Influence of the bulk diffusion of rubidium and sodium atoms in glass on their surface dwell time

2017 ◽  
Vol 53 (3) ◽  
pp. 278-287
Author(s):  
S. N. Atutov ◽  
F. A. Benimetskii ◽  
A. O. Makarov
Keyword(s):  
Dwell Time ◽  
Bulk Diffusion ◽  
Sodium Atoms

TEM STUDIES OF THE MICROMECHANISMS OF SOLID STATE REACTIONS IN Ni-Zr BULK DIFFUSION COUPLES

1990 ◽  
Vol 51 (C4) ◽  
pp. C4-121-C4-130
Author(s):  
U. KÖSTER ◽  
R. PRIES ◽  
G. BEWERNICK ◽  
B. SCHUHMACHER ◽  
M. BLANK-BEWERSDORFF
Keyword(s):  
Solid State ◽  
Bulk Diffusion ◽  
Solid State Reactions ◽  
Diffusion Couples

Small Molecule Permeation Across Membrane Channels: Chemical Modification to Quantify Transport Across OmpF

2018 ◽  
Author(s):  
Jiajun Wang ◽  
Jayesh Arun Bafna ◽  
Satya Prathyusha Bhamidimarri ◽  
Mathias Winterhalter
Keyword(s):  
Dwell Time ◽  
Covalent Binding ◽  
Channel Structure ◽  
Ion Current ◽  
E Coli ◽  
Current Fluctuation ◽  
Wide Range ◽  
Outer Membrane Channel ◽  
Biological Channels ◽  
Constriction Region

Biological channels facilitate the exchange of small molecules across membranes, but surprisingly there is a lack of general tools for the identification and quantification of transport (i.e., translocation and binding). Analyzing the ion current fluctuation of a typical channel with its constriction region in the middle does not allow a direct conclusion on successful transport. For this, we created an additional barrier acting as a molecular counter at the exit of the channel. To identify permeation, we mainly read the molecule residence time in the channel lumen as the indicator whether the molecule reached the exit of the channel. As an example, here we use the well-studied porin, OmpF, an outer membrane channel from <i>E. coli</i>. Inspection of the channel structure suggests that aspartic acid at position 181 is located below the constriction region (CR) and we subsequently mutated this residue to cysteine, where else cysteine free and functionalized it by covalent binding with 2-sulfonatoethyl methanethiosulfonate (MTSES) or the larger glutathione (GLT) blockers. Using the dwell time as the signal for transport, we found that both mono-arginine and tri-arginine permeation process is prolonged by 20% and 50% respectively through OmpF<sub>E181C</sub>MTSES, while the larger sized blocker modification OmpF<sub>E181C</sub>GLT drastically decreased the permeation of mono-arginine by 9-fold and even blocked the pathway of the tri-arginine. In case of the hepta-arginine as substrate, both chemical modifications led to an identical ‘blocked’ pattern observed by the dwell time of ion current fluctuation of the OmpF<sub>wt</sub>. As an instance for antibiotic permeation, we analyzed norfloxacin, a fluoroquinolone antimicrobial agent. The modulation of the interaction dwell time suggests possible successful permeation of norfloxacin across OmpF<sub>wt</sub>. This approach may discriminate blockages from translocation events for a wide range of substrates. A potential application could be screening for scaffolds to improve the permeability of antibiotics.

Visual asymmetries during face encoding Increased dwell time and fixations in the upper and left hemifields

2018 ◽  
Author(s):  
Fatima Maria Felisberti
Keyword(s):  
Face Recognition ◽  
Eye Movements ◽  
Visual Field ◽  
Face Processing ◽  
Dwell Time ◽  
The Other ◽  
Environmental Cues ◽  
Reading Habits ◽  
The Right

Visual field asymmetries (VFA) in the encoding of groups rather than individual faces has been rarely investigated. Here, eye movements (dwell time (DT) and fixations (Fix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each of the three groups were placed in the upper left (UL), upper right (UR), lower left (LL), or lower right (LR) quadrants. Face recognition was equally high in the three groups. In contrast, the proportion of DT and Fix were higher for faces in the left than the right hemifield and in the upper rather than the lower hemifield. The overall time spent looking at the UL was higher than in the other quadrants. The findings are relevant to the understanding of VFA in face processing, especially groups of faces, and might be linked to environmental cues and/or reading habits.

LADA Synchronization for Symmetric and Asymmetric ATE Test Program Cycles

2019 ◽  
Author(s):  
Arun Kumar Karunanithi ◽  
Joseph Caroselli ◽  
Jason Christensen ◽  
Michell Espitia
Keyword(s):  
Cycle Time ◽  
Dwell Time ◽  
Turnaround Time ◽  
Test Program ◽  
Area Of Interest ◽  
Marginal State ◽  
Structural Failures ◽  
Major Factors ◽  
High Level ◽  
Program Cycle

Abstract Laser Assisted Device Alteration (LADA) or Soft Defect Localization (SDL) is commonly used to root cause device marginality due to functional or structural failures. At a high level, LADA involves setting the device under test (DUT) at its marginal state and using focused near infra-red laser beams to perturb sensitive circuitry [1]. Scanning the focused laser beam over the die can be a long and time-consuming process. In this paper, two LADA cases are presented, which involve a parametric measurement failure while running a dynamic ATE test. Using LADA technique, these two cases were root caused. These two cases also explain how a parametric measurement-based LADA can be setup on ATE, as well as a synchronization method independent of vectors in a pattern. Synchronization was necessitated in the 2nd case due to the asymmetric test program loop, as well as the long test program cycle time. There are many factors which impact LADA turnaround time and it can take anywhere between few seconds to one day. The two major factors are the size of the Area of Interest (AOI) and test program cycle time. Test program cycle time influences the laser “dwell time” for LADA. Dwell time, in simple terms, is the total time the laser is parked at each pixel. The laser can also be synchronized with the test program cycle, keeping the two always in phase. This is explained in Case 2, where LADA synchronization was implemented, and the analysis was successfully completed in time, even though the test cycle time was very long.

scholarly journals Single nucleotide detection using bilayer MoS2 nanopores with high efficiency

RSC Advances ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 6114-6123
Author(s):  
Payel Sen ◽  
Manisha Gupta
Keyword(s):  
Dna Sequencing ◽  
Dwell Time ◽  
High Efficiency ◽  
Single Nucleotide

Bilayer MoS2 nanopores are suitable for fast and high-efficiency single nucleotide detection and DNA sequencing due to fast analyte capture and improved dwell time.

Sign in / Sign up

Export Citation Format

Share Document