for rheology simulation.  

Energy Technology Data Exchange (ETDEWEB)

The objective of the experimental effort is to provide a model particle system that will enable modeling of the macroscopic rheology from the interfacial and environmental structure of the particles and solvent or melt as functions of applied shear and volume fraction of the solid particles. This chapter describes the choice of the model particle system, methods for synthesis and characterization, and results from characterization of colloidal dispersion, particle film formation, and the shear and oscillatory rheology in the system. Surface characterization of the grafted PDMS interface, dispersion characterization of the colloids, and rheological characterization of the dispersions as a function of volume fraction were conducted.

Schunk, Peter Randall; Tallant, David Robert; Piech, Martin (United Technologies Research Center, East Hartford, CT); Bell, Nelson Simmons; Frischknecht, Amalie Lucile

2008-10-01

86

Rheological phenomena in focus  

CERN Document Server

More than possibly any other scientific discipline, rheology is easily visualized and the relevant literature contains many excellent photographs of unusual and often bizarre phenomena. The present book brings together these photographs for the first time. They are supported by a full explanatory text. Rheological Phenomena in Focus will be an indispensable support manual to all those who teach rheology or have to convince colleagues of the practical relevance of the subject within an industrial setting. For those who teach fluid mechanics, the book clearly illustrates the difference be

Boger, DV

1993-01-01

87

Synthesis and characterization of polyvinyl alcohol copolymer/phosphomolybdic acid-based crosslinked composite polymer electrolyte membranes  

Energy Technology Data Exchange (ETDEWEB)

Polymer electrolyte membrane fuel cells (PEMFCs) are very promising as future energy source due to their high-energy conversion efficiency and will help to solve the environmental concerns of energy production. Polymer electrolyte membrane (PEM) is recognised as the key element for an efficient PEMFC. Chemically crosslinked composite membranes consisting of a poly(vinyl alcohol-co-vinyl acetate-co-itaconic acid) (PVACO) and phosphomolybdic acid (PMA) have been prepared by solution casting and evaluated as proton conducting polymer electrolytes. The proton conductivity of the membranes is investigated as a function of PMA composition, crosslinking density and temperature. The membranes have also been characterized by FTIR spectroscopy, TGA, AFM and TEM. The proton conductivity of the composite membranes is of the order of 10{sup -3} S cm{sup -1} and shows better resistance to methanol permeability than Nafion 117 under similar measurement conditions. (author)

Anis, Arfat; Banthia, A.K. [Materials Science Centre, Indian Institute of Technology, Kharagpur (India); Bandyopadhyay, S. [School of Materials Science and Engineering, University of New South Wales, Sydney (Australia)

2008-04-15

88

Rheology of waxy oils  

Energy Technology Data Exchange (ETDEWEB)

It is well known that below the crystallization temperature the rheology of waxy oils changes from Newtonian to an extremely complex non-Newtonian behavior, which is shear-rate and temperature-history dependent. Along the last decades a lot of effort has been put into obtaining reliable rheological measurements from different oils so as to understand the yielding of waxy oils as well as the effects of shear and temperature histories on rheological properties, such as viscosity, yield stress, storage and loss moduli. In this paper we examine in detail the related literature, discussing the main reasons for some disagreements concerning the history effects on the flow properties of waxy oils. In addition, we performed temperature ramps and stress-amplitude-sweep tests and compared the results obtained with the main trends observed, highlighting the effects of cooling and shear on the microstructure and consequently on the rheological properties of these oils. (author)

Alicke, Alexandra A.; Marchesini, Flavio H.; Mendes, Paulo R. de Souza [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)], e-mails: fhmo@puc-rio.br, pmendes@puc-rio.br; Ziglio, Claudio [Petrobras Research Center, Rio de Janeiro, RJ (Brazil)], e-mail: ziglio@petrobras.com.br

2010-07-01

89

Electrolytic cell  

Science.gov (United States)

An apparatus is described for the separation of the anolyte and the catholyte during electrolysis. The electrolyte flows through an electrolytic cell between the oppositely charged electrodes. The cell is equipped with a wedge-shaped device, the tapered end is located between the electrodes on the effluent side of the cell. The wedge diverts the flow of the electrolyte to either side of the wedge, substantially separating the anolyte and the catholyte.

Bullock, J. S.; Hale, B. D.

1984-09-01

90

Ce0.8Sm0.2O1.9 synthesis for solid oxide fuel cell electrolyte by ultrasound assisted co-precipitation method.  

Science.gov (United States)

In this study, the synthesis of Ce(0.8)Sm(0.2)O(1.9) (SDC) solid electrolyte by the ultrasound assisted co-precipitation method was accomplished to explore the effects of ultrasound power, ultrasound pulse ratio and probe type upon the ionic conductivity of SDC as well as the lattice parameter, the microstructure and the density. Fine powders of uniform crystallite sizes (average 11.70±0.62nm) were obtained, needing lower sintering temperature. The SDC powders were successfully sintered to a relative density of over 95% at 1200°C (5°Cmin(-1)) for 6h. The micrograph of SDC pellets showed non-agglomerated and well-developed grains with average size of about 200nm. X-ray diffraction analysis showed that the lattice parameter increased with increasing acoustic intensity and reached a maximum for the 14.94Wcm(-2). Further, a linear relationship was detected between the lattice parameter and the ionic conductivity, inspiring a dopant like effect of US on the electrolyte properties. The highest ionic conductivity as ?(800°C)=3.07×10(-2)Scm(-1) with an activation energy E(a)=0.871kJmol(-1) was obtained with pulsed ultrasound for an acoustic intensity of 14.94Wcm(-2), using 19mm probe and 8:2 pulse ratio. PMID:23178079

Okkay, Hikmet; Bayramoglu, Mahmut; Faruk Öksüzömer, M

2012-11-06

91

Ce0.8Sm0.2O1.9 synthesis for solid oxide fuel cell electrolyte by ultrasound assisted co-precipitation method.  

UK PubMed Central (United Kingdom)

In this study, the synthesis of Ce(0.8)Sm(0.2)O(1.9) (SDC) solid electrolyte by the ultrasound assisted co-precipitation method was accomplished to explore the effects of ultrasound power, ultrasound pulse ratio and probe type upon the ionic conductivity of SDC as well as the lattice parameter, the microstructure and the density. Fine powders of uniform crystallite sizes (average 11.70±0.62nm) were obtained, needing lower sintering temperature. The SDC powders were successfully sintered to a relative density of over 95% at 1200°C (5°Cmin(-1)) for 6h. The micrograph of SDC pellets showed non-agglomerated and well-developed grains with average size of about 200nm. X-ray diffraction analysis showed that the lattice parameter increased with increasing acoustic intensity and reached a maximum for the 14.94Wcm(-2). Further, a linear relationship was detected between the lattice parameter and the ionic conductivity, inspiring a dopant like effect of US on the electrolyte properties. The highest ionic conductivity as ?(800°C)=3.07×10(-2)Scm(-1) with an activation energy E(a)=0.871kJmol(-1) was obtained with pulsed ultrasound for an acoustic intensity of 14.94Wcm(-2), using 19mm probe and 8:2 pulse ratio.

Okkay H; Bayramoglu M; Faruk Öksüzömer M

2013-05-01

92

Propriedades reológicas e microestruturais de eletrólito de ZrO2/Y2O3/ Microstructural and rheological properties of ZrO2/Y2O3 electrolyte  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Para reduzir a temperatura de operação das pilhas a combustível de óxido sólido (PaCOS), estruturas com filmes finos de eletrólito depositados, por aerografia, sobre suportes de anodo porosos foram desenvolvidas. As barbotinas, empregadas para fabricação dos filmes, foram preparadas a partir de suspensões com pós de zircônia estabilizada com ítria (ZEI), solventes, dispersantes, ligantes e plastificantes apropriados. Neste trabalho, foi feito o estudo da influ (more) ência dos ligantes sobre a estabilidade das suspensões e as propriedades microestruturais dos filmes de ZEI. Três barbotinas foram elaboradas com composições diferentes de ligantes (0,5; 1,0 e 2,0 % p/p). Todas apresentaram comportamento de fluidos pseudoplásticos e tixotrópicos, de acordo com medidas de viscosidade e taxa de cisalhamento. Os filmes foram sinterizados a 1500 ºC/6h. As micrografias eletrônicas de varredura (MEV) foram tratadas através do programa Quantikov para determinar a porosidade do filme e o tamanho médio de grão da ZEI. Os filmes apresentaram porosidade adequada para serem empregados como eletrólito das PaCOS (entre 0,2 e 0,4 % ) e tamanho médio de grão entre 2,0 e 6,0 µm. A técnica de aerografia é adequada para fabricar eletrólito de ZEI para PaCOS. Abstract in english To reduce the operating temperature of solid oxide fuel cells, structures with thin films electrolytes, deposited by spray coating on porous anode were developed. The slurries used for the fabrication of the films were prepared using appropriates suspensions with ytria-stabilized zirconia (YSZ) powers, solvents, dispersants, binders and plasticizers appropriates. In this work the study of the influence of the binders in the stability of the suspensions and the microstruct (more) ures properties of the YSZ films were done. Three slurries were made with different composition of binders (0.5; 1.0 and 2.0 % in weight). All of them showed pseudo-plastics and thixotropics flow behavior, according to viscosities measurements and shear rate. The films were sintered to 1500 ºC /6 hours. The images of scanning electron micrographs (SEM) were treated by Quantikov program to determine the porosity of the film and average grain size of YSZ. The films showed adequate porosity for being used as SOFC electrolyte (between 0.2 and 0.4%) and average grain size between 2.0 and 6.0 µ m. The spray coating is a suitable technique to fabricate the YSZ electrolytes for SOFC.

Taroco, H.A.; Basaglia, R. M. F.; Domingues, R. Z.; Brant, M.; Matencio, T.

2008-09-01

93

Synthesis and studies of boron based anion receptors and their use in non-aqueous electrolytes for lithium batteries  

Energy Technology Data Exchange (ETDEWEB)

A new family of anion receptors based on boron compounds has been synthesized. These compounds can be used as anion receptors in lithium battery electrolytes and can greatly increase solubility and ionic conductivities of various lithium salts, such as LiF, LiCl, CF{sub 3}COOLi and C{sub 2}F{sub 5}COOLi, in DME solutions. Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy studies show that Cl{sup {minus}} anions of LiCl are complexed with these compounds in DME solutions. The electrochemical stability of lithium salts and one of the boron compounds in deferent solvents was studied. For the first time, LiF has been successfully used as conducting salt in a novel electrolyte with this boron compound as an additive in DME. A rechargeable Li/LiMn{sub 2}O{sub 4} cell using this electrolyte was successfully cycled 51 times. However, the capacity fades with cycling due to decomposition of the solvent. The cycling performance of the battery was greatly improved by replacing DME with PC-EC-DMC as the solvent.

Sun, X.; Yang, X.Q.; Lee, H.S.; McBreen, J. [Brookhaven National Lab., Upton, NY (United States); Choi, L.S. [Naval Research Lab., Washington, DC (United States)

1998-12-31

94

PETC fuel rheology laboratory  

Energy Technology Data Exchange (ETDEWEB)

This document summarizes the results of investigations into the rheological properties of alternate fuel mixtures, such as coal-oil mixtures, coal-water mixtures, and coal-alcohol mixtures. Primary emphasis in this paper is placed on the procedures and techniques used to evaluate alternate slurry fuels in the rheology laboratory at PETC through the spring of 1983. Sophisticated, bench-scale equipment was used to examine viscometric properties and to make settling velocity measurements. Examples of the data developed during this program are given to support the choice of measurement procedures and test conditions. Furthermore, a brief discussion of the applicability of various mathematical models for settling characteristics and rheological properties are included. Areas in which additional development of techniques is required are discussed. 25 references, 21 figures, 7 tables.

Ekmann, A.C.; Ekmann, J.M.

1984-08-01

95

Rheology of giant micelles  

CERN Multimedia

Giant micelles are elongated, polymer-like objects created by the self-assembly of amphiphilic molecules (such as detergents) in solution. Giant micelles are typically flexible, and can become highly entangled even at modest concentrations. The resulting viscoelastic solutions show fascinating flow behaviour (rheology) which we address theoretically in this article at two levels. First, we summarise advances in understanding linear viscoelastic spectra and steady-state nonlinear flows, based on microscopic constitutive models that combine the physics of polymer entanglement with the reversible kinetics of self-assembly. Such models were first introduced two decades ago, and since then have been shown to explain robustly several distinctive features of the rheology in the strongly entangled regime, including extreme shear-thinning. We then turn to more complex rheological phenomena, particularly involving spatial heterogeneity, spontaneous oscillation, instability, and chaos. Recent understanding of these comp...

Cates, M E; Cates, Michael E.; Fielding, Suzanne M.

2006-01-01

96

Food Rheology; Folding Fun  

Science.gov (United States)

In this activity students analyze the rheologic and structural properties of various foods (everything from pudding to white bread) and think about how they expect them to behave under lateral pressure and how they will affect each other. They design experiments, run the experiments and then do lab write-ups. Depending on your emphasis, you can use this to help teach folding mechanics, rheology, why beds deform the way they do, decollements (pudding works great), deformation mechanisms, folding and even more. It is a single lecture activity, though the lead-in lecture and activity and clean-up take about 40-50 minutes.

Beutel, Erin K.

97

Rheology of liquid foam  

International Nuclear Information System (INIS)

[en] Liquid foams can behave like solids or liquids, depending on the applied stress and on the experimental timescale. Understanding the origin of this complex rheology which gives rise to many applications and which resembles that of many other forms of soft condensed matter made of closely packed soft units requires challenging theoretical questions to be solved. We briefly recall the basic physics and physicochemistry of foams and review the experiments, numerical simulations and theoretical models concerning foam rheology published in recent years. (topical review)

2005-10-19

98

Effects of chemical synthesis parameters on the Zr O2: 8% mol Mg O solid electrolytes electric conductivity and microstructure  

International Nuclear Information System (INIS)

Electrical conductivity measurements and scanning electron microscope observations have been done in Zr O2 - 8 mol % Mg O solid electrolytes. The main purpose was to investigate to what extent some processing variables can influence the electrical behaviour and microstructural characteristics of the sintered ceramic. Zirconia powders have been prepared under different pH and temperature of precipitation, and washing media conditions. The results show that many structural characteristics of the calcined powders are 'lost' during sintering, giving rise to ceramics with similar electrical properties, besides minor differences in the final microstructure. The washing media play the major role on both microstructural development and electrical conductivity. (author)

1996-01-01

99

Solid Electrolyte Materials for use in Lithium-water Primary Batteries And the Synthesis and Characterization of Lanthanide Orthoferrite Magnetic Nanomaterials  

Science.gov (United States)

This thesis was developed in two parts with the overall goals of this work being (1) synthesize and develop solid electrolyte materials for use in a lithium-water battery and (2) synthesize and characterize ternary magnetic nanomaterials. Lithium metal in combination with water is a highly attractive power source due to its high specific energy. Because of the vigorous nature of the reaction between lithium and water, many obstacles must be overcome in order to harness the energy that this system is capable of producing. Parasitic reactions must be controlled so as not to passivate the lithium or consume it totally. In addition, production of hydrogen gas that accompanies both the electrochemical and parasitic reactions can present a serious challenge. As a result it is difficult to maintain high voltage and control the current density in these systems. In order to overcome these obstacles we have developed composite membranes of various lithium-ion conducting solid electrolytes and polymers. Lithium-ion conducting solid electrolytes are known to achieve ionic conductance as high as 10-3 S/cm2. Utilizing these materials in conjunction with polymers, we have created hydrophobic membranes that allow us to limit the parasitic reactions and maintain low cell impedance. Lanthanide orthoferrite materials are technologically important classes of magnetic materials. They have found application in magneto-optical devices as well as in magnetic recording devices. We have explored the syntheses and magnetic properties of nanocrystalline materials. The synthesis of the nanomaterials was done by co-reduction of lanthanide, Ln3+, and iron, Fe 3+, cations with alkalide solution producing the Ln-Fe alloy of the desired stoichiometry. Removal of the byproducts and oxidization of the alloy was accomplished by washing the product with aerated water. Presented herein, several nanoscale lanthanide orthoferrite materials (LnFeO3, Ln = Gd, Tb, Er, Tm, Sm, Dy, Ho, and La) have been prepared. The products have been characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and magnetic properties characterized by use of a Superconducting Quantum Interference Device (SQUID).

Cook, Clifford Corlin

100

Rheology of Attractive Emulsions  

CERN Multimedia

We show how attractive interactions dramatically influence emulsion rheology. Unlike the repulsive case, attractive emulsions below random close packing, RCP, can form soft gel-like elastic solids. However, above RCP, attractive and repulsive emulsions have similar elasticities. Such compressed attractive emulsions undergo an additional shear-driven relaxation process during yielding. Our results suggest that attractive emulsions begin to yield at weak points through the breakage of bonds, and, above RCP, also undergo droplet configurational rearrangements.

Datta, Sujit S; Rhodes, Travers S; Mason, Thomas G; Weitz, David A; 10.1103/PhysRevE.84.041404

2012-01-01

 
 
 
 
101

Synthesis of nanocrystalline Ce(0.8)Gd(0.2)O(2-delta) electrolyte materials for IT-SOFC.  

Science.gov (United States)

We successfully synthesized nano-sized Ce(0.8)Gd(0.2)O(2-delta) powders by combustion method, using gelatin as fuel. The calcined powders showed high-quality characteristics, i.e., nano-scale size (14-35 nm) and narrow size distribution. The structural, morphological, and electrical characteristics of the sintered Ce(0.8)Gd(0.2)O(2-delta) were studied systematically, depending on sintering temperature. The crystal structure of the Ce(0.8)Gd(0.2)O(2-delta) belonged to the cubic fluorite structure. The gelatin-assisted combustion synthesized Ce(0.8)Gd(0.2)O(2-delta) powders allowed to sinter well at low temperature for dense and ultra-fine Ce(0.8)Gd(0.2)O(2-delta) electrolyte with good electrical conductivity. The sintering temperature of the Ce(0.8)Gd(0.2)O2 powder was approximately 300 degrees C lower than that of conventional solid-state synthesized powder. The nanopowder produced was sintered into pellets with relative densities over 99.1% of the theoretical value even at 1400 degrees C. The Ce(0.8)Gd(0.2)O(2-delta) sintered at 1400 degrees C exhibited a conductivity of 0.101 S/cm at 800 degrees C in air. PMID:21138014

Park, K; Choi, J W; Hwang, H K; Saradha, T

2010-11-01

102

Synthesis of nanocrystalline Ce(0.8)Gd(0.2)O(2-delta) electrolyte materials for IT-SOFC.  

UK PubMed Central (United Kingdom)

We successfully synthesized nano-sized Ce(0.8)Gd(0.2)O(2-delta) powders by combustion method, using gelatin as fuel. The calcined powders showed high-quality characteristics, i.e., nano-scale size (14-35 nm) and narrow size distribution. The structural, morphological, and electrical characteristics of the sintered Ce(0.8)Gd(0.2)O(2-delta) were studied systematically, depending on sintering temperature. The crystal structure of the Ce(0.8)Gd(0.2)O(2-delta) belonged to the cubic fluorite structure. The gelatin-assisted combustion synthesized Ce(0.8)Gd(0.2)O(2-delta) powders allowed to sinter well at low temperature for dense and ultra-fine Ce(0.8)Gd(0.2)O(2-delta) electrolyte with good electrical conductivity. The sintering temperature of the Ce(0.8)Gd(0.2)O2 powder was approximately 300 degrees C lower than that of conventional solid-state synthesized powder. The nanopowder produced was sintered into pellets with relative densities over 99.1% of the theoretical value even at 1400 degrees C. The Ce(0.8)Gd(0.2)O(2-delta) sintered at 1400 degrees C exhibited a conductivity of 0.101 S/cm at 800 degrees C in air.

Park K; Choi JW; Hwang HK; Saradha T

2010-11-01

103

Synthesis of novel acid electrolytes for phosphoric-acid fuel cells. Annual report, May 1986-April 1987  

Energy Technology Data Exchange (ETDEWEB)

Construction of a 40-mmole-per-hour scale aerosol direct-fluorination reactor was completed June 26, 1986. F-Methyl F-4-methoxybutanoate and F-4-methoxybutanoyl fluoride were synthesized by aerosol direct fluorination of methyl 4-methoxybutanoate. Basic hydrolysis of the perfluorinated derivatives produce sodium F-4-methoxybutanoate which was pyrolyzed to F-3-methoxy-1-propene. F-3-ethoxy-1-propene, F-3,3dimethylbutene, and F-3-(2-methoxyethoxy)-1-propene were prepared in a similar manner. Ten, six, and seven gram samples of the first three compounds were provided to other GRI contractors for synthesis of perfluorinated sulfur (VI) and phosphorous (V) acids.

Adcock, J.L.

1987-06-01

104

Advanced nuclear power conversion process using high temperature electrolyte and multi power generation system of electric power and hydrogen energy productions by high temperature gas cooled reactors (2). Synthesis of nano ordered high temperature thin electrolyte film  

International Nuclear Information System (INIS)

[en] In order to develop new energy conversion technique, that is, electric power and hydrogen multi generation system by partial oxidation reaction of methane source using thermo nuclear power, sol-gel and spin coating techniques were employed to make nano ordered thin solid electrolyte film of Ce0.8Sm0.2O1.9, which is expected to exhibit high ion conductivity and low loss of self-electric resistivity in the temperature range of 1073-1273 K. The Ce0.8Sm0.2O1.9 solid electrolyte thin film was investigated to obtain its fundamental properties, and the following conclusions were derived; (1) Nano ordered electrolyte thin film of Ce0.8Sm0.2O1.9 was synthesized by the combination of sol-gel and spin coating techniques on sapphire substrate from Ce(NO3)36H2O and Sm(NO3)3 6H2O in ethylene glycol solution. (2) High crystal perfection and high density of Ce0.8Sm0.2O1.9 nano ordered thin electrolyte film was achieved by firing at 1273 K. (3) The highest ion conductivity of high temperature electrolytes in the order of 1.4 S·cm-1 at 1273 K was achieved by the formation of the Ce0.8Sm0.2O1.9 nano thin electrolyte film. This would be world record of the high temperature electrolytes. (author)

2002-01-01

105

Synthesis of novel fluorinated phosphonic acid electrolytes for phosphoric acid fuel cells. Final report, January 1, 1989-June 30, 1991  

Energy Technology Data Exchange (ETDEWEB)

A practical synthesis of fluorine-containing phosphonic acids of the type, (HO)2P(O)(CF2)nP(O)(OH)2 (n = 1,2,3,4,6) has been developed from commercially available precursors. Preliminary electrochemical evaluation of (HO)2P(O)CF2CF2P(O)(OH)2 demonstrated the enhanced oxygen solubility of this acid, and the performance of this acid exceeded H3PO4 in short term fuel cell experiments. Methodology for the preparation of (HO)2P(O)CF2SO3H and F2C=CF(CF2)nP(O)(OH)2 (n = 0,1) has also been developed.

Burton, D.J.

1992-01-01

106

Rheological behavior study of a clay-polymer mixture: effects of the polymer addition  

International Nuclear Information System (INIS)

[en] The aim of the present work is to establish a bibliographical synthesis on the microstructure, the colloidal and rheological characterization of bentonite suspensions with and without polymer/surfactant addition; to lead to a rheological characterization of clay-additive mixtures and to understand the interaction between the clay particles and polymer/surfactants. Different experimental measurements: rheology, particle sizing, and x-ray diffraction were used to study the rheological character of the water-bentonite-anionic additive mixtures (CMC, SDS, xanthane) as well as the nature of the particle-particle interactions and particle-additive. The modeling part led to the adoption of Tiu and Boger's model to predict the thixotropy of the bentonite suspensions without additive. Thus, a new model is proposed with physical parameters for a better correlation of the rheological behavior of the various studied mixtures. (author)

2006-01-01

107

Materials with rheological properties  

CERN Document Server

Materials with Rheological Properties presents the evolution of the mathematical models used to calculate the resistance structures and the conditions which enable progress to be made in this field. The author presents equations describing the behavior of each possible type of resistance structure (with discrete collaboration, continuous collaboration and complex composition). These equations are then redefined in the particular concrete form for each type of structure, by using the notions and known parameters from the construction's statics. The mathematical models are then tested u

Cristescu, Constantin

2010-01-01

108

Rheology and elastohydrodynamic lubrication  

Energy Technology Data Exchange (ETDEWEB)

This book summarizes progress in this field during the last 25 years. The author intends `a description of a large part of the current knowledge about lubricant rheology, elastohydrodynamic lubrication and the effects of surface roughness and particulate contamination in the lubricant on the overall behavior of a heavily loaded lubricated contact.` Jacobson reviews specialized theological models for shearing flows of liquid lubricants and discusses their role in analyses of elastohydrodynamic lubrication. However, the author succeeds best while drawing heavily on his own research to measure lubricant behavior at elevated pressures and to describe wear processes in rolling bearings.

Jacobson, B.O.

1991-12-31

109

Solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

This invention pertains to Li ion (Li.sup.+) conductive solid polymer electrolytes composed of solvates of Li salts immobilized (encapsulated) in a solid organic polymer matrix. In particular, this invention relates to solid polymer electrolytes derived by immobilizing complexes (solvates) formed between a Li salt such as LiAsF.sub.6, LiCF.sub.3 SO.sub.3 or LiClO.sub.4 and a mixture of aprotic organic solvents having high dielectric constants such as ethylene carbonate (EC) (dielectric constant=89.6) and propylene carbonate (PC) (dielectric constant=64.4) in a polymer matrix such as polyacrylonitrile, poly(tetraethylene glycol diacrylate), or poly(vinyl pyrrolidinone).

Abraham, Kuzhikalail M. (Needham, MA); Alamgir, Mohamed (Dedham, MA)

1993-06-15

110

Structure making in rheologically complex disperse systems during drying  

Energy Technology Data Exchange (ETDEWEB)

This paper presents work to experimentally and theoretically substantiate the factors responsible for the formation of the structure of disperse materials during drying. The investigations were carried out with peat as a rheologically complex disperse system. Electrolytes were used to regulate the structure-making processes in the peat. The shrinking of the peat samples during drying was measured with the aid of deformation indicators with a dial. It is shown that in order to obtain strong structures based on rheologically complex disperse materials, their drying must be followed by the destruction of the aggregates of particles and lowering of the limiting shearing stress for the beginning of shrinkage (in the region of the hygroscopic state of the material), which occurs as a result of the long-range interparticle forces. In this case, dense packing of the structural components of the material, which provides for the high strength of the final product, can be obtained.

Abramets, A.M.; Churaev, N.V.; Ivaskevich, L.S.; Lishtvan, I.I.

1986-09-01

111

Design and Synthesis of Cross-Linked Copolymer Membranes Based on Poly(benzoxazine) and Polybenzimidazole and Their Application to an Electrolyte Membrane for a High-Temperature PEM Fuel Cell  

Directory of Open Access Journals (Sweden)

Full Text Available Elevated-temperature (100~200 °C) polymer electrolyte membrane (PEM) fuel cells have many features, such as their high efficiency and simple system design, that make them ideal for residential micro-combined heat and power systems and as a power source for fuel cell electric vehicles. A proton-conducting solid-electrolyte membrane having high conductivity and durability at elevated temperatures is essential, and phosphoric-acid-containing polymeric material synthesized from cross-linked polybenzoxazine has demonstrated feasible characteristics. This paper reviews the design rules, synthesis schemes, and characteristics of this unique polymeric material. Additionally, a membrane electrode assembly (MEA) utilizing this polymer membrane is evaluated in terms of its power density and lifecycle by an in situ accelerated lifetime test. This paper also covers an in-depth discussion ranging from the polymer material design to the cell performance in consideration of commercialization requirements.

Seong-Woo Choi; Jung Ock Park; Chanho Pak; Kyoung Hwan Choi; Jong-Chan Lee; Hyuk Chang

2013-01-01

112

Solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Solid electrolytes with dimensional stability at room temperature composed of solutions of alkali metal salts in a plurality of miscible aprotic organic liquids is described, immobilized in an organic solid polymer matrix which itself can complex with the alkali metal salts wherein the liquids are ethylene carbonate and propylene carbonate and the polymer is selected from the group consisting of polyacrylonitrile and poly-N-vinyl-2-pyrrolidinone.

Abraham, K.M.; Alamgir, M.

1993-06-15

113

Electrolytic fixer.  

UK PubMed Central (United Kingdom)

Interest in the recovery of silver from radiographic film generates a need to understand the operating procedures of recovery units utilizing the electrolytic fixer principle. Tailing or terminal units and recirculation units using electrolysis are evaluated. Difficulties encountered in the number of Coulombs applied to a specific amount of fixer are discussed. Reduction of sulfiding as a result of electrolysis and variations in film volumes are noted. The quantity and quality of silver collected can be improved by being aware of alterations in chemical activity used in a silver recovery program.

Stevens

1982-12-01

114

Electrolytic fixer.  

Science.gov (United States)

Interest in the recovery of silver from radiographic film generates a need to understand the operating procedures of recovery units utilizing the electrolytic fixer principle. Tailing or terminal units and recirculation units using electrolysis are evaluated. Difficulties encountered in the number of Coulombs applied to a specific amount of fixer are discussed. Reduction of sulfiding as a result of electrolysis and variations in film volumes are noted. The quantity and quality of silver collected can be improved by being aware of alterations in chemical activity used in a silver recovery program. PMID:10262504

Stevens

1982-12-01

115

Imprintable, bendable, and shape-conformable polymer electrolytes for versatile-shaped lithium-ion batteries.  

UK PubMed Central (United Kingdom)

A class of imprintable, bendable, and shape-conformable polymer electrolyte with excellent electrochemical performance in a lithium battery system is reported. The material consists of a UV-cured polymer matrix, high-boiling point liquid electrolyte, and Al2 O3 nanoparticles, formulated for use in lithium-ion batteries with 3D-structured electrodes or flexible characteristics. The unique structural design and well-tuned rheological characteristics of the UV-curable electrolyte mixture, in combination with direct UV-assisted nanoimprint lithography, allow the successful fabrication of polymer electrolytes in geometries not accessible with conventional materials.

Kil EH; Choi KH; Ha HJ; Xu S; Rogers JA; Kim MR; Lee YG; Kim KM; Cho KY; Lee SY

2013-03-01

116

Imprintable, bendable, and shape-conformable polymer electrolytes for versatile-shaped lithium-ion batteries.  

Science.gov (United States)

A class of imprintable, bendable, and shape-conformable polymer electrolyte with excellent electrochemical performance in a lithium battery system is reported. The material consists of a UV-cured polymer matrix, high-boiling point liquid electrolyte, and Al2 O3 nanoparticles, formulated for use in lithium-ion batteries with 3D-structured electrodes or flexible characteristics. The unique structural design and well-tuned rheological characteristics of the UV-curable electrolyte mixture, in combination with direct UV-assisted nanoimprint lithography, allow the successful fabrication of polymer electrolytes in geometries not accessible with conventional materials. PMID:23280571

Kil, Eun-Hye; Choi, Keun-Ho; Ha, Hyo-Jeong; Xu, Sheng; Rogers, John A; Kim, Mi Ri; Lee, Young-Gi; Kim, Kwang Man; Cho, Kuk Young; Lee, Sang-Young

2012-12-21

117

Rheology of carbon nanotube dispersions  

CERN Multimedia

We report on rheological properties of a dispersion of multi-walled carbon nanotubes in a viscous polymer matrix. Particular attention is paid to the process of nanotubes mixing and dispersion, which we monitor by the rheological signature of the composite. The response of the composite as a function of the dispersion mixing time and conditions indicates that a critical mixing time t* needs to be exceeded to achieve satisfactory dispersion of aggregates, this time being a function of nanotube concentration and the mixing shear stress. At shorter times of shear mixing, tt*, has several universal rheological features; at nanotube concentration above a characteristic value ~2-3wt% the effective elastic gel network is formed, while the low-concentration composite remains a viscous liquid. We use this rheological approach to determine the effects of aging and re-aggregation.

Huang, Y Y; Terentyev, E M

2006-01-01

118

Rheological measurements on cement grouts  

International Nuclear Information System (INIS)

This report describes the techniques which have been developed at Winfrith for assessing the rheological properties of cement grouts. A discussion of the theory of rheology and its application to cement is given and the methodology for calibrating a special paddle measuring system for a commercial viscometer is described. The use of the system for determining flow curves, equilibrium viscosity, viscosity as a function of shearing time and structure changes is also discussed. (author).

1986-01-01

119

Rheological characterization of okra pectins  

UK PubMed Central (United Kingdom)

Polysaccharides from okra pods (Abelmoschus esculentus) were extracted using a sequential extraction protocol and compared with a simple extraction at pH 6. Rheological properties of three okra extracts were then investigated by means of molecular weight determination, dilute solution rheology, steady shear and oscillatory rheological measurements. The extraction protocols resulted in extracts of relatively high purity and multimodal molecular weight distribution. Furthermore, molecular parameters of the isolated biopolymers such as intrinsic viscosity, Huggins constant, critical concentration and coil overlap parameter were calculated from dilute solution viscometry. Investigation of the generalized flow behaviour using a modified Cross equation and Cox–Merz plots showed evidence that as concentration increases specific interactions start taking place among the polymeric chains that modify the rheological behaviour of the extracts. The change in the rheological behaviour could not only be explained by differences in the molecular weight of the samples but also should be attributed to the fine structure of the chains that are obtained under the different extraction protocols. Present investigation shows that further optimization of such protocols may result in polysaccharide fractions with specific rheological properties.

Kontogiorgos V; Margelou I; Georgiadis N; Ritzoulis C

2012-12-01

120

Solid state electrolyte systems  

Energy Technology Data Exchange (ETDEWEB)

Lanthanum gallates are a new family of solid electrolytes that exhibit high ionic conductivity and are stable to high temperatures. Compositions have been developed that are as much as a factor of two more conductive than yttria-stabilized zirconia at a given temperature, through partial replacement of lanthanum by calcium, strontium, and/or barium and through partial replacement of gallium by magnesium. Oxide powders were prepared using combustion synthesis techniques developed in this laboratory; these were sintered to >95% of theoretical density and consisted of a single crystalline phase. Electrical conductivities, electron and ion transference numbers, thermal expansion, and phase behavior were evaluated as a function of temperature and oxygen partial pressure. A key advantage of the use of lanthanum gallate electrolytes in solid oxide fuel cells is that the temperature of operation may be lowered to perhaps 800 C, yet provide approximately the same power density as zirconia-based cells operating at 1000 C. Ceramic electrolytes that conduct both oxygen ions and electrons are potentially useful to passively separate pure oxygen from an air source at low cost. In such materials, an oxygen ion flux in one direction is charge-compensated by an opposing electron flux. The authors have examined a wide range of mixed ion and electron conducting perovskite ceramics in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, where M = Sr, Ca, and Ba, and N = Pr, Mn, Ni, Cu, Ti, and Al, as well as mixed conducting brownmillerite ceramics, and have characterized oxygen permeation behavior, defect chemistry, structural and phase stability, and performance as cathodes.

Pederson, L.R.; Armstrong, B.L.; Armstrong, T.R. [Pacific Northwest Lab., Richland, WA (United States)] [and others

1997-12-01

 
 
 
 
121

Surface rheology and interface stability.  

Energy Technology Data Exchange (ETDEWEB)

We have developed a mature laboratory at Sandia to measure interfacial rheology, using a combination of home-built, commercially available, and customized commercial tools. An Interfacial Shear Rheometer (KSV ISR-400) was modified and the software improved to increase sensitivity and reliability. Another shear rheometer, a TA Instruments AR-G2, was equipped with a du Nouey ring, bicone geometry, and a double wall ring. These interfacial attachments were compared to each other and to the ISR. The best results with the AR-G2 were obtained with the du Nouey ring. A Micro-Interfacial Rheometer (MIR) was developed in house to obtain the much higher sensitivity given by a smaller probe. However, it was found to be difficult to apply this technique for highly elastic surfaces. Interfaces also exhibit dilatational rheology when the interface changes area, such as occurs when bubbles grow or shrink. To measure this rheological response we developed a Surface Dilatational Rheometer (SDR), in which changes in surface tension with surface area are measured during the oscillation of the volume of a pendant drop or bubble. All instruments were tested with various surfactant solutions to determine the limitations of each. In addition, foaming capability and foam stability were tested and compared with the rheology data. It was found that there was no clear correlation of surface rheology with foaming/defoaming with different types of surfactants, but, within a family of surfactants, rheology could predict the foam stability. Diffusion of surfactants to the interface and the behavior of polyelectrolytes were two subjects studied with the new equipment. Finally, surface rheological terms were added to a finite element Navier-Stokes solver and preliminary testing of the code completed. Recommendations for improved implementation were given. When completed we plan to use the computations to better interpret the experimental data and account for the effects of the underlying bulk fluid.

Yaklin, Melissa A.; Cote, Raymond O.; Moffat, Harry K.; Grillet, Anne Mary; Walker, Lynn; Koehler, Timothy P.; Reichert, Matthew D. (Carnegie Mellon University, Pittsburgh, PA); Castaneda, Jaime N.; Mondy, Lisa Ann; Brooks, Carlton, F.

2010-11-01

122

Blood rheology and aging  

Directory of Open Access Journals (Sweden)

Full Text Available The flow properties of blood play significant roles in tissue perfusion by contributing to hydrodynamic resistance in blood vessels. These properties are influenced by pathophysiological processes, thereby increasing the clinical relevance of blood rheology information. There is well-established clinical evidence for impaired blood fluidity in humans of advanced age, including enhanced plasma and whole blood viscosity, impaired red blood cell (RBC) deformability and enhanced RBC aggregation. Increased plasma fibrinogen concentration is a common finding in many studies owing to the pro-inflammatory condition of aged individuals; this finding of increased fibrinogen concentration explains the higher plasma viscosity and RBC aggregation in elderly subjects. Enhanced oxidant stress in advanced age is also known to contribute to altered blood fluidity, with RBC deformability being an important determinant of blood viscosity. Several studies have shown that physical activity may improve the hemorheological picture in elderly subjects, yet well-designed observational and mechanistic studies are required to determine the specific effects of regular exercise on hemorheological parameters in healthy and older individuals.

Michael J. Simmonds; Herbert J. Meiselman; Oguz K. Baskurt

2013-01-01

123

Blood rheology and aging.  

UK PubMed Central (United Kingdom)

The flow properties of blood play significant roles in tissue perfusion by contributing to hydrodynamic resistance in blood vessels. These properties are influenced by pathophysiological processes, thereby increasing the clinical relevance of blood rheology information. There is well-established clinical evidence for impaired blood fluidity in humans of advanced age, including enhanced plasma and whole blood viscosity, impaired red blood cell (RBC) deformability and enhanced RBC aggregation. Increased plasma fibrinogen concentration is a common finding in many studies owing to the pro-inflammatory condition of aged individuals; this finding of increased fibrinogen concentration explains the higher plasma viscosity and RBC aggregation in elderly subjects. Enhanced oxidant stress in advanced age is also known to contribute to altered blood fluidity, with RBC deformability being an important determinant of blood viscosity. Several studies have shown that physical activity may improve the hemorheological picture in elderly subjects, yet well-designed observational and mechanistic studies are required to determine the specific effects of regular exercise on hemorheological parameters in healthy and older individuals.

Simmonds MJ; Meiselman HJ; Baskurt OK

2013-09-01

124

Applications of solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Papers are presented on various possible applications of solid electrolytes currently under consideration. Specific topics include the application of solid state electrochemical cells to kinetic measurements, couliodes and memoriodes, the lithium-iodine charge transfer complex solid electrolyte battery, the properties of the beta-alumina solid electrolyte in sodium-sulfur cells, the use of solid electrolyte oxygen gas analyzers, applications of the oxygen probe in the steelmaking process, and high-temperature fuel and electrolysis cells employing zirconia solid electrolytes.

Takahashi, T.; Kozawa, A.

1980-01-01

125

Summary of 2009 Rheology Modifier Program.  

Science.gov (United States)

The overall objective of the EM-31 Rheological Modifiers and Wetting Agents program is to utilize commercially available rheology modifiers to increase the solids fraction of radioactive sludge based waste streams, resulting in an increase in throughput a...

