Manufacture and rehabilitation of guardrail posts using composite fabrics

The West Virginia Department of Transportation (WVDOT) uses approximately 50,000 wood and 200,000 steel guardrail posts on an annual basis. The need to develop guardrail posts made of a different material is motivated by the high cost of steel, along with the greater difficulty associated with driving large diameter wood posts.;The primary objective of this study was to develop a Glass Fiber Reinforced Polymer (GFRP) wood post that is more cost effective than a steel post and has smaller diameter than a conventional wood post. Another objective was to develop a portable fabric-wrapping machine for field applications.;Unwrapped and GFRP wrapped posts were tested for flexural properties. The experimental data were compared with published values. Unwrapped and GFRP wrapped posts were tested under dynamic loads to determine their natural frequencies. Free vibration tests of unwrapped, GFRP wrapped, and damaged posts were performed to establish amplitude decay for damping characteristics. (Abstract shortened by UMI.)

Non-Intrusive Temperature Measurements Using Microscale Visualization Techniques

lPIV is a widely accepted tool for making measured. This method allows simultaneous non-intrusive temperature and velocity measurements in integrated accurate measurements in microscale flows. The particles cooling systems and lab-on-a-chip devices. that are used to seed the flow, due to their small size, undergo Brownian motion which adds a random noise component to the measurements. Brownian motion intro- duces an undesirable error in the velocity measurements, but also contains valuable temperature information. A PIV algorithm which detects both the location and broadening of the correlation peak can measure velocity as well as temperature simultaneously using the same set of images. The approach presented in this work eliminates the use of the calibration constant used in the literature (Hohreiter et al. in Meas Sci Technol 13(7):1072–1078, 2002), mak- ing the method system-independent, and reducing the uncertainty involved in the technique. The temperature in a stationary fluid was experimentally measured using this technique and compared to that obtained using the particle tracking thermometry method and a novel method, low image density PIV. The method of cross-correlation PIV was modified to measure the temperature of a moving fluid. A standard epi-fluorescence lPIV system was used for all the measurements. The experiments were conducted using spherical fluorescent polystyrene-latex particles suspended in water. Temperatures ranging from 20 to 80°C wer

Engineered Nanostructures for High Thermal Conductivity Substrates

In the DARPA Thermal Ground Plane (TGP) program[1],we are developing a new thermal technology that will enable a monumental thermal technological leap to an entirely new class of electronics, particularly electronics for use in high-tech military systems. The proposed TGP is a planar, thermal expansion matched heat spreader that is capable of moving heat from multiple chips to a remote thermal sink. DARPA’s final goals require the TGP to have an effective conductivity of 20,000 W/mK, operate at 20g, with minimal fluid loss of less than 0.1%/year and in a large ultra-thin planar package of 10cmx20cm, no thicker than 1mm. The proposed TGP is based on a heat pipe architecture[2], whereby the enhanced transport of heat is made possible by applying nanoengineered surfaces to the evaporator, wick, and condenser surfaces. Ultra-low thermal resistances are engineered using superhydrophilic and superhydrophobic nanostructures on the interior surfaces of the TGP envelope. The final TGP design will be easily integrated into existing printed circuit board manufacturing technology. In this paper, we present the transport design, fabrication and packaging techniques, and finally a novel fluorescence imaging technique to visualize the capillary flow in these nanostructured wicks.United States. Defense Advanced Research Projects Agency (SSC SD Contract No. N66001-08-C-2008

Mixing Characteristics in a Serpentine Microchannel”,

ABSTRACT Mixing characteristics in a 2D serpentine micro-channe

Localized lentivirus delivery via peptide interactions

Gene delivery from biomaterial scaffolds has been employed to induce the expression of tissue inductive factors for applications in regenerative medicine. The delivery of viral vectors has been described as reflecting a balance between vector retention and release. Herein, we investigated the design of hydrogels in order to retain the vector at the material in order to enhance transgene expression. Poly(ethylene‐glycol) (PEG) hydrogels were modified with poly‐l‐lysine (PLL) to non‐covalently bind lentivirus. For cells cultured on the hydrogels, increasing the PLL molecular weight from 1 to 70 kDa led to increased transgene expression. The incubation time of the virus with the hydrogel and the PLL concentration modulated the extent of virus adsorption, and adsorbed virus had a 20% increase in the half‐life at 37°C. Alternatives to high molecular weight PLL were identified through phage display technology, with peptide sequences specific for the VSV‐G ectodomain, an envelope protein pseudotyped on the virus. These affinity peptides could easily be incorporated into the hydrogel, and expression was increased 20‐fold relative to control peptide, and comparable to levels observed with the high molecular weight PLL. The modification of hydrogels with affinity proteins or peptides to bind lentivirus can be a powerful strategy to enhance and localized transgene expression. Biotechnol. Bioeng. 2016;113: 2033–2040. © 2016 Wiley Periodicals, Inc.By conjugating affinity peptides to poly(ethylene‐glycol) (PEG) hydrogels, lentiviral vectors were non‐covalently bound to the hydrogel surface. Poly‐l‐lysine (PLL) and short, 12‐amino acid sequences identified via phage display, were analyzed. The modification of hydrogels with affinity proteins or peptides to bind lentivirus can be a powerful strategy to enhance and localized transgene expression.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/133589/1/bit25961.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/133589/2/bit25961_am.pd