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Solange I. Mussatto Giuliano Dragone Marcela Fernandes Adriane M. F. Milagres Inês C. Roberto 《Cellulose (London, England)》2008,15(5):711-721
Brewer’s spent grain components (cellulose, hemicellulose and lignin) were fractionated in a two-step chemical pretreatment
process using dilute sulfuric acid and sodium hydroxide solutions. The cellulose pulp produced was hydrolyzed with a cellulolytic
complex, Celluclast 1.5 L, at 45 °C to convert the cellulose into glucose. Several conditions were examined: agitation speed
(100, 150 and 200 rpm), enzyme loading (5, 25 and 45 FPU/g substrate), and substrate concentration (2, 5 and 8% w/v), according
to a 23 full factorial design aiming to maximize the glucose yield. The obtained results were interpreted by analysis of variance
and response surface methodology. The optimal conditions for enzymatic hydrolysis of brewer’s spent grain were identified
as 100 rpm, 45 FPU/g and 2% w/v substrate. Under these conditions, a glucose yield of 93.1% and a cellulose conversion (into
glucose and cellobiose) of 99.4% was achieved. The easiness of glucose release from BSG makes this substrate a raw material
with great potential to be used in bioconversion processes. 相似文献
156.
Giuliano BM Bizzocchi L Cooke S Banser D Hess M Fritzsche J Grabow JU 《Physical chemistry chemical physics : PCCP》2008,10(15):2078-2088
The pure rotational spectra of 41 isotopic species of PbSe and PbTe have been measured in their X 1Sigma+ electronic state with a resonator pulsed-jet Fourier transform microwave spectrometer. The molecules were prepared by laser ablation of suitable target rods and stabilised in supersonic jets of noble gas. Global multi-isotopologue analyses yielded spectroscopic Dunham parameters Y01, Y11, Y21, Y31, Y02, and Y12 for both species, as well as effective Born-Oppenheimer breakdown (BOB) coefficients delta01 for Pb, Se and Te. Unusual large values of the BOB parameters for Pb have been rationalized in terms of finite nuclear size (field shift) effect. A direct fit of the same data sets to an appropriate radial Hamiltonian yielded analytic potential energy functions and BOB radial functions for the X 1Sigma+ electronic state of both PbSe and PbTe. Additionally, the magnetic hyperfine interactions produced by the uneven mass number A nuclei 207Pb, 77Se, 123Te, and 125Te were observed, yielding first determinations of the corresponding nuclear spin-rotation coupling constants. 相似文献
157.
In this work, a new method for the determination of the thermodynamical properties of fluids, based on experimental speed-of-sound measurements, is described. This method consists in the solution of recursive equations (REM, Recursive Equations Method) for the determination of the density ρ(p,T) and specific heat capacity at constant pressure cp(p,T), using the initial values of density ρ(p0,T) and isobaric specific heat capacity cp(p0,T) known at a reference pressure p0, as a function of the temperature, if the speed-of-sound function, u(p,T), is known, at least over a certain temperature and pressure range. A complete uncertainty analysis has also been developed. As an example of the good performances of this analysis method, firstly density and isobaric specific heat capacity have been calculated for water and the results have been compared with those predicted by the International Association for the Properties of Water and Steam 95 Formulation (IAPWS-95), as delivered by Wagner and Pruss. One more application has been made starting from experimental speed-of-sound values in pure acetone. These results have been compared with those calculated by the most advanced numerical integration methods and with the prevision of the dedicated NIST equation of state (EoS) by Lemmon and Span. 相似文献
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Femoni C Iapalucci MC Longoni G Tiozzo C Wolowska J Zacchini S Zazzaroni E 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(23):6544-6554
The synthesis, structure, spectroscopic characterization and electrical resistivity of the [EtV](2)[Fe(4)Pt(CO)(16)], [EtV][Fe(3)Pt(3)(CO)(15)].THF, [EtV][Fe(4)Au(CO)(16)](2)2.THF (EtV=1,1'-diethyl-4,4'-bipyridilium cation) and [NEt(4)](2)[Fe(4)Au(CO)(16)] is reported. The crystal structure of [EtV](2)[Fe(4)Pt(CO)(16)] is based on infinite stacks of [(EtV)(*+)](2) pi-dimers rotated by 90 degrees and isolated [Fe(4)Pt(CO)(16)](2-) ions. Within each pi-dimer, the [EtV](*+) radical ions are perfectly eclipsed and the distance between their mean planes is 3.275 A. The EPR spectrum of the solid material at room temperature clearly indicates the presence of a significantly populated triplet state of the pi-dimer, by showing signals both at Deltam=1 and Deltam=2. The solid-state structure of [EtV][Fe(3)Pt(3)(CO)(15)].THF is based on the ionic packing of [EtV](2+) and [Fe(3)Pt(3)(CO)(15)](2-) ions, inferred from a comparison of their molecular parameters with literature data. Significant electron transfer could have been expected to give [EtV](*+)[Fe(3)Pt(3)(CO)(15)](*-) on the basis of their formal redox potentials. In spite of their different stoichiometries, the structures of [EtV][Fe(4)Au(CO)(16)](2).2 THF and [NEt(4)](2)[Fe(4)Au(CO)(16)] both contain an isomer of the monoanion [Fe(4)Au(CO)(16)](-) in solution (previously characterized in the solid state as a [NMe(3)CH(2)Ph](2)[Fe(4)Au(CO)(16)]Cl mixed salt). Resistivity measurements on pellets of powdered samples of the above compounds indicate that their tetrasubstituted ammonium salts, and complex [EtV][Fe(4)Au(CO)(16)](2)2.THF, largely behave as insulators. However, the [EtV](2)[Fe(4)Pt(CO)(16)] and [EtV][Fe(3)Pt(3)(CO)(15)].THF samples respectively display resistivities 3 and 4 orders of magnitude less than those of their corresponding ammonium salts and could be classified as semiconductor materials. 相似文献