Particle Deposition onto Enclosure Surfaces

DTIC Science & Technology

2009-08-20

Deposition on Semiconductor Wafers," Aerosol Sci. Technol. 6, 215 (1987). 3. S. E. Pratsinis, T. T. Kodas , M. P. Dudukovic, and S. K. Friedlander...29, 511 (1998). 11. T. T. Kodas , "Generation of Complex Metal Oxides by Aerosol Processes: Superconducting Ceramic Particles and Films," Adv. Mater

High Energy Density Dielectrics for Pulsed Power Applications

DTIC Science & Technology

2008-09-01

Energy/Power/Thermal Division //Signature// DEREK M. LINCOLN, Major, USAF Deputy Chief Energy/Power/Thermal Division Propulsion Directorate...comparative study," J. Vac. Sci. Technol. A 16, (1998), 2804-2815. 11 T.T. Leung and C.W. Ong . “Nearly amorphous to epitxial growth of aluminum nitride

Helicon antenna radiation patterns in a high-density hydrogen linear plasma device

NASA Astrophysics Data System (ADS)

Caneses, J. F.; Blackwell, B. D.; Piotrowicz, P.

2017-11-01

Antenna radiation patterns in the vicinity of a helicon antenna are investigated in hydrogen plasmas produced in the MAGPIE linear plasma device. Using a uniform cold-plasma full-wave code, we model the wave physics in MAGPIE and find good agreement with experimental wave measurements. We show for the first time which antenna elements in a helicon device couple most strongly to the plasma and discuss the physical mechanism that determines this effect. Helicon wavefields in the near field of the antenna are best described in terms of the group velocity and ray direction, while far from the antenna, helicon wavefields behave like plane waves and are best described in terms of eigen-modes. In addition, we present recent 2D axis-symmetric full-wave simulations of the 120 kW helicon source in ProtoMPEX [Rapp et al., IEEE Trans. Plasma Sci. 44(12), 3456-3464 (2016); Caughman et al., J. Vac. Sci. Technol. Vac. Surf. Films 35, 03E114 (2017); and Goulding et al., Fusion Sci. Technol. 72(4), 588-594 (2017)] ( n e ˜ 5 × 1019 m-3, B 0 ˜ 70 mT, and f = 13.56 MHz) where the antenna radiation patterns are evident, and we provide an interpretation of the numerical results using the ideas developed in this paper.

Richard Ahrenkiel | NREL

Science.gov Websites

Kuciauskas, J Tynan, "Dual-sensor technique for characterization of carrier lifetime decay transients in semiconductors", Journal of Applied Physics 116 (21), 214510 (2014) J. Moseley, M.M. Al-Jassim, H.R For Contactless Measurement of Carrier Lifetime", J. Vac. Sci. Technol. B 31, 04D113 R. K

Cyclodextrin-Enhanced In Situ Removal of Organic Contaminants from Groundwater at Department of Defense Sites

DTIC Science & Technology

2004-05-01

Advantage Nontoxic to humans and resident microbial populations Cyclodextrins are widely used in pharmaceuticals, food processing, and cosmetics ...dechlorination of tetrachloroethene by the Fenton reaction. Environ. Sci. Technol., 17 (9): 1689-1694. 25. Yin, Y., Allen, H.E., 1999: In situ chemical

Post-CMOS Micromachining of Surface and Bulk Structures

DTIC Science & Technology

2002-05-06

Structures iii Acknowledgements I would like to thank my advisors, Professor Gary K. Fedder and Professor Dave W. Greve, for their continuing support...Donnelly, Plasma Chem. Plasma Process, vol. 1, pp. 37, 1981. [54] J. L. Mauer, J. S. Logan, L. B. Zielinski , and G. S. Schwartz, J. Vac. Sci. Technol

Optoelectronic Integration

DTIC Science & Technology

1992-03-20

34 Interband Transitions in InGaAs/GaAs Strained Layer Superlattices ," J. of Vac. Sci and Technol. B, Vol. 7(5), pp. 1106-1110, 1989. 33 B. Kh...2 II. C. Resonant Cavity-Enhanced Photodetectors ................................ .............. 3 II. D. Wavelength Selective Optoelectronic...Simultions of Electronic States in Semiconductor Quantum Wells and Superlattices under Electrical Field ................................ ....... 5 II. G . G

Contact Formation (Hg, CD)Te

DTIC Science & Technology

1989-12-01

Davis, W.A. Beck, D.G. Kilday, J.T. McKinley, and G. Margaritondo, J. Vac. Sci. Technol. A 7, 870 (1989). 312 J.M. Pawlikowski, Acta Physica Polonica A49...139 (1976). J.M. Pawlikowski, Acta Physica Polonica A49, 563 (1976). J.M. Pawlikowski, Acta Physica Polonica A51, 95 (1977). SJ.M. Pawlikowski, Phys

Navigating Tensions between Conceptual and Metaconceptual Goals in the Use of Models

ERIC Educational Resources Information Center

Delgado, Cesar

2015-01-01

Science education involves learning about phenomena at three levels: concrete (facts and generalizations), conceptual (concepts and theories), and metaconceptual (epistemology) (Snir et al. in "J Sci Educ Technol" 2(2):373-388, 1993). Models are key components in science, can help build conceptual understanding, and may also build…

Impedance Spectroscopy as a Tool for Non-Intrusive Detection of Extracellular Mediators in Microbial Fuel Cells

DTIC Science & Technology

2009-12-01

bioseparation. Hoboken, NJ: John Wiley & Sons, p. 267. HernandezME, Kappler A, Newman DK. 2004. Phenazines and other redox active antibiotics promote...Verstraete W. 2005. Microbial phenazine production enhances electron transfer in biofuel cells. Environ Sci Technol 39:3401. Ramasamy RP, Ren Z, Mench MM

Reduced PM2.5 Emissions for Military Gas Turbine Engines using Fuel Additives

DTIC Science & Technology

2006-08-12

indicator of the presence of PAH species in hydrocarbon flames [ Naegeli 1998, Bomse 1992]. Although fluorescence originates from a wide range of aromatic...Env. Sci. Technol., 32:2033, 1998. Mueller, M. , R Yetter, F. Dryer, ChemKinet 31 (1999) 705-724. Naegeli , D.W. and K.H. Childress, "Lower

Chaiwat Engtrakul | NREL

Science.gov Websites

, College Park B.S. Chemistry, Gettysburg College Featured Publications M.Z. Hu, C. Engtrakul, B.L. Bischoff Applications." Separ. Sci. Technol., 53, 528-543. C. Engtrakul, M.Z. Hu, B.L. Bischoff, G.G. Jang (2016 Catalytic Fast Pyrolysis of Pine Biomass." Energy Fuels, 30, 8343-8348. C. Engtrakul, C. Mukarakate

Electrolytic Transformation of Hexahydro-1,3,5-Trinitro-1,3,5-Triazine (RDX) and 2,4,6-Trinitrotoluene (TNT) in Aqueous Solutions

DTIC Science & Technology

2005-08-01

several years (Bunce et al. 1997; de Lima Leite et al. 2003; Panizza and Cerisola 2004). Treatment is achieved by either oxidation (anodic) or...and mixed anaerobic cultures," Environ. Sci. Technol. 35, 4341-4346. Panizza , M., and Cerisola, G. (2004). "Influence of anode material on the

Strained InGaAs/InAlAs Quantum Wells for Complementary III-V Transistors

DTIC Science & Technology

2014-01-01

GaAs substrates for low power and high frequency applications, J. Appl. Phys. 109 (2011) 033706. [28] A. Ali, H. Madan , A. Agrawal, I. Ramirez, R...Growth of InAsSb-channel high electron mobility transistor structures, J. Vac. Sci. Technol. B 23 (2005) 1441–1444. [30] A. Ali, H. Madan , M.J

Finite Element Modeling of Viscoelastic Behavior and Interface Damage in Adhesively Bonded Joints

DTIC Science & Technology

2012-01-01

eccentricity of the axis of a lap joint gives rise to transverse or peel stresses at the Report Documentation Page Form ApprovedOMB No. 0704-0188...Computers and Structures 29, 1011 (1988). 21 S. Roy and J. N. Reddy, Tire Sci. Technol. 16, 146 (1988). 22 S. Roy and J. N. Reddy, Intl. J. Numer

Investigation of Schottky Barriers

DTIC Science & Technology

1989-12-01

W. E. Spicer, I. Lindau, P. R. Skeath, C. Y. Su and P. W. Chye , Phys. Rev. Lett. 44, 420 (1980); W. E. Spicer, P. W. Chye , P. R. Skeath, C. Y. Su and...Kahn, D. G. Kilday, and G. Margaritondo, J. Vac. Sci. Technol. B5, 987 (1987). 8. R. Cao, K. Miyano, T. Kendelewicz, K. K. Chin , I. Lindau, and W. E

Development of a Miniature Snapshot Multispectral Imager

DTIC Science & Technology

2010-09-01

ZnS ) and SiO2, however since ITC had no prior experience with ZnS , the next best choice of TiO2 and SiO2 was selected for fabrication of dielectric...Bass, S. J.; Apsley, N. High Quality InP /InGaAs Fabry-Perrot Etalons Grown by AP MOCVD. Semicon. Sci. Technol. 1987, 2, 466–467. 13. Szipocs, R

Changes in redox properties of humic acids upon sorption to alumina

NASA Astrophysics Data System (ADS)

Subdiaga, Edisson; Orsetti, Silvia; Jindal, Sharmishta; Haderlein, Stefan B.

2016-04-01

1. Introduction A prominent role of Natural Organic Matter (NOM) in biogeochemical processes is its ability to act as an electron shuttle, accelerating rates between a bulk electron donor and an acceptor. The underlying processes are reversible redox reactions of quinone moieties.1 This shuttling effect has been studied in two major areas: transformation of redox active pollutants and microbial respiration.2-3 Previous studies primarily compared effects in the presence or absence of NOM without addressing the redox properties of NOM nor its speciation. The interaction between humic acids (HA) and minerals might change properties and reactivity of organic matter. Specifically, we investigate whether changes in the redox properties of a HA occur upon sorption to redox inactive minerals. Since fractionation and conformational rearrangements of NOM moieties upon sorption are likely to happen, the redox properties of the NOM fractions upon sorption might differ as well. 2. Materials and methods Elliot Soil Humic Acid (ESHA), Pahokee Peat Humic Acid (PPHA) and Suwannee River Humic Acid (SRHA) were used as received from IHSS. Aluminum oxide (Al2O3) was suspended in 0.1M KCl. Sorption was studied at pH 7.0 in duplicate batch experiments for several HA/Al2O3 ratios. For the suspension (mineral + sorbed HA, plus dissolved HA), the filtrate (0.45μm) and the HA stock solution, the electron donating and accepting capacities (EDC and EAC) were determined following established procedures.4 3. Results All studied HA-Al2O3 systems showed similar behavior with regard to changes in redox properties. There was a significant increase in the EDC of the whole suspension compared to the stock solutions and the non-sorbed HA in the filtrate (up to 300% for PPHA). This effect was more pronounced with increasing amounts of sorbed HA in the suspension. Although ESHA had the highest sorption capacity on Al2O3 (~ 6 times higher than PPHA & SRHA), it showed the smallest changes in redox properties upon sorption. Considering the total electron exchange capacities, significant changes were found mainly at higher amounts of sorbed PPHA and SRHA. 4. Conclusions Overall, our results suggest a change in the redox properties of sorbed HA but not for the dissolved fraction. The sorbed fraction showed a higher redox capacity than the stock samples. Given the absence of redox transfer between the HA and the redox inert aluminum oxide, such changes might be due to conformational changes in the humic substances. 5. References [1] Scott D., Mcknight, D., Blunt-Harris, E., Kolesar, S., Lovley, A. Environ. Sci. Technol. 1998, 32, 2984-2989. [2] Dunnivant, F. Schwarzenbach, R., Macalady, D. Environ. Sci. Technol. 1992, 26(11), 2133-2141. [3] Jiang, J. & Kappler, A. Environ. Sci. Technol. 2008, 42(10), 3562-3569. [4] Aeschbacher, M., Sander M., Schwarzenbach, R. Environ. Sci. Technol. 2010, 44(1), 87-93.

EDITORIAL: The 20th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases The 20th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases

NASA Astrophysics Data System (ADS)

Petrović, Zoran Lj; Marić, Dragana; Malović, Gordana

2011-03-01

This special issue consists of papers that are associated with invited lectures, workshop papers and hot topic papers presented at the 20th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases (ESCAMPIG XX). This conference was organized in Novi Sad (Serbia) from 13 to 17 July 2010 by the Institute of Physics of the University of Belgrade. It is important to note that this is not a conference 'proceedings'. Following the initial selection process by the International Scientific Committee, all papers were submitted to the journal by the authors and have been fully peer reviewed to the standard required for publication in Plasma Sources Science and Technology (PSST). The papers are based on presentations given at the conference but are intended to be specialized technical papers covering all or part of the topic presented by the author during the meeting. The ESCAMPIG conference is a regular biennial Europhysics Conference of the European Physical Society focusing on collisional and radiative aspects of atomic and molecular physics in partially ionized gases as well as on plasma-surface interaction. The conference focuses on low-temperature plasma sciences in general and includes the following topics: Atomic and molecular processes in plasmas Transport phenomena, particle velocity distribution function Physical basis of plasma chemistry Plasma surface interaction (boundary layers, sheath, surface processes) Plasma diagnostics Plasma and discharges theory and simulation Self-organization in plasmas, dusty plasmas Upper atmospheric plasmas and space plasmas Low-pressure plasma sources High-pressure plasma sources Plasmas and gas flows Laser-produced plasmas During ESCAMPIG XX special sessions were dedicated to workshops on: Atomic and molecular collision data for plasma modeling, organized by Professors Z Lj Petrovic and N Mason Plasmas in medicine, organized by Dr N Puac and Professor G Fridman. The conference topics were represented in the program by 16 invited lectures, 7 selected hot topics, and 191 poster presentations. The largest number of contributed papers was submitted in Topic 5: Plasma diagnostics (37). The workshop topics were addressed by 10 invited lectures, 5 oral presentations and 7 posters. A post-conference workshop with 5 invited lectures was organized, dealing with the data needs for modeling of plasma sources of light. ESCAMPIG XX was attended by 185 scientists from 31 countries. Of the participants, 30% were PhD students (55). The list includes scientists from the USA, Japan, Australia, Mexico and other non-European countries, which indicates the truly international status of the conference. We would like to thank the authors for their efforts in preparing stimulating lectures and interesting articles for the readers of PSST, and the scientific community dealing with ionized gases, plasma sources and atomic, molecular and chemical physics of low-temperature plasmas for continued interest in the field of ESCAMPIG. We would like to thank the organizers of all previous ESCAMPIG conferences for setting the standards for organization and, in particular, the organizers of ESCAMPIG XVIII and XIX for their direct help and insight. Finally the International Scientific Committee and its chairman in particular have worked hard to select the best possible program and to keep us in line with almost 40 years of tradition and standards of the conference. Most importantly this has been the 20th conference. The quality of new papers shows maturity and new vistas in the field that has produced so much fundamental understanding of complex, non-equilibrium, even nonlinear plasmas. At the same time the field has led to some of the key technologies of modern civilization and has shown that responsible science that pays attention to its societal benefits should have no fear for its future. All critical issues studied today were presented at the meeting and only a small part is represented here. For example, discharges in liquids or above liquids were covered by several lectures represented by two papers. Verreycken et al [1] studied optical emission spectroscopy and Rayleigh scattering in discharges above water electrodes in order to measure gas temperature. At the same time Starikovsky et al [2] showed that it is possible to strike a breakdown directly in the liquid phase without gaseous evaporation or bubbles. Another key issue of present-day low-temperature plasma physics is atmospheric pressure discharges. Application of atmospheric pressure microwave plasma was considered by Belmonte et al [3] as a source for plasma-enhanced chemical vapour deposition. Strategies to produce nanosize structures and high deposition rates have also been proposed. Akishev et al [4] presented modeling results showing why spatial reproducibility of the origins of micro-discharges in a dielectric barrier discharge (DBD) is very high while the stochastic nature of the breakdown leads to jitter. Associated with the application of plasmas in many systems is control plasma chemistry. Tanarro and Herrero [5] performed measurements and modeling of dominant species in a hollow cathode discharge with variation of pressure. Dramatic changes in composition were noticed in H2, H2/Ar, and air. For example, NO becomes the second most abundant neutral under some conditions while at high mean energies H2+ ions become more abundant than H3+. Loureiro et al [6] presented the most detailed self-consistent model of discharges in N2, both pure and in mixtures with H2 and CH4. The model includes coupling of different mechanisms in the gas phase and on surfaces. A further example of detailed plasma chemistry and modeling of possible industrial applications is the work of De Bie et al [7] who studied the conversion of methane to more complex hydrocarbons and other gases in a detailed model of kinetic and plasma chemistry of a DBD reactor. Associated with plasma chemistry models but with a completely different final goal is the work of Taccogna et al [8]. They provide a detailed model of negative ion production in an ITER source of fast neutrals for heating of fusion plasma. Low-temperature plasmas have made their most significant impact through application of etching and other plasma techniques in the production of integrated circuits. Associated with this there have been several papers dealing with control of plasmas relevant for plasma etching applications. Czarnetzki et al [9] presented the modeling of an electrical asymmetry effect which allows independent control of plasma symmetry, bias and consequently properties of ions reaching the surfaces. Separate control of the flux and energy of ions from capacitively coupled plasmas, while an interesting fundamental issue, is also one of the key issues in the manufacture of integrated circuits. Makabe and Yagisawa [10] gave a detailed presentation of the top-down model of plasma devices for etching and other plasma-related nanotechnologies. Their paper presents a complex model covering atomic and molecular collisions and transport, plasma kinetics in complex geometries, and plasma interaction with surfaces with the ability to calculate the development of etched profiles, and the damage-inducing potentials within the wafer. Finally, as the basis of all modeling of plasmas, atomic and molecular collision and transport data were a much more prominent part of ESCAMPIG conferences in the past. We tried to initiate the return of elementary processes to ESCAMPIG from numerous specialized conferences by organizing a workshop on the data for modeling. Bartschat and Zatsarinny [11] gave a presentation of the foundation of the B-spline R-matrix method and a number of cross section results that extend the databases for plasma modeling of atomic gases. State-of-the-art calculations presented here focus on threshold regions of electronic excitation cross sections where complex structures exist due to resonances. These threshold regions of the excitation cross sections, however, determine the distribution function in the region of the ionization, The interface between plasma modeling and atomic physics is swarm studies, and those are based on transport theory that has recently become quite complex and versatile. Dujko et al [12] considered a Boltzmann equation solution to the transport of charged particles, especially in crossed electric and magnetic fields. Apart from indicating the necessity to include transport properties in E × B fields in plasma modeling, these results show complexity and kinetic phenomena that require kinetic models to be properly included. Finally, Makabe and Tatsumi [13] presented the structure of a comprehensive model of plasma etching devices and focused on the requirements for the atomic and collision cross section data. The winner of the W Crookes Prize was Zoltán Donkó [14] who gave a review of particle-in-cell and Monte Carlo simulation methods and presented a review of a large number of systems where he and his co-workers have applied this technique. In particular the lecture gives examples of different kinetic phenomena that arise in modeling of different plasmas. This presentation covers both applications in the control of low-pressure capacitively coupled plasmas and DC breakdown and glow discharges as well as the issues of modeling of elementary processes in the gas phase and on surfaces. Finally, to reply to Harold Pinter and his famous quote, apart from the known and the unknown there is the joy of extending the border of the 'known' and sharing it with colleagues at conferences like ESCAMPIG. Every answer that is reached opens new horizons and new realms of the 'unknown' to explore, and conferences like ESCAMPIG have proven to be a continuous source of ideas and inspiration for all colleagues within the field of low-temperature plasmas and elementary processes. We can certainly hope that the 20th ESCAMPIG was no exception in this regard. References Verreycken T, van Gessel A F H, Pageau A and Bruggeman P 2011 Plasma Sources Sci. Technol. 20 024002 Starikovsky A, Yang Y, Cho Y I and Fridman A 2011 Plasma Sources Sci. Technol. 20 024003 Belmonte T, Gries T, Cardoso R P, Arnoult R, Kosior F and Henrion G 2011 Plasma Sources Sci. Technol. 20 024004 Akishev Y, Aponin G, Balakirev A, Grushin M, Karalnik V, Petryakov A and Trushkin N 2011 Plasma Sources Sci. Technol. 20 024005 Tanarro I and Herrero V J 2011 Plasma Sources Sci. Technol. 20 024006 Loureiro J, Guerra V, Sá P A, Pintassilgo C D and Lino da Silva M 2011 Plasma Sources Sci. Technol. 20 024007 De Bie C, Martens T, van Dijk, Paulussen S, Verheyde B and Bogaerts A 2011 Plasma Sources Sci. Technol. 20 024008 Taccogna F, Minelli P, Diomede P, Longo S, Capitelli M and Schneider R 2011 Plasma Sources Sci. Technol. 20 024009 Czarnetzki U, Schulze J, Schungel E and Donkó Z 2011 Plasma Sources Sci. Technol. 20 024010 Makabe T and Yagisawa T 2011 Plasma Sources Sci. Technol. 20 024011 Bartschat K and Zatsarinny O 2011 Plasma Sources Sci. Technol. 20 024012 Dujko S, White R D, Petrovic Z Lj and Robson R E 2011 Plasma Sources Sci. Technol. 20 024013 Makabe T and Tatsumi T 2011 Plasma Sources Sci. Technol. 20 024014 Donkó Z 2011 Plasma Sources Sci. Technol. 20 024001

Electrolytic Transformation of Hexyhydro-1,3,5-Trinitro-1,3,5-Triazine (RDX) and 2,4,6-Trinitrotoluene (TNT) in Aqueous Solutions

DTIC Science & Technology

2005-08-01

several years (Bunce et al. 1997; de Lima Leite et al. 2003; Panizza and Cerisola 2004). Treatment is achieved by either oxidation (anodic) or reduction...Hexahydro-1,3,5-trinitro- 1,3,5-triazine mineralization by zerovalent iron and mixed anaerobic cultures,” Environ. Sci. Technol. 35, 4341-4346. Panizza

Electrolytic Transformation of Hexahydro-1,3,5-Trinitro-1,3,5-Triazine (RDX) and 2,4,6-Trintrotoluene (TNT) in Aqueous Solutions

DTIC Science & Technology

2005-08-01

several years (Bunce et al. 1997; de Lima Leite et al. 2003; Panizza and Cerisola 2004). Treatment is achieved by either oxidation (anodic) or reduction...Hexahydro-1,3,5-trinitro- 1,3,5-triazine mineralization by zerovalent iron and mixed anaerobic cultures,” Environ. Sci. Technol. 35, 4341-4346. Panizza

Nutrient Recycling Impacts by Zebra Mussels in Harper’s Ferry Slough, Upper Mississippi River

DTIC Science & Technology

2000-12-01

ing pro duc tiv ity in the slough (also see Caraco et al. (1997)). In Harper’s Ferry Slough and other aquatic sys tems, the mag ni tude of ze bra mus...the Upper Mississippi River with zebra mussels (Dreissena polymorpha),” Environ. Sci. Technol. 33, 4385-4390. ERDC WQTN-PD-07 December 2000 11 Caraco , N

Combustion of Alane and Aluminum with Water for Hydrogen and Thermal Energy Generation

DTIC Science & Technology

2010-01-01

Herr, Green Rocket Propulsion by Reaction of Al and Mg Powders and Water, AIAA 2004-4037, 2004. [9] J.L. Sabourin , G.A. Risha, R.A. Yetter, S.F. Son...Wiley and Sons, Inc., 1992. [32] G.A. Risha, J.L. Sabourin , V. Yang, R.A. Yetter, S.F. Son, B.C. Tappan, Combust. Sci. Technol. 180 (2008) 2127–2142

Recent Naval Postgraduate School Publications.

DTIC Science & Technology

1985-09-30

of the performance of a new storm tracking methodology Prepared for Naval Environmental Prediction Res. Facility Monterey, Calif., Naval Postgraduate...Aerospace Sci. Mtg., Jr’., 1983. Sarpkaya, T; Storm , M A ydrodynamic forces from combined wave and current flow on smooth and rough circular cylinders...Houston, Tx., May, 1982. IN Proc 1982 Offshore Technol. Conf., vol. 1, p.731-736, (1982). Sarpkaya, T; Storm , M A ydrodynamic forces from combined wave

Impaired Clearance And Enhanced Pulmonary Inflammatory/Fibrotic Response To Carbon Nanotubes In Myeloperoxidase-Deficient Mice

DTIC Science & Technology

2012-03-30

utilized SWCNT, it is highly likely that multi-walled carbon nanotubes, fullerenes , graphene and other carbonaceous particles may also undergo MPO...screening and analysis system to distinguish between the organic tissue and the inorganic SWCNT (under bright field imaging settings). Optically...Cytotoxicity of carbon nanomaterials: single-wall nanotube, multi-wall nanotube, and fullerene . Environ Sci Technol 39: 1378–1383. 7. Kisin ER, Murray

A New Family of Schroder's Method and Its Variants Based on Power Means for Multiple Roots of Nonlinear Equations

ERIC Educational Resources Information Center

Kanwar, V.; Sharma, Kapil K.; Behl, Ramandeep

2010-01-01

In this article, we derive one-parameter family of Schroder's method based on Gupta et al.'s (K.C. Gupta, V. Kanwar, and S. Kumar, "A family of ellipse methods for solving non-linear equations", Int. J. Math. Educ. Sci. Technol. 40 (2009), pp. 571-575) family of ellipse methods for the solution of nonlinear equations. Further, we introduce new…

Reactive high power impulse magnetron sputtering

NASA Astrophysics Data System (ADS)

Gudmundsson, J. T.; Magnus, F.; Tryggvason, T. K.; Sveinsson, O. B.; Olafsson, S.

2012-10-01

Here we discuss reactive high power impulse magnetron sputtering sputtering (HiPIMS) [1] of Ti target in an Ar/N2 and Ar/O2 atmosphere. The discharge current waveform is highly dependent on both the pulse repetition frequency and discharge voltage. The discharge current increases with decreasing frequency or voltage. This we attribute to an increase in the secondary electron emission yield during the self-sputtering phase of the pulse, as nitride [2] or oxide [3] forms on the target. We also discuss the growth of TiN films on SiO2 at temperatures of 22-600 ^oC. The HiPIMS process produces denser films at lower growth temperature and the surface is much smoother and have a significantly lower resistivity than dc magnetron sputtered films on SiO2 at all growth temperatures due to reduced grain boundary scattering [4].[4pt] [1] J. T. Gudmundsson, N. Brenning, D. Lundin and U. Helmersson, J. Vac. Sci. Technol. A, 30 030801 (2012)[0pt] [2] F. Magnus, O. B. Sveinsson, S. Olafsson and J. T. Gudmundsson, J. Appl. Phys., 110 083306 (2011)[0pt] [3] F. Magnus, T. K. Tryggvason, S. Olafsson and J. T. Gudmundsson, J. Vac. Sci. Technol., submitted 2012[0pt] [4] F. Magnus, A. S. Ingason, S. Olafsson and J. T. Gudmundsson, IEEE Elec. Dev. Lett., accepted 2012

Advanced Coatings from Natural-Based Polymers for Metals

DTIC Science & Technology

2000-07-01

Polyimide Interfaces," J. surfaces using a simple dipping-withdrawing coating Vac. Sci. Technol., 3,1390 (1985).converted into the solid layers by heat...Tang, C.H., "Interface Reaction During Metalliza- more, the Al metal in the substrate favorably interacted tion of Cured Polyimide : An XPS Study," 1...property together with its biocompatability was the reason why CS is widely used in biomedical applications, for example, a bacteriostatic agent, a

Nitrogen Plasma Optimization for High-Quality Dilute Nitrides

DTIC Science & Technology

2005-02-01

Available online 1 February 2005Abstract Growth of GaInNAs by molecular beam epitaxy (MBE) generally requires a nitrogen plasma, which complicates growth...InGaAs and InGaAsP lasers. This paper addresses several of the challenges of plasma-assisted molecular beam epitaxy (MBE) of high-quality dilute nitrides...A.L. Holmes, Using beam flux monitor as Langmuir probe for plasma-assisted molecular beam epitaxy , J. Vac. Sci. Technol. B, in press.

Virtual Impactor for Sub-micron Aerosol Particles

NASA Astrophysics Data System (ADS)

Bolshakov, A. A.; Strawa, A. W.; Hallar, A. G.

2005-12-01

The objective of a virtual impactor is to separate out the larger particles in a flow from the smaller particles in such a way that both sizes of particles are available for sampling. A jet of particle-laden air is accelerated toward a collection probe so that a small gap exists between the acceleration nozzle and the probe. A vacuum is applied to deflect a major portion of the airstream away form the collection probe. Particles larger than a certain size have sufficient momentum so that they cross the deflected streamlines and enter the collection probe, whereas smaller particles follow the deflected streamlines. The result is that the collection probe will contain a higher concentration of larger particles than is in the initial airstream. Typically, virtual impactors are high-flow devices used to separate out particles greater than several microns in diameter. We have developed a special virtual impactor to concentrate aerosol particles of diameters between 0.5 to 1 micron for the purpose of calibrating the optical cavity ring-down instrument [1]. No similar virtual impactors are commercially available. In our design, we have exploited considerations described earlier [2-4]. Performance of our virtual impactor was evaluated in an experimental set-up using TSI 3076 nebulizer and TSI 3936 scanning mobility particle size spectrometer. Under experimental conditions optimized for the best performance of the virtual impactor, we were able to concentrate the 700-nm polystyrene particles no less than 15-fold. However, under experimental conditions optimized for calibrating our cavity ring-down instrument, a concentration factor attainable was from 4 to 5. During calibration experiments, maximum realized particle number densities were 190, 300 and 1600 cm-3 for the 900-nm, 700-nm and 500-nm spheres, respectively. This paper discusses the design of the impactor and laboratory studies verifying its performance. References: 1. A.W. Strawa, R. Castaneda, T. Owano, D.S. Baer, B.A. Paldus, J. Atm. Ocean. Technol., 20, 454-465 (2003). 2. V.A. Marple, K.L. Rubow, B.A. Olson, Aerosol Sci. Technol., 22, 140-150 (1995). 3. B.T. Chen, H.C. Yeh, Y.S. Cheng, J. Aerosol Sci., 16, 343-354 (1985). 4. V.A. Marple, C.M. Chien, Environ. Sci. Technol., 14, 976-985 (1980).

