scholarly journals Dynein-Inspired Multilane Exclusion Process with Open Boundary Conditions

Entropy ◽  
2021 ◽  
Vol 23 (10) ◽  
pp. 1343
Author(s):  
Riya Nandi ◽  
Uwe C. Täuber ◽  
Priyanka Priyanka
Keyword(s):  
Time Distribution ◽  
Dwell Time ◽  
Exclusion Process ◽  
High Load ◽  
Open Boundary ◽  
Current Phase ◽  
Open Boundary Conditions ◽  
Double Exponential ◽  
Low Load ◽  
Load Conditions

Motivated by the sidewise motions of dynein motors shown in experiments, we use a variant of the exclusion process to model the multistep dynamics of dyneins on a cylinder with open ends. Due to the varied step sizes of the particles in a quasi-two-dimensional topology, we observe the emergence of a novel phase diagram depending on the various load conditions. Under high-load conditions, our numerical findings yield results similar to the TASEP model with the presence of all three standard TASEP phases, namely the low-density (LD), high-density (HD), and maximal-current (MC) phases. However, for medium- to low-load conditions, for all chosen influx and outflux rates, we only observe the LD and HD phases, and the maximal-current phase disappears. Further, we also measure the dynamics for a single dynein particle which is logarithmically slower than a TASEP particle with a shorter waiting time. Our results also confirm experimental observations of the dwell time distribution: The dwell time distribution for dyneins is exponential in less crowded conditions, whereas a double exponential emerges under overcrowded conditions.

scholarly journals EFFECTS OF LANGMUIR KINETICS ON TWO-LANE TOTALLY ASYMMETRIC EXCLUSION PROCESSES OF MOLECULAR MOTOR TRAFFIC

2007 ◽  
Vol 18 (09) ◽  
pp. 1483-1496 ◽  
Author(s):  
RUILI WANG ◽  
RUI JIANG ◽  
MINGZHE LIU ◽  
JIMING LIU ◽  
QING-SONG WU
Keyword(s):  
Finite Size ◽  
Exclusion Process ◽  
Mean Field Approximation ◽  
Open Boundary ◽  
Finite Size Effect ◽  
Open Boundary Conditions ◽  
Density Profiles ◽  
Lane Changing ◽  
Langmuir Kinetics ◽  
Changing Rate

In this paper, we study a two-lane totally asymmetric simple exclusion process (TASEP) coupled with random attachment and detachment of particles (Langmuir kinetics) in both lanes under open boundary conditions. Our model can describe the directed motion of molecular motors, attachment and detachment of motors, and free inter-lane transition of motors between filaments. In this paper, we focus on some finite-size effects of the system because normally the sizes of most real systems are finite and small (e.g., size ≤ 10 000). A special finite-size effect of the two-lane system has been observed, which is that the density wall moves left first and then move towards the right with the increase of the lane-changing rate. We called it the jumping effect. We find that increasing attachment and detachment rates will weaken the jumping effect. We also confirmed that when the size of the two-lane system is large enough, the jumping effect disappears, and the two-lane system has a similar density profile to a single-lane TASEP coupled with Langmuir kinetics. Increasing lane-changing rates has little effect on density profiles after the density reaches maximum. Also, lane-changing rate has no effect on density profiles of a two-lane TASEP coupled with Langmuir kinetics at a large attachment/detachment rate and/or a large system size. Mean-field approximation is presented and it agrees with our Monte Carlo simulations.

