bluuebunny/crossref_metadata_2025_split huggingface dataset:
Translating Research Into the Classroom: The NIST Summer Institute for Middle School Science Teachers
Authors: Satterfield Mary B. , Ratcliffe Toby , Heller-Zeisler Susan 
Published: June 2019

ABSTRACTThe National Institute of Standards and Technology (NIST) has developed a dynamic and on-going educational outreach program designed to support middle school science teachers and increase their understanding of the science they teach with applications to the real world and connections to the latest NIST research. In the NIST Summer Institute for Middle School Science Teachers, science topics are taken from NIST research pertinent to the middle school curriculum, and the research is translated for use in the classroom. During the two-week summer program teachers from around the country are given the opportunity to focus on NIST research as it relates to the middle school classroom by participating in a combination of hands-on activities, lectures, tours, and visits with scientists and engineers in their laboratories. The NIST Summer Institute is designed to increase teacher understanding of the subjects they teach, provide inquiry activities for the classroom, rekindle teachers’ enthusiasm for science, provide increased understanding of how scientific research is performed, create a learning community of teachers and scientists, and provide role models for the teachers. Teachers finish the NIST Summer Institute with a wealth of knowledge about core topics in introductory biology, chemistry, physics, and materials to integrate these topics into their existing curriculum.The NIST Summer Institute has spawned additional related outreach activities, including “Science Afternoons at NIST,” in which teachers are invited back to NIST during the school year for events in which the focus is on a single topic such as designing buildings to resist earthquakes, infrared energy, and nanomagnetism. Based on continued requests from participants in the NIST Summer Institute, an additional program, the NIST Research Experience for Teachers program, was begun in 2011 with teachers performing research at NIST under the guidance of NIST scientists and engineers, and designing ways to take their research experience back into the classroom to share with their students. This proceeding will give examples of topics covered and activities developed in past Summer Institutes, as well as ways similar Institutes are being implemented at other locations. While not a teaching institution but a research institute focused on meeting the measurement science needs of the nation, NIST has a wealth of resources for the education community. The NIST Summer Institute for Middle School Science Teachers is one way of sharing these resources and building partnerships between middle school science teachers and their students and NIST scientists and engineers.
HERE AND NOW
Authors: Gordon Robert , Thir Shawn 
Published: June 2019

ABSTRACTHitachi High Technologies is On the Frontlines of Science Education Outreach Programs. Hitachi High-Technologies Corporation (Hitachi High-Tech), a global leader in the electron microscope industry, is working to inspire a new generation of achievement in science education. In loaning out its tabletop microscopes Hitachi High-Tech is tackling the problem of waning interest in science education, which is becoming a global issue throughout all industrialized nations. Hitachi High-Tech aims to become the global leader in providing high-tech solutions, and its support for science extends beyond Japan to North America, South America, and Europe.
MATERIALS, DESIGN, AND INNOVATION IN NONMAJORS SCIENCE EDUCATION
Authors: Puthoff Jonathan B. , Bentley Anne K. , Autumn Kellar , DePaula Julio 
Published: June 2019

ABSTRACTIn-depth materials science course offerings are crucial for training the next generation of researchers in many pure and applied fields. However, translating discoveries from the laboratory into domestic and industrial settings requires contributions from professionals outside of these strictly technical areas. Providing non-major students instruction in core scientific ideas and illustrating the myriad pathways by which these ideas become innovative technologies should be an additional goal of science and engineering programs. “Technologies of the Future” (ToF) is a novel course for non-science/engineering majors in which students participate in team-based laboratory and design projects with modern materials systems. After learning about a phenomenon or physical principle in class, students are given the opportunity to explore it in lab and are tasked with the design of a novel device that incorporates it. Example laboratory topics include superhydrophobic surfaces and dye-sensitized solar cells. In the design phase, instructors act as “consultants”, lending their expertise to students unfamiliar with engineering analysis or ancillary physical concepts. Summative activities are designed to leverage the diverse talents of the interdisciplinary teams of students. The course concepts and activities are designed to prepare students for both a modern workplace that requires innovative thinking and a modern world in which emerging technologies offer solutions to pressing environmental and social problems.
Hot Exciton Dissociation at Organic Interfaces
Authors: Grancini G. , Fazzi D. , Maiuri M. , Petrozza A. , Egelhaaf H-J. , Brida D. , Cerullo G. , Lanzani G. 
Published: June 2019

