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1. Paper surfaces functionalized by nanoparticles

Author

Ngo, Ying Hui, Li, Dan, Simon, George P., and Garnier, Gil

Subjects
*NANOPARTICLES, *NANOSTRUCTURED materials, *ELECTRIC properties of materials, *SURFACE chemistry, *OPTICAL properties, *CATALYSIS, *SURFACE plasmon resonance
Abstract

Abstract: Nanomaterials with unique electronic, optical and catalytic properties have recently been at the forefront of research due to their tremendous range of applications. Taking gold, silver and titania nanoparticles as examples, we have reviewed the current research works on paper functionalized by these nanoparticles. The functionalization of paper with only a very small concentration of nanoparticles is able to produce devices with excellent photocatalytic, antibacterial, anti-counterfeiting, Surface Enhanced Raman Scattering (SERS) and Surface Plasmon Resonance (SPR) performances. This review presents a brief overview of the properties of gold, silver and titania nanoparticles which contribute to the major applications of nanoparticles-functionalized paper. Different preparation methods of the nanoparticles-functionalized paper are reviewed, focusing on their ability to control the morphology and structure of paper as well as the spatial location and adsorption state of nanoparticles which are critical in achieving their optimum applications. In addition, main applications of the nanoparticles-functionalized papers are highlighted and their critical challenges are discussed, followed by perspectives on the future direction in this research field. Whilst a few studies to date have characterized the distribution of nanoparticles on paper substrates, none have yet optimized paper as a nanoparticles'' substrate. There remains a strong need to improve understanding on the optimum adsorption state of nanoparticles on paper and the heterogeneity effects of paper on the properties of these nanoparticles. [Copyright &y& Elsevier]

Published
2011
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2. Matching in local labor markets: a stochastic frontier approach.

Author

Hynninen, Sanna-Mari

Subjects
RESEARCH, LABOR market, LABOR supply, INDUSTRIAL efficiency, PAPER, EMPLOYEE selection, ARITHMETIC mean, VACANCY chains
Abstract

This paper investigates the technical efficiency of labor market matching from a stochastic frontier approach. The true fixed-effects model (Greene J Prod Anal 23:7–32, ; J Econom 126:269–303, ) is utilised in order to separate cross-sectional heterogeneity from inefficiency, and inefficiency terms are modelled following Battese and Coelli (Empir Econ 20:325–332, ). The data set consists of almost 17,000 observations from Local Labor Offices (LLOs) in Finland. According to the results, there are notable differences in matching efficiency between regions, and these differences contribute significantly to the number of filled vacancies. If all regions were as efficient as the most efficient one, the number of total matches per month would increase by over 23%. The heterogeneity of the job-seeker stock is an important determinant of matching efficiency: the weight of the composition of the job-seeker stock in the inefficiency terms is on average 85%. [ABSTRACT FROM AUTHOR]

Published
2009
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3. Polyaxial stress-dependent permeability of a three-dimensional fractured rock layer

Author

Xiaoguang Wang, Qinghua Lei, John-Paul Latham, and Jiansheng Xiang

Subjects
Paper, Environmental Engineering, 010504 meteorology & atmospheric sciences, Bedding, 04 Earth Sciences, 0211 other engineering and technologies, 02 engineering and technology, Stress, 01 natural sciences, 09 Engineering, Fractured rocks, Earth and Planetary Sciences (miscellaneous), Geotechnical engineering, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Water Science and Technology, Shearing (physics), Hydrogeology, Overburden pressure, Stress field, Permeability (earth sciences), Hydraulic properties, Shear (geology), FEMDEM, Heterogeneity, Groundwater, Geology
Abstract

A study about the influence of polyaxial (true-triaxial) stresses on the permeability of a three-dimensional (3D) fractured rock layer is presented. The 3D fracture system is constructed by extruding a two-dimensional (2D) outcrop pattern of a limestone bed that exhibits a ladder structure consisting of a “through-going” joint set abutted by later-stage short fractures. Geomechanical behaviour of the 3D fractured rock in response to in-situ stresses is modelled by the finite-discrete element method, which can capture the deformation of matrix blocks, variation of stress fields, reactivation of pre-existing rough fractures and propagation of new cracks. A series of numerical simulations is designed to load the fractured rock using various polyaxial in-situ stresses and the stress-dependent flow properties are further calculated. The fractured layer tends to exhibit stronger flow localisation and higher equivalent permeability as the far-field stress ratio is increased and the stress field is rotated such that fractures are preferentially oriented for shearing. The shear dilation of pre-existing fractures has dominant effects on flow localisation in the system, while the propagation of new fractures has minor impacts. The role of the overburden stress suggests that the conventional 2D analysis that neglects the effect of the out-of-plane stress (perpendicular to the bedding interface) may provide indicative approximations but not fully capture the polyaxial stress-dependent fracture network behaviour. The results of this study have important implications for understanding the heterogeneous flow of geological fluids (e.g. groundwater, petroleum) in subsurface and upscaling permeability for large-scale assessments., Hydrogeology Journal, 25 (8), ISSN:1431-2174, ISSN:1435-0157

Published
2016

4. Structural differences among serum IgA proteins of chimpanzee, rhesus monkey and rat origin

Subjects
Carbohydrate structure, Electrophoresis, Paper, Chromatography, Gel, Pan troglodytes, Protein Conformation, Molecular Sequence Data, Oligosaccharides, Species-specific, Macaca mulatta, Immunoglobulin A, Rats, Carbohydrate Sequence, Species Specificity, Carbohydrate Conformation, Sialic Acids, Animals, Safety, Heterogeneity, IgA
Abstract

Asparagine-linked sugar chains were quantitatively released from chimpanzee, Rhesus monkey and rat IgA proteins as oligosaccharides by hydrazinolysis, converted to radioactive oligosaccharides by reduction with NaB3H4, and separated into neutral and two acidic fractions by paper electrophoresis. The acidic oligosaccharides were converted to neutral ones by sialidase digestion, indicating that they are sialyl derivatives. However, the content of N-acetyl and N-glycolyl neuraminic acids was different among three species. The neutral and sialidase-treated acidic oligosaccharides were fractionated by Bio-Gel P-4 column chromatography in combination with linkage-specific sequential exoglycosidase digestion. Although IgA molecules from these species have mainly biantennary complex-type sugar chains, the contents of fucose and bisecting N-acetylglucosamine residues displayed marked species differences. In addition to these sugar chains, a small amount of the high mannose-type sugar chains was detected in chimpanzee and rat, but not in Rhesus monkey IgA. These results indicated that the processing of asparagine-linked sugar chains of IgA is different in each species.

Published
1997