Initial Results on a New Light-Duty 2.7L Opposed-Piston Gasoline Compression Ignition Multi-Cylinder Engine

2018 ◽  
Author(s):  
Ashwin Salvi ◽  
Reed Hanson ◽  
Rodrigo Zermeno ◽  
Gerhard Regner ◽  
Mark Sellnau ◽  
...  
Keyword(s):  
Pressure Rise ◽  
High Load ◽  
Combustion Stability ◽  
Residual Fraction ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Peak Cylinder Pressure ◽  
Low Load ◽  
Initial Results ◽  
Load Conditions

Gasoline compression ignition (GCI) is a cost-effective approach to achieving diesel-like efficiencies with low emissions. Traditional challenges with GCI arise at low-load conditions due to low charge temperatures causing combustion instability and at high-load conditions due to peak cylinder pressure and noise limitations. The fundamental architecture of the two-stroke Achates Power Opposed-Piston Engine (OP Engine) enables GCI by decoupling piston motion from cylinder scavenging, allowing for flexible and independent control of cylinder residual fraction and temperature leading to improved low load combustion. In addition, the high peak cylinder pressure and noise challenges at high-load operation are mitigated by the lower BMEP operation and faster heat release for the same pressure rise rate of the OP Engine. These advantages further solidify the performance benefits of the OP Engine and demonstrate the near-term feasibility of advanced combustion technologies, enabled by the opposed-piston architecture. This paper presents initial results from a steady state testing on a brand new 2.7L OP GCI multi-cylinder engine. A part of the recipe for successful GCI operation calls for high compression ratio, leading to higher combustion stability at low-loads, higher efficiencies, and lower cycle HC+NOx emissions. In addition, initial results on catalyst light-off mode with GCI are also presented. The OP Engine’s architectural advantages enable faster and earlier catalyst light-off while producing low emissions, which further improves cycle emissions and fuel consumption over conventional engines.

Perceptual Load Improves the Expression but not Learning of Relevant Sequence Information

2009 ◽  
Vol 56 (2) ◽  
pp. 84-91 ◽  
Author(s):  
Natacha Deroost ◽  
Daphné Coomans ◽  
Eric Soetens
Keyword(s):  
Learning Process ◽  
Sequence Learning ◽  
Perceptual Load ◽  
Relevant Information ◽  
High Load ◽  
Cognitive System ◽  
Perceptual Identification ◽  
Sequence Information ◽  
Low Load ◽  
Load Conditions

In two experiments, we investigated the hypothesis of Rowland and Shanks (2006a) that sequence learning of relevant information is resistant to variations in perceptual load. Under conditions of increased selection difficulty, participants incidentally learned a sequence of targets presented together with three distractors. Target and distractors were composed of pairs of letters and shared more or less features with each other, rendering perceptual identification of the target either more (high load) or less (low load) attention demanding. The expression of sequence learning improved significantly under high load conditions as compared to low load conditions. This could indicate that the cognitive system promotes the development of response-based sequence learning in order to cope with the attentional demands arising from high perceptual load. However, the learning process proved to be unaffected by perceptual load when tested under baseline conditions without distractors (Experiment 1) or under opposite load conditions as during training (Experiment 2). This demonstrates that sequence learning is not influenced by increasing selection demands and suggests that sequence learning runs independently of input attention.

Performance of a 650V SiC Diode with Reduced Chip Thickness

2012 ◽  
Vol 717-720 ◽  
pp. 921-924 ◽  
Author(s):  
Roland Rupp ◽  
Rolf Gerlach ◽  
Uwe Kirchner ◽  
Andreas Schlögl ◽  
Ronny Kern
Keyword(s):  
Chip Thickness ◽  
Differential Resistance ◽  
High Load ◽  
Performance Gain ◽  
Charge Reduction ◽  
Wafer Thickness ◽  
Low Load ◽  
Chip Size ◽  
Significant Performance ◽  
Load Conditions

A significant performance gain of 650V SiC diodes is possible by reducing the wafer thickness from the standard thickness of 350 µm to < 150 µm. Not only the differential resistance of the diodes but also the Rth benefit from this chip thickness reduction. As consequence a further chip size reduction with accompanying capacitive charge reduction leads to a device with improved efficiency in PFC applications under both high load and low load conditions.

scholarly journals Differential Benefits of Prospective Memory Reminders Depending on Cognitive Load