Using Amphiphilic Nanostructures to Enable Long-Range Ensemble Coalescence and Surface Rejuvenation in Dropwise Condensation

DTIC Science & Technology

2012-01-01

in high-humidity environments. Nature-inspired superhydrophobic surfaces have been actively explored to enhance heat and mass transfer rates by...challenge with superhydrophobic surfaces, as observed in nature on the lotus leaf21 and on synthetic surfaces,22,23 is that they are often rendered...Dynamics. Rev. Mod. Phys. 1985, 57, 827–863. 2. Kim, S. H. Fabrication of Superhydrophobic Surfaces. J. Adhes. Sci. Technol. 2008, 22, 235–250. 3

Rapid Formation of Acrylated Microstructures by Microwave-Induced Thermal Crosslinking

DTIC Science & Technology

2010-01-01

Kagawa, M. Okubo, Chem. Rev. 2008, 108, 3747. [10] C. O. Kappe, D. Dallinger, Nature Rev. Drug Disc. 2006, 5, 51. [11] R. Hoogenboom , U. S. Schubert...of Electronic Imaging 2004, 13. [24] R. M. Paulus, C. R. Becer, R. Hoogenboom , U. S. Schubert, Aust. J. Chem. 2009, 62, 254. [25] S. S. Cutie, D. E...Kohn, Macromolecules 1992, 25, 4476. [27] H. Zhang, R. Hoogenboom , M. Meier, U. Schubert, Meas. Sci. Technol. 2005, 16, 203. 13

Joint Services Electronics Program.

DTIC Science & Technology

1986-09-30

IEEE Computer Society Conference on Trends and Aplications , Gaithersburg, MD, 57-62, May 1983. R.W. Miksad, D.W. Choi and E.J. Powers, "Application of...Estimators for Weakl Nonlinear Esti’mation Problems, M.S. Thesis , Dept. of Electrica Engineering, University of Texas at Austin, May 1982. 7 %- (Page...Chen, J. Vac. Sci. Technol. 17,911 (1980). 6. N.I. Cho, Masters Thesis , unpublished. 7. EI-Saied M. Aly and J.P. Stark, J. Appl. Phys. 53(4), 3063

Scanning Tunneling Microscopy, Atomic Force Microscopy, and Related Techniques

DTIC Science & Technology

1992-02-26

92. (B47) Fujui, T.; Suzuki, MA.; Miyashita, MA.; Yamaguchi, M.; Onuki , T.; Nakamura, H .; Matsubara, T.; Yamada, H .; Nakayamia, K. J. Vac. Sd...and seven deflection detection systems (A 15). (Al) Binnig, G.; Rohrer, H .; Gerber, Ch.; Weibel, E. Phys. Rev. Lett. 1982, 49, 57. (A2) Ray, M.A...J. J. Vac Sci. Technol. A 1ඣ, 9, 44-50. (AS) Scanning Tunneling Microscopy and Related Methods; Behm, RJ., Garcia, N., Rohrer, H ., Eds.; NATO ASI

Enhanced etching of tin-doped indium oxide due to surface modification by hydrogen ion injection

NASA Astrophysics Data System (ADS)

Li, Hu; Karahashi, Kazuhiro; Friederich, Pascal; Fink, Karin; Fukasawa, Masanaga; Hirata, Akiko; Nagahata, Kazunori; Tatsumi, Tetsuya; Wenzel, Wolfgang; Hamaguchi, Satoshi

2018-06-01

It is known that the etching yield (i.e., sputtering yield) of tin-doped indium oxide (ITO) by hydrocarbon ions (CH x +) is higher than its corresponding physical sputtering yield [H. Li et al., J. Vac. Sci. Technol. A 33, 060606 (2015)]. In this study, the effects of hydrogen in the incident hydrocarbon ion beam on the etching yield of ITO have been examined experimentally and theoretically with the use of a mass-selected ion beam system and by first-principles quantum mechanical (QM) simulation. As in the case of ZnO [H. Li et al., J. Vac. Sci. Technol. A 35, 05C303 (2017)], mass-selected ion beam experiments have shown that the physical sputtering yield of ITO by chemically inert Ne ions increases after a pretreatment of the ITO film by energetic hydrogen ion injection. First-principles QM simulation of the interaction of In2O3 with hydrogen atoms shows that hydrogen atoms embedded in In2O3 readily form hydroxyl (OH) groups and weaken or break In–O bonds around the hydrogen atoms, making the In2O3 film less resistant to physical sputtering. This is consistent with experimental observation of the enhanced etching yields of ITO by CH x + ions, considering the fact that hydrogen atoms of the incident CH x + ions are embedded into ITO during the etching process.

High Resolution Continuous Flow Analysis System for Polar Ice Cores

NASA Astrophysics Data System (ADS)

Dallmayr, Remi; Azuma, Kumiko; Yamada, Hironobu; Kjær, Helle Astrid; Vallelonga, Paul; Azuma, Nobuhiko; Takata, Morimasa

2014-05-01

In the last decades, Continuous Flow Analysis (CFA) technology for ice core analyses has been developed to reconstruct the past changes of the climate system 1), 2). Compared with traditional analyses of discrete samples, a CFA system offers much faster and higher depth resolution analyses. It also generates a decontaminated sample stream without time-consuming sample processing procedure by using the inner area of an ice-core sample.. The CFA system that we have been developing is currently able to continuously measure stable water isotopes 3) and electrolytic conductivity, as well as to collect discrete samples for the both inner and outer areas with variable depth resolutions. Chemistry analyses4) and methane-gas analysis 5) are planned to be added using the continuous water stream system 5). In order to optimize the resolution of the current system with minimal sample volumes necessary for different analyses, our CFA system typically melts an ice core at 1.6 cm/min. Instead of using a wire position encoder with typical 1mm positioning resolution 6), we decided to use a high-accuracy CCD Laser displacement sensor (LKG-G505, Keyence). At the 1.6 cm/min melt rate, the positioning resolution was increased to 0.27mm. Also, the mixing volume that occurs in our open split debubbler is regulated using its weight. The overflow pumping rate is smoothly PID controlled to maintain the weight as low as possible, while keeping a safety buffer of water to avoid air bubbles downstream. To evaluate the system's depth-resolution, we will present the preliminary data of electrolytic conductivity obtained by melting 12 bags of the North Greenland Eemian Ice Drilling (NEEM) ice core. The samples correspond to different climate intervals (Greenland Stadial 21, 22, Greenland Stadial 5, Greenland Interstadial 5, Greenland Interstadial 7, Greenland Stadial 8). We will present results for the Greenland Stadial -8, whose depths and ages are between 1723.7 and 1724.8 meters, and 35.520 to 35.636 kyr b2k 7), respectively. The results show the conductivity measured upstream and downstream of the debubbler. We will calculate the depth resolution of our system and compare it with earlier studies. 1) Bigler at al, "Optimization of High-Resolution Continuous Flow Analysis For Transient Climate Signals in Ice Cores". Environ. Sci. Technol. 2011, 45, 4483-4489 2) Kaufmann et al, "An Improved Continuous Flow Analysis System for High Resolution Field Measurements on Ice Cores". Environmental Environ. Sci. Technol. 2008, 42, 8044-8050 3) Gkinis, V., T. J. Popp, S. J. Johnsen and T, Blunier, 2010: A continuous stream flash evaporator for the calibration of an IR cavity ring down spectrometer for the isotopic analysis of water. Isotopes in Environmental and Health Studies, 46(4), 463-475. 4) McConnell et al, "Continuous ice-core chemical analyses using inductively coupled plasma mass spectrometry. Environ. Sci. Technol. 2002, 36, 7-11 5) Rhodes et al, "Continuous methane measurements from a late Holocene Greenland ice core : Atmospheric and in-situ signals" Earth and Planetary Science Letters. 2013, 368, 9-19 6) Breton et al, "Quantifying Signal Dispersion in a Hybrid Ice Core Melting System". Environ. Sci. Technol. 2012, 46, 11922-11928 7) Rasmussen et al, " A first chronology for the NEEM ice core". Climate of the Past. 2013, 9, 2967--3013

A novel heat engine for magnetizing superconductors

NASA Astrophysics Data System (ADS)

Coombs, T. A.; Hong, Z.; Zhu, X.; Krabbes, G.

2008-03-01

The potential of bulk melt-processed YBCO single domains to trap significant magnetic fields (Tomita and Murakami 2003 Nature 421 517-20 Fuchs et al 2000 Appl. Phys. Lett. 76 2107-9) at cryogenic temperatures makes them particularly attractive for a variety of engineering applications including superconducting magnets, magnetic bearings and motors (Coombs et al 1999 IEEE Trans. Appl. Supercond. 9 968-71 Coombs et al 2005 IEEE Trans. Appl. Supercond. 15 2312-5). It has already been shown that large fields can be obtained in single domain samples at 77 K. A range of possible applications exist in the design of high power density electric motors (Jiang et al 2006 Supercond. Sci. Technol. 19 1164-8). Before such devices can be created a major problem needs to be overcome. Even though all of these devices use a superconductor in the role of a permanent magnet and even though the superconductor can trap potentially huge magnetic fields (greater than 10 T) the problem is how to induce the magnetic fields. There are four possible known methods: (1) cooling in field; (2) zero field cooling, followed by slowly applied field; (3) pulse magnetization; (4) flux pumping. Any of these methods could be used to magnetize the superconductor and this may be done either in situ or ex situ. Ideally the superconductors are magnetized in situ. There are several reasons for this: first, if the superconductors should become demagnetized through (i) flux creep, (ii) repeatedly applied perpendicular fields (Vanderbemden et al 2007 Phys. Rev. B 75 (17)) or (iii) by loss of cooling then they may be re-magnetized without the need to disassemble the machine; secondly, there are difficulties with handling very strongly magnetized material at cryogenic temperatures when assembling the machine; thirdly, ex situ methods would require the machine to be assembled both cold and pre-magnetized and would offer significant design difficulties. Until room temperature superconductors can be prepared, the most efficient design of machine will therefore be one in which an in situ magnetizing fixture is included. The first three methods all require a solenoid which can be switched on and off. In the first method an applied magnetic field is required equal to the required magnetic field, whilst the second and third approaches require fields at least two times greater. The final method, however, offers significant advantages since it achieves the final required field by repeated applications of a small field and can utilize a permanent magnet (Coombs 2007 British Patent GB2431519 granted 2007-09-26). If we wish to pulse a field using, say, a 10 T magnet to magnetize a 30 mm × 10 mm sample then we can work out how big the solenoid needs to be. If it were possible to wind an appropriate coil using YBCO tape then, assuming an Ic of 70 A and a thickness of 100 µm, we would have 100 turns and 7000 A turns. This would produce a B field of approximately 7000/(20 × 10-3) × 4π × 10-7 = 0.4 T. To produce 10 T would require pulsing to 1400 A! An alternative calculation would be to assume a Jc of say 5 × 108A m-1 and a coil 1 cm2 in cross section. The field would then be 5 × 108 × 10-2 × (2 × 4π × 10-7) = 10 T. Clearly if the magnetization fixture is not to occupy more room than the puck itself then a very high activation current would be required and either constraint makes in situ magnetization a very difficult proposition. What is required for in situ magnetization is a magnetization method in which a relatively small field of the order of millitesla repeatedly applied is used to magnetize the superconductor. This paper describes a novel method for achieving this.

Water Temperature and Concentration Measurements Within the Expanding Blast Wave of a High Explosive

DTIC Science & Technology

2011-03-15

Please scroll down to see the full text article. 2011 Meas. Sci. Technol. 22 045601 (http://iopscience.iop.org/0957-0233/22/4/045601) Download...Glumac [15] recently demonstrated the use of a Nd:YAG pumped dye laser for absorption measurements (single shot per detonation experiment, 10 ns...weighing 2.6 or 21 g for the 12.7 and 25.4 mm cylinders, respectively. A thin layer of vacuum grease was applied to the face of the detonator so that the

Sources & Transport Mechanisms of Sediments in the Oceans.

DTIC Science & Technology

1982-03-31

estuaries 03si e m arh ket. The. peristaltic action, dugt is. pro ~gre- and oceans. The concentration of doe suspended sample was testig were obtained by...waters: Clays Clay Minerals, Seventh National Con - weer: Progress in water technology. v. 7, p. 207-216. ference, p. 1-79. Guess, R. J. (1977), Clay...the (10) ZAbawa, C. Science (Wahigton, D.C) 1978,202,49.4 dlyt Of the GMo wer 45 jum wit a meal portion (11) G b.I J.; Kenwar, L Environ. Sci. Technol

Laser Surface Melting of Stainless Steel Anodes for Reduced Hydrogen Outgassing (Postprint)

DTIC Science & Technology

2016-12-29

including baking [8– 12], vacuum baking [8,11,13,14], polishing [8,14], and surface treatments to create oxide or other protective surface films. Elec...quantity [15] and may necessitate an additional bake to thoroughly degas the surface [8]. The purpose of the work described here was to determine the...9] M. Bernardini, Air bake -out to reduce hydrogen outgassing from stainless steel, J. Vac. Sci. Technol. A Vacuum, Surfaces, Film 16 (1998) 188–193.4

Interface-induced localization in AlSb/InAs heterostructures

NASA Astrophysics Data System (ADS)

Shaw, M. J.; Briddon, P. R.; Jaros, M.

1995-12-01

The existence of localized states at perfect InSb-like interfaces in AlSb/InAs superlattices is predicted from ab initio pseudopotential calculations. Localized states are predicted in both the valence and conduction bands, the former being identifiable with the interface states proposed by Kroemer, Nguyen, and Brar [J. Vac. Sci. Technol. 10, 1769 (1990)]. The existence of these interface localized states is invoked to explain the reported experimental dependence of the band gap upon interface types in such superlattices.

Soil Column Evaluation of Factors Controlling Biodegradation of DNT in the Vadose Zone

DTIC Science & Technology

2003-01-01

Environ. Sci. Technol. 2003, 37, 3382-3391 3382 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 37, NO. 15, 2003 10.1021/es021066s CCC: $25.00  2003 American...American Society of Agronomy: Madison, WI, 1986; pp 363-375. c EPA 600/2-78-054. VOL. 37, NO. 15, 2003 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 3383...initial concentration of 2,4-DNT was 5 mM 3384 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 37, NO. 15, 2003 To ensure accurate quantification of

Evidence for negative thermal expansion in the superconducting precursor phase SmFeAsO

NASA Astrophysics Data System (ADS)

Zhou, H. D.; Sarte, P. M.; Conner, B. S.; Balicas, L.; Wiebe, C. R.; Chen, X. H.; Wu, T.; Wu, G.; Liu, R. H.; Chen, H.; Fang, D. F.

2018-03-01

The fluorine-doped rare-earth iron oxypnictide series SmFeAsO1-x F x (0 ≤slant x ≤slant 0.10) was investigated with high resolution powder x-ray scattering. In agreement with previous studies (Margadonna et al 2009 Phys. Rev. B. 79 014503), the parent compound SmFeAsO exhibits a tetragonal-to-orthorhombic structural distortion at T{S}   =  130 K which is rapidly suppressed by x ≃ 0.10 deep within the superconducting dome. The change in unit cell symmetry is followed by a previously unreported magnetoelastic distortion at 120 K. The temperature dependence of the thermal expansion coefficient αV reveals a rich phase diagram for SmFeAsO: (i) a global minimum at 125 K corresponds to the opening of a spin-density wave instability as measured by pump-probe femtosecond spectroscopy (Mertelj et al 2010 Phys. Rev. B 81 224504) whilst (ii) a global maximum at 110 K corresponds to magnetic ordering of the Sm and Fe sublattices as measured by magnetic x-ray scattering (Nandi et al 2011 Phys. Rev. B 84 055419). At much lower temperatures than T{N} , SmFeAsO exhibits a significant negative thermal expansion on the order of  -40 ppm · K-1 in contrast to the behaviour of other rare-earth oxypnictides such as PrFeAsO (Kimber et al 2008 Phys. Rev. B 78 140503) and the actinide oxypnictide NpFeAsO (Klimczuk et al 2012 Phys. Rev. B 85 174506) where the onset of αV < 0 only appears in the vicinity of magnetic ordering. Correlating this feature with the temperature and doping dependence of the resistivity and the unit cell parameters, we interpret the negative thermal expansion as being indicative of the possible condensation of itinerant electrons accompanying the opening of a SDW gap, consistent with transport measurements (Tropeano et al 2009 Supercond. Sci. Technol. 22 034004).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zarzycki, Piotr; Rosso, Kevin M.

Understanding Fe(II)-catalyzed transformations of Fe(III)- (oxyhydr)oxides is critical for correctly interpreting stable isotopic distributions and for predicting the fate of metal ions in the environment. Recent Fe isotopic tracer experiments have shown that goethite undergoes rapid recrystallization without phase change when exposed to aqueous Fe(II). The proposed explanation is oxidation of sorbed Fe(II) and reductive Fe(II) release coupled 1:1 by electron conduction through crystallites. Given the availability of two tracer exchange data sets that explore pH and particle size effects (e.g., Handler et al. Environ. Sci. Technol. 2014, 48, 11302-11311; Joshi and Gorski Environ. Sci. Technol. 2016, 50, 7315-7324), wemore » developed a stochastic simulation that exactly mimics these experiments, while imposing the 1:1 constraint. We find that all data can be represented by this model, and unifying mechanistic information emerges. At pH 7.5 a rapid initial exchange is followed by slower exchange, consistent with mixed surface- and diffusion-limited kinetics arising from prominent particle aggregation. At pH 5.0 where aggregation and net Fe(II) sorption are minimal, that exchange is quantitatively proportional to available particle surface area and the density of sorbed Fe(II) is more readily evident. Our analysis reveals a fundamental atom exchange rate of ~10-5 Fe nm-2 s-1, commensurate with some of the reported reductive dissolution rates of goethite, suggesting Fe(II) release is the rate-limiting step in the conduction mechanism during recrystallization.« less

The "Mendel syndrome" in science: durability of scientific literature and its effects on bibliometric analysis of individual scientists.

PubMed

Costas, Rodrigo; van Leeuwen, Thed N; van Raan, Anthony F J

2011-10-01

The obsolescence and "durability" of scientific literature have been important elements of debate during many years, especially regarding the proper calculation of bibliometric indicators. The effects of "delayed recognition" on impact indicators have importance and are of interest not only to bibliometricians but also among research managers and scientists themselves. It has been suggested that the "Mendel syndrome" is a potential drawback when assessing individual researchers through impact measures. If publications from particular researchers need more time than "normal" to be properly acknowledged by their colleagues, the impact of these researchers may be underestimated with common citation windows. In this paper, we answer the question whether the bibliometric indicators for scientists can be significantly affected by the Mendel syndrome. Applying a methodology developed previously for the classification of papers according to their durability (Costas et al., J Am Soc Inf Sci Technol 61(8):1564-1581, 2010a; J Am Soc Inf Sci Technol 61(2):329-339, 2010b), the scientific production of 1,064 researchers working at the Spanish Council for Scientific Research (CSIC) in three different research areas has been analyzed. Cases of potential "Mendel syndrome" are rarely found among researchers and these cases do not significantly outperform the impact of researchers with a standard pattern of reception in their citations. The analysis of durability could be included as a parameter for the consideration of the citation windows used in the bibliometric analysis of individuals.

Stochastic Simulation of Isotopic Exchange Mechanisms for Fe(II)-Catalyzed Recrystallization of Goethite.

PubMed

Zarzycki, Piotr; Rosso, Kevin M

2017-07-05

Understanding Fe(II)-catalyzed transformations of Fe(III)-(oxyhydr)oxides is critical for correctly interpreting stable isotopic distributions and for predicting the fate of metal ions in the environment. Recent Fe isotopic tracer experiments have shown that goethite undergoes rapid recrystallization without phase change when exposed to aqueous Fe(II). The proposed explanation is oxidation of sorbed Fe(II) and reductive Fe(II) release coupled 1:1 by electron conduction through crystallites. Given the availability of two tracer exchange data sets that explore pH and particle size effects (e.g., Handler et al. Environ. Sci. Technol. 2014 , 48 , 11302 - 11311 ; Joshi and Gorski Environ. Sci. Technol. 2016 , 50 , 7315 - 7324 ), we developed a stochastic simulation that exactly mimics these experiments, while imposing the 1:1 constraint. We find that all data can be represented by this model, and unifying mechanistic information emerges. At pH 7.5 a rapid initial exchange is followed by slower exchange, consistent with mixed surface- and diffusion-limited kinetics arising from prominent particle aggregation. At pH 5.0 where aggregation and net Fe(II) sorption are minimal, that exchange is quantitatively proportional to available particle surface area and the density of sorbed Fe(II) is more readily evident. Our analysis reveals a fundamental atom exchange rate of ∼10 -5 Fe nm -2 s -1 , commensurate with some of the reported reductive dissolution rates of goethite, suggesting Fe(II) release is the rate-limiting step in the conduction mechanism during recrystallization.

Particle processing technology

NASA Astrophysics Data System (ADS)

Sakka, Yoshio

2014-02-01

In recent years, there has been strong demand for the development of novel devices and equipment that support advanced industries including IT/semiconductors, the environment, energy and aerospace along with the achievement of higher efficiency and reduced environmental impact. Many studies have been conducted on the fabrication of innovative inorganic materials with novel individual properties and/or multifunctional properties including electrical, dielectric, thermal, optical, chemical and mechanical properties through the development of particle processing. The fundamental technologies that are key to realizing such materials are (i) the synthesis of nanoparticles with uniform composition and controlled crystallite size, (ii) the arrangement/assembly and controlled dispersion of nanoparticles with controlled particle size, (iii) the precise structural control at all levels from micrometer to nanometer order and (iv) the nanostructural design based on theoretical/experimental studies of the correlation between the local structure and the functions of interest. In particular, it is now understood that the application of an external stimulus, such as magnetic energy, electrical energy and/or stress, to a reaction field is effective in realizing advanced particle processing [1-3]. This special issue comprises 12 papers including three review papers. Among them, seven papers are concerned with phosphor particles, such as silicon, metals, Si3N4-related nitrides, rare-earth oxides, garnet oxides, rare-earth sulfur oxides and rare-earth hydroxides. In these papers, the effects of particle size, morphology, dispersion, surface states, dopant concentration and other factors on the optical properties of phosphor particles and their applications are discussed. These nanoparticles are classified as zero-dimensional materials. Carbon nanotubes (CNT) and graphene are well-known one-dimensional (1D) and two-dimensional (2D) materials, respectively. This special issue also includes two papers on the fabrication of mechanically reliable nanocomposites by dispersing graphene into a ceramic matrix, and on supercapacitors with high energy densities in a Co(OH)2 system decorated with graphene and carbon nanotubes. As a novel preparation method of oxide films, the fabrication of alumina films with laminated structures by ac anodization is reviewed. Moreover a new type of nanosheet has been fabricated by the exfoliation of layered, ternary transition-metal carbide and nitride compounds, known as Mn + 1AXn phases (or MAX phases) where M is an early transition metal, such as Ti or Nb, A is an A group element, such as Si or Al, X is carbon and/or nitrogen and n = 1-3 [4]. Among the MAX phases, those containing Mo have been theoretically calculated by first-principles calculations to be a source for obtaining Mo2C nanosheets with potentially unique properties. As an example of improving bulk ceramic properties, texturing by using a high magnetic field [5] and sintering by the electric current activated/assisted sintering (ECAS) technology [6] have been demonstrated for ultra-high temperature ceramics with high-temperature strength. A project on the development of materials and particle processing for the field of environment and energy has been ongoing at the National Institute for Materials Science since April 2011. This project employs various core competence technologies for particle processing such as ion beam irradiation for nanoparticle fabrication [7], fullerene nanomaterial processing using liquid-liquid interface precipitation [8], a gas reduction nitridation process to obtain Si3N4-based phosphor materials [9], advanced phosphors via novel processing [10, 11], ultra-high pressure technology for processing and in situ analysis [12, 13], colloidal processing in a high magnetic field to obtain laminated, textured ceramics [1, 3, 5], the ECAS process for nanostructuring ceramics [6] and so forth. Here, I would like to introduce some research achievements that are not covered in this special issue. (1) The evolution of hydrogen by the reaction of fine metal particles such as Al [14] and Mg [15] with water; the specific surface area and surface modification are important factors.(2) The realization of new carbon related materials with 1D and 2D structures consisting of fullerenes prepared by liquid-liquid interface precipitation: alkaline-doped superconductive nanotubes consisting of fullerenes [16], application to solar cells of fullerene/cobalt porphyrin hybrid nanosheets [17], etc.(3) The fabrication of textured films and bulk materials with excellent functional properties by colloidal processing methods such as slip casting [5], gel casting [18] and electrophoretic deposition [3, 19], in a high magnetic field, and with subsequent heating; examples of such materials include dye-sensitized TiO2 solar cells, thermoelectric materials and cathode materials for solid state Li-ion batteries and dielectric ceramics.(4) The fabrication of high-strength and high-toughness MAX phase ceramics [20, 21] inspired by the nacreous structure [22].(5) The modeling and development of the ECAS process [6]. This involves two-step pressure application [23] and high-pressure application above 400 MPa to fabricate transparent oxides [24-26], and rapid heating to obtain dense nanocomposites of ceramic-CNT [27] and diamonds [28].(6) The contraction of ternary phase diagrams for oxide ion conductor systems such as zirconia [29] and apatite systems [30], leading to an increased understanding of the stability of such systems and assisting the search for high oxygen ion conductors. Acknowledgments I am grateful to the authors who have contributed to this special issue, and sincerely hope that the readers will expand their knowledge of particle processing technology. References [1] Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [2] Badica P, Crisan A, Aldica G, Endo K, Borodianska H, Togano K, Awaji S, Vasylkiv O and Sakka Y 2011 Sci. Technol. Adv. Mater. 12 013001 [3] Sakka Y and Uchikoshi T 2010 KONA Powder Particle J. 28 74 (kona.or.jp/search/28_074.pdf) [4] Naguib M, Mashtalir O, Carle J, Presser V, Lu J, Hultman L, Gogotsi Y and Barsoum M W 2012 ACS Nano 6 1322 [5] Sakka Y and Suzuki T S 2005 J. Ceram. Soc. Japan 113 26 [6] Grasso S, Sakka Y and Maizza G 2009 Sci. Technol. Adv. Mater. 10 053001 [7] Nakao H, Tokonami S, Hamada T, Shiigi H, Nagaoka T, Iwate F and Takeda Y 2012 Nanoscale 4 6814 [8] Miyazawa K and Hotta K 2010 J. Cryst. Growth 312 2764 [9] Suehiro T, Xie R and Hirosaki N 2013 Indust. Eng. Chem. Res. 52 7453 [10] Zhu Q, Li J-G, Li X, Sun X and Sakka Y 2011 Sci. Technol. Adv. Mater. 12 055001 [11] Li J, Li J-G, Zhang Z, Wu X, Liu S, Li X, Sun X and Sakka Y 2012 Sci. Technol. Adv. Mater. 13 035007 [12] Kawamura F, Yusa H and Taniguchi T 2012 Appl. Phys. Lett. 100 251910 [13] Watanabe K and Taniguchi T 2011 Int. J. Appl. Ceram. Technol. 8 977 [14] Deng Z-Y, Ferreira J M F and Sakka Y 2008 J. Am. Ceram. Soc. 91 3825 [15] Uda M, Okuyama H, Suzuki T S and Sakka Y 2012 Sci. Technol. Adv. Mater. 13 025009 [16] Takeya H, Kato R, Wakahara T, Miyazawa K, Yamaguchi T, Ozaki T, Okazaki H and Takano Y 2013 Mater. Res. Bull. 48 343 [17] Wakahara T, D'Angelo P, Miyazawa K, Nemoto Y, Ito O, Tanigaki N, Bradley D D C and Anthopoulos T D 2012 J. Am. Chem. Soc. 134 7204 [18] Wiecinska P, Sakka Y, Suzuki T S, Uchikoshi T, Mizerski T and Szafran M 2013 J. Ceram. Soc. Japan 121 89 [19] Kawakita M, Uchikoshi T, Kawakita J and Sakka Y 2009 J. Am. Ceram. Soc. 92 984 [20] Hu C, Sakka Y, Grasso S, Nishimura T, Guo S and Tanaka H 2011 Scr. Mater. 64 765 [21] Hu C, Sakka Y, Nishimura T, Guo S, Grasso S and Tanaka H 2011 Sci. Technol. Adv. Mater. 12 044603 [22] Kakisawa H and Sumitomo T 2011 Sci. Technol. Adv. Mater. 12 064710 [23] Grasso S, Hu C F, Maizza G, Kim B N and Sakka Y 2011 J. Am. Ceram. Soc. 94 1405 [24] Grasso S, Kim B N, Hu C F, Maizza G and Sakka Y 2010 J. Am. Ceram. Soc. 93 2460 [25] Zhang H B, Kim B N, Morita K, Hiraga K, Yoshida H and Sakka Y 2012 Sci. Technol. Adv. Mater. 13 055003 [26] Kim B-N, Hiraga K, Grasso S, Morita K, Yoshida H, Zhang H and Sakka Y 2012 J. Ceram. Soc. Japan 120 116 [27] Estili M, Kawasaki A and Sakka Y 2012 Adv. Mater. 24 4322 [28] Grasso S, Hu C F, Maizza G and Sakka Y 2012 J. Am. Ceram. Soc. 95 2423 [29] Andrievskaya E R, Kornienko O A, Sayir A, Vasylkiv O and Sakka Y 2011 J. Am. Ceram. Soc. 94 1911 [30] Kobayashi K and Sakka Y 2012 Sci. Technol. Adv. Mater. 13 045006

Ultrashort Pulse Inscription of Photonic Structures in ZnSe and GaAs for Mid Infrared Applications

DTIC Science & Technology

2010-08-01

structure shown in Figure 2 is an example of a type I waveguide where guiding occurs in the modified region created at the focus of the fabrication beam...turn produces a refractive index change. The end facet cross sections of type I and type II waveguide structures are illustrated below in Figure 2 and...and E. Mazur, Meas. Sci. Technol. 12, 1784 (2001). 4) A. G. Okhrimchuk, V. K. Mezentsev, H. Schmitz, M. Dubov, and I . Bennion, Laser Phys. 19 1415

Interface Properties of Wide Bandgap Semiconductor Structures

DTIC Science & Technology

1994-06-01

resistive than silicides and their chemistry with 126I I Si-based materials more complex. However, in a series of studies, M. 0. Aboelfotoh et al. have...clarification of these issues. CuGe contacts on Ge:GaN and Mg:GaN. To date, the properties of Cu3Ge films have been documented by Aboelfotoh et al., but the...Martin, V. Malhotra, and J. E. Mahan, J. Vac. Sci. Technol. B 3, 836 (1985). 25. L. Krusin-Elbaum and M. 0. Aboelfotoh , Appl. Phys. Lett. 58(12), 1341

The Application of Advanced Diagnostics to the Study of Non-Equilibrium Air Plasmas

DTIC Science & Technology

2002-09-01

26. The 10-, 100-, and 1000-µs pulses monotonically increase with N2 dilution, and the shapes agree with the calculation of Garscadden and Nagpal ...efficiency of H2 in a steady-state H2–N2 gas-mixture discharge has been measured by Nagpal et al.,24 and their analysis of the energy balance showed that...Bletzinger, J. Appl. Phys. 82, 4772 (1997). 49 23. A. Garscadden and R. Nagpal , Plasma Sources Sci. Technol. 4, 268 (1995). 24. R. Nagpal , B. N

Chemical Bonding, Interdiffusion and Electronic Structure at InP, GaAs, and Si-Metal Interfaces.