E. K. Hansen

2009-01-01

126

Study of an industrial process for the synthesis of high molar mass ethylene oxide-propylene oxide copolymers usable as extrusible electrolyte; Etude d`un procede industriel de synthese de copolymeres oxyde d`ethylene-oxyde de propylene de hautes masses molaires utilisables comme electrolyte extrudable  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to develop an industrial process for the synthesis of an extrusible electrolyte polymer for lithium batteries. From literature data and precise specifications the high molar mass EO/OP copolymers synthesis by coordinative catalysis has been studied in order to reach a high productivity and to minimize the treatment steps. Two catalytic systems have been studied: the aluminium alkoxide-based Vandenberg-type catalysis and the calcium alcoholate amides catalysis. The first catalysis performed in solution gives excellent results. Its adaptation to silicon supported catalysis leads to a directly usable polymer in suspension but the productivity falls down and remains to be optimized. The calcium amide catalysis in heptane suspension generates acceptable productivities but also a too high proportion of low molar masses. Various approaches have been studied to minimize this proportion due to the presence of secondary sites that generate a cationic mechanism. The two synthesis ways explored are promising but remain to be optimized in order to increase the productivity of the efficient catalytic site and to reduce the formation of low molar masses generated by parasite catalytic sites. (J.S.) 9 refs.

Gramain, Ph. [Ecole Nationale Superieure de Chimie de Montpellier, 34 (France); Caselles, E. [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France)

1996-12-31

127

Rheological Behaviour of Raw Cement  

Directory of Open Access Journals (Sweden)

Full Text Available A series of rheometric tests was conducted on raw cement at different concentrations and particle finesses as well. The paste of raw cement, formed by a set of particles suspensions in water, presents rheological properties that make it different from the fluids commonly used. The obtained results have showed that the rheological behaviour is the shear-thinning type and can be described satisfactorily by a model of Herschel-Bulkley, characterized by three parameters ?0, K and n which connect the shear stress to the shear rate. In addition, the parameter ?0 was correlated by an exponential function of the volume concentration of particles, this correlation is valid for both the raw cement and limestone. This latter is the main component of raw cement, for that reason its rheology has been studied.

A. Lachemet; D. Touil; S. Belaadi; N. Bentaieb; C. Frances

2008-01-01

128

Synthesis, processing and characterization of the solid oxide half-cells cathode/electrolyte of strontium-doped lanthanum manganite/Yttria-stabilized zirconia  

International Nuclear Information System (INIS)

[en] The ceramic films of strontium-doped lanthanum manganite (LSM) and strontium doped lanthanum manganite/Yttria-stabilized zirconia (LSM/YSZ) are used as cathodes of the high temperature solid oxide fuel cells (HTSOFC). These porous ceramic films had been deposited on the YSZ dense ceramic substrate, used as electrolyte, structural component of the module, thus conferring a configuration of half-cell called auto-support. The study of the half-cell it is basic, therefore in the interface cathode/electrolyte occurs the oxygen reduction reaction, consequently influencing in the performance of the HTSOFC. In this direction, the present work contributes for the processing of thin films, using the wet powder spraying technique, adopted for the conformation of the ceramic films for allowing the attainment of porous layers with thicknesses varied in the order of micrometers. The LSM powders were synthesized by the citrate technique and the LSM/YSZ powders synthesized by the solid mixture technique. In the stage of formation were prepared organic suspensions of LSM and LSM/YSZ fed by gravity in a manual aerograph. For the formation of the YSZ substrate was used a hydraulic uniaxial press. The attainment of solid oxide half-cells cathode/electrolyte was possible of crystalline structures hexagonal for phase LSM and cubic for phase YSZ. The half-cells micrographs show that the YSZ substrate is dense, enough to be used as solid electrolyte, and the LSM and LSM/YSZ films are presented porous with approximately 30 ?m of thickness and good adherence between the cathodes and the electrolyte. The presence of composite cathode between the LSM cathode and YSZ substrate, presented an increase in the electrochemical performance in the oxygen reduction reaction. (author)

2010-01-01

129

Fuel cell having electrolyte  

Energy Technology Data Exchange (ETDEWEB)

A fuel cell having an electrolyte control volume includes a pair of porous opposed electrodes. A maxtrix is positioned between the pair of electrodes for containing an electrolyte. A first layer of backing paper is positioned adjacent to one of the electrodes. A portion of the paper is substantially previous to the acceptance of the electrolyte so as to absorb electrolyte when there is an excess in the matrix and to desorb electrolyte when there is a shortage in the matrix. A second layer of backing paper is positioned adjacent to the first layer of paper and is substantially impervious to the acceptance of electrolyte.

Wright, Maynard K. (Bethel Park, PA)

1989-01-01

130

Simple rheology of mixed proteins  

Science.gov (United States)

Mixing different proteins to form strong gel networks for food applications may create synergistic increases in viscoelasticity that cannot be achieved with a single protein. In this study, small amplitude oscillatory shear analyses were used to investigate the rheology of calcium caseinate (CC), e...

131

Molten salt electrolyte separator  

Energy Technology Data Exchange (ETDEWEB)

A molten salt electrolyte/separator for battery and related electrochemical systems including a molten electrolyte composition and an electrically insulating solid salt dispersed therein, to provide improved performance at higher current densities and alternate designs through ease of fabrication.

Kaun, Thomas D. (New Lenox, IL)

1996-01-01

132

Fluid and Electrolyte Balance  

Science.gov (United States)

... They are in your blood, urine and body fluids. Maintaining the right balance of electrolytes helps your ... them from the foods you eat and the fluids you drink. Levels of electrolytes in your body ...

133

Synthesis, characterization and electrical properties of solid electrolyte for solid oxide fuel cell; Preparacao, caracterizacao e propriedades eletricas de eletrolito solido para celula a combustivel de oxido solido  

Energy Technology Data Exchange (ETDEWEB)

Solid electrolytes of BaCe{sub 08}Gd{sub O29} were prepared by the polymeric precursor method. X-ray diffraction data shows a single phase with orthorhombic crystalline structure. The densification process was followed by scanning electronic microscopy and apparent density measurements. The apparent density was developed for different temperatures of sintering, reaching > 96% for sintered temperature of 1550 {sup 0}C deg . The electrochemical impedance analysis was development in the temperature of 400-700 deg C, in air atmosphere at 700 deg C a value of 30,6 mS.cm{sup -1} was obtained. The results of conductivity have confirmed the gadolinium doped barium cerate has a great potential for use as solid electrolyte for intermediate temperature solid oxide fuel cell, at experimental controlled conditions. (author)

Berton, Marco Antonio Coelho; Garcia, Carlos Mario; Matos, Jeferson Hrenechen [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)], Emails: felsky@latec.org.br, garcia@latec.org.br, jeferson.h@latec.org.br

2010-04-15

134

Fuel cell electrolyte  

Energy Technology Data Exchange (ETDEWEB)

This invention relates to a novel intermediate temperature fuel cell electrolyte, fuel cells containing this electrolyte and a process for operating these fuel cells. The fuel cell electrolyte composition comprises one or more phosphonic acids. The fuel cell electrolyte composition can include a gelling agent and can be effectively used in fuel cells wherein the fuel is hydrogen, the oxidizer is oxygen and the operating temperature is between about 100/sup 0/C and 250/sup 0/C.

Walsh, E.N.

1986-11-11

135

Lithium ion conducting electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The present invention relates generally to highly conductive alkali-metal ion non-crystalline electrolyte systems, and more particularly to novel and unique molten (liquid), rubbery, and solid electrolyte systems which are especially well suited for use with high current density electrolytic cells such as primary and secondary batteries.

Angell, Charles Austen (Mesa, AZ); Liu, Changle (Midland, MI); Xu, Kang (Montgomery Village, MD); Skotheim, Terje A. (Tucson, AZ)

1999-01-01

136

Nanoporous polymer electrolyte  

Energy Technology Data Exchange (ETDEWEB)

A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at 25.degree. C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

Elliott, Brian (Wheat Ridge, CO); Nguyen, Vinh (Wheat Ridge, CO)

2012-04-24

137

Summary Of 2009 Rheology Modifier Program  

International Nuclear Information System (INIS)

[en] The overall objective of the EM-31 Rheological Modifiers and Wetting Agents program is to utilize commercially available rheology modifiers to increase the solids fraction of radioactive sludge based waste streams, resulting in an increase in throughput and decreasing the overall processing time. The program first investigates the impact of rheology modifiers on slurry simulants and then utilizes the most effective rheology modifiers on radioactive slurries. The work presented in this document covers the initial investigation of rheology modifier testing with simulants. This task is supported by both the Savannah River National Laboratory (SRNL) and Pacific Northwest National Laboratory (PNNL). The SRNL EM-31 task, for this year, was to investigate the use of rheology modifiers on simulant Defense Waste Processing Facility (DWPF) melter feeds. The task is to determine, based on the impact of the rheology modifier, if there are rheology modifiers that could reduce the water content of the slurry going to the DWPF melter, hence increasing the melt rate by decreasing the water loading. The rheology modifier in essence would allow a higher solids content slurry to have the same type of rheology or pumpability of a lower solids slurry. The modifiers selected in this report were determined based on previous modifiers used in high level waste melter feed simulants, on-going testing performed by counterparts at PNNL, and experiences gain through use of modifiers in other Department of Energy (DOE) processes such as grout processing. There were 12 rheology modifiers selected for testing, covering both organic and inorganic types and they were tested at four different concentrations for a given melter feed. Five different DWPF melter feeds were available and there was adequate material in one of the melter feeds to increase the solids concentration, resulting in a total of six simulants for testing. The mass of melter feed available in each simulant was not adequate for testing each rheology modifier, hence based on the changes in rheology for a given rheology modifier, rheology modifiers were either dropped or added between simulants. Three rheology modifiers were used on all simulants. The results from this testing indicate that citric acid or polycarboxylate based rheology modifiers are the most effective in reducing the yield stress, by as much as 70% at the higher rheology modifier additions and were effective on most of the tested simulants. These rheology modifiers are organic, hence the can also be used as reductants in melter operations. The most effective non-organic rheology modifiers, sodium metasilicate reduced the yield stress by 10%. It is recommended that both citric acid and commercially available polycarboxylate rheology modifiers be further investigated. Different molecular weight polycarboxylates and different types of polycarboxylates used in other industries must be considered. These polycarboxylates are extensively utilized in the cement, ceramic, and water treatment processes, hence readily available. Future work on DWPF melter feeds involving rheology modifiers should include, assuming the present method of processing sludge through DPWF does not change, is: (1) Investigate the use of polycarboxylate in various processes and procure polycarboxylates for testing. Limit rheology modifier selection and future testing between four and eight different types. (2) Test rheology modifiers on at least two different chemical types or bounding DWPF SME product simulants. Test to include the impact of boiling and the effectiveness in reducing water content via rheology versus weight percent curves. (3) Based on selected modifiers, perform testing on actual radioactive melter feed based on results from simulant testing.

2009-01-01

138

SUMMARY OF 2009 RHEOLOGY MODIFIER PROGRAM  

Energy Technology Data Exchange (ETDEWEB)

The overall objective of the EM-31 Rheological Modifiers and Wetting Agents program is to utilize commercially available rheology modifiers to increase the solids fraction of radioactive sludge based waste streams, resulting in an increase in throughput and decreasing the overall processing time. The program first investigates the impact of rheology modifiers on slurry simulants and then utilizes the most effective rheology modifiers on radioactive slurries. The work presented in this document covers the initial investigation of rheology modifier testing with simulants. This task is supported by both the Savannah River National Laboratory (SRNL) and Pacific Northwest National Laboratory (PNNL). The SRNL EM-31 task, for this year, was to investigate the use of rheology modifiers on simulant Defense Waste Processing Facility (DWPF) melter feeds. The task is to determine, based on the impact of the rheology modifier, if there are rheology modifiers that could reduce the water content of the slurry going to the DWPF melter, hence increasing the melt rate by decreasing the water loading. The rheology modifier in essence would allow a higher solids content slurry to have the same type of rheology or pumpability of a lower solids slurry. The modifiers selected in this report were determined based on previous modifiers used in high level waste melter feed simulants, on-going testing performed by counterparts at PNNL, and experiences gain through use of modifiers in other Department of Energy (DOE) processes such as grout processing. There were 12 rheology modifiers selected for testing, covering both organic and inorganic types and they were tested at four different concentrations for a given melter feed. Five different DWPF melter feeds were available and there was adequate material in one of the melter feeds to increase the solids concentration, resulting in a total of six simulants for testing. The mass of melter feed available in each simulant was not adequate for testing each rheology modifier, hence based on the changes in rheology for a given rheology modifier, rheology modifiers were either dropped or added between simulants. Three rheology modifiers were used on all simulants. The results from this testing indicate that citric acid or polycarboxylate based rheology modifiers are the most effective in reducing the yield stress, by as much as 70% at the higher rheology modifier additions and were effective on most of the tested simulants. These rheology modifiers are organic, hence the can also be used as reductants in melter operations. The most effective non-organic rheology modifiers, sodium metasilicate reduced the yield stress by 10%. It is recommended that both citric acid and commercially available polycarboxylate rheology modifiers be further investigated. Different molecular weight polycarboxylates and different types of polycarboxylates used in other industries must be considered. These polycarboxylates are extensively utilized in the cement, ceramic, and water treatment processes, hence readily available. Future work on DWPF melter feeds involving rheology modifiers should include, assuming the present method of processing sludge through DPWF does not change, is: (1) Investigate the use of polycarboxylate in various processes and procure polycarboxylates for testing. Limit rheology modifier selection and future testing between four and eight different types. (2) Test rheology modifiers on at least two different chemical types or bounding DWPF SME product simulants. Test to include the impact of boiling and the effectiveness in reducing water content via rheology versus weight percent curves. (3) Based on selected modifiers, perform testing on actual radioactive melter feed based on results from simulant testing.

Hansen, E.

2009-12-08

139

Rheology of sludge. Rupture behavior  

Energy Technology Data Exchange (ETDEWEB)

Rheological measurements were carried out for the suspension at high concentration(6-16 vol %), that is, Na Bentonite sludge which is a typical exsample of developed hydrogen bridge. Uniaxial compression was applied to specimen. It was found from experimental results that sludge failed at the yield point of suspension and the rheological behavior up to the failure could be partially explained by using Burgers model but the nonlinearity could not be neglected as a whole. The upper Gammerm(=0.10) and lower Gammerm(=0.03) were found for the failed strains, which were independent of the concentration. In this connection, it was found that the specimen was deformed uniformly as a whole up to slip failure and the Gammerm, compression stress at the failure, was only dependent upon the concentration. (10 figs, 9 refs)

Nakamaru, Hachiro; Yuzuki, Takayuki; Nagase, Yoichi

1988-06-20

140

Rheological Interpretation of Rayleigh Damping  

CERN Document Server

Damping is defined through various terms such as energy loss per cycle (for cyclic tests), logarithmic decrement (for vibration tests), complex modulus, rise-time or spectrum ratio (for wave propagation analysis), etc. For numerical modeling purposes, another type of damping is frequently used : it is called Rayleigh damping. It is a very convenient way of accounting for damping in numerical models, although the physical or rheological meaning of this approach is not clear. A rheological model is proposed to be related to classical Rayleigh damping : it is a generalized Maxwell model with three parameters. For moderate damping (<25%), this model perfectly coincide with Rayleigh damping approach since internal friction has the same expression in both cases and dispersive phenomena are negligible. This is illustrated by finite element (Rayleigh damping) and analytical (generalized Maxwell model) results in a simple one-dimensional case.

Semblat, Jean-François

2009-01-01

 
 
 
 
141

Molecular simulation of rheological properties using massively parallel supercomputers  

Energy Technology Data Exchange (ETDEWEB)

Advances in parallel supercomputing now make possible molecular-based engineering and science calculations that will soon revolutionize many technologies, such as those involving polymers and those involving aqueous electrolytes. We have developed a suite of message-passing codes for classical molecular simulation of such complex fluids and amorphous materials and have completed a number of demonstration calculations of problems of scientific and technological importance with each. In this paper, we will focus on the molecular simulation of rheological properties, particularly viscosity, of simple and complex fluids using parallel implementations of non-equilibrium molecular dynamics. Such calculations represent significant challenges computationally because, in order to reduce the thermal noise in the calculated properties within acceptable limits, large systems and/or long simulated times are required.

Bhupathiraju, R.K.; Cui, S.T.; Gupta, S.A.; Cummings, P.T. [Univ. of Tennessee, Knoxville, TN (United States). Dept of Chemical Engineering; Cochran, H.D. [Oak Ridge National Lab., TN (United States)

1996-11-01

142

RHEOLOGICAL PROPERTIES OF MINERAL OIL  

Directory of Open Access Journals (Sweden)

Full Text Available In this article presents us rheological behavior of mineral oil. Apparent viscosity of mineral oil was determined at temperatures between 400C-900C and shear rates ranging from 3.3-120s-1. This study is to find a polynomial dependence on temperature and oil viscosity shear rate. Value of parameters of the theoretical models described by equations and correlation coefficient were determined by correlating a characteristic polynomial equation of each curve.

IOANA STANCIU

2011-01-01

143

New polysaccharide-based polymer electrolytes; Nouveaux electrolytes polymeres a base de polysaccharides  

Energy Technology Data Exchange (ETDEWEB)

Polysaccharides like cellulose and chitosan are known for their filmic properties. This paper concerns the synthesis and the study of chitosan-based polymer electrolytes. A preliminary work concerns the study of glucosamine reactivity. The poly-condensation of chitosan ethers (obtained by reaction with ethylene oxide or propylene oxide) with bifunctional and monofunctional oligo-ethers leads to the formation of thin lattices (10 {mu}m) having excellent mechanical properties. The presence of grafted polyether chains along the polysaccharide skeleton allows to modify the vitreous transition temperature and the molecular disorder of the system. Two type of polymer electrolytes have been synthesized: electrolytes carrying a dissolved alkaline metal salt and ionomers. The analysis of their thermal, dynamical mechanical, nuclear magnetic relaxation, electrical, and electrochemical properties shows that this new class of polymer electrolytes has the same performances as ethylene poly-oxide based amorphous lattices plus the advantage of having good filmic properties. Abstract only. (J.S.)

Velasquez-Morales, P.; Le Nest, J.F.; Gandini, A. [Ecole Francaise de Papeterie et des Industries Graphique, 38 - Saint Martin d`Heres (France)

1996-12-31

144

Synthesis, Multinuclear NMR Characterization and Dynamic Property of Organic–Inorganic Hybrid Electrolyte Membrane Based on Alkoxysilane and Poly(oxyalkylene) Diamine  

Directory of Open Access Journals (Sweden)

Full Text Available Organic–inorganic hybrid electrolyte membranes based on poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether) complexed with LiClO4 via the co-condensation of tetraethoxysilane (TEOS) and 3-(triethoxysilyl)propyl isocyanate have been prepared and characterized. A variety of techniques such as differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, alternating current (AC) impedance and solid-state nuclear magnetic resonance (NMR) spectroscopy are performed to elucidate the relationship between the structural and dynamic properties of the hybrid electrolyte and the ion mobility. A VTF (Vogel-Tamman-Fulcher)-like temperature dependence of ionic conductivity is observed for all the compositions studied, implying that the diffusion of charge carriers is assisted by the segmental motions of the polymer chains. A maximum ionic conductivity value of 5.3 × 10?5 Scm?1 is obtained at 30 °C. Solid-state NMR results provide a microscopic view of the effects of salt concentrations on the dynamic behavior of the polymer chains.

Diganta Saikia; Yu-Chi Pan; Hsien-Ming Kao

2012-01-01

145

Synthesis and characterization of polyether urethane acrylate -LiCF{sub 3}SO{sub 3}-based polymer electrolytes by UV-curing in lithium batteries  

Energy Technology Data Exchange (ETDEWEB)

The prepolymers of polyether urethane acrylate (PEUA) were synthesized from polyether polyol (polyethylene glycol (PEG) or polypropylene glycol (PPG)), diisocyanate (hexamethylene diisocyanate (HMDI) or toluene, 2,4-diisocyanate (TDI)), and the caprolactone-modified hydroxyethyl acrylate (FA2D) using the catalyst (dibutyltin dilaurate (DBTDL)) by stepwise addition reaction. Lithium triflate (LiCF{sub 3}SO{sub 3}) was dissolved in PEUA prepolymers, and plasticizer (propylene carbonate (PC)) was added into prepolymer and salt mixtures. Then photoinitiator (Irgacure 184) was also dissolved in the mixtures. Thin films were prepared by casting on the glass plate, and then by curing the plasticized prepolymer and salt mixtures under UV radiation. Electrochemical and electrical properties of PEUA-LiCF{sub 3}SO{sub 3}-based polymer electrolytes were evaluated and discussed to be used in lithium batteries. (orig.)

Kim, Cheon Soo; Kim, Bo Hyun; Kim, Keon [Korea Univ., Seoul (Korea). Dept. of Chemistry

1999-11-01

146

Electrolytic purification of metals  

Energy Technology Data Exchange (ETDEWEB)

A method of electrolytically separating metal from impurities comprises providing the metal and impurities in a molten state in a container having a porous membrane therein, the membrane having a thickness in the range of about 0.01 to 0.1 inch, being capable of containing the molten metal in the container, and being permeable by a molten electrolyte. The metal is electrolytically transferred through the membrane to a cathode in the presence of the electrolyte for purposes of separating or removing impurities from the metal.

Bowman, Kenneth A. (Leechburg, PA)

1980-01-01

147

Design of magneto-rheological (MR) valve  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Magneto-Rheological Fluid (“MRF”) technology has been successfully employed in various low and high volume automotive applications. Good understanding of specific design constraints is required to define and to optimize a magneto-rheological device. This article presents parametrical analyses with m...

Grunwald, Artur; Olabi, Abdul-Ghani

148

Cellular Hydraulics Suggests a Poroelastic Cytoplasm Rheology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The cytoplasm represents the largest part of the cell by volume and hence its rheology sets the rate at which cellular shape change can occur. Recent experimental evidence suggests that cytoplasmic rheology can be described using a poroelastic formulation in which the cytoplasm is considered a biph...

Mahadevan, Lakshminarayanan; Moeendarbary, E.; Valon, L.; Fritzsche, M.; Moulding, D. A.; Thrasher, A. J.; Stride, E.

149

Effects of Astaxanthin on Human Blood Rheology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Effects of astaxanthin (AX) derived from H. pluvialis on human blood rheology were investigated in 20 adult men with a single-blind method. The experimental group was 57.5 ± 9.8 years of age and the placebo group was 50.8 ± 13.1 years of age. A blood rheology test that measures whole blood transit t...

Miyawaki, Hiromi; Takahashi, Jiro; Tsukahara, Hiroki; Takehara, Isao

150

Chocolate rheology Reologia de chocolate  

Directory of Open Access Journals (Sweden)

Full Text Available Rheology is the science that studies the deformation and flow of solids and fluids under the influence of mechanical forces. The rheological measures of a product in the stage of manufacture can be useful in quality control. The microstructure of a product can also be correlated with its rheological behavior allowing for the development of new materials. Rheometry permits attainment of rheological equations applied in process engineering, particularly unit operations that involve heat and mass transfer. Consumer demands make it possible to obtain a product that complies with these requirements. Chocolate industries work with products in a liquid phase in conching, tempering, and also during pumping operations. A good design of each type of equipment is essential for optimum processing. In the design of every process, it is necessary to know the physical characteristics of the product. The rheological behavior of chocolate can help to know the characteristics of application of the product and its consumers. Foods are generally in a metastable state. Their texture depends on the structural changes that occur during processing. Molten chocolate is a suspension with properties that are strongly affected by particle characteristics including not only the dispersed particles but also the fat crystals formed during chocolate cooling and solidification. Chocolate rheology is extensively studied, and it is known that chocolate texture and stability is strongly affected by the presence of specific crystalsReologia é a ciência que estuda a deformação e fluxo de sólidos e fluidos sob a influência de forças mecânicas. As determinações reológicas de um produto no estágio de produção podem ser úteis no controle de qualidade. A microestrutura de um produto pode ser correlacionada com o comportamento reológico, permitindo desenvolver novos materiais. A reometria permite a aplicação de equações reológicas em processos de engenharia, particularmente nas operações unitárias que envolvem aquecimento e transferência de massa. A demanda dos consumidores torna possível obter um produto que esteja de acordo com as necessidades. As indústrias de chocolates trabalham com o produto na fase líquida na concha, na temperadeira e também durante o bombeamento. O desenho de cada tipo de equipamento é essencial para o ótimo processamento. No desenho de cada processo é necessário conhecer as características físicas do produto. O comportamento reológico do chocolate pode auxiliar no conhecimento das características de aplicação e dos consumidores do produto. Alimentos estão geralmente em estado metaestável. Sua textura depende das trocas estruturais que ocorrem com seu processamento. Chocolate líquido é uma suspensão com propriedades que são fortemente afetadas pelas características das partículas, incluindo não somente partículas dispersas mas também cristais de gordura formados durante o resfriamento e solidificação. A reologia de chocolates é extensivamente estudada, a textura do chocolate e sua estabilidade são fortemente afetadas pela presença de cristais específicos

Estela Vidal Gonçalves; Suzana Caetano da Silva Lannes

2010-01-01

151

Chocolate rheology/ Reologia de chocolate  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Reologia é a ciência que estuda a deformação e fluxo de sólidos e fluidos sob a influência de forças mecânicas. As determinações reológicas de um produto no estágio de produção podem ser úteis no controle de qualidade. A microestrutura de um produto pode ser correlacionada com o comportamento reológico, permitindo desenvolver novos materiais. A reometria permite a aplicação de equações reológicas em processos de engenharia, particularmente nas operaç (more) ões unitárias que envolvem aquecimento e transferência de massa. A demanda dos consumidores torna possível obter um produto que esteja de acordo com as necessidades. As indústrias de chocolates trabalham com o produto na fase líquida na concha, na temperadeira e também durante o bombeamento. O desenho de cada tipo de equipamento é essencial para o ótimo processamento. No desenho de cada processo é necessário conhecer as características físicas do produto. O comportamento reológico do chocolate pode auxiliar no conhecimento das características de aplicação e dos consumidores do produto. Alimentos estão geralmente em estado metaestável. Sua textura depende das trocas estruturais que ocorrem com seu processamento. Chocolate líquido é uma suspensão com propriedades que são fortemente afetadas pelas características das partículas, incluindo não somente partículas dispersas mas também cristais de gordura formados durante o resfriamento e solidificação. A reologia de chocolates é extensivamente estudada, a textura do chocolate e sua estabilidade são fortemente afetadas pela presença de cristais específicos Abstract in english Rheology is the science that studies the deformation and flow of solids and fluids under the influence of mechanical forces. The rheological measures of a product in the stage of manufacture can be useful in quality control. The microstructure of a product can also be correlated with its rheological behavior allowing for the development of new materials. Rheometry permits attainment of rheological equations applied in process engineering, particularly unit operations that (more) involve heat and mass transfer. Consumer demands make it possible to obtain a product that complies with these requirements. Chocolate industries work with products in a liquid phase in conching, tempering, and also during pumping operations. A good design of each type of equipment is essential for optimum processing. In the design of every process, it is necessary to know the physical characteristics of the product. The rheological behavior of chocolate can help to know the characteristics of application of the product and its consumers. Foods are generally in a metastable state. Their texture depends on the structural changes that occur during processing. Molten chocolate is a suspension with properties that are strongly affected by particle characteristics including not only the dispersed particles but also the fat crystals formed during chocolate cooling and solidification. Chocolate rheology is extensively studied, and it is known that chocolate texture and stability is strongly affected by the presence of specific crystals

Gonçalves, Estela Vidal; Lannes, Suzana Caetano da Silva

2010-12-01

152

Rheology of unstable mineral emulsions  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, the rheology of mineral oils and their unstable water emulsion were investigated. The oil samples were domestic crude oil UA, its fractions UA1, UA4 and blend semi-product UP1, while the concentration of oil in water emulsions was in the range from 1 up to 30%. The results were analyzed based on shear stress. The oil samples UA, UA1 and UP1 are Newtonian fluids, while UA4 is pseudoplastic fluid. The samples UA and UA4 show higher value of shear stress (83.75 Pa, 297 Pa), then other two samples UA1 and UP1 (18.41 Pa, 17.52 Pa). Rheology of investigated oils due to its complex chemical composition should be analyzed as a simultaneous effect of all their components. Therefore, structural composition of the oils was determined, namely content of paraffins, naphthenes, aromatics and asphaltenes. All samples contain paraffins, naphthenes and aromatics but only oils UA and UA4 contain asphaltenes as well. All investigated emulsions except 30% EUA4 are Newtonian fluids. The EUA4 30% emulsion shows pseudoplastic behaviour, and it is the only 30% emulsion among investigated ones that achieves lower shear stress then its oil. The characteristics of oil samples that could have an influence on their properties and their emulsion rheology, were determined. These characteristics are: neutralization number, interfacial tension, dielectric constant, and emulsivity. Oil samples UA and UA4 have significantly higher values of neutralization number, dielectric constants, and emulsivity. The sample UA has the lowest value of interface tension and the greatest emulsivity, indicating that this oil, among all investigated, has the highest preference for building emulsion. This could be the reason why 20% and 30% emulsions of the oil UA achieve the highest shear stress among all investigated emulsions.

Sokolovi? Dunja S.; Še?erov-Sokolovi? Radmila M.; Sokolovi? Slobodan M.

2013-01-01

153

Hydrogen selenide treatment of electrolytes  

Energy Technology Data Exchange (ETDEWEB)

A method for lowering the activation energy of a polycrystalline ceramic electrolyte is disclosed. Polycrystalline ceramic electrolytes, such as beta-alumina, when contacted with hydrogen selenide exhibit a lower activation energy than untreated electrolytes.

Rasmussen, J. R.; Virkar, A. V.

1985-01-29

154

Rheology of Soft Glassy Materials  

CERN Multimedia

We attribute similarities in the rheology of many soft materials (foams, emulsions, slurries, etc.) to the shared features of structural disorder and metastability. A generic model for the mesoscopic dynamics of ``soft glassy matter'' is introduced, with interactions represented by a mean-field noise temperature x. We find power law fluid behavior either with (x<1) or without (1

Sollich, P; Hébraud, P; Cates, M E; Sollich, Peter; Lequeux, Francois; Hebraud, Pascal; Cates, Michael E

1997-01-01

155

Laboratory Exercise: What Controls Rheology?  

Science.gov (United States)

A short laboratory exercise, conducted by students, is used to illustrate the multiple factors that contribute to rocks' varied responses to deformation. Analogue materials (play-doh, notebook springs, butter, silly putty, plastic bags, etc.) are used to illustrate many of the controlling factors such as lithology, stress, temperature, confining pressure, strain rate, preexisting weaknesses, and accumulated strain. The analogue experiments are presented in conjunction with parallel data from deformation experiments and field studies. The tandem presentation of analogue experiment and real data requires the students to obtain a natural "feel" for rheologic parameters and more exhaustively analyze the important conclusions obtained from field and deformation experiment data.

Czeck, Dyanna

156

Rheological behaviour of coal-water mixtures. 2. Effects of surfactants and temperature  

Energy Technology Data Exchange (ETDEWEB)

The rheological characteristics of coal-water mixture (CWM) were investigated, including the effects of surfactant type and concentration, presence of added electrolytes and slurry temperature. The slurryability of coal could be enhanced considerably by the addition of surfactants and some electrolytes and the slurries almost exhibited shear-thinning behaviour i.e. were pseudoplastic with n{lt}1, which is a desirable rheological characteristic for CWM. The slurry viscosity increased as the temperature, the amount of anionic surfactant and electrolyte, and the HLB value of non-ionic surfactant decreased. The addition of nonylphenol non-ionic surfactants also enhanced the resistance of CWM to sedimentation, and this effect was more pronounced, the greater the number of ethylene oxide groups in the surfactant molecule. The CWMs displayed a higher degree of pseudoplasticity with decreasing amount of surfactant and temperature. The effect of temperature on the slurry viscosity could be described by the simple Andrade equation, but the rate of reduction of apparent viscosity associated with the temperature rise began to decrease above a certain temperature which seems to mark the onset of an adverse effect of temperature. 22 refs., 7 figs., 1 tab.

Nam-Sun Roh; Dae-Hyun Shin; Dong-Chan Kim; Jong-Duk Kim [Korea Institute of Energy Research, Taejon (Republic of Korea). Fuel Research Team

1995-09-01

157

Ceramic solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Strategies for the design of ceramic solid electrolytes are reviewed. Problems associated with stoichiometric and doped compounds are compared. In the illustration of design principles, emphasis is given to oxide-ion electrolytes for use in solid-oxide fuel cells, oxygen pumps, and oxygen sensors

Goodenough, John B. [Center for Materials Science and Engineering, University of Texas at Austin, Austin, TX (United States)

1997-02-15

158

Alkaline polymer electrolyte membranes for fuel cell applications.  

UK PubMed Central (United Kingdom)

In this review, we examine the most recent progress and research trends in the area of alkaline polymer electrolyte membrane (PEM) development in terms of material selection, synthesis, characterization, and theoretical approach, as well as their fabrication into alkaline PEM-based membrane electrode assemblies (MEAs) and the corresponding performance/durability in alkaline polymer electrolyte membrane fuel cells (PEMFCs). Respective advantages and challenges are also reviewed. To overcome challenges hindering alkaline PEM technology advancement and commercialization, several research directions are then proposed.

Wang YJ; Qiao J; Baker R; Zhang J

2013-07-01

159

Electrolyte-tolerant polymers for high-temperature drilling fluids  

Energy Technology Data Exchange (ETDEWEB)

New high temperature synthetic organic polymers are discussed in the light of existing technology and their application in water-base drilling fluids. Salt-tolerant polymeric deflocculants and filtration control agents with high temperature stability are prime considerations for extending the utility range. Laboratory results from temperature and electrolyte studies as well as rheological measurements to 550/sup 0/ F and 10,000 psi with a new high pressure/ high temperature test system are shown. The new polymers can be used alone or in combination with conventional materials. Examples of field use and benefits are described.

Clements, W.R.; Nevins, M.J.; Scearce, F.A.

1985-03-01

160

Nonlinear rheology of colloidal dispersions  

International Nuclear Information System (INIS)

[en] Colloidal dispersions are commonly encountered in everyday life and represent an important class of complex fluid. Of particular significance for many commercial products and industrial processes is the ability to control and manipulate the macroscopic flow response of a dispersion by tuning the microscopic interactions between the constituents. An important step towards attaining this goal is the development of robust theoretical methods for predicting from first-principles the rheology and nonequilibrium microstructure of well defined model systems subject to external flow. In this review we give an overview of some promising theoretical approaches and the phenomena they seek to describe, focusing, for simplicity, on systems for which the colloidal particles interact via strongly repulsive, spherically symmetric interactions. In presenting the various theories, we will consider first low volume fraction systems, for which a number of exact results may be derived, before moving on to consider the intermediate and high volume fraction states which present both the most interesting physics and the most demanding technical challenges. In the high volume fraction regime particular emphasis will be given to the rheology of dynamically arrested states. (topical review)

2010-09-15

 
 
 
 
161

RHEOLOGIC BEHAVIOR OF PASTRY CREAMS  

Directory of Open Access Journals (Sweden)

Full Text Available The increased social and economic importance of ready–made food production, together with the complexity of production technology, processing, handling and acceptance of these fragile and perishable products requires extensive knowledge of their physical properties. Viscoelastic properties play an important role in the handling and quality attributes of creams.Our study was to investigate the rheological properties of different confectionary creams, by scanning the field of shear rates at constant temperature and frequency, angular frequency scanning at small deformations and quantification of rheological changes during application of deformation voltages. The creams tested were made in the laboratory using specific concentrates as fine powders, marketed by the company “Dr. Oetker” compared with similar creams based on traditional recipes and techniques. Following the researches conducted we could conclude that both traditional creams and the instant ones are semi fluid food products with pseudoplastic and thixotropic shear flow behavior, with structural viscosity. Instant and traditional creams behaved as physical gels with links susceptible to destruction, when subjected to deformation forces.

Camelia Vizireanu; Aurelia Ionescu,; Daniela Istrati; Felicia Dima

2012-01-01

162

Rheology and Methods of Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available Rheology is defined as the science of flow and deformation of materials. The term came from Greek rheo meaning to flow and logos means science.1It is the study of the change in form and the flow of matter, embracing elasticity, viscosity and plasticity. Rheological properties are studied with rheometry. In rheometry is used to determine the correlations between deformation, shear stress and time.Viscometry:Study of flow of materials and determines the correlations between shear rate, shear stress and time.Viscosity:Viscosity is an expression of the resistance of fluid to flow; the higher the viscosity, the greater the resistance2. Viscosity is a material property, which is independent of geometry3. It is defined as the internal friction of a fluid, caused by molecular attraction, which makes it resist a tendency to flow. This friction becomes apparent when a layer of fluid is made to move in relation to another layer. The greater the friction, the greater the amount of force required to cause this movement, which is called shear. Viscosity is a quantity that describes a samples resistance to flow in contradiction to quantities as plasticity, elasticity and viscoelasticity. Sample is forced to flow by the force F (Figure 1). When force is removed the sample stops to flow. This is described by the quantity called dashpot. The dashpot is a symbol for Newtonian flow according to Newton’s viscosity law.

Prof. S. S. Patil; Dr. C. S. Magdum

2006-01-01

163

RHEOLOGICAL CHARACTERIZATION OF AGED ASPHALTS  

Directory of Open Access Journals (Sweden)

Full Text Available The present work shows the rheological properties of the three Colombian asphalts produced in the refineries at Barrancabermeja, Cartagena and Apiay, exposed to the open air during 18 months using a specially designed testing bank. Rheological behavior was evaluated using the new specifications of SHRP technology in the Brookfield and DSR rheometers to determine viscosity, Shear Stress, Shear Rate, Dynamic Share Modulus and other related variables. The measurements were made using different temperatures and load times.En el presente trabajo se estudian las propiedades reológicas de los tres tipos de asfaltos industriales producidos en Colombia, en las refinerías de Barrancabermeja, Cartagena y Apiay, después del envejecimiento durante 18 meses en un banco de pruebas al aire libre especialmente diseñado. La evaluación del comportamiento reológico se realizó a través de ensayos basados en las nuevas especificaciones de la tecnología SHRP en los reómetros Brookfield y DSR para determinar características tales como: viscosidad, esfuerzo de corte, susceptibilidad térmica, velocidad de deformación y módulo de corte dinámico, a diferentes temperaturas y tiempos de carga.

Natalia Afanasieva; Mario Álvarez; Mónica J. Ortiz

2002-01-01

164

Synthesis of 8YSZ-LSGM Composite Thick Film Ceramics for Solid Electrolyte From Nanopowder Utilizing Local Zircon Prepared Using Sol Gel Process  

International Nuclear Information System (INIS)

Thick film ceramics of 8% mol Y2O3 doped-ZrO2(8YSZ)-La0.8Sr0.2Ga0.2Mg0.8O3(LSGM) composite for solid electrolyte have been synthesized from nanopowder. Concentration of LSGM was 0 and 10% weight. A paste for the thick films was made from 8YSZ nanopowder prepared using sol gel method and LSGM powder prepared by solid state reaction. Precursors for the 8YSZ nanopowder preparation were ZrOCl2·8H2O derived from local zircon as byproduct of Tin processing at Bangka Island using caustic fusion method, and Y(NO3)3. The thick films were produced by screen printing technique on alumina substrates. The films were sintered at 1500 deg. C for 2 hours in air. X-ray diffraction (XRD) data showed that the nanopowder of 8YSZ was well produced with broad peaks. The particle size of the 8YSZ powder was about 12 nm as calculated using Debye Scherrer method. The thick films of 8YSZ and 8YSZ-LSGM (90:10 in weight %) composite could be produced, however, the films still contain voids. The ionic conductance of the YSZ-10LSGM films was smaller than that of the YSZ films.