2021 ◽  
Author(s):  
Philip Peper ◽  
Durna Alakbarova ◽  
Hunter Ball
Keyword(s):  
Task Performance ◽  
Prospective Memory ◽  
Past Research ◽  
High Load ◽  
Retrospective Memory ◽  
Ongoing Task ◽  
Target Information ◽  
Low Load ◽  
Event Based ◽  
Load Conditions

Prospective memory (PM) refers to the ability to remember to complete a task at the appropriate moment in the future. Past research has found reminders can improve PM performance in both laboratory and naturalistic settings, but few projects have examined the circumstances when reminders are most beneficial. Three experiments in the present study tested the effect of reminders in an event-based PM task under different cognitive loads. In Experiments 1 (specific targets) and 2 (nonspecific targets), load was manipulated by having participants respond to a single (low load) or multiple (high load) targets. In Experiment 3, the association between pairs was manipulated by presenting strongly associated pairs (low load) or weakly associated pairs (high load). Half of the participants in each experiment received reminders whereby PM target information was placed at the top of the computer screen. Across all three experiments, it was found that the benefit of reminders was greater under high load than low load conditions. Importantly, the improvements in PM from reminders generally occurred without any additional cost to ongoing task performance and without any reduction of retrospective memory for the targets at the end of the experiment. Together these results suggest that reminders can be beneficial for reducing PM failures, particularly under high load, without the potential downside of increased effort expenditure.

scholarly journals Effect of Temperature and Dwell Time on Fatigue Crack Growth Behavior of CP-Ti

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1031 ◽  
Author(s):  
Chuan-Yi Su ◽  
Chang-Yu Zhou ◽  
Lei Lu ◽  
Jian Li ◽  
Peng-Yan Sun ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Dwell Time ◽  
Pure Titanium ◽  
Load Ratio ◽  
High Load ◽  
Fracture Surface Morphology ◽  
Commercial Pure Titanium ◽  
Low Load ◽  
Cp Ti

In this paper, the effects of temperature and dwell time on the Fatigue Crack Growth (FCG) behavior of commercial pure titanium were studied under high and low load ratios. Besides, combined with the fracture surface morphology, the specific characteristics of FCG were analyzed under pure fatigue and dwell fatigue conditions. The experiment results show that the FCG rate of commercial pure titanium (CP-Ti) increases with the temperature under low load ratio, and the dwell time increases the FCG rate. Also, the enhancement of the dwell time increases as the temperature rises. The dwell effect tends to be saturated when the temperature rises to 200 °C. Under high load ratio, the FCG rate of CP-Ti also exhibits a temperature-sensitive enhancement. The enhancement effect of the dwell time on the FCG rate under high load ratio is more significant. However, the effect of the hold time on the FCG rate does not increase at 300 °C. The da/dN–ΔK/E FCG curves for CP-Ti have a tendency to approach each other under different load ratios, which indicates that the E-modulus is an important factor for the difference. The effect of dwell time on the FCG behavior of CP-Ti is dominated by the creep deformation mechanism under different load ratios from room temperature to 300 °C. At the same time, the oxidation effect gradually becomes significant as the load ratio increases to 300 °C. The fracture surface morphology shows that the secondary cracks and the roughness increase with temperature or dwell time under low load ratio condition, while, under high load ratio, the effect of creep deformation on the FCG behavior is more obviously enhanced, and plastic deformation is gradually significant with increase of the dimples.