DTIC Science & Technology

1984-01-15

1980) 420. 37. A. Hiraki , K. Shuts. F. Kim. W. Kammura. and W. Iwami, A\\ppl. Phys. Len. 31 (1977) 611, and references therein. 38. L.J. Brilison, C.F...and references therein. 5. A. Hiraki , M.A. Nicolet, and J.W. Mayer, Appi. Phys. Lett. !a, 178 (1971); A. Hiraki , K. Shuto, F. Kim, W. Kammura, and W...IZ, 1005 (1980) and references therein. 7. T. Narusawa, K. Kinoshita, W.M. Gibson, and A. Hiraki , J. Vac. Sci. Technol.. Ia. 872 (1981). 8. J

Encapsulation and Annealing of Sulfur and Selenium Implanted Gallium Arsenide

DTIC Science & Technology

1978-03-24

Nisse, and F. L. Vook, Plenum Press, New York 1974 (p. 141). 3. J. A. Borders and S. T. Picraux, Proc. IEEE 62, 1224 (1974). 4. A. Hiraki , M. A. Nicolet...and J. W. Mayer, Appl. Phys. Letters 18, 178 (1971). 5. A. Hiraki and E. Lugujjo, J. Vacuum Sci. Technol. 9, 155 (1972). 6. A. Hiraki , E. Lugujjo, M...A. Nicolet, and J. W. Mayer, phys. stat. sol (a) 7, 401 (1971). 7. A. Hiraki , E. Lugujjo, and J. W. Mayer, J. Appl. Phys. 43, 3643 (1972). 8. J. M

Development of Toxicity Benchmarks for Nitrogen-based Energetic Materials for the Enchytraeid Worm, Enchytraeus crypticus

DTIC Science & Technology

2013-11-01

pp 177–182. Anzhi, Z.L.; Marx, K.A.; Walker, J.; Kaplan, D.L. Trinitrotoluene and Metabolites Binding to Humic Acid . Environ. Sci. Technol. 1997...2001, pp 293–312. Thorn, K.A.; Kennedy, K.R. 15 N NMR Investigation of the Covalent Binding of Reduced TNT Amines to Soil Humic Acid , Model...9 3.2 Toxicity of Reference Toxicant, Boric Acid , to the Potworm E. crypticus ......15 3.3 Effects of 2,4-DNT on the Potworm E. crypticus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kokkoris, George; Boudouvis, Andreas G.; Gogolides, Evangelos

An integrated framework for the neutral flux calculation inside trenches and holes during plasma etching is described, and a comparison between the two types of structure in a number of applications is presented. First, a detailed and functional set of equations for the neutral and ion flux calculations inside long trenches and holes with cylindrical symmetry is explicitly formulated. This set is based on early works [T. S. Cale and G. B. Raupp, J. Vac. Sci. Technol. B 8, 1242 (1990); V. K. Singh et al., J. Vac. Sci. Technol. B 10, 1091 (1992)], and includes new equations for themore » case of holes with cylindrical symmetry. Second, a method for the solution of the respective numerical task, i.e., one or a set of linear or nonlinear integral equations, is described. This method includes a coupling algorithm with a surface chemistry model and resolves the singularity problem of the integral equations. Third, the fluxes inside trenches and holes are compared. The flux from reemission is the major portion of the local flux at the bottom of both types of structure. The framework is applied in SiO{sub 2} etching by fluorocarbon plasmas to predict the increased intensity of reactive ion etching lag in SiO{sub 2} holes compared to trenches. It is also applied in deep Si etching: By calculating the flux of F atoms at the bottom of very high aspect ratio (up to 150) Si trenches and holes during the gas chopping process, the aspect ratio at which the flux of F atoms is eliminated and etching practically stops is estimated.« less

Effect of frequency on the uniformity of symmetrical RF CCP discharges

NASA Astrophysics Data System (ADS)

Liu, Yue; Booth, Jean-Paul; Chabert, Pascal

2018-05-01

A 2D Cartesian electrostatic particle-in-cell/Monte Carlo collision (PIC/MCC) model presented previously (Liu et al 2018 Plasma Sources Sci. Technol. 27 025006) is used to investigate the effect of the driving frequency (over the range of 15–45 MHz) on the plasma uniformity in radio frequency (RF) capacitively coupled plasma (CCP) discharges in a geometrically symmetric reactor with a dielectric side wall in argon gas. The reactor size (12 cm electrode length, 2.5 cm gap) and driving frequency are sufficiently small that electromagnetic effects can be ignored. Previously, we showed (Liu et al 2018 Plasma Sources Sci. Technol. 27 025006) that for 15 MHz excitation, Ohmic heating of electrons by the electric field perpendicular to the electrodes is enhanced in a region in front of the dielectric side wall, leading to a maximum in electron density there. In this work we show that increasing the excitation frequency (at constant applied voltage amplitude) not only increases the overall electron heating and density but also causes a stronger, narrower peak in electron heating closer to the dielectric wall, improving the plasma uniformity along the electrodes. This heating peak comes both from enhanced perpendicular electron heating and from the appearance at high frequency of significant parallel heating. The latter is caused by the presence of a significant parallel-direction RF oscillating electric field in the corners. Whereas at the reactor center the sheaths oscillate perpendicularly to the electrodes, near the dielectric edge they move in and out of the corners and must be treated in two dimensions.

Understanding helicon plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tarey, R. D.; Sahu, B. B.; Ganguli, A.

2012-07-15

This paper presents a comprehensive overview of work on the helicon plasmas and also discusses various aspects of RF power deposition in such plasmas. Some of the work presented here is a review of earlier work on theoretical [A. Ganguli et al., Phys. Plasmas 14, 113503 (2007)] and experimental [A. Ganguli et al., Plasma Sources Sci. Technol. 20(1), 015021 (2011)] investigations on helicon plasmas in a conducting cylindrical waveguide for m = -1 mode. This work also presents an approach to investigate the mechanisms by which the helicon and associated Trivelpiece-Gould (TG) waves are responsible for RF power deposition inmore » Helicon discharges. Experiment design adopts the recent theory of damping and absorption of Helicon modes in conducting waveguides [A. Ganguli et al., Phys. Plasmas 14, 113503 (2007)]. The effort has also been made to detect the warm electrons, which are necessary for ionization, because Helicon discharges are of high density, low T{sub e} discharges and the tail of the bulk electron population may not have sufficient high-energy electrons. Experimental set up also comprises of the mirror magnetic field. Measurements using RF compensated Langmuir probes [A. Ganguli et al., Plasma Sources Sci. Technol. 17, 015003 (2008)], B-dot probe and computations based on the theory shows that the warm electrons at low pressure (0.2-0.3 mTorr) Helicon discharges, are because of the Landau damping of TG waves. In collisional environment, at a pressure Almost-Equal-To 10 mTorr, these high-energy electrons are due to the acceleration of bulk electrons from the neighboring regions across steep potential gradients possibly by the formation of double layers.« less

Process diagnostics and monitoring using the multipole resonance probe in an inhomogeneous plasma for ion-assisted deposition of optical coatings

NASA Astrophysics Data System (ADS)

Styrnoll, T.; Harhausen, J.; Lapke, M.; Storch, R.; Brinkmann, R. P.; Foest, R.; Ohl, A.; Awakowicz, P.

2013-08-01

The application of a multipole resonance probe (MRP) for diagnostic and monitoring purposes in a plasma ion-assisted deposition (PIAD) process is reported. Recently, the MRP was proposed as an economical and industry compatible plasma diagnostic device (Lapke et al 2011 Plasma Sources Sci. Technol. 20 042001). The major advantages of the MRP are its robustness against dielectric coating and its high sensitivity to measure the electron density. The PIAD process investigated is driven by the advanced plasma source (APS), which generates an ion beam in the deposition chamber for the production of high performance optical coatings. With a background neutral pressure of p0 ˜ 20 mPa the plasma expands from the source region into the recipient, leading to an inhomogeneous spatial distribution. Electron density and electron temperature vary over the distance from substrate (ne ˜ 109 cm-3 and Te,eff ˜ 2 eV) to the APS (ne ≳ 1012 cm-3 and Te,eff ˜ 20 eV) (Harhausen et al 2012 Plasma Sources Sci. Technol. 21 035012). This huge variation of the plasma parameters represents a big challenge for plasma diagnostics to operate precisely for all plasma conditions. The results obtained by the MRP are compared to those from a Langmuir probe chosen as reference diagnostics. It is demonstrated that the MRP is suited for the characterization of the PIAD plasma as well as for electron density monitoring. The latter aspect offers the possibility to develop new control schemes for complex industrial plasma environments.

Room temperature deposition of gold onto the diffuse and sharp diffraction spot Si(111)-( 3 × 3) R30° Au surfaces

NASA Astrophysics Data System (ADS)

Plass, Richard; Marks, Laurence D.

1996-06-01

Room temperature gold depositions onto Si(111)-( 3 × 3) R30° Au surfaces with diffuse and sharp diffraction spots [Surf. Sci. 242 (1991) 73] (diffuse and sharp 3 × 3 Au hereafter) under UHV conditions has been monitored using transmission electron diffraction (TED). Both systems display an increase in surface structure diffraction spot intensities up to the completion of 1.0 monolayer (ML) after which the surface beams display an exponential decrease in intensity with coverage. The exponential decay rate decreases after roughly 1.33 ML. These results can be attributed to gold initially diffusing to and filling 3 × 3 Au gold trimer sites in vacancy type surface domain walls [Surf. Sci. 342 (1995) 233], then filling one of three possible sites on the 3 × 3 Au structure with essentially no surface diffusion, disrupting nearby gold trimers. Gold deposition onto the diffuse type structure caused the formation and expansion of satellite arcs around the strongest 3 × 3 beams similar to those seen by others [Surf. Sci. 242 (1991) 73; Jpn. J. Appl. Phys. 16 (1977) 891; J. Vac. Sci. Technol. A 10 (1992) 3486] at elevated temperatures while the sharp structure displayed only a modest shoulder formation near the strongest 3 × 3 beams.

COLLABORATIVE RESEARCH AND DEVELOPMENT (CR&D) Delivery Order 0063: Flexible and Transparent Electronics (FAT) Development

DTIC Science & Technology

2008-02-01

Suzuki, T . Matsushita, T . Aoki and M. Okuda, Thin Solid Films, 445, p263 (2003). 7 S.M. Park, T . Ikegami , K. Ebihara and P.K. Shin, App. Surf...quality films and substrates have negligible scatter therefore we may take the absorption to be 1- T -R, where T and R are the specularly resolved...1995. 2 T . Minami, Semicond. Sci. Technol. 20, S35–S44 (2005). 3 G. Fang, D. Li and B.L. Yao, Vacuum 68, p363 (2003). 4 T . Minami, S. Suzuki and T

Sensitive Spin Detection Using An On-Chip Squid-Waveguide Resonator

NASA Astrophysics Data System (ADS)

Yue, Guang

Quantum computing gives novel way of computing using quantum mechanics, which furthers human knowledge and has exciting applications. Quantum systems with diluted spins such as rare earth ions hosted in single crystal, molecule-based magnets etc. are promising qubits candidates to form the basis of a quantum computer. High sensitivity measurement and coherent control of these spin systems are crucial for their practical usage as qubits. The micro-SQUID (direct-current micrometer-sized Superconducting QUantum Interference Device) is capable to measure magnetization of spin system with high sensitivity. For example, the micro-SQUID technique can measure magnetic moments as small as several thousand muB as shown by the study of [W. Wernsdorfer, Supercond. Sci. Technol. 22, 064013 (2009)]. Here we develop a novel on-chip setup that combines the micro-SQUID sensitivity with microwave excitation. Such setup can be used for electron spin resonance measurements or coherent control of spins utilizing the high sensitivity of micro-SQUID for signal detection. To build the setup, we studied the fabrication process of the micro-SQUID, which is made of weak-linked Josephson junctions. The SQUID as a detector is integrated on the same chip with a shorted coplanar waveguide, so that the microwave pulses can be applied through the waveguide to excite the sample for resonance measurements. The whole device is plasma etched from a thin (˜ 20nm) niobium film, so that the SQUID can work at in large in-plane magnetic fields of several tesla. In addition, computer simulations are done to find the best design of the waveguide such that the microwave excitation field is sufficiently strong and uniformly applied to the sample. The magnetization curve of Mn12 molecule-based magnet sample is measured to prove the proper working of the micro-SQUID. Electron spin resonance measurement is done on the setup for gadolinium ions diluted in a CaWO4 single crystal. The measurement shows clear evidence of the resonance signal from the 1st transition of the gadolinium ions' energy levels, which shows the setup is successfully built. Due to the high sensitivity of micro-SQUID and the ability to concentrate microwave energy in small areas of the chip, this setup can detect signals from a small number of spins (107) in a small volume (several mum 3).

Microfluidic Experiments Studying Pore Scale Interactions of Microbes and Geochemistry

NASA Astrophysics Data System (ADS)

Chen, M.; Kocar, B. D.

2016-12-01

Understanding how physical phenomena, chemical reactions, and microbial behavior interact at the pore-scale is crucial to understanding larger scale trends in groundwater chemistry. Recent studies illustrate the utility of microfluidic devices for illuminating pore-scale physical-biogeochemical processes and their control(s) on the cycling of iron, uranium, and other important elements 1-3. These experimental systems are ideal for examining geochemical reactions mediated by microbes, which include processes governed by complex biological phenomenon (e.g. biofilm formation, etc.)4. We present results of microfluidic experiments using a model metal reducing bacteria and varying pore geometries, exploring the limitations of the microorganisms' ability to access tight pore spaces, and examining coupled biogeochemical-physical controls on the cycling of redox sensitive metals. Experimental results will provide an enhanced understanding of coupled physical-biogeochemical processes transpiring at the pore-scale, and will constrain and compliment continuum models used to predict and describe the subsurface cycling of redox-sensitive elements5. 1. Vrionis, H. A. et al. Microbiological and geochemical heterogeneity in an in situ uranium bioremediation field site. Appl. Environ. Microbiol. 71, 6308-6318 (2005). 2. Pearce, C. I. et al. Pore-scale characterization of biogeochemical controls on iron and uranium speciation under flow conditions. Environ. Sci. Technol. 46, 7992-8000 (2012). 3. Zhang, C., Liu, C. & Shi, Z. Micromodel investigation of transport effect on the kinetics of reductive dissolution of hematite. Environ. Sci. Technol. 47, 4131-4139 (2013). 4. Ginn, T. R. et al. Processes in microbial transport in the natural subsurface. Adv. Water Resour. 25, 1017-1042 (2002). 5. Scheibe, T. D. et al. Coupling a genome-scale metabolic model with a reactive transport model to describe in situ uranium bioremediation. Microb. Biotechnol. 2, 274-286 (2009).

Variation of thermophysical parameters of PCM CaCl2.6H2O with dopant from T-history data analysis

NASA Astrophysics Data System (ADS)

Sutjahja, I. M.; Silalahi, Alfriska O.; Sukmawati, Nissa; Kurnia, D.; Wonorahardjo, S.

2018-03-01

T-history is a powerful method for deriving the thermophysical parameters of a phase change material (PCM), which consists of solid and liquid specific heats as well as latent heat enthalpy. The performance of a PCM for thermal energy storage could be altered by chemical dopants added directly to the PCM in order to form a stable suspension. We described in this paper the role of chemical dopants in the variation of thermophysical parameters for CaCl2 · 6H2O inorganic PCM with 1 wt% and 2 wt% dopant concentration and BaSO4 (1 wt%) as a nucleator using the T-history method. The dopant consists graphite and CuO nanoparticles. The data analysis follows the original method proposed by (Zhang et al 1999 Meas. Sci. Technol. 10 201–205) and its modification by (Hong et al 2004 Int. J. Refrig. 27 360–366). In addition, the enthalpy-temperature curve is obtained by adopting a method proposed by (Marín et al 2003 Meas. Sci. Technol. 14 184–189). We found that the solid specific heat tends to increase non-linearly with increased dopant concentration for all dopants. The increased liquid specific heat, however, indicates the optimum value for 1 wt% graphite dopant. In contrast, the CuO dopant shows a smaller increase in dopant concentration. The specific heat data are analyzed based on the interacting mesolayer model for a nanofluid. The heat of fusion show strong variation with dopant type, in agreement with other experimental data for various PCMs and dopant particles.

[Analysis on literatures about clinical treatment of low back pain with acupuncture and moxibustion published in the periodicals included by SCI in recent 5 years].

PubMed

Jiang, Chui-gang

2007-03-01

To explore the development state of acupuncture and moxibustion therapy in the world. Retrieve and analyze the literatures about clinically treating low back pain with acupuncture and moxibustion published at periodicals included by SCI in recent 5 years in Pubmed. Nineteen concerned literatures were retrieved. Authors of the literatures come from USA, Germany, Hong Kong of China, UK (including Northern Ireland) , Austria, Sweden and Italy. The literatures were published at Altern Ther Health Med, Am J Phys Med Rehabil, Anesth Analg, Arch Intern Med, Forsch Komplementärmed Klass Naturheilkd, Health Technol Assess, Rheumatology (Oxford), South Med J, Spine, Complment Ther Med, Pain. Three researches show that efficacy of acupuncture is uncertain. Other researches support the efficacy of acupuncture. The researches on treating low back pain with acupuncture and moxibustion are still mainly about efficacy of the acupuncture and moxibustion therapy. The acupuncture and moxibustion therapy is still in the process of gradually admitted by international medicine.

Studies of Turbulence and Transport in Alcator C-Mod H-Mode Plasmas with Phase Contrast Imaging and Comparisons with GYRO

NASA Astrophysics Data System (ADS)

Porkolab, M.; Lin, L.; Edlund, E. M.; Rost, J. C.; Fiore, C. L.; Greenwald, M.; Mikkelsen, D.

2008-11-01

We present recent experimental measurements of turbulence and transport in C-Mod H-Mode plasmas with and without internal transport barriers (ITB) using the phase contrast imaging (PCI) diagnostic and compare the results with GYRO predictions. In plasmas without ITB, the fluctuation above 300 kHz observed by PCI agrees with ITG in GYRO simulation, including the direction of propagation, wavenumber spectrum, and absolute intensity within experimental uncertainly (+/-75%). After transition to ITBs, the observed overall fluctuation intensity increases. GYRO simulation in the core shows that ITG dominates in ITBs but its intensity is lower than the overall experimental measurements which may also include contributions from the plasma edge. These results, as well as the impact of varying ∇Ti, ∇n, and ExB shear on turbulence will be discussed. C.L. Fiore et al., Fusion Sci. Technol., 51, 303 (2007). M. Porkolab et al., IEEE Trans. Plasma Sci. 34, 229 (2006). J. Candy et al., Phys. Rev. Lett., 91, 045001 (2003).

Localized heating of electrons in ionization zones: Going beyond the Penning-Thornton paradigm in magnetron sputtering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anders, Andre

2014-12-07

The fundamental question of how energy is supplied to a magnetron discharge is commonly answered by the Penning-Thornton paradigm invoking secondary electrons. Huo et al. (Plasma Sources Sci. Technol. 22, 045005, (2013)) used a global discharge model to show that electron heating in the electric field of the magnetic presheath is dominant. In this contribution, this concept is applied locally taking into account the electric potential structure of ionization zones. Images of ionization zones can and should be interpreted as diagrams of the localization of electric potential and related electron energy, where certain collisions promote or dampen their formation.

Manufacturable Tri-Stack AlSb/InAs HEMT Low-Noise Amplifiers Using Wafer-Level-Packaging Technology for Light-Weight and Ultralow-Power Applications

DTIC Science & Technology

2009-05-01

shown in Fig. 1 was grown by molecular - beam epitaxy (MBE) on 3-inch semi-insulating GaAs substrates. AlGaSb was used as a buffer. AlSb was used as... beam epitaxy for low-power applications,” J. Vac. Sci. Technol. B. 24, pp. 2581-2585, 2006. [12] Y. C. Chou, L. J. Lee, J. M. Yang, M. D. Lange, P...passivation AlGaSb buffer Figure 1: Cross section of an AlSb/InAs HEMT device on a 3-inch GaAs substrate. The interface region between the

Temperature Dependent Spectral Response and Detectivity of GeSn Photoconductors on Silicon for Short Wave Infrared Detection

DTIC Science & Technology

2014-01-01

Littler, M. Canonico, S. Zollner, J. Kouvetakis, and J. Menéndez, "Optical critical points of thin- film Ge1−ySny alloys : A comparative Ge1−ySny∕Ge1...Bernardy, T. Stoica, D. Grützmacher, and S. Mantl, "Reduced Pressure CVD Growth of Ge and Ge1−xSnx Alloys ," ECS J. of Solid State Sci. and Technol. 2... oxide etch, 10 nm of Cr followed by 200 nm of Au was deposited for the Ohmic contacts. These contacts showed a linear I-V behavior, thus no

Recent Experimental Advances to Determine (noble) Gases in Waters

NASA Astrophysics Data System (ADS)

Kipfer, R.; Brennwald, M. S.; Huxol, S.; Mächler, L.; Maden, C.; Vogel, N.; Tomonaga, Y.

2013-12-01

In aquatic systems noble gases, radon, and bio-geochemically conservative transient trace gases (SF6, CFCs) are frequently applied to determine water residence times and to reconstruct past environmental and climatic conditions. Recent experimental breakthroughs now enable ● to apply the well-established concepts of terrestrial noble gas geochemistry in waters to the minute water amounts stored in sediment pore space and in fluid inclusions (A), ● to determine gas exchange processes on the bio-geochemical relevant time scales of minutes - hours (B), and ● to separate diffusive and advective gas transport in soil air (C). A. Noble-gas analysis in water samples (< 1 g) facilitates determining the solute transport in the pore space and identifying the origin of bio- and geogenic fluids in (un) consolidated sediments [1]. Advanced techniques that combine crushing and sieving speleothem samples in ultra-high-vacuum to a specific grain size allow to separate air and water-bearing fluid inclusions and thus enables noble-gas-based reconstruction of environmental conditions from water masses as small as 1mg [2]. B. The coupling of noble gas analysis with approaches of gas chromatography permits combined analysis of noble gases and other gases species (e.g., SF6, CFCs, O2, N2) from a single water sample. The new method substantially improves ground water dating by SF6 and CFCs as excess air is quantified from the same sample and hence can adequately be corrected for [3]. Portable membrane-inlet mass spectrometers enable the quasi-continuous and real-time analysis of noble gases and other dissolved gases directly in the field, allowing, for instance, quantification of O2 turnover rates on small time scales [4]. C. New technical developments perfect 222Rn analysis in water by the synchronous the determination of the short-lived 220Rn. The combined 220,222Rn analysis sheds light on the emanation behaviour of radon by identifying soil water content to be the crucial control of 220Rn occurrence in the environment, e.g., making an argument why 220Rn is not detectable in water, but in soil air. As 220Rn occurrence is of 'very local origin' the combined analysis of 220,222Rn in soil air allows differentiating between advective and diffusive soil gas transport [5]. By discussing these recent achievements, we intend to stimulate a broader discussion to identify future applications of noble and other gases in (un) conventional aquatic systems, such as blood. [1] Tomonaga et al. (2011) Limnol. Oceanogr. Methods, 9, 42-49, doi:10:4319/lom.2011.9.42. [2] Vogel et al. (2013) Geochem. Geophys. Geosyst., 14, doi:10.1002/ggge.20164. [3] Brennwald et al. (2013) Environ. Sci. Technol., Article ASAP, DOI: 10.1021/es401698p. [4] Mächler et al. (2012) Environ. Sci. Technol., 47, 7060-7066. [5] Huxol et al. Environ. Sci. Technol., in revision.

3D-calibration of three- and four-sensor hot-film probes based on collocated sonic using neural networks

NASA Astrophysics Data System (ADS)

Kit, Eliezer; Liberzon, Dan

2016-09-01

High resolution measurements of turbulence in the atmospheric boundary layer (ABL) are critical to the understanding of physical processes and parameterization of important quantities, such as the turbulent kinetic energy dissipation. Low spatio-temporal resolution of standard atmospheric instruments, sonic anemometers and LIDARs, limits their suitability for fine-scale measurements of ABL. The use of miniature hot-films is an alternative technique, although such probes require frequent calibration, which is logistically untenable in field setups. Accurate and truthful calibration is crucial for the multi-hot-films applications in atmospheric studies, because the ability to conduct calibration in situ ultimately determines the turbulence measurements quality. Kit et al (2010 J. Atmos. Ocean. Technol. 27 23-41) described a novel methodology for calibration of hot-film probes using a collocated sonic anemometer combined with a neural network (NN) approach. An important step in the algorithm is the generation of a calibration set for NN training by an appropriate low-pass filtering of the high resolution voltages, measured by the hot-film-sensors and low resolution velocities acquired by the sonic. In Kit et al (2010 J. Atmos. Ocean. Technol. 27 23-41), Kit and Grits (2011 J. Atmos. Ocean. Technol. 28 104-10) and Vitkin et al (2014 Meas. Sci. Technol. 25 75801), the authors reported on successful use of this approach for in situ calibration, but also on the method’s limitations and restricted range of applicability. In their earlier work, a jet facility and a probe, comprised of two orthogonal x-hot-films, were used for calibration and for full dataset generation. In the current work, a comprehensive laboratory study of 3D-calibration of two multi-hot-film probes (triple- and four-sensor) using a grid flow was conducted. The probes were embedded in a collocated sonic, and their relative pitch and yaw orientation to the mean flow was changed by means of motorized traverses. The study demonstrated that NN-calibration is a powerful tool for calibration of multi-sensor 3D-hot film probes embedded in a collocated sonic, and can be employed in long-lasting field campaigns.