2010-10-24

165

Synthesis of 8YSZ-LSGM Composite Thick Film Ceramics for Solid Electrolyte From Nanopowder Utilizing Local Zircon Prepared Using Sol Gel Process  

Science.gov (United States)

Thick film ceramics of 8% mol Y2O3 doped-ZrO2 (8YSZ)-La0.8Sr0.2Ga0.2Mg0.8O3 (LSGM) composite for solid electrolyte have been synthesized from nanopowder. Concentration of LSGM was 0 and 10% weight. A paste for the thick films was made from 8YSZ nanopowder prepared using sol gel method and LSGM powder prepared by solid state reaction. Precursors for the 8YSZ nanopowder preparation were ZrOCl2.8H2O derived from local zircon as byproduct of Tin processing at Bangka Island using caustic fussion method, and Y(NO3)3. The thick films were produced by screen printing technique on alumina substrates. The films were sintered at 1500° C for 2 hours in air. X-ray diffraction (XRD) data showed that the nanopowder of 8YSZ was well produced with broad peaks. The particle size of the 8YSZ powder was about 12 nm as calculated using Debye Scherrer method. The thick films of 8YSZ and 8YSZ-LSGM (90:10 in weight %) composite could be produced, however, the films still contain voids. The ionic conductance of the YSZ-10LSGM films was smaller than that of the YSZ films.

Syarif, Dani Gustaman; Soepriyanto, Syoni; Ismunandar; Korda, Akhmad

2010-10-01

166

Possibilities of applying rheological measurements in metallurgy  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: The purpose of this paper is to analyse from the literature point of view the issues concerning modern methods of measuring the viscosity of liquid steel and solid-liquid steel in the course of rheological research with the use of a high temperature rheometer. The paper reviews the subject of measuring and modelling the viscosity value of steel with the use of equations and data available in the literature. It also presents the difficulties connected to rheological measurements of liquid steel and metallurgical slag.Design/methodology/approach: The main purpose of this paper is to present the issues relating to rheological measurements and the possibilities of their application in metallurgy.Findings: The paper describes the issues pertaining to the viscosity measurements of liquid and metallurgical slag.Research limitations/implications: In the future the authors are planning to develop an empirical model which would include rheological parameters and would be used to calculate the viscosity of liquid iron solutions on the basis of conducted rheological measurements of liquid steel.Practical implications: The results of investigation might be used in the future in semi-solid metal (SSM) forming. A fundamental and detailed understanding of the steel rheology is crucial for industrialization.Originality/value: The paper presents the issues connected to the subject of and difficulties encountered in the course of rheological measurements of liquid ferroalloys and metallurgical slag.

M. Korolczuk-Hejnak

2012-01-01

167

Analogy between dynamics of thermo-rheological and piezo-rheological pendulums  

International Nuclear Information System (INIS)

The constitutive stress-strain relations of the standard thermo-rheological and piezo-rheological hereditary element in differential form as well as in two different integro-differential forms are defined. The considered problem of a thermo-rheological hereditary discrete system nonlinear dynamics in the form of thermo-rheological double pendulum system with coupled pendulums gets the significance of two constrained bodies in plane motion problem, as a problem important for studying a sensor dynamics or actuator dynamics in active structure dynamics. System of the averaged equations in the first approximation for amplitudes and phases are derived and qualitatively analyzed. Analogy between nonlinear dynamics of the double pendulum systems with thermo-rheological and piezo-rheological properties between pendulums is pointed out

2008-01-01

168

High efficiency solid state dye sensitized solar cells with graphene-polyethylene oxide composite electrolytes.  

UK PubMed Central (United Kingdom)

Novel and highly effective composite electrolytes were prepared by combining the two dimensional graphene (Gra) and polyethylene oxide (PEO) for the solid electrolyte of dye sensitized solar cells (DSSCs). Gra sheets were uniformly coated by the polymer layer through the ester carboxylate bonding between oxygenated species on Gra sheets and PEO. The Gra-PEO composite electrolyte showed the large scale generation of iodide ions in a redox couple. From rheological analysis, the decrease in viscosity after the addition of LiI and I2 in the Gra-PEO electrolyte might be explained by the dipolar interactions being severely disrupted by the ionic interactions of Li(+), I(-), and I3(-) ions. A composite electrolyte with 0.5 wt% Gra presented a higher ionic conductivity (3.32 mS cm(-1)) than those of PEO and other composite electrolytes at room temperature. A high overall conversion efficiency (?5.23%) with a very high short circuit current (JSC) of 18.32 mA cm(-2), open circuit voltage (VOC) of 0.592 V and fill factor (FF) of 0.48 was achieved in DSSCs fabricated with the 0.5 wt% Gra-PEO composite electrolyte. This enhanced photovoltaic performance might be attributed to the large scale formation of iodide ions in the redox electrolyte and the relatively high ionic conductivity.

Akhtar MS; Kwon S; Stadler FJ; Yang OB

2013-06-01

169

High efficiency solid state dye sensitized solar cells with graphene-polyethylene oxide composite electrolytes  

Science.gov (United States)

Novel and highly effective composite electrolytes were prepared by combining the two dimensional graphene (Gra) and polyethylene oxide (PEO) for the solid electrolyte of dye sensitized solar cells (DSSCs). Gra sheets were uniformly coated by the polymer layer through the ester carboxylate bonding between oxygenated species on Gra sheets and PEO. The Gra-PEO composite electrolyte showed the large scale generation of iodide ions in a redox couple. From rheological analysis, the decrease in viscosity after the addition of LiI and I2 in the Gra-PEO electrolyte might be explained by the dipolar interactions being severely disrupted by the ionic interactions of Li+, I-, and I3- ions. A composite electrolyte with 0.5 wt% Gra presented a higher ionic conductivity (3.32 mS cm-1) than those of PEO and other composite electrolytes at room temperature. A high overall conversion efficiency (~5.23%) with a very high short circuit current (JSC) of 18.32 mA cm-2, open circuit voltage (VOC) of 0.592 V and fill factor (FF) of 0.48 was achieved in DSSCs fabricated with the 0.5 wt% Gra-PEO composite electrolyte. This enhanced photovoltaic performance might be attributed to the large scale formation of iodide ions in the redox electrolyte and the relatively high ionic conductivity.

Akhtar, M. Shaheer; Kwon, Soonji; Stadler, Florian J.; Yang, O. Bong

2013-05-01

170

Rheology  

Science.gov (United States)

The properties of a rheid represent essentially all Earth materials: they behave elastically over short time scales and plastically over long time scales. In this demonstration, silly putty is used to help explain these properties as well as the yield strength of a material.

Barker, Jeffrey

171

Electrochemically stable electrolytes  

Energy Technology Data Exchange (ETDEWEB)

This invention relates generally to inorganic ionic liquids which function as electrolytes and do not crystallize at ambient temperature. More specifically, this invention is directed to quasi-salt inorganic ionic liquids which comprise the reaction product of a strong Lewis acid with an inorganic halide-donating molecule. This invention is further directed to quasi-salt inorganic ionic liquid mixtures which comprise combinations of electrolyte additives and quasi-salt inorganic ionic liquids. These quasi-salt inorganic ionic liquid mixtures are useful electrolytes.

Angell, Charles Austen (Mesa, AZ); Zhang, Sheng-Shui (Tucson, AZ); Xu, Kang (Tempe, AZ)

1999-01-01

172

Stable electrolytes for lithium batteries  

Energy Technology Data Exchange (ETDEWEB)

The physical and chemical properties of organic electrolytes for lithium batteries, and the factors affecting their conductivity, are discussed. In particular, attention is focussed on the modification of the solvent structure, organic electrolytes based on sulfolane or dimethyl sulfoxide, the addition effect of special organic compounds into the electrolyte, and some characteristics of miscellaneous electrolytes.

Matsuda, Y.

1987-05-01

173

Synthesis of novel fluorinated phosphonic and phosphinic acid electrolytes for phosphoric acid fuel cells. Annual report, January 1, 1989-December 31, 1989  

Energy Technology Data Exchange (ETDEWEB)

A practical synthesis of (HO)2P(O)CF2CF2P(O)(OH)2(H2O) has been developed from commercially available precursors. Preliminary electrochemical evaluation of the bis phosphonic acid has provided encouraging results. Methodology for the preparation of homologous flourinated bis phosphonic acids of the type (HO)2P(O)(CF2)nP(O)(OH)2 (where n = 3,4,6) has been developed. In addition, samples of (HO)2P(O)(CF2)nSO3H(H2O) (where n = 1,2) have been prepared. Methodology to demonstrate the preparation of (RO)2P(O)(CF2)xO(CF2)ySO3H has proven successful.

Burton, D.J.

1990-01-01

174

The Rheology of Concentrated Suspensions  

Energy Technology Data Exchange (ETDEWEB)

Research program on the rheological properties of flowing suspensions. The primary purpose of the research supported by this grant was to study the flow characteristics of concentrated suspensions of non-colloidal solid particles and thereby construct a comprehensive and robust theoretical framework for modeling such systems quantitatively. At first glance, this seemed like a modest goal, not difficult to achieve, given that such suspensions were viewed simply as Newtonian fluids with an effective viscosity equal to the product of the viscosity of the suspending fluid times a function of the particle volume fraction. But thanks to the research findings of the Principal Investigator and of his Associates, made possible by the steady and continuous support which the PI received from the DOE Office of Basic Energy Sciences, the subject is now seen to be more complicated and therefore much more interesting in that concentrated suspensions have been shown to exhibit fascinating and unique rheological properties of their own that have no counterpart in flowing Newtonian or even non-Newtonian (polymeric) fluids. In fact, it is generally acknowledged that, as the result of these investigations for which the PI received the 2001 National Medal of Science, our understanding of how suspensions behave under flow is far more detailed and comprehensive than was the case even as recently as a decade ago. Thus, given that the flow of suspensions plays a crucial role in many diverse physical processes, our work has had a major and lasting impact in a subject having both fundamental as well as practical importance.

Andreas Acrivos

2004-09-07

175

Progress in Solid Electrolytes.  

Science.gov (United States)

This volume brings together comprehensive state-of-the-art papers on the recent developments in understanding and using solid electrolytes. Internationally recognized experts were invited by CANMET to contribute papers on selected topics in this rapidly e...

T. A. Wheat A. Ahmad A. K. Kuriakose

1983-01-01

176

Common electrolyte manifold battery  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a common electrolyte manifold battery. The battery includes at least one module having cells, at least one common electrolyte manifold traversing the cells for transporting an electrolyte, an anode and a cathode, the one cell comprising an anode plate having an end proximal to the manifold and an end distal to the manifold, the distal end being connected to the anode; a cathode plate, positioned parallel with the anode plate, having an end proximal to the manifold and an end distal to the manifold, the distal end being connected to the cathode; and a layer of insulator enveloping each of the proximal end of the anode plate and the cathode plate, the insulator layers being contiguous with the common electrolyte manifold, whereby short circuiting of the one cell is minimized.

Wilson, J.P.

1986-12-02

177

Methods for the rheological characterization of food  

Directory of Open Access Journals (Sweden)

Full Text Available The present paper represents a summary of some rheological methods available for food characterization. Rheology, meaning "the science of the deformation and flow of matter", is studying the mechanical properties of gases, liquids, plastic, liquids etc.. The rheological data are very useful for food industry (calculates for a wide range of equipments, for the evaluation of food texture, shelf life testing of foods, intermediate or final control quality of food). The rheological methods can be divided into two major categories: rotational type and tube type. The tube type methods involves: glass capillary, high pressure capillary and pipe. The rotational type methods involve: cone and plate viscometry, parallel plate viscometry, concentric cylinder viscometry and mixer viscometry)

Mircea Oroian

2010-01-01

178

On shear rheology of gel propellants  

Energy Technology Data Exchange (ETDEWEB)

Selected fuel, oxidizer and simulant gels were prepared and rheologically characterized using a rotational rheometer. For fuel gelation both organic and inorganic gellants were utilized, whereas oxidizers and simulants were gelled with addition of silica and polysaccharides, respectively. The generalized Herschel-Bulkley constitutive model was found to most adequately represent the gels studied. Hydrazine-based fuels, gelled with polysaccharides, were characterized as shear-thinning pseudoplastic fluids with low shear yield stress, whereas inhibited red-fuming nitric acid (IRFNA) and hydrogen peroxide oxidizers, gelled with silica, were characterized as yield thixotropic fluids with significant shear yield stress. Creep tests were conducted on two rheological types of gels with different gellant content and the results were fitted by Burgers-Kelvin viscoelastic constitutive model. The effect of temperature on the rheological properties of gel propellant simulants was also investigated. A general rheological classification of gel propellants and simulants is proposed. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Rahimi, Shai; Peretz, Arie [RAFAEL, MANOR Propulsion and Explosive Systems Division, Haifa (Israel); Natan, Benveniste [Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Haifa (Israel)

2007-04-15

179

Microfluidic rheology of non-Newtonian liquids.  

UK PubMed Central (United Kingdom)

We investigate the rheological properties of a non-Newtonian glass-former liquid within lithographically defined microchannels in the range of temperatures above the vitrification region. The non-Newtonian behavior of the fluid, as evidenced by rotational rheology, is well described by a power law dependence of the viscosity on the shear rate. Taking into account such non-Newtonian character in the equations for the microfluidic motion, we relate the penetration dynamics into capillaries with the liquid rheological properties. The temperature dependence of the viscosity, determined over 1 order of magnitude in the temperature range 286-333 K and for shear rates between 0.07 and 1 s-1, can be described by a Vogel-Fulcher-Tamman law, consistent with the fragile nature of the investigated compound. Microfluidics is a promising analytical approach for the investigation of the rheology of non-Newtonian fluids within confined microenvironments.

Girardo S; Cingolani R; Pisignano D

2007-08-01

180

Performance of composite electrolyte SOFCs  

Energy Technology Data Exchange (ETDEWEB)

In an effort to minimize the ohmic losses in solid oxide fuel cells (SOFC), especially at lower operating temperatures around 800 C, an alternate electrolyte material such as ceria is often adopted. However, ceria based electrolytes develop mixed conduction, which lowers faradaic efficiency. To alleviate this effect, ceria electrolytes were coated with a thin layer zirconia using high temperature magnetron sputter deposition. This paper discusses the characterization of electrolytes and performance of single cells fabricated from these composite electrolytes.

Khandkar, A.C.; Elangovan, S.; Milliken, C. [Ceramatec, Inc., Salt Lake City, UT (United States); Guruswamy, S. [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Metallurgy

1994-12-31

 
 
 
 
181

Zirconia ceramic solid electrolytes  

International Nuclear Information System (INIS)

Magnesia partially stabilized zirconia ceramic solid electrolytes have been studied for the design of electrochemical transducers for oxygen detection. The main results show that around 3% MgO is the optimum solid solution level for ionic conductivity maximum, 2% alumina addition facilitates densification with no further degradation of the electrical behavior, and that thermal hysteresis of the electrical conductivity in zirconia-magnesia solid electrolytes with alumina additions is due in part to the decrease in cubic phase content. (author).

1990-01-01

182

Nuclear electrolytic hydrogen  

International Nuclear Information System (INIS)

An extensive study of hydrogen supply has recently been carried out by Ontario Hydro which indicates that electrolytic hydrogen produced from nuclear electricity could offer the lowest cost option for any future large scale hydrogen supply in the Province of Ontario, Canada. This paper provides a synopsis of the Ontario Hydro study, a brief overview of the economic factors supporting the study conclusion and discussion of a number of issues concerning the supply of electrolytic hydrogen by electric power utilities

1982-01-01

183

Investigation of interfacial rheology & foam stability.  

Energy Technology Data Exchange (ETDEWEB)

The rheology at gas-liquid interfaces strongly influences the stability and dynamics of foams and emulsions. Several experimental techniques are employed to characterize the rheology at liquid-gas interfaces with an emphasis on the non-Newtonian behavior of surfactant-laden interfaces. The focus is to relate the interfacial rheology to the foamability and foam stability of various aqueous systems. An interfacial stress rheometer (ISR) is used to measure the steady and dynamic rheology by applying an external magnetic field to actuate a magnetic needle suspended at the interface. Results are compared with those from a double wall ring attachment to a rotational rheometer (TA Instruments AR-G2). Micro-interfacial rheology (MIR) is also performed using optical tweezers to manipulate suspended microparticle probes at the interface to investigate the steady and dynamic rheology. Additionally, a surface dilatational rheometer (SDR) is used to periodically oscillate the volume of a pendant drop or buoyant bubble. Applying the Young-Laplace equation to the drop shape, a time-dependent surface tension can be calculated and used to determine the effective dilatational viscosity of an interface. Using the ISR, double wall ring, SDR, and MIR, a wide range of sensitivity in surface forces (fN to nN) can be explored as each experimental method has different sensitivities. Measurements will be compared to foam stability.

Yaklin, Melissa A.; Cote, Raymond O.; Grillet, Anne Mary; Walker, Lynn M. (Carnegie Mellon University, Pittsburg, PA); Koehler, Timothy P.; Reichert, Matthew D.; Castaneda, Jaime N.; Mondy, Lisa Ann; Brooks, Carlton, F.

2010-05-01

184

The rheology of collapsing zeolites amorphized by temperature and pressure.  

UK PubMed Central (United Kingdom)

Low-density zeolites collapse to the rigid amorphous state at temperatures that are well below the melting points of crystals of the same composition but of conventional density. Here we show, by using a range of experimental techniques, how the phenomenon of amorphization is time dependent, and how the dynamics of order-disorder transitions in zeolites under temperature and pressure are equivalent. As a result, thermobaric regions of instability can be charted, which are indicative of polyamorphism. Moreover, the boundaries of these zones depend on the rate at which temperature or pressure is ramped. By directly comparing the rheology of collapse with structural relaxation in equivalent melts, we conclude that zeolites amorphize like very strong liquids and, if compression occurs slowly, this is likely to lead to the synthesis of perfect glasses.

Greaves GN; Meneau F; Sapelkin A; Colyer LM; ap Gwynn I; Wade S; Sankar G

2003-09-01

185

Comportamento reológico de suspensões aquosas de cromito de lantânio/ Rheological behaviour of lanthanum chromite aqueous suspension  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O cromito de lantânio (LaCrO3) é o material mais estudado para a produção de interconectores para células a combustível de óxido sólido (SOFC). Devido a complexidade das microestruturas e geometrias das SOFCs, freqüentemente são necessárias, técnicas de processamento coloidal, os quais têm recebido maior atenção nos últimos anos por permitirem a obtenção de partes complexas com microestrutura controlada e reprodutíveis. Nos últimos anos, muito esforço (more) tem sido direcionado ao processamento dos eletrólitos e eletrodos, mas aos componentes como o interconector, pouca atenção tem sido dada. Este artigo apresenta o estudo reológico e de conformação em moldes de gesso do cromito de lantânio para a produção de interconectores para SOFCs. A composição La0,80Sr0,20Cr0,92Co0,08O3, obtida por reação de combustão, foi utilizada. As suspensões aquosas foram preparadas com conteúdo de sólidos variando de 8 a 17,5% vol. utilizando-se, poliacrilato de amônia (PAA) como polieletrólito/dispersante e hidróxido de tetrametilamônio (HTMA) como provedor de alcalinidade. A influência da concentração dos aditivos e o tempo em moinho de bolas foram estudados. Os resultados indicam que o tempo 24 h de homogeneização em moinho de bolas, com 3% e 1%, em massa, de PAA e HTMA respectivamente, proporcionam as melhores condições para colagem em moldes de gesso, sendo possível obter peças após sinterização com densidades relativas elevadas. Abstract in english Lanthanum chromite (LaCrO3) is the most studied material for SOFC's interconnectors' production. The complexity of microstructures and geometries of SOFC devices often requires the use of colloidal processing techniques, which have received increased attention in the last years for obtaining complex parts with controlled microstructure and high reliability. Much effort has been devoted to the processing of electrodes and electrolytes but the other layers, such as that of (more) interconnecting material, have received scarce attention. This paper deals with the rheology and casting behaviour of lanthanum chromite based materials to produce interconnectors for SOFCs. A powder with the composition La0.80Sr0.20Cr0.92Co0.08O3 was obtained by combustion synthesis. Aqueous suspensions were prepared to solids loading ranging from 8 to 17.5 vol.%, using ammonium polyacrylate (PAA) as polyelectrolyte/dispersant and tetramethylammonium hydroxide (TMAH) to assure basic pH. The influence of the additives concentrations and suspension ball milling time were studied. Suspensions prepared with 24 h ball milling, with 3 wt.% and 1 wt.%, of PAA and TMAH respectively, yielded the best conditions for successful slip casting, leading to relatively dense sintered materials.

Setz, L. F. G.; Santacruz, I.; Colomer, M. T.; Moreno, R.; Mello-Castanho, S. R. H.

2011-06-01

186

Comportamento reológico de suspensões aquosas de cromito de lantânio Rheological behaviour of lanthanum chromite aqueous suspension  

Directory of Open Access Journals (Sweden)

Full Text Available O cromito de lantânio (LaCrO3) é o material mais estudado para a produção de interconectores para células a combustível de óxido sólido (SOFC). Devido a complexidade das microestruturas e geometrias das SOFCs, freqüentemente são necessárias, técnicas de processamento coloidal, os quais têm recebido maior atenção nos últimos anos por permitirem a obtenção de partes complexas com microestrutura controlada e reprodutíveis. Nos últimos anos, muito esforço tem sido direcionado ao processamento dos eletrólitos e eletrodos, mas aos componentes como o interconector, pouca atenção tem sido dada. Este artigo apresenta o estudo reológico e de conformação em moldes de gesso do cromito de lantânio para a produção de interconectores para SOFCs. A composição La0,80Sr0,20Cr0,92Co0,08O3, obtida por reação de combustão, foi utilizada. As suspensões aquosas foram preparadas com conteúdo de sólidos variando de 8 a 17,5% vol. utilizando-se, poliacrilato de amônia (PAA) como polieletrólito/dispersante e hidróxido de tetrametilamônio (HTMA) como provedor de alcalinidade. A influência da concentração dos aditivos e o tempo em moinho de bolas foram estudados. Os resultados indicam que o tempo 24 h de homogeneização em moinho de bolas, com 3% e 1%, em massa, de PAA e HTMA respectivamente, proporcionam as melhores condições para colagem em moldes de gesso, sendo possível obter peças após sinterização com densidades relativas elevadas.Lanthanum chromite (LaCrO3) is the most studied material for SOFC's interconnectors' production. The complexity of microstructures and geometries of SOFC devices often requires the use of colloidal processing techniques, which have received increased attention in the last years for obtaining complex parts with controlled microstructure and high reliability. Much effort has been devoted to the processing of electrodes and electrolytes but the other layers, such as that of interconnecting material, have received scarce attention. This paper deals with the rheology and casting behaviour of lanthanum chromite based materials to produce interconnectors for SOFCs. A powder with the composition La0.80Sr0.20Cr0.92Co0.08O3 was obtained by combustion synthesis. Aqueous suspensions were prepared to solids loading ranging from 8 to 17.5 vol.%, using ammonium polyacrylate (PAA) as polyelectrolyte/dispersant and tetramethylammonium hydroxide (TMAH) to assure basic pH. The influence of the additives concentrations and suspension ball milling time were studied. Suspensions prepared with 24 h ball milling, with 3 wt.% and 1 wt.%, of PAA and TMAH respectively, yielded the best conditions for successful slip casting, leading to relatively dense sintered materials.

L. F. G. Setz; I. Santacruz; M. T. Colomer; R. Moreno; S. R. H. Mello-Castanho

2011-01-01

187

Electrolyte modified photoelectrochemical solar cells  

Energy Technology Data Exchange (ETDEWEB)

Rationale electrolyte modification of photoelectrochemical systems can be used to (1) enhance facile charge transfer, (2) suppress competing reactions and suppress both (3) electrode and (4) electrolyte decomposition products, as well as (5) substantially effect the open-circuit photovoltage. Studies on polysulfide, ferrocyanide, polyselenide and polyiodide electrolyte modification of photoelectrochemical solar cells are discussed. Electrolyte modification of semiconductor/electrolyte systems entails investigation of the primary photo-redox species, the nature of the counter ion, the distribution of species in solution, and related competing reactions. The examples presented emphasize the fundamental and practical importance of probing the active electrolytic constituents pertinent to overall photoelectrochemical energy conversion

Licht, Stuart [Clark University, Department of Chemistry, Worcester, MA (United States)

1995-08-01

188

Polymer electrolytes for a rechargeable li-Ion battery  

Energy Technology Data Exchange (ETDEWEB)

Lithium-ion polymer electrolyte battery technology is attractive for many consumer and military applications. A Li{sub x}C/Li{sub y}Mn{sub 2}O{sub 4} battery system incorporating a polymer electrolyte separator base on novel Li-imide salts is being developed under sponsorship of US Army Research Laboratory (Fort Monmouth NJ). This paper reports on work currently in progress on synthesis of Li-imide salts, polymer electrolyte films incorporating these salts, and development of electrodes and cells. A number of Li salts have been synthesized and characterized. These salts appear to have good voltaic stability. PVDF polymer gel electrolytes based on these salts have exhibited conductivities in the range 10{sup -4} to 10{sub -3} S/cm.

Argade, S.D.; Saraswat, A.K.; Rao, B.M.L. [Technochem Co., Greensboro, NC (United States); Lee, H.S.; Xiang, C.L.; McBreen, J. [Brookhaven National Lab., Upton, NY (United States)

1996-10-01

189

The rheology of solid glass  

Science.gov (United States)

As the glass transition is approached from the high temperature side, viewed as a liquid, the properties of the ever more viscous supercooled liquid are continuous functions of temperature and pressure. The point at which we decide to classify the fluid as a solid is therefore subjective. This subjective decision does, however, have discontinuous consequences for how we determine the rheological properties of the glass. We apply the recently discovered relaxation theorem to the time independent, nondissipative, nonergodic glassy state to derive an expression for the phase space distribution of an ensemble of glass samples. This distribution is then used to construct a time dependent linear response theory for aged glassy solids. The theory is verified using molecular dynamics simulations of oscillatory shear for a realistic model glass former with excellent agreement being obtained between the response theory calculations and direct nonequilibrium molecular dynamics calculations. Our numerical results confirm that unlike all the fluid states, including supercooled liquids, a solid glass (in common with crystalline states) has a nonzero value for the zero frequency shear modulus. Of all the states of matter, a supercooled fluid approaching the glass transition has the highest value for the limiting zero frequency shear viscosity. Finally, solid glasses like dilute gases and crystals have a positive temperature coefficient for the shear viscosity whereas supercooled and normal liquids have a negative temperature coefficient.

Williams, Stephen R.; Evans, Denis J.

2010-05-01

190

Toughness of membranes applied in polymer electrolyte fuel cells  

Energy Technology Data Exchange (ETDEWEB)

Since several years we apply the radiation-grafting technique to prepare polymeric membranes for application in polymer electrolyte fuel cells (PEFCs). Our investigations presented here focus on changes in toughness of these materials after the various synthesis steps and the importance of membrane toughness for their application in PEFCs. (author) 2 figs., 4 refs.

Kiefer, J.; Brack, H.P.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

191

Electrolyte additive and electrolyte and lithium ion battery containing same  

UK PubMed Central (United Kingdom)

The invention provides an electrolyte additive. The additive is a pyridine compound with a special structure, and can improve comprehensive performance of the battery containing the electrolyte additive. The additive not only improves the safety performance of the battery, but also improves the high-rate discharge performance, cycle performance and high-temperature storage performance the batterycontaining the electrolyte additive.

SHENG WANG; YAN WANG

192

Initial rheological description of high performance concretes  

Directory of Open Access Journals (Sweden)

Full Text Available Concrete is defined as a composite material and, in rheological terms, it can be understood as a concentrated suspension of solid particles (aggregates) in a viscous liquid (cement paste). On a macroscopic scale, concrete flows as a liquid. It is known that the rheological behavior of the concrete is close to that of a Bingham fluid and two rheological parameters regarding its description are needed: yield stress and plastic viscosity. The aim of this paper is to present the initial rheological description of high performance concretes using the modified slump test. According to the results, an increase of yield stress was observed over time, while a slight variation in plastic viscosity was noticed. The incorporation of silica fume showed changes in the rheological properties of fresh concrete. The behavior of these materials also varied with the mixing procedure employed in their production. The addition of superplasticizer meant that there was a large reduction in the mixture's yield stress, while plastic viscosity remained practically constant.

Alessandra Lorenzetti de Castro; Jefferson Benedicto Libardi Liborio

2006-01-01

193

Initial rheological description of high performance concretes  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Concrete is defined as a composite material and, in rheological terms, it can be understood as a concentrated suspension of solid particles (aggregates) in a viscous liquid (cement paste). On a macroscopic scale, concrete flows as a liquid. It is known that the rheological behavior of the concrete is close to that of a Bingham fluid and two rheological parameters regarding its description are needed: yield stress and plastic viscosity. The aim of this paper is to present (more) the initial rheological description of high performance concretes using the modified slump test. According to the results, an increase of yield stress was observed over time, while a slight variation in plastic viscosity was noticed. The incorporation of silica fume showed changes in the rheological properties of fresh concrete. The behavior of these materials also varied with the mixing procedure employed in their production. The addition of superplasticizer meant that there was a large reduction in the mixture's yield stress, while plastic viscosity remained practically constant.

Castro, Alessandra Lorenzetti de; Liborio, Jefferson Benedicto Libardi

2006-12-01

194

Nonaqueous electrolyte photoelectrochemical cell  

Energy Technology Data Exchange (ETDEWEB)

Solid-liquid interface photoelectrochemical cells are provided wherein the liquid phase comprises a nonaqueous solvent, an electrolyte dissolved therein forming an ionically conductive solution and a redox couple suitable to accept and donate electrons from and to the electrodes. The redox couple is present in an amount sufficient to sustain a predetermined current and the concentrations of the electrolyte and redox couple in the solution are sufficient to provide no greater than a selected small voltage drop relative to the output voltage of the cell. The efficiency of conversion of light to electrical energy of such photoelectrochemical cells are 10% and greater.

Gibbons, J.F.; Cogan, G.W.; Gronet, C.M.; Lewis, N.

1984-07-10

195

Seebeck effect in electrolytes.  

UK PubMed Central (United Kingdom)

We study Seebeck effect in liquid electrolytes, starting from its simple neutral analog--thermodiffusion (so-called Ludwig-Soret or Soret effect). It is observed that when two or more subsystems of mobile particles are subjected to the temperature gradient, various types of them respond to it differently. In the case when these fractions, with different mobility parameters (Soret coefficients), are oppositely charged (a case typical for electrolytes), the nonhomogeneous internal electric field is generated. The latter field prevents these fractions from space separation and determines the intensity of the appearing Seebeck effect.

Chikina I; Shikin V; Varlamov AA

2012-07-01

196

Circulating Electrolyte Fuel Cell Powerplant.  

Science.gov (United States)

The technical feasibility of a hydrogen-air circulating alkaline electrolyte fuel cell system incorporating electrolyte regeneration capability has been demonstrated. The fuel cell design features four channels on the air side through which the potassium ...

T. G. Schiller W. R. Peak

1971-01-01

197

Rheological behavior study of a clay-polymer mixture: effects of the polymer addition; Etude du comportement rheologique de melanges argiles - polymeres. Effets de l'ajout de polymeres  

Energy Technology Data Exchange (ETDEWEB)

The aim of the present work is to establish a bibliographical synthesis on the microstructure, the colloidal and rheological characterization of bentonite suspensions with and without polymer/surfactant addition; to lead to a rheological characterization of clay-additive mixtures and to understand the interaction between the clay particles and polymer/surfactants. Different experimental measurements: rheology, particle sizing, and x-ray diffraction were used to study the rheological character of the water-bentonite-anionic additive mixtures (CMC, SDS, xanthane) as well as the nature of the particle-particle interactions and particle-additive. The modeling part led to the adoption of Tiu and Boger's model to predict the thixotropy of the bentonite suspensions without additive. Thus, a new model is proposed with physical parameters for a better correlation of the rheological behavior of the various studied mixtures. (author)

Benchabane, A

2006-11-15

198

Improved electrolytes for fuel cells  

Energy Technology Data Exchange (ETDEWEB)

Present day fuel cells based upon hydrogen and oxygen have limited performance due to the use of phosphoric acid as an electrolyte. Improved performance is desirable in electrolyte conductivity, electrolyte management, oxygen solubility, and the kinetics of the reduction of oxygen. Attention has turned to fluorosulfonic acids as additives or substitute electrolytes to improve fuel cell performance. The purpose of this project is to synthesize and electrochemically evaluate new fluorosulfonic acids as superior alternatives to phosphoric acid in fuel cells. (VC)

Gard, G.L.; Roe, D.K.

1991-06-01

199

Batteries using molten salt electrolyte  

Energy Technology Data Exchange (ETDEWEB)

An electrolyte system suitable for a molten salt electrolyte battery is described where the electrolyte system is a molten nitrate compound, an organic compound containing dissolved lithium salts, or a 1-ethyl-3-methlyimidazolium salt with a melting temperature between approximately room temperature and approximately 250.degree. C. With a compatible anode and cathode, the electrolyte system is utilized in a battery as a power source suitable for oil/gas borehole applications and in heat sensors.

Guidotti, Ronald A. (Albuquerque, NM)

2003-04-08

200

Solid state lithium secondary batteries using an amorphous solid electrolyte in the system (100-x)(0.6Li{sub 2}S{center_dot}0.4SiS{sub 2}){center_dot}xLi{sub 4}SiO{sub 4} obtained by mechanochemical synthesis  

Energy Technology Data Exchange (ETDEWEB)

Electrochemical cells were constructed using amorphous materials in the system (100-x)(0.6Li{sub 2}S{center_dot}0.4SiS{sub 2}){center_dot}xLi{sub 4}SiO{sub 4}, obtained by mechanochemical synthesis, as an electrolyte, LiCoO{sub 2} as a positive electrode and indium as a negative electrode. Charge and discharge behaviors of the cells at a constant current were investigated to see the possibility for utilization as secondary batteries. Charge-discharge efficiency at the 1st cycle was more than 75% in the cells using the solid electrolytes synthesized by mechanical milling (MM) for more than 5 h. Charge-discharge curves of the cells using the amorphous materials milled for more than 10 h, were similar to those of the cells using the corresponding melt-quenched glass samples. The charge-discharge capacity decreased gradually from 90 to 70 mA h/g till about the 10th cycle, and became stable after the 10th cycle. The Coulombic efficiency of the cell showed almost 100%, except for the 1st and 2nd cycles. The amorphous materials synthesized by MM were concluded to work as the electrolyte for solid state lithium secondary batteries.

Komiya, R.; Hayashi, A.; Morimoto, H.; Tatsumisago, M.; Minami, T. [Department of Applied Materials Science, Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531, Osaka (Japan)

2001-03-01

 
 
 
 
201

Rheological properties of alumina injection feedstocks  

Directory of Open Access Journals (Sweden)

Full Text Available The rheological behavior of alumina molding feedstocks containing polyethylene glycol (PEG), polyvinylbutyral (PVB) and stearic acid (SA) and having different powder loads were analyzed using a capillary rheometer. Some of the feedstocks showed a pseudoplastic behavior of n < 0, which can lead to the appearance of weld lines on molded parts. Their viscosity also displayed a strong dependence on the shear rate. The slip phenomenon, which can cause an unsteady front flow, was also observed. The results indicate that the feedstock containing a lower powder load displayed the best rheological behavior. The 55 vol. % powder loaded feedstock presented the best rheological behavior, thus appearing to be more suitable than the formulation containing a vol. 59% powder load, which attained viscosities exceeding 10³ Pa.s at low shear rates, indicating its unsuitability for injection molding.

Vivian Alexandra Krauss; Eduardo Nunes Pires; Aloísio Nelmo Klein; Márcio Celso Fredel

2005-01-01

202

Electrolyte additive for lithium rechargeable organic electrolyte battery  

Energy Technology Data Exchange (ETDEWEB)

This invention relates in general to a rechargeable lithium organic electrolyte battery and, in particular, to an electrolyte additive for such a battery that provides overcharge protection. Rechargeable lithium-organic electrolyte batteries are being developed to provide low-cost, high-energy-density power sources for communication, night vision and various other Army applications. Typically, a rechargeable lithium organic electrolyte battery includes a lithium anode, a cathode including compounds such as titanium disulfide, molybdenum oxide, molybdenum sulfide, vanadium oxide, vanadium sulfide, chromium oxide, etc an electrolyte solution including an inorganic lithium salt such as lithium hexafluoroarsenate, lithium perchlorate, etc.

Behl, W.K.; Chin, D.T.

1988-02-08

203

Spin coating of electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Methods for spin coating electrolytic materials onto substrates are disclosed. More particularly, methods for depositing solid coatings of ion-conducting material onto planar substrates and onto electrodes are disclosed. These spin coating methods are employed to fabricate electrochemical sensors for use in measuring, detecting and quantifying gases and liquids.

Stetter, Joseph R. (Naperville, IL); Maclay, G. Jordan (Maywood, IL)

1989-01-01

204

Solid electrolyte structure  

Science.gov (United States)

A solid electrolyte structure for fuel cells and other electrochemical devices providing oxygen ion transfer by a multiplicity of exposed internal surfaces made of a composition containing an oxide of a multivalent transition metal and forming small pore-like passages sized to permit oxygen ion transfer while limiting the transfer of oxygen gas.

Fraioli, Anthony V. (Hawthorn Woods, IL)

1984-01-01

205

Solid polymer electrolyte  

Energy Technology Data Exchange (ETDEWEB)

A solid polymer electrolyte is described comprising an ionic salt and a compound able to dissolve the ionic salt and having a crosslinked network structure, wherein the crosslinked network structure is formed by polymerizing a first acryloyl compound having two acryloyl groups with a second acryloyl compound having one acryloyl group.

Izuti, Shyuiti; Noda, Tomohiko; Imachi, Hiroshi.

1993-08-31

206

Characterizing the rheology of fluidized granular matter.  

UK PubMed Central (United Kingdom)

In this study we characterize the rheology of fluidized granular matter subject to secondary forcing. Our approach consists of first fluidizing granular matter in a drum half filled with grains via simple rotation and then superimposing oscillatory shear perpendicular to the downhill flow direction. The response of the system is mostly linear, with a phase lag between the grain motion and the oscillatory forcing. The rheology of the system can be well characterized by the GDR MiDi model if the system is forced with slow oscillations. The model breaks down when the forcing time scale becomes comparable to the characteristic time for energy dissipation in the flow.

Desmond KW; Villa U; Newey M; Losert W

2013-09-01

207

Characterizing the rheology of fluidized granular matter  

Science.gov (United States)

In this study we characterize the rheology of fluidized granular matter subject to secondary forcing. Our approach consists of first fluidizing granular matter in a drum half filled with grains via simple rotation and then superimposing oscillatory shear perpendicular to the downhill flow direction. The response of the system is mostly linear, with a phase lag between the grain motion and the oscillatory forcing. The rheology of the system can be well characterized by the GDR MiDi model if the system is forced with slow oscillations. The model breaks down when the forcing time scale becomes comparable to the characteristic time for energy dissipation in the flow.

Desmond, Kenneth W.; Villa, Umberto; Newey, Mike; Losert, Wolfgang

2013-09-01

208

Rheology of interfacial protein-polysaccharide composites  

Science.gov (United States)

The morphology and mechanical properties of protein adsorption layers can significantly be altered by the presence of surfactants, lipids, particles, other proteins, and polysaccharides. In food emulsions, polysaccharides are primarily considered as bulk thickener but can under appropriate environmental conditions stabilize or destabilize the protein adsorption layer and, thus, the entire emulsion system. Despite their ubiquitous usage as stabilization agent, relatively few investigations focus on the interfacial rheology of composite protein/polysaccharide adsorption layers. The manuscript provides a brief review on both main stabilization mechanisms, thermodynamic phase separation and electrostatic interaction and discusses the rheological response in light of the environmental conditions such as ionic strength and pH.

Fischer, P.

2013-05-01

209

Rheological study of chitosan in solution  

International Nuclear Information System (INIS)

Chitosan is an abundant biopolymer with remarkable physicochemical and biological properties, usually employed in a wide range of applications. It acts as a cationic polyelectrolyte in aqueous acid solutions, leading to unique characteristics. In this work, chitosan was characterized by 1H NMR and its rheological behavior were studied as function of chitosan sample, shear rate, polymer concentration, ionic strength, time and temperature. In order to calculate rheological parameters and to understand the macromolecular dynamic in solution, the Otswald-de Waele model was fitted. (author)

2009-01-01

210

Flame-retardant solid electrolytes  

UK PubMed Central (United Kingdom)

A flame retardant solid electrolyte comprising an ion conductive polymer matrix having moieties capable of imparting flame retardance to the polymer matrix and ether bonds in the molecule and an electrolyte salt dispersed in the polymer matrix. The flame retardant solid electrolyte may be one which comprises a non-ion-conductive polymer matrix and a liquid electrolyte consisting of an electrolyte salt dissolved in a solvent therefor, which is dispersed in the polymer matrix. The flame retardance-imparting moieties are derived from halogen or phosphorus-bearing compounds.

