Accuracy of a simple diffusion theory model of fluorescence for estimating fluorophore concentration

2003 ◽  
Author(s):  
Kevin R. Diamond ◽  
Michael S. Patterson ◽  
Thomas J. Farrell
Keyword(s):  
Diffusion Theory ◽  
Theory Model ◽  
Simple Diffusion

Three-Group Albedo Method Applied to the Diffusion Phenomenon with Up-Scattering of Neutrons

2006 ◽  
Vol 258-260 ◽  
pp. 403-408
Author(s):  
André Miguel Barge Pontes Torres Terra ◽  
Jorge Alberto Valle da Silva ◽  
Ronaldo Glicério Cabral
Keyword(s):  
Radiation Transport ◽  
Diffusion Theory ◽  
Theory Model ◽  
Model Case ◽  
Diffusion Phenomenon ◽  
Conventional Radiation ◽  
Major Application ◽  
Albedo Method ◽  
Transport Method

The main objective of this research is to develop a three-group neutron Albedo algorithm considering the up-scattering of neutrons in order to analyze the diffusion phenomenon in nonmultiplying media. The neutron Albedo method is an analytical method that does not try to solve explicit describing equations for the neutron fluxes [1,2]. Thus the neutron Albedo methodology is very different from the conventional methodology, as the neutron diffusion theory model. Graphite is analyzed as a model case. One major application is in the determination of the nonleakage probabilities with more understandable results in physical terms than conventional radiation transport method calculations.

Optical Limiting with Lithium Niobate

1999 ◽  
Vol 597 ◽  
Author(s):  
Gary Cook ◽  
David C. Jones ◽  
Craig J. Finnan ◽  
Lesley L. Taylor ◽  
Tony W. Vere ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Diffusion Theory ◽  
Photovoltaic Effect ◽  
Optical Gain ◽  
Optical Limiting ◽  
Dark Conductivity ◽  
Simple Diffusion ◽  
Beam Coupling ◽  
Coupling Equations ◽  
Focusing Lens

AbstractIron doped lithium niobate (Fe:LiNbO3) in a simple focal plane geometry has demonstrated efficient optical limiting through two-beam coupling. The performance is largely independent of the total Fe concentration and the oxidation state of the Fe ions, providing the linear optical transmission of uncoated crystals is between 30% and 60%. Fe has been found to be the best dopant for LiNbO3, giving the widest spectral coverage and the greatest optical limiting. Optical limiting in Fe:LiNbO3 has been shown to be very much greater than predicted by simple diffusion theory. The reason for this is a higher optical gain than expected. It is suggested that this may be due to an enhancement of the space-charge field arising from the photovoltaic effect. The standard two-beam coupling equations have been modified to include the effects of the dark conductivity. This has produced a theoretical intensity dependence on the ΔOD which closely follows the behaviour observed in the laboratory. A further modification to the theory has also shown that the focusing lens f-number greatly affects the optical limiting characteristics of Fe:LiNbO3. A lens f-number of approximately 20 gives the best results.

Diffusion of Colloids and Other Waste Species in Brine–Saturated Backfill Materials

1983 ◽  
Vol 26 ◽  
Author(s):  
E. J. Nowak
Keyword(s):  
Colloidal Gold ◽  
Diffusion Theory ◽  
Distribution Coefficients ◽  
Low Density ◽  
Sorption Data ◽  
Simple Diffusion ◽  
Diffusion Cells ◽  
Backfill Materials ◽  
Cylindrical Diffusion ◽  
Waste Repositories

ABSTRACTThe diffusion of plutonium (IV) and pertechnetate and the migration of colloidal gold in brine-saturated bentonite was measured. High ionic strength brine characterizes potentially intruding groundwater for radioactive waste repositories in salt. Plastic diffusion cells containing cylindrical diffusion columns were used for low density bentonite. Metal diffusion cells constructed entirely from Hastelloy C-276 were used for the diffusion of pertechnetate in highly compacted bentonite. Apparent distribution coefficients calculated from plutonium diffusion in two columns of low density bentonite are 2 m3/kg and 3 m3/kg. These values are in good agreement with the value of 3m3/kg that was calculated from previous batch sorption data. Pertechnetate anions migrated out of a brine-saturated high density bentonite diffusion column at rates that are too large to be rationalized with a simple diffusion theory. Additional measurements that take into account possible channeling of pertechnetate are required. Colloidal gold was excluded from low density brine-saturated bentonite, but colloidal gold may have channeled between the bentonite and the wall of the diffusion cell. These results support the effectiveness of brine-saturated bentonite as an engineered barrier to plutonium. The results also highlight the need for additional measurements of pertechnetate and gold transport in bentonite. Needs for transport measurements that take into account site-specific materials interactions are also described.

Improved Methods for Departments' Intention for RFID Use

2013 ◽  
Vol 694-697 ◽  
pp. 2322-2326
Author(s):  
Yu Cheng Lee ◽  
Yin Cheng Hsiao ◽  
Pei Yu Hsieh ◽  
Yun Tien Ma
Keyword(s):  
Radio Frequency Identification ◽  
Cognitive Theory ◽  
Diffusion Theory ◽  
Theory Model ◽  
Ease Of Use ◽  
Factors Affecting ◽  
Carbon Reduction ◽  
Innovation Diffusion Theory ◽  
Parking Lot ◽  
And Behavior

Radio Frequency Identification (RFID) Government departments and enterprises in Taiwan apply RFID universally in the fields of animal microchip, door access management, Auto chip of anti-theft de-vice, MRT Easy Card, parking lot man-agement, anti-counterfeiting and material management, but the multifunctional in-telligent card with integration of RFID applications has not been developed so far. If we can develop a card with integration of the functions which are closely related to people's daily life such as ID card, NHI IC card, fingerprint, E-signature and E-commerce (E-wallet), it will not only save time and money spent on applying these cards for people, but also will lower the governmental ex-penditure and achieve the effect of energy saving and carbon reduction. The previous studies mostly explore the factors affecting the user’s intention and behavior of RFID use from the initial beliefs (ease-of-use and usefulness) and attitude. For example, to what extent the knowledge, belief, attitude, perceived value, it deserves further exploration. To resolve the above problems, this study out differences from Social cognitive theory, Innovation Diffusion theory and Expectation confirmation theory, and establishes the theory model of the user's intention and behavior of using RFID continuously, which is also verified in this paper.

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