bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards the Reduction of Optical Losses in Transition Metal-Based Nanomaterials
Authors: Gavrilenko A. V. , Gonder C. A. , Baker D. J. , Gavrilenko V. I. 
Published: September 2011

ABSTRACTEquilibrium geometries and cohesion energies of Ag0.94Cd0.06, Ag0.94In0.06, Au0.94Cd0.06, and Au0.94In0.06 solid alloys have been studied from the first principles within the Density Functional Theory using ab initio pseudopotentials. Equilibrium geometries are obtained by total energy minimization method using the Local Density Approximation and Generalized Gradient Approximation methods. Optical functions are calculated within the independent particles picture. We report essentially different behavior of Cd and In impurity atoms in Au- and Ag-based alloys: the aggregated (or quasi aggregated) phases in In-containing alloys are expected in contrast to the alloys with Cd atom where homogeneous impurity distribution over the bulk should dominate. Study of optical spectra in Ag0.94Cd0.06 and Au0.94Cd0.06 alloys indicate that optical losses in visible and near ultraviolet spectral range remarkably increase at bigger Cd concentrations. In ultraviolet spectral region redistribution of optical oscillator strengths results in both increase and decrease of optical losses in selected spectral regions.
Tight Integration of Plasmonic Nanoresonators with On-chip Silicon Nitride Photonic Guided Wave Structures
Authors: Chamanzar Maysamreza , Hosseini Ehsan Shah , Yegnanarayanan Siva , Adibi Ali 
Published: September 2011

ABSTRACTPlasmonic nanoresonators can localize light beyond diffraction limit and can provide large field enhancements and thus can be used in sensing and spectroscopy applications. Here, we numerically show that efficient excitation of plasmonic resonances of nanoparticles is possible when they are integrated with Silicon Nitride waveguides in an integrated hybrid photonic-plasmonic platform.
Solution Growth and Characterization of Icosahedral Boron Arsenide (B12As2)
Authors: Whiteley C.E. , Zhang Y. , Mayo A. , Edgar J.H. , Gong Y. , Kuball M. , Dudley M. 
Published: September 2011

ABSTRACTThe crystallographic properties of bulk icosahedral boron arsenide (B12As2) crystals grown by precipitation from molten nickel solutions were characterized. Large crystals (5-8 mm) were produced by dissolving the boron in nickel at 1150°C for 48-72 hours, reacting with arsenic vapor, and slowly cooling to room temperature. The crystals varied in color from black and opaque to clear and transparent. Raman spectroscopy, x-ray topography (XRT), and defect selective etching revealed that the B12As2 single crystals were high quality with low dislocation densities. Furthermore, XRT results suggest that the major face of the plate-like crystals was (111) type, while (100), (010) and (001) type facets were also observed optically. The predominant defect in these crystals was edge character growth dislocations with a <001> Burgers vector, and <-110> line direction. In short, XRT characterization shows that solution growth is a viable method for producing good quality B12As2 crystals.
Using Antibiotic Conjugated Magnetic Nanoparticles and a Magnetic Field for the Treatment of Bone Prosthetic Infections
Authors: Taylor Erik N. , Aninwene George E. , Webster Thomas J. 
Published: September 2011

ABSTRACTBacterial infection of bone (called osteomyelitis) is of great concern to the medical community. In addition to bone, numerous medical devices are susceptible to microbial colonization when implanted. These infections are chronic since bacteria form a robust adhesion to surfaces, can be protected by sticky slime matrix (called a biofilm) from the body’s immune system (which would otherwise naturally clear the bacteria), and antibiotic treatments may not resolve such infections (due to antibiotic resistance). Here, the multifunctional properties of magnetic nanoparticles (termed here superparamagnetic iron oxide nanoparticles, or SPION) will be explored for their antibacterial activity, magnetic properties, and drug deliverable properties. This study provides a first step towards the development of a new type of pharmaceutical useful for orthopedic or other device related infections by demonstrating physical (magnetic) control of antibiotics towards bacteria and biofilms.
The Synthesis and Self-Assembly Studies of Two Bioactive BMP-7 Short Peptides Modified Rosette Nanotubes for Bone Tissue Engineering
Authors: Alsbaiee Alaaeddin , El Bakkari Mounir , Fenniri Hicham 
Published: September 2011

