A study of the i-layer porosity as a function of the deposition parameters by PECVD technique, is presented here. It is demonstrated in particular, that for a fixed deposition rate of 2 Ays, increasing the plasma power tends to increase the layer ̊ density, while increasing the pressure tends to increase the layer porosity. Regarding the cells, no correlation between the layer density and the in...

Although extensive efforts have been put into the development of porous scaffolds for bone regeneration, with encouraging results, all porous materials have a common limitation: the inherent lack of strength associated with porosity. Hence, the development of porous hydroxyapatite scaffolds has been hindered to non-load bearing applications. We report here how freeze casting can be applied to s...

This editor’s note gives an overview of the content this issue which is sponsored by Oregon Sea Grant.

Nanoscale porosity is critical for cellulose reactivity and can be detrimentally affected by wet pressing. The present study evaluated how wet pressing reduced the nanoscale porosity of a set of pulps produced from sugarcane bagasse. The pulps were produced using hydrothermal treatments, followed by either 160 °C alkaline (sodium hydroxide) or 190 °C organosolv (ethanol-water) pulping. Pulping ...

A reactive fluid dissolving the surrounding rock matrix can trigger an instability in the dissolution front, leading to spontaneous formation of pronounced channels or wormholes. Theoretical investigations of this instability have typically focused on a steadily propagating dissolution front that separates regions of high and low porosity. In this paper we show that this is not the only possibl...

Patients with monoclonal gammopathy of undetermined significance (MGUS) are at increased fracture risk, and we have previously shown that MGUS patients have altered trabecular bone microarchitecture compared with controls. However, there are no data on whether the porosity of cortical bone, which may play a greater role in bone strength and the occurrence of fractures, is increased in MGUS. Thu...

This paper describes a new variant of the least-mean-squares (LMS) algorithm, with low computational complexity, for updating an adaptive lter. The reduction in complexity is obtained by using values of the input data and the output error, quantized to the nearest power of two, to compute the gradient. This eliminates the need for multipliers or shifters in the algorithm's update section. The q...

Hydroxyapatite ceramics (HAp) have been used as bone graft materials, due to their excellent biocompatibility and osteoconductivity. Moreover, they had a wide range of porosity for using various bone defect parts. For example, HAp from 0 to 15 % porosity with high strength was useful as an ilium spacer, intervertebral spacer which requires high strength. HAp from 30 to 40% porosity was useful a...

It is acknowledged that cellular responses are highly affected by biomaterial porosity. The investigation of this effect is important for the development of implanted biomaterials that integrate with bone tissue. Zirconia and alumina ceramics exhibit outstanding mechanical properties and are among the most popular implant materials used in orthopedics, but few data exist regarding the effect of...