EDITORIAL: Outgoing Editor-in-Chief Outgoing Editor-in-Chief

NASA Astrophysics Data System (ADS)

Hauptmann, Peter

2012-01-01

I started in 2002 as Editor-in-Chief of a well established journal—MST (Measurement Science and Technology). It was a time when modern means of communication offered new opportunities for the scientific community—for all scientists and engineers whether at universities, in industry or at other institutions—to access better quality information in a shorter time. This development helped us to be more efficient in our daily scientific work and to anticipate new trends faster than before. A flood of information was created by different search engines. A few online journals or journals published in emerging countries with a similar profile to MST appeared on the market. MST had to provide new answers in response to these developments. In 2002 I postulated two requirements to the journal. Firstly, the publisher has to be up to date. My impression over the years has been that IOPP is excellently organized. That has made it easier for the board members and all our reviewers to concentrate on the scientific aspects of our input to the journal. During all my visits to Bristol or my contacts with the IOPP staff I always met very professional and enthusiastic staff members. They have not only supported and encouraged the ideas and initiatives of the Editorial Board members, but they have also worked hard on establishing one of the most effective journal operations in the field of measurement science and technology. Many authors are well aware of this. Thus I am able to declare that the first requirement for a successful journal has been met. Secondly, the scientific level has to be high and the journal should attract readers from all over the world. This task was the responsibility of the Editorial Board members and of myself. Our strategy was on the one hand to ensure continuity in MST but on the other hand to be open to new trends and developments. Examples of these new aspects of the journal are fields like micro- and nanometrology, measurement techniques for biological, medical and life science applications or sensors and sensing systems. Selected papers or special features in recent issues of MST attest to this development [1-3]. In parallel with these new fields, board members have always kept their eye on the other journal topics. Many papers published in MST have been downloaded very often and highly cited. This shows the acceptance and reputation of MST. Thanks to the activity of all board members over the last ten years MST has published a number of excellent review articles. This has strengthened the prestige of MST. A new series of articles was introduced under the banner of 'Perspectives' in 2008. They highlight milestones in a selected field and indicate some future challenges from the point of view of the author [4]. In summary, it can be stated that MST is on a good path. This was created thanks to the activity of all members of the Editorial Board. In recent years we have enlarged this board with well known scientists from universities and industry from all over the world. This will ensure a continuously positive development of MST. As outgoing Editor-in-Chief, I can say that I have found my task fascinating and I have enjoyed it very much. I have learned a lot in this time because I have come into close contact with a large number of scientists from a vast spectrum of technical areas and parts of our world. My special gratitude is dedicated to all the Editorial Board members of the last ten years and especially to Sharon D'Souza from IOPP. Furthermore, I would like to pass on to my successor, Professor David Birch from University of Strathclyde, Glasgow, my best wishes for an enjoyable and successful tenure as Editor-in-Chief! References [1] Tanaka M, Baba T and Postek M T 2011 Nanometrology Meas. Sci. Technol. 22 020101 [2] Potyrailo R A et al 2011 RFID sensors as the common sensing platform for single-use biopharmaceutical manufacturing Meas. Sci. Technol. 22 082001 [3] Fritze H 2011 High-temperature bulk acoustic wave sensors Meas. Sci. Technol. 22 012002 [4] Birch D J S 2011 Fluorescence detections and directions Meas. Sci. Technol. 22 052002

Determination of the composition of HgCdTe oxide films by neutron activation analysis

NASA Astrophysics Data System (ADS)

Gnade, B.; Simmons, A.; Little, D.; Strong, R.

1987-04-01

The composition of HgCdTe oxides grown by anodic oxidation in a standard KOH/ethylene glycol solution has been determined by neutron activation analysis (NAA). This technique is not hindered by the difficulties normally associated with methods using ion beams or electron beams. Neutron activation analysis has the advantage of being quantitative, and also NAA is not affected by the chemical composition of the matrix. The analysis of the KOH/ethylene glycol oxide film by neutron activation yields Hg:Cd:Te ratios of 0.534:0.19:1, in close agreement with Rutherford backscattering spectroscopy analysis (R.L. Strong et al., J. Vac. Sci. Technol. A4 (4) (1986) 1992).

Integration of snow management practices into a detailed snow pack model

NASA Astrophysics Data System (ADS)

Spandre, Pierre; Morin, Samuel; Lafaysse, Matthieu; Lejeune, Yves; François, Hugues; George-Marcelpoil, Emmanuelle

2016-04-01

The management of snow on ski slopes is a key socio-economic and environmental issue in mountain regions. Indeed the winter sports industry has become a very competitive global market although this economy remains particularly sensitive to weather and snow conditions. The understanding and implementation of snow management in detailed snowpack models is a major step towards a more realistic assessment of the evolution of snow conditions in ski resorts concerning past, present and future climate conditions. Here we describe in a detailed manner the integration of snow management processes (grooming, snowmaking) into the snowpack model Crocus (Spandre et al., Cold Reg. Sci. Technol., in press). The effect of the tiller is explicitly taken into account and its effects on snow properties (density, snow microstructure) are simulated in addition to the compaction induced by the weight of the grooming machine. The production of snow in Crocus is carried out with respect to specific rules and current meteorological conditions. Model configurations and results are described in detail through sensitivity tests of the model of all parameters related to snow management processes. In-situ observations were carried out in four resorts in the French Alps during the 2014-2015 winter season considering for each resort natural, groomed only and groomed plus snowmaking conditions. The model provides realistic simulations of the snowpack properties with respect to these observations. The main uncertainty pertains to the efficiency of the snowmaking process. The observed ratio between the mass of machine-made snow on ski slopes and the water mass used for production was found to be lower than was expected from the literature, in every resort. The model now referred to as "Crocus-Resort" has been proven to provide realistic simulations of snow conditions on ski slopes and may be used for further investigations. Spandre, P., S. Morin, M. Lafaysse, Y. Lejeune, H. François and E. George-Marcelpoil, Integration of snow management processes into a detailed snowpack model, Cold Reg. Sci. Technol., in press.

Application of common y-intercept regression parameters for log Kp vs 1/ T for predicting gas-particle partitioning in the urban environment

NASA Astrophysics Data System (ADS)

Pankow, James F.

Gas-particle partitioning is examined using a partitioning constant Kp = ( F/ TSP)/ A, where F (ng m -3) and A (ng m -3) are the particulate-associated and gas-phase concentrations, respectively, and TSP is the total suspended particulate matter level (μg m -3). Compound-dependent values of Kp depend on temperature ( T) according to Kp = mp/ T + bp. Limitations in data quality can cause errors in estimates of mp and bp obtained by simple linear regression (SLR). However, within a group of similar compounds, the bp values will be similar. By pooling data, an improved set of mp and a single bp can be obtained by common y-intercept regression (CYIR). SLR estimates for mp and bp for polycyclic aromatic hydrocarbons (PAHs) sorbing to urban Osaka particulate matter are available (Yamasaki et al., 1982, Envir. Sci. Technol.16, 189-194), as are CYIR estimates for the same particulate matter (Pankow, 1991, Atmospheric Environment25A, 2229-2239). In this work, a comparison was conducted of the ability of these two sets of mp and bp to predict A/ F ratios for PAHs based on measured T and TSP values for data obtained in other urban locations, specifically: (1) in and near the Baltimore Harbor Tunnel by Benner (1988, Ph.D thesis, University of Maryland) and Benner et al. (1989, Envir. Sci. Technol.23, 1269-1278); and (2) in Chicago by Cotham (1990, Ph.D. thesis, University of South Carolina). In general, the CYIR estimates for mp and bp obtained for Osaka particulate matter were found to be at least as reliable, and for some compounds more reliable than their SLR counterparts in predicting gas-particle ratios for PAHs. This result provides further evidence of the utility of the CYIR approach in quantitating the dependence of log Kp values on 1/ T.

EDITORIAL: Letter from the Editor Letter from the Editor

NASA Astrophysics Data System (ADS)

Hauptmann, Peter

2011-01-01

Dear authors and reviewers of articles for Measurement Science and Technology, I would like to thank all those who have published papers with us in 2010, and special thanks go to those of you who have kindly reviewed articles for the journal. I would also like to take this opportunity to update you on some of the developments on the journal and look ahead to 2011. As many of you are no doubt aware, our impact factor (a measure of the average number of times recent papers are referred to by others) is currently 1.317. This is often taken as an indication of the quality and relevance of recently published research, and although as readers we develop our own instinct for journals of high quality, it is gratifying as an Editor to see the data from an independent organization (Thomson ISI) agreeing with my own assessment. Measurement Science and Technology is a journal with a broad scope covering new measurement techniques in all fields of science and engineering. I therefore find it particularly enjoyable to read summaries of recent research in our strong topical review programme as these cover many varied topics of interest. In 2010 several interesting articles by international leaders in their field were published, for example: Single-photon generation and detection, by G S Buller and R J Collins of Heriot-Watt University [1]. Fluorescence lifetime imaging microscopy in life sciences, by Jan Willem Borst and Antonie J W G Visser, from the Microspectroscopy Centre of Wageningen University [2]. Biological and chemical sensors for cancer diagnosis, by Elfriede Simon of Siemens AG [3]. I hope that these articles, and the others published in 2010 and now in 2011, will provide a useful overview for our readers, and be helpful to new researchers. When speaking to young researchers I am particularly aware that having their articles published in a timely fashion is important, and I am pleased that our publication times are highly competitive, with most authors receiving a publication decision within 7 weeks and most articles being published a month after acceptance. Looking forward to 2011, we will continue to rely on you, our esteemed reviewers, for your help in determining which articles make a significant contribution to the field of measurements. Your work is highly valued, not only by those of us who work directly on the journal, but also by the readers who can continue to refer to MST knowing that only work of a high standard is published here. There simply remains for me to say thank you again for your contribution to Measurement Science and Technology in 2010, and I wish you all the best for a successful 2011! References [1] Buller G S and Collins R J 2010 Single-photon generation and detection Meas. Sci. Technol. 21 012002 [2] Borst J W and Visser A J W G 2010 Fluorescence lifetime imaging microscopy in life sciences Meas. Sci. Technol. 21 102002 [3] Simon E 2010 Biological and chemical sensors for cancer diagnosis Meas. Sci. Technol. 21 112002

The cause of ‘weak-link’ grain boundary behaviour in polycrystalline Bi2Sr2CaCu2O8 and Bi2Sr2Ca2Cu3O10 superconductors

NASA Astrophysics Data System (ADS)

Wang, Guanmei; Raine, Mark J.; Hampshire, Damian P.

2018-02-01

The detrimental effects of grain boundaries have long been considered responsible for the low critical current densities ({J}{{c}}) in high temperature superconductors. In this paper, we apply the quantitative approach used to identify the cause of the ‘weak-link’ grain boundary behaviour in YBa2Cu3O7 (Wang et al 2017 Supercond. Sci Technol. 30 104001), to the Bi2Sr2CaCu2O8 and Bi2Sr2Ca2Cu3O10 materials that we have fabricated. Magnetic and transport measurements are used to characterise the grain and grain boundary properties of micro- and nanocrystalline materials. Magnetisation measurements on all nanocrystalline materials show non-Bean-like behaviour and are consistent with surface pinning. Bi2Sr2CaCu2O8: our microcrystalline material has very low grain boundary resistivity ({ρ }{{GB}}), which is similar to that of the grains ({ρ }{{G}}) such that {ρ }{{GB}}≈ {ρ }{{G}}=2× {10}-5 {{Ω }}{{m}} (assuming a grain boundary thickness (d) of 1 nm) equivalent to an areal resistivity of {ρ }{{G}}=2× {10}-14 {{{Ω }}{{m}}}2. The transport {J}{{c}} values are consistent with well-connected grains and very weak grain boundary pinning. However, unlike low temperature superconductors (LTS) in which decreasing grain size increases the pinning along the grain boundary channels, any increase in pinning produced by making the grains in our Bi2Sr2CaCu2O8 materials nanocrystalline was completely offset by a decrease in the depairing current density of the grain boundaries caused by their high resistivity. We suggest a different approach to increasing {J}{{c}} from that used in LTS materials, namely incorporating additional strong grain and grain boundary pinning sites in microcrystalline materials to produce high {J}{{c}} values. Bi2Sr2Ca2Cu3O10: both our micro- and nanocrystalline samples have {ρ }{{GB}}/{ρ }{{G}} of at least 103. This causes strong suppression of {J}{{c}} across the grain boundaries, which explains the low transport {J}{{c}} values we find experimentally. Our calculations show that low {J}{{c}} in untextured polycrystalline Bi2Sr2Ca2Cu3O10 material is to be expected and the significant effort in the community in texturing samples and removing grain boundaries altogether is well-founded.

Green engineering education through a U.S. EPA/academia collaboration.

PubMed

Shonnard, David R; Allen, David T; Nguyen, Nhan; Austin, Sharon Weil; Hesketh, Robert

2003-12-01

The need to use resources efficiently and reduce environmental impacts of industrial products and processes is becoming increasingly important in engineering design; therefore, green engineering principles are gaining prominence within engineering education. This paper describes a general framework for incorporating green engineering design principles into engineering curricula, with specific examples for chemical engineering. The framework for teaching green engineering discussed in this paper mirrors the 12 Principles of Green Engineering proposed by Anastas and Zimmerman (Environ. Sci. Technol. 2003, 37, 94A-101A), especially in methods for estimating the hazardous nature of chemicals, strategies for pollution prevention, and approaches leading to efficient energy and material utilization. The key elements in green engineering education, which enlarge the "box" for engineering design, are environmental literacy, environmentally conscious design, and beyond-the-plant boundary considerations.

Approximating the nonlinear density dependence of electron transport coefficients and scattering rates across the gas-liquid interface

NASA Astrophysics Data System (ADS)

Garland, N. A.; Boyle, G. J.; Cocks, D. G.; White, R. D.

2018-02-01

This study reviews the neutral density dependence of electron transport in gases and liquids and develops a method to determine the nonlinear medium density dependence of electron transport coefficients and scattering rates required for modeling transport in the vicinity of gas-liquid interfaces. The method has its foundations in Blanc’s law for gas-mixtures and adapts the theory of Garland et al (2017 Plasma Sources Sci. Technol. 26) to extract electron transport data across the gas-liquid transition region using known data from the gas and liquid phases only. The method is systematically benchmarked against multi-term Boltzmann equation solutions for Percus-Yevick model liquids. Application to atomic liquids highlights the utility and accuracy of the derived method.

Digital particle image thermometry/velocimetry: a review

NASA Astrophysics Data System (ADS)

Dabiri, Dana

2009-02-01

Digital particle image thermometry/velocimetry (DPIT/V) is a relatively new methodology that allows for measurements of simultaneous temperature and velocity within a two-dimensional domain, using thermochromic liquid crystal tracer particles as the temperature and velocity sensors. Extensive research has been carried out over recent years that have allowed the methodology and its implementation to grow and evolve. While there have been several reviews on the topic of liquid crystal thermometry (Moffat in Exp Therm Fluid Sci 3:14-32, 1990; Baughn in Int J Heat Fluid Flow 16:365-375, 1995; Roberts and East in J Spacecr Rockets 33:761-768, 1996; Wozniak et al. in Appl Sci Res 56:145-156, 1996; Behle et al. in Appl Sci Res 56:113-143, 1996; Stasiek in Heat Mass Transf 33:27-39, 1997; Stasiek and Kowalewski in Opto Electron Rev 10:1-10, 2002; Stasiek et al. in Opt Laser Technol 38:243-256, 2006; Smith et al. in Exp Fluids 30:190-201, 2001; Kowalewski et al. in Springer handbook of experimental fluid mechanics, 1st edn. Springer, Berlin, pp 487-561, 2007), the focus of the present review is to provide a relevant discussion of liquid crystals pertinent to DPIT/V. This includes a background on liquid crystals and color theory, a discussion of experimental setup parameters, a description of the methodology’s most recent advances and processing methods affecting temperature measurements, and finally an explanation of its various implementations and applications.

Ligand-controlled Fe mobilization catalyzed by adsorbed Fe(II) on Fe(hydr)oxides

NASA Astrophysics Data System (ADS)

Kang, Kyounglim; Biswakarma, Jagannath; Borowski, Susan C.; Hug, Stephan J.; Hering, Janet G.; Schenkeveld, Walter D. C.; Kraemer, Stephan M.

2017-04-01

Dissolution of Fe(hydr)oxides is a key process in biological iron acquisition. Due to the low solubility of iron oxides in environments with a circumneutral pH, organisms may exude organic compounds catalyzing iron mobilization by reductive and ligand controlled dissolution mechanisms. Recently, we have shown synergistic effects between reductive dissolution and ligand-controlled dissolution that may operate in biological iron acquisition. The synergistic effects were observed in Fe mobilization from single goethite suspensions as well as in suspensions containing calcareous soil[1],[2]. However, how the redox reaction accelerates Fe(hydr)oxide dissolution by ligands is not studied intensively. In our study, we hypothesized that electron transfer to structural Fe(III) labilizes the Fe(hydr)oxide structure, and that this can accelerate ligand controlled dissolution. Systematical batch dissolution experiments were carried out under anoxic conditions at environmentally relevant pH values in which various Fe(hydr)oxides (goethite, hematite, lepidocrocite) interacted with two different types of ligand (desferrioxamine B (DFOB) and N,N'-Di(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid monohydrochloride (HBED)). Electron transfer to the structure was induced by adsorbing Fe(II) to the mineral surface at various Fe(II) concentrations. Our results show a distinct catalytic effect of adsorbed Fe(II) on ligand controlled dissolution, even at submicromolar Fe(II) concentrations. We observed the effect for a range of iron oxides, but it was strongest in lepidocrocite, most likely due to anisotropy in conductivity leading to higher near-surface concentration of reduced iron. Our results demonstrate that the catalytic effect of reductive processes on ligand controlled dissolution require a very low degree of reduction making this an efficient process for biological iron acquisition and a potentially important effect in natural iron cycling. References 1. Wang, Z. M.; Schenkeveld, W. D. C.; Kraemer, S. M.; Giammar, D. E. Environ. Sci. Technol. 2015, 49, (12), 7236-7244. 2. Schenkeveld, W. D. C.; Wang, Z. M.; Giammar, D. E.; Kraemer, S. M. Environ. Sci. Technol. 2016, 50, (12), 6381-6388.

Emission Spectroscopy of Atmospheric-Pressure Ball Plasmoids: Higher Energy Reveals a Rich Chemistry

NASA Astrophysics Data System (ADS)

Dubowsky, Scott E.; Rose, Amber Nicole; Glumac, Nick; McCall, Benjamin J.

2017-06-01

Ball plasmoids (self-sustaining spherical plasmas) are a particularly unique example of a non-equilibrium air plasma. These plasmoids have lifetimes on the order of hundreds of milliseconds without an external power source, however, current models dictate that a ball plasmoid should recombine in a millisecond or less. Ball plasmoids are considered to be a laboratory analogue of natural ball lightning, a phenomenon that has eluded scientific explanation for centuries. We are searching for the underlying physicochemical mechanism(s) by which ball plasmoids and (by extension) ball lightning are stabilized using a variety of diagnostic techniques. This presentation will focus on optical emission spectroscopy (OES) of ball plasmoid discharges between 190-850 nm. The previous generation of OES measurements of this system showed emission from only a few atomic and molecular species, however, the energy available for the discharges in these experiments was limited by the size of the capacitor banks and voltages to which the capacitor banks were charged. We are capable of generating plasmoids at much higher energies, and as a result we are the first to report a very rich chemistry previously not observed in ball plasmoids. We have identified signals from species including NO A^{2}Σ^{+}→X^{2}Π, OH A^{2}Σ^{+}→X^{2}Π, NH A^{3}Π→X^{3}Σ^{-}, AlO A^{2}Π→X^{2}Σ^{+}, NH^{+} B^{2}Δ→X^{2}Π, W I, Al I, Cu I, and H_{α}, all of which have not yet been reported for this system. Analysis of the emission spectra and fitting procedures will be discussed, rotational temperatures of constituent species will be reported, and theories of ball plasmoid stabilization based upon these new results will be presented. Versteegh, A.; Behringer, K.; Fantz, U.; Fussman, G.; Jüttner, B.; Noack, S. Plas. Sour. Sci. Technol. 2008, 17(2), 024014 Stephan, K. D.; Dumas, S.; Komala-Noor, L.; McMinn, J. Plas. Sour. Sci. Technol. 2013, 22(2), 025018

Self-Organized Composition Modulation During Epitaxial Growth

NASA Astrophysics Data System (ADS)

Barabási

1998-03-01

There is extensive recent experimental evidence of spontaneous superlattice (SL) formation in various II-VI and III-V semiconductors. Here we propose an atomistic mechanism responsible for SL formation, and derive a relation predicting the temperature, flux and miscut dependence of the SL layer thickness(A.-L. Barabási, Appl. Phys. Lett.) 70, 764 (1996).. Moreover, the model explains the existence of a critical miscut angle below which no SL is formed, in agreement with results on ZnSeTe(S.P Ahrenkiel et al.), Phys. Rev. Lett. 75, 1586 (1995)., and predicts the formation of a platelet structure for deposition onto high symmetry surfaces, similar to that observed in InAsSb(A.G. Norman, et al.) Semicond. Sci. Technol. 8, S9 (1991).. Work done in collaboration with I. Daruka and J.K. Furdyna.

Experimental identification of nonlinear coupling between (intermediate, small)-scale microturbulence and an MHD mode in the core of a superconducting tokamak

NASA Astrophysics Data System (ADS)

Sun, P. J.; Li, Y. D.; Ren, Y.; Zhang, X. D.; Wu, G. J.; Xu, L. Q.; Chen, R.; Li, Q.; Zhao, H. L.; Zhang, J. Z.; Shi, T. H.; Wang, Y. M.; Lyu, B.; Hu, L. Q.; Li, J.; The EAST Team

2018-01-01

In this paper, we present clear experimental evidence of core region nonlinear coupling between (intermediate, small)-scale microturbulence and an magnetohydrodynamics (MHD) mode during the current ramp-down phase in a set of L-mode plasma discharges in the experimental advanced superconducting tokamak (EAST, Wan et al (2006 Plasma Sci. Technol. 8 253)). Density fluctuations of broadband microturbulence (k\\perpρi˜2{-}5.2 ) and the MHD mode (toroidal mode number m = -1 , poloidal mode number n = 1 ) are measured simultaneously, using a four-channel tangential CO2 laser collective scattering diagnostic in core plasmas. The nonlinear coupling between the broadband microturbulence and the MHD mode is directly demonstrated by showing a statistically significant bicoherence and modulation of turbulent density fluctuation amplitude by the MHD mode.

A spin-orbit coupling for a neutral particle from Lorentz symmetry breaking effects in the CPT-odd sector of the Standard Model Extension

NASA Astrophysics Data System (ADS)

Belich, H.; Bakke, K.

2015-07-01

We start by investigating the arising of a spin-orbit coupling and a Darwin-type term that stem from Lorentz symmetry breaking effects in the CPT-odd sector of the Standard Model Extension. Then, we establish a possible scenario of the violation of the Lorentz symmetry that gives rise to a linear confining potential and an effective electric field in which determines the spin-orbit coupling for a neutral particle analogous to the Rashba coupling [E. I. Rashba, Sov. Phys. Solid State 2, 1109 (1960)]. Finally, we confine the neutral particle to a quantum dot [W.-C. Tan and J. C. Inkson, Semicond. Sci. Technol. 11, 1635 (1996)] and analyze the influence of the linear confining potential and the spin-orbit coupling on the spectrum of energy.

Turbulent equipartition pinch of toroidal momentum in spherical torus

NASA Astrophysics Data System (ADS)

Hahm, T. S.; Lee, J.; Wang, W. X.; Diamond, P. H.; Choi, G. J.; Na, D. H.; Na, Y. S.; Chung, K. J.; Hwang, Y. S.

2014-12-01

We present a new analytic expression for turbulent equipartition (TEP) pinch of toroidal angular momentum originating from magnetic field inhomogeneity of spherical torus (ST) plasmas. Starting from a conservative modern nonlinear gyrokinetic equation (Hahm et al 1988 Phys. Fluids 31 2670), we derive an expression for pinch to momentum diffusivity ratio without using a usual tokamak approximation of B ∝ 1/R which has been previously employed for TEP momentum pinch derivation in tokamaks (Hahm et al 2007 Phys. Plasmas 14 072302). Our new formula is evaluated for model equilibria of National Spherical Torus eXperiment (NSTX) (Ono et al 2001 Nucl. Fusion 41 1435) and Versatile Experiment Spherical Torus (VEST) (Chung et al 2013 Plasma Sci. Technol. 15 244) plasmas. Our result predicts stronger inward pinch for both cases, as compared to the prediction based on the tokamak formula.

Laser irradiance scaling in polar direct drive implosions on the National Ignition Facility

DOE PAGES

Murphy, T. J.; Krasheninnikova, N. S.; Kyrala, G. A.; ...

2015-09-17

Polar-direct-drive experiments conducted at the National Ignition Facility [E. I. Moses, Fusion Sci. Technol. 54, 361 (2008)] performed at laser irradiance between 1 and 2×10 15 W/cm 2 exhibit increased hard x-ray emission, decreased neutron yield, and reduced areal density as the irradiance is increased. Experimental x-ray images at the higher irradiances show x-ray emission at the equator, as well as degraded symmetry, that is not predicted in hydrodynamic simulations using flux-limited energy transport, but that appear when non-local electron transport together with a model to account for cross beam energy transfer (CBET) is utilized. The reduction in laser powermore » for equatorial beams required in the simulations to reproduce the effects of CBET on the observed symmetry also reproduces the yield degradation consistent with experimental data.« less

Damage healing ability of a shape-memory-polymer-based particulate composite with small thermoplastic contents

NASA Astrophysics Data System (ADS)

Nji, Jones; Li, Guoqiang

2012-02-01

The purpose of this study is to investigate the potential of a shape-memory-polymer (SMP)-based particulate composite to heal structural-length scale damage with small thermoplastic additive contents through a close-then-heal (CTH) self-healing scheme that was introduced in a previous study (Li and Uppu 2010 Comput. Sci. Technol. 70 1419-27). The idea is to achieve reasonable healing efficiencies with minimal sacrifice in structural load capacity. By first closing cracks, the gap between two crack surfaces is narrowed and a lesser amount of thermoplastic particles is required to achieve healing. The particulate composite was fabricated by dispersing copolyester thermoplastic particles in a shape memory polymer matrix. It is found that, for small thermoplastic contents of less than 10%, the CTH scheme followed in this study heals structural-length scale damage in the SMP particulate composite to a meaningful extent and with less sacrifice of structural capacity.

Oxygen adsorption and incorporation at irradiated GaN(0001) and GaN(0001¯) surfaces: First-principles density-functional calculations

NASA Astrophysics Data System (ADS)

Sun, Qiang; Selloni, Annabella; Myers, T. H.; Doolittle, W. Alan

2006-11-01

Density functional theory calculations of oxygen adsorption and incorporation at the polar GaN(0001) and GaN(0001¯) surfaces have been carried out to explain the experimentally observed reduced oxygen concentration in GaN samples grown by molecular beam epitaxy in the presence of high energy (˜10keV) electron beam irradiation [Myers , J. Vac. Sci. Technol. B 18, 2295 (2000)]. Using a model in which the effect of the irradiation is to excite electrons from the valence to the conduction band, we find that both the energy cost of incorporating oxygen impurities in deeper layers and the oxygen adatom diffusion barriers are significantly reduced in the presence of the excitation. The latter effect leads to a higher probability for two O adatoms to recombine and desorb, and thus to a reduced oxygen concentration in the irradiated samples, consistent with experimental observations.

RAPID COMMUNICATION: Optical distortion correction for liquid droplet visualization using the ray tracing method: further considerations

NASA Astrophysics Data System (ADS)

Minor, G.; Oshkai, P.; Djilali, N.

2007-11-01

The original work of Kang et al (2004 Meas. Sci. Technol. 15 1104 12) presents a scheme for correcting optical distortion caused by the curved surface of a droplet, and illustrates its application in PIV measurements of the velocity field inside evaporating liquid droplets. In this work we re-derive the correction algorithm and show that several terms in the original algorithm proposed by Kang et al are erroneous. This was not evident in the original work because the erroneous terms are negligible for droplets with approximately hemispherical shapes. However, for the more general situation of droplets that have shapes closer to that of a sphere, with heights much larger than their contact-line radii, these errors become quite significant. The corrected algorithm is presented and its application illustrated in comparison with that of Kang et al.

Exact cone beam reconstruction formulae for functions and their gradients for spherical and flat detectors

NASA Astrophysics Data System (ADS)

Louis, Alfred K.

2016-11-01

We derive unified inversion formulae for the cone beam transform similar to the Radon transform. Reinterpreting Grangeat’s formula we find a relation between the Radon transform of the gradient of the searched-for function and a quantity computable from cone beam data. This gives a uniqueness result for the cone beam transform of compactly supported functions under much weaker assumptions than the Tuy-Kirillov condition. Furthermore this relation leads to an exact formula for the direct calculation of derivatives of the density distribution; but here, similar to the classical Radon transform, complete Radon data are needed, hence the Tuy-Kirillov condition has to be imposed. Numerical experiments reported in Hahn B N et al (2013 Meas. Sci. Technol. 24 125601) indicate that these calculations are less corrupted by beam-hardening noise. Finally, we present flat detector versions for these results, which are mathematically less attractive but important for applications.

Navigating Tensions Between Conceptual and Metaconceptual Goals in the Use of Models

NASA Astrophysics Data System (ADS)

Delgado, Cesar

2015-04-01

Science education involves learning about phenomena at three levels: concrete (facts and generalizations), conceptual (concepts and theories), and metaconceptual (epistemology) (Snir et al. in J Sci Educ Technol 2(2):373-388, 1993). Models are key components in science, can help build conceptual understanding, and may also build metaconceptual understanding. Technology can transform teaching and learning by turning models into interactive simulations that learners can investigate. This paper identifies four characteristics of models and simulations that support conceptual learning but misconstrue models and science at a metaconceptual level. Ahistorical models combine the characteristics of several historical models; they conveniently compile ideas but misrepresent the history of science (Gilbert in Int J Sci Math Educ 2(2):115-130, 2004). Teleological models explain behavior in terms of a final cause; they can lead to useful heuristics but imply purpose in processes driven by chance and probability (Talanquer in Int J Sci Educ 29(7):853-870, 2007). Epistemological overreach occurs when models or simulations imply greater certainty and knowledge about phenomena than warranted; conceptualizing nature as being well known (e.g., having a mathematical structure) poses the danger of conflating model and reality or data and theory. Finally, models are inevitably ontologically impoverished. Real-world deviations and many variables are left out of models, as models' role is to simplify. Models and simulations also lose much of the sensory data present in phenomena. Teachers, designers, and professional development designers and facilitators must thus navigate the tension between conceptual and metaconceptual learning when using models and simulations. For each characteristic, examples are provided, along with recommendations for instruction and design. Prompts for explicit reflective activities around models are provided for each characteristic

Quantifying the decadal changes of PM2.5 over New York through a combination of satellite, model and in-situ measurements

NASA Astrophysics Data System (ADS)

Jin, X.; Fiore, A. M.; Curci, G.; Lyapustin, A.; Wang, Y.; Civerolo, K.; Ku, M.; van Donkelaar, A.; Martin, R.

