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1

Promoted oxidation of phenol in aqueous solution using molecular oxygen at mild conditions  

SciTech Connect

Wet oxidation with molecular oxygen at mild conditions (temperature < 200 C, pressure {le} 2 MPa) is an economically attractive pretreatment step for non-biodegradable aqueous waste streams. In order to overcome the low reactivity of molecular oxygen towards organic molecules at these mild process conditions, an initiator was used in combination with ferrous ions in the acidic range. The promoted oxidation of phenol in aqueous solution was investigated in a 4 liters stirred autoclave. It was possible to degrade the phenol at temperatures as low as 100 C without observing an induction time. The remaining solution contained mainly acetic and formic acid and was well biodegradable. The oxidative behavior of the oxygen/phenol system could be explained using the well-known autoxidation mechanism for aliphatic molecules. 4-hydroperoxy-phenol is suggested as a key intermediate. Measured products are p-benzoquinone, hydroquinone, catechol, maleic, oxalic, pyruvic, formic, and acetic acid. Dimers could also be identified in sample extracts. A global pathway including all identified products is presented.

Vogel, F.; Harf, J.; Hug, A.; Rohr, P.R. von [Swiss Federal Inst. of Tech., Zuerich (Switzerland). Inst. of Process Engineering] [Swiss Federal Inst. of Tech., Zuerich (Switzerland). Inst. of Process Engineering

1999-05-01

2

Chemical constraints governing the origin of metabolism: the thermodynamic landscape of carbon group transformations under mild aqueous conditions  

NASA Technical Reports Server (NTRS)

The thermodynamics of organic chemistry under mild aqueous conditions was examined in order to begin to understand its influence on the structure and operation of metabolism and its antecedents. Free energies (deltaG) were estimated for four types of reactions of biochemical importance carbon-carbon bond cleavage and synthesis, hydrogen transfer between carbon groups, dehydration of alcohol groups, and aldo-keto isomerization. The energies were calculated for mainly aliphatic groups composed of carbon, hydrogen, and oxygen. The energy values showed (1) that generally when carbon-carbon bond cleavage involves groups from different functional group classes (i.e., carboxylic acids, carbonyl groups, alcohols, and hydrocarbons), the transfer of the shared electron-pair to the more reduced carbon group is energetically favored over transfer to the more oxidized carbon group, and (2) that the energy of carbon-carbon bond transformation is primarily determined by the functional group class of the group that changes oxidation state in the reaction (i.e., the functional group class of the group that donates the shared electron-pair during cleavage, or that accepts the incipient shared electron-pair during synthesis). In contrast, the energy of hydrogen transfer between carbon groups is determined by the functional group class of both the hydrogen-donor group and the hydrogen-acceptor group. From these and other observations we concluded that the chemistry involved in the origin of metabolism (and to a lesser degree modern metabolism) was strongly constrained by (1) the limited redox-based transformation energy of organic substrates that is readily dissipated in a few energetically favorable irreversible reactions; (2) the energy dominance of a few transformation half-reactions that determines whether carbon-carbon bond transformation (cleavage or synthesis) is energetically favorable (deltaG < -3.5 kcal/mol), reversible (deltaG between +/-3.5 kcal/mol), or unfavorable (deltaG > +3.5 kcal/mol); and (3) the dependence of carbon group transformation energy on the functional group class (i.e., oxidation state) of participating groups that in turn is contingent on prior reactions and precursors in the synthetic pathway.

Weber, Arthur L.

2002-01-01

3

Aqueous hydrodechlorination of 4-chlorophenol over an Rh/reduced graphene oxide synthesized by a facile one-pot solvothermal process under mild conditions.  

PubMed

Reduced graphene oxide (RGO) supported rhodium nanoparticles (Rh-NPs/RGO) was synthesized through one-pot polyol co-reduction of graphene oxide (GO) and rhodium chloride. The catalytic property of Rh-NPs/RGO was investigated for the aqueous phase hydrodechlorination (HDC) of 4-chlorophenol (4-CP). A complete conversion of 4-CP into high valued products of cyclohexanone (selectivity: 23.2%) and cyclohexanol (selectivity: 76.8%) was successfully achieved at 303K and balloon hydrogen pressure in a short reaction time of 50 min when 1.5 g/L of 4-CP was introduced. By comparing with Rh-NPs deposited on the other supports, Rh-NPs/RGO delivered the highest initial rate (111.4 mmol/gRh min) for 4-CP HDC reaction under the identical conditions. The substantial catalytic activity of Rh-NPs/RGO can be ascribed to the small and uniform particle size of Rh (average particle size was 1.7 ± 0.14 nm) on the surface of the RGO sheets and an electron-deficient state of Rh in the catalyst as a result of the strong interaction between the active sites and the surface function groups of RGO. PMID:24762698

Ren, Yanlin; Fan, Guangyin; Wang, Chenyu

2014-06-15

4

Explosivity Conditions of Aqueous Solutions  

Microsoft Academic Search

This paper focuses on the conditions for explosive boiling and gas exsolution of aqueous solutions from a thermodynamic point\\u000a of view. Indeed, the kinetic nature of these processes, hence their explosivity, can be assessed by considering their relation\\u000a with the spinodal curve of these liquids. First, the concepts of mechanical and diffusion spinodals are briefly described,\\u000a which allows us to

R. Thiéry; L. Mercury

2009-01-01

5

Selective hydrogen production from methanol with a defined iron pincer catalyst under mild conditions.  

PubMed

Molecularly well-defined iron pincer complexes promote the aqueous-phase reforming of methanol to carbon dioxide and hydrogen, which is of interest in the context of a methanol and hydrogen economy. For the first time, the use of earth-abundant iron complexes under mild conditions for efficient hydrogen generation from alcohols is demonstrated. PMID:24339396

Alberico, Elisabetta; Sponholz, Peter; Cordes, Christoph; Nielsen, Martin; Drexler, Hans-Joachim; Baumann, Wolfgang; Junge, Henrik; Beller, Matthias

2013-12-23

6

Aldehyde decarbonylation catalysis under mild conditions  

SciTech Connect

Reaction of [RhCl(NBD)]{sub 2} with 2.0 equiv of triphos (triphos = bis(2-diphenylphosphinoethyl)phenylphosphine; NBD = bicyclo[2.2.1]hepta-2,5-diene) in THF solution at room temperature affords [Rh(NBD)(triphos)][Cl] (4a), which was isolated as [Rh(NBD)(triphos)][SbF{sub 6}] (4b) in 67% yield. Treatment of 4b with aqueous formaldehyde in THF solution at 80 C forms [Rh(CO)(triphos)][SbF{sub 6}] (2a), which reversibly binds a second equivalent of CO{sub (g)} to give [Rh(CO){sub 2}(triphos)][SbF{sub 6}] (2b). The complex [Rh(CO)(triphos)][SbF{sub 6}] has been found to be an effective aldehyde decarbonylation catalyst for primary and aryl aldehydes at temperatures as low as that of refluxing dioxane, with little or no undesirable side products resulting from {beta} elimination or radical rearrangement.

Beck, C.M.; Rathmill, S.E.; Park, Y.J.; Chen, J.; Crabtree, R.H.; Liable-Sands, L.M.; Rheingold, A.L.

1999-12-06

7

Solvolytic liquefaction of wood under mild conditions  

SciTech Connect

Conversion of wood to liquid products requires cleavage of bonds which crosslink the wood structure. This study examines a low-severity wood solubilization process utilizing a solvent medium consisting of a small amount of sulfuric acid and a potentially wood-derivable alcohol. In one half hour of reaction time at 250/sup 0/C under 15 psia starting nitrogen pressure, over 95% of the wood (maf) was rendered acetone-soluble. The product is a soft, black, bitumen-like solid at room temperature but readily softens at 140/sup 0/C. Between 25 and 50% of the original wood oxygen, depending on alcohol used, was removed as water. Approximately 2 to 17% of the alcohols were retained in the product. Gel permeation chromatography showed that the product's median molecular weight is around 300. Based on experimental and literature results, a mechanism for wood solubilization is proposed. This involves protonation of the etheric oxygen atoms, leading to subsequent bond scission to form carbonium ions which are stabilized by solvent alkoxylation. At severe conditions, polymerization and condensation reactions result in acetone-insoluble materials.

Yu, S.M.

1982-04-01

8

TEM Examination of MWCNTs Oxidized by Mild Experimental Conditions  

Microsoft Academic Search

A detailed transmission electron microscopy (TEM) examination of the surface of multi-walled carbon nanotubes (MWCNTs) oxidized using mild experimental conditions shows evidence of nanotube length shortening after acid treatments and important modifications at the nanostructural level, such as damage to the graphitic structure and stripping of the inner layers. It is shown that damage caused to the MWCNTs strongly depends

F. Avilés; A. Ponce; J. V. Cauich-Rodríguez; G. T. Martínez

2012-01-01

9

Chronoamperometric study of mild steel pitting in sodium sulfide aqueous solution  

SciTech Connect

Mild steel samples were studied by chronoamperometry in sodium sulfide (Na[sub 2]S) aqueous solution. Pit nucleation and growth also were monitored by optical microscopy. The influence of variables such as temperature, polarization potential, surface roughness, the presence of electrochemically generated oxide layers, and the simultaneous presence of potassium hydroxide (KOH) was studied. The influence of each parameter on pit shape and growth was reviewed. Different reactions and competitive processes were proposed based on the experimental results.

Otero, T.F.; Achucarro, C. (Lab. de Electroquimica, San Sebastian (Spain). Dept. de Ciencia y Tecnologia de Polimeros)

1994-08-01

10

Pd-Catalyzed Synthesis of Ar-SCF3 Compounds under Mild Conditions  

E-print Network

Good to excellent yields of aryl trifluoromethyl sulfides, which are an important class of compounds in both the pharmaceutical and agrochemical areas, can be achieved under mild conditions by the Pd-catalyzed reaction of ...

Teverovskiy, Georgiy

11

Integration of advanced oxidation processes at mild conditions in wet scrubbers for odourous sulphur compounds treatment.  

PubMed

The effectiveness of different advanced oxidation processes on the treatment of a multicomponent aqueous solution containing ethyl mercaptan, dimethyl sulphide and dimethyl disulphide (0.5 mg L(-1) of each sulphur compound) was investigated with the objective to assess which one is the most suitable treatment to be coupled in wet scrubbers used in odour treatment facilities. UV/H2O2, Fenton, photo-Fenton and ozone treatments were tested at mild conditions and the oxidation efficiency obtained was compared. The oxidation tests were carried out in magnetically stirred cylindrical quartz reactors using the same molar concentration of oxidants (hydrogen peroxide or ozone). The results show that ozone and photo-Fenton are the most efficient treatments, achieving up to 95% of sulphur compounds oxidation and a mineralisation degree around 70% in 10 min. Furthermore, the total costs of the treatments taking into account the capital and operational costs were also estimated for a comparative purpose. The economic analysis revealed that the Fenton treatment is the most economical option to be integrated in a wet scrubber to remove volatile organic sulphur compounds, as long as there are no space constraints to install the required reactor volume. In the case of reactor volume limitation or retrofitting complexities, the ozone and photo-Fenton treatments should be considered as viable alternatives. PMID:24873715

Vega, Esther; Martin, Maria J; Gonzalez-Olmos, Rafael

2014-08-01

12

Preparation and Characterization of Colloidal Silica Particles under Mild Conditions  

ERIC Educational Resources Information Center

A microscale laboratory experiment for the preparation and characterization of silica particles at neutral pH and ambient temperature conditions is described. Students first employ experimental fabrication methods to make spherical submicrometer silica particles via the condensation of an alkoxysilane and polyethyleneimine, which act to catalyze…

Neville, Frances; Zin, Azrinawati Mohd.; Jameson, Graeme J.; Wanless, Erica J.

2012-01-01

13

The Formation of Fe/Mg Smectite Under Mildly Acidic Conditions on Early Mars  

NASA Technical Reports Server (NTRS)

The detection of Fe/Mg smectites and carbonate in Noachian and early Hesperian terrain of Mars suggests that neutral to mildly alkaline conditions prevailed during the early history of Mars. If early Mars surface geochemical conditions were neutral to moderately alkaline with a denser CO2 atmosphere than today, then large carbonates deposits should be more widely detected in Noachian terrain. Why have so few carbonate deposits been detected compared to Fe/Mg smectites? Fe/Mg smectites on early Mars formed under mildly acidic conditions, which would preclude the extensive formation of carbonate deposits. The goal of the proposed work is to evaluate the formation of Fe/Mg smectites under mildly acidic conditions.

Sutter, B.; Golden, D. C.; Ming, Douglas W.; Niles, P. B.

2011-01-01

14

Mild palladium-catalyzed cyanation of (hetero)aryl halides and triflates in aqueous media.  

PubMed

A mild, efficient, and low-temperature palladium-catalyzed cyanation of (hetero)aryl halides and triflates is reported. Previous palladium-catalyzed cyanations of (hetero)aryl halides have required higher temperatures to achieve good catalytic activity. This current reaction allows the cyanation of a general scope of (hetero)aryl halides and triflates at 2-5 mol % catalyst loadings with temperatures ranging from rt to 40 °C. This mild method was applied to the synthesis of lersivirine, a reverse transcriptase inhibitor. PMID:25555140

Cohen, Daniel T; Buchwald, Stephen L

2015-01-16

15

EIS characterization of the inhibition of mild steel corrosion with carboxylates in neutral aqueous solution  

Microsoft Academic Search

Electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP) measurements were used to study the ability of monocarboxylates to support the passivation of mild steel by dissolved oxygen in near neutral solution. It was shown that the effectiveness of monocarboxylates depends on their ability to form weakly soluble Fe(III) compounds and to adsorb on the oxide covered surface. The inhibition

Ursula Rammelt; Silvio Köhler; Georg Reinhard

2008-01-01

16

Explosivity Conditions of Aqueous Solutions and L. Mercury2  

E-print Network

1 Explosivity Conditions of Aqueous Solutions R. Thiéry1 and L. Mercury2 Revised version February. Address: 1A, rue de la Férollerie, F-45071, Orléans Cedex, France. e-mail: lionel.mercury,version1-8Sep2009 #12;3 1 Introduction Water is the main natural explosive agent on the Earth. This fact

Paris-Sud XI, Université de

17

Facile synthesis of nano-sized hollow single crystal zeolites under mild conditions.  

PubMed

We report a method to synthesize hollow ZSM-5 single crystals of a size below 100 nm that could function as nanoreactors with access through the zeolite micropores only. In the first step, ZSM-5 is synthesized with the respective crystal size. In the second, the zeolite is base leached and acid washed under mild conditions. PMID:24213357

Fodor, Daniel; Pacosová, Lucie; Krumeich, Frank; van Bokhoven, Jeroen A

2014-01-01

18

Copper-promoted oxidative-fluorination of arylphosphine under mild conditions.  

PubMed

An efficient method for the synthesis of phosphoric fluoride via oxidative coupling between hydrophosphine oxide and NaF is reported. DDQ serves as the oxidizing reagent as well as the hydrogen acceptor. The process involves a Cu(II) catalysis and exhibits great functional group tolerance under mild reaction conditions. PMID:25090483

Liu, Na; Mao, Liu-Liang; Yang, Bin; Yang, Shang-Dong

2014-09-25

19

The Formation of Fe/Mg Smectite Under Mildly Acidic Conditions on Early Mars  

NASA Astrophysics Data System (ADS)

The detection of Fe/Mg smectites and carbonate in Noachian and early Hesperian terrain of Mars has been used to suggest that neutral to mildly alkaline conditions prevailed during the early history of Mars. However, if early Mars was neutral to moderately alkaline with a denser CO2 atmosphere than today, then "large" carbonates deposits should be more widely detected in Noachian terrain. The critical question is: Why have so few carbonate deposits been detected compared to Fe/Mg smectites? We suggest that Fe/Mg smectites on early Mars formed under mildly acidic conditions, which would inhibit the extensive formation of carbonate deposits. The goal of this work is to evaluate the formation of Fe/Mg smectites under mildly acidic conditions. The stability of smectites under mildly acidic conditions is attributed to elevated Fe/Mg activities that inhibit smectite dissolution. Beidelite and saponite have been shown to form from hydrothermal alteration of basaltic glass at pH 3.5-4.0 in seawater solutions. Nontronite is also known to be stable in mildly acidic systems associated with mafic and ultramafic rock. Nontronite was shown to form in acid sulfate soils in the Bangkok Plain, Thailand due to oxidation of Fe-sulfides that transformed saponite to nontronite. Smectite is known to transform to kaolinite in naturally acid soils due to selective leaching of Mg. However, if Mg removal is limited, then based on equilibrium relationships, the dissolution of smectite should be minimized. If Fe and Mg solution activities are sufficiently high, such as might be found in a low water/rock ratio system that is poorly drained, smectite could form and remain stable under mildly acidic conditions on Mars. The sources of mild acidity on early Mars includes elevated atmospheric CO2 levels, Fe-hydrolysis reactions, and the presence of volcanic SO2 aerosols. Equilibrium calculations dictate that water equilibrated with an early Mars CO2 atmosphere at 1 to 4 bar yields a pH of 3.6 to 3.9. Fe hydrolysis reactions on Mars is another source of protons that would have contributed to acidity. The presence of SO2 from volcanic processes could also have contributed to geochemical acidification. These sources of acidity competed with base-forming cations that resulted in mildly acidic solutions that were not favorable for carbonate formation but may have allowed for Fe/Mg smectite formation. Noachian to early Hesperian Mars could have been mildly acidic, allowing Fe/Mg smectite formation but preventing widespread carbonate deposition. This paradigm shift from an early Mars that was neutral-alkaline to mildly acidic may possibly explain why there is a disparity between the occurrence of carbonate and Fe/Mg smectites. Potential microbiological activity would not be eliminated under a mildly acidic Mars; however, there could be tighter constraints as to the type and species of microbiology that could exist.

Sutter, B.; Golden, D. C.; Ming, D.; Niles, P. B.

2011-12-01

20

The Formation of Fe/Mg Smectite Under Mildly Acidic Conditions on Early Mars  

NASA Technical Reports Server (NTRS)

The detection of Fe/Mg smectites and carbonate in Noachian and early Hesperian terrain of Mars has been used to suggest that neutral to mildly alkaline conditions prevailed during the early history of Mars. However, if early Mars was neutral to moderately alkaline with a denser CO2 atmosphere than today, then large carbonates deposits should be more widely detected in Noachian terrain. The critical question is: Why have so few carbonate deposits been detected compared to Fe/Mg smectites? We suggest that Fe/Mg smectites on early Mars formed under mildly acidic conditions, which would inhibit the extensive formation of carbonate deposits. The goal of this work is to evaluate the formation of Fe/Mg smectites under mildly acidic conditions. The stability of smectites under mildly acidic conditions is attributed to elevated Fe/Mg activities that inhibit smectite dissolution. Beidelite and saponite have been shown to form from hydrothermal alteration of basaltic glass at pH 3.5-4.0 in seawater solutions. Nontronite is also known to be stable in mildly acidic systems associated with mafic and ultramafic rock. Nontronite was shown to form in acid sulfate soils in the Bangkok Plain, Thailand due to oxidation of Fe-sulfides that transformed saponite to nontronite. Smectite is known to transform to kaolinite in naturally acid soils due to selective leaching of Mg. However, if Mg removal is limited, then based on equilibrium relationships, the dissolution of smectite should be minimized. If Fe and Mg solution activities are sufficiently high, such as might be found in a low water/rock ratio system that is poorly drained, smectite could form and remain stable under mildly acidic conditions on Mars. The sources of mild acidity on early Mars includes elevated atmospheric CO2 levels, Fe-hydrolysis reactions, and the presence of volcanic SO2 aerosols. Equilibrium calculations dictate that water equilibrated with an early Mars CO2 atmosphere at 1 to 4 bar yields a pH of 3.6 to 3.9. Fe hydrolysis reactions on Mars is another source of protons that would have contributed to acidity. The presence of SO2 from volcanic processes could also have contributed to geochemical acidification. These sources of acidity competed with base-forming cations that resulted in mildly acidic solutions that were not favorable for carbonate formation but may have allowed for Fe/Mg smectite formation. Noachian to early Hesperian Mars could have been mildly acidic, allowing Fe/Mg smectite formation but preventing widespread carbonate deposition. This paradigm shift from an early Mars that was neutral-alkaline to mildly acidic may possibly explain why there is a disparity between the occurrence of carbonate and Fe/Mg smectites. Potential microbiological activity would not be eliminated under a mildly acidic Mars; however, there could be tighter constraints as to the type and species of microbiology that could exist.

Sutter, Brad; Golden, D. C.; Ming, Douglas W.; Niles, P. B.

2011-01-01

21

Ionic-liquid-catalyzed efficient transformation of ?-valerolactone to methyl 3-pentenoate under mild conditions.  

PubMed

Green nylons! Acidic ionic-liquid catalysis for the transformation of ?-valerolactone into methyl 3-pentenoate (M3P) is shown to be performed efficiently under mild conditions. M3P is obtained selectively from a reaction at 170 °C for 3.5 h in the presence of an acidic ionic liquid that has a low vapor pressure, high thermal stability, and excellent catalytic performance. A possible reaction pathway for this conversion is also presented. PMID:23468313

Zeng, Fan-Xin; Liu, Hai-Feng; Deng, Li; Liao, Bing; Pang, Hao; Guo, Qing-Xiang

2013-04-01

22

Fabrication of porous scaffolds by three-dimensional plotting of a pasty calcium phosphate bone cement under mild conditions.  

PubMed

The major advantage of hydroxyapatite (HA)-forming calcium phosphate cements (CPCs) used as bone replacement materials is their setting under physiological conditions without the necessity for thermal treatment that allows the incorporation of biological factors. In the present study, we have combined the biocompatible consolidation of CPCs with the potential of rapid prototyping (RP) techniques to generate calcium phosphate-based scaffolds with defined inner and outer morphology. We demonstrate the application of the RP technique three-dimensional (3D) plotting for the fabrication of HA cement scaffolds. This was realized by utilizing a paste-like CPC (P-CPC) which is stable as a malleable paste and whose setting reaction is initiated only after contact with aqueous solutions. The P-CPC showed good processability in the 3D plotting process and allowed the fabrication of stable?3D structures of different geometries with adequate mechanical stability and compressive strength. The cytocompatibility of the plotted P-CPC scaffolds was demonstrated in a cell culture experiment with human mesenchymal stem cells. The mild conditions during 3D plotting and post-processing and the realization of the whole procedure under sterile conditions make this approach highly attractive for fabrication of individualized implants with respect to patient-specific requirements by simultaneous plotting of biological components. PMID:22933381

Lode, Anja; Meissner, Katrin; Luo, Yongxiang; Sonntag, Frank; Glorius, Stefan; Nies, Berthold; Vater, Corina; Despang, Florian; Hanke, Thomas; Gelinsky, Michael

2014-09-01

23

Mild, single-pot hydrocarboxylation of gaseous alkanes to carboxylic acids in metal-free and copper-promoted aqueous systems.  

PubMed

A direct, selective and highly efficient method has been developed for the hydrocarboxylation of C(n) gaseous alkanes into C(n+1) carboxylic acids, in aqueous acid-solvent-free medium at low temperatures. The approach is based on a metal-free or copper-promoted reaction of ethane, propane or n-butane with carbon monoxide and water, in a H(2)O/MeCN medium at 50-60 degrees C, in the presence of potassium peroxodisulfate. The effects of various reaction parameters, such as the absence or presence of a copper promoter, solvent composition, temperature, time, CO and alkane pressure, were studied. A free radical mechanism was confirmed by radical trap experiments involving acyl radical formation, oxidation and subsequent hydroxylation by water. Remarkable yields (based on alkane) of carboxylic acids in the 34-41 % range were achieved even in the metal-free systems, although in the presence of a tetracopper(II) triethanolaminate derived promoter they reach superior values of 58 and 87 % for the hydrocarboxylations of propane and n-butane, respectively; in these cases, branched isobutyric and 2-methylbutyric acids were the predominant products. From a green perspective, important features of the present alkane hydrocarboxylations include the exceptional metal-free, mild and acid-solvent-free reaction conditions, the operation in aqueous medium with a rare hydroxylating role of water, with high selectivities, and yields of carboxylic acids. Taken together, these conditions correspond to the mildest and the most efficient method so far reported for the oxidative functionalisation of gaseous alkanes. PMID:20455222

Kirillova, Marina V; Kirillov, Alexander M; Pombeiro, Armando J L

2010-08-16

24

Differential Response in Downstream Processing of CHO Cells Grown Under Mild Hypothermic Conditions  

PubMed Central

The manufacture of complex therapeutic proteins using mammalian cells is well established, with several strategies developed to improve productivity. The application of sustained mild hypothermic conditions during culture has been associated with increases in product titer and improved product quality. However, despite associated cell physiological effects, very few studies have investigated the impact on downstream processing (DSP). Characterization of cells grown under mild hypothermic conditions demonstrated that the stationary phase was prolonged by delaying the onset of apoptosis. This enabled cells to maintain viability for extended periods and increase volumetric productivity from 0.74 to 1.02 g L?1. However, host cell proteins, measured by ELISA, increased by ?50%, attributed to the extended time course and higher peak and harvest cell densities. The individual components making up this impurity, as determined by SELDI-TOF MS and 2D-PAGE, were shown to be largely comparable. Under mild hypothermic conditions, cells were less shear sensitive than those maintained at 37°C, enhancing the preliminary primary recovery step. Adaptive changes in membrane fluidity were further investigated by adopting a pronounced temperature shift immediately prior to primary recovery and the improvement observed suggests that such a strategy may be implementable when shear sensitivity is of concern. Early and late apoptotic cells were particularly susceptible to shear, at either temperature, even under the lowest shear rate investigated. These findings demonstrate the importance of considering the impact of cell culture strategies and cell physiology on DSP, by implementing a range of experimental methods for process characterization. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:688–696, 2013 PMID:23636936

Tait, Andrew S; Tarrant, Richard D R; Velez-Suberbie, M Lourdes; Spencer, Daniel I R; Bracewell, Daniel G

2013-01-01

25

Efficient Chemisorption of Organophosphorous Redox Probes on Indium Tin Oxide Surfaces under Mild Conditions.  

PubMed

We report a mild and straightforward one-step chemical surface functionalization of indium tin oxide (ITO) electrodes by redox-active molecules bearing an organophosphoryl anchoring group (i.e., alkyl phosphate or alkyl phosphonate group). The method takes advantage of simple passive adsorption in an aqueous solution at room temperature. We show that organophosphorus compounds can adsorb much more strongly and stably on an ITO surface than analogous redox-active molecules bearing a carboxylate or a boronate moiety. We provide evidence, through quantitative electrochemical characterization (i.e., by cyclic voltammetry) of the adsorbed organophosphoryl redox-active molecules, of the occurrence of three different adsorbate fractions on ITO, exhibiting different stabilities on the surface. Among these three fractions, one is observed to be strongly chemisorbed, exhibiting high stability and resistance to desorption/hydrolysis in a free-redox probe aqueous buffer. We attribute this remarkable stability to the formation of chemical bonds between the organophosphorus anchoring group and the metal oxide surface, likely occurring through a heterocondensation reaction in water. From XPS analysis, we also demonstrate that the surface coverage of the chemisorbed molecules is highly affected by the degree of surface hydroxylation, a parameter that can be tuned by simply preconditioning the freshly cleaned ITO surfaces in water. The lower the relative surface hydroxide density on ITO, the higher was the surface coverage of the chemisorbed species. This behavior is in line with a chemisorption mechanism involving coordination of a deprotonated phosphoryl oxygen atom to the non-hydroxylated acidic metal sites of ITO. PMID:25611977

Forget, Amélie; Limoges, Benoît; Balland, Véronique

2015-02-17

26

Organic cation transporter inhibition increases medial hypothalamic serotonin under basal conditions and during mild restraint  

PubMed Central

The dorsomedial hypothalamus (DMH) has been implicated in the coordination of stress responses. Restraint stress or systemic corticosterone (CORT) treatment induces a rapid increase in tissue concentrations of serotonin (5-hydroxytryptamine; 5-HT) in the DMH. Although the mechanism for rapid changes in 5-HT concentrations in the DMH is not clear, earlier results suggest that stress-induced increases in CORT may inhibit 5-HT transport from the extracellular fluid by acting on corticosterone-sensitive organic cation transporters (OCTs). We tested the hypothesis that perfusion of the medial hypothalamus (MH), which includes the DMH, with the OCT blocker decynium 22 (D-22) would potentiate the effects of mild restraint on extracellular 5-HT. Male Sprague-Dawley rats, implanted with a microdialysis probe into the MH, were treated with reverse-dialysis of D-22 (20 ?M; 40 min) or vehicle and subjected to either 40 min mild restraint or undisturbed control conditions. Perfusates collected from a separate group of rats were evaluated for the effect of restraint on extracellular CORT concentrations in the MH. Reverse dialysis of D-22 induced an increase (200%) in extracellular 5-HT concentrations in the MH in undisturbed control rats. Restraint in the absence of D-22 did not significantly affect MH CORT or 5-HT concentrations. However, perfusion of the MH with D-22 during restraint led to an increased magnitude and duration of extracellular 5-HT concentrations, relative to D-22 by itself. These results are consistent with the hypothesis that OCTs in the DMH contribute to the clearance of 5-HT from the extracellular fluid under both baseline conditions and mild restraint. PMID:20171957

Feng, Na; Lowry, Christopher A.; Lukkes, Jodi L.; Orchinik, Miles; Forster, Gina L.; Renner, Kenneth J.

2010-01-01

27

Degradation of textile dyes using immobilized lignin peroxidase-like metalloporphines under mild experimental conditions  

PubMed Central

Background Synthetic dyes represent a broad and heterogeneous class of durable pollutants, that are released in large amounts by the textile industry. The ability of two immobilized metalloporphines (structurally emulating the ligninolytic peroxidases) to bleach six chosen dyes (alizarin red S, phenosafranine, xylenol orange, methylene blue, methyl green, and methyl orange) was compared to enzymatic catalysts. To achieve a green and sustainable process, very mild conditions were chosen. Results IPS/MnTSPP was the most promising biomimetic catalyst as it was able to effectively and quickly bleach all tested dyes. Biomimetic catalysis was fully characterized: maximum activity was centered at neutral pH, in the absence of any organic solvent, using hydrogen peroxide as the oxidant. The immobilized metalloporphine kept a large part of its activity during multi-cycle use; however, well-known redox mediators were not able to increase its catalytic activity. IPS/MnTSPP was also more promising for use in industrial applications than its enzymatic counterparts (lignin peroxidase, laccase, manganese peroxidase, and horseradish peroxidase). Conclusions On the whole, the conditions were very mild (standard pressure, room temperature and neutral pH, using no organic solvents, and the most environmental-friendly oxidant) and a significant bleaching and partial mineralization of the dyes was achieved in approximately 1 h. Therefore, the process was consistent with large-scale applications. The biomimetic catalyst also had more promising features than the enzymatic catalysts. PMID:23256784

2012-01-01

28

Reusable task-specific ionic liquids for a clean ?-caprolactam synthesis under mild conditions.  

PubMed

Brønsted-acidic ionic liquids that bear a sulfonic acid group, known as Forbes acids, show a good catalytic activity for the Beckmann rearrangement, used to prepare ?-caprolactam, which is a precursor of Nylon?6. The activity essentially stems from the acidity of the sulfonic acid group. Although these task specific ionic liquids suffer from a high viscosity, this drawback can be circumvented at higher temperatures. A combination of the hydrogen sulfate anion and the sulfonic acid group of the cation is needed to obtain the rearrangement product rapidly under mild conditions. When using an excess of ionic liquid, we postulate that the internal pressure of the ionic medium, generated by the high viscosity and the high number of hydrogen-bonds, is strong enough to contribute to a decrease of the thermodynamic barrier. In accordance with the "Principles of Green Chemistry," we have developed a synthesis of ?-caprolactam that requires no additional chemicals except cyclohexanone oxime and the reusable TSIL. PMID:21117118

Turgis, Raphaël; Estager, Julien; Draye, Micheline; Ragaini, Vittorio; Bonrath, Werner; Lévêque, Jean-Marc

2010-12-17

29

Mild gasification of steam-conditioned bituminous coal in fluidized beds: Technical note  

SciTech Connect

A detailed systems analysis of a commercial-scale mild gasification process has been performed. The process includes (1) a conceptual design of the process, (2) mass and energy balances that were calculated with the use of the Advanced System for Process Engineering (ASPEN) process simulator, and (3) a detailed economic assessment that includes several sensitivity studies. In this conceptual study, 1 million tons per year, dry basis, of Pittsburgh No. 8 coal are conditioned with steam at 700/degree/F for 5 minutes in a fluidized-bed and devolatilized at 1000/degree/F for 3 minutes in a second fluidized-bed. Volatiles are condensed and liquid condensate and gas are separated. Liquid production is 340,000 tons per year (approximately 1,870,000 barrels per year) based on an increased liquid yield due to steam conditioning of 37 weight percent of dry, ash-free coal (DAF). This assumed yield is based on bench-scale experimental results for steam-conditioned coal (Graff 1987). Gas produced in the process is internally consumed for char heating and steam generation. Net char production is 466,000 ton/yr. 27 refs., 3 figs., 3 tabs.

Gessner, A.W.; Hand, T.J.; Klara, J.M.

1988-02-01

30

On the convergence of Newton-type methods under mild differentiability conditions  

NASA Astrophysics Data System (ADS)

We introduce the new idea of recurrent functions to provide a new semilocal convergence analysis for Newton-type methods, under mild differentiability conditions. It turns out that our sufficient convergence conditions are weaker, and the error bounds are tighter than in earlier studies in some interesting cases (Chen, Ann Inst Stat Math 42:387-401, 1990; Chen, Numer Funct Anal Optim 10:37-48, 1989; Cianciaruso, Numer Funct Anal Optim 24:713-723, 2003; Cianciaruso, Nonlinear Funct Anal Appl 2009; Dennis 1971; Deuflhard 2004; Deuflhard, SIAM J Numer Anal 16:1-10, 1979; Gutiérrez, J Comput Appl Math 79:131-145, 1997; Hernández, J Optim Theory Appl 109:631-648, 2001; Hernández, J Comput Appl Math 115:245-254, 2000; Huang, J Comput Appl Math 47:211-217, 1993; Kantorovich 1982; Miel, Numer Math 33:391-396, 1979; Miel, Math Comput 34:185-202, 1980; Moret, Computing 33:65-73, 1984; Potra, Libertas Mathematica 5:71-84, 1985; Rheinboldt, SIAM J Numer Anal 5:42-63, 1968; Yamamoto, Numer Math 51: 545-557, 1987; Zabrejko, Numer Funct Anal Optim 9:671-684, 1987; Zinc?ko 1963). Applications and numerical examples, involving a nonlinear integral equation of Chandrasekhar-type, and a differential equation are also provided in this study.

Argyros, Ioannis; Hilout, Saïd

2009-12-01

31

Synthesis of boron suboxide from boron and boric acid under mild pressure and temperature conditions  

SciTech Connect

Graphical abstract: Well-crystallized and icosahedral B{sub 6}O crystals were prepared by reacting boron and boric acid at milder reaction conditions (1 GPa and 1300 {sup o}C for 2 h) as compared to previous work.. Research highlights: {yields} Well-crystallized icosahedral B{sub 6}O was synthesized by reacting boric acid and boron. {yields} The synthesis conditions (1 GPa and 1300 {sup o}C for 2 h) are milder in comparison with previous work. {yields} The more practical synthesis method may make B{sub 6}O as a potential substitute for diamond in industry. -- Abstract: Boron suboxide (B{sub 6}O) was synthesized by reacting boron and boric acid (H{sub 3}BO{sub 3}) at pressures between 1 and 10 GPa, and at temperatures between 1300 and 1400 {sup o}C. The B{sub 6}O samples prepared were icosahedral with diameters ranging from 20 to 300 nm. Well-crystallized and icosahedral crystals with an average size of {approx}100 nm can be obtained at milder reaction conditions (1 GPa and 1300 {sup o}C for 2 h) as compared to previous work. The bulk B{sub 6}O sample was stable in air at 600 {sup o}C and then slowly oxidized up to 1000 {sup o}C. The relatively mild synthetic conditions developed in this study provide a more practical synthesis of B{sub 6}O, which may potentially be used as a substitute for diamond in industry as a new superhard material.

Jiao, Xiaopeng; Jin, Hua; Ding, Zhanhui; Yang, Bin; Lu, Fengguo; Zhao, Xudong [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)] [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Liu, Xiaoyang, E-mail: liuxy@jlu.edu.cn [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)] [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Peng, Liping, E-mail: pengliping64@yahoo.cn [The 1st Norman Bethune Hospital, Jilin University, 71 Xinmin Street, Changchun 130021 (China)] [The 1st Norman Bethune Hospital, Jilin University, 71 Xinmin Street, Changchun 130021 (China)

2011-05-15

32

Evolutionary optimization for conditions of variable BHF for springback reduction in AHSS-mild steel TWB  

NASA Astrophysics Data System (ADS)

In this study, the advanced high strength steels (AHSS)/mild steel TWB sheet is applied to the U-draw bending springback under non-constant blank holding force (BHF). On both sides of the blank, two different BHF-punch stroke are applied. A systematic approach to obtain optimal BHF-stroke profiles is proposed. The optimal condition would require satisfying two conflicting objectives simultaneously: (1) minimize springback deformation and (2) minimize the forming severity, leading to a Pareto-optimal problem. The optimization procedure consists of the following steps: sampling design, finite element (FE) simulations, metamodeling, and finally the calculation of a Pareto-frontier. PAM-STAMP® FE software is employed in this study. The generated outputs of FE simulations on some statistically significant sampling points are then used for the construction of metamodels of optimum accuracy and complexity, which, in turn, were used to evaluate the output for any set of inputs, replacing the computing intensive FE simulations. A novel genetic algorithms based multi-objective optimization technique is applied for optimization. Yet far to be completely removed, springback in TWB can be appreciably reduced using the proposed approach of variable BHF control.

Nguyen, N.-T.; Chakraborti, N.; Barlat, F.

2013-12-01

33

Addition of Ethylene or Hydrogen to a Main-Group Metal Cluster under Mild Conditions.  

PubMed

Reaction of the tin cluster Sn8 (Ar?Me?6)4 (Ar?Me?6=C6 H2 -2,6-(C6 H3 -2,4,6-Me3 )2 ) with excess ethylene or dihydrogen at 25?°C/1?atmosphere yielded two new clusters that incorporated ethylene or hydrogen. The reaction with ethylene yielded Sn4 (Ar?Me?6)4 (C2 H2 )5 that contained five ethylene moieties bridging four aryl substituted tin atoms and one tin-tin bond. Reaction with H2 produced a cyclic tin species of formula (Sn(H)Ar?Me?6)4 , which could also be synthesized by the reaction of {(Ar?Me?6)Sn(?-Cl)}2 with DIBAL-H. These reactions represent the first instances of direct reactions of isolable main-group clusters with ethylene or hydrogen under mild conditions. The products were characterized in the solid state by X-ray diffraction and IR spectroscopy and in solution by multinuclear NMR and UV/Vis spectroscopies. Density functional theory calculations were performed to explain the reactivity of the cluster. PMID:25631067

Vasko, Petra; Wang, Shuai; Tuononen, Heikki M; Power, Philip P

2015-03-16

34

Enzymatic Formulation Capable of Degrading Scrapie Prion under Mild Digestion Conditions  

PubMed Central

The prion agent is notoriously resistant to common proteases and conventional sterilisation procedures. The current methods known to destroy prion infectivity such as incineration, alkaline and thermal hydrolysis are harsh, destructive, environmentally polluting and potentially hazardous, thus limit their applications for decontamination of delicate medical and laboratory devices, remediation of prion contaminated environment and for processing animal by-products including specified risk materials and carcases. Therefore, an environmentally friendly, non-destructive enzymatic degradation approach is highly desirable. A feather-degrading Bacillus licheniformis N22 keratinase has been isolated which degraded scrapie prion to undetectable level of PrPSc signals as determined by Western Blot analysis. Prion infectivity was verified by ex vivo cell-based assay. An enzymatic formulation combining N22 keratinase and biosurfactant derived from Pseudomonas aeruginosa degraded PrPSc at 65°C in 10 min to undetectable level -. A time-course degradation analysis carried out at 50°C over 2 h revealed the progressive attenuation of PrPSc intensity. Test of residual infectivity by standard cell culture assay confirmed that the enzymatic formulation reduced PrPSc infectivity to undetectable levels as compared to cells challenged with untreated standard scrapie sheep prion (SSBP/1) (p-value?=?0.008 at 95% confidence interval). This novel enzymatic formulation has significant potential application for prion decontamination in various environmentally friendly systems under mild treatment conditions. PMID:23874511

Okoroma, Emeka A.; Purchase, Diane; Garelick, Hemda; Morris, Roger; Neale, Michael H.; Windl, Otto; Abiola, Oduola O.

2013-01-01

35

Facile one-step fabrication of magnetite particles under mild hydrothermal conditions  

NASA Astrophysics Data System (ADS)

Hydrophilic magnetite particles for biological applications were synthesized by hydrothermal method in the presence of D-Glucose as both reducing and capping agent in a facile, one-step, low energy and environmentally friendly route. The role of D-Glucose as a reducing agent in the formation of magnetite particles under mild hydrothermal conditions has been investigated. The absence of D-Glucose results in the formation of hematite. The magnetite particles synthesized were characterized using powder X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, High Resolution Scanning Electron Microscopy (HR-SEM), Dynamic Light Scattering (DLS) and Vibrating Sample Magnetometery (VSM). The influence of the quantity of D-Glucose used and the reaction duration on the formation of magnetite were studied. DLS and HR-SEM results show that the size of the particles was in nano- to micron range. The antioxidant potency of the particles was confirmed using DPPH assay, where 2,2- Diphenyl-1-picrylhydrazyl was used as a source of free radicals. Hence the magnetite particles obtained could be considered for the use in various biological applications.

Keerthana, D. Shanthini; Namratha, K.; Byrappa, K.; Yathirajan, H. S.

2015-03-01

36

Catalytic epoxidation activity of keplerate polyoxomolybdate nanoball toward aqueous suspension of olefins under mild aerobic conditions.  

PubMed

Catalytic efficiency of a sphere-shaped nanosized polyoxomolybdate {Mo132} in the aerobic epoxidation of olefins in water at ambient temperature and pressure in the absence of reducing agent is exploited which resulted good-to-high yields and desired selectivity. PMID:23799637

Rezaeifard, Abdolreza; Haddad, Reza; Jafarpour, Maasoumeh; Hakimi, Mohammad

2013-07-10

37

Pulse radiolysis of tetrazolium violet in aqueous and aqueous-alcoholic solutions under oxidative and reductive conditions  

NASA Astrophysics Data System (ADS)

The radiolytic reduction of colourless tetrazolium salts to coloured formazans in liquid and solid state is suggested for dosimetry purposes. In order to clarify the reaction mechanism, a pulse radiolysis study was conducted in aqueous and aqueous-alcoholic solutions under oxidative and reductive conditions. Under reducing conditions, fast formation of the electron adduct tetrazolinyl radical was observed: coloured formazan final product formed during the decay of electron adduct. Both the decay of the tetrazolinyl radical and the formation of the formazan were found to be second order. The spectra of the formazan were similar in neutral and alkaline solutions, but with higher absorbance in the latter solutions due to the higher molar absorption coefficient. Under oxidative conditions formazan did not form; hydroxylated products through OH-adducts were observed in the pH range studied.

Kovács, A.; Wojnárovits, L.; Pálfi, T.; Emi-Reynolds, G.; Fletcher, J.

2008-09-01

38

Palladium(II)-catalyzed Heck reaction of aryl halides and arylboronic acids with olefins under mild conditions  

PubMed Central

Summary A series of general and selective Pd(II)-catalyzed Heck reactions were investigated under mild reaction conditions. The first protocol has been developed employing an imidazole-based secondary phosphine oxide (SPO) ligated palladium complex (6) as a precatalyst. The catalytic coupling of aryl halides and olefins led to the formation of the corresponding coupled products in excellent yields. A variety of substrates, both electron-rich and electron-poor olefins, were converted smoothly to the targeted products in high yields. Compared with the existing approaches employing SPO–Pd complexes in a Heck reaction, the current strategy features mild reaction conditions and broad substrate scope. Furthermore, we described the coupling of arylboronic acids with olefins, which were catalyzed by Pd(OAc)2 and employed N-bromosuccinimide as an additive under ambient conditions. The resulted biaryls have been obtained in moderate to good yields. PMID:23946858

Shaikh, Tanveer Mahamadali

2013-01-01

39

TOPEX/El Nino Watch - Mild La Nina Conditions Developing, November 12, 1999  

NASA Technical Reports Server (NTRS)

Unusually warm ocean temperatures off Asia and cool waters in the eastern and equatorial Pacific are signaling La Nina's mild return, according to the latest sea-surface heights observed by the joint NASA-French space agency's TOPEX/Poseidon satellite.

Lower than normal sea-surface heights in the eastern North Pacific and abnormally high sea-surface heights in the western and mid-latitude Pacific are expected to drive storms coming out of the Pacific this winter, the mission data indicate. Those conditions will most likely steer storms north into the Pacific Northwest and keep the southwestern United States dryer than normal.

The latest measurements, processed after a 10-day data cycle November 4-13 at NASA's Jet Propulsion Laboratory, Pasadena, CA, are available at http://www.jpl.nasa.gov/elnino . Sea-surface height is shown relative to normal (green) and reveals cooler water(blue and purple) measuring between 8 and 24 centimeters (3 to 9 inches) lower than average in the eastern North Pacific, from the Gulf of Alaska to central Alaska, and along the equator.

Unusual conditions persist in the western and mid-latitude Pacific Ocean as well, with higher than average sea-surface heights(red and white) of between 8 and 24 centimeters (3 to 9 inches). These areas of increased sea-surface height and unusually warm water were present last year, but the increase in height has surpassed last year's measurements.

The TOPEX/Poseidon satellite's measurements over the last seven and a half years have provided scientists with a comprehensive record of the 1997-1999 El Nino/La Nina climate pattern by measuring changing sea-surface heights to within 4centimeters (1.5 inches) precision.

The U.S./French mission is managed by the Jet Propulsion Laboratory for NASA's Earth Sciences Enterprise, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov/

1999-01-01

40

Chemo-, regio-, and stereoselective Heck-Matsuda arylation of allylic alcohols under mild conditions.  

PubMed

Heck arylation with allylic alcohol is extremely challenging due to chemo-, regio-, and stereoselective scrambling. Here we report a mild protocol for the alcohol selective ?- and ?-arylation of allylic and cinnamyl alcohols respectively with aryldiazonium salts. The steric and electronic parameters of the alkene play a prominent role in the regioselectivity. PMID:25814005

Chaudhari, Tohasib Yusub; Hossian, Asik; Manna, Manash Kumar; Jana, Ranjan

2015-04-22

41

Highly efficient and chemoselective zinc-catalyzed hydrosilylation of esters under mild conditions.  

PubMed

A mild and highly efficient catalytic hydrosilylation protocol for room-temperature ester reductions has been developed using diethylzinc as the catalyst. The methodology is operationally simple, displays high functional group tolerance and provides for a facile access to a broad range of different alcohols in excellent yields. PMID:25524811

Kovalenko, Oleksandr O; Adolfsson, Hans

2015-02-01

42

Assessment and Diagnosis of Mild Traumatic Brain Injury, Posttraumatic Stress Disorder, and Other Polytrauma Conditions: Burden of Adversity Hypothesis  

Microsoft Academic Search

Objective\\/Method: Military personnel returning from Iraq and Afghanistan have been exposed to physical and emotional trauma. Challenges related to assessment and intervention for those with posttraumatic stress disorder (PTSD) and\\/or history of mild traumatic brain injury (TBI) with sequelae are discussed, with an emphasis on complicating factors if conditions are co-occurring. Existing literature regarding cumulative disadvantage is offered as a

Lisa A. Brenner; Rodney D. Vanderploeg; Heidi Terrio

2009-01-01

43

Microstructural and aqueous corrosion aspects of laser-surface-melted type 304 SS plasma-coated mild steel  

NASA Astrophysics Data System (ADS)

Plasma spray deposition of metals, ceramics, or plastics onto base metals to produce wear- and corrosion-resistant surfaces is a promising technique whereby base metal performance can be considerably im-proved. Because these coatings invariably contain pores, voids, and cracks, laser surface melting may be employed to improve their homogeneity. This study focuses on the corrosion performance of laser- sur-face- melted type 304 SS plasma- coated mild steel specimens. Mild steel strips were plasma coated with an approximately 100 to 200 ?m thick layer of type 304 by transferred plasma jet. These specimens were sub-sequently laser irradiated using a 3 kW continuous- wave CO2 gas laser. Eight different sets of specimens were selected based on different laser beam travel speeds. Scanning electron microscopic studies of the plasma- coated specimens revealed both pancake and flowery types of deposited particles. Optical micro-scopic studies followed by anodic polarization experiments were carried out on these specimens in IN H2SO4 medium. It was observed that specimens with laser beam interaction times ranging from 30 to 120 ms showed relatively better general corrosion performance than specimens with interaction times of from 15 to 24 ms.

Pujar, M. G.; Dayal, R. K.; Singh Raman, R. K.

1994-06-01

44

Microstructural and aqueous corrosion aspects of laser-surface melted type 304 SS plasma-coated mild steel  

SciTech Connect

Plasma spray deposition of metals, ceramics, or plastics onto base metals to produce wear- and corrosion-resistance surfaces is a promising technique whereby base metal performance can be considerably improved. Because these coatings invariably contain pores, voids, and cracks, laser surface melting may be employed to improve their homogeneity. This study focuses on the corrosion performance of laser-surface-melted type 304 SS plasma-coated mild steel specimens. Mild steel strips were plasma coated with an approximately 100 to 200 [mu]m thick layer of type 304 by transferred plasma jet. These specimens were subsequently laser irradiated using a 3 kW continuous-wave CO[sub 2] gas laser. Eight different sets of specimens were selected based on different laser beam travel speeds. Scanning electron microscopic studies of the plasma-coated specimens revealed both pancake and flowery types of deposited particles. Optical microscopic studies followed by anodic polarization experiments were carried out on these specimens in 1N H[sub 2]SO[sub 4] medium. It was observed that specimens with laser beam interaction times ranging from 30 to 120 ms showed relatively better general corrosion performance than specimens with interaction times of from 15 to 24 ms.

Pujar, M.G.; Dayal, R.K.; Raman, R.K.S. (Indira Ghandhi Centre for Atomic Research, Kalpakkam (India))

1994-06-01

45

Mild Cognitive Impairment  

MedlinePLUS

About Alzheimer's Disease: Mild Cognitive Impairment Mild cognitive impairment (MCI) is a condition in which people have memory or other ... as severe as those seen in people with Alzheimer’s disease. More older people with MCI, compared with those ...

46

Aqueous alteration of VHTR fuels particles under simulated geological conditions  

NASA Astrophysics Data System (ADS)

Very High Temperature Reactor (VHTR) fuels consist of the bistructural-isotropic (BISO) or tristructural-isotropic (TRISO)-coated particles embedded in a graphite matrix. Management of the spent fuel generated during VHTR operation would most likely be through deep geological disposal. In this framework we investigated the alteration of BISO (with pyrolytic carbon) and TRISO (with SiC) particles under geological conditions simulated by temperatures of 50 and 90 °C and in the presence of synthetic groundwater. Solid state (scanning electron microscopy (SEM), micro-Raman spectroscopy, electron probe microanalyses (EPMA) and X-ray photoelectron spectroscopy (XPS)) and solution analyses (ICP-MS, ionique chromatography (IC)) showed oxidation of both pyrolytic carbon and SiC at 90 °C. Under air this led to the formation of SiO2 and a clay-like Mg-silicate, while under reducing conditions (H2/N2 atmosphere) SiC and pyrolytic carbon were highly stable after a few months of alteration. At 50 °C, in the presence and absence of air, the alteration of the coatings was minor. In conclusion, due to their high stability in reducing conditions, HTR fuel disposal in reducing deep geological environments may constitute a viable solution for their long-term management.

Ait Chaou, Abdelouahed; Abdelouas, Abdesselam; Karakurt, Gökhan; Grambow, Bernd

2014-05-01

47

Efficient conversion of brown grease produced by municipal wastewater treatment plant into biofuel using aluminium chloride hexahydrate under very mild conditions.  

PubMed

Wastes produced by oil/water separation at the wastewater treatment plant of Bari West (Southern Italy) were taken, characterized and converted. About 12% of this material was composed of greases, mainly made of free fatty acids (50%) and soaps (34%), and was easily separable by the aqueous phase through a hot centrifugation. After chemical activation of this fatty fraction, a direct esterification was carried out under very mild conditions (320K and atmospheric pressure), converting more than 90% of the original free fatty acids into the respective methyl esters in less than 4h, by using AlCl3·6H2O. The activation energy correlated to the use of this catalyst was also calculated (Eaest=43.9kJmol(-1)). The very low cost of the biodiesel produced (0.45€L(-1)) and the associated relevant specific energy (5.02MJ kgFAMEs(-1)) make such a process a really sustainable and effective example of valorization of a waste. PMID:24434702

Pastore, Carlo; Lopez, Antonio; Mascolo, Giuseppe

2014-03-01

48

Single-step delamination of a MWW borosilicate layered zeolite precursor under mild conditions without surfactant and sonication.  

PubMed

Layered borosilicate zeolite precursor ERB-1P (Si/B = 11) is delaminated via isomorphous substitution of Al for B using a simple aqueous Al(NO3)3 treatment. Characterization by PXRD shows loss of long-range order, and TEM demonstrates transformation of rectilinear layers in the precursor to single and curved layers in the delaminated material. N2 physisorption and base titration confirm the expected decrease of micropore volume and increase in external surface area for delaminated materials relative to their calcined 3D zeolite counterpart, whereas FTIR and multinuclear NMR spectroscopies demonstrate synthesis of Brønsted acid sites upon delamination. Comparative synthetic studies demonstrate that this new delamination method requires (i) a borosilicate layered zeolite precursor, in which boron atoms can be isomorphously substituted by aluminum, (ii) neutral amine pore fillers instead of rigid and large quaternary amine SDAs, and (iii) careful temperature control, with the preferred temperature window being around 135 °C for ERB-1P delamination. Acylation of 2-methoxynaphthalene was used as a model reaction to investigate the catalytic benefits of delamination. A partially dealuminated delaminated material displays a 2.3-fold enhancement in its initial rate of catalysis relative to the 3D calcined material, which is nearly equal to its 2.5-fold measured increase in external surface area. This simple, surfactant- and sonication-free, mild delamination method is expected to find broad implementation for the synthesis of delaminated zeolite catalysts. PMID:24345282

Ouyang, Xiaoying; Hwang, Son-Jong; Runnebaum, Ron C; Xie, Dan; Wanglee, Ying-Jen; Rea, Thomas; Zones, Stacey I; Katz, Alexander

2014-01-29

49

Reversible Hydrogen Storage using CO2 and a Proton-Switchable Iridium Catalyst in Aqueous Media under Mild Temperatures and Pressures  

SciTech Connect

Green plants convert CO{sub 2} to sugar for energy storage via photosynthesis. We report a novel catalyst that uses CO{sub 2} and hydrogen to store energy in formic acid. Using a homogeneous iridium catalyst with a proton-responsive ligand, we show the first reversible and recyclable hydrogen storage system that operates under mild conditions using CO{sub 2}, formate and formic acid. This system is energy-efficient and green because it operates near ambient conditions, uses water as a solvent, produces high-pressure CO-free hydrogen, and uses pH to control hydrogen production or consumption. The extraordinary and switchable catalytic activity is attributed to the multifunctional ligand, which acts as a proton-relay and strong {pi}-donor, and is rationalized by theoretical and experimental studies.

Hull J. F.; Himeda, Y.; Wang, W.-H.; Hashiguchi, B.; Szalda, D.J.; Muckerman, J.T.; Fujita, E.

2012-05-01

50

Imidazole-Catalyzed Henry Reactions in Aqueous Medium  

Microsoft Academic Search

2-Nitroalkanols can be efficiently synthesized using imidazole as a mild Lewis basic catalyst in aqueous medium as well as in organic solvents. The products have been found in good yields without purification (> 95% purity by H NMR) for aromatic aldehydes. Additionally, the very mild reaction conditions prevent the particular side reactions such as aldol condensation, Cannizzaro reaction, or dehydration of

Mridula Phukan; Kalyan Jyoti Borah; Ruli Borah

2008-01-01

51

A new class of single-component absorbents for reversible carbon dioxide capture under mild conditions.  