ABSTRACTBone fractures are one of the most common bone complications. In more severe cases, bone fixation is accomplished using titanium (Ti) implant materials. Unfortunately, the need for revision surgery often arises due to implant loosening and/or deterioration of the implant/bone interface. Rosette nanotubes (RNTs) are a class of self-assembled organic materials obtained through the self-assembly of a guanine-cytosine hybrid base (G∧C motif). These organic materials have been found to increase osteoblast (bone forming cells) adhesion and hydroxyapatite deposition (bone regeneration) on titanium implants as well as on engineered hydrogels. In order to increase the bioactivity of RNTs to enhance bone cell function on Ti implants, two RNT motifs functionalized with different bioactive deca-peptides (A, B) chosen from the knuckle region of bone morphogenic proteins-7 (BMP-7) were synthesized. Their self-assembly process was investigated in water using UV-Vis and SEM techniques.
Science Saturdays: A Simple Science Outreach Model to Achieve Broad Impact
Authors: Ramirez Ainissa G. 
Published: September 2011

AbstractThe National Science Foundation (NSF) evaluates grant applications based on two criteria: intellectual merit and broader impact. The broader impact criterion (BIC), or the science outreach criterion, is intended to connect science, technology, engineering, and math (STEM) research to the general public, and has grown in its relevance for successful grants. A method to increase the competitiveness of a grant application and, in turn, the quality of science outreach programs is to suggest successful science outreach models for connecting scientists to the public. Science Saturdays is a fun science lecture series for the general public that is a simple, scalable, and transferable model. Its main mission is to introduce participants to excellent communicators of science and to shatter stereotypes about those who do science. It aims to inspire and motivate children as they traverse the STEM pipeline by emphasizing that science is fun. This paper discusses the elements needed to create this outreach program and the lessons learned from its development.
The Undergraduate Science Research Experience (USRE) and its Transformative Nature for Houston Community College Students
Authors: Sheinberg Bartlett M. 
Published: September 2011

ABSTRACTSince 2005 the author has provided community college science and engineering students the opportunity to conduct substantive summer research projects in the areas of materials science, physical sciences, engineering disciplines and other multidisciplinary research areas. To date, nineteen students have participated in research experiences at regional universities and NASA-Johnson Space Center. This paper will examine the genesis of the program, providing an overview of the program structure, the role that materials research has played in the success of the various student experiences, and thoughts on future directions and improvements.
Magnetocaloric Properties Desired for Magnetic Refrigeration System near Room Temperature
Authors: Wada H. 
Published: September 2011

ABSTRACTIn order to realize the magnetic refrigeration system, it is necessary to develop a 100 W class refrigerator with COP > 7.5. This requires us to find new magnetic refrigerant materials, of which cooling capacity is 2.5 times higher than that of Gd. In this paper, first we discuss the cooling capacity of magnetic refrigerant materials to achieve COP = 7.5. Then, we compare the experimental results of MnAsSb, MnFe(PGe) and La(FeCoSi)13 compounds with the calculated cooling capacity. It is suggested that a composite layer material of MnFe(PGe) would show excellent cooling capacity in the temperature span of 20 K.
School-based Clubs as a Mechanism to Increase Student Interest in Materials Science Engineering and Nanotechnology among Underserved Groups
Authors: Dika Sandra L. , Alvarez Jaquelina E. , Santos Jeannette , Suárez O. Marcelo 
Published: September 2011

ABSTRACTSince 2005, the University of Puerto Rico-Mayagüez (UPRM) has co-facilitated materials science and engineering (MSE) clubs at low-income middle and high schools in Western Puerto Rico to increase awareness and interest in the areas of materials science, nanotechnology, and engineering. In this article, we describe the club activities and share the results of the 2009 end-of-year assessment regarding knowledge, interest, and educational aspirations in MSE, along with differences based on gender, parent education level, and school level. Overall, participants expressed positive opinions about engineering as a career. While students expressed high interest in pursuing university studies in science and engineering, some differences became apparent based on gender, parent education level, and school level. There were also differences between boys and girls in perceived knowledge gains. The results of this assessment provide promising evidence that school-based MSE clubs may help attract underserved students into the MSE pipeline.
Ultrafine Silicon Nano-wall Hollow Needles and Applications in Inclination Sensor and Gas Transport
Authors: Sanaee Z. , Mohajerzadeh S. , Mehran M. , Araghchini M. 
Published: September 2011

