Search results for " barrier"

SIGNAL ANALYSIS AND PERFORMANCE EVALUATION OF A VEHICLE CRASH TEST WITH A FIXED SAFETY BARRIER BASED ON HAAR WAVELETS

2011

Author's version of an article published in the journal: International Journal of Wavelets, Multiresolution and Information Processing. Also available from the publisher at: http://dx.doi.org/10.1142/s0219691311003979 This paper deals with the wavelet-based performance analysis of the safety barrier for use in a full-scale test. The test involves a vehicle, a Ford Fiesta, which strikes the safety barrier at a prescribed angle and speed. The vehicle speed before the collision was measured. Vehicle accelerations in three directions at the center of gravity were measured during the collision. The yaw rate was measured with a gyro meter. Using normal speed and high-speed video cameras, the beha…

Social Stress Induces Blood-Brain Barrier Leakiness and Molecular Alterations Promoting Depression or Stress Resilience

2020

Analysis of Transition Metal Oxides based Heterojunction Solar Cells with S-shaped J-V curves

2020

The use of transition metal oxides for the selective carrier contact in the crystalline silicon solar cells technology is rising to interest for the excellent optoelectrical properties of these materials whose implementation, however, can result in lousy performing cells due to an S-shaped electrical characteristic. In this paper, we fabricated solar cells showing S-shaped J-V curve and carried out an analysis of the reasons of such behavior using a model involving the series of a standard cell equivalent circuit with a Schottky junction in order to explain these atypical performances. A good matching between the experimental measurements and the adopted theoretical model was obtained. The …

Stability measures in metastable states with Gaussian colored noise

2009

We present a study of the escape time from a metastable state of an overdamped Brownian particle, in the presence of colored noise generated by Ornstein-Uhlenbeck process. We analyze the role of the correlation time on the enhancement of the mean first passage time through a potential barrier and on the behavior of the mean growth rate coefficient as a function of the noise intensity. We observe the noise enhanced stability effect for all the initial unstable states used, and for all values of the correlation time $\tau_c$ investigated. We can distinguish two dynamical regimes characterized by weak and strong correlated noise respectively, depending on the value of $\tau_c$ with respect to …

Escape from a metastable state with fluctuating barrier

2003

Abstract We investigate the escape of a Brownian particle from fluctuating metastable states. We find the conditions for the noise enhanced stability (NES) effect for periodical driving force. We obtain general equations useful to calculate the average escape time for randomly switching potential profiles. For piece-wise linear potential profile we reveal the noise enhanced stability (NES) effect, when the height of “reverse” potential barrier of metastable state is comparatively small. We obtain analytically the condition for the NES phenomenon and the average escape time as a function of parameters, which characterize the potential and the driving dichotomous noise.

Noise driven translocation of short polymers in crowded solutions

2008

In this work we study the noise induced effects on the dynamics of short polymers crossing a potential barrier, in the presence of a metastable state. An improved version of the Rouse model for a flexible polymer has been adopted to mimic the molecular dynamics by taking into account both the interactions between adjacent monomers and introducing a Lennard-Jones potential between all beads. A bending recoil torque has also been included in our model. The polymer dynamics is simulated in a two-dimensional domain by numerically solving the Langevin equations of motion with a Gaussian uncorrelated noise. We find a nonmonotonic behaviour of the mean first passage time and the most probable tran…

Modelling strategic alliances in the wide-body long range aircraft market

2007

Abstract The wide-body long-range aircrafts market is characterized by increasing rivalry between Airbus and Boeing. One of the factors that drive their strategic behaviour is technological. We propose a technology indicator to identify conditions under which the aircraft companies have incentives to join a coalition. For this, we provide measurement of the side-payments necessary to sign a strategic alliance aimed at reducing technological barriers in the market. The results suggest that the existence of side-payments guarantees the stability of a strategic alliance if the gap in the technological level between the firms is high, or competition is through prices. For monopoly, a strategic …

Permeability properties of a three-cell type in vitro model of blood-brain barrier.

2005

We previously found that RBE4.B brain capillary endothelial cells (BCECs) form a layer with blood‐brain barrier (BBB) properties if co‐cultured with neurons for at least one week. As astrocytes are known to modulate BBB functions, we further set a culture system that included RBE4.B BCECs, neurons and astrocytes. In order to test formation of BBB, we measured the amount of (3)H‐sucrose able to cross the BCEC layer in this three‐cell type model of BBB. Herein we report that both neurons and astrocytes induce a decrease in the permeability of the BCEC layer to sucrose. These effects are synergic as if BCECs are cultured with both neurons and astrocytes for 5 days, permeability to sucrose decr…

Application of superconductor-semiconductor Schottky barrier for electron cooling

2003

Abstract Electronic cooling in superconductor–semiconductor–superconductor structures at sub kelvin temperatures has been demonstrated. Effect of the carrier concentration in the semiconductor on performance of the micro-cooler has been investigated.

Quantitative description of C-60 diffusion on an insulating surface

2010

The diffusion of ${\text{C}}_{60}$ molecules on large, atomically flat terraces of the ${\text{CaF}}_{2}(111)$ surface is studied under ultrahigh vacuum conditions at various substrate temperatures below room temperature. The weak molecule-substrate interaction on this insulating surface makes a direct observation of hopping events difficult. Therefore, to determine a quantitative value of the diffusion barrier, we employ the so-called onset method. This method is based on the analysis of spatial properties of islands created by nucleation of diffusing ${\text{C}}_{60}$ molecules, as measured by noncontact atomic force microscopy. We first determine the critical cluster size to be ${i}^{\en…