Thermobifida fuscacellulases exhibit limited surface diffusion on bacterial micro-crystalline cellulose

2012 ◽  
Vol 110 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Jose M. Moran-Mirabal ◽  
Jacob C. Bolewski ◽  
Larry P. Walker
Keyword(s):  
Surface Diffusion ◽  
Crystalline Cellulose ◽  
Limited Surface

scholarly journals Barrier-limited surface diffusion in atom lithography

2004 ◽  
Vol 95 (4) ◽  
pp. 1749-1755 ◽  
Author(s):  
E. te Sligte ◽  
K. M. R. van der Stam ◽  
B. Smeets ◽  
P. van der Straten ◽  
R. E. Scholten ◽  
...  
Keyword(s):  
Surface Diffusion ◽  
Atom Lithography ◽  
Limited Surface

Fast Growth Rate Epitaxy by Chloride Precursors

2013 ◽  
Vol 740-742 ◽  
pp. 167-172 ◽  
Author(s):  
Francesco La Via ◽  
Massimo Camarda ◽  
Andrea Canino ◽  
Andrea Severino ◽  
Antonino La Magna ◽  
...  
Keyword(s):  
Growth Rate ◽  
Surface Roughness ◽  
Surface Diffusion ◽  
Basal Plane ◽  
Stacking Faults ◽  
Fast Growth ◽  
Threading Dislocations ◽  
The Cost ◽  
Limited Surface ◽  
Fast Growth Rate

In this paper the epitaxial process with chloride precursors has been described. In particular it has been shown that the growth rate can be increased to about 100 μm/h but higher growth rate can be difficult to reach due to the limited surface diffusion at the usual temperature of SiC epitaxy. This process gives several advantages because it gives the opportunity to increase the throughput and consequently to reduce the cost of epitaxy, using new reactor structures, and to reduce several kind of defects (Basal Plane Dislocations, Stacking Faults, Threading Dislocations) and to decrease the surface roughness at the same time.

A theory of contamination in electron microscopes by surface diffusion

1978 ◽  
Vol 36 (1) ◽  
pp. 116-117
Author(s):  
J.T. Fourie
Keyword(s):  
Electron Beam ◽  
Surface Diffusion ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Physical Parameters ◽  
Carbon Compounds ◽  
Hydrocarbon Molecules ◽  
Electron Microscopes ◽  
Primary Electrons ◽  
Long Chain

Contamination in electron microscopes can be a serious problem in STEM or in situations where a number of high resolution micrographs are required of the same area in TEM. In modern instruments the environment around the specimen can be made free of the hydrocarbon molecules, which are responsible for contamination, by means of either ultra-high vacuum or cryo-pumping techniques. However, these techniques are not effective against hydrocarbon molecules adsorbed on the specimen surface before or during its introduction into the microscope. The present paper is concerned with a theory of how certain physical parameters can influence the surface diffusion of these adsorbed molecules into the electron beam where they are deposited in the form of long chain carbon compounds by interaction with the primary electrons.

Blue Sapphire with Partial Red Surface Diffusion

2020 ◽  
Vol 37 (1) ◽  
pp. 23-24
Author(s):  
Bear Williams ◽  
Cara Williams ◽  
Charles I. Carmona
Keyword(s):  
Surface Diffusion

Formulation and Evaluation of Nelfinavir Extended Release Trilayer Matrix Tablets by Design of Experiment

2018 ◽  
Vol 11 (5) ◽  
pp. 4259-4268
Author(s):  
Nirmala Rangu ◽  
Gande Suresh
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Hydroxypropyl Methylcellulose ◽  
Magnesium Stearate ◽  
Zero Order ◽  
Matrix Tablets ◽  
Drug Dissolution ◽  
Crystalline Cellulose ◽  
Dissolution Profile ◽  
Release Formulation

The present study was aimed to develop once-daily controlled release trilayer matrix tablets of nelfinavir to achieve zero-order drug release for sustained plasma concentration. Nelfinavir trilayer matrix tablets were prepared by direct compression method and consisted of middle active layer with different grades of hydroxypropyl methylcellulose (HPMC), PVP (Polyvinyl Pyrrolidine) K-30 and MCC (Micro Crystalline Cellulose). Barrier layers were prepared with Polyox WSR-303, Xanthan gum, microcrystalline cellulose and magnesium stearate. Based on the evaluation parameters, drug dissolution profile and release drug kinetics DF8 were found to be optimized formulation. The developed drug delivery system provided prolonged drug release rates over a period of 24 h. The release profile of the optimized formulation (DF8) was described by the zero-order and best fitted to Higuchi model. FT-IR studies confirmed that there were no chemical interactions between drug and excipients used in the formulation. These results indicate that the approach used could lead to a successful development of a controlled release formulation of nelfinavir in the management of AIDS.

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