PubMed

Some inexpensive and commercially available secondary amines reversibly react with CO2 at room temperature and ambient pressure to yield carbonated species in the liquid phase in the absence of any additional solvent. These solvent-free absorbents have a high CO2 capture capacity (0.63-0.65?mol CO2 /mol amine) at 1.0?bar (=100?kPa), combined with low-temperature reversibility at ambient pressure. (13) C?NMR spectroscopy analysis identified the carbonated species as the carbamate salts and unexpected carbamic acids. These absorbents were used for CO2 (15 and 40?% in air) capture in continuous cycles of absorption-desorption carried out in packed columns, yielding an absorption efficiency of up to 98.5?% at absorption temperatures of 40-45?°C and desorption temperatures of 70-85?°C at ambient pressure. The absence of any parasitic solvent that requires to be heated and stability towards moisture and heating could result in some of these solvent-free absorbents being a viable alternative to aqueous amines for CO2 chemical capture. PMID:25410150

Barzagli, Francesco; Lai, Sarah; Mani, Fabrizio

2015-01-01

52

A New Biarylphosphine Ligand for the Pd-Catalyzed Synthesis of Diaryl Ethers under Mild Conditions  

E-print Network

A new bulky biarylphosphine ligand (L8) has been developed that allows the Pd-catalyzed C–O cross-coupling of a wide range of aryl halides and phenols under milder conditions than previously possible. A direct correlation ...

Salvi, Luca

53

Cannabinoid modulation of chronic mild stress-induced selective enhancement of trace fear conditioning in adolescent rats.  

PubMed

History of stress is considered a major risk factor for the development of major depression and posttraumatic stress disorder (PTSD). Elucidating the neurobiological mechanisms of Pavlovian fear conditioning may provide insight into the etiology of PTSD. In the current study, adolescent male Sprague-Dawley rats were exposed to 3 weeks of a chronic-mild-unpredictable stress (CMS) protocol. Immediately following the CMS, the animals were subjected to hippocampal-dependent (trace and contextual) and hippocampal-independent (delay) fear conditioning. CMS exposure enhanced trace freezing behavior compared to non-stress controls. This effect was not observed in contextual or delay conditioned animals. Given that the endocannabinoid system is negatively affected by CMS procedures, separate groups of stressed rats were administered the CB1 receptor agonist, ACEA (0.1 mg/kg), prior to trace fear conditioning or a memory-recall test. Regardless of administration time, ACEA significantly reduced freezing behavior in stressed animals. Furthermore, when administered during the first memory recall test, ACEA enhanced long-term extinction in both stress and non-stress groups. The results demonstrate that chronic unpredictable stress selectively enhances hippocampal-dependent episodic fear memories. Pathologies of the episodic memory and fear response may increase the susceptibility of developing PTSD. Reduction in fear responses via exogenous activation of the CB1 receptor suggests that a deficiency in the endocannabinoid system contributes to this pathology. PMID:23926242

Reich, Christian G; Iskander, Anthony N; Weiss, Michael S

2013-10-01

54

Characterization of a dimeric unfolding intermediate of bovine serum albumin under mildly acidic condition  

Microsoft Academic Search

Protein aggregation is a well-known phenomenon related to serious medical implications. Bovine serum albumin (BSA), a structural analogue of human serum albumin, has a natural tendency for aggregation under stress conditions. While following effect of moderately acidic pH on BSA, a state was identified at pH 4.2 having increased light scattering capability at 350 nm. It was essentially a dimer

Amrita Brahma; Chhabinath Mandal; Debasish Bhattacharyya

2005-01-01

55

Synthesis of boron suboxide from boron and boric acid under mild pressure and temperature conditions  

Microsoft Academic Search

Boron suboxide (B6O) was synthesized by reacting boron and boric acid (H3BO3) at pressures between 1 and 10GPa, and at temperatures between 1300 and 1400°C. The B6O samples prepared were icosahedral with diameters ranging from 20 to 300nm. Well-crystallized and icosahedral crystals with an average size of ?100nm can be obtained at milder reaction conditions (1GPa and 1300°C for 2h)

Xiaopeng Jiao; Hua Jin; Zhanhui Ding; Bin Yang; Fengguo Lu; Xudong Zhao; Xiaoyang Liu; Liping Peng

2011-01-01

56

Catalytic and regioselective oxidation of carbohydrates to synthesize keto-sugars under mild conditions.  

PubMed

A new catalytic and regioselective approach for the synthesis of keto-sugars is described. An organotin catalyst, Oc2SnCl2, in the presence of trimethylphenylammonium tribromide ([TMPhA](+)Br3(-)) accelerates the regioselective oxidation at the "axial"-OH group of 1,2-diol moieties in galactopyranosides. The reaction conditions can also be used for the regioselective oxidation of various carbohydrates. PMID:25198882

Muramatsu, Wataru

2014-09-19

57

Multiple H2 occupancy of cages of clathrate hydrate under mild conditions.  

PubMed

Experiments were carried out by reacting H(2) gas with N(2) hydrate at a temperature of 243 K and a pressure of 15 MPa. The characterizations of the reaction products indicated that multiple H(2) molecules can be loaded into both large and small cages of structure II clathrate hydrates. The realization of multiple H(2) occupancy of hydrate cages under moderate conditions not only brings new insights into hydrogen clathrates but also refreshes the perspective of clathrate hydrates as hydrogen storage media. PMID:22587651

Lu, Hailong; Wang, Jianwei; Liu, Changling; Ratcliffe, Christopher I; Becker, Udo; Kumar, Rajnish; Ripmeester, John

2012-06-01

58

Cyclization of ortho-hydroxycinnamates to coumarins under mild conditions: A nucleophilic organocatalysis approach  

PubMed Central

Summary (E)-Alkyl ortho-hydroxycinnamates cyclize to coumarins at elevated temperatures of 140–250 °C. We find that the use of tri-n-butylphosphane (20 mol %) as a nucleophilic organocatalyst in MeOH solution allows cyclization to take place under much milder conditions (60–70 °C). Several coumarins were prepared, starting from ortho-hydroxyarylaldehydes, by Wittig reaction with Ph3P=CHCO2Me to (E)-methyl ortho-hydroxycinnamates, followed by the phosphane catalyzed cyclization. PMID:23209495

Boeck, Florian; Blazejak, Max; Anneser, Markus R

2012-01-01

59

Stability of Lysozyme in Aqueous Extremolyte Solutions during Heat Shock and Accelerated Thermal Conditions  

PubMed Central

The purpose of this study was to investigate the stability of lysozyme in aqueous solutions in the presence of various extremolytes (betaine, hydroxyectoine, trehalose, ectoine, and firoin) under different stress conditions. The stability of lysozyme was determined by Nile red Fluorescence Spectroscopy and a bioactivity assay. During heat shock (10 min at 70°C), betaine, trehalose, ectoin and firoin protected lysozyme against inactivation while hydroxyectoine, did not have a significant effect. During accelerated thermal conditions (4 weeks at 55°C), firoin also acted as a stabilizer. In contrast, betaine, hydroxyectoine, trehalose and ectoine destabilized lysozyme under this condition. These findings surprisingly indicate that some extremolytes can stabilize a protein under certain stress conditions but destabilize the same protein under other stress conditions. Therefore it is suggested that for the screening extremolytes to be used for protein stabilization, an appropriate storage conditions should also be taken into account. PMID:24465983

van Streun, Erwin L. P.; Frijlink, Henderik W.; Hinrichs, Wouter L. J.

2014-01-01

60

Intrinsic formation of nanocrystalline neptunium dioxide under neutral aqueous conditions relevant to deep geological repositories.  

PubMed

The dilution of aqueous neptunium carbonate complexes induces the intrinsic formation of nanocrystalline neptunium dioxide (NpO2) particles, which are characterised by UV/Vis and X-ray absorption spectroscopies and transmission electron microscopy. This new route of nanocrystalline NpO2 formation could be a potential scenario for the environmental transport of radionuclides from the waste repository (i.e. under near-field alkaline conditions) to the geological environment (i.e. under far-field neutral conditions). PMID:25479067

Husar, Richard; Hübner, René; Hennig, Christoph; Martin, Philippe M; Chollet, Mélanie; Weiss, Stephan; Stumpf, Thorsten; Zänker, Harald; Ikeda-Ohno, Atsushi

2015-01-25

61

Palladium-pyridyl catalytic films: a highly active and recyclable catalyst for hydrogenation of styrene under mild conditions.  

PubMed

Palladium-pyridyl catalytic films, (PdCl2/bpy)n, were created by alternating immersions of a substrate in PdCl2 and bpy (bpy=4, 4'-bipyridyl) solutions. The as-prepared (PdCl2/bpy)10 catalyst demonstrated a remarkable catalytic activity toward hydrogenation of styrene under mild conditions and the turnover frequency (TOF) is as high as 6944h(-1). Pd(II) ions of (PdCl2/bpy)n films are in situ reduced to Pd nanoparticles (NPs) during the hydrogenation of styrene process, which results in the catalytic activity of the films. The results of X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) further demonstrate that Pd(II) ions of (PdCl2/bpy)n films were gradually converted to Pd(0) states. The catalytic activity is related to bilayer numbers and the activity increases with the number of bilayers below 10 bilayers. The solid substrates coated with (PdCl2/bpy)n multilayer catalysts were easily removed from the reaction mixture without separation filtration. Moreover, (PdCl2/bpy)n catalysts were reused for 10 consecutive reactions without loss of activity. The present (PdCl2/bpy)n heterogeneous catalysts have the advantages of easy separation and good recyclability. PMID:25490567

Gao, Shuiying; Li, Weijin; Cao, Rong

2015-03-01

62

Sulphamic Acid (H2NSO3H): A Low Cost, Mild and an Efficient Catalyst for the Synthesis of Substituted N-Phenylpyrazoles Under Solvent-Free Conditions  

Microsoft Academic Search

N-phenylpyrazoles are synthesized by condensing phenylhydrazine and 1,3-diketones in the presence of catalytic amount of sulphamic acid, a mild and an efficient solid acid catalyst, under solvent-free conditions. This condensation proceeds smoothly in shorter reaction time.

Mohan R. Shetty; Shriniwas D. Samant

2011-01-01

63

Sulfamic Acid (H2NSO3H): A Low-Cost, Mild, and Efficient Catalyst for the Synthesis of Substituted N-Phenylpyrazoles Under Solvent-Free Conditions  

Microsoft Academic Search

N-Phenylpyrazoles are synthesized by condensing phenylhydrazine and 1,3-diketones in the presence of a catalytic amount of sulfamic acid, a mild and an efficient solid acid catalyst, under solvent-free conditions. This condensation proceeds smoothly in shorter reaction time.

Mohan R. Shetty; Shriniwas D. Samant

2012-01-01

64

CO? carbonation under aqueous conditions using petroleum coke combustion fly ash.  

PubMed

Fly ash from petroleum coke combustion was evaluated for CO2 capture in aqueous medium. Moreover the carbonation efficiency based on different methodologies and the kinetic parameters of the process were determined. The results show that petroleum coke fly ash achieved a CO2 capture yield of 21% at the experimental conditions of 12 g L(-1), 363°K without stirring. The carbonation efficiency by petroleum coke fly ash based on reactive calcium species was within carbonation efficiencies reported by several authors. In addition, carbonation by petroleum coke fly ash follows a pseudo-second order kinetic model. PMID:25000300

González, A; Moreno, N; Navia, R

2014-12-01

65

A general and facile one-pot process of isothiocyanates from amines under aqueous conditions  

PubMed Central

Summary A general and facile one-pot protocol for the preparation of a broad range of alkyl and aryl isothiocyanates has been developed from their corresponding primary amines under aqueous conditions. This synthetic process involves an in situ generation of a dithiocarbamate salt from the amine substrate by reacting with CS2 followed by elimination to form the isothiocyanate product with cyanuric acid as the desulfurylation reagent. The choice of solvent is of decisive importance for the successful formation of the dithiocarbamate salt particularly for highly electron-deficient substrates. This novel and economical method is suitable for scale-up activities. PMID:22423272

Sun, Nan; Li, Bin; Shao, Jianping; Hu, Baoxiang; Shen, Zhenlu

2012-01-01

66

Methylene-bridged bis(benzimidazolium) salt as a highly efficient catalyst for the benzoin reaction in aqueous media.  

PubMed

Benzoin reactions are catalyzed effectively by a methylene-bridged bis(benzimidazolium) salt to yield alpha-hydroxy ketones, and the reactions proceed in water as the aqueous medium under mild conditions. PMID:18292884

Iwamoto, Ken-ichi; Kimura, Hitomi; Oike, Masaaki; Sato, Masayuki

2008-03-01

67

Conditions of aqueous alteration of 9 CM chondrites estimated from mineralogy and compositional variations of matrix  

NASA Astrophysics Data System (ADS)

CM chondrites have undergone prevailed aqueous alteration in the parent asteroids and the alteration changed mineralogical and isotope signatures of water-bearing C-type asteroids.[1,2] In the previous studies, classification schemes of CM chondrites by the alteration degree were proposed by )[3,4] In the present study, we have performed a mineralogical study of 9 CM chondrites found in Antarctica in order to estimatie the nature and extents of aqueous alteration reactions. At first, small pieces (200 microns in size) of matrix were picked up and analyzed by synchroton radiation X-ray diffraction to identify minerals and relative abundances. The results of the X-ray diffraction analysis and SEM observations indicate that serpentine is present in the matrix of all samples as a major phase, suggesting that all samples have undergone aqueous alteration and have not been heated to temperature enough to dehydrate serpentine. Two out of 9 samples (LEW85311 and LAP03178 hereafter GroupA) contain Fe-Ni metal grains in both chondrule and matrix and anhydrous silicates (olivine and pyroxene) in matrix. Five of 9 samples (GRA06172, MET01072, LEW87022, LAP02269 and GRO95566 hereafter GroupB) contain fine-grained PCPs and anhydrous silicates but no metallic phases in matrix. In addition their chondrules are altered only in glassy parts and in limited parts of anhydrous silicates. The rest two of 9 samples (LAP031166 and MAC88100 hereafter GroupC) don't contain Fe-Ni metal and PCPs and contain little anhydrous silicates in matrix. In addition chondrules are almost completely altered. Since metallic phases are more susceptible to aqueous alteration than anhydrous silicates, the results suggest that the alteration degree is in the order of GroupA< GrouB< GroupC. The EPMA analysis indicates that most data of matrix composition fall within the triangle area defined by [1]: the area is enclosed by the composition of PCPs and two serpentines (the serpentin compositions are defined by those from Murry and Nogoya meteorites) in a Mg-Fe-Si ternary diagram. Nine samples have different compositional trends and PCP/(PCP+serpentine) ratios, suggesting that these 9 samples have suffered various extents of aqueous alteration. The matrix compositions reflect the conditions of aqueous alteration, because of its fine-grained nature. Therefore, it is expected that, for instance, GroupA samples show compositional trends similar within the Group, but different from other Groups. However, GroupA sample (LAP03178) has the same trend as GroupB sample (GRO95566), and GroupB sample (MET01072) has the same trend as GroupC sample (MAC88100).This suggests that aqueous alteration process is very complex: the starting matrix compositions are variable, and the resultant matrix compositions are also different. This indicates that matrix chemical composition alone is not enough to define the alteration degree. [1]McSween (1986), GCA 51, 2469-2477 [2]Clayton and Mayeda (1984) Earth and Planetary Science Letters 67, 151-161 [3]Zolensky et.al (1997) GCA 61, 5099-5115 [4]Rubin et al. (2007) GCA 71, 2361-2382

Yoshioka, K.; Nakamura, T.; Fujimaki, H.

2011-12-01

68

Mechanics and mechanisms of surface damage in Al-Si alloys under ultra-mild wear conditions  

NASA Astrophysics Data System (ADS)

Al-Si alloys intended for use in engine components must operate under ultra-mild wear (UMW) conditions to fit an acceptable amount of wear during a typical vehicle life. This study simulated surface damage in a UMW regime on five chemically etched Al-Si alloy surfaces using a pin-on-disc tribometer at low loads (0.5-2.0 N) under boundary lubricated conditions. The five alloys contained 11 to 25 wt.% Si and differed in matrix hardness, silicon particle morphology, and size. The mechanisms leading to the UMW damage and the role that the matrix hardness and microstructure play on said mechanisms were studied. Quantitative measurement methods based on statistical analysis of particle height changes and material loss from elevated aluminum using a profilometer technique were developed and used to assess UMW. The Greenwood and Tripp's numerical model was adapted to analyze the contact that occurred between Al-Si alloys with silicon particles protruding above the aluminum and steel balls. The estimation of the real contact pressure applied to the silicon particles was used to rationalize the damage mechanisms. The UMW mechanisms consisted of (i) abrasive wear on the top of the silicon particle surfaces; (ii) sinking-in of the silicon particles; (iii) piling-up of the aluminium around sunken-in particles and (vi) wear of the aluminium by the counterface, which eventually led to the initiation of UMW-II. Increasing the size or areal density of silicon particles with small aspect ratios delayed the onset of UMW-II by providing resistance against the silicon particles sinking-in and the aluminum piling-up. The UMW wear rates, however, began to decrease after long sliding cycles once an oil residue layer supported by hardened ultra-fine subsurface grains formed on the deformed aluminium matrix. The layer formation depended on the microstructure and applied load. Overall experimental observations suggested that Al-11% Si with small silicon particles exhibited optimal long-term wear performance.

Chen, Ming

69

Folding Study of Venus Reveals a Strong Ion Dependence of Its Yellow Fluorescence under Mildly Acidic Conditions*S  

E-print Network

Folding Study of Venus Reveals a Strong Ion Dependence of Its Yellow Fluorescence under Mildly- cencethatisrelativelyinsensitivetochangesinpHandionconcen- trations. Here, we present a detailed study of the stability and fold- ing of Venus. By following hydrogen-deuterium exchange of 15 N-labeled Venus using NMR spectroscopy over 13 months, residue

Jackson, Sophie

70

Zirconium Tetrakis(dodecylsulfate) as an Efficient and Recyclable Lewis Acid-Surfactant-Combined Catalyzed CC and CN Bond Forming Under Mild and Environmentally Benign Conditions  

Microsoft Academic Search

A green catalytic method for C-C and C-N bond forming via Michael addition of aromatic amines and indoles to electron-deficient olefins using Zirconium tetrakis(dodecylsulfate) in water under mild conditions with high yields and selectivity has been developed. The reusability of the catalyst has been successfully examined without any noticeable loss of its catalytic activity. Development of more environmental friendly synthetic

Maasoumeh Jafarpour; Abdolreza Rezaeifard; Marzieh Aliabadi

2009-01-01

71

Aqueous Dissolution of Silver Iodide and Associated Iodine Release Under Reducing Conditions with Sulfide  

SciTech Connect

Aqueous dissolution tests of silver iodide (AgI) were performed in Na{sub 2}S solutions in order to evaluate, empirically, dissolution of AgI to release iodine under reducing conditions with sulfide. The results indicated that AgI dissolves to release iodine being controlled by mainly precipitation of Ag{sub 2}S. However, the dissolution of AgI can be depressed to proceed, and the thermodynamic equilibrium cannot be attained easily. Solid phase analysis for the reacted AgI suggested that a thin layer of solid silver forming at AgI surface may evolve to be protective against transportation of reactant species, which can lead to the depression in the dissolution of AgI. (authors)

Yaohiro Inagaki; Toshitaka Imamura; Kazuya Idemitsu; Tatsumi Arima [Kyushu University, Fukuoka, 819-0395 (Japan); Osamu Kato [Kobe Steel Inc., Kobe, 657-0845 (Japan); Hidekazu Asano; Tsutomu Nishimura [RWMC, Tokyo, 105-0001 (Japan)

2007-07-01

72

Oxidative degradation of organic pollutants in aqueous solution using zero valent copper under aerobic atmosphere condition.  

PubMed

Oxidative degradation of organic pollutants and its mechanism were investigated in aqueous solution using zero valent copper (ZVC) under aerobic atmosphere condition. Diethyl phthalate (DEP) was completely oxidized after 120 min reaction by ZVC at initial pH 2.5 open to the air. DEP degradation followed the pseudo-first-order kinetics after the lag period, and the degradation rate of DEP increased gradually with the increase of ZVC dosage, and the decrease of initial pH from 5.8 to 2.0. ZVC required a shorter induction time and exhibited persistent oxidation capacity compared to that of zero valent iron and zero valent aluminium. The mechanism investigation showed that remarkable amount of Cu(+)/Cu(2+) and H2O2 were formed in ZVC acidic system, which was due to the corrosive dissolution of ZVC and the concurrent reduction of oxygen. The addition of tert-butanol completely inhibited the degradation of DEP and the addition of Fe(2+) greatly enhanced the degradation rate, which demonstrated that hydroxyl radical was mainly responsible for the degradation of DEP in ZVC acidic system under aerobic atmosphere condition, and the formation of hydroxyl radical was attributed to the Fenton-like reaction of in situ formed Cu(+) with H2O2. PMID:24857902

Wen, Gang; Wang, Sheng-Jun; Ma, Jun; Huang, Ting-Lin; Liu, Zheng-Qian; Zhao, Lei; Xu, Jin-Lan

2014-06-30

73

Hierarchically organized silica-titania monoliths prepared under purely aqueous conditions.  

PubMed

Hierarchically organized silica-titania monoliths were synthesized under purely aqueous conditions by applying a new ethylene glycol-modified single-source precursor, such as 3-[3-{tris(2-hydroxyethoxy)silyl}propyl]acetylacetone coordinated to a titanium center. The influence of the silicon- and titanium-containing single-source precursor, the novel glycolated organofunctional silane, and the addition of tetrakis(2-hydroxyethyl)orthosilicate on the formation of the final porous network was investigated by SEM, TEM, nitrogen sorption, and SAXS/WAXS. In situ SAXS measurements were performed to obtain insight into the development of the mesoporous network during sol-gel transition. IR-ATR, UV/Vis, XPS, and XAFS measurements showed that up to a Si/Ti ratio of 35:1, well-dispersed titanium centers in a macro-/mesoporous SiO2 network with a specific surface area of up to 582?m(2) ?g(-1) were obtained. An increase in Ti content resulted in a decrease in specific surface area and a loss of the cellular character of the macroporous network. With a 1:1 Si/Ti ratio, silica-titania powders with circa 100?m(2) ?g(-1) and anatase domains within the SiO2 matrix were obtained. PMID:25367386

Flaig, Sylvia; Akbarzadeh, Johanna; Dolcet, Paolo; Gross, Silvia; Peterlik, Herwig; Hüsing, Nicola

2014-12-22

74

Diverse Aqueous Conditions on Mars from New Orbital Detections of Carbonate and Sulfate  

NASA Astrophysics Data System (ADS)

Diverse aqueous environments on ancient Mars have been a key inference from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on NASA's Mars Reconnaissance Orbiter, which has identified many alteration minerals in a range of settings [e.g., 1-4]. Here we report two new minerals detected using CRISM. In the southern highlands northwest of the Hellas basin, a mid-sized crater exposes carbonate in its central uplift. Spectral absorptions at 1, 2.33, and 2.53 microns are most consistent with Fe-carbonate, distinct from the Mg-carbonates identified from orbit by [5]. Fe-carbonate is associated with Mg-phyllosilicate in fractured materials formerly buried kilometers beneath the surface, and--like the Mg/Fe-carbonate found by the Spirit rover [6]--suggests a reducing, neutral-to-alkaline alteration environment. One of the largest phyllosilicate exposures on Mars occurs in the Mawrth Vallis region [e.g., 7]. We identify bassanite (Ca-sulfate hemihydrate) in layers underlying the phyllosilicate-bearing beds [8], a stratigraphy distinct from that predicted by global models of martian aqueous history [9]. Bassanite could have formed via acid-sulfate alteration of Ca-carbonate, through dehydration of gypsum, or under hydrothermal conditions [10]. These detections expand the known mineralogic diversity of Mars and the range of environments to explore for past habitability. [1] Mustard, J. F. et al. (2008) Nature 454, 305-309. [2] Murchie, S. L. et al. (2009) J. Geophys. Res. 114, E00D06. [3] Ehlmann, B. L. et al. (2009) J. Geophys. Res. 114, E00D08. [4] Wray, J. J. et al. (2009) Geology 37, 1043-1046. [5] Ehlmann, B. L. et al. (2008) Science 322, 1828-1832. [6] Morris, R. V. et al. Science, in press, doi:10.1126/science.1189667. [7] Poulet, F. et al. (2005) Nature 438, 623-627. [8] Wray, J. J. et al. Icarus, in press, doi:10.1016/j.icarus.2010.06.001. [9] Bibring, J.-P. et al. (2006) Science 312, 400-404. [10] Vaniman, D. T. et al. (2009) LPSC 40, 1654.

Wray, James J.; Squyres, S. W.

2010-10-01

75

Effect of condensation agents and minerals for oligopeptide formation under mild and hydrothermal conditions in related to chemical evolution of proteins  

NASA Astrophysics Data System (ADS)

The role of condensation agents and minerals for oligopeptide formation was inspected to see whether minerals possess catalytic activity under mild and hydrothermal conditions. Under mild conditions, oligopeptide formation from negatively charged amino acids (Asp and Glu) using different minerals and the elongation of alanine oligopeptides ((Ala) 2-(Ala) 5) were attempted using apatite minerals. Oligo(Asp) up to 10 amino acid units from Asp were observed in the presence of 1-ethyl-3-(3-dimethylaminopropyl carbodiimide (EDC). Notable influence of minerals was not detected for the oligo(Asp) formation. Oligo(Asp) was gradually degraded by the further incubation in the presence of EDC in both the absence and presence of minerals. The formation of oligo(Glu) was less efficient in the presence of carbonyldiimidazole. The elongation from (Ala) 3, (Ala) 4, and (Ala) 5 and the formation of diketopiperazine from (Ala) 2 proceeded immediately in the presence of EDC in the meantime of the sample preparations. In addition, it was unexpected that the disappearance of the products and the reformation of the reactants occurred by the further incubation for 24 h; for instance, (Ala) 5 decreased but (Ala) 4 increased with increasing the reaction time in the reaction of (Ala) 4 with EDC. These facts suggest that the activation of the reactant amino acids or peptides immediately occurs. Under the simulated hydrothermal conditions, EDC did not enhance the formation of oligopeptides from Asp, Glu or Ala nor the spontaneous formation of (Ala) 5 from (Ala) 4.

Kawamura, Kunio; Takeya, Hitoshi; Kushibe, Takao

2009-07-01

76

CHEMICAL TRANSFORMATIONS USING NON-TRADITIONAL APPROACHES: MICROWAVE-ASSISTED GREENER SYNTHESES IN AQUEOUS MEDIA OR UNDER SOLVENT-FREE CONDITIONS  

EPA Science Inventory

Microwave (MW) irradiation in conjunction with water as reaction media has proven to be a 'greener' chemical approach for expeditious N -alkylation reactions of amines and hydrazines wherein the reactions under mildly basic conditions afford tertiary amines and double N...

77

Dissolution of Columbia River Basalt Under Mildly Acidic Conditions as a Function of Temperature: Experimental Results Relevant to the Geological Sequestration of Carbon Dioxide  

SciTech Connect

Increasing attention is being focused on the rapid rise of carbon dioxide levels in the atmosphere, which many believe to be the major contributing factor to global climate change. Sequestering CO2 in deep geological formations has been proposed as a long-term solution to help stabilize CO2 levels. However, before such technology can be developed and implemented, a basic understanding of H2O-CO2 systems and the chemical interactions of these fluids with the host formation must be obtained. Important issues concerning mineral stability, reaction rates, and carbonate formation are all controlled or at least significantly impacted by the kinetics of rock-water reactions in mildly acidic, CO2-saturated solutions. Basalt has recently been identified as a potentially important host formation for geological sequestration. Dissolution kinetics of the Columbia River Basalt (CRB) were measured for a range of temperatures (25° to 90°C) under mildly acidic to neutral pH conditions using the single-pass flow-through test method. Under anaerobic conditions, the normalized dissolution rates for CRB decrease with increasing pH (3?pH?7) with a slope, ?, of -0.12 ± 0.02. An activation energy, Ea, has been estimated at 30.3 ± 2.4 kJ mol-1. Dissolution kinetics measurements like these are essential for modeling the rate at which the CO2 reacts with basalt and ultimately converted to carbonate minerals in situ.

Schaef, Herbert T.; McGrail, B. Peter

2009-05-01

78

Asian dust particles converted into aqueous droplets under remote marine atmospheric conditions  

PubMed Central

The chemical history of dust particles in the atmosphere is crucial for assessing their impact on both the Earth’s climate and ecosystem. So far, a number of studies have shown that, in the vicinity of strong anthropogenic emission sources, Ca-rich dust particles can be converted into aqueous droplets mainly by the reaction with gaseous HNO3 to form Ca(NO3)2. Here we show that other similar processes have the potential to be activated under typical remote marine atmospheric conditions. Based on field measurements at several sites in East Asia and thermodynamic predictions, we examined the possibility for the formation of two highly soluble calcium salts, Ca(NO3)2 and CaCl2, which can deliquesce at low relative humidity. According to the results, the conversion of insoluble CaCO3 to Ca(NO3)2 tends to be dominated over urban and industrialized areas of the Asian continent, where the concentrations of HNO3 exceed those of HCl ([HNO3/HCl] >  ? 1). In this regime, CaCl2 is hardly detected from dust particles. However, the generation of CaCl2 becomes detectable around the Japan Islands, where the concentrations of HCl are much higher than those of HNO3 ([HNO3/HCl] <  ? 0.3). We suggest that elevated concentrations of HCl in the remote marine boundary layer are sufficient to modify Ca-rich particles in dust storms and can play a more important role in forming a deliquescent layer on the particle surfaces as they are transported toward remote ocean regions. PMID:20921372

Tobo, Yutaka; Zhang, Daizhou; Matsuki, Atsushi; Iwasaka, Yasunobu

2010-01-01

79

Mild Salt Stress Conditions Induce Different Responses in Root Hydraulic Conductivity of Phaseolus vulgaris Over-Time  

PubMed Central

Plants respond to salinity by altering their physiological parameters in order to maintain their water balance. The reduction in root hydraulic conductivity is one of the first responses of plants to the presence of salt in order to minimize water stress. Although its regulation has been commonly attributed to aquaporins activity, osmotic adjustment and the toxic effect of Na+ and Cl? have also a main role in the whole process. We studied the effects of 30 mM NaCl on Phaseolus vulgaris plants after 9 days and found different responses in root hydraulic conductivity over-time. An initial and final reduction of root hydraulic conductivity, stomatal conductance, and leaf water potential in response to NaCl was attributed to an initial osmotic shock after 1 day of treatment, and to the initial symptoms of salt accumulation within the plant tissues after 9 days of treatment. After 6 days of NaCl treatment, the increase in root hydraulic conductivity to the levels of control plants was accompanied by an increase in root fructose content, and with the intracellular localization of root plasma membrane aquaporins (PIP) to cortex cells close to the epidermis and to cells surrounding xylem vessels. Thus, the different responses of bean plants to mild salt stress over time may be connected with root fructose accumulation, and intracellular localization of PIP aquaporins. PMID:24595059

Calvo-Polanco, Monica; Sánchez-Romera, Beatriz; Aroca, Ricardo

2014-01-01

80

Modelling of Chlorophenol Treatment in Aqueous Solutions. 1. Ozonation and Ozonation Combined with UV Radiation under Acidic Conditions  

Microsoft Academic Search

Treatment of 2-chlorophenol (2-CP), 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) in aqueous solutions with direct photolysis (254 nm), ozonation and ozonation with photolysis was studied. A model was developed to simulate chlorophenol treatment in a semibatch column using these processes under acidic conditions in which the chemical reactions are slow. Satisfactory results were obtained in simulating the chlorophenol and ozone concentrations,

Marjaana Hautaniemi; Juha Kallas; Rein Munter; Marina Trapido

1998-01-01

81

Guiding functional connectivity estimation by structural connectivity in MEG: an application to discrimination of conditions of mild cognitive impairment  

PubMed Central

Whole brain resting state connectivity is a promising biomarker that might help to obtain an early diagnosis in many neurological diseases, such as dementia. Inferring resting-state connectivity is often based on correlations, which are sensitive to indirect connections, leading to an inaccurate representation of the real backbone of the network. The precision matrix is a better representation for whole brain connectivity, as it considers only direct connections. The network structure can be estimated using the graphical lasso (GL), which achieves sparsity through l1-regularization on the precision matrix. In this paper, we propose a structural connectivity adaptive version of the GL, where weaker anatomical connections are represented as stronger penalties on the corresponding functional connections. We applied beamformer source reconstruction to the resting state MEG recordings of 81 subjects, where 29 were healthy controls, 22 were single-domain amnestic Mild Cognitive Impaired (MCI), and 30 were multiple-domain amnestic MCI. An atlas-based anatomical parcellation of 66 regions was obtained for each subject, and time series were assigned to each of the regions. The fiber densities between the regions, obtained with deterministic tractography from diffusion-weighted MRI, were used to define the anatomical connectivity. Precision matrices were obtained with the region specific time series in five different frequency bands. We compared our method with the traditional GL and a functional adaptive version of the GL, in terms of log-likelihood and classification accuracies between the three groups. We conclude that introducing an anatomical prior improves the expressivity of the model and, in most cases, leads to a better classification between groups. PMID:25111472

Pineda-Pardo, José Angel; Bruña, Ricardo; Woolrich, Mark; Marcos, Alberto; Nobre, Anna C.; Maestú, Fernando; Vidaurre, Diego

2014-01-01

82

Kinetics of carbonate dissolution in CO2-saturated aqueous system at reservoir conditions  

NASA Astrophysics Data System (ADS)

In recent years, carbon capture and storage (CCS) has emerged as a key technology for limiting anthropogenic CO2 emissions while allowing the continued utilisation of fossil fuels. The most promising geological storage sites are deep saline aquifers because the capacity, integrity and injection economics are most favourable, and the environmental impact can be minimal. Many rock-fluid chemical reactions are known to occur both during and after CO2 injection in saline aquifers. The importance of rock-fluid reactions in the (CO2 + H2O) system can be understood in terms of their impact on the integrity and stability of both the formation rocks and cap rocks. The chemical interactions between CO2-acidified brines and the reservoir minerals can influence the porosity and permeability of the formations, resulting in changes in the transport processes occurring during CO2 storage. Since carbonate minerals are abundant in sedimentary rocks, one of the requirements to safely implement CO2 storage in saline aquifers is to characterise the reactivity of carbonate minerals in aqueous solutions at reservoir conditions. In this work, we reported measurements of the intrinsic rate of carbonate dissolution in CO2-saturated water under high-temperature high-pressure reservoir conditions extending up to 373 K and 14 MPa. The rate of carbonate dissolution in CO2-free HCl(aq) was also measured at ambient pressure at temperatures up to 353 K. Various pure minerals and reservoir rocks were investigated in this study, including single-crystals of calcite and magnesite, and samples of dolomite, chalks and sandstones. A specially-designed batch reactor system, implementing the rotating disc technique, was used to obtain the intrinsic reaction rate at the solid/liquid interface, free of mass transfer effects. The effective area and mineralogy of the exposed surface was determined by a combination of surface characterisation techniques including XRD, SEM, EDX and optical microscopy. The results of the study indicate that the rotating disc technique can allow accurate measurement of the carbonate dissolution rate under surface-reaction-controlled conditions, and that the carbonate dissolution rate typically increases with the increase of temperature, CO2 partial pressure and solution acidity. The study shows that the dissolution of carbonate in CO2-free acidic solutions can be described as a first order heterogeneous reaction; however, this model is not sufficient to describe the reaction kinetics of carbonate minerals in the (CO2 + H2O) system, particularly for high reactivity carbonates, such as calcite, at reservoir conditions. For these systems, both pH and the activity of CO2(aq) influence the dissolution rate. Based on the experimental results, kinetic models have been developed and parameterised to describe the dissolution of different carbonate minerals. The results of this study should facilitate more rigorous modelling of mineral dissolution in deep saline aquifers used for CO2 storage. We gratefully acknowledge the funding of QCCSRC provided jointly by Qatar Petroleum, Shell, and the Qatar Science & Technology Park. Keywords: Carbon Dioxide, Carbonate, High Pressure, High Temperature, Reaction Kinetics.

Peng, Cheng; Crawshaw, John P.; Maitland, Geoffrey; Trusler, J. P. Martin

2014-05-01

83

A literature survey and an experimental study of coal devolatilization at mild and severe conditions: Influence of heating rate, temperature, and reactor type on product yield and composition  

SciTech Connect

The objectives of this study were to investigate how relatively mild operating conditions (i.e., relatively low temperatures and pressures) influence product quality by comparing devolatilized products obtained at various temperatures and heating rates. Fixed-, fluid-, and entrained-flow reactor units were used to obtain pyrolysis products. In addition, available literature data on tar yield in various reactor units at a range of temperatures and residence times were surveyed and compared with the data generated in the present study. Liquids were characterized by a number of techniques (e.g., field ionization mass spectroscopy or FIMS, sequential elution solvent chromatography or SESC, fourier transform infrared spectroscopy or FTIR, elemental analysis). 34 refs., 21 figs., 2 tabs.

Khan, M.R.

1989-06-01

84

New iridium catalysts for the selective alkylation of amines by alcohols under mild conditions and for the synthesis of quinolines by acceptor-less dehydrogenative condensation.  

PubMed

A novel family of iridium catalysts stabilised by P,N-ligands have been introduced. The ligands are based on imidazo[1,5-b]pyridazin-7-amines and can be synthesised with a broad variety of substitution patterns. The catalysts were synthesised quantitatively from the protonated ligands and a commercially available iridium precursor. The catalysts mediate the alkylation of amines by alcohols under mild conditions (70?°C). In addition, the synthesis of quinolines from secondary or primary alcohols and amino alcohols is reported. This sustainable synthesis proceeds through the liberation of two equivalents of water and two equivalents of dihydrogen. The investigations indicate that catalysts suitable for hydrogen autotransfer or borrowing hydrogen chemistry might also be suitable for acceptor-less dehydrogenative condensation reactions. PMID:25186522

Ruch, Susanne; Irrgang, Torsten; Kempe, Rhett

2014-10-01

85

Direct conversion of cellulose to glucose and valuable intermediates in mild reaction conditions over solid acid catalysts  

Microsoft Academic Search

The direct hydrolysis of cellulose to glucose, HMF and other soluble by-products at 190°C in water solution using zeolites (H-BEA, H-MOR), sulphated zirconia supported over mesoporous silica (SBA-15), Amberlyst®15, heteropolyacids and AlCl3·6H2O as acid catalysts was studied using a high cellulose to catalyst ratio (10), not-pretreated (neither mechanically nor chemically) cellulose and a static (not mixed) autoclave. Under these conditions,

P. Lanzafame; D. M. Temi; S. Perathoner; A. N. Spadaro; G. Centi

86

Complexes of earth-abundant metals for catalytic electrochemical hydrogen generation under aqueous conditions.  

PubMed

Growing global energy demands and climate change motivate the development of new renewable energy technologies. In this context, water splitting using sustainable energy sources has emerged as an attractive process for carbon-neutral fuel cycles. A key scientific challenge to achieving this overall goal is the invention of new catalysts for the reductive and oxidative conversions of water to hydrogen and oxygen, respectively. This review article will highlight progress in molecular electrochemical approaches for catalytic reduction of protons to hydrogen, focusing on complexes of earth-abundant metals that can function in pure aqueous or mixed aqueous-organic media. The use of water as a reaction medium has dual benefits of maintaining high substrate concentration as well as minimizing the environmental impact from organic additives and by-products. PMID:23034627

Thoi, V Sara; Sun, Yujie; Long, Jeffrey R; Chang, Christopher J

2013-03-21

87

Mild balanoposthitis.  

PubMed Central

AIM--To identify and study cases of mild balanoposthitis (MBP) with penile pathology among patients observed at a dermatology clinic over an 18-month period. MATERIALS--The study included 321 patients with penile pathology. The term MBP was used to describe balanoposthitis of a localised, inflammatory nature with few, non-specific symptoms and a tendency to become chronic or recur. Two hundred and seventy had diseases clearly identifiable by clinical examination or laboratory tests; 51 cases were diagnosed as MBP and these patients had blood tests (to evaluate immune status) and microbiological examination; when these proved negative, a series of patch tests was also used. RESULTS--Of the 51 patients diagnosed as having MBP, the cause was ascertained in 34 cases (infection, mechanical trauma, contact irritation, contact allergy, etc.), whereas no specific aetiological factor was detected to explain the symptoms in the remaining 17 cases. PMID:8001949

Fornasa, C V; Calabr?, A; Miglietta, A; Tarantello, M; Biasinutto, C; Peserico, A

1994-01-01

88

Catalysis of peptide formation by inorganic oxides: High efficiency of alumina under mild conditions on the earth-like planets  

NASA Astrophysics Data System (ADS)

Amino acid condensation catalyzed by inorganic oxides is a widely recognized way for prebiotic peptide formation. Silica and alumina are widely distributed in the Earth-like planets' crust as minerals of different complexity, and thus are attractive model catalysts for the studies of abiotic peptide synthesis. Experiments performed in other laboratories have shown that this process can be efficient at >80 °C, which is not easy to find on the planetary surface in combination with sufficient concentrations of amino acids and necessary catalysts. In the present work we tested catalytic activity of three forms of alumina (which proved to be an efficient catalyst for this process) in the intermolecular condensation of L-alanine. We expanded the temperature interval down to 55 °C and used the simplest permanent heating procedure, without employing fluctuating drying/wetting conditions. The most important finding is that even under the lowest temperature considered ( i.e. 55 °C), short peptide formation can be detected already after 10-30 days of heating. This fact implies that the abiotic peptide formation might occur in a wide variety of planetary environments, without need for high temperatures, given the presence of amino acid building blocks and alumina-containing minerals.

Basiuk, V. A.; Sainz-Rojas, J.

89

Catalysis of peptide formation by inorganic oxides: high efficiency of alumina under mild conditions on the Earth-like planets.  

PubMed

Amino acid condensation catalyzed by inorganic oxides is a widely recognized way for prebiotic peptide formation. Silica and alumina are widely distributed in the Earth-like planets' crust as minerals of different complexity, and thus are attractive model catalysts for the studies of abiotic peptide synthesis. Experiments performed in other laboratories have shown that this process can be efficient at > 80 degrees C, which is not easy to find on the planetary surface in combination with sufficient concentrations of amino acids and necessary catalysts. In the present work we tested catalytic activity of three forms of alumina (which proved to be an efficient catalyst for this process) in the intermolecular condensation of L-alanine. We expanded the temperature interval down to 55 degrees C and used the simplest permanent heating procedure, without employing fluctuating drying/wetting conditions. The most important finding is that even under the lowest temperature considered (i.e. 55 degrees C), short peptide formation can be detected already after 10-30 days of heating. This fact implies that the abiotic peptide formation might occur in a wide variety of planetary environments, without need for high temperatures, given the presence of amino acid building blocks and alumina-containing minerals. PMID:11605636

Basiuk, V A; Sainz-Rojas, J

2001-01-01

90

Effect of Hydrolysis Conditions on the Direct Formation of Nanoparticles of Ceria–Zirconia Solid Solutions from Acidic Aqueous Solutions  

Microsoft Academic Search

The effect of the cation concentration, hydrolysis temperature, and composition in the CeO2–ZrO2 system on the direct precipitation of ceria–zirconia solid solutions and the structure of the precipitates from acidic aqueous solutions of (NH4)2Ce(NO3)6 and ZrOCl2 by hydrolysis under hydrothermal conditions were investigated. Nanometer-sized (8–10 nm) ceria–zirconia solid solution particles in a composition range of 0 to 60 mol% ZrO2

Masanori Hirano; Kaname Hirai

2003-01-01

91

Characteristics of CuO-MoO3-P2O5 catalyst and its catalytic wet oxidation (CWO) of dye wastewater under extremely mild conditions.  

PubMed

In order to develop a catalyst with high activity for catalytic wet oxidation (CWO) processing at lower temperatures (35 degrees C) and atmospheric pressure, a new CuO-MoO3-P2O5 catalystwas synthesized by a solid-state reaction method and was characterized by X-ray diffraction (XRD), Fourier transformation infrared spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), selected area electronic diffraction (SAED), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) for elemental mapping. Methylene blue (MB) was adopted to investigate the catalytic activity of CuO-MoO3-P2O5 in CWO processing. The results show that this new catalyst has a high catalytic activity to decolorize MB under mild condition. The color removal of MB (the initial concentration was 0.3 g L(-1) and initial pH was 5) can reach to 99.26% within 10 min at 35 degrees C and atmospheric pressure. Catalyst lifespan and selectivity were also tested, and the results show that after the catalyst was used three times, catalyst activity still remains. Selectivity testing shows that CuO-MoO3-P2O5 has high catalytic activity on degradation of MB, whereas this catalyst has less impact on methyl orange (the color removal was 99.65% for MB and 55% for methyl orange under the same conditions). According to the experimental results, a possible mechanism of catalytic degradation of MB was proposed. PMID:18044531

Ma, Hongzhu; Zhuo, Qiongfang; Wang, Bo

2007-11-01

92

Acetylation of sugarcane bagasse using NBS as a catalyst under mild reaction conditions for the production of oil sorption-active materials.  

PubMed

Sugarcane bagasse was esterified with acetic anhydride using N-bromosuccinimide as a catalyst under mild conditions in a solvent free system. The extent of acetylation was measured by weight percent gain, which varied from 2.1% to 24.7% by changing the reaction temperature (25-130 degrees C) and duration (0.5-6.0 h). N-Bromosuccinimide was found to be a novel and highly effective catalyst for acetylation of hydroxyl groups in bagasse. At a concentration of 1% of the catalyst in acetic anhydride, a weight percent gain of 24.7% was achieved at 120 degrees C for 1 h, compared with 5.1% for the un-catalyst reaction under the same reaction condition. FT-IR and CP-MAS 13C-NMR studies produced evidence for acetylation. The thermal stability of the products decreased slightly upon chemical modification, but no significant decrease in thermal stability was observed for WPG > or = 24.7%. More importantly, the acetylation significantly increased hydrophobic properties of the bagasse. The oil sorption capacity of the acetylated bagasse obtained at 80 degrees C for 6 h, was 1.9 times higher than the commercial synthetic oil sorbents such as polypropylene fibres. Therefore, these oil sorption-active materials can be used to substitute non-biodegradable materials in oil spill cleanup. PMID:15288278

Sun, X F; Sun, R C; Sun, J X

2004-12-01

93

Characterizing photochemical transformation of aqueous nC60 under environmentally relevant conditions.  

PubMed

Engineered nanomaterials may undergo transformation upon interactions with various environmental factors. In this study, photochemical transformation of aqueous nC60 was investigated under UVA irradiation. nC60 underwent photochemical transformation in the presence of dissolved O2, resulting in surface oxygenation and hydroxylation as demonstrated by XPS and ATR-FTIR analyses. The reaction followed a pseudo-first order rate law with the apparent reaction rate constant of 2.2 x 10(-2) h(-1). However, the core of the nanoparticles remained intact over 21 days of irradiation. Although no mineralization or dissolution of nC60 was observed, experiments using fullerol as a reference fullerene derivative suggested likely dissolution and partial mineralization of nC60 under long-term UVA exposure. Aquatic humic acid reduced nC60 transformation kinetics presumably due to scavenging of reactive oxygen species. Results from this study imply that photochemical transformation is an important factor controlling nC60 physical and chemical properties as well as its fate and transport in the natural aqueous environment. In addition, changes in nC60 surface chemistry drastically reduced C60 extraction efficiency by toluene, suggesting that the existing analytical method for C60 may not be applicable to environmental samples. PMID:20337472

Hwang, Yu Sik; Li, Qilin

2010-04-15

94

Aldehyde-alcohol reactions catalyzed under mild conditions by chromium(III) terephthalate metal organic framework (MIL-101) and phosphotungstic acid composites.  

PubMed

Porous materials based on chromium(III) terephthalate metal organic frameworks (MIL-101) and their composites with phosphotungstic acid (PTA) were studied as heterogeneous acid catalysts in aldehyde-alcohol reactions exemplified by acetaldehyde-phenol (A-P) condensation and dimethylacetal formation from benzaldehyde and methanol (B-M reaction). The MIL-101 was synthesized solvothermically in water, and the MIL101/PTA composite materials were obtained by either impregnation of the already prepared MIL-101 porous matrix with phosphotungstic acid solution or by solvothermic treatment of aqueous mixtures of Cr(NO(3))(3), and terephthalic and phosphotungstic acids. The MIL101/PTA materials appeared to be effective catalysts for both A-P and B-M reactions occurring at room temperature, with half-lives ranging from 0.5 h (A-P) to 1.5-2 h (B-M) and turnover numbers over 600 for A-P and over 2900 for the B-M reaction, respectively. A synergistic effect of the strong acidic moieties (PTA) addition to mildly acidic Brønsted and Lewis acid cites of the MIL-101 was observed with the MIL101/PTA composites. The ability of the PTA and MIL101/PTA materials to strongly absorb and condense acetaldehyde vapors was discovered, with the MIL101/PTA absorbing over 10-fold its dry weight of acetaldehyde condensate at room temperature. The acetaldehyde was converted rapidly to crotonaldehyde and higher-molecular-weight compounds while in contact with MIL-101 and MIL101/PTA materials. The stability of the MIL-101 and MIL101/PTA catalysts was assessed within four cycles of the 1-day alcohol-aldehyde reactions in terms of the overall catalyst recovery, PTA or Cr content, and reaction rate constants in each cycle. The loss of the catalyst over 4 cycles was approximately 10 wt % for all tested catalysts due to the incomplete recovery and minute dissolution of the components. The reaction rates in all cycles remained unchanged and the catalyst losses stopped after the third cycle. The developed MIL101/PTA composites appear to be feasible for industrial catalytic applications. PMID:22091761

Bromberg, Lev; Hatton, T Alan

2011-12-01

95

Diffusion behavior of lysozyme in aqueous ammonium sulfate solutions under varying solution conditions as determined by dynamic light scattering  

SciTech Connect

As proteins gain significance in commercial applications such as pharmaceuticals, detergents, organic waste management and cosmetics, efficient and economical recovery of these valuable biomolecules is of increasing importance. the salting-out process has found widespread application in the area of protein separations. To date, salt-induced precipitation of proteins from complex aqueous solutions remains largely an empirical process; no comprehensive model exists to predict salting-out phase equilibria in protein solutions. Rational predictive models for salt-induced precipitation will therefore be of great value in protein purification, both on the preparative and the analytical scale. Any attempt to model theoretically salt-induced protein precipitation must include the known physics of protein interactions in aqueous solution. With this in mind, it is crucial to acknowledge that protein precipitation is fundamentally an aggregation process. In order to incorporate aggregation effects into ongoing efforts to model salting out of proteins, it is necessary to quantify the degree of aggregation as a function of solution conditions. Therefore, dynamic light scattering measurements were performed with a well-studied protein, hen-egg-white lysozyme, under several solution conditions.

Fornefeld, U.M.; Kuehner, D.E.; Blanch, H.W.; Prausnitz, J.M. (Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering Lawrence Berkeley Lab., CA (United States). Chemical Sciences Div.)

1994-12-01

96

Composition and freezing of aqueous H2SO4/HNO3 solutions under polar stratospheric conditions  

NASA Technical Reports Server (NTRS)

The results of laboratory investigations of the freezing behavior of aqueous acid solutions indicate that in the stratosphere H2SO/H2O aerosol droplets would not freeze at temperatures above the ice frost point in the absence of HNO3; however, in the presence of typical levels of HNO3 liquid sulfuric acid aerosols take up significant amounts of HNO3 and H2O vapors and freeze much more readily. This is a consequence of the very rapid change in composition of the liquid droplets as the temperature drops to within two to three degrees of the equilibrium temperature at which HNO3 and H2O vapors would co-condense to form a liquid solution. In the high latitude stratosphere this HNO3/H2O 'dew point' is typically around 192-194 K at 100 mbar.

Beyer, K. D.; Seago, S. W.; Chang, H. Y.; Molina, M. J.

1994-01-01

97

Molecular engineering of a cobalt-based electrocatalytic nanomaterial for H? evolution under fully aqueous conditions.  

PubMed

The viability of a hydrogen economy depends on the design of efficient catalytic systems based on earth-abundant elements. Innovative breakthroughs for hydrogen evolution based on molecular tetraimine cobalt compounds have appeared in the past decade. Here we show that such a diimine-dioxime cobalt catalyst can be grafted to the surface of a carbon nanotube electrode. The resulting electrocatalytic cathode material mediates H(2) generation (55,000 turnovers in seven hours) from fully aqueous solutions at low-to-medium overpotentials. This material is remarkably stable, which allows extensive cycling with preservation of the grafted molecular complex, as shown by electrochemical studies, X-ray photoelectron spectroscopy and scanning electron microscopy. This clearly indicates that grafting provides an increased stability to these cobalt catalysts, and suggests the possible application of these materials in the development of technological devices. PMID:23247177

Andreiadis, Eugen S; Jacques, Pierre-André; Tran, Phong D; Leyris, Adeline; Chavarot-Kerlidou, Murielle; Jousselme, Bruno; Matheron, Muriel; Pécaut, Jacques; Palacin, Serge; Fontecave, Marc; Artero, Vincent

2013-01-01

98

Reversible thermal switching of aqueous dispersibility of multiwalled carbon nanotubes.  

PubMed

Easily reversible aqueous dispersion/precipitation of multiwalled carbon nanotubes (MWNTs) has been demonstrated using small-molecule non-ionic pyrene-based surfactants, which exhibit lower critical solution temperature (LCST) phase behaviour. The MWNTs are dispersed by means of non-covalent interactions. The dispersibility can be switched "off" (i.e., MWNTs precipitated) upon heating and switched "on" (i.e., MWNTs re-dispersed) upon cooling and merely swirling the sample at room temperature, that is, under very mild conditions. This effect is also observed under high ionic strength conditions with NaCl in the aqueous phase. PMID:25639258

O'Driscoll, Luke J; Welsh, Daniel J; Bailey, Steven W D; Visontai, David; Frampton, Harry; Bryce, Martin R; Lambert, Colin J

2015-03-01

99

Stimuli-sensitive hydrogel based on N-isopropylacrylamide and itaconic acid for entrapment and controlled release of Candida rugosa lipase under mild conditions.  

PubMed

Stimuli responsive pH- and temperature-sensitive hydrogel drug delivery systems, as those based on N-isopropylacrylamide (NiPAAm) and itaconic acid (IA), have been attracting much of the attention of the scientific community nowadays, especially in the field of drug release. By adjusting comonomer composition, the matrix is enabled to protect the incorporated protein in the highly acidic environment of upper gastrointestinal tract and deliver it in the neutral or slightly basic region of the lower intestine. The protein/poly(NiPAAm-co-IA) hydrogels were synthetized by free radical crosslinking copolymerization and were characterized concerning their swelling capability, mechanical properties, and morphology. The pore structure and sizes up to 1.90?nm allowed good entrapment of lipase molecules. Model protein, lipase from Candida rugosa, was entrapped within hydrogels upon mild conditions that provided its protection from harmful environmental influences. The efficiency of the lipase entrapment reached 96.7%, and was dependent on the initial concentration of lipase solution. The swelling of the obtained hydrogels in simulated pH and temperature of gastrointestinal tract, the lipase entrapment efficiency, and its release profiles from hydrogels were investigated as well. PMID:24982870

Milašinovi?, Nikola; Kneževi?-Jugovi?, Zorica; Milosavljevi?, Nedeljko; Lu?i? Škori?, Marija; Filipovi?, Jovanka; Kalagasidis Kruši?, Melina

2014-01-01

100

Stimuli-Sensitive Hydrogel Based on N-Isopropylacrylamide and Itaconic Acid for Entrapment and Controlled Release of Candida rugosa Lipase under Mild Conditions  

PubMed Central

Stimuli responsive pH- and temperature-sensitive hydrogel drug delivery systems, as those based on N-isopropylacrylamide (NiPAAm) and itaconic acid (IA), have been attracting much of the attention of the scientific community nowadays, especially in the field of drug release. By adjusting comonomer composition, the matrix is enabled to protect the incorporated protein in the highly acidic environment of upper gastrointestinal tract and deliver it in the neutral or slightly basic region of the lower intestine. The protein/poly(NiPAAm-co-IA) hydrogels were synthetized by free radical crosslinking copolymerization and were characterized concerning their swelling capability, mechanical properties, and morphology. The pore structure and sizes up to 1.90?nm allowed good entrapment of lipase molecules. Model protein, lipase from Candida rugosa, was entrapped within hydrogels upon mild conditions that provided its protection from harmful environmental influences. The efficiency of the lipase entrapment reached 96.7%, and was dependent on the initial concentration of lipase solution. The swelling of the obtained hydrogels in simulated pH and temperature of gastrointestinal tract, the lipase entrapment efficiency, and its release profiles from hydrogels were investigated as well. PMID:24982870

Milašinovi?, Nikola; Kneževi?-Jugovi?, Zorica; Milosavljevi?, Nedeljko; Lu?i? Škori?, Marija; Filipovi?, Jovanka; Kalagasidis Kruši?, Melina

2014-01-01

101

Mizoroki-heck cross-coupling reactions catalyzed by dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium under mild reaction conditions.  

