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One Possible Solution (one + possible_solution)
Selected AbstractsMembrane engineering for process intensification: a perspectiveJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2007Enrico Drioli Abstract Pushed by the increasing demand for materials, energy and products, chemical engineering today faces a crucial challenge: to support a sustainable industrial growth. One possible solution is process intensification (PI), the innovative design strategy aiming to improve manufacturing and processing by decreasing the equipment size/productivity ratio, energy consumption and waste production using innovative technical solutions. Membrane processes meet the requirements of PI because they have potential to replace conventional energy-intensive techniques, to accomplish the selective and efficient transport of specific components, and to improve the performance of reactive processes. Here, we identify the most interesting aspects of membrane engineering in some strategic industrial sectors. The opportunity to integrate conventional membrane units with innovative systems in order to exploit the potential advantages coming from their synergic applications is also emphasized. Copyright © 2007 Society of Chemical Industry [source] Solutions out of context: Examining the transfer of business concepts to nonprofit organizationsNONPROFIT MANAGEMENT & LEADERSHIP, Issue 2 2008Tammy E. Beck Small nonprofit organizations face a dilemma when applying management theories and techniques developed for large, private businesses. Research evidence suggests both benefits and problems associated with application of these techniques. To avoid potential problems, nonprofit managers commonly limit the selection and transfer of business techniques to those that solve specific problems or appear consistent with nonprofit orientations. One consequence is that business solutions often create unintended negative outcomes that are due to contextual differences between the two types of organizations. One possible solution to this dilemma is adoption of bundles, or configurations, of practices that introduce important contextual checks and balances along with the specific tools and techniques. We explore this option through a critical, participatory ethnographic analysis of a small nonprofit service organization. [source] Transdermal drug delivery by coated microneedles: geometry effects on drug concentration in bloodASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2009Barrak Al-Qallaf Abstract Drug administration through transdermal delivery is restricted by the top layer of skin, the stratum corneum. One possible solution to overcome the barrier function of the stratum corneum is to employ microneedle arrays. However, detailed theoretical models relating drug-coated microneedles and their geometry to the drug concentration in the blood are limited. This article aims to address this issue by examining the blood concentration profiles for a model drug, insulin, that has been administered via coated microneedles. A mathematical model is introduced and applied to predict theoretical blood concentrations. Furthermore, the insulin concentration in blood is calculated for a range of different microneedle shapes and dimensions to identify the most effective geometry. The results indicate that the optimum microneedle geometry in terms of maximizing insulin concentration was a rocket-shaped needle with a constant tip angle of 90°. Also, it has been found that the number of microneedles in an array is the most significant factor in determining maximum insulin concentration in the blood (Cb, max). Penetration depth of the microneedle, centre-to-centre spacing and microneedle thickness had a less significant effect on the maximum insulin concentration in the blood. It is envisaged that the current study will help in designing microneedles of optimum size and shape for transdermal drug delivery. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Laser-guided direct writing for three-dimensional tissue engineeringBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2005Yaakov Nahmias Abstract One of the principal limitations to the size of an engineered tissue is oxygen and nutrient transport. Lacking a vascular bed, cells embedded in an engineered tissue will consume all available oxygen within hours while out branching blood vessels will take days to vascularize the implanted tissue. One possible solution is to directly write vascular structures within the engineered tissue prior to implantation, reconstructing the tissue according to its native architecture. The cell patterning technique, laser-guided direct writing (LGDW), can pattern multiple cells types with micrometer resolution on arbitrary surfaces, including biological gels. Here we show that LGDW can pattern human umbilical vein endothelial cells (HUVEC) in two- and three-dimensions with micrometer accuracy. By patterning HUVEC on Matrigel, we can direct their self-assembly into vascular structures along the desired pattern. Finally, co-culturing the vascular structures with hepatocytes resulted in an aggregated tubular structure similar in organization to a hepatic sinusoid. This capability can facilitate studies of tissue architecture at the single cell level, and of heterotypic interactions underlying processes such as liver and pancreas morphogenesis, differentiation, and angiogenesis. Copyright © 2005 Wiley Periodicals, Inc. [source] | ||||||||||