ABSTRACTWe report on the realization of high precision hollow structures directly on silicon suitable for liquid and gas/vapor transport. The formation of hollow structures requires high aspect ratio etching combined with bulk back-side micro-machining to realize silicon-based membranes. The use of a slant angle deposition method has been used as an alternative method for three-dimensional lithography. The transfer of acetone vapor through such tiny holes shows an anomalous behavior where a sharp rise is observed followed by an exponential and gradual decay. These structures can be eventually used as mass ion separation devices.
Macroporous Carbon Monoliths with Large Surface Area for Electric Double-Layer Capacitor
Authors: Hasegawa George , Aoki Mami , Kanamori Kazuyoshi , Nakanishi Kazuki , Hanada Teiichi , Tadanaga Kiyoharu 
Published: September 2011

ABSTRACTMacro/meso/microporous carbon monoliths doped with sulfur have been prepared from sulfonated polydivinylbenzene networks followed by the activation with CO2 resulted in the activated carbon monoliths with high surface area of 2400 m2 g−1. The monolithic electrode of the activated carbon shows remarkably high specific capacitance (175 F g−1 at 5 mV s−1 and 206 F g−1 at 0.5 A g−1).
Ionic Electroactive Polymer Actuators with Aligned Carbon Nanotube/Nafion Nanocomposite Electrodes
Authors: Liu Yang , Liu Sheng , Cebeci Hülya , Guzman de Villoria Roberto , Lin Jun-Hong , Wardle Brian L. , Zhang Q. M. 
Published: September 2011

ABSTRACTRecent advances in fabricating controlled-morphology vertically aligned carbon nanotube (VA-CNTs) with ultrahigh volume fraction create unique opportunities for markedly improving the electromechanical performance of ionic polymer conductor network composite actuators (IPCNCs). Actuator experiments show that the continuous paths through inter-VA-CNT channels and low electrical conduction resistance due to the continuous CNTs in the composite electrodes of the IPCNC lead to fast ion transport and actuation speed (>10% strain/second). One critical issue in developing advanced actuator materials is how to suppress or eliminate unwanted strains generated under electric stimulation, which reduce the actuation efficiency and also the actuation strains. We observe that the VA-CNTs in the composite electrodes yields non-isotropic elastic modulus that suppresses the unwanted strain and markedly enhances the actuation strain (>8% strain under 4 volts). A transmission line model has been developed to understand the electrical properties of the actuator device.
Deformation Behavior of Natural Wood Having Hierarchical Structure Under A Compression State
Authors: MIKI Tsunehisa , SUGIMOTO Hiroyuki , KANAYAMA Kozo 
Published: September 2011

ABSTRACTA large deformation of bulk wood using slipping between the wood cells has been found just like a plastic deformation generated by slip band in metallic materials. This phenomenon is caused by the hierarchical structure of the wood cell, and the intercellular layer becomes selectively softened in moistened states of wood. In such conditions, bulk wood subject to compression at elevated temperatures can easily be deformed perpendicular to the longitudinal direction of the cells by shear flow stress after being collapsed.
Development of a Robust Design of a Wet Etched Co-integrated Pressure Sensor
Authors: Schreiber-Prillwitz Wolfgang , Saukoski Mikko , Chmiel Gerhard , Job Reinhart 
Published: September 2011

ABSTRACTThe performance of a co-integrated silicon pressure sensor for the 1-bar full scale range was optimized. A gain in signal of ca. 5% was calculated and verified by optimizing the piezoresis-tors position on the membrane. The influence of alignment errors between the backside cavity mask and the positions of the piezoresistors on the membrane’s front side were calculated. De-pending on the asymmetry, a maximal electrical signal deviation of 1% was found. The impact of underetching effects (KOH) at the backside mask on electrical signals was also analyzed. Un-deretching has a certain range, alters the membrane size, and has a strong impact on sensor per-formances. In a worst case scenario signal variations caused by underetching could be finally reduced from 15% to 4%.
Carbon-Rich Nanostructures from Molecular Precursors
Authors: Hoheisel Tobias N. , Szilluweit Ruth , Schrettl Stephen , Frauenrath Holger 
Published: September 2011