PubMed

Dichloro-bis(aminophosphine) complexes of palladium with the general formula of [(P{(NC5H10)3-n(C6H11)n})2Pd(Cl)2] (where n = 0-2), belong to a new family of easy accessible, very cheap, and air stable, but highly active and universally applicable C-C cross-coupling catalysts with an excellent functional group tolerance. Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium [(P(NC5H10)3)2Pd(Cl)2] (1), the least stable complex within this series towards protons; e.g. in the form of water, allows an eased nanoparticle formation and hence, proved to be the most active Heck catalyst within this series at 100 °C and is a very rare example of an effective and versatile catalyst system that efficiently operates under mild reaction conditions. Rapid and complete catalyst degradation under work-up conditions into phosphonates, piperidinium salts and other, palladium-containing decomposition products assure an easy separation of the coupling products from catalyst and ligands. The facile, cheap, and rapid synthesis of 1,1',1"-(phosphinetriyl)tripiperidine and 1 respectively, the simple and convenient use as well as its excellent catalytic performance in the Heck reaction at 100 °C make 1 to one of the most attractive and greenest Heck catalysts available. We provide here the visualized protocols for the ligand and catalyst syntheses as well as the reaction protocol for Heck reactions performed at 10 mmol scale at 100 °C and show that this catalyst is suitable for its use in organic syntheses. PMID:24686532

Oberholzer, Miriam; Frech, Christian M

2014-01-01

102

Establishing and maintaining specific pathogen free (SPF) conditions in aqueous solutions using ozone  

Microsoft Academic Search

The paper discusses the use of ozone in space applications for the elimination of pathogens, and the enhancement of the oxidation potential of ozone using hydrogen peroxide and ultraviolet radiation. These combinations will be possible to set up in space conditions. The sterilizing effect versus free radical generation is an important equilibrium to establish when specific pathogen free conditions are

B. Vestergård

1994-01-01

103

Experimental chlorine partitioning between forsterite, enstatite and aqueous fluid at upper mantle conditions?  

PubMed Central

Cl partition coefficients between forsterite, enstatite and coexisting Cl-bearing aqueous fluids were determined in a series of high pressure and temperature piston cylinder experiments at 2 GPa between 900 and 1300 °C in the system MgO–SiO2–H2O–NaCl–BaO–C±CaCl2±TiO2±Al2O3±F. Diamond aggregates were added to the experimental capsule set-up in order to separate the fluid from the solid residue and enable in situ analysis of the quenched solute by LA-ICP-MS. The chlorine content of forsterite and enstatite was measured by electron microprobe, and the nature of hydrous defects was investigated by infrared spectroscopy. Partition coefficients show similar incompatibility for Cl in forsterite and enstatite, with DClfo/fl = 0.0012 ± 0.0006, DClen/fl = 0.0018 ± 0.0008 and DClfo/en = 1.43 ± 0.71. The values determined for mineral/fluid partitioning are very similar to previously determined values for mineral/melt. Applying the new mineral/fluid partition coefficients to fluids in subduction zones, a contribution between 0.15% and 20% of the total chlorine from the nominally anhydrous minerals is estimated. Infrared spectra of experimental forsterite show absorption bands at 3525 and 3572 cm?1 that are characteristic for hydroxyl point defects associated with trace Ti substitutions, and strongly suggest that the TiO2 content of the system can influence the chlorine and OH incorporation via the stabilization of Ti-clinohumite-like point defects. The water contents for coexisting forsterite and enstatite in some runs were determined using unpolarized IR spectra and calculated water partition coefficients DH2Ofo/en are between 0.01 and 0.5. PMID:25843971

Fabbrizio, Alessandro; Stalder, Roland; Hametner, Kathrin; Günther, Detlef

2013-01-01

104

Characterizing stability of ``click'' modified glass surfaces to common microfabrication conditions and aqueous electrolyte solutions  

NASA Astrophysics Data System (ADS)

Microfluidic and nanofluidic systems are dominated by fluid-wall interactions due to enormous surface-area-to-volume ratios in these devices. Therefore, strategies to control wall properties in a reliable and repeatable manner can be important for device operation. Chemical modification of surfaces provides one such method. However, the stability of the surface adhered layers under fabrication and likely device operating conditions have not been evaluated in depth. This paper presents the stability analysis of three surface layers used in the `click' chemistry methodology for surface modification. The three surface layers have bromo, amine, and methyl termination on glass surfaces. All three surface groups are exposed to various wet and dry conditions including acid, base, solvent, electrolyte buffer solutions, oxidative plasmas, UV light, and thermal processing conditions. Contact angle measurements, X-ray photoelectron spectroscopy, and atomic force microscopy were used to quantify the stability of the adhered surface layers. The data show that the brominated surface was stable to most test conditions, while both the amine and methyl surface layers were stable to a narrower set of test conditions.Microfluidic and nanofluidic systems are dominated by fluid-wall interactions due to enormous surface-area-to-volume ratios in these devices. Therefore, strategies to control wall properties in a reliable and repeatable manner can be important for device operation. Chemical modification of surfaces provides one such method. However, the stability of the surface adhered layers under fabrication and likely device operating conditions have not been evaluated in depth. This paper presents the stability analysis of three surface layers used in the `click' chemistry methodology for surface modification. The three surface layers have bromo, amine, and methyl termination on glass surfaces. All three surface groups are exposed to various wet and dry conditions including acid, base, solvent, electrolyte buffer solutions, oxidative plasmas, UV light, and thermal processing conditions. Contact angle measurements, X-ray photoelectron spectroscopy, and atomic force microscopy were used to quantify the stability of the adhered surface layers. The data show that the brominated surface was stable to most test conditions, while both the amine and methyl surface layers were stable to a narrower set of test conditions. Electronic supplementary information (ESI) available. See DOI: 10.1039/c1nr10261c

Prakash, Shaurya; Karacor, Mehmet B.

2011-08-01

105

Hydrothermal diamond anvil cell for XAFS studies of first-row transition elements in aqueous solutions up to supercritical conditions  

USGS Publications Warehouse

A hydrothermal diamond anvil cell (HDAC) has been modified by drilling holes with a laser to within 150 ??m of the anvil face to minimize the loss of X-rays due to absorption and scatter by diamond. This modification enables acquisition of K-edge X-ray absorption fine structure (XAFS) spectra from first-row transition metal ions in aqueous solutions at temperatures ranging from 25??C to 660??C and pressures up to 800 MPa. These pressure-temperature (P-T) conditions are more than sufficient for carrying out experimental measurements that can provide data valuable in the interpretation of fluid inclusions in minerals found in ore-forming hydrothermal systems as well as other important lithospheric processes involving water. (C) 2000 Elsevier Science B.V. All rights reserved.

Bassett, William A.; Anderson, Alan J.; Mayanovic, Robert A.; Chou, I.-Ming

2000-01-01

106

Mild traumatic brain injury.  

PubMed

Mild traumatic brain injury (mTBI) can have a profoundly negative effect on the injured person's quality of life, producing cognitive, physical, and psychological symptoms; impeding postinjury family reintegration; creating psychological distress among family members; and often having deleterious effects on spousal and parental relationships. This article reviews the most commonly reported signs and symptoms of mTBI, explores the condition's effects on both patient and family, and provides direction for developing nursing interventions that promote patient and family adjustment. PMID:25319524

Hyatt, Kyong S

2014-11-01

107

Behaviour of Sb(V) in the presence of dissolved sulfide under controlled anoxic aqueous conditions  

E-print Network

: D. Rickard Keywords: Antimony Dissolved sulfide Metastibnite HG-AFS Antimony (Sb) exists in natural concentrations and conditions. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Until recently, antimony(V) is usually the predominant oxidation state of antimony in oxic waters likely present as Sb(OH)6 - at p

Belzile, Nelson

108

Behaviour of Sb(V) in the presence of dissolved sulfide under controlled anoxic aqueous conditions  

E-print Network

: Antimony Dissolved sulfide Metastibnite HG-AFS Antimony (Sb) exists in natural waters in two oxidation. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Until recently, antimony (Sb) had largely been oxidation state of antimony in oxic waters likely present as Sb(OH)6 - at pH conditions of natural systems

Belzile, Nelson

109

Behaviour of Sb(V) in the presence of dissolved sulfide under controlled anoxic aqueous conditions  

Microsoft Academic Search

Antimony (Sb) exists in natural waters in two oxidation states, Sb(V) and Sb(III), with the reduced form generally leading to more toxic behaviour. Factors leading to the appearance of Sb(III) are therefore important from toxicity, bioavailability and ultimately water quality standpoints, particularly under reducing conditions found in eutrophic lakes and sediment porewaters. In this study, kinetics of the reduction of

Russell Polack; Yu-Wei Chen; Nelson Belzile

2009-01-01

110

Inhibitory Effect of Berberis vulgaris Aqueous Extract on Acquisition and Reinstatement Effects of Morphine in Conditioned Place Preferences (CPP) in Mice  

PubMed Central

Background: It has been elucidated that Berberis vulgaris (barberry) can alleviate morphine withdrawal syndrome. Also it has been reported that aqueous extract of barberry possibly have inhibitory effect on NMDA receptors. Objectives: In this study, we decided to evaluate the effects of aqueous extract of B. vulgaris fruit on morphine tendency in mice using conditioned place preference (CPP) method. Materials and Methods: In experiment 1 (acquisition phase), mice underwent morphine-induced conditioned place preference (CPP) training with injections of morphine (40 mg/kg). In experiment 2 (extinction and reinstatement phases), mice underwent the same CPP training as in experiment 1 and subsequent extinction training on day 16th a reinstatement by CPP was done by injection of reminding 10 mg/kg morphine. Results: The administration of morphine (40 mg/kg for four days) produced place preference. In the first method, the aqueous extract of barberry (200 mg/kg) prevented morphine tendency to white cell in CPP method. In the second method, after inter-peritoneal injection of aqueous extracts of barberry at 100 and 200 mg/kg, the animals tendency toward the white cells of CPP chamber on the sixteenth day (after a reminder injection of morphine 10 mg/kg) was significantly reduced. Conclusions: These results show that aqueous extract of barberry can reduce the acquisition and reinstatement of morphine-induced conditioned place preference. PMID:25237645

Imenshahidi, Mohsen; Qaredashi, Reza; Hashemzaei, Mahmoud; Hosseinzadeh, Hossein

2014-01-01

111

Mild traumatic brain injury.  

PubMed

Mild traumatic brain injury (TBI) is common but accurate diagnosis and defining criteria for mild TBI and its clinical consequences have been problematic. Mild TBI causes transient neurophysiologic brain dysfunction, sometimes with structural axonal and neuronal damage. Biomarkers, such as newer imaging technologies and protein markers, are promising indicators of brain injury but are not ready for clinical use. Diagnosis relies on clinical criteria regarding depth and duration of impaired consciousness and amnesia. These criteria are particularly difficult to confirm at the least severe end of the mild TBI continuum, especially when relying on subjective, retrospective accounts. The postconcussive syndrome is a controversial concept because of varying criteria, inconsistent symptom clusters and the evidence that similar symptom profiles occur with other disorders, and even in a proportion of healthy individuals. The clinical consequences of mild TBI can be conceptualized as two multidimensional disorders: (1) a constellation of acute symptoms that might be termed early phase post-traumatic disorder (e.g., headache, dizziness, imbalance, fatigue, sleep disruption, impaired cognition), that typically resolve in days to weeks and are largely related to brain trauma and concomitant injuries; (2) a later set of symptoms, a late phase post-traumatic disorder, evolving out of the early phase in a minority of patients, with a more prolonged (months to years), sometimes worsening set of somatic, emotional, and cognitive symptoms. The later phase disorder is highly influenced by a variety of psychosocial factors and has little specificity for brain injury, although a history of multiple concussions seems to increase the risk of more severe and longer duration symptoms. Effective early phase management may prevent or limit the later phase disorder and should include education about symptoms and expectations for recovery, as well as recommendations for activity modifications. Later phase treatment should be informed by thoughtful differential diagnosis and the multiplicity of premorbid and comorbid conditions that may influence symptoms. Treatment should incorporate a hierarchical, sequential approach to symptom management, prioritizing problems with significant functional impact and effective, available interventions (e.g., headache, depression, anxiety, insomnia, vertigo). PMID:25702214

Katz, Douglas I; Cohen, Sara I; Alexander, Michael P

2015-01-01

112

X-ray photoelectron spectroscopic study of surface chemistry of dibenzyl-disulfide on steel under mild and severe wear conditions  

NASA Technical Reports Server (NTRS)

Wear tests were performed on 304 stainless steel lubricated with pure mineral oil with and without dibenzyl-disulfide. Both mild and severe wear were observed. The type of wear was distinguished by a marked change in wear rate, friction coefficient, and wear scar appearance. The chemical composition of the wear scar surface was examined with X-ray photoelectron spectroscopy in conjunction with argon ion sputter etching. In severe wear scars, a sulfide was formed at the expense of the normal oxide layer. In mild wear scars, there were only superficial sulfur compounds, but there was a substantial increase in the oxide thickness.

Wheeler, D. R.

1977-01-01

113

Transparent ZnO Films Deposited by Aqueous Solution Process Under Various pH Conditions  

NASA Astrophysics Data System (ADS)

ZnO films were deposited using a spin-spray method with the source solution containing zinc nitrate and an oxidizing solution containing trisodium citrate onto glass substrates under various pH conditions. A ZnO film with a columnar structure was obtained at pH higher than 7.0, while no ZnO film was formed at a mixed solution pH of 6.7. The transparent and conductive ZnO film obtained from a mixed solution with pH 10.7 exhibited the lowest resistivity of 9.9 × 10-3 ? cm with a high transmittance above 90%.

Hong, Jeong Soo; Wagata, Hajime; Ohashi, Naoki; Katsumata, Ken-ichi; Okada, Kiyoshi; Matsushita, Nobuhiro

2015-02-01

114

Immobilization of selenate by iron in aqueous solution under anoxic conditions and the influence of uranyl  

NASA Astrophysics Data System (ADS)

In proposed high level radioactive waste repositories a large part of the spent nuclear fuel (SNF) canisters are commonly composed of iron. Selenium is present in spent nuclear fuel as a long lived fission product. This study investigates the influence of iron on the uptake of dissolved selenium in the form of selenate and the effect of the presence of dissolved uranyl on the above interaction of selenate. The iron oxide, and selenium speciation on the surfaces was investigated by Raman spectroscopy. X-ray Absorption Spectroscopy was used to determine the oxidation state of the selenium and uranium on the surfaces. Under the simulated groundwater conditions (10 mM NaCl, 2 mM NaHCO 3, <0.1 ppm O 2) the immobilized selenate was found to be reduced to oxidation states close to zero or lower and uranyl was found to be largely reduced to U(IV). The near simultaneous reduction of uranyl was found to greatly enhance the rate of selenate reduction. These findings suggest that the presence of uranyl being reduced by an iron surface could substantially enhance the rate of reduction of selenate under anoxic conditions relevant for a repository.

Puranen, Anders; Jonsson, Mats; Dähn, Rainer; Cui, Daqing

2009-08-01

115

Diffusion and polymerization of styrene in an aqueous solution of potassium persulfate under static conditions  

SciTech Connect

The potassium persulfate-initiated polymerization of styrene in a mechanically agitated mixture of water and monomer leads to the formation of a stable, monodisperse latex. In order to explain the mechanism of the stabilization of the latex particles in this system, the authors present a detailed investigation of the polymerization of styrene in a specially constructed electrochemical cell under static conditions. A schematic of the cell is shown. Results show that the capacity of the electrical double layer on the platinum electrode remains constant with time in a system containing only a solution of electrolyte, either K/sub 2/SO/sub 4/ or K/sub 2/S/sub 2/O/sub 8/.

Oganesyan, A.A.; Boyadzhyan, V.G.; Gritskova, I.A.; Gukasyan, A.V.; Matsoyan, S.G.; Pravednikov, A.N.

1985-10-01

116

Synthesis, characterization and microwave-promoted catalytic activity of novel N-phenylbenzimidazolium salts in Heck-Mizoroki and Suzuki-Miyaura cross-coupling reactions under mild conditions.  

PubMed

A number of novel benzimidazolium salts having aryl substituents such as N-phenyl, 4-chlorophenyl and various alkyl substituents were synthesized. Their microwave-assisted catalytic activities were evaluated in Heck-Mizoroki and Suzuki-Miyaura cross-coupling reactions using a catalytic system consisting of Pd(OAc)(2)/K(2)CO(3) in DMF/H(2)O under mild reaction conditions with consistent high yields, except those of 2-bromopyridine. PMID:23439565

Y?lmaz, Ülkü; Küçükbay, Hasan; Deniz, Selma; ?ireci, Nihat

2013-01-01

117

Flow and morphological conditions associated with the directional solidification of aqueous ammonium chloride  

SciTech Connect

Using 27% aq. NH[sub 4]Cl solutions as transparent analog, shadowgraphy and dye injection were used to observe flow and morphology in unidirectional solidification (UDS) from below. Dendritic crystals that form at the cold surface reject lighter, solute-deficient fluid, and instability is shown by finger-type double-diffusive convection. As the mushy two-phase region grows, perturbations at the liquidus interface cause localized remelting and downward development of channels. Solsutal plumes emanate from the channels, and in time, double-diffusive convection layers also form in the melt. When the solution is chilled at the sides as well as at the bottom, conditions are influenced by detachment and settling of crystals from the sidewall and by plumes from slanted channels. When a slow, oscillatory rocking motion is imposed on UDS, the freckle-type segregates in the final cast is suppressed. Within the melt, plumes and double-diffusive convection are eliminated. Inertially induced convection mixes the melt and produces a dense slurry. Although channels are eliminated from the bottom mushy region, overall heat transfer and macrosegregation in the cavity are unaffected by the slow rocking. Numerical simulations qualitatively predict trends in the field variables and provide insights on interdendritic flows and macrosegregation (freckle-, A-type segregates), although its quantitative predictions are hampered by simplifying assumptions.

Magirl, C.S.; Incropera, F.P.

1993-01-01

118

Flow and morphological conditions associated with the directional solidification of aqueous ammonium chloride. Annual performance report  

SciTech Connect

Using 27% aq. NH{sub 4}Cl solutions as transparent analog, shadowgraphy and dye injection were used to observe flow and morphology in unidirectional solidification (UDS) from below. Dendritic crystals that form at the cold surface reject lighter, solute-deficient fluid, and instability is shown by finger-type double-diffusive convection. As the mushy two-phase region grows, perturbations at the liquidus interface cause localized remelting and downward development of channels. Solsutal plumes emanate from the channels, and in time, double-diffusive convection layers also form in the melt. When the solution is chilled at the sides as well as at the bottom, conditions are influenced by detachment and settling of crystals from the sidewall and by plumes from slanted channels. When a slow, oscillatory rocking motion is imposed on UDS, the freckle-type segregates in the final cast is suppressed. Within the melt, plumes and double-diffusive convection are eliminated. Inertially induced convection mixes the melt and produces a dense slurry. Although channels are eliminated from the bottom mushy region, overall heat transfer and macrosegregation in the cavity are unaffected by the slow rocking. Numerical simulations qualitatively predict trends in the field variables and provide insights on interdendritic flows and macrosegregation (freckle-, A-type segregates), although its quantitative predictions are hampered by simplifying assumptions.

Magirl, C.S.; Incropera, F.P.

1993-01-01

119

A new method of reconstituting the P-T conditions of fluid circulation in an accretionary prism (Shimanto, Japan) from microthermometry of methane-bearing aqueous inclusions  

NASA Astrophysics Data System (ADS)

In paleo-accretionary prisms and the shallow metamorphic domains of orogens, circulating fluids trapped in inclusions are commonly composed of a mixture of salt water and methane, producing two types of fluid inclusions: methane-bearing aqueous and methane-rich gaseous fluid inclusions. In such geological settings, where multiple stages of deformation, veining and fluid influx are prevalent, textural relationships between aqueous and gaseous inclusions are often ambiguous, preventing the microthermometric determination of fluid trapping pressure and temperature conditions. To assess the P-T conditions of deep circulating fluids from the Hyuga unit of the Shimanto paleo-accretionary prism on Kyushu, Japan, we have developed a new computational code, applicable to the H2O-CH4-NaCl system, which allows the characterization of CH4-bearing aqueous inclusions using only the temperatures of their phase transitions estimated by microthermometry: Tmi, the melting temperature of ice; Thyd, the melting temperature of gas hydrate and Th,aq, homogenization temperature. This thermodynamic modeling calculates the bulk density and composition of aqueous inclusions, as well as their P-T isochoric paths in a P-T diagram with an estimated precision of approximatively 10%. We use this computational tool to reconstruct the entrapment P-T conditions of aqueous inclusions in the Hyuga unit, and we show that these aqueous inclusions cannot be cogenetic with methane gaseous inclusions present in the same rocks. As a result, we propose that pulses of a high-pressure, methane-rich fluid transiently percolated through a rock wetted by a lower-pressure aqueous fluid. By coupling microthermometric results with petrological data, we infer that the exhumation of the Hyuga unit from the peak metamorphic conditions was nearly isothermal and ended up under a very hot geothermal gradient. In subduction or collision zones, modeling aqueous fluid inclusions in the ternary H2O-CH4-NaCl system and not simply in the binary H2O-NaCl is necessary, as the addition of even a small amount of methane to the water raises significantly the isochores to higher pressures. Our new code provides therefore the possibility to estimate precisely the pressure conditions of fluids circulating at depth.

Raimbourg, Hugues; Thiéry, Régis; Vacelet, Maxime; Ramboz, Claire; Cluzel, Nicolas; Le Trong, Emmanuel; Yamaguchi, Asuka; Kimura, Gaku

2014-01-01

120

Rare-earth metal oxide doped transparent mesoporous silica plates under non-aqueous condition as a potential UV sensor.  

PubMed

Transparent mesoporous silica plates doped with rare-earth metal oxide were prepared using solvent-evaporation method based on the self-organization between structure-directing agent and silicate in a non-aqueous solvent. A triblock copolymer, Pluronic (F127 or P123), was used as the structure-directing agent, while tetraethyl orthosilicate (TEOS) was used as a silica source. The pore diameter and the surface area of the mesoporous silica plate prepared with the optimized conditions were ca 40 A and 600 m2 g(-1), respectively, for both structure-directing agent. Rare-earth metal oxides (Eu, Tb, Tm oxide) in mesochannel were formed via one-step synthetic route based on the preparation method of a silica plate. Optical properties of rare-earth metal oxide-doped mesoporous silica plates were investigated by UV irradiation and photoluminescence (PL) spectroscopy. Under the exitation wavelength of 254 nm, the doped mesoporous silica plates emitted red, green and blue for Eu, Tb and Tm oxides, respectively. Rare-earth metal oxide-doped mesoporous silica plates showed enhanced PL intensity compared to that of the bulk rare-earth metal oxide. PMID:24245274

Lee, Sang-Joon; Park, Sung Soo; Lee, Sang Hyun; Hong, Sang-Hyun; Ha, Chang-Sik

2013-11-01

121

NaNO2-mediated transformation of aliphatic secondary nitroalkanes into ketones or oximes under neutral, aqueous conditions: how the nitro derivative catalyzes its own transformation.  

PubMed

The nitrosation of secondary nitro derivatives into ketones or oximes depending on the nitro substituents has been reinvestigated. The reaction efficiently takes place under neutral conditions, thus allowing acid-sensitive substrates to be converted in very good yields. The generation of nitrosating species under such mild conditions is unprecedented. Mechanistic investigations strongly suggest that they result from the nucleophilic attack of the nitrite anion on the aci-nitro(nate) form of the secondary nitroalkane. The latter acts in turn as an autocatalyst for its own transformation by means of the nitrosating species generated in situ from it. PMID:15609931

Gissot, Arnaud; N'Gouela, Silvere; Matt, Christophe; Wagner, Alain; Mioskowski, Charles

2004-12-24

122

Steady-state ?-radiolysis of aqueous methyl ethyl ketone (2-butanone) under postulated nuclear reactor accident conditions  

Microsoft Academic Search

The steady-state ?-radiolysis of aqueous solutions containing 1×10?3 mol dm?3 methyl ethyl ketone (MEK) has been studied at a dose rate of 0.12 Gy s?1, 25°C and an initial pH of 10. Experiments were conducted in air-, Ar- or N2O-purged aqueous solutions, or in Ar-purged solutions with added tert-butanol. MEK, its radiolytic products, and the change in pH resulting from

P. Driver; G. Glowa; J. C. Wren

2000-01-01

123

Sodium Perborate Tetrahydrate-Mediated Transformations of 2?Hydroxy chalcones to Flavanones, Flavones and 3?, 5?-Diiodoflavone Under Mild Environmentally Friendly Conditions  

Microsoft Academic Search

Sodium perborate tetrahydrate has been utilized as a nucleophilic catalyst for facile conversion of 2?-hydroxychalcones to flavanones in warm aqueous acetonitrile, whereas these chalcones, upon oxidative cyclization, in warm acetic acid with an excess of the same reagent afforded flavones in acceptable yields. One-pot synthesis of 3?, 5?-diiodoflavone has been accomplished by diacetoxyiodobenzene-catalyzed iodination of 2?-hydroxychalcone with tetra-n-butylammonium iodide in

Nemai C. Ganguly; Sumanta Chandra; Sujoy Kumar Barik

2012-01-01

124

Serpentinization, iron oxidation, and aqueous conditions in an ophiolite: Implications for hydrogen production and habitability on Mars  

NASA Astrophysics Data System (ADS)

Molecular hydrogen produced through iron oxidation during formation of serpentine and magnetite can sustain terrestrial subsurface ecosystems. The Fe3+ in serpentine partitions into octahedral and tetrahedral sites differently as serpentinization proceeds, and tetrahedral Fe3+ is present toward the end of serpentinization. We map Fe oxidation states in a serpentinite to determine the degree to which serpentinization progressed and where hydrogen production has been maximized to assess habitability at an abandoned chrysotile mine in Norbestos, Quebec, in association with the Canadian Space Agency's Mars Methane Analogue Mission. We also analyzed stable isotopes of carbon and oxygen in carbonates to constrain the conditions of water-rock interaction during serpentinization. Iron oxidation and coordination was determined through field imaging of rock walls with a visible hyperspectral imager (420-720 nm), and samples collected from imaged rocks and elsewhere in the mine were imaged in the laboratory (420-1100 nm). Sample chemistry, mineralogy, and oxidation state were determined with laboratory measurements of visible through mid-infrared reflectance spectra, major element chemistry, mineralogy, and Mössbauer spectroscopy. Mapping with hyperspectral imaging of outcrops and hand samples shows that tetrahedral Fe3+ is common in serpentinites at this site, and results are confirmed through other measurements. Major element chemistry and mineralogy are consistent with serpentine plus minor carbonate. Carbonate samples show an exceptional range in ?13C (-13.14 to + 16.12 ‰ VPDB) and ?18O (-15.48 to - 3.20 ‰ VPDB) that vary with location in the mine. Carbonates south of a shear zone (?13C more positive) likely formed during periods of serpentinization in a carbon-limited reservoir closed to carbon addition but open to methane escape. Carbonates in a shear zone (?13C more negative) probably formed later at low temperatures through CO2-metasomatism or atmospheric weathering, and isotopic trends are consistent with kinetic fractionation. The extensive presence of tetrahedral Fe3+ in serpentine shows the system liberally produced H2 while the isotope systematics have implications for preservation of indicators of the aqueous conditions that formed serpentinites on Mars and their habitability.

Greenberger, Rebecca N.; Mustard, John F.; Cloutis, Edward A.; Pratt, Lisa M.; Sauer, Peter E.; Mann, Paul; Turner, Kathryn; Dyar, M. Darby; Bish, David L.

2015-04-01

125

OH-radical formation by ultrasound in aqueous solution – Part II: Terephthalate and Fricke dosimetry and the influence of various conditions on the sonolytic yield  

Microsoft Academic Search

Terephthalate and Fricke dosimetry have been carried out to determine the sonolytic energy yields of the OH free radical and of its recombination product H2O2 in aqueous solutions under various operating conditions (nature of operating gas, power, frequency, temperature). For example, in the sonolysis of Ar-saturated terephthalate solutions at room temperature, a frequency of 321kHz, and a power of 170Wkg?1,

Gertraud Mark; Armin Tauber; Rüdiger Laupert; Heinz-Peter Schuchmann; Dorothea Schulz; Andreas Mues; Clemens von Sonntag

1998-01-01

126

Efficient Solid-Phase Synthesis of 3-Substituted-5-Oxo-5H-Thiazolo[2,3-b]Quinazoline-8-Carboxamide under Mild Conditions with Two Diversity Positions  

PubMed Central

Highly efficient solid-phase synthesis of thiazolo[2,3,b]quinazolines under mild conditions was developed using resin-bound 2-amino-terephthalamic acid, Fmoc-NCS, and bromoketones. Primary amines immobilized to an acid-cleavable backbone amide linker were acylated with 1-methyl-2-aminoterephtalate. Following cleavage of the methyl ester, Fmoc-NCS was used to form a resin-bound thiourea. Bromoketones were subsequently added to form an aminothiazole ring and the cyclization was performed using DIC/HOBt to afford thiazolo[2,3,b]quinazolines. Highly efficient solid-phase synthesis is amenable to high throughput/combinatorial synthesis. PMID:17907790

Bouillon, Isabelle; Krch?ák, Viktor

2008-01-01

127

Modeling Mild Collisions  

NASA Astrophysics Data System (ADS)

It is a surprisingly common phenomenon that two objects collide with each other and emerge only mildly altered. We motivate a dynamic-independent, analytical framework to study these mild collisions through two specific examples: (1) Head-on collision between two non-integrable solitons, and (2) Gravitational self-interaction for a collapsing shell of radiation.

Yang, I.-Sheng

2015-01-01

128

Hydrogenation of calcium carbonate in aqueous systems catalyzed by Rh(I)- and Ru(II)-complexes using poly(methylhydrosiloxane) or hypophosphite as hydrogen sources  

Microsoft Academic Search

The two abundant natural carbon sources, calcium carbonate and carbon dioxide were combined under mild conditions to yield\\u000a calcium formate and formic acid upon reduction in aqueous systems using poly(methylhydrosiloxane) or sodium hypophosphite\\u000a as reductants with Rh(I)- and Ru(II)-complexes of monosulfonated triphenylphosphine as catalysts.

István Jószai; Ferenc Joó

2007-01-01

129

One-pot synthesis of 2-substituted 4H-3,1-benzoxazin-4-one derivatives under mild conditions using iminium cation from cyanuric chloride/dimethylformamide as a cyclizing agent  

PubMed Central

Background The derivatives of 2-substituted 4H-3,1-benzoxazin-4-one belong to a significant category of heterocyclic compounds, which have shown a wide spectrum of medical and industrial applications. Results A new and effective one-pot method for the synthesis of 2-substituted 4H-3,1-benzoxazin-4-one derivatives is described in this paper. By using the iminium cation from a mixture of cyanuric chloride and dimethylformamide as a cyclizing agent, a series of 2-substituted 4H-3,1-benzoxazin-4-one derivatives was synthesized in high yield under mild conditions and simple workup. Conclusions The iminium cation from a mixture of cyanuric chloride and N,N-dimethylformamide is an effective cyclizing agent for the room temperature one-pot synthesis of 2-substituted 4H-3,1-benzoxazin-4-one derivatives in high yields through a cyclodehydration reaction. Furthermore, the method was performed under mild conditions characterized by simplified pathways and workup, minimized energy, and fewer reaction steps, compared with the previous methods. The proposed method, which is a simpler alternative than the published methods, is applicable for the synthesis of other 2-substituted 4H-3,1-benzoxazin-4-one derivatives. PMID:23537478

2013-01-01

130

Oxalic acid mediated synthesis of WO{sub 3}.H{sub 2}O nanoplates and self-assembled nanoflowers under mild conditions  

SciTech Connect

Tungsten oxide hydrate (WO{sub 3}.H{sub 2}O) nanoplates and flower-like assemblies were successfully synthesized via a simple aqueous method. The effects of reaction parameters in solution on the preparation were studied. Nanoplates and nanoflowers can be selectively prepared by changing the amount of H{sub 2}C{sub 2}O{sub 4}. In-situ assembly of nanoplates to nanoflowers was also proposed for the formation of assembled nanostructures. In addition, the reaction time and temperature have important effects on the sizes of the as-obtained samples. Crystal structure, morphology, and composition of final nanostructures were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical properties of the synthesized samples and the growth mechanism were studied by UV-vis detection. Degradation experiments of Rhodamine B (RhB) were also performed on samples of nanoplates and nanoflowers under visible light illumination. Nanoflower sample exhibited preferable photocatalytic property to nanoplate sample. - Graphical abstract: The oxalic acid has a key role for the structure of WO{sub 3}.H{sub 2}O evolution from plates to flowers and the dehydration process of WO{sub 3}.2H{sub 2}O to WO{sub 3}.H{sub 2}O. Highlights: > Tungsten oxides hydrate was synthesized via a simple aqueous method. > The size of WO{sub 3}.H{sub 2}O was controlled by the reaction time and temperature. > The assembly of WO{sub 3}.H{sub 2}O nanoplates to nanoflowers was achieved with higher H{sub 2}C{sub 2}O{sub 4}/Na{sub 2}WO{sub 4} ratio. > Oxalic acid has a key role in the dehydration process of WO{sub 3}.2H{sub 2}O to WO{sub 3}.H{sub 2}O.

Li Linzhi [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Zhao Jingzhe, E-mail: zhaojz@hnu.edu.cn [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Wang Yi [Department of Regenerative Medicine, School of Pharmaceutical Sciences, Jilin University, Changchun 130023 (China); Li Yunling [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); College of Chemistry, Jilin University, Changchun, 130012 (China); Ma Dechong [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Zhao Yan [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); College of Chemistry, Jilin University, Changchun, 130012 (China); Hou Shengnan; Hao Xinli [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

2011-07-15

131

Effect of acute asenapine treatment on Fos expression in the forebrain structures under normal conditions and mild stress preconditioning in the rat.  

PubMed

Asenapine (ASE) is a novel atypical antipsychotic drug approved for the treatment of schizophrenia and bipolar disorder. Stress is an inseparable part of the human life, which may interfere with the therapeutic effect of different drugs. The aim of the present study was: (1) to delineate the quantitative and qualitative profiles of the ASE effect on Fos expression in the striatum, septum, nucleus accumbens, and the prefrontal cortex and (2) to find out whether a chronic unpredictable variable mild stress (CMS) preconditioning may modify the effect of acute ASE treatment. Stress paradigms included restrain, social isolation, crowding, swimming, and cold. The animals were exposed to CMS for 21 days and on the 22nd day received an injection of vehicle (saline 300 ?l/rat s.c.) or ASE (0.3mg/kg s.c.). They were sacrificed 90 min after the treatments. Fos protein was visualized by avidin biotin peroxidase (ABC). Four groups of animals were investigated: controls+vehicle, controls+ASE, CMS+vehicle, and CMS+ASE. The number of Fos labeled neurons was calculated per total investigated area, which was selective for each structure, and also recalculated per unified sector. ASE treatment induced significant and very similar increase of the Fos expression in both ASE control and ASE CMS animals in comparison with saline control and CMS ones. Moreover, ASE induced regional differences in the number of Fos-positive neurons. In both ASE groups most pronounced response in the number of Fos profiles occurred in the dorsolateral striatum, ventrolateral septum, shell of the nucleus accumbens, and the medial prefrontal cortex. Mild Fos response was seen in the dorsomedial and ventromedial striatum and core of the nucleus accumbens. No response was seen in the dorsolateral septum. The present paper demonstrates for the first time the character of the Fos distribution in the forebrain structures induced by acute ASE treatment as well as ASE response to 21 days CMS preconditioning. The study provides an important comparative background that may help in the further understanding of the effect of ASE on the brain activation as well as its responsiveness to CMS challenges. PMID:25171958

Majercikova, Zuzana; Cernackova, Alena; Horvathova, Lubica; Osacka, Jana; Pecenak, Jan; Kiss, Alexander

2014-09-01

132

UV – INDUCED SYNTHESIS OF AMINO ACIDS FROM AQUEOUS STERILIZED SOLUTION OF AMMONIUM FORMATE AND AMMONIA UNDER HETROGENEOUS CONDITIONS  

PubMed Central

Irradiation of sterilized aqueous solution of ammonium formate and ammonia with UV light in the presence and or absence of certain inorganic sensitizers for 25 hrs. gave six ninhydrin positive products in appreciable amounts. Out of the six products observed fiver were characterized as lysine, serine, glutemic acid, n-amino butyric acid and leucine. The sensitizing effect of additives on ammonium formate was observed in the order; uranium oxide > ammonium formate > ferric oxide > arsenic oxide. PMID:22556511

Bisht, G.; Bisht, L. S.

1990-01-01

133

Effects of precursor chemistry and thermal treatment conditions on obtaining phase pure bismuth ferrite from aqueous gel precursors  

Microsoft Academic Search

Phase pure BiFeO3 powders are synthesized by an entirely aqueous solution–gel route, starting from water soluble Fe(III) nitrate or citrate, and Bi(III) citrate as precursors. In order to obtain stable solutions, which transform to homogeneous gels upon drying, the pH is adjusted to 7 and a citric acid content equimolar to the metal ions is selected.The presence of nitrate strongly

A. Hardy; S. Gielis; H. Van den Rul; J. D’Haen; M. K. Van Bael; J. Mullens

2009-01-01

134

Corrosion protection of mild steel by coatings containing polyaniline  

Microsoft Academic Search

The anti-corrosion performance of polyaniline coated mild steel samples exposed to artificial brine and dilute hydrochloric acid environments was evaluated. Samples of mild steel (UNS G10100) coated with polyaniline deposited from solution, and overcoated with an epoxy barrier paint, when scratched to expose precise areas of bare metal, exhibited corrosion rates in aqueous 3.5% NaCl solutions 2 times less, and

Wei-Kang Lu; Ronald L. Elsenbaumer; Bernhard Wessling

1995-01-01

135

Mild Cognitive Impairment Research  

MedlinePLUS Videos and Cool Tools

... Media Text Size Videos and Media Virtual Library Brain Tour Facts & Figures Spotlight on Researchers Web Links ... early diagnosis Mild Cognitive Impairment Research Inside the brain Genetics in Alzheimer's Advances in brain imaging Diet ...

136

Mild Traumatic Brain Injury  

Microsoft Academic Search

\\u000a Mild traumatic brain injuries (MTBI) are heterogeneous. This injury falls on a broad spectrum, from very mild neurometabolic\\u000a changes in the brain with rapid recovery to permanent problems due to structural brain damage. It is incorrect to assume that\\u000a MTBIs cannot cause permanent brain damage and it is incorrect to assume that MTBIs typically cause permanent brain damage. This is

Grant L. Iverson; Rael T. Lange

137

Improving glutathione extraction from crude yeast extracts by optimizing aqueous two-phase system composition and operation conditions  

Microsoft Academic Search

PEG-Dextran and PEG-salt aqueous two-phase systems (ATPS) have been applied to separate glutathione (GSH) from crude yeast\\u000a extracts. Single-factor experiments were carried out to determine the important factors influencing the partition coefficient\\u000a and extraction yield. The effect of PEG molecular weight, phase-forming components, PEG and Dextran concentration, pH value,\\u000a and temperature on the GSH partitioning behavior in ATPS was investigated.

Xiangting Wu; Linmei Tang; Yinming Du; Zhinan Xu

2010-01-01

138

Relaxation of the structure of simple metal ion complexes in aqueous solutions at up to supercritical conditions  

USGS Publications Warehouse

Recently x-ray absorption fine structure (XAFS) studies of various ions in aqueous solutions showed a variation of cation-ligand bond lengths, often coupled with other structure changes, with increasing temperatures. Thus, the variations of the structure of several metal ion complexes with temperature based on observations from the X-ray absorption fine structure (XAFS) studies in the hope that it will stimulate the development of either first- principles theory or molecular dynamics simulations that might adequately describes these results are discussed.

Mayanovic, Robert A.; Jayanetti, S.; Anderson, Alan J.; Bassett, William A.; Chou, I.-Ming

2003-01-01

139

Steady-state ?-radiolysis of aqueous methyl ethyl ketone (2-butanone) under postulated nuclear reactor accident conditions  

NASA Astrophysics Data System (ADS)

The steady-state ?-radiolysis of aqueous solutions containing 1×10 -3 mol dm -3 methyl ethyl ketone (MEK) has been studied at a dose rate of 0.12 Gy s -1, 25°C and an initial pH of 10. Experiments were conducted in air-, Ar- or N 2O-purged aqueous solutions, or in Ar-purged solutions with added tert-butanol. MEK, its radiolytic products, and the change in pH resulting from MEK decomposition were analysed as a function of time (or total absorbed dose). The main initial step for the radiolytic decomposition of MEK is the H abstraction from MEK by rad OH, produced by ?-radiolysis of water, to form MEK radical. In the absence of O, the main decay path of the MEK radical appears to be dimerization to form 3,4-dimethyl-2,5-hexanedione. In the presence of oxygen, the MEK radical reacts primarily with O to form the MEK peroxyl radical. This radical ultimately results in a series of progressively smaller oxidation products. The formation of organic acids, and eventually CO 2, reduces the pH of the solution. This paper presents the experimental data and proposes the MEK decay kinetics and mechanism.

Driver, P.; Glowa, G.; Wren, J. C.

2000-01-01

140

Kinetics of OH-initiated oxidation of some oxygenated organic compounds in the aqueous phase under tropospheric conditions  

NASA Astrophysics Data System (ADS)

The interest for multiphase interactions of Volatile Organic Compounds (VOCs) in the troposphere has increased for a few years. Inside the clouds water droplets, soluble VOCs can be oxidized by free radicals thus modifying the droplet composition. This reactivity has an impact on the tropospheric oxidizing capacity as well as the aerosols' properties. In the present work, we measured aqueous phase OH-initiated oxidation rate constants of several oxygenated organic compounds relevant to the atmosphere or chosen as test compounds (ethanol, t-butanol, 1-butanol, iso-propanol, 1-propanol, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, phenol, ethyl ter-butyl ether (ETBE), n-propyl acetate, acetone, methyl ethyl ketone (MEK), methyl iso-butyl ketone (MIBK), ethyl formate). Experiments took place in an aqueous phase photoreactor. The rate constants were determinated using the relative kinetic method. Different OH-radical sources were tested, as well as different reference compounds in order to detect any artifact. The results have shown validation of the experimental protocol on test compounds. The overall results allowed to propose a structure reactivity method in order to predict OH-oxidation rate constant of new compounds. Finally, tropospheric life times of the studied compounds were compared inside and outside a cloud.

Poulain, L.; Grubert, S.; François, S.; Monod, A.; Wortham, H.

2003-04-01

141

Molecular engineering of a cobalt-based electrocatalytic nanomaterial for H2 evolution under fully aqueous conditions  

NASA Astrophysics Data System (ADS)

The viability of a hydrogen economy depends on the design of efficient catalytic systems based on earth-abundant elements. Innovative breakthroughs for hydrogen evolution based on molecular tetraimine cobalt compounds have appeared in the past decade. Here we show that such a diimine-dioxime cobalt catalyst can be grafted to the surface of a carbon nanotube electrode. The resulting electrocatalytic cathode material mediates H2 generation (55,000 turnovers in seven hours) from fully aqueous solutions at low-to-medium overpotentials. This material is remarkably stable, which allows extensive cycling with preservation of the grafted molecular complex, as shown by electrochemical studies, X-ray photoelectron spectroscopy and scanning electron microscopy. This clearly indicates that grafting provides an increased stability to these cobalt catalysts, and suggests the possible application of these materials in the development of technological devices.

Andreiadis, Eugen S.; Jacques, Pierre-André; Tran, Phong D.; Leyris, Adeline; Chavarot-Kerlidou, Murielle; Jousselme, Bruno; Matheron, Muriel; Pécaut, Jacques; Palacin, Serge; Fontecave, Marc; Artero, Vincent

2013-01-01

142

On the formation and structure of rare-earth element complexes in aqueous solutions under hydrothermal conditions with new data on gadolinium aqua and chloro complexes  

USGS Publications Warehouse

Synchrotron X-ray spectroscopy experiments were made on the Gd(III) aqua and chloro complexes in low pH aqueous solutions at temperatures ranging from 25 to 500????C and at pressures up to 480??MPa using a hydrothermal diamond anvil cell. Analysis of fluorescence Gd L3-edge X-ray absorption fine structure (XAFS) spectra measured from a 0.006m Gd/0.16m HNO3 aqueous solution at temperatures up to 500????C and at pressures up to 260??MPa shows that the Gd-O distance of the Gd3+ aqua ion decreases steadily at a rate of ??? 0.007??A??/100????C whereas the number of coordinated H2O molecules decreases from 9.0 ?? 0.5 to 7.0 ?? 0.4. The loss of water molecules in the Gd3+ aqua ion inner hydration shell over this temperature range (a 22% reduction) is smaller than exhibited by the Yb3+ aqua ion (42% reduction) indicating that the former is significantly more stable than the later. We conjecture that the anomalous enrichment of Gd reported from measurement of REE concentrations in ocean waters may be attributed to the enhanced stability of the Gd3+ aqua ion relative to other REEs. Gd L3-edge XAFS measurements of 0.006m and 0.1m GdCl3 aqueous solutions at temperatures up to 500????C and pressures up to 480??MPa reveal that the onset of significant Gd3+-Cl- association occurs around 300????C. Partially-hydrated stepwise inner-sphere complexes most likely of the type Gd(H2O)??-nCln+3-n occur in the chloride solutions at higher temperatures, where ?? ??? 8 at 300????C decreasing slightly to an intermediate value between 7 and 8 upon approaching 500????C. This is the first direct evidence for the occurrence of partially-hydrated REE Gd (this study) and Yb [Mayanovic, R.A., Jayanetti, S., Anderson, A.J., Bassett, W.A., Chou, I-M., 2002a. The structure of Yb3+ aquo ion and chloro complexes in aqueous solutions at up to 500 ??C and 270 MPa. J. Phys. Chem. A 106, 6591-6599.] chloro complexes in hydrothermal solutions. The number of chlorides (n) of the partially-hydrated Gd(III) chloro complexes increases steadily with temperature from 0.4 ?? 0.2 to 1.7 ?? 0.3 in the 0.006m chloride solution and from 0.9 ?? 0.7 to 1.8 ?? 0.7 in the 0.1m GdCl3 aqueous solution in the 300-500????C range. Conversely, the number of H2O ligands of Gd(H2O)??-nCln+3-n complexes decreases steadily from 8.9 ?? 0.4 to 5.8 ?? 0.7 in the 0.006m GdCl3 aqueous solution and from 9.0 ?? 0.5 to 5.3 ?? 1.0 in the 0.1m GdCl3 aqueous solution at temperatures from 25 to 500????C. Analysis of our results shows that the chloride ions partially displace the inner-shell water molecules during Gd(III) complex formation under hydrothermal conditions. The Gd-OH2 bond of the partially-hydrated Gd(III) chloro complexes exhibits slightly smaller rates of length contraction (??? 0.005??A??/100????C) for both solutions. The structural aspects of chloride speciation of Gd(III) as measured from this study and of Yb(III) as measured from our previous experiments are consistent with the solubility of these and other REE in deep-sea hydrothermal fluids. ?? 2006 Elsevier B.V. All rights reserved.

Mayanovic, R.A.; Anderson, A.J.; Bassett, W.A.; Chou, I.-M.

2007-01-01

143

Myocardial protection with mild hypothermia.  

PubMed

Mild hypothermia, 32-35° C, is very potent at reducing myocardial infarct size in rabbits, dogs, sheep, pigs, and rats. The benefit is directly related to reduction in normothermic ischaemic time, supporting the relevance of early and rapid cooling. The cardioprotective effect of mild hypothermia is not limited to its recognized reduction of infarct size, but also results in conservation of post-ischaemic contractile function, prevention of no-reflow or microvascular obstruction, and ultimately attenuation of left ventricular remodelling. The mechanism of the anti-infarct effect does not appear to be related to diminished energy utilization and metabolic preservation, but rather to survival signalling that involves either the extracellular signal-regulated kinases and/or the Akt/phosphoinositide 3-kinase/mammalian target of rapamycin pathways. Initial clinical trials of hypothermia in patients with ST-segment elevation myocardial infarction were disappointing, probably because cooling was too slow to shorten normothermic ischaemic time appreciably. New approaches to more rapid cooling have recently been described and may soon be available for clinical use. Alternatively, it may be possible to pharmacologically mimic the protection provided by cooling soon after the onset of ischaemia with an activator of mild hypothermia signalling, e.g. extracellular signal-regulated kinase activator, that could be given by emergency medical personnel. Finally, the protection afforded by cooling can be added to that of pre- and post-conditioning because their mechanisms differ. Thus, myocardial salvage might be greatly increased by rapidly cooling patients as soon as possible and then giving a pharmacological post-conditioning agent immediately prior to reperfusion. PMID:22131353

Tissier, Renaud; Ghaleh, Bijan; Cohen, Michael V; Downey, James M; Berdeaux, Alain

2012-05-01

144

Partial complex I deficiency due to the CNS conditional ablation of Ndufa5 results in a mild chronic encephalopathy but no increase in oxidative damage.  

PubMed

Deficiencies in the complex I (CI; NADH-ubiquinone oxidoreductase) of the respiratory chain are frequent causes of mitochondrial diseases and have been associated with other neurodegenerative disorders, such as Parkinson's disease. The NADH-ubiquinone oxidoreductase 1 alpha subcomplex subunit 5 (NDUFA5) is a nuclear-encoded structural subunit of CI, located in the peripheral arm. We inactivated Ndufa5 in mice by the gene-trap methodology and found that this protein is required for embryonic survival. Therefore, we have created a conditional Ndufa5 knockout (KO) allele by introducing a rescuing Ndufa5 cDNA transgene flanked by loxP sites, which was selectively ablated in neurons by the CaMKII?-Cre. At the age of 11 months, mice with a central nervous system knockout of Ndufa5 (Ndufa5 CNS-KO) showed lethargy and loss of motor skills. In these mice cortices, the levels of NDUFA5 protein were reduced to 25% of controls. Fully assembled CI levels were also greatly reduced in cortex and CI activity in homogenates was reduced to 60% of controls. Despite the biochemical phenotype, no oxidative damage, neuronal death or gliosis were detected in the Ndufa5 CNS-KO brain at this age. These results showed that a partial defect in CI in neurons can lead to late-onset motor phenotypes without neuronal loss or oxidative damage. PMID:24154540

Peralta, Susana; Torraco, Alessandra; Wenz, Tina; Garcia, Sofia; Diaz, Francisca; Moraes, Carlos T

2014-03-15

145

Growth kinetics and long-term stability of CdS nanoparticles in aqueous solution under ambient conditions  

Microsoft Academic Search

The ubiquity of naturally occurring nanoparticles in the aquatic environment is now widely accepted, but a better understanding\\u000a of the conditions that promote their formation and persistence is needed. Using cadmium sulfide (CdS) as a model metal sulfide\\u000a species, thiolate-capped CdS nanoparticles were prepared in the laboratory to evaluate how aquatic conditions influence metal\\u000a sulfide nanoparticle growth and stability. This

Katherine M. MullaughGeorge; George W. Luther

2011-01-01

146

The secondary formation of inorganic aerosols in the droplet mode through heterogeneous aqueous reactions under haze conditions  

NASA Astrophysics Data System (ADS)

Secondary inorganic aerosols play important roles in visibility reduction and in regional haze pollution. To investigate the characteristics of size distributions of secondary sulfates and nitrates as well as their formation mechanisms under hazes, size-resolved aerosols were collected using a Micro-Orifice Uniform Deposit Impactor (MOUDI) at an urban site in Jinan, China, in all four seasons (December 2007-October 2008). In haze episodes, the secondary sulfates and nitrates primarily formed in fine particles, with elevated concentration peaks in the droplet mode (0.56-1.8 ?m). The fine sulfates and nitrates were completely neutralized by ammonia and existed in the forms of (NH4)2SO4 and NH4NO3, respectively. The secondary formation of sulfates, nitrates and ammonium (SNA) was found to be related to heterogeneous aqueous reactions and was largely dependent on the ambient humidity. With rising relative humidity, the droplet-mode SNA concentration, the ratio of droplet-mode SNA to the total SNA, the fraction of SNA in droplet-mode particles and the mass median aerodynamic diameter of SNA presented an exponential, logarithmic or linear increase. Two heavily polluted multi-day haze episodes in winter and summer were analyzed in detail. The secondary sulfates were linked to heterogeneous uptake of SO2 followed by the subsequent catalytic oxidation by oxygen together with iron and manganese in winter. The fine nitrate formation was strongly associated with the thermodynamic equilibrium among NH4NO3, gaseous HNO3 and NH3, and showed different temperature-dependences in winter and summer.

Wang, Xinfeng; Wang, Wenxing; Yang, Lingxiao; Gao, Xiaomei; Nie, Wei; Yu, Yangchun; Xu, Pengju; Zhou, Yang; Wang, Zhe

2012-12-01

147

Mass spectrometric elucidation of triacylglycerol content of Brevoortia tyrannus (menhaden) oil using non-aqueous reversed-phase liquid chromatography under ultra high pressure conditions.  

PubMed

A non-aqueous reversed phase high performance liquid chromatography method was developed, and optimized for triacylglycerol analysis in a Brevoortia tyrannus (menhaden) oil sample. Four columns were serially coupled to tackle such a task, for a total length of 60 cm of shell-packed stationary phase, and operated under ultra high pressure conditions. As detection, positive-ion atmospheric pressure chemical ionization mass spectrometry was used to attain identification of the analyzed sample components. A number of 137 triacylglycerols containing up to 19 fatty acids, with 14-22 carbon atom alkyl chain length and 0-6 double bonds, were positively identified in the complex lipidic sample. This is the first work that reports an extensive characterization of the triacylglycerol fraction of menhaden oil. PMID:22503927

Dugo, Paola; Beccaria, Marco; Fawzy, Nermeen; Donato, Paola; Cacciola, Francesco; Mondello, Luigi

2012-10-12

148

Selective dechlorination of chlorinated phenoxy herbicides in aqueous medium by electrocatalytic reduction over palladium-loaded carbon felt  

Microsoft Academic Search

The highly selective dechlorinations of phenoxy herbicides (2,4-D and 2,4,5-T) and other chlorinated phenoxyacetic acids in aqueous solution with MeOH, trifluoroacetic acid and tetraalkylammonium salt were achieved under very mild experimental conditions by electrocatalytic reduction with the solution permeable cathodes made of Pd-loaded carbon felt. The chlorinated phenoxyacetic acids tested in this work were wholly dechlorinated to phenoxyacetic acid with

Andrey I. Tsyganok; Kiyoshi Otsuka

1999-01-01

149

Properties of aqueous solutions of lithium and calcium chlorides: formulations for use in air conditioning equipment design  

Microsoft Academic Search

The dehydration of air, for air conditioning purposes, either for human comfort or for industrial processes, is done most of the times by making it contact a surface at a temperature below its dew point. In this process not only is it necessary to cool that surface continuously, but also the air is cooled beyond the temperature necessary to the

Manuel R. Conde

2004-01-01

150

Initial results from dissolution rate testing of N-Reactor spent fuel over a range of potential geologic repository aqueous conditions  

SciTech Connect

Hanford N-Reactor spent nuclear fuel (HSNF) may ultimately be placed in a geologic repository for permanent disposal. To determine whether the engineered barrier system that will be designed for emplacement of light-water-reactor (LWR) spent fuel will also suffice for HSNF, aqueous dissolution rate measurements were conducted on the HSNF. The purpose of these tests was to determine whether HSNF dissolves faster or slower than LWR spent fuel under some limited repository-relevant water chemistry conditions. The tests were conducted using a flowthrough method that allows the dissolution rate of the uranium matrix to be measured without interference by secondary precipitation reactions that would confuse interpretation of the results. Similar tests had been conducted earlier with LWR spent fuel, thereby allowing direct comparisons. Two distinct corrosion modes were observed during the course of these 12 tests. The first, Stage 1, involved no visible corrosion of the test specimen and produced no undissolved corrosion products. The second, Stage 2, resulted in both visible corrosion of the test specimen and left behind undissolved corrosion products. During Stage 1, the rate of dissolution could be readily determined because the dissolved uranium and associated fission products remained in solution where they could be quantitatively analyzed. The measured rates were much faster than has been observed for LWR spent fuel under all conditions tested to date when normalized to the exposed test specimen surface areas. Application of these results to repository conditions, however, requires some comparison of the physical conditions of the different fuels. The surface area of LWR fuel that could potentially be exposed to repository groundwater is estimated to be approximately 100 times greater than HSNF. Therefore, when compared on the basis of mass, which is more relevant to repository conditions, the HSNF and LWR spent fuel dissolve at similar rates.