PERCEPTUAL LOAD MANIPULATION DOES NOT REVEAL SENSITIVITY ON THE N170 ERP COMPONENT OF MANIPULATED FACES AND BODIES

2017 ◽  
Vol 15 (3) ◽  
pp. 0-0
Author(s):  
Tarik N. Mohamed
Keyword(s):  
Visual Acuity ◽  
Selective Attention ◽  
Perceptual Load ◽  
High Load ◽  
Normal Visual Acuity ◽  
Load Theory ◽  
Low Load ◽  
The Face ◽  
Specific Letter ◽  
Load Conditions

Background: It has been controversial in the face recognition literaturę whether face-sensitive N170 is affected by selective attention. Attention was manipulated according to Lavie’s perceptual load theory, examining the effect of selective attention on the processing of faces and human bodies. Faces and human bodies were presented either intact or manipulated. Material/Methods: 18 Students (9Males) from Sohag University, aged between 19 and 22 years (M = 19.38, SD = 0.48) contributed data in this study. All participants were right handed, and had normal or corrected-to-normal visual acuity. Participants were instructed to detect specific letter strings „X or N” among different (i.e., High load), or identical (Low load) letters. Letters were superimposed on different distractors. Stimuli were presented intact (Exp.1), or manipulated (Exp.2-4), by removing certain features or parts in the face and body respectively. ERP technique was used and prominent N170 and LNC were measured. Results: It was found that there is no effect of selective attention on the face sensitive N170. It seems that cropped face N170 is not affected by selective attention. However, the N170 of faces and human bodies are not affected by selective attention. The LNC findings showed that this component is affected by selective attention with enhanced negativity under low load Conditions compared to high load conditions. Conclusions: The findings of the current study showed that either cropped faces and human bodies does not reveal sensitivity on the N170 ERP component of manipulated faces and bodies.

THEORETICAL INVESTIGATION OF SYNCHRONOUS TOTALLY ASYMMETRIC EXCLUSION PROCESSES ON LATTICES WITH A SHORTCUT

2010 ◽  
Vol 24 (28) ◽  
pp. 5539-5546 ◽  
Author(s):  
SONG XIAO ◽  
JIU-JU CAI ◽  
FEI LIU ◽  
MINGZHE LIU
Keyword(s):  
Phase Diagram ◽  
Exclusion Process ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Exclusion Processes ◽  
Density Profiles ◽  
Simple Exclusion Process ◽  
Asymmetric Simple Exclusion ◽  
Asymmetric Exclusion Processes ◽  
Good Agreement

In this paper, a synchronous totally asymmetric simple exclusion process (TASEP) with a shortcut under open boundary conditions is investigated. The shortcut is located in the bulk and characterized by shortcut probability q. The phase diagram and density profiles of the model are obtained. It is found that the phase diagram of the model includes three regions, similar to the normal synchronous TASEP. Interestingly, the phase diagram does not change with q. Monte Carlo simulations are used to obtain the bulk density of different phases and they are in good agreement with the approximate stationary state solutions of the model.

The Heisenberg Chain as a Dynamical Model for Protein Synthesis - Some Theoretical and Experimental Results

1997 ◽  
Vol 11 (01n02) ◽  
pp. 197-202 ◽  
Author(s):  
Gunter M. Schütz
Keyword(s):  
Exact Solution ◽  
Protein Synthesis ◽  
Lattice Gas ◽  
Mean Field ◽  
Exclusion Process ◽  
Open Boundary ◽  
Asymmetric Exclusion Process ◽  
Open Boundary Conditions ◽  
Heisenberg Chain ◽  
Boundary Fields

The integrable Heisenberg quantum chain with certain non-diagonal boundary fields is the generator of a Markov process known as asymmetric exclusion process with open boundary conditions. This is a driven lattice gas where particles hop randomly along a one-dimensional chain and are injected and absorbed at the boundaries. This model has been suggested in 1968 by MacDonald, Gibbs and Pipkin as a model for the kinetics of protein synthesis on nucleic acid templates. The exact solution of the steady state of the system (corresponding to the exact ground state of the Heisenberg chain) which was obtained recently is shown to be in qualitative agreement with experimental data. The exact solution supports some of the original conclusions drawn from a mean field treatment by MacDonald et al. but gives deeper insight into one important aspect.

Sign in / Sign up

Export Citation Format

Share Document