HASEGAWA JUN; MURAMATSU HIROMOCHI; SAITO HIROHIKO; KONO MICHIYUKI; KOMORI HIROHITO

211

Electrolytic cell with reference electrode  

Energy Technology Data Exchange (ETDEWEB)

A reference electrode device is provided for a high temperature electrolytic cell used to electrolytically recover uranium from spent reactor fuel dissolved in an anode pool, the device having a glass tube to enclose the electrode and electrolyte and serve as a conductive membrane with the cell electrolyte, and an outer metal tube about the glass tube to serve as a shield and basket for any glass sections broken by handling of the tube to prevent their contact with the anode pool, the metal tube having perforations to provide access between the bulk of the cell electrolyte and glass membrane.

Kessie, Robert W. (Naperville, IL)

1989-01-01

212

Atomic force microscopy for the examination of single cell rheology.  

UK PubMed Central (United Kingdom)

Rheological properties of living cells play important roles in regulating their various biological functions. Therefore, measuring cell rheology is crucial for not only elucidating the relationship between the cell mechanics and functions, but also mechanical diagnosis of single cells. Atomic force microscopy (AFM) is becoming a useful technique for single cell diagnosis because it allows us to measure the rheological properties of adherent cells at any region on the surface without any modifications. In this review, we summarize AFM techniques for examining single cell rheology in frequency and time domains. Recent applications of AFM for investigating the statistical analysis of single cell rheology in comparison to other micro-rheological techniques are reviewed, and we discuss what specificity and universality of cell rheology are extracted using AFM.

Okajima T

2012-11-01

213

Ultrasonic irradiation to modify the PEO/P(VDF-HFP)/TiO2 nanoparticle composite polymer electrolyte for dye sensitized solar cells  

International Nuclear Information System (INIS)

As a novel technology, ultrasonic irradiation was applied to modify the PEO/P(VDF-HFP)/TiO2 nanoparticle composite polymer electrolyte for dye sensitized solar cells (DSSCs). The ultrasonic irradiation effectively changes the rheology and the glass transition temperature and the crystallinity of the composite polymer. The experiments showed that 20 min moderate ultrasonic irradiation resulted in better penetration of the polymer electrolyte into the TiO2 nanoporous photo-anode, and the ionic conductivity was improved to 0.956 ms cm-1 compared with 0.386 ms cm-1 of the original polymer electrolyte. The DSSC fabricated with 20 min ultrasonic irradiation modified polymer electrolyte exhibited an improved solar energy conversion efficiency of 4.39% compared with the 3.6% of the unmodified polymer electrolyte DSSC at 30.2 mW cm-2 light intensity.

2007-07-25

214

Morphology and rheology in filamentous cultivations.  

UK PubMed Central (United Kingdom)

Because of their metabolic diversity, high production capacity, secretion efficiency, and capability of carrying out posttranslational modifications, filamentous fungi are widely exploited as efficient cell factories in the production of metabolites, bioactive substances, and native or heterologous proteins, respectively. There is, however, a complex relationship between the morphology of these microorganisms, transport phenomena, the viscosity of the cultivation broth, and related productivity. The morphological characteristics vary between freely dispersed mycelia and distinct pellets of aggregated biomass, every growth form having a distinct influence on broth rheology. Hence, the advantages and disadvantages for mycelial or pellet cultivation have to be balanced out carefully. Because of the still inadequate understanding of the morphogenesis of filamentous microorganisms, fungal morphology is often a bottleneck of productivity in industrial production. To obtain an optimized production process, it is of great importance to gain a better understanding of the molecular and cell biology of these microorganisms as well as the relevant approaches in biochemical engineering. In this chapter, morphology and growth of filamentous fungi are described, with special attention given to specific problems as they arise from fungal growth forms; growth and mass transfer in fungal biopellets are discussed as an example. To emphasize the importance of the flow behavior of filamentous cultivation broths, an introduction to rheology is also given, reviewing important rheological models and recent studies concerning rheological parameters. Furthermore, current knowledge on morphology and productivity in relation to the environom is outlined in the last section of this review.

Wucherpfennig T; Kiep KA; Driouch H; Wittmann C; Krull R

2010-01-01

215

Morphology and rheology in filamentous cultivations.  

Science.gov (United States)

Because of their metabolic diversity, high production capacity, secretion efficiency, and capability of carrying out posttranslational modifications, filamentous fungi are widely exploited as efficient cell factories in the production of metabolites, bioactive substances, and native or heterologous proteins, respectively. There is, however, a complex relationship between the morphology of these microorganisms, transport phenomena, the viscosity of the cultivation broth, and related productivity. The morphological characteristics vary between freely dispersed mycelia and distinct pellets of aggregated biomass, every growth form having a distinct influence on broth rheology. Hence, the advantages and disadvantages for mycelial or pellet cultivation have to be balanced out carefully. Because of the still inadequate understanding of the morphogenesis of filamentous microorganisms, fungal morphology is often a bottleneck of productivity in industrial production. To obtain an optimized production process, it is of great importance to gain a better understanding of the molecular and cell biology of these microorganisms as well as the relevant approaches in biochemical engineering. In this chapter, morphology and growth of filamentous fungi are described, with special attention given to specific problems as they arise from fungal growth forms; growth and mass transfer in fungal biopellets are discussed as an example. To emphasize the importance of the flow behavior of filamentous cultivation broths, an introduction to rheology is also given, reviewing important rheological models and recent studies concerning rheological parameters. Furthermore, current knowledge on morphology and productivity in relation to the environom is outlined in the last section of this review. PMID:20602989

Wucherpfennig, T; Kiep, K A; Driouch, H; Wittmann, C; Krull, R

2010-01-01

216

RHEOLOGY OF CONCENTRATED SOLUTIONS OF HYPERBRANCHED POLYESTERS  

Science.gov (United States)

The solution rheology of different generations of hyperbranched polyesters in N-methyl-2- pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amido...

217

Progress and Challenges in Computational Rheology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Our research work over the last few years serves to illustrate the basic issues associated with the numerical prediction of rheologically-complex flows, with particular emphasis on viscoelastic fluids. Numerical challenges in this field are shown to be tightly coupled to the mathematical nature of t...

Keunings, Roland; GOLDEN JUBILEE MEETING OF THE BRITISH SOC OF RHEOLOGY / 3RD EUROPEAN CONF ON RHEOLOGY

218

Rheological Characterization of Shale – Mud Interactions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In a bid to identify a best drilling fluid for a problematic oil field in the Niger Delta region, rheological tests were carried out on three mud samples; BW1, BW3 and BW4. The results affirm that the load bearing capacity...

W. O. Emofurieta; A. O. Odeh

219

PVC paste rheology: Study of process dependencies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A plastisol is a dispersion (suspension) of fine particles of poly(vinyl chloride) with a plasticizer that is normally applied over a substrate, by spreading or coating, before the gelification and fusion into the final product. Because of the first step, the plastisol rheology study is a very impor...

Rasteiro, M. G.; Tomás, A.; Ferreira, L.; Figueiredo, S.

220

Rheology of latex-modified grouts  

Energy Technology Data Exchange (ETDEWEB)

The pumpability and ability of cementitious grouts to penetrate voids and cracks is strongly dependent on the rheological behavior of the grout. This is important in diverse grouting applications including ground treatment, repair of concrete, reduction of rock or soil permeability, environmental remediation, prestressing concrete, rock anchors, sealing radioactive waste repositories, and well completion. The rheology of grouts containing latex was investigated. The two latex additives used were carboxylated styrene-butadiene and acrylic. The influences of superplasticizer, fly ash, and blast furnace slag on the rheology of latex-modified grouts were addressed. Shear stress-shear rate curves were determined for a variety of mix proportions. The time-dependent behavior of selected grouts was also studied. It was determined that the yield stress and apparent viscosity are influenced by latex content and that the grouts are shear thinning at low water/cement ratios. Latex imparts stability and thixotropy in grouts. Partial replacement of cement with either fly ash or slag diminishes the effect of latex on rheology.

Allan, M.L. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science

1997-12-01

 
 
 
 
221

Rheology and molecular structure of HPG gels  

Energy Technology Data Exchange (ETDEWEB)

Hydroxypropyl guar (HPG) polymer solutions crosslinked with titanates (Ti) are used in hydraulic fracturing operations. The rheology of these gels arise from the complex interaction of polymer chemistry, metal ion chemistry, and flow history. The authors have employed several techniques (steady shear viscosity, dynamic oscillatory shear, Laser Doppler Anemometry, and freeze fracture electron microscopy) to develop a consistent picture of the factors controlling gel rheology. An impingement mixing technique has been developed to prepare uniform HPG gels and reproducible rheological data has bee obtained. Dynamic oscillatory rheological measurements have been used as diagnostic probes of gel structure, and are shown to be useful in understanding chemical effects on gel structure. Laser Doppler Anemometry, a non-invasive technique for measuring velocity distributions, has been used to measure velocity profiles for gels under flow. Classical wall slip is not observed, rather distortions of the velocity profiles are observed for gels that have gelled under quiescent conditions. For gels made with impingement mixing linear velocity profiles are observed. Freeze fracture electron microscopy has been used to image gel structure and the results show the fracture of gel structure by shear. These observations demonstrate the mechaism of temperature stabilization of the viscosity of cross-linked gels. Temperature stability measurements of gel viscosity have been made using a novel reciprocating capillary viscometer.

Kramer, J.; Chu, A.; Prud' homme, R.K.

1986-01-01

222

Advances in rheology. Volume 4: Applications  

Energy Technology Data Exchange (ETDEWEB)

This book contains over 50 selections. Some of the titles are: Rheology and mass transfer in a stationary or pulsatile two phase flow of suspended particles investigated by electrochemical techniques; The helical screw rheometer; Characterization of polymer solutions in flow through porous media; A discrete model for the recovery of oil from a reservoir; and Nonlinear creep characteristics of Devonian oil shale.

Mena, B.; Garcia-Rejon, A.; Rangel-Nafaile, C.

1984-01-01

223

Non-Newtonian Rheology in Blood Circulation  

CERN Multimedia

Blood is a complex suspension that demonstrates several non-Newtonian rheological characteristics such as deformation-rate dependency, viscoelasticity and yield stress. In this paper we outline some issues related to the non-Newtonian effects in blood circulation system and present modeling approaches based mostly on the past work in this field.

Sochi, Taha

2013-01-01

224

Rheological properties of defense waste slurries  

International Nuclear Information System (INIS)

The major objective of this two-year project has been to obtain refined and reliable experimental data about the rheological properties of melter feeds. The research has involved both experimental studies and model development. Two experimental facilities have been set up to measure viscosity and pressure drop. Mathematical models have been developed as a result of experimental observation and fundamental rheological theory. The model has the capability to predict the viscosity of melter slurries in a range of experimental conditions. The final results of the investigation could be used to enhance the current design base for slurry transportation systems and improve the performance of the slurry mixing process. If successful, the cost of this waste treatment will be reduced, and disposal safety will be increased. The specific objectives for this project included: (1) the design, implementation, and validation of the experimental facility in both batch and continuous operating modes; (2) the identification and preparation of melter feed samples of both the SRS and Hanford waste slurries at multiple solids concentration levels; (3) the measurement and analysis of the melter feeds to determine the effects of the solids concentration, pH value, and other factors on the rheological properties of the slurries; (4) the correlation of the rheological properties as a function of the measured physical and chemical parameters; and (5) transmission of the experimental data and resulting correlation to the DOE site user to guide melter feed preparation and transport equipment design.

1998-01-01

225

NEW RHEOLOGICAL MODELS FOR MINERAL OIL  

Directory of Open Access Journals (Sweden)

Full Text Available This article proposes new rheological models for mineral oil. The purpose of this study was to find an exponential and linear dependence between temperature and dynamic viscosity of mineral oil, using the equations. Equation constants a, b c and ?o were determined by fitting exponential.

IOANA STANCIU

2013-01-01

226

Rheological hysteresis in soft glassy materials.  

UK PubMed Central (United Kingdom)

The nonlinear rheology of a soft glassy material is captured by its constitutive relation, shear stress versus shear rate, which is most generally obtained by sweeping up or down the shear rate over a finite temporal window. For a huge amount of complex fluids, the up and down sweeps do not superimpose and define a rheological hysteresis loop. By means of extensive rheometry coupled to time-resolved velocimetry, we unravel the local scenario involved in rheological hysteresis for various types of well-studied soft materials. We introduce two observables that quantify the hysteresis in macroscopic rheology and local velocimetry, respectively, as a function of the sweep rate ?t(-1). Strikingly, both observables present a robust maximum with ?t, which defines a single material-dependent time scale that grows continuously from vanishingly small values in simple yield stress fluids to large values for strongly time-dependent materials. In line with recent theoretical arguments, these experimental results hint at a universal time scale-based framework for soft glassy materials, where inhomogeneous flows characterized by shear bands and/or pluglike flow play a central role.

Divoux T; Grenard V; Manneville S

2013-01-01

227

Coprecipitation synthesis and characterization of La0.8Sr0.2Ga(0.8-x)Mg0.2Co(x)O2.8 for intermediate temperature solid oxide fuel cell electrolytes.  

UK PubMed Central (United Kingdom)

La0.8Sr0.2Ga(0.8-x)Mg0.2CO(x)O2.8 (LSGMC) electrolyte powders containing different amount of Co (0 < or = x < or = 0.15) were prepared by ammonium carbonate coprecipitation method. The precursors, the calcined powders, and the sintered pellets were characterized by thermogravimetry/differential thermal analysis, X-ray diffractometry, scanning electron microscopy, and an impedance analyzer. The thermal decomposition of the LSGMC precursors was completed at around 900 degrees C with the total weight loss of approximately 35%. The LSGMC samples sintered at 1350 degrees C consisted of the pure perovskite structure. The ionic conductivity was significantly improved by Co doping for the Ga-site of the La0.8Sr0.2Ga0.8Mg0.2O2.8 (LSGM) electrolytes. The ionic conductivity of LSGMC (x = 0.1) exhibited the highest values of 1.6 x 10(-1) S cm(-1) at 700 degrees C with an activation energy for the oxide-ion conduction of 0.29 eV. The results of this study indicated that the Co-doped LSGM electrolytes had excellent properties for use as an electrolyte in an IT-SOFC and the ammonium carbonate coprecipitation process could be employed as the efficient method for the preparation of the Co-doped LSGM electrolytes.

Lee JG; Yoon HH

2012-01-01

228

Alkaline polymer electrolyte membranes for fuel cell applications.  

Science.gov (United States)

In this review, we examine the most recent progress and research trends in the area of alkaline polymer electrolyte membrane (PEM) development in terms of material selection, synthesis, characterization, and theoretical approach, as well as their fabrication into alkaline PEM-based membrane electrode assemblies (MEAs) and the corresponding performance/durability in alkaline polymer electrolyte membrane fuel cells (PEMFCs). Respective advantages and challenges are also reviewed. To overcome challenges hindering alkaline PEM technology advancement and commercialization, several research directions are then proposed. PMID:23640049

Wang, Yan-Jie; Qiao, Jinli; Baker, Ryan; Zhang, Jiujun

2013-07-01

229

The rheological properties of different GNPs  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Rheological analysis can be employed as a sensitive tool in predicting the physical properties of gold nanoparticles (GNPs). Understanding the rheological properties of GNPs can help to develop a better therapeutic cancer product, since these physical properties often link material formulation and processing stages with the ultimate end use. The rheological properties of GNPs have not been previously documented. The present study attempted to characterize the rheological properties of different sizes of GNPs at: 1) fixed temperature and wide range of shear rates; 2) varied temperature and fixed shear rate. Methods 10, 20 and 50 nm GNPs was used in this study. Several rheological parameters of GNPs such as viscosity, torque%, shear stress and shear rate were evaluated using Brookfield LVDV-III Programmable rheometer supplied with temperature bath and controlled by a computer. To measure fluid properties (viscosity as function of shear rate), e.g., to determine whether the flow is Newtonian or non-Newtonian flow behaviour, and viscoelasticity (viscosity as function of temperature), rheological parameters were firstly measured at starting temperature of 37°C and wide range of shear rates from 375 to 1875 s-1, and secondly at a gradual increase of temperature from 37 to 42°C and fixed shear rate of 1875 s-1. Results The 10, 20 and 50 nm GNPs showed mean size of 9.45 ± 1.33 nm, 20.18 ± 1.80 nm, and 50 nm GNPs, respectively. The 10 and 20 nm GNPs showed spherical morphology while 50 nm GNPs showed hexagonal morphology using the transmission electron microscope (TEM). The relation between viscosity (cp) and shear rate (s-1) for 10, 20 and 50 nm GNPs at a temperature of 37°C showed non-Newtonian behaviour. Although the relationship between SS (dyne/cm2) and SR (s-1) for 10, 20 and 50 nm GNPs was linearly related however their fluid properties showed non-Newtonian behaviour. Conclusions The torque%, viscosity (cp) and SS (dyne/cm2) of all GNP sizes decreased with increasing the temperature and with decreasing the GNP size (for each fixed temperature value). For each shear rate value, the viscosity of all GNPs decreased with decreasing the GNP size. This study demonstrates that the physical, dimensional and morphological changes of GNPs have effective influence on their rheological properties. To understand and categorize the role of GNPs in drug delivery and cancer therapy, GNPs of varying size, number of particles, shape and surface should be taken into consideration. Moreover, further additional in vivo studies after administration of GNPs in rats should be performed to support this hypothesis.

Abdelhalim Mohamed Anwar K

2012-01-01

230

Oxide ion electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Oxide ion electrolytes are used in sensors, oxygen pumps, and - potentially - high temperature electrolysis and fuel cells. However, their range of application is limited by too low an oxide ion conductivity below 800degC in the electrolytes now available commercially. The paper outlines a strategy for the identification of improved materials. Preliminary studies have identified inexpensive oxides readily prepared by conventional ceramic techniques that promise acceptable performance at temperatures as low as 400degC. They are compared with the Bi{sub 4}V{sub 1.8}Cu{sub 0.2}O{sub 10.7} oxide conductor developed at Lille. The mechanisms of oxide ion conduction for the different compounds are discussed. (orig.).

Goodenough, J.B.; Manthiram, A.; Paranthaman, M.; Zhen, Y.S. (Center for Materials Science and Engineering, Univ. of Texas, Austin (United States))

1992-02-29

231

Solid electrolyte. Festelektrolyt  

Energy Technology Data Exchange (ETDEWEB)

The invention refers to a solid electrolyte with a ceramic based on aluminium oxide and sodium oxide. According to the invention, the ceramic forming the solid electrolyte has a composition with the formula A1+z1+2z/2/MIz2/MIIz1/A111-z2-z/1/017 and by X-ray analysis consists 100% of a fully stabilized beta''-A1203 phase. A means an alkali metal, silver, hydrogen or a compound of hydrogen, MI and MII are elements which supply univalent or bivalent ions. The indices z1 and z2 represent parameters which describe the proportions of material of the elements or compounds concerned, particularly those of A, MI, MII, aluminium and oxygen. z1 and z2 can have values between 0 and 1.

Harbach, F.

1987-06-19

232

Ice electrode electrolytic cell  

Energy Technology Data Exchange (ETDEWEB)

This invention relates to a method and apparatus for removing heavy metals from waste water, soils, or process streams by electrolytic cell means. The method includes cooling a cell cathode to form an ice layer over the cathode and then applying an electric current to deposit a layer of the heavy metal over the ice. The metal is then easily removed after melting the ice. In a second embodiment, the same ice-covered electrode can be employed to form powdered metals.

Glenn, David F. (Idaho Falls, ID); Suciu, Dan F. (Idaho Falls, ID); Harris, Taryl L. (Idaho Falls, ID); Ingram, Jani C. (Idaho Falls, ID)

1993-01-01

233

Thin film composite electrolyte  

Science.gov (United States)

The invention is a thin film composite solid (and a means for making such) suitable for use as an electrolyte, having a first layer of a dense, non-porous conductive material; a second layer of a porous ionic conductive material; and a third layer of a dense non-porous conductive material, wherein the second layer has a Coefficient of thermal expansion within 5% of the coefficient of thermal expansion of the first and third layers.

Schucker, Robert C. (The Woodlands, TX)

2007-08-14

234

Ice electrode electrolytic cell  

Energy Technology Data Exchange (ETDEWEB)

This invention relates to a method and apparatus for removing heavy metals from waste water, soils, or process streams by electrolytic cell means. The method includes cooling a cell cathode to form an ice layer over the cathode and then applying an electric current to deposit a layer of the heavy metal over the ice. The metal is then easily removed after melting the ice. In a second embodiment, the same ice-covered electrode can be employed to form powdered metals.

Glenn, D.F.; Suciu, D.F.; Harris, T.L.; Ingram, J.C.

1992-12-31

235

Aprotic gel polymer electrolytes.  

Czech Academy of Sciences Publication Activity Database

. Brno : University of Technology Brno, 2008, s. 71-72. ISBN 978-80-214-3659-6.[International Conference Advanced Batteries and Accumulators /9./. Brno (CZ), 29.06.2008-03.07.2008]Grant CEP: GA ?R(CZ) GA104/06/1471; GA AV ?R(CZ) KJB208130604Výzkumný zám?r: CEZ:AV0Z40320502Klí?ová slova: gel polymer electrolytesKód oboru RIV: CA - Anorganická chemie

Vondrák, Ji?íG; Sedla?íková, M.; Krejza, O.

236

Solid-state Graft Copolymer Electrolytes for Lithium Battery Applications.  

UK PubMed Central (United Kingdom)

Battery safety has been a very important research area over the past decade. Commercially available lithium ion batteries employ low flash point (<80 °C), flammable, and volatile organic electrolytes. These organic based electrolyte systems are viable at ambient temperatures, but require a cooling system to ensure that temperatures do not exceed 80 °C. These cooling systems tend to increase battery costs and can malfunction which can lead to battery malfunction and explosions, thus endangering human life. Increases in petroleum prices lead to a huge demand for safe, electric hybrid vehicles that are more economically viable to operate as oil prices continue to rise. Existing organic based electrolytes used in lithium ion batteries are not applicable to high temperature automotive applications. A safer alternative to organic electrolytes is solid polymer electrolytes. This work will highlight the synthesis for a graft copolymer electrolyte (GCE) poly(oxyethylene) methacrylate (POEM) to a block with a lower glass transition temperature (Tg) poly(oxyethylene) acrylate (POEA). The conduction mechanism has been discussed and it has been demonstrated the relationship between polymer segmental motion and ionic conductivity indeed has a Vogel-Tammann-Fulcher (VTF) dependence. Batteries containing commercially available LP30 organic (LiPF6 in ethylene carbonate (EC):dimethyl carbonate (DMC) at a 1:1 ratio) and GCE were cycled at ambient temperature. It was found that at ambient temperature, the batteries containing GCE showed a greater overpotential when compared to LP30 electrolyte. However at temperatures greater than 60 °C, the GCE cell exhibited much lower overpotential due to fast polymer electrolyte conductivity and nearly the full theoretical specific capacity of 170 mAh/g was accessed.

Hu Q; Caputo A; Sadoway DR

2013-01-01

237

Synthesis and characterization of inorganic solid electrolytes of Li2O-SiO2-P2O5 and Li2O-TiO2-SiO2-P2O5 systems  

International Nuclear Information System (INIS)

The lithium-ion-conducting inorganic solid electrolytes in the oxide systems Li2O-SiO2-P2O5 and Li2O-TiO2-SiO2-P2O5 were prepared by the solid-state reaction, and the electrolyte pellet made by cold-pressing method had diameter of 13 mm and was about 1 mm thick. Phase identification and surface morphology of the products were carried out by X-ray diffraction and scanning electron microscopy. Ionic conductivity of the pellets was investigated through ac impedance. The results show that the adding of other cations can improve the ionic conductivity of the solid electrolyte, and the sintering temperature and duration can influence the ionic conductivity. The maximum ionic conductivity in the samples is 9.9 x 10-4 S/cm in the Li2O-TiO2-SiO2-P2O5 system

2007-01-01

238

Manufacturing method of solid electrolyte  

Energy Technology Data Exchange (ETDEWEB)

In order to apply solid electrolyte as fuel cell, it is necessary to form solid electrolyte as thin as possible and on its both sides, fuel gas and air exist through porous electrodes and both of them must not leak. In order to obtain a big power output, such requirements ought to be fulfilled that the solid electrolyte must bear a big back pressure and at the same time, a mass production system must be established. For solving these matters, this invention proposes the method which follows the processes mentioned below: (1) the first process to form a porous electrode by application or elusion on the surface of a porous substrate, (2) the second process to form a solid electrolyte layer with thickness which occupies the most of the planned thickness by the slurry application method of the powder of the solid electrolytic material of the first process on the surface of the solid electrode material above, (3) the third process to make the thickness of the solid electrolyte layer to be the planned thickness by chemical vapor deposition of the solid electrolytic material of the second process on the surface of the above solid electrolyte layer and at the same time seal off the layer, and (4) the fourth process to form porous electrode material by application or emusion on the surface of the sealed-off solid electrolyte layer above. 3 figures.

Murakami, Nobuaki; Miyazaki, Tatsuro; Miyazaki, Yasunori; Nishi, Toshiro

1988-11-22

239

Electrolytic cell. Elektrolytische Zelle  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the invention is an air or fuel cell, which has a catalytic electrode as depolariser equipped to activate oxygen in air, an anode, and an aquaeous alkali hydroxide electrolyte in a common case with an air inlet on the case; there is a collecting device in the case between the air inlet and the catalytic electrode, consisting of a thin porous basic material, into which LiOH has been deposited by impregnation and subsequent drying. The electric cells of this invention make it possible to supply the catalytic electrode with air free of carbon dioxide.

Tuburaya, Y.

1982-05-06

240

Glass electrolyte composition  

Energy Technology Data Exchange (ETDEWEB)

An ionically conductive glass is disclosed for use as electrolyte in a high temperature electrochemical cell, particularly a cell with sodium anode and sulfur cathode. The glass includes the constituents Na/sub 2/O, ZrO/sub 2/, Al/sub 2/O/sub 3/ and SiO/sub 2/ in selected proportions to be a single phase solid solution substantially free of crystalline regions and undissolved constituents. Other advantageous properties are an ionic conductivity in excess of 2 x 10/sup -3/ (ohm-cm)/sup -1/ at 300/sup 0/C and a glass transition temperature in excess of 500/sup 0/C.

Kucera, G.H.; Roche, M.F.

1985-01-08

 
 
 
 
241

Glass electrolyte composition  

Energy Technology Data Exchange (ETDEWEB)

An ionically conductive glass is disclosed for use as electrolyte in a high temperature electrochemical cell, particularly a cell with sodium anode and sulfur cathode. The glass includes the constituents Na.sub.2 O, ZrO.sub.2, Al.sub.2 O.sub.3 and SiO.sub.2 in selected proportions to be a single phase solid solution substantially free of crystalline regions and undissolved constituents. Other advantageous properties are an ionic conductivity in excess of 2.times.10.sup.-3 (ohm-cm).sup.-1 at 300.degree. C. and a glass transition temperature in excess of 500.degree. C.

Kucera, Gene H. (Downers Grove, IL); Roche, Michael F. (Downers Grove, IL)

1985-01-01

242

Electrolytic activation of water  

UK PubMed Central (United Kingdom)

The commercial unipolar activation of water to disinfect raw water supply from rivers or wells, seawater, or waste water from sewage, animal waste, processing plant waste, cooling tower water, swimming pool and spa water, ship ballast water and similar polluted waters. Disinfection is accomplished by hydrogen peroxide and ozone including biocides from chlorine and sulphur compounds in the water that are produced during the electrolytic unipolar activation of the water. Unipolar activation can also be used to perform chemical reactions such as in the activation of seawater. This invention can also produce alkaline water that is beneficial for health.

GOMEZ RODOLFO ANTONIO M

243

SUBSTITUTED POLY(ALKYLENEDIOXYTHIOPHENES) AS SOLID ELECTROLYTES IN ELECTROLYTIC CAPACITORS  

UK PubMed Central (United Kingdom)

The invention relates to electrolytic capacitors comprising specifically substituted poly(alkylenedioxythiophenes) comprising recurring units of the formula (I) (see formula I) as solid electrolytes and their production and also conductive layers comprising the poly(alkylenedioxythiophenes), their production and use.

MERKER UDO; REUTER KNUD; LERCH KLAUS

244

The rheology of field-responsive suspensions  

CERN Document Server

We present some aspects of the rheology of field-responsive suspensions, a class of field-responsive liquid matter systems possessing the ability to undergo significant changes in their strength upon application of an external field. Both the single-particle and the many-particle domains are discussed. In the former, consideration of the full nonlinear dynamics of the particles leads to an anomalous behavior of the viscosity whereas in the latter the most salient feature is the formation of chains and fractal structures. We indicate how to deal with the rheology at moderately concentrations leaving open the problem at higher concentrations for which the complexity of the emergent structures strongly limits the knowledge of their dynamics.

Rubí, J M

2000-01-01

245

Glass transitions and shear thickening suspension rheology  

CERN Document Server

We introduce a class of simple models for shear thickening and/ or `jamming' in colloidal suspensions. These are based on schematic mode coupling theory (MCT) of the glass transition, having a memory term that depends on a density variable, and on both the shear stress and the shear rate. (Tensorial aspects of the rheology, such as normal stresses, are ignored for simplicity.) We calculate steady-state flow curves and correlation functions. Depending on model parameters, we find a range of rheological behaviours, including `S-shaped' flow curves, indicating discontinuous shear thickening, and stress-induced transitions from a fluid to a nonergodic (jammed) state, showing zero flow rate in an interval of applied stress. The shear thickening and jamming scenarios that we explore appear broadly consistent with experiments on dense colloids close to the glass transition, despite the fact that we ignore hydrodynamic interactions. In particular, the jamming transition we propose is conceptually quite different from...

Holmes, C B; Fuchs, M; Sollich, P

2004-01-01

246

Rheological behaviour of heated potato starch dispersions  

Science.gov (United States)

The study was designed to investigate the rheological properties of heated potato starch dispersions. Water suspensions of starch were heated at 65, 80 or 95°C for 5, 15, 30 or 60 min. The dispersions obtained were examined for granule size distribution and rheology. It was found that the starch dispersions significantly differed in both respects. The mean diameters of starch granules were largest for the dispersion heated at 65°C and smallest for that heated at 95°C. As the heating temperature was raised, the yield stresses and consistency coefficients decreased, while the flow behaviour indexes and Casson plastic viscosities increased. There were also differences in the viscoelastic properties of the dispersions: for those heated at 65°C the storage and loss moduli increased with heating time whereas for those heated at 80°C both moduli decreased.

Juszczak, L.; Witczak, M.; Ziêba, T.; Fortuna, T.

2012-10-01

247

Nonlinear rheology of a nanoconfined simple fluid.  

UK PubMed Central (United Kingdom)

We probe the rheology of the model liquid octamethylcyclotetrasiloxane (OMCTS) confined into molecularly thin films, using a unique surface force apparatus allowing us to explore a large range of shear rates and confinement. We thus show that OMCTS under increasing confinement exhibits the viscosity enhancement and the nonlinear flow properties characteristic of a sheared supercooled liquid approaching its glass transition. Besides, we study the drainage of confined OMCTS via the propagation of "squeeze-out" fronts. The hydrodynamic model proposed by Becker and Mugele [Phys. Rev. Lett. 91, 166104 (2003)] to describe such front dynamics leads to a conclusion in apparent contradiction with the dynamical slowdown evidenced by rheology measurements, which suggests that front propagation is not controlled by large scale flow in the confined films.

Bureau L

2010-05-01

248

Nonlinear rheology of a nanoconfined simple fluid.  

Science.gov (United States)

We probe the rheology of the model liquid octamethylcyclotetrasiloxane (OMCTS) confined into molecularly thin films, using a unique surface force apparatus allowing us to explore a large range of shear rates and confinement. We thus show that OMCTS under increasing confinement exhibits the viscosity enhancement and the nonlinear flow properties characteristic of a sheared supercooled liquid approaching its glass transition. Besides, we study the drainage of confined OMCTS via the propagation of "squeeze-out" fronts. The hydrodynamic model proposed by Becker and Mugele [Phys. Rev. Lett. 91, 166104 (2003)] to describe such front dynamics leads to a conclusion in apparent contradiction with the dynamical slowdown evidenced by rheology measurements, which suggests that front propagation is not controlled by large scale flow in the confined films. PMID:20867143

Bureau, Lionel

2010-05-25

249

[Osmotic homeostasis and blood rheology in patients in the acute period of ischemic cerebral infarction].  

Science.gov (United States)

The authors describe the role of changes in osmotic homeostasis and hemorheology in the pathogenesis of ischemic brain stroke. 48 patients experiencing an acute period of ischemic brain stroke were examined. For this purpose the following methods were employed: measurements of blood, urine and CSF osmolality by Knauer osmometer; glucose and urea by the enzymatic assay; blood electrolytes by flame photometer; aggregation of platelets, red blood cells, blood viscosity, fibrinogen, hematocrit; the ethanol test, and thromboelastography. The data obtained demonstrate that the unfavorable prognostic signs may include steady and increasing hyperosmia, rise of the mmol discriminant of osmolality to over 35-40 mOsm/l, a progressive decrease of the rheological blood parameters and of colloid-osmotic pressure together with a progressive reduction of the urine/blood osmolality, which points to the rupture of the compensation for osmotic homeostasis and decompensation for the functional system regulating the blood aggregation state. PMID:2175076

Gusev, E I; Chukanova, E I; Iasamanova, A N

1990-01-01

250

[Osmotic homeostasis and blood rheology in patients in the acute period of ischemic cerebral infarction  

UK PubMed Central (United Kingdom)

The authors describe the role of changes in osmotic homeostasis and hemorheology in the pathogenesis of ischemic brain stroke. 48 patients experiencing an acute period of ischemic brain stroke were examined. For this purpose the following methods were employed: measurements of blood, urine and CSF osmolality by Knauer osmometer; glucose and urea by the enzymatic assay; blood electrolytes by flame photometer; aggregation of platelets, red blood cells, blood viscosity, fibrinogen, hematocrit; the ethanol test, and thromboelastography. The data obtained demonstrate that the unfavorable prognostic signs may include steady and increasing hyperosmia, rise of the mmol discriminant of osmolality to over 35-40 mOsm/l, a progressive decrease of the rheological blood parameters and of colloid-osmotic pressure together with a progressive reduction of the urine/blood osmolality, which points to the rupture of the compensation for osmotic homeostasis and decompensation for the functional system regulating the blood aggregation state.

Gusev EI; Chukanova EI; Iasamanova AN

1990-01-01

251

Rheology of a confined granular material  

CERN Document Server

We study the rheology of a granular material slowly driven in a confined geometry. The motion is characterized by a steady sliding with a resistance force increasing with the driving velocity and the surrounding relative humidity. For lower driving velocities a transition to stick-slip motion occurs, exhibiting a blocking enhancement whith decreasing velocity. We propose a model to explain this behavior pointing out the leading role of friction properties between the grains and the container's boundary.

Ovarlez, G; Clément, E; Ovarlez, Guillaume; Kolb, Evelyne; Cl\\'{e}ment, Eric

2001-01-01

252

From Reactor to Rheology in LDPE Modeling  

International Nuclear Information System (INIS)

[en] In recent years the association between molecular structure and linear rheology has been established and well-understood through the tube concept and its extensions for well-characterized materials (e.g. McLeish, Adv. Phys. 2002). However, for industrial branched polymeric material at processing conditions this piece of information is missing. A large number of phenomenological models have been developed to describe the nonlinear response of polymers. But none of these models takes into account the underlying molecular structure, leading to a fitting procedure with arbitrary fitting parameters. The goal of applied molecular rheology is a predictive scheme that runs in its entirety from the molecular structure from the reactor to the non-linear rheology of the resin. In our approach, we use a model for the industrial reactor to explicitly generate the molecular structure ensemble of LDPE's, (Tobita, J. Polym. Sci. B 2001), which are consistent with the analytical information. We calculate the linear rheology of the LDPE ensemble with the use of a tube model for branched polymers (Das et al., J. Rheol. 2006). We then, separate the contribution of the stress decay to a large number of pompom modes (McLeish et al., J. Rheol. 1998 and Inkson et al., J. Rheol. 1999) with the stretch time and the priority variables corresponding to the actual ensemble of molecules involved. This multimode pompom model allows us to predict the nonlinear properties without any fitting parameter. We present and analyze our results in comparison with experimental data on industrial materials

2008-07-07

253

Structural and rheological properties of meibomian lipid.  

UK PubMed Central (United Kingdom)

PURPOSE: We explore the unique rheological and structural properties of human and bovine meibomian lipids to provide insight into the physical behavior of the human tear-film lipid layer (TFLL). METHODS: Bulk rheological properties of pooled meibomian lipids were measured by a commercial stress-controlled rheometer; a home-built interfacial stress rheometer (ISR) probed the interfacial viscoelasticity of spread layers of meibomian lipids. Small- and wide-angle x-ray scattering detected the presence and melting of dispersed crystal structures. Microscope examination under cross polarizers provided confirmation of ordered crystals. A differential scanning calorimeter (DSC) analyzed phase transitions in bulk samples of bovine meibum. RESULTS: Bulk and interfacial rheology measurements show that meibum is extremely viscous and highly elastic. It is also a non-Newtonian, shear-thinning fluid. Small- and wide-angle x-ray diffraction (SAXS and WAXS), as well as differential scanning calorimetry (DSC) and polarizing microscopy, confirm the presence of suspended lamellar-crystal structures at physiologic temperature. CONCLUSIONS: We studied meibum architecture and its relation to bulk and interfacial rheology. Bovine and human meibomian lipids exhibit similar physical properties. From all structural probes utilized, we find a melt transition near eye temperature at which lamellar crystals liquefy. Our proposed structure for the tear-film lipid layer at physiologic temperature is a highly viscoelastic, shear-thinning liquid suspension consisting of lipid lamellar-crystallite particulates immersed in a continuous liquid phase with no long-range order. When spread over on-eye tear, the TFLL is a duplex film that exhibits bulk liquid properties and two separate interfaces, air/lipid and water/lipid, with aqueous protein and surfactantlike lipids adsorbed at the water/lipid surface.

Rosenfeld L; Cerretani C; Leiske DL; Toney MF; Radke CJ; Fuller GG

2013-04-01

254

Two dimensional foam rheology with viscous drag  

CERN Document Server

We formulate and apply a continuum model that incorporates elasticity, limit stress, plasticity and viscous drag. It is motivated by the two-dimensional foam rheology experiment of Debregeas \\emph{et al.} [G. Debr\\'egeas, H. Tabuteau, and J.-M. di Meglio, {\\em Phys. Rev. Lett.} {\\bf 87}, 178305 (2001).], and is successful in exhibiting its principal feature, that is velocity and strain localisation. Transient effects are also identified.

Weaire, D; Hutzler, S

2006-01-01

255

Rheological characterization of coal liquefaction preheater slurries  

Energy Technology Data Exchange (ETDEWEB)

Rheological characterizations were made for a coal liquefaction preheater slurry; measurements were made in line at high temperature and high pressure. Above 400/degree/K, the coal-solvent slurry (35 wt.% coal) was pseudoplastic and was adequately modeled by a power-law equation. Experimental data over a temperature range of 400 to 700/degree/K were correlated, and critical slurry velocities for transition from laminar flow were calculated for flow in several pipe diameters. 15 refs.

Thurgood, J.R.; Hanks, R.W.; Oswald, G.E.; Youngblood, E.L.

1982-01-01

256

Electrolyte creepage barrier for liquid electrolyte fuel cells  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2008-01-22

257

Polyethylene Imine-Metal Salt Solid Electrolyte.  

Science.gov (United States)

This patent application pertains to battery electrolytes. Accordingly, it is an object of invention to provide new solid electrolytes. Another object of this invention is to provide new polymeric electrolytes. A further object of this invention is to prov...