Gray, W.J.; Einziger, R.E.

1998-04-01

151

The structure of turbulent boundary layers along mildly curved surfaces  

Microsoft Academic Search

The structure of turbulence in boundary layers along mildly curved convex and concave surfaces is studied. Measurements of turbulent energy balance, autocorrelations, auto- and cross-power spectra, amplitude probability distributions, and conditional correlations are reported. It is observed that even mild curvature has very strong effects on the various aspects of the turbulent structure. For example, convex curvature suppresses the diffusion

B. R. Ramaprian; B. G. Shivaprasad

1978-01-01

152

Sustainability of mild combustion of hydrogen-containing hybrid fuels  

Microsoft Academic Search

Nowadays a process of sensitization on the fundamental problems related to energetic sources and their environmental impact is observed. In this context, the so-called flameless or mild combustion technology offers great advantages in terms of thermal efficiency and pollution emissions with respect to conventional burner-stabilized firing. The achievement of mild conditions requires to heat up the combustion chamber above a

Marco Derudi; Alessandro Villani; Renato Rota

2007-01-01

153

Solubility of platinum in aqueous solutions at 25C and pHs 4 to 10 under oxidizing conditions  

E-print Network

9 to 15.5. Finally, according to these new measurements of the solubility of platinum systems: Pt-K-HC8H4O4-H2O (pH 4.02), Pt-Na-HCO3-Cl-H2O (pH 6.40), Pt-Na-K- H2PO4-HPO4-H2O (pH 6.90), Pt-Na-HCO3-H2O (pH 8.30), Pt-Na-OH-H2O (pH 8.54), and Pt- Na-HCO3-H2O (pH 9.91). The redox conditions

Boyer, Edmond

154

Self-assembled dicopper(II) diethanolaminate cores for mild aerobic and peroxidative oxidation of alcohols.  

PubMed

The new dicopper(ii) complexes [Cu(2)(?-Hmdea)(2)(NCS)(2)] (1) and [Cu(2)(?-Hedea)(2)(N(3))(2)]·(H(2)O)(0.25) (2) with the {Cu(2)(?-O)(2)} diethanolaminate cores have been easily generated by aqueous medium self-assembly reactions of copper(ii) nitrate with N-methyl- or N-ethyldiethanolamine (H(2)mdea or H(2)edea, respectively), in the presence of sodium thiocyanate (for 1) or sodium azide (for 2) as ancillary ligands sources. They have been isolated as air-stable crystalline solids and fully characterized by IR and UV-vis spectroscopies, ESI-MS(+), elemental and single-crystal X-ray diffraction analyses. The latter complex also features a fourfold linkage of neighbouring dimeric units via strong intermolecular O-HO hydrogen bonds, giving rise to the formation of tetracopper aggregates. The catalytic activity of compounds 1 and 2 has been studied for the mild (50-80 °C) and selective oxidations of alcohols, namely for (i) the aerobic aqueous medium oxidation of benzyl alcohols to benzaldehydes, mediated by TEMPO radical, and for (ii) the solvent-free oxidation of secondary alcohols to ketones by t-BuOOH under microwave (MW) irradiation. Complex 2 shows the highest efficiency in both oxidation systems, resulting in up to 99% molar yields (based on the alcohol substrate) of products. In addition, remarkably high values of TON (1020) and TOF (4080 h(-1)) have been achieved in the MW-assisted peroxidative oxidation of 1-phenylethanol to acetophenone (model reaction). Attractive green features of these catalytic systems include the operation in aqueous or solvent-free reaction medium, under mild conditions and with high yields and selectivities, using Cu catalyst precursors that are readily available by self-assembly in water of simple chemicals. PMID:20844801

Figiel, Pawe? J; Kirillov, Alexander M; Guedes da Silva, M Fátima C; Lasri, Jamal; Pombeiro, Armando J L

2010-11-01

155

Highly dispersed pd catalyst locked in knitting aryl network polymers for Suzuki-Miyaura coupling reactions of aryl chlorides in aqueous media.  

PubMed

Highly dispersed palladium chloride catalysts locked in triphenylphosphine-functionalized knitting aryl network polymers (KAPs) are developed and exhibit excellent activity under mild conditions in the Suzuki-Miyaura cross-coupling reactions of aryl chlorides in aqueous media. This work highlights that the microporous polymers not only play the role of support materials, but also protect the Pd species from aggregation and precipitation, hence, positively effect the catalysis activity. PMID:22674537

Li, Buyi; Guan, Zhenhong; Wang, Wei; Yang, Xinjia; Hu, Jianglin; Tan, Bien; Li, Tao

2012-07-01

156

Conditionals  

E-print Network

This article introduces the classic accounts of the meaning of conditionals (material implication, strict implication, variably strict conditional) and discusses the difference between indicative and subjunctive/counterfactual ...

von Fintel, Kai

2011-01-01

157

Cognitive Processing in Mild Disabilities.  

ERIC Educational Resources Information Center

Research regarding the cognitive processing of students with learning disabilities, mild mental handicap, and emotional handicap is reviewed. In considering cognitive processing for students with mild mental handicap, research attention has been directed to the issues of memory and learning, acquisition and retrieval deficits, inefficient…

Al-Hilawani, Yasser A.; Poteet, James A.

158

Neuroprotection of mild hypothermia: differential effects  

Microsoft Academic Search

To estimate whether mild hypothermia during repetitive hypoxia provides a neuroprotective effect on brain tissue, hippocampal slice preparations were subjected to repetitive hypoxic episodes under different temperature conditions. Slices of guinea pig hippocampus (n=40) were placed at the interface of artificial cerebrospinal fluid (aCSF) and gas (normoxia: 95% O2, 5% CO2; hypoxia: 95% N2, 5% CO2). Evoked potentials (EP) and

C. Greiner; S. Hülsmann; H. Wassmann; D. Moskopp; A. Schmidinger; J. Wölfer; R. Köhling; A. Lücke; E.-J. Speckmann

1998-01-01

159

Mild Cognitive Impairment  

PubMed Central

Purpose of Review: The term mild cognitive impairment (MCI) is used to describe older subjects with demonstrable cognitive impairment who have not crossed the threshold for dementia. Because patients with MCI have an increased risk of developing dementia, especially Alzheimer disease (AD), there is significant interest in the clinical characterization of these subjects and in understanding the pathophysiology of the transition from MCI to AD. Recent Findings: The MCI syndrome, as an expression of an incipient disorder that may lead to dementia, is extremely heterogeneous and may coexist with systemic, neurologic, or psychiatric disorders that can cause cognitive deficits. Recent clinical criteria were designed to take into account the different forms of clinical presentation of the syndrome, and introduced the possible contribution of biomarkers to the clinical diagnosis. Bedside diagnosis of MCI can be difficult, since patients who report having cognitive problems may have normal scores in global cognitive scales or in brief neuropsychological instruments. Summary: This article presents the evolution of the clinical concept of MCI, the operationalization of its current definitions, the development of biomarkers that can help to identify an underlying neurodegenerative process as the etiology of the syndrome, and its proposed treatments. PMID:23558486

Lopez, Oscar L.

2013-01-01

160

A Rootstock Provides Water Conservation for a Grafted Commercial Tomato (Solanum lycopersicum L.) Line in Response to Mild-Drought Conditions: A Focus on Vegetative Growth and Photosynthetic Parameters  

PubMed Central

The development of water stress resistant lines of commercial tomato by breeding or genetic engineering is possible, but will take considerable time before commercial varieties are available for production. However, grafting commercial tomato lines on drought resistant rootstock may produce drought tolerant commercial tomato lines much more rapidly. Due to changing climates and the need for commercial production of vegetables in low quality fields there is an urgent need for stress tolerant commercial lines of vegetables such as tomato. In previous observations we identified a scion root stock combination (‘BHN 602’ scion grafted onto ‘Jjak Kkung’ rootstock hereafter identified as 602/Jjak) that had a qualitative drought-tolerance phenotype when compared to the non-grafted line. Based on this initial observation, we studied photosynthesis and vegetative above-ground growth during mild-drought for the 602/Jjak compared with another scion-rootstock combination (‘BHN 602’ scion grafted onto ‘Cheong Gang’ rootstock hereafter identified as 602/Cheong) and a non-grafted control. Overall above ground vegetative growth was significantly lower for 602/Jjak in comparison to the other plant lines. Moreover, water potential reduction in response to mild drought was significantly less for 602/Jjak, yet stomatal conductance of all plant-lines were equally inhibited by mild-drought. Light saturated photosynthesis of 602/Jjak was less affected by low water potential than the other two lines as was the % reduction in mesophyll conductance. Therefore, the Jjak Kkung rootstock caused aboveground growth reduction, water conservation and increased photosynthetic tolerance of mild drought. These data show that different rootstocks can change the photosynthetic responses to drought of a high yielding, commercial tomato line. Also, this rapid discovery of one scion-rootstock combination that provided mild-drought tolerance suggests that screening more scion-rootstock combination for stress tolerance may rapidly yield commercially viable, stress tolerant lines of tomato. PMID:25531435

Nilsen, Erik T.; Freeman, Joshua; Grene, Ruth; Tokuhisa, James

2014-01-01

161

Metal-free activation of H 2 O 2 by synergic effect of ionic liquid and microwave: chemoselective oxidation of benzylic alcohols to carbonyls and unexpected formation of anthraquinone in aqueous condition  

Microsoft Academic Search

H2O2 mediated oxidation of alcohols in ionic liquid is revisited, wherein, ionic liquids under the influence of microwave irradiation\\u000a have been found to facilitate activation of H2O2 without any metal catalyst in aqueous condition. The method utilizes a neutral ionic liquid [hmim]Br both as catalyst and\\u000a solvent for efficient and chemoselective oxidation of benzyl alcohol derivatives on aromatic (?, ?)

Rakesh Kumar; Nandini Sharma; Naina Sharma; Abhishek Sharma; Arun K. Sinha

162

Mild pretreatment and enzymatic saccharification of cellulose with recycled ionic liquids towards one-batch process.  

PubMed

The development of second-generation bioethanol involves minimizing the energy input throughout the processing steps. We report here that efficient ionic liquid pretreatments of cellulose can be achieved with short duration times (20 min) at mild temperature (45°C) with [Emim](+)[MeO(H)PO(2)](-) and at room temperature (25 °C) with [Emim](+)[CH(3)COO](-). In these conditions, yields of glucose were increased by a factor of 3. In addition, the recycling of these two imidazolium-based ILs can be performed in maintaining their efficiency to pretreat cellulose. The short time and mild temperature of cellulose solubilization allowed a one-batch processing of [Emim](+)[MeO(H)PO(2)](-) IL-pretreatment and saccharification. In the range from 0 to 100% IL in an aqueous enzymatic medium, the glucose yields were improved at IL proportions between 10 and 40%. The maximum yield at 10% IL is very promising to consider one batch process as efficient as two-step process. PMID:22840005

Auxenfans, Thomas; Buchoux, Sébastien; Djellab, Karim; Avondo, Carine; Husson, Eric; Sarazin, Catherine

2012-10-01

163

Mortality associated with mild, untreated xerophthalmia.  

PubMed Central

The high mortality rate among children with severe corneal xerophthalmia is well recognized. The present study investigates, for the first time, mortality among the very much larger number of otherwise healthy free-living children with mild xerophthalmia (night blindness and Bitot's spots). An average of 3481 children (under 6 years of age) living in six Indonesian villages were reexamined by an ophthalmologist, pediatrician, and nutritionist every 3 months for 18 months. The overall prevalence of mild xerophthalmia was 4.9%. During the 18 months of observation, 132 children died. Of these, 24 had mild xerophthalmia and 108 had normal eyes at the 3-monthly examination preceding their death. Mortality rates were calculated for each 3-month interval by classifying all children by their ocular status at the start of the interval, and then dividing the number of deaths within the interval by the number of children of the same ocular status followed up for that interval. Mortality rates for the six 3-month intervals were then added together, and the results expressed as deaths per 1000 "child-intervals" of follow-up. Overall mortality rates for children with mild xerophthalmia and for children with normal eyes were 23.3 and 5.3, respectively, a ratio of 4 to 1. Excess mortality among the mildly xerophthalmic children increased with the severity of their xerophthalmia. Mortality rates for children with night blindness, with Bitot's spots, and with the two conditions concurrently were 2.7, 6.6, and 8.6 times the mortality rate of non-xerophthalmic children. This direct, almost linear relation between mortality and the severity of mild xerophthalmia was still present after standardizing for age and for the presence or absence of respiratory infection and protein-energy malnutrition. In the population studied, 16% of all deaths in children 1 to 6 years of age were directly related to vitamin A deficiency identified by the presence of mild xerophthalmia. These results suggest: that the existence of mild vitamin A deficiency in a community justifies initiation of vigorous intervention measures to reduce mortality, as much as to prevent the rarer cases of blindness; that night blindness and Bitot's spots should be accorded the same respect as is low "weight for height" in identifying those children in urgent need of medical attention; that ocular criteria used for determining the existence and severity of a vitamin A problem be reevaluated; and that the ophthalmic community, which has long been responsible for managing xerophthalmia, must now re-alert nutritionists, pediatricians, and public health workers to the serious systemic consequences accompanying even mild Images FIGURE 1 A FIGURE 1 B FIGURE 2 A FIGURE 2 B FIGURE 3 A FIGURE 3 B FIGURE 4 A C FIGURE 4 B D PMID:6610243

Sommer, A

1983-01-01

164

Characteristics and antioxidative activity of the acetone-soluble and -insoluble fractions of a defatted rice bran extract obtained by using an aqueous organic solvent under subcritical conditions.  

PubMed

The defatted rice bran extracts obtained by being treated with various subcritical aqueous fluids at 230 °C for 5 min were further subjected to an acetone-solubilization treatment. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity depended on the total phenolic content of a sample, the acetone-soluble fraction of the extract obtained with 40% (v/v) aqueous acetone showing the highest activity. Based on the UV spectrometric and HPLC analyses, the substances with higher absorbance around 280 nm and higher hydrophobicity were found solubilizing out from the extracts into the acetone during fractionation. A gel permeation chromatographic analysis suggested that the extracts comprised monomeric or oligomeric substances. The antioxidative activity was evaluated by a DPPH radical scavenging activity analysis, rancidity test, and autoxidation analysis, revealing that it would be most likely to exert a radical scavenging effect more effectively during the initial stage of lipid oxidation than during the propagation stage. PMID:23470769

Chiou, Tai-Ying; Kobayashi, Takashi; Adachi, Shuji

2013-01-01

165

Neuropsychological function in mild hyperphenylalaninemia.  

PubMed

Whether specific cognitive deficits related to frontal-lobe dysfunction that have been reported in individuals with phenylketonuria (PKU) are also characteristic of mild hyperphenylalaninemia (MHP) was investigated. Tests of executive function and control tasks not assessing executive function were administered to a group of individuals with MHP and a group without MHP, similar in age, gender, and IQ. Tests of academic skills and behavior-rating questionnaires were also administered to the group with MHP. No group differences were found for any measure, suggesting that the mild elevations of phenylalanine in individuals with MHP are not sufficient to produce behavioral and cognitive impairments characteristic of PKU. PMID:10755172

Smith, M L; Saltzman, J; Klim, P; Hanley, W B; Feigenbaum, A; Clarke, J T

2000-03-01

166

In situ study of mass transfer in aqueous solutions under high pressures via Raman spectroscopy: A new method for the determination of diffusion coefficients of methane in water near hydrate formation conditions  

USGS Publications Warehouse

A new method was developed for in situ study of the diffusive transfer of methane in aqueous solution under high pressures near hydrate formation conditions within an optical capillary cell. Time-dependent Raman spectra of the solution at several different spots along the one-dimensional diffusion path were collected and thus the varying composition profile of the solution was monitored. Diffusion coefficients were estimated by the least squares method based on the variations in methane concentration data in space and time in the cell. The measured diffusion coefficients of methane in water at the liquid (L)-vapor (V) stable region and L-V metastable region are close to previously reported values determined at lower pressure and similar temperature. This in situ monitoring method was demonstrated to be suitable for the study of mass transfer in aqueous solution under high pressure and at various temperature conditions and will be applied to the study of nucleation and dissolution kinetics of methane hydrate in a hydrate-water system where the interaction of methane and water would be more complicated than that presented here for the L-V metastable condition. ?? 2006 Society for Applied Spectroscopy.

Lu, W.J.; Chou, I.-Ming; Burruss, R.C.; Yang, M.Z.

2006-01-01

167

Educating Students with Mild Disabilities.  

ERIC Educational Resources Information Center

The book contains 19 papers from the journal, "Focus on Exceptional Children," that discuss new perspectives and practices in educating students with mild disabilities. The first half of the book is titled "New Perspectives" and includes the following articles: "Beyond the Regular Education Initiative/Inclusion and the Resource Room Controversy"…

Meyen, Edward L., Ed.; And Others

168

Determination of formal kinetic constants of thermal decomposition of aqueous hydrogen peroxide solution in a mixture of magnetic powder, based on experimental thermogram, obtained in adiabatic conditions  

NASA Astrophysics Data System (ADS)

Process of thermal decomposition of hydrogen peroxide aqueous solution with the addition of magnetic powder in the form of toner for printers and lanthanum manganite were considered. Obtained resulting from an experiment in the Dewar container conducted thermogram analyzed using mass balance equations and heat. Formal kinetic parameters determined, and conclude that the magnetic powder in the mixture does not have catalytic properties. The described technique is recommended as a rapid analysis of the kinetics of the various reactions to substances having predefined thermal and thermodynamic properties.

Zaripov, Jamshed; Borisov, Boris; Bondarchuk, Sergey

2014-08-01

169

Tannin (Polyphenol) Stability in Aqueous Solutions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Understanding the chemical stability of tannins (polyphenolics) in soils is critical to understanding their biological activities and fate. We examined the stability of chemically defined tannins in aqueous solutions under conditions simulating natural and laboratory conditions. We evaluated tanni...

170

Influence of Aqueous-Salt Conditions on the Structure and Dynamics of the Monomeric and Novel Dimeric forms of the Alzheimer s ABeta21-30 protein fragment  

NASA Astrophysics Data System (ADS)

The behavior of the Alzheimer's related peptide Abeta is the subject of much study. In typical computational studies the environment local to the peptide is assumed to be pure water; however, in vivo the peptide is found in the extracellular space near the plasma membrane which is rich in ionic species. In this thesis, the hypothesis that the presence of group I/IIA salts will result in increased sampling of disordered structures as well as modify the dynamics of meta-stable structural motifs in the small folding nucleus of the Abeta peptide (Abeta21-30) is examined under a variety of ionic environments and was shown that of the tested salts, CaCl2 (and MgCl2, to a much lesser degree) did increase the propensity for disordered states; while, the group IA salts, KCl and NaCl, had little effect on the secondary structure of the peptide. Further, study of three familial mutations of this peptide region is also performed under aqueous salt-environments to elucidate further mechanistic details of how aqueous salts modify the region's behavior. Finally, as experimental results have highlighted that aggregation rates of the full-length peptide are modified by the presence of CaCl2, this work examines novel dimers states of Abeta21-30 and their stabilities when exposed to CaCl2.

Smith, Micholas Dean

171

Bioglycerol-based sulphonic acid functionalized carbon: an efficient and recyclable, solid acid catalyst for the regioselective azidolysis of epoxides in aqueous acetonitrile.  

PubMed

A convinent and efficient method was developed for the synthesis of 1,2-azidoalcohols by ring opening of terminal epoxides with sodium azide employing glycerol-based sulphonic acid functionalized carbon as heterogeneous catalyst in aqueous acetonitrile. The reaction is highly regioselective and affords the corresponding products in excellent yields (78-100%) under mild reaction conditions. The catalyst exhibited efficient reusability without loosing its activity even after 5 cycles of azidolysis of methyl 10,11-epoxy undecanoate under optimized conditions within 2 h. PMID:24088523

Vijay, Manneganti; Prasad, Rachapudi Badari Narayana; Devi, Bethala Lakshmi Anu Prabhavathi

2013-01-01

172

Development of an advanced continuous mild gasification process for the production of coproducts. Final report  

Microsoft Academic Search

This report is a final brief summary of development of a mild-gasification and char conversion process. Morgantown Energy Technology Center developed a concept called mild gasification. In this concept, devolatilization of coal under nonoxidizing and relatively mild temperature and pressure conditions can yield three marketable products: (1) a high-heating-value gas, (2) a high-aromatic coal liquid, and (3) a high-carbon char.

N. W. Merriam; M. C. Jha

1991-01-01

173

Development of an advanced continuous mild gasification process for the production of coproducts  

Microsoft Academic Search

This report is a final brief summary of development of a mild-gasification and char conversion process. Morgantown Energy Technology Center developed a concept called mild gasification. In this concept, devolatilization of coal under nonoxidizing and relatively mild temperature and pressure conditions can yield three marketable products: (1) a high-heating-value gas, (2) a high-aromatic coal liquid, and (3) a high-carbon char.

N. W. Merriam; M. C. Jha

1991-01-01

174

Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel  

NASA Astrophysics Data System (ADS)

Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil

2014-09-01

175

Development of mild gasification process  

SciTech Connect

Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1 -- Test Plan; Task 2 -- Optimization of Mild Gasification Process; Task 3 -- Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4 -- Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

Chu, C.I.C.; Williams, S.W.

1989-01-01

176

Development of mild gasification process  

SciTech Connect

Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1 -- Test Plan; Task 2 -- Optimization of Mild Gasification Process; Task 3 -- Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4 -- Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

Chu, C.I.C.; Gillespie, B.L.

1987-11-01

177

Development of mild gasification process  

SciTech Connect

Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. DE-AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1-Test Plan; Task 2-Optimization of Mild Gasification Process; Task 3-Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4-Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

Chu, C.I.C.; Gillespie, B.L.

1988-02-01

178

Development of mild gasification process  

SciTech Connect

Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1 -- Test Plan; Task 2 -- Optimization of Mild Gasification Process; Task 3 -- Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4 -- Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

Chu, C.I.C.; Derting, T.M.

1988-07-01

179

Mild uncatalyzed hydroamination of an electrophilic alkyne, ethynylcobalticinium.  

PubMed

Primary and secondary amines react with ethynylcobalticinium under mild conditions in the absence of a catalyst and an additional solvent to give quantitative yields of dark-red microcrystalline cobalticinium trans-enamines that show a remarkable push-pull electronic structure. PMID:23703549

Wang, Yanlan; Rapakousiou, Amalia; Latouche, Camille; Daran, Jean-Claude; Singh, Anu; Ledoux-Rak, Isabelle; Ruiz, Jaime; Saillard, Jean-Yves; Astruc, Didier

2013-07-01

180

Turbulent boundary layer on a mildly curved convex surface  

Microsoft Academic Search

Extensive single point turbulence measurements made in the boundary layer on a mildly curved heated convex wall show that the turbulence heat fluxes and Stanton number are more sensitive to a change in wall curvature than the Reynolds stresses and skinfriction coefficient, and that downstream, as the flow adjusts to new curved conditions, the St\\/cf ratio of Reynolds analogy is

M. M. Gibson; C. A. Verriopoulos

1984-01-01

181

Mars aqueous chemistry experiment  

NASA Technical Reports Server (NTRS)

The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

Clark, Benton C.; Mason, Larry W.

1993-01-01

182

Standard partial molar volumes of some aqueous alkanolamines and alkoxyamines at temperatures up to 325 degrees C: functional group additivity in polar organic solutes under hydrothermal conditions.  

PubMed

Apparent molar volumes of dilute aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), N,N-dimethylethanolamine (DMEA), ethylethanolamine (EAE), 2-diethylethanolamine (2-DEEA), and 3-methoxypropylamine (3-MPA) and their salts were measured at temperatures from 150 to 325 degrees C and pressures as high as 15 MPa. The results were corrected for the ionization and used to obtain the standard partial molar volumes, Vo2. A three-parameter equation of state was used to describe the temperature and pressure dependence of the standard partial molar volumes. The fitting parameters were successfully divided into functional group contributions at all temperatures to obtain the standard partial molar volume contributions. Including literature results for alcohols, carboxylic acids, and hydroxycarboxylic acids yielded the standard partial molar volume contributions of the functional groups >CH-, >CH2, -CH3, -OH, -COOH, -O-, -->N, >NH, -NH2, -COO-Na+, -NH3+Cl-, >NH2+Cl-, and -->NH+Cl- over the range (150 degrees C aqueous organic solutes composed of these groups at temperatures up to approximately 310 degrees C and pressures of 10-20 MPa to within a precision of +/-5 cm3 x mol(-1). The model could not be extended to higher temperatures because of uncertainties caused by thermal decomposition. At temperatures above approximately 250 degrees C, the order of the group contributions to Vo2 changes from that observed at 25 degrees C, to become increasingly consistent with the polarity of each functional group. The effect of the dipole moment of each molecule on the contribution to Vo2 from long-range solvent polarization was calculated from the multipole expansion of the Born equation using dipole moments estimated from restricted Hartree-Fock calculations with Gaussian 03 (Gaussian, Inc., Wallingford, CT) and the Onsager reaction-field approximation for solvent effects. Below 325 degrees C, the dipole contribution was found to be less than 2 cm3 x mol(-1) for all the solute molecules studied. At higher temperatures and pressures near steam saturation, the effect is much larger and may explain anomalies in functional group additivity observed in small, very polar solutes. PMID:18412415

Bulemela, E; Tremaine, Peter R

2008-05-01

183

Development of an advanced continuous mild gasification process for the production of coproducts  

SciTech Connect

This report is a final brief summary of development of a mild-gasification and char conversion process. Morgantown Energy Technology Center developed a concept called mild gasification. In this concept, devolatilization of coal under nonoxidizing and relatively mild temperature and pressure conditions can yield three marketable products: (1) a high-heating-value gas, (2) a high-aromatic coal liquid, and (3) a high-carbon char. The objective of this program is to develop an advanced, continuous, mild-gasification process to produce products that will make the concept economically and environmentally viable. (VC)

Merriam, N.W.; Jha, M.C.

1991-11-01

184

Development of an advanced continuous mild gasification process for the production of coproducts. Final report  

SciTech Connect

This report is a final brief summary of development of a mild-gasification and char conversion process. Morgantown Energy Technology Center developed a concept called mild gasification. In this concept, devolatilization of coal under nonoxidizing and relatively mild temperature and pressure conditions can yield three marketable products: (1) a high-heating-value gas, (2) a high-aromatic coal liquid, and (3) a high-carbon char. The objective of this program is to develop an advanced, continuous, mild-gasification process to produce products that will make the concept economically and environmentally viable. (VC)

Merriam, N.W.; Jha, M.C.

1991-11-01

185

Hematite Spherules in Basaltic Tephra Altered Under Aqueous, Acid-Sulfate Conditions on Mauna Kea Volcano, Hawaii: Possible Clues for the Occurrence of Hematite-Rich Spherules in the Burns Formation at Meridiani Planum, Mars  

NASA Technical Reports Server (NTRS)

Iron-rich spherules (>90% Fe2O3 from electron microprobe analyses) approx.10-100 microns in diameter are found within sulfate-rich rocks formed by aqueous, acid-sulfate alteration of basaltic tephra on Mauna Kea volcano, Hawaii. Although some spherules are nearly pure Fe, most have two concentric compositional zones, with the core having a higher Fe/Al ratio than the rim. Oxide totals less than 100% (93-99%) suggest structural H2O and/or /OH. The transmission Moessbauer spectrum of a spherule-rich separate is dominated by a hematite (alpha-Fe2O3) sextet whose peaks are skewed toward zero velocity. Skewing is consistent with Al(3+) for Fe(3+) substitution and structural H2O and/or /OH. The grey color of the spherules implies specular hematite. Whole-rock powder X-ray diffraction spectra are dominated by peaks from smectite and the hydroxy sulfate mineral natroalunite as alteration products and plagioclase feldspar that was present in the precursor basaltic tephra. Whether spherule formation proceeded directly from basaltic material in one event (dissolution of basaltic material and precipitation of hematite spherules) or whether spherule formation required more than one event (formation of Fe-bearing sulfate rock and subsequent hydrolysis to hematite) is not currently constrained. By analogy, a formation pathway for the hematite spherules in sulfate-rich outcrops at Meridiani Planum on Mars (the Burns formation) is aqueous alteration of basaltic precursor material under acid-sulfate conditions. Although hydrothermal conditions are present on Mauna Kea, such conditions may not be required for spherule formation on Mars if the time interval for hydrolysis at lower temperatures is sufficiently long.

Morris, R. V.; Ming, D. W.; Graff, T. G.; Arvidson, R. E.; Bell, J. F., III; Squyres, S. W.; Mertzman, S. A.; Gruener, J. E.; Golden, D. C.; Robinson, G. A.

2005-01-01

186

Procedures for Increasing Sustained Attention in Adults with Mild Intellectual Disabilities  

ERIC Educational Resources Information Center

This research compared the effects of several factors on sustained attention in four participants with mild or mild-to-moderate intellectual disabilities. In each session, each participant received an extended number of conditional discriminations that required a differential response to infrequently occurring target stimuli. We assessed sustained…

Doughty, Adam H.; Williams, Dean C.

2013-01-01

187

The dissolution of benzene, toluene, m-xylene and naphthalene from a residually trapped non-aqueous phase liquid under mass transfer limited conditions  

NASA Astrophysics Data System (ADS)

The results of dissolution experiments for benzene, toluene, m-xylene and naphthalene (BTXN) from a relatively insoluble oil phase (tridecane), residually trapped in a non-sorbing porous medium, are described. This mixture was chosen to simulate dissolution of soluble aromatic compounds from a petroleum hydrocarbon mixture, e.g., crude oil, for which a large fraction of the mixture is relatively insoluble. The experiments were carried out at a small source length to interstitial velocity ratio, L/ v, so that dissolution would be mass transfer limited (MTL). When fitted to data for toluene, a multiregion mass transfer model was found to predict the experimental data satisfactorily for the other components without adjustment of the mass transfer rate parameters. These results indicate that the dissolution process can be generalized for various hydrophobic organic compounds present in a multicomponent non-aqueous phase liquid (NAPL) when mass transfer limitations are present. This also suggests that dissolution data obtained for one compound can be useful for predicting the dissolution histories for other compounds from petroleum hydrocarbon mixtures.

Garg, Sanjay; Rixey, William G.

1999-03-01

188

Effect of the water content on the retention and enantioselectivity of albendazole and fenbendazole sulfoxides using amylose-based chiral stationary phases in organic-aqueous conditions.  

PubMed

Four commercially available immobilized amylose-derived CSPs (Chiralpak IA-3, Chiralpak ID-3, Chiralpak IE-3 and Chiralpak IF-3) were used in the HPLC analysis of the chiral sulfoxides albendazole (ABZ-SO) and fenbendazole (FBZ-SO) and their in vivo sulfide precursor (ABZ and FBZ) and sulfone metabolite (ABZ-SO2 and FBZ-SO2) under organic-aqueous mode. U-shape retention maps, established by varying the water content in the acetonitrile- and ethanol-water mobile phases, were indicative of two retention mechanisms operating on the same CSP. The dual retention behavior of polysaccharide-based CSPs was exploited to design greener enantioselective and chemoselective separations in a short time frame. The enantiomers of ABZ-SO and FBZ-SO were baseline resolved with water-rich mobile phases (with the main component usually being 50-65% water in acetonitrile) on the IF-3 CSP and ethanol-water 100:5 mixture on the IA-3 and IE-3 CSPs. A simultaneous separation of ABZ (or FBZ), enantiomers of the corresponding sulfoxide and sulfone was achieved on the IA-3 using ethanol-water 100:60 (acetonitrile-water 100:100 for FBZ) as a mobile phase. PMID:24411094

Materazzo, Sabrina; Carradori, Simone; Ferretti, Rosella; Gallinella, Bruno; Secci, Daniela; Cirilli, Roberto

2014-01-31

189

Removal of aqueous rinsable flux residues in a batch spray dishwater  

SciTech Connect

An alkaline detergent solution used in an industrial dishwasher was evaluated to remove aqueous rinsable flux residues on printed wiring boards (PWBs) after hot air solder leveling and hot oil solder dip and leveling. The dishwasher, a batch cleaning process, was compared to an existing conveyorized aqueous cleaning process. The aqueous soluble flux residues from both soldering processes were removed with a solution of a mild alkaline detergent dissolved in hot deionized (DI) water.

Slanina, J.T.

1992-02-01

190

ENCOAL Mild Coal Gasification Project  

SciTech Connect

ENCOAL Corporation, a wholly-owned subsidiary of Shell Mining Company, is constructing a mild gasification demonstration plant at Triton Coal Company's Buckskin Mine near Gillette, Wyoming. The process, using Liquids From Coal (LFC) technology developed by Shell and SGI International, utilizes low-sulfur Powder River Basin Coal to produce two new fuels, Process Derived Fuel (PDF) and Coal Derived Liquids (CDL). The products, as alternative fuels sources, are expected to significantly reduce current sulfur emissions at industrial and utility boiler sites throughout the nation, thereby reducing pollutants causing acid rain.

Not Available

1992-02-01

191

Neuroprotection of mild hypothermia: differential effects.  

PubMed

To estimate whether mild hypothermia during repetitive hypoxia provides a neuroprotective effect on brain tissue, hippocampal slice preparations were subjected to repetitive hypoxic episodes under different temperature conditions. Slices of guinea pig hippocampus (n=40) were placed at the interface of artificial cerebrospinal fluid (aCSF) and gas (normoxia: 95% O2, 5% CO2; hypoxia: 95% N2, 5% CO2). Evoked potentials (EP) and direct current (DC) potentials were recorded from hippocampal CA1 region. Slices were subjected to two repetitive hypoxic episodes under the following temperature conditions: (A) 34 degrees C/34 degrees C, (B) 30 degrees C/30 degrees C and (C) 34 degrees C/30 degrees C. Hypoxic phases lasted until an anoxic terminal negativity (ATN) occurred. The recovery after first hypoxia lasted 30 min. Tissue function was assessed regarding the latency of ATN and the recovery of evoked potentials. The ATN latencies with protocol A (n = 25) for the first and second hypoxia were 5.9+/-1.3 min (mean+/-S.E.M., 1st hypoxia) and 2.4+/-0.9 min (2nd hypoxia), with protocol B the latencies (n = 7) were significantly longer: 25.2+/-7.1 min and 15.6+/-7.7 min. With protocol C (n=8), the latencies were 5.6+/-1.8 and 3.3+/-0.5 min. No differences were seen in the recovery of the EPs with protocols A-C. Our results suggest that a mild hypothermia is only neuroprotective if applied from an initial hypoxia onwards. PMID:9555052

Greiner, C; Hülsmann, S; Wassmann, H; Moskopp, D; Schmidinger, A; Wölfer, J; Köhling, R; Lücke, A; Speckmann, E

1998-03-01

192

Aqueous foam toxicology evaluation and hazard review  

SciTech Connect

Aqueous foams are aggregates of bubbles mechanically generated by passing air or other gases through a net, screen, or other porous medium that is wetted by an aqueous solution of surface-active foaming agents (surfactants). Aqueous foams are important in modem fire-fighting technology, as well as for military uses for area denial and riot or crowd control. An aqueous foam is currently being developed and evaluated by Sandia National Laboratories (SNL) as a Less-Than-Lethal Weapon for the National Institute of Justice (NIJ). The purpose of this study is to evaluate the toxicity of the aqueous foam developed for the NIJ and to determine whether there are any significant adverse health effects associated with completely immersing individuals without protective equipment in the foam. The toxicity of the aqueous foam formulation developed for NIJ is determined by evaluating the toxicity of the individual components of the foam. The foam is made from a 2--5% solution of Steol CA-330 surfactant in water generated at expansion ratios ranging from 500:1 to 1000:1. SteoI CA-330 is a 35% ammonium laureth sulfate in water and is produced by Stepan Chemical Company and containing trace amounts (<0.1%) of 1,4-dioxane. The results of this study indicate that Steol CA-330 is a non-toxic, mildly irritating, surfactant that is used extensively in the cosmetics industry for hair care and bath products. Inhalation or dermal exposure to this material in aqueous foam is not expected to produce significant irritation or systemic toxicity to exposed individuals, even after prolonged exposure. The amount of 1,4-dioxane in the surfactant, and subsequently in the foam, is negligible and therefore, the toxicity associated with dioxane exposure is not significant. In general, immersion in similar aqueous foams has not resulted in acute, immediately life-threatening effects, or chronic, long-term, non-reversible effects following exposure.

Archuleta, M.M.

1995-10-01

193

Bioenhanced dissolution of dense non-aqueous phase of trichloroethylene as affected by iron reducing conditions: model systems and environmental samples.  

PubMed

The anaerobic biotransformation of trichloroethylene (TCE) can be affected by competing electron acceptors such as Fe (III). This study assessed the role of Fe (III) reduction on the bioenhanced dissolution of TCE dense non-aqueous phase liquid (DNAPL). Columns were set up as 1-D diffusion cells consisting of a lower DNAPL layer, a layer with an aquifer substratum and an upper water layer that is regularly refreshed. The substrata used were either inert sand or sand coated with 2-line ferrihydrite (HFO) or two environmental Fe (III) containing samples. The columns were inoculated with KB-1 and were repeatedly fed with formate. In none of the diffusion cells, vinyl chloride or ethene was detected while dissolved and extractable Fe (II) increased strongly during 60 d of incubation. The cis-DCE concentration peaked at 4.0 cm from the DNAPL (inert sand) while it was at 3.4 cm (sand+HFO), 1.7 cm and 2.5 cm (environmental samples). The TCE concentration gradients near the DNAPL indicate that the DNAPL dissolution rate was larger than that in an abiotic cell by factors 1.3 (inert sand), 1.0 (sand+HFO) and 2.2 (both environmental samples). This results show that high bioavailable Fe (III) in HFO reduces the TCE degradation by competitive Fe (III) reduction, yielding lower bioenhanced dissolution. However, Fe (III) reduction in environmental samples was not reducing TCE degradation and the dissolution factor was even larger than that of inert sand. It is speculated that physical factors, e.g. micro-niches in the environmental samples protect microorganisms from toxic concentrations of TCE. PMID:25460750

Paul, Laiby; Smolders, Erik

2015-01-01

194

Mild cognitive impairment: The dilemma  

PubMed Central

Memory complaints are ubiquitous in our aging population. Many older adults fear that today’s forgetfulness will usher in tomorrow’s dementia. Mild cognitive impairment (MCI) is considered by many as an intermediary stage for dementia. Though the nomenclature has been varied and extensive, the criteria by the American Academy of Neurology and the EADC have been helpful. Prevalence rates varying from 3% to as high as 59% with a conversion rate to dementia varying from 8 to 15% only increases the need for diagnostic tests and markers which are in the form of neuropsychological tests, neuroimaging and other biological markers. Medications indicated for treatment of mild to severe Alzheimer’s Disease (AD) are offered to persons with MCI with a varying type of response which does not hold in the long run to newer strategies of exploring disease modifying drugs which hold a better promise. This benefit with management of risk factors like hypertension and diabetes coupled with non-pharmacological approaches like exercise and social networking has thrust upon us the necessity for coordinating our efforts to improve detection and management of MCI. PMID:21416016

Pinto, Charles; Subramanyam, Alka A.

2009-01-01

195

Non-hydrolytic synthesis of mesoporous silica-titania catalysts for the mild oxidation of sulfur compounds with hydrogen peroxide.  

PubMed

A SiO(2)-TiO(2) mesoporous xerogel prepared in one-step by a non-hydrolytic route shows excellent performance in the mild oxidation of sulfides, sulfoxides and thiophenes with aqueous solutions of H(2)O(2). PMID:18985209

Cojocariu, Ana Mihaela; Mutin, P Hubert; Dumitriu, Emil; Fajula, François; Vioux, André; Hulea, Vasile

2008-11-14

196

Effect of resistivity on the corrosion mechanism of mild steel in sodium sulfate solutions  

Microsoft Academic Search

Electrochemical impedance spectroscopy (EIS) was used to study the corrosion behavior of mild steel samples immersed in 1, 0.1, 0.01 and 0.001% Na2SO4 aqueous solutions at room temperature in order to analyze the corrosion mechanism and obtain representative values of corrosion rates in environments with different resistivity. The EIS technique was used to measure corrosion current densities in 1 to

S. Arzola; M. E. PALOMAR-PARDAVE ´; J. Genesca

2003-01-01

197

Reaction mechanism for the aqueous-phase mineral carbonation of heat-activated serpentine at low temperatures and pressures in flue gas conditions.  

PubMed

Mineral carbonation is known as one of the safest ways to sequester CO2. Nevertheless, the slow kinetics and low carbonation rates constitute a major barrier for any possible industrial application. To date, no studies have focused on reacting serpentinite with a relatively low partial pressure of CO2 (pCO2) close to flue gas conditions. In this work, finely ground and heat-treated serpentinite [Mg3Si2O5(OH)4] extracted from mining residues was reacted with a 18.2 vol % CO2 gas stream at moderate global pressures to investigate the effect on CO2 solubility and Mg leaching. Serpentinite dissolution rates were also measured to define the rate-limiting step. Successive batches of gas were contacted with the same serpentinite to identify surface-limiting factors using scanning electron microscopy (SEM) analysis. Investigation of the serpentinite carbonation reaction mechanisms under conditions close to a direct flue gas treatment showed that increased dissolution rates could be achieved relative to prior work, with an average Mg dissolution rate of 3.55 × 10(-11) mol cm(-2) s(-1). This study provides another perspective of the feasibility of applying a mineral carbonation process to reduce industrial greenhouse gas (GHG) emissions from large emission sources. PMID:24669999

Pasquier, Louis-César; Mercier, Guy; Blais, Jean-François; Cecchi, Emmanuelle; Kentish, Sandra

2014-05-01

198

Flow of Aqueous Humor  

MedlinePLUS

... Involved Research Grants Special Events Flow of Aqueous Humor © 2000 BrightFocus Foundation Unauthorized reprints not allowed. Most , ... remains normal when some of the fluid (aqueous humor) produced by the eye's ciliary body flows out ...

199

Development of an advanced, continuous mild gasification process for the production of co-products. Quarterly technical progress report, April--June 1988  

Microsoft Academic Search

The Department of Energy is investigating a process concept called Mild Gasification in which rapid devolatilization of coal under mild conditions of temperature and pressure would yield three product slates: a low- or medium-BTU gas, a valuable hydrocarbon condensate, and a reactive char. The ongoing objective of this program is to develop a continuous mild gasification process which will produce

Ness; R. O. Jr

1988-01-01

200

Mukaiyama Aldol Reactions in Aqueous Media  

PubMed Central

Mukaiyama aldol reactions in aqueous media have been surveyed. While the original Mukaiyama aldol reactions entailed stoichiometric use of Lewis acids in organic solvents under strictly anhydrous conditions, Mukaiyama aldol reactions in aqueous media are not only suitable for green sustainable chemistry but are found to produce singular phenomena. These findings led to the discovery of a series of water-compatible Lewis acids such as lanthanide triflates in 1991. Our understanding on these beneficial effects in the presence of water will be deepened through the brilliant examples collected in this review. 1 Introduction 2 Rate Enhancement by Water in the Mukaiyama Aldol Reaction 3 Lewis Acid Catalysis in Aqueous or Organic Solvents 3.1 Water-Compatible Lewis Acids 4 Lewis-Base Catalysis in Aqueous or Organic Solvents 5 The Mukaiyama Aldol Reactions in 100% Water 6 Asymmetric Catalysts in Aqueous Media and Water 7 Conclusions and Perspective PMID:24971045

Kitanosono, Taku; Kobayashi, Sh?

2013-01-01

201

Mild, Pd-catalyzed stannylation of radioiodination targets.  

PubMed

Trialkylstannanes are versatile precursors for chemical transformations, including radiolabeling with a variety of halogens, particularly iodine. In the present work a convenient, Pd-mediated stannylation method is presented that can be performed in an open flask. The method is selective for aryl iodides allowing selective stannylations in the presence of other halogen atoms. The reaction conditions are mild, making the method compatible with chemically sensitive bioactive compounds. PMID:25777268

Pickett, Julie E; Váradi, András; Palmer, Travis C; Grinnell, Steven G; Schrock, Joel M; Pasternak, Gavril W; Karimov, Rashad R; Majumdar, Susruta

2015-04-15

202

Current treatment options for depression after mild traumatic brain injury  

Microsoft Academic Search

Opinion statement  Mild traumatic brain injury (MTBI) is the most common neurologic condition in the United States; about 503 of every 100,000\\u000a persons visiting the emergency department have this diagnosis. A complex cluster of neurologic signs and symptoms are associated\\u000a with an acceleration-deceleration mechanism of injury. Unfortunately, many persons do not seek treatment for MTBI. Depression\\u000a following MTBI adds to the

Esther Bay

2009-01-01

203

Differential Working Memory Load Effects after Mild Traumatic Brain Injury  

Microsoft Academic Search

The objective of this study was to explore the effects of increasing working memory (WM) processing load on previously observed abnormalities in activation of WM circuitry shortly after mild traumatic brain injury (MTBI). Brain activation patterns in response to increasing WM processing load (auditory n-back: 0-, 1-, 2-, and 3-back conditions) were assessed with fMRI in 18 MTBI patients within

Thomas W. McAllister; Molly B. Sparling; Laura A. Flashman; Stephen J. Guerin; Alexander C. Mamourian; Andrew J. Saykin

2001-01-01

204

Intelligence in mild atypical phenylketonuria.  

PubMed

In 82 children with mild phenylketonuria (PKU) (blood phenylalanine (Phe) concentrations consistently below 900 mumol/l throughout follow up) the relationship between intelligence at age 4 (IQ by Stanford-Binet) and average blood Phe concentrations from birth to 4 years was examined. Of the 82 children 24 had received no treatment. In the group as a whole, and in the 24 untreated subjects alone, mean IQs were significantly below population norms, with deficits of approximately 4.5 points and 9 points respectively. After allowing for social class IQ fell progressively by approximately 6 points for each 100 mumol/l rise in mean Phe concentrations in both the treated and untreated subjects. This relationship resembled that previously reported in early treated children with more severe forms of PKU, except that the scale of the relationship was even greater. We conclude that all children whose blood Phe concentrations reach 400 mumol/l or above should receive a low Phe diet, at least during the preschool years, and that the aim should be to control blood Phe levels below 400 mumol/l throughout early childhood in all forms of PKU. PMID:8194559

Costello, P M; Beasley, M G; Tillotson, S L; Smith, I

1994-04-01

205

Outpatient Diverticulitis: Mild or Myth?  

PubMed Central

Background Diverticulitis is considered common in the outpatient population, with mild variants of described diagnostic criteria: left lower quadrant pain, fever, and leukocytosis. Here, expected criteria utilization among outpatients with a possible diagnosis of diverticulitis is assessed. Study Design Primary care acute clinic visits in 2008 for diverticulitis (ICD-9 562.11/562.13) or left lower quadrant pain (789.04) were identified among patients ?40 years old. Encounters were reviewed through structured manual chart abstraction, and evaluated for diagnostic accuracy compared to expected criteria. Analysis included inter-rater reliability (kappa tests) and descriptive frequencies by diagnosis code and diverticulitis rating (?2-tests). Results 376 acute visits were identified with codes for diverticulitis (n=97) or left lower quadrant pain (n=279). High inter-rater reliability was demonstrated for key clinical variables (kappa=0.84–1.0). Left lower quadrant pain was reported in >75% of patients, while temperature and white blood cell count data were frequently unavailable. Lack of these expected criteria resulted in low diagnostic accuracy ratings ("No/Unlikely" – 53.6% diverticulitis, 88.2% left lower quadrant pain, p<0.001). Conclusions This investigation raises concern for low accuracy in the outpatient diagnosis of diverticulitis due to inconsistent use of expected criteria, suggesting a smaller population with true diverticulitis than previously anticipated, or lack of criteria applicability in this setting. PMID:22411489

O’Connor, Erin S.; Smith, Maureen A.; Heise, Charles P.

2013-01-01

206

Direct transformation of xylan-type hemicelluloses to furfural via SnCl4 catalysts in aqueous and biphasic systems.  

PubMed

Direct catalytic transformation of xylan-type hemicelluloses to furfural in the aqueous system and the biphasic system were comparatively investigated under mild conditions. Screening of several promising chlorides for conversion of beech xylan in the aqueous system revealed the Lewis acid SnCl4 was the most effective catalyst. Comparing to the single aqueous system, the bio-based 2-methyltetrahydrofuran (2-MTHF)/H2O biphasic system was more conducive to the synthesis of furfural, in which the highest furfural yield of 78.1% was achieved by using SnCl4 as catalysts under the optimized reaction conditions (150°C, 120min). Additionally, the influences of xylan-type hemicelluloses with different chemical and structural features from beech, corncob and bagasse on the furfural production were studied. It was found that furfural yield to some extent was determined by the xylose content in hemicelluloses and also had relationships with the molecular weight of hemicelluloses and the degree of crystallization. PMID:25742750

Wang, Wenju; Ren, Junli; Li, Huiling; Deng, Aojie; Sun, Runcang

2015-05-01

207

Chemical reactions at aqueous interfaces  

NASA Astrophysics Data System (ADS)

Interfaces or phase boundaries are a unique chemical environment relative to individual gas, liquid, or solid phases. Interfacial reaction mechanisms and kinetics are often at variance with homogeneous chemistry due to mass transfer, molecular orientation, and catalytic effects. Aqueous interfaces are a common subject of environmental science and engineering research, and three environmentally relevant aqueous interfaces are investigated in this thesis: 1) fluorochemical sonochemistry (bubble-water), 2) aqueous aerosol ozonation (gas-water droplet), and 3) electrolytic hydrogen production and simultaneous organic oxidation (water-metal/semiconductor). Direct interfacial analysis under environmentally relevant conditions is difficult, since most surface-specific techniques require relatively `extreme' conditions. Thus, the experimental investigations here focus on the development of chemical reactors and analytical techniques for the completion of time/concentration-dependent measurements of reactants and their products. Kinetic modeling, estimations, and/or correlations were used to extract information on interfacially relevant processes. We found that interfacial chemistry was determined to be the rate-limiting step to a subsequent series of relatively fast homogeneous reactions, for example: 1) Pyrolytic cleavage of the ionic headgroup of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) adsorbed to cavitating bubble-water interfaces during sonolysis was the rate-determining step in transformation to their inorganic constituents carbon monoxide, carbon dioxide, and fluoride; 2) ozone oxidation of aqueous iodide to hypoiodous acid at the aerosol-gas interface is the rate-determining step in the oxidation of bromide and chloride to dihalogens; 3) Electrolytic oxidation of anodic titanol surface groups is rate-limiting for the overall oxidation of organics by the dichloride radical. We also found chemistry unique to the interface, for example: 1) Adsorption of dilute PFOS(aq) and PFOA(aq) to acoustically cavitating bubble interfaces was greater than equilibrium expectations due to high-velocity bubble radial oscillations; 2) Relative ozone oxidation kinetics of aqueous iodide, sulfite, and thiosulfate were at variance with previously reported bulk aqueous kinetics; 3) Organics that directly chelated with the anode surface were oxidized by direct electron transfer, resulting in immediate carbon dioxide production but slower overall oxidation kinetics. Chemical reactions at aqueous interfaces can be the rate-limiting step of a reaction network and often display novel mechanisms and kinetics as compared to homogeneous chemistry.

Vecitis, Chad David

2009-12-01

208

Cerebrovascular pathophysiology following mild traumatic brain injury.  

PubMed

Mild traumatic brain injury (mTBI) or sport-induced concussion has recently become a prominent concern not only in the athletic setting (i.e. sports venue) but also in the general population. The majority of research to date has aimed at understanding the neurological and neuropsychological outcomes of injury as well as return-to-play guidelines. Remaining relatively unexamined has been the pathophysiological aspect of mTBI. Recent technological advances including transcranial Doppler ultrasound and near infrared spectroscopy have allowed researchers to examine the systemic effects of mTBI from rest to exercise, and during both asymptomatic and symptomatic conditions. In this review, we focus on the current research available from both human and experimental (animal) studies surrounding the pathophysiology of mTBI. First, the quest for a unified definition of mTBI, its historical development and implications for future research is discussed. Finally, the impact of mTBI on the control and regulation of cerebral blood flow, cerebrovascular reactivity, cerebral oxygenation and neuroautonomic cardiovascular regulation, all of which may be compromised with mTBI, is discussed. PMID:21078064

Len, T K; Neary, J P

2011-03-01

209

Toxicity studies of mild gasification products  

SciTech Connect

The objectives of this project are: (1) to perform mutagenicity studies with the Ames Salmonella/microsomal assay system on coal liquids produced by mild gasification from different coals and/or processing conditions, (2) to determine whether coal liquids which are mutagenic to bacteria are also genotoxic to mammalian cells, (3) to establish correlations between mutagenicity, aromaticity, and boiling point range of coal liquids, and (4) to identify the chemical classes which are likely to be responsible for the mutagenic activity of gasification products. Four of the seven samples tested so far failed to demonstrate any mutagenic activity under any conditions tested. Those samples were SHELL{number_sign}830331, MG-122IBP-420{degree}F, MG-122 420--720{degree}F, and MG-122 720{degree}F+. Table 1 summarizes the results from all samples tested in DMSO and Tween 80. When solvated in DMSO, MG-119 and MG-120 composite materials displayed slight, but ultimately insignificant, genotoxic activity on TA98 and TA1OO in the presence of S9. When Tween 80 was used as the solvent, MG-119 and MG-120 displayed slight, but significant, geno-toxic activity on TA98 with S9 (Figure 4). CTC{number_sign}11 in DMSO displayed significant genotoxic activity on both TA98 and TA1OO with and without S9. The activity was higher on TA98 than TA100, and higher with S9 than without, primarily indicating the presence of indirect-acting frameshift mutagen. The results of the testing on CTC{number_sign}11 were similar for both solvents, DMSO and Tween 80 (Table 2).

Ong, T.M.; Whong, W.Z.; Ma, J.; Zhong, B.Z.; Bryant, D.

1992-11-01

210

Toxicity studies of mild gasification products  

SciTech Connect

The objectives of this project are: (1) to perform mutagenicity studies with the Ames Salmonella/microsomal assay system on coal liquids produced by mild gasification from different coals and/or processing conditions, (2) to determine whether coal liquids which are mutagenic to bacteria are also genotoxic to mammalian cells, (3) to establish correlations between mutagenicity, aromaticity, and boiling point range of coal liquids, and (4) to identify the chemical classes which are likely to be responsible for the mutagenic activity of gasification products. Four of the seven samples tested so far failed to demonstrate any mutagenic activity under any conditions tested. Those samples were SHELL[number sign]830331, MG-122IBP-420[degree]F, MG-122 420--720[degree]F, and MG-122 720[degree]F+. Table 1 summarizes the results from all samples tested in DMSO and Tween 80. When solvated in DMSO, MG-119 and MG-120 composite materials displayed slight, but ultimately insignificant, genotoxic activity on TA98 and TA1OO in the presence of S9. When Tween 80 was used as the solvent, MG-119 and MG-120 displayed slight, but significant, geno-toxic activity on TA98 with S9 (Figure 4). CTC[number sign]11 in DMSO displayed significant genotoxic activity on both TA98 and TA1OO with and without S9. The activity was higher on TA98 than TA100, and higher with S9 than without, primarily indicating the presence of indirect-acting frameshift mutagen. The results of the testing on CTC[number sign]11 were similar for both solvents, DMSO and Tween 80 (Table 2).

Ong, T.M.; Whong, W.Z.; Ma, J.; Zhong, B.Z.; Bryant, D.

1992-01-01

211

Treatment Alternatives Following Mild Head Injury.  

ERIC Educational Resources Information Center

Discusses treatment alternatives which may alleviate problems in recovery following mild head injury, including providing education, cognitive stimulation, stress management training, individual counseling, group discussion, and physical activity in a day treatment setting. (Author/ABL)

Novack, Thomas A.; And Others

1988-01-01

212

Evaluation of aqueous-foam surfactants for geothermal drilling fluids  

SciTech Connect

Aqueous foams are potentially useful drilling and cleanout fluids for geothermal applications. Successful use of foams requires surfactants (foaming agents) that can survive in the high-temperature geothermal environment. In this study, solutions of aqueous-foam-forming surfactants have been exposed to 260/sup 0/C (500/sup 0/F) and 310/sup 0/C (590/sup 0/F) in various chemical environments to determine if they can survive and make foams after exposure. Comparison of foams before and after exposure and the change in solution pH were used to evaluate their performance. Controlled liquid-volume-fraction foams, made in a packed-bed foam generator, were used for all tests. These tests have shown that many commercially available surfactants can survive short high-temperature cycles in mild acids, mild bases, and salt solutions as evidenced by their ability to make foams after exposure to high temperatures.

