bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Micro fluidic Nanoscale Protein Sensor Device for Improving Vascular Surgical Outcomes
Authors: Prasad Shalini 
Published: April 2011

ABSTRACTThe normal physiologic response of vascular surgery is one of acute and intense inflammation and thrombosis. Research to date on improving outcomes after surgery has focused on drugs known to be active with the adrenergic system more specifically statins. Till date there has been no correlation between inflammation post surgery and the effect of perioperative anti-inflammatory drugs on improving surgical outcomes. The goal of this research is to characterize the role perioperative inflammation and thrombosis plays in determining outcomes after surgery. The goal of this particular application is to identify two specific pro-inflammatory protein markers namely C-reactive protein (CRP) and Myloperoxidase (MPO) associated with thrombosis from a wide range of serum samples. This is achieved by integrating the principles of fabrication associated with micro and nanotechnology to develop a sensor device comprising of nano ordered porous alumina membrane embedded in an elastomer (polydimethylsiloxane, PDMS) micro fluidic base. The nano porous membrane is selectively functionalized by a two level masking technique to the binding of CRP and MPO in selected areas. The binding event results in an electrochemical reaction that in turn produces a change in the surface charge. This in turn produces a measurable change to the electrical voltage. This is measured in an in-situ, non-invasive manner from selectively metalized areas of the nano membrane. Energy density analysis yielded unique electrical identifiers for each of the protein markers. Detection sensitivity of the order of 10 ppm was observed.
Ink-jet printing of ferroelectric poly(vinylidene fluoride-trifluoroethylene) copolymers
Authors: Zhang Shihai , Liang Ziqi , Wang Qing , Zhang Q.M. 
Published: April 2011

AbstractPoly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymers are well known for their excellent ferroelectric and other related properties and they are being exploited as active components in many microdevices such as ferroelectric memory cells and infrared sensors. Compared with conventional photolithography, ink-jet printing provides a low-cost versatile method to fabricate polymer micro-devices. In this paper, the influences of driving waveform at the jet head, ink concentration, substrate chemistry, and the solvent quality on the printed P(VDF-TrFE) dots were investigated. It was found that well-defined P(VDF-TrFE) micro-dots with diameter of less than 30 mm and thickness of ∼1 μm can be printed by using a mixed solvent system, consisting of a good solvent with relatively low boiling temperature and a poor solvent with high boiling temperature, on perfluorinated hydrophobic gold surface. The printed P(VDF-TrFE) micro-dots possess crystallinity comparable to that of the bulk sample, suggesting that ink-jet printing technology is a promising micro-fabrication technology for manufacturing P(VDF-TrFE)-based micro-sensors and other micro-devices.
Investigation of the Physics of Transduction in Nafion / Ionic Liquid Composite Membranes
Authors: Bennett Matthew , Akle Barbar , Leo Donald 
Published: April 2011

ABSTRACTIonomeric polymer actuators based on Nafion membranes exhibit large bending motion (1%) under the application of small voltages (1-5 V). Actuation in these materials is believed to arise from the field-induced motion of mobile charges when a voltage is applied. In order for this charge motion to occur, the material must be swollen with a diluent, typically water. However, dehydration of the water limits the lifetime of these actuators in non-aqueous environments. Recently, highly stable ionic liquids have been demonstrated as viable diluents for these actuators. In the current paper, the physics of transduction in these ionic liquid-swollen Nafion membranes are investigated. Small-angle X-ray scattering reveals that the structure and properties of the ionic liquid have a strong influence on the morphology of the composites. Infrared spectroscopy is used to probe the ion associations within the films and shows that the ionic liquids are able to effectively mobilize the counterions of the Nafion membrane. Nuclear magnetic resonance spectroscopy is also used to investigate the composites and reveals that the mobility of the counterions increases as the content of ionic liquid within the membrane is increased. The results of these characterizations are compared to an experimental investigation of transduction in Nafion / ionic liquid composites to form an interpretation of the mechanisms of actuation. This comparison reveals that the counterions of the Nafion membrane are the primary charge carriers and that it is the motion of these mobile charges that gives rise to the actuation behavior of the films.
Organic Field-Effect Transistors, Inverters, and Logic Circuits on Gate Electrets
Authors: Huang Cheng , West James E. , Katz Howard E. 
Published: April 2011