G. T. Davis C. K. Chiang T. Takahashi

1985-01-01

258

Drilling mud rheology and the API recommended measurements  

Energy Technology Data Exchange (ETDEWEB)

Drilling fluids are, among other things, expected to transport cuttings and control fluid loss. The rheology of drilling fluids plays an important roll in both of these aspects of drilling fluid performance. A number of years ago the American Petroleum Institute established a set of standards for evaluating the rheology of drilling fluids. While drilling fluid technology has evolved and drilling fluids have become more rheologically complex, the standards have not changed sufficiently to adequately characterize the new generation of drilling fluids.

Clark, P.E.

1995-12-31

259

ALTERATION OF RHEOLOGICAL PROPERTIES OF BLOOD AT PATIENTS WITH TONSILLITIS  

Directory of Open Access Journals (Sweden)

Full Text Available Complex research of rheological properties of blood at patients with lacunar tonsillitis lead depending on the period of disease. It is shown, that inflammatory process at patients to a great extent defines disturbances of rheological properties of blood. During normalization of a clinical presentation of disease there is no full recovery of rheological properties of blood due to preservation of blood raised viscosity and low deformability of erythrocytes membranes.

O.I. Kulapina; V.F. Kirichuk; I.A. Zaitseva

2008-01-01

260

Ageing and Rheology in Soft Materials  

CERN Multimedia

We study theoretically the role of ageing in the rheology of soft materials. We define several generalized rheological response functions suited to ageing samples (in which time translation invariance is lost). These are then used to study ageing effects within a simple scalar model (the "soft glassy rheology" or SGR model) whose constitutive equations relate shear stress to shear strain among a set of elastic elements, with distributed yield thresholds, undergoing activated dynamics governed by a "noise temperature", $x$. (Between yields, each element follows affinely the applied shear.) For $1

Fielding, S M; Cates, M E

1999-01-01

 
 
 
 
261

Rheological Characterization of Shale – Mud Interactions  

Directory of Open Access Journals (Sweden)

Full Text Available In a bid to identify a best drilling fluid for a problematic oil field in the Niger Delta region, rheological tests were carried out on three mud samples; BW1, BW3 and BW4. The results affirm that the load bearing capacity of XP-07 formulated as BW3 and BW4 in this investigation is excellent and fall within the same range or even better than those of REF Mud with a more than 90% drilling success history in Niger Delta. The rheological changes of XP-07 with increase in temperature and “assimilated” microscopic shale particles are very negligible and smaller than those of REF mud. XP-07 has been strongly recommended for all drilling operations in the problematic field. It has been re-emphasised as part of our recommendations that new guidelines for the close monitoring of drilling fluids supplied by mud companies and those actually used in the field (during drilling) be put in place.Key words: Shale – mud interactions; Rheological characterization; Niger delta

W. O. Emofurieta; A. O. Odeh

2012-01-01

262

Structure and rheology of organoclay suspensions  

International Nuclear Information System (INIS)

We have characterized a montmorillonite-based organoclay dispersed in three different nonaqueous solvents using a combination of x-ray scattering, small-angle neutron scattering (SANS), and ultrasmall angle neutron scattering (USANS), together with rheological measurements. Consistent with these measurements, we present a structural model for the incompletely dispersed clay as consisting of randomly oriented tactoids made of partially overlapping clay sheets, with transverse dimensions of several microns. Intersheet correlation peaks are visible in x-ray scattering, and quantitatively fit by our model structure factor. SANS and USANS together show a power law of about -3 over a wide range of wave numbers below the intersheet correlation peak. Our model relates this power law to a power law distribution of the number of locally overlapping layers in a tactoid. The rheology data show that both storage and loss moduli, as well as yield stress, scale with a power law in volume fraction of about three. Equating the gel onset composition with the overlap of randomly oriented tactoids and taking into account the large transverse dimensions of the tactoids, we predict the gel point to be at or below 0.006 volume fraction organoclay. This is consistent with the rheology data.

2007-01-01

263

Structure and rheology of organoclay suspensions  

Science.gov (United States)

We have characterized a montmorillonite-based organoclay dispersed in three different nonaqueous solvents using a combination of x-ray scattering, small-angle neutron scattering (SANS), and ultrasmall angle neutron scattering (USANS), together with rheological measurements. Consistent with these measurements, we present a structural model for the incompletely dispersed clay as consisting of randomly oriented tactoids made of partially overlapping clay sheets, with transverse dimensions of several microns. Intersheet correlation peaks are visible in x-ray scattering, and quantitatively fit by our model structure factor. SANS and USANS together show a power law of about -3 over a wide range of wave numbers below the intersheet correlation peak. Our model relates this power law to a power law distribution of the number of locally overlapping layers in a tactoid. The rheology data show that both storage and loss moduli, as well as yield stress, scale with a power law in volume fraction of about three. Equating the gel onset composition with the overlap of randomly oriented tactoids and taking into account the large transverse dimensions of the tactoids, we predict the gel point to be at or below 0.006 volume fraction organoclay. This is consistent with the rheology data.

King, H. E., Jr.; Milner, Scott T.; Lin, Min Y.; Singh, John P.; Mason, T. G.

2007-02-01

264

Rheology of high internal phase emulsions.  

UK PubMed Central (United Kingdom)

The mechanical dispersion technology used in this study employs rotor-stator mixers that produce water-continuous high internal phase emulsions (HIPEs) with narrow drop size distributions and small drop sizes, even when the internal phase (oil) viscosity is quite high. Analysis of these HIPEs reveals trends that are consistent with formation by a capillary instability mechanism in which a shear deformation produces highly elongated drops that rupture to form uniform, small droplets. In the search for a predictive tool to aid in the manufacture and use of HIPEs, rheology data for these shear-thinning HIPEs have been compared to data for models in the literature. Existing models do not correctly account for the effect of a high internal phase viscosity on the rheological properties of the HIPE. Another shortcoming is failure to correctly address the shear-thinning exponent. Whereas internal phase viscosity does not seem to affect the shear-thinning exponent, the surfactant apparently plays an important role, possibly through its modification of the interfacial tension and continuous phase rheology.

Welch CF; Rose GD; Malotky D; Eckersley ST

2006-02-01

265

Solid electrolyte. Festelektrolyt  

Energy Technology Data Exchange (ETDEWEB)

The invention refers to a solid electrolyte with a ceramic based on aluminium oxide and sodium oxide. According to the invention, the ceramic forming the solid electrolyte has a composition with the formula Asub(1+z/1+2z/2)Msup(I)sub(z/2)Msup(II)sub(z/1)Alsub(11-z/2-z/1)O/sub 17/ and by X-ray analysis consists 100% of a fully stabilized ..beta..''-Al/sub 2/O/sub 3/ phase. A means an alkali metal, silver, hydrogen or a compound of hydrogen, Msup(I) and Msup(II) are elements which supply univalent or bivalent ions. The indices Z/sub 1/ and Z/sub 2/ represent parameters which describe the proportions of material of the elements or compounds concerned, particularly those of A, Msup(I), Msup(II), aluminium and oxygen. z/sub 1/ and z/sub 2/ can have values between 0 and 1. (orig.).

Harbach, F.

1984-06-28

266

Post-seismic stress relaxation with a linear transient rheology  

Directory of Open Access Journals (Sweden)

Full Text Available We performed an analysis of post-seismic stress relaxation, taking into account generalized linear rheologies. We compared the stress field (and its derived functions) obtained with a classical Maxwell rheology with that obtained with a transient Burgers body. From a set of synthetic case studies, we have revealed quantitative and qualitative differences both in relaxation times and in local stress values when a transient rheology is introduced. As a practical application, we modeled the time evolution of the Coulomb failure function following the 2009 L'Aquila earthquake, and we show that a transient rheology can lead to non-monotonic time dependence.

Valentina Cannelli; Daniele Melini; Antonio Piersanti

2010-01-01

267

Thin film polymeric gel electrolytes  

Science.gov (United States)

Novel hybrid thin film electrolytes, based on an organonitrile solvent system, which are compositionally stable, environmentally safe, can be produced efficiently in large quantity and which, because of their high conductivities {approx_equal}10{sup {minus}3}{Omega}{sup {minus}1} cm{sup {minus}1} are useful as electrolytes for rechargeable lithium batteries. 1 fig.

Derzon, D.K.; Arnold, C. Jr.; Delnick, F.M.

1996-12-31

268

Physics of Electrolytic Gas Evolution  

CERN Multimedia

A brief analysis of the physics and effects of electrolytic gas evolution is presented. Aspects considered include bubble nucleation, growth, and detachment, enhancement of mass and heat transfer, and decrease of apparent electrical conductivity of bubble containing electrolytes. This analysis is mainly oriented to hydrogen/oxygen evolving electrodes.

Sequeira, Cesar A C; Sljukic, Biljana; Amaral, Luis

2013-01-01

269

Thin film polymeric gel electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Novel hybrid thin film electrolyte, based on an organonitrile solvent system, which are compositionally stable, environmentally safe, can be produced efficiently in large quantity and which, because of their high conductivities .apprxeq.10.sup.-3 .OMEGA..sup.-1 cm.sup.-1 are useful as electrolytes for rechargeable lithium batteries.

Derzon, Dora K. (1554 Rosalba St. NE., Albuquerque, Bernalillo County, NM 87112); Arnold, Jr., Charles (3436 Tahoe, NE., Albuquerque, Bernalillo County, NM 87111); Delnick, Frank M. (9700 Fleming Rd., Dexter, MI 48130)

1996-01-01

270

PLANT-BASED ELECTROLYTE COMPOSITIONS  

UK PubMed Central (United Kingdom)

This invention relates, inter alia, to various plant-based electrolyte compositions, methods of preparing them and methods of using them. One embodiment concerns a plant-based electrolyte composition comprising a plant-derived electrolyte content high in potassium relative to sodium, and a plant-derived carbohydrate content less than about 6% weight/volume. Another embodiment concerns a method for re-hydrating an individual or preventing dehydration or over-hydration of an individual or for preventing or treating potassium deficiency in an individual, by administering to the individual a plant-based electrolyte composition. The electrolyte compositions can be prepared from sugarcane juice, sugar beet juice, sweet sorghum juice, palm syrup, maple sap, vegetable juice or fruit juice.

STANLEY ROGER ANTHONY; WIJESINGHE BANDUPALA; MEREDDY KODANDA RAM REDDY

271

Perovskite solid electrolytes for SOFC  

International Nuclear Information System (INIS)

The object of this program is to experimentally determine the utility of selected perovskite related solid electrolytes for application in SOFC's operating at intermediate temperatures (600-750 degrees C). Specific technical objectives addressed in this program include: Gaining useful insight into those crystallographic and thermodynamic parameters which influence both activation energy (Ea) for ionic transport and the population of ionic charge carriers. Synthesizing selected perovskite related solid electrolyte powders expected to possess (i) low Ea for ionic conduction and (ii) an intrinsically high population of ionic charge carriers. Preparing sintered solid electrolyte disks and determine their ionic conductivity. Incorporating solid electrolytes demonstrating acceptable ionic conductivity into small research size SOFC's operating at intermediate temperatures and determine their electrochemical performance. Determining the long-term stability of selected solid electrolyte materials incorporated into SOFC'S.

1992-01-01

272

Electrolyte treatment for aluminum reduction  

Energy Technology Data Exchange (ETDEWEB)

A method of treating an electrolyte for use in the electrolytic reduction of alumina to aluminum employing an anode and a cathode, the alumina dissolved in the electrolyte, the treating improving wetting of the cathode with molten aluminum during electrolysis. The method comprises the steps of providing a molten electrolyte comprised of ALF.sub.3 and at least one salt selected from the group consisting of NaF, KF and LiF, and treating the electrolyte by providing therein 0.004 to 0.2 wt. % of a transition metal or transition metal compound for improved wettability of the cathode with molten aluminum during subsequent electrolysis to reduce alumina to aluminum.

Brown, Craig W. (Seattle, WA); Brooks, Richard J. (Seattle, WA); Frizzle, Patrick B. (Seattle, WA); Juric, Drago D. (Bulleen, AU)

2002-01-01

273

Electrolyte paste for molten carbonate fuel cells  

Energy Technology Data Exchange (ETDEWEB)

The electrolyte matrix and electrolyte reservoir plates in a molten carbonate fuel cell power plant stack are filled with electrolyte by applying a paste of dry electrolyte powder entrained in a dissipatable carrier to the reactant flow channels in the current collector plate. The stack plates are preformed and solidified to final operating condition so that they are self sustaining and can be disposed one atop the other to form the power plant stack. Packing the reactant flow channels with the electrolyte paste allows the use of thinner electrode plates, particularly on the anode side of the cells. The use of the packed electrolyte paste provides sufficient electrolyte to fill the matrix and to entrain excess electrolyte in the electrode plates, which also serve as excess electrolyte reservoirs. When the stack is heated up to operating temperatures, the electrolyte in the paste melts, the carrier vaporizes, or chemically decomposes, and the melted electrolyte is absorbed into the matrix and electrode plates.

Bregoli, Lawrance J. (Southwick, MA); Pearson, Mark L. (New London, CT)

1995-01-01

274

pH Effects on the Molecular Structure of ?-Lactoglobulin Modified Air-Water Interfaces and Its Impact on Foam Rheology.  

UK PubMed Central (United Kingdom)

Macroscopic properties of aqueous ?-lactoglobulin (BLG) foams and the molecular properties of BLG modified air-water interfaces as their major structural element were investigated with a unique combination of foam rheology measurements and interfacial sensitive methods such as sum-frequency generation and interfacial dilatational rheology. The molecular structure and protein-protein interactions at the air-water interface can be changed substantially with the solution pH and result in major changes in interfacial dilational and foam rheology. At a pH near the interfacial isoelectric point BLG molecules carry zero net charge and disordered multilayers with the highest interfacial dilatational elasticity are formed at the air-water interface. Increasing or decreasing the pH with respect to the isoelectric point leads to the formation of a BLG monolayer with repulsive electrostatic interactions among the adsorbed molecules which decrease the interfacial dilational elasticity. The latter molecular information does explain the behavior of BLG foams in our rheological studies, where in fact the highest apparent yield stresses and storage moduli are established with foams from electrolyte solutions with a pH close to the isoelectric point of BLG. At this pH the gas bubbles of the foam are stabilized by BLG multilayers with attractive intermolecular interactions at the ubiquitous air-water interfaces, while BLG layers with repulsive interactions decrease the apparent yield stress and storage moduli as stabilization of gas bubbles with a monolayer of BLG is less effective.

Engelhardt K; Lexis M; Gochev G; Konnerth C; Miller R; Willenbacher N; Peukert W; Braunschweig B

2013-09-01

275

pH Effects on the Molecular Structure of ?-Lactoglobulin Modified Air-Water Interfaces and Its Impact on Foam Rheology.  

Science.gov (United States)

Macroscopic properties of aqueous ?-lactoglobulin (BLG) foams and the molecular properties of BLG modified air-water interfaces as their major structural element were investigated with a unique combination of foam rheology measurements and interfacial sensitive methods such as sum-frequency generation and interfacial dilatational rheology. The molecular structure and protein-protein interactions at the air-water interface can be changed substantially with the solution pH and result in major changes in interfacial dilational and foam rheology. At a pH near the interfacial isoelectric point BLG molecules carry zero net charge and disordered multilayers with the highest interfacial dilatational elasticity are formed at the air-water interface. Increasing or decreasing the pH with respect to the isoelectric point leads to the formation of a BLG monolayer with repulsive electrostatic interactions among the adsorbed molecules which decrease the interfacial dilational elasticity. The latter molecular information does explain the behavior of BLG foams in our rheological studies, where in fact the highest apparent yield stresses and storage moduli are established with foams from electrolyte solutions with a pH close to the isoelectric point of BLG. At this pH the gas bubbles of the foam are stabilized by BLG multilayers with attractive intermolecular interactions at the ubiquitous air-water interfaces, while BLG layers with repulsive interactions decrease the apparent yield stress and storage moduli as stabilization of gas bubbles with a monolayer of BLG is less effective. PMID:23961700

Engelhardt, Kathrin; Lexis, Meike; Gochev, Georgi; Konnerth, Christoph; Miller, Reinhard; Willenbacher, Norbert; Peukert, Wolfgang; Braunschweig, Björn

2013-09-06

276

POLYMER ELECTROLYTE MEMBRANE FUEL CELLS  

DEFF Research Database (Denmark)

A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes. With the thermally resistant polymer, e.g., polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled with an acid doped solid electrolyte membrane by hot-press. The fuel cell can operate at temperatures up to at least 200 °C with hydrogen-rich fuel containing high ratios of carbon monoxide such as 3 vol% carbon monoxide or more, compared to the carbon monoxide tolerance of 10-20 ppm level for Nafion$m(3)-based polymer electrolyte fuel cells.

Bjerrum, Niels Technical University of Denmark,

277

Design and application of magneto-rheological fluid  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Magneto-Rheological Fluid (MRF) technology is an old “newcomers” coming to the market at high speed. Various industries including the automotive industry are full of potential MRF applications. Magneto-Rheological Fluid technology has been successfully employed already in various low and high volume...

Olabi, Abdul-Ghani; Grunwald, Artur

278

Rheologies and morphologies of three actinomycetes in submerged culture.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The broth rheologies and morphologies of three actinomycetes (Saccharopolyspora erythraea, Actinomadura roseorufa, and Streptomyces rimosus) in submerged culture have been examined. The rheology of all the broths became pseudoplastic as soon as significant growth occurred with the power law index, n...

Warren, SJ; Keshavarz-Moore, E; Shamlou, PA; Lilly, MD; Thomas, CR; Dixon, K

279

The rheological behavior of HDPE/coal blends  

Energy Technology Data Exchange (ETDEWEB)

The antistatic functional material of HDPE/coal [high density polyethylene mixed with coal fines] has a higher tensile strength, higher resistance and stability. The rheological properties of the blends are important for their processing and practical use. It was necessary to study the rheological behavior of the blends. P. Ujas et al (1994) had studied the rheology of HDPE/nylon-11 blends and the effect of nylon-11 on the rheological behavior of HDPE. If Shenfu coal is used as a special polymer, it has necessarily an important affect on the rheological behavior of HDPE. In this paper, the rheological behavior of HDPE/coal blends were investigated to study the effect of the coal polymer on the rheology of HDPE. The rheological behavior of the blends were found to be very different from that of HDPE. The curves of shear viscosity for the blends at different temperatures (478, 488, and 498K) reveal that HDPE and the blends are characteristic of pseudoplastic fluid, that is, there is a decrease of shear viscosity with an increase of shearing rate.

Zhou Anning; Ge Lingmei [Xi`an Mining Inst. (China). Dept. of New Material Engineering; Guo Shucai [Dalian Univ. of Technology (China)

1997-12-31

280

Rheological Properties of Aqueous Nanometric Alumina Suspensions  

Energy Technology Data Exchange (ETDEWEB)

Colloidal processing is an effective and reliable approach in the fabrication of the advanced ceramic products. Successful colloidal processing of fine ceramic powders requires accurate control of the rheological properties. The accurate control relies on the understanding the influences of various colloidal parameters on the rheological properties. Almost all research done on the rheology paid less attention to the interactions of particle and solvent. However, the interactions of the particles are usually built up through the media in which the particles are suspended. Therefore, interactions of the particle with the media, the adsorbed layers on the particle surface, and chemical and physical properties of media themselves must influence the rheology of the suspension, especially for the dense suspensions containing nanosized particles. Relatively little research work has been reported in this area. This thesis addresses the rheological properties of nanometric alumina aqueous suspensions, and paying more attention to the interactions between particle and solvent, which in turn influence the particle-particle interactions. Dense nanometric alumina aqueous suspensions with low viscosity were achieved by environmentally-benign fructose additives. The rheology of nanometric alumina aqueous suspensions and its variation with the particle volume fraction and concentration of fructose were explored by rheometry. The adsorptions of solute (fructose) and solvent (water) on the nanometric alumina particle surfaces were measured and analyzed by TG/DSC, TOC, and NMR techniques. The mobility of water molecules in the suspensions and its variation with particle volume fractions and fructose additive were determined by the {sup 17}O NMR relaxation method. The interactions between the nanometric alumina particles in water and fructose solutions were investigated by AFM. The results indicated that a large number of water layers were physically bound on the particles' surfaces in the aqueous suspension. The viscosity of the suspension increases dramatically when the solid volume fraction exceeds 30 vol.%. The overlap of physically adsorbed water layers at this level causes the sharp increase in viscosity. Fructose molecules can weaken the interactions between the particle surfaces and water molecules, as a consequence, they release some bound water layers from the surfaces to the bulk medium. It is believed that fraction of the water that is bound by the solid surface is reduced hence becoming available for flow. The oxygen-17 relaxation time decreased with the increase of particle volume fractions in the suspension. Fructose addition increased the overall water mobility in the suspension. Only part of the alumina particle surfaces was covered with fructose molecules. This adsorption of fructose molecules on the particle surfaces increased the pH of the suspension with a concomitant decrease in {zeta}-potential of the alumina nanoparticles. The interactions between the nanometric alumina particles in water to a large extent can be explained by the DLVO theory. However, the interactions between particles in fructose solutions cannot be well described by the DLVO theory. The interaction forces (magnitude and range) as well as adhesive force and surface tension between nanometric alumina particles were decreased with the fructose concentration.

Chuanping Li

2004-12-19

 
 
 
 
281

Fast micro structuring with electrolyte jet machining  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the electrolyte jet machining (EJM), the electrolytic current between the anodic work piece and the cathodic nozzle is supplied via an electrolyte jet which is ejected from a nozzle. The main advantage compared to other EC-processes is, that the electrolytic current is restricted to a limited are...

Hackert, M.; Meichsner, G.; Schubert, A.

282

RHEOLOGICAL BEHAVIOR STUDY OF HIDRAULIC OIL  

Directory of Open Access Journals (Sweden)

Full Text Available Rheological behavior of this article presents hydraulic oil. Dynamic viscosity of hydraulic oil was determined at temperatures between 400C -900C and shear rates ranging from 3.3-120s^-1. Temperature of hydraulic oil at 313K has a Bingham fluid behavior with correlation coefficient value close to one. Between 323 and 333K temperature behavior of oil has a Casson fluid and the temperature range 343 to363K oil and behaves like an Ostwald-de Waele fluid.

IOANA STANCIU

2012-01-01

283

Rheology, and how to stop aging  

CERN Multimedia

Recent analytical developments in glass theory are equally relevant to the understanding of anomalous rheology, with characteristic features such as the Reynolds dilatancy and the driving-power dependence of the viscosity arising naturally. A notion of effective temperature based on the fluctuation-dissipation relation can be introduced in the limit of small driving power. Within mean-field, the analogue of the Edwards compactivity can be computed, and it coincides with this effective temperature. The approach does not invoke any particular geometry for the constituents of the fluid, provided it has glassy behaviour.

Kurchan, J

1998-01-01

284

Rheological properties of polypropylene/ attapulgite nanocomposite.  

UK PubMed Central (United Kingdom)

The rheological properties of nanocomposites consisting of organic modified attapulgite and polypropylene are investigated. The morphology of the nanocomposites was studied with scanning electron microscopy and X-ray diffraction. Linear dynamic viscoelasticity and steady state flow step of the nanocomposites are presented. For the nanocomposites, the deviation from linear behavior occurs earlier than pure polypropylene at the strain. The storage moduli, loss moduli and dynamic viscosities of the nanocomposites increase monotonically with organoclay concentration. However, the nanocomposites show greater shear thinning tendency than pure polypropylene because of the orientation of the organoclay fibers. Therefore, the nanocomposites have higher moduli but better processibility compared with pure polypropylene.

Zhang X; Guo J; Zhang L; Yang S; Zhang J; He Y

2010-08-01

285

Rheological properties of polypropylene/ attapulgite nanocomposite.  

Science.gov (United States)

The rheological properties of nanocomposites consisting of organic modified attapulgite and polypropylene are investigated. The morphology of the nanocomposites was studied with scanning electron microscopy and X-ray diffraction. Linear dynamic viscoelasticity and steady state flow step of the nanocomposites are presented. For the nanocomposites, the deviation from linear behavior occurs earlier than pure polypropylene at the strain. The storage moduli, loss moduli and dynamic viscosities of the nanocomposites increase monotonically with organoclay concentration. However, the nanocomposites show greater shear thinning tendency than pure polypropylene because of the orientation of the organoclay fibers. Therefore, the nanocomposites have higher moduli but better processibility compared with pure polypropylene. PMID:21125882

Zhang, Xiaohu; Guo, Jinshan; Zhang, Liji; Yang, Shiyuan; Zhang, Jie; He, Yutao

2010-08-01

286

Morphology and Rheology of Cocontinuous Blends  

Science.gov (United States)

The time evolution of the elastic modulus and the geometrical parameters of interfaces in a 50/50 PS/SAN cocontinuous blend are analyzed during annealing. The interfaces were tracked via LSCM (laser scanning confocal microscopy) coupled with 3D-image analysis. The evolution of G' and the geometrical variables can be described with power laws. Experiments reveal that interfaces relax faster (dQ/dt~Q2.4) than predicted by the Doi-Ohta theory (dQ/dt~Q2) [1]. Rheological behavior is a result of interfacial relaxation which includes interface expansion and curvature relaxation.

Barron, Carlos R. Lopez; Macosko, Christopher W.

2008-07-01

287

Ceramic-metal solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The sodium-sulfur battery is a candidate for application to electric vehicles and utility load-leveling. The electrolyte in this battery, ..beta..-Al/sub 2/O/sub 3/, often fails by fracture, which in many cases is initiated by electrolytic degradation. Technology developed at ORNL to produce shock-resistant mechanically tough ..cap alpha..-Al/sub 2/O/sub 3/-based cermets has been extended to include solid electrolytes based on ..beta..-Al/sub 2/O/sub 3/. Compositions examined, ..beta..-Al/sub 2/O/sub 3/-Pt and ..beta..-Al/sub 2/O/sub 3/-Cr, were found to have ionic conductivities comparable to ..beta..-Al/sub 2/O/sub 3/ fabricated in the same way. No special problems with the submicron-size metal inclusions were observed in preliminary tests. This concept is generic and could conceivably be applied to ceramic solid electrolytes in other chemical systems.

Lauf, R.J.; Morgan, C.S.

1982-03-01

288

Electrolyte salts for power sources  

Energy Technology Data Exchange (ETDEWEB)

Electrolyte salts for power sources comprising salts of phenyl polysulfonic acids and phenyl polyphosphonic acids. The preferred salts are alkali and alkaline earth metal salts, most preferably lithium salts.

Doddapaneni, Narayan (10516 Royal Birkdale, NE., Albuquerque, NM 87111); Ingersoll, David (5824 Mimosa Pl., NE., Albuquerque, NM 87111)

1995-01-01

289

Composite solid polymer electrolyte membranes  

Energy Technology Data Exchange (ETDEWEB)

The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.

Formato, Richard M. (Shrewsbury, MA); Kovar, Robert F. (Wrentham, MA); Osenar, Paul (Watertown, MA); Landrau, Nelson (Marlborough, MA); Rubin, Leslie S. (Newton, MA)

2001-06-19

290

Plasma spray synthesis of La{sub 10}(SiO{sub 4}){sub 6}O{sub 3} as a new electrolyte for intermediate temperature solid oxide fuel cells  

Energy Technology Data Exchange (ETDEWEB)

The apatite-type lanthanum silicate films were successfully synthesized by modified atmosphere plasma spraying using lanthanum oxide and silicon oxide mixed powders and precalcined hypereutectic powders in the size range 1-3 {mu}m and 5-8 {mu}m, respectively, as starting feedstock materials. The films differed not only in microstructural scale, but also in the characteristic of the degree of film densification. A detail describing the evolution of microstructure has been discussed. A considerable improvement in densification of the La{sub 10}(SiO{sub 4}){sub 6}O{sub 3} electrolyte films has been observed. (author)

Gao, Wei [LERMPS, University of Technology of Belfort-Montbeliard, Belfort 90010 (France); National Lab of Superhard Materials, Jilin University, Changchun 130012 (China); Liao, Han-Lin; Coddet, Christian [LERMPS, University of Technology of Belfort-Montbeliard, Belfort 90010 (France)

2008-05-01

291

Interfacial Tension of Electrolyte Solutions  

CERN Multimedia

A theory is presented to account for the increase in surface tension of water in the presence of electrolyte. Unlike the original ``grand-canonical'' calculation of Onsager and Samaras, which relied on the Gibbs adsorption isotherm and lead to a result which could only be expressed as an infinite series, our approach is ``canonical'' and produces an analytic formula for the excess surface tension. For small concentrations of electrolyte, our result reduces to the Onsager-Samaras limiting law.

Levin, Y

2000-01-01

292

High cation transport polymer electrolyte  

Energy Technology Data Exchange (ETDEWEB)

A solid state ion conducting electrolyte and a battery incorporating same. The electrolyte includes a polymer matrix with an alkali metal salt dissolved therein, the salt having an anion with a long or branched chain having not less than 5 carbon or silicon atoms therein. The polymer is preferably a polyether and the salt anion is preferably an alkyl or silyl moiety of from 5 to about 150 carbon/silicon atoms.

Gerald, II, Rex E. (Brookfield, IL); Rathke, Jerome W. (Homer Glen, IL); Klingler, Robert J. (Westmont, IL)

2007-06-05

293

Shear rheology of a cell monolayer  

International Nuclear Information System (INIS)

[en] We report a systematic investigation of the mechanical properties of fibroblast cells using a novel cell monolayer rheology (CMR) technique. The new technique provides quantitative rheological parameters averaged over ?106 cells making the experiments highly reproducible. Using this method, we are able to explore a broad range of cell responses not accessible using other present day techniques. We perform harmonic oscillation experiments and step shear or step stress experiments to reveal different viscoelastic regimes. The evolution of the live cells under externally imposed cyclic loading and unloading is also studied. Remarkably, the initially nonlinear response becomes linear at long timescales as well as at large amplitudes. Within the explored rates, nonlinear behaviour is only revealed by the effect of a nonzero average stress on the response to small, fast deformations. When the cell cytoskeletal crosslinks are made permanent using a fixing agent, the large amplitude linear response disappears and the cells exhibit a stress stiffening response instead. This result shows that the dynamic nature of the cross-links and/or filaments is responsible for the linear stress-strain response seen under large deformations. We rule out the involvement of myosin motors in this using the inhibitor drug blebbistatin. These experiments provide a broad framework for understanding the mechanical responses of the cortical actin cytoskeleton of fibroblasts to different imposed mechanical stimuli

2007-01-01

294

Vortex jamming in superconductors and granular rheology  

International Nuclear Information System (INIS)

We demonstrate that a highly frustrated anisotropic Josephson junction array (JJA) on a square lattice exhibits a zero-temperature jamming transition, which shares much in common with those in granular systems. Anisotropy of the Josephson couplings along the horizontal and vertical directions plays roles similar to normal load or density in granular systems. We studied numerically static and dynamic response of the system against shear, i.e. injection of external electric current at zero temperature. Current-voltage curves at various strength of the anisotropy exhibit universal scaling features around the jamming point much as do the flow curves in granular rheology, shear-stress versus shear-rate. It turns out that at zero temperature the jamming transition occurs right at the isotropic coupling and anisotropic JJA behaves as exotic fragile vortex matter: it behaves as a superconductor (vortex glass) in one direction, whereas it is a normal conductor (vortex liquid) in the other direction even at zero temperature. Furthermore, we find a variant of the theoretical model for the anisotropic JJA quantitatively reproduces universal master flow-curves of the granular systems. Our results suggest an unexpected common paradigm stretching over seemingly unrelated fields-the rheology of soft materials and superconductivity.

2009-01-01

295

Vortex jamming in superconductors and granular rheology  

Energy Technology Data Exchange (ETDEWEB)

We demonstrate that a highly frustrated anisotropic Josephson junction array (JJA) on a square lattice exhibits a zero-temperature jamming transition, which shares much in common with those in granular systems. Anisotropy of the Josephson couplings along the horizontal and vertical directions plays roles similar to normal load or density in granular systems. We studied numerically static and dynamic response of the system against shear, i.e. injection of external electric current at zero temperature. Current-voltage curves at various strength of the anisotropy exhibit universal scaling features around the jamming point much as do the flow curves in granular rheology, shear-stress versus shear-rate. It turns out that at zero temperature the jamming transition occurs right at the isotropic coupling and anisotropic JJA behaves as exotic fragile vortex matter: it behaves as a superconductor (vortex glass) in one direction, whereas it is a normal conductor (vortex liquid) in the other direction even at zero temperature. Furthermore, we find a variant of the theoretical model for the anisotropic JJA quantitatively reproduces universal master flow-curves of the granular systems. Our results suggest an unexpected common paradigm stretching over seemingly unrelated fields-the rheology of soft materials and superconductivity.

Yoshino, Hajime [Department of Earth and Space Science, Faculty of Science, Osaka University, Toyonaka 560-0043 (Japan); Nogawa, Tomoaki [Division of Physics, Hokkaido University, Sapporo, Hokkaido 060-0810 Japan (Japan); Kim, Bongsoo [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of)], E-mail: yoshino@ess.sci.osaka-u.ac.jp

2009-01-15

296

Rheology of rock glaciers: a preliminary assessment  

Energy Technology Data Exchange (ETDEWEB)

Movement of rock debris under the influence of gravity, i.e., mass movement, generates a range of phenomena from soil creep, through solifluction,debris flows and rock glaciers to rock falls. Whereas the resultant forms of these phenomena are different, common elements in the mechanics of movement are utilized in the basic interpretation of the processes of formation. Measurements of morphologic variables provide data for deductive analyses of processes that operate too slowly to observe or for processes that generated relict phenomena. External and internal characteristics or rock glacier morphometry and measured rates of motion serve as the basis for the development of a rheological model to explain phenomena classified as rock glaciers. A rock glacier in the Sangre de Cristo Mountains of Southern Colorado, which exhibits a large number of ridges and furrows and lichen bare fronts of lobes, suggests present day movement. A strain-net established on the surface provides evidence of movement characteristics. These data plus morphologic and fabric data suggest two rheological models to explain the flow of this rock glacier. Model one is based upon perfect plastic flow and model two is based upon stratified fluid movement with viscosity changing with depth. These models permit a better understanding of the movement mechanics and demonstrate that catastrophic events and slow creep contribute to the morphologic characteristics of this rock glacier.

Giardino, J.R.; Vitek, J.D.; Hoskins, E.R.

1985-01-01

297

Analysis of rheological properties of bone cements.  

UK PubMed Central (United Kingdom)

The rheological properties of three commercially available bone cements, CMW 1, Palacos R and Cemex ISOPLASTIC, were investigated. Testing was undertaken at both 25 and 37 degrees C using an oscillating parallel plate rheometer. Results showed that the three high viscosity cements exhibited distinct differences in curing rate, with CMW 1 curing in 8.7 min, Palacos R and Cemex ISOPLASTIC in 13 min at 25 degrees C. Furthermore it was found that these curing rates were strongly temperature dependent, with curing rates being halved at 37 degrees C. By monitoring the change of viscosity with time over the entire curing process, the results showed that these cements had differing viscosity profiles and hence exhibit very different handling characteristics. However, all the cements reached the same maximum viscosity of 75 x 10(3) Pa s. Also, the change in elastic/viscous moduli and tan delta with time, show the cements changing from a viscous material to an elastic solid with a clear peak in the viscous modulus during the latter stages of curing. These results give valuable information about the changes in rheological properties for each commercial bone cement, especially during the final curing process.

Nicholas MK; Waters MG; Holford KM; Adusei G

2007-07-01

298

Analysis of rheological properties of bone cements.  

Science.gov (United States)

The rheological properties of three commercially available bone cements, CMW 1, Palacos R and Cemex ISOPLASTIC, were investigated. Testing was undertaken at both 25 and 37 degrees C using an oscillating parallel plate rheometer. Results showed that the three high viscosity cements exhibited distinct differences in curing rate, with CMW 1 curing in 8.7 min, Palacos R and Cemex ISOPLASTIC in 13 min at 25 degrees C. Furthermore it was found that these curing rates were strongly temperature dependent, with curing rates being halved at 37 degrees C. By monitoring the change of viscosity with time over the entire curing process, the results showed that these cements had differing viscosity profiles and hence exhibit very different handling characteristics. However, all the cements reached the same maximum viscosity of 75 x 10(3) Pa s. Also, the change in elastic/viscous moduli and tan delta with time, show the cements changing from a viscous material to an elastic solid with a clear peak in the viscous modulus during the latter stages of curing. These results give valuable information about the changes in rheological properties for each commercial bone cement, especially during the final curing process. PMID:17277981

Nicholas, M K D; Waters, M G J; Holford, K M; Adusei, G

2007-02-03

299

Microstructure and rheology of lime putty.  

UK PubMed Central (United Kingdom)

The rheology of lime binders, which is critical in the final performance of lime mortars and plasters, is poorly understood, particularly in its relationship with the microstructure and colloidal characteristics of slaked lime (Ca(OH)(2)) suspensions (i.e., lime putties). Here, the contrasting flow behavior of lime putties obtained upon slaking (hydration) of soft and hard burnt quicklimes (CaO) is compared and discussed in terms of the differences found in particle size, morphology, degree of aggregation, and fractal nature of aggregates as well as their evolution with aging time. We show that lime putties behave as non-Newtonian fluids, with thixotropic and rheopectic behavior observed for hard and soft burnt limes, respectively. Aggregation of portlandite nanoparticles in the aqueous suspension controls the time evolution of the rheological properties of lime putty, which is also influenced by the dominant slaking mechanism, that is, liquid versus vapor slaking in hard and soft burnt quicklimes, respectively. These results may be of relevance in the selection of optimal procedures and conditions for the preparation of lime mortars used in the conservation of historical buildings.

Ruiz-Agudo E; Rodriguez-Navarro C

2010-03-01

300

Improving feed slurry rheology by colloidal techniques  

Energy Technology Data Exchange (ETDEWEB)

Pacific Northwest Laboratory (PSN) has investigated three colloidal techniques in the laboratory to improve the sedimentation and flowability of Hanford simulated (nonradioactive) current acid waste (CAW) melter feed slurry: polymer-induced bridging flocculation; manipulating glass former (raw SiO/sub 2/ or frit) particle size; and alteration of nitric acid content. All three methods proved successful in improving the rheology of the simulated CAW feed. This initially had exhibited nearly worst-case flow and clogging properties, but was transformed into a flowable, resuspendable (nonclogging) feed. While each has advantages and disadvantages, the following three specific alternatives proved successful: addition of a polyelectrolyte in 2000 ppM concentration to feed slurry; substitution of a 49 wt % SiO/sub 2/ colloidal suspension (approx. 10-micron particle size) for the -325 mesh (less than or equal to 44-micron particle size) raw-chemical SiO/sub 2/; and increase of nitric acid content from the reference 1.06 M to optimum 1.35 M. The first method, polymer-induced bridging flocculation, results in a high sediment volume, nonclogging CAW feed. The second method, involving the use of colloidal silica particles results in a nonsedimenting feed that when left unagitated forms a gel. The third method, increase in feed acidity, results in a highly resuspendable (nonclogging) melter feed. Further research is therefore required to determine which of the three alternatives is the preferred method of achieving rheological control of CAW melter feeds.

Heath, W.O.; Ternes, R.L.