ABSTRACTInterface physics is at the heart of organic photovoltaics (OPV). Here we reveal for the first time the actual charge generation mechanism in a low-band-gap polymer: fullerene blend as prototypical system for efficient OPV. We demonstrate that the photogenerated excitons dissociate into bound interfacial charge transfer states (CTS) and free charges in 20-50 fs, with a branching ratio that depends on the excess energy. Providing an excess energy, high energy singlet polymer states are excited, giving a direct hot electron transfer into the interfacial hot CTS* before internal energy dissipation occurs. This process ultimately leads to a higher fraction of free charges. Thanks to strong electronic coupling between high-energy-states and hot CTS, we demonstrate the opening of additional paths for charge generation that would otherwise be quenched by internal conversion to the lowest-lying states. Our results provide a new framework to understand charge generation in OPV system, suggesting that hot dissociation is a strategic option to enhance the photovoltaic conversion.
Carbon Nano-Onion Ultracapacitor Model
Authors: Parigi Fabio , Gachovska Tanya , Gao Yang , Zhou Yunshen , Hudgins Jerry L. , Lu Yongfeng 
Published: June 2019

ABSTRACTThis paper describes a novel ultracapacitor made from carbon nano-onions. Characterization of the material was performed including measurement of the impedance spectra and cyclic voltammetry. A new ultracapacitor model composed of an LRC circuit and a constant phase element was developed along with a parameter extraction procedure. The model was validated using experimental data and simulation.
Improving the Efficiency of Organic Photovoltaic Devices through Interface Engineering
Authors: Liu Feilong , Crone Brian K. , Ruden Paul , Smith Darryl L. 
Published: June 2019

ABSTRACTWe explore theoretically the effect of incorporating a thin tunnel barrier between the electron and hole transport layers of organic heterostructure photovoltaic devices. The device efficiency can be improved significantly by controlling the rates of microscopic processes associated with exciton dissociation and recombination at the interface between the electron and hole transport layers. The effects of different parameters are examined, and conclusions for organic photovoltaic device design are discussed.
Processing of pristine single and multiwalled carbon nanotubes as different stacking layers in bulk heterojunction solar cells
Authors: Khan M. Alam , Matsumura Michio , Manasreh Omar 
Published: June 2019

ABSTRACTA study on the individualization of commercially purchased SWCNT and MWCNT were made in an N-N dimethyl tetraformamide solvent by a combination of ultrasonication and centrifugation, and processing of these individualized CNTs are applied as a stacking layer in bulk-heterojunction (BHJ) solar cells. The wt% (mg) of pristine CNTs loading was optimized in respect to volume of solvent (ml). Then as prepared BHJ devices were modified by spin casting at 4000 rpm/30s of these pristine individualized CNTs by incorporating a stacking layer (∼30 nm) for efficiency evaluation. Comparisons of the devices made with known functionalized CNTs (acid treated) and found that stacking of pristine individualized CNTs between the PEDOT:PSS and active (P3HT:PCBM) layer demonstrate a significantly enhanced efficiency of 2.1% (JSC of 9 mA/cm2, VOC of 0.6, FF of 39) from the normal BHJ of 1.2% (JSC of 5.3 mA/cm2, VOC of 0.62, FF of 33). However, SWCNT with acid treated when applied in BHJ shows degrading efficiency (0.51%) which can be attributed to the degradation of corrugated tubular side walls leading to potential loss of opt-oelectric properties. The enhanced efficiency of devices with pristine individualize CNTs can be conjectured due to better opto-electrical properties and undamaged tubes. The microstructures of the heterojunction active layer were examined by using UV-Vis spectra, IV curve and EQE techniques.
Hydrothermal Synthesis and Characterization of ThO2, UxTh1-xO2, and UOx
Authors: Castilow Jacob , Zens Timothy W , Mann J. Matthew , Kolis Joseph W. , McMillen Colin D. , Petrosky James 
Published: June 2019