ABSTRACTBy incorporating dielectrics with stored electric fields and organic semiconductors, new organic electronic components such as circuits with controlling voltages “restored” for transistor tuning can be developed. We have successfully used excellent electret materials including charged and surface-treated silicon dioxide (SiO2) and silsesquioxane (SSQ) polymers as the dielectric layer in organic field-effect transistors (OFETs). Charge injection and quasipermanent charge storage induce threshold voltage shifts and current modulation, which results from the built-in electric fields in the conduction channels. Static and dynamic characteristics of organic thin-film transistors (OTFTs) such as charging conditions and voltage/current retention were evaluated. In addition, self-assembled monolayers (SAMs) of dipolar molecules have been utilized in the dielectric layer, with different mechanisms but similar effects compared to charged dielectrics. We also present new OFET unipolar inverters, comprised of only two simple OTFTs with enhancement-mode driver and depletion-mode load to implement full-swing organic logic circuits for process simplification of electronic components in organic electronics.
Electronic Structure of PuCoGa5 and UCoGa5
Authors: Bauer Eric , Durakiewicz T. , Butterfield M. T. , Guziewicz E. , Joyce J. J. , Olson C. G. , Morales L. A. , Sarrao J. L. , Thompson J. D. 
Published: April 2011

AbstractThe electronic structure of the Pu-based superconductor PuCoGa5 and the Pauli paramagnet UCoGa5 is investigated using photoemission spectroscopy. The photoemission data of PuCoGa5 reveal features at the Fermi energy EF and about 1-1.5 eV below EF indicative of itinerant and localized f-electrons, respectively. Angle-resolved spectra of UCoGa5 show two peaks at similar energies that are highly dispersive, providing evidence for itinerant character of the f-electrons in this material. A comparison of the PuCoGa5 and UCoGa5 data to the spectra of α-Pu and δ-Pu serves to place PuCoGa5 within the context of the more general electronic structure problem in elemental Pu.
Polymer Assisted Deposition (PAD) of thin metal films: A new technique to the preparation of metal oxides and reduced metal films
Authors: Shukla Piyush , Lin Yuan , Minogue Edel M , Burrell Anthony K , McCleskey T Mark , Jia Quanxi , Lu Ping 
Published: April 2011

AbstractCurrently, there are a variety of techniques to deposit metal thin films ranging from high vacuum techniques such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), through to solution methods like sol-gel. While the vacuum techniques can be limited by size and cost, sol-gel can be limited be the availability of appropriate precursors. All of these techniques have the further limitation that they cannot be used to coat porous materials conformally.Polymer assisted deposition (PAD) addresses some of the limitations of sol-gel and costs of high vacuum techniques. PAD utilizes an aqueous polymer to bind a metal or metal complex that serves both to encapsulate the metal to prevent chemical reaction and maintain an even distribution of the metal in solution. Another advantage that PAD has is that the same solution can be used as precursors for the growth of metal oxide or reduced metal films. Herein, we report on the utility of PAD in preparing metal oxide films used to conformally coat porous material and reduced metal films.
Design and application of gradient annealing devices for the parallel thermal processing of Fe/Pt multilayers
Authors: Thienhaus Sigurd , Hiergeist Robert , Savan Alan , Ludwig Alfred 
Published: April 2011

AbstractThis paper discusses the design and use of gradient annealing devices. Generally, it is intended to use such devices for the rapid optimization of thin film materials by simultaneous thermal processing at different temperatures. Furthermore, these devices are efficient for short- time annealing experiments. They are used in order to quickly vary the annealing parameters (temperature, time) from sample to sample. Here, nanoscale Fe/Pt multilayer precursor thin films for the fabrication of hard magnetic Fe-Pt thin films are investigated as a test system. First results prove the usefulness of the gradient annealing devices for high-throughput experiments.
Combinatorial synthesis of (Al,Ti)N thin films via pulsed laser deposition
Authors: Cho Clara Ji-Hyun , Gerhardt Rosario A , G. Kelekanjeri V. Siva Kumar , Koinuma Hideomi 
Published: April 2011

