Multilayer porous ionizer Patent

Multilayer porous refractory metal ionizer design with thick, porous, large-grain substrates and thin, porous micron-grain substrate

Porous zirconia scaffold modified with mesoporous bioglass coating

Porous yttria-stabilized zirconia (YSZ) has been regarded as a potential candidate for bone substitute as its high mechanical strength. However, porous YSZ bodies are biologically inert to bone tissue. It is therefore necessary to introduce bioactive coatings onto the walls of the porous structures to enhance the bioactivity. In this study, the porous zirconia scaffolds were prepared by infiltration of Acrylonitrile Butadiene Styrene (ABS) scaffolds with 3 mol% yttria stabilized zirconia slurry. After sintering, a method of sol-gel dip coating was involved to make coating layer of mesoporous bioglass (MBGs). The porous zirconia without the coating had high porosities of 60.1% to 63.8%, and most macropores were interconnected with pore sizes of 0.5-0.8mm. The porous zirconia had compressive strengths of 9.07-9.90MPa. Moreover, the average coating thickness was about 7μm. There is no significant change of compressive strength for the porous zirconia with mesoporous biogalss coating. The bone marrow stromal cell (BMSC) proliferation test showed both uncoated and coated zirconia scaffolds have good biocompatibility. The scanning electron microscope (SEM) micrographs and the compositional analysis graphs demonstrated that after testing in the simulated body fluid (SBF) for 7 days, the apatite formation occurred on the coating surface. Thus, porous zirconia-based ceramics were modified with bioactive coating of mesoporous bioglass for potential biomedical applications

Processing of Bioceramic Implants Via Fused Deposition Process

Porous ceramic structures have long been a subject of investigation as bone sl..bstitute. Most of these porous structures are typically made by techniques that result .randomly arranged pores with a wide variety of pore sizes. In recent years, SFF methods are being used for the fabrication of porous bioceramic implants. Porous ceramic structures have been fabricated using indirect route where a .polymeric mold is fitst created via fused deposition process. The mold was then infiltrated with ceramic slurry, dried. and ·then subjected to a binder bum out and sintering cycle. In this paper, processing of 3D honeycomb porous alumina ceramic structures and some.initial mechanical properties for bone implants will be discussed.Mechanical Engineerin

Porous Concrete Design

Porous concrete is a special kind of concrete that has high porosity. The only difference between porous concrete and normal concrete is that a porous concrete mix does not consist of sand or other small particles. The lack of sand and small particles creates voids in the concrete. The voids that area created are the reason why water is able to pass through a porous concrete mix. Porous concrete is used for low traffic areas such as parking lots and pavements. The main purpose of porous concrete is to reduce or even eliminate storm water runoff which has a number of benefits. For this project, the team developed a porous pavement mixture that will be applicable for practical and real life use. This means that the porous concrete mixture must have a certain permeability and compressive strength. There were two main parts to the project. Initially the team found what value of water to cement ratio would give the highest possible compression strength. The team started with experimenting with water to cement ratio due to the fact that it is the only variable that affects compressive strength and barely, if at all, affects permeability. After figuring out what the best water to cement ratio was, the next part of the project was about experimenting with other variables that affect the permeability and compression strength of a porous concrete. After acquiring the best water to cement ratio for the highest compression strength, the second part of the experiment will consist of varying two other variables, which were aggregate size and types of aggregate. By optimizing these variables, an optimal porous concrete mixture was found that could be used for practical use. The hope was to find a mixture that can be used for either pavements or parking lots

Packing dimension of mean porous measures

We prove that the packing dimension of any mean porous Radon measure on $\mathbb R^d$ may be estimated from above by a function which depends on mean porosity. The upper bound tends to $d-1$ as mean porosity tends to its maximum value. This result was stated in \cite{BS}, and in a weaker form in \cite{JJ1}, but the proofs are not correct. Quite surprisingly, it turns out that mean porous measures are not necessarily approximable by mean porous sets. We verify this by constructing an example of a mean porous measure $\mu$ on $\mathbb R$ such that $\mu(A)=0$ for all mean porous sets $A\subset\mathbb R$.Comment: Revised versio