Rand, P.B.; Montoya, O.J.

1983-07-01

213

Aqueous Ozonation of Pesticides: A Review  

Microsoft Academic Search

The ozonation reactions of pesticides in aqueous solution have been reviewed. Degree of reaction and reaction product identity are included. Compounds are classified into five groups: chlorinated hydrocarbons, organophosphorus compounds, phenoxyalkyl acid derivatives, organonitrogen compounds, and phenolic compounds. Experimental conditions for each study are summarized. Much work has been carried out under conditions atypical of those encountered at drinking water

G. Reynolds; N. Graham; R. Perry; R. G. Rice

1989-01-01

214

Leaf responses to mild drought stress in natural variants of Arabidopsis.  

PubMed

Although the response of plants exposed to severe drought stress has been studied extensively, little is known about how plants adapt their growth under mild drought stress conditions. Here, we analyzed the leaf and rosette growth response of six Arabidopsis (Arabidopsis thaliana) accessions originating from different geographic regions when exposed to mild drought stress. The automated phenotyping platform WIWAM was used to impose stress early during leaf development, when the third leaf emerges from the shoot apical meristem. Analysis of growth-related phenotypes showed differences in leaf development between the accessions. In all six accessions, mild drought stress reduced both leaf pavement cell area and number without affecting the stomatal index. Genome-wide transcriptome analysis (using RNA sequencing) of early developing leaf tissue identified 354 genes differentially expressed under mild drought stress in the six accessions. Our results indicate the existence of a robust response over different genetic backgrounds to mild drought stress in developing leaves. The processes involved in the overall mild drought stress response comprised abscisic acid signaling, proline metabolism, and cell wall adjustments. In addition to these known severe drought-related responses, 87 genes were found to be specific for the response of young developing leaves to mild drought stress. PMID:25604532

Clauw, Pieter; Coppens, Frederik; De Beuf, Kristof; Dhondt, Stijn; Van Daele, Twiggy; Maleux, Katrien; Storme, Veronique; Clement, Lieven; Gonzalez, Nathalie; Inzé, Dirk

2015-03-01

215

Leaf Responses to Mild Drought Stress in Natural Variants of Arabidopsis1[OPEN  

PubMed Central

Although the response of plants exposed to severe drought stress has been studied extensively, little is known about how plants adapt their growth under mild drought stress conditions. Here, we analyzed the leaf and rosette growth response of six Arabidopsis (Arabidopsis thaliana) accessions originating from different geographic regions when exposed to mild drought stress. The automated phenotyping platform WIWAM was used to impose stress early during leaf development, when the third leaf emerges from the shoot apical meristem. Analysis of growth-related phenotypes showed differences in leaf development between the accessions. In all six accessions, mild drought stress reduced both leaf pavement cell area and number without affecting the stomatal index. Genome-wide transcriptome analysis (using RNA sequencing) of early developing leaf tissue identified 354 genes differentially expressed under mild drought stress in the six accessions. Our results indicate the existence of a robust response over different genetic backgrounds to mild drought stress in developing leaves. The processes involved in the overall mild drought stress response comprised abscisic acid signaling, proline metabolism, and cell wall adjustments. In addition to these known severe drought-related responses, 87 genes were found to be specific for the response of young developing leaves to mild drought stress. PMID:25604532

Clauw, Pieter; Coppens, Frederik; De Beuf, Kristof; Dhondt, Stijn; Van Daele, Twiggy; Maleux, Katrien; Storme, Veronique; Clement, Lieven; Gonzalez, Nathalie; Inzé, Dirk

2015-01-01

216

Laboratory studies of the aqueous-phase oxidation of polyols: submicron particles vs. bulk aqueous solution  

NASA Astrophysics Data System (ADS)

Oxidation in the atmospheric aqueous phase (cloud droplets and deliquesced particles) has received recent attention as a potential pathway for the formation of highly oxidized organic aerosol. Most laboratory studies of aqueous-phase oxidation, however, are carried out in bulk solutions rather than aqueous droplets. Here we describe experiments in which aqueous oxidation of polyols (water-soluble species with chemical formula CnH2n+2On) is carried out within submicron particles in an environmental chamber, allowing for significant gas-particle partitioning of reactants, intermediates, and products. Dark Fenton chemistry is used as a source of hydroxyl radicals, and oxidation is monitored using a high-resolution aerosol mass spectrometer (AMS). Aqueous oxidation is rapid, and results in the formation of particulate oxalate; this is accompanied by substantial loss of carbon to the gas phase, indicating the formation of volatile products. Results are compared to those from analogous oxidation reactions carried out in bulk solution. The bulk-phase chemistry is similar to that in the particles, but with substantially less carbon loss. This is likely due to differences in partitioning of early-generation products, which evaporate out of the aqueous phase under chamber conditions (in which liquid water content is low), but remain in solution for further aqueous processing in the bulk phase. This work suggests that the product distributions from oxidation in aqueous aerosol may be substantially different from those in bulk oxidation experiments. This highlights the need for aqueous oxidation studies to be carried out under atmospherically relevant partitioning conditions, with liquid water contents mimicking those of cloud droplets or aqueous aerosol.

Daumit, K. E.; Carrasquillo, A. J.; Hunter, J. F.; Kroll, J. H.

2014-10-01

217

Laboratory studies of the aqueous-phase oxidation of polyols: submicron particles vs. bulk aqueous solution  

NASA Astrophysics Data System (ADS)

Oxidation in the atmospheric aqueous phase (cloud droplets and deliquesced particles) has received recent attention as a potential pathway for the formation of highly oxidized organic aerosol. Most laboratory studies of aqueous-phase oxidation, however, are carried out in bulk solutions rather than aqueous droplets. Here we describe experiments in which aqueous oxidation of polyols (water-soluble species with chemical formula CnH2n+2On) is carried out within submicron particles in an environmental chamber, allowing for significant gas-particle partitioning of reactants, intermediates, and products. Dark Fenton chemistry is used as a source of hydroxyl radicals, and oxidation is monitored using a high-resolution aerosol mass spectrometer (AMS). Aqueous oxidation is rapid, and results in the formation of particulate oxalate; this is accompanied by substantial loss of carbon to the gas phase, indicating the formation of volatile products. Results are compared to those from analogous oxidation reactions carried out in bulk solution. The bulk-phase chemistry is similar to that in the particles, but with substantially less carbon loss. This is likely due to differences in partitioning of early-generation products, which evaporate out of the aqueous phase under chamber conditions (in which liquid water content is low), but remain in solution for further aqueous processing in the bulk phase. This work suggests that the product distributions from oxidation in aqueous aerosol may be substantially different from those in bulk oxidation experiments. This highlights the need for aqueous oxidation studies to be carried out under atmospherically relevant partitioning conditions, with liquid water contents mimicking those of cloud droplets or aqueous aerosol.

Daumit, K. E.; Carrasquillo, A. J.; Hunter, J. F.; Kroll, J. H.

2014-05-01

218

[A case report of mild from of phenylketonuria].  

PubMed

We report a 19-year-old man with mild form of phenylketonuria. The diagnosis was first made when he was examined for the tremor at 19 years of age. He had not received the Guthrie's screening test for phenylketonuria in infancy. His development of speech and walking was almost normal. Action and positional tremor developed at two years of age, and psychomotor deterioration at five years. His intelligence was of borderline, and he entered the special class for the mentally retarded at elementary school and junior high school. His skin and iris were less pigmented than those of Japanese young adults, and his hair was rather reddish. He had mild action tremor. He showed mild mental retardation, and the WAIS was 46 in PIQ, 70 in VIQ and 53 in total IQ. T2-weighted MRI of the brain showed high signal of the deep white matter around the posterior conus of the lateral ventricles. EEG showed paroxysmal abnormalities. Serum aminogram disclosed a marked elevation of phenylalanine. Analyses of pteridine in the serum and urine disclosed a low ratio of neopterine/biopterine. An assay of the dehydropteridine reductase in erythrocytes was normal. These laboratory data indicated that his condition was caused by a deficiency of phenylalanine hydroxylase deficiency. PMID:8905994

Komada, S; Masuzugawa, S; Taniguchi, A; Narita, Y; Kuzuhara, S

1996-05-01

219

Effect of Machining Parameters on Oxidation Behavior of Mild Steel  

NASA Astrophysics Data System (ADS)

This study aims to find out a correlation between machining parameters, resultant microstructure, and isothermal oxidation behavior of lathe-machined mild steel in the temperature range of 660-710 °C. The tool rake angles "?" used were +20°, 0°, and -20°, and cutting speeds used were 41, 232, and 541 mm/s. Under isothermal conditions, non-machined and machined mild steel samples follow parabolic oxidation kinetics with activation energy of 181 and ~400 kJ/mol, respectively. Exaggerated grain growth of the machined surface was observed, whereas, the center part of the machined sample showed minimal grain growth during oxidation at higher temperatures. Grain growth on the surface was attributed to the reduction of strain energy at high temperature oxidation, which was accumulated on the sub-region of the machined surface during machining. It was also observed that characteristic surface oxide controlled the oxidation behavior of the machined samples. This study clearly demonstrates the effect of equivalent strain, roughness, and grain size due to machining, and subsequent grain growth on the oxidation behavior of the mild steel.

Majumdar, P.; Shekhar, S.; Mondal, K.

2015-01-01

220

Flavanols, Mild Cognitive Impairment, and Alzheimer's Dementia  

PubMed Central

Alzheimer's disease (AD) is a dementing neurological disorder that results in progressive memory loss and cognitive decline thought to be associated with buildup of amyloid plaques and neurofibrillary tangles in the brain. Vascular Dementia (VaD) is another common dementing disorder characterized by decreased brain perfusion. Together, AD and VaD constitute mixed dementia, an extremely common type of dementia associated with aging. Neuroimaging research suggests that brain vascular atrophy results in mild cognitive impairment (MCI), a possible precursor for AD. Additionally, literature suggests that attention to cardiovascular risk factors such as hypertension could reduce or delay the incidence of mixed dementia. Furthermore, foods and beverages rich in natural antioxidant flavanoids (i.e. epicatechin and catechin) are currently being advocated as possible preventative agents for a number of pathological conditions ranging from coronary heart disease to dementia. Experimental evidence is mounting that oxidative stress is involved in the pathophysiology of AD, and numerous studies are indicating that polyphenolic antioxidants found in fruits and vegetables can be useful in countering this and blocking neuronal death. More specifically, several cocoa studies suggest that daily intake of cocoa flavanols leads to cardiovascular benefits including vasodilatation via a nitric oxide mechanism and increased brain perfusion. The following text will consider an important question that thus arises regarding the potential of flavanols as effective agents for the prevention and delay of the onset of brain vascular atrophy and subsequently MCI and AD. It will also review the molecular mechanisms through which flavanols operate to accomplish their protective effects. PMID:19079672

Patel, Ami K.; Rogers, Jack T.; Huang, Xudong

2008-01-01

221

Mild Traumatic Brain Injury in Translation  

PubMed Central

Abstract This Introduction to a Special Issue on Mild Traumatic Brain Injury (mTBI) highlights the methodological challenges in outcome studies and clinical trials involving patients who sustain mTBI. Recent advances in brain imaging and portable, computerized cognitive tasks have contributed to protocols that are sensitive to the effects of mTBI and efficient in time for completion. Investigation of civilian mTBI has been extended to single and repeated injuries in athletes and blast-related mTBI in service members and veterans. Despite differences in mechanism of injury, there is evidence for similar effects of acceleration-deceleration and blast mechanisms of mTBI on cognition. Investigation of repetitive mTBI suggests that the effects may be cumulative and that repeated mTBI and repeated subconcussive head trauma may lead to neurodegenerative conditions. Although animal models of mTBI using cortical impact and fluid percussion injury in rodents have been able to reproduce some of the cognitive deficits frequently exhibited by patients after mTBI, modeling post-concussion symptoms is difficult. Recent use of closed head and blast injury animal models may more closely approximate clinical mTBI. Translation of interventions that are developed in animal models to patients with mTBI is a priority for the research agenda. This Special Issue on mTBI integrates basic neuroscience studies using animal models with studies of human mTBI, including the cognitive sequelae, persisting symptoms, brain imaging, and host factors that facilitate recovery. PMID:23046349

Robertson, Claudia S.

2013-01-01

222

A comparison of emotional decoding abilities in patients with amnestic mild cognitive impairment, very mild and mild Alzheimer's disease.  

PubMed

Deficits in emotional decoding abilities were described in patients with Alzheimer's dementia and amnestic type of mild cognitive impairment (a-MCI). However the pattern of decline and its dependency on the type of emotional stimuli has not been investigated so far. In our study, 5 sets of cartoon-like drawings portraying various human emotions of increasing complexity were presented to patients with very mild and mild Alzheimer's dementia, a-MCI and control subjects. Patients with Alzheimer's dementia, a-MCI and control subjects decoded emotions with similar accuracy. The pattern of decoding abilities was similar in Alzheimer's dementia, a-MCI patients and healthy control subjects. Decoding abilities depended on a manner the emotional stimuli were presented. PMID:24359502

Klimkowicz-Mrowiec, Aleksandra; Krzywoszanski, Lukasz; Spisak, Karolina; Donohue, Bryan E; Szczudlik, Andrzej; Slowik, Agnieszka

2014-02-01

223

Modelling paradigms for MILD combustion  

E-print Network

of the facilities of 23 HECToR, the UK’s national high-performance computing service, which is provided by UoE HPCx Ltd at the University of Edinburgh, Cray Inc and NAG Ltd, and funded by the Office of Science and Technology through EPSRCs High End Computing... conditions for direct simulations of compress- ible viscos flows. J. Comput. Phys. 101, 104–129. ROGALLO, R. S. 1981 Numerical experiments in homogeneous turbulence. NASA TM p. 81315. SMOOKE, M. D. & GIOVANGIGLI, V. 1991 Formulation of the premixed and non...

Minamoto, Y.; Swaminathan, N.

2014-04-26

224

The pathways by which mild hypothermia inhibits neuronal apoptosis following ischemia/reperfusion injury  

PubMed Central

Several studies have demonstrated that mild hypothermia exhibits a neuroprotective role and it can inhibit endothelial cell apoptosis following ischemia/reperfusion injury by decreasing caspase-3 expression. It is hypothesized that mild hypothermia exhibits neuroprotective effects on neurons exposed to ischemia/reperfusion condition produced by oxygen-glucose deprivation. Mild hypothermia significantly reduced the number of apoptotic neurons, decreased the expression of pro-apoptotic protein Bax and increased mitochondrial membrane potential, with the peak of anti-apoptotic effect appearing between 6 and 12 hours after the injury. These findings indicate that mild hypothermia inhibits neuronal apoptosis following ischemia/reperfusion injury by protecting the mitochondria and that the effective time window is 6–12 hours after ischemia/reperfusion injury.

Luo, Chun; Pan, Su-yue

2015-01-01

225

PRODUCTION OF HIGH QUALITY LIQUID FUELS FROM COAL BY MILD PYROLYSIS OF COAL-LIME MIXTURES  

Microsoft Academic Search

The most recent studies of coal devolatilization processes have emphasized maximisation of liquids yield by use of extreme process conditions such as high heating rate. The liquids produced by such processes are often unsuitable for utilization without extensive upgrading. The aim of the study reported here was to optimize product quality by use of relatively mild conditions. Low-temperature devolatilization (slow

M. Rashid Khan

1987-01-01

226

Microbial risks in mild hot smoking of fish.  

PubMed

Hot smoked fish should fulfill the requirements set up for ready-to-eat foods. The total bacterial count on the raw material is 10(3) to 10(5) CFU per cm2 of skin and 10(2) to 10(9) CFU per gram of intestines. Contamination with pathogenic bacteria is very low, mainly with Clostridium botulinum, Listeria monocytogenes, Staphylococcus aureus, and Vibrio parahaemolyticus. In the premises of low hygiene, the contamination may increase due to unsanitary procedures, rotation of assigned duties of workers, and airborne microorganisms during packing of the product. Hot smoking in mild conditions at temperature in the fish not exceeding 65 degrees C and low concentration of salt does not inactivate all pathogens or inhibit bacteria during storage. Thus the required safety can be obtained only by using very fresh fish handled in hygienic conditions, controlling the processing and the plant hygiene in critical control points, and chilling of the product to about 2 degrees C. Most critical are the hygienic conditions in handling of the product after smoking. The use of preservatives for extending the shelf life of smoked fish is being investigated. High-quality shelf life of mild hot smoked mackerel at about 2 degrees C is at least 3 weeks. PMID:11833636

Sikorski, Zdzis?aw E; Ka?odziejska, Ilona

2002-01-01

227

Prognosis for mild traumatic brain injury: results of the who collaborating centre task force on mild traumatic brain injury  

Microsoft Academic Search

We searched the literature on the epidemiology, diagnosis, prognosis, treatment and costs of mild traumatic brain injury. Of 428 studies related to prognosis after mild traumatic brain injury, 120 (28%) were accepted after critical review. These comprise our best-evidence synthesis on prognosis after mild traumatic brain injury. There was consistent and methodologically sound evidence that chil- dren's prognosis after mild

Linda J Carroll; J. David Cassidy; Paul M. Peloso; Jörgen Borg; Hans von Holst; Lena Holm; Chris Paniak; Michel Pépin

2004-01-01

228

Mild and General Palladium-Catalyzed Synthesis of Methyl Aryl Ethers Enabled by the Use of a Palladacycle Precatalyst  

E-print Network

A general method for the Pd-catalyzed coupling of methanol with (hetero)aryl halides is described. The reactions proceed under mild conditions with a wide range of aryl and heteroaryl halides to give methyl aryl ethers in ...

Cheung, Chi Wai

229

Neuropsychological function following mild exposure to pentaborane  

SciTech Connect

Neuropsychological tests and self-report personality inventories were administered to 14 workers and rescue squad personnel approximately 2 months following mild exposure to pentaborane, a highly toxic volatile liquid boron hydride. Performance decrements were evident on 5 of 11 neuropsychological tests, including Block Design and measures of sustained attention and recent memory. Neuropsychological deficits were not related to emotional changes reported on the Hopkins Symptom Checklist nor to the presence of CT scan abnormality. These results indicate mild residual brain dysfunction following pentaborane intoxication, including possible dysfunction in subcortical regions mediating memory processes and in cortical areas mediating visuo-spatial abilities.

Hart, R.P.; Silverman, J.J.; Garrettson, L.K.; Schulz, C.; Hamer, R.M.

1984-01-01

230

Selective extraction of metal ions from aqueous phase to ionic liquids: a novel thermodynamic approach to separations.  

PubMed

The selective extraction of metals from aqueous mixtures has generally relied on the use of selective ionophores. We present an alternative strategy that exploits a recently developed approach to extraction into an ionic liquid phase, and show that a high degree of control over selectivity can be obtained by tuning the relative concentrations of extraction agents. A thermodynamic model for the approach is presented, and an experimental separation of strontium and potassium ions is performed. It is shown that tuning the concentrations of the species involved can shift the ratio of potassium to strontium in the ionic liquid phase from 4:1 to 3:4. This extraction is performed under mild conditions with relatively common reagents. The result is a proof-of-concept for a novel separations scheme that could have great importance in a wide range of technological applications. PMID:25155578

Janssen, Camiel H C; Sánchez, Antonio; Kobrak, Mark N

2014-11-10

231

Behavior of cellulose and xylan in aqueous ammonia pretreatment.  

PubMed

The effect of aqueous ammonia on the solubilization of cellulose and xylans was investigated by detecting the amounts of reducing sugars and monosaccharides in the treatment liquors. The degree of cellulose and xylan solubilization increased with the increase of treatment temperature. When the treatment temperature increased from 20 to 90 °C, the amounts of reducing sugars released from Avicel and cellulose fiber by 21 % ammonia at a solid to liquid ratio of 1:10 for 24 h increased from 1.0 and 0.9 to 4.4 and 2.7 mg/g dry matter (DM), respectively. The amounts of reducing sugars released from wheat straw, beechwood, and oat spelt xylans increased from 1.2-7.0 to 3.3-13.5 mg/g DM. Xylans appeared to be more susceptible than cellulose in aqueous ammonia treatment. Structure analysis of untreated and treated Avicel and cellulose fiber showed that aqueous ammonia increased the specific surface area and crystallinity index of cellulose. Most of the cellulose and xylan that were solubilized existed in the form of oligomers such as cello-oligosaccharides and xylo-oligosaccharides. Xylobiose and xylotriose were the main oligosaccharides released from oat spelt xylan by aqueous ammonia treatment as confirmed by electrospray ionization-mass spectrometry. The results here indicated that a slight amount of cellulose and xylans was solubilized and low amounts of cellulase inhibitors, oligomers, were found during mild aqueous ammonia pretreatment process. Therefore, from the economical perspectives, mild ammonia pretreatment would be favorable for aqueous ammonia pretreatment of lignocelluloses. PMID:25245678

Xin, Donglin; Jia, Lili; Zhao, Chengjuan; Zhang, Junhua

2014-12-01

232

Removal of dimethylsulfoxide from wastewater using mild oxidation with H2O2 over Ti-based catalysts.  

PubMed

The mild catalytic oxidation of dimethylsulfoxide (DMSO) into biodegradable dimethylsulfone is proposed as an efficient pretreatment of wastewaters subjected to biological treatment processes. A SiO(2)-TiO(2) mesoporous xerogel prepared by a non-hydrolytic route, as well as titanium silicalite TS-1 showed very good activity and stability in the catalytic oxidation of DMSO with H(2)O(2) in dilute aqueous solution, at room temperature. PMID:19800653

Cojocariu, Ana Mihaela; Mutin, P Hubert; Dumitriu, Emil; Vioux, André; Fajula, François; Hulea, Vasile

2009-11-01

233

NMR study of a membrane protein in detergent-free aqueous solution  

E-print Network

NMR study of a membrane protein in detergent-free aqueous solution Manuela Zoonens*, Laurent J to membrane protein (MP) structural studies is the destabilizing effect of detergents. Amphipols (APols) are short amphipathic polymers that can substitute for detergents to keep MPs water-soluble under mild

234

Reflectance of aqueous solutions  

NASA Technical Reports Server (NTRS)

The optical properties and optical constants of water and aqueous solutions were studied to develop an accurate tabulation of graphical representations of the optical constants through a broad spectrum. Manuscripts of articles are presented concerning extinction coefficients, relative specular reflectance, and temperature effect on the water spectrum. Graphs of absolute reflectance, phase shifts, index of refraction, and extinction coefficients for water, heavy water and aqueous solutions are included.

Querry, M. R.

1972-01-01

235

Accommodation Strategies for Mildly Handicapped Students.  

ERIC Educational Resources Information Center

The reference handbook is the product of an Iowa Department of Education, Bureau of Special Education project entitled "Accommodation Strategies." The project attempted to: facilitate mildly handicapped students in regular education through the development and utilization of unique educational strategies; enhance cooperative endeavors between…

Keystone Area Education, Elkader, IA.

236

Recognition memory deficits in mild cognitive impairment  

Microsoft Academic Search

There is no agreement on the pattern of recognition memory deficits characteristic of patients diagnosed with mild cognitive impairment (MCI). Whereas lower performance in recollection is the hallmark of MCI, there is a strong controversy about possible deficits in familiarity estimates when using recognition memory tasks. The aim of this research is to shed light on the pattern of responding

Salvador Algarabel; Manuel Fuentes; Joaquín Escudero; Alfonso Pitarque; Vicente Peset; José-Francisco Mazón; Juan-Carlos Meléndez

2012-01-01

237

Learning Strategies for Adolescents with Mild Disabilities  

ERIC Educational Resources Information Center

Learning strategy instruction is an evidence-based practice for teaching adolescents with mild disabilities. However, researchers have not developed strategies for every content area or skill. Therefore, teachers need to be able develop strategies based on the needs of their students. This article reviews the process for developing and teaching…

Conderman, Greg; Koman, Kara; Schibelka, Mary; Higgin, Karen; Cooper, Cody; Butler, Jordyn

2013-01-01

238

Mildly Retarded Adults: Their Attitudes Toward Retardation  

ERIC Educational Resources Information Center

Responses to a 40-item questionnaire distributed to 50 mildly mentally retarded (MR) adults indicate that the majority possess accurate information about MR, hold realistic attitudes toward their own needs and abilities, and advocate community integration of the retarded. (Author/JG)

Gan, Jennifer; And Others

1977-01-01

239

Perinatal Risk Factors for Mild Motor Disability  

ERIC Educational Resources Information Center

The aetiology of mild motor disability (MMD) is a complex issue and as yet is poorly understood. The aim of this study was to identify the prevalence of perinatal risk factors in a cohort of 10-year-old boys and girls with (n = 362) and without (n = 1193) MMD. Among the males with MMD there was a higher prevalence of postpartum haemorrhage,…

Hands, Beth; Kendall, Garth; Larkin, Dawne; Parker, Helen

2009-01-01

240

Mild Cognitive Impairment: Clinical Characterization and Outcome  

Microsoft Academic Search

Results: The primary distinction between control sub- jects and subjects with MCI was in the area of memory, while other cognitive functions were comparable. How- ever, when the subjects with MCI were compared with the patients with very mild AD, memory performance was similar, but patients with AD were more impaired in other cognitive domains as well. Longitudinal performance dem-

Ronald C. Petersen; Glenn E. Smith; Stephen C. Waring; Robert J. Ivnik; Eric G. Tangalos; Emre Kokmen

1999-01-01

241

The extent of aqueous alteration in C-class asteroids, and the survival of presolar isotopic signatures in chondrites  

NASA Astrophysics Data System (ADS)

Several sample return missions are being planned by different space agencies for in situ sampling of undifferentiated bodies. Such missions wish to bring back to Earth pristine samples from C-class asteroids and comets to obtain clues on solar system formation conditions. A careful selection of targeted areas is required as many C-class asteroids and periodic comets have been subjected to collisional and space weathering processing since their formation. Their surfaces have been reworked by impacts as pointed out by the brecciated nature of many chondrites arrived to Earth, exhibiting different levels of thermal and aqueous alteration. It is not surprising that pristine chondrites can be considered quite rare in meteorite collections because they were naturally sampled in collisions, but several groups of carbonaceous chondrites contain a few members with promising unaltered properties. The CI and CM groups suffered extensive aqueous alteration [1], but for the most part escaped thermal metamorphism (only a few CMs evidence heating temperature over several hundred K). Both chondrite groups are water-rich, containing secondary minerals as consequence of the pervasive alteration of their primary mineral phases [2]. CO, CV, and CR chondrite groups suffered much less severe aqueous alteration, but some CRs are moderately aqueously altered. All five groups are good candidates to find unequilibrated materials between samples unaffected by aqueous alteration or metamorphism. The water was incorporated during accretion, and was released as consequence of shock after impact compaction, and/or by mild radiogenic heating. Primary minerals were transformed by water into secondary ones. Water soaking the bodies participated in chemical homogenization of the different components [1]. Hydrothermal alteration and collisional metamorphism changed the abundances of isotopically distinguishable presolar silicates [3]. Additional instruments in the landers to identify aqueous alteration signatures could help to get samples unbiased by parent body processes. Future work in this regard could be essential to successfully getting back to Earth samples to unveil the conditions in which the solar system formed. REF: [1] Trigo-Rodriguez J.M. & Blum J. 2009. Plan. Space Sci.57,243; [2] Rubin et al. (2007) GCA 71,2361; [3] Trigo-Rodriguez J.M. & Blum J. (2009). Pub.Ast.Soc.Aust.26,289

Trigo-Rodriguez, J. M.

2011-05-01

242

Iron oxide functionalized graphene nano-composite for dispersive solid phase extraction of chemical warfare agents from aqueous samples.  

PubMed

Present study deals with the preparation and evaluation of graphene based magnetic nano-composite for dispersive solid phase extraction of Chemical Weapons Convention (CWC) relevant chemicals from aqueous samples. Nano-composite, Fe3O4@SiO2-G was synthesized by covalently bonding silica coated Fe3O4 onto the graphene sheets. Nerve agents (NA), Sulfur mustard (SM) and their non-toxic environmental markers were the target analytes. Extraction parameters like amount of sorbent, extraction time and desorption conditions were optimized. Dispersion of 20 milligram of sorbent in 200mL of water sample for 20min. followed by methanol/chloroform extraction produced average to good recoveries (27-94%) of targeted analytes. Recoveries of real agents exhibited great dependency upon sample pH and ionic strength. Sarin produced maximum recovery under mild acidic conditions (56% at pH 5) while VX demanded alkaline media (83% at pH 9). Salts presence in the aqueous samples was found to be advantageous, raising the recoveries to as high as 94% for SM. Excellent limits of detection (LOD) for sulphur mustard and VX (0.11ngmL(-1) and 0.19ngmL(-1) respectively) proved the utility of the developed method for the off-site analysis of CWC relevant chemicals. PMID:25828545

Chinthakindi, Sridhar; Purohit, Ajay; Singh, Varoon; Tak, Vijay; Goud, D Raghavender; Dubey, D K; Pardasani, Deepak

2015-05-15

243

Use of the clock drawing task in the diagnosis of mild and very mild Alzheimer's disease.  

PubMed

The purpose of this study was to examine the utility of the clock drawing task (CDT) in differentiating between patients with mild and very mild Alzheimer's disease (AD) and normal controls. Thirty normal elderly individuals and 30 patients with probable AD were entered into the study and asked, in a standard fashion, to draw a clock from memory. All the clocks were scored according to two previously described standardized scoring systems, and the accuracy of classification into normal or AD groups was determined. Both CDT scales could discriminate between moderate AD and normal aging but lacked sensitivity in the very mild AD cases; mild cases showed intermediate sensitivity. In conclusion, the CDT as a test for AD is insensitive in the early-stage cases, but sensitivity improves with increasing severity of dementia. The CDT is unlikely to be useful in distinguishing between AD in its early stages and normal aging. PMID:9116182

Lee, H; Swanwick, G R; Coen, R F; Lawlor, B A

1996-01-01

244

Development of an advanced, continuous mild gasification process for the production of co-products  

SciTech Connect

The objective of this project is to develop a continuous mild gasification process to convert highly caking coals to coal liquids, char and coke for near term commercial application. Task 3, Bench-Scale Char Upgrading Study, has been underway since September 1989. In char upgrading studies, ``green`` uncured char briquettes have been prepared and calcined in 20-pound batches to evaluate the effects of char, binders, and heating conditions on final coke properties. A total of 150. formulations have been tested thus far in this work. Work on Task 4, Process Development Unit (PDU) Mild Gasification Study, has been in progress since February 1991, with the completion of a Continuous Mild Gasification Unit (CMGU) with a design rate of 1000 lb./hr. Since start-up of the CMGU, there have been 72 runs with a variety of operating conditions and coal types.

Wolfe, R.A.; Wright, R.E.; Im, C.J.; Henkelman, M.R.; O`Neal, G.W.

1992-11-01

245

Preparation of Re(I)- and (99m)Tc(I)-metallocarboranes in water under weakly basic reaction conditions.  

PubMed

A new method for the preparation of Re- and (99m)Tc-metallocarboranes in water under mild reaction conditions was developed. Three nido-carborane ligands were reacted with [Re(CO)(3)Br(3)](2)(-) in the presence of aqueous potassium fluoride to give the corresponding eta(5)-Re(CO)(3)-carborane complexes. The use of KF as a base afforded the desired Re-metallocarboranes in good yields while avoiding the formation of Re clusters, which are byproducts commonly observed when reactions are carried out in the presence of strong aqueous bases. The reaction was also performed at the tracer level producing the first (99m)Tc-carborane complex, which was isolated in 80% radiochemical yield following a simple Sep-Pak purification process. The resulting organometallic complex was stable to cysteine and histidine challenges for more than 24 h. PMID:15132607

Sogbein, Oyebola O; Merdy, Patricia; Morel, Pierre; Valliant, John F

2004-05-17

246

A Modified Controlled Cortical Impact Technique to Model Mild Traumatic Brain Injury Mechanics in Mice  

PubMed Central

For the past 25?years, controlled cortical impact (CCI) has been a useful tool in traumatic brain injury (TBI) research, creating injury patterns that includes primary contusion, neuronal loss, and traumatic axonal damage. However, when CCI was first developed, very little was known on the underlying biomechanics of mild TBI. This paper uses information generated from recent computational models of mild TBI in humans to alter CCI and better reflect the biomechanical conditions of mild TBI. Using a finite element model of CCI in the mouse, we adjusted three primary features of CCI: the speed of the impact to achieve strain rates within the range associated with mild TBI, the shape, and material of the impounder to minimize strain concentrations in the brain, and the impact depth to control the peak deformation that occurred in the cortex and hippocampus. For these modified cortical impact conditions, we observed peak strains and strain rates throughout the brain were significantly reduced and consistent with estimated strains and strain rates observed in human mild TBI. We saw breakdown of the blood–brain barrier but no primary hemorrhage. Moreover, neuronal degeneration, axonal injury, and both astrocytic and microglia reactivity were observed up to 8?days after injury. Significant deficits in rotarod performance appeared early after injury, but we observed no impairment in spatial object recognition or contextual fear conditioning response 5 and 8?days after injury, respectively. Together, these data show that simulating the biomechanical conditions of mild TBI with a modified cortical impact technique produces regions of cellular reactivity and neuronal loss that coincide with only a transient behavioral impairment. PMID:24994996

Chen, YungChia; Mao, Haojie; Yang, King H.; Abel, Ted; Meaney, David F.

2014-01-01

247

Biothanol production from barley hull using SAA (Soaking in aqueous ammonia) pretreatment  

Technology Transfer Automated Retrieval System (TEKTRAN)

Barley hull, a type of lignocellulosic biomass, was pretreated using aqueous ammonia to improve its enzymatic saccharification. Barley hull was soaked in 15-30 wt.% aqueous ammonia (SAA method) at 30-75'C for 1 day-11 weeks using a batch reactor. Under these conditions, SAA (soaking in aqueous ammon...

248

Sensitization of fear learning to mild unconditional stimuli in male and female rats.  

PubMed

Stress-enhanced fear learning (SEFL) refers to the long-lasting nonassociative sensitization produced by intense stress (e.g., repeated and unpredictable footshock) that results in increased fear learning to a mild conditioning regimen (e.g., one shock). SEFL experiments suggest that one component of posttraumatic behavior is inappropriately strong fear conditioning occurring to relatively mild stressors. Past reports of SEFL have used the same intensity (1 mA) of footshock to cause both the sensitization and conditioning of new fear. SEFL would be a particularly problematic component of posttrauma behavior if intense stress results in substantial fear conditioning under conditions that would not normally support conditioning. Therefore, we determined if SEFL occurred when the conditioning shock was substantially milder than the SEFL-inducing shock. The results indicate that exposure to a sensitizing regimen of shock can convert a mild footshock that normally does not support measurable levels of fear conditioning into one that causes substantial learned fear. Moreover, as the intensity of single footshock increases, so does the capacity of the prior stressor to contribute to the sensitization of fear responses. Consistent with prior studies, males acquired and retained a greater level of fear conditioning than female rats, however the level of sensitization did not differ between sexes. PMID:25621793

Poulos, Andrew M; Zhuravka, Irina; Long, Virginia; Gannam, Camille; Fanselow, Michael

2015-02-01

249

Corrosion inhibitor for aqueous ammonia absorption system  

DOEpatents

A method is described for inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425 F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25 C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425 F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer. 5 figs.

Phillips, B.A.; Whitlow, E.P.

1998-09-22

250

Corrosion inhibitor for aqueous ammonia absorption system  

DOEpatents

A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

Phillips, Benjamin A. (Benton Harbor, MI); Whitlow, Eugene P. (St. Joseph, MI)

1998-09-22

251

The ENCOAL Mild Gasification Demonstration Project  

SciTech Connect

The DOE plans to enter into a Cooperative Agreement with ENCOAL Corporation, a wholly owned subsidiary of Shell Mining Company, for the cost-shared design, construction and operation of a mild gasification facility based on Liquids-from-Coal (LFC) technology. The facility is planned to be located at the Triton Coal Company's Buckskin Mine near Gillette, Wyoming. The mild gasification process to be demonstrated will produce two new, low-sulfur fuel forms (a solid and a liquid) from subbituminous coal. The new fuel forms would be suitable for combustion in commercial, industrial, and utility boilers. This environmental assessment has been prepared by the DOE to comply with the requirements of the NEPA. Pollutant emissions, land use, water, and waste management are briefly discussed. 3 figs., 5 tabs.

Not Available

1990-07-01

252

Disposable baby wipes: efficacy and skin mildness.  

PubMed

The results of a series of four clinical studies demonstrated that disposable baby wipes were milder to the skin than use of a cotton washcloth and water, recognized as a "gold standard" for skin mildness. Importantly, the baby wipes caused no significant change from the baseline value in any of the skin parameters examined. This observation verified that the test wipes are minimally disruptive to the epidermal barrier and thus suitable for use on intact or compromised, irritated skin. PMID:11917305

Odio, M; Streicher-Scott, J; Hansen, R C

2001-04-01

253

Rheology of aqueous foams  

NASA Astrophysics Data System (ADS)

Aqueous foams are suspensions of bubbles inside aqueous phases. Their multiphasic composition leads to a complex rheological behavior that is useful in numerous applications, from oil recovery to food/cosmetic processing. Their structure is very similar to the one of emulsions, so that both materials share common mechanical properties. In particular, the presence of surfactants at the gas-liquid interfaces leads to peculiar interfacial and dissipative properties. Foam rheology has been an active research topics and is already reported in several reviews, most of them covering rheometry measurements at the scale of the foam, coupled with interpretations at the local scale of bubbles or interfaces. In this review, we start following this approach, then we try to cover the multiscale features of aqueous foam flows, emphasizing regimes where intermediate length scales need to be taken into account or regimes fast enough regarding internal time scales so that the flow goes beyond the quasi-static limit. xml:lang="fr"

Dollet, Benjamin; Raufaste, Christophe

2014-10-01

254

A compliant tower design for mild environments  

SciTech Connect

The compliant tower type of offshore platform is a bottom-fixed structure that is basically the same as the traditional steel ``Fixed Platform.`` However, the compliant tower is intended for deepwater application and is configured to be very much more compliant. It can thereby greatly reduce the effect of waveloads. Consequently, it can provide an economical platform in much deeper water-depths than the traditional fixed platform. Over at least the past two decades, numerous variations based on the principle of compliance have been developed to greater or lesser detail. This paper describes a particular design for mild environments as typified by offshore West Africa, for example. Relative to the designs deemed appropriate for somewhat more severe environments such as the Gulf of Mexico, the structure is significantly simplified, and can achieve substantial reductions in materials. Some performance data for the mild environment design is described and discussed, with some comparisons to other environments and the conventional fixed platform. For mild environments, the compliant tower appears particularly attractive in that it can offer the safety and reliability of a fixed platform operation, combined with very significant savings in materials and construction.

Reusswig, G.H.; Nair, V.V. [Mobil Research and Development Corp., Dallas, TX (United States). Dallas E and P Engineering

1994-12-31

255

Subacute to chronic mild traumatic brain injury.  

PubMed

Although a universally accepted definition is lacking, mild traumatic brain injury and concussion are classified by transient loss of consciousness, amnesia, altered mental status, a Glasgow Coma Score of 13 to 15, and focal neurologic deficits following an acute closed head injury. Most patients recover quickly, with a predictable clinical course of recovery within the first one to two weeks following traumatic brain injury. Persistent physical, cognitive, or behavioral postconcussive symptoms may be noted in 5 to 20 percent of persons who have mild traumatic brain injury. Physical symptoms include headaches, dizziness, and nausea, and changes in coordination, balance, appetite, sleep, vision, and hearing. Cognitive and behavioral symptoms include fatigue, anxiety, depression, and irritability, and problems with memory, concentration and decision making. Women, older adults, less educated persons, and those with a previous mental health diagnosis are more likely to have persistent symptoms. The diagnostic workup for subacute to chronic mild traumatic brain injury focuses on the history and physical examination, with continuing observation for the development of red flags such as the progression of physical, cognitive, and behavioral symptoms, seizure, progressive vomiting, and altered mental status. Early patient and family education should include information on diagnosis and prognosis, symptoms, and further injury prevention. Symptom-specific treatment, gradual return to activity, and multidisciplinary coordination of care lead to the best outcomes. Psychiatric and medical comorbidities, psychosocial issues, and legal or compensatory incentives should be explored in patients resistant to treatment. PMID:23198672

Mott, Timothy F; McConnon, Michael L; Rieger, Brian P

2012-12-01

256

Industrial market assessment of the products of mild gasification: Final report  

Microsoft Academic Search

The goal of this study is to determine the best available conditions, in terms of market volumes and prices, for the products from a mild gasification facility. A process feasibility study will then have to determine the cost of building and operating a facility to make those products. The study is presented as a summary of the options available to

Sinor

1988-01-01

257

Coal desulfurization by mild pyrolysis in a dual-auger coal feeder  

Microsoft Academic Search

A dual-screw coal feeder reactor was constructed and tested for desulfurization of coal. The reactor consists of two concentric screw tubes, the inner tube acting as a coal pyrolyzer and the outer tube acting as a desulfurizer with hot calcined lime (CaO) pellets or other renewable sorbent pellets. The experimental results showed that under mild pyrolysis conditions, the devolatilization and

L. Lin; S. J. Khang; T. C. Keener

1997-01-01

258

People with Mild to Moderate Intellectual Disability Talking about Their Diabetes and How They Manage  

ERIC Educational Resources Information Center

Background: The prevalence of diabetes is relatively high in people with intellectual disability (ID). However, little is known about how people with ID experience having diabetes and how they manage the condition. Method: Seventeen people with mild to moderate ID who have diabetes were interviewed. A framework on illness perceptions having an…

Cardol, M.; Rijken, M.; van Schrojenstein Lantman-de Valk, H.

2012-01-01

259

Effects of a Mindfulness-Based Smoking Cessation Program for an Adult with Mild Intellectual Disability  

ERIC Educational Resources Information Center

Smoking is a major risk factor for a number of health conditions and many smokers find it difficult to quit smoking without specific interventions. We developed and used a mindfulness-based smoking cessation program with a 31-year-old man with mild intellectual disabilities who had been a smoker for 17 years. The mindfulness-based smoking…

Singh, Nirbhay N.; Lancioni, Giulio E.; Winton, Alan S. W.; Singh, Ashvind N. A.; Singh, Judy; Singh, Angela D. A.

2011-01-01

260

Relationship between critical tensile stress and fracture toughness in mild steel  

Microsoft Academic Search

SUMMARY AN ANALYSIS is presented which relates the critical value of tensile stress (a,) for unstable cleavage fracture to the fracture toughness (K,,) for a high-nitrogen mild steel under plane strain conditions. The correlation is based on (i) the model for cleavage cracking developed by E. Smith and (ii) accurate plastic*lastic solutions for the stress distributions ahead of a sharp

R. O. Ritchie; J. F. Knott; J. R. Rice

1973-01-01

261

COMMENTARIES The Importance of Awareness for Eyeblink Conditioning Is Conditional  

E-print Network

), such as a tone, is followed by the presentation of an unconditioned stimulus (US), such as a mild puff of air). In its simplest form (single-cue delay condi- tioning), a single neutral conditioned stimulus (CS awareness of the stimulus contingen- cies and conditioning? How is conditioning performance related

Squire, Larry R.

262

Fast and sensitive detection of protein concentration in mild environments.  

PubMed

Determination of protein concentration in mild environments is of great significance in the clinic diagnose and bioassay. Herein, a simple, fast and sensitive method for protein quantitative determination in neutral solution (pH 7.0) is developed. This assay is based on competition adsorption of the sample protein and fluorescently labeled dog serum albumin (FITC-DSA) onto gold nanoparticles (AuNPs). As the competitor FITC-DSA molecules are added into the mixture solution of sample protein conjugated AuNPs, they will compete for active sites of AuNPs, resulting in decrease in fluorescence intensity due to the quenching effect of AuNPs via fluorescence resonance energy transfer (FRET). Thus, quantitative determination of sample protein concentration can be achieved. Under the optimum conditions, the decrease in fluorescence intensity of the solution is related to the concentration of sample protein and a low detection limit of 0.01 µg/mL BSA can be achieved in 5 min. For the validation of our strategy in practical applications, the total protein content in human serum was determined using the as-proposed method. The result is in well agreement with that of measured by other conventional methods, suggesting a simple, accurate, and mild approach for protein detection in bioassay. PMID:25640132

Wang, Chen; Zhou, Yue; Zhang, Ke-Xin; Nie, Xing-Guo; Xia, Xing-Hua

2015-04-01

263

Inorganic Nitrogen Reduction Stability under Simulated Hydrothermal Conditions  

NASA Astrophysics Data System (ADS)

Availability of reduced nitrogen is considered a prerequisite for the genesis of life from prebiotic precursors. Most atmospheric and oceanic models for the Hadean Earth predict a mildly oxidizing environment that is conducive to the formation and stability of only oxidized forms of nitrogen. A possible environment where reduction of oxidized nitrogen to ammonium has been speculated to occur is aqueous hydrothermal systems. We examined a suite of transition metal oxides and sulfides for their ability to reduce nitrate and nitrite, as well as oxidize ammonia, under hot (300°C) high-pressure (50 500 MPa) aqueous conditions. In general, iron sulfides exhibited the most rapid and complete conversion noted, followed by nickel and copper sulfides to a much lower degree. Of the oxides examined, only magnetite exhibited any ability to reduce NO3- or NO2-. Ammonium was stable or exhibited small losses (<20%) in contact with all the mineral phases and conditions tested. The results support the idea that hydrothermal systems could have provided significant amounts of reduced nitrogen to their immediate environments. The enhanced availability of reduced nitrogen in hydrothermal systems also has important implications for prebiotic metabolic pathways where nitrogen availability is critical to the production of amino acids and other nitrogenous compounds.

Brandes, Jay A.; Hazen, Robert M.; Yoder, Hatten S., Jr.

2008-12-01

264

Diffusion in the aqueous compartment  

PubMed Central

Measurements of diffusion of molecules in cells can provide information about cytoplasmic viscosity and structure. In a series of studies electron-spin resonance was used to measure the diffusion of a small spin label in the aqueous cytoplasm of mammalian cells. Translational and rotational motion were determined from the same spectra. Based on measurements made in model systems, it was hypothesized that calculations of the apparent viscosity of the cytoplasm from both rotational and translational motion would distinguish between the effects of viscosity and structure on diffusion. The diffusion constant measured in several cell lines averaged 3.3 X 10(-6) cm2/s. It was greater in growing cells and in cells treated with cytochalasin B than in quiescent cells. The viscosity of the cytoplasm calculated from the translational diffusion constant or the rotational correlation time was 2.0-3.0 centipoise, about two to three times that of the spin label in water. Therefore, over the dimensions measured by the technique, 50-100 A, solvent viscosity appears to be the major determinant of particle movement in cells under physiologic conditions. However, when cells were subjected to hypertonic conditions, the translational motion of the spin label decreased threefold, whereas the rotational motion changed by less than 20%. These data suggest that the decrease in cell volume under hypertonic conditions is accompanied by an increase in cytoplasmic barriers and a decrease in the space between existing cytoplasmic components without a significant increase in viscosity in the aqueous phase. In addition, a comparison of reported diffusion values of a variety of molecules in water and in cells indicates that cytoplasmic structure plays an important role in the diffusion of proteins such as bovine serum albumin. PMID:6086666

Mastro, A. M.; Keith, A. D.

1984-01-01

265

Turning unreactive copper acetylides into remarkably powerful and mild alkyne transfer reagents by oxidative umpolung.  

PubMed

This is not breaking news: copper acetylides, readily available polymeric rock-stable solids, have been known for more than a century to be unreactive species and piteous nucleophiles. This lack of reactivity actually makes them ideal alkyne transfer reagents that can be easily activated under mild oxidizing conditions. When treated with molecular oxygen in the presence of simple chelating nitrogen ligands such as TMEDA, phenanthroline or imidazole derivatives, they are smoothly oxidized to highly electrophilic species that formally behave like acetylenic carbocations and can therefore be used for the mild and practical alkynylation of a wide range of nitrogen, phosphorus and carbon nucleophiles. PMID:24911768

Evano, G; Jouvin, K; Theunissen, C; Guissart, C; Laouiti, A; Tresse, C; Heimburger, J; Bouhoute, Y; Veillard, R; Lecomte, M; Nitelet, A; Schweizer, S; Blanchard, N; Alayrac, C; Gaumont, A-C

2014-09-11

266

Carbon dioxide solubility in aqueous solutions of sodium chloride at geological conditions: Experimental results at 323.15, 373.15, and 423.15 K and 150 bar and modeling up to 573.15 K and 2000 bar  

NASA Astrophysics Data System (ADS)

A new experimental system was designed to measure the solubility of CO2 at pressures and temperatures (150 bar, 323.15-423.15 K) relevant to geologic CO2 sequestration. At 150 bar, new CO2 solubility data in the aqueous phase were obtained at 323.15, 373.15, and 423.15 K from 0 to 6 mol kg-1 NaCl(aq) for the CO2-NaCl-H2O system. A ? - ? (activity coefficient - fugacity coefficient) type thermodynamic model is presented for the calculation of both the solubility of CO2 in the aqueous phase and the solubility of H2O in the CO2-rich phase for the CO2-NaCl-H2O system. Validation of the model calculations against literature data and other models (MZLL2013, AD2010, SP2010, DS2006, and OLI) show that the proposed model is capable of predicting the solubility of CO2 in the aqueous phase for the CO2-H2O and CO2-NaCl-H2O systems with a high degree of accuracy (AAD <3.9%) at temperatures from 273.15 to 573.15 K and pressures up to 2000 bar. A comparison of modeling results with experimental values revealed a pressure-bounded “transition zone” in which the CO2 solubility decreases to a minimum then increases as the temperature increases. CO2 solubility is not a monotonic function of temperature in the transition zone but outside of that transition zone, the CO2 solubility is decrease or increase monotonically in response to increased temperature. A link of web-based CO2 solubility computational tool can be provided by sending a message to Haining Zhao at hzz5047@gmail.com.

Zhao, Haining; Fedkin, Mark V.; Dilmore, Robert M.; Lvov, Serguei N.

2015-01-01

267

Mild head injury is not always mild; implications for damage litigation.  

PubMed

The traditional view that mild head injury involves an essentially reversible physiological process is examined and is found to be largely invalid. It is concluded that long-term impairment following mild head injury is fairly common and that the degree of impairment can be assessed clinically. Such an assessment involves a combination of objective electrophysiological and psychometric investigations as well as professional interpretation. With the use of this approach the possibility of malingering can be ruled out in most cases and significant impairment, when it exists, can be demonstrated beyond reasonable doubt. PMID:8366786

Blakely, T A; Harrington, D E

1993-07-01

268

Isocratic non-aqueous reversed-phase high-performance liquid chromatographic separation of capsanthin and capsorubin in red peppers (Capsicum annuum L.), paprika and oleoresin.  

PubMed

A simple, rapid high-performance liquid chromatography method has been devised in order to separate and quantify the xanthophylls capsorubin and capasanthin present in red pepper (Capsicum annuum L.) fruits and preparations made from them (paprika and oleoresin). A reversed-phase isocratic non-aqueous system allows the separation of xanthophylls within a few minutes, with detection at 450 nm, using methyl red as internal standard to locate the various carotenoids and xanthophylls found in plant extracts. The selection of extraction solvents, mild saponification conditions, and chromatographic features is evaluated and discussed. The method is proposed for rapid screening of large plant populations, plant selection, as well as for paprika products and oleoresin, and also for nutrition and quality control studies. PMID:9025261

Weissenberg, M; Schaeffler, I; Menagem, E; Barzilai, M; Levy, A

1997-01-01

269

ENCOAL mild coal gasification project. Annual report  

SciTech Connect

This document is the combination of the fourth quarter report (July--September 1993) and the 1993 annual report for the ENCOAL project. The following pages include the background and process description for the project, brief summaries of the accomplishments for the first three quarters, and a detailed fourth quarter report. Its purpose is to convey the accomplishments and current progress of the project. ENCOAL Corporation, has completed the construction of a mild gasification demonstration plant at Triton Coal Company`s Buckskin Mine near Gillette, Wyoming. The process, using Liquids From Coal (LFC) technology developed by SMC and SGI International, utilizes low-sulfur Powder River Basin coal to produce two new fuels, Process Derived Fuel (PDF) and Coal Derived Liquids (CDL). ENCOAL submitted an application to the US Department of Energy (DOE) in August 1989, soliciting joint funding of the project in the third round of the Clean Coal Technology Program. The project was selected by DOE in December, 1989 and the Cooperative Agreement approved in September, 1990. Construction, commissioning, and start-up of the ENCOAL mild coal gasification facility was completed in June of 1992, and the project is currently in the operations phase. Some plant modifications have been required and are discussed in this report.

Not Available

1993-10-01

270

Mild traumatic brain injuries in adults  

PubMed Central

Mild traumatic brain injury (mTBI) is the commonest form of TBI. Though the name implies, it may not be mild in certain cases. There is a lot of heterogeneity in nomenclature, classification, evaluation and outcome of mTBI. We have reviewed the relevant articles on mTBI in adults, particularly its definition, evaluation and outcome, published in the last decade. The aspects of mTBI like pediatric age group, sports concussion, and postconcussion syndrome were not reviewed. There is general agreement that Glasgow coma score (GCS) of 13 should not be considered as mTBI as the risk of intracranial lesion is higher than in patients with GCS 14–15. All patients with GCS of <15 should be evaluated with a computed tomography (CT) scan. Patients with GCS 15 and risk factors or neurological symptoms should also be evaluated with CT scan. The outcome of mTBI depends on the combination of preinjury, injury and postinjury factors. Overall outcome of mTBI is good with mortality around 0.1% and disability around 10%. PMID:21808509

Shukla, Dhaval; Devi, B Indira

2010-01-01

271

Tunable Aqueous Virtual Micropore  

PubMed Central

A charged micro-particle can be trapped in an aqueous environment by forming a narrow virtual pore – a cylindrical space region in which the particle motion in the radial direction is limited by forces emerging from dynamical interactions of the particle charge and dipole moment with external radio-frequency quadrupole electric field. If the particle satisfies the trap stability criteria its mean motion is reduced exponentially with time due to the viscosity of the aqueous environment. Thereafter the long-time motion of particle is subject only to random, Brownian fluctuations, whose magnitude, influenced by the electrophoretic and dielectrophoretic effects and added to the particle size, determines the radius of the virtual pore, which we demonstrate by comparison of computer simulations and experiment. The measured size of the virtual nanopore could be utilized to estimate the charge of a trapped micro-object. PMID:22271580

Park, Jae Hyun; Guan, Weihua; Reed, Mark A.; Krsti?, Predrag S.

2012-01-01

272

Lithium ion aqueous cells  

NASA Astrophysics Data System (ADS)

Lithium ion aqueous cells were investigated using lithium intercalating compounds as anodes and cathodes. The aqueous electrolyte consisted of 4 to 5 molar solutions of either lithium perchlorate or lithium nitrate which contained lithium hydroxide in millimolar amounts to make the solutions slightly basic with a pH of about 8.5. Several electrode combinations were evaluated using lithium intercalating compounds such as lithium cobalt oxide and lithium manganese oxide as cathodes and lithium vanadium oxide, lithium manganese oxide, titanium disulfide, and molybdenum dioxide as the anodes. The cell employing manganese oxide as both the anode and cathode exhibited good charge-discharge characteristics with an open circuit potential of about one volt.

Plichta, Edward J.; Behl, Wishvender K.

1995-02-01

273

Continuous aqueous tritium monitor  

DOEpatents

An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture are selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration. 2 figs.

McManus, G.J.; Weesner, F.J.

1987-10-19

274

Conversion of carbohydrate biomass to ?-valerolactone by using water-soluble and reusable iridium complexes in acidic aqueous media.  

PubMed

Mild-mannered manipulation: A catalytic method for the conversion of carbohydrate biomass to ?-valerolactone in acidic aqueous media has been developed. The water-soluble iridium complexes were observed to be extremely catalytically active for providing ?-valerolactone in high yields with high TONs. The homogeneous catalysts can also be recycled and reused by applying a simple phase separation process. PMID:23757330

Deng, Jin; Wang, Yan; Pan, Tao; Xu, Qing; Guo, Qing-Xiang; Fu, Yao

2013-07-01

275

Luminescence of Tb3+ and Gd3+ ions in sonolysis under the conditions of a single bubble moving in aqueous solutions of TbCl3 and GdCl3  

NASA Astrophysics Data System (ADS)

Luminescence bands of Tb3+ and Gd3+ ions are detected during sonolysis in the regime of a moving single bubble in aqueous solutions of TbCl3 and GdCl3 salts with concentration 1-2 mol/L. Saturation with argon, low temperatures of solutions (-5°C), and a high concentration of salts are the factors facilitating sonoluminescence of the metal. Comparison with the characteristics of sonoluminescence of lanthanide ions studied earlier in the regimes of multibubble and single-bubble sonolysis with a stationary bubble shows that the electron excitation of metal ions in the given case is associated with translational displacements of the bubble. Our results confirm the validity of the sonochemical model of microdroplet injection, which explains the penetration of nonvolatile salts into cavitation bubbles as a result of their deformation during intense movements.

