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Hole Size (hole + size)
Selected AbstractsCompact and Light Supercapacitor Electrodes from a Surface-Only Solid by Opened Carbon Nanotubes with 2,200 m2 g,1 Surface AreaADVANCED FUNCTIONAL MATERIALS, Issue 3 2010Tatsuki Hiraoka Abstract An approach is presented to make a "surface-only solid" with a surface area of 2,240,m2 g,1 (1,310,m2,cm,3), corresponding to 85% of the atoms constituting a surface, by opening single-walled carbon nanotube forests and solids via controlled oxidation. The controllability of the approach is demonstrated by tailoring the hole size to match the guest molecule, for example, nitrogen, fullerene, or solvated ions. These features make the surface-only solid an ideal vessel for material and energy storage, as demonstrated by its use for electrodes to realize a light and compact supercapacitor with high energy (24.7,W h kg,1) and power (98.9,kW kg,1) densities, exceeding those of activated carbon (16.9,W h kg,1 and 35.7,kW kg,1). [source] Effects of bivalve shell particles of hyriopsis cumingii on the performances of epoxy resin studied by positron annihilationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Xudong Sun Abstract Mussel shell particles sized in micrometer level have been prepared with a ball mill. The X-ray powder diffractrometer (XRD) and Fourier transform infrared (FTIR) results proved that the shell particles contained mainly CaCO3 in the form of aragonite, together with small amount of organic phase. EP modified with shell particles showed a much rougher fracture surface than unfilled EP. The mechanical properties have been improved obviously by adding the shell particles in EP from 1% to 5%. The particle would occupy a number of free volume holes of the EP matrix. This would lead to a decrease in the total free volume concentration of the composites. The particles acted as a bridge to make more molecules interconnected for the good interfacial adhesion, resulting in a reduction of the free volume hole size in the interfacial layers. I2 reached its highest value when 3% shell particles were added and then decreased as the shellparticles content increased. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Effect of chain architecture on biaxial orientation and oxygen permeability of polypropylene filmJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008P. Dias Abstract Films of two isotactic propylene homopolymers prepared with different catalysts and a propylene/ethylene copolymer were biaxially oriented under conditions of temperature and strain rate that were similar to those encountered in a commercial film process. The draw temperature was varied in the range between the onset of melting and the peak melting temperature. It was found that the stress response during stretching depended on the residual crystallinity in the same way for all three polymers. Biaxial orientation reduced the oxygen permeability of the oriented films, however, the reduction did not correlate with the amount of orientation as measured by birefringence, with the fraction of amorphous phase as determined by density, or with free volume hole size as determined by PALS. Rather, the decrease in permeability was attributed to reduced mobility of amorphous tie molecules. A single one-to-one correlation between the oxygen permeability and the intensity of the dynamic mechanical ,-relaxation was demonstrated for all the polymers used in the study. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Using scanning electron, confocal and optical microscopes to measure microscopic holes in traysPACKAGING TECHNOLOGY AND SCIENCE, Issue 6 2005Laura Bix Abstract Package integrity is of paramount importance to the medical device industry. As healthcare costs soar and integrity testers become more and more sensitive, concern with the question ,what hole size allows microbial penetration into device packages?' is re-ignited. However, producing a consistent and measurable defect in the microcosm presents challenges. Varying techniques are currently employed to produce these defects. Use of an excimer laser is one of the most precise and accurate techniques, and holes ,certified' to be a given size can be purchased at a significant cost. To verify the accuracy and precision of holes drilled with an excimer laser, researchers measured laser-drilled ,exit' and ,entry' holes in glycol-modified polyetheylene terephthalate (PETG) trays using scanning electron microscopy (SEM) and confocal microscopy. This data and the certification data provided by the laser driller were analysed using a mixed-model analysis of variance (ANOVA). Both the effect of measuring technique and hole side (entry vs. exit) were found to be significant. These significant differences have the potential to impact the question that the industry faces with regard to penetration threshold. This suggests that a shift in thinking is needed. Perhaps it would be better if the industry stops thinking about hole size and begins to think in terms of what researchers have referred to as the ,effective hole', which is defined as the volume of gas that will flow through a hole of defined size per unit time. Copyright © 2005 John Wiley & Sons, Ltd. [source] Poly[[(pentaethylenehexamine)manganese(II)] [hepta-,-selenido-tritin(IV)]]: a tin,selenium net with remarkable flexibilityACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2009Guo-Hai Xu The title compound, {[Mn(C10H28N6)][Sn3Se7]}n, consists of anionic ,{[Sn3Se7]2,} layers interspersed by [Mn(peha)]2+ complex cations (peha is pentaethylenehexamine). Pseudocubic (Sn3Se4) cluster units within each layer are held together to form a 63 net with a hole size of 8.74 × 13.87,Å. Weak N,H...Se interactions between the host inorganic frameworks and metal complexes extend the components into a three-dimensional network. The incorporation of metal complexes into the flexible anion layer dictates the distortion of the holes. [source] Macular hole surgery with and without internal limiting membrane peelingACTA OPHTHALMOLOGICA, Issue 2009C KOURENTIS Purpose To compare the results of surgery for idiopathic macular hole with or without the surgical removal of the internal limiting membrane (ILM) and the effect on anatomical and functional success rates. Methods 41 consecutive patients with idiopathic macular hole stage II (n=11), III (n=22) and IV (n=8) underwent pars plana vitrectomy and intraocular gas tamponade in this study. The surgery was performed either with ILM peeling,Group A (n=28), or without, Group B (n=13). Ocular coherence tomography and ETDRS visual acuity were measured pre- and postoperatively to assess macular hole size and anatomical hole closure as well as visual function. Results The postoperative macular hole closure rate was 100% (28/28) in Group A and 84,6% (11/13) in Group B. The 2 cases that failed to close with primary surgery had a hole size greater than 400µm. There was no significant difference between the two groups in the postoperative visual outcome once anatomical success was achieved. Conclusion The study suggests that more evidence based trials are necessary to investigate the benefit of ILM peeling especially in the treatment of larger macular holes. [source] Urban Textural Analysis from Remote Sensor Data: Lacunarity Measurements Based on the Differential Box Counting MethodGEOGRAPHICAL ANALYSIS, Issue 4 2006Soe W. Myint Lacunarity is related to the spatial distribution of gap or hole sizes. For low lacunarity, all gap sizes are the same and geometric objects are deemed homogeneous; conversely, for high lacunarity, gap sizes are variable and objects are therefore heterogeneous. Textures that are homogeneous at small scales can be quite heterogeneous at large scales and vice versa, and hence, lacunarity can be considered a scale-dependent measure of heterogeneity or texture. In this article, we use a lacunarity method based on a differential box counting approach to identify urban land-use and land-cover classes from satellite sensor data. Our methodology focuses on two different gliding box methods to compute lacunarity values and demonstrate a mirror extension approach for a local moving window. The extension approach overcomes, or at least minimizes, the boundary problem. The results from our study suggest that the overlapping box approach is more effective than the skipping box approach, but that there is no significant difference between window sizes. Our work represents a contribution to not only advances in textural and spatial metrics as used in remote-sensing pattern interpretation but also for broadening understanding of the computational geometry of nonlinear shape models of which lacunarity is the reciprocal of fractal theory. [source] | ||||||||||