2017-12-01

Ambient exposure to fine particulate matter (PM2.5) is one of the top global health concerns. Efforts have been made to regulate PM2.5 precursor emissions across the U.S.A, which are expected to mitigate the air pollution related health impacts. However, quantifying the health outcomes from emission controls requires robust estimates of PM2.5 exposures that accurately describe the spatial and temporal variability of PM2.5. Satellite remote sensing offers the potential to fill the gaps of the sparse, limited sampling of in situ measurement networks and is increasingly being used in health assessments. We provide new estimates of PM2.5 over New York State with 1 km spatial resolution that use Multi-Angle Implementation of Atmospheric Correction (MAIAC) AOD and a regional air quality model (CMAQ) to estimate the AOD-PM2.5 scaling factors. Next, we evaluate three major sources of uncertainties of satellite-derived PM2.5 data and their impacts on the derived decadal changes: 1) satellite retrieval of AOD, 2) optical properties of the particles, 3) relationships between the aerosol burden in the planetary boundary layer and full atmospheric column. Finally, we analyze the decadal changes of PM2.5 over New York State using the newly developed PM2.5 data, alongside four other PM2.5 estimates including satellite-derived PM2.5 developed by van Donkelaar et al. (2015), statistical land use regression developed by Beckerman et al. (2013), CMAQ simulations, and a Bayesian fusion of CMAQ and ground-based measurements. By evaluating the decadal changes of PM2.5 from multiple datasets over areas with dense (e.g. New York City area) and sparse ground-based measurements (e.g. upstate New York), we evaluate the extent to which satellite remote sensing could help better quantify the health outcomes of emission controls. References: Beckerman et al., (2013), A Hybrid Approach to Estimating National Scale Spatiotemporal Variability of PM2.5 in the Contiguous United States, Environ. Sci. Technol., 47(13), 7233-7241. van Donkelaar et al. (2015), High-Resolution Satellite-Derived PM2.5 from Optimal Estimation and Geographically Weighted Regression over North America, Environ. Sci. Technol., 49(17), 10482-10491.

Rapid Measurements of Aerosol Size Distribution and Hygroscopic Growth via Image Processing with a Fast Integrated Mobility Spectrometer (FIMS)

NASA Astrophysics Data System (ADS)

Wang, Y.; Pinterich, T.; Spielman, S. R.; Hering, S. V.; Wang, J.

2017-12-01

Aerosol size distribution and hygroscopicity are among key parameters in determining the impact of atmospheric aerosols on global radiation and climate change. In situ submicron aerosol size distribution measurements commonly involve a scanning mobility particle sizer (SMPS). The SMPS scanning time is in the scale of minutes, which is often too slow to capture the variation of aerosol size distribution, such as for aerosols formed via nucleation processes or measurements onboard research aircraft. To solve this problem, a Fast Integrated Mobility Spectrometer (FIMS) based on image processing was developed for rapid measurements of aerosol size distributions from 10 to 500 nm. The FIMS consists of a parallel plate classifier, a condenser, and a CCD detector array. Inside the classifier an electric field separates charged aerosols based on electrical mobilities. Upon exiting the classifier, the aerosols pass through a three stage growth channel (Pinterich et al. 2017; Spielman et al. 2017), where aerosols as small as 7 nm are enlarged to above 1 μm through water or heptanol condensation. Finally, the grown aerosols are illuminated by a laser sheet and imaged onto a CCD array. The images provide both aerosol concentration and position, which directly relate to the aerosol size distribution. By this simultaneous measurement of aerosols with different sizes, the FIMS provides aerosol size spectra nearly 100 times faster than the SMPS. Recent deployment onboard research aircraft demonstrated that the FIMS is capable of measuring aerosol size distributions in 1s (Figure), thereby offering a great advantage in applications requiring high time resolution (Wang et al. 2016). In addition, the coupling of the FIMS with other conventional aerosol instruments provides orders of magnitude more rapid characterization of aerosol optical and microphysical properties. For example, the combination of a differential mobility analyzer, a relative humidity control unit, and a FIMS was used to measure aerosol hygroscopic growth. Such a system reduced the time of measuring the hygroscopic properties of submicron aerosols (six sizes) to less than three minutes in total, with an error within 1%. Pinterich et al. (2017) Aerosol Sci. Technol. accepted Spielman et al. (2017) Aerosol Sci. Technol. accepted Wang et al. (2016) Nature 539:416-419

Anthropogenic Osmium in Airborne Particles from Woods Hole, Massachusetts, USA

NASA Astrophysics Data System (ADS)

Peucker-Ehrenbrink, B.; Sen, I. S.; Geboy, N.

2012-12-01

The global geochemical cycle of osmium has been significantly disturbed by the introduction of automobile exhaust catalysts to convert noxious gas emissions into more benign forms. Anthropogenic osmium has been reported in rainwater, snow, and in the urban airborne particles from around the world to reveal global-scale osmium pollution [1, 2]. In this study, we report on the platinum group element (PGE) concentrations and osmium isotope ratios of airborne particles (PM10) collected in Woods Hole, a small coastal town in Massachusetts to better understand inputs of anthropogenic osmium to rural environments. We further investigate the use of osmium isotopes to track sources of airborne particles and support source apportionment studies on a continental scale. The samples used in this study were collected at Woods Hole Oceanographic Institution over one year (2008-2009). From this collection twelve samples for which the backward air mass trajectories have been determined were selected for osmium isotope analyses. Our results show that the osmium and platinum concentrations are an order of magnitude lower when compared to downtown Boston [2]. The average Os, Pt and Ir concentrations are 0.006±0.012, 0.019±0.023, and 0.685±0.634 pg m-3, respectively. The 187Os/188Os of the aerosols range from 0.275 to 0.788. As continental crust is radiogenic (187Os/188Os >1) and PGE ore bodies generally have unradiogenic 187Os/188Os (~0.2), the unradiogenic 187Os/188Os signature of the aerosols indicates anthropogenic contributions. With 95% of the total osmium mobilization on land being attributed to human activities [3], it is clear that human imprint on airborne particles is not restricted to urban centers with high traffic flows, but also affects rural environments. Aerosol particles that have backward air mass trajectories from the Southwest, the densely populated and industrialized Eastern seaboard, are characterized by unradiogenic osmium, while air masses from the North have radiogenic signatures. Our results suggest that 187Os/188Os has potential for source apportionment studies. [1] Rauch et al. (2005), Environ. Sci. Technol., 39, p. 9464-9470 [2] Chen et al. (2009), PNAS, 106, p. 7724-7728 [3] Sen and Peucker-Ehrenbrink (2012), Environ. Sci. Technol., dx.doi.org/10.102/es301261x

Effect of ionic strength on barium transport in porous media

NASA Astrophysics Data System (ADS)

Prigiobbe, V.; Ye, Z.

2017-12-01

Hydraulic fracturing (or fracking) is a well stimulation technique used to extract resourcesfrom a low permeability formation. During the operation large volumes of brine, rich ofhazardous chemicals, are produced. Spills of brine from a well or a pit might negativelyimpact underground water resources and one of the major concerns is for the migrationof radionuclides, such as, e.g., radium (Ra2+), into the shallow subsurface [1]. However, thetransport behaviour of Ra2+ through a reactive porous medium under conditions typical of abrine, i.e., high salinity, is not well understood, yet. Here, a study on the transport behaviour ofbarium (Ba2+, congener of radium) through a porous medium containing a common mineralsuch as goethite (FeO(OH)) is presented [2]. Batch and column flood tests were carried out atconditions resembling the produced water, i.e., large values of ionic strength (I), namely, 1to 3 mol/kg. The measurements were described with the triple layer surface complexationmodel coupled with the Pitzer activity coefficient method and a reactive transport model,in the case of the transport tests. The experimental results show that the adsorption of Ba2+onto FeO(OH) increases with pH but decreases with I and it becomes negligible at the brineconditions. Moreover, even if isotherms show adsorption at large I, at the same conditionsduring transport, Ba2+ travels without retardation through the FeO(OH) porous medium. The triple layer model agrees very well with all batch data but it cannot capture wellthe transport test, in particular, at large I values (Figure 1). This may suggest that thechemical reactions at the solid-liquid interface cannot describe well the adsorption of Ba2+onto FeO(OH) at large salinity. Finally, observations in this study suggest that in the case of a produced water spill, barium and potentially its congeners, namely, radium, calcium,magnesium, and strontium, contained in the brine may travel at the average flow velocity through a soil containing iron oxide minerals. References[1] Patterson et al. Environ. Sci. Technol. 2017, 51, 2563-2573.[2] Ye, Z. and Prigiobbe, V. In preparation for: Environ. Sci. Technol. 201X. Figure 1. Measurements and simulations of Ba2+ transport tests for experiments performedusing (a) NaCl = 0 and (b) NaCl = 1 mole/kg.

EDITORIAL: Perspectives Perspectives

NASA Astrophysics Data System (ADS)

Dewhurst, Richard

2011-05-01

In this issue, we are delighted to publish the second in a series of articles under the banner of Perspectives. The series commenced in late 2008, when Udo Kaatze [1] published an article about the powerful technique of dielectric spectrometry for liquid measurements. In addition to examining the very wide frequency range from 10-6 Hz to 10-13 Hz, an outline of possible future developments was presented. Some challenging tasks for the future were briefly outlined. The format of the article was different to the usual style of a contributed paper or review article. Instead, it represented a short summary of recent work in the field and offered a viewpoint of an expert in the area. Its commentary noted several milestones that had been recently achieved, and then looked to the future. The Perspective format allowed the author to provide some opinion about the challenges of the future not normally permitted in a Topical Review. The journal now intends to publish several more Perspectives. For example, in this issue David Birch [2] presents a Perspective about another important measurement science, namely fluorescence detections and their future directions. These are based on an old technique which provided the basis for detecting the presence of molecular species. Successful research led to an understanding and description of the phenomenon of molecular fluorescence in terms of excited state energies, transitions, symmetries and rate parameters. More recently, using fluorescence as a probe, and with the exploitation of new technologies, new applications have included the study of protein, vision, photosynthesis, membranes and DNA. Indeed nowhere has fluorescence had more impact than in the biosciences. Once again, the intention of the Perspective article has been to highlight recent milestones within the field. Importantly, it also indicates some of the future challenges. Such Perspectives are an occasional series. They are not intended to deflect from the balance of MST, where about 20% of papers involve special features, special issues and review articles. The remaining 80% of papers are original, contributed, papers. Nevertheless, we hope readers will find that these new Perspectives are both useful commentaries and also provide an insight into the future of topical fields of research. References [1] Kaatze U 2008 Perspectives in dielectric measurement techniques for liquids Meas. Sci. Technol. 19 112001 [2] Birch D J S 2011 Fluorescence detections and directions Meas. Sci. Technol. 22 052002

Analysis of reversibility and reaction products of glyoxal uptake onto ammonium sulfate aerosol

NASA Astrophysics Data System (ADS)

Galloway, M. M.; Chhabra, P. S.; Chan, A. W.; Surratt, J. D.; Kwan, A. J.; Wennberg, P. O.; Flagan, R. C.; Seinfeld, J. H.; Keutsch, F. N.

2009-04-01

Glyoxal, the smallest alpha-dicarbonyl, is an oxidation product of both biogenic and anthropogenic volatile organic compounds (Fu et al. JGR 113, D15303, 2008). Despite its low molecular weight, its role in secondary organic aerosol (SOA) formation has gained interest and a recent study suggested that it accounts for more than 15% of SOA in Mexico City (Volkamer et al. GRL 34, L19807, 2007). Despite numerous previous studies, questions remain regarding the processes controlling glyoxal uptake onto aerosol, including the role of acid catalysis, degree of reversibility, and identity of aerosol phase reaction products. We present results of chamber aerosol studies (Galloway et al. ACPD 8, 20799, 2008) and laboratory studies of bulk samples aimed at improving the understanding of these processes, in particular formation of oligomers and organosulfates of glyoxal, as well as the formation of imidazoles (carbon-nitrogen containing heterocyclic aromatic compounds) under dark and irradiated conditions. The relevance of these classes of reaction products extends beyond glyoxal, as evidence of oligomers and organosulfates other than those of glyoxal have been found in ambient aerosol (Surratt et al. JPCA 112, 8345, 2008; Denkenberger et al. Environ. Sci. Technol. 41, 5439, 2007). Experiments in which a chamber air mass was diluted after equilibration of glyoxal uptake onto ammonium sulfate seed aerosol (relative humidity 60% and glyoxal mixing ratios of 25-200 ppbv) shows that under these conditions uptake is reversible. The most important condensed phase products are hydrated oligomers of glyoxal, which are also formed reversibly under these conditions. Our studies show that organosulfates were not formed under dark conditions for neutral or acidified aerosol; similarly, Minerath et al. have recently shown that formation of a different class of organosulfates (alkyl sulfates) also proceeds very slowly even under acidic conditions (Environ. Sci. Technol. 42, 4410, 2008). The masses assigned to sulfate esters in previous work (Liggio et al. Environ. Sci. Technol. 39, 1532, 2005) via low resolution AMS studies were assigned as glyoxal oligomers in our study via high resolution AMS spectra. However, organosulfates were identified under irradiated conditions, and we present attempts to identify the specific species via comparison with lab synthesized organosulfates. The influence of irradiation on organosulfate formation is still under investigation. Under irradiated conditions we see clear evidence for active oxidative photochemistry. The aerosol phase becomes increasingly oxidized and oxidation products, such as organic acids, similar to those observed in studies using bulk samples by Carlton et al. (Atmos. Environ. 41, 7588, 2007) are formed. Overall uptake is reduced under our experimental conditions, likely due to increasing temperature and decreasing relative humidity. We also report observation of imidazoles (carbon-nitrogen containing aromatic heterocycles) resulting from reaction of glyoxal with the nitrogen component of the ammonium sulfate seed aerosol. The imidazoles form irreversibly under dark and irradiated conditions, in ammonium sulfate and acidified ammonium sulfate (pH~1) aerosol. The molecular framework of imidazoles is very stable as a result of the aromaticity. The primary imidazole product, which has a low vapor pressure estimated at 0.0014 Torr, is predicted to be present as a (protonated) cation, owing to its basicity (pKB = 7). It is thus likely not a candidate for repartitioning to the gas phase. Evidence for participation of ammonium in reactions with glyoxal using bulk samples has recently been reported by Noziere et al. (JPCA 113, 231, 2008; ACPD 9, 1, 2009). This study reveals the complex chemistry occurring within ammonium sulfate seed aerosol even for systems with greatly reduced complexity compared to atmospheric aerosol. The results increase our understanding of the contribution of glyoxal to SOA formation processes. More specifically, these results provide valuable insights into important aerosol processes, such as organosulfate and oligomer formation, as well as the formation of aromatic nitrogen containing heterocycles from reaction of a carbonyl with ammonium sulfate aerosol.

Heterogeneous freezing of droplets with immersed surface modified mineral dust particles

NASA Astrophysics Data System (ADS)

Hartmann, Susan

2010-05-01

In the framework of the international measurement campaign FROST II (FReezing Of duST), the heterogeneous freezing of droplets with an immersed surface modified size-segregated mineral dust particles was investigated at LACIS (Leipzig Aerosol Cloud Interaction Simulator, Stratmann et al. 2004). The following measurements were done: LACIS, CFDC (Continuous Flow thermal gradient Diffusion Chamber, Rogers (1988)) and FINCH (Fast Ice Nucleus Chamber Counter, Bundke et al (2008)) were used to analyze the immersion freezing behavior of the treated Arizona Test Dust (ATD) particles at different temperature regimes. The ability to act as IN (Ice Nucleus) in the deposition nucleation mode was quantified by the PINC (Portable Ice Nucleation Chamber) and the CFDC instrument. AMS (Aerosol Mass Spectrometers, e.g. Schneider et al. (2005)) and ATOFMS (Aerosol Time-Of-Flight Mass Spectrometer) measurements were applied to determine particle composition. The hygroscopic growth and the critical super-saturations needed for droplet activation were determined by means of an H-TDMA (Humidity-Tandem Differential Mobility Analyzer) and CCN counter (Cloud Condensation Nucleus counter, Droplet Measurement Technologies, Roberts and Nenes (2005)). The 300 nm ATD particles were chemically and physically treated by coating with sulphuric acid (H2SO4, three different coating thicknesses) and ammonium sulphate ((NH4)2SO4) or by thermal treatment with a thermodenuder operating at 250°C. The H2SO4 coating modified the particles by reacting with particle material, forming soluble sulfates and therefore changing surface properties. AMS showed free H2SO4 only for thick H2SO4 coatings. In the heated section of the thermodenuder coating materials were evaporated partly and the surface properties of the particles were additionally altered. Uncoated particles and those coated with thin coatings of H2SO4, showed almost no hygroscopic growth. Particles coated with thicker coatings of H2SO4 and of (NH4)2SO4 grew noticeably above 95% relative humidity. All investigated particles were found to activate at atmospherically relevant super-saturations. All kinds of treatment lower the IN-ability, whereas the deposition nucleation was more sensitive to treatments than the immersion freezing mode. Considering the immersion freezing behavior, pure ATD particles and particles coated with thin coatings of H2SO4 were more efficient IN, than particles with thick H2SO4 or (NH4)2SO4 coatings. Thermal treatments of the particles led to further decrease of the IN capability except for particles coated with (NH4)2SO4, where the heating did not effect the immersion freezing behavior likely due to their already reduced IN ability. In order to specify the temperature-dependent immersion freezing, two parameterization based on either stochastic or singular hypothesis were performed. From both theoretical approaches it can be concluded that the treatments lead to particle surface modifications lowering the nucleation efficiency. References: Bundke, U., B. Nillius, et al. (2008), The fast Ice Nucleus chamber FINCH, Atmospheric Research 90(2-4): 180-186. Rader, D. J. and P. H. McMurry (1986), Application of the Tandem Differential Mobility Analyzer to studies of droplet growth or evaporation, J. Aerosol Sci., Vol. 17, No. 5, pp. 771-787. Roberts, G., and A. Nenes (2005), A continuous-flow streamwise thermal-gradient CCN chamber for atmospheric measurements, Aerosol Sci. Technol., 39, 206-221. Schneider, J., N. Hock, S. Weimer, S. Borrmann, U. Kirchner, R. Vogt, and V. Scheer (2005), Nucleation particles in Diesel exhaust: Composition inferred from in situ mass spectrometric analysis, Environ. Sci. Technol., 39, 6153-6161. Rogers,D .C. (1988), Developmenot f a continuousflow thermal gradient diffusion chamber for ice nucleation studies. Atmospheric Research, 22, 149-181. Stratmann, F., A. Kiselev, S. Wurzler, M. Wendisch, J. Heintzenberg, R. J. Charlson, K. Diehl, H. Wex, and S. Schmidt (2004), Laboratory studies and numerical simulations of cloud droplet formation under realistic super-saturation conditions, J. Atmos. Oceanic Technol., 21, 876-887.

Modeling spatially- and temporally-explicit water stress indices for use in life cycle assessment

NASA Astrophysics Data System (ADS)

Scherer, L.; Venkatesh, A.; Karuppiah, R.; Usadi, A.; Pfister, S.; Hellweg, S.

2013-12-01

Water scarcity is a regional issue in many areas across the world, and can affect human health and ecosystems locally. Water stress indices (WSIs) have been developed as quantitative indicators of such scarcities - examples include the Falkenmark indicator, Social Water Stress Index, and the Water Supply Stress Index1. Application of these indices helps us understand water supply and demand risks for multiple users, including those in the agricultural, industrial, residential and commercial sectors. Pfister et al.2 developed a method to calculate WSIs that were used to estimate characterization factors (CFs) in order to quantify environmental impacts of freshwater consumption within a life cycle assessment (LCA) framework. Global WSIs were based on data from the WaterGAP model3, and presented as annual averages for watersheds. Since water supply and demand varies regionally and temporally, the resolution used in Pfister et al. does not effectively differentiate between seasonal and permanent water scarcity. This study aims to improve the temporal and spatial resolution of the water scarcity calculations used to estimate WSIs and CFs. We used the Soil and Water Assessment Tool (SWAT)4 hydrological model to properly simulate water supply in different world regions with high spatial and temporal resolution, and coupled it with water use data from WaterGAP3 and Pfister et al.5. Input data to SWAT included weather, land use, soil characteristics and a digital elevation model (DEM), all from publicly available global data sets. Potential evapotranspiration, which affects water supply, was determined using an improved Priestley-Taylor approach. In contrast to most other hydrological studies, large reservoirs, water consumption and major water transfers were simulated. The model was calibrated against observed monthly discharge, actual evapotranspiration, and snow water equivalents wherever appropriate. Based on these simulations, monthly WSIs were calculated for a few model regions (including Africa and North America). These WSIs were used to estimate revised CFs for freshwater consumption to be used in LCAs. Future work will extend results to a global scale. References 1. Brown, A., Matlock, M., 2011. A Review of Water Scarcity Indices and Methodologies, University of Kansas, The Sustainability Consortium, White Paper #106. 2. Pfister, S., Koehler, A., Hellweg, S., 2009. Assessing the Environmental Impacts of Freshwater Consumption in LCA. Environ. Sci. Technol. 43 (11), 4098-4104. 3. Alcamo, J.; Doll, P.; Henrichs, T.; Kaspar, F.; Lehner, B.; Rosch, T.; Siebert, S. Development and testing of the WaterGAP 2 global model of water use and availability Hydrol. Sci. J. 2003, 48 (3) 317- 337. 4. Arnold, J.G., Srinivasan, R., Muttiah, R.S., Allen, P.M., 1999. Continental scale simulation of the hydrologic balance. J. Am.Water Resour. Assoc. 35 (5), 1037-1051. 5. Pfister, S., Bayer, P., Koehler, A., Hellweg, S., 2011. Environmental Impacts of Water Use in Global Crop Production: Hotspots and Trade-Offs with Land Use. Environ. Sci. Technol. 45 (13), 5761- 5768.

EDITORIAL: Announcing the 2007 Measurement Science and Technology Outstanding Paper Awards

NASA Astrophysics Data System (ADS)

Foss, John; Dewhurst, Richard; Fujii, Kenichi; Regtien, Paul

2008-05-01

Since 1991, Measurement Science and Technology has awarded a Best Paper prize. The Editorial Board of this journal believes that such a prize is an opportunity to thank authors for submitting their work, and serves as an integral part of the on-going quality review of the journal. The current breadth of topical areas that are covered by MST has made it advisable to expand the recognition of excellent publications. Hence, since 2005 the Editorial Board have presented 'Outstanding Paper Awards' in four subject categories: Fluid Mechanics; Measurement Science; Precision Measurements; and Sensors and Sensing Systems. 2007 Award Winners—Fluid Mechanics An adaptive sampling and windowing interrogation method in PIV R Theunissen, F Scarano and M L Riethmuller von Karman Institute for Fluid Dynamics, Chaussée de Waterloo 72, 1640 Sint-Genesius Rode, Belgium and Department of Aerospace Engineering, Delft University of Technology, Delft, PO Box 5058, 2600 GB Delft, The Netherlands The co-authored paper [1] has been selected as the Outstanding Paper in Fluid Mechanics for 2007. This paper provides a strategy whereby the placement and the size of the interrogation regions are adapted to the image signal strength (seeding density) and the spatial variations of the velocity magnitudes. Two, quite distinct, test cases demonstrate the efficacy of their method: a shockwave- boundary layer interaction and an aircraft vortex wake. The Selection Committee—Drs T Fansler, J Foss, I Marusic, S Morris, K Okamoto and M Wernet—selected this paper from a strongly competitive shortlist of four candidates. Their selection process was influenced by the perceived utility of the contribution to the numerous investigators who utilize PIV methods. 2007 Award Winners—Measurement Science Broadband single cell impedance spectroscopy using maximum length sequences: theoretical analysis and practical considerations Tao Sun, Shady Gawad, Catia Bernabini, Nicolas G Green and Hywel Morgan Nanoscale Systems Integration Group, School of Electronics and Computer Science, University of Southampton, Southampton SO17 1BJ, UK The paper [2] describes a novel impedance spectroscopic measurement method for applications in the identification of biological cells. The frequency-dependent impedance is obtained in the frequency domain by applying a fast M-sequence transform (FMT), and a fast Fourier transform (FFT) in the time domain response. Using FMT, the evaluation takes place within a short timescale of the order of milliseconds. This technique is used in a microfluidic impedance cytometer, for the analysis of single biological cells in suspension. The theory of the technique is analysed in depth. It is then applied to an experimental system that characterizes the impedance spectrum of red blood cells within the microfluidic system. Measured spectra show good agreement with simulations. The paper has a short but excellent introduction, supported by a solid reference list of about 55 papers describing related work. Most of these papers are citations from 2000 onwards. This is followed by a detailed analysis of maximum length sequences and theory used for predictions of spectra. It then continues with a useful description of a cytometer that was used to confirm theoretical predictions of spectra. Results are at an early stage. The system is still under development, since there are issues arising from the fact that the particle flows during the acquisition of data, and is not static in the electric field as assumed by the model. Nevertheless, the paper possesses good clarity of the motivation behind the work, of the measurement techniques developed and of the potential relevance to applications in the life sciences. 2007 Award Winners—Precision Measurement Ultraprecision micro-CMM using a low force 3D touch probe A Küng, F Meli and R Thalmann Swiss Federal Office of Metrology (METAS), Lindenweg 50, CH-3003 Bern-Wabern, Switzerland The paper [3] describes a new three-dimensional coordinate measuring machine (CMM) developed for traceable measurement for small objects. The most sophisticated component of the system lies in the structure of its touch probe. It was designed based on a parallel kinematic mechanism with flexure hinges in order to minimize the moving mass and to ensure an isotropic low stiffness. This head features very weak probing forces, below 0.5 mN, and supports exchangeable probes down to 0.1 mm diameter, realizing a measurement without introducing any plastic deformation on the surface of the object. It was then combined with a highly accurate 90 mm × 90 mm × 38 mm air bearing stage with interferometric position measurement with no Abbe offset, achieving a typical reproducibility of 5 nm in measuring various shapes of the objects. In order to evaluate the contribution of the shape deviation of the probing sphere to the uncertainty, a new calibration method with three spheres has been developed in this work. In addition, a scanning measurement procedure was also implemented for fast measurement without any loss of accuracy, contributing to practical measurement for users. The selection committee members on precision measurement—Drs K Fujii and A Yacoot—and Editorial Board members Drs P Hauptmann, U Kaatze and M Player, selected this paper from a strongly competitive list of nine candidates. The paper opened a new way for achieving an unprecedented accuracy in coordinate metrology. 2007 Award Winners—Sensors and Sensing Systems Two-dimensional optical accelerometer based on commercial DVD pick-up head Chih-Liang Chu, Cha-Hao Lin and Kuang-Chao Fan Department of Mechanical Engineering, Southern Taiwan University of Technology, Tainan, Taiwan, Republic of China and Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan, Republic of China The authors describe in this paper [4] a 2D accelerometer that is based on a simple DVD pick-up head. It is a considerable extension of an earlier paper [5] dealing with a similar device but restricted to 1D only. In the awarded paper, not only is the extension to 2D presented, but also a thorough analysis of the system's performance is given. A clear description of the general concept is followed by the derivation of the intensity distribution on the four-quadrant photodetector. In the next section, the design of the mechanical part is detailed, including a FEM analysis for obtaining optimal performance characteristics in terms of resonance frequency, sensitivity and range. The system is extensively tested, and the paper presents a useful selection of the measurement data in graphical and numerical format. Altogether, theory, experimental and measurement results are presented in a clear and well balanced way, and illustrated with neat graphics. A missing uncertainty analysis is the only deficiency in this otherwise excellent paper. A sequel to this paper from the same authors appeared a few issues later [6], presenting the DVD head as a nanoscale touch trigger probe. Both papers belong to the top 60 most downloaded papers in the 2007 volume. The Outstanding Paper Awards, comprising a cash honorarium and certificate, will be presented to the authors of the winning papers at suitable venues in the near future. The Editorial Board would like to congratulate the winning authors and would like to encourage all researchers to think of Measurement Science and Technology as the home for your best submissions. References [1] Theunissen R, Scarano F and Riethmuller M L 2007 An adaptive sampling and windowing interrogation method in PIV Meas. Sci. Technol. 18 275-87 [2] Sun T, Gawad S, Bernabini C, Green N G and Morgan H 2007 Broadband single cell impedance spectroscopy using maximum length sequences: theoretical analysis and practical considerations Meas. Sci. Technol. 18 2859-68 [3] Küng A, Meli F and Thalmann R 2007 Ultraprecision micro-CMM using a low force 3D touch probe Meas. Sci. Technol. 18 319-27 [4] Chu C-L, Lin C-H and Fan K-C 2007 Two-dimensional optical accelerometer based on commercial DVD pick-up head Meas. Sci. Technol. 18 265-74 [5] Chu C-L and Lin C-H 2005 Development of an optical accelerometer with a DVD pick-up head Meas. Sci. Technol. 16 2498-502 [6] Chu C-L and Chiu C-Y 2007 Development of a low-cost nanoscale touch trigger probe based on two commercial DVD pick-up heads Meas. Sci. Technol. 18 1831-42

Comparison of different measurement methods for transmittance haze

NASA Astrophysics Data System (ADS)

Yu, Hsueh-Ling; Hsaio, Chin-Chai

2009-08-01

Transmittance haze is increasingly important to the LCD and solar cell industry. Most commercial haze measurement instruments are designed according to the method recommended in the documentary standards like ASTM D 1003 (ASTM 2003 Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics), JIS K 7361 (JIS 1997 Plastics—Determination of the Total Luminous Transmittance of Transparent Materials—Part 1: Single Beam Instrument) and ISO 14782 (ISO 1997 Plastics—Determination of Haze of Transparent Materials). To improve the measurement accuracy of the current standards, a new apparatus was designed by the Center for Measurement Standards (Yu et al 2006 Meas. Sci. Technol. 17 N29-36). Besides the methods mentioned above, a double-beam method is used in the design of some instruments. There are discrepancies between the various methods. But no matter which method is used, a white standard is always needed. This paper compares the measurement results from different methods, presents the effect of the white standard, and analyses the measurement uncertainty.

