Laboratory experiments were conducted to study the micromechanics leading to fracture-like breakouts in vertical holes drilled into Mansfield sandstone and the relationship between their geometric characteristics and ...
详细信息
Laboratory experiments were conducted to study the micromechanics leading to fracture-like breakouts in vertical holes drilled into Mansfield sandstone and the relationship between their geometric characteristics and the applied far-field state of stress (σh, σH, σv). Fracture-like breakouts are tabular, long, and very narrow, originating and extending along the σh springline, where the maximum compressive stress concentration occurs. Several series of tests revealed a clear correlation between the applied stress regime and breakout length, indicating a potential use of these breakouts as stress magnitude indicators. The average breakout width in all the tests is constant regardless of the far-field stress conditions, suggesting that this is a material property related to the lower porosity narrow band developed ahead of the breakout tip. The latter is viewed as a zone of localized compaction formed by the debonding of weakly-sutured grains and their repacking as a result of the high stress concentration along σh springline. Fracture-like breakouts are produced by the removal, with the help of the circulating drilling fluid, of loosened intact and cracked grains from within this compaction band. Copyright 2004, ARMA, American Rock Mechanics Association.
Polymer blend technology was used to create highly anisotropic membranes for fuel cell applications. An important factor for creating structures of high proton conductivity and low methanol permeability was the applic...
详细信息
Polymer blend technology was used to create highly anisotropic membranes for fuel cell applications. An important factor for creating structures of high proton conductivity and low methanol permeability was the application of electric fields of selected magnitude and frequency during the formation of the membrane.
Magnetic semiconductors are of interest for emerging spintronic applications, such as the integration of electronic information processing with magnetic data storage. We report on a new approach - furnace annealing un...
详细信息
Anodic aluminum oxide (AAO) has long been considered n viable material for templuted growth of nanomaterials for electronic, magnetic and optical applications due to the ability to form self-organized, high aspect-rat...
详细信息
The specific sensing of antigen-antibody interaction was examined by using a PEGylated sensor. For the surface modification, acetal-PEG-SH was prepared and by using acetal-PEG-SH, PEG brush was constructed on the gold...
详细信息
ISBN:
(纸本)1877040193
The specific sensing of antigen-antibody interaction was examined by using a PEGylated sensor. For the surface modification, acetal-PEG-SH was prepared and by using acetal-PEG-SH, PEG brush was constructed on the gold sensor chip surface. Modification of antibody was carried out by conjugation of SH group in Fab' to the maleimide group at the distal end of PEG chains on the surface. The result shows that the suitable modification of antibody on the PEG brush surface is very important to obtain high sensing character.
Surface forces and shape changes were simultaneously measured during the approach and coalescence of two liquid-liquid and liquid-air interfaces. Large normal and lateral deformations were observed that are neverthele...
详细信息
Surface forces and shape changes were simultaneously measured during the approach and coalescence of two liquid-liquid and liquid-air interfaces. Large normal and lateral deformations were observed that are nevertheless consistent with a simple theoretical analysis of the long-range effects of short-range attractive van der Waals forces. The results imply that two fluidlike structures such as liquid droplets and soft biological cells can sense each other at much larger separations than previously assumed based on criteria taken from the interactions of hard particles.
Lightweight metal matrix nemo-composites (MMNCs) (metal matrix with nano-sized ceramic particles) can be of significance for automobile, aerospace and numerous other applications. However, it is extremely difficult to...
详细信息
The use of ultrasonic nonlinear effects to disperse nano-sized ceramic particles in molten metal has been studied and nano-sized SiC particle reinforced AZ91D magnesium composites were fabricated. The microstructure o...
详细信息
The stable dispersion of quantum dot nanoparticles (QD) in aqueous solution using polymers containing poly(ethylene glycol) (PEG) segment was investigated. It was found that using PEG/poly(2-N,N-dimethylaminoethyl met...
详细信息
ISBN:
(纸本)1877040193
The stable dispersion of quantum dot nanoparticles (QD) in aqueous solution using polymers containing poly(ethylene glycol) (PEG) segment was investigated. It was found that using PEG/poly(2-N,N-dimethylaminoethyl methacrylate) (PEG-b-PAMA) enables stabilization of QD in aqueous phase. The photochemical characteristics of the PEG-modified QD were found to be almost same as unmodified QD. It was observed that as he PEG/PAMA block copolymer-modified QDs possess PEG tethered chains on the surface, it is highly dispersion stable in aqueous media and also showed non-fouling character.
We demonstrate the facile fabrication of crack-free nanostructured crystalline titania into microsystems. Titania layers were formed by reacting Ti thin films, deposited by evaporation and sputtering, with aqueous H2O...
We demonstrate the facile fabrication of crack-free nanostructured crystalline titania into microsystems. Titania layers were formed by reacting Ti thin films, deposited by evaporation and sputtering, with aqueous H2O2. Cracks were observed in titania layers formed on blanket Ti films but absent on arrays of patterned Ti pads below a threshold dimension. Nanostructured titania formed from sputtered and evaporated Ti films consists of aligned fibrous and sponge-like nanoporous morphologies, respectively. Rat fibroblasts L-cells cultured on these titania fibers remain viable up to 3 days. These observations demonstrate the feasibility of this technique to integrate nanostructured titania into Nano|Micro-Electromechanical systems (N|MEMS) devices.
暂无评论