Sharipov, G. L.; Abdrakhmanov, A. M.; Gareev, B. M.

2013-02-01

276

Extending diesel fuel by carbureting aqueous ethanol  

Microsoft Academic Search

Aqueous ethanol was carbureted into a secondary intake line of a Ford 4000, naturally-aspirated, direct-injection diesel engine. The carbureted ethanol and injected diesel fuel were as effective as diesel fuel alone at three-quarter and full load conditions. The maximum amount of diesel energy replaced was 23% at full load with 190 proof ethanol carbureted at a flowrate of 35% by

H. C. L. Pringle; M. M. Mayeux

1982-01-01

277

Bench-scale development of mild gasification char desulfurization. Technical report, 1 March--31 May 1994  

SciTech Connect

The goal of this project is to scale up a process, developed under a previous ICCI grant, for desulfurization of mild gasification char by treatment with hydrogen-rich process-derived fuel gas at 650--760 C and 7--15 atm. The char can be converted into a low-sulfur metallurgical form coke. In the prior study, IBC-105 coal with 4.0 wt% sulfur was converted to chars with less than 1.0 wt% sulfur in a laboratory-scale batch reactor. The susceptibility of the char to desulfurization was correlated with physicochemical char properties and mild gasification conditions. Acid pretreatment of the coal prior to mild gasification was also shown to significantly enhance subsequent sulfur removal. In this study, IGT is conducting continuous bench-scale tests in a 1-lb/h fluidized-bed reactor to determine the preferred process conditions and obtain steady-state data necessary for process design and scale-up. The desulfurized chars are to be used to produce low-sulfur form coke, which will be evaluated for density, reactivity, and strength properties relevant to utilization in blast furnaces. This quarter, 2,500 g of mild gasification char was produced from untreated IBC-105 coal in the bench-scale reactor. Half of this char will be subjected to sulfuric acid treatment to enhance subsequent desulfurization. Char-producing runs were also initiated with acid-pretreated coal, which will produce about 1,250 g of char.

Knight, R.A. [Inst. of Gas Technology, Chicago, IL (United States)

1994-09-01

278

Cationic polymerization of vinyl monomers in aqueous media: from monofunctional oligomers to long-lived polymer chains.  

PubMed

Polymer latexes are easily prepared on a multimillion ton scale in industry using free radical initiated emulsion and suspension polymerizations in water, a cheap, nonviscous, heat-controlling, and environmentally benign solvent. Until recently, researchers had done little investigation into ionic polymerization because even a small amount of water would easily deactivate the conventional catalysts used in these processes. In the last decade, however, cationic polymerization in aqueous media has emerged as a new and attractive method for controlling the polymerization reactions using mild experimental conditions. This Account reviews the current science of and future outlook for cationic polymerization of vinyl monomers in aqueous media. We particularly emphasize the design and evolution of catalytic systems and the precision synthesis of functional polymers. Early work to tailor the suspension and emulsion cationic polymerizations of reactive monomers such as p-methoxystyrene and vinyl ethers used long-chain strong acids, called INISURF for their dual roles as initiators and surfactants, and lanthanide triflates. These polymerization processes shared two main features: (i) all reactions (initiation, propagation, and termination) occurred at the particle interface; (ii) synthesized polymers have limits on their molecular weight, attributed to the "critical DP" effect, related to the entry of oligomers inside the particles as they become increasingly hydrophobic. The next generation of catalysts, named "Lewis acid-surfactant combined catalysts" (LASC), shifted the polymerization locus from the interface to the inside of the monomer droplets, allowing for the production of long polymer chains. Recently, catalytic systems based on boranes, (BF(3)OEt(2), B(C(6)F(5))(3), (C(6)F(4)-1,2-[B(C(6)F(5))(2)]), and (C(6)F(4)-1,2-[B(C(12)F(8))](2))), have shown great potential in controlling the cationic polymerization in "wet" solution, containing an excess of water relative to Lewis acid, or aqueous media of such industrially important monomers as styrene, cyclopentadiene, and even isobutylene. PMID:19957949

Kostjuk, Sergei V; Ganachaud, Francois

2010-03-16

279

Tau Reduction Diminishes Spatial Learning and Memory Deficits after Mild Repetitive Traumatic Brain Injury in Mice  

PubMed Central

Objective Because reduction of the microtubule-associated protein Tau has beneficial effects in mouse models of Alzheimer's disease and epilepsy, we wanted to determine whether this strategy can also improve the outcome of mild traumatic brain injury (TBI). Methods We adapted a mild frontal impact model of TBI for wildtype C57Bl/6J mice and characterized the behavioral deficits it causes in these animals. The Barnes maze, Y maze, contextual and cued fear conditioning, elevated plus maze, open field, balance beam, and forced swim test were used to assess different behavioral functions. Magnetic resonance imaging (MRI, 7 Tesla) and histological analysis of brain sections were used to look for neuropathological alterations. We also compared the functional effects of this TBI model and of controlled cortical impact in mice with two, one or no Tau alleles. Results Repeated (2-hit), but not single (1-hit), mild frontal impact impaired spatial learning and memory in wildtype mice as determined by testing of mice in the Barnes maze one month after the injury. Locomotor activity, anxiety, depression and fear related behaviors did not differ between injured and sham-injured mice. MRI imaging did not reveal focal injury or mass lesions shortly after the injury. Complete ablation or partial reduction of tau prevented deficits in spatial learning and memory after repeated mild frontal impact. Complete tau ablation also showed a trend towards protection after a single controlled cortical impact. Complete or partial reduction of tau also reduced the level of axonopathy in the corpus callosum after repeated mild frontal impact. Interpretation Tau promotes or enables the development of learning and memory deficits and of axonopathy after mild TBI, and tau reduction counteracts these adverse effects. PMID:25551452

Cheng, Jason S.; Craft, Ryan; Yu, Gui-Qiu; Ho, Kaitlyn; Wang, Xin; Mohan, Geetha; Mangnitsky, Sergey; Ponnusamy, Ravikumar; Mucke, Lennart

2014-01-01

280

Computational Scheme Guided Design of a Hybrid Mild Gasifier  

Microsoft Academic Search

A mild gasification method has been developed to provide an innovative clean coal technology. The objectives of this study are to (a) incorporate a fixed rate devolatilization model into the existing 2D multiphase reaction model, (b) expand the 2D model to 3D and (c) utilize the improved model to investigate the mild-gasification process and guide modification of the mild-gasifier design.

You Lu

2012-01-01

281

Employment Interventions for Persons with Mild Cognitive Disorders  

Microsoft Academic Search

\\u000a For purposes of this chapter, we will focus our review on people with mild traumatic brain injury (TBI) and the employment\\u000a interventions for this population. There are many similarities between mild cognitive impairment (MCI) and mild TBI. MCI has\\u000a been reported to be between 2.8 and 5.3% of the population (Larrieu et al. 2002) and typically presents as issues with

Robert T. Fraser

282

South: in the mild southern tradition  

SciTech Connect

Trends in the development of current and future energy resources in the southern states of the U.S. are reviewed. The south has the advantages of a mild climate and abundant sources of natural gas, coal, and hydro power, however, the supply and distribution of energy are primarily controlled by private and federal monopolies. The Tennessee Valley Authority (TVA) has a program for funding 100,000 solar domestic hot water systems plus low interest loans for wood heaters, zero interest conservation loans, and financing of passive solar homes. TVA will also construct a large passive solar complex. Other applications of solar technology discussed include installation in a brewery, apartment buildings, abandoned city housing, a duplex, an environmental center, a planned community, and a kiln company.

Price, T.L.

1980-01-01

283

Feasibility of mild gasification of coal: research needs  

SciTech Connect

This report is an outcome of a series of activities in ''mild gasification,'' defined as a coal devolatilization process that emphasizes production of low-cost condensates (hydrocarbons) from coal. The first part of this report reviews previous work, presents an appraisal of the effects of process conditions on coal devolatilization, and describes advantages and limitations of these pyrolysis processes. It is recognized that a viable (economic) mild gasification process may have attributes such as little or no H/sub 2/ consumption, inexpensive and recyclable reactant usage (if applicable), low-cost or regenerable catalysts' application, efficient operation, and effective end usage of all generated products (solid, liquid, and gases). These attributes served as guidelines in the assessment of the existing literature, and in the identification of technical gaps. The essence of this study is the identification of a number of key research areas, some of which are listed. The investigations regarding the effects of potentially reactive gas atmospheres and vacuum configurations, and the assessment of low yield/high quality processes, can be considered as the highest priority work. A parallel effort should concentrate on evaluating process economics and sensitivities to process variables. The investigation of low-cost catalysts for coal conversion should be addressed next. Finally, the combustion characteristics of char and char/tar slurries and the potential application of high-energy fields should be investigated. It is believed that the findings in the above areas may provide the groundwork for efficient processes that produce clean fuels from coal economically. 73 refs., 8 figs., 29 tabs.

Khan, M.R.; Kurata, T.M.

1985-07-01

284

Aqueous phase processing of secondary organic aerosol from isoprene photooxidation  

NASA Astrophysics Data System (ADS)

Transport of reactive air masses into humid and wet areas is highly frequent in the atmosphere, making the study of aqueous phase processing of secondary organic aerosol (SOA) very relevant. We have investigated the aqueous phase processing of SOA generated from gas-phase photooxidation of isoprene using a smog chamber. The SOA collected on filters was extracted by water and subsequently oxidized in the aqueous phase either by H2O2 under dark conditions or by OH radicals in the presence of light, using a photochemical reactor. Online and offline analytical techniques including SMPS, HR-AMS, H-TDMA, TD-API-AMS, were employed for physical and chemical characterization of the chamber SOA and nebulized filter extracts. After aqueous phase processing, the particles were significantly more hygroscopic, and HR-AMS data showed higher signal intensity at m/z 44 and a lower signal intensity at m/z 43, thus showing the impact of aqueous phase processing on SOA aging, in good agreement with a few previous studies. Additional offline measurement techniques (IC-MS, APCI-MS2 and HPLC-APCI-MS) permitted the identification and quantification of sixteen individual chemical compounds before and after aqueous phase processing. Among these compounds, small organic acids (including formic, glyoxylic, glycolic, butyric, oxalic and 2,3-dihydroxymethacrylic acid (i.e. 2-methylglyceric acid)) were detected, and their concentrations significantly increased after aqueous phase processing. In particular, the aqueous phase formation of 2-methylglyceric acid and trihydroxy-3-methylbutanal was correlated with the consumption of 2,3-dihydroxy-2-methyl-propanal, and 2-methylbutane-1,2,3,4-tetrol, respectively, and an aqueous phase mechanism was proposed accordingly. Overall, the aging effect observed here was rather small compared to previous studies, and this limited effect could possibly be explained by the lower liquid phase OH concentrations employed here, and/or the development of oligomers observed during aqueous phase processing.

Liu, Y.; Monod, A.; Tritscher, T.; Praplan, A. P.; DeCarlo, P. F.; Temime-Roussel, B.; Quivet, E.; Marchand, N.; Dommen, J.; Baltensperger, U.

2012-07-01

285

Fluoride-Induced Hierarchical Ordering of Mesoporous Silica in Aqueous  

E-print Network

silica un- der acidic aqueous conditions. The non-ionic poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene,19] recently used non-ionic poly(alkylene oxide) block copolymers, under acidic conditions, to prepare well oxide) tri- block copolymer EO20PO70EO20 (Pluronic P123) has been employed as the structure

Yang, Peidong

286

Aqueous cleaning design presentation  

NASA Technical Reports Server (NTRS)

The phase-out of CFC's and other ozone depleting chemicals has prompted industries to re-evaluate their present methods of cleaning. It has become necessary to find effective substitutes for their processes as well as to meet the new cleaning challenges of improved levels of cleanliness and to satisfy concerns about environmental impact of any alternative selected. One of the most popular alternatives being selected is aqueous cleaning. This method offers an alternative for removal of flux, grease/oil, buffing compound, particulates and other soils while minimizing environmental impact. What I will show are methods that can be employed in an aqueous cleaning system that will make it environmentally friendly, relatively simple to maintain and capable of yielding an even higher quality of cleanliness than previously obtained. I will also explore several drying techniques available for these systems and other alternatives along with recent improvements made in this technology. When considering any type of cleaning system, a number of variables should be determined before selecting the basic configuration. Some of these variables are: (1) Soil or contaminants being removed from your parts; (2) The level of cleanliness required; (3) The environmental considerations of your area; (4) Maintenance requirements; and (5) Operating costs.

Maltby, Peter F.

1995-01-01

287

Mars aqueous chemistry experiment  

NASA Technical Reports Server (NTRS)

Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

Clark, Benton C.; Mason, Larry W.

1994-01-01

288

Aqueous coal slurry composition  

SciTech Connect

An aqueous coal slurry composition is provided which comprises: (a) at least one compound selected from (a-1) a polyether polyol compound prepared by adding ethylene oxide and/or propylene oxide to an active hydrogen-containing compound, (a-2) a compound prepared by esterifying compound (a-1), (a-3) a compound prepared by phosphating, sulfating or carboxyalkylating compound (a-1) or a salt thereof, (a-4) a compound prepared by crosslinking compound (a-1) with a crosslinking agent, (a-5) a compound prepared by reacting compound (a-1) with epihalohydrin and (a-6) an isocyanate-erminated compound prepared by reacting compound (a-1) with a polyvalent isocyanate, (b) at least one surface active agent selected from (b-1) a sulfonation product of naphthalene or its salt or an aliphatic aldehyde addition condensate thereof, (b-2) an aliphatic aldehyde condensate of a sulfonic acid group-containing aminotriazine or its salt and (b-3) a sulfonation product of creosote oil or its salt or an aliphatic aldehyde addition condensate thereof, (c) water and (d) a coal powder. The aqueous coal slurry has good fluidity and static stability.

Yamamura, M.; Fujii, N.; Kiyonaga, Y.; Watanabe, Sh.

1984-09-11

289

Flow measurements in a model of the mildly curved femoral artery of man  

NASA Technical Reports Server (NTRS)

The effects of curvature on the flow rate near the wall in the vicinity of the mildly curved femoral artery of man, and on the pressure distributions along the curved segment, were investigated using glass and tygon flow models constructed to conform to the shape of the femoral angiogram of a human subject. The test fluid was 33 percent aqueous sucrose. Steady flow observations, made using a dye flow visualization system, revealed a flow pattern like that observed in coiled pipes. A double helical type flow was found to develop, with converging streamlines in the wall vicinity from the upper and lower plane of curvature merging asymptotically along the inner curvature in a stable manner. Pressure measurements for steady flow revealed progressively larger pressure drops with distance along the entrance region of the curved segment, relative to that for a straight lumen.

Back, L. H.; Kwack, E. Y.; Crawford, D. W.

1990-01-01

290

[Toxicity studies of mild gasification products]. [Quarterly report, October 1, 1992--December 31, 1992  

SciTech Connect

Mild gasification of coal is a technology being developed by the United States Department of Energy and private industry with the hope that a cleaner method of coal use can help meet future energy needs. As the technology develops and its commercial use becomes a more viable possibility, efforts are being made to study the safety or possible toxicity of the mild gasification products. DOE and the National Institute for occupational Safety and Health (NIOSH) are cooperating through an interagency agreement to examine some of these products for their genotoxic potential. NIOSH has studied the mutagenicity of several mild gasification product samples using the Ames Salmonella/microsomal assay. As reported earlier PSIS{number_sign}830331 failed to demonstrate genotoxic activity in the Ames assay under all conditions tested. Since the mild gasification products are complex mixtures, interactions between various components are likely to occur. Such interactions between various components of complex mixtures may increase or decrease genotoxic activity in short-term assays like the Ames test. Although all synergistic interactions may not be detailed, the separate analysis of those components in several classes provides a more accurate view of the genotoxicity of each component and better allows for chemical characterization of the possible mutagens in the mixture. NIOSH has performed mutagenicity studies on the subfractions of PSIS{number_sign}830331. The results of those studies are detailed in this report.

Not Available

1992-12-31

291

Turbulence measurements in boundary layers along mildly curved surfaces  

Microsoft Academic Search

This paper presents results of turbulence measurements in boundary layers over surfaces of mild longitudinal curvature. The study indicates that convex wall curvature decreases both the length and velocity scales of turbulent motions, whereas concave curvature has the opposite effect. While being qualitatively similar to those brought about by stronger wall curvature, mild curvature effects are found to be much

B. G. Shivaprasad; B. R. Ramaprian

1978-01-01

292

Exposure to mild stress enhances the reinforcing efficacy of intravenous heroin self-administration in rats  

Microsoft Academic Search

The effect of a mild footshock on intravenous heroin self-administration was examined in male rats. Animals in the stress condition were exposed to 10 min of intermittent footshock (0.5 mA; 0.5 s on, with a mean off period of 40 s) before each of four daily self-administration sessions. Animals in the control group were not exposed to footshock. Following acquisition

Yavin Shaham; Jane Stewart

1994-01-01

293

A mild Ni/Cu-catalyzed silylation via C-O cleavage.  

PubMed

A Ni/Cu-catalyzed silylation of unactivated C-O electrophiles derived from phenols or benzyl alcohols is described. This transformation is characterized by its wide scope and mild conditions, providing a direct access to synthetically versatile silylated compounds. The protocol allows for the coupling of C(sp(2))-O and even C(sp(3))-O bonds with similar efficiency. PMID:24476124

Zarate, Cayetana; Martin, Ruben

2014-02-12

294

Numerical study of the effect of turbulence on rate of reactions in the MILD combustion regime  

Microsoft Academic Search

In this paper, the importance of fluctuations in flow field parameters is studied under MILD combustion conditions. In this way, a turbulent non-premixed CH4+H2 jet flame issuing into a hot and deficient co-flow air is modeled using the RANS Axisymmetric equations. The modeling is carried out using the EDC model to describe the turbulence-chemistry interaction. The DRM-22 reduced mechanism and

Amir Mardani; Sadegh Tabejamaat; Mohammadreza Baig Mohammadi

2011-01-01

295

Plasmon-driven sequential chemical reactions in an aqueous environment  

PubMed Central

Plasmon-driven sequential chemical reactions were successfully realized in an aqueous environment. In an electrochemical environment, sequential chemical reactions were driven by an applied potential and laser irradiation. Furthermore, the rate of the chemical reaction was controlled via pH, which provides indirect evidence that the hot electrons generated from plasmon decay play an important role in plasmon-driven chemical reactions. In acidic conditions, the hot electrons were captured by the abundant H+ in the aqueous environment, which prevented the chemical reaction. The developed plasmon-driven chemical reactions in an aqueous environment will significantly expand the applications of plasmon chemistry and may provide a promising avenue for green chemistry using plasmon catalysis in aqueous environments under irradiation by sunlight. PMID:24958029

Zhang, Xin; Wang, Peijie; Zhang, Zhenglong; Fang, Yurui; Sun, Mengtao

2014-01-01

296

Plasmon-driven sequential chemical reactions in an aqueous environment  

NASA Astrophysics Data System (ADS)

Plasmon-driven sequential chemical reactions were successfully realized in an aqueous environment. In an electrochemical environment, sequential chemical reactions were driven by an applied potential and laser irradiation. Furthermore, the rate of the chemical reaction was controlled via pH, which provides indirect evidence that the hot electrons generated from plasmon decay play an important role in plasmon-driven chemical reactions. In acidic conditions, the hot electrons were captured by the abundant H+ in the aqueous environment, which prevented the chemical reaction. The developed plasmon-driven chemical reactions in an aqueous environment will significantly expand the applications of plasmon chemistry and may provide a promising avenue for green chemistry using plasmon catalysis in aqueous environments under irradiation by sunlight.

Zhang, Xin; Wang, Peijie; Zhang, Zhenglong; Fang, Yurui; Sun, Mengtao

2014-06-01

297

Mild cognitive impairment in Parkinson's disease.  

PubMed

The concept of mild cognitive impairment (MCI) in the general population has received increased attention over recent years, and is associated with risk of progression to Alzheimer's disease. Within Parkinson's disease (PD), MCI (PD-MCI) is also now recognised to be relatively common, with certain subtypes predicting progression to Parkinson's disease dementia (PDD). Recently, criteria to better characterise PD-MCI and its subtypes have been produced by the Movement Disorder Society. In contrast to the population as a whole, where amnestic MCI is the most common subtype, non-amnestic PD-MCI dominates, with prominent executive and attention dysfunction. Although the pathophysiology of PD-MCI is poorly understood and encompasses both PD and non-PD pathology, it is most likely the result of a complex interaction between neurotransmitter dysfunction, synaptic pathology, protein aggregation and neuronal damage. Determining the factors that influence the progression of these pathologies in PD and the individuals at risk of ultimately developing PDD is critical for targeted intervention and drug discovery studies. Further work is required, however, to determine the significance of PD-MCI and also to validate the diagnostic criteria. This would be best delivered in the form of longitudinal studies in homogenous cohorts of PD participants, to allow prognostication and generalisation among the PD population. At the present time, no drug therapies are available for PD-MCI. Management includes screening for the disorder, excluding treatable causes of cognitive decline and cautious use of dopamine agonists and medications such as anticholinergics. PMID:23868092

Yarnall, Alison Jane; Rochester, Lynn; Burn, David John

2013-09-01

298

Maternal non-phenylketonuric mild hyperphenylalaninemia.  

PubMed

Unlike maternal phenylketonuria (PKU) which produces severe birth defects when untreated during pregnancy, maternal non-PKU mild hyperphenylalaninemia (MHP) has a less severe impact but whether it is benign or may have long-term consequences for offspring has been unclear. From an international survey of maternal MHP we obtained information about 86 mothers (blood phenylalanine (Phe) 150-720 mumol/l), their 219 untreated pregnancies and 173 offspring. Spontaneous fetal loss and congenital anomalies were no more frequent than normally expected. Median Z-scores for birth length and birth head circumference and offspring IQ (100), however, were significantly lower for maternal Phe > 400 mumol/l than for maternal Phe < 400 mumol/l, in which the median offspring IQ was 108. Data on maternal MHP from the prospective Maternal PKU Collaborative Study (MPKUCS) are as yet incomplete but seem to be conforming to the general pattern of the international survey. We conclude that maternal blood Phe levels above 400 mumol/l in maternal MHP are associated with lower birth measurements and slightly lower offspring IQ. It would seem that dietary intervention to lower the maternal Phe levels to below 400 mumol/l might be indicated in maternal MHP pregnancies with the higher blood Phe levels. PMID:8828603

Levy, H L; Waisbren, S E; Lobbregt, D; Allred, E; Leviton, A; Koch, R; Hanley, W B; Rouse, B; Matalon, R; de la Cruz, F

1996-07-01

299

Bacterial Phosphating of Mild (Unalloyed) Steel  

PubMed Central

Mild (unalloyed) steel electrodes were incubated in phosphate-buffered cultures of aerobic, biofilm-forming Rhodococcus sp. strain C125 and Pseudomonas putida mt2. A resulting surface reaction leading to the formation of a corrosion-inhibiting vivianite layer was accompanied by a characteristic electrochemical potential (E) curve. First, E increased slightly due to the interaction of phosphate with the iron oxides covering the steel surface. Subsequently, E decreased rapidly and after 1 day reached ?510 mV, the potential of free iron, indicating the removal of the iron oxides. At this point, only scattered patches of bacteria covered the surface. A surface reaction, in which iron was released and vivianite precipitated, started. E remained at ?510 mV for about 2 days, during which the vivianite layer grew steadily. Thereafter, E increased markedly to the initial value, and the release of iron stopped. Changes in E and formation of vivianite were results of bacterial activity, with oxygen consumption by the biofilm being the driving force. These findings indicate that biofilms may protect steel surfaces and might be used as an alternative method to combat corrosion. PMID:11010888

Volkland, Hans-Peter; Harms, Hauke; Müller, Beat; Repphun, Gernot; Wanner, Oskar; Zehnder, Alexander J. B.

2000-01-01

300

Mild-split SUSY with flavor  

NASA Astrophysics Data System (ADS)

In the framework of a gauge mediated quiver-like model, the standard model flavor texture can be naturally generated. The model — like the MSSM — has furthermore a region in parameter space where the lightest Higgs mass is fed by heavy stop loops, which in turn sets the average squark mass scale near 10 - 20TeV. We perform a careful flavor analysis to check whether this type of mild-split SUSY passes all flavor constraints as easily as envisioned in the original type of split SUSY. Interestingly, it turns out to be on the border of several constraints, in particular, the branching ratio of ? ? e? and, if order one complex phases are assumed, also ? K , neutron and electron EDM. Furthermore, we consider unification as well as dark matter candidates, especially the gravitino. Finally, we provide a closed-form formula for the soft masses of matter in arbitrary representations of any of the gauge groups in a generic quiver-like model with a general messenger sector.

Eliaz, Latif; Giveon, Amit; Gudnason, Sven Bjarke; Tsuk, Eitan

2013-10-01

301

Thermal Comptonization in Mildly Relativistic Pair Plasmas  

E-print Network

We use a Monte Carlo simulation to calculate the spectra of mildly relativistic thermal plasmas in pair balance. We use the exact integral expression for the electron-positron thermal annihilation spectrum, and provide accurate expressions for the Gaunt factors of electron-ion, electron-electron, and electron-positron thermal bremsstrahlung in the transrelativistic temperature regime. The particles are assumed to be uniformly distributed throughout a sphere, and the pair opacity is self-consistently calculated from the energy and angular distribution of scattered photons. The resultant photon spectra are compared with the nonrelativistic diffusion treatment of Sunyaev and Titarchuk, the bridging formulas of Zdziarski, and the relativistic corrections proposed by Titarchuk. We calculate allowed pair-balanced states of thermal plasmas with no pair escape which include bremsstrahlung and internal soft photons. The results are presented in the spectral index/compactness plane, and can be directly compared with observations of spectra from AGNs and Galactic black hole candidates. By comparing with X-ray spectral indices of Seyfert AGNs and compactnesses inferred from X-ray variability data, we find that the allowed solutions for pair equilibrium plasma imply that the temperatures of Seyfert galaxies are $\\lesssim 300$ keV. This prediction can be tested with more sensitive gamma-ray observations of Seyfert galaxies. We find that if the X-ray variability time scale gives an accurate measure of the compactness, pair-dominated solutions are inconsistent with the data.

J. G. Skibo; C. D. Dermer; R. Ramaty; J. M. McKinley

1994-12-21

302

Mild hyperthermia influence on Herceptin® properties  

PubMed Central

Background Mild hyperthermia (mHT) increases the tumor perfusion and vascular permeability, and reduces the interstitial fluid pressure, resulting in better intra-tumoral bioavailability of low molecular weight drugs. This approach is potentially also attractive for delivery of therapeutic macromolecules, such as antibodies. Here, we investigated the effects of mHT on the stability, immunological and pharmacological properties of Herceptin®, a clinically approved antibody, targeting the human epidermal growth factor receptor 2 (HER-2) overexpressed in breast cancer. Results Herceptin® was heated to 37°C (control) and 42°C (mHT) for 1 hour. Formation of Herceptin® aggregates was measured using Nile Red assay. mHT did not result in additional Herceptin® aggregates compared to 37°C, showing the Herceptin® stability is unchanged. Immunological and pharmacological properties of Herceptin® were evaluated following mHT using HER-2 positive breast cancer cells (BT-474). Exposure of Herceptin® to mHT preserved recognition and binding affinity of Herceptin® to HER-2. Western-blot and cell proliferation assays on BT-474 cells showed that mHT left the inhibitory activities of Herceptin® unchanged. Conclusions The stability, and the immunological and pharmacological properties of Herceptin® are not negatively affected by mHT. Further in-vivo studies are required to evaluate the influence of mHT on intra-tumoral bioavailability and therapeutic effectiveness of Herceptin®.

Escoffre, Jean-Michel; Deckers, Roel; Sasaki, Noboru; Bos, Clemens; Moonen, Chrit

2015-01-01

303

Radio frequency radiation-induced hyperthermia using Si nanoparticle-based sensitizers for mild cancer therapy.  

PubMed

Offering mild, non-invasive and deep cancer therapy modality, radio frequency (RF) radiation-induced hyperthermia lacks for efficient biodegradable RF sensitizers to selectively target cancer cells and thus avoid side effects. Here, we assess crystalline silicon (Si) based nanomaterials as sensitizers for the RF-induced therapy. Using nanoparticles produced by mechanical grinding of porous silicon and ultraclean laser-ablative synthesis, we report efficient RF-induced heating of aqueous suspensions of the nanoparticles to temperatures above 45-50 °C under relatively low nanoparticle concentrations (<1 mg/mL) and RF radiation intensities (1-5 W/cm(2)). For both types of nanoparticles the heating rate was linearly dependent on nanoparticle concentration, while laser-ablated nanoparticles demonstrated a remarkably higher heating rate than porous silicon-based ones for the whole range of the used concentrations from 0.01 to 0.4 mg/mL. The observed effect is explained by the Joule heating due to the generation of electrical currents at the nanoparticle/water interface. Profiting from the nanoparticle-based hyperthermia, we demonstrate an efficient treatment of Lewis lung carcinoma in vivo. Combined with the possibility of involvement of parallel imaging and treatment channels based on unique optical properties of Si-based nanomaterials, the proposed method promises a new landmark in the development of new modalities for mild cancer therapy. PMID:25391603

Tamarov, Konstantin P; Osminkina, Liubov A; Zinovyev, Sergey V; Maximova, Ksenia A; Kargina, Julia V; Gongalsky, Maxim B; Ryabchikov, Yury; Al-Kattan, Ahmed; Sviridov, Andrey P; Sentis, Marc; Ivanov, Andrey V; Nikiforov, Vladimir N; Kabashin, Andrei V; Timoshenko, Victor Yu

2014-01-01

304

Radio frequency radiation-induced hyperthermia using Si nanoparticle-based sensitizers for mild cancer therapy  

NASA Astrophysics Data System (ADS)

Offering mild, non-invasive and deep cancer therapy modality, radio frequency (RF) radiation-induced hyperthermia lacks for efficient biodegradable RF sensitizers to selectively target cancer cells and thus avoid side effects. Here, we assess crystalline silicon (Si) based nanomaterials as sensitizers for the RF-induced therapy. Using nanoparticles produced by mechanical grinding of porous silicon and ultraclean laser-ablative synthesis, we report efficient RF-induced heating of aqueous suspensions of the nanoparticles to temperatures above 45-50°C under relatively low nanoparticle concentrations (<1 mg/mL) and RF radiation intensities (1-5 W/cm2). For both types of nanoparticles the heating rate was linearly dependent on nanoparticle concentration, while laser-ablated nanoparticles demonstrated a remarkably higher heating rate than porous silicon-based ones for the whole range of the used concentrations from 0.01 to 0.4 mg/mL. The observed effect is explained by the Joule heating due to the generation of electrical currents at the nanoparticle/water interface. Profiting from the nanoparticle-based hyperthermia, we demonstrate an efficient treatment of Lewis lung carcinoma in vivo. Combined with the possibility of involvement of parallel imaging and treatment channels based on unique optical properties of Si-based nanomaterials, the proposed method promises a new landmark in the development of new modalities for mild cancer therapy.

Tamarov, Konstantin P.; Osminkina, Liubov A.; Zinovyev, Sergey V.; Maximova, Ksenia A.; Kargina, Julia V.; Gongalsky, Maxim B.; Ryabchikov, Yury; Al-Kattan, Ahmed; Sviridov, Andrey P.; Sentis, Marc; Ivanov, Andrey V.; Nikiforov, Vladimir N.; Kabashin, Andrei V.; Timoshenko, Victor Yu

2014-11-01

305

Synthesis of Aqueous Ferrofluid  

NSDL National Science Digital Library

This video lab manual, by the Interdisciplinary Education Group of the University of Wisconsin â?? Madison Materials Research Science and Engineering Center (MRSEC), walks students through the process synthesizing aqueous ferrofluids, which "respond to an external magnetic field enabling the solution's location to be controlled through the application of a magnetic field." Each step of the procedure is detailed and accompanied with a video showing it as it is performed. A brief background of the procedure and the necessary safety and laboratory materials are also given. This detailed resource helps students to explore nanotechnology and advanced materials science through hands-on laboratory activities. A printer-friendly version with an example image for each step is also available, perfect for an in-class handout.

Breitzer, Jonathan

306

Alzheimer's disease and mild cognitive impairment: effects of shifting and interference in simple arithmetic.  

PubMed

The present study investigated arithmetic processing in patients with mild dementia of Alzheimer's type (DAT) and patients with mild cognitive impairment (MCI) without dementia. Arithmetic processing (e.g., 2+3=?, 3 x 4=?) was evaluated in (1) 'blocked' condition (without extra load on attentional and executive functions), in (2) 'mixed' condition (shifting between different operations was required), and in (3) 'Stroop-like' condition (executive control and inhibition of automatic retrieval processes were needed). Both DAT and MCI patients showed intact arithmetic knowledge retrieval from long-term memory in the blocked condition. However, DAT patients were compromised whenever load was put on executive functions, whereas MCI patients succeeded to shift between operations (mixed condition) but had difficulties to inhibit overlearned associations (Stroop-like condition). In line with previous studies, these findings point to the contribution of attentional and executive functions in arithmetic. The present investigation is also of clinical relevance: it suggests that it may be important to assess arithmetic processing not only in blocked presentation but also in mixed presentation. The mixed condition has a high ecological value because it mimics daily-life arithmetic activities (e.g., checking the grocery bill). As indicated by the present results, DAT and MCI patients who are in the normal range at routine neuropsychological (blocked) arithmetic assessments may experience difficulties by extra requirement of non-numerical resources. That means, they possibly process arithmetic not efficiently in daily-life situations. PMID:17628603

Zamarian, Laura; Semenza, Carlo; Domahs, Frank; Benke, Thomas; Delazer, Margarete

2007-12-15

307

Cognitive Impairment in Mild General Paresis of the Insane: AD-Like Pattern  

Microsoft Academic Search

Background\\/Aims: We investigated the clinical and cognitive features of patients with mild general paresis of the insane (GPI) in comparison to Alzheimer’s disease (AD) patients, mild frontotemporal dementia (FTD) patients and normal elderly individuals. Methods: Twelve patients with mild GPI, 24 patients with mild AD, 11 patients with mild FTD and 36 healthy subjects participated in the current study. A

Jianhong Wang; Qihao Guo; Pingyu Zhou; Jun Zhang; Qianhua Zhao; Zhen Hong

2011-01-01

308

Thermal conductivity of aqueous foam  

SciTech Connect

Thermal conductivity plays an important part in the response of aqueous foams used as geothermal drilling fluids. The thermal conductivity of these foams was measured at ambient conditions using the thermal conductivity probe technique. Foam densities studied were from 0.03 to 0.2 g/cm/sup 3/, corresponding to liquid volume fractions of the same magnitude. Microscopy of the foams indicated bubble sizes in the range 50 to 300 ..mu..m for nitrogen foams, and 30 to 150 ..mu..m for helium foams. Bubble shapes were observed to be polyhedral at low foam densities and spherical at the higher densities. The measured conductivity values ranged from 0.05 to 0.12 W/m-K for the foams studied. The predicted behavior in foam conductivity caused by a change in the conductivity of the discontinuous gas phase was observed using nitrogen or helium gas in the foams. Analysis of the probe response data required an interpretation using the full intergral solution to the heat conduction equation, since the thermal capacity of the foam was small relative to the thermal mass of the probe. The measurements of the thermal conductivity of the foams were influenced by experimental effects such as the probe input power, foam drainage, and the orientation of the probe and test cell. For nitrogen foams, the thermal conductivity vs liquid volume fraction was observed to fall between predictions based on the parallel ordering and Russell models for thermal conduction in heterogeneous materials.

Drotning, W.D.; Ortega, A.; Havey, P.E.

1982-05-01

309

Inverse Compton Scattering in Mildly Relativistic Plasma  

NASA Technical Reports Server (NTRS)

We investigated the effect of inverse Compton scattering in mildly relativistic static and moving plasmas with low optical depth using Monte Carlo simulations, and calculated the Sunyaev-Zel'dovich effect in the cosmic background radiation. Our semi-analytic method is based on a separation of photon diffusion in frequency and real space. We use Monte Carlo simulation to derive the intensity and frequency of the scattered photons for a monochromatic incoming radiation. The outgoing spectrum is determined by integrating over the spectrum of the incoming radiation using the intensity to determine the correct weight. This method makes it possible to study the emerging radiation as a function of frequency and direction. As a first application we have studied the effects of finite optical depth and gas infall on the Sunyaev-Zel'dovich effect (not possible with the extended Kompaneets equation) and discuss the parameter range in which the Boltzmann equation and its expansions can be used. For high temperature clusters (k(sub B)T(sub e) greater than or approximately equal to 15 keV) relativistic corrections based on a fifth order expansion of the extended Kompaneets equation seriously underestimate the Sunyaev-Zel'dovich effect at high frequencies. The contribution from plasma infall is less important for reasonable velocities. We give a convenient analytical expression for the dependence of the cross-over frequency on temperature, optical depth, and gas infall speed. Optical depth effects are often more important than relativistic corrections, and should be taken into account for high-precision work, but are smaller than the typical kinematic effect from cluster radial velocities.

Molnar, S. M.; Birkinshaw, M.

1998-01-01

310

Aqueous solution synthesis of Pt-M (M = Fe, Co, Ni) bimetallic nanoparticles and their catalysis for the hydrolytic dehydrogenation of ammonia borane.  

PubMed

Platinum-based bimetallic nanocatalysts have attracted much attention due to their high-efficiency catalytic performance in energy-related applications such as fuel cell and hydrogen storage, for example, the hydrolytic dehydrogenation of ammonia borane (AB). In this work, a simple and green method has been demonstrated to successfully prepare Pt-M (M = Fe, Co, Ni) NPs with tunable composition (nominal Pt/M atomic ratios of 4:1, 1:1, and 1:4) in aqueous solution under mild conditions. All Pt-M NPs with a small size of 3-5 nm show a Pt fcc structure, suggesting the bimetallic formation (alloy and/or partial core-shell), examined by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray absorption fine structure (XAFS) analysis. The catalytic activities of Pt-M NPs in the hydrolytic dehydrogenation of AB reveal that Pt-Ni NPs with a ratio of 4:1 show the best catalytic activity and even better than that of pure Pt NPs when normalized to Pt molar amount. The Ni oxidation state in Pt-Ni NPs has been suggested to be responsible for the corresponding catalytic activity for hydrolytic dehydrogenation of AB by XAFS study. This strategy for the synthesis of Pt-M NPs is simple and environmentally benign in aqueous solution with the potential for scale-up preparation and the in situ catalytic reaction. PMID:25058566

Wang, Shuai; Zhang, Duo; Ma, Yanyun; Zhang, Hui; Gao, Jing; Nie, Yuting; Sun, Xuhui

2014-08-13

311

Nanofibrous architecture of silk fibroin scaffolds prepared with a mild self-assembly process  

PubMed Central

Besides excellent biocompatibility and biodegradability, a useful tissue engineering scaffold should provide suitable macropores and nanofibrous structure, similar to extracellular matrix (ECM), to induce desired cellular activities and to guide tissue regeneration. In the present study, a mild process to prepare porous and nanofibrous silk based scaffolds from aqueous solution is described. Using collagen to control the self-assembly of silk, nanofibrous silk scaffolds were firstly achieved through lyophilization. Water annealing was used to generate insolubility in the silk based scaffolds, thereby avoiding the use of organic solvents. The nano-fibrils formed in the silk-collagen scaffolds had diameters of 20-100 nanometers, similar with native collagen in ECM. The silk-collagen scaffolds dissolved slowly in PBS solution, with about a 28% mass lost after 4 weeks. Following the dissolution or degradation, the nanofibrous structure inside the macropore walls emerged and interacted with cells directly. During in vitro cell culture, the nanofibrous silk-collagen scaffolds containing 7.4% collagen demonstrated significantly improved cell-compatibility when compared with salt-leached silk scaffolds and silk-collagen scaffolds containing 20% collagen that emerged less nano-fibrils. Therefore, this new process provides useful scaffolds for tissue engineering applications. Furthermore, the process involves all-aqueous, room temperature and pressure processing without the use of toxic chemicals or solvents, offering new green chemistry approaches, as well as options to load bioactive drugs or growth factors into process. PMID:20970185

Lu, Qiang; Wang, Xiuli; Lu, Shenzhou; Li, Mingzhong; Kaplan, David L; Zhu, Hesun

2010-01-01

312

Mild cognitive impairment and its management in older people  

PubMed Central

Mild cognitive impairment (MCI) is a common condition in the elderly. It is characterized by deterioration of memory, attention, and cognitive function that is beyond what is expected based on age and educational level. MCI does not interfere significantly with individuals’ daily activities. It can act as a transitional level of evolving dementia with a range of conversion of 10%–15% per year. Thus, it is crucial to protect older people against MCI and developing dementia. The preventive interventions and appropriate treatments should improve cognitive performance, and retard or prevent progressive deficits. The avoidance of toxins, reduction of stress, prevention of somatic diseases, implementation of mental and physical exercises, as well as the use of dietary compounds like antioxidants and supplements can be protective against MCI. The modification of risk factors such as stopping smoking, as well as the treatment of deficiency in vitamins and hormones by correcting behaviors and lifestyle, can prevent cognitive decline in the elderly. The progressive increase in the growth rate of the elderly population can enhance the rate of MCI all over the world. There is no exact cure for MCI and dementia; therefore, further studies are needed in the future to determine causes of MCI and risk factors of progression from MCI to dementia. This will help to find better ways for prevention and treatment of cognitive impairment worldwide.

Eshkoor, Sima Ataollahi; Hamid, Tengku Aizan; Mun, Chan Yoke; Ng, Chee Kyun

2015-01-01

313

Operational characteristics of a parallel jet MILD combustion burner system  

SciTech Connect

This study describes the performance and stability characteristics of a parallel jet MILD (Moderate or Intense Low-oxygen Dilution) combustion burner system in a laboratory-scale furnace, in which the reactants and exhaust ports are all mounted on the same wall. Thermal field measurements are presented for cases with and without combustion air preheat, in addition to global temperature and emission measurements for a range of equivalence ratio, heat extraction, air preheat and fuel dilution levels. The present furnace/burner configuration proved to operate without the need for external air preheating, and achieved a high degree of temperature uniformity. Based on an analysis of the temperature distribution and emissions, PSR model predictions, and equilibrium calculations, the CO formation was found to be related to the mixing patterns and furnace temperature rather than reaction quenching by the heat exchanger. The critical equivalence ratio, or excess air level, which maintains low CO emissions is reported for different heat exchanger positions, and an optimum operating condition is identified. Results of CO and NO{sub x} emissions, together with visual observations and a simplified two-dimensional analysis of the furnace aerodynamics, demonstrate that fuel jet momentum controls the stability of this multiple jet system. A stability diagram showing the threshold for stable operation is reported, which is not explained by previous stability criteria. (author)

Szegoe, G.G.; Dally, B.B.; Nathan, G.J. [School of Mechanical Engineering, The University of Adelaide, South Australia, 5005 (Australia)

2009-02-15

314

Mild cognitive impairment: conceptual, assessment, ethical, and social issues.  

PubMed

Mild cognitive impairment (MCI) is defined as a condition characterized by newly acquired cognitive decline to an extent that is beyond that expected for age or educational background, yet not causing significant functional impairment. The concept of MCI has received considerable attention in the literature over the past few years, and aspects related to its definition, prevalence, and evolution have been extensively studied and reviewed. Here we attempt to synthesize the implications of the current status of this entity, focusing on the conceptual, methodological, and, in particular, the social and ethical aspects of MCI which have attracted less attention. We discuss the weaknesses of the concept of MCI, which is heterogeneous in etiology, manifestations, and outcomes, and suggest that the emergence of the syndrome at this stage reflects industrial interests related to possible development of drugs for this disorder. On the other hand, the formal diagnosis of MCI, with its implications that the person may develop dementia, may have a grave impact on the psychological state of the individual, at a stage when prediction of outcome is tenuous and possibilities of useful interventions are meager. We present suggestions for the direction of future research in these areas. PMID:18982912

Werner, Perla; Korczyn, Amos D

2008-01-01

315

Critical Heat Flux of Butanol Aqueous Solution  

NASA Astrophysics Data System (ADS)

It is known that the addition of small amount of alcohol such as butanol to water enhances the CHF. Such aqueous solution is actively applied to heat transfer devices such as heat pipes and microchannel cooling systems, however, the fundamental characters of boiling have not been fully understood. In the present research, the experiment of boiling heat transfer is performed on a heated wire by employing butanol aqueous solution as a typical test solution and by changing concentration 1-butanol and subcooling in a wide range. Bubbling aspects were observed using high-speed video camera. It is found from the experiment that CHF is 2 to 3 times higher than that of pure water and generating bubbles are tiny even at the saturated condition. The dependence of CHF on subcooling is found to be curious showing that CHF decreases first, takes a minimum, and then increases with increasing subcooling. These results suggest that the butanol aqueous solution is a promising liquid for the application of boiling to a small-scaled cooling device.

Nishiguchi, Shotaro; Shoji, Masahiro

316

Two types of metal fume fever: Mild vs. serious  

SciTech Connect

Some physicians recognize the mild form of Metal Fume Fever (MFF); few recognize MFF's serious form. Mild MFF is self-limited and is caused by inhaling metal oxide fumes. Serious MFF may be life-threatening and is caused by inhalation of military smoke. Initial manifestations of the two forms are similar but their pathophysiologies and managements are different. Mild MFF patients recover within 48 hours and rarely require hospitalization. Serious MFF symptoms remit but may relapse 24 to 48 hours later with significant morbidity and mortality. Serious MFF patients require admission for observation. Military physicians need to differentiate these forms of MFF.26 references.

Blount, B.W. (Madigan Army Medical Center, Tacoma, WA (USA))

1990-08-01

317

Effects of Concept Mapping Instruction on the Vocabulary Acquisition Skills of Seventh-Graders with Mild Disabilities: A Replication Study  

ERIC Educational Resources Information Center

The present investigation replicates and extends an earlier study comparing 2 conditions, a dictionary approach versus a concept mapping model, on the learning of vocabulary words among 4 students with mild disabilities (i.e., emotional and/or behavioral disorders and other health impairments) attending a middle school. An A-B-A-B design was used…

Palmer, Jessica; Boon, Richard T.; Spencer, Vicky G.

2014-01-01

318

Bench-scale development of mild gasification char desulfurization; [Quarterly] report, September 1--November 30, 1993  

SciTech Connect

This goal of this project is to scale up a process, developed under a previous ICCI grant, for desulfurization of mild gasification char by treatment with hydrogen-rich process-derived fuel gas at 650{degree}--760{degree}C and 7-15 atm. The char can be converted into a low-sulfur metallurgical form coke. In the prior study, IBC-105 coal with 4.0 wt % sulfur was converted to chars with less than 1.0 wt % sulfur in a laboratory-scale batch reactor. The susceptibility of the char to desulfurization was correlated with physicochemical char properties and mild gasification conditions. Acid pretreatment of the coal prior to mild gasification was also shown to significantly enhance subsequent sulfur removal. In this study, IGT is conducting continuous bench-scale tests in a 1-lb/h fluidized-bed reactor to determine the preferred process conditions and obtain steady-state data necessary for process design and scale-up. The desulfurized chars are to be used to produce low-sulfur form coke, which will be evaluated for density, reactivity, and strength properties relevant to utilization in blast furnaces. During the first quarter, 180 lb (82 kg) of IBC-105 coal was obtained and subjected to crushing, and sizing to prepare 49 lb (22 kg) of material for test operation.

Knight, R.A.

1994-03-01

319

Mars Aqueous Processing System  

NASA Technical Reports Server (NTRS)

The goal of the Mars Aqueous Processing System (MAPS) is to establish a flexible process that generates multiple products that are useful for human habitation. Selectively extracting useful components into an aqueous solution, and then sequentially recovering individual constituents, can obtain a suite of refined or semi-refined products. Similarities in the bulk composition (although not necessarily of the mineralogy) of Martian and Lunar soils potentially make MAPS widely applicable. Similar process steps can be conducted on both Mars and Lunar soils while tailoring the reaction extents and recoveries to the specifics of each location. The MAPS closed-loop process selectively extracts, and then recovers, constituents from soils using acids and bases. The emphasis on Mars involves the production of useful materials such as iron, silica, alumina, magnesia, and concrete with recovery of oxygen as a byproduct. On the Moon, similar chemistry is applied with emphasis on oxygen production. This innovation has been demonstrated to produce high-grade materials, such as metallic iron, aluminum oxide, magnesium oxide, and calcium oxide, from lunar and Martian soil simulants. Most of the target products exhibited purities of 80 to 90 percent or more, allowing direct use for many potential applications. Up to one-fourth of the feed soil mass was converted to metal, metal oxide, and oxygen products. The soil residue contained elevated silica content, allowing for potential additional refining and extraction for recovery of materials needed for photovoltaic, semiconductor, and glass applications. A high-grade iron oxide concentrate derived from lunar soil simulant was used to produce a metallic iron component using a novel, combined hydrogen reduction/metal sintering technique. The part was subsequently machined and found to be structurally sound. The behavior of the lunar-simulant-derived iron product was very similar to that produced using the same methods on a Michigan iron ore concentrate, which demonstrates that lunar-derived material can be used in a manner similar to conventional terrestrial iron. Metallic iron was also produced from the Mars soil simulant. The aluminum and magnesium oxide products produced by MAPS from lunar and Mars soil simulants exhibited excellent thermal stability, and were shown to be capable of use for refractory oxide structural materials, or insulation at temperatures far in excess of what could be achieved using unrefined soils. These materials exhibited the refractory characteristics needed to support iron casting and forming operations, as well as other thermal processing needs. Extraction residue samples contained up to 79 percent silica. Such samples were successfully fused into a glass that exhibited high light transmittance.

Berggren, Mark; Wilson, Cherie; Carrera, Stacy; Rose, Heather; Muscatello, Anthony; Kilgore, James; Zubrin, Robert

2012-01-01

320

Effective catalysts for decomposition of aqueous ozone  

Microsoft Academic Search

Activities of a series of oxide supports and dozens of supported metal catalysts toward the decomposition of aqueous ozone have been investigated. Under reaction conditions, active carbon (AC) showed comparatively high activity, while zeolite (HY and mordenite), Al2O3, SiO2, SiO2·Al2O3 and TiO2 showed no or negligible activity. Noble metals showed high activity. Among four kinds (Al2O3, SiO2, SiO2·Al2O3 and TiO2)

Jianjun Lin; Akimasa Kawai; Tsuyoshi Nakajima

2002-01-01

321

Mediterranean Diet and Mild Cognitive Impairment  

PubMed Central

Background Higher adherence to the Mediterranean diet (MeDi) may protect from Alzheimer’s disease (AD) but its association with Mild Cognitive Impairment (MCI) has not been explored. Objective To investigate the association between MeDi and MCI. Design, Setting, Patients, Outcomes In a multiethnic community study in New York, we used Cox proportional hazards to investigate the association between adherence to the MeDi (0 – 9 scale; higher scores higher adherence) and (1) incidence of MCI and (2) progression from MCI to AD. All models were adjusted for cohort, age, gender, ethnicity, education, APOE genotype, caloric intake, body mass index and time duration between baseline dietary assessment and baseline diagnosis. Results There were 1393 cognitively normal participants, 275 of whom developed MCI during 4.5 (± 2.7, 0.9–16.4) years of follow-up. Compared to subjects in the lowest MeDi adherence tertile, subjects in the middle MeDi tertile had 17 % (HR, 0.83; 95% CI, 0.62 – 1.12; p=0.24) less risk of developing MCI, while those at the highest MeDi adherence tertile had 28 % (HR, 0.72; 95% CI, 0.52 – 1.00; p=0.05) less risk of developing MCI (trend HR, 0.85; 95% CI, 0.72 – 1.00; p for trend= 0.05). There were 482 subjects with MCI, 106 of whom developed AD during 4.3 (± 2.7, 1.0 – 13.8) years of follow-up. Compared to subjects in the lowest MeDi adherence tertile, subjects in the middle MeDi adherence tertile had 45 % (HR, 0.55; 95% CI, 0.34 – 0.90; p=0.01) less risk of developing AD, while those at the highest MeDi adherence tertile had 48 % (HR, 0.52; 95% CI, 0.30 – 0.91; p=0.02) less risk of developing AD (trend HR, 0.71; 95% CI, 0.53 – 0.95; p for trend= 0.02). Conclusions Higher adherence to the MeDi is associated with a trend for reduced risk for developing MCI and with reduced risk for MCI conversion to AD. PMID:19204158

Scarmeas, Nikolaos; Stern, Yaakov; Mayeux, Richard; Manly, Jennifer; Schupf, Nicole; Luchsinger, Jose A.

2009-01-01

322

Nutritional condition of Northern Yellowstone Elk  

USGS Publications Warehouse

Ultrasonography and body condition scoring was used to estimate nutritional condition of northern Yellowstone elk in late winter. Probability of pregnancy was related to body fat, and lactating cows had 50% less fat than non-lactating cows. For mild to normal winters, most of the elk were in good condition.

Cook, R.C.; Cook, J.G.; Mech, L.D.

2004-01-01

323

Aqueous chemical wash compositions  

SciTech Connect

This patent describes an aqueous, substantially unfoamed chemical wash composition having properties making it suitable for use as a pre-flush in well cementing operations and/or for removal of drilling mud from a borehole at a temperature of from about 150/sup 0/F to about 270/sup 0/F, the wash a. being predominantly composed of water, b. containing an active surfactant component comprising a combination of (1) from about 0.1 to about 1.5 weight percent (total weight basis) of a water soluble anionic surfactant; (2) from about 0.1 to about 1.5 weight percent (total weight basis) of a nonionic surfactant; and (3) from about 0.05 to about 0.54 weight percent (total weight basis) of at least one water soluble amphoteric surfactant, and c. having dispersed therein a heterogeneous mixture of distinct particles comprising both a first particulate oil soluble resin which is friable and a second particulate oil soluble resin which is pliable and where the size of the friable resin particles ranges from about 0.5 to about 300 microns and the size of the pliable resin particles ranges from about 0.05 to about 30 microns. The amount of the friable-pliable resin mixture is sufficient to impart effective fluid loss control to the chemical wash composition.

Bannister, C.E.

1987-07-21

324

Aqueous chlorination of resorcinol  

USGS Publications Warehouse

An investigation of the aqueous chlorination (NaOCl) of resorcinol is reported. The following intermediates were detected in moderate to high yield at different pH values and varying percentages of chlorination: 2-chloro-, 4-chloro-, 2,4-dichloro-, 4,6-dichloro- and 2,4,6-trichlororesorcinol. Only trace amounts of the intermediates were detected when the chlorination was conducted in the presence of phosphate buffer. This result has significant implications since resorcinol in phosphate buffer has been used as a model compound in several recent studies on the formation of chlorinated hydrocarbons during chlorination of drinking water. Relative rates of chlorination were determined for resorcinol and several of the chlorinated resorcinols. Resorcinol was found to chlorinate only three times faster than 2,4,6-trichlororesorcinol. The structure 2,4,6-trichlororesorcinol was established as a monohydrate even after sublimation. A tetrachloro or pentachloro intermediate was not detected, suggesting that the ring-opening step of such an intermediate must be rapid. ?? 1989.

Heasley, V.L.; Burns, M.D.; Kemalyan, N.A.; Mckee, T.C.; Schroeter, H.; Teegarden, B.R.; Whitney, S.E.; Wershaw, R.L.

1989-01-01

325

Aqueous photolysis of niclosamide  

USGS Publications Warehouse

The photodegradation of [14C]niclosamide was studied in sterile, pH 5, 7, and 9 buffered aqueous solutions under artificial sunlight at 25.0 A? 1.0 A?C. Photolysis in pH 5 buffer is 4.3 times faster than in pH 9 buffer and 1.5 times faster than in pH 7 buffer. In the dark controls, niclosamide degraded only in the pH 5 buffer. After 360 h of continuous irradiation in pH 9 buffer, the chromatographic pattern of the degradates was the same regardless of which ring contained the radiolabel. An HPLC method was developed that confirmed these degradates to be carbon dioxide and two- and four-carbon aliphatic acids formed by cleavage of both aromatic rings. Carbon dioxide was the major degradate, comprising 40% of the initial radioactivity in the 360 h samples from both labels. The other degradates formed were oxalic acid, maleic acid, glyoxylic acid, and glyoxal. In addition, in the chloronitroaniline-labeled irradiated test solution, 2-chloro-4-nitroaniline was observed and identified after 48 h of irradiation but was not detected thereafter. No other aromatic compounds were isolated or observed in either labeled test system.

