Symmetric Linear Rise and Fall of Conductance in a Trilayer Stack Engineered ReRAM-Based Synapse

2020 ◽  
Vol 2 (10) ◽  
pp. 3263-3269
Author(s):  
Kavita Vishwakarma ◽  
Rishabh Kishore ◽  
Arnab Datta
Keyword(s):  
Linear Rise

scholarly journals Understanding jökulhlaups: From tale to theory

2010 ◽  
Vol 56 (200) ◽  
pp. 1002-1010 ◽  
Author(s):  
Helgi Björnsson
Keyword(s):  
Theoretical Models ◽  
Frictional Heat ◽  
Drainage Systems ◽  
Linear Rise ◽  
Observed Behaviour ◽  
Flow Through ◽  
Discharge Patterns ◽  
The One ◽  
Different Sources ◽  
Source Geometry

AbstractThe study of jökulhlaups has advanced from describing them qualitatively to measuring systematically on site their discharge curves and source geometry, as well as investigating conditions when particular floods were initiated. In the early days of this science, hypotheses were formulated which attempted to explain the processes responsible for unstable flood growth. The general theory of time-dependent turbulent water flow through intraglacial conduits marked a breakthrough in understanding jökulhlaup hydraulics and has since remained a classical foundation for jökulhlaup studies. This theory described flood evolution in terms of water input into the upper end of a tunnel leading from a reservoir, taking account of sensible stored lake heat and geometry. Such a tunnel expands by positive feedback, since its ice walls melt through frictional heat produced by the flowing water. While this model successfully described jökulhlaups in which the discharge hydrograph increases more or less exponentially over time, other floods were observed which are in stark contrast. In them, pressurized floodwater propagates in a turbulent subglacial water sheet which opens and expands a system of conduits, with an extremely rapid linear rise in discharge. The rushing water enlarges its subglacial pathway not only by melting the ice around it but also by lifting, deforming and fracturing it. Subsequent drainage is nourished by two different sources, with conduit growth being controlled not only by water input at the upper end of the flood path but also by further water joining in, all the way to the edge of the glacier. Moreover, the trigger for releasing meltwater from glacial lakes has been seen to be either of two conduit opening mechanisms, which also determine whether a turbulent subglacial water sheet will result or not. On the one hand, drainage may begin by expanding already existing conduits, in which case the pressure remains lower than that of the ice overburden at the dam and the conduits grow slowly. On the other hand, lake levels may rise until flotation of the ice dam, abruptly opening a sufficient gap for water to propagate as a sheet flow. In order to explain which of these two initiation mechanisms will act, further studies are required into the structure of hydrological drainage systems under ice dams and into their linkage with these two mechanisms. Although current theoretical models of jökulhlaups drainage have managed to reproduce the observed discharge patterns, inconsistencies with the observed behaviour of subglacial drainage systems along the flood path demand further exploration of the actual hydraulic and glaciodynamic processes of jökulhlaups.

Two modes of interspike interval shortening by brief transient depolarizations in cat neocortical neurons

1993 ◽  
Vol 69 (5) ◽  
pp. 1661-1672 ◽  
Author(s):  
A. D. Reyes ◽  
E. E. Fetz
Keyword(s):  
Sodium Current ◽  
Regenerative Process ◽  
Neuronal Firing ◽  
Time Of Arrival ◽  
Initial Portion ◽  
Neocortical Neurons ◽  
Amplitude Increase ◽  
Linear Rise ◽  
The Mean ◽  
Layer V

