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991.
nding the large particles becomes less in case ofa bidisperse mixture, as compared to a monodisperse system with the same volume fraction. We further investigated this discrepancy by calculating the volume per particle by means of Voronoi tessellation. 相似文献
992.
Donald A. Ross Alexander H. Chu Thomas J. Nikolai Jon M. Ryan Donald G. Schaefer Andrew R. Schmidt 《Adsorption》1999,5(4):391-398
Continuous perfusion cell culture, using albumin containing medium, offers the potential advantages of higher recombinant Prourokinase (r-ProUK) yields, higher initial product purity and increased throughput compared to batch culture technology using medium supplemented with fetal bovine serum. We have characterized the production of r-ProUK in medium supplemented with a lipid rich bovine serum albumin (Albumax) in a perfusion system. The results of these studies showed that it was necessary to modify the r-ProUK batch recovery scheme to process r-ProUK from a perfusion system. To accommodate large volumes of perfusate harvested over a ten to fourteen day production cycle, cation exchange and hydrophobic interaction chromatography (HIC) resins were identified that had increased product binding capacity, better flow characteristics and wider pH ranges which allowed caustic cleaning. The mobile phase composition, pH and ionic strength were modified to improve r-ProUK yields from the identified resins, and procedures were developed to eliminate r-ProUK degradation products. Strategies were defined for processing continuous harvest, which contained four to seven times the amount of r-ProUK of batch harvests. 相似文献
993.
994.
995.
A simple procedure is proposed for the assessment of reinforced rectangular concrete columns under combined biaxial bending
and axial loads and for the design of a correct amount of FRP-strengthening for underdesigned concrete sections. Approximate
closed-form equations are developed based on the load contour method originally proposed by Bresler for reinforced concrete
sections. The 3D failure surface is approximated along its contours, at a constant axial load, by means of equations given
as the sum of the acting/resisting moment ratio in the directions of principal axes of the sections, raised to a power depending
on the axial load, the steel reinforcement ratio, and the section shape. The method is extended to FRP-strengthened sections.
Moreover, to make it possible to apply the load contour method in a more practical way, simple closed-form equations are developed
for rectangular reinforced concrete sections with a two-way steel reinforcement and FRP strengthenings on each side. A comparison
between the approach proposed and the fiber method (which is considered exact) shows that the simplified equations correctly
represent the section interaction diagram.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 44, No. 3, pp. 443–462, May–June, 2008. 相似文献
996.
Gunjan Pandey Tasneem Fatma Sudha M. Cowsik Sneha Sudha Komath 《Journal of photochemistry and photobiology. B, Biology》2009,97(2):87-93
Recent research has shown that, like porphyrins, phycocyanin (PC) too can produce singlet oxygen upon excitation with the appropriate radiation and hence could be useful in photodynamic therapy (PDT) for cancer. Unlike porphyrins, PC has the advantage of being a non-toxic, non-carcinogenic, soluble protein. However, the challenge would be to target the fluorescent phycobiliprotein to malignant cells. We report here that the tumor-specific lectin, jacalin, binds PC specifically in a carbohydrate-independent manner and with affinities better than that for porphyrins. Hence the lectin could prove to be a useful carrier for targeted delivery of PC. The interaction involves both ionic and hydrophobic interactions and more than one contact site. 相似文献
997.
Marcia Salzano 《Journal of statistical physics》1999,97(3-4):817-826
We continue our study of the ergodic behavior of the contact process on infinite connected graphs of bounded degree. Examples are provided of trees on which, as the infection parameter increases, complete convergence alternates between holding and failing infinitely many times. 相似文献
998.
Recent non-contact atomic force microscopy studies have demonstrated that imaging of single atom defects is possible. However, the imaging mechanism was unclear. Long-range forces of attraction, which are normally associated with non-contact mode, are not known to produce sufficient lateral resolution to image atoms. In this study, we suggest a mechanism that could be responsible for the resolution achieved. We use realistic interatomic interaction parameters to do numerical simulations. These simulations are in good agreement with experimental data. As a result, we are able to ‘separate' the attractive and repulsive forces acting between the AFM tip and the sample surface. Calculations indicate that the force responsible for image contrast in the experimental studies mentioned above, is in most cases the repulsive contact force, and not the long-range attractive force. We check our conclusions against a variety of interatomic interaction parameters and our results remain valid for any reasonable set of such parameters, including the power law of the attractive potential N<9. 相似文献
999.
A model representing a coupling between a heat conducting medium and a solid structure is considered. We establish a Carleman
inequality for this model. Next we deduce a null controllability result with an internal control in the conducting medium
and there is no control in the solid part. 相似文献
1000.
The existence and uniqueness of the weak solution to the model for the dynamics of a viscoelastic rod which is in adhesive contact with an obstacle is established. The model consists of a hyperbolic equation for the vibrations of the rod coupled with a nonlinear ordinary differential equation (ODE) for the evolution of the bonding function. The model allows for failure, i.e., complete debonding, in finite time. The existence of the weak solution is established by using an existence result for ODEs and the Schauder fixed-point theorem. The limit of an elastic rod when the viscosity vanishes is studied, too. 相似文献