The use of hydrofluoroether liquid wetted wipes for the decontamination of sensitive equipment is attracting great interest. Contacting the contaminated equipment with such wipes results in the rapid removal of surface contaminants. Because adsorption from the liquid phase involves larger molecules than those found in the gas phase, the pores in the activated carbon needed to capture contaminants require pores with diameters above the micropore range (diameters <2 nm). In this work, the effects of the specific surface area (900-1300 m 2 /g), the total pore volume (0.40-0.70 cm 3 /g), and the pore size distribution (mean pore diameter ranged from <0.1 to 2.9 nm) of commercially available activated carbon fabrics (ACF) on the removal of 2-chloroethyl ethyl sulfide, a chemical warfare agent (CWA) simulant, from solution in hydrofluoroethers were examined. The highest adsorption loadings were obtained with the ACF with a mean pore diameter of 2.9 nm.

Summary Conventional gravel pack completions often reduce the wells productivity by increasing the completion skin. This paper describes a methodology backed by a systematic technique to predict the necessary drawdown, frac length, and conductivity to prevent formation failure and remove the completion damage. This method enables the engineer to optimize the fracture dimensions while obtaining the necessary decrease in drawdown near wellbore that would cause the unpacked perforation to fail. This technique will greatly reduce the chance for formation failure and improve the well performance without the need to gravel pack. Introduction Gravel packing has been the standard practice for controlling sand production from producing wells. These treatments are considered successful if the well produces sand free with a minimum drawdown across the perforations. Considerable time, money and research has gone into developing techniques that improve the performance of gravel packed completions by minimizing the damage caused by the completion. Despite these efforts experience has shown that even the most sophisticated sand control technology affects well productivity because of near wellbore damage caused by the gravel pack procedure. Table 1 shows a comparison of skin and productivity index for over 70 wells that have been completed using various completion techniques. As can be seen even the best internal gravel packed wells experience high skins when compared to perforated non-gravel packed wells. It has also been known for a number of ears that applying relatively large volumes of grave at above fracture gradient pressures followed by a internal gravel pack have resulted in less damage and good productivity improvements. These operations, called "Sand Oil Squeezes", were effectively a combination of a gravel pack and a hydraulic fracturing treatment, and are now called "Frac and Pack's". This technology is now being advanced so that the fracturing part of a "Frac and Pack" is not only used to improve the well productivity but also as a sand remediation technique. The sand control is accomplished by reducing the pressure drop across the perforation. Previous investigators merely postulated probable physical mechanisms and field procedures, whereas this paper presents a theory that couples sand production prediction and fracturing. This technique is currently being used in the North Sea and, as described in this paper, in the Gulf Coast of the United States.

Self-compacting concrete (SCC) is claimed to offer faster construction, safer sites and more consistent concrete quality, but little corroborative research data exist on performance advantages, particularly in comparison with traditional construction. Industry opinions also appear to be divided. For these reasons, an extensive interview programme was undertaken with UK contractors -from large national concrete frame contractors to small, locally based housebuilders -to assess whether benefits were being achieved and to try to understand the reasons why SCC is, or is not, being used. The 48 participants reported that decisions on the suitability of SCC were inherently complex and, if selected, there were challenges in understanding 'how' construction should be planned and managed to accommodate the use of SCC and to fully utilise its advantages. The findings identify the need for a step change in the industry's perception of SCC, such that it should be considered as a construction method, not simply as a material.

Additional Information:• Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees Self-compacting concrete or self-consolidating concrete (as it is known in North America) (SCC) is used on the basis of its unique properties of flowability, passability and resistance to segregation. It requires no external energy to achieve full compaction, so is advantageous on site, but there is evidence that its higher cost is a significant barrier to greater adoption. The research entailed work measurement of 14 UK single-family home residential projects (eliciting data on construction time and labour productivity) and cost modelling of three slab scenarios (exploring the relationship between material and labour costs). The study found SCC was placed up to 73% faster than conventional concrete and, when labour and material costs are included, the supplier is able to price SCC to closely match conventional concrete, hence making SCC more viable for the contractor. This relationship between as-built costs for SCC and conventional concrete is clarified by developing P max, providing a new mechanism for understanding project profitability and viability of SCC.