ENVIRONMENTALLY FRIENDLY TECHNOLOGY: THE BEHAVIOUR OF NATURAL AND SYNTHETIC BINDER SYSTEMS WITHIN PAPER COATINGS

Coating shrinkage upon drying is a phenomenon well known to the paper coating industry, where it often causes changes in the final structure of the coating layer leading to poor results in terms of gloss, light scattering, surface strength, coverage, uniformity and printability. Such shrinkage has in previous studies been wrongly associated with shrinkage of the polymeric binders used in the coating formulation, by making erroneous comparison with solvent-based paint systems. Natural binders, as starch or proteins, which come from renewable resources and are therefore environmentally friendly, suffer more from this shrinkage phenomenon than synthetic binders. The aim of this research project was to improve the understanding of the processes involved in the drying of a coating layer and to create a model able to describe them. Shrinkage while the coating layer dries has been successfully measured by observing the deflection of coated strips of a synthetic elastically-deformable substrate. Ground calcium carbonate was used as the coating pigment, together with latex binders of both low and high glass transition temperature, Tg, respectively, and also with starch which is a natural film-forming water soluble binder. The final dry coatings were studied with mercury porosimetry and by scanning electron microscopy in order to characterise their porous structure. The flow and rheological properties of the coating colour formulations were measured in order to probe the particle-particle interaction between the different species in the wet coating colour. The void space of the dry coating layers was modelled using Pore-Cor, a software which generates simulated porous networks. A new algorithm was developed to model, within the simulated void space, the effective particles or "skeletal elements" representative of the solid phase of the dried porous system. The water-filled porous structures at the beginning of the shrinkage process (first critical concentration, FCC) were subsequently modelled by creating Pore-Cor structures with the same solid skeletal elements distribution as at the second critical concentration (at which the particles lock their positions), but with higher given porosity to account for the water present The capillary forces acting on the surface of the simulated coating were calculated, and found to be several orders of magnitude larger than the measured shrinkage forces. The shrinkage process was thus described as resulting from the effect of capillary forces in the plane of the coating layer resisted by a stick-slip process, where the capillary forces yield shrinkage only if a resistance force within the drying coating layer holds the structure in place and allows the menisci to form. The stick-slip theory was strongly supported by quantitative comparisons between the experimental forces required to intrude mercury, and the capillary forces within the simulated void structure.Omya AG, Oftringen, Switzerlan

The Foreign Corrupt Practices Act: Unbridled Enforcement and Flawed Culpability Standards Deter SMEs from Entering the Global Marketplace

In the wake of the Watergate Scandal, which exposed a variety of corporate as well as political abuses, the Securities and Exchange Commission (SEC) discovered that a staggering number of large corporations had made questionable or illegal payments exceeding $300 million to foreign government officials, politicians, and political parties. In 1977, Congress passed the Foreign Corrupt Practices Act (FCPA) to curb the negative impact of these corrupt payments on United States foreign policy objectives regarding the promotion of democracy and the free market system. In the decades since the passage of the FCPA, the government has expanded the use of the statute beyond its original target (large corporations) to small- and medium-sized enterprises (SMEs), which often lack the resources and international business sophistication to guard against bribery and extortion in all its forms and thus avoid liability. Additionally, the government’s enforcement regime exists largely outside the courts. As a result, the investigative tactics and settlement agreements are overly harsh on SMEs, exceed statutorily proscribed penalties, and discourage utilization and litigation of a variety of statutory provisions designed to protect businesses from liability. This Comment argues that the FCPA should be amended to provide SMEs proper defenses against liability through the mental state provisions for domestic concerns and require more judicial oversight of the Department of Justice (DOJ) and the SEC enforcement policies. These changes will encourage SMEs to enter the international marketplace and protect SMEs from investigative costs and settlement penalties that do serious harm to their financial situation and are often disproportionate to the alleged wrongdoing

