In this work we present measurements of permeability, effective porosity and tortuosity on a variety of rock samples using NMR/MRI of thermal and laser-polarized gas. Permeability and effective porosity are measured simultaneously using MRI to monitor the inflow of laser-polarized xenon into the rock core. Tortuosity is determined from measurements of the time-dependent diffusion coefficient using thermal xenon in sealed samples. The initial results from a limited number of rocks indicate inverse correlations between tortuosity and both effective porosity and permeability. Further studies to widen the number of types of rocks studied may eventually aid in explaining the poorly understood connection between permeability and tortuosity of rock cores.
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http://dx.doi.org/10.1016/j.mri.2004.11.044 | DOI Listing |
Sci Rep
January 2025
School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran, Iran.
In this research, the effect of different plasticizers with different amounts on the properties of monolithic alumina-based refractories has been investigated. All samples were fired at 1100 °C and 1550 °C. In order to evaluate the desired properties, first the rheological properties of the samples were examined, and then for further investigations, loss on ignition (LOI), percentage of permanent linear changes (PLC), apparent porosity (AP), bulk density (BD) and cold crushing strength (CCS) tests were used.
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January 2025
College of Mechanical and Transportation Engineering, Southwest Forestry University, Kunming, 650224, China.
The current piston material, Al-12Si, lacks sufficient passivation in the acidic lubrication system of biodiesel engines, making it prone to corrosion in the presence of Cl. Fe amorphous particles exhibit good compatibility with Al-12Si, possessing strong corrosion resistance, excellent passivation ability, and good high-temperature stability. They are a potential reinforcement for enhancing the Al-12Si piston material.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Pharmacy, Weifang Medical University, Weifang 261053, Shandong PR China.
As one of the most promising means to repair diseased tissues, stem cell therapy with immense potential to differentiate into mature specialized cells has been rapidly developed. However, the clinical application of stem-cell-dominated regenerative medicine was heavily hindered by the loss of pluripotency during the long-term in vitro expansion. Here, a composite three-dimensional (3D) graphene-based biomaterial, denoted as GO-Por-CMP@CaP, with hierarchical pore structure (micro- to macropore), was developed to guide the directional differentiation of human umbilical cord MSCs (hucMSCs) into osteoblasts.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
This study introduces a novel bilayer wound dressing that integrates a quaternized chitosan-polyacrylic acid (QCs-PAA) sponge as the top layer with electrospun nanofibers containing curcumin as the bottom layer. For the first time, QCs and PAA were combined in an 80:20 ratio through freeze-drying to form a porous sponge layer with ideal structural properties, including 83 ± 6 % porosity and pore diameters of 290 ± 12.5 μm.
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March 2025
Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, PR China; Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, PR China. Electronic address:
The limited membrane permeability and bacterial resistance pose significant challenges in the management of intracellular drug-resistant bacterial infections. To overcome this issue, we developed a bacterial-targeted drug delivery system based on quaternary ammonium chitosan-modified mesoporous silica nanoparticles (MSN-NH-CFP@HACC) for the treatment of intracellular Methicillin-resistant Staphylococcus aureus (MRSA) infections. This system utilizes amino-functionalized mesoporous silica nanoparticles to efficiently load cefoperazone (CFP), and the nanoparticles' surface is coated with 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) to target bacteria and enhance macrophage uptake.
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