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91.
Evaluation of tocopherol recovery through simulation of molecular distillation process 总被引:7,自引:0,他引:7
E. B. Moraes C. B. Batistella M. E. Torres Alvarez Rubens Maciel Filho M. R. Wolf Maciel 《Applied biochemistry and biotechnology》2004,114(1-3):689-711
DISMOL simulator was used to determine the best possible operating conditions to guide, in future studies, experimental works.
This simulator needs several physical-chemical properties and often it is very difficult to determine them because of the
complexity of the involved components. Their determinations must be made through correlations and/or predictions, in order
to characterize the system and calculate it. The first try is to have simulation results of a system that later can be validated
with experimental data. To implement, in the simulator, the necessary parameters of complex systems is a difficult task. In
this work, we aimed to determe these properties in order to evaluate the tocopherol (vitamin E) recovery using a DISMOL simulator.
The raw material used was the crude deodorizer distillate of soya oil. With this procedure, it is possible to determine the
best operating conditions for experimental works and to evaluated the process in the separation of new systems, analyzing
the profiles obtained from these simulations for the falling film molecular distillator. 相似文献
92.
E. C. da Silva Filho Oberto G. da Silva Maria G. da Fonseca Luiza N. H. Arakaki C. Airoldi 《Journal of Thermal Analysis and Calorimetry》2007,87(3):775-778
A series of compounds with
composition of Ca1–xCuxHPO4,
where x varied from 0.05 to 0.5 were synthesized
by precipitation method. The compounds were characterized by elemental analysis,
X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and
thermogravimetry. The chemical stabilities of solids were investigated at
several pH. Elemental analysis of copper, calcium and phosphorus are in agreement
with the proposed composition. The formation of lamellar phosphates was evidenced.
The stability of the set of compounds was better for samples with high copper
content. 相似文献
93.
C.H.O. Costa P.H.R. Barbosa F.F. Barbosa Filho M.S. Vasconcelos E.L. Albuquerque 《Solid State Communications》2010,150(47-48):2325-2328
In this work we investigate magnonic band gaps, in the terahertz (THz) frequency range, in periodic and quasiperiodic (Fibonacci sequence) magnonic crystals formed by layers of Cobalt (Co) and Permalloy (Py). Our theoretical model is based on a magnetic Heisenberg Hamiltonian in the exchange regime, together with a transfer-matrix treatment within the random-phase approximation (RPA). For periodic arrangements the bulk band structure is analogous to those found in photonic crystals, while for quasiperiodic multilayers it presents additional pass bands similar to those found in doped electronic materials. 相似文献
94.
Annals of Global Analysis and Geometry - This paper studies timelike minimal surfaces in the De Sitter space $$\mathbb S^3_1(1) \subset \mathbb R^4_1$$ via a complex variable. Using complex... 相似文献
95.
96.
The static dielectric properties of (001)(GaAs)(p)/(AlAs)(p) superlattices have been calculated as a function of their period p for 1< or = p < or =12, starting from density-functional theory. The interplay between quantum confinement and local field effects is shown to be crucial. For light polarized in the growth direction it leads to the otherwise surprising justification of the use of a classical effective medium theory, even for the smallest periods. Only the inclusion of both contributions allows in ab initio and in semiempirical calculations to reproduce the experimentally observed birefringence. 相似文献
97.
A. L. F. Porto G. M. Campos-Takaki J. L. Lima Filho 《Applied biochemistry and biotechnology》1996,60(2):115-122
The influence of nitrogen and phosphate sources on the production of extracellular protease activity byStreptomyces clavuligerus has been investigated. The experiments were carried out in batch fermentation using soy-bean flour as nitrogen source and
potassium phosphate dibasic as phosphate source. High protease yield was obtained after 24 h of fermentation with an initial
pH of 7.0. The maximal protease activity (112.68 and 88.72 U/mg) was obtained the phosphate concentration of the 21 and 29
mM for strains 3585 and 644, respectively. With regard to the nitrogen concentration in both strains, the maximal protease
activity was achieved with 0.5% (154.89 U/mg and 228.36 U/mg for 3585 and 644 strains, respectively). Enzyme production appeared
to be modulated by an inducer system where ammonia, complex nitrogen, and phosphate sources might have been involved. 相似文献
98.
Alberto Andreussi Lucio Bianco Salvatore Ricciardelli 《European Journal of Operational Research》1981,8(4):345-354
The objective of this study is the development of a simulation model to assist in aircraft sequencing operations in the terminal area. After the definition of the main characteristics of the model, a general structure of a terminal area is considered with a variable number of feeder fixes and alternative paths from the fixes to the runways. The model is designed so as to evaluate different operating policies. A discrete events simulation philosophy, using Fortran as simulation language, is employed. Finally a model application to the Rome terminal area is illustrated. The results obtained show that the model, here presented, is general enough to simulate the terminal area behaviour of any airport. 相似文献
99.
100.
Mishkovsky M Frydman L 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2005,173(2):344-350
A new protocol for processing the data arising in ultrafast 2D NMR is discussed and exemplified, based on the interlaced Fourier transformation. This approach is capable of dealing in a single, combined fashion, with the two mirror-imaged interferograms arising in this kind of experiment as a result of the acquisition of a train of magnetic field gradient echoes. By combining all the acquired data points into a common Fourier processing procedure the spectral width along the direct-acquisition domain becomes effectively doubled, giving the opportunity of employing acquisition gradients that are approximately half as strong as hitherto required. This in turn should lead to an overall enhancement in the signal-to-noise ratio of the experiment of ca. 2, as well as to improvements in the achievable digital resolution. These expectations were tested by carrying out a series of homo- and heteronuclear ultrafast 2D NMR acquisitions, and found systematically fulfilled. The robustness and conditions that allow the interlaced numerical procedure to be implemented in routine analytical applications were explored and are briefly discussed. 相似文献