1. The effects of small, brief depolarizing pulses and excitatory postsynaptic potentials (EPSPs) on neuronal firing were examined in layer V neurons in slices of cat sensorimotor cortex. During intracellular recording, brief depolarizing current pulses (duration, 0.5-2.0 ms; amplitude, 0.1-4.0 nA) were injected in neurons to produce pulse potentials (PPs) with a near-linear rise to a peak (0.08-3.6 mV; rise time = pulse duration) followed by an exponential decay. These PPs resembled EPSPs evoked by electrical stimulation of adjacent sites. When injected in neurons that were induced to discharge tonically, the PPs shortened the interspike intervals (ISIs) in two ways, depending on their time of arrival in the ISI. 2. Toward the end of the ISI, the PPs crossed a time-varying firing level, thereby directly evoking action potentials and shortening the ISIs. These directly evoked spikes occurred during the rise or peak of the PPs. The absolute firing level increased with the membrane trajectory during the latter part of the ISI. 3. PPs that appeared earlier in the ISI did not cross firing level directly but could nevertheless shorten the ISI by a slow regenerative process. The indirectly evoked spikes occurred after the peak of the PPs, at latencies whose magnitude and variability increased as the PPs appeared at successively earlier times in the ISI. PPs that occurred during the initial portion (approximately the 1st 3rd) of the ISI did not affect ISI duration. 4. Stimulus-evoked EPSPs shortened the ISIs in a manner similar to that of PPs. Like PPs, EPSPs caused direct crossings late in the ISI and indirect crossings earlier. Comparison of the mean and maximum ISI shortenings and the range of delays in which the PPs and EPSPs consistently produced ISI shortenings revealed no systematic differences. These similarities suggest that PPs may be used to simulate the ISI shortenings caused by EPSPs. 5. To characterize possible mechanisms underlying the ISI shortening, we examined the PP shapes at different times in the ISI. PPs immediately following a spike were smaller and decayed more rapidly than those evoked by the same current at rest. Late in the ISI, when the membrane potential was > 5 mV above rest, the PP height exceeded that of the PP at rest. This amplitude increase may be due to activation of the persistent sodium current.(ABSTRACT TRUNCATED AT 400 WORDS)

Modelling the hysteretic characteristics of a magnetorheological fluid damper

2003 ◽  
Vol 217 (7) ◽  
pp. 537-550 ◽  
Author(s):  
En Rong Wang ◽  
Xiao Qing Ma ◽  
S Rakhela ◽  
C Y Su
Keyword(s):  
Measured Data ◽  
Test Conditions ◽  
Proposed Model ◽  
Wide Range ◽  
Fluid Damper ◽  
Linear Rise ◽  
Force Velocity ◽  
Hysteretic Characteristics ◽  
Mr Fluid Damper ◽  
Excitation Conditions

A generalized model is proposed to characterize the biviscous hysteretic force characteristics of a magnetorheological (MR) fluid damper using symmetric and asymmetric sigmoid functions on the basis of a fundamental force generation mechanism, observed qualitative trends and measured data under a wide range of control and excitation conditions. Extensive laboratory measurements were performed to characterize the hysteretic force properties of an MR damper under a wide range of magnitudes of control current and excitation conditions (frequency and stroke). The global model is realized upon formulation and integration of component functions describing the preyield hysteresis, saturated hysteresis loop, linear rise and current-induced rise. The validity of the proposed model is demonstrated by comparing the simulation results with measured data in terms of hysteretic forcedisplacement and force-velocity characteristics under a wide range of test conditions. The results revealed reasonably good agreement between the measured data and model results, irrespective of the test conditions considered. The results of the study suggest that the proposed model could be effectively applied for characterizing the damper hysteresis and for development of an optimal controller for implementation in vehicular suspension applications.

scholarly journals The observant mind: self-awareness of attentional status

2010 ◽  
Vol 277 (1699) ◽  
pp. 3421-3426 ◽  
Author(s):  
Noriko Yamagishi ◽  
Stephen J. Anderson ◽  
Mitsuo Kawato
Keyword(s):  
Threshold Model ◽  
Discrimination Performance ◽  
Attentional Focus ◽  
Orientation Discrimination ◽  
Self Awareness ◽  
Neural Basis ◽  
Attentional Processes ◽  
Delay Times ◽  
Linear Rise ◽  
High Level