Graebing, P.W.; Chib, J.S.; Hubert, T.D.; Gingerich, W.H.

2004-01-01

326

Characterizing and modeling combustion of mild-gasification chars in pressurized fluidized beds  

SciTech Connect

Oak Ridge National Laboratory (ORNL) is supported by the Morgantown Energy Technology Center (METC) of the Department of Energy (DOE) under FWP-FEAA310 to characterize the fuel properties of liquid and char coproducts from the mild gasification of coal, Because most of the energy content of coals subjected to mild gasification is retained in the byproduct char, efficient and cost-effective utilization of the char is essential in insuring that candidate gasification processes are commercially viable. One potential use for char of particular interest to DOE is pressurized fluidized bed combustion (PFBC). PFBC is of particular interest because it has the potential for 10 to 30 percent greater overall energy efficiency than atmospheric fluidized bed combustion (AFBC), While bench-scale tools and analytical procedures for characterizing fuels for AFBC have been recently demonstrated, no such tools have been reliably demonstrated for PFBC. This report summarizes the results of joint research collaboration between ORNL and B&W that has been directed at modifying the previously developed AFBC fuel characterization procedures to be applicable for mild-gasification chars and PFBC conditions. The specific objectives were to: (1) characterize the combustion reactivity of a selected set of candidate mild- gasification chars at PFB conditions; (2) compare the measured char characteristics with those of more conventional PFBC fuels; (3) modify an AFBC computer code previously developed by B&W and ORNL for the Electric Power Research Institute (EPRI) to predict PFBC performance; and (4) apply the modified code and measured char combustion characteristics to make performance predictions for the candidate chars relative to more conventional fuels.

Daw, C.S.

1995-10-01

327

Mild, Moderate, Severe Asthma: What Do Grades Mean?  

MedlinePLUS

... Grades Mean? Health Issues Listen Mild, Moderate, Severe Asthma: What Do Grades Mean? Article Body After confirming ... is when assessed at follow-up visits. Intermittent Asthma A child who has symptoms of wheezing and ...

328

Reifying Relevance in MCI Reifying Relevance in Mild Cognitive Impairment  

E-print Network

people with well defined dementia symptoms and multiple cognitive and functional impairments who's disease, construction, dementia, market forces, mild cognitive impairment We thank the reviewers degeneration and the physical and cognitive impairments that manifest in people affected by dementia disorders

Paris-Sud XI, Université de

329

Pink Eye: Usually Mild and Easy to Treat  

MedlinePLUS

... Submit What's this? Submit Button CDC Features Pink Eye: Usually Mild and Easy to Treat Language: English ... reddish color. What Are the Symptoms of Pink Eye? The signs and symptoms of pink eye may ...

330

Mild Cognitive Impairment and Progession to Dementia: New Findings  

MedlinePLUS

... C.S. Breitner Mild cognitive impairment and progression to dementia: New findings This information is current as of ... assessment_of_cognitive_dis Assessment of cognitive disorders/dementia entia http://www.neurology.org//cgi/collection/all_ ...

331

Separation and Purification Technology 25 (2001) 117126 Perovskite membranes by aqueous combustion synthesis  

E-print Network

Separation and Purification Technology 25 (2001) 117­126 Perovskite membranes by aqueous combustion. The aqueous combustion synthesis of LSC powders was investigated over a wide range of synthesis conditions, , the reaction can proceed in three different modes: Smoldering Combustion Synthesis (SCS), B0.7, with maximum

Mukasyan, Alexander

332

Hydrodynamics of aqueous humor outflow  

E-print Network

Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness resulting from elevated intraocular pressure caused by a pathologic increase in the resistance to aqueous humor outflow from the eye. Currently, ...

Overby, Darryl Ray, 1974-

2002-01-01

333

Comparison of treatments for mild secondary hyperparathyroidism in hemodialysis patients  

Microsoft Academic Search

Comparison of treatments for mild secondary hyperparathyroidism in hemodialysis patients.BackgroundIn the management of patients with mild secondary hyperparathyroidism, it is not known whether calcium supplementation alone is sufficient to correct abnormalities in bone and mineral metabolism or if calcitriol is needed in either physiologic oral or intravenous pharmacologic doses.MethodsThis was a 40-week prospective nonmasked trial of 52 patients [parathyroid hormone

Olafur S Indridason; L Darryl Quarles

2000-01-01

334

Viscosity-stabilized aqueous solutions  

SciTech Connect

Thiourea functions as a solution viscosity stabilizer in aqueous compositions comprising thiourea, nonionic polymers such as polyalkylene oxides and anionic surfactants such as petroleum sulfonates. The aqueous compositions are useful in connection with fluid-drive oil recovery processes, processes for drilling, completing, or working over wells, or the like processes in which a thickened fluid is injected into or brought into contact with a subterranean earth formation.

Wier, D. R.

1981-01-27

335

Coal desulfurization by aqueous chlorination  

NASA Technical Reports Server (NTRS)

A method of desulfurizing coal is described in which chlorine gas is bubbled through an aqueous slurry of coal at low temperature below 130 degrees C., and at ambient pressure. Chlorinolysis converts both inorganic and organic sulfur components of coal into water soluble compounds which enter the aqueous suspending media. The media is separated after chlorinolysis and the coal dechlorinated at a temperature of from 300 C to 500 C to form a non-caking, low-sulfur coal product.

Kalvinskas, J. J.; Vasilakos, N.; Corcoran, W. H.; Grohmann, K.; Rohatgi, N. K. (inventors)

1982-01-01

336

Experimental aqueous fluidization of ignimbrite  

NASA Astrophysics Data System (ADS)

Experiments were carried out on the aqueous fluidization behaviour of ignimbrite and the associated formation of fluid-escape pipes. The starting material was an ignimbrite that had been saturated with water under vacuum until 80±15% of the vesicles were filled. This aimed to reproduce water-logging conditions of a hot pyroclastic flow in contact with water, such as in the case of a lahar or of a pyroclastic flow entering the sea. The ignimbrite sample was fluidized by water at vertical velocities from 0.005 to 7 mm s -1 for durations of 10-180 min. Channelling occurred almost immediately, at even the lowest velocities, and pipe (channel) size increased slightly with time. The pipes had the form of elongated, upwardly flared funnels and grew downwards and sideways with time, even under decreasing flow conditions. Pipe nucleation and growth generated irregular pressure fluctuations in the sample, showing that the standard ? P- U plots commonly used in fluidization studies are not useful for coarse-grained, poorly sorted samples. Each pipe was stratified internally, with a basal layer rich in dense lithic and crystals, an intermediate layer rich in pumice, and an upper layer rich in fine components. As much as 30% of the initial sample mass was elutriated (including platy mica crystals) at the highest flow rates. At velocities exceeding 2 mm s -1 (duration of experiment: 10 min) single pipes grew and coalesced rapidly, either forming a single, large pipe or causing the entire sample to become segregation-layered. In natural water-lain sediments, pipes may form near the end of deposition and during compaction, because during transport shear may reduce channelling by water. We also measured the degree of crystal enrichment in pipes. We conclude that the presence of fluid-escape pipes in ignimbrite-like sediment cannot be used to infer a gas-fluidized origin of the deposit, since the geometry, granulometry, and degree of crystal enrichment in water-generated pipes are similar to those in pipes formed by gas under dry conditions.

Roche, O.; Druitt, T. H.; Cas, R. A. F.

2001-12-01

337

Motivation and neuropsychological test performance following mild head injury.  

PubMed

Effect of motivation on neuropsychological test performance in mild head injury was assessed. Motivation was measured using the Portland Digit RecognitionTest. Three groups were compared: (a) mildhead injury, financial incentives, good motivation; (b) mild head injury, financial incentives, poor motivation; (c) moderate/severe head injury, good motivation. The neuropsychological battery included measures of sensory function, motor function, attention, intelligence, abstract reasoning, and memory. Mild head injury well motivated patients performed significantly better than the other two groups on some tests. Mild head injury poorly motivated individuals and moderate-severe head injury patients were indistinguishable on many tests. Consistent with previous reports, tactile sensory (finger recognition and Fingertip Number Writing Perception) and recognition memory (Rey Auditory Verbal Learning) tasks were identified as clinically useful measures of poor motivation. On these measures mild head injury well motivated examinees performed no better than moderate-severe patients, with both groups superior to mild head injury poorly motivated examinees. Sensitivity and specificity data are reported. Our measures of tactile sensation and verbal recognition memory were more affected by motivation than by the severity of head injury. PMID:12916654

Binder, Laurence M; Kelly, Mark P; Villanueva, Michael R; Winslow, Michelle M

2003-05-01

338

A better mild traumatic brain injury model in the rat.  

PubMed

The primary pathology associated with mild -traumatic brain injury (TBI) is selective axonal injury, which may characterize the vast majority of blast-induced TBIs. Axonal injuries in cases of mild TBI have been considered to be the main factors responsible for the long-lasting memory or attentional impairment in affected subjects. Among these axonal injuries, recent attention has been focused on the cingulum bundle (CB). Furthermore, recent studies with diffusion tensor MR imaging have shown the presence of injuries of the CB in cases of mild TBI in humans. This study aimed to provide a better laboratory model of mild TBI.Sprague-Dawley rats were subjected to mild TBI using laser-induced shock waves (LISW) (sham, 0.5 J/cm(2), or 1.0 J/cm(2); n = 4 per group). Bodian-stained brain sections 14 days after LISW at 0.5 J/cm(2) or 1.0 J/cm(2) showed a decrease in the CB axonal density compared with the sham group, whereas there were no differences in the axonal density of the corpus callosum.The present study shows that this model is capable of reproducing the histological changes associated with mild TBI. PMID:23564112

Takeuchi, Satoru; Nawashiro, Hiroshi; Sato, Shunichi; Kawauchi, Satoko; Nagatani, Kimihiro; Kobayashi, Hiroaki; Otani, Naoki; Osada, Hideo; Wada, Kojiro; Shima, Katsuji

2013-01-01

339

Development of an advanced continuous mild gasification process for the production of coproducts: Task 4. 6, Technical and economic evaluation  

SciTech Connect

Morgantown Energy Technology Center (METC) of DOE has sponsored, and continues to sponsor, programs for the development of technology and market strategies which will lead to the commercialization of processes for the production of coproducts from mild gasification of coal. It has been recognized by DOE and industry that mild gasification is a promising technology with potential to economically convert coal into marketable products, thereby increasing domestic coal utilization. In this process, coal is devolatilized under non- oxidizing conditions at mild temperature (900--1100{degrees}F) and pressure (1--15psig). Condensation of the vapor will yield a liquid product that can be upgraded to a petroleum substitute, and the remaining gas can provide the fuel for the process. The residual char can be burned in a power plant. Thus, in a long-term national scenario, implementation of this process will result in significant decrease of imported oil and increase in coal utilization.

Hogsett, R.F.; Jha, M.C.

1991-12-01

340

All-aqueous multiphase microfluidics  

PubMed Central

Immiscible aqueous phases, formed by dissolving incompatible solutes in water, have been used in green chemical synthesis, molecular extraction and mimicking of cellular cytoplasm. Recently, a microfluidic approach has been introduced to generate all-aqueous emulsions and jets based on these immiscible aqueous phases; due to their biocompatibility, these all-aqueous structures have shown great promises as templates for fabricating biomaterials. The physico-chemical nature of interfaces between two immiscible aqueous phases leads to unique interfacial properties, such as an ultra-low interfacial tension. Strategies to manipulate components and direct their assembly at these interfaces needs to be explored. In this paper, we review progress on the topic over the past few years, with a focus on the fabrication and stabilization of all-aqueous structures in a multiphase microfluidic platform. We also discuss future efforts needed from the perspectives of fluidic physics, materials engineering, and biology for fulfilling potential applications ranging from materials fabrication to biomedical engineering. PMID:24454609

Song, Yang; Sauret, Alban; Cheung Shum, Ho

2013-01-01

341

Photochemistry of aqueous pyruvic acid  

PubMed Central

The study of organic chemistry in atmospheric aerosols and cloud formation is of interest in predictions of air quality and climate change. It is now known that aqueous phase chemistry is important in the formation of secondary organic aerosols. Here, the photoreactivity of pyruvic acid (PA; CH3COCOOH) is investigated in aqueous environments characteristic of atmospheric aerosols. PA is currently used as a proxy for ?-dicarbonyls in atmospheric models and is abundant in both the gas phase and the aqueous phase (atmospheric aerosols, fog, and clouds) in the atmosphere. The photoreactivity of PA in these phases, however, is very different, thus prompting the need for a mechanistic understanding of its reactivity in different environments. Although the decarboxylation of aqueous phase PA through UV excitation has been studied for many years, its mechanism and products remain controversial. In this work, photolysis of aqueous PA is shown to produce acetoin (CH3CHOHCOCH3), lactic acid (CH3CHOHCOOH), acetic acid (CH3COOH), and oligomers, illustrating the progression from a three-carbon molecule to four-carbon and even six-carbon molecules through direct photolysis. These products are detected using vibrational and electronic spectroscopy, NMR, and MS, and a reaction mechanism is presented accounting for all products detected. The relevance of sunlight-initiated PA chemistry in aqueous environments is then discussed in the context of processes occurring on atmospheric aerosols. PMID:23821751

Griffith, Elizabeth C.; Carpenter, Barry K.; Shoemaker, Richard K.; Vaida, Veronica

2013-01-01

342

Experimental measurements of U60 nanocluster stability in aqueous solution  

NASA Astrophysics Data System (ADS)

In this study, the aqueous behavior of isolated U60 nanoclusters (K16Li25[UO2(O2)OH]60)-19 was studied under several pH conditions and nanocluster concentrations to determine if the nanoclusters exhibit solid phase buffering behavior or if they exhibit behavior more like aqueous complexes. U60 is a cage cluster consisting of 60 (UO2)(O2)2(OH)2 uranyl polyhedral which share OH and O2 groups with their neighboring uranyl polyhedral, resulting in negatively charged cage clusters whose charge is at least partially offset by K+ and Li+ in the aqueous phase. Batch experiments to monitor nanocluster stability were conducted for 16 days at pH 7.5, 8.0 and 8.5 at nanocluster suspension concentrations of 1.4, 2.8 and 6.0 g/L. The aqueous concentrations of U, Li, and K, determined after 10 kDa molecular weight filtration, achieved steady-state with the nanoclusters within 24 h. The steady-state aqueous U, Li, and K concentrations were independent of solution pH, however they increased with increasing nanocluster concentration, indicating that the nanoclusters do not buffer the aqueous activities as a bulk solid phase would, but exhibit behavior that is more characteristic of dissolved aqueous complexes. The ion activity product (I.A.P.) value was calculated using two approaches: (1) treating the nanoclusters as a solid phase with an activity of one, and (2) treating the nanoclusters as aqueous complexes with a non-unit activity equal to their concentration in solution. The I.A.P. values that were calculated with non-unit activity for the nanoclusters exhibited significantly less variation as a function of nanocluster concentration compared to the I.A.P. values calculated with a nanocluster activity of one. The results yield a calculated log dissociation constant for the U60 nanoclusters of 9.2 + 0.2/-0.3 (1?). Our findings provide a better understanding of the thermodynamic stability and behavior of U60 nanoclusters in aqueous systems, and can be used to estimate the dissociation behavior of nanoclusters under a range of aqueous conditions.

Flynn, Shannon L.; Szymanowski, Jennifer E. S.; Gao, Yunyi; Liu, Tianbo; Burns, Peter C.; Fein, Jeremy B.

2015-05-01

343

Human aqueous humor exosomes.  

PubMed

Aqueous humor (AH) is a dynamic intraocular fluid that supports the vitality of tissues that regulate intraocular pressure. We recently discovered that extracellular nanovesicles called exosomes are a major constituent of AH. Exosomes function in extracellular communication and contain proteins and small RNA. Our goal was to characterize the physical properties of AH exosomes and their exosomal RNA (esRNA) content. We isolated exosomes from human AH collected during cataract surgery from five patients using serial ultracentrifugation. We measured the size and concentration of AH exosomes in solution using nanoparticle tracking analysis. We found a single population of vesicles having a mean size of 121 ± 11 nm in the unprocessed AH. Data show that centrifugation does not significantly affect the mean particle size (121 ± 11 nm versus 124 ± 21 nm), but does impact the final number of exosomes in solution (87% loss from the unprocessed AH; n = 5). We extracted esRNA from the pooled human AH samples using miRCURY RNA isolation kit from Exiqon. The quality of extracted esRNA was evaluated using Agilent Bioanalyzer 2100 and was used to generate a sequencing library for small RNA sequencing with Illumina MiSeq sequencer. More than 10 different miRNAs were identified; abundant species included miR-486-5p, miR-204, and miR-184. We found that the majority of extracellular vesicles in the AH were in the exosome size range, suggesting that miRNAs housed within exosomes may function in communication between AH inflow and outflow tissues. PMID:25619138

Dismuke, W Michael; Challa, Pratap; Navarro, Iris; Stamer, W Daniel; Liu, Yutao

2015-03-01

344

A Nationwide Survey of Mild Cognitive Impairment and Dementia, Including Very Mild Dementia, in Taiwan  

PubMed Central

An increasing population of dementia patients produces substantial societal impacts. We assessed the prevalence of mild cognitive impairment (MCI) and all-cause dementia, including very mild dementia (VMD), in Taiwan. In a nationwide population-based cross-sectional survey, participants were selected by computerized random sampling from all 19 Taiwan counties and were enrolled between December 2011 and March 2013. Cases were identified through in-person interviews based on the National Institute on Aging-Alzheimer’s Association clinical criteria. Demographic data and histories involving mental status and function in daily living were collected. The principal objective assessments were the Taiwanese Mental Status Examination and Clinical Dementia Rating. In all, 10,432 people aged 65 years or older (mean age 76.2±6.7, 52.3% women) were interviewed. The age-adjusted prevalence of all-cause dementia was 8.04% (95% CI 7.47–8.61), including a 3.25% (95% CI 2.89–3.61) prevalence of VMD; that of MCI was 18.76% (95% CI 17.91–19.61). Women had a higher prevalence than men of both all-cause dementia (9.71% vs. 6.36%) and MCI (21.63% vs. 15.57%). MCI affects a considerable portion of the population aged 65 and above in Taiwan. The inclusion of VMD yields dementia prevalence rates higher than those previously reported from Taiwan. Old age, female gender, and a low educational level are significant associated factors. PMID:24940604

Sun, Yu; Lee, Huey-Jane; Yang, Shu-Chien; Chen, Ta-Fu; Lin, Ker-Neng; Lin, Chung-Chih; Wang, Pei-Ning; Tang, Li-Yu; Chiu, Ming-Jang

2014-01-01

345

Oxidation of aqueous phenol by ozone and peroxidase  

Microsoft Academic Search

Aqueous phenol was ozonated for the first time at pH over 12. Results obtained under conditions favoring rapid generation of radicals completely eliminated the possibility deduced from the absorption theory that the indirect radical reaction might be one of the reaction pathways. Meanwhile, it was found in this study that the apparent first-order rate constant of phenol ozonation decreased logarithmically

Jiangning Wu; Klaas Rudy; Josef Spark

2000-01-01

346

Fenton chemistry at aqueous interfaces  

PubMed Central

In a fundamental process throughout nature, reduced iron unleashes the oxidative power of hydrogen peroxide into reactive intermediates. However, notwithstanding much work, the mechanism by which Fe2+ catalyzes H2O2 oxidations and the identity of the participating intermediates remain controversial. Here we report the prompt formation of O=FeIVCl3? and chloride-bridged di-iron O=FeIV·Cl·FeIICl4? and O=FeIV·Cl·FeIIICl5? ferryl species, in addition to FeIIICl4?, on the surface of aqueous FeCl2 microjets exposed to gaseous H2O2 or O3 beams for <50 ?s. The unambiguous identification of such species in situ via online electrospray mass spectrometry let us investigate their individual dependences on Fe2+, H2O2, O3, and H+ concentrations, and their responses to tert-butanol (an ·OH scavenger) and DMSO (an O-atom acceptor) cosolutes. We found that (i) mass spectra are not affected by excess tert-butanol, i.e., the detected species are primary products whose formation does not involve ·OH radicals, and (ii) the di-iron ferryls, but not O=FeIVCl3?, can be fully quenched by DMSO under present conditions. We infer that interfacial Fe(H2O)n2+ ions react with H2O2 and O3 >103 times faster than Fe(H2O)62+ in bulk water via a process that favors inner-sphere two-electron O-atom over outer-sphere one-electron transfers. The higher reactivity of di-iron ferryls vs. O=FeIVCl3? as O-atom donors implicates the electronic coupling of mixed-valence iron centers in the weakening of the FeIV–O bond in poly-iron ferryl species. PMID:24379389

Enami, Shinichi; Sakamoto, Yosuke; Colussi, Agustín J.

2014-01-01

347

Fenton chemistry at aqueous interfaces.  

PubMed

In a fundamental process throughout nature, reduced iron unleashes the oxidative power of hydrogen peroxide into reactive intermediates. However, notwithstanding much work, the mechanism by which Fe(2+) catalyzes H2O2 oxidations and the identity of the participating intermediates remain controversial. Here we report the prompt formation of O=Fe(IV)Cl3(-) and chloride-bridged di-iron O=Fe(IV) · Cl · Fe(II)Cl4(-) and O=Fe(IV) · Cl · Fe(III)Cl5(-) ferryl species, in addition to Fe(III)Cl4(-), on the surface of aqueous FeCl2 microjets exposed to gaseous H2O2 or O3 beams for <50 ?s. The unambiguous identification of such species in situ via online electrospray mass spectrometry let us investigate their individual dependences on Fe(2+), H2O2, O3, and H(+) concentrations, and their responses to tert-butanol (an · OH scavenger) and DMSO (an O-atom acceptor) cosolutes. We found that (i) mass spectra are not affected by excess tert-butanol, i.e., the detected species are primary products whose formation does not involve · OH radicals, and (ii) the di-iron ferryls, but not O=Fe(IV)Cl3(-), can be fully quenched by DMSO under present conditions. We infer that interfacial Fe(H2O)n(2+) ions react with H2O2 and O3 >10(3) times faster than Fe(H2O)6(2+) in bulk water via a process that favors inner-sphere two-electron O-atom over outer-sphere one-electron transfers. The higher reactivity of di-iron ferryls vs. O=Fe(IV)Cl3(-) as O-atom donors implicates the electronic coupling of mixed-valence iron centers in the weakening of the Fe(IV)-O bond in poly-iron ferryl species. PMID:24379389

Enami, Shinichi; Sakamoto, Yosuke; Colussi, Agustín J

2014-01-14

348

Role of hard second phases in the mild oxidational wear mechanism of high-speed steel-based materials  

Microsoft Academic Search

In the case of dry unlubricated wear of metals, an oxidational wear mechanism can be established under certain conditions, with oxide films being developed on the sliding surface which markedly influence the friction and wear behaviour. For high-speed steel-based materials containing various hard second phases, an a-Fe2O3 film is formed during pin-on-disc testing (under mild conditions of load and sliding

M. Vardavoulias

1994-01-01

349

Application of maghemite nanoparticles as sorbents for the removal of Cu(II), Mn(II) and U(VI) ions from aqueous solution in acid mine drainage conditions  

NASA Astrophysics Data System (ADS)

The adsorptive removal of Cu(II), Mn(II) and U(VI) by maghemite nanoparticles (NPs) was investigated under acid mine drainage (AMD) conditions to assess NP potential for remediating AMD-contaminated water. The effects of time, NP and metal concentration, as well as manganese and sulphate ions were quantified at pH 3. Adsorption of all three ions was rapid, and equilibrium was attained in 5 min or less. 56 % of Cu, 53 % of Mn and 49 % of U were adsorbed. In addition, adsorption efficiencies were enhanced by ?10 % in the presence of manganese and sulphate ions, although Cu sorption was reduced in 1:2 Cu-to-Mn solutions. Adsorption also increased with pH: 86 % Cu, 62 % Mn and 77 % U were removed from solution at pH 9 and increasing initial metal concentrations. Increasing NP concentrations did not, however, always increase metal removal. Kinetics data were best described by a pseudo-second-order model, implying chemisorption, while isotherm data were better fitted by the Freundlich model. Metal removal by NPs was then tested in AMD-contaminated surface and ground water. Removal efficiencies of up to 46 % for Cu and 54 % for Mn in surface water and 8 % for Cu and 50 % for Mn in ground water were achieved, confirming that maghemite NPs can be applied for the removal of these ions from AMD-contaminated waters. Notably, whereas sulphates may increase adsorption efficiencies, high Mn concentrations in AMD will likely inhibit Cu sorption.

Etale, Anita; Tutu, Hlanganani; Drake, Deanne C.

2014-06-01

350

ENCOAL Mild Coal Gasification Demonstration Project. Annual report, October 1993--September 1994  

SciTech Connect

ENCOAL Corporation, a wholly-owned subsidiary of SMC Mining Company (formerly Shell Mining Company, now owned by Zeigler Coal Holding Company), has completed the construction and start-up of a mild gasification demonstration plant at Triton Coal Company`s Buckskin Mine near Gillette, Wyoming. The process, using Liquids From Coal (LFC) technology developed by SMC and SGI International, utilizes low-sulfur Powder River Basin coal to produce two new fuels, Process Derived Fuel (PDF) and Coal Derived Liquids (CDL). The LFC technology uses a mild pyrolysis or mild gasification process which involves heating the coal under carefully controlled conditions. The process causes chemical changes in the feed coal in contrast to conventional drying, which leads only to physical changes. Wet subbituminous coal contains considerable water, and conventional drying processes physically remove some of this moisture, causing the heating value to increase. The deeper the coal is physically dried, the higher the heating value and the more the pore structure permanently collapses, preventing resorption of moisture. However, deeply dried Powder River Basin coals exhibit significant stability problems when dried by conventional thermal processes. The LFC process overcomes these stability problems by thermally altering the solid to create PDF and CDL. Several of the major objectives of the ENCOAL Project have now been achieved. The LFC Technology has been essentially demonstrated. Significant quantities of specification CDL have been produced from Buckskin coal. Plant operation in a production mode with respectable availability (approaching 90%) has been demonstrated.

NONE

1995-03-01

351

Industrial market assessment of the products of mild gasification: Final report  

SciTech Connect

The goal of this study is to determine the best available conditions, in terms of market volumes and prices, for the products from a mild gasification facility. A process feasibility study will then have to determine the cost of building and operating a facility to make those products. The study is presented as a summary of the options available to a coal producer for creating added product value. For this reason, three specific coal mines owned by AMAX Inc. were chosen, and the options were analyzed from the viewpoint of increasing the total revenue derived from those coals. No specific mild gasification, or mild devolatilization technology was assumed during the assessment. The analysis considers only product prices, volumes, and specifications. It does not assign any intangible value or national benefit to substituting coal for oil or to producing a cleaner fuel. Although it would be desirable to conceive of a product slate which would be immune from energy price fluctuations, such a goal is probably unattainable and no particular emphasis was placed on it. 76 figs., 75 tabs.

Sinor, J.E.

1988-01-01

352

Mild hypothermia for hemispheric cerebral infarction after evacuation of an acute subdural hematoma in an infant.  

PubMed

The use of mild hypothermia to treat hemispheric infarction after evacuation of an acute subdural hematoma in an infant is reported. The patient, a 2-year-old boy, presented with a deteriorating level of consciousness after a fall from a tree. Computed tomography (CT) scan revealed an acute subdural hematoma on the right side with marked midline shift, and emergency evacuation of the hematoma was performed. The postoperative course was uneventful until the patient's intracranial pressure (ICP) rose and his condition deteriorated 3 days after surgery. CT scan revealed a hemispheric infarction on the injured side. Mild hypothermia was induced to control the ICP and protect the brain. While the hypothermia was effective in lowering the elevated ICP, it failed to arrest progression of the infarction. The patient was discharged with mild disability 2 months after the injury. No serious complications occurred during or after the hypothermia. Our experience indicates that hypothermia can be a useful procedure for controlling the ICP in children with severe traumatic brain injury including acute subdural hematoma, although its capability to protect the brain from severe, progressive ischemia appears to be limited. PMID:11981630

Inamasu, Joji; Ichikizaki, Kiyoshi; Matsumoto, Shinji; Nakamura, Yoshiki; Saito, Ryoichi; Horiguchi, Takashi; Kanai, Ryuichi

2002-04-01

353

ATP induces mild hypothermia in rats but has a strikingly detrimental impact on focal cerebral ischemia.  

PubMed

Ischemic stroke is a devastating condition lacking effective therapies. A promising approach to attenuate ischemic injury is mild hypothermia. Recent studies show that adenosine nucleotides can induce hypothermia in mice. The purpose of the present study was to test the hypothesis that adenosine 5'-triphosphate (ATP) induces mild hypothermia in rats and reduces ischemic brain injury. We found that intraperitoneal injections of ATP decreased core body temperature in a dose-dependent manner; the dose appropriate for mild hypothermia was 2 g/kg. When ATP-induced hypothermia was applied to stroke induced by middle cerebral artery occlusion, however, a neuroprotective effect was not observed. Instead, the infarct volume grew even larger in ATP-treated rats. This was accompanied by an increased rate of seizure events, hemorrhagic transformation, and higher mortality. Continuous monitoring of physiologic parameters revealed that ATP reduced heartbeat rate and blood pressure. ATP also increased blood glucose, accompanied by severe acidosis and hypocalcemia. Western blotting showed that ATP decreased levels of both phospho-Akt and total-Akt in the cortex. Our results reveal that, despite inducing hypothermia, ATP is not appropriate for protecting the brain against stroke. Instead, we show for the first time that ATP treatment is associated with exaggerated ischemic outcomes and dangerous systemic side effects. PMID:23072747

Zhang, Meijuan; Li, Wenjin; Niu, Guangming; Leak, Rehana K; Chen, Jun; Zhang, Feng

2013-01-01

354

DEVELOPMENT OF A CO2 SEQUESTRATION MODULE BY INTEGRATING MINERAL ACTIVATION AND AQUEOUS CARBONATION  

SciTech Connect

Mineral carbonation is a promising concept for permanent CO{sub 2} sequestration due to the vast natural abundance of the raw minerals, the permanent storage of CO{sub 2} in solid form as carbonates, and the overall reaction being exothermic. However, the primary drawback to mineral carbonation is the reaction kinetics. To accelerate the reaction, aqueous carbonation processes are preferred, where the minerals are firstly dissolved in solution. In aqueous carbonation, the key step is the dissolution rate of the mineral, where the mineral dissolution reaction is likely to be surface controlled. In order to accelerate the dissolution process, the serpentine can be ground to very fine particle size (<37 {micro}m), but this is a very energy intensive process. Alternatively, magnesium could be chemically extracted in aqueous solution. Phase I showed that chemical surface activation helps to dissolve the magnesium from the serpentine minerals (particle size {approx}100 {micro}m), and furthermore, the carbonation reaction can be conducted under mild conditions (20 C and 650 psig) compared to previous studies that required >185 C, >1850 psig and <37 {micro}m particle size. Phase I also showed that over 70% of the magnesium can be extracted at ambient temperature leaving amorphous SiO{sub 2} with surface areas {approx} 330m{sup 2}/g. The overall objective of Phase 2 of this research program is to optimize the active carbonation process developed in Phase I in order to design an integrated CO{sub 2} sequestration module. During the current reporting period, Task 1 ''Mineral activation'' was initiated and focused on a parametric study to optimize the operation conditions for the mineral activation, where serpentine and sulfuric acid were reacted, as following the results from Phase 1. Several experimental factors were outlined as having a potential influence on the mineral activation. This study has focused to date on the effects of varying the acid concentration, particle size, and the reaction time. The reaction yields and the characterization of the reaction products by ICP/AES, TGA, and BET analyses were used to describe the influence of each of the experimental variables. The reaction yield was as high as 48% with a 5M acid concentration, with lower values directly corresponding to lower acid concentrations. ICP/AES results are indicative of the selective dissolution of magnesium with reaction yields. Significant improvements in the removal of moisture, as observed from TGA studies, as well as in the dissolution can be realized with the comminution of particles to a D{sub 50} less than 125 {micro}m. A minimum threshold value of 3M concentration of sulfuric acid was determined to exist in terms of the removal of moisture from serpentine. Contrary to expected, the reaction time, within this design of experiments, has been shown to be insignificant. Potentially coupled with this unexpected result are low BET surface areas of the treated serpentine. These results are issues of further consideration to be addressed under the carbonation studies. The remaining results are as expected, including the dissolution of magnesium, which is to be utilized within the carbonation unit. Phase 1 studies have shown that carbonation reactions could be carried out under a milder regime through the implementation of NaOH titration with the magnesium solution. The optimization of acid concentration, particle size, and reaction temperature will ultimately be determined according to the carbonation efficiencies. Therefore and according to the planned project schedule, research efforts are moving into Task 2 ''Aqueous carbonation'' as the redesign of the reactor unit is nearly completed.

M. Mercedes Maroto-Valer; John M. Andresen; George Alexander

2004-11-15

355

Dissolution of K-feldspar at CO2-saturated conditions  

NASA Astrophysics Data System (ADS)

Underground storage of carbon dioxide on a very large scale is widely considered to be an essential part of any strategy to reduce greenhouse gas emissions to the atmosphere. Aquifers in deep sedimentary basins have been identified as suitable targets for geological carbon dioxide storage, especially aquifers located in sandstone host rock. This has led to renewed interest in studying the interaction between sandstone minerals and aqueous fluids, as there is a paucity of data for CO2-containing systems at relevant conditions. In an attempt to improve data coverage for important silicate minerals, we have measured the dissolution kinetics of K-feldspar in CO2-saturated fluids over a range of temperatures. K-feldspar fragments were hand-picked from a larger sample, crushed to a narrow size range and cleaned. The grains were reacted with water in batch-type reactors at temperatures from 20°C to 200°C and pressures up to 200 bar, and the dissolution was followed by periodic withdrawal of aliquots of solution. The mineral grains were allowed to react with pure water for a number of weeks before injection of CO2 into the system. Excess CO2 was provided to ensure CO2 saturation in the experimental systems. While the reaction time before injection was not long enough to attain complete equilibrium, it did considerably lower the degree of undersaturation with respect to K-feldspar and helped highlight the effect of CO2 injection into a rock-equilibrated aqueous fluid. At all temperatures studied, injection of CO2 resulted in a rapid increase in the soluble concentrations of K and Si (and also Na from a plagioclase component). The dissolution then reached apparent steady state conditions after a few days, with observed dissolution rates in the range of 1E-9 to 1E-12 mol/m2/s over the temperature range studied. The CO2-saturated solutions maintained mildly acidic conditions throughout the experiments and the observed rates therefore fall roughly between rates measured in strong acids and rates measured in unbuffered aqueous solution. However, our rates are slightly slower than those predicted based solely on pH, a fact that we preliminary attribute to our choice to pre-react the mineral and fluid before the CO2 injection. The exact cause of this effect is still under investigation.

Rosenqvist, Jörgen; Kilpatrick, Andrew D.; Yardley, Bruce W. D.; Rochelle, Christopher A.

2014-05-01

356

Electroresponsive Aqueous Silk Protein As “Smart” Mechanical Damping Fluid  

PubMed Central

Here we demonstrate the effectiveness of an electroresponsive aqueous silk protein polymer as a smart mechanical damping fluid. The aqueous polymer solution is liquid under ambient conditions, but is reversibly converted into a gel once subjected to an electric current, thereby increasing or decreasing in viscosity. This nontoxic, biodegradable, reversible, edible fluid also bonds to device surfaces and is demonstrated to reduce friction and provide striking wear protection. The friction and mechanical damping coefficients are shown to modulate with electric field exposure time and/or intensity. Damping coefficient can be modulated electrically, and then preserved without continued power for longer time scales than conventional “smart” fluid dampers. PMID:24750065

2015-01-01

357

Heat transfer of aqueous suspensions of carbon nanotubes (CNT nanofluids)  

Microsoft Academic Search

This paper is mainly concerned about the heat transfer behaviour of aqueous suspensions of multi-walled carbon nanotubes (CNT nanofluids) flowing through a horizontal tube. Significant enhancement of the convective heat transfer is observed and the enhancement depends on the flow conditions (Reynolds number, Re), CNT concentration and the pH, with the effect of pH smallest. Given other conditions, the enhancement

Yulong Ding; Hajar Alias; Dongsheng Wen; Richard A. Williams

2006-01-01

358

Converting sugars to sugar alcohols by aqueous phase catalytic hydrogenation  

DOEpatents

The present invention provides a method of converting sugars to their corresponding sugar alcohols by catalytic hydrogenation in the aqueous phase. It has been found that surprisingly superior results can be obtained by utilizing a relatively low temperature (less than 120.degree. C.), selected hydrogenation conditions, and a hydrothermally stable catalyst. These results include excellent sugar conversion to the desired sugar alcohol, in combination with long life under hydrothermal conditions.

Elliott, Douglas C. (Richland, WA); Werpy, Todd A. (West Richland, WA); Wang, Yong (Richland, WA); Frye, Jr., John G. (Richland, WA)

2003-05-27

359

Subgrid scale modelling for MILD combustion  

E-print Network

both Reynolds Averaged Navier– Stokes (RANS) [12–17] and Large Eddy Simula- tion (LES) [18] approaches. The computational results from these studies compare reasonably to experimental results, suggesting that the EDC model is satisfactory. However, its... Þ=jrT jmax, and dF of MIFE are 1.66 m/s, 1.29 mm and 0.22 mm respectively. The DNS domain is cubic of size Lx #5; Ly#5; Lz ¼ 10#5; 10#5; 10 mm3 with inflow and non- reflecting outflow boundaries specified using Navier–Stokes characteristic boundary condition...

Minamoto, Y.; Swaminathan, N.

2014-07-27

360

SONOCHEMICAL DECHLORINATION OF HAZARDOUS WASTES IN AQUEOUS SYSTEMS. (R825513C004)  

EPA Science Inventory

Physical processes resulting from ultrasonication of aqueous solutions and suspensions produce extreme conditions that can affect the chemistry of dissolved and suspended chemicals. The purpose of this work was to explore the use of sonochemistry in treating chlorinated chemic...

361

Modeling a set of heavy oil aqueous pyrolysis experiments  

SciTech Connect

Aqueous pyrolysis experiments, aimed at mild upgrading of heavy oil, were analyzed using various computer models. The primary focus of the analysis was the pressure history of the closed autoclave reactors obtained during the heating of the autoclave to desired reaction temperatures. The models used included a means of estimating nonideal behavior of primary components with regard to vapor liquid equilibrium. The modeling indicated that to match measured autoclave pressures, which often were well below the vapor pressure of water at a given temperature, it was necessary to incorporate water solubility in the oil phase and an activity model for the water in the oil phase which reduced its fugacity below that of pure water. Analysis also indicated that the mild to moderate upgrading of the oil which occurred in experiments that reached 400{degrees}C or more using a FE(III) 2-ethylhexanoate could be reasonably well characterized by a simple first order rate constant of 1.7xl0{sup 8} exp(-20000/T)s{sup {minus}l}. Both gas production and API gravity increase were characterized by this rate constant. Models were able to match the complete pressure history of the autoclave experiments fairly well with relatively simple equilibria models. However, a consistent lower than measured buildup in pressure at peak temperatures was noted in the model calculations. This phenomena was tentatively attributed to an increase in the amount of water entering the vapor phase caused by a change in its activity in the oil phase.

Thorsness, C.B.; Reynolds, J.G.

1996-11-01

362

Aqueous Alteration of Basalts: Earth, Moon, and Mars  

NASA Technical Reports Server (NTRS)

The geologic processes responsible for aqueous alteration of basaltic materials on Mars are modeled beginning with our knowledge of analog processes on Earth, i.e., characterization of elemental and mineralogical compositions of terrestrial environments where the alteration and weathering pathways related to aqueous activity are better understood. A key ingredient to successful modeling of aqueous processes on Mars is identification of phases that have formed by those processes. The purpose of this paper is to describe what is known about the elemental and mineralogical composition of aqueous alteration products of basaltic materials on Mars and their implications for specific aqueous environments based upon our knowledge of terrestrial systems. Although aqueous alteration has not occurred on the Moon, it is crucial to understand the behaviors of basaltic materials exposed to aqueous environments in support of human exploration to the Moon over the next two decades. Several methods or indices have been used to evaluate the extent of basalt alteration/weathering based upon measurements made at Mars by the Mars Exploration Rover (MER) Moessbauer and Alpha Particle X-Ray Spectrometers. The Mineralogical Alteration Index (MAI) is based upon the percentage of total Fe (Fe(sub T)) present as Fe(3+) in alteration products (Morris et al., 2006). A second method is the evaluation of compositional trends to determine the extent to which elements have been removed from the host rock and the likely formation of secondary phases (Nesbitt and Young, 1992; Ming et al., 2007). Most of the basalts that have been altered by aqueous processes at the two MER landing sites in Gusev crater and on Meridiani Planum have not undergone extensive leaching in an open hydrolytic system with the exception of an outcrop in the Columbia Hills. The extent of aqueous alteration however ranges from relatively unaltered to pervasively altered materials. Several experimental studies have focused upon the aqueous alteration of lunar materials and simulants (e.g., Keller and Huang, 1971; Eick et al., 1996). Lunar basalts are void of water and highly reduced, hence, these materials are initially very reactive when exposed to water under oxidizing conditions.

Ming, Douglas W.

2007-01-01

363

Preparation of novel magnetic chitosan nanoparticle and its application for removal of humic acid from aqueous solution  

NASA Astrophysics Data System (ADS)

A novel magnetic chitosan nanoparticle (MCNP) with a BET surface area of 108.32 m2/g was prepared using a time and energy saving method at mild condition. MCNP exhibits an excellent ability to adsorb humic acid (HA) from aqueous solution in a wide range of initial HA concentration. The rate of HA adsorption is rapid with more than 50% of HA can be adsorbed in initial 10 min, and the equilibrium state can be reached in 60 min. The adsorption kinetics data fits well to the pseudo-second-order model, and the adsorption process is transport-limited at low initial HA concentration and attachment-limited at high initial HA concentration. The Langmuir isotherm model fits the equilibrium data better than the Freundlich isotherm model, indicating that the adsorption of HA onto MCNP is a monolayer adsorption. Based on the Langmuir isotherm model, the maximum adsorption capacity of HA is 32.6 mg/g at 25 °C. Thermodynamic parameters presents that the adsorption of HA onto MCNP is spontaneous and endothermic in nature. The mechanism for the adsorption of HA onto MCNP involves electrostatic interaction and hydrogen bonding. Regeneration studies indicate that MCNP can be recyclable for a long term. All the experimental results suggest that MCNP is a promising adsorbent for treating water that is contaminated with humic acid.

Dong, Changlong; Chen, Wei; Liu, Cheng

2014-02-01

364

Activity restriction in mild COPD: a challenging clinical problem  

PubMed Central

Dyspnea, exercise intolerance, and activity restriction are already apparent in mild chronic obstructive pulmonary disease (COPD). However, patients may not seek medical help until their symptoms become troublesome and persistent and significant respiratory impairment is already present; as a consequence, further sustained physical inactivity may contribute to disease progression. Ventilatory and gas exchange impairment, cardiac dysfunction, and skeletal muscle dysfunction are present to a variable degree in patients with mild COPD, and collectively may contribute to exercise intolerance. As such, there is increasing interest in evaluating exercise tolerance and physical activity in symptomatic patients with COPD who have mild airway obstruction, as defined by spirometry. Simple questionnaires, eg, the modified British Medical Research Council dyspnea scale and the COPD Assessment Test, or exercise tests, eg, the 6-minute or incremental and endurance exercise tests can be used to assess exercise performance and functional status. Pedometers and accelerometers are used to evaluate physical activity, and endurance tests (cycle or treadmill) using constant work rate protocols are used to assess the effects of interventions such as pulmonary rehabilitation. In addition, alternative outcome measurements, such as tests of small airway dysfunction and laboratory-based exercise tests, are used to measure the extent of physiological impairment in individuals with persistent dyspnea. This review describes the mechanisms of exercise limitation in patients with mild COPD and the interventions that can potentially improve exercise tolerance. Also discussed are the benefits of pulmonary rehabilitation and the potential role of pharmacologic treatment in symptomatic patients with mild COPD. PMID:24940054

O’Donnell, Denis E; Gebke, Kevin B

2014-01-01

365

Mild Lafora disease: clinical, neurophysiologic, and genetic findings.  

PubMed

We report clinical, neurophysiologic, and genetic features of an Italian series of patients with Lafora disease (LD) to identify distinguishing features of those with a slowly progressive course. Twenty-three patients with LD (17 female; 6 male) were recruited. Mean age (± SD) at the disease onset was 14.5 ± 3.9 years and mean follow-up duration was 13.2 ± 8.0 years. NHLRC1 mutations were detected in 18 patients; EPM2A mutations were identified in 5. Patients who maintained >10 years gait autonomy were labeled as "mild" and were compared with the remaining LD patients with a typical course. Six of 23 patients were mild and presented significantly delay in the age at onset, lower neurologic disability score at 4 years after the onset, less severe seizure phenotype, lower probability of showing both photoparoxysmal response on electroencephalography (EEG) and giant somatosensory evoked potentials, as compared to patients with typical LD. However, in both mild and typical LD patients, EEG showed disorganization of background activity and frequent epileptiform abnormalities. Mild LD patients had NHLRC1 mutations and five of six carried homozygous or compound heterozygous D146N mutation. This mutation was found in none of the patients with typical LD. The occurrence of specific NHLRC1 mutations in patients with mild LD should be taken into account in clinical practice for appropriate management and counseling. PMID:25270369

Ferlazzo, Edoardo; Canafoglia, Laura; Michelucci, Roberto; Gambardella, Antonio; Gennaro, Elena; Pasini, Elena; Riguzzi, Patrizia; Plasmati, Rosaria; Volpi, Lilia; Labate, Angelo; Gasparini, Sara; Villani, Flavio; Casazza, Marina; Viri, Maurizio; Zara, Federico; Minassian, Berge A; Turnbull, Julie; Serratosa, Jose M; Guerrero-López, Rosa; Franceschetti, Silvana; Aguglia, Umberto

2014-12-01

366

Functional disorganization of small-world brain networks in mild Alzheimer's Disease and amnestic Mild Cognitive Impairment: an EEG study using Relative Wavelet Entropy (RWE)  

PubMed Central

Previous neuroscientific findings have linked Alzheimer's Disease (AD) with less efficient information processing and brain network disorganization. However, pathological alterations of the brain networks during the preclinical phase of amnestic Mild Cognitive Impairment (aMCI) remain largely unknown. The present study aimed at comparing patterns of the detection of functional disorganization in MCI relative to Mild Dementia (MD). Participants consisted of 23 cognitively healthy adults, 17 aMCI and 24 mild AD patients who underwent electroencephalographic (EEG) data acquisition during a resting-state condition. Synchronization analysis through the Orthogonal Discrete Wavelet Transform (ODWT), and directional brain network analysis were applied on the EEG data. This computational model was performed for networks that have the same number of edges (N = 500, 600, 700, 800 edges) across all participants and groups (fixed density values). All groups exhibited a small-world (SW) brain architecture. However, we found a significant reduction in the SW brain architecture in both aMCI and MD patients relative to the group of Healthy controls. This functional disorganization was also correlated with the participant's generic cognitive status. The deterioration of the network's organization was caused mainly by deficient local information processing as quantified by the mean cluster coefficient value. Functional hubs were identified through the normalized betweenness centrality metric. Analysis of the local characteristics showed relative hub preservation even with statistically significant reduced strength. Compensatory phenomena were also evident through the formation of additional hubs on left frontal and parietal regions. Our results indicate a declined functional network organization even during the prodromal phase. Degeneration is evident even in the preclinical phase and coexists with transient network reorganization due to compensation. PMID:25206333

Frantzidis, Christos A.; Vivas, Ana B.; Tsolaki, Anthoula; Klados, Manousos A.; Tsolaki, Magda; Bamidis, Panagiotis D.

2014-01-01

367

A Study on the Aqueous Formation of Secondary Organic Aerosols  

NASA Astrophysics Data System (ADS)

The effect aerosols have on radiative forcing in the atmosphere is recognized as one of the largest uncertainties in the radiation budget. About 80% of organic aerosol mass in the atmosphere is estimated to be created though secondary processes. Recently, the aqueous formation of secondary organic aerosols (SOA) has become recognized as important when considering the source, transformation and radiative impacts of SOA. This work focuses on implementing a mechanism for aqueous SOA formation that can be used in atmospheric chemistry and models of all scales, from box to global. A box model containing a simplified chemical mechanism for the aqueous production of precursors of aqueous SOA (Myriokefalitakis et al. (2011) is coupled to gas-phase chemistry which uses the carbon bond mechanism (CBM) IV is presented. The model implements aqueous chemistry of soluble gases, both in-cloud and aerosol water, including organic compounds such as glyoxal and methylglyoxal, which have been shown as potentially significant sources for dissolved secondary organic aerosols. This mechanism implements aqueous phase mass transfer and molecular dissociation. The model's performance is evaluated against previous box model studies from the literature. A comparison is conducted between the detailed GAMMA model (McNeill et al., 2012), which is constrained with chamber experiments and the one developed here. The model output under different atmospheric conditions is explored and differences and sensitivities are assessed. The objective of this work is to create a robust framework for simulating aqueous phase formation of SOA and maximizing the computational efficiency of the model, while maintaining accuracy, in order to later use the exact mechanism in global climate simulations.

Sinclair, K.; Tsigaridis, K.

2013-12-01

368

Solubility Measurements of Crystalline NiO in Aqueous Solution as a Function of Temperature and pH  

Microsoft Academic Search

Results of solubility experiments involving crystalline nickel oxide (bunsenite) in aqueous solutions are reported as functions\\u000a of temperature (0 to 350?°C) and pH at pressures slightly exceeding (with one exception) saturation vapor pressure. These\\u000a experiments were carried out in either flow-through reactors or a hydrogen-electrode concentration cell for mildly acidic\\u000a to near neutral pH solutions. The results were treated successfully

Donald A. Palmer; Pascale Bénézeth; Caibin Xiao; David J. Wesolowski; Lawrence M. Anovitz

2011-01-01

369

Aqueous-phase source of formic acid in clouds  

NASA Technical Reports Server (NTRS)

The coupled gas- and aqueous-phase cloud chemistry of HCOOH were examined for controlling factors in the acidity of cloud and rainwater. Attention was given to the aqueous OH/HO2 system that yields an OH species that is highly reactive with other species, notably SO2 and the formaldehyde/formic acid complex. A numerical model was developed to simulate the cloud chemistry in the remote troposphere, with considerations given to CH4-CO-NO(x)-O3-H(x)O(y) system. It was determined that aqueous phase OH radicals can produce and destroy formic acid droplets in daylight conditions, as well as control formic acid levels in rainwater. It is sugested that the same types of reactions may be involved in the control of acetic acid and other organic acids.

Chameides, W. L.; Davis, D. D.

1983-01-01

370

NMR Studies on the Aqueous Phase Photochemical Degradation of TNT  

SciTech Connect

Aqueous phase photochemical degradation of 2,4,6-trinitrotoluene (TNT) is an important pathway in several environments, including washout lagoon soils, impact craters from partially detonated munitions that fill with rain or groundwater, and shallow marine environments containing unexploded munitions that have corroded. Knowledge of the degradation products is necessary for compliance issues on military firing ranges and formerly used defense sites. Previous laboratory studies have indicated that UV irradiation of aqueous TNT solutions results in a multicomponent product mixture, including polymerization compounds, that has been only partially resolved by mass spectrometric analyses. This study illustrates how a combination of solid and liquid state 1H, 13C, and 15N NMR spectroscopy, including two dimensional analyses, provides complementary information on the total product mixture from aqueous photolysis of TNT, and the effect of reaction conditions. Among the degradation products detected were amine, amide, azoxy, azo, and carboxylic acid compounds.

Thorn, Kevin A.; Cox, Larry G.

2008-04-06

371

Alcoholic extraction of vegetable oils. V. Pilot plant extraction of cottonseed by aqueous ethanol  

Microsoft Academic Search

Summary  Cottonseed flakes were extracted by aqueous ethanol in a countercurrent pilot plant unit to determine the effect of operating\\u000a variables and the optimum operating conditions.\\u000a \\u000a This investigation has shown that direct extraction of cottonseed, using aqueous ethanol as a solvent, is a feasible process\\u000a in the type of equipment developed previously in this laboratory. The optimum operating conditions for the

Rama Kanth Rao; Lionel K. Arnold

1958-01-01

372

Aqueous Corrosion Rates for Waste Package Materials  

SciTech Connect

The purpose of this analysis, as directed by ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]), is to compile applicable corrosion data from the literature (journal articles, engineering documents, materials handbooks, or standards, and national laboratory reports), evaluate the quality of these data, and use these to perform statistical analyses and distributions for aqueous corrosion rates of waste package materials. The purpose of this report is not to describe the performance of engineered barriers for the TSPA-LA. Instead, the analysis provides simple statistics on aqueous corrosion rates of steels and alloys. These rates are limited by various aqueous parameters such as temperature (up to 100 C), water type (i.e., fresh versus saline), and pH. Corrosion data of materials at pH extremes (below 4 and above 9) are not included in this analysis, as materials commonly display different corrosion behaviors under these conditions. The exception is highly corrosion-resistant materials (Inconel Alloys) for which rate data from corrosion tests at a pH of approximately 3 were included. The waste package materials investigated are those from the long and short 5-DHLW waste packages, 2-MCO/2-DHLW waste package, and the 21-PWR commercial waste package. This analysis also contains rate data for some of the materials present inside the fuel canisters for the following fuel types: U-Mo (Fermi U-10%Mo), MOX (FFTF), Thorium Carbide and Th/U Carbide (Fort Saint Vrain [FSVR]), Th/U Oxide (Shippingport LWBR), U-metal (N Reactor), Intact U-Oxide (Shippingport PWR, Commercial), aluminum-based, and U-Zr-H (TRIGA). Analysis of corrosion rates for Alloy 22, spent nuclear fuel, defense high level waste (DHLW) glass, and Titanium Grade 7 can be found in other analysis or model reports.

S. Arthur

2004-10-08

373

The effect of stress on the magnetization of mild steel at moderate field strengths  

SciTech Connect

Measurements are presented of the magnetization of mild steel, at field strengths between 100 A/m and 1200 A/m, for hysteretic and anhysteretic conditions. Magnetization was parallel or perpendicular to an applied uniaxial stress. The experimental results showed that tension parallel to the field or compression perpendicular to the field had relatively little effect on the flux density, but parallel compression or perpendicular tension reduced the flux density considerably. The theory presented predicts this symmetry, but it cannot account for other features of the measurements.

Langman, R.

1985-07-01

374

A mild, ferrocene-catalyzed C-H imidation of (hetero)arenes.  

PubMed

A simple method for direct C-H imidation is reported using a new perester-based self-immolating reagent and a base-metal catalyst. The succinimide products obtained can be easily deprotected in situ (if desired) to reveal the corresponding anilines directly. The scope of the reaction is broad, the conditions are extremely mild, and the reaction is tolerant of oxidizable and acid-labile functionality, multiple heteroatoms, and aryl iodides. Mechanistic studies indicate that ferrocene (Cp2Fe) plays the role of an electron shuttle in the decomposition of the perester reagent, delivering a succinimidyl radical ready to add to an aromatic system. PMID:24654983

Foo, Klement; Sella, Eran; Thomé, Isabelle; Eastgate, Martin D; Baran, Phil S

2014-04-01

375

The mildly non-linear regime of structure formation  

SciTech Connect

We present a simple physically motivated picture for the mildly non-linear regime of structure formation, which captures the effects of the bulk flows. We apply this picture to develop a method to significantly reduce the sample variance in cosmological N-body simulations at the scales relevant to the Baryon Acoustic Oscillations (BAO). The results presented in this paper will allow for a speed-up of an order of magnitude (or more) in the scanning of the cosmological parameter space using N-body simulations for studies which require a good handle of the mildly non-linear regime, such as those targeting the BAO. Using this physical picture we develop a simple formula, which allows for the rapid calculation of the mildly non-linear matter power spectrum to percent level accuracy, and for robust estimation of the BAO scale.