FPGA-based photon-counting phase-modulation fluorometer and a brief comparison with that operated in a pulsed-excitation mode

NASA Astrophysics Data System (ADS)

Iwata, Tetsuo; Taga, Takanori; Mizuno, Takahiko

2018-02-01

We have constructed a high-efficiency, photon-counting phase-modulation fluorometer (PC-PMF) using a field-programmable gate array, which is a modified version of the photon-counting fluorometer (PCF) that works in a pulsed-excitation mode (Iwata and Mizuno in Meas Sci Technol 28:075501, 2017). The common working principle for both is the simultaneous detection of the photoelectron pulse train, which covers 64 ns with a 1.0-ns resolution time (1.0 ns/channel). The signal-gathering efficiency was improved more than 100 times over that of conventional time-correlated single-photon-counting at the expense of resolution time depending on the number of channels. The system dead time for building a histogram was eliminated, markedly shortening the measurement time for fluorescent samples with moderately high quantum yields. We describe the PC-PMF and make a brief comparison with the pulsed-excitation PCF in precision, demonstrating the potential advantage of PC-PMF.

Current profile redistribution driven by neutral beam injection in a reversed-field pinch

NASA Astrophysics Data System (ADS)

Parke, E.; Anderson, J. K.; Brower, D. L.; Den Hartog, D. J.; Ding, W. X.; Johnson, C. A.; Lin, L.

2016-05-01

Neutral beam injection in reversed-field pinch (RFP) plasmas on the Madison Symmetric Torus [Dexter et al., Fusion Sci. Technol. 19, 131 (1991)] drives current redistribution with increased on-axis current density but negligible net current drive. Internal fluctuations correlated with tearing modes are observed on multiple diagnostics; the behavior of tearing mode correlated structures is consistent with flattening of the safety factor profile. The first application of a parametrized model for island flattening to temperature fluctuations in an RFP allows inferrence of rational surface locations for multiple tearing modes. The m = 1, n = 6 mode is observed to shift inward by 1.1 ± 0.6 cm with neutral beam injection. Tearing mode rational surface measurements provide a strong constraint for equilibrium reconstruction, with an estimated reduction of q0 by 5% and an increase in on-axis current density of 8% ± 5%. The inferred on-axis current drive is consistent with estimates of fast ion density using TRANSP [Goldston et al., J. Comput. Phys. 43, 61 (1981)].

Theoretical analysis of field emission from a metal diamond cold cathode emitter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lerner, P.; Cutler, P.H.; Miskovsky, N.M.

Recently, Geis {ital et al.} [J. Vac. Sci. Technol. B {bold 14}, 2060 (1996)] proposed a cold cathode emitter based on a Spindt-type design using a diamond film doped by substitutional nitrogen. The device is characterized by high field emission currents at very low power. Two properties, the rough surface of the metallic injector and the negative electron affinity of the (111) surface of the diamond are essential for its operation. We present a first consistent quantitative theory of the operation of a Geis{endash}Spindt diamond field emitter. Its essential features are predicated on nearly {ital zero-field conditions} in the diamondmore » beyond the depletion layer, {ital quasiballistic transport} in the conduction band, and applicability of a modified {ital Fowler{endash}Nordheim equation} to the transmission of electrons through the Schottky barrier at the metal-diamond interface. Calculated results are in good qualitative and quantitative agreement with the experimental results of Geis {ital et al.} {copyright} {ital 1997 American Vacuum Society.}« less

Improvement of the ESR detection of irradiated food containing cellulose employing a simple extraction method

NASA Astrophysics Data System (ADS)

Delincée, Henry; Soika, Christiane

2002-03-01

Fruit may be irradiated at rather low doses, below 1 kGy in combination treatments or for quarantine purposes. To improve the ESR detection sensitivity of irradiated fruit de Jesus et al. (Int. J. Food Sci. Technol. 34 (1999) 173.) proposed extracting the fruit pulp with 80% ethanol and measuring the residue with ESR using low power (0.25 mW) for detection of 'cellulosic' radicals. An improvement in ESR sensitivity using the extraction procedure could be confirmed in this paper for strawberries and papayas. In most cases, a radiation dose of 0.5 kGy could be detected in both fruits even after 2-3 weeks storage. In addition, some herbs and spices were also tested, but only for a few of them the ESR detection of the 'cellulosic' signal was improved by previous alcoholic extraction. As an alternative to ESR measurements, other detection methods like DNA Comet Assay and thermoluminescence were also tested.

Exploring the limits of case-to-capsule ratio, pulse length, and picket energy for symmetric hohlraum drive on the National Ignition Facility Laser

NASA Astrophysics Data System (ADS)

Callahan, D. A.; Hurricane, O. A.; Ralph, J. E.; Thomas, C. A.; Baker, K. L.; Benedetti, L. R.; Berzak Hopkins, L. F.; Casey, D. T.; Chapman, T.; Czajka, C. E.; Dewald, E. L.; Divol, L.; Döppner, T.; Hinkel, D. E.; Hohenberger, M.; Jarrott, L. C.; Khan, S. F.; Kritcher, A. L.; Landen, O. L.; LePape, S.; MacLaren, S. A.; Masse, L. P.; Meezan, N. B.; Pak, A. E.; Salmonson, J. D.; Woods, D. T.; Izumi, N.; Ma, T.; Mariscal, D. A.; Nagel, S. R.; Kline, J. L.; Kyrala, G. A.; Loomis, E. N.; Yi, S. A.; Zylstra, A. B.; Batha, S. H.

2018-05-01

We present a data-based model for low mode asymmetry in low gas-fill hohlraum experiments on the National Ignition Facility {NIF [Moses et al., Fusion Sci. Technol. 69, 1 (2016)]} laser. This model is based on the hypothesis that the asymmetry in these low fill hohlraums is dominated by the hydrodynamics of the expanding, low density, high-Z (gold or uranium) "bubble," which occurs where the intense outer cone laser beams hit the high-Z hohlraum wall. We developed a simple model which states that the implosion symmetry becomes more oblate as the high-Z bubble size becomes large compared to the hohlraum radius or the capsule size becomes large compared to the hohlraum radius. This simple model captures the trends that we see in data that span much of the parameter space of interest for NIF ignition experiments. We are now using this model as a constraint on new designs for experiments on the NIF.

A mathematical analysis of the ABCD criteria for diagnosing malignant melanoma

NASA Astrophysics Data System (ADS)

Lee, Hyunju; Kwon, Kiwoon

2017-03-01

The medical community currently employs the ABCD (asymmetry, border irregularity, color variegation, and diameter of the lesion) criteria in the early diagnosis of a malignant melanoma. Although many image segmentation and classification methods are used to analyze the ABCD criteria, it is rare to see a study containing mathematical justification of the parameters that are used to quantify the ABCD criteria. In this paper, we suggest new parameters to assess asymmetry, border irregularity, and color variegation, and explain the mathematical meaning of the parameters. The suggested parameters are then tested with 24 skin samples. The parameters suggested for the 24 skin samples are displayed in three-dimensional coordinates and are compared to those presented in other studies (Ercal et al 1994 IEEE Trans. Biomed. Eng. 41 837-45, Cheerla and Frazier 2014 Int. J. Innovative Res. Sci., Eng. Technol. 3 9164-83) in terms of Pearson correlation coefficient and classification accuracy in determining the malignancy of the lesions.

Amplification of terahertz pulses in gases beyond thermodynamic equilibrium

NASA Astrophysics Data System (ADS)

Schwaab, G. W.; Schroeck, K.; Havenith, M.

2007-03-01

In Ebbinghaus [Plasma Sources Sci. Technol. 15, 72 (2006)] we reported terahertz time-domain spectroscopy in a plasma at low pressure, we observed a simultaneous absorption and amplification process within each single rotational transition. Here we show that this observation is a direct consequence of the short interaction time of the pulsed terahertz radiation with the plasma, which is shorter than the average collision time between the molecules. Thus, during the measurement time the molecular states may be considered entangled. Solution of the time-dependent Schrödinger equation yields a linear term that may be neglected for long observation times, large frequencies, or nonentangled states. We determine the restrictions for the observation of this effect and calculate the spectrum of a simple diatomic molecule. Using this model we are able to explain the spectral features showing a change from emission to absorption as observed previously. In addition we find that the amplification and absorption do not follow the typical Lambert-Beer exponential law but an approximate square law.

Phenomenological scattering-rate model for the simulation of the current density and emission power in mid-infrared quantum cascade lasers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurlov, S. S.; Institute of Semiconductor Physics, National Academy of Sciences, pr. Nauki 45, Kiev-03028; Flores, Y. V.

2016-04-07

A phenomenological scattering-rate model introduced for terahertz quantum cascade lasers (QCLs) [Schrottke et al., Semicond. Sci. Technol. 25, 045025 (2010)] is extended to mid-infrared (MIR) QCLs by including the energy dependence of the intersubband scattering rates for energies higher than the longitudinal optical phonon energy. This energy dependence is obtained from a phenomenological fit of the intersubband scattering rates based on published lifetimes of a number of MIR QCLs. In our approach, the total intersubband scattering rate is written as the product of the exchange integral for the squared moduli of the envelope functions and a phenomenological factor that dependsmore » only on the transition energy. Using the model to calculate scattering rates and imposing periodical boundary conditions on the current density, we find a good agreement with low-temperature data for current-voltage, power-current, and energy-photon flux characteristics for a QCL emitting at 5.2 μm.« less

Numerical Simulation for Predicting Fatigue Damage Progress in Notched CFRP Laminates by Using Cohesive Elements

NASA Astrophysics Data System (ADS)

Okabe, Tomonaga; Yashiro, Shigeki

This study proposes the cohesive zone model (CZM) for predicting fatigue damage growth in notched carbon-fiber-reinforced composite plastic (CFRP) cross-ply laminates. In this model, damage growth in the fracture process of cohesive elements due to cyclic loading is represented by the conventional damage mechanics model. We preliminarily investigated whether this model can appropriately express fatigue damage growth for a circular crack embedded in isotropic solid material. This investigation demonstrated that this model could reproduce the results with the well-established fracture mechanics model plus the Paris' law by tuning adjustable parameters. We then numerically investigated the damage process in notched CFRP cross-ply laminates under tensile cyclic loading and compared the predicted damage patterns with those in experiments reported by Spearing et al. (Compos. Sci. Technol. 1992). The predicted damage patterns agreed with the experiment results, which exhibited the extension of multiple types of damage (e.g., splits, transverse cracks and delaminations) near the notches.

Summary: Update to ASTM guide E 1523 to charge control and charge referencing techniques in x-ray photoelectron spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baer, D.R.

2005-05-01

An updated version of the American Society for Testing and Materials (ASTM) guide E 1523 to the methods to charge control and charge referencing techniques in x-ray photoelectron spectroscopy has been released by ASTM [Annual Book of ASTM Standards Surface Analysis (American Society for Testing and Materials, West Conshohocken, PA, 2004), Vol. 03.06]. The guide is meant to acquaint x-ray photoelectron spectroscopy (XPS) users with the various charge control and charge referencing techniques that are and have been used in the acquisition and interpretation of XPS data from surfaces of insulating specimens. The current guide has been expanded to includemore » new references as well as recommendations for reporting information on charge control and charge referencing. The previous version of the document had been published in 1997 [D. R. Baer and K. D. Bomben, J. Vac. Sci. Technol. A 16, 754 (1998)].« less

Responding to Students' Learning Preferences in Chemistry

NASA Astrophysics Data System (ADS)

Lewthwaite, Brian; Wiebe, Rick

2014-04-01

This paper reports on a teacher's and his students' responsiveness to a new tetrahedral-oriented (Mahaffy in J Chem Educ 83(1):49-55, 2006) curriculum requiring more discursive classroom practices in the teaching of chemistry. In this instrumental case study, we identify the intentions of this learner-centered curriculum and a teacher's development in response to this curriculum. We also explore the tensions this teacher experiences as students subsequently respond to his adjusted teaching. We use a Chemistry Teacher Inventory (Lewthwaite and Wiebe in Res Sci Educ 40(11):667-689, 2011; Lewthwaite and Wiebe in Can J Math Sci Technol Educ 12(1):36-61, 2012; Lewthwaite in Chem Educ Res Pract. doi:10.1039/C3RP00122A, 2014) to assist the teacher in monitoring how he teaches and how he would like to improve his teaching. We also use a student form of the instrument, the Chemistry Classroom Inventory and Classroom Observation Protocol (Lewthwaite and Wiebe 2011) to verify the teacher's teaching and perception of student preferences for his teaching especially in terms of the discursive processes the curriculum encourages. By so doing, the teacher is able to use both sets of data as a foundation for critical reflection and work towards resolution of the incongruence in data arising from students' preferred learning orientations and his teaching aspirations. Implications of this study in regards to the authority of students' voice in triggering teachers' pedagogical change and the adjustments in `teachering' and `studenting' required by such curricula are considered.

Label-free carbon particulates detection in bio (medical) settings (Conference Presentation)

NASA Astrophysics Data System (ADS)

Steuwe, Christian; Bové, Hannelore; vandeVen, Martin J.; Ameloot, Marcel; Roeffaers, Maarten B. J.

2017-02-01

The adverse health effects of particulate matter exposure are a generally accepted concern. Dramatic statistical figures suggest that fine dust is a main environmental risk in Europe and can be held accountable for hundreds of thousands of deaths per year [1]. Locating and tracking these nanometer sized particles, however, is not straight forward: In epidemiological and toxicology research only measurements based on labels [2] such as radionuclide markers have been applied. In this paper we present a direct, label-free optical contrast mechanism to detect carbon nanoparticles immersed in aqueous environments [3]. The virtue of this technique is its ability to perform in body fluids such as urine but also in cells and tissues. The mechanism is based on white light (WL) generation upon illumination with femtosecond pulsed near-infrared and is therefore non-incandescence related. We demonstrate the technique in various biological settings with dry and suspended carbon black particles (CB), a widely used model compound for soot [4]. Our approach allows for the unequivocal localization of CB alongside of common fluorophores and markers and can be performed on multiphoton laser-scanning microscopy platforms, a system commonly available in research laboratories. [1] European Environment Agency (2015). Press release. [2] Kong et al. Int. J. Mol. Sci. 2013, 14, (11), 22529-22543 [3] Bové and Steuwe et al. Nano letters, 2016, (16) , pages 3173-3178 [4] Arnal et al. Combust. Sci. Technol. 2012, 184, (7-8), 1191-1206.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metzler, Dominik; Li, Chen; Engelmann, Sebastian

With the increasing interest in establishing directional etching methods capable of atomic scale resolution for fabricating highly scaled electronic devices, the need for development and characterization of atomic layer etching (ALE) processes, or generally etch processes with atomic layer precision, is growing. In this work, a flux-controlled cyclic plasma process is used for etching of SiO 2 and Si at the Angstrom-level. This is based on steady-state Ar plasma, with periodic, precise injection of a fluorocarbon (FC) precursor (C 4F 8 and CHF 3), and synchronized, plasma-based Ar+ ion bombardment [D. Metzler et al., J Vac Sci Technol A 32,more » 020603 (2014), and D. Metzler et al., J Vac Sci Technol A 34, 01B101 (2016)]. For low energy Ar+ ion bombardment conditions, physical sputter rates are minimized, whereas material can be etched when FC reactants are present at the surface. This cyclic approach offers a large parameter space for process optimization. Etch depth per cycle, removal rates, and self-limitation of removal, along with material dependence of these aspects, were examined as a function of FC surface coverage, ion energy, and etch step length using in situ real time ellipsometry. The deposited FC thickness per cycle is found to have a strong impact on etch depth per cycle of SiO 2 and Si, but is limited with regard to control over material etching selectivity. Ion energy over the 20 to 30 eV range strongly impacts material selectivity. The choice of precursor can have a significant impact on the surface chemistry and chemically enhanced etching. CHF 3 has a lower FC deposition yield for both SiO 2 and Si, and also exhibits a strong substrate dependence of FC deposition yield, in contrast to C4F 8. The thickness of deposited FC layers using CHF 3 is found to be greater for Si than for SiO 2. X-ray photoelectron spectroscopy was used to study surface chemistry. When thicker FC films of 11 Å are employed, strong changes of FC film chemistry during a cycle are seen whereas the chemical state of the substrate varies much less. On the other hand, for FC film deposition of 5 Å for each cycle, strong substrate surface chemical changes are seen during an etching cycle. The nature of this cyclic etching with periodic deposition of thin FC films differs significantly from conventional etching with steady-state FC layers since surface conditions change strongly throughout each cycle.« less

A thermal desorption mass spectrometer for freshly nucleated secondary aerosol particles

NASA Astrophysics Data System (ADS)

Held, A.; Gonser, S. G.

2012-04-01

Secondary aerosol formation in the atmosphere is observed in a large variety of locations worldwide, introducing new particles to the atmosphere which can grow to sizes relevant for health and climate effects of aerosols. The chemical reactions leading to atmospheric secondary aerosol formation are not yet fully understood. At the same time, analyzing the chemical composition of freshly nucleated particles is still a challenging task. We are currently finishing the development of a field portable aerosol mass spectrometer for nucleation particles with diameters smaller than 30 nm. This instrument consists of a custom-built aerosol sizing and collection unit coupled to a time-of-flight mass spectrometer (TOF-MS). The aerosol sizing and collection unit is composed of three major parts: (1) a unipolar corona aerosol charger, (2) a radial differential mobility analyzer (rDMA) for aerosol size separation, and (3) an electrostatic precipitator for aerosol collection. After collection, the aerosol sample is thermally desorbed, and the resulting gas sample is transferred to the TOF-MS for chemical analysis. The unipolar charger is based on corona discharge from carbon fibres (e.g. Han et al., 2008). This design allows efficient charging at voltages below 2 kV, thus eliminating the potential for ozone production which would interfere with the collected aerosol. With the current configuration the extrinsic charging efficiency for 20 nm particles is 32 %. The compact radial DMA similar to the design of Zhang et al. (1995) is optimized for a diameter range from 1 nm to 100 nm. Preliminary tests show that monodisperse aerosol samples (geometric standard deviation of 1.09) at 10 nm, 20 nm, and 30 nm can easily be separated from the ambient polydisperse aerosol population. Finally, the size-segregated aerosol sample is collected on a high-voltage biased metal filament. The collected sample is protected from contamination using a He sheath counterflow. Resistive heating of the filament allows temperature-controlled desorption of compounds of different volatility. We will present preliminary characterization experiments of the aerosol sizing and collection unit coupled to the mass spectrometer. Funding by the German Research Foundation (DFG) under grant DFG HE5214/3-1 is gratefully acknowledged. Han, B., Kim, H.J., Kim, Y.J., and Sioutas, C. (2008) Unipolar charging of ultrafine particles using carbon fiber ionizers. Aerosol Sci. Technol, 42, 793-800. Zhang, S.-H., Akutsu, Y., Russell, L.M., Flagan, R.C., and Seinfeld, J.H. (1995) Radial Differential Mobility Analyzer. Aerosol Sci. Technol, 23, 357-372.

Experimental investigation of concentration and stable isotopes signals during organic contaminants back diffusion

NASA Astrophysics Data System (ADS)

Jin, Biao; Nika, Chrysanthi-Elisabeth; Rolle, Massimo

2017-04-01

Back diffusion of organic contaminants is often the cause of groundwater plumes' persistence and can significantly hinder cleanup interventions [1, 2]. In this study we perform a high-resolution investigation of back diffusion in a well-controlled flow-through laboratory setup. We considered cis-dichloroethene (cis-DCE) as model contaminant and we investigated its back diffusion from an impermeable source into a permeable saturated layer, in which advection-dominated flow conditions were established. We used concentration and stable chlorine isotope measurements to investigate the plumes originated by cis-DCE back diffusion in a series of flow-through experiments, performed in porous media with different hydraulic conductivity and at different seepage velocities (i.e., 0.4, 0.8 and 1.2 m/day). A two-centimeter thick agarose gel layer was placed at the bottom of the setup to simulate the source of cis-DCE back diffusion from an impervious layer. Intensive sampling (>1000 measurements) was carried out, including the withdrawal of aqueous samples at closely spaced (1 cm) outlet ports, as well as the high-resolution sampling of the source zone (agarose gel) at the end of each experiment. The transient behavior of the plumes originated by back diffusion was investigated by sampling the outlet ports at regular intervals in the experiments, each run for a total time corresponding to 15 pore volumes. The high-resolution sampling allowed us to resolve the spatial and temporal evolution of concentration and stable isotope gradients in the flow-through setup. In particular, steep concentration and stable isotope gradients were observed at the outlet. Lateral isotope gradients corresponding to chlorine isotope fractionation up to 20‰ were induced by cis-DCE back diffusion and subsequent advection-dominated transport in all flow-through experiments. A numerical modeling approach, tracking individually all chlorine isotopologues, based on the accurate parameterization of local dispersion, as well as on the values of aqueous diffusion coefficients and diffusion-induced isotope fractionation from a previous study [3], provided a good agreement with the experimental data. References [1] Mackay, D. M.; Cherry, J. A. Groundwater contamination: Pumpand-treat remediation. Environ. Sci. Technol. 1989, 23, 630-636. [2] Parker, B. L.; Chapman, S. W.; Guilbeault, M. A. Plume persistence caused by back diffusion from thin clay layers in a sand aquifer following TCE source-zone hydraulic isolation. J. Contam. Hydrol. 2008, 102, 19-19. [3] Jin, B., Rolle, M., Li, T., Haderlein, S.B., 2014. Diffusive fractionation of BTEX and chlorinated ethenes in aqueous solution: quantification of spatial isotope gradients. Environ. Sci. Technol. 48, 6141-6150.

Characterizing fluorocarbon assisted atomic layer etching of Si using cyclic Ar/C4F8 and Ar/CHF3 plasma

NASA Astrophysics Data System (ADS)

Metzler, Dominik; Li, Chen; Engelmann, Sebastian; Bruce, Robert L.; Joseph, Eric A.; Oehrlein, Gottlieb S.

2017-02-01

With the increasing interest in establishing directional etching methods capable of atomic scale resolution for fabricating highly scaled electronic devices, the need for development and characterization of atomic layer etching processes, or generally etch processes with atomic layer precision, is growing. In this work, a flux-controlled cyclic plasma process is used for etching of SiO2 and Si at the Angstrom-level. This is based on steady-state Ar plasma, with periodic, precise injection of a fluorocarbon (FC) precursor (C4F8 and CHF3) and synchronized, plasma-based Ar+ ion bombardment [D. Metzler et al., J. Vac. Sci. Technol., A 32, 020603 (2014) and D. Metzler et al., J. Vac. Sci. Technol., A 34, 01B101 (2016)]. For low energy Ar+ ion bombardment conditions, physical sputter rates are minimized, whereas material can be etched when FC reactants are present at the surface. This cyclic approach offers a large parameter space for process optimization. Etch depth per cycle, removal rates, and self-limitation of removal, along with material dependence of these aspects, were examined as a function of FC surface coverage, ion energy, and etch step length using in situ real time ellipsometry. The deposited FC thickness per cycle is found to have a strong impact on etch depth per cycle of SiO2 and Si but is limited with regard to control over material etching selectivity. Ion energy over the 20-30 eV range strongly impacts material selectivity. The choice of precursor can have a significant impact on the surface chemistry and chemically enhanced etching. CHF3 has a lower FC deposition yield for both SiO2 and Si and also exhibits a strong substrate dependence of FC deposition yield, in contrast to C4F8. The thickness of deposited FC layers using CHF3 is found to be greater for Si than for SiO2. X-ray photoelectron spectroscopy was used to study surface chemistry. When thicker FC films of 11 Å are employed, strong changes of FC film chemistry during a cycle are seen whereas the chemical state of the substrate varies much less. On the other hand, for FC film deposition of 5 Å for each cycle, strong substrate surface chemical changes are seen during an etching cycle. The nature of this cyclic etching with periodic deposition of thin FC films differs significantly from conventional etching with steady-state FC layers since surface conditions change strongly throughout each cycle.

On the modified Tabor parameter for the JKR-DMT transition in the presence of a liquid meniscus.

PubMed

Xu, Dewei; Liechti, Kenneth M; Ravi-Chandar, K

2007-11-15

The JKR, DMT, Maugis models and Tabor parameter for contact under normal loading have been developed based mainly on solid-solid (van der Waals) interactions. In this case, the characteristic length scale for the adhesive forces in the Tabor parameter is the equilibrium interatomic spacing. However, for contact in humid environments, where a liquid meniscus may be present, capillary forces with a longer force range related to the Kelvin radius dominate. Fogden and White [J. Colloid Interface Sci. 138 (1990) 414] introduced a parameter that includes the Kelvin radius for the JKR-DMT transition. This topic was also addressed by Maugis and Gauthier-Manuel [J. Adhes. Sci. Technol. 8 (1994) 1311] who included capillary effects within the frame work that Maugis had previously established. The parameters introduced by Fogden and White and Maugis and Gauthier-Manuel can be viewed as a modified Tabor parameter for the JKR-DMT transition. In the present work, the Kelvin equation linking the Kelvin radius and the relative humidity was explicitly included in the modified Tabor parameter. This provided a quantitative description of the JKR-DMT transition in terms of the relative humidity. This parameter was examined via load and contact radius measurements, where the latter were obtained from Bowden and Tabor's assumption that the friction force f=tauA. The friction experiments were conducted at two different humidity levels using a newly-developed mesoscale friction tester (MFT), which provides a very wide range of contact radii. The modified Tabor parameter was used to reexamine data from pull-off experiments in water and cyclohexane vapor environments [L.R. Fisher, J.N. Israelachvili, Colloids Surf. 3 (1981) 303 and H.K. Christenson, J. Colloid Interface Sci. 121 (1988) 170]. Finally, guidelines are presented for the appropriate choice of contact mechanics models to be used in interpreting data from SFA and AFM experiments in humid environments.

Evaluation of Microlon and Technol-G : final report.

DOT National Transportation Integrated Search

1982-01-01

An evaluation was made of the cost-effectiveness of the automotive products Microlon, an engine treatment consisting of Teflon suspended in a solvent, and Technol-G, a gasoline treating additive consisting of a blend of aliphatic and aromatic distill...

Current profile redistribution driven by neutral beam injection in a reversed-field pinch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parke, E.; Department of Physics, University of Wisconsin-Madison 1150 University Ave., Madison, Wisconsin 53706; Anderson, J. K.

2016-05-15

Neutral beam injection in reversed-field pinch (RFP) plasmas on the Madison Symmetric Torus [Dexter et al., Fusion Sci. Technol. 19, 131 (1991)] drives current redistribution with increased on-axis current density but negligible net current drive. Internal fluctuations correlated with tearing modes are observed on multiple diagnostics; the behavior of tearing mode correlated structures is consistent with flattening of the safety factor profile. The first application of a parametrized model for island flattening to temperature fluctuations in an RFP allows inferrence of rational surface locations for multiple tearing modes. The m = 1, n = 6 mode is observed to shift inward by 1.1 ± 0.6 cm withmore » neutral beam injection. Tearing mode rational surface measurements provide a strong constraint for equilibrium reconstruction, with an estimated reduction of q{sub 0} by 5% and an increase in on-axis current density of 8% ± 5%. The inferred on-axis current drive is consistent with estimates of fast ion density using TRANSP [Goldston et al., J. Comput. Phys. 43, 61 (1981)].« less

Detection of concealed explosives at stand-off distances using wide band swept millimetre waves

NASA Astrophysics Data System (ADS)

Andrews, David A.; Rezgui, Nacer D.; Smith, Sarah E.; Bowring, Nicholas; Southgate, Matthew; Baker, John G.

2008-10-01

Millimetre waves in the range 20 to 110 GHz have been used to detect the presence and thickness of dielectric materials, such as explosives, by measuring the frequency response of the return signal. Interference between the reflected signals from the front and back surfaces of the dielectric provides a characteristic frequency variation in the return signal, which may be processed to yield its optical depth [Bowring et al, Meas. Sci. Technol. 19, 024004 (2008)]. The depth resolution depends on the sweep bandwidth, which is typically 10 to 30 GHz. By using super-heterodyne detection the range of the object can also be determined, which enables a signal from a target, such as a suicide bomber to be extracted from background clutter. Using millimetre wave optics only a small area of the target is illuminated at a time, thus reducing interference from different parts of a human target. Results are presented for simulated explosive materials with water or human backing at stand-off distances. A method of data analysis that involves pattern recognition enables effective differentiation of target types.