ABSTRACTA synthesis for protected, glycosylated, amphiphilic oligo(ethynylene)s was developed. After their deprotection, two different glycosylated hexa(ethynylene)s were investigated for their self-assembly properties as well as their reactivity in aqueous solutions and at the air-water interface. Aggregation was observed in aqueous solution by UV spectroscopy, and the molecules formed films at the air-water interface.
Measurements of Resonance Frequency of Parylene Microspring Arrays Using Atomic Force Microscopy
Authors: Gaire C. , He M. , Zandiatashbar A. , Wang P.-I. , Picu R. C. , Wang G.-C. , Lu T.-M. 
Published: September 2011

ABSTRACTA mechanical vibration system was made by sandwiching an array of parylene-C microsprings between two flat plates of Si. This system was driven mechanically in forced oscillation using a piezo transducer attached to the bottom Si plate. An atomic force microscope was used to record the displacement of the top plate in both the contact and non-contact modes. At the resonance, the system was observed to give large vertical displacement amplitude of up to 100 nm with a Q-factor of up to 900.
Project VISTA: Building University/K-12 Learning Communities by Developing Materials Science Experiments
Authors: Bakker Martin G. , Gleason Jim , Nichols Sherry , Kuntz Aaron , Sundberg Cheryl , Busenlehner Laura , Chopra Nitin , Evans Victoria , Spencer Rosin P. , Murphy Amy K. 
Published: September 2011

ABSTRACTOne consequence of “high stakes testing” in Tuscaloosa area schools has been exclusion of materials science faculty from any meaningful participation in middle and high school classrooms. Beyond the loss of resources from the classroom that Materials Science faculty and their students represent, this also has negative consequences for faculty wanting to build ties to schools to address NSF’s “broader impact” criteria. A group of STEM and Education faculty at The University of Alabama have been testing a team based approach designed to overcome the systemic constraints that prevent effective STEM/K-12 collaboration. Teams consisting of a high school teacher, a STEM faculty member, and a STEM graduate student have spent three weeks during summer 2010 to identify/develop and implement an inquiry based science experiments. The experiments are being tested on science campers at McWane Science Center prior to being assessed in the teachers’ classrooms during the fall semester. The experiments were chosen by each team and represent significant advances over those currently available in the schools. By setting a problem that no team member is able to solve alone an environment was produced where success requires meaningful collaboration. Preliminary qualitative evaluation indicates deeper understanding of the school environment by the STEM faculty and greater respect for the skills teachers bring to this endeavor. Successes in this pilot program have generated credibility with the local school district, opening the door to scaling up the project, and developing further positive ties. Incorporation of lead teachers from Alabama Science in Motion also allows the experiments developed to be widely disseminated throughout Alabama, as well as providing a mechanism to identify existing experiments to enhance.
On the Electrochemical Properties of α-Li3FeF6 Prepared by Precipitation from Aqueous-Alcohol Based Solutions
Authors: Basa A. , Gonzalo E. , Kuhn A. , García-Alvarado F. 
Published: September 2011

ABSTRACTThe α-polymorph of Li3FeF6 has been prepared from aqueous-based solution by precipitation under different conditions to obtain small particles. Several alcohols have been used to vary the precipitation media. Among them 2-propanol has been found to provide particles of about 100 nm under controlled conditions of temperature and H2O: R-OH volume ratio. The average particle size of some of the as-prepared samples is smaller than that obtained for those samples obtained by precipitation in water. However, the expected enhancement of electrochemical performances does not occur for the as-prepared samples. Inserted amount of lithium into the cryolite structure of Li3FeF6 increases significantly only when composites of asprepared Li3FeF6 and carbon are milled mechanically. For example 12h milling is needed to reach 64 mAh/g (45% of theoretical capacity).
Atomic Layer Deposition of Gallium-Doped Zinc Oxide Transparent Conducting Oxide films
Authors: Chalker Paul R. , Marshall Paul A. , Romani Simon , Rosseinsky Matthew J. , Rushworth Simon , Williams Paul A. , Buckett John , McSporran Neil , Ridealgh John 
Published: September 2011

