Selective diffusion spectroscopy using excitation sculpting

2015 ◽  
Vol 55 (5) ◽  
pp. 433-437 ◽  
Author(s):  
Peter W. A. Howe
Keyword(s):  
Selective Diffusion ◽  
Excitation Sculpting

scholarly journals Adaptive Chaotic Image Encryption Algorithm Based on RNA and Pixel Depth

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1770
Author(s):  
Xiaoqiang Zhang ◽  
Xuangang Yan
Keyword(s):  
Image Encryption ◽  
Three Dimensional ◽  
Encryption Algorithm ◽  
Current Time ◽  
Plain Image ◽  
Scope Of Application ◽  
Selective Diffusion ◽  
Chaotic Image Encryption ◽  
And Diffusion ◽  
Image Encryption Algorithm

To prevent the leakage of image content, image encryption technology has received increasing attention. Most current algorithms are only suitable for the images of certain types and cannot update keys in a timely manner. To tackle such problems, we propose an adaptive chaotic image encryption algorithm based on RNA and pixel depth. Firstly, a novel chaotic system, two-dimensional improved Logistic-adjusted-Sine map is designed. Then, we propose a three-dimensional adaptive Arnold transform for scrambling. Secondly, keys are generated by the hash values of the plain image and current time to achieve one-image, one-key, and one-time pad simultaneously. Thirdly, we build a pre-permuted RNA cube for 3D adaptive scrambling by pixel depth, chaotic sequences, and adaptive RNA coding. Finally, selective diffusion combined with pixel depth and RNA operations is performed, in which the RNA operators are determined by the chemical structure and properties of amino acids. Pixel depth is integrated into the whole procedure of parameter generation, scrambling, and diffusion. Experiments and algorithm analyses show that our algorithm has strong security, desirable performance, and a broader scope of application.

scholarly journals Sequence design and evaluation of the reproducibility of water-selective diffusion-weighted imaging of the breast at 3 T

2014 ◽  
Vol 27 (9) ◽  
pp. 1030-1036 ◽  
Author(s):  
He Zhu ◽  
Lori R. Arlinghaus ◽  
Jennifer G. Whisenant ◽  
Ming Li ◽  
John C. Gore ◽  
...  
Keyword(s):  
Diffusion Weighted Imaging ◽  
Sequence Design ◽  
Diffusion Weighted ◽  
Selective Diffusion

scholarly journals Simulated features of the air-hydrate formation process in the Antarctic ice sheet at Vostok

1999 ◽  
Vol 29 ◽  
pp. 191-201 ◽  
Author(s):  
Andrey N. Salamatin ◽  
Vladimir Ya. Lipenkov ◽  
Takeo Hondoh ◽  
Tomoko Ikeda
Keyword(s):  
Ice Core ◽  
Hydrate Formation ◽  
Ice Cores ◽  
Air Bubbles ◽  
Air Bubble ◽  
Self Diffusion ◽  
Rate Limiting Step ◽  
Typical Time ◽  
Polar Ice Sheets ◽  
Selective Diffusion

AbstractA recently developed theory of post-nucleation conversion of an air bubble to air-hydrate crystal in ice is applied to simulate two different types of air-hydrate formation in polar ice sheets. The work is focused on interpretation of the Vostok (Antarctica) ice-core data. The hydrostatic compression of bubbles is the rate-limiting step of the phase transformation which is additionally influenced by selective diffusion of the gas components from neighboring air bubbles. The latter process leads to the gas fractionation resulting in lower (higher) N2/O2 ratios in air hydrates (coexisting bubbles) with respect to atmospheric air. The typical time of the post-nucleation conversion decreases at Vostok from 1300-200 a at the beginning to 50-3 a at the end of the transition zone. The model of the diffusive transport of the air constituents from air bubbles to hydrate crystals is constrained by the data of Raman spectra measurements. The oxygen and nitrogen self-diffusion (permeation) coefficients in ice are determined at 220 K as 4.5 × 10−8 and 9.5 × 10−8 mm2 a−1, respectively while the activation energy is estimated to be about 50 kJ mol−1. The gas-fractionation time-scale at Vostok, τF ∼300 a, appears to be two orders of magnitude less than the typical time of the air-hydrate nucleation, τz ∼30-35 ka, and thus the condition for the extreme gas fractionation, τF ≪ τz is satisfied. Application of the theory to the GRIP and GISP2 ice cores shows that on average, a significant gas fractionation cannot be expected for air hydrates in central Greenland. However, a noticeable (statistically valid) nitrogen enrichment might be observed in the last air bubbles at the end of the transition.

scholarly journals Holey barrier

2003 ◽  
Vol 161 (3) ◽  
pp. 459-460 ◽  
Author(s):  
Karl Matter ◽  
Maria S. Balda
Keyword(s):  
Small Molecules ◽  
Blood Brain Barrier ◽  
Transmembrane Protein ◽  
Brain Barrier ◽  
Brain Endothelial Cell ◽  
Critical Determinant ◽  
Blood Brain ◽  
Functional Part ◽  
Selective Diffusion ◽  
Selective Increase

Endothelial tight junctions (TJs)**Abbreviations used in this paper: BBB, blood-brain barrier; BEC, brain endothelial cell; TJ, tight junction. are an important functional part of the blood-brain barrier (BBB). In this issue, Nitta et al. (2003) demonstrate that claudin-5, a transmembrane protein of TJs, is a critical determinant of BBB permeability in mice. Unexpectedly, knockout of claudin-5 did not result in a general breakdown of TJs but in a selective increase in paracellular permeability of small molecules. This suggests that the BBB can be manipulated to allow selective diffusion of small molecules and makes claudin-5 a possible target for the development of drugs for this purpose.

Planar 4H- and 6H-SiC p–n diodes fabricated by selective diffusion of boron

2001 ◽  
Vol 45 (12) ◽  
pp. 1987-1990 ◽  
Author(s):  
Y Gao ◽  
S Soloviev ◽  
T.S Sudarshan
Keyword(s):  
Selective Diffusion
Sign in / Sign up

Export Citation Format

Share Document