AbstractAluminum nitride (AlN), a wide band gap semiconductor (Eg = 6.2eV), has potential applications in microelectronics due to its excellent insulating properties and compatibility with silicon [1,2]. More recently, the use of AlN thin films in high electron mobility transistors, light emitting diodes and UV sources is explored by altering the band gap of the material [3]. The present work describes the combinatorial synthesis of (Al,Ti)N thin films via pulsed laser deposition (PLD) technique to obtain desirable compositional spreads and corresponding variations in the electrical properties. Films of AlN, TiN and (Al,Ti)N were deposited on 6H-SiC (0001) substrates held at a temperature of 680°C. The surface quality of the films examined using an AFM revealed island growth of SiO2 and other growth patterns possibly related to substrate defects.X-ray diffraction studies indicated that the growth of AlN and TiN films occurred with corresponding habit planes of (0002) and (111) parallel to the substrate surface. Compositional investigations conducted using energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) showed systematic changes in the Al and Ti composition across the thickness of the compositional spread film. Cross-sectional analysis of (Al,Ti)N films conducted in a high-resolution transmission electron microscope revealed that the films were multi-layered. Several orders of magnitude decrease in the measured resistivity across a 15 mm length (Al,Ti)N film was noted corresponding to a systematic increase in the Ti content. Further optimization of deposition conditions is essential for producing thicker films.
Rules-Driven Materials Design Using an Informatics-Based Approach
Authors: Muellerleile Joan T. , Ferris Kim F. , Jones Dumont M. , Hyatt Roger W. 
Published: April 2011

AbstractA rules-driven, informatics-based approach to multiply-constrained materials design is outlined, employing the example of polymer coating design for silica fibers. This approach to the inverse mapping problem of structure generation from design constraints and quantitative structure-property relationships (QSPRs) emphasizes design rule generation and analysis. Using this approach addresses several issues in new materials discovery: 1) factoring a larger design problem into tractable components, 2) integrating physical and non-physical requirements (such as cost), 3) identifying information gaps that must be resolved to complete a design, and 4) identifying situations in which a solution consistent with known information is not feasible.
High-Throughput Measurement of Magnetostriction Using MEMS and Composition Spreads
Authors: Woo Noble C. , Ng Bryan G. , van Dover R. B. 
Published: April 2011

AbstractWhile measurement of magnetostriction in bulk materials is readily accomplished using a strain gauge, measurement of this quantity for thin films presents a greater challenge, and typically involves measurement of the overall wafer curvature (for a film of uniform composition) as a function of field. In order to evaluate magnetostriction locally in composition-spread samples, we have developed a method using a dense array of pre-fabricated cantilever beams on a silicon substrate prepared using MEMS techniques. Differential strain in the thin film/cantilever system results in curvature which is detected using an optical (laser/position-sensitive-detector) system. A magnetic field is applied using two orthogonal Helmholtz coils, and the resulting deflection-field curves are used to determine the saturation magnetostriction λs as well as dλ/dH. Our composition-spread films are prepared using a three gun on-axis magnetron cosputtering system. The position-dependent composition is inferred using rate calibrations and verified with electron microprobe and Rutherford Backscattering Spectroscopy. Preliminary experiments have validated the technique and the system has been used to measure magnetostriction in the Ni-Fe system. Our approach can also be used to measure properties of giant magnetostrictive materials (e.g. TbFe/Fe multilayers) as a function of layer thicknesses, or thin film shape-memory alloys, including magnetic shape-memory alloys.
Warehousing the Dental Materials Data: A Prototype
Authors: Li Yong 
Published: April 2011