ABSTRACTThin transparent conducting oxide (TCO) films of gallium-doped zinc oxide have been deposited on glass substrates by atomic layer deposition (ALD) using diethyl zinc, triethyl gallium and water vapour as precursors. The gallium-doped zinc oxide films were deposited over the temperature range 100-350°C. Transmission electron microscopy reveals that the as-deposited films are polycrystalline in character. The electrical resistivity of the gallium-doped zinc oxide films was evaluated using four-point probe and contactless measurement methods as a function of film thickness. The lowest sheet resistance of 16 Ω/☐ was measured from a film thickness of 400nm and a gallium content of 5 atomic percent. The electron Hall mobility of this film was 12.3 cm2/Vs. The visible transmittance of the films was 78% with a haze of 0.2%.
Bandgap engineered high mobility indium oxide thin films for photovoltaic applications
Authors: Gupta R.K. , Ghosh K. , Kahol P.K. 
Published: September 2011

ABSTRACTMagnesium and titanium doped indium oxide (IMTO) thin films were grown using pulsed laser deposition technique. Magnesium was added to enhance the bandgap, whereas titanium was added to improve carrier concentrations and mobility of indium oxide films. The effect of growth temperature on structural, optical, and electrical properties were studied. It was observed that the optical transparency of the films strongly depends on growth temperature and increases with increase in growth temperature. The films grown at 600 °C showed optical transparency > 85%. We observed widening in bandgap of indium oxide by doping with magnesium and titanium. The bandgap of IMTO films increases with increase in growth temperature. The maximum bandgap of 3.9 eV was observed for film grown at 600 °C. It was observed that growth temperature strongly affects the electrical properties such as resistivity, carrier concentration, and mobility. The electrical resistivity and mobility of the films increases with increase in growth temperature. On the other hand, carrier concentration decreases with increase in growth temperature. Temperature dependence electrical resistivity measurements showed that films grown at low temperatures are semiconducting in nature, while films grown at high temperature showed transition from semiconducting to metallic behavior. These wide bandgap, highly transparent, and high mobility films could be used for photovoltaic applications.
Effect of Growth Conditions on Electronic and Structural Properties of GZO Films Grown by Plasma-enhanced Molecular Beam Epitaxy on p-GaN(0001)/Sapphire Templates
Authors: Liu H.Y. , Avrutin V. , Izyumskaya N. , Reshchikov M.A. , Wolgast S. , Kurdak C. , Yankovich A.B. , Kvit A. , Voyles P. , Özgür Ü. , Morkoç H. 
Published: September 2011

Abstract:We report on a strong effect of p-GaN surface morphology on the growth mode and surface roughness of ZnO:Ga films grown by plasma-assisted molecular-beam epitaxy on p-GaN/c-sapphire templates. A range of ZnO:Ga surface morphologies varying from rough surfaces with well defined three-dimensional islands, capable to enhance light extraction in light-emitting diodes, to rather smooth surfaces with a surface roughness of ~ 2 nm suitable for vertical-cavity lasers can be achieved by controlling the surface morphologies of p-GaN. Optical transmittance measurements revealed high transparency exceeding 90% in the visible spectral range for ZnO:Ga with both types of surface morphology.
Surface Characterization of Ga-doped ZnO layers
Authors: McNamara J.D. , Ferguson J.D. , Foussekis M. , Ruchala I. , Reshchikov M.A. , Baski A.A. , Liu H. , Avrutin V. , Morkoç H. 
Published: September 2011

ABSTRACTEpitaxial ZnO layers heavily doped with Ga (GZO) were grown at 400 °C under metaland oxygen-rich conditions in terms of metal-to-reactive oxygen ratio by plasma-assisted molecular beam epitaxy (MBE). Several atomic force microscopy (AFM) techniques were used to characterize the surface morphology and electrical properties of these GZO films in ambient conditions. Local I-V spectra indicate that layers grown under both O-rich and metal-rich conditions are highly resistive until a relatively high voltage sweep (±12 V) is used. After removal of an insulating surface layer, conduction is possible at lower voltages, but eventually the film resistivity increases and it again becomes insulating. In addition to local I-V spectra, local charge injection and subsequent surface potential measurements were used to probe surface charging characteristics. For charge injection experiments, a reverse-bias voltage is applied to the sample while scanning in contact mode with a metallized tip. The resultant change in surface potential due to trapped charge is subsequently observed using scanning Kelvin probe microscopy (SKPM). The layers deposited in a metal-rich environment demonstrate the expected behavior, but the O-rich layers show anomalous negative and positive charging. Finally, surface photovoltage (SPV) measurements using above-bandgap UV illumination were performed. The GZO layers produce SPV values of 0.4 to 0.5 eV, where the films deposited in an O-rich environment have slightly higher SPV values and faster restoration.