foam injection is widely applied in amounts of fields to drilling, production, and formation protection. sometimes, the application result is disappointing, which is caused by the failure of bubble generation in foam flooding. therefore, it is necessary to seek ways for improving the performance of foam injection. an increased disturbance to the stratum, like the vibration caused by a seismic o...

Electrospun nanofibrous structures provide good performance to scaffolds in tissue engineering. We measured the local diffusion coefficients of 3-kDa FITC-dextran in line patterns of electrospun nanofibrous structures fabricated by the direct-write electrospinning (DWES) technique using the fluorescence recovery after photobleaching (FRAP) method. No significant differences were detected betwee...

In this note we present an immersed boundary (IB) method for restricted diffusion with permeable interfaces. These problems arise under a variety of circumstances, e.g., in thermal contact problems [7]. Diffusion in a medium consisting of two regimes separated by permeable boundaries is another example. It is well-known that cell boundaries in a living tissue are permeable to oxygen and water m...

A permeable cell system has been developed by treatment with saponin for studying in vitro replication of DNA and chromatin. DNA replication of simian virus 40 nucleoprotein complexes (SV40 chromatin) in saponin-treated permeable cells was found to be more efficient than that in digitonin-treated permeable cells. Autoradiography of the agarose-gel revealed that [alpha-32P]dCTP was incorporated ...

Given the a priori knowledge of the environment and the goal position, mobile robot navigation refers to the robot’s ability to safely move towards the goal using its knowledge and the sensorial information of the surrounding environment. Even though there are many different ways to approach navigation, most of them share a set of common components or blocks, among which path planning and obsta...

It is a well-established fact that the cells of many anima1 and plant tissues are bounded by semi-permeable surfaces-surfaces which are more permeable to water than they are to saIts and sugars in solution. This fact is particularly well estabhshed in the case of vertebrate striated muscle; and there is much further evidence for the view that the irritability of this tissue is dependent on the ...

PURPOSE To present our initial results in the treatment of nasolacrimal obstruction by placing a polyurethane stent. METHODS 74 nasolacrimal stents were implanted under fluoroscopic guidance in obstructed nasolacrimal systems of 64 patients. Dacryocystography and CT were used to verify the position and patency of the stents. Mean follow-up was 15 months. Clinical examinations were done at the...

We have used the chemically synthesized sequence of pre-pro-parathyroid hormone and several of its analogues to test the notion that the capacity of amphipathic peptides to aggregate in membranes and form ion-permeable channels correlates with their ability to function as signal sequences for secreted proteins. We found that pre-pro-parathyroid hormone (the signal sequence and pro-region of par...

The saturation-strip model for piezoelectric crack is re-examined in a permeable environment to analyze fracture toughness of a piezoelectric ceramic. In this study, a permeable crack is modeled as a vanishing thin but finite rectangular slit with surface charge deposited along crack surfaces. This permeable saturation crack model reveals that there exists a possible leaky mode for electrical f...