The Foreign Corrupt Practices Act: Unbridled Enforcement and Flawed Culpability Standards Deter SMEs from Entering the Global Marketplace

In the wake of the Watergate Scandal, which exposed a variety of corporate as well as political abuses, the Securities and Exchange Commission (SEC) discovered that a staggering number of large corporations had made questionable or illegal payments exceeding $300 million to foreign government officials, politicians, and political parties. In 1977, Congress passed the Foreign Corrupt Practices Act (FCPA) to curb the negative impact of these corrupt payments on United States foreign policy objectives regarding the promotion of democracy and the free market system. In the decades since the passage of the FCPA, the government has expanded the use of the statute beyond its original target (large corporations) to small- and medium-sized enterprises (SMEs), which often lack the resources and international business sophistication to guard against bribery and extortion in all its forms and thus avoid liability. Additionally, the government’s enforcement regime exists largely outside the courts. As a result, the investigative tactics and settlement agreements are overly harsh on SMEs, exceed statutorily proscribed penalties, and discourage utilization and litigation of a variety of statutory provisions designed to protect businesses from liability. This Comment argues that the FCPA should be amended to provide SMEs proper defenses against liability through the mental state provisions for domestic concerns and require more judicial oversight of the Department of Justice (DOJ) and the SEC enforcement policies. These changes will encourage SMEs to enter the international marketplace and protect SMEs from investigative costs and settlement penalties that do serious harm to their financial situation and are often disproportionate to the alleged wrongdoing

Porometry, porosimetry, image analysis and void network modelling in the study of the pore-level properties of filters

We present fundamental and quantitative comparisons between the techniques of porometry (or flow permporometry), porosimetry, image analysis and void network modelling for seven types of filter, chosen to encompass the range of simple to complex void structure. They were metal, cellulose and glass fibre macro- and meso-porous filters of various types. The comparisons allow a general re-appraisal of the limitations of each technique for measuring void structures. Porometry is shown to give unrealistically narrow void size distributions, but the correct filtration characteristic when calibrated. Shielded mercury porosimetry can give the quaternary (sample-level anisotropic) characteristics of the void structure. The first derivative of a mercury porosimetry intrusion curve is shown to underestimate the large number of voids, but this error can be largely corrected by the use of a void network model. The model was also used to simulate the full filtration characteristic of each sample, which agreed with the manufacturer's filtration ratings. The model was validated through its correct a priori simulation of absolute gas permeabilities for track etch, cellulose nitrate and sintered powder filters. © 2011 Elsevier Ltd

Characterisation of the porous structure of Gilsocarbon graphite using pycnometry, cyclic porosimetry and void-network modeling

file: :C$$:/pdf/1-s2.0-S000862231400164X-main.pdf:pdfThe cores of the fourteen Advanced Gas-cooled nuclear Reactors (AGRs) within the UK comprise Gilsocarbon graphite, a manufactured material surrounded predominantly by CO2 at high pressure and temperature to provide heat exchange. The intense ionising radiation within the reactors causes radiolytic oxidation, and the resulting mass loss is a primary factor in determining reactor lifetime. The void structure of the porous Gilsocarbon graphite affects the permeability and diffusion of the carbon dioxide, and the sites of oxidation. To model this void structure, the porosities and densities of ten virgin Gilsocarbon graphite samples have been measured by powder and helium pycnometry. For comparison, results are also presented for highly ordered pyrolytic graphite (HOPG), and a fine-grained Ringsdorff graphite. Samples have been examined at a range of magnifications by electron microscopy. Total porosities and percolation characteristics have been measured by standard and cyclic mercury porosimetry up to an applied mercury pressure of 400MPa. Inverse modelling of the cyclic intrusion curves produces simulated void structures with characteristics which closely match those of experiment. Void size distributions of the structures are presented, together with much Supplementary Information. The simulated void networks provide the bases for future simulations of the radiolytic oxidation process itself