ABSTRACTHydrothermal synthesis of ThO2, UxTh1-xO2, and UOxat temperatures between 670°C and 700°C has been demonstrated. Synthesis at these temperatures is 50-80°C below prior growth studies and represents a new lower bound of successful growth. ThO2single crystals of dimensions 6.49mm x 4.89mm x 3.89 mm and weighing 0.633g have been synthesized at average growth rates near 0.125mm/week. Single crystal UxTh1-xO2crystals with mole fractions up to x≈0.30 have also been grown. The largest alloyed crystal with mole fraction x≈0.23 has dimensions of 2.97mm x 3.23mm x ∼3mm and recorded average growth rates near 0.2mm/week. Four structures were solved from X-ray diffraction data and their crystallographic data reported here. Rocking curve analysis determined a dislocation density of 1.2×109cm-2.
Enhanced Attachment and Proliferation of Fibroblasts on Anodized 316L Stainless Steel with Nano-pit Arrays
Authors: Ni Siyu , Sun Linlin , Ercan Batur , Liu Luting , Ziemer Katherine , Webster Thomas J. 
Published: June 2019

ABSTRACTThe aim of this study was to prepare various sized nano-pits on 316 L stainless steel and examine their effects on the attachment and proliferation of fibroblasts. In this study, 316L stainless steel with tunable pit sizes (0, 25, 50, and 60 nm) were fabricated by an anodization procedure in an ethylene glycol electrolyte solution containing 5 vol.% perchloric acid. The surface morphology of 316L stainless steel were characterized by scanning electron microscopy (SEM). The nano-pit arrays on all the 316L stainless steel samples were in a regular arrangement. The surface properties of the 316L stainless steel nano-pit surface showed improved wettability properties as compared to the untreated 316L stainless steel. The nano-pit surfaces with 50 nm and 60 nm diameter were rougher at the nanoscale than other samples. The attachment and proliferation of fibroblasts were investigated for up to 3 days in culture using MTT assays. Compared to unanodized (that is, nano-smooth) and smooth surfaces, 50 and 60 nm diameter nano-pit surfaces dramatically enhanced the initial fibroblast attachment and growth up to 3 days in culture. The results reported in this study showed that the 50 and 60 nm nano-pit surfaces promoted fibroblast adhesion and proliferation by increasing the surface roughness and adsorption of fibronectin. Such nano-pit surfaces can be designed to support fibroblast growth and be important for improving the use of 316L stainless steel for various implant applications (such as for improved skin healing for amputee devices or for percutaneous implants).
Bone Microenvironment Tissue Surrogates Engineered for Reporting of Metastasized Breast Cancer Osteolytic Activity
Authors: Dumas Jerald E. , Parks Akia N. , Platt Manu O. 
Published: June 2019

ABSTRACTBreast cancer metastasis to bone continues to be a major clinical problem, and patient-to-patient variability in rates of disease progression and metastasis complicate treatment even further. This may be due to differences in the cancer cells, the osteoclasts, or the pre-metastatic niche, but all of these contribute to proteolytic remodeling necessary for osteolytic lesion establishment, primarily through secretion of cathepsin K, the most powerful human collagenase. There is debate about the relative contributions of breast cancer cells and osteoclasts and synergism between the two in altering the biochemical and biomechanical properties of the colonized bone, as these are difficult to parse with animal models. To quantify the relative contributions of breast cancer cells and osteoclasts in bone resorption, we have been developing engineered bone microenvironment tissue surrogates by adapting a poly(ester urethane) urea system embedded with microbone particles. Here, we report their use with MDA-MB-231 breast cancer cells and RAW264.7 derived osteoclasts, to provide temporal, multiscale reporters of bone resorption that can be measured non-destructively: 1) collagen degradation measured by C-terminal collagen fragment release, 2) mineral dissolution by measuring calcium released with the calcium arsenazo assay, and also show their beneficial effects in upregulating cathepsin K expression compared to tissue culture polystyrene controls. These more natural derived bone surrogates may be useful tools in mimicking bone metastatic niche and determining differences between proteolytic activity of different patients’ tumor and bone resident cells in a controlled manner.
Electrochemical Performance of Cu Nanoparticle/Carbonized Wood Electrode for Supercapacitor Application
Authors: Teng Shiang , Tiwari Ashutosh 
Published: June 2019