1984-06-01

 
 
 
 
301

REVIEW OF RHEOLOGY MODIFIERS FOR HANFORD WASTE  

Energy Technology Data Exchange (ETDEWEB)

As part of Savannah River National Laboratory (SRNL)?s strategic development scope for the Department of Energy ? Office of River Protection (DOE-ORP) Hanford Tank Waste Treatment and Immobilization Plant (WTP) waste feed acceptance and product qualification scope, the SRNL has been requested to recommend candidate rheology modifiers to be evaluated to adjust slurry properties in the Hanford Tank Farm. SRNL has performed extensive testing of rheology modifiers for use with Defense Waste Processing Facility (DWPF) simulated melter feed ? a high undissolved solids (UDS) mixture of simulated Savannah River Site (SRS) Tank Farm sludge, nitric and formic acids, and glass frit. A much smaller set of evaluations with Hanford simulated waste have also been completed. This report summarizes past work and recommends modifiers for further evaluation with Hanford simulated wastes followed by verification with actual waste samples. Based on the review of available data, a few compounds/systems appear to hold the most promise. For all types of evaluated simulated wastes (caustic Handford tank waste and DWPF processing samples with pH ranging from slightly acidic to slightly caustic), polyacrylic acid had positive impacts on rheology. Citric acid also showed improvement in yield stress on a wide variety of samples. It is recommended that both polyacrylic acid and citric acid be further evaluated as rheology modifiers for Hanford waste. These materials are weak organic acids with the following potential issues:  The acidic nature of the modifiers may impact waste pH, if added in very large doses. If pH is significantly reduced by the modifier addition, dissolution of UDS and increased corrosion of tanks, piping, pumps, and other process equipment could occur. Smaller shifts in pH could reduce aluminum solubility, which would be expected to increase the yield stress of the sludge. Therefore, it is expected that use of an acidic modifier would be limited to concentrations that do not appreciably change the pH of the waste.  Organics are typically reductants and could impact glass REDOX if not accounted for in the reductant addition calculations.  Stability of the modifiers in a caustic, radioactive environment is not known, but some of the modifiers tested were specifically designed to withstand caustic conditions.  These acids will add to the total organic carbon content of the wastes. Radiolytic decomposition of the acids could result in organic and hydrogen gas generation. These potential impacts must be addressed in future studies with simulants representative of real waste and finally with tests using actual waste based on the rheology differences seen between SRS simulants and actual waste. The only non-organic modifier evaluated was sodium metasilicate. Further evaluation of this modifier is recommended if a reducing modifier is a concern.

Pareizs, J.

2013-09-30

302

Solution rheology of polyelectrolytes and polyelectrolyte-surfactant systems  

Science.gov (United States)

The fundamental understanding of polyelectrolytes in aqueous solutions is an important branch of polymer research. In this work, the rheological properties of polyelectrolytes and polyelectrolyte/surfactant systems are studied. Various synthetic poly electrolytes are chosen with varied hydrophobicity. We discuss the effects of adding various surfactants to aqueous solutions of poly(ethylene oxide)-b-poly(propylene oxide)- b-polyethylene oxide)-g-poly(acrylic acid) (PEO-PPO-PAA) in the first chapter. Thermogelation in aqueous solutions of PEO-PPO-PAA is due to micellization caused by aggregation of poly(propylene oxide) (PPO) blocks resulting from temperature-induced dehydration of PPO. When nonionic surfactants with hydrophilic-lipophilic balance (HLB) parameter exceeding 11 or Cn alkylsulfates; n-octyl (C8), n-decyl (C 10) and n-dodecyl (C12) sulfates are added, the gelation threshold temperature (Tgel) of 1.0wt% PEO-PPO-PAA in aqueous solutions increases. In contrast, when nonionic surfactants with HLB below 11 are added, the gelation temperature decreases. On the other hand, alkylsulfates with n = 16 or 18 and poly(ethylene oxide) (PEO) do not affect the Tgel. The results imply that both hydrophobicity and tail length of the added surfactant play important roles in the interaction of PEO-PPO-PAA micelles and the surfactant. In the second chapter, the solution behavior of alternating copolymers of maleic acid and hydrophobic monomer is studied. The alternating structure of monomers with two-carboxylic groups and hydrophobic monomers make these copolymers unique. Under appropriate conditions, these carboxylic groups dissociate leaving charges on the chain. The potentiometric titrations of copolymer solutions with added CaCl2 reveal two distinct dissociation processes corresponding to the dissociation of the two adjacent carboxylic acids. The viscosity data as a function of polymer concentration of poly(isobutylene-alt-sodium maleate), poly(styrene-alt-sodium maleate) and poly(diisobutylene- alt-sodium maleate) show the polyelectrolyte behavior as predicted. However, the viscosity as a function of concentration of sodium maleate based copolymers with 1-alkenes; 1-octene (C8), 1-decene (C10), 1-dodecene (C12) and 1-hexene (C14) exhibit an abnormal scaling power, which might be caused by aggregation of the alkene tails to form micelles. In the last chapter, we report the rheological properties of aqueous solutions of poly(acrylic acid) and oppositely charged surfactant, dodecyl trimethylammonium bromide (C12TAB). The solution viscosity decreases as surfactant is added, partly because the polyelectrolyte wraps around the surface of the spherical surfactant micelles, shortening the effective chain length. The effects of polymer molecular weight, polymer concentration, and polymer charge have been studied with no added salt. The results are compared with the predictions of a simple model based on the scaling theory for the viscosity of dilute and unentangled semidilute polyelectrolyte solutions in good solvent. This model takes into account two effects of added surfactant. The effective chain length of the polyelectrolyte is shortened when a significant fraction of the chain wraps around micelles. Another effect is the change of solution ionic strength resulting from surfactant addition that further lowers the viscosity. The parameters used in this model are independently determined, allowing the model to make a quantitative prediction of solution viscosity with no adjustable parameters. The model is also applied to predict the decrease in viscosity of various polyelectrolyte/oppositely charged surfactant systems reported in literature. The results are in good agreement with experimental data, proving that our model applies to all polyelectrolytes mixed with oppositely charged surfactants that form spherical micelles.

Plucktaveesak, Nopparat

303

Monopolar membrane electrolytic cell  

Energy Technology Data Exchange (ETDEWEB)

A monopolar membrane electrolytic cell is comprised of a plurality of anodes wherein each anode is comprised of a first foraminous surface and a second foraminous surface positioned in parallel and spaced apart, and a frame enclosing the first and the second foraminous surfaces. The frame has two side members, a top member, and a bottom member attached to the foraminous surfaces. A chamber is formed between the foraminous surfaces and bounded by the frame. Conductor rods pass through one of the side members of the frame into the chamber, the conductor rods being spaced apart from the foraminous surfaces. Foraminous conductive connectors are positioned in the chamber and attached to the conductor rods and to the foraminous surfaces; a plurality of cathodes wherein each cathode is comprised of at least one foraminous surface, and a frame which encloses the foraminous surface. The cathodes are alternatingly interleaved with the anodes; a plurality of sheets of cation exchange membrane material, each of the sheets being pressed between each opposite pair of the anodes and the cathodes. The cation exchange membrane material is comprised of a blend of a first fluorinated polymer which contains sulfonyl functional groups and a second fluorinated polymer which contains carboxylic acid functional groups; the cell has raw material supply conduits and product withdrawal conduits communicating with the interior of each of the anodes and the cathodes; means for supplying electric current to the anodes and removing electric current from the cathodes are provided, and pressing means provided for pressing the anodes and the cathodes together to form a substantially fluid-tight cell.

Kircher, M.S.; Harrison, C.H.; Justice, D.D.; Woodard, K.E. Jr.

1984-03-27

304

Rheological study of a water based oil well drilling fluid  

Energy Technology Data Exchange (ETDEWEB)

Organic polymers are commonly used to control the rheology and filtrate loss required for water-based drilling fluids. An ecologically-friendly water-based drilling fluid was developed by studying the rheological behavior of tamarind gum and polyanionic cellulose on bentonite water suspensions. The effect of drilling fluid filtrate on formation damage was also analyzed. The drilling fluid that was developed has better rheological properties and fluid loss control which are required for optimum performance of oil well drilling. In addition, the drilling fluid filtrate exhibits minimum formation damage on sandstone cores.

Mahto, Vikas; Sharma, V.P. [Department of Petroleum Engineering, Indian School of Mines, Dhanbad-826004, Jharkhand (India)

2004-11-30

305

Rheological study of chitosan and its blends: An overview  

Directory of Open Access Journals (Sweden)

Full Text Available Chitosan, a modified natural carbohydrate polymer derived from carapaces of crabs and shrimps, has received a great deal of attention for its applications in diverse fields owing to its biodegradability, biocompatibility, non-toxicity and anti-bacterial property. The wide-ranging applications involve a broad spectrum of characterisation techniques and rheology represents one technique of growing importance in this field. This paper is an attempt to review the latest development in the rheology of chitosan, either on its own or associated with other materials, including the parameters that strongly influence its rheological behaviour such as concentration, pH and temperature.

Esam A. El-hefian

2010-01-01

306

Oligosaccharides as modulators of rheology in complex mucous systems.  

UK PubMed Central (United Kingdom)

Mucus rheology is integral to physiological function with the exact secretion rheology resulting from the macromolecular components, both mucin and nonmucin, and the interactions between these macromolecules. Here we present data demonstrating that low-molecular-weight guluronic acid oligomers extracted from alginate are able to disrupt intermolecular interactions in both purified and native mucous systems, resulting in rheological changes that are compatible with a lower cross-link density and thus reduced resistance to deformation. Additionally, these changes are associated with altered physiological function, raising the possibility of the use of such oligomers in biomedical applications.

Nordgård CT; Draget KI

2011-08-01

307

Rheological properties of cupuassu and cocoa fats  

Directory of Open Access Journals (Sweden)

Full Text Available Cocoa butter is an important ingredient in chocolate formulation as it dictates the main properties (texture, sensation in the mouth, and gloss). In the food industry, the texture of fat-containing products strongly depends on the macroscopic properties of the fat network formed within the finished product. Cupuassu ( Theobroma grandiflorum , Sterculiaceae) is an Amazonian native fruit and the seeds can be used to derive a cocoa butter like product. In general, these fats are similar to those of cocoa, although they are different in some physical properties. The objective of this study was to analyze several properties of the cupuassu fat and cocoa butter (crystal formation at 25 ° C, rheological properties, and fatty acid composition) and mixtures between the two fats (rheological properties), in order to understand the behavior of these fats for their use in chocolate products. Fat flow was described using common rheological models ( Newton , Power Law, Casson and Bingham plastic).La manteca de cacao es un ingrediente muy importante en la formulación de chocolates y es responsable de la mayor parte de sus propiedades (textura, palatibilidad y brillo). En la industria de alimentos, la textura de productos que contienen grasa depende enormemente de las propiedades macroscópicas de la red cristalina de la grasa en el producto final. El cupuaçu es una fruta nativa de la región amazónica y sus semillas pueden ser usadas para obtener una grasa semejante a la manteca de cacao. En general, esta grasa es similar a la manteca de cacao, pero difiere en algunas de sus propiedades fisicas . El objetivo de este estudio fue analizar algunas propiedades de la grasa de cupuaçu y de la manteca de cacao (formación de cristales a 25 °C, propiedades reológicas y composición en ácidos grasos) y de algunas mezclas entre las dos grasas (propiedades reológicas), a fin de conocer el comportamiento de estas grasas para ser usadas en productos de la industria del chocolate. El flujo de la grasa se ha descrito utilizando modelos reológicos comunes (Newton, ley de la potencia, Casson y plástico de Bingham).

Lannes, S. C. S.; Medeiros, M. L.; Gioielli, L. A.

2004-01-01

308

Electrolytic cell with reference electrode  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an electrolytic cell. It comprises: a housing, an anode, cathode and reference electrode and is adapted to contain a molten-salt electrolyte above the anode. The reference electrode comprises an elongated glass tube of one-piece construction extending from the housing into the interior of the cell and having a lower closed-ended section with ionic conductivity, a metal electrode supported in the glass tube and in Separated juxtaposition with the closed end, an electrolyte in the lower section in contact with the electrode and an electrical insulator physically Separating the electrode and glass tube; an elongated metal tube extending from the housing over the glass tube as a protective cover and basket. The metal tube has a perforated side wall adapted to be in contact with the cell electrolyte and being closed-ended with respect to collecting any broken glass from the glass tube so as to act as a basket to minimize the amount of broken glass from otherwise falling through the electrolyte into the anode; means for supporting the glass tube within the metal tube and means supporting the metal tube in the cell housing.

Kessie, R.W.

1989-12-19

309

Rheological characteristics of coal-water mixture  

Energy Technology Data Exchange (ETDEWEB)

The rheological characteristics of coal-water mixtures(CWM) were studied to put CWM to practical use concerning coal concentration at higher concentrations, kinds of additives and concentration of additives. CWMs containing no additives were Newtonian fluids at lower coal concentration(less than 10%), and became pseudo-plastic fluids with increase of coal concentration, but the pseudoplasticity became weak by addition of additives to CWM. Two highly loaded CWMs, one containing a multi-branched high molecular nonionic surfactant and other containing the sodium salt of the formalin naphthalenesulfonate, showed pseudo-plastic flow. At lower coal concentration, CWM containing a nonionic surfactant was converted to Newtonian fluids. CWMs containing an anionic surfactant gradually lost pseudoplasticity. (10 figs, 1 tab, 12 refs)

Naka, Akihiro; Mayuzumi, Tominobu; Sugiyama, Hiroshi; Nishida, Yoshihisa

1988-02-20

310

Rheological effects in roll coating of paints  

Directory of Open Access Journals (Sweden)

Full Text Available the aim of this work is the study of the problems that arise during roll coating application of paints on steel sheets. We put in evidence the particular effects due to the non-Newtonian properties of these fluids. At speeds above a certain critical value, the flow of paint through the applicator suffers a hydrodynamical instability called ribbing, which generates a patterned interface on the film applied. Threshold of instability as well as waveform of the pattern is function of rheological properties of paints as well as surface tension. Thixotropy of paints as well as shear-thinning behaviour has been determined for several industrial paints used in the steel industry, and correlated with levelling performance after application.

F. Varela López; M. Rosen

2002-01-01

311

Rheology of spinel sludge in molten glass  

International Nuclear Information System (INIS)

[en] Spinel sludge, which forms while vitrifying high-level waste, obstructs the flow of molten glass and damages the melter. The effectiveness of removing spinel sludge from a high-level waste glass melter depends on its rheological behavior. We prepared spinel sludge in a laboratory crucible by allowing spinel to settle from molten glass and measured the response of the sludge to shear using a rotating spindle viscometer. The shear stress increased nonlinearly with the velocity gradient (the shear rate) and with time at a constant velocity gradient, as is typical for a pseudoplastic rheopectic liquid. The apparent viscosity of the sludge substantially increased when RuO-2 needles were present

1999-01-01

312

Erythrocyte dynamics in flow affects blood rheology  

International Nuclear Information System (INIS)

[en] Normal blood consists of highly deformable particles (red blood cells, RBC, or erythrocytes) suspended in a Newtonian fluid (blood plasma). As a rough physical model of erythrocytes, giant unilamellar vesicles (GUV) are successfully used to probe their membrane properties. In shear flows vesicles and red blood cells show rich variety of dynamical behaviours influencing the rheological properties of their suspensions. Here, we focus on new experimental aspects of the problem in the case, when a combination of an oscillatory shear rate and a basic constant shear rate is applied to suspensions. Experimental examples with concentrated RBC suspensions are presented together with a discussion on the importance of the superposition of a constant shear flow to the pure oscillation, which is usually used to extract the viscoelastic properties of a complex fluid.

2012-12-10

313

Rheology of Vimentin Intermediate Filament Networks  

Science.gov (United States)

A cell's ability to function is highly dependent on its structure and material properties - its capacity to withstand and respond to forces in its environment. The cytoskeleton, which largely determines the cellular mechanical properties, is comprised of biopolymer networks, including filamentous actin, microtubules, and intermediate filaments (IF). Intermediate filaments are much less studied than actin and microtubules. They are much more varied and specialized as well, and have been suggested as being an important platform in mechanotransduction processes in cells. It is thought that they can withstand very high strains and exhibit strain stiffening behavior. We are characterizing vimentin, a type III IF that is found in all vertebrate cells, using rheological techniques. Vimentin elasticity increases upon addition of multivalent cations, which act like molecular crosslinkers. By varying the concentration of cations, we can extract valuable information about how the networks assemble and function.

Wu, Huayin

2012-02-01

314

Rheological properties of sodium smectite clay  

International Nuclear Information System (INIS)

The rheological properties of Na-smectite Mx-80 have been investigated by various laboratory tests. The investigations include determination of the hydraulic conductivity, the undrained stress-strain-strength properties, the creep properties, the compression and swelling properties in drained and undrained conditions and the undrained thermomechanical properties. Measurements have been made at different densities, clay/sand mixtures and pore water compositions. The influence of temperature, rate of strain and testing technique has also been considered. The investigation has led to a supply of basic data for the material models which will be used at performance calculations. The results have also increased the general understanding of the function of smectitic clay as buffer material. The microstructural behaviour has been considered at the validation of the different test results and the validity of the effective stress theory has been discussed. Comparisons with the properties of Ca-smectite have also been made. (orig.).

1988-01-01

315

Rheological characterisation of municipal sludge: A review.  

UK PubMed Central (United Kingdom)

Sustainable sludge management is becoming a major issue for wastewater treatment plants due to increasing urban populations and tightening environmental regulations for conventional sludge disposal methods. To address this problem, a good understanding of sludge behaviour is vital to improve and optimize the current state of wastewater treatment operations. This paper provides a review of the recent experimental works in order for researchers to be able to develop a reliable characterization technique for measuring the important properties of sludge such as viscosity, yield stress, thixotropy, and viscoelasticity and to better understand the impact of solids concentrations, temperature, and water content on these properties. In this context, choosing the appropriate rheological model and rheometer is also important.

Eshtiaghi N; Markis F; Yap SD; Baudez JC; Slatter P

2013-10-01

316

Rheology of petroleum coke-water slurry  

Energy Technology Data Exchange (ETDEWEB)

This paper reports the results of the studies carried out on the optimization of particle size distribution, the rheological characteristics and stability of highly loaded petroleum coke-water slurry using three additives. The solids loading achieved in the slurries were in the range of 65% to 75.6% depending on the additives used. Slurry viscosity varied between 267 to 424 mPas at 128 s{sup {minus}} shear rate. The petroleum coke-water slurries exhibited pseudoplastic characteristics with yield tending towards Bingham plastic as the solids loading progressively increased. The effect of addition of petroleum coke to the extent of 25% in coal-water slurry prepared from low ash Ledo coal of Makum field in Assam was also examined. The slurry containing coal-petroleum coke blend showed better stability, having shelf life of 7 days as compared to 5 days in the case of petroleum coke-water slurry.

Prasad, M.; Mall, B.K.; Mukherjee, A.; Basu, S.K.; Verma, S.K.; Narasimhan, K.S.

1998-07-01

317

Rheology of irradiated honey from Parana region  

International Nuclear Information System (INIS)

Viscosity characteristics can be governed by the molecular chain length of sugars present in the honey. Honey is essentially a mixture of sugar and water. When a physical treatment, as gamma radiation, is applied to food, some changes on its viscosity may occur. Viscosity is one of the important properties of honey and depends on water and sugar quantities. The objective of this work was to verify the rheological behavior of irradiated honey from Parana region in comparison to the unirradiated one. Each rheogram was measured at different shear rates that was increased to a certain value then immediately decreased to the starting point ('up and down curves'). These measurements were made for control and irradiated samples (5 and 10 kGy) in different temperatures (30 deg. C, 35 deg. C and 40 deg. C). The curves constructed with shear stress against shear rate presented linearity. Honey, irradiated and control, showed a Newtonian behavior and gamma radiation did not affect it.

2004-01-01

318

Rheological Characterization of Vegetal Pear (Sechium edule)  

Science.gov (United States)

The national production of Mexican vegetal pear (Sechium edule) is located at the present time in more than 130,000 ton/year. The vegetal pear that produced in the center zone of the state of Veracruz is known in international markets; however it is a product that practically has not been studied. This work identifies the rheological behavior of vegetal pear (Sechium edule). A rheometer MCR301 of Anton Paar was utilized for viscosity and shear stress measurements. The objective of this experimental was modeling the rheological behavior of vegetal pear suspensions at three concentrations (1, 2 and 3% w/w), three particle size (1.00, 1.19 and 1.40 mm), at the same conditions of temperature (25, 40 and 70 °C). The results showed that all the suspensions there was a phenomenological behavior as a dilatants fluid (n>1) the performance of flow was represented by the Herschel-Bulkley model, and present values of ``yield stress'' between from 0.1 to 15 Pa for the different experiments. During evaluation of the activation energy of the suspensions of vegetal pear was found that decreases from 154.4039 kJ/mol to 9.1086 kJ/mol for a particle size of 1.00 mm to 1.4 mm, which implies that the effect of temperature is higher with smaller grains, in this case 1.00 mm. Furthermore, we assessed the effect of particle size by the Péclet number, showing an increase of the viscosity when the Péclet number also increases.

Castillo-Reyes, José A.; Luna-Solano, Guadalupe; Cantú-Lozano, Denis

2008-07-01

319

Improved stability of quasi-solid-state dye-sensitized solar cell based on poly (ethylene oxide)-poly (vinylidene fluoride) polymer-blend electrolytes  

Energy Technology Data Exchange (ETDEWEB)

We report two improved stability dye-sensitized TiO{sub 2} solar cells using poly (ethylene oxide)-poly (vinylidene fluoride) (PEO-PVDF) polymer-blend electrolytes modified with water and ethanol as hydroxyl-rich small-molecule additives. The effect of additive on the thermal property, viscosity, conductivity and the corresponding performance of the dye-sensitized solar cell (DSSC) were studied. After introducing the water and ethanol into the PEO-PVDF polymer-blend electrolytes, the conductivity is improved compared to that of the un-added electrolyte. This is due to the enhanced free ion concentration and ion transport channels in the electrolyte because of the cross-linking ability of these hydroxyl-rich additives. The increased ion concentration can be proved by the enhanced concentration of I{sup -} and I{sub 3}{sup -} in the additive-modified electrolytes from UV-vis studies. The increased cross-linking network can be explained by the increased glass transition temperature (T{sub g}) and viscosity of these additive-modified electrolytes from DSC and rheology studies. A more homogeneous morphology of ethanol-modified electrolyte from SEM study is used to further explain the better conductivity and stability of the cells based on these additive-modified electrolytes. From the evaluation of additive effect on the performance of the corresponding DSSC, we find that introducing water and ethanol leads to an increase in short-circuit photocurrent density (J{sub sc}). This is due to the efficient transport of I{sup -}/I{sup 3-} caused by enhanced I{sup -}/I{sup 3-} concentration and increased ion transport channels in the electrolyte by adding additives. The best efficiency of 3.9% is achieved in the cell with ethanol-modified electrolyte. (author)

Yang, Ying; Zhou, Cong-hua; Xu, Sheng; Hu, Hao; Chen, Bo-lei; Zhang, Jing; Wu, Su-juan; Liu, Wei [Department of Physics, Wuhan University, Wuhan 430072 (China); Zhao, Xing-zhong [Department of Physics, Wuhan University, Wuhan 430072 (China); Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education, Wuhan University, Wuhan 430072 (China)

2008-12-01

320

Advances in the rheology of polymers. Novoe v reologii polimerov  

Energy Technology Data Exchange (ETDEWEB)

The topics of the papers embrace a wide range of problems in theoretical, experimental, and instrumental rheology, pertaining to the properties of solutions and melts of macromolecular compounds, suspensions, pasty disperse systems, and highly filled composites.

Vinogradov, G.V.

1981-01-01

 
 
 
 
321

Rheology and Contact Lifetime Distribution in Dense Granular Flows  

CERN Multimedia

We study the rheology and distribution of interparticle contact lifetimes for gravity-driven, dense granular flows of non-cohesive particles down an inclined plane using large-scale, three dimensional, granular dynamics simulations. Rather than observing a large number of long-lived contacts as might be expected for dense flows, brief binary collisions predominate. In the hard particle limit, the rheology conforms to Bagnold scaling, where the shear stress is quadratic in the strain rate. As the particles are made softer, however, we find significant deviations from Bagnold rheology; the material flows more like a viscous fluid. We attribute this change in the collective rheology of the material to subtle changes in the contact lifetime distribution involving the increasing lifetime and number of the long-lived contacts in the softer particle systems.

Silbert, L E; Brewster, R; Levine, A J; Silbert, Leonardo E.; Grest, Gary S.; Brewster, Robert; Levine, Alex J.

2007-01-01

322

Bentonites from Boa Vista, Brazil: physical, mineralogical and rheological properties  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this work is to characterize physically and mineralogically six samples of natural and industrialized bentonites from Paraíba, Brazil, and to study its rheological properties to be used as a components of water based drilling fluids. Also it is intended to compare the evolution of the mineralogical composition and rheology of these clays after 40 years of exploitation. The natural bentonite clays were transformed into sodium bentonite by addition of concentrated Na2CO3 solution. The suspensions were prepared with 4.86% w/w to measure their rheological properties (apparent and plastic viscosities and water loss). The results showed that: i) the samples present typical mineralogical compositions of bentonites, but after four decades of exploitation, presents inferior quality and ii) among the clays samples, only one presented satisfactory rheological properties be used as a components of water based drilling fluids.

Luciana Viana Amorim; Cynthia Morais Gomes; Helio de Lucena Lira; Kepler Borges França; Heber Carlos Ferreira

2004-01-01

323

Bentonites from Boa Vista, Brazil: physical, mineralogical and rheological properties  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The aim of this work is to characterize physically and mineralogically six samples of natural and industrialized bentonites from Paraíba, Brazil, and to study its rheological properties to be used as a components of water based drilling fluids. Also it is intended to compare the evolution of the mineralogical composition and rheology of these clays after 40 years of exploitation. The natural bentonite clays were transformed into sodium bentonite by addition of concentrat (more) ed Na2CO3 solution. The suspensions were prepared with 4.86% w/w to measure their rheological properties (apparent and plastic viscosities and water loss). The results showed that: i) the samples present typical mineralogical compositions of bentonites, but after four decades of exploitation, presents inferior quality and ii) among the clays samples, only one presented satisfactory rheological properties be used as a components of water based drilling fluids.

Amorim, Luciana Viana; Gomes, Cynthia Morais; Lira, Helio de Lucena; França, Kepler Borges; Ferreira, Heber Carlos

2004-12-01

324

Rheology of Carbon Fibre Reinforced Cement-Based Mortar  

International Nuclear Information System (INIS)

[en] Carbon fibre reinforced cement based materials (CFRCs) offer the possibility of fabricating 'smart' electrically conductive materials. Rheology of the fresh mix is crucial to satisfactory moulding and fresh CFRC conforms to the Bingham model with slight structural breakdown. Both yield stress and plastic viscosity increase with increasing fibre length and volume concentration. Using a modified Viskomat NT, the concentration dependence of CFRC rheology up to 1.5% fibre volume is reported

2008-07-07

325

An automatic viscosimeter for measuring the rheology of radioactive substances  

International Nuclear Information System (INIS)

[en] This paper describes an automatic capillary viscosimeter that was developed to measure the rheological characteristics of radio-active slurries. The system is designed for use in a glove box and uses disposable modules in the active cell. The data acquisition and monitoring equipment, which is computer controlled, is stationed outside the active area. Once set up the system can measure a full rheogram in a few minutes and correlate the results to a given rheological model. (author)

1992-01-01

326

Standardized rheology measurement for coal-water slurries  

Energy Technology Data Exchange (ETDEWEB)

Rheology of thixotropic liquids is considered as a branch of science of great complexity. An attempt is made to explain and quantify thixotropic behavior of combustible coal water slurries (CWS). A testing procedure is recommended to isolate time dependent and shear dependent behavior of CWS and other thixotropic liquids. Experiments show considerable variation in values of apparent viscosities if time dependency of thixotropic liquids is not isolated. A model is proposed for quantification of thixotropic rheology.

Phulgaonkar, S.R.

1986-01-01

327

Rheological behavior of superplastic nanocrystalline and amorphous materials  

International Nuclear Information System (INIS)

[en] Demonstrating structural superplasticity as compared with crystallized metallic melts and amorphous materials, rheological behavior of metallic and ceramic materials is analyzed. The rheological state of the materials varies from tough to tough-plastic one. Superplasticity at high deformation rates and low values of shear viscosity being peculiar to the materials is considered as enough prospecting for development of new metal forming processes[ru] ????????????? ????????????? ????????? ????????????? ? ???????????? ??????????, ??????????????? ??????????? ????????????????? ? ????????? ? ?????????????????? ?????????????? ?????????? ? ????????? ???????????. ????????????? ????????? ???? ?????????? ?????????? ?? ????? ??????? ?? ??????????????????. ????????????????? ??? ??????? ????????? ?????????? ? ????? ????? ???????? ????????? ????????, ???????? ???? ??????????, ??????????????? ??? ?????? ????????????? ??? ???????? ????? ?????????? ????????? ???????? ?????????

2001-01-01

328

Superionic solids and solid electrolytes  

International Nuclear Information System (INIS)

[en] Superionic solids and solid electrolytes are a special group of materials showing high ionic conductivity with tremendous technological potential. This book updates the present status of the field. Starting with an overview of recent trends in solid state ionics, the book ends with the assessment of future implications. Different theoretical, experimental (including NMR), and materials aspects have been covered along with applications. Important materials covered include alkali and silver ion conductors, fluorites, Nasicon, heterogeneous solid electrolytes, and glasses. The theoretical topics covered in this volume include phenomenological models, fractal techniques, the pre-exponential problem, and fluctuations

1989-01-01

329

Ambient and Subambient Temperature Polymeric Electrolytes.  

Science.gov (United States)

In this project, studies were carried out on three basic systems: (1) Polymer gel electrolytes based on glycidyl methacrylate homopolymer and copolymers; (2) Electrolytes with immobilized anions based on styrene-maleic anhydride copolymers; and (3) Poly(e...

1993-01-01

330

API revises procedures to measure cement slurry rheology  

Energy Technology Data Exchange (ETDEWEB)

The American Petroleum Institute's Committee 10 has developed a procedure which generates highly repeatable data when using a rotational viscometer for measuring the rheology of cement slurries. In the past, investigators in the oil industry observed that different laboratories reported widely differing results when predicting pump rates for turbulent flow and friction pressures for a given job, using the same slurry. It was determined that the API procedure to measure cement slurry rheology was not always being followed, and in those cases where the procedure was being followed, the method did not produce acceptable repeatability among the different industry laboratories. It was also observed that after obtaining the slurry rheology data, each company used a different set of equations to arrive at the predictions of flow regime and friction pressures, which again contributed to the differences in reported data. Realizing the need for more standardization work in the area of cement slurry rheology, the API committee on standardization of well cements (API Committee 10) formed the Task Group on cement slurry rheology in late 1978. Samples of a homogenized batch of cement were sent to several participating laboratories asking for rheology measurements on neat cement slurries using the ''old'' API procedure.

Beirute, R.M.

1986-09-01

331

Ultrasound assisted design of sulfur/carbon cathodes with partially fluorinated ether electrolytes for highly efficient Li/S batteries.  

UK PubMed Central (United Kingdom)

A one-step, eco-friendly ultrasound-assisted process is established for the rapid synthesis of sulfur-carbon composite cathode materials, avoiding the widely used, energy inefficient "melt-down" process for Li-S batteries. It is demonstrated that, without inserting sulfur into pores of carbon, the coulombic efficiency of SC/Li cell in the new DOL/D2 electrolyte is greater than 96% for 100 cycles, which is far superior to the reported numerous electrolyte formulations.

Weng W; Pol VG; Amine K

2013-03-01

332

Dispersions of silica nanoparticles in ionic liquids investigated with advanced rheology  

International Nuclear Information System (INIS)

[en] The colloidal stabilities of dispersions of unmodified and surface-functionalized SiO2 nanoparticles in hydrophobic and hydrophilic imidazolium-based ionic liquids were studied with advanced rheology at three temperatures (25, 100, and 200 °C). The rheological behavior of the dispersions was strongly affected by the ionic liquids hydrophilicity, by the nanoparticles surface, by the concentration of the nanoparticles in the dispersion as well as by the temperature. The unmodified hydrophilic nanoparticles showed a better compatibility with the hydrophilic ionic liquid. The SiO2 surface functionalization with hydrophobic groups clearly improved the colloidal stability of the dispersions in the hydrophobic ionic liquid. The temperature increase was found to lead to a destabilization in all studied systems, especially at higher concentrations. The results of this study imply that ionic liquids with tailored properties could be used in absorbers directly after reactors for gas-phase synthesis of nanoparticles or/and as solvents for their further surface functionalization without agglomeration or aggregation.

2012-01-01

333

Polymer Electrolytes for Lithium/Sulfur Batteries  

Directory of Open Access Journals (Sweden)

Full Text Available This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S) batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes.

Yan Zhao; Yongguang Zhang; Denise Gosselink; The Nam Long Doan; Mikhail Sadhu; Ho-Jae Cheang; Pu Chen

2012-01-01

334

LOWER TEMPERATURE ELECTROLYTE AND ELECTRODE MATERIALS  

Energy Technology Data Exchange (ETDEWEB)

A thorough literature survey on low-temperature electrolyte and electrode materials for SOFC is given in this report. Thermodynamic stability of selected electrolyte and its chemical compatibility with cathode substrate were evaluated. Preliminary electrochemical characterizations were conducted on symmetrical cells consisting of the selected electrolyte and various electrode materials. Feasibility of plasma spraying new electrolyte material thin-film on cathode substrate was explored.

Keqin Huang

2003-04-30

335

REVIEW OF RHEOLOGY MODELS FOR HANFORD WASTE BLENDING  

Energy Technology Data Exchange (ETDEWEB)

The area of rheological property prediction was identified as a technology need in the Hanford Tank Waste ? waste feed acceptance initiative area during a series of technical meetings among the national laboratories, Department of Energy-Office of River Protection, and Hanford site contractors. Meacham et al. delivered a technical report in June 2012, RPP-RPT-51652 ?One System Evaluation of Waste Transferred to the Waste Treatment Plant? that included estimating of single shell tank waste Bingham plastic rheological model constants along with a discussion of the issues inherent in predicting the rheological properties of blended wastes. This report was selected as the basis for moving forward during the technical meetings. The report does not provide an equation for predicting rheological properties of blended waste slurries. The attached technical report gives an independent review of the provided Hanford rheological data, Hanford rheological models for single tank wastes, and Hanford rheology after blending provided in the Meacham report. The attached report also compares Hanford to SRS waste rheology and discusses some SRS rheological model equations for single tank wastes, as well as discussing SRS experience with the blending of waste sludges with aqueous material, other waste sludges, and frit slurries. Some observations of note: Savannah River Site (SRS) waste samples from slurried tanks typically have yield stress >1 Pa at 10 wt.% undissolved solids (UDS), while core samples largely have little or no yield stress at 10 wt.% UDS. This could be due to how the waste has been processed, stored, retrieved, and sampled or simply in the differences in the speciation of the wastes.. The equations described in Meacham?s report are not recommended for extrapolation to wt.% UDS beyond the available data for several reasons; weak technical basis, insufficient data, and large data scatter. When limited data are available, for example two to three points, the equations are not necessarily satisfactory (justified) for interpolations, due to the number of unknown variables equal the number of known data points, resulting in a coefficient of determination of one. SRS has had some success predicting the rheology of waste blends for similar waste types using rheological properties of the individual wastes and empirical blending viscosity equations. Both the Kendall-Monroe and Olney-Carlson equations were used. High accuracy was not obtained, but predictions were reasonable compared to measured flow curves. Blending SRS processed waste with frit slurry (much larger particles and the source of SRS glass formers) is a different sort of problem than that of two similar slurries of precipitated waste particles. A different approach to rheology prediction has had some success describing the incorporation of large frit particles into waste than the one used for blending two wastes. In this case, the Guth-Simha equation was used. If Hanford waste is found to have significant particles in the >100 μm diameter range, then it might be necessary to handle those particles differently from broadly distributed waste particles that are primarily <30 μm in diameter. The following are recommendations for the Hanford tank farms: ? Investigate the impact of large-scale mixing operations on yield stress for one or more Hanford tanks to see if Hanford waste rheological properties change to become more like SRS waste during both tank retrieval and tank qualification operations. ? Determine rheological properties of mobilized waste slurries by direct measurement rather than by prediction ? Collect and characterize samples during the waste feed qualification process for each campaign. o From single source tanks that feed the qualification tanks o Blends from the qualification tanks ? Predictive rheological models must be used with caution, due to the lack of data to support such models and the utilization of the results that come from these models in making process decisions (e.g. the lack of actual operation expe

Koopman, D.; Stone, M.

2013-09-26

336

Electrolytic hydrogen-metal interactions  

Energy Technology Data Exchange (ETDEWEB)

The electrolyte composition and the electrodic conditions have a major effect on the entry of electrolytic hydrogen into metals. In the case of ferrous metals there is a large body of literature and various promoters have been identified. Only a few inhibitors have been found, such as organic nitriles. This paper reports the complete inhibition of the entry of hydrogen into iron by UPD Zn in concentrated alkali solutions. Less is known about the effect of electrolyte on the entry of hydrogen into palladium. The present work shows that many of the known promoters for ferrous metals actually inhibit the entry and egress of hydrogen from palladium. Permeation results on a Pd membrane in pure 0.1 M NaOH indicate that only 20% of the surface is used for the entry of hydrogen into the metal. In 0.1 M NaOH + 10{sup {minus}3} M NaCN it drops to 5%. The fraction of the surface used strongly depends on electrolyte purity. Impurity effects can account for the discrepant results for electrochemical hydrogen loading of Pd.

McBreen, J.

1991-12-31

337

Electrolytic hydrogen-metal interactions  

Energy Technology Data Exchange (ETDEWEB)

The electrolyte composition and the electrodic conditions have a major effect on the entry of electrolytic hydrogen into metals. In the case of ferrous metals there is a large body of literature and various promoters have been identified. Only a few inhibitors have been found, such as organic nitriles. This paper reports the complete inhibition of the entry of hydrogen into iron by UPD Zn in concentrated alkali solutions. Less is known about the effect of electrolyte on the entry of hydrogen into palladium. The present work shows that many of the known promoters for ferrous metals actually inhibit the entry and egress of hydrogen from palladium. Permeation results on a Pd membrane in pure 0.1 M NaOH indicate that only 20% of the surface is used for the entry of hydrogen into the metal. In 0.1 M NaOH + 10{sup {minus}3} M NaCN it drops to 5%. The fraction of the surface used strongly depends on electrolyte purity. Impurity effects can account for the discrepant results for electrochemical hydrogen loading of Pd.

McBreen, J.

1991-01-01

338

Zinc electrode in alkaline electrolyte  

Energy Technology Data Exchange (ETDEWEB)

The zinc electrode in alkaline electrolyte is unusual in that supersaturated zincate solutions can form during discharge and spongy or mossy zinc deposits can form on charge at low overvoltages. The effect of additives on regular pasted ZnO electrodes and calcium zincate electrodes is discussed. The paper also reports on in situ x-ray absorption (XAS) results on mossy zinc deposits.

McBreen, J.

1995-12-31

339

Plasticizers for Solid Polymer Electrolytes.  

Science.gov (United States)

The ionic conductivity of a solid polymer electrolyte based on a lithium salt dissolved in a poly(ethylene oxide) (PEO) host was significantly improved with the use of plasticizing agents and a lithium ion coordinating compound. Either a plasticizing salt...

C. W. Walker M. Salomon

1995-01-01

340

Handbook of aqueous electrolyte thermodynamics  

Energy Technology Data Exchange (ETDEWEB)

This handbook, describes the details of an electrolyte thermodynamics and the engineer's need for a source of recommended calculations and thermodynamic data either through recommended tabular values or annotated bibliographies which point to suitable sources. It provides a systematic presentation of electrolyte thermodynamics from basic definitions of equilibrium constants of ionic reactions to the prediction of activity coefficients of various species in multicomponent aqueous solutions of strong and/or weak electrolytes as well as the resulting phase equilibria calculative techniques. It is designed to assist the engineer in solving industrially important problems involving aqueous solutions of electrolytes and understanding the possible alternatives available as well as how they may be applied to solve problems either with available data or through available data prediction and analysis techniques. Several examples are used to illustrate the calculative techniques needed for the solution of different types of problems. Examples cited can be solved with limited computer facilities. Techniques can be expanded for the solution of more complex problems.

Zemaitis, J.F. Jr.; Clark, D.M.; Rafal, M.; Scrivner, N.D.

