Despite substantial growth in wind energy technology in recent decades, aerodynamic modeling of wind turbines relies on momentum models derived in the late 19th and early 20th centuries, which are well-known to break down under flow regimes in which wind turbines often operate. This gap in theoretical modeling for rotors that are misaligned with the inflow and also for high-thrust rotors has resulted in the development of numerous empirical corrections which are widely applied in textbooks, research articles, and open-source and industry design codes. This work reports a Unified Momentum Model to efficiently predict power production, thrust force, and wake dynamics of rotors under arbitrary inflow angles and thrust coefficients without empirical corrections.
View Article and Find Full Text PDFis globally distributed but evidence of zoonotic transmission in the Caribbean region is scarce. The bacterium presence is suspected on the Caribbean island of St. Kitts.
View Article and Find Full Text PDFCholangiocarcinoma is an aggressive malignancy with poor overall survival. Approximately 15% of intrahepatic cholangiocarcinomas contain alterations. Infigratinib is an oral FGFR 1-3 kinase inhibitor.
View Article and Find Full Text PDFGlobal power production increasingly relies on wind farms to supply low-carbon energy. The recent Intergovernmental Panel on Climate Change (IPCC) Special Report predicted that renewable energy production must leap from [Formula: see text] of the global energy mix in 2018 to [Formula: see text] by 2050 to keep global temperatures from rising 1.5°C above preindustrial levels.
View Article and Find Full Text PDFThe applications of biosensors range from environmental testing and biowarfare agent detection to clinical testing and cell analysis. In recent years, biosensors have become increasingly prevalent in clinical testing and point-of-care testing. This is driven in part by the desire to decrease the cost of health care, to shift some of the analytical tests from centralized facilities to "frontline" physicians and nurses, and to obtain more precise information more quickly about the health status of a patient.
View Article and Find Full Text PDFA nanopatternable polydimethylsiloxane (PDMS) oligomer layer is demonstrated as an interfacial adhesive for its intrinsic transferability and universal adhesiveness. Utilizing the well-established surface modification and bonding techniques of PDMS surfaces, irreversible bonding is formed (up to 400 kPa) between a wide range of substrate pairs, representing ones within and across different materials categories, including metals, ceramics, thermoset, and thermoplastic polymers.
View Article and Find Full Text PDFWe report the development of a microdevice for detecting local interferon gamma (IFN-γ) release from primary human leukocytes in real time. Our microdevice makes use of miniature aptamer-modified electrodes integrated with microfluidics to monitor cellular production of IFN-γ. The aptamer species consists of a DNA hairpin molecule with thiol groups on the 3'-end for self-assembly onto Au electrodes.
View Article and Find Full Text PDFWe have investigated the response of solid-supported phospholipid bilayers to short doses of photogenerated oxidative stress to characterize physical membrane changes during early phases of membrane oxidation. The low-dose oxidative stress is generated by uniformly exposing the bilayer samples using short-wavelength UV radiation (184-257 nm) for short periods (approximately 3 min) and resulting membrane morphological transformations characterized using a combination of wide-field epifluorescence microscopy and imaging ellipsometry measurements. Our results establish that the early phase of membrane oxidation is characterized by the nucleation and growth of discrete microscopic voids within the bilayer.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2009
This paper describes a novel surface engineering approach that combines oxygen plasma treatment and electrochemical activation to create micropatterned cocultures on indium tin oxide (ITO) substrates. In this approach, photoresist was patterned onto an ITO substrate modified with poly(ethylene) glycol (PEG) silane. The photoresist served as a stencil during exposure of the surface to oxygen plasma.
View Article and Find Full Text PDFNeutron reflectometry was used to probe in situ the structure of supported lipid bilayers at the solid-liquid interface during the early stages of UV-induced oxidative degradation. Single-component supported lipid bilayers composed of gel phase, dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and fluid phase, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), phospholipids were exposed to low-dose oxidative stress generated by UV light and their structures were examined by neutron reflectometry. An interrupted illumination mode, involving exposures in 15 min increments with 2 h intervals between subsequent exposures, and a continuous mode involving a single 60 (or 90) min exposure period were employed.
View Article and Find Full Text PDFIn this paper we describe a microfabrication-derived approach for defining interactions between distinct groups of cells and integrating biosensors with cellular micropatterns. In this approach, photoresist lithography was employed to micropattern cell-adhesive ligand (collagen I) on silane-modified glass substrates. Poly(ethylene glycol) (PEG) photolithography was then used to fabricate hydrogel microstructures in registration with existing collagen I domains.
View Article and Find Full Text PDFThe asymmetric distribution of charged molecules between the leaflets of solid-substrate-supported phospholipid bilayers is studied using imaging ellipsometry, fluorescence microscopy, and numerical solutions of the Poisson-Boltzmann equation. Experiments are facilitated by the use of patterned substrates that allow for side-by-side comparison of lipid monolayers and supported bilayers. On silica surfaces, negatively charged lipid components are shown to be enriched in the outer leaflet of a supported bilayer system at modest salt concentrations.
View Article and Find Full Text PDFSubnanometer-scale vertical z-resolution coupled with large lateral area imaging, label-free, noncontact, and in situ advantages make the technique of optical imaging ellipsometry (IE) highly suitable for quantitative characterization of lipid bilayers supported on oxide substrates and submerged in aqueous phases. This article demonstrates the versatility of IE in quantitative characterization of structural and functional properties of supported phospholipid membranes using previously well-characterized examples. These include 1), a single-step determination of bilayer thickness to 0.
View Article and Find Full Text PDFWe show that two dips of an oxidized silicon substrate through a prepolymerized n-octadecylsiloxane monolayer at an air-water interface in a rapid succession produces periodic, linear striped patterns in film morphology extending over macroscopic area of the substrate surface. Langmuir monolayers of n-octadecyltrimethoxysilane were prepared at the surface of an acidic subphase (pH 2) maintained at room temperature (22 +/- 2 degrees C) under relative humidities of 50-70%. The substrate was first withdrawn at a high dipping rate from the quiescent aqueous subphase (upstroke) maintained at several surface pressures corresponding to a condensed monolayer state and lowered soon after at the same rate into the monolayer covered subphase (downstroke).
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