Visual perception is dependent not only on low-level sensory input but also on high-level cognitive factors such as attention. In this paper, we sought to determine whether attentional processes can be internally monitored for the purpose of enhancing behavioural performance. To do so, we developed a novel paradigm involving an orientation discrimination task in which observers had the freedom to delay target presentation—by any amount required—until they judged their attentional focus to be complete. Our results show that discrimination performance is significantly improved when individuals self-monitor their level of visual attention and respond only when they perceive it to be maximal. Although target delay times varied widely from trial-to-trial (range 860 ms–12.84 s), we show that their distribution is Gaussian when plotted on a reciprocal latency scale. We further show that the neural basis of the delay times for judging attentional status is well explained by a linear rise-to-threshold model. We conclude that attentional mechanisms can be self-monitored for the purpose of enhancing human decision-making processes, and that the neural basis of such processes can be understood in terms of a simple, yet broadly applicable, linear rise-to-threshold model.

Skew and linear rise of MMF across slot modelling-winding function approach

1999 ◽  
Vol 14 (3) ◽  
pp. 315-320 ◽  
Author(s):  
J.M. Gojko ◽  
D.D. Momir ◽  
O.B. Aleksandar
Keyword(s):  
Function Approach ◽  
Linear Rise

scholarly journals ESTIMATION OF TIME SINCE DEATH FROM THE CHANGES IN VITREOUS HUMOUR SODIUM (Na+) AND POTASSIUM (K+) LEVEL

2021 ◽  
Vol 5 (7) ◽  
Author(s):  
Binaca Gandhi ◽  
Shailendra Khichi ◽  
Mahendra Khokhar
Keyword(s):  
Postmortem Interval ◽  
Ion Concentration ◽  
Vitreous Humour ◽  
Time Since Death ◽  
Criminal Cases ◽  
Medicine Department ◽  
Medical College ◽  
Linear Rise ◽  
Relationship Of ◽  
Estimation Of Time

Background: For investigation of crime, it is very important to determine ‘time since death’ i.e. the interval between death and the time of postmortem examination also called as ‘postmortem interval. This is very important in criminal cases as it shows the track to the investigators to reach the suspected person and to obligate the innocent ones. Methods: The present study was conducted in Forensic Medicine Department on cases died in Dr. S.N. Medical College & associated Group of Hospitals, Jodhpur in association with Department of Biochemistry. Results: The linear correlation of the vitreous sodium (Na+) ion concentration was found statistically insignificant (r=0.045) therefore the coefficient of correlation could not be derived. Conclusion: We have observed linear rise of potassium (K+) ion concentration in the vitreous humour. The linear relationship of the increase in vitreous potassium (K+) ion concentration with increasing postmortem interval is both arithmatic as well as logarithmatic (statistically significant). Keywords: Na, K, Postmortem.

scholarly journals Salvage surgery for continent ileostomies (CI) after a first successful revision: more long-term blame on the reservoir than the nipple valve

2021 ◽  
Author(s):  
Karl-Wilhelm Ecker ◽  
Mathias Tönsmann ◽  
Nils Karl Josef Ecker ◽  
Gabriela Möslein
Keyword(s):  
Revisional Surgery ◽  
Underlying Disease ◽  
Cumulative Probability ◽  
Nipple Valve ◽  
Retrospective Data Analysis ◽  
Kaplan Meier ◽  
Linear Rise ◽  
Cumulative Probabilities