ABSTRACTThe electrochemical effects of embedding Cu nanoparticles in carbonized wood supercapacitor electrodes have been investigated. The nanoparticles were embedded using a solution method. Subsequent X-ray diffraction (XRD) and scanning electron microscopy (SEM) results showed that the Cu nanoparticles were anchored uniformly on the surface and deep within the pores of the electrode. Cyclic voltammetry measurements showed that the electrode has typical pseudocapacitive behavior, with two pairs of redox reaction peaks. The charge-discharge cycling also indicated that the redox charge transformation was a reversible process. An ultra-high specific capacitance of 888 F/g and an energy density of 123 Wh/kg were observed for the Cu loaded electrodes, as compared to the pure carbonized wood electrodes, which had a specific capacitance of 282 F/g and an energy density of 39 Wh/kg. Furthermore, both the carbonized wood and Cu loaded electrodes exhibited excellent long cycle abilities with at least 95% of the specific capacitance retained after 2000 cycles. These remarkable results demonstrate the potential for using Cu nanoparticle loaded carbonized wood as a high performance and environmentally friendly supercapacitor electrode material.
Influence of deposition chamber pressure and substrate temperature on the properties of fluorescent blue and phosphorescent red OLED deposited by OVPD
Authors: van Gemmern Philipp , Zimmermann Christoph , Niyamakom Phenwisa , Wuttig Matthias , Brand Sabine , Schwab Holger , Becker Heinrich , Fortte Rocco , Heuken Michael , Kalisch Holger , Jansen Rolf H. 
Published: June 2019

ABSTRACTOrganic light-emitting diodes (OLED) offer the potential to replace conventional light sources such as incandescent bulbs and fluorescent tubes. The question which thin-film technology is most favorable to produce OLED on an industrial scale is still unanswered. The most established technology for the deposition of small-molecule organic layers is vacuum thermal evaporation. A comparably novel technology is organic vapor phase deposition (OVPD), which offers some unique features in terms of adjustable process parameters such as deposition chamber pressure (P) and substrate temperature (TS). The impact of these parameters on the morphology of organic single layers as well as on the performance of OLED is mostly unknown. In this work, phosphorescent red OLED were produced with different TS and a strong influence on the device efficiency was found. Atomic force microscopy measurements were conducted to investigate the morphology of the hole injection and hole transport layers of the devices deposited at different TS. In addition to this, the influence of TS and P on the performance of fluorescent blue OLED and the morphology of organic single layers was tested. By varying TS and P for the emission layer only, current efficiencies in the range from 4.3 to 6.8 cd/A were found despite the fact that all devices had the same structure. Atomic force microscopy measurements conducted on organic single layers which were deposited at the same process conditions showed rms values ranging from 1.4 to 57 nm.
Microstructure and Fracture At the Cement Paste-Aggregate Interface
Authors: Struble L. 
Published: June 2019

ABSTRACTThe mechanical behavior of concrete is thought to be affected by the microstructure of the paste-aggregate interface, which differs in several respects from the microstructure of bulk paste. General aspects of interfacial microstructure, which appear to be fairly well understood, are reviewed. Recent microstructural studies using backscattered electron imaging show that there is a zone along the interface (approximately 50 μm wide) within which there are generally few large unhydrated clinker grains, many large voids (greater than 5 μm), a generally porous microstructure, many hollow-shell hydration grains, and in some cases little calcium hydroxide. The tendency for cracks to develop or grow along the paste-aggregate interface is discussed in relation to specific features of the interfacial microstructure.
Effect of Fiber-Matrix Bond Strength on the Crack Resistance of Synthetic Fiber Reinforced Cementitious Composites
Authors: Li Victor C. , Wang Youjiang , Backer Stanley 
Published: June 2019

