scholarly journals Facile Fabrication of “Dual Click” One- and Two-Dimensional Orthogonal Peptide Concentration Gradients

2013 ◽  
Vol 14 (3) ◽  
pp. 665-671 ◽  
Author(s):  
Yanrui Ma ◽  
Jukuan Zheng ◽  
Emily F. Amond ◽  
Christopher M. Stafford ◽  
Matthew L. Becker
2013 ◽  
Vol 1 (29) ◽  
pp. 4497 ◽  
Author(s):  
Seungho Cho ◽  
Ji-Wook Jang ◽  
Juwon Park ◽  
Sungwook Jung ◽  
Sanghwa Jeong ◽  
...  

2000 ◽  
Author(s):  
E. Sélard ◽  
A. Shirazi-Adl ◽  
J. P. G. Urban

Abstract The intervertebral disc consists of a water-rich extra-cellular matrix which is synthesized and maintained by its cells. The disc is the largest avascular tissue in the body with its cells lying as much as 8mm away from the blood supply. Nutrients, essential for maintaining cellular viability, diffuse through the matrix from blood supply under a concentration gradient arising from cellular demand. The oxygen concentration gradients in the intervertebral disc are investigated to examine the effects of exchange area and disc thickness on oxygen flux in the disc. The concentration gradients are computed using the two-dimensional Poisson’s equation and measured values for oxygen consumption rate and oxygen diffusion.


2001 ◽  
Vol 1 (2) ◽  
pp. 57-65 ◽  
Author(s):  
G. Putz ◽  
D.W. Smith

Wastewater treatment facilities commonly discharge effluent to large receiving streams. An effluent plume may easily extend for many tens of kilometres downstream of a discharge point. A characteristic of the effluent plume is the existence of significant transverse concentration gradients in the river as the discharged effluent slowly mixes with the river water. Within this two-dimensional, transverse mixing zone accurate delineation of the effluent plume is essential for water quality monitoring and for management of the receiving stream. The capability to mathematically model two-dimensional river mixing and to predict effluent plume concentrations is a valuable tool for water quality management. An overview of two-dimensional river mixing theory is presented. Tracer methods for delineating effluent plumes resulting from continuous or transient input to rivers are described, and the results of tracer studies conducted on the Athabasca River in western Canada are presented. A computer modelling procedure for simulating two-dimensional river mixing is described. Application of the model is explained and comparison of model output to measured tracer concentrations is presented.


2014 ◽  
Vol 35 (5) ◽  
pp. 736-745
Author(s):  
David Sean ◽  
Yixuan E. Wang ◽  
Gary W. Slater

1974 ◽  
Vol 1 (14) ◽  
pp. 65
Author(s):  
Brian A. O'Connor ◽  
Samir Zein

The present paper describes the application of a two-dimensional numerical suspended sediment model to problems having analytical solutions, as well as to laboratory and field situations. The model is based upon an implicit finite-difference solution to a two-* dimensional (longitudinal and vertical) diffusion-advection equation for suspended sediment transport. Horizontal eddy diffusion is neglected in comparison with vertical diffusion and vertical water motion is assumed negligible in comparison with the sediment fall velocity. The various applications indicate that the greatest errors in the model are due to large spatial concentration gradients and that errors can be controlled by a suitable choice of space and time step. In addition, it is considered that the model has great flexibility and seems to have an acceptable level of accuracy, at least in the field situations tested, provided the physical parameters of the model can also be determined accurately.


1974 ◽  
Vol 63 (3) ◽  
pp. 577-592 ◽  
Author(s):  
J. S. Turner ◽  
C. F. Chen

The limitations of existing one-dimensional experiments on double-diffusive convection are discussed, and a variety of new two-dimensional phenomena are described. We have used the sugar-salt system and shadowgraph photography to make exploratory studies of motions which can arise in a fluid with two smooth, opposing, vertical concentration gradients, with and without horizontal gradients. Many different effects have been observed, the most important of which are the following, (a) In the ‘finger’ case, local disturbances can propagate rapidly as wave motions, which cause a simultaneous breakdown to convection over large horizontal distances. (b) Layers formed in the’ diffusive’ sense overturn locally to produce fingers, but propagate more slowly, as convective rather than wave motions, (c) A series of layers, separated by diffusive interfaces, can become unstable, in the sense that successive layers merge in time as their densities become equal, (d) The presence of horizontally separated sources of water of similar density but differentT,Scharacteristics can lead to the development of strong vertical gradients and extensive quasi-horizontal layering.Most of our results are qualitative, but it is hoped that they will stimulate further quantitive work on each of the new processes described. It is already clear that much more needs to be done before the mechanism of formation of layers observed in the ocean can be regarded as properly understood.


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