Tassev, Svetlin [Center for Astrophysics, Harvard University, 60 Garden St., Cambridge, MA 02138 (United States); Zaldarriaga, Matias, E-mail: stassev@cfa.harvard.edu, E-mail: matiasz@ias.edu [School of Natural Sciences, Institute for Advanced Study, Olden Lane, Princeton, NJ 08540 (United States)

2012-04-01

376

Johnson - Cook Strength Models for Mild and DP 590 Steels  

NASA Astrophysics Data System (ADS)

Automotive steels, Mild and Dual Phase590 (DP590) are characterized in tension at room temperature, using the quasi-static and split Hopkinson bar techniques at various strain rates ranging from ˜10-3/s to ˜1800/s. Tension stress-strain data for both the steels are analyzed to determine the Johnson-Cook Strength model constants, J-C strength model constants for mild steel are A=217 MPa, B = 234 MPa, n = 0.643 and C = 0.076 and for DP590 steel are A = 430 MPa, B = 824 MPa, n = 0.510 and C = 0.017. Higher value of strain rate sensitivity constant C for mild steel (0.076) compared to DP 590 (0.017) is also reflected in the stress- strain data at various strain rates.

Vedantam, K.; Bajaj, D.; Brar, N. S.; Hill, S.

2006-07-01

377

Mild Anemia and Pregnancy Outcome in a Swiss Collective  

PubMed Central

Background. Over half of all women in the world experience anemia during their pregnancy. Our aim was to investigate the relation between hemoglobin and iron status examined in second trimester and pregnancy outcome. Methods. In a prospective longitudinal study, 382 pregnant women were included. Blood samples were examined for hematological status and serum ferritin between 16 and 20 weeks and for hemoglobin before delivery. The adverse maternal and perinatal outcomes were determined. Regression analysis was performed to establish if anemia and low serum ferritin are risk factors for pregnancy complications. Results. There was no increase of complications in women with mild anemia and in women with depleted iron stores. The finding showed that mild iron deficiency anemia and depleted iron stores are not risk factors for adverse outcomes in iron supplemented women. Conclusions. Mild anemia and depleted iron stores detected early in pregnancy were not associated with adverse maternal and perinatal outcomes in iron supplemented women. PMID:25478229

Bencaiova, Gabriela; Breymann, Christian

2014-01-01

378

Non-aqueous primary cell  

NASA Astrophysics Data System (ADS)

This patent application relates to electrochemical cells and especially to high-energy, liquid cathode, non-aqueous lithium electrochemical cells free from highly toxic materials. A non-aqueous lithium electrochemical cell is described which includes a halocarbon cathode depolarizer which is 1,2-dichloroethane, 1.1,2-trichloroethane, 1,1,2,2-tetrachloroethane, 1,2-dichloro-1,1-difluoroethane or mixtures thereof and a cathode catalyst which is copper, rhodium, palladium, cobalt phthalocyanine, nickel phthalocyanine, iron phthalocyanine, a cobalt tetraaza-(14)-annulene, a nickel tetraaza-(14)-annulene, a iron tetraaza-(14)-annulene, a cobalt porphyrin, a nickel porphyrin, a iron porphyrin, or a mixture thereof.

James, S. D.; Smith, P. H.; Oneill, K. M.; Wilson, M. H.

1986-05-01

379

Immunoglobulins in human aqueous humour.  

PubMed Central

The immunoglobulin concentrations in human aqueous humour from 44 patients aged 35 to 85 years with cataracts were measured by a standard immunodiffusion method. IgG was found in all the samples (mean level 7-0 mg/100 ml. IgD, IgA or IgM could not be detected. There was no significant difference in IgG levels in aqueous humour between the two sexes, in different age groups, and in the different types of cataracts. PMID:403928

Sen, D. K.; Sarin, G. S.; Saha, K.

1977-01-01

380

Difference in determinants of caregiver burden between amnestic mild cognitive impairment and mild Alzheimer?s disease.  

PubMed

Care for the disabled elderly can be stressful and exhausting, especially in cases of dementia. There have been a number of studies on the dementia caregiver burden, but studies focusing on differences by stages of the disease are rare. The caregiver burden of 85 caregivers of patients with amnestic mild cognitive impairment (aMCI) and 106 caregivers of patients with mild Alzheimer?s disease (AD) was evaluated by the short version of the Japanese version of the Zarit Burden Interview (sZBI). The caregiver burden in mild AD was more severe than that in aMCI. In mild AD, the risk factors of caregiver burden were neurobehavioral symptoms and disturbances instrumental activities of daily living (IADL), whereas the risk factors in aMCI were neurobehavioral symptoms and memory dysfunction. The severity of dementing disease affects the caregiver burden, and somewhat different factors contribute to the burden at different stages. We should pay attention to different factors in evaluating and reducing the caregiver burden in aMCI and mild AD. PMID:25631688

Ikeda, Chikako; Terada, Seishi; Oshima, Etsuko; Hayashi, Satoshi; Okahisa, Yuko; Takaki, Manabu; Inagaki, Masatoshi; Yokota, Osamu; Uchitomi, Yosuke

2015-03-30

381

Cumulative effects of repetitive mild traumatic brain injury.  

PubMed

The majority of traumatic brain injuries (TBI) in the USA are mild in severity. Sports, particularly American football, and military experience are especially associated with repetitive, mild TBI (mTBI). The consequences of repetitive brain injury have garnered increasing scientific and public attention following reports of altered mood and behavior, as well as progressive neurological dysfunction many years after injury. This report provides an up-to-date review of the clinical, pathological, and pathophysiological changes associated with repetitive mTBI, and their potential for cumulative effects in certain individuals. PMID:24923392

Bailes, Julian E; Dashnaw, Matthew L; Petraglia, Anthony L; Turner, Ryan C

2014-01-01

382

Repeated mild injury causes cumulative damage to hippocampal cells.  

PubMed

An interesting hypothesis in the study of neurotrauma is that repeated traumatic brain injury may result in cumulative damage to cells of the brain. However, post-injury sequelae are difficult to address at the cellular level in vivo. Therefore, it is necessary to complement these studies with experiments conducted in vitro. In this report, the effects of single and repeated traumatic injury in vitro were investigated in cultured mouse hippocampal cells using a well characterized model of stretch-induced injury. Cell damage was assessed by the level of propidium iodide (PrI) uptake and retention of fluorescein diacetate (FDA). Uninjured control wells displayed minimal PrI uptake and high levels of FDA retention. Mild, moderate and severe levels of stretch caused increasing amounts of PrI uptake, respectively, when measured at 15 min and 24 h post-injury, indicating increased cellular damage with increasing amounts of stretch. For repeated injury studies, cultures received a second injury 1 h after the initial insult. Repeated mild injury caused a slight increase in PrI uptake compared with single injury at 15 min and 24 h post-injury, which was evident primarily in glial cells. However, the neurites of neurones in cultures that received repeated insults showed signs of damage that were not evident after a single mild injury. The release of neurone-specific enolase (NSE) and S-100beta protein, two common clinical markers of CNS damage, was also measured following the repeated injuries paradigm. When measured at 6 h post-injury, both NSE and S-100beta were found to be elevated after repeated mild injuries when compared with the single injury group. These results suggest that cells of the hippocampus may be susceptible to cumulative damage following repeated mild traumatic insults. Both glial cells and neurones appear to exhibit increased signs of damage after repetitive injury. To our knowledge, this study represents the first report on the effects of repeated mechanical insults on specific cells of the brain using an in vitro model system. The biochemical pathways of cellular degradation following repeated mild injuries may differ considerably from those that are activated by a single mild insult. Therefore, we hope to use this model in order to investigate secondary pathways of cellular damage after repeated mild traumatic injury, and as a rapid and economical means of screening possibilities for treatment strategies, including pharmaceutical intervention. PMID:12429597

Slemmer, Jennifer E; Matser, Erik J T; De Zeeuw, Chris I; Weber, John T

2002-12-01

383

Models of globular proteins in aqueous solutions  

NASA Astrophysics Data System (ADS)

Protein crystallization is a continuing area of research. Currently, there is no universal theory for the conditions required to crystallize proteins. A better understanding of protein crystallization will be helpful in determining protein structure and preventing and treating certain diseases. In this thesis, we will extend the understanding of globular proteins in aqueous solutions by analyzing various models for protein interactions. Experiments have shown that the liquid-liquid phase separation curves for lysozyme in solution with salt depend on salt type and salt concentration. We analyze a simple square well model for this system whose well depth depends on salt type and salt concentration, to determine the phase coexistence surfaces from experimental data. The surfaces, calculated from a single Monte Carlo simulation and a simple scaling argument, are shown as a function of temperature, salt concentration and protein concentration for two typical salts. Urate Oxidase from Asperigillus flavus is a protein used for studying the effects of polymers on the crystallization of large proteins. Experiments have determined some aspects of the phase diagram. We use Monte Carlo techniques and perturbation theory to predict the phase diagram for a model of urate oxidase in solution with PEG. The model used includes an electrostatic interaction, van der Waals attraction, and a polymerinduced depletion interaction. The results agree quantitatively with experiments. Anisotropy plays a role in globular protein interactions, including the formation of hemoglobin fibers in sickle cell disease. Also, the solvent conditions have been shown to play a strong role in the phase behavior of some aqueous protein solutions. Each has previously been treated separately in theoretical studies. Here we propose and analyze a simple, combined model that treats both anisotropy and solvent effects. We find that this model qualitatively explains some phase behavior, including the existence of a lower critical point under certain conditions.

Wentzel, Nathaniel James

384

Aqueous alteration of the Nakhla meteorite  

NASA Technical Reports Server (NTRS)

Interior samples of three different Nakhla specimens contain an iron-rich silicate 'rust' (which includes a tentatively identified smectite), Ca-carbonate (probably calcite), Ca-sulfate (possibly gypsum or bassanite), Mg-sulfate (possibly epsomite or kieserite), and NaCl (halite); the total abundance of these phases is estimated as less than 0.01 weight percent of the bulk meteorite. Rust veins are truncated and decrepitated by fusion crust and are preserved as faulted segments in partially healed olivine crystals, indicating that the rust is preterrestrial in origin. Because Ca-carbonate and Ca-sulfate are intergrown with the rust, they are also indicated to be of preterrestrial origin. Similar textural evidence regarding origins of the NaCl and Mg-sulfate is lacking. Impure and poorly crystallized sulfates and halides on the fusion crust of the meteorite suggest leaching of interior (preterrestrial) salts from the interior after Makhla arrived on earth, but coincidental addition of these same salts by terrestrial contamination cannot be exluded. At least the clay-like silicate 'rust', Ca-carbonate, and Ca-sulfate were formed by precipitation from water-based solutions on the Nakhla parent planet, although temperature and pressure conditions of aqueous precipitation are unconstrained by currently available data. It is possible that aqueous alteration on the parent body was responsible for the previously observed disturbance of the Rb-Sr geochronometer in Nakhla at or near 1.3 Ga.

Gooding, James L.; Zolensky, Michael E.; Wentworth, Susan J.

1991-01-01

385

Corrosion problems with aqueous coolants, final report  

SciTech Connect

The results of a one year program to characterize corrosion of solar collector alloys in aqueous heat-transfer media are summarized. The program involved a literature review and a laboratory investigation of corrosion in uninhibited solutions. It consisted of three separate tasks, as follows: review of the state-of-the-art of solar collector corrosion processes; study of corrosion in multimetallic systems; and determination of interaction between different waters and chemical antifreeze additives. Task 1 involved a comprehensive review of published literature concerning corrosion under solar collector operating conditions. The reivew also incorporated data from related technologies, specifically, from research performed on automotive cooling systems, cooling towers, and heat exchangers. Task 2 consisted of determining the corrosion behavior of candidate alloys of construction for solar collectors in different types of aqueous coolants containing various concentrations of corrosive ionic species. Task 3 involved measuring the degradation rates of glycol-based heat-transfer media, and also evaluating the effects of degradation on the corrosion behavior of metallic collector materials.

Diegle, R B; Beavers, J A; Clifford, J E

1980-04-11

386

Development of an advanced continuous mild gasification process for the production of coproducts. Task 4, Mild gasification tests  

SciTech Connect

Western Research Institute (WRI) teamed with the AMAX Research and Development Center and Riley Stoker Corporation on Development of an Advanced, Continuous Mild-Gasification Process for the Production of Coproducts under contract DE-AC21-87MC24268 with the Morgantown Energy Technology of the US Department of Energy. The strategy for this project is to produce electrode binder pitch and diesel fuel blending stock by mild gasification of Wyodak coal. The char is upgraded to produce anode-grade carbon, carbon black, and activated carbon. This report describes results of mild-gasification tests conducted by WRI. Char upgrading tests conducted by AMAX will be described in a separate report.

Merriam, N.W.; Cha, C.Y.; Kang, T.W.; Vaillancourt, M.B.

1990-12-01

387

Reduced Sympathetic Response to Head-Up Tilt in Subjects with Mild Cognitive Impairment or Mild Alzheimer's Dementia  

PubMed Central

Background Hemodynamic control was compared in patients with mild cognitive impairment (MCI) or mild Alzheimer's dementia (AD) as well as in healthy elderly subjects. Methods Noninvasive, continuous hemodynamic recordings were obtained from 14 patients and 48 controls during supine rest (tilt of 30 and 70°). Cardiac output, end-diastolic volume, total peripheral resistance, heart rate variability (HRV), systolic blood pressure variability (SBPV), and baroreceptor sensitivity were calculated. Results At 70° tilt, the HRV indices differed significantly, with higher high-frequency (HF) variability as well as lower low-frequency (LF) variability and LF/HF ratios in the patients. The patients had significantly lower SBPV in the LF range at 30° tilt. Conclusions The results indicate a poorer sympathetic response to orthostatic stress in MCI and mild AD. © 2015 S. Karger AG, Basel

Mellingsæter, Marte Rognstad; Wyller, Torgeir Bruun; Ranhoff, Anette Hylen; Bogdanovic, Nenad; Wyller, Vegard Bruun

2015-01-01

388

Effects of aqueous soil-biochar extracts on representative aquatic organisms: a first evaluation  

NASA Astrophysics Data System (ADS)

Increasing considerations of biochar application to soils has raised concerns over implications to overall environmental quality, associated to some of its components. The heterogeneity of biochar composition is well documented in relation to co-existing chemical species, as a function of feedstock and pyrolysis conditions. Robust ecotoxicology studies with focus on bioavailable biochar components in soil remain scarce and have only started to emerge. This pilot study provides an insight into the potential ecotoxicological effects of aqueous extracts of biochar-amended soil on a range of aquatic organisms (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna), using a battery of standard aquatic bioassays. The use of such bioassays in environmental risk assessment of soil-biochar elutriates is here suggested as a crucial tool, to bridge the gap between biochar's 'inert' fraction in soil and that bioavailable to edaphic organisms. Aqueous extracts were obtained from LUFA 2.2 standard soil (control) and following amendment with pine biochar at common field application rates (80 ton ha-1). Acute exposure to soil-biochar extracts allowed estimating toxicity parameters and developing dose-response curves for all tested species, through well-established methodological guidelines. The bioluminescent bacteria V. fischeri showed negligible EC50 (effect concentration corresponding to 50% luminescence decline) values in the MICROTOX® basic test (independent of exposure time), suggesting low susceptibility to soil-biochar extracts. Mild toxicity was also observed in the microalgae P. subcapitata growth inhibition test, where significant deleterious effects on growth rate occurred only at the highest (100%) extract concentration (p<0.05). Among the tested species, toxicity was generally more marked in the primary consumer D. magna, with an EC50 (effect concentration corresponding to 50% immobilisation) of 2.95%. The pattern and extent of observed effects were species-specific, thus the use of multiple test species, as part of an integrative ecotoxicological approach, has shown relevance. Preliminary results suggest potential trophic unbalances in aquatic systems, as a result of exposure to leachates from biochar-amended soils.

Bastos, A. C.; Abrantes, N.; Prodana, M.; Verheijen, F.; Keizer, J. J.; Soares, A. M. V. M.; Loureiro, S.

2012-04-01

389

Aqueous Processing Material Accountability Instrumentation  

SciTech Connect

Increased use of nuclear power will require new facilities. The U.S. has not built a new spent nuclear fuel reprocessing facility for decades. Reprocessing facilities must maintain accountability of their nuclear fuel. This survey report on the techniques used in current aqueous reprocessing facilities, and provides references to source materials to assist facility design efforts.

Robert Bean

2007-09-01

390

UPDATE: GERMINATION IN AQUEOUS SOLUTIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Germination in aqueous solutions is a reasonable predictor of seedlot field emergence of sugarbeet. We used this approach to clone a gene that appears to be responsible for enhanced emergence. We have followed these experiments, previously done only at room temperature (23 C), to look at germinatio...

391

CAPROLACTAM RECOVERY FROM AQUEOUS MANUFACTURING STREAMS  

EPA Science Inventory

Pilot-plant runs using plant samples have demonstrated the feasibility of a novel extraction process for caprolactam recovery from dilute aqueous solutions. Following extraction, aqueous effluent caprolactam concentrations as low as 30 ppm were obtained. Further effluent treatmen...

392

Photorelease of phosphates: Mild methods for protecting phosphate derivatives  

PubMed Central

Summary We have developed a new photoremovable protecting group for caging phosphates in the near UV. Diethyl 2-(4-hydroxy-1-naphthyl)-2-oxoethyl phosphate (14a) quantitatively releases diethyl phosphate upon irradiation in aq MeOH or aq MeCN at 350 nm, with quantum efficiencies ranging from 0.021 to 0.067 depending on the solvent composition. The deprotection reactions originate from the triplet excited state, are robust under ambient conditions and can be carried on to 100% conversion. Similar results were found with diethyl 2-(4-methoxy-1-naphthyl)-2-oxoethyl phosphate (14b), although it was significantly less efficient compared with 14a. A key step in the deprotection reaction in aq MeOH is considered to be a Favorskii rearrangement of the naphthyl ketone motif of 14a,b to naphthylacetate esters 25 and 26. Disruption of the ketone-naphthyl ring conjugation significantly shifts the photoproduct absorption away from the effective incident wavelength for decaging of 14, driving the reaction to completion. The Favorskii rearrangement does not occur in aqueous acetonitrile although diethyl phosphate is released. Other substitution patterns on the naphthyl or quinolin-5-yl core, such as the 2,6-naphthyl 10 or 8-benzyloxyquinolin-5-yl 24 platforms, also do not rearrange by aryl migration upon photolysis and, therefore, do not proceed to completion. The 2,6-naphthyl ketone platform instead remains intact whereas the quinolin-5-yl ketone fragments to a much more complex, highly absorbing reaction mixture that competes for the incident light. PMID:25246963

Senadheera, Sanjeewa N; Yousef, Abraham L

2014-01-01

393

Sonochemical dechlorination of hazardous wastes in aqueous systems  

SciTech Connect

Physical processes resulting from ultrasonication of aqueous solutions and suspensions produce extreme conditions that can affect the chemistry of dissolved and suspended chemicals. The purpose of this work was to explore the use of sonochemistry in treating chlorinated chemicals in water. The compounds examined for susceptibility to aqueous sonochemical transformation were chlorpyrifos, 3,3{prime},4,4{prime}-tetrachloroazoxybenzene, 2-chlorobiphenyl, 2,4,8-trichlorodibenzofuran, lindane (hexachlorocyclohexane, {gamma}-isomer), hexachlorobenzene, aldrin, and a complex mixture of chlorinated olefins, paraffins, and aromatics from a Louisiana Superfund Site. It was fond that many chemicals were dechlorinated and/or otherwise transformed by sonochemical treatment under minimal conditions. Evidence for sonochemical transformation and dechlorination of the target chemicals and mixtures was obtained from controlled experiments measuring (1) increases in titratable chloride from sonochemical treatment, (2) decreases in pH, (3) changes in aqueous phase UV/visible absorption spectra, (4) changes in aqueous electrochemistry, and (5) generation of sonolysis products and/or decreases in target compounds vs appropriate control in internally standardized GC-MS analysis of extracts.

Catallo, W.J.; Junk, T. [Louisiana State Univ., Baton Rouge, LA (United States)] [Louisiana State Univ., Baton Rouge, LA (United States)

1995-12-31

394

Sporostatic and Sporocidal Properties of Aqueous Formaldehyde  

PubMed Central

Aqueous formaldehyde is shown to exert both sporostatic and sporocidal effects on Bacillus subtilis spores. The sporostatic effect is a result of the reversible inhibition of spore germination occasioned by aqueous formaldehyde; the sporocidal effect is due to temperature-dependent inactivation of these spores in aqueous formaldehyde. The physicochemical state of formaldehyde in solution provides a framework with which to interpret both the sporostatic and sporocidal properties of aqueous formaldehyde. PMID:4623282

Trujillo, Ralph; David, Thomas J.

1972-01-01

395

Novel concept development of an internal recirculation catalyst for mild gasification: Progress report, June 1-August 31, 1987  

SciTech Connect

Results of 14 separate tests to investigate (1) the lack of CsOH volatility seen in the pyrolysis-gas chromatography tests using CsOH-catalyzed coals conducted during the previous quarter, and (2) the effect of H/sub 2/S in the carrier gas on products of mild gasification/devolatilization of Illinois No. 6 coal, are discussed herein. Three tests were conducted in a thermal gravimetric analyzer (TGA) to: (1) determine the volatility of pure cesium hydroxide in steam as a function of temperature and, (2) the effect of coal char on the volatility of CsOH under mild gasification conditions. The results of the cesium volatilization tests show that, as expected, pure cesium hydroxide volatilizes rapidly in steam at temperatures used in mild gasification. The addition of CsOH to coal char and activated carbon enhances their reactivity in steam at mild gasification temperatures while its addition to coal results in the production of more gas and less oils and tar than uncatalyzed coal under the same conditions. However, the results of these tests also indicate that CsOH and rendering it unsuitable as an internal recirculation catalyst. Three tests were also conducted this quarter PY-GC-FID to determine the effect of H/sub 2/S in the carrier gas on the products of mild gasification/devolatilization of Illinois No. 6 coal. The results of the coal pyrolysis tests with H/sub 2/S and He show no significant difference in the C/sub 6/-C/sub 44/ liquid production and distribution, and only a small (5 weight percent) increase in the overall coal conversion using H/sub 2/S. 2 refs., 11 figs., 12 tabs.

Solka, B.H.; Hill, A.H.; Feldkirchner, H.L.; Babu, S.P.

1987-10-01

396

Congenital Syndromes and Mildly Handicapped Students: Implications for Special Educators.  

ERIC Educational Resources Information Center

Many learning disabilities or cases of mild retardation are due to medically diagnosable, congenital syndromes, such as fetal alcohol syndrome, sex chromosome abnormalities, multiple anomaly syndromes, phenylketonuria, and Tourette Syndrome. These syndromes are discussed, and suggestions are given for special education management. (Author/JDD)

Smith, Sandra M.

1989-01-01

397

Social behavior in mild cognitive impairment and early dementia  

Microsoft Academic Search

Social behavioral abnormalities are commonly seen in the later stages of dementia. However, there has been only limited empirical study of social functioning in the earlier stages of the disease, or in individuals diagnosed with mild cognitive impairment (MCI). The aim of the present study was to test whether these clinical groups show more socially inappropriate and prejudicial behavior relative

Julie D. Henry; William von Hippel; Claire Thompson; Polly Pulford; Perminder Sachdev; Henry Brodaty

2012-01-01

398

PET of Brain Amyloid and Tau in Mild Cognitive Impairment  

Microsoft Academic Search

Abstract Background Amyloid senile plaques and tau neurofibrillary tangles are neuropathological hall- marks of Alzheimer’s disease that accumulate,in the cortical regions of the brain in persons with mild cognitive impairment,who are at risk for Alzheimer’s disease.

Gary W. Small; Vladimir Kepe; Linda M. Ercoli; Prabha Siddarth; Susan Y. Bookheimer; Karen J. Miller; Helen Lavretsky; Alison C. Burggren; Greg M. Cole; Harry V. Vinters; Paul M. Thompson; S.-C. Huang; N. Satyamurthy; Michael E. Phelps; Jorge R. Barrio

2006-01-01

399

Functional Curriculum Models for Secondary Students with Mild Mental Impairment  

ERIC Educational Resources Information Center

This paper analyzed 10 commercially available functional curriculum models designed for secondary students with mild-to-moderate mental impairment. The models were examined with respect to the inclusion of functional curriculum components, the domains and subdomains of adulthood, the materials identified by the model to be used to deliver the…

Bouck, Emily C.

2009-01-01

400

Constructivist mathematics education for students with mild mental retardation  

Microsoft Academic Search

This study examined the effects of a constructivist mathematics intervention for students with mild mental retardation, as compared to direct instruction, which is often recommended for these children. A total of 69 students from elementary schools for special education participated in the study, which focused on multiplication learning. They received one of two kinds of mathematics intervention, guided or directed

Evelyn H. Kroesbergen; Johannes E. H. Van Luit

2005-01-01

401

Limiting Your Legal Liability--Caring for Mildly Ill Children.  

ERIC Educational Resources Information Center

Identifies some of the major issues associated with liability and exposure in caring for mildly ill children and highlights some recommended strategies for minimizing liability. Examines issues related to preventing the spread of disease, administering medications, emergency medical authorization, and confidentiality. (KB)

Cohen, Abby J.

1998-01-01

402

Numerical Magnitude Processing in Children with Mild Intellectual Disabilities  

ERIC Educational Resources Information Center

The present study investigated numerical magnitude processing in children with mild intellectual disabilities (MID) and examined whether these children have difficulties in the ability to represent numerical magnitudes and/or difficulties in the ability to access numerical magnitudes from formal symbols. We compared the performance of 26 children…

Brankaer, Carmen; Ghesquiere, Pol; De Smedt, Bert

2011-01-01

403

Working Memory in Mild Alzheimer's Disease and Early Parkinson's Disease  

E-print Network

Working Memory in Mild Alzheimer's Disease and Early Parkinson's Disease Elizabeth A. Kensinger of Technology Alzheimer's disease (AD) and Parkinson's disease (PD) impair working memory (WM). It is unclear an expanding interest in how neurological diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD

Corkin, Suzanne

404

Mild cognitive impairment: hope for stability, plan for progression.  

PubMed

Mild cognitive impairment (MCI) is a common heterogeneous syndrome that in some cases is transitional between normal age-related cognitive changes and dementia. Identifying it early may lead to prompt recognition of reversible causes and allows for timely future planning. This article describes definitions of MCI and its evaluation, differential diagnosis, and management. PMID:23208990

Patel, Birju B; Holland, N Wilson

2012-12-01

405

The Gross Motor Skills of Children with Mild Learning Disabilities  

ERIC Educational Resources Information Center

Many international studies have examined the gross motor skills of children studying in special schools while local studies of such nature are limited. This study investigated the gross motor skills of children with Mild Learning Disabilities (MLD; n = 14, M age = 8.93 years, SD = 0.33) with the Test of Gross Motor Development-2 (TGMD-2, Ulrich,…

Nonis, Karen P.; Jernice, Tan Sing Yee

2014-01-01

406

Vegetarian diet in mild hypertension: a randomised controlled trial  

Microsoft Academic Search

In a randomised crossover trial 58 subjects aged 30-64 with mild untreated hypertension were allocated either to a control group eating a typical omnivorous diet or to one of two groups eating an ovolactovegetarian diet for one of two six week periods. A fall in systolic blood pressure of the order of 5 mm Hg occurred during the vegetarian diet

B M Margetts; L J Beilin; R Vandongen; B K Armstrong

1986-01-01

407

Mild traumatic brain injury and Postconcussion Syndrome: a neuropsychological perspective  

Microsoft Academic Search

Symptoms of mild traumatic brain injury typically resolve within days or weeks. However, a significant group of patients may report symptoms of Post-concussional Syndrome (PCS) weeks, months and years postinjury. This review presents an overview of the pathogenesis, diagnosis and treatment options for PCS. The authors review the evidence for factors that may predict such symptoms. At early phases, there

W Huw Williams; Seb Potter; Helen Ryland

2010-01-01

408

Nonassertiveness, dysfunctional attitudes, and mild levels of depression  

Microsoft Academic Search

The present study addressed the possible relationships between nonassertion, dysfunctional attitudes, and mild levels of depression. Participants in this study completed two self-report measures of assertion (the Conflict Resolution Scale and the Assertion Inventory), along with the Beck Depression Inventory and the Dysfunctional Attitudes Scale (DAS). In accord with past research, it was found that assertion deficits increased significantly with

L. JOAN OLINGER; BRIAN F. SHAW; NICHOLAS A. KUIPER

1987-01-01

409

Care Partner Responses to the Onset of Mild Cognitive Impairment  

ERIC Educational Resources Information Center

Purpose: We examined characteristics, responses, and psychological well-being of care partners who support and assist older adults recently diagnosed with mild cognitive impairment (MCI). Design and Methods: Based on a sample of 106 care partners of community residents diagnosed with MCI at memory clinics, we conducted face-to-face interviews…

Blieszner, Rosemary; Roberto, Karen A.

2010-01-01

410

Multiple Cognitive Deficits in Amnestic Mild Cognitive Impairment  

Microsoft Academic Search

Objective: To determine if more widespread cognitive deficits are present in a narrowly defined group of patients with the amnestic form of mild cognitive impairment (MCI). Methods: From a larger sample of patients clinically diagnosed as meeting the criteria of Petersen et al. for amnestic MCI, we selected 22 subjects who had Clinical Dementia Rating scores of zero on all

Joel H. Kramer; Adam Nelson; Julene K. Johnson; Kristine Yaffe; Shenly Glenn; Howard J. Rosen; Bruce L. Miller

2006-01-01

411

Documenting the Developmental Origins of Mild Mental Retardation  

Microsoft Academic Search

Evidence of the developmental origins (by age 18) of mild mental retardation (MMR) in adults is discussed. Multiple sources of evidence are reviewed and evaluated. The availability and uses of evidence from the developmental period are cited in the context of evaluations for Social Security income (SSI) eligibility and death penalty appeals due to MMR. The use of records from

Daniel J. Reschly

2009-01-01

412

Adaptive chaos: Mild disorder may help contain major disease  

E-print Network

of adaptive chaos for sleep diseases, e.g., enuresis, and other potentially life threatening disorders be examples of how a disorder can treat a disease. Sleep medicine offers multiple examples of sleep disordersAdaptive chaos: Mild disorder may help contain major disease Alexander Golbin a , Alexander

Umantsev, Alexander

413

“Good Old Days” Bias Following Mild Traumatic Brain Injury  

Microsoft Academic Search

A small percentage of people with a mild traumatic brain injury (MTBI) report persistent symptoms and problems many months or even years following injury. Preliminary research suggests that people who sustain an injury often underestimate past problems (i.e., “good old days” bias), which can impact their perceived level of current problems and recovery. The purpose of this study was to

Grant L. Iverson; Rael T. Lange; Brian L. Brooks; V. Lynn Ashton Rennison

2010-01-01

414

Use of Lithium Hexafluoroisopropoxide as a Mild Base for  

E-print Network

Use of Lithium Hexafluoroisopropoxide as a Mild Base for Horner-Wadsworth-Emmons Olefination The weak base lithium 1,1,1,3,3,3-hexafluoroisopropoxide (LiHFI) is shown to be highly effective of base-sensitive substrates, leading to the discovery that lithium 1,1,1,3,3,3-hexafluoroisopropoxide (Li

415

Human Capability, Mild Perfectionism and Thickened Educational Praxis  

ERIC Educational Resources Information Center

This paper argues for a mild perfectionism in applying Amartya Sen's capability approach for an education transformative of student agency and well-being. Key to the paper is the significance of education as a process of being and becoming in the future, and education's fundamental objective of a positively changed human being. The capability…

Walker, Melanie

2008-01-01

416

Task 2: Mild gasification technology development process research unit tests using slipstream sampling, February 1988--March 1990  

SciTech Connect

Under USDOE sponsorship, a project team consisting of the Institute of Gas Technology (IGT), Peabody Holding Company, Inc., and Bechtel Group is developing a process for the mild gasification of coal in a 100-pound/hour capacity isothermal process research unit (PRU) at IGT in Chicago. The IGT process is capable of converting bituminous coals to value-added co-products that can open new markets for the US coal industry. The conceptual IGT mild gasification process incorporates an integrated fluidized-/entrained-bed reactor supplying heat indirectly by a combination of char and gas recycle. The use of mild operating conditions (1000{degree} to 1300{degree}F), low pressures (<50 psig), and continuous operation in closed reactors, combined with the sale of value-added co-products, offer an environmentally sound and economical approach to advanced coal utilization. The PRU consists of an 8-inch-ID {times} 8-foot-long fluidized-bed reactor closely coupled to a 4-inch-ID {times} 13-foot-long entrained-bed reactor. The PRU test results have demonstrated process performance, including the effect of coal type and temperature on mild gasification co-product yields and their properties. The fates of the heteroatoms have also been analyzed. 9 refs., 16 figs., 41 tabs.

Knight, R.A.; Gissy, J.; Onischak, M.; Babu, S.P.; Wootten, J.M.; Duthie, R.G.

1990-07-01

417

Pulse Radiolysis of Aqueous Thiocyanate Solution  

SciTech Connect

The pulse radiolysis of N2O saturated aqueous solutions of KSCN was studied under neutral pH conditions. The observed optical absorption spectrum of the SCN• radical in solution is more complex than previously reported, but it is in good agreement with that measured in the gas phase. Kinetic traces at 330 nm and 472 nm corresponding to SCN• and (SCN)2•¯, respectively, were fit using a Monte Carlo simulation kinetic model. The rate coefficient for the oxidation of SCN¯ ions by OH radicals, an important reaction used in competition kinetics measurements, was found to be 1.4 ± 0.1 x 1010 M-1 s-1, about 30 % higher than the normally accepted value. A detailed discussion of the reaction mechanism is presented.

Milosavljevic, Bratoljub H.; LaVerne, Jay A.

2005-01-13

418

Toxicity of calcium salts to aqueous microorganisms  

SciTech Connect

This article investigates the toxicity of calcium to aqueous microogranisms by means of a procedure developed by VNII VODGEO (All-Union Scientific-Research Institute of Water Supply, Sewer Systems, Hydrotechnical Facilities, and Engineering Hydrogeology), with certain changes in the preparation of the culture water. Proposes that with this method, calcium toxicity can be determined for groups of microorganisms that are among the most important in biochemical wastewater treatment and self-purification of water bodies (saprophytes, phase I and II nitrifiers). Finds that calcium in the form of the hydroxide and chloride is nontoxic under the following conditions: for protozoa in concentrations up to 2 g/liter, for saprophytic bacteria up to 3 g/liter, for phase I nitrifiers up to 1 g/liter, and for phase II nitrifiers up to 0.1 g/liter.

Lakhina, K.G.; Dolganova, A.V.; Yakobi, L.K.

1983-03-01

419

Management of women with mild and moderate cervical dyskaryosis.  

PubMed Central

OBJECTIVE--To compare the outcomes in women with mild and moderate dyskaryosis after increasing periods of surveillance and thereby to define a rational protocol for managing such women. DESIGN--Prospective study with randomisation of women to one of four treatment groups, each with a different period of surveillance; one group in which the women were given immediate treatment and three other groups in which the women were under surveillance for six, 12, and 24 months. SETTING--A dedicated colposcopy clinic in Aberdeen, Scotland. SUBJECTS--902 women who presented with a mildly or moderately dyskaryotic smear for the first time. INTERVENTIONS--Cytological and colposcopic examinations at intervals of six months until the allocated period of surveillance was completed, at which time biopsy was performed. Women with severe dyskaryosis were withdrawn from surveillance and a biopsy was performed. MAIN OUTCOME MEASURES--The histological findings after punch biopsy or large loop excision of the transformation zone, and the trends in cytological appearances of serial cervical smears. RESULTS--793 women completed the study. In all, 769 women had an adequate final smear, of which 197 were normal cytologically, 328 were still mildly or moderately dyskaryotic, and 244 were severely dyskaryotic. Seventeen of the 67 (25%) women with one repeat smear showing non-dyskaryosis had cervical intraepithelial neoplasia grade III compared with only one of the 31 (3%) women with no dyskaryosis in four repeat cervical smears (P < 0.0001). None of the women had invasive cancer. Of 158 women whose index smear showed mild dyskaryosis and who were allocated to the group under surveillance for two years, only 40 had not defaulted or still had dyskaryotic smears by the end of the two years. CONCLUSION--Cytological surveillance, although safe, is not an efficient strategy for managing women with mildly abnormal smears. Women with any degree of dyskaryosis in a smear should be referred for colposcopy. PMID:8019248

Flannelly, G.; Anderson, D.; Kitchener, H. C.; Mann, E. M.; Campbell, M.; Fisher, P.; Walker, F.; Templeton, A. A.

1994-01-01

420

Development of an advanced, continuous mild gasification process for the production of co-products  

SciTech Connect

Research continued on the production of co-products from mild gasification. This quarter, 10 mild gasification tests were conducted in the 8-inch-I.D. process research unit (PRU). Modifications to the PRU were made during this period to improve mixing and to overcome the caking tendency of the Illinois No. 6 coal. Six of the tests resulted in satisfactory operation at steady conditions for 2.25 to 3.25 hours. Samples of char, gas, water, and organic condensables were collected over a one-hour period from each of these successful tests and analyzed. The effects of process temperature over the range of 1025{degree} to 1390{degree} was studied during this quarter. Compositional effects on the oils and tars observed with increased temperature are increased light oil content, decreased pitch content, decreased oxygen content, increased nitrogen and sulfur content, and increasing aromaticity. Char upgrading studies continued during the quarter. Briquettes made in a laboratory press, using either a pitch binder or Illinois No. 6 coal to provide an in-situ binder, were calcined and tested for diametral compression strength. Char was also subjected to steam activation at a variety of conditions to determine the potential for use as a low-cost absorbent for water treatment. 2 refs., 15 figs., 11 tabs.

Knight, R.A.; Gissy, J.; Onischak, M.; Kline, S.; Babu, S.P.

1990-01-01

421

Study of Corrosion Behavior of Arc Sprayed Aluminum Coating on Mild Steel  

NASA Astrophysics Data System (ADS)

In the current study, aluminum coating was deposited on mild steel by arc spraying. A well-adhered coating with low level of porosity was successfully obtained. To evaluate the corrosion behavior of the coating, electrochemical impedance spectroscopy (EIS) and polarization tests in 3.5% NaCl solution were carried out. The as-coated samples were also subjected to a 1500-h salt spray assay. Polarization tests indicated that the corrosion current density of the aluminum coating is more than that of bulk aluminum. This could be due to the penetration of the electrolyte through open pores, resulted in the acceleration of aluminum corrosion. EIS measurements showed that the corrosion performance of the coating is improved during a long time immersion and exposure to saline mist. This could be due to plugging of pores by corrosion products which hinder further penetration of the electrolyte through the coating. The results obtained indicated that twin wire arc sprayed aluminum coatings can reliably protect steel structures against corrosion in chloride-containing aqueous solutions.

Abedi Esfahani, Erfan; Salimijazi, Hamidreza; Golozar, Mohamad A.; Mostaghimi, Javad; Pershin, Larry

2012-12-01

422

Pain rating schema: three distinct subgroups of individuals emerge when rating mild, moderate, and severe pain  

PubMed Central

Background While the validity of pain assessment has been well documented, the underlying schema (ie, organized, preconceived ideas) of how individuals interpret numerical pain ratings is not well understood. This study’s objectives were to examine numerical pain intensity ratings, from (0 to 10 cm on the visual analog scale [VAS]) across multiple severities of commonly experienced acute pain conditions to determine whether the ratings differed between these pain conditions and/or between individuals. Methods A community sample (N=365, 66% female) rated their anticipated pain intensity (VAS) for threshold, mild, moderate, severe, and tolerance level, using several common pain conditions: headache, toothache, joint injury, delayed-onset muscle soreness, burns, and “general pain.” Results Cluster analysis revealed three subgroups of individuals, suggesting three types of underlying pain rating schema: 1) Low Rating subgroup (low VAS pain intensity ratings across all the pain severity categories); 2) Low/High Rating subgroup (low VAS pain intensity rating for mild, but high VAS pain intensity rating for severe pain); and 3) High Rating subgroup (high VAS pain intensity ratings across all the pain severity categories). Overall, differences between pain conditions were small: muscle soreness pain intensity was consistently rated lower than the other pain types across severities. The highest pain ratings varied between joint injury and general pain, depending on severity level. No effects of sex or current experience of pain were noted. Conclusion The results indicate that: 1) three distinct pain schemas were present in this community-based sample, indicating significant variation in how pain scales are utilized and/or interpreted between clusters of individuals; 2) pain ratings vary by condition, but these differences are minor; and 3) pain rating schemas are not significantly different between males and females or between individuals with and without current pain. PMID:24379696

Frey-Law, Laura A; Lee, Jennifer E; Wittry, Alex M; Melyon, Myles

2014-01-01

423

Conversion of Mild Cognitive Impairment to Dementia: Predictive Role of Mild Cognitive Impairment Subtypes and Vascular Risk Factors  

Microsoft Academic Search

Mild cognitive impairment (MCI) is regarded as a precursor to dementia, but not all patients with MCI develop dementia. We followed up 165 elderly outpatients with MCI for a mean of 3 years. The aims were (1) to investigate the risk of conversion to dementia for different MCI subtypes diagnosed according to standardized criteria (amnestic; impairment of memory plus other

Giovanni Ravaglia; Paola Forti; Fabiola Maioli; Mabel Martelli; Lucia Servadei; Nicoletta Brunetti; Gaia Pantieri; Erminia Mariani

2006-01-01

424

Diagnostic procedures in mild traumatic brain injury: results of the who collaborating centre task force on mild traumatic brain injury  

Microsoft Academic Search

We examined diagnostic procedures in mild traumatic brain injury by a systematic literature search. After screening 38,806 abstracts, we critically reviewed 228 diagnostic studies and accepted 73 (32%). The estimated prevalence of intracranial CT scan abnormalities is 5% in patients presenting to hospital with a Glasgow Coma Scale score of 15 and 30% or higher in patients presenting with a

Jörgen Borg; Lena Holm; J. David Cassidy; Paul M. Peloso; Linda J. Carroll; Hans von Holst; Kaj Ericson

2004-01-01

425

Development of a CO2 Sequestration Module by Integrating Mineral Activation and Aqueous Carbonation  

SciTech Connect

Mineral carbonation is a promising concept for permanent CO{sub 2} sequestration due to the vast natural abundance of the raw materials and the permanent storage of CO{sub 2} in solid form as carbonates. The sequestration of CO{sub 2} through the employment of magnesium silicates--olivine and serpentine--is beyond the proof of concept stage. For the work done in this project, serpentine was chosen as the feedstock mineral due to its abundance and availability. Although the reactivity of olivine is greater than that of serpentine, physical and chemical treatments have been shown to increase greatly the reactivity of serpentine. The primary drawback to mineral carbonation is reaction kinetics. To accelerate the carbonation, aqueous processes are preferred, where the minerals are first dissolved in solution. In aqueous carbonation, the key step is the dissolution rate of the mineral, where the mineral dissolution reaction is likely to be surface-controlled. The relatively low reactivity of serpentine has warranted research into physical and chemical treatments that have been shown to greatly increase its reactivity. The use of sulfuric acid as an accelerating medium for the removal of magnesium from serpentine has been investigated. To accelerate the dissolution process, the mineral can be ground to very fine particle size, <37 {micro}m, but this is a very energy-intensive process. Previous work in our laboratory showed that chemical surface activation helps to dissolve magnesium from the serpentine (of particle size {approx} 100 {micro}m) and that the carbonation reaction can be conducted under mild conditions (20 C and 4.6 MPa) compared to previous studies that required >185 C, >13 MPa, and <37 {micro}m particle size. This work also showed that over 70% of the magnesium can be extracted at ambient temperature, leaving an amorphous silica with surface area of about 330 m{sup 2}/g. The overall objective of this research program is to optimize the active carbonation process to design an integrated CO{sub 2} sequestration module. A parametric study was conducted to optimize conditions for mineral activation, in which serpentine and sulfuric acid were reacted. The study focused on the effects of varying the acid concentration, particle size, and reaction time. The reaction yield was as high as 48% with a 5 M acid concentration, with lower values directly corresponding to lower acid concentrations. Significant improvements in the removal of moisture, as well as in the dissolution, can be realized with comminution of particles to a D{sub 50} less than 125 ?m. A minimum threshold of 3 M concentration of sulfuric acid was found to exist in terms of removal of moisture from serpentine. The effect of reaction time was insignificant. The treated serpentine had low BET surface areas. Results demonstrated that acid concentration provided primary control on the dissolution via the removal of water, which is closely correlated with the extraction of magnesium from serpentine. Single-variable experimentation demonstrated dissolution enhancements with increased reaction time and temperature. An increase in magnesium dissolution of 46% and 70%, relative to a baseline test, occurred for increased reaction time and temperature, respectively. In addition to the challenges presented by the dissolution of serpentine, another challenge is the subsequent carbonation of the magnesium ions. A stable hydration sphere for the magnesium ion reduces the carbonation kinetics by obstructing the formation of the carbonation products. Accordingly, this research has evaluated the solubility of carbon dioxide in aqueous solution, the interaction between the dissociation products of carbon dioxide, and the carbonation potential of the magnesium ion.

George Alexander; Parvana Aksoy; John Andresen; Mercedes Maroto-Valer; Harold Schobert

2006-08-14

426

Effect of ceramic conversion treatments on the surface damage and nickel ion release of NiTi alloys under fretting corrosion conditions.  

PubMed

Recent researches have demonstrated that surface modification can improve the fretting wear resistance of NiTi alloys in air or enhance their aqueous corrosion resistance without fretting. However, little is known about the behaviour of surface engineered NiTi under fretting corrosion conditions. This is important for such body implants as orthodontic arch wires and orthopedic bone fixation devices because they need to withstand the combined attack of corrosion from body fluid and mechanical fretting. In this study, a NiTi alloy was ceramic conversion (CC) treated at 400 and 650 degrees C. The effect of the surface treatment on the fretting corrosion behaviour of NiTi alloy was investigated using fretting corrosion tests in the Ringer's solution. The experimental results have shown that the CC treatment can convert the surface of NiTi into a TiO2 layer, which can effectively improve the fretting corrosion resistance of NiTi alloy and significantly reduce Ni ion release into the Ringer's solution. Detailed SEM observations revealed that the untreated samples were severely damaged by adhesion and delamination; the high temperature (HT) (650 degrees C/1 h) treated samples were damaged mainly by spallation and adhesion; and the low temperature (LT) (400 degrees C/50 h) treated samples were characterised by mild abrasion. Mild oxidation and corrosion were also observed for all three types of samples tested under fretting corrosion conditions. PMID:17665097

Dong, H; Ju, X; Yang, H; Qian, L; Zhou, Z

2008-02-01

427

Environmental Conditions Environmental Conditions  

E-print Network

in habitat conditions. Stream flows, water temperatures, substrate characteristics and other combined watershed processes and human activities that influence flow, water quality, upland and riparian conditions feet in one mile The watershed includes approximately 760 miles of perennial streams and 1,440 miles

428

Interaction between pirenoxine and bovine serum albumin in aqueous solution  

NASA Astrophysics Data System (ADS)

This work concerns the interaction of prenoxine sodium (PRX) and bovine serum albumin (BSA), which was conducted by spectroscopic means: fluorescence spectra, ultraviolet-visible spectra (UV-vis) and circular dichroism spectra (CD spectra) in physiological conditions. The results revealed the PRX can quench the fluorescence of BSA remarkably in aqueous solution. The quench mechanism has been obtained after corrected the fluorescence intensities for inner filter effects. The binding constants (Ka) were calculated according to the relevant fluorescence data at different temperatures. Moreover, from a series of analyses, we have obtained the binding sites, the binding distance and binding force. The effect of PRX on the conformation of BSA has been analyzed using synchronous fluorescence under experimental conditions. In addition, the CD spectra proved that the secondary structure of BSA changed in the presence of PRX in aqueous solution.

Liao, Zhixi; Yu, Xianyong; Yao, Qing; Yi, Pinggui

2014-08-01

429

How does aqueous solubility of organic reactant affect a water-promoted reaction?  

PubMed

It was widely reported that under the "on water" condition, various water-promoted organic reactions can proceed with very high speed. Thus, it is considered that the aqueous solubility of reactant is not an important issue in these reactions. Three types of water-promoted organic reactions were investigated in the current study to distinguish whether the reaction rate of an aqueous reaction was affected by the aqueous solubilities of the reactants. The results showed that, for a Diels-Alder reaction which was fast under the neat conditions, the aqueous solubilities of reactants had little influence on the reaction. However, for the reactions which proceeded slowly under the neat conditions, such as [2?+2?+2?] cycloaddition reactions and epoxide aminolysis reactions, the reactants with good aqueous solubilities proceeded fast in water. Poorly aqueous soluble reactants reacted slowly or did not react under the "on water" condition, and an appropriate amount of organic cosolvent was needed to make the reaction become efficient. This evidence suggested that for these two types of reactions, the dissolution of the reactants in water was required. PMID:25000435

Zuo, Yi-Jie; Qu, Jin

2014-08-01

430

The Melting of Aqueous Foams  

NASA Technical Reports Server (NTRS)

Diffusing-wave spectroscopy measurements show that ordinarily solid aqueous foams flow by a series of stick-slip avalanche-like rearrangements of neighboring bubbles from one tight packing configuration to another. Contrary to a recent prediction, the distribution of avalanche sizes do not obey a power-law distribution characteristic of self-organized criticality. This can be understood from a simple model of foam mechanics based on bubble-bubble interactions.

Durian, Douglas J.; Gopal, Anthony D.; Vera, Moin U.; Langer, Stephen A.

1996-01-01

431

Aqueous Ozonation Of Fatty Acids  

Microsoft Academic Search

The reactivity of a series of fatty acids toward ozone was examined in aqueous solution at low substrate concentration (?g.L range). Saturated fatty acids were unreactive, unsaturated fatty acids were readily consumed. A number of reaction products or their methylated derivatives were identified by gas chromatography and gas chromatography-mass spectrometry. The products identified are consistent with a 1,3-dipolar cyclo-addotion reaction.

G. Reynolds; C. Corless; N. Graham; R. Perry; T. M. Gibson; J. Haley

1989-01-01

432

Aqueous Humor Rapidly Stimulates Myocilin Secretion from Human Trabecular Meshwork Cells  

PubMed Central

Myocilin, a protein associated with the development of glaucoma, is expressed in most eye tissues with highest expression observed in trabecular meshwork cells. In culture, primary human trabecular meshwork cells incubated in 10% fetal bovine serum have reduced myocilin expression compared to in vivo, but incubation in human aqueous humor, their normal in vivo nutrient source, restores myocilin expression to near in vivo levels. To investigate the mechanism by which human aqueous humor stimulates myocilin accumulation in conditioned media from normal human trabecular meshwork cells, three independent trabecular meshwork cell lines were cultured in Dulbecco’s Modified Eagle’s Medium (DMEM) containing various supplements: fetal bovine serum (10%), human serum (0.2%), porcine aqueous humor (50%), bovine serum albumin (0.1%), dexamethasone (10?7 M), human aqueous humor (50%) or heat-inactivated human aqueous humor (50%). Conditioned media from cultured primary trabecular meshwork cells following incubation in human aqueous humor showed significant accumulation of myocilin in a time- (15 minutes) and dose-dependent manner (half maximal effective concentration ~ 30%) while intracellular myocilin levels decreased. Minimal myocilin accumulation was observed in conditioned media isolated from trabecular meshwork cells cultured in DMEM containing fetal bovine or human serum, bovine serum albumin, porcine aqueous humor, dexamethasone or DMEM alone. Heat inactivation of human aqueous humor nearly eliminated human aqueous humor-stimulated myocilin secretion. Inhibitors of new protein synthesis, gene transcription, the endoplasmic reticulum/Golgi system and endocytic/exocytic secretory pathways failed to inhibit human aqueous humor-stimulated myocilin secretion. Using immunolabeling and transmission electron microscopy, myocilin was found associated with 70–90 nm vesicle-like structures within the cytoplasm of human aqueous humor treated trabecular meshwork cells. These studies suggest that myocilin secretion from trabecular meshwork cells occurs in a Golgi-independent manner following human aqueous humor treatment. Heat-labile factors in human aqueous humor are responsible for the time- and dose-dependent release of myocilin from vesicle-like structures within the cytoplasm of trabecular meshwork cells. PMID:20932969

Resch, Zachary T.; Hann, Cheryl R.; Cook, Kimberly A.; Fautsch, Michael P.

2010-01-01

433

Viscosities of cetylpyridinium bromide solutions (aqueous and aqueous KBr) in the presence of alcohols and amines  

SciTech Connect

Among the large number of additives, alcohols hold a special place, being by far the most common cosurfactants which are added to surfactant-oil combinations to generate microemulsions. Though the studies using amines as cosurfactant in microemulsions are few, it has been proved that they are also potential candidates for such formulations. The effect of organic additives (aliphatic/aromatic amines or alcohols) on the viscosities of aqueous and 0.1 M KBr solutions of 0.05 or 0.1 M cetylpyridinium bromide have been measured under Newtonian flow conditions. The viscosity changed dramatically in the presence of KBr. This is explained by the favorable conditions produced by the salt which assists the micellar growth by organic additives with a concomitant enhancement in viscosity. Reasons for the effectiveness of these additives are suggested. The causes of the viscosity decrease at higher concentrations of the additive are also explained.

David, S.L.; Kumar, S.; Kabir-ud-Din [Aligarh Muslim Univ. (India). Dept. of Chemistry] [Aligarh Muslim Univ. (India). Dept. of Chemistry

1997-01-01

434

Effect of drug-polymer interactions on the aqueous solubility of milled solid dispersions.  

PubMed

The role of molecular interactions in ball milled solid dispersions in determining the aqueous solubility of the poorly water-soluble drug, griseofulvin (GF) has been examined. Ball milled solid dispersions of GF and hydroxypropylmethylcellulose acetate succinate (HPMCAS) and GF and polyvinylpyrrolidone (PVP) were prepared and characterized by laser diffraction, scanning electron microscopy and X-ray powder diffraction and the aqueous saturation solubility measured and analyzed using one way ANOVA. The results showed that solid dispersions of GF and HPMCAS possessed an aqueous GF saturation solubility of about ten times higher than the GF solubility achieved from PVP-based solid dispersions. Furthermore, although the aqueous solubility of GF did not vary with the milling conditions used to prepare the solid dispersions with PVP, significant changes in solubility were observed upon changing the milling conditions for preparation of the GF/HPMCAS solid dispersions. Surprisingly, the GF/HPMCAS solid dispersion prepared using spray drying exhibited a significantly lower aqueous solubility than those prepared by bead milling despite their smaller particle size and GF being fully in its amorphous form. It is thought that the higher surface energy of the spray-dried solid dispersions negatively affected the aqueous solubility of GF. In conclusion, the results suggest that the molecular interactions occurring between GF and HPMCAS affect the aqueous solubility of GF and that the molecular interactions appear to remain in the liquid state. In contrast no molecular interactions were evident in the GF/PVP solid dispersions. PMID:23410988

Al-Obaidi, Hisham; Lawrence, M Jayne; Shah, Sonal; Moghul, Henna; Al-Saden, Noor; Bari, Fiza

2013-03-25

435

Decomposition of phorate in aqueous solution by ozonation  

Microsoft Academic Search

Phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate) dissolved in aqueous solution was almost completely decomposed by ozonation to form various species within 10 minutes of reaction time for the experimental conditions examined in this research. The generation rate of sulfate was found to be fairly independent of solution pH value. However, the formation of phosphate and carbonate was more favorable for alkaline solutions

Young Ku; Hung Shian Lin; Wen Wang; Chih Ming Ma

2007-01-01

436

Mathematical Model of Carbon Dioxide Absorption into Mixed Aqueous Solutions  

Microsoft Academic Search

In this paper, a mathematical model of CO2 chemical absorption system using MDEA (MethylDiEthanolAmine) and PZ (Piperazine) aqueous solutions is investigated. Precisely, the complex reactive absorption behavior is modeled by an NLP mathematical model. The resulting mathematical model is implemented in GAMS and CONOPT is used as NLP solver. The proposed model will allow to optimize the operating conditions to

Patricia Mores; Nicolas Scenna; Sergio Mussati

2009-01-01

437

Chromate removal from aqueous wastes by reduction with ferrous ion  

Microsoft Academic Search

Experimental measurements of reaction stoichiometries indicate that optimum conditions for chromate removal from oxygenated, 25°C aqueous wastes by reduction with ferrous ion occur at pH less than 10.0 in solutions containing the following anions: ClOâ⁻, Cl⁻, F⁻, NOâ⁻, and POâ\\/sup 3 -\\/. At pH greater than 10.0 and at lower pH in solutions that contain greater than 10⁻⁴ M total

L. E. Eary; Dhanpat Rai

1988-01-01