ABSTRACTFiber matrix bond characteristics can be changed by treatments of the fiber surface. The effect of such treatments on the fiber reinforced concrete (FRC) tension-softening behavior and crack resistance is studied in this paper. Various R-curve behaviors are predicted based on a simple double cantilevered beam (DCB) model using the experimentally derived tensionsoftening curves. The result suggests that fiber surface treatments can substantially alter the composite fracture resistance as measured by the R-curve.
Silica Fume Effects on the Pull-Out Behavior of Randomly Oriented Steel Fibers from Concrete
Authors: Soroushian Parviz , Bayasi Ziadz 
Published: June 2019

ABSTRACTSilica fume is known to improve the pore system of cementitious pastes and their adhesion capacity to fibers and other mix inclusions. This study has been mainly concerned with the effect of silica fume on the pull-out strength of randomly oriented steel fibers from concrete. Silica fume effects on the fresh mix workability and the overall flexural and compressive behavior of steel fiber reinforced and plain concretes were also assessed. The only variable in different fibrous and plain mixes was the fraction of portland cement substituted with silica fume. This fraction ranged from 0% to 20%.The workability of plain and fibrous mixes were obtained by slump and inverted slump cone tests, respectively. In both the flexure and compression tests on fiber concrete, the complete load-deformation relationship was obtained. The pull-out strength of randomly oriented fibers was assessed through analysis of the flexural test data.All aspects of the fresh and hardened steel fiber reinforced concrete performance considered in this study, especially the pull-out strength of randomly oriented fibers from concrete, were observed to improve with the increase in silica fume-cementitious ratio up to a certain limit, after which the trends in silica fume effects were reversed.
The Effect of Blast Furnace Slag on the Microstructure of the Cement Paste/Steel Interface
Authors: Onabolu O. A. , Pratt P. L. 
Published: June 2019

ABSTRACTThe microstructures of steel reinforced ordinary Portland cement mortar samples, and those containing 40% and 70% slag as cement replacement, have been studied by electron optical techniques, after exposure to stagnant sea-water at 23°C for 320 days. Fracture surfaces along the interface with steel were examined using secondary electron imaging in the SEM. This revealed differences between the OPC and slag specimens as regards the morphology of the phases and the amounts of calcium hydroxide present. The microstructure at the interface with steel was studied by means of back scattered electron imaging combined with quantitative image analysis. Chloride concentrations at sections around the interface were determined by means of an EDXA facility linked to the SEM. Even after 320 days immersion in sea-water, there was some calcium hydroxide present in the interfacial zone.
Adhesion Between Concrete and Treated or Untreated Flat Metal Surfaces
Authors: Montgomery D. G. , Samarin A. 
Published: June 2019

ABSTRACTModern construction techniques for floor and slab systems often make use of the composite action developed between steel and concrete. Knowledge of the magnitude of adhesive force, other than mechanical bond, is necessary in the design of permanent steel formwork, which ultimately becomes an integral part of the load bearing reinforced concrete structure. To investigate the extent of adhesion at the interface between concrete and flat metal surfaces, different treatments of the metal surfaces were considered. Results are presented for six types of treated and untreated metal plates when tested in a pull-off mode with conventional concrete. The mode and the type of failures were investigated, and those parameters, which are considered to be significant in the study of this phenomenon, evaluated
Changing the Interface Cementitious Materials/Aqueous Solution For Performing Electroosmosis
Authors: Kuin A. J. , Stein H. N. 
Published: June 2019

ABSTRACTRemoval of excess water from cement/sand/water mixes can be effected by electroosmosis with an efficiency of several hundred g per Watt sec, if an additive is applied which increases the absolute value of the zeta potential.
The Influence of the Matrix-Aggregate Bond on the Strength and Brittleness of Concrete
Authors: Keru Wu , Jianhua Zhou 
Published: June 2019

ABSTRACTIn this paper, the influence of the matrix-aggregate bond on the strength and brittleness of concrete is studied. Six different matrixaggregate interfaces are used to evaluate the interfacial bond capability. The results obtained on the strength and brittleness index of concrete show that strengthening and toughening of concrete can be obtained simultaneously, if the interfacial bonds are changes so that they conform to a rational distribution according to aggregate size. These results are discussed in terms of the energy dissipation and crack propagation during failure of concrete.