scholarly journals A multiplexing meta-hologram with separate control of amplitude and phase

2021 ◽  
Author(s):  
Rao Fu ◽  
Xin SHAN ◽  
Liangui Deng ◽  
Qi Dai ◽  
Zhiqiang Guan ◽  
...  
Keyword(s):  
Separate Control

Mechanically assisted droplet transfer process in gas metal arc welding

2002 ◽  
Vol 216 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Y Wu ◽  
R Kovacevic
Keyword(s):  
Transfer Process ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Droplet Transfer ◽  
Macroscopic Appearance ◽  
Transfer Mode ◽  
Metal Arc Welding ◽  
Separate Control

Gas metal arc welding has been generally accepted as the preferred joining technique due to its advantages in high production and automated welding applications. Separate control of arc energy and arc force is an essential way to improve the welding quality and to obtain the projected metal transfer mode. One of the most effective methods for obtaining separate control is to exert an additional force on the metal transfer process. In this paper, the droplet transfer process with additional mechanical force is studied. The welding system is composed of an oscillating wire feeder. The images of molten metal droplets are captured by a high-speed digital camera, and both the macroscopic appearance and the cross-sectional profiles of the weld beads are analysed. It is shown that the droplet transfer process can be significantly improved by wire electrode oscillation, and a projected spray transfer mode can be established at much lower currents. By increasing the oscillation frequency, the droplet transfer rate increases while the droplet size decreases. In addition, the improvement in the droplet transfer process with wire oscillation leads to an enhancement of the surface quality and a modification of the geometry of the weld beads that could be of importance for overlay cladding and rapid prototyping based on deposition by welding.

scholarly journals Single-molecule FRET unveils induced-fit mechanism for substrate selectivity in flap endonuclease 1

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Fahad Rashid ◽  
Paul D Harris ◽  
Manal S Zaher ◽  
Mohamed A Sobhy ◽  
Luay I Joudeh ◽  
...  
Keyword(s):  
Single Molecule ◽  
Genome Stability ◽  
Substrate Recognition ◽  
Induced Fit ◽  
Flap Endonuclease 1 ◽  
Catalytic Selectivity ◽  
Single Molecule Fret ◽  
Diffusion Limited ◽  
Separate Control ◽  
Dna Substrate

Human flap endonuclease 1 (FEN1) and related structure-specific 5’nucleases precisely identify and incise aberrant DNA structures during replication, repair and recombination to avoid genomic instability. Yet, it is unclear how the 5’nuclease mechanisms of DNA distortion and protein ordering robustly mediate efficient and accurate substrate recognition and catalytic selectivity. Here, single-molecule sub-millisecond and millisecond analyses of FEN1 reveal a protein-DNA induced-fit mechanism that efficiently verifies substrate and suppresses off-target cleavage. FEN1 sculpts DNA with diffusion-limited kinetics to test DNA substrate. This DNA distortion mutually ‘locks’ protein and DNA conformation and enables substrate verification with extreme precision. Strikingly, FEN1 never misses cleavage of its cognate substrate while blocking probable formation of catalytically competent interactions with noncognate substrates and fostering their pre-incision dissociation. These findings establish FEN1 has practically perfect precision and that separate control of induced-fit substrate recognition sets up the catalytic selectivity of the nuclease active site for genome stability.

Gradient-Driven Diffusion Using Dual Control Volume Grand Canonical Molecular Dynamics (DCV-GCMD)

1995 ◽  
Vol 408 ◽  
Author(s):  
Frank Van Swol ◽  
Grant S. Heffelfinger
Keyword(s):  
Molecular Dynamics ◽  
Chemical Potential ◽  
Control Volume ◽  
Simulation Method ◽  
Steady State Mode ◽  
Transient Phenomena ◽  
Insertion And Deletion ◽  
Separate Control ◽  
Control Volumes ◽  
Grand Canonical

AbstractRecently we developed a new nonequilibrium molecular simulation method [1] that allows the direct study of interdiffusion in multicomponent mixtures. The method combines stochastic insertion and deletion moves characteristic of grand canonical (GC) simulations with molecular dynamics (MD) to control the chemical potential μi of a species i. Restricting the insertions and deletions to two separate control volumes (CV's) one can apply different μ's in distinct locations, and thus create chemical potential gradients. DCV-GCMD can be used to study transient phenomena such as the filling of micropores or used in steady-state mode to determine the diffusion coefficients in multicomponent fluid mixtures. We report on the effects of molecular interactions and demonstrate how in a sufficiently nonideal ternary mixture this can lead to up-hill or reverse diffusion. In addition we introduce a novel extension of DCV-GCMD that is specifically designed for the study of gradient-driven diffusion of molecules that are simply too large to be inserted and deleted.

scholarly journals Evidence for separate control of slow version and vergence eye movements: support for Hering's Law

1998 ◽  
Vol 38 (8) ◽  
pp. 1145-1152 ◽  
Author(s):  
John L. Semmlow ◽  
Weihong Yuan ◽  
Tara L. Alvarez
Keyword(s):  
Eye Movements ◽  
Separate Control ◽  
Hering’S Law

Separate Control Strategy for a Biomimetic Gliding Robotic Fish

2021 ◽  
pp. 1-10
Author(s):  
Huijie Dong ◽  
Zhengxing Wu ◽  
Pengfei Zhang ◽  
Jian Wang ◽  
Min Tan ◽  
...  
Keyword(s):  
Control Strategy ◽  
Robotic Fish ◽  
Separate Control

Separate control of number density and size of ErAs nanoparticles by a modified diffusion length process using two flux conditions during molecular beam epitaxy

