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71.
This work presents a phenomenologically based semi-physical model (PBSM) for the liquid–solid adsorption process, which has been experimentally validated. Two modes of operation of adsorption of direct blue 2 dye (DB2) on corn cobs in a fixed bed are discussed by applying the PBSM. The first mode of operation is the typical continuous liquid flow, whereas the second is a semicontinuous mode with the recirculation of liquid leaving the column. These modes of operation were used to illustrate different ways in which the system reaches equilibrium conditions. The equilibrium distribution curve (EDC) for low DB2 concentration was reached with the best fit using the Langmuir–Freundlich model ( R 2 = 0.998 ). The local mass transfer coefficient for the solid phase was evaluated by the PBSM deduction, and subsequently, the diffusivity of the surface solid was experimentally evaluated through comparison in terms of the PBSM. Regardless of the mode of operation, surface diffusion is associated with only the nature of the adsorbent material rather than the concentration of the liquid phase. In addition, the PBSM exhibited liquid and solid concentration changes at different points in the column. Moreover, different operating curves of the process were constructed and validated, exhibiting similar results when comparing the predictions of the model and the experimental data. These findings support the strength of the constructed model, enabling its extension to other adsorbent–dye systems.  相似文献   
72.
The object of this study was to determine the allergenicity of goat milk (GM) and cow milk (CM) and that of their respective lactosera (GML and CML), by in vivo and in vitro assays. Two systemic tests for anaphylaxis were carried out in guinea pigs, the animals being sensitized orally with the 2 types of milk and lactosera. Sera were taken from the orbital sinus of the experimental animals at 0 and 22 d of the experiment to perform the serological study and the passive cutaneous anaphylaxis test. For the latter, the guinea pigs were sensitized passively with antibodies against the 4 antigen solutions. Enzyme-linked immunosorbent assay and Western blot were used to determine the specific antibodies of the isotypes immunoglobulin G1 and immunoglobulin G(Fc) developed against the same 4 antigen solutions. From these anaphylaxis and antibody-production tests, it was concluded that GM is hypoallergenic when compared with CM. The lactosera produced more closely grouped results, with values always below those of the corresponding milk. None of the proteins in the 4 immunizing solutions were identified as being their main allergen. These results show the hypoallergenicity of GM versus CM, and also that both casein and lactoserum proteins may be responsible for allergy in each case. To analyze the possibility of producing an innocuous food for those allergic to milk proteins, it would be of interest to identify the epitope(s) responsible for such allergenicity.  相似文献   
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74.
A simple electroanalytical method using square wave voltammetry at a Pt band ultramicroelectrode to perform a qualitative and quantitative analysis of different synthetic antioxidant mixtures permitted by official regulations in edible oils is proposed. The methodology was based on the comparison of voltammetric signals obtained in acetonitrile + 0.1 M (C4H9)4NF6P with those recorded in the same reaction medium when different aliquots of (C4H9)4NOH were added to allow a qualitative differentiation between antioxidants. Firstly, studies on solutions prepared from commercial reagents were carried out. Then, the results obtained were transferred to the analysis of a real matrix, i.e., an edible olive oil. From real samples spiked with a known amount of different synthetic antioxidant mixtures, we could deduce the presence of these antioxidants by comparing results obtained in the neutral medium with those obtained after the successive addition of base. The standard addition method was used to quantify the individually spiked synthetic antioxidants in the real sample. Recovery percentages were between 88% and 118%. The reproducibility was 1.5%, 3.1%, 4.1% and 4.1% in ACN + 0.1 M TBAHFP and 1.5%, 4.6%, 6.6% and 2.5% in Bz/EtOH (1:2) + 0.1 M H2SO4 for TBHQ, BHA, BHT and PG, respectively. The repeatability was 1% for PG in both media. These parameters show a good system performance.  相似文献   
75.
Monocyte chemoattractant proteins (MCPs) are cytokines that direct immune cells bearing appropriate receptors to sites of inflammation or injury and are therefore attractive therapeutic targets for inhibitory molecules. 11K2 is a blocking mouse monoclonal antibody active against several human and murine MCPs. A 2.5 A structure of the Fab fragment of this antibody in complex with human MCP-1 has been solved. The Fab blocks CCR2 receptor binding to MCP-1 through an adjacent but distinct binding site. The orientation of the Fab indicates that a single MCP-1 dimer will bind two 11K2 antibodies. Several key residues on the antibody and on human MCPs were predicted to be involved in antibody selectivity. Mutational analysis of these residues confirms their involvement in the antibody-chemokine interaction. In addition to mutations that decreased or disrupted binding, one antibody mutation resulted in a 70-fold increase in affinity for human MCP-2. A key residue missing in human MCP-3, a chemokine not recognized by the antibody, was identified and engineering the preferred residue into the chemokine conferred binding to the antibody.  相似文献   
76.
Hernan Diaz Alonso redefines ‘excess’ and ‘exuberance’ on his own terms. Fully au fait and comfortable with the excessive, he describes how in relation to his own work he views excess as more of a tendency or a logic, which sums up his approach; whereas he perceives the exuberant as removed from the design process and more like an ‘adjective’, an ‘emerging quality’ observed by others. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
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78.
This paper presents a new low-loss modulation technique for the hybrid three-level four-leg converter. The total losses of the converter are reduced by about 18% on average compared to the standard three-leg neutral-point-clamped converter. Furthermore, the low-frequency voltage oscillation in the neutral point is completely cancelled, and the maximum benefit of the dc-link voltage is obtained. All these facts, together with the fault-tolerant ability due to the fourth leg, make this topology very interesting for applications such as wind generation, in which it is important to maximize efficiency and reliability. Some experimental results confirm the good performance of the proposed modulation technique.  相似文献   
79.
The findings demonstrated that creative thinking, operationally defined as the cognitive ability to generate a large number of original ideas/solutions predicted creative thinking in solving problems in architecture. Research participants were 111 students of architectural design. A strong correlation was found between the predictor and criterion measures, r = .45, p r = .51, p r = .31, p  相似文献   
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