CLOTHING,TEXTILES, AND HUMAN PERFORMANCE

Abstract

Fluid transport is one of the most frequently observed phenomena in the processing and end uses of fibrous materials. Fibrous materials have a unique structure of complex geometry, characterized by system anisotropy and heterogeneity. The characterization of fibrous materials, therefore, is critical in the understanding of transport behavior through fibrous structures, and is discussed after an introductory section. Subsequent sections cover topics of various transport processes through fibrous structures, including wicking and wetting, resin impregnation in liquid composite molding, filtration and separation in geotextiles, aerosol filtration in fibrous filters, micro/nano scale transport phenomena, and biomedical applications. The fibrous structure is also known for its multi-scale pore distribution from intra-fiber to inter-fiber spaces. This multi-scale effect is even more prominent when micro or nano fibrous materials are concerned, and so multi-scale approaches to address the scale effects of transport behavior in fibrous materials are discussed. Finally, the Ising model of statistical mechanics, a robust computer-simulation tool dealing with the fluid transport problems in fibrous materials, is introduced.     

Rotating waves in rings of coupled oscillators

In this paper we discuss the types of stable oscillation created via Hopf bifurcations for a ring of identical nonlinear oscillators, each of which is diffusively and symmetrically coupled to both its neighbours, and which, when uncoupled, undergo a supercritical Hopf bifurcation creating a stable periodic orbit as a parameter, λ is increased. We show that for small enough coupling, the only stable rotating waves produced are either one or a conjugate pair, depending on the parity of the number of oscillators in the ring and the sign of the coupling constant, and that the magnitude of the phase difference between neighbouring oscillators for these rotating waves is either zero (i.e. the oscillators are synchronized) or the maximum possible, depending on the sign of the coupling constant. These brances of rotating waves are produced supercritically.     

Solid media thermal storage for parabolic trough power plants

For parabolic trough power plants using synthetic oil as the heat transfer medium, the application of solid media sensible heat storage is an attractive option regarding investment and maintenance costs. In the project WESPE that is described in this paper, solid media sensible heat storage materials have been researched. Two storage systems with a storage capacity of about 350 kW h each and maximum temperatures of 390 °C have been developed. The test storage units of WESPE are erected at the Plataforma Solar de Almeria in Spain. The thermal energy is provided by a parabolic trough loop with a maximum thermal power of 480 kW. The first tests were performed at storage temperatures up to 325 °C by March of 2004; testing will be continued during 2004 to achieve the nominal operation conditions of 390 °C and to gain experience for long term behaviour. These storage systems are composed of modules with two different storage materials to identify the characteristics of these materials. A tubular heat exchanger is integrated into the storage material. This heat exchanger demands a significant share of the investment costs. The selection of geometry parameters like tube diameter and number of tubes therefore play an important role in the optimisation. The design of the WESPE test module is based on results provided by a numerical tool for simulation of the transient performance of storage systems.     

Molecular lysis of synovial lining cells by in vivo herpes simplex virus-thymidine kinase gene transfer

Herpes simples virus thymidine kinase (HSV-TK) expression plasmid DNA was injected into the joint space of rabbits with antigen-induced arthritis (AIA). Purified plasmid DNA was able to mediate transfection of synovial lining cells and transient overexpression of HSV-TK in the context of active synovial inflammation. The pharmacodynamic distribution of intraarticular expression plasmid DNA was confined to the joint space. Arthritic rabbits treated with intraarticular expression plasmid DNA followed by intravenous ganciclovir (GCV, 5 mg/kg) twice daily for 3 days showed histologic evidence of synovial lining layer cytolysis when articular tissues were examined 21 days posttreatment. There was also a reduction in joint swelling in the TK-treated knees. No untoward clinical effects were observed in the rabbits and no evidence of cytolytic damage specific to the TK-GCV gene therapy was observed either in the articular cartilage or bone. The application of TK-GCV intraarticular gene therapy using purified expression plasmid DNA for the induction of synovial cytolysis may be applicable to the treatment of human inflammatory arthritis.     

DNA Three‐Way Junctions Stabilized by Hydrophobic Interactions for Creation of Functional Nanostructures

The construction of nanomaterials from oligonucleotides by modular assembly invariably requires the use of branched nucleic acid architectures such as three‐ and four‐way junctions (3WJ and 4WJ). We describe the stabilization of DNA 3WJ by using non‐nucleotide lipophilic spacers to create a hydrophobic pocket within the junction space. Stabilization of nucleic acid junctions is of particular importance when constructing nanostructures in the “ultra‐nano” size range (<20 nm) with shorter double‐stranded regions. UV thermal melting studies show that lipophilic spacers strategically placed within the junction space significantly increased thermal stability. For a 3WJ with eight base pair arms, thermal stability was increased from 30.5 °C for the unmodified junction to a maximum stability of 55.0 °C. The stability of the junction can be modulated within this temperature range by using the appropriate combinations of spacers.