2019 ◽  
Vol 692 ◽  
pp. 137586
Author(s):  
Yuanchang Zhang ◽  
Kurt G. Eyink ◽  
Madelyn Hill ◽  
Brittany Urwin ◽  
Krishnamurthy Mahalingam
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Diffusion Length ◽  
Number Density ◽  
Separate Control

Different Learned Coordinate Frames for Planning Trajectories and Final Positions in Reaching

2007 ◽  
Vol 98 (6) ◽  
pp. 3614-3626 ◽  
Author(s):  
Claude Ghez ◽  
Robert Scheidt ◽  
Hank Heijink
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Hand Position ◽  
Control Mechanisms ◽  
Final Position ◽  
Visuomotor Rotation ◽  
Coordinate Frames ◽  
Single Target ◽  
Starting Point ◽  
Separate Control

We previously reported that the kinematics of reaching movements reflect the superimposition of two separate control mechanisms specifying the hand's spatial trajectory and its final equilibrium position. We now asked whether the brain maintains separate representations of the spatial goals for planning hand trajectory and final position. One group of subjects learned a 30° visuomotor rotation about the hand's starting point while performing a movement reversal task (“slicing”) in which they reversed direction at one target and terminated movement at another. This task required accuracy in acquiring a target mid-movement. A second group adapted while moving to—and stabilizing at—a single target (“reaching”). This task required accuracy in specifying an intended final position. We examined how learning in the two tasks generalized both to movements made from untrained initial positions and to movements directed toward untrained targets. Shifting initial hand position had differential effects on the location of reversals and final positions: Trajectory directions remained unchanged and reversal locations were displaced in slicing whereas final positions of both reaches and slices were relatively unchanged. Generalization across directions in slicing was consistent with a hand-centered representation of desired reversal point as demonstrated previously for this task whereas the distributions of final positions were consistent with an eye-centered representation as found previously in studies of pointing in three-dimensional space. Our findings indicate that the intended trajectory and final position are represented in different coordinate frames, reconciling previous conflicting claims of hand-centered (vectorial) and eye-centered representations in reach planning.

Effect of tunicamycin on maturation of fetal mouse lung

1993 ◽  
Vol 265 (3) ◽  
pp. L250-L259
Author(s):  
E. H. Webster ◽  
S. R. Hilfer ◽  
R. L. Searls ◽  
J. Kornilow
Keyword(s):  
Extracellular Matrix ◽  
Fetal Lung ◽  
Mouse Lung ◽  
Type I ◽  
Type Ii ◽  
Fetal Mouse ◽  
Type Ii Pneumocytes ◽  
Separate Control ◽  
Normal Controls

The mesodermal capsule of the fetal lung plays a role in differentiation of the respiratory region. It has been proposed for other epithelial organs that the mesodermal capsule influences development by modifying the basal lamina or the extended extracellular matrix. The effect could be on deposition or turnover of collagens, proteoglycans, and/or glycoproteins. This study tests the role of glycoproteins in differentiation of respiratory endings by inhibiting their synthesis with the antibiotic tunicamycin (TM). Lungs at 16 and 18 days gestation and 3 days after birth were cultured with TM and examined for morphological and biochemical differences from normal controls. With TM, alveolar regions did not expand properly and formed fewer type I pneumocytes, although type II pneumocytes were unaffected. The epithelium of untreated respiratory regions showed greater incorporation of radioactive mannose than the airways region or mesenchyme. This incorporation was diminished in TM, but the pattern persisted. Comparison with the results obtained with beta-xyloside suggested that differentiation of type I and type II pneumocytes is under separate control.

scholarly journals Altered mechanisms of sympathetic activation during rhythmic forearm exercise in heart failure

1998 ◽  
Vol 84 (5) ◽  
pp. 1551-1559 ◽  
Author(s):  
David H. Silber ◽  
Greg Sutliff ◽  
Qing X. Yang ◽  
Michael B. Smith ◽  
Lawrence I. Sinoway ◽  
...  
Keyword(s):  
Heart Failure ◽  
Matched Control ◽  
Circulatory Arrest ◽  
Voluntary Contraction ◽  
Control Group ◽  
Resonance Spectroscopy ◽  
Muscle Metaboreflex ◽  
Separate Control ◽  
Forearm Exercise ◽  
Exercise Induced

In congestive heart failure (CHF), the mechanisms of exercise-induced sympathoexcitation are poorly defined. We compared the responses of sympathetic nerve activity directed to muscle (MSNA) and to skin (SSNA, peroneal microneurography) during rhythmic handgrip (RHG) at 25% of maximal voluntary contraction and during posthandgrip circulatory arrest (PHG-CA) in CHF patients with those of an age-matched control group. During RHG, the CHF patients fatigued prematurely. At end exercise, the increase in MSNA was similar in both groups (CHF patients, n = 12; controls, n = 10). However, during PHG-CA, in the controls MSNA returned to baseline, whereas it remained elevated in CHF patients ( P < 0.05). Similarly, at end exercise, the increase in SSNA was comparable in both groups (CHF patients, n = 11; controls, n = 12), whereas SSNA remained elevated during PHG-CA in CHF patients but not in the controls ( P < 0.05). In a separate control group ( n = 6), even high-intensity static handgrip was not accompanied by sustained elevation of SSNA during PHG-CA. 31P-nuclear magnetic resonance spectroscopy during RHG demonstrated significant muscle acidosis and accumulation of inorganic phosphate in CHF patients ( n = 7) but not in controls ( n = 9). We conclude that in CHF patients rhythmic forearm exercise leads to premature fatigue and accumulation of muscle metabolites. The prominent PHG-CA response of MSNA and SSNA in CHF patients suggests activation of the muscle metaboreflex. Because, in contrast to controls, in CHF patients both MSNA and SSNA appear to be under muscle metaboreflex control, the mechanisms and distribution of sympathetic outflow during exercise appear to be different from normal.

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