PUBLISHER'S ANNOUNCEMENT: Important changes for 2008

NASA Astrophysics Data System (ADS)

Bedrock, Claire

2008-01-01

Having reviewed several aspects of IOP journal content, both in print and online, we have made some changes for 2008, some of which affect Semiconductor Science and Technology. Article numbering In common with many other IOP journals, Semiconductor Science and Technology has moved from sequential page numbering to an article numbering system. Articles will continue to be published on the web in advance of the print edition. The bibliographic citation will change slightly. Articles should be referenced using the six-digit article number in place of a page number, and this number must include any leading zeros. For instance: Surname X and Surname Y 2008 Semicond. Sci. Technol. 18 015003 A new look and feel Semiconductor Science and Technology has changed from European A4 format to a slightly smaller size, closer to US Letter format, and we have taken the opportunity to refresh the cover, in order to modernise the typography, and create a consistent look and feel across our range of publications. If you have any questions or comments about any of these changes, please contact us at sst@iop.org

Resistive sensitivity functions for van der Pauw astroid and rounded crosses and cloverleafs

NASA Astrophysics Data System (ADS)

Koon, Daniel; Hansen, Ole

2014-03-01

We have calculated the sensitivity of van der Pauw resistances to local resistive variations for circular, square and astroid discs of infinitesimal thickness, as well as for the families of rounded crosses and cloverleafs, as a function of specimen parameters, using the direct formulas of our recent paper (Koon et al. 2013 J. Appl. Phys.114 163710) applied to ``reciprocally dual geometries'' (swapped Dirichlet and Neumann boundary conditions) described by Mareš et al.(2012 Meas. Sci. Technol. 23 045004). These results show that (a) the product of any such sensitivity function times differential area, and thus (b) the ratio of any two sensitivities, is invariant under conformal mapping, allowing for the pointwise determination of the conformal mapping function. The family of rounded crosses, which is bounded in parameter space by the square, the astroid and an ``infinitesimally thin'' cross, seems to represent the best geometry for focusing transport measurements on the center of the specimen while minimizing errors due to edge- or contact-effects. Made possible by an SLU Faculty research grant.

Theory of electron g-tensor in bulk and quantum-well semiconductors

NASA Astrophysics Data System (ADS)

Lau, Wayne H.; Flatte', Michael E.

2004-03-01

We present quantitative calculations for the electron g-tensors in bulk and quantum-well semiconductors based on a generalized P.p envelope function theory solved in a fourteen-band restricted basis set. The dependences of g-tensor on structure, magnetic field, carrier density, temperature, and spin polarization have been explored and will be described. It is found that at temperatures of a few Kelvin and fields of a few Tesla, the g-tensors for bulk semiconductors develop quasi-steplike dependences on carrier density or magnetic field due to magnetic quantization, and this effect is even more pronounced in quantum-well semiconductors due to the additional electric quantization along the growth direction. The influence of quantum confinement on the electron g-tensors in QWs is studied by examining the dependence of electron g-tensors on well width. Excellent agreement between these calculated electron g-tensors and measurements [1-2] is found for GaAs/AlGaAs QWs. This work was supported by DARPA/ARO. [1] A. Malinowski and R. T. Harley, Phys. Rev. B 62, 2051 (2000);[2] Le Jeune et al., Semicond. Sci. Technol. 12, 380 (1997).

Characterizing Fluorocarbon Assisted Atomic Layer Etching of Si Using Cyclic Ar/C 4F 8 and Ar/CHF 3 Plasma

DOE PAGES

Metzler, Dominik; Li, Chen; Engelmann, Sebastian; ...

2016-09-08

With the increasing interest in establishing directional etching methods capable of atomic scale resolution for fabricating highly scaled electronic devices, the need for development and characterization of atomic layer etching (ALE) processes, or generally etch processes with atomic layer precision, is growing. In this work, a flux-controlled cyclic plasma process is used for etching of SiO 2 and Si at the Angstrom-level. This is based on steady-state Ar plasma, with periodic, precise injection of a fluorocarbon (FC) precursor (C 4F 8 and CHF 3), and synchronized, plasma-based Ar+ ion bombardment [D. Metzler et al., J Vac Sci Technol A 32,more » 020603 (2014), and D. Metzler et al., J Vac Sci Technol A 34, 01B101 (2016)]. For low energy Ar+ ion bombardment conditions, physical sputter rates are minimized, whereas material can be etched when FC reactants are present at the surface. This cyclic approach offers a large parameter space for process optimization. Etch depth per cycle, removal rates, and self-limitation of removal, along with material dependence of these aspects, were examined as a function of FC surface coverage, ion energy, and etch step length using in situ real time ellipsometry. The deposited FC thickness per cycle is found to have a strong impact on etch depth per cycle of SiO 2 and Si, but is limited with regard to control over material etching selectivity. Ion energy over the 20 to 30 eV range strongly impacts material selectivity. The choice of precursor can have a significant impact on the surface chemistry and chemically enhanced etching. CHF 3 has a lower FC deposition yield for both SiO 2 and Si, and also exhibits a strong substrate dependence of FC deposition yield, in contrast to C4F 8. The thickness of deposited FC layers using CHF 3 is found to be greater for Si than for SiO 2. X-ray photoelectron spectroscopy was used to study surface chemistry. When thicker FC films of 11 Å are employed, strong changes of FC film chemistry during a cycle are seen whereas the chemical state of the substrate varies much less. On the other hand, for FC film deposition of 5 Å for each cycle, strong substrate surface chemical changes are seen during an etching cycle. The nature of this cyclic etching with periodic deposition of thin FC films differs significantly from conventional etching with steady-state FC layers since surface conditions change strongly throughout each cycle.« less

Reactive Gaseous Mercury Formation Over The North Pacific Ocean: Influence Of Environmental Parameters On Elemental Mercury Oxidation In The Marine Boundary Layer

NASA Astrophysics Data System (ADS)

Laurier, F. J.

2002-12-01

Global mercury models have identified wet and dry particle deposition and evasion of dissolved gaseous mercury from the ocean and from land as key controls over global mercury cycling (1,2). Recent ocean studies (3,4) however, have indicated that estimated mercury evasion rates from the ocean substantially exceed estimated deposition. Oxidized reactive gaseous mercury species (RGHg) are now known to play a major role in the global mercury cycle (2,5). RGHg species are water-soluble, exhibit a much shorter atmospheric lifetime than elemental mercury, and contribute to a large extent to atmospheric mercury deposition (2,3,6). Although recent global mercury models have accounted for the dry deposition of RGHg derived from point source emissions (6,7), the formation and deposition of RGHg in remote areas have not been incorporated. We suggest that the oxidation of elemental mercury over the ocean, by gas phase or heterogeneous reactions, is an important part the global mercury cycle. In agreement with previous studies (3,8,9) our recent data from atmospheric collections over the North Pacific Ocean support the notion of enhanced oxidation in the marine boundary layer. Our results show an inverse correlation between RGHg production and ozone, and a diurnal cycle with highest concentrations during periods of highest UV irradiation. In addition, the relationship between RGHg and other parameters measured during the cruise will be discussed. Our results clearly show that RGHg deposition to the ocean must be an important Hg source, and a crucial part of the global Hg cycle. (1) Mason R.P., Fitzgerald W.F., and Morel F.M.M. (1994), The biogeochemical cycling of elemental mercury: Anthropogenic influences, Geochim. Cosmochim. Acta, 58: 3191-3198 (2) Shia R.L., Seigneur C., Pai P., Ko M., and Sze N.-D. (1999), Global simulation of atmospheric mercury concentrations and deposition fluxes, J. Geophy. Res., 104(D19), 23, 747-23, 760 (3) Mason, R.P., Lawson N.M., and Sheu G.-R. (2001), Mercury in the Atlantic Ocean: factors controlling air-sea exchange of mercury and its distribution in the upper water, Deep-Sea Res. II, 2829-2853 (4) Lamborg, C.H., Rolfus K.R., and Fitzgerald W.F. (1999), The atmospheric cycling and air-sea exchange of mercury species in the south and equatorial Atlantic Ocean, Deep-Sea Res. II, 957-977 (5) Lindberg S.E., Brooks S., Lin C.-J., Scott K. J., Landis M. S., Stevens R.K., Goodsite M., and Richter A. (2002), Dynamic oxidation of gaseous mercury in the arctic troposphere at polar sunrise, Environ. Sci. Technol., 1245-1256 (6) Bullock O.R. (2000), Modeling assessment of transport and deposition patterns of anthropogenic mercury air emissions in the United States and Canada, Sci Total Environ., 259(1-3), 145-157 (7) Xu X., Yang X., Miller d.R., Helble J.J., and Carley R.J. (2000), a regional scale modelling study of atmospheric transport and formation of mercury. II. Simulation results for the northeast United states, Atmos. Environ., 34: 4945-4955 (8) Sheu G.-R. (2001), Speciation and distribution of atmospheric mercury: Significance of reactive gaseous mercury in the global mercury cycle. PhD. thesis, University of Maryland, College park, pp. 170 (9) Guentzel J.L., Landing W.M., Gill G.A., and Pollman C.D. (2001), Processes influencing rainfall deposition of mercury in Florida, Environ. Sci. Technol., 35: 863-873

Examining the relationship between mercury and organic matter in lake sediments along a latitudinal transect in subarctic Canada

NASA Astrophysics Data System (ADS)

Galloway, Jennifer M.; Sanei, Hamed; Parsons, Michael; Swindles, Graeme T.; Macumber, Andrew L.; Patterson, R. Timothy; Palmer, Michael; Falck, Hendrik

2016-04-01

The accumulation of Hg in aquatic environments at both high and low latitudes can be controlled by organic matter through algal scavenging, thus complicating the interpretation of historical Hg profiles in lake sediments1,2,3. However, other recent studies suggest that algal scavenging is not important in governing Hg flux to sediments4, in some cases because of dilution by inorganic materials5. This study examines relationships between Hg and organic matter (OM) in over 100 lakes located between 60.5 and 65.4 °N and crossing the latitudinal tree-line in subarctic Canada. The latitudinal gradient approach in our study offers an opportunity to better understand climate and environmental controls on OM accumulation and its role in influencing Hg deposition in subarctic lacustrine environments. We used Rock Eval 6 pyrolysis to determine total organic carbon (TOC%), S1 (soluble OM consisting of degradable lipids and algal pigments), S2 (OM derived from highly aliphatic biomacromolecule structure of algal cell walls), and S3 (OM dominated by carbohydrates, lignins, and plant materials). Total Hg in sediments was measured using thermal decomposition, amalgamation, and atomic absorption spectrophotometry. In these lake sediments, S2 composes the majority of TOC (Pearson's r = 0.978, p<0.01) and is negatively correlated with latitude (r = -0.475, p<0.01). S1 and TOC are also negatively correlated with latitude (r = -0.237 and -0.452, respectively, p<0.01). These associations are interpreted to reflect less autochthonous OM production and proportionally higher allochthonous OM input to more northern lakes (oxygen index vs. latitude r = 0.371, p<0.01). Similar to previous studies1,2,3 Mercury displays a significant positive association with S1 (r = 0.556, p<0.01), S2 (r = 0.518, p<0.01), and TOC (r = 0.504, p<0.01),supporting the hypothesis that OM influences Hg accumulation in subarctic lake sediments. References 1Sanei, H., Goodarzi, F. 2006. Relationship between organic matter and mercury in recent lake sediment: the physical-geochemical aspects. Appl Geochem 21: 1900-12. 2Outridge, P.M., Sanei, H., Stern, G.A., Hamilton, P.B., Goodarzi, F. 2007. Evidence for control of mercury accumulation rates in Canadian high Arctic lake sediments by variations of aquatic primary productivity. Environ Sci Technol 41: 5259-65. 3Wu, F., Zu, L., Liao, H., Guo, F., Zhao, X., Giesy, J. 2013. Relationship between mercury and organic carbon in sediment cores from Lakes Qinghai and Chenghai, China. J Soils Sediments 13: 1084-1092.4Kirk, J.L., Muir, D.C.G., Antoniades, D., Douglas, M.S.V., Evans, M.S., Jackson, T.A., Kling, H., Lamoureux, S., Lim, D.S.S., Pienitz, R., Smol, J.P., Stewart, K., Wang, X., Yang, F. 2011. Response to comment on climate change and mercury accumulation in Canadian high and subarctic lakes. Environ Sci Technol 45: 6705-06.5Deison, R., Smol, J.P., Kokelj, S.V., Pisaric, M.F.J., Kimpe, L.E., Poulain, A.J., Sanei, H., Theinpoint, J.R., Blais, J.M. 2012. Spatial and temporal assessment of mercury and organic matter in thermokarst affected lakes of the Mackenzie Delta Uplands, NT, Canada. Environ Sci Tech 46: 8748-55.

Nonlinear Polarization Conversion using Microring Resonators

DTIC Science & Technology

2007-06-08

Office MURI grant W911NF-04-01-0203. References 1. B. E. Little and S. T. Chu, Opt. Photon. News 11(11), 24 (2000). 2. G. Griffel , IEEE Photon. Technol...Thompson Learning, 1976). 15. S. J. Choi, K. Djordjev, S. J. Choi, P. D. Dapkus, W. Lin, G. Griffel , R. Menna, and J. Connoly, IEEE Photon. Technol. Lett

A high brightness source for nano-probe secondary ion mass spectrometry

NASA Astrophysics Data System (ADS)

Smith, N. S.; Tesch, P. P.; Martin, N. P.; Kinion, D. E.

2008-12-01

The two most prevalent ion source technologies in the field of surface analysis and surface machining are the Duoplasmatron and the liquid metal ion source (LMIS). There have been many efforts in this area of research to develop an alternative source [ S.K. Guharay, J. Orloff, M. Wada, IEEE Trans. Plasma Sci. 33 (6) (2005) 1911; N.S. Smith, W.P. Skoczylas, S.M. Kellogg, D.E. Kinion, P.P. Tesch, O. Sutherland, A. Aanesland, R.W. Boswell, J. Vac. Sci. Technol. B 24 (6) (2006) 2902-2906] with the brightness of a LMIS and yet the ability to produce secondary ion yield enhancing species such as oxygen. However, to date a viable alternative has not been realized. The high brightness and small virtual source size of the LMIS are advantageous for forming high resolution probes but a significant disadvantage when beam currents in excess of 100 nA are required, due to the effects of spherical aberration from the optical column. At these higher currents a source with a high angular intensity is optimal and in fact the relatively moderate brightness of today's plasma ion sources prevail in this operating regime. Both the LMIS and Duoplasmatron suffer from a large axial energy spread resulting in further limitations when forming focused beams at the chromatic limit where the figure-of-merit is inversely proportional to the square of the energy spread. Also, both of these ion sources operate with a very limited range of ion species. This article reviews some of the latest developments and some future potential in this area of instrument development. Here we present an approach to source development that could lead to oxygen ion beam SIMS imaging with 10 nm resolution, using a 'broad area' RF gas phase ion source.

Toward Understanding the Nature of a Partnership Between an Elementary Classroom Teacher and an Informal Science Educator

NASA Astrophysics Data System (ADS)

Weiland, Ingrid S.; Akerson, Valarie L.

2013-12-01

This study explored the nature of the relationship between a fifth-grade teacher and an informal science educator as they planned and implemented a life science unit in the classroom, and sought to define this relationship in order to gain insight into the roles of each educator. In addition, student learning as a result of instruction was assessed. Prior research has predominately examined relationships and roles of groups of teachers and informal educators in the museum setting (Tal et al. in Sci Educ 89:920-935, 2005; Tal and Steiner in Can J Sci Math Technol Educ 6:25-46, 2006; Tran 2007). The current study utilized case study methodology to examine one relationship (between two educators) in more depth and in a different setting—an elementary classroom. The relationship was defined through a framework of cooperation, coordination, and collaboration (Buck 1998; Intriligator 1986, 1992) containing eight dimensions. Findings suggest a relationship of coordination, which requires moderate commitment, risk, negotiation, and involvement, and examined the roles that each educator played and how they negotiated these roles. Consistent with previous examinations in science education of educator roles, the informal educator's role was to provide the students with expertise and resources not readily available to them. The roles played by the classroom teacher included classroom management, making connections to classroom activities and curricula, and clarifying concepts. Both educators' perceptions suggested they were at ease with their roles and that they felt these roles were critical to the optimization of the short time frames (1 h) the informal educator was in the classroom. Pre and posttest tests demonstrated students learned as a result of the programs.

Life cycle assessment of automobile/fuel options.

PubMed

MacLean, Heather L; Lave, Lester B

2003-12-01

We examine the possibilities for a "greener" car that would use less material and fuel, be less polluting, and would have a well-managed end-of-life. Light-duty vehicles are fundamental to our economy and will continue to be for the indefinite future. Any redesign to make these vehicles greener requires consumer acceptance. Consumer desires for large, powerful vehicles have been the major stumbling block in achieving a "green car". The other major barrier is inherent contradictions among social goals such as fuel economy, safety, low emissions of pollutants, and low emissions of greenhouse gases, which has led to conflicting regulations such as emissions regulations blocking sales of direct injection diesels in California, which would save fuel. In evaluating fuel/vehicle options with the potential to improve the greenness of cars [diesel (direct injection) and ethanol in internal combustion engines, battery-powered, gasoline hybrid electric, and hydrogen fuel cells], we find no option dominates the others on all dimensions. The principles of green design developed by Anastas and Zimmerman (Environ. Sci. Technol. 2003, 37, 94A-101A) and the use of a life cycle approach provide insights on the key sustainability issues associated with the various options.

Electrostatic turbulence intermittence driven by biasing in Texas Helimak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toufen, D. L.; Institute of Physics, University of São Paulo, 05315-970 São Paulo, São Paulo; Pereira, F. A. C.

We investigate changes in the intermittent sequence of bursts in the electrostatic turbulence due to imposed positive bias voltage applied to control the plasma radial electric field in Texas Helimak [K. W. Gentle and H. He, Plasma Sci. Technol. 10, 284 (2008)]—a toroidal plasma device with a one-dimensional equilibrium, magnetic curvature, and shear. We identify the burst characteristics by analyzing ion saturation current fluctuations collected in a large set of Langmuir probes. The number of bursts increase with positive biasing, giving rise to a long tailed skewed turbulence probability distribution function. The burst shape does not change much with themore » applied bias voltage, while their vertical velocity increases monotonically. For high values of bias voltage, the bursts propagate mainly in the vertical direction which is perpendicular to the radial density gradient and the toroidal magnetic field. Moreover, in contrast with the bursts in tokamaks, the burst velocity agrees with the phase velocity of the overall turbulence in both vertical and radial directions. For a fixed bias voltage, the time interval between bursts and their amplitudes follows exponential distributions. Altogether, these burst characteristics indicate that their production can be modelled by a stochastic process.« less

Numerical study of multiscale compaction-initiated detonation

NASA Astrophysics Data System (ADS)

Gambino, J. R.; Schwendeman, D. W.; Kapila, A. K.

2018-02-01

A multiscale model of heterogeneous condensed-phase explosives is examined computationally to determine the course of transient events following the application of a piston-driven stimulus. The model is a modified version of that introduced by Gonthier (Combust Sci Technol 175(9):1679-1709, 2003. https://doi.org/10.1080/00102200302373) in which the explosive is treated as a porous, compacting medium at the macro-scale and a collection of closely packed spherical grains capable of undergoing reaction and diffusive heat transfer at the meso-scale. A separate continuum description is ascribed to each scale, and the two scales are coupled together in an energetically consistent manner. Following piston-induced compaction, localized energy deposition at the sites of intergranular contact creates hot spots where reaction begins preferentially. Reaction progress at the macro-scale is determined by the spatial average of that at the grain scale. A parametric study shows that combustion at the macro-scale produces an unsteady detonation with a cyclical character, in which the lead shock loses strength and is overtaken by a stronger secondary shock generated in the partially reacted material behind it. The secondary shock in turn becomes the new lead shock and the process repeats itself.

Instability analysis of charges trapped in the oxide of metal-ultra thin oxide-semiconductor structures

NASA Astrophysics Data System (ADS)

Aziz, A.; Kassmi, K.; Maimouni, R.; Olivié, F.; Sarrabayrouse, G.; Martinez, A.

2005-09-01

In this paper, we present the theoretical and experimental results of the influence of a charge trapped in ultra-thin oxide of metal/ultra-thin oxide/semiconductor structures (MOS) on the I(Vg) current-voltage characteristics when the conduction is of the Fowler-Nordheim (FN) tunneling type. The charge, which is negative, is trapped near the cathode (metal/oxide interface) after constant current injection by the metal (Vg<0). Of particular interest is the influence on the Δ Vg(Vg) shift over the whole I(Vg) characteristic at high field (greater than the injection field (>12.5 MV/cm)). It is shown that the charge centroid varies linearly with respect to the voltage Vg. The behavior at low field (<12.5 MV/cm) is analyzed in référence A. Aziz, K. Kassmi, Ka. Kassmi, F. Olivié, Semicond. Sci. Technol. 19, 877 (2004) and considers that the trapped charge centroid is fixed. The results obtained make it possible to analyze the influence of the injected charge and the applied field on the centroid position of the trapped charge, and to highlight the charge instability in the ultra-thin oxide of MOS structures.

Impact of Propene on Secondary Organic Aerosol Formation from m-Xylene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Chen; Na, Kwangsam; Warren, Bethany

2007-10-15

Propene is widely used in smog chamber experiments to increase the hydroxyl radical (OH) level based on the assumption that the formation of secondary organic aerosol (SOA) from parent hydrocarbon is unaffected. A series ofm-xylene/NOx photooxidation experiments were conducted in the presence of propene in the University of California CECERT atmospheric chamber facility. The experimental data are compared with previousm-xylene/NOx photooxidation work performed in the same chamber facility in the absence of propene (Song et al. Environ. Sci. Technol. 2005, 39, 3143-3149). The result shows that, for similar initial conditions, experiments with propene have lower reaction rates of m-xylene thanmore » those without propene, which indicates that propene reduces OH in the system. Furthermore, experiments with propene showed more than 15% reduction in SOA yield compared to experiments in the absence of propene. Additional experiments ofm-xylene/NOx with CO showed similar trends of suppressing OH and SOA formation. These results indicate that SOA from m-xylene/NOx photooxidation is strongly dependent on the OH level present, which provides evidence for the critical role of OH in SOA formation from aromatic hydrocarbons.« less

Influence of kinetic effects on the resonance behavior of the Multipole Resonance Probe

NASA Astrophysics Data System (ADS)

Oberrath, Jens; Mussenbrock, Thomas; Brinkmann, Ralf Peter

2012-10-01

Active plasma resonance spectroscopy is a well known diagnostic method. Many concepts of this method are theoretically investigated and realized as a diagnostic tool. One of these tools is the multipole resonance probe (MRP) [1]. The application of such a probe in plasmas with pressures of only a few Pa raises the question whether kinetic effects have to be taken into account or not. To address this question a kinetic model is necessary. A general kinetic model for an electrostatic concept of active plasma resonance spectroscopy has already been presented by the authors [2]. This model can be used to describe the dynamical behavior of the MRP, which is interpretable as a special case of the general model. Neglecting electron-neutral collisions, this model can be solved analytically. Based on this solution we derive an approximated expression for the admittance of the system to investigate the influence of kinetic effects on the resonance behavior of the MRP. [4pt] [1] M. Lapke et al., Plasma Sources Sci. Technol. 20, 2011, 042001[0pt] [2] J. Oberrath et al., Proceedings of the 30th International Conference on Phenomena in Ionized Gases, 28th August - 2nd September, 2011

Improved Kolsky tension bar for high-rate tensile characterization of materials

NASA Astrophysics Data System (ADS)

Song, Bo; Antoun, Bonnie R.; Connelly, Kevin; Korellis, John; Lu, Wei-Yang

2011-04-01

A new Kolsky tension bar has been re-designed and developed at Sandia National Laboratories, CA. The new design uses the concept that a solid striker is fired to impact an end cap attached to the open end of the gun barrel to generate dynamic tensile loading. The gun barrel here serves as part of the loading device. The incident bar that is connected to the gun barrel and the transmission bar follow the design similar to the Kolsky compression bar. The bar supporting and aligning systems are the same as those in the Kolsky compression bar design described by Song et al (2009 Meas. Sci. Technol. 20 115701). Due to the connection complication among the gun barrel, bars and specimen, stress-wave propagation in the new Kolsky tension bar system is comprehensively analyzed. Based on the stress-wave analysis, the strain gage location on the incident bar needs to be carefully determined. A highly precise laser-beam measurement system is recommended to directly measure the displacement of the incident bar end. Dynamic tensile characterization of a 4330-V steel using this new Kolsky tension bar is presented as an example.

Comprehensive evaluation of the linear stability of Alfvén eigenmodes driven by alpha particles in an ITER baseline scenario

NASA Astrophysics Data System (ADS)

Figueiredo, A. C. A.; Rodrigues, P.; Borba, D.; Coelho, R.; Fazendeiro, L.; Ferreira, J.; Loureiro, N. F.; Nabais, F.; Pinches, S. D.; Polevoi, A. R.; Sharapov, S. E.

2016-07-01

The linear stability of Alfvén eigenmodes in the presence of fusion-born alpha particles is thoroughly assessed for two variants of an ITER baseline scenario, which differ significantly in their core and pedestal temperatures. A systematic approach based on CASTOR-K (Borba and Kerner 1999 J. Comput. Phys. 153 101; Nabais et al 2015 Plasma Sci. Technol. 17 89) is used that considers all possible eigenmodes for a given magnetic equilibrium and determines their growth rates due to alpha-particle drive and Landau damping on fuel ions, helium ashes and electrons. It is found that the fastest growing instabilities in the aforementioned ITER scenario are core-localized, low-shear toroidal Alfvén eigenmodes. The largest growth-rates occur in the scenario variant with higher core temperatures, which has the highest alpha-particle density and density gradient, for eigenmodes with toroidal mode numbers n≈ 30 . Although these eigenmodes suffer significant radiative damping, which is also evaluated, their growth rates remain larger than those of the most unstable eigenmodes found in the variant of the ITER baseline scenario with lower core temperatures, which have n≈ 15 and are not affected by radiative damping.

Tritium Decay Helium-3 Effects in Tungsten

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shimada, M.; Merrill, B. J.

2016-06-01

A critical challenge for long-term operation of ITER and beyond to a Demonstration reactor (DEMO) and future fusion reactor will be the development of plasma-facing components (PFCs) that demonstrate erosion resistance to steady-state/transient heat fluxes and intense neutral/ion particle fluxes under the extreme fusion nuclear environment, while at the same time minimizing in-vessel tritium inventories and permeation fluxes into the PFC’s coolant. Tritium will diffuse in bulk tungsten at elevated temperatures, and can be trapped in radiation-induced trap site (up to 1 at. % T/W) in tungsten [1,2]. Tritium decay into helium-3 may also play a major role in microstructuralmore » evolution (e.g. helium embrittlement) in tungsten due to relatively low helium-4 production (e.g. He/dpa ratio of 0.4-0.7 appm [3]) in tungsten. Tritium-decay helium-3 effect on tungsten is hardly understood, and its database is very limited. Two tungsten samples (99.99 at. % purity from A.L.M.T. Co., Japan) were exposed to high flux (ion flux of 1.0x1022 m-2s-1 and ion fluence of 1.0x1026 m-2) 0.5%T2/D2 plasma at two different temperatures (200, and 500°C) in Tritium Plasma Experiment (TPE) at Idaho National Laboratory. Tritium implanted samples were stored at ambient temperature in air for more than 3 years to investigate tritium decay helium-3 effect in tungsten. The tritium distributions on plasma-exposed was monitored by a tritium imaging plate technique during storage period [4]. Thermal desorption spectroscopy was performed with a ramp rate of 10°C/min up to 900°C to outgas residual deuterium and tritium but keep helium-3 in tungsten. These helium-3 implanted samples were exposed to deuterium plasma in TPE to investigate helium-3 effect on deuterium behavior in tungsten. The results show that tritium surface concentration in 200°C sample decreased to 30 %, but tritium surface concentration in 500°C sample did not alter over the 3 years storage period, indicating possible tritium retention in helium-3 bubble. This paper reports the initial experimental observation of tritium-decay helium-3 in tungsten exposed to deuterium/tritium plasma along with electron microscope analysis and also discusses a Tritium Migration Analysis Program (TMAP) analysis of tritium-decay helium-3 effects on tritium retention in tungsten for DEMO and future fusion reactor. [1] Y. Hatano, et.al., Nucl. Fusion 53 (2013) 073006 [2] M. Shimada, et.al., Nucl. Fusion 55 (2015) 013008 [3] M. Sawan, Fus. Sci. Technol. 66 (2014) 272 [4] T. Otsuka, Fus. Sci. Technol. 60 (2011) 1539 This work was prepared for the U.S. Department of Energy, Office of Fusion Energy Sciences, under the DOE Idaho Field Office contract number DE-AC07-05ID14517.« less

Sample-morphology effects on x-ray photoelectron peak intensities. III. Simulated spectra of model core–shell nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powell, Cedric J., E-mail: cedric.powell@nist.gov; Chudzicki, Maksymilian; Werner, Wolfgang S. M.