1986-01-01

 
 
 
 
341

Ionic conductivity of solid electrolytes  

International Nuclear Information System (INIS)

[en] It is defined, that in the solid electrolytes the conductivity is determines by both liquid and jump mechanisms. In the ionic conductors of NASICON-type it is possible realization of superionic conductivity due to mainly by the liquid mechanism of conductivity. (author)

2005-01-01

342

Rheology of Melt-bearing Crustal Rocks  

Science.gov (United States)

A review and reinterpretation of previous experimental data on the deformation of melt-bearing crustal rocks (Rosenberg and Handy, 2005) revealed that the relationship of aggregate strength to melt fraction is non-linear, even if plotted on a linear ordinate and abscissa. At melt fractions, ? 0.07, the dependence of aggregate strength on ? is significantly greater than at ? > 0.07. This melt fraction (?= 0.07) marks the transition from a significant increase in the proportion of melt-bearing grain boundaries up to this point to a minor increase thereafter. Therefore, we suggest that the increase of melt-interconnectivity causes the dramatic strength drop between the solidus and a melt fraction of 0.07. A second strength drop occurs at higher melt fractions and corresponds to the breakdown of the solid (crystal) framework, corresponding to the well-known "rheologically critical melt percentage" (RCMP; Arzi, 1978). Although the strength drop at the RCMP is about 4 orders of magnitude, the absolute value of this drop is small compared to the absolute strength of the unmelted aggregate, rendering the RCMP invisible in a linear aggregate strength vs. melt fraction diagram. Predicting the rheological properties and thresholds of melt-bearing crust on the basis of the results and interpretations above is very difficult, because the rheological data base was obtained from experiments performed at undrained conditions in the brittle field. These conditions are unlikely to represent the flow of partially melted crust. The measured strength of most of the experimentally deformed, partially-melted samples corresponds to their maximum differential stress, before the onset of brittle failure, not to their viscous strength during "ductile" (viscous) flow. To overcome these problems, we extrapolated a theoretically-derived flow law for partially melted granite deforming by diffusion-accommodated grain-boundary sliding (Paterson, 2001) and an experimentally-derived flow law for quartz deforming in the dislocation creep regime in the presence of 1-2 % of melt (Gleason and Tullis, 1995). In addition, we compared these data with deformation experiments on olivine plus basalt melt, also conducted in the ductile (viscous) field (Hirth and Kohlstedt, 2003). All these data show a dramatic decrease in viscosity for melt fractions < 0.06. Therefore, they are consistent with the aforementioned results of experimentally deformed granite in the brittle field. Extrapolation of these results to natural conditions suggests that localisation of deformation should effectively coincide with the onset of melting, or with very small melt fractions (0.06-0.07), which may not always be detected in the field. References: Arzi, A. 1978. Tectonophysics, 44: 173-184. Hirth, G. and D. Kohlstedt. 2003. Geophysical Monograph, 138: 83-105. Gleason, G.C. and Tullis, J., 1995. Tectonophysics, 247: 1-23. Paterson, M.S. 2001. Tectonophysics, 335: 51-61. Rosenberg, C.L., and M.R. Handy. 2005. Journal of Metamorphic Geology, 23:19-28.

Rosenberg, C. L.; Medvedev, S.; Handy, M. R.

2006-12-01

343

THERMOPHYSICAL AND RHEOLOGIC PROPERTIES OF BIOOIL SAMPLES  

Directory of Open Access Journals (Sweden)

Full Text Available This article deals with thermal properties of selected biooils Plahyd S biooil No1 and Plahyd N biooil No2 and rheologic properties of rapeseed oil. Plahyd S is a synthetic, rapidly biodegradable fluid which is based on sustainable raw materials. It is exceptionally suitable for applications in mobile and stationary hydraulic systems. Plahyd N is multigrade hydraulic oil based on rapeseed oil used in agricultural and construction machinery. For thermal parameters measurements was used Hot wire method. The experiment is based on measuring of the temperature rise vs. time evaluation of an electrically heated wire embedded in the tested material. The thermal conductivity is derived from the resulting change in temperature over a known time interval. Dependency of material resistance against the probe rotation was used at measurement of rheologic properties with instrument viscometer Anton Paar DV 3P. For two samples of biooils Plahyd N and Plahyd S were determined basic thermophysical parameters thermal conductivity, thermal diffusivity and volume specific heat. For each biooil samples were made two series of measurements. In the first series were measured thermal conductivity and thermal diffusivity at constant room temperature 20 C. Every thermophysical parameter was measured 10 times for each sample. The results were statistically processed. For biooil No1 thermal conductivity was 0.325 W*m 1 .K1 , it was higher value than we obtained for biooil No2 0.224 W*m 1 .K 1 . The similar results were obtained for thermal diffusivity of biooil No1 2.140.10 7 m 2 *s 1 and biooil No2 2.604.10 7 m 2* s 1 . For samples with constant temperature were calculated basic statistical characteristics as standard deviation for biooil No1 0.056 W*m 1*K 1 and biooil No2 0.054 W*m 1*K 1; probable error of the arithmetic average for biooil No 1 0.012 W*m 1*K 1 and biooil No 2 0.005 W*m 1*K 1, relative probable error in for biooil No1 3.69 per cent and biooil No2 2.23. The same statistical characteristics were calculated for thermal diffusivity. In the second series of measurements were measured relations of thermal conductivity and thermal diffusivity to the temperature in temperature range 20 29 C. From results was evident that all measured dependencies are nonlinear. For both thermophysical parameters were obtained polynomial functions of the second degree described by the polynomial coefficients. Type of function was selected according to statistical evaluation based on the coefficient of determination for every thermophysical parameter graphical dependency. In temperature dependency of rapeseed oil dynamic viscosity was used decreasing exponential function, which is in accordance with Arrhenius equation. The results obtained by the implementation of thermophysical and rheologic measurements on samples of biooils could be compared with the values presented in the literature.

Monika Bozikova; Peter Hlavac

2013-01-01

344

Ozone electrosynthesis in an electrolyzer with solid polymer electrolyte  

Energy Technology Data Exchange (ETDEWEB)

Environmental problems have provided a focus of growing attention within the past few years. Of particular interest are preparation techniques for ozone, which is known to be an environmentally clean oxidant applicable to conditioning of potable water, sewage treatment, and disinfection of various domestic media. It also can be employed in chemical synthesis and a number of other applications. An electrolyzer with PbO{sub 2}-covered anode pressed against a membrane of a solid polymer electrolyte of sulfocationite type is shown to exhibit high operational qualities in electrochemical production of ozone.

Babak, A.A.; Fateev, V.N. [Institute of Hydrogen and Plasma Engineering, Moscow (Russian Federation); Amadelli, R. [Ferrara Univ. (Italy); Potapova, G.F. [Karpov Institute of Physical Chemistry, Moscow (Russian Federation)

1994-06-01

345

Bioadhesive, rheological, lubricant and other aspects of an oral gel formulation intended for the treatment of xerostomia.  

UK PubMed Central (United Kingdom)

Xerostomia is commonly known as 'dry mouth' and is characterised by a reduction or loss in salivary production. A bioadhesive gel for its localised treatment was formulated to help enhance the residence time of the product, based on the polymer Carbopol 974P. The bioadhesion of various formulations was evaluated on different mucosal substrates, as simulations of the oral mucosa of xerostomic patients. Depending on the type of model substrate used, the mechanism of bioadhesion could alter. When the rheology of various formulations was examined, changes in bioadhesion were more easily interpreted, as the presence of other excipients caused an alteration in the rheological profile, with a change from a fully expanded and partially cross-linked system to an entangled system. Improving the lubricity of the product was considered important, with optimum incorporation of vegetable oil causing a desirable lowering of the observed friction of the product. The final complex formulation developed also contained salivary levels of electrolytes to help remineralisation of teeth, fluoride to prevent caries, zinc to enhance taste sensation, triclosan as the main anti-microbial/anti-inflammatory agent and non-cariogenic sweeteners with lemon flavour to increase the palatability of the product while stimulating any residual salivary function.

Kelly HM; Deasy PB; Busquet M; Torrance AA

2004-07-01

346

Electrochemical and rheological behaviour of a fluid zinc paste; Comportement electrochimique et rheologique d`une pate de zinc fluide  

Energy Technology Data Exchange (ETDEWEB)

Zinc is a performing anodic material in numerous types of batteries. The anode of alkaline cells is typically a suspension of metallic powder in a gelled potassium hydroxide electrolyte, called zinc paste. We process such a homogeneous, fluid and stable paste, we study its physical electrochemical and rheological properties. Electrical power delivered during galvano-static electrolysis is about a few tens of mW.cm{sup -2} for anodic overvoltages inferior to 200 mV until the complete oxidation of the metal, 10 oxidation-reduction cycles are realised on paste samples of few mm width. In other respects, the product has a Bingham-type flow behavior, of critical shearing stress close to 200 Pa, and plastic viscosity about Pa.s, valid from 0,1 s{sup -1} shear rate. Zinc paste circulates in a slim rectangular section channel. Movement is ensured by a peristaltic pump placed on a cylindrical flexible tube. The paste transit between rectangular and circular sections is made through a profiled mechanical piece called a fish tail, without draft edge or roughness. An electrolytic separator and a current collector form the walls of the parallelopipedal channel, thus an electrolysis cell is framed. We record electrical and rheological characteristics of 2 oxidation-reduction cycles, during which the paste continues to flow and remains conductive. Established performances on the elementary cell allow to make up an air-zinc circulating paste battery for an electrical vehicle: the hydraulic recharge of a 100 l anodic paste tank is made in a few minutes, corresponding to a 300 km autonomy. (author) 87 refs.

Sajot, N.

1997-12-04

347

Electrical controlled rheology of a suspension of weakly conducting particles in dielectric liquid  

CERN Multimedia

The properties of suspensions of fine particles in dielectric liquid (electrorheological fluids) subjected to an electric field lead to a drastic change of the apparent viscosity of the fluid. For high applied fields (~ 3-5 kV/mm) the suspension congeals to a solid gel (particles fibrillate span the electrode gap) having a finite yield stress. For moderate fields the viscosity of the suspension is continuously controlled by the electric field strength. We have roposed that in DC voltage the field distribution in the solid (particles) and liquid phases of the suspension and so the attractive induced forces between particles and the yield stress of the suspension are controlled by the conductivities of the both materials. In this paper we report investigation and results obtained with nanoelectrorheological suspensions: synthesis of coated nanoparticles (size ~ 50 to 600 nm, materials Gd2O3:Tb, SiOx...), preparation of ER fluids (nanoparticles mixed in silicone oil), electrical and rheological characterization ...

Guegan, Q; Foulc, J N; Tillement, O; Guegan, Quentin

2006-01-01

348

Gas producing electrolytic cell for portable devices  

Energy Technology Data Exchange (ETDEWEB)

A gas producing electrolytic cell for portable devices comprising a vessel, an electrolyte, a cap, a gas space, channel labyrinths, a separating wall and contacts. The channel labyrinths eliminate the outflow of the electrolyte from the cell in its overturned position, tender the return of electrolyte to the vessel, to the original level possible. The contacts can be inundated by the electrolyte and in this way an outer electric circuit can be closed for cutting out the stream of electrolyse and for signalizating the overturned position of the cell.

Noszticzius, Z.; Olah, K.; Palmai, G.; Patonay, G.; Szommer, F.; Vajta, Z.

1982-06-01

349

Polymeric electrolytes for ambient temperature lithium batteries  

Energy Technology Data Exchange (ETDEWEB)

A new type of highly conductive Li{sup +} polymer electrolyte, referred to as the Innovision polymer electrolyte, is completely amorphous at room temperature and has an ionic conductivity in the range of 10{sup {minus}3} S/cm. This report discusses the electrochemical characteristics (lithium oxidation and reduction), conductivity, and physical properties of Innovision electrolytes containing various dissolved salts. These electrolytes are particularly interesting since they appear to have some of the highest room-temperature lithium ion conductivities yet observed among polymer electrolytes. 13 refs. 11 figs., 2 tabs.

Farrington, G.C. (Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Materials Science and Engineering)

1991-07-01

350

Electrolyte measurement device and measurement procedure  

Science.gov (United States)

A method and apparatus for measuring the through-thickness resistance or conductance of a thin electrolyte is provided. The method and apparatus includes positioning a first source electrode on a first side of an electrolyte to be tested, positioning a second source electrode on a second side of the electrolyte, positioning a first sense electrode on the second side of the electrolyte, and positioning a second sense electrode on the first side of the electrolyte. current is then passed between the first and second source electrodes and the voltage between the first and second sense electrodes is measured.

Cooper, Kevin R. (Southern Pines, NC); Scribner, Louie L. (Southern Pines, NC)

2010-01-26

351

[Study of pure titanium electrolytic polishing  

UK PubMed Central (United Kingdom)

This study attempted to polish pure titanium test pieces electrolytically to mirror surface at the size of cast denture frames. Electrolytic polishing of pure titanium could be done on an area of 30 cm2 with a non-aqueous electrolyte. Small pure titanium plates could be polished electrolytically, but a uniformly smooth surface could not be obtained easily with large testpiece. The optimal electrolytic conditions were 30 V for 6 min at 25 degrees C using a solution consisting of 70 ml ethyl alcohol, 30 ml iso-propyl alcohol, 6 g aluminum chloride, and 25 g zinc chloride. The solution was safe and had less restriction of frequency of use.

Morita N

1990-03-01

352

"Green"-enzymatic synthesis of pegylated phenolic macromer and polymer.  

UK PubMed Central (United Kingdom)

Environmentally benign synthesis of novel pegylated polyphenolics, by combining the extraordinary selectivities of a lipase and an oxidase to develop polymeric electrolytes for applications in dye sensitised solar cells.

Kumar R; Bruno F; Parmar VS; Kumar J; Watterson AC; Chittibabu KG; Samuelson LA

2004-04-01

353

Rheology of irradiated honey from Parana region  

Energy Technology Data Exchange (ETDEWEB)

Viscosity characteristics can be governed by the molecular chain length of sugars present in the honey. Honey is essentially a mixture of sugar and water. When a physical treatment, as gamma radiation, is applied to food, some changes on its viscosity may occur. Viscosity is one of the important properties of honey and depends on water and sugar quantities. The objective of this work was to verify the rheological behavior of irradiated honey from Parana region in comparison to the unirradiated one. Each rheogram was measured at different shear rates that was increased to a certain value then immediately decreased to the starting point ('up and down curves'). These measurements were made for control and irradiated samples (5 and 10 kGy) in different temperatures (30 deg. C, 35 deg. C and 40 deg. C). The curves constructed with shear stress against shear rate presented linearity. Honey, irradiated and control, showed a Newtonian behavior and gamma radiation did not affect it.

Sabato, S.F. E-mail: sfsabato@ipen.br

2004-10-01

354

Rheological characterization of hydraulic fracturing slurries  

Energy Technology Data Exchange (ETDEWEB)

Few studies have dealt with the flow behavior of concentrated suspensions or slurries prepared with non-Newtonian carrier fluids. Therefore, the purpose of this investigation is to present experimental results obtained by pumping various hydraulic fracturing slurries into a fracture model and gathering data on differential pressure vs. flow rate. Several concentrations of hydroxypropyl guard (HPG), a wide range of proppant concentrations, and three test temperatures were studies. The effects of such variables as polymer gelling-agent concentration, proppant concentration, test temperature, and fracture-flow shear rate on the rheological properties of slurries were investigated. The correlations for predicting the relative slurry viscosity for these HPG fluids are presented. Substantial increases in viscosity of fracturing gels were observed, and results are discussed in light of several affecting variables. Results also are compared with those available for Newtonian and non-Newtonian concentrated suspensions. Applications of these correlations to estimate the hindered particle-settling velocity in the fracture caused by the presence of surrounding particles also is discussed. The correlations presented can easily be included in any currently available 2D or 3D fracture-design simulators; thus, the information can be applied directly to predict fracture geometry and extension.

Shah, S.N. (Halliburton Services, Duncan, OK (United States). Research and Engineering Dept.)

1993-05-01

355

Rheology of microsphere formation and refinement  

Energy Technology Data Exchange (ETDEWEB)

Two important steps in the fabrication of microsphere laser fusion targets have been analyzed by simple mathematical modeling. Volatile-containing droplets emerging from a nozzle with imposed oscillation first undergo a spontaneous blowing process, driven by the evaporation of volatile solvent which pushes the polymeric shell outward. These hollow particles then enter a refinement zone, where a centering process takes place to eliminate eccentricity between the shell internal and external surfaces. The confined vapor partially permeates to the surroundings, allowing shrinkage of the microspheres in this zone to the desired final dimensions and sphericity. Biaxial extensional flow dominates the rheology of micropshere expansion, whereas detailed dynamics of radial flow results in improved concentricity and sphericity. The effects of viscoelasticity on the rate and stress associated with microsphere expansion have been studied using the Newtonian and Maxwell constitutive equations. Simple analytic results to describe microsphere refinement have been obtained for conditions representative of the centering process where Newtonian behavior prevails as the fluid flow is relatively weak.

Amundson, K.R.; Bousfield, D.W.; Soong, D.S.

1986-04-01

356

Rheology of microsphere formation and refinement  

International Nuclear Information System (INIS)

Two important steps in the fabrication of microsphere laser fusion targets have been analyzed by simple mathematical modeling. Volatile-containing droplets emerging from a nozzle with imposed oscillation first undergo a spontaneous blowing process, driven by the evaporation of volatile solvent which pushes the polymeric shell outward. These hollow particles then enter a refinement zone, where a centering process takes place to eliminate eccentricity between the shell internal and external surfaces. The confined vapor partially permeates to the surroundings, allowing shrinkage of the microspheres in this zone to the desired final dimensions and sphericity. Biaxial extensional flow dominates the rheology of micropshere expansion, whereas detailed dynamics of radial flow results in improved concentricity and sphericity. The effects of viscoelasticity on the rate and stress associated with microsphere expansion have been studied using the Newtonian and Maxwell constitutive equations. Simple analytic results to describe microsphere refinement have been obtained for conditions representative of the centering process where Newtonian behavior prevails as the fluid flow is relatively weak.

1986-01-01

357

Influence of Fat Content on Chocolate Rheology  

Science.gov (United States)

Molten chocolate is a suspension having properties strongly affected by particle characteristics including not only the dispersed particles but also the fat crystals formed during chocolate cooling and solidification. Even though chocolate rheology is extensively studied, mainly viscosity at high temperature was determined and no information on amount and type of fat crystals can be detected in these conditions. However chocolate texture and stability is strongly affected by the presence of specific crystals. In this work a different approach, based on creep test, was proposed to characterize chocolate samples at typical process temperatures (approximately 30 °C). The analysis of compliance, as time function, at short times enable to evaluate a material ``elasticity'' related to the solid-like behavior of the material and given by the differential area between the Newtonian and the experimental compliance. Moreover a specific time dependent elasticity was defined as the ratio between the differential area, in a time range, and total area. Chocolate samples having a different fat content were prepared and they were conditioned directly on rheometer plate by applying two different controlled cooling rate; therefore creep were performed by applying a low stress to ensure material linear behavior. Experimental data were analyzed by the proposed method and specific elasticity was related to single crystal properties. It was found that fat crystal amount and properties depend in different way on fat content and cooling rate; moreover creep proved to be able to detect even small differences among tested samples.

Gabriele, D.; Migliori, M.; Baldino, N.; de Cindio, B.

2008-07-01

358

Foam rheology: a model of viscous phenomena  

International Nuclear Information System (INIS)

A theoretical model for foam rheology that includes viscous forces is developed by considering the deformation of two-dimensional, spatially periodic cells in simple shearing and planar extensional flow. The undeformed hexagonal cells are separated by thin liquid films. Plateau border curvature and liquid drainage between films is neglected. Interfacial tension and viscous tractions due to stretching lamellar liquid determine the individual film tensions. The network motion is described by a system of nonlinear ordinary differential equations for which numerical solutions are obtained. Coalescense and disproportionation of Plateau borders results in the relative separation of cells and provides a mechanism for yielding and flow. This process is assumed to occur when a film's length reduces to its thickness. The time and position dependence of the cell-scale dynamics are computed explicitly. The effective continuum stress of the foam is described by instantaneous and time-averaged quantities. The capillary number, a dimensionless deformation rate, represents the relative importance of viscous and surface tension effects. The small-capillary-number or quasistatic response determines a yield stress. The dependence of the shear and normal stress material functions upon deformation rate, foam structure and physical properties is determined. A plausible mechanism for shear-induced material failure, which would determine a shear strength, is revealed for large capillary numbers. The mechanism involves large cell distortion and film thinning, which provide favorable conditions for film rupture.

1987-01-01

359

Rheological properties of cold recycled mixtures  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents some of the results of research focused on cold recycled mixtures properties. Within the study, eight mixtures with a different amount of reclaimed asphalt, bitumen emulsion and cement were evaluated. The results of static creep, complex modulus and fatigue conducted on trapezoidal specimens are discussed in the paper. The static creep modulus and the complex modulus were investigated at temperatures 27 ºC, 11 ºC and 0 ºC. These temperatures represent temperatures of asphalt layer with a thickness in the range from 20 to 25 cm for summer, spring/ autumn and winter in Slovakia. In addition fatigue was investigated at the temperature of 27 ºC. It was found that the binder combination plays an important role in rheological performance of cold recycled mixtures. However, at different contents of reclaimed asphalt, the effect of bitumen emulsion was different. This can be observable particularly when analyzing the results of the fatigue test. The mixtures with a higher amount of cement were better in terms of the fatigue life. The investigated mixtures in general were little sensitive to the change of loading frequency which simulates the traffic speed.

Ján Gillinger

2007-01-01

360

Rheology of water ices V and VI  

International Nuclear Information System (INIS)

[en] We have measured the mechanical strength (?) of pure water ices V and VI under steady state deformation conditions. Constant displacement rate compressional tests were conducted in a gas apparatus at confining pressures from 400 -7 -4 s-1. Most of the results fit to an empirical flow law of the form ampersand = A ?n exp (-E + PV)/RT, where the four material constants A, n, E, and I/* are (for ampersand in inverse seconds and P and ? in megapascals) 1023,0, 6.0, 136 kJ/mol, and 29 cm3/mol, respectively, for ice V; and 106,7, 4.5, 66 kJ/mol, and 11 cm3mol, respectively, for ice VI. Ice VI may weaken to a mechanism of higher E at T > 250 K. Ices V and VI are thus rheologically distinct but by coincidence have approximately the same strength under the conditions chosen for these experiments. To avoid misidentification, these tests are therfore accompanied by careful observations of the occurrences and characteristics of phase changes. One sample each of ice V and VI was quenched at pressure to metastably retain the high-pressure phase and the acquired deformation microstructures; X ray diffraction analysis of these samples confirmed the phase identification. Surface replicas of the deformed and quenched samples suggest that ice V probably deforms largely by dislocation creep, while ice VI deforms by a more complicated process involving substantial grain size reduction through recrystallization. 25 refs., 10 figs., 3 tabs

1996-02-10

 
 
 
 
361

Rheological Studies of Polysaccharides for Skin Scaffolds.  

UK PubMed Central (United Kingdom)

Polysaccharide hydrogels are good candidates for skin scaffolds due to their inherent biocompatibility and water transport properties. In the current study, hydrogels were made from a mixture of four polysaccharides: xanthan gum, konjac gum, iota-carrageenan, and kappa-carrageenan. Gel formation, strength, and structure of these polysaccharides were studied using rheological and thermal techniques. All gel samples studied were strong gels at all times due to the gradual water loss. However, after 12 hours of storage, elastic (G') and loss (G") moduli of hydrogel mixture containing all the ingredients is of one to two orders of magnitude greater than that of mixtures not containing either xanthan gum or iota-carrageenan, which confirmed the varied levels of gel strength. This is mainly due to the rate of water loss in each of these mixtures, resulting in gels of varying structures and dynamic moduli over a period of time. Iota carrageenan and xanthan gum differ in their effect on gel strength and stability in combination with konjac gum and kappa carrageenan.

Almeida N; Mueller A; Hirschi S; Rakesh L

2013-05-01

362

Thermodynamic interpretation of soft glassy rheology models.  

UK PubMed Central (United Kingdom)

Mesoscopic models play an important role in our understanding of the deformation and flow of amorphous materials. One such description, based on the shear transformation zone theory, has recently been reformulated within a nonequilibrium thermodynamics framework and found to be consistent with it. We show here that a similar interpretation can be made for the soft glassy rheology (SGR) model. Conceptually this means that the "noise temperature" x, proposed phenomenologically in the SGR model to control the dynamics of a set of slow mesoscopic degrees of freedom, can consistently be interpreted as their actual thermodynamic temperature. (Because such modes are slow to equilibrate, this generally does not coincide with the temperature of the fast degrees of freedom and/or heat bath.) If one chooses to make this interpretation, the thermodynamic framework significantly constrains extensions of the SGR approach to models in which x is a dynamical variable. We assess in this light some such extensions recently proposed in the context of shear banding.

Sollich P; Cates ME

2012-03-01

363

Thermodynamic interpretation of soft glassy rheology models.  

Science.gov (United States)

Mesoscopic models play an important role in our understanding of the deformation and flow of amorphous materials. One such description, based on the shear transformation zone theory, has recently been reformulated within a nonequilibrium thermodynamics framework and found to be consistent with it. We show here that a similar interpretation can be made for the soft glassy rheology (SGR) model. Conceptually this means that the "noise temperature" x, proposed phenomenologically in the SGR model to control the dynamics of a set of slow mesoscopic degrees of freedom, can consistently be interpreted as their actual thermodynamic temperature. (Because such modes are slow to equilibrate, this generally does not coincide with the temperature of the fast degrees of freedom and/or heat bath.) If one chooses to make this interpretation, the thermodynamic framework significantly constrains extensions of the SGR approach to models in which x is a dynamical variable. We assess in this light some such extensions recently proposed in the context of shear banding. PMID:22587058

Sollich, Peter; Cates, Michael E

2012-03-20

364

Manufacturing method of solid electrolyte fuel cell  

Energy Technology Data Exchange (ETDEWEB)

In the conventional solid electrolyte fuel cell, an electrolyte layer which is formed with a film-forming means between a pair of electrodes. An electrolyte layer formed by a fast film-forming means does not give a dense layer, but a slow film-forming method is slow but gives a dense electrolyte layer. This invention has shortened a time of production and yet has given a dense electrolyte layer by placing the 1st. electrolyte layer, rapidly formed between a pair of electrodes and the 2nd. electrolyte layer which was slowly formed. Method of rapid film forming is film coating and a slurry method. Slow speed film forming method is EVD, CVD, PVD and EB evaporating method. (2 figs)

Kaneko, Shozo; Gengo, Yoshinori; Murakami, Nobuaki

1988-07-07

365

Electrolytic indium refining from cadmium in glycerine electrolyte  

International Nuclear Information System (INIS)

[en] The results of investigations directed on development of electrochemical indium cleaning from cadmium in glycerine base electrolyte are presented. Optimal operational conditions, specific consumption of reactants and electric power are determined. Relationship between variation of concentration of cadmium impurity in refined metal and duration of electrolysis is revealed. The method for determination of cleaning time is proposed. Developed process was put into commercial operation

1998-01-01

366

Measurement of blood rheology using model capillaries; Mosai kekkan model wo mochiita ketsueki rheology keisoku  

Energy Technology Data Exchange (ETDEWEB)

This paper describes measurement of blood rheology using micro processing flow paths (model capillaries). The description includes the following matters: since red blood cells have transformation capability, blood can maintain high fluidity in spite of ratio of volume of red blood cells in blood accounting for nearly half of the blood volume; human blood capillaries have an inner diameter of about 6 {mu}m, while the diameter of red blood cells is about 8 {mu}m, hence the transformation capability of red blood cells is especially important in blood capillaries; in order to measure rheological characteristics of blood cells, grooves with the same size (30 {mu}m long, 7 {mu}m wide and 4.5 {mu}m deep) were cut in a large number in parallel on the surface of a silicon monocrystal substrate, optically polished on the substrate surface, and a glass plate was pressure bonded to make a model blood capillary; and when human blood sample was injected onto it to measure flow rate under pressure difference of 20-cm water column, the red blood cells flew too quickly causing total failure of visual identification (under a microscope). 14 refs., 3 figs.

Kikuchi, Y. [Ministry of Agriculture, Forestry and Fisheries, Tokyo (Japan)

1998-03-05

367

Electrolytic production of neodymium metal from a molten chloride electrolyte  

International Nuclear Information System (INIS)

[en] This paper reports that the U.S. Bureau of Mines conducted experiments on electrowinning of neodymium metal by using a molten-metal cathode at 650 degrees C and an electrolyte of 50 mol pet NdCl, (neodymium chloride) and 50 mol pet KCl (potassium chloride). The molten-metal cathodes were alloys of magnesium and zinc or magnesium and cadmium. Current efficiencies were 90 pct with a Mg-Zn cathode and 80 pct with a Mg-Cd cathode. The Mg-Cd cathode was easily separated from the electrolyte. In contrast, the Mg-Zn cathode tended to mix with the electrolyte, making separation difficult. The cathode metals were separated from the neodymium by distillation at 1,100 degrees C under a vacuum of 10-4 torr. Neodymium metal of 99.9 + purity was recovered from the Mg-Cd alloy cathode after 30 min distillation time. The neodymium recovered from the Mg-Zn system contained almost 2 pct Zn after vacuum distillation. Continuous operation using the Mg-Cd alloy cathode was demonstrated

1991-01-01

368

Electrolytic production of neodymium metal from a molten chloride electrolyte  

Energy Technology Data Exchange (ETDEWEB)

This paper reports that the U.S. Bureau of Mines conducted experiments on electrowinning of neodymium metal by using a molten-metal cathode at 650{degrees} C and an electrolyte of 50 mol pet NdCl, (neodymium chloride) and 50 mol pet KCl (potassium chloride). The molten-metal cathodes were alloys of magnesium and zinc or magnesium and cadmium. Current efficiencies were 90 pct with a Mg-Zn cathode and 80 pct with a Mg-Cd cathode. The Mg-Cd cathode was easily separated from the electrolyte. In contrast, the Mg-Zn cathode tended to mix with the electrolyte, making separation difficult. The cathode metals were separated from the neodymium by distillation at 1,100{degrees} C under a vacuum of 10{sup {minus}4} torr. Neodymium metal of 99.9 + purity was recovered from the Mg-Cd alloy cathode after 30 min distillation time. The neodymium recovered from the Mg-Zn system contained almost 2 pct Zn after vacuum distillation. Continuous operation using the Mg-Cd alloy cathode was demonstrated.

Chambers, M.F.; Murphy, J.E.

1991-01-01

369

Effect of a novel amphipathic ionic liquid on lithium deposition in gel polymer electrolytes  

International Nuclear Information System (INIS)

Highlights: · Synthesis of a dimeric ionic liquid. · Gel polymer electrolytes providing uniform lithium deposit pathway. · An amphipathic ionic liquid locates at the interface between an electrolyte-rich phase and a polymer matrix in a gel polymer electrolyte. · The presence of PDMITFSI ionic liquid leads to the suppression of dendritic lithium formation on a lithium metal electrode. - Abstract: A novel dimeric ionic liquid based on imidazolium cation and bis(trifluoromethanesulfonyl) imide (TFSI) anion has been synthesized through a metathesis reaction. Its chemical shift values and thermal properties are identified via 1H nuclear magnetic resonance (NMR) imaging and differential scanning calorimetry (DSC). The effect of the synthesized dimeric ionic liquid on the interfacial resistance of gel polymer electrolytes is described. Differences in the SEM images of lithium electrodes after lithium deposition with and without the 1,1'-pentyl-bis(2,3-dimethylimidazolium) bis(trifluoromethane-sulfonyl)imide (PDMITFSI) ionic liquid in gel polymer electrolytes are clearly discernible. This occurs because the PDMITFSI ionic liquid with hydrophobic moieties and polar groups modulates lithium deposit pathways onto the lithium metal anode. Moreover, high anodic stability for a gel polymer electrolyte with the PDMITFSI ionic liquid was clearly observed.

2011-08-30

370

Effect of a novel amphipathic ionic liquid on lithium deposition in gel polymer electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Highlights: {center_dot} Synthesis of a dimeric ionic liquid. {center_dot} Gel polymer electrolytes providing uniform lithium deposit pathway. {center_dot} An amphipathic ionic liquid locates at the interface between an electrolyte-rich phase and a polymer matrix in a gel polymer electrolyte. {center_dot} The presence of PDMITFSI ionic liquid leads to the suppression of dendritic lithium formation on a lithium metal electrode. - Abstract: A novel dimeric ionic liquid based on imidazolium cation and bis(trifluoromethanesulfonyl) imide (TFSI) anion has been synthesized through a metathesis reaction. Its chemical shift values and thermal properties are identified via {sup 1}H nuclear magnetic resonance (NMR) imaging and differential scanning calorimetry (DSC). The effect of the synthesized dimeric ionic liquid on the interfacial resistance of gel polymer electrolytes is described. Differences in the SEM images of lithium electrodes after lithium deposition with and without the 1,1'-pentyl-bis(2,3-dimethylimidazolium) bis(trifluoromethane-sulfonyl)imide (PDMITFSI) ionic liquid in gel polymer electrolytes are clearly discernible. This occurs because the PDMITFSI ionic liquid with hydrophobic moieties and polar groups modulates lithium deposit pathways onto the lithium metal anode. Moreover, high anodic stability for a gel polymer electrolyte with the PDMITFSI ionic liquid was clearly observed.

Choi, Nam-Soon, E-mail: nschoi@unist.ac.kr [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Koo, Bonjae; Yeon, Jin-Tak [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Lee, Kyu Tae, E-mail: ktlee@unist.ac.kr [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Kim, Dong-Won [Department of Chemical Engineering, Hanyang University, Seungdong-Gu, Seoul 133-791 (Korea, Republic of)

2011-08-30

371

Rheological study of interactions between non-ionic surfactants and polysaccharide thickeners used in textile printing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The influence of four non-ionic surfactants (isododecyl and cetyl polyoxyethylene ethers) on aqueous polysaccharide solutions (sodium alginate, guar gum, and sodium carboxymethyl guar), applicable for textile printing pastes, were studied via rheological measurements. Rheology of polysaccharide-surf...

Fijan, Rebeka; Šostar-Turk, Sonja; Lapasin, Romano

372

Coal-water mixture fuel and preliminary studies on its rheological characteristics (Part 2)  

Energy Technology Data Exchange (ETDEWEB)

In the second part of this paper, studies of the rheological properties of concentrated fuel slurries prepared with Indian coals at the Rheology Laboratory of the Pittsburgh Energy Technology Centre are described. 12 references.

Chakraborty, M.

1985-06-01

373

Solid electrolyte fuel cell. Kotai denkaishitsu nenryo denchi  

Energy Technology Data Exchange (ETDEWEB)

In a solid electrolyte fuel cell, oxygen in the air becomes oxygen ion at the contact surface of the solid electrolyte and air electrode, and moves in the solid electrolyte. However, the moving distance of electron gets longer and the cell resistance increases if the baking proceeds with time or if minute pores cannot be formed. In this invention, the solid electrolyte consists of the 1st solid electrolyte layer having no mixed electroconductivity formed on the fuel electrode and the 2nd solid electrolyte layer having mixed conductivity formed on the 1st solid electrolyte layer. By making a boundary surface with the air electrode of the solid electrolyte the 2nd solid electrolyte having a mixed electroconductivity, the resistance at the time of electronplow across the solid electrolyte can be decreased. The 1st solid electrolyte having no mixed conductivity uses an electrolyte of YSZ, and the 2nd solid electrolyte layer uses ceria-based electrolyte. 4 figs.

Kuru, N.; Yamauchi, Y.; Yamashita, A. (Mitsubishi Heavy Industries Ltd., Tokyo (Japan))

1991-08-20

374

Rheological and pumping characteristics of coal-water suspensions  

Energy Technology Data Exchange (ETDEWEB)

In order to determine the technical, economic and environmental feasibility of using coal-water mixtures as an alternate fuel, it is first necessary to determine if suitable coal-water suspensions can be achieved and, if so, what the power requirements are to transport the material by pipeline. A study was undertaken, therefore, to determine the stability and rheological properties of coal-water mixtures. A bituminous (Illinois No. 5) coal was used. Using the rheological data, the power requirements to pump the suspensions through a pipeline were then determined. Mixtures ranging from 33% to 58% of coal to water by weight were ground in a ball mill for a grinding time of 6 hours. The stability for each suspension was determined. The rheological properties were measured by means of a Rotovisco RV-12 viscometer at temperatures of 25/sup 0/C to 40/sup 0/C. The rheological properties are presented on plots of shearing stress versus strain rate as a function of concentration of coal to water and temperature. The power requirements to pump the various mixtures through a pipeline are determined using the rheological properties in a computer program for that purpose. The suspensions were found to be pseudoplastic material. It is concluded that suitable coal-water stable suspensions can be achieved by use of a ball mill and that it is feasible to transport the resulting mixtures through a pipeline.

Davis, P.K.; Shrivastava, P.

1982-01-01

375

Determination of rheological properties using hybrid optimisation method  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: of this paper is description of special software developed for identification of parameters values of rheological models used by ProCAST package for simulation of state of stress in the solidifying castings.Design/methodology/approach: The PyTensionTest uses a hybrid optimization algorithm. This algorithm includes the stochastic method which searches the starting point for direct search optimization method. The identification of parameters values is based on measurement results obtained within the confines of the material tests carried out using the testing machine.Findings: This paper presents the results of approximation of stress-strain relationship for two grades of steel using the elasto-plastic rheological model with power law hardening where its parameters are linearly dependent on temperature.Research limitations/implications: This paper presents the special software that allows user to define any rheological model.Practical implications: Application of obtained values of rheological parameters in the ProCAST software allows to determine stress and strain distribution in continuous castings. It can help to optimize important process parameters.Originality/value: Developed software can approximate the results of static tension tests using rheological model depended on material temperature. This software makes possible an approximation of several stressstrain curves simultaneously. Application of the hybrid optimization method allows to obtain very precise approximation due to determination of the global minimum of the goal function.

B. Foder; K. So?ek

2012-01-01

376

Flow properties and rheology of slag from coal gasification  

Energy Technology Data Exchange (ETDEWEB)

We have studied the rheological characteristics of Texaco gasifier slag at high-temperature. Slag samples have been analyzed by X-ray fluorescence, X-ray diffraction, and scanning electron microscopy. The rheological behavior of the slag has been investigated experimentally using a high-temperature rheometer at temperatures between 1200{sup o}C and 1340{sup o}C. The effects of the shear rate and temperature on the rheological behavior of the slag have been explored. Moreover, the observed rheological behavior of the slag has been correlated with its solid-phase content, as calculated with the aid of the computer software package FactSage. The results show that the sensitivity of the slag viscosity to temperature decreases with increasing rotation speed. Above its liquidus temperature calculated by FactSage, the slag behaves as a Newtonian fluid; below its liquidus temperature, however, the rheological behavior of the slag becomes non-Newtonian owing to its increased solid-phase content. Meanwhile, slag containing a number of crystalline particles shows dramatic shear-thinning and thixotropic behavior. Moreover, the shear-thinning behavior of the slag becomes ever more distinct as the temperature is decreased. The yield stress values of the slag and the number and particle size of the crystalline particles in the slag increase with decreasing temperature. 47 refs., 11 figs., 1 tab.

Wenjia Song; Lihua Tang; Xuedong Zhu; Yongqiang Wu; Zibin Zhu; Shuntarou Koyama [East China University of Science and Technology, Shanghai (China). Engineering Research Center of Large Scale Reactor Engineering and Technology

2010-07-15

377

Model of ciliary clearance and the role of mucus rheology.  

Science.gov (United States)

It has been observed that the transportability of mucus by cilial mats is dependent on the rheological properties of the mucus. Mucus is a non-Newtonian fluid that exhibits a plethora of phenomena such as stress relaxation, tensile stresses, shear thinning, and yielding behavior. These observations motivate the analysis in this paper that considers the first two attributes in order to construct a transport model. The model developed here assumes that the mucus is transported as a rigid body, the metachronal wave exhibits symplectic behavior, that the mucus is thin compared to the metachronal wavelength, and that the effects of individual cilia can be lumped together to impart an average strain to the mucus during contact. This strain invokes a stress in the mucus, whose non-Newtonian rheology creates tensile forces that persist into unsheared regions and allow the unsupported mucus to move as a rigid body whereas a Newtonian fluid would retrograde. This work focuses primarily on the Doi-Edwards model but results are generalized to the Jeffrey's and Maxwell fluids as well. The model predicts that there exists an optimal mucus rheology that maximizes the shear stress imparted to the mucus by the cilia for a given cilia motion. We propose that this is the rheology that the body strives for in order to minimize energy consumption. Predicted optimal rheologies are consistent with results from previous experimental studies when reasonable model parameters are chosen. PMID:21405727

Norton, Michael M; Robinson, Risa J; Weinstein, Steven J

2011-01-31

378

Model of ciliary clearance and the role of mucus rheology.  

