Results 291 to 300 of about 463,274 (346)

Critical instability at moving keyhole tip generates porosity in laser melting

Science, 2020
Driving the pores away The formation of “keyholes” (vapor-filled depressions) during additive manufacturing leads to porosity, which degrades alloy performance, especially fracture properties, and remains a big challenge for the 3D printing of metals ...
Cang Zhao, N. Parab, Xuxiao Li, K. Fezzaa, W. Tan, A. Rollett, T. Sun   +6 more
semanticscholar   +1 more source

Pervious concrete: effects of porosity on permeability and strength

Magazine of Concrete Research, 2021
Pervious concrete needs to have many pores to achieve high water permeability, but excessive porosity may cause a serious reduction in strength.
L. Li, Jia-Jian Feng, Jiang Zhu, S. Chu, A. Kwan   +4 more
semanticscholar   +1 more source

Contrasting Symmetric Porosity and Porosity

Journal of Applied Analysis, 1998
The aim of the paper is to compare the behaviour of sets with respect to symmetric porosity and porosity. The authors have found several similarities as well as several differences.
Michael J. Evans, Paul D. Humke
openaire   +2 more sources

Multiple-porosity Variable Critical Porosity Model [PDF]

Proceedings, 2015
Compared with conventional reservoirs, complex reservoirs often have more variety of pore types and more complex pore shape. For example, carbonate rocks can have a variety of pore types, such as moldic, vuggy, interparticle, intraparticle and crack.
J.J. Zhang, G.Z. Zhang, F. He
openaire   +1 more source

Porosity in composite resins

Biomaterials, 1995
Porosity in the pastes of composite resins before and after polymerization has been measured. The influence of the diameter of the extrusion orifices and the spatulation of the chemically-activated pastes has been evaluated. Considering that thin layers of these materials are transparent, the investigation has been carried out mainly by analysis of ...
V. FANO, K. POZELA, ORTALLI, Ida
openaire   +2 more sources

Porosity… Advantage or Disadvantage?

Microscopy and Microanalysis, 2015
Nowadays, due to the increasing demand on portable electronic devices with ultrahigh density data storage and lower power consumption, the miniaturization of ferroelectrics has become an important issue. This progressive development requires the morphology control of the materials and the understanding of the effects of size reduction on the properties
Castro, Alichandra, Ferreira, Paula, Rodriguez, Brian J, Vilarinho, Paula M   +3 more
openaire   +4 more sources

Balancing Mechanical Stability and Ultrahigh Porosity in Crystalline Framework Materials.

Angewandte Chemie, 2018
A new mesoporous metal-organic framework (MOF; DUT-60) was conceptually designed in silico using Zn4 O6+ nodes, ditopic and tritopic linkers to explore the stability limits of framework architectures with ultrahigh porosity.
Ines M Hönicke, I. Senkovska, V. Bon, I. Baburin, Nadine Bönisch, S. Raschke, J. Evans, S. Kaskel   +7 more
semanticscholar   +1 more source

Porosity and Permeability

2012
The nature of reservoir rocks containing oil and gas dictates the quantities of fluids trapped within the void space of these rocks, the ability of these fluids to flow through the rocks, and other related physical properties. Undoubtedly, the two most important petrophysical parameters that have dominated the petroleum engineering literature since the
Djebbar Tiab, Erle C. Donaldson
openaire   +2 more sources

Deep learning reservoir porosity prediction based on multilayer long short-term memory network

Geophysics, 2020
The cost of obtaining a complete porosity value using traditional coring methods is relatively high, and as the drilling depth increases, the difficulty of obtaining the porosity value also increases. Nowadays, the prediction of fine reservoir parameters
Wei Chen, Liuqing Yang, Bei Zha, Mi Zhang, Yangkang Chen   +4 more
semanticscholar   +1 more source

Evaluating Porosity Parameters for Porosity–Property Relations

Journal of the American Ceramic Society, 1993
Porosity parameters are considered from the standpoint of a map of the volume fraction porosity (P) and the ratio of normalized radii of the pore (rp) and the solid particles, webs, or ligaments (rs) defining the pores. For pore structures derived from uniform stacking of identical spherical particles or bubbles, this “map” turns out to be a single S ...
openaire   +2 more sources