AbstractThis paper presents a preliminary investigation on the effectiveness of the new data management technique of data warehousing in organizing dental materials data in order to provide the efficient information services such as data retrieval and materials selection. A scaled-down version of the data warehouse for dental materials is constructed and an English Query application, which allows the end users to formulate their queries in natural English language, is developed on top of the data warehouse. The data warehouse supports five types of queries from basic practice of data retrieval to more advanced information service of materials selection. The results have demonstrated that the data warehousing technique is of a great potential in storing, processing and managing dental materials data.
Towards Low Cost Disposable High Throughput Screening Devices
Authors: Diaz-Quijada Gerardo Antonio , Peytavi Regis , Nantel André , Roy Emmanuel , Bergeron Michel G. , Dumoulin Michel M. , Veres Teodor 
Published: April 2011

AbstractMicroarrays have become one of the most convenient tools for high throughput screening, supporting major advances in genomics and proteomics. Other important applications can be found in medical diagnostics, detection of biothreats, drug discovery, etc. Integration of microarrays with microfluidic devices can be highly advantageous in terms of portability, shorter analysis time and lower consumption of expensive biological analytes. Since fabrication of microfluidic devices using traditional materials such as glass is rather expensive, there is a high interest in employing polymeric materials as a low cost alternative that is suitable for mass production. A number of commercially available plastic materials were reviewed for this purpose and poly(methylmethacrylate) and Zeonor™ 1060R were identified as promising candidates, for which methods for surface modification and covalent immobilization of DNA oligonucleotide were developed. In addition, we present proof-of-concept plastic-based microarrays with and without integration with microfluidics.
High-Porosity Nanoporous Silica via Nanocasting Template of Hydrogels
Authors: Nakamura Takanori , Kurumada Ken-ichi , Suzuki Atsushi , Umeda Naoki , Kishimoto Naoki 
Published: April 2011

AbstractHigh-porosity nanoporous silica was prepared by nanocasting method using N-isopropylacrylamide (NIPAm) cross-linked by N, N’-methelenbisacrylamide (BIS) as the templating agent. The obtained silica was a bulk silica with good transparency indicating that the characteristic length-scale of the obtained silica is in the nanoscopic scale being much smaller than that of the wave length of visible light. Nitrogen adsorption/desorption measurements revealed that the nano porosity increases up to 80% with the weight ratio of NIPAm to silica. The mean pore size (radius) also increased with the weight ratio in the region smaller than 10nm. TEM observation revealed that the nanoscopic network structure was replicated into tube-like nanopores randomly distributed in the silica matrix. The whole nanoscopic morphology of these tube-like nanopores was much like as the predicted for the cross-linked polymer.
biomimetic Hydrogel/apatite Nanocomposite Scaffolds for Bone Regeneration
Authors: Jabbari Esmaiel 
Published: April 2011

AbstractBone is a composite material consisting of aqueous gel and mineral phases. The aqueous gel phase gives bone its form and contributes to its ability to resist tension, while the mineral component resists compression. The combination of a hard inorganic phase and an elastic gel network provides bone with unique mechanical properties as well as a medium for diffusion and release of biologically active agents and it also facilitates communication with the cellular environment. A tissue engineered synthetic biomaterial as a scaffold for bone regeneration should provide temporary structural support to the reconstructed region and a medium for solubilization, diffusion, release of nutrients and growth factors, and their interactions with cells. In this work, the material and biologic properties of a novel synthetic matrix metalloproteinase (MMP) degradable hydrogel/apatite nanocomposite is investigated for its usefulness as a model matrix to mimic the gel and mineral components of the bone matrix and to fabricate aqueous-based scaffolds for bone regeneration. The gel phase is made from poly(lactide-ethylene oxide-fumarate), hereafter designated as PLEOF, terpolymer in which the water content can be adjusted by changing the ratio of the hydrophobic (lactide) to hydrophilic (ethylene oxide) oligomers. The hydrogel and apatite phases are crosslinked using an MMP degradable peptide crosslinker to modulate the matrix degradation kinetics with the migration of bone marrow stromal (BMS) cells. The results demonstrate that MMP degradable scaffolds fabricated from the PLEOF hydrogel and apatite nanoparticles are biocompatible and support cell attachment and migration.
Transport of molecules through carbon nanotube channels in aqueous environment: A molecular dynamics study
Authors: Xue Yongqiang , Chen Maodu 
Published: April 2011