UK PubMed Central (United Kingdom)

It has been observed that the transportability of mucus by cilial mats is dependent on the rheological properties of the mucus. Mucus is a non-Newtonian fluid that exhibits a plethora of phenomena such as stress relaxation, tensile stresses, shear thinning, and yielding behavior. These observations motivate the analysis in this paper that considers the first two attributes in order to construct a transport model. The model developed here assumes that the mucus is transported as a rigid body, the metachronal wave exhibits symplectic behavior, that the mucus is thin compared to the metachronal wavelength, and that the effects of individual cilia can be lumped together to impart an average strain to the mucus during contact. This strain invokes a stress in the mucus, whose non-Newtonian rheology creates tensile forces that persist into unsheared regions and allow the unsupported mucus to move as a rigid body whereas a Newtonian fluid would retrograde. This work focuses primarily on the Doi-Edwards model but results are generalized to the Jeffrey's and Maxwell fluids as well. The model predicts that there exists an optimal mucus rheology that maximizes the shear stress imparted to the mucus by the cilia for a given cilia motion. We propose that this is the rheology that the body strives for in order to minimize energy consumption. Predicted optimal rheologies are consistent with results from previous experimental studies when reasonable model parameters are chosen.

Norton MM; Robinson RJ; Weinstein SJ

2011-01-01

379

Electrolytic conductivity of synthetic organomineral complexes  

Directory of Open Access Journals (Sweden)

Full Text Available The mechanism of the formation of organomineral complexes in soils is very complex and still little known. Examination of the complexes in unaltered form, as isolated from the soil, is very difficult due to the dispersing effect of all extraction agents which break the complexes up, destroying their natural properties. It is much easier to perform most of the tests on preparations of organomineral complexes obtained under laboratory conditions. This paper is concerned with model research on the formation of synthetic complexes of humic acids with minerals: Na-montmorillonite, mica, kaolinite at various pH values (3-7) and in the presence of aluminum ions. The aim of the research was to develop an optimum reaction of suspension for the synthesis of organomineral complexes, to study the role of aluminum ions, and to attempt to determine the degree of their complexity on the basis of the electrolytic conductivity (EC). An important influence of the suspension pH value on the value of EC was observed. The greatest correlation was found in the organomineral preparations with kaolinite and with aluminum (r = 0.93***). Generally, it can be stated that the degree of reaction of humic acids with minerals depended most of all on the type of mineral, on the pH value, and on the presence of aluminum.

Ksiezopolska Alicja

2005-01-01

380

Iron-containing coatings obtained by microplasma method on aluminum with usage of homogeneous electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The microplasma synthesis method of multicomponent oxide coatings including iron oxide on an aluminum alloy surface has been studied. The homogeneous electrolytes containing iron complexes with Edta{sup 4-} under pH 9-10 have been used. The dynamics reducing the pH of the electrolyte during formation process have been studied. The content of iron in the coatings has been measured spectrophotometricaly. Morphlogy and phase composition of the coatings have been studied by the scanning electron microscopy and X-ray powder diffraction.

Rogov, A.B., E-mail: alex-lab@bk.ru [Nikolaev Institute of Inorganic Chemistry, 3, Acad. Lavrentiev Ave, Novosibirsk, 630090 (Russian Federation); Terleeva, O.P., E-mail: oterleeva@yandex.ru [Nikolaev Institute of Inorganic Chemistry, 3, Acad. Lavrentiev Ave, Novosibirsk, 630090 (Russian Federation); Mironov, I.V., E-mail: imir@niic.nsc.ru [Nikolaev Institute of Inorganic Chemistry, 3, Acad. Lavrentiev Ave, Novosibirsk, 630090 (Russian Federation); Slonova, A.I., E-mail: antaris@ngs.ru [Nikolaev Institute of Inorganic Chemistry, 3, Acad. Lavrentiev Ave, Novosibirsk, 630090 (Russian Federation)

2012-01-15

 
 
 
 
381

Iron-containing coatings obtained by microplasma method on aluminum with usage of homogeneous electrolytes  

International Nuclear Information System (INIS)

The microplasma synthesis method of multicomponent oxide coatings including iron oxide on an aluminum alloy surface has been studied. The homogeneous electrolytes containing iron complexes with Edta4- under pH 9-10 have been used. The dynamics reducing the pH of the electrolyte during formation process have been studied. The content of iron in the coatings has been measured spectrophotometricaly. Morphlogy and phase composition of the coatings have been studied by the scanning electron microscopy and X-ray powder diffraction.

2012-01-15

382

Granular nanocrystalline zirconia electrolyte layers deposited on porous SOFC cathode substrates  

International Nuclear Information System (INIS)

Thin granular yttria-stabilized zirconia (YSZ) electrolyte layers were prepared by chemical vapor synthesis and deposition (CVD/CVS) on a porous substoichiometric lanthanum-strontium-manganite (ULSM) solid oxide fuel cell cathode substrate. The substrate porosity was optimized with a screen printed fine porous buffer layer. Structural analysis by scanning electron microscopy showed a homogeneous, granular nanocrystalline layer with a microstructure that was controlled via reactor settings. The CVD/CVS gas-phase process enabled the deposition of crack-free granular YSZ films on porous ULSM substrates. The electrolyte layers characterized with impedance spectroscopy exhibited enhanced grain boundary conductivity.

2009-08-15

383

Perovskite solid electrolytes for SOFC  

Energy Technology Data Exchange (ETDEWEB)

We have synthesized a new series of brownmillerite solid electrolyte phases Ba{sub 2}GdIn{sub 1-x}Ga{sub x}O{sub 5} (x = 0,0.2,0.4) with the x = 0.2 phase exhibiting an unusually low E. relative to both the observed ionic conductivity in this phase and to E{sub a}s observed in similar compounds. We attribute measured ionic conductivities to a lack of available charge carriers in Ba{sub 2}GdIn{sub 0.8}Ga{sub 0.2}O{sub 5}. However, the low E{sub a} supports the premise that brownmillerite solid electrolyte structures are suitable for supporting high ionic conductivity. Current work is focusing on enhancing the amount of charge carriers in these materials by systematically introducing disorder into the brownmillerite lattice.

Sammells, A.F.

1993-11-01

384

Monolithic solid electrolyte oxygen pump  

Science.gov (United States)

A multi-layer oxygen pump having a one-piece, monolithic ceramic structure affords high oxygen production per unit weight and volume and is thus particularly adapted for use as a portable oxygen supply. The oxygen pump is comprised of a large number of small cells on the order of 1-2 millimeters in diameter which form the walls of the pump and which are comprised of thin, i.e., 25-50 micrometers, ceramic layers of cell components. The cell components include an air electrode, an oxygen electrode, an electrolyte and interconnection materials. The cell walls form the passages for input air and for exhausting the oxygen which is transferred from a relatively dilute gaseous mixture to a higher concentration by applying a DC voltage across the electrodes so as to ionize the oxygen at the air electrode, whereupon the ionized oxygen travels through the electrolyte and is converted to oxygen gas at the oxygen electrode.

Fee, Darrell C. (2529 Lee St., Woodridge, IL 60517); Poeppel, Roger B. (67 Stephanie La., Glen Ellyn, IL 60137); Easler, Timothy E. (564 N. Pinecrest, Bolingbrook, IL 60439); Dees, Dennis W. (6224 Middaugh Ave., Downers Grove, IL 60517)

1989-01-01

385

Cerium ion conducting solid electrolyte  

Science.gov (United States)

A cerium ion conducting solid electrolyte, (CexZr1-x)4/4-xNb(PO4)3, was successfully realized with the NASICON-type structure which possesses a three-dimensional network, especially suitable for bulky ion migration. The cerium ion conductivity exceeds approximately one order of magnitude in comparison to that of the rare-earth ion conducting R2(WO4)3 and R1/3Zr2(PO4)3 (R=Sc, Y, Eu-Lu) series and the value is in the range between typical oxide anion conductors of yttria stabilized zirconia (YSZ) and calcia stabilized zirconia (CSZ). Since cerium ion has been demonstrated to be another migrating ion species in solid electrolyte field, a promising application for various functional materials is greatly expected.

Hasegawa, Yasunori; Imanaka, Nobuhito; Adachi, Gin-Ya

2003-02-01

386

Cerium ion conducting solid electrolyte  

International Nuclear Information System (INIS)

[en] A cerium ion conducting solid electrolyte, (CexZr1-x)4/4-xNb(PO4)3, was successfully realized with the NASICON-type structure which possesses a three-dimensional network, especially suitable for bulky ion migration. The cerium ion conductivity exceeds approximately one order of magnitude in comparison to that of the rare-earth ion conducting R2(WO4)3 and R1/3Zr2(PO4)3 (R=Sc, Y, Eu-Lu) series and the value is in the range between typical oxide anion conductors of yttria stabilized zirconia (YSZ) and calcia stabilized zirconia (CSZ). Since cerium ion has been demonstrated to be another migrating ion species in solid electrolyte field, a promising application for various functional materials is greatly expected

2003-03-01

387

Composite electrode/electrolyte structure  

Energy Technology Data Exchange (ETDEWEB)

Provided is an electrode fabricated from highly electronically conductive materials such as metals, metal alloys, or electronically conductive ceramics. The electronic conductivity of the electrode substrate is maximized. Onto this electrode in the green state, a green ionic (e.g., electrolyte) film is deposited and the assembly is co-fired at a temperature suitable to fully densify the film while the substrate retains porosity. Subsequently, a catalytic material is added to the electrode structure by infiltration of a metal salt and subsequent low temperature firing. The invention allows for an electrode with high electronic conductivity and sufficient catalytic activity to achieve high power density in ionic (electrochemical) devices such as fuel cells and electrolytic gas separation systems.

Visco, Steven J. (Berkeley, CA); Jacobson, Craig P. (El Cerrito, CA); DeJonghe, Lutgard C. (Lafayette, CA)

2004-01-27

388

Meso-SiO2–C12EO10OH–CF3SO3H — a novel proton-conducting solid electrolyte  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper describes the synthesis and characterization of a novel mesostructured solid electrolyte composite material, denoted meso-SiO2-C12EO10OH-CF3SO3H. A lyotropic non-ionic surfactant-triflic acid-silicate liquid crystal is used as a supramolecular template for a one-pot synthesis of the mater...

Halla, J.D.; Mamak, M.; Williams, D.E.; Ozin, G.A.

389

Electrolytes levels in asthmatic patients  

Directory of Open Access Journals (Sweden)

Full Text Available Background: abnormal electrolytes concentrations in asthma patients can be attributed to low intake or secondary to asthma medications.Objectives: to identify the pattern of changes in electrolytes concentrations among asthmatic patients and to detect correlations between concentrations of electrolytes and pulmonary function measurements.Materials and Methods: the study involved a control group of 56 non-asthmatic subjects matched for gender and age with a study group of 100 patients with a medical history of asthma but no other respiratory diseases. IQ TQ Spirometer was used to assess pulmonary function according to ATS/ERS standards. Sodium, potassium, calcium and magnesium concentrations were measured from venous blood samples.Results: There were significant positive correlations between potassium concentration and FEV1, FEF50%, FEF25-75% (P 0.05).Conclusion: sodium and magnesium concentrations of asthmatic patients showed no significant differences in the means when compared with the control group, but elevated levels of sodium were associated with poor ventilatory function. High levels of potassium were associated with better pulmonary ventilation.

Mohamed Faisal Lutfi

2013-01-01

390

Degradation phenomena in solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The critical current density above which degradation occurs in beta-alumina has been determined by means of acoustic emissions tests on sodium/sulfur cells. Cells were tested by passing a current which increased linearly with time, as the stress or strain is increased in mechanical testing. The critical current density was found to depend on the rate of increase of the current density, indicating that some type of time dependent degradation is occurring. Microstructural investigation of used electrolytes showed some dissolution of electrolyte from inside cracks, and some used electrolytes had a degraded layer on the sodium exit surface, again indicating some type of time dependent attack. The degradation is attributed to mechanical cracking due to Poiseuille pressure as sodium flows out of surface flaws during charging at high current density. At low current density, long time chemical attack due to changes in the composition of the sodium electrode becomes important. Crack velocity as a function of crack length and current density is estimated for this stress corrosion.

Hitchcock, D.C.

1984-11-01

391

Degradation phenomena in solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The critical current density above which degradation occurs in beta''-alumina was determined by means of acoustic emissions tests on sodium/sodium cells. Cells were tested by passing current that increased linearly with time, as the stress or strain is increased in mechanical testing. The critical current density was found to depend on the rate of increase of the current density, indicating that some type of time dependent degradation is occurring. Microstructural investigation of used electrolytes showed some dissolution of electrolyte from inside cracks, and some used electrolytes had a degraded layer on the sodium exit surface, again indicating some type of time dependent attack. The degradation is attributed to mechanical cracking due to Poiseuille pressure as sodium flows out of surface flaws during charging at high current density. At low current density, long time chemical attack due to changes in the composition of the sodium electrode becomes important. Crack velocity as a function of crack length and current density is estimated for this stress corrosion.

Hitchcock, D.C.

1985-01-01

392

Polymers containing amide groups for controlling rheology  

UK PubMed Central (United Kingdom)

Amide-containing polymers are new. Amide-containing polymers of the general formula A-X-CO-(CH2)2-NR1-R2-(Y-R3-Y-R4)a-B' (I) or their salts with carboxylic acids, phosphoric esters and sulfonic acids; are new. A : R5 or R6-Y-(R4-Y-R3-Y)b-R2-NR1-(CH2)- 2-CO-X-R7; B' : Y-R6 or NR1-(CH2)2-CO-X-R5; R1H and/or (CH2)2-CO-X-R5 and/or CONH-R'; R' : R8 or C6H3(CH3)-NHCOO-R8; R2 - R4 and R71-40C alkylene, 3-40C alkenylene, 5-40C cyclo-alkylene, arylene, 7-40C aralkylene, poly-oxyalkylene or polyester; R5H, a 1-22C alkyl, aryl, 7-12C aralkyl, 5-12C cycloalkyl, hydroxyalkyl or N,N'-dialkyl-amino, hydroxyl, 1-22C alkoxy, 5-12C cycloalkoxy, 7-12C aralkoxypolyoxyalkylene, 1-22C alkanol, 5-12C cyclo-alkanol; or 7-12C-aralkanol-, 1-22C-alkoxy-, 5-12C-cycloalkoxy- or 7-12C-aralkoxy-polyoxyalkylene-started polyester; R61-30C alkyl, 3-22C alkenyl, hydroxyalkyl, 4-13C cycloalkyl, aryl or 7-12C aralkyl; R81-22C alkyl, aryl, 7-12C aralkyl, 5-12C cycloalkyl, 1-22C alkoxy, 5-12C cycloalkoxy, 7-12C aralkoxypolyoxyalkylene; or 1-22C-alkanol-, 5-12C-cyclo-alkanol-, 7-12C-aralkanol-, 1-22C-alkoxy-, 6-12C-cycloalkoxy-, or 7-12C aralkoxypolyoxyalkylene-started polyester; X : O, NH or NR9; R91-22C alkyl, aryl, 7-12C aralkyl, hydroxyalkyl, or 5-12C cycloalkyl; Y : COO, OCO, NHCO, CONH, NHCOO, OOCNH or NHCONH; a and b : 1 - 19. Independent claims are included for the following: (1) preparation of the amide-containing polymers (I); and (2) a rheology control additive comprising the polymers (I). The rheology control additive is for a solvent-free or solvent-borne coating materials based on binders; (3) cured and uncured polymer compositions comprising amide-containing polymers (I); and (4) compounds of formulae H2N-R2-(Y-R3-Y-R4)a-NH2 (i) and H2N-R2-(Y-R3-Y-R4)a-YR'6 (ii').; R'61-30C alkyl, 3-22C alkenyl, hydroxyalkyl, 4-13C cycloalkyl, aryl or 7-12C aralkyl.

HAUBENNESTEL KARLHEINZ; MOESSMER STEFAN DR; ORTH ULRICH DR; BETCKE DANIELA

393

Ice rheology and tidal heating of Enceladus  

Science.gov (United States)

For the saturnian satellite Enceladus, the possible existence of a global ocean is a major issue. For the stability of an internal ocean, tidal heating is suggested as an effective heat source. However, assuming Maxwell rheology ice, it has been shown that a global scale ocean on Enceladus cannot be maintained (Roberts, J.F., Nimmo, F. [2008]. Icarus 194, 675-689). Here, we analyze tidal heating and the stability of a global ocean from the aspect of anelastic behavior. The Maxwell model is the most typical and widely used viscoelastic model. However, in the tidal frequency domain, energy is also dissipated by the anelastic response involving time-dependent or transient creep mechanisms, which is different from the viscoelastic response caused by steady-state creep. The Maxwell model cannot adequately address anelasticity, which has a large effect in the high viscosity range. Burgers and Andrade models are suggested as suitable models for the creep behavior of ice in the frequency domain. We calculate tidal heating in the ice layer and compare it with the radiated heat assuming both convection and conduction of the ice layer. Though anelastic behavior increases the heating rate, it is insufficient to maintain a global subsurface ocean if the ice layer is convecting, even though a wide parameter range is taken into account. One possibility to maintain a global ocean is that Enceladus' ice shell is conductive and its tidal response is similar to that of the Burgers body with comparatively small transient shear modulus and viscosity. If the surface ice with large viscosity is dissipative by anelastic response, the heat produced in the ice layer would supersede the cooling rate and a subsurface ocean could be maintained without freezing.

Shoji, D.; Hussmann, H.; Kurita, K.; Sohl, F.

2013-09-01

394

Rheology of water ices V and VI  

Energy Technology Data Exchange (ETDEWEB)

We have measured the mechanical strength ({sigma}) of pure water ices V and VI under steady state deformation conditions. Constant displacement rate compressional tests were conducted in a gas apparatus at confining pressures from 400 < P < 800 MPa, temperatures from 209 < T < 270 K, and strain rates 7 x 10{sup {minus}7} < & < 7 x 10{sup {minus}4} s{sup {minus}1}. Most of the results fit to an empirical flow law of the form & = A {sigma}{sup n} exp (-E + PV)/RT, where the four material constants A, n, E, and I/* are (for & in inverse seconds and P and {sigma} in megapascals) 10{sup 23,0}, 6.0, 136 kJ/mol, and 29 cm{sup 3}/mol, respectively, for ice V; and 10{sup 6,7}, 4.5, 66 kJ/mol, and 11 cm{sup 3}mol, respectively, for ice VI. Ice VI may weaken to a mechanism of higher E at T > 250 K. Ices V and VI are thus rheologically distinct but by coincidence have approximately the same strength under the conditions chosen for these experiments. To avoid misidentification, these tests are therfore accompanied by careful observations of the occurrences and characteristics of phase changes. One sample each of ice V and VI was quenched at pressure to metastably retain the high-pressure phase and the acquired deformation microstructures; X ray diffraction analysis of these samples confirmed the phase identification. Surface replicas of the deformed and quenched samples suggest that ice V probably deforms largely by dislocation creep, while ice VI deforms by a more complicated process involving substantial grain size reduction through recrystallization. 25 refs., 10 figs., 3 tabs.

Durham, W.B. [Lawrence Livermore National Lab., CA (United States); Stern, L.A.; Kirby, S.H. [Geological Survey, Menlo Park, CA (United States)

1996-02-10

395

Dielectric Relaxation and Rheological Behavior of Supramolecular Polymeric Liquid  

Energy Technology Data Exchange (ETDEWEB)

A model self-complementary supramolecular polymer based on thymine and diamidopyridine triple hydrogen-bonding motifs has been synthesized, and its dielectric and rheological behavior has been investigated. The formation of supramolecular polymers has been unequivocally demonstrated by nuclear magnetic resonance, electrospray ionization mass spectrometry with traveling wave ion mobility separation, dielectric spectroscopy, and rheology. The dynamical behaviors of this associating polymer generally conform to those of type-A polymers, with a low-frequency chain relaxation and a high-frequency relaxation visible in both rheological and dielectric measurements. The dielectric chain relaxation shows the ideal symmetric Debye-like shape, resembling the peculiar features of hydrogen-bonding monoalcohols. Detailed analysis shows that there exists a weak decoupling between the mechanical terminal relaxation and dielectric Debye-like relaxation. The origin of the Debye-like dielectric relaxation is further discussed in the light of monoalcohols.

Lou, Nan [Shanghai Jiao Tong University, China; Wang, Yangyang [ORNL; Li, Xiaopeng [University of Akron, Akron, Ohio; Li, Haixia [Shanghai Jiao Tong University, Shanghai China; Wang, Ping [Dow Chemicals Company Limited, Shanghai China

2013-01-01

396

Kinetic characterization of non-linear soft-glassy rheology  

CERN Document Server

Based on numerical simulations of a lattice kinetic model for soft-glassy materials, we characterize the global rheology of a dense emulsion-like system, under three representative load conditions: Couette flow, time-oscillating Couette flow and Kolmogorov flow. In all cases, it is found that the rheology is described by a Herschel-Bulkley (HB) relation, $\\sigma = {\\sigma}_{Y} + A S^{\\beta}$, with the yield stress ${\\sigma}_{Y}$ largely independent of the loading scenario. Under a proper rescaling of the HB parameters, we can also describe the local rheological behavior, which turns out to be different from the global one because of the spatial heterogeneities. Our analysis illuminates the crucial role of numerical simulations in allowing a seamless exploration of different loading scenarios and enabling measurements of local energy transfer within the flowing material.

Benzi, R; Sbragaglia, M; Succi, S

2013-01-01

397

Rheological Characterization of Unusual DWPF Slurry Samples (U)  

Energy Technology Data Exchange (ETDEWEB)

A study was undertaken to identify and clarify examples of unusual rheological behavior in Defense Waste Processing Facility (DWPF) simulant slurry samples. Identification was accomplished by reviewing sludge, Sludge Receipt and Adjustment Tank (SRAT) product, and Slurry Mix Evaporator (SME) product simulant rheological results from the prior year. Clarification of unusual rheological behavior was achieved by developing and implementing new measurement techniques. Development of these new methods is covered in a separate report, WSRC-TR-2004-00334. This report includes a review of recent literature on unusual rheological behavior, followed by a summary of the rheological measurement results obtained on a set of unusual simulant samples. Shifts in rheological behavior of slurries as the wt. % total solids changed have been observed in numerous systems. The main finding of the experimental work was that the various unusual DWPF simulant slurry samples exhibit some degree of time dependent behavior. When a given shear rate is applied to a sample, the apparent viscosity of the slurry changes with time rather than remaining constant. These unusual simulant samples are more rheologically complex than Newtonian liquids or more simple slurries, neither of which shows significant time dependence. The study concludes that the unusual rheological behavior that has been observed is being caused by time dependent rheological properties in the slurries being measured. Most of the changes are due to the effect of time under shear, but SB3 SME products were also changing properties while stored in sample bottles. The most likely source of this shear-related time dependence for sludge is in the simulant preparation. More than a single source of time dependence was inferred for the simulant SME product slurries based on the range of phenomena observed. Rheological property changes were observed on the time-scale of a single measurement (minutes) as well as on a time scale of hours to weeks. The unusual shape of the slurry flow curves was not an artifact of the rheometric measurement. Adjusting the user-specified parameters in the rheometer measurement jobs can alter the shape of the flow curve of these time dependent samples, but this was not causing the unusual behavior. Variations in the measurement parameters caused the time dependence of a given slurry to manifest at different rates. The premise of the controlled shear rate flow curve measurement is that the dynamic response of the sample to a change in shear rate is nearly instantaneous. When this is the case, the data can be fitted to a time independent rheological equation, such as the Bingham plastic model. In those cases where this does not happen, interpretation of the data is difficult. Fitting time dependent data to time independent rheological equations, such as the Bingham plastic model, is also not appropriate.

Koopman, D. C.

2005-09-01

398

Rheological controls on the development of the convergent margins  

Science.gov (United States)

We use thermo-mechanical numerical models to explore the impact of rheological structure, brittle-elastic-ductile rheology and metamorphic reactions on localization and style of deformation in convergent contexts, during ocean-continent or continent-continent interactions. Even though continental subduction may occur in most cases of strong lithospheres with competent mantle at sufficiently high initial convergence rates (>1-1.5 cm/y), the subduction/collision styles and topography evolution are quite different depending on the initial configuration and preceding tectonic history but also on the particular structure of the continental crust, eventually affected by tectonic heritage, and localising properties of the subduction channel. Depending on lower and intermediate crustal rheology, the entire (upper, intermediate, lower) crust, intermediate or only the lower crust can deform independently of the mantle lithosphere. This results in different characteristic tectonic styles (leading, for example, to development of thin-sheet to thick-sheet tectonics structures), wavelengths, altitudes of surface topography and slab geometries. Certain rheological structures of the continental crust, while looking plausible from the geological and experimental rock mechanics point of view, are not compatible with the development of continental subduction, resulting in either blockage of the subduction channel and transition to folding and collision, or in gravitationally instable behaviours. Phase changes leading to material softening significantly improve chances for stable subduction, which is marked by exhumation of UHP-HP rocks to the surface that is particularly favoured if the crustal rheological profile has internal ductile decolement levels between the upper and lower or intermediate crust and the lower crust and mantle lithosphere. Pure shear or unstable RT-type collision is dominant when the mantle is rheologically weak or at convergence rates lower than 1-1.5 cm/yr. In continent-continent convergence settings, formation of high plateaux instead of rather narrow mountain ranges is conditioned by the degree of locking of the subduction channel, slow-down of the convergence causing slab retreat and by the rheological structure of both the upper and lower plates. Similarly, obduction and the associated exhumation processes appear to be largely dependent on the rheological properties of both the continental and oceanic crust, so that obduction is only possible for very specific combinations of rheological properties, requiring, in particular, relatively weak lower crust of the continental counterpart and presence of a weak serpentinized layer between the oceanic crust and mantle. These conditions drastically narrow the range of the rheological parameters compatible with tectonically realistic scenario of evolution of convergent zones allowing us to put a number of quantified constraints on the ductile rheology laws for crustal and mantle materials, and hence providing new possibilities for extrapolation of laboratory based rheology laws to geodynamic spatial and temporal scales.

Burov, Evgueni; Francois, Thomas; Duretz, Thibault; Agard, Philippe; Meyer, Bertrand; Yamato, Philippe

2013-04-01

399

Rheological behaviors of doughs reconstituted from wheat gluten and starch.  

Science.gov (United States)

Hydrated starch-gluten reconstituted doughs were prepared and dynamic rheological tests of the reconstituted doughs were performed using dynamic strain and dynamic frequency sweep modes. Influence of starch/gluten ratio on rheological behaviors of the reconstituted doughs was investigated. The results showed that the reconstituted doughs exhibited nonlinear rheological behavior with increasing strain. The mechanical spectra revealed predominantly elastic characteristics in frequency range from 10(-1) rad s(-1) to 10(2) rad s(-1). Cole-Cole functions were applied to fit the mechanical spectra to reveal the influence of starch/gluten ratio on Plateau modulus and longest relaxation time of the dough network. The time-temperature superposition principle was applicable to a narrow temperature range of 25°C ~40°C while it failed at 50°C due to swelling and gelatinization of the starch. PMID:23572776

Yang, Yanyan; Song, Yihu; Zheng, Qiang

2011-02-11

400

Rheological behaviors of doughs reconstituted from wheat gluten and starch.  

UK PubMed Central (United Kingdom)

Hydrated starch-gluten reconstituted doughs were prepared and dynamic rheological tests of the reconstituted doughs were performed using dynamic strain and dynamic frequency sweep modes. Influence of starch/gluten ratio on rheological behaviors of the reconstituted doughs was investigated. The results showed that the reconstituted doughs exhibited nonlinear rheological behavior with increasing strain. The mechanical spectra revealed predominantly elastic characteristics in frequency range from 10(-1) rad s(-1) to 10(2) rad s(-1). Cole-Cole functions were applied to fit the mechanical spectra to reveal the influence of starch/gluten ratio on Plateau modulus and longest relaxation time of the dough network. The time-temperature superposition principle was applicable to a narrow temperature range of 25°C ~40°C while it failed at 50°C due to swelling and gelatinization of the starch.

Yang Y; Song Y; Zheng Q

2011-08-01

 
 
 
 
401

Rheological and microbiological study of flour treated by irradiation  

International Nuclear Information System (INIS)

the aim this work is to study the effectiveness of radio treatment and its effect on the conservation of flour and their various parameters (physico-chemical and rheological). The flour has been treated with different doses (0, 0.75, 1.5 and 3 kGy), physico-chemical, rheological, microbiological and sensory analyses were made.The results show that the irradiation as a treatment for decontamination gave a highly effective. Indeed, a dose of 1.5 kGy allows a total destruction of yeasts and molds. Thus, from the point of view physico-chemical, increasing the dose of radiation causes a change in physical and chemical properties and rheological of flour. for the characteristics of bread, increasing the dose of radiation affects the quality of bread. (Author). 38 refs.

2007-01-01

402

Field-responsive smart composite particle suspension: materials and rheology  

Science.gov (United States)

Both electrorheological (ER) and magnetorheological (MR) fluids are known to be smart materials which can be rapidly and reversibly transformed from a fluid-like to a solid-like state within milliseconds by showing dramatic and tunable changes in their rheological properties under external electrical or magnetic field strength, respectively. Here, among various smart composite particles studied, recently developed core-shell structured polystyrene/graphene oxide composite based ER material as well as the dual-step functionally coated carbonyl iron composite based MR material are briefly reviewed along with their rheological characteristics under external fields.

Zhang, Wen Ling; Liu, Ying Dan; Choi, Hyoung Jin

2012-09-01

403

The Concentration Effect on the Rheological Behavior of Bauxite Slurry  

Science.gov (United States)

The rheological behavior of mineral settling slurries is a complex and an important matter for minerals industries. Several processes, as milling, dewatering and pumping, are affected by rheological properties. In this work, a bauxite slurry was analyzed using a rotational rheometer, with cylindrical and vane geometries. It was observed that the slurry behavior changed from thixotropic to rheopetical, as the concentration increased. At lower shear rates, the flow resistance decreased abruptly as we could observe in the flow curves. The mineral characterization was performed using X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF) and particle size distribution (PSD) analysis. The advantages and limitations in using both geometries are discussed.

Nascimento, Christine R.; Calado, Verônica

2008-07-01

404

Nonlinear rheology of Laponite suspensions under an external drive  

CERN Multimedia

We investigate the nonlinear rheological behavior of colloidal suspensions of Laponite, a synthetic clay, driven by a steady and homogeneous shear strain. We show that the external drive leads to a drastic slowing down of the aging dynamics or even, in some cases, in the rejuvenation of the system. Under shear, after a surprisingly long time, the spontaneous aging process observed at rest is suppressed. The system then reaches a non-equilibrium stationary state, characterised by a complex viscosity depending on the applied shear rate. In addition, the glass exhibits a non-Newtonian shear-thinning behavior. These rheological behaviors confirm recent numerical and theoretical predictions.

Abou, B; Meunier, J; Bonn, Daniel; Meunier, Jacques

2003-01-01

405

Flow instabilities in complex fluids: Nonlinear rheology and slow relaxations  

CERN Multimedia

We here present two simplified models aimed at describing the long-term, irregular behaviours observed in the rheological response of certain complex fluids, such as periodic oscillations or chaotic-like variations. Both models exploit the idea of having a (non-linear) rheological equation, controlling the temporal evolution of the stress, where one of the participating variables (a "structural" variable) is subject to a distinct dynamics with a different relaxation time. The coupling between the two dynamics is a source of instability.

Aradian, A

2003-01-01

406

Rheology of Wormlike Micelles Equilibrium Properties and Shear Banding Transition  

CERN Document Server

We review the experimental and theoretical results obtained during the past decade on the structure and rheology of wormlike micellar solutions. We focus on the linear and nonlinear viscoelasticity and emphasize the analogies with polymers. Based on a comprehensive survey of surfactant systems, the present study shows the existence of standard rheological behaviors for semidilute and concentrated solutions. One feature of this behavior is a shear banding transition associated with a stress plateau in the nonlinear mechanical response. For concentrated solutions, we show that in the plateau region the shear bands are isotropic and nematic.

Berret, J F

2004-01-01

407

REAL WASTE TESTING OF SLUDGE BATCH 5 MELTER FEED RHEOLOGY  

Energy Technology Data Exchange (ETDEWEB)

Clogging of the melter feed loop at the Defense Waste Processing Facility (DWPF) has reduced the throughput of Sludge Batch 5 (SB5) processing. After completing a data review, DWPF attributed the clogging to the rheological properties of the Slurry Mix Evaporator (SME) project. The yield stress of the SB5 melter feed material was expected to be high, based on the relatively high pH of the SME product and the rheological results of a previous Chemical Process Cell (CPC) demonstration performed at the Savannah River National Laboratory (SRNL).

Reboul, S.; Stone, M.

2010-03-17

408

Rheology of Savannah River site tank 42 HLW radioactive sludge  

Energy Technology Data Exchange (ETDEWEB)

Knowledge of the rheology of the radioactive sludge slurries at the Savannah River Site is necessary in order to ensure that they can be retrieved from waste tanks and processed for final disposal. At Savannah River Site, Tank 42 sludge represents on of the first HLW radioactive sludges to be vitrified in the Defense Waste Processing Facility. The rheological properties of unwashed Tank 42 sludge slurries at various solids concentrations were measured remotely in the Shielded Cells at the Savannah River Technology Center using a modified Haake Rotovisco viscometer.

Ha, B.C.

1997-11-05

409

Herschel-Bulkley shearing rheology near the athermal jamming transition.  

Science.gov (United States)

We consider the rheology of soft-core frictionless disks in two dimensions in the neighborhood of the athermal jamming transition. From numerical simulations of bidisperse, overdamped particles, we argue that the divergence of the viscosity below jamming is characteristic of the hard-core limit, independent of the particular soft-core interaction. We develop a mapping from soft-core to hard-core particles that recovers all the critical behavior found in earlier scaling analyses. Using this mapping we derive a relation that gives the exponent of the nonlinear Herschel-Bulkley rheology above jamming in terms of the exponent of the diverging viscosity below jamming. PMID:23005330

Olsson, Peter; Teitel, S

2012-09-06

410

Herschel-Bulkley shearing rheology near the athermal jamming transition.  

UK PubMed Central (United Kingdom)

We consider the rheology of soft-core frictionless disks in two dimensions in the neighborhood of the athermal jamming transition. From numerical simulations of bidisperse, overdamped particles, we argue that the divergence of the viscosity below jamming is characteristic of the hard-core limit, independent of the particular soft-core interaction. We develop a mapping from soft-core to hard-core particles that recovers all the critical behavior found in earlier scaling analyses. Using this mapping we derive a relation that gives the exponent of the nonlinear Herschel-Bulkley rheology above jamming in terms of the exponent of the diverging viscosity below jamming.

Olsson P; Teitel S

2012-09-01

411

UNUSUAL RHEOLOGICAL BEHAVOIUR OF A NATURAL SOLID DISPERSION  

Directory of Open Access Journals (Sweden)

Full Text Available Recent studies of some solid natural dispersion like quick sand evidenced theirunusual rheological behavior. Quick sand might be regarded as a bridge between dry granularmaterials and wet tixotropic gels. In this work, we have studied the behavior of a natural quicksand. We determined the rheological behaviour following the evolution of viscosity as functionof time and composition at different weight concentrations. The mechanical behaviour resultsfrom the competition between aging and progressive rejuvenation by the shear flow. Theincipient flow destroyed the structure of the materials, entailing a viscosity decrease, which inturn accelerates the flow: avalanche behaviour results.

Mihaela Olteanu; Diana Achimescu

2005-01-01

412

Rheological study of mutarotation of fructose in anhydrous state.  

UK PubMed Central (United Kingdom)

Rheological measurement was employed to study the mutarotation of D-fructose in anhydrous state. By monitoring the evolution of shear viscosity with time, rate constants for mutarotation were estimated, and two different stages of this reaction were identified. One of the mutarotation stages is rapid and has a low activation energy, whereas the other is much slower and has a much higher activation energy. Possible conversions corresponding to these two phases are discussed. This work demonstrates that, in addition to the routine techniques such polarimetry and gas-liquid chromatography, rheological measurement can be used as an alternative method to continuously monitor the mutarotation of sugars.

Wang Y; Wlodarczyk P; Sokolov AP; Paluch M

2013-02-01

413

Rheological study of mutarotation of fructose in anhydrous state.  

Science.gov (United States)

Rheological measurement was employed to study the mutarotation of D-fructose in anhydrous state. By monitoring the evolution of shear viscosity with time, rate constants for mutarotation were estimated, and two different stages of this reaction were identified. One of the mutarotation stages is rapid and has a low activation energy, whereas the other is much slower and has a much higher activation energy. Possible conversions corresponding to these two phases are discussed. This work demonstrates that, in addition to the routine techniques such polarimetry and gas-liquid chromatography, rheological measurement can be used as an alternative method to continuously monitor the mutarotation of sugars. PMID:23316792

Wang, Yangyang; Wlodarczyk, Patryk; Sokolov, Alexei P; Paluch, Marian

2013-01-24

414

Analysis of Rheological Models of Selected Cement Slurries  

Directory of Open Access Journals (Sweden)

Full Text Available Cement slurries become more and more widely applicable in reinforcing and strengthening the rock mass. The processes taking place in fresh cement slurries were presented and their complex character analysed. The equations describing rheological models, e.g. cement slurries, were given. The selected cement slurries were analysed in laboratory conditions for various water-cement parameters and three temperatures. The obtained results were statistically analysed and the best fit of the rheological model to the individual cement slurries was shown.

Gonet Andrzej; Stryczek Stanislaw; Pinka Ján

2004-01-01

415

The Rheology of the Earth in the Intermediate Time Range  

Directory of Open Access Journals (Sweden)

Full Text Available The evidence bearing upon the rheology of the " tectonicallysignificant layers" of the Earth (" tectonosphere ") in the intermediatetime range (4 hours to 15000 years) is analyzed. This evidence isbased upon observations of rock-behavior in the laboratory, of seismicaftershock sequences, of Earth tides and of the decay of the Chandler wobble.It is shown that of the rheological models (Maxwell-material, Kelvin-material,and logarithmically creeping material) advocated in the literature, only thatbased on logarithmic creep does not contradict any of the observationalevidence available to date. In addition, a strength limit may be present.

A. E. SCHEIDEGGER

1970-01-01

416

Documentation rheology 1985/1986. Dokumentation Rheologie 1985/1986  

Energy Technology Data Exchange (ETDEWEB)

The documentation rheology is an organized reference guide to the world's published literature on deformation and flow of both materials and living systems. The volume contains current rheological work with 5,000 references a year, and therefore, all materials available as sources (primary as well as secondary) are scanned and exhausted for references. The following publications are covered: Papers; books; collections; reports and monographs; dissertations; preprints; bibliographies; standards and test methods; industrial literature (not merely commercial); occasionally even abstracts of papers thus far only presented in lectures.

1986-01-01

417

Rheological Models of Blood: Sensitivity Analysis and Benchmark Simulations  

Science.gov (United States)

Modeling of blood flow with respect to rheological parameters of the blood is the objective of this paper. Casson type equation was selected as a blood model and the blood flow was analyzed based on Backward Facing Step benchmark. The simulations were performed using ADINA-CFD finite element code. Three output parameters were selected, which characterize the accuracy of flow simulation. Sensitivity analysis of the results with Morris Design method was performed to identify rheological parameters and the model output, which control the blood flow to significant extent. The paper is the part of the work on identification of parameters controlling process of clotting.

Szeliga, Danuta; Macio?, Piotr; Banas, Krzysztof; Kopernik, Magdalena; Pietrzyk, Maciej

2010-06-01

418

Electrolyte battery anti-splash system  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a method of providing a battery having a casing including a cell chamber for receiving electrolyte battery elements including positive and negative battery plates disposed for immersion in the electrolyte in the cell chamber, a cover for the casing spaced from the battery elements in the cell chamber, and a gas venting device for that cell chamber extending through the cover. The improvement described here is to prevent electrolyte from splashing through the gas venting device during vibration of the battery, comprising in combination the steps of: providing separately from the gas venting device a baffle plate capable of floating on the electrolyte in the cell chamber; disposing the baffle plate between the battery plates and the gas venting device for flotation on the electrolyte below the gas venting device, and diverting with the floating baffle plate any splashing electrolyte away from the gas venting device.

Manthis, D.O.

1986-09-30

419