نتایج جستجو برای: so mri porosity should always be compared with gravimetry porosity second

تعداد نتایج: 10529454  

Natural ventilation is one of the most essential issues in the concept of high-performance architecture. The porosity has a lot to do with wind-phil architecture to meet high efficiency in integrated architectural design and materialization a high-performance building. Natural ventilation performance in porous buildings is influenced by a wide range of interre...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1392

abstract in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...

2010
Tarun R. Naik

The presence of capillary pores and air voids influences concrete permeability to a large extent. Concrete density is inversely proportional to its porosity. The ingress of aggressive agents into the pore structure is responsible for various durability problems in concrete structures. Therefore, a durable concrete should have low permeability. Permeability of concrete increases with the increas...

Journal: :Journal of Materials Science. Materials in Medicine 2007
Menno B. Claase Joost D. de Bruijn Dirk W. Grijpma Jan Feijen

Scaffolds from poly(ethylene oxide) and poly(butylene terephthalate), PEOT/PBT, with a PEO molecular weight of 1,000 and a PEOT content of 70 weight% (1000PEOT70PBT30) were prepared by leaching salt particles (425-500 microm). Scaffolds of 73.5, 80.6 and 85.0% porosity were treated with a CO(2) gas plasma and seeded with rat bone marrow stromal cells (BMSCs). After in vitro culture for 7 days (...

2007
Jun Zhou Hai-Lung Tsai

Porosity has been frequently observed in solidified, deep penetration pulsed laser welds. Porosity is detrimental to weld quality. Our previous study shows that porosity formation in laser welding is associated with the weld pool dynamics, keyhole collapse, and solidification processes. The objective of this paper is to use mathematical models to systematically investigate the transport phenome...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1389

the quest for power has formed much of the world history especially in 20th and 21st centuries. oil (energy) particularly after industrial revolution has been a tool for conquest and power and has been transformed to a geopolitical issue. from a geopolitical point of view this has been the case for the last two centuries in central asia and caucasus. central asia and caucasus has always been...

1999
Sandor Mulsow Bernard P. Boudreau

Ubiquitous porosity gradients have a potentially important effect on the mixing of particle-bound tracers, such as 210Pb Mass-depth coordinates cannot be used to deal with these effects if values of the traditional mixing coefficient, D,, are required. This paper compares and evaluates three different means of dealing directly with porosity gradients while modeling bioturbation, i.e. mean const...

Petrophysical parameters such as porosity, water and oil saturations, formation resistivity factor, etc. describe the storage capability of the porous media or the capacity of rocks to hold fluids. The modified Archie’s equation . / . , also called the saturation equation, is used to determine the water saturation. Archie’s parameters, namely , , and , are sometimes assumed constant to simp...

Journal: :Biomaterials 2008
Christine Knabe Christian Koch Alexander Rack Michael Stiller

This study examines the effect of two beta-tricalcium phosphate (TCP) particulate bone grafting materials with varying porosity on bone formation and on osteogenic marker expression 6 months after sinus floor augmentation. Unilateral sinus grafting was performed in 20 patients using a combination (4:1 ratio) of beta-TCP particles with 35% porosity (TCP-C) or 65% porosity (TCP-CM) and autogenous...

2017
Jihwan Song Junhyung Kim Taewook Kang Dongchoul Kim

Typical cathode materials of Li-ion battery suffer from a severe loss in specific capacity, and this problem is regarded as a major obstacle in the expansion of newer applications. To overcome this, porous cathodes are being extensively utilized. However, although it seems that the porosity in the cathode would be a panacea for high performance of LIBs, there is a blind point in the cathode con...

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