AbstractWe present molecular dynamics simulation of molecules transporting through carbon nanotubes for applications in engineered flow channels, focusing on the dynamics of molecules spontaneously inserted into the nanotube channel in aqueous environment. The molecules studied include a C60 molecule, a finite segment of carbon nanotube with smaller diameter, and single/double- stranded DNA molecules. We show that in the absence of water solvation, the van der Waals interaction between the molecule and the nanotube wall can induce a rapid spontaneous encapsulation of the molecule inside the nanotube channel. The encapsulation process is strongly impeded for nanotube dissolved in water due to the competition between the van der Waals, hydrophobic and hydrogen bonding interactions in the nanotube/water/molecule complex. Water adsorption inside the nanotube channel plays an important role in determining the dynamics of the spontaneous insertion process.
Microstructured Surfaces for Drag Reduction Purposes: Experiments and Simulations on Rectangular 2D Riblets
Authors: Rapp Håkan , Zoric Igor , Kasemo Bengt 
Published: April 2011

AbstractIt is well established that properly structured surface exhibits a lower friction drag, when exposed to a turbulent boundary layer, than a smooth surface under the same flow conditions. The observed drag decrease is usually attributed to an increased thickness of the viscous sublayer. In this work we examine the friction drag reducing mechanism. Two parallel approaches towards achieving this goal are presented. Photolithography was used to manufacture rectangular riblets in the 10∝m range on a standard 4” silicon wafer. A special compact plane channel system was designed and used for measurements of the frictional drag on structured surfaces in the turbulent flow covering a wide Reynolds number range. Navier-Stokes equation, for the examined drag reducing geometry, was solved in the laminar regime with appropriate boundary conditions. The resulting velocity field was used to extract the protrusion heights difference for streamwise and spanwise flows over the structured surface. The latter was then related to the experimentally measured drag reduction slope. We show that in case of a rectangular riblet, with a size of the order of one wall unit, the observed drag reduction can be accounted for within the above model.
Formation of water at a Pt(111) surface: A study using the reactive force field (ReaxFF)
Authors: Buehler Markus J. , Duin Adri C.T. van , Jacob Timo , Jang Yunhee , Merinov Boris , Goddard William A. 
Published: April 2011

ABSTRACTIn this paper, we report preliminary studies of formation of water from molecular oxygen and hydrogen. Using a series of atomistic simulations carried at finite temperature, we describe the dynamics of water formation at a Pt catalyst using a new reactive ReaxFF potential. By performing a series of studies, we obtain statistically meaningful trajectories to extract rate constants of water formation. This allows an estimate for the activation energy during water formation, which is found to be in reasonable agreement with the activation barrier calculated by restraint driven molecular dynamics simulation of water formation at the Pt surface.
Synthesis and Optical Properties of Oriented Cu Nanoparticles
Authors: Siwach Om Parkash , Sen P. 
Published: April 2011

ABSTRACTCrystallographic orientation of atomic planes makes a metal amenable to specific properties as desired in catalysis and environment sensing. Oriented metal nanoparticles are however less known. Here we present X-ray diffraction, transmission electron microscopy and atomic force microscopy data to provide evidence of copper nanoparticles with preferred orientation, achieved by electro-explosion of copper wires in an aqueous medium. The optical absorption in these particles is devoid of the usual Mie resonance at ∼ 580 nm, while maintaining bulk-like lattice periodicity. Under the highest reorientation (largest orientation index), absorption in the ultraviolet region is characterized by distinct and sharp resonant peaks, which are correlated with occupied valence band density of state (DOS) from copper clusters, making these truly crystalline particles with atom-like electronic properties.