Abstract:
Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.
Abstract:
Embodiment of the present invention relate to dendrimers useful for application as catalysts, in particular as improved electrocatalysts for polymer electrolyte membrane fuel cells (PEM-FCs). Methods of preparing such catalysts are described. Examples include dendritic nanostructured metal catalysts, such as platinum and platinum-alloy catalysts.
Abstract:
A micro-analytical platform for performing electrophoresis-based immunoassays was developed by integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device. The microfluidic immunoassays are performed by gel electrophoretic separation and quantifying analyte concentration based upon conventional polyacrylamide gel electrophoresis (PAGE). To retain biological activity of proteins and maintain intact immune complexes, native PAGE conditions were employed. Both direct (non-competitive) and competitive immunoassay formats are demonstrated in microchips for detecting toxins and biomarkers (cytokines, c-reactive protein) in bodily fluids (serum, saliva, oral fluids). Further, a description of gradient gels fabrication is included, in an effort to describe methods we have developed for further optimization of on-chip PAGE immunoassays. The described chip-based PAGE immunoassay method enables immunoassays are fast (minutes) and require very small amounts of sample (less than a few microliters). Use of microfabricated chips as a platform enables integration, parallel assays, automation and development of portable devices.
Abstract:
A fibrous properties-switching article comprises a mat consisting of fibers having a fiber diameter of 2 microns or less. The fibers comprise a polymer, copolymer, polymer blend, or polymer network, wherein the fibers have a diameter of 2 μιη or less. The surface and/or bulk property of the mat changes over a range of temperatures, wherein the polymer, copolymer, polymer blend, or polymer network undergoes a structural change over the range of temperatures. The fiber mat is formed by electrospinning. In an exemplary embodiment, a blend of polystyrene and poly((N-isopropyl acrylamide) (bl-PS/PNIPA) in dimethylformamide (DMF) is electrospun to form a mat consisting of fibers with a diameter less than 2 μηι that shows a transition from a superhydrophilic surface to a nearly superhydrophobic surface over a temperature range from 30 °C to 45 °C. A fiber mat formed by electrospinning a DMF solution comprising poly(N-isopropyl acrylamide-co- methacylicacid) (PNIPAMAA), comprises fibers having a diameter less than 2 μιτι and are cross linked after spinning. The crosslinked PNIPAMAA, (xl-PNIPAMAA) fiber mat displays a transition from a hydrophilic surface to a nearly hydrophobic surface over a temperature range from 30 °C to 45 °C.
Abstract:
In an embodiment, an optical filter device includes an input polarizer for selectively transmitting an input signal. The device includes a wave-plate structure positioned to receive the input signal, which includes first and second substantially zero-order, zero-wave plates arranged in series with and oriented at an angle relative to each other. The first and second zero-wave plates are configured to alter a polarization state of the input signal passing in a manner that depends on the power of the input signal. Each zero-wave plate includes an entry and exit wave plate each having a fast axis, with the fast axes oriented substantially perpendicular to each other. Each entry wave plate is oriented relative to a transmission axis of the input polarizer at a respective angle. An output polarizer is positioned to receive a signal output from the wave -plate structure and selectively transmits the signal based on the polarization state.
Abstract:
Devices (100) and methods for thermally lysing of biological material, for example vegetative bacterial cells and bacterial spores, are provided. Hot solution methods for solubilizing bacterial spores are described. Systems for direct analysis are disclosed including thermal lysers (100) coupled to sample preparation stations. Integrated systems capable of performing sample lysis, labeling and protein fingerprint analysis of biological material, for example, vegetative bacterial cells, bacterial spores and viruses are provided.
Abstract:
Injection molding is used to form microfluidic devices with integrated functional components. One or more functional components are placed in a mold cavity, which is then closed. Molten thermoplastic resin is injected into the mold and then cooled, thereby forming a solid substrate including the functional component(s). The solid substrate including the functional component(s) is then bonded to a second substrate, which may include microchannels or other features.
Abstract:
This disclosure describes fabric and a method for making fabric, for use in a flexible pressure vessel or other fabric structures, which has an unbalanced woven construction and has a balanced or nearly balanced modulus of elasticity for the end-use conditions of this fabric. Unbalanced woven fabrics that do not have balanced properties produce unequal stretching and are susceptible to premature failure. The present invention of unbalanced woven fabric construction with balanced mechanical properties such as modulus of elasticity can be used to optimize fabric strength, mass, volume, and performance characteristics and also reduce manufacturing costs for various fabric structure applications. Balanced mechanical properties for the fabric structure are achieved by altering the force of the fabric by increasing or decreasing the number of yarns in a particular direction of the fabric, by changing the strain during stretch of the fabric, or by alternative weaves of the fabric.