2015-09-15

The National Institute of Standards and Technology database for the simulation of electron spectra for surface analysis has been used to simulate Cu 2p photoelectron spectra for four types of spherical copper–gold nanoparticles (NPs). These simulations were made to extend the work of Tougaard [J. Vac. Sci. Technol. A 14, 1415 (1996)] and of Powell et al. [J. Vac. Sci. Technol. A 31, 021402 (2013)] who performed similar simulations for four types of planar copper–gold films. The Cu 2p spectra for the NPs were compared and contrasted with analogous results for the planar films and the effects of elastic scatteringmore » were investigated. The new simulations were made for a monolayer of three types of Cu/Au core–shell NPs on a Si substrate: (1) an Au shell of variable thickness on a Cu core with diameters of 0.5, 1.0, 2.0, 5.0, and 10.0 nm; (2) a Cu shell of variable thickness on an Au core with diameters of 0.5, 1.0, 2.0, 5.0, and 10.0 nm; and (3) an Au shell of variable thickness on a 1 nm Cu shell on an Au core with diameters of 0.5, 1.0, 2.0, 5.0, and 10.0 nm. For these three morphologies, the outer-shell thickness was varied until the Cu 2p{sub 3/2} peak intensity was the same (within 2%) as that found in our previous work with planar Cu/Au morphologies. The authors also performed similar simulations for a monolayer of spherical NPs consisting of a CuAu{sub x} alloy (also on a Si substrate) with diameters of 0.5, 1.0, 2.0, 5.0, and 10.0 nm. In the latter simulations, the relative Au concentration (x) was varied to give the same Cu 2p{sub 3/2} peak intensity (within 2%) as that found previously. For each morphology, the authors performed simulations with elastic scattering switched on and off. The authors found that elastic-scattering effects were generally strong for the Cu-core/Au-shell and weak for the Au-core/Cu-shell NPs; intermediate elastic-scattering effects were found for the Au-core/Cu-shell/Au-shell NPs. The shell thicknesses required to give the selected Cu 2p{sub 3/2} peak intensity for the three types of core–shell NPs were less than the corresponding film thicknesses of planar samples since Cu 2p photoelectrons can be detected from the sides and, for the smaller NPs, bottoms of the NPs. Elastic-scattering effects were also observed on the Au atomic fractions found for the CuAu{sub x} NP alloys with different diameters.« less

Annually-layered lake sediments reveal strongly increased release of persistent chemicals due to accelerated glacier melting

NASA Astrophysics Data System (ADS)

Anselmetti, Flavio S.; Blüthgen, Nancy; Bogdal, Christian; Schmid, Peter

2010-05-01

Melting glaciers may represent a secondary source of chemical pollutants that have previously been incorporated and stored in the ice. Of particular concern are persistent organic pollutants (POPs), such as the insecticide dichlorodiphenyl trichloroethane (DDT) and industrial chemicals like polychlorinated biphenyls (PCBs), which are hazardous environmental contaminants due to their persistent, bioaccumulative and toxic properties. They were introduced in the 1930s and eventually banned in the 1970s. After release into the environment these chemicals were atmospherically transported to even remote areas such as the Alps and were deposited and stored in glaciers. Ongoing drastic glacier melting due to global warming, which is expected to further accelerate, implies the significance of studying the fate of these 'legacy pollutants'. Proglacial lake sediments provide well-dated and high-resolution archives to reconstruct timing and quantities of such a potentially hazardous remobilization. The goal of this study is to reconstruct the historical inputs of POPs into remote alpine lakes and to investigate the accelerated release of POPs from melting glaciers. Due to their lipophilic character, these chemicals exhibit a high tendency to adsorb to particles whereas concentrations in water are expected to be low. Therefore, quantitative determination in annually-layered lake sediment provides an excellent way to investigate the temporal trend of inputs into lakes that act as particle sinks. For this purpose, sediment cores were sampled from proglacial lakes in the Bernese Alps (Switzerland), which are exclusively fed by glacial melt waters. For comparison, cores were also taken from nearby high-alpine lakes located in non-glaciated catchments, which only should record the initial atmospheric fall-out. Sediment layers were dated by annual varve counting and radionuclide measurements; they cover the time period from the mid 20th century to today. The measured time series of POPs indicate indeed different patterns in proglacial and non-glacial lakes. Similar to lowland Swiss plateau lakes [1,2], high-alpine lakes show a historic maximum of POP-concentrations some decades ago, which is synchronous with their primary use at that time. However, only proglacial lakes exhibit a dramatic re-increase in POP-input during the last years, thus confirming the crucial role of glaciers as reservoir and secondary source of these pollutants. The burden of pollutants in these sediments due to glacier melting is already in the same range as the earlier accumulations from direct atmospheric fall-out. Furthermore, the undiminished increase of the fluxes of many POPs into the sediment of proglacial lakes does not yet indicate an exhaust of the glacial inventory of these contaminants. Considering ongoing global warming and accelerated massive glacier melting predicted for the future, our study indicates the potential for significant environmental hazards due to pollutants delivered into such remote mountainous areas. [3] [1] Zennegg M. et al., Chemosphere 2007, 67, 1754. [2] Bogdal C. et al., Env. Sci. & Technol. 2008, 47, 6817. [3] Bogdal C. et al., Env. Sci. & Technol. 2009, 43, 8173.

Reactions of SIV species with organic compounds: formation mechanisms of organo-sulfur derivatives in atmospheric aerosols

NASA Astrophysics Data System (ADS)

Passananti, Monica; Shang, Jing; Dupart, Yoan; Perrier, Sébastien; George, Christian

2015-04-01

Secondary organic aerosol (SOA) have an important impact on climate, air quality and human health. However the chemical reactions involved in their formation and growth are not fully understood or well-constrained in climate models. It is well known that inorganic sulfur (mainly in oxidation states (+IV) and (+VI)) plays a key role in aerosol formation, for instance sulfuric acid is known to be a good nucleating gas. In addition, acid-catalyzed heterogeneous reactions of organic compounds has shown to produce new particles, with a clear enhancement in the presence of ozone (Iinuma 2013). Organosulfates have been detected in tropospheric particles and aqueous phases, which suggests they are products of secondary organic aerosol formation process (Tolocka 2012). Originally, the production of organosulfates was explained by the esterification reaction of alcohols, but this reaction in atmosphere is kinetically negligible. Other formation pathways have been suggested such as hydrolysis of peroxides and reaction of organic matter with sulfite and sulfate radical anions (SO3-, SO4-) (Nozière 2010), but it remains unclear if these can completely explain atmospheric organo-sulfur aerosol loading. To better understand the formation of organo-sulfur compounds, we started to investigate the reactivity of SIV species (SO2 and SO32-) with respect to specific functional groups (organic acids and double bonds) on atmospherically relevant carboxylic acids and alkenes. The experiments were carried out in the homogeneous aqueous phase and at the solid-gas interface. A custom built coated-wall flow tube reactor was developed to control relativity humidity, SO2 concentration, temperature and gas flow rate. Homogeneous and heterogeneous reaction kinetics were measured and resulting products were identified using liquid chromatography coupled with an orbitrap mass spectrometer (LC-HR-MS). The experiments were performed with and without the presence of ozone in order to evaluate any impact on the SIV oxidation and product formation. Preliminary results reveal that oxidation of SIV species can occur under a variety of atmospherically relevant conditions. Furthermore, LC-HR-MS analysis confirms the formation of organo-sulfur compounds that could derive from sulfate and/or the sulfite radical anion. These results elucidate the role of organo-sulfates aqueous and interfacial chemistry, important for our scientific understanding of atmospheric SOA formation. Iinuma Y., Kahnt A., Mutzel A., Böge O., Herrmann H., Environ. Sci. Technol., 2013, (47), 3639-3647, DOI: 10.1021/es305156z. Mauldin III R. L., Berndt T., Sipilä M., Paasonen P., Petäjä T., Kim S., Kurtén T., Stratmann F., Kerminen V.-M., Kulmala M., Nature, 2012, (488), 193-196, DOI: 10.1038/nature11278. Nozière B., Ekström S., AlsbergT., Holmström S., Geophys. Res. Lett., 2010, (37), 1-6, DOI: 10.1029/2009GL041683. Tolocka M.P., Turpin B., Environ. Sci. Technol., 2012, (46), 7978-7983, DOI: 10.1021/es300651v.

Molecular Simulations of the Diffusion of Uranyl Carbonate Species in Nanosized Mineral Fractures

NASA Astrophysics Data System (ADS)

Kerisit, S.; Liu, C.

2010-12-01

Uranium is a major groundwater contaminant at uranium processing and mining sites as a result of intentional and accidental discharges of uranium-containing waste products into subsurface environments. Recent characterization has shown that uranium preferentially associates with intragrain and intra-aggregate domains in some of the uranium-contaminated sediments collected from the US Department of Energy Hanford Site [1, 2]. In these sediments, uranium existed as precipitated and/or adsorbed phases in grain micropores with nano- to microscale sizes. Desorption and diffusion characterization studies and continuum-scale modeling indicated that ion diffusion in the microfractures is a major mechanism that led to preferential uranium concentration in the microfracture regions and will control the future mobility of uranium in the subsurface sediments [1, 3-4]. However, the diffusion properties of uranyl species in the intragrain regions, especially at the solid-liquid interface, are still poorly understood. Therefore, a general aim of this work is to provide atomic-level insights into the contribution of microscopic surface effects to the slow diffusion process of uranyl species in porous media with nano- to microsized fractures. In this presentation, we will first present molecular dynamics (MD) simulations of feldspar-water interfaces to investigate their interfacial structure and dynamics and establish a theoretical framework for subsequent simulations of water and ion diffusion at these interfaces [5]. We will then report on MD simulations carried out to probe the effects of confinement and of the presence of the mineral surface on the diffusion of water and electrolyte ions in nanosized feldspar fractures [6]. Several properties of the mineral-water interface were varied, such as the fracture width, the ionic strength of the contacting solution, and the surface charge. Our calculations reveal a 2.0-2.5 nm interfacial region within which the diffusion properties of water and that of the electrolyte ions differ significantly from those in bulk aqueous solutions. We will then present MD simulations of the diffusion of a series of alkaline-earth uranyl carbonate species in aqueous solutions [7]. The MD simulations show that the alkaline-earth uranyl carbonate complexes have distinct water exchange dynamics, which could lead to different reactivities. Finally, we will present recent results on the diffusion and adsorption of uranyl carbonate species in intragrain micropores, modeled with the feldspar-water interfaces mentioned in the above, to help interpret the diffusion behavior of uranium in contaminated sediments. [1] Liu C. et al. Geochim. Cosmochim. Acta 68 4519 (2004) [2] McKinley J. P. et al. Geochim. Cosmochim. Acta 70 1873 (2006) [3] Liu C. et al. Water Resour. Res. 42 W12420 (2006) [4] Ilton E. S. et al. Environ. Sci. Technol. 42 1565 (2009) [5] Kerisit S. et al. Geochim. Cosmochim. Acta 72 1481 (2008) [6] Kerisit S. and Liu C. Environ. Sci. Technol. 43 777 (2009) [7] Kerisit S. and Liu C. Geochim. Cosmochim. Acta 74 4937 (2010)

Japan Report, Science and Technology.

DTIC Science & Technology

1986-12-15

Sakamoto, "Glutathione," KODANSHA SCIENTIFIC (1985). 2. T. Tochikura, et al., J. FERMENT . TECHNOL., 45, 511 (1967). 3. Ibid., 46, 957 (1968). 4. S...Watanabe, et al., AGRIC. BIOL. CHEM., 36, 2265 (1972). 5. T. Tochikura, et al., J. FERMENT . TECHNOL., 48, 763 (1970). 6. T. Tachiki, et al., J. GEN. APPL...Tachiki and T. Tochikura, Fermentation and Industry, 41, 736, 1983). 13. K. Murata, J. Kato, and I. Senhata, Ibid., 39, 900 (1981). 14. Y. Isokazu

EDITORIAL: Announcing the 2011 Measurement Science and Technology Outstanding Paper Awards Announcing the 2011 Measurement Science and Technology Outstanding Paper Awards

NASA Astrophysics Data System (ADS)

Foss, John; Dewhurst, Richard; Fujii, Kenichi; Regtien, Paul; Tatam, Ralph

2012-06-01

Since 1991, Measurement Science and Technology has awarded a Best Paper prize. The Editorial Board of this journal believe that such a prize is an opportunity to thank authors for submitting their work, and serves as an integral part of the on-going quality review of the journal. The current breadth of topical areas that are covered by MST has made it advisable to expand the recognition of excellent publications. Hence, since 2005 the Editorial Board have presented 'Outstanding Paper Awards'. This year awards were presented in the areas of 'Measurement Science', 'Fluid Mechanics' and 'Precision Measurement'. Although the categories mirror subject sections in the journal, the Editorial Board consider articles from all categories in the selection process. 2011 Award Winners—Measurement Science Simultaneous measurement of internal and surrounding flows of a moving droplet using multicolour confocal micro-particle image velocimetry (micro-PIV) M Oishi, H Kinoshita, T Fujii and M Oshima Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo 153-8505, Japan Interfaculty Initiative in Information Studies, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo 153-8505, Japan Whilst the award last year [1] was concerned with the application of microscopy to ultra-high vacuum dynamic force measurements, this year's award [2] goes to another micro-measurement technique, one concerned with measurements related to particle image velocimetry. The technique relates to multiphase flow in microfluidic devices, and offers a non-contact methodology for examining simultaneous dynamic interactions between flows having different phases. There are several features which make this an excellent paper. It introduces its subject with a clear and concise description of previous advances in related measurement methods, before introducing the additional feature of two-colour fluorescent monitoring of flow in two independent optical channels. By adapting a conventional confocal microscope for PIV measurements, the authors describe how to measure multiphase flow having separate phases in a simultaneous way, exploiting fluorescent markers with wavelength separation. The measurement technique required the integration of several optical systems, including two different laser excitation sources. The novelty of the paper resides with the multicolour separation unit and its optical design, with two synchronized camera systems. Alignment and setting of optical components are crucial for efficient monitoring of light from the conjugate focus. All these experimental features are described in detail and with clarity. The technique gives a measurement methodology for velocity measurements in the x-y plane, in a two-phase medium. Additionally, the out-of-plane, z, component of velocity has been estimated analytically using three-dimensional two-component measured velocity data and the continuity equation. This computational method was exploited with experimental data in a post-processing operation to derive full three-dimensional velocity distributions. Examples are then provided of the behaviour of droplets with surrounding flow. Image sizes are typically 800 × 600 pixels with resolution in the x-y plane of 0.284 µm/pixel. For examples discussed within the paper, the recording frame rate was 990 fps with an exposure time of about 1 ms for high quality PIV images. The results section is detailed and convincing, before the paper reaches a set of concise conclusions. There is also a useful list of 22 references at the end of the paper. The paper was rated as excellent by one of the referees in the initial refereeing process, and since publication it has attracted a high number of downloads. It is bound to make an impact within the PIV community. Readers may also like to know that the authors have since published a related paper [3] which uses this technique to measure the microscopic interaction between red blood cells (RBCs) and surrounding flow. 2011 Award Winners—Fluid Mechanics Acoustic tomographic imaging of temperature and flow fields in air Manuela Barth and Armin Raabe University of Leipzig, Institute for Meteorology, Stephanstraße 3, 04103 Leipzig, Germany This paper [4] provides a valuable measurement strategy for volumetric measurements of the velocity and temperature fields in an airflow over large fields. Given that the speed of sound in the medium is influenced by humidity, the recovered temperature is termed 'acoustic virtual temperature' (Tav). The method is demonstrated for a volume of order 1 m3. It can, in principle, be scaled to a much larger domain. The inferred quantities, T(x, y, z, t) and bar v(x, y, z, t), are not intended to replace discrete point measurements (which can be obtained with substantially greater accuracy albeit with intrusive probes or added scattering particles). Rather, the time-resolved measurements will likely be very valuable for HVAC or micro-meteorological, etc measurements. The supporting theory and the respective literature base are succinctly presented. The experimental strategy, in which pairs of counter-propagating acoustic emitters/receivers criss-cross the measurement domain, is supported by the authors' form of an algebraic tomographic reconstruction technique. The demonstration experiment and representative results are clearly presented. The selection committee anticipates a positive response by those investigators whose application problem is compatible with the capabilities offered by this paper. 2011 Award Winner—Precision Measurement Diameter measurements of polystyrene particles with atomic force microscopy J Garnaes Danish Fundamental Metrology, Matematiktorvet 307, DK-2800 Kgs. Lyngby, Denmark This paper [5] describes a geometric diameter measurement of polystyrene spheres with nominal diameters of about 100 nm using atomic force microscopy (AFM). Although electron microscopy has conventionally been used for small diameter measurements, the method can only be used in vacuum, leading to significant changes in deformation as no meniscus of water is formed on the surface of the spheres placed in a vacuum. In this work, AFM is used for the height and distance measurements of the spheres placed on a mica substrate, allowing the measurement in air. Uncertainties in the diameter measurements have been evaluated in detail by taking into account influences of the deformations due to the AFM tip, substrate, surface tension effect of a thin water layer, interaction between the two spheres, and so on. The influence of air gaps introduced by imperfect packing of the spheres has also been evaluated quantitatively from the distribution of the measured diameters. Finally the geometric diameter of the polystyrene spheres has been determined with an uncertainty of 3 nm from the height and packing distance measurements. This paper has been downloaded more than 300 times since its publication. The selection committee members on the Precision Measurement Award, Dr K Fujii, Dr A Yacoot, Dr P Williams, Dr H Bosse, Professor X Chen and Dr T Eom, selected this paper from a strongly competitive list of ten candidates for its sophisticated idea and detailed evaluation of uncertainty in measurement. Considering its impact on accurate evaluation of particles using AFM, the paper was selected as the winner of the MST Precision Measurement Award for 2011. The chairmen would like to thank the authors for choosing to publish their work in Measurement Science and Technology, and hope that other researchers enjoy reading these works and feel encouraged to submit their own best work to the journal. References [1] Lübbe J, Tröger L, Torbrügge S, Bechstein R, Richter C, Kühnle A and Reichling M 2010 Achieving high effective Q-factors in ultra-high vacuum dynamic force microscopy Meas. Sci. Technol. 21 125501 (9pp) [2] Oishi M, Kinoshita H, Fujii T and Oshima M 2011 Simultaneous measurement of internal and surrounding flows of a moving droplet using multicolour confocal micro-particle image velocimetry (micro-PIV) Meas. Sci. Technol. 22 105401 (13pp) [3] Oishi M, Utsubo K, Kinoshita H, Fujii T and Oshima M 2012 Continuous and simultaneous measurement of the tank-treading motion of red blood cells and the surrounding flow using translational confocal micro-particle image velocimetry (micro-PIV) with sub-micron resolution Meas. Sci. Technol. 23 035301 (18pp) [4] Barth M and Raabe A 2011 Acoustic tomographic imaging of temperature and flow fields in air Meas. Sci. Technol. 22 035102 (13pp) [5] Garnaes J 2011 Diameter measurements of polystyrene particles with atomic force microscopy Meas. Sci. Technol. 22 094001 (8pp)

Two types of nonlinear wave equations for diffractive beams in bubbly liquids with nonuniform bubble number density.

PubMed

Kanagawa, Tetsuya

2015-05-01

This paper theoretically treats the weakly nonlinear propagation of diffracted sound beams in nonuniform bubbly liquids. The spatial distribution of the number density of the bubbles, initially in a quiescent state, is assumed to be a slowly varying function of the spatial coordinates; the amplitude of variation is assumed to be small compared to the mean number density. A previous derivation method of nonlinear wave equations for plane progressive waves in uniform bubbly liquids [Kanagawa, Yano, Watanabe, and Fujikawa (2010). J. Fluid Sci. Technol. 5(3), 351-369] is extended to handle quasi-plane beams in weakly nonuniform bubbly liquids. The diffraction effect is incorporated by adding a relation that scales the circular sound source diameter to the wavelength into the original set of scaling relations composed of nondimensional physical parameters. A set of basic equations for bubbly flows is composed of the averaged equations of mass and momentum, the Keller equation for bubble wall, and supplementary equations. As a result, two types of evolution equations, a nonlinear Schrödinger equation including dissipation, diffraction, and nonuniform effects for high-frequency short-wavelength case, and a Khokhlov-Zabolotskaya-Kuznetsov equation including dispersion and nonuniform effects for low-frequency long-wavelength case, are derived from the basic set.

Sub-grid scale combustion models for large eddy simulation of unsteady premixed flame propagation around obstacles.

PubMed

Di Sarli, Valeria; Di Benedetto, Almerinda; Russo, Gennaro

2010-08-15

In this work, an assessment of different sub-grid scale (sgs) combustion models proposed for large eddy simulation (LES) of steady turbulent premixed combustion (Colin et al., Phys. Fluids 12 (2000) 1843-1863; Flohr and Pitsch, Proc. CTR Summer Program, 2000, pp. 61-82; Kim and Menon, Combust. Sci. Technol. 160 (2000) 119-150; Charlette et al., Combust. Flame 131 (2002) 159-180; Pitsch and Duchamp de Lageneste, Proc. Combust. Inst. 29 (2002) 2001-2008) was performed to identify the model that best predicts unsteady flame propagation in gas explosions. Numerical results were compared to the experimental data by Patel et al. (Proc. Combust. Inst. 29 (2002) 1849-1854) for premixed deflagrating flame in a vented chamber in the presence of three sequential obstacles. It is found that all sgs combustion models are able to reproduce qualitatively the experiment in terms of step of flame acceleration and deceleration around each obstacle, and shape of the propagating flame. Without adjusting any constants and parameters, the sgs model by Charlette et al. also provides satisfactory quantitative predictions for flame speed and pressure peak. Conversely, the sgs combustion models other than Charlette et al. give correct predictions only after an ad hoc tuning of constants and parameters. Copyright 2010 Elsevier B.V. All rights reserved.

Simultaneous electrical and optical study of spoke rotation, merging and splitting in HiPIMS plasma

NASA Astrophysics Data System (ADS)

Klein, P.; Lockwood Estrin, F.; Hnilica, J.; Vašina, P.; Bradley, J. W.

2017-01-01

To gain more information on the temporal and spatial behaviour of self-organized spoke structures in HiPIMS plasmas, a correlation between the broadband optical image of an individual spoke (taken over 200 ns) and the current it delivers to the target has been made for a range of magnetron operating conditions. As a spoke passes over a set of embedded probes in the niobium cathode target, a distinct modulation in the local current density is observed, (typically up to twice the average value), matching very well the radially integrated optical emission intensities (obtained remotely with an ICCD camera). The dual diagnostic system allows the merging and splitting of a set of spokes to be studied as they rotate. It is observed that in the merger of two spokes, the trailing spoke maintains its velocity while the leading spoke either decreases its velocity or increases its azimuthal length. In the spoke splitting process, the total charge collected by an embedded probe is conserved. A simple phenomenological model is developed that relates the spoke mode number m to the spoke dimensions, spoke velocity and gas atom velocity. The results are discussed in the context of the observations of spoke dynamics made by Hecimovic et al (2015 Plasma Sources Sci. Technol. 24 045005)

Modeling the local biodiversity impacts of agricultural water use: case study of a wetland in the coastal arid area of Peru.

PubMed

Verones, Francesca; Bartl, Karin; Pfister, Stephan; Jiménez Vílchez, Ricardo; Hellweg, Stefanie

2012-05-01

Global water use is dominated by agriculture and has considerable influence on people's livelihood and ecosystems, especially in semiarid and arid regions. Methods to address the impacts of water withdrawal and consumption on terrestrial and aquatic ecosystems within life cycle assessment are still sparse and very generic. Regionalized characterization factors (CFs) for a groundwater-fed wetland at the arid coast of Peru are developed for groundwater and surface water withdrawal and consumption in order to address the spatial dependency of water use related impacts. Several agricultural scenarios for 2020 were developed in a workshop with local stakeholders and used for calculating total biodiversity impacts. In contrast to assumptions used in top-down approaches (e.g., Pfister et al. Environ. Sci Technol. 2009, 43, 4098 ), irrigation with surface water leads in this specific region to benefits for the groundwater-fed wetland, due to additional groundwater recharge from surplus irrigation water. However, irrigation with groundwater leads to ecological damage to the wetland. The CFs derived from the different scenarios are similar and can thus be used as general CFs for this region, helping local decision-makers to plan future agricultural development, including irrigation technologies, crop choices, and protection of the wetland. © 2012 American Chemical Society

U(VI) bioreduction with emulsified vegetable oil as the electron donor--model application to a field test.

PubMed

Tang, Guoping; Watson, David B; Wu, Wei-Min; Schadt, Christopher W; Parker, Jack C; Brooks, Scott C

2013-04-02

We amended a shallow fast-flowing uranium (U) contaminated aquifer with emulsified vegetable oil (EVO) and subsequently monitored the biogeochemical responses for over a year. Using a biogeochemical model developed in a companion article (Tang et al., Environ. Sci. Technol.2013, doi: 10.1021/es304641b) based on microcosm tests, we simulated geochemical and microbial dynamics in the field test during and after the 2-h EVO injection. When the lab-determined parameters were applied in the field-scale simulation, the estimated rate coefficient for EVO hydrolysis in the field was about 1 order of magnitude greater than that in the microcosms. Model results suggested that precipitation of long-chain fatty acids, produced from EVO hydrolysis, with Ca in the aquifer created a secondary long-term electron donor source. The model predicted substantial accumulation of denitrifying and sulfate-reducing bacteria, and U(IV) precipitates. The accumulation was greatest near the injection wells and along the lateral boundaries of the treatment zone where electron donors mixed with electron acceptors in the groundwater. While electron acceptors such as sulfate were generally considered to compete with U(VI) for electrons, this work highlighted their role in providing electron acceptors for microorganisms to degrade complex substrates thereby enhancing U(VI) reduction and immobilization.

Mobility of long-chain DNA in two-dimensional artificial gels

NASA Astrophysics Data System (ADS)

Turner, Stephen W. P.; Han, Jongyoon; Craighead, Harold G.

2000-03-01

In this study, a two-dimensional array of nanofabricated obstacles is used as an artificial gel to study the electrophoretic mobility dependence of DNA as a function of pore size, molecule length and electric field. Limitations in feature size have prevented previous studies from testing the crossover from the separating to the non-separating regime predicted by the biased reptation model of Lumpkin, Dejardin and Zimm[1] and the modified model of Duke, Semenov and Viovy.[2] That limitation is overcome in this work with the use of electron beam lithography to define features as small as 30 nm. Attainment of these feature sizes was made possible by the use of a sacrificial-layer-based technique for fluidics fabrication.[3] A novel band-launching strategy is used to provide band separation data for the first time in this system. Molecule lengths between 5 and 150 kilobases are studied for electric field strengths from 0.1 to 20 Volts per meter. [1] O. Lumpkin, P. Dejardin and B. Zimm, Biopolymers, Vol. 24, 1573-1593 (1985) [2] T. Duke, A. Semenov and J. Viovy, Phys. Rev. Lett. Vol. 69, No. 22, 3260-3263 (1992) [3] S. Turner, A. Perez, A. Lopez, and H. Craighead, J. Vac. Sci. Technol. B 16(6) 3835-3840 (1998)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lunden, Melissa M.; Delp, William W.

Effective exhaust hoods can mitigate the indoor air quality impacts of pollutant emissions from residential cooking. This study reports capture efficiencies (CE) measured for cooking generated particles for scripted cooking procedures in a 121-m3 chamber with kitchenette. CEs also were measured for burner produced CO2 during cooking and separately for pots and pans containing water. The study used four exhaust hoods previously tested by Delp and Singer (Environ. Sci. Technol., 2012, 46, 6167-6173). For pan-frying a hamburger over medium heat on the back burner, CEs for particles were similar to those for burner produced CO2 and mostly above 80percent. Formore » stir-frying green beans in a wok (high heat, front burner), CEs for burner CO2 during cooking varied by hood and airflow: CEs were 34-38percent for low (51?68 L s-1) and 54?72percent for high (109?138 L s-1) settings. CEs for 0.3?2.0 ?m particles during front burner stir-frying were 3?11percent on low and 16?70percent on high settings. Results indicate that CEs measured for burner CO2 are not predictive of CEs of cooking-generated particles under all conditions, but they may be suitable to identify devices with CEs above 80percent both for burner combustion products and for cooking-related particles.« less

Characterization of homoionic Fe 2+-type montmorillonite: Potential chemical species of iron contaminant

NASA Astrophysics Data System (ADS)

Kozai, Naofumi; Inada, Koichi; Adachi, Yoshifusa; Kawamura, Sachi; Kashimoto, Yusuke; Kozaki, Tamotsu; Sato, Seichi; Ohnuki, Toshihiko; Sakai, Takuro; Sato, Takahiro; Oikawa, Masakazu; Esaka, Fumitaka; Mitamura, Hisayoshi

2007-08-01

Fe 2+-montmorillonite with Fe 2+ ions occupying cation exchange sites is an ideal transformation product in bentonite buffer material. In our previous study on preparation and characterization of Fe 2+-montmorillonite, the montmorillonite sample that adsorbed Fe 2+ ions on almost all of the cation exchange sites was prepared using a FeCl 2 solution under an inert gas condition [N. Kozai, Y. Adachi, S. Kawamura, K. Inada, T. Kozaki, S. Sato, H. Ohashi, T. Ohnuki, T. Banba, J. Nucl. Sci. Technol. 38 (2001) 1141]. In view of the unstable nature of iron(II) chemical species, this study attempted to determine the potential contaminant iron chemical species in the sample. Nondestructive elemental analysis revealed that a small amount of chloride ions remained dispersed throughout the clay particles. The chloride ion retention may be due to the adsorption of FeCl + ion pairs in the initial FeCl 2 solution and the subsequent containment of the Cl - ions that are dissociated from the FeCl + ion pairs during excess salt removal treatment. Two explanations are advanced for the second process: the slow release of the remaining Cl - ions from the collapsed interlayer of the montