In this work, the charge dynamics characteristics of injection, transport and decay in porous and non-porous polytetrafluoroethylene (PTFE) film electrets were investigated by means of corona charging, isothermal and thermal stimulating surface-potential decay measurements. The results showed that the initial surface potential, whether positively or negatively charging, is much higher in non-po...

We show a general method of construction of non-porous sets in complete metric spaces. This method enables us to answer several open questions. We prove that each non-porous Suslin subset of a topologically complete metric space contains a non-porous closed subset. We show also a suucient condition, which gives that a certain system of compact sets contains a non-porous element. Namely, if we d...

In this paper we present our recent progresses towards effkient light emitting diodes based on porous silicon. We will touch the two following topics: 1) All porous silicon microcavities. Through the formation of a planar optical cavity it is possible to vary the spontaneous emission rate of porous silicon films. We demonstrate this by showing luminescence, and time resolved luminescence measur...

The reintroduction of superficially porous particles has resulted in a leap forward for the separation performance in liquid chromatography. The underlying reasons for the higher efficiency of columns packed with these particles are discussed. The performance of the newly introduced 5 μm superficially porous particles is evaluated and compared to 2.7 μm superficially porous and 3.5 and 5 μm ful...

A series of novel hierarchical nanoporous microstructures have been synthesized through one-step chemical reduction of micron size Cu2O and Co3O4 particles. By controlling the reduction time, non-porous Cu2O microcubes sequentially transform to nanoporous Cu/Cu2O/Cu dented cubic composites and hollow eightling-like Cu microparticles. The mechanism involved in the complex structural evolution is...

The morphology of the porous network in porous SiC has been studied. It has been found that pore formation starts with a few pores on the surface and then the porous network grows in a V-shaped branched structure below the surface. The hydrogen etching rates of porous and nonporous SiC have been measured. Etch rates of porous and nonporous wafers of various miscuts are found to be equal within ...

porous silicon layers have been prepared from n-type silicon wafers of (100) orientation. sem, ftir and pl have been used to characterize the morphological and optical properties of porous silicon. the influence of varying etching time in the anodizing solution, on structural and optical properties of porous silicon has been investigated. it is observed that pore size increases with etching tim...

After tumor resection, bone reconstruction such as skull base reconstruction using interconnected porous structure is absolutely necessary. In this study, porous scaffolds for bone reconstruction were prepared using heat-pressing and salt-leaching methods. High-density polyethylene (HDPE) and poly(ethylene-co-acrylic acid) (PEAA) were chosen as the polymer composites for producing a porous scaf...

A triple-layer composite membrane with porous-dense-porous structure was proposed to develop a high performance membrane reactor. The triple-layer composite membrane consists of a porous Sr0.7Ba0.3Fe0.9Mo0.1O3 δ (SBFM) layer, a dense 0.5 wt% Nb2O5-doped SrCo0.8Fe0.2O3 δ (SCFNb) layer and a porous La0.8Sr0.2MnO3 δ–yttria stabilized zirconia (LSM/YSZ) layer. The porous layers can effectively redu...