Abstract Purpose The aim of the study was to investigate the underlying cause of long-term complications in patients requiring at least one revision surgery of a continent ileostomy (CI) and to analyze functional outcome. Methods Only patients with CI at least one revision were included in the retrospective data analysis. Four different classes of complications (Cl A–D) were defined: Cl A = Nipple valve (NV), Cl B = pouch, Cl C = outlet (stoma), and Cl D = afferent loop (AL). Associations between underlying disease and origin of complications were analyzed. Cumulative probabilities were calculated using Kaplan–Meier analysis. Results A total of 77 patients were identified with a follow-up of 30 years, requiring 133 surgeries for 148 complications (c.). Cl A 49 c. (33.1%), Cl B 50 c. (33.8%), Cl C 39 c. (26.4%), and Cl D 10 c. (6.8%). Cl A and C complications were not correlated to underlying disease, whereas Cl B and D complications were only found in ulcerative colitis (UC) and Crohn’s disease (CD). The cumulative probability of a second revision showed a linear rise, reaching 62.5% after 20 years. Cl A and B complications both reached 42.1%. Eleven (14.3%) patients (10 Cl B) had pouch failure in a follow-up period of 11.5 ± 8.7 years (1–31 years), whereas 66 (85.7%) had successful revisional surgery. Overall CI survival was 78.8% at 44 years. Conclusion CI survival is limited by inflammatory complications of the pouch based on the underlying disease and not by mechanical limitations of the NV. Trial registration numbers None.

Studies of Temperature and Pressure Dependence in Thermocompression Gold Joints

2005 ◽  
Author(s):  
X. F. Ang ◽  
G. G. Zhang ◽  
J. Wei ◽  
Z. Chen ◽  
C. C. Wong
Keyword(s):  
Shear Strength ◽  
Critical Temperature ◽  
Pressure Dependence ◽  
Bonding Temperature ◽  
Interfacial Stress ◽  
3D Integration ◽  
Bonding Pressure ◽  
Barrier Films ◽  
Linear Rise ◽  
Temperature And Pressure

Low temperature interconnection is a critical component of 3D integration and packaging technology. In this study, we investigate the characteristics of thermocompression metal bonding using gold stud bumps formed on Si die in the temperature range of 100-300 °C and the pressure range of 200–600 g/bump. We observed a critical bonding temperature below which bonding did not occur and above which shear strength improves linearly with bonding temperature. This critical temperature can be interpreted to be the onset of the break-up of organic barrier films while the linear rise in shear strength can be attributed to the increase in the true bonded area. Above this critical temperature, the tensile strength of the Au-Au bond exhibits a maximum with increasing bonding pressure. This can be related to the pressure dependence of the interfacial stress distribution and its effect on unbonded radius, r. SEM fractographs of the failed surfaces suggest a combination of cohesive and adhesive failures along the bonded interface.

Adsorption of DL-alanine by allophane: effect of pH and unit particle aggregation

Clay Minerals ◽  
1999 ◽  
Vol 34 (2) ◽  
pp. 233-238 ◽  
Author(s):  
H. Hashizume ◽  
B. K. G. Theng
Keyword(s):  
Adsorption Isotherms ◽  
Linear Increase ◽  
Particle Aggregation ◽  
Published Data ◽  
Effect Of Ph ◽  
Linear Rise ◽  
Equilibrium Concentrations ◽  
Ph Dependent ◽  
High Concentrations

AbstractThe adsorption of DL-alanine at pH 4, 6 and 8 by a soil allophane has been determined. Two sets of experiments were carried out: (1) in which the allophane had been kept in a moist state throughout; and (2) in which the mineral had previously been dried at 50°C. In both instances, the adsorption isotherms showed three distinct regions as the concentration of alanine in solution was increased: (1) an initial, nearly linear, rise at low equilibrium concentrations; (2) a levelling off to a plateau at intermediate concentrations; and (3) a steep linear increase at high concentrations. For comparable concentrations of alanine in solution, adsorption decreased in the order pH 6 > pH 8 > pH 4. Irrespective of pH, however, more alanine was adsorbed by the ‘wet’ allophane than by its ‘dry’ counterpart. These observations are interpreted in terms of the morphology and aggregation of allophane unit particles together with the pH-dependent charge characteristics of allophane and alanine. The results are compared with published data on the adsorption of alanine by montmorillonite.

Sign in / Sign up

Export Citation Format

Share Document