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71.
72.
Senthilkumar Sivaprakasam Moira Monika Schuler Adel Hama Katie-Marie Hughes Ian W. Marison 《Journal of Thermal Analysis and Calorimetry》2011,104(1):75-85
Control of bioprocesses requires reliable and robust on- or in-line monitoring tools providing real-time information on process
dynamics. Heat generation related to metabolic activity of living systems is currently gaining importance in bioprocess industry
due to its non-invasive and essentially instantaneous characteristics. This study deals with monitoring and control of pure
aerobic fed-batch cultures of three Crabtree-negative yeast strains, Kluyveromyces marxianus, Candida utilis and Pichia pastoris, based on in-line measured, metabolic heat flow signals. A high resolution biocalorimeter (BioRC1) was developed from a standard
bench-scale heat flow calorimeter (RC1). The BioRC1 was equipped with in-line (dielectric spectroscopy, pH probe and dissolved
oxygen probe) and at-line (exit gas analyser) sensors to characterise the growth behaviour of the yeast cells. Both metabolic
heat flow and biomass profiles exhibited similar behaviour proving the significance of employing heat flow signal as a key-parameter
for the system under investigation. A simple estimator for biomass concentration and specific growth rate was formulated based
on heat flow values. In order to evaluate the potential of calorimetry as a reliable and powerful process monitoring tool,
the robustness, reliability as well as the broad applicability of the developed estimators was assessed through comparison
with off-line measurement techniques and showed promising results for general applicability with a wide range of bioprocesses. 相似文献
73.
Fatiha Mesdoui Nabil Shawagfeh Adel Ouannas 《Mathematical Methods in the Applied Sciences》2021,44(1):1003-1012
This study considers the problem of control and synchronization between fractional‐order and integer‐order, N‐components reaction‐diffusion systems with nonidentical coefficients and different nonlinear parts. The control scheme is designed using the Lyapunov direct method. The results are exemplified by two significant biochemical models, namely, the fractional‐order Lengyel‐Epstein model and the Gray‐Scott model. To illustrate the effectiveness of the proposed scheme, numerical simulations are performed in one and two space dimensions using Homotopy Analysis Method (HAM). 相似文献
74.
Aadil Lahrouz Adel Settati Mohamed El Fatini Abdessamad Tridane 《Mathematical Methods in the Applied Sciences》2021,44(1):1137-1146
In this paper, we aim to analyze the classical SIS epidemic model with a generalized force of infection (including nonmonotonic cases), where the transmission rate is perturbed by white noise. Using Feller's test for explosions, we prove that the disease dies out with probability one without any restriction on the model parameters. 相似文献
75.
The ionic exchange behavior of Zn2+, Ni2+, and Cu2+ metallic ions on Amberlyst-15 commercial resin was studied as a function of resin solution contact time, initial concentration of metallic ions, nature of the solvent, and the amount of resin. The metallic ions were studied in ternary mixtures using both column and batch experiments. In addition, water, methanol, ethanol, and propan-2-ol were used as solvents for dissolving metallic ions. It was found that the resin behavior depends on the solvent nature and the metallic ion concentration. The analysis of solutions by atomic absorption spectrometry revealed that the affinity of the resin for the studied metallic ions followed the sequence Cu2+ > Ni2+ > Zn2+ in the case of an aqueous medium. Furthermore, uptake increased with increasing amount of resin. A better uptake was observed in the case of the 75:25 % water/methanol compositions when the column technique was used. For the batch technique, we noted a better uptake using 100 % water. The uptake rate decreased with an increase in the number of carbons for the 50 % water–50 % alcohol solvents. The acid–base properties of Amberlyst-15 commercial resin were studied by 2-propanol decomposition test. Propene and acetone are the main expected products and it is believed that they are formed through dehydration or dehydrogenation reaction on acid and base sites, respectively. 相似文献
76.
77.
Transition Metal Chemistry - Poly(5-vinylsalicylidene)aniline homopolymer and polymer complexes of 5-vinylsalicylideneaniline with CuII, CoII, NiII, CdII and $? UO_{2}^{2+}$ have been... 相似文献
78.
V. A. Shvetsov N. V. Adel’shina V. V. Pakhomova N. B. Kosheleva L. A. Bezrukova 《Journal of Analytical Chemistry》2008,63(8):718-722
A procedure is proposed for the sample preparation of gold-containing ores of the second and third groups for assay analysis; it allows for an improvement in the accuracy of the results of analysis. 相似文献
79.
The far-from-resonance transfers and the de-excitation processes in CO2-NO and N2O-NO systems have been studied by measuring fluorescence decay rate constants of CO2 or N2O excited to the (00°1) level by laser radiation. The diagrams giving the variations of these rate constants versus the molar fraction of CO2 or N2O have been set out. From these diagrams, the relative importance of the V-V transfer and V-T de-excitation rate constants is discussed. The transfer rate constants have been calculated from a semiclassical theory in which the interaction potential is a sum of four atom-atom Morse potentials. The disagreement observed between calculated and experimental values probably results from the attractive multipolar forces which the theory does not take into account. 相似文献
80.
The problem of locating one or more new facilities relative to a number of existing rectangular regions is treated for the case where the rectilinear norm is used. The new facilities are to be located such that the total weighted distance is minimized. If there is interfacility interaction among the new facilities, a gradient-free nonlinear search algorithm is utilized. Computational experience suggests that this algorithm is expedient even in the solution of large problems. 相似文献