Analyses of Lattice Traffic Flow Model on a Gradient Highway

The optimal current difference lattice hydrodynamic model is extended to investigate the traffic flow dynamics on a unidirectional single lane gradient highway. The effect of slope on uphill/downhill highway is examined through linear stability analysis and shown that the slope significantly affects the stability region on the phase diagram.Using nonlinear stability analysis, the Burgers, Korteweg-deVries(KdV) and modified Korteweg-deVries(mKdV) equations are derived in stable, metastable and unstable region, respectively. The effect of reaction coefficient is examined and concluded that it plays an important role in suppressing the traffic jams on a gradient highway. The theoretical findings have been verified through numerical simulation which confirm that the slope on a gradient highway significantly influence the traffic dynamics and traffic jam can be suppressed efficiently by considering the optimal current difference effect in the new lattice model.     

Effect of Compressive Straining on Nanoindentation Elastic Modulus of Trabecular Bone

Trabecular bone with its porous structure is an important compressive load bearing member. Different structural factors such as porosity, non-homogeneous deformation, varying trabeculae thickness, connectivity, and nanoscale (10 nm to 1 μm) to macroscale (~0.1 mm to 10 mm) composition hierarchy determine the failure properties of trabecular bone. While the above factors have important bearing on bone properties, an understanding of how the local nanoscale properties change at different macroscale compressive strain levels can be important to develop an understanding of how bone fails. In the present work, such analyses are performed on bovine femoral trabecular bone samples derived from a single animal. Analyses focus on measuring nanoindentation elastic moduli at three distinct levels of compressive strains in the bone samples: (1) when the samples are not loaded; (2) after the samples have been loaded to a strain level just before apparent yielding and the macroscale compression test is stopped; and (3) after the samples have been compressed to a strain level after apparent yielding and the macroscale compression test is stopped. Nanoindentation elastic modulus values are two orders of magnitude higher than the macroscale compressive elastic modulus values of all samples. A high variability in macroscale compressive elastic modulus values is observed because of porous architecture and small sample size. Nanoindentation elastic modulus values show a progressive reduction with increase in the extent of macroscale compressive deformation. Apparent yielding has a significant effect on this trend. The decrease in nanoindentation modulus value for all samples accelerates from approximately 20% before yielding to approximately 60% after yielding in comparison to the nanoindentation modulus values at 0% strain level. The level of variation in the predicted nanoindentation modulus values is the lowest for uncompressed samples (~16–18%). However, with increase in the extent of compression, the level of variation increases. It varied between 50% and 90% for the samples tested after yielding showing a widespread heterogeneity in local nanoscale structural order after apparent yielding. Scanning electron microscope (SEM) observations suggest that apparent yielding significantly destroys local nanoscale structural order. However, quantitative results suggest that a significant residual nanoscale stiffness varying from 5 GPa to 8 GPa among different samples still remains for possible repair facilitation.     

A novel confocal optical pulse stretcher for laser pulses

We present an analytical and experimental study of a novel confocal optical pulse stretcher (COPS). The simple and passive pulse stretcher consists of two concave mirrors and a scraper beam-splitter and its optical configuration ensures a perfect spatial overlapping of laser pulses at the beam-splitter. The pulse stretcher is compact and suitable for laser pulses of large divergences. The confocal optical pulse stretcher is demonstrated on a pulsed copper vapour laser to convert a 40 ns (1/e² % points) pulse into a 55 ns with reduction of peak power by a factor of 1.375 without loss of pulse energy.     

Development of Humidity Sensor Using Nanoporous Polycarbonate Membranes

Russian Journal of Physical Chemistry A - In the present work, the effect of temperature and moisture has been studied on nano-porous polycarbonate membranes of size 15, 50, and 80 nm, respectively...     

Information patterns and Nash equilibria in extensive games: 1

In this paper we explore the relation between information patterns and Nash Equilibria in extensive games. By information we mean what players know about moves made by others, as well as by chance. For the most part we confine ourselves to pure strategies. But in Section 2 behavioral strategies are also examined. It turns out that they can be modeled as pure strategies of an appropriately enlarged game. Our results, applied to the enlarged game, can then be reinterpreted in terms of the behavioral strategies of the original game.     

Heat transfer at low temperatures: Application to sapphire

It is found that at low temperatures, the Callaway expression for the lattice thermal conductivity of a sample having dislocations reduces to the expression obtained by Dubey based on the nonlinear heat transfer theory. The obtained expression is used to explain the measurements of Wolfimeyer and Dillinger of phonon conductivity of sapphire in the temperature range 0.4–4 K.     

Effects of ultraviolet B exposure on the expression of proliferating cell nuclear antigen in murine skin

Proliferating cell nuclear antigen (PCNA) is an active nuclear protein involved in DNA replication, recombination and repair. PCNA is found throughout the basal layer in normal skin and in all layers of the epidermis in malignancy. This study evaluates PCNA's expression after acute and chronic UV-B irradiation. Skh-1 hairless mice exposed to 1.5 and 4.5 kJ/m2 of UV-B were sacrificed at 6, 12, 24, 48, 72 and 168 h. Immunohistochemical analysis revealed PCNA expression throughout the basal layer of untreated skin, with diminished expression at 6 h, indicative of immediate UV damage, and evidenced by the observable upregulation in pyrimidine dimer formation early on. Subsequently, PCNA immunoreactivity progressively increased, demonstrating an aberrant upward epidermal migratory pattern in association with chronic exposure. The 4.5 kJ/m2 group exhibited prolonged recovery in staining and also demonstrated this altered migratory pattern with chronic exposure. Progressive reactivation of PCNA expression occurs with repair. PCNA migration to upper layers of the epidermis indicates proliferation and possibly a subsequent increased malignant potential. We conclude that PCNA can serve as a marker of DNA repair and indirectly as an indicator of UV-B-induced damage, expression being time dependent and dose related. Specific immunoreactivity patterns and the observable atypia in keratinocytes are relevant in elucidating malignant potentiation.