Search results for " press"
showing 10 items of 4213 documents
Effective Removal and Mineralization of 8-Hydroxyquinoline-5-sulfonic Acid through a Pressurized Electro-Fenton-like Process with Ni−Cu−Al Layered Do…
2020
Ni−Cu−Al layered double hydroxide (Ni−Cu−Al LDH) was proposed as an electro‐Fenton‐like catalyst for 8‐hydroxyquinoline‐5‐sulfonic acid (8‐HQS) removal in water. The properties of the prepared catalysts were characterized by using X‐ray, SEM and EDAX analyses. The effect of numerous operative parameters on the removal of 8‐HQS and total organic carbon (TOC) was studied. Very high level removal of both 8‐HQS and TOC (87 and 79 %, respectively) were obtained by using a pressurized electro‐Fenton‐like process (PrEFL‐LDH) at P=10 bars, using a Ti/IrO2‐Ta2O5 anode for 6 h. The process presented good performances in a large range of pH (3–10) and gave better removals of 8‐HQS and TOC with respect…
Optical Absorption of Zinc Selenide Doped with Cobalt (Zn1-xCoxSe) under Hydrostatic Pressure
2000
Optical absorption of the diluted magnetic semiconductor Zn 1-x Co x Se (x = 0.02) has been measured at room temperature under hydrostatic pressure up to 14 GPa in a membrane diamond-anvil cell. We found two absorption features: (i) an absorption structure in the energy range 1.5 to 1.8 eV, with a negligible pressure shift (i.e. (0.45 ± 0.05) meV/GPa) which we have identified as the Co 2+ (3d 7 ) internal transition 4 A 2 (F) → 4 T 1 (P) and (ii) an onset in the energy range 2 to 2.7 eV which redshifts with pressure (dE/dP = (-8.1 ± 0.6) meV/GPa). We have attributed such absorption edge to charge transfer between the ZnSe valence band and the Co 2+ (3d 7 ) levels. On the assumption that tho…
Eine oligomeranaloge friessche umlagerung oligomerer 2-acetoxy-1,3-phenylenmethylene
1979
α-Hydro-ω-hydroxypoly(5-chloro-2-hydroxy-1,3-phenylenemethylene)s (1a, b), the oligomeric condensation products from 4-chloro-2,6-bis(hydroxymethyl)phenol and 4-chlorophenol with hydrochloric acid in 1,4-dioxane, could be completely dehalogenated at room temperature and atmospheric pressure with hydrogene/Raney-Ni. The resulting oligomers 2a, b were esterified with acetic anhydride, and the esters 3a, b were subjected to a oligomer analogous Fries rearrangement to form the linear α-hydro-ω-hydroxypoly(5-acetyl-2-hydroxy-1,3-phenylenemethylene)s 4a and 4b. The characterization of the products was mainly done by spectroscopic methods.
Données expérimentales et modélisation d’adsorption des systèmes N2(g)/montmorillonite potassique de Camp-Berteau et N2(g)/hydrotalcite carbonatée
1999
Resume In this paper capacities of adsorption of nitrogen onto two clays at 77 K are compared and analyzed. One system is a montmorillonite of Camp-Berteau saturated by potassium cation and the second one is an hydrotalcite saturated by carbonate anion. Adsorbed amounts have been obtained using a volumetric technique. So it is shown that the smectite adsorbed more than the hydrotalcite at the same relative pressure of nitrogen. The modelling of experimental data by various theories of adsorption as de Brunauer, Emmett et Teller (BET) and t-method are used to calculate the specific surface and to have access to the porosity of these materials at 77 K. Then it is shown that the adsorption of …
Evidence for the formation of sodium hassate(VIII)
2004
SummaryHassium, element 108, was produced in the fusion reaction between26Mg and248Cm. The hassium recoils were oxidizedin-situto a highly volatile oxide, presumably HsO4, and were transported in a mixture of He and O2to a deposition and detection system. The latter consisted of 16 silicon PIN-photodiodes facing a layer of NaOH, which served, in the presence of a certain partial pressure of water in the transport gas, as reactive surface for the deposition of the volatile tetroxides. Six correlated α-decay chains of Hs were detected in the first 5 detectors centred around detection position 3. In analogy to OsO4, which forms Na2[OsO4(OH)2], an osmate(VIII), with aqueous NaOH, HsO4presumably…
Separation of Enantiomers in a Monolayer of Racemic 3-Hexadecyl-oxy-propane-1,2-diol
1993
Monolayers of a racemic mixture and of the pure S enantiomer of 3-hexadecyloxy-propane-1,2-diol have been characterized by thermodynamic measurements at the air/water interface as well as by fluorescence microscopy. The critical temperatire T c , the limiting molecular area at high pressure and the pressure π c corresponding to the observed main phase transition, derived from the isotherms, slightly depend on chiral purity
Isobaric Vapor−Liquid Equilibrium for Ethanol + Water + Strontium Nitrate
1996
Isobaric vapor−liquid equilibrium for ethanol (1) + water (2) + potassium nitrate (3) at various concentrations of salt and with ethanol mole fractions from 0 to 0.642 has been measured at 100.0 kPa. The results were correlated by assuming that the salt was in ionic form and it was associated only with the water.
Isobaric vapor-liquid equilibria for binary systems composed of octane, decane, and dodecane at 20 kPa
1996
Vapor−liquid equilibria were measured for binary systems of octane + decane, decane + dodecane, and octane + dodecane at 20.00 kPa using a recirculating still. The results are thermodynamically consistent according to the point-to-point consistency test, and deviation from ideal behavior is small for all systems.
Die chemische molekulargewichtsbestimmung von polystyrol mit hilfe colorimetrisch bestimmbarer endgruppen. III. Mitt.
1964
Ein mit dem Diacylperoxyd der 3-Benzolazo-benzoesare hergestelltes Polystyrol enthalt Endgruppen, die durch Extinktionsmessungen bei 442, 319 und 262,5 mμ bestimmt wurden. Es wurde eine Extinktionszahl-Molekulargewichts-Beziehung aufgestellt, die dem bekannten VAN'T HOFFschen Gesetz entspricht. Falls die Zahl der charakteristisch absorbierenden Endgruppen je Makromolekul unbekannt ist, wurden fur die experimentelle Bestimmung eines Mindestmolekulargewichts mehrere voneinander unabhangige Gleichungen gefunden. Viskosimetrisch und uber Extinktionsmessungen bestimmte Molekulargewichte wurden verglichen. Polystyrene, prepared by means of a diacylperoxide of the 3-benzeneazobenzoic acid, contain…
Determination of aminoglycoside and macrolide antibiotics in meat by pressurized liquid extraction and LC-ESI-MS
2010
A simple method for the simultaneous determination of dihydrostreptomycin, spectinomycin, spiramycin, streptomycin, tilmicosin, and tylosin in meat has been developed using pressurized liquid extraction and LC-triple quadrupole MS (LC-ESI-MS/MS). The pressurized liquid extraction operational parameters were optimized and no protein precipitating and fat removing steps were required. A gradient HPLC separation was developed with ion-pair mobile phases consisting of aqueous 1 mM heptafluorobutyric acid water and methanol. Protonated molecules were used as precursor ions for CID. Data acquisition under MS/MS was achieved by applying multiple reaction monitoring of three fragment ion transition…