A series of shape-persistent phenylene-ethynylene-naphthylene-butadiynylene macrocycles with different extraannular alkyl groups and intraannular bridges is synthesized by oxidative Glaser-coupling of the appropriate precursors. The intraannular bridges serve in this case as templates that reduce the oligomerization even when the reaction is not performed under pseudo high-dilution conditions. ...

This paper examined the adhesive strength of paint-on resin to crown and bridge composites after soaking in water and thermal-cycling. Three shades of paint-on resin were coated on three kinds of crown and bridge composite under four surface treatment conditions (a combination of sandblaster and pretreatment liquid). These specimens were soaked in water at 37 degrees C for 1 day, 1 month, and 1...

high speed trains are an indispensable part of rapid transportation systems in many countries. as the fastest means of transport on the ground, these trains are extremely sensitive to the terrain and track conditions. geometrical irregularities and mechanical characteristics of the track, together with inconsistencies in the lane (including bridges that support the track) are considered importa...

1. Introduction: Surface tension driven break-up of cylindrical fluid elements into droplets plays a crucial role in the use or processing of many multicomponent complex fluids like paints, inks, insecticides, cosmetics, food, etc [1, 2]. These industrial fluids are typically formulated using dilute polymer solutions, and are exposed to a wide range of shear and extension rates. Since the polym...

Flexible pressure sensors have many potential applications in wearable electronics, robotics, health monitoring, and more. In particular, liquid-metal-based sensors are especially promising as they can undergo strains of over 200% without failure. However, current liquid-metal-based strain sensors are incapable of resolving small pressure changes in the few kPa range, making them unsuitable for...

Abstract. In this paper, we investigate the dynamic process of liquid bridge formation between two parallel hydrophobic plates with hydrophilic patches, previously studied in [1]. We propose a dynamic Hele-Shaw model to take advantage of the small aspect ratio between the gap width and the plate size. A constrained level set method is applied to solve the model equations numerically, where a gl...

We evaluate the feasibility of manipulating droplets in two dimensions by exploiting Coulombic forces acting on conductive droplets immersed in a dielectric fluid. When a droplet suspended in an immiscible fluid is located near an electrode under a dc voltage, the droplet can be charged by direct contact, by charge transfer along an electrically conducting path, or by both mechanisms. This proc...

performance of structures during recent earthquakes shows that the effect of vertical component of earthquake (vce) could be considered as one of the main causes of bridges collapse. in most of bridge design codes, for seismic analysis of bridges, vce is not taken into account or a distinguished method isn’t presented for assessment of vce. in the present work, the effect of vce on two existing...

past earthquakes have demonstrated that old rc bridges may be seismically vulnerable. bridge responses during the last decades illustrated the necessity of the seismic assessment of bridges especially those which were designed with old codes. in this research an existing concrete bridge representative of the most common bridges in the highway system in iran are studied. push over and nonlinear ...

In this paper, full scale load test of a horizontally curved steel box-girder bridge is carried out in order to detect structural defects, which reportedly result in unwanted vibrations in nearby buildings. The bridge is tested under the passage of six heavy vehicles at different speeds, so as to determine its static and dynamic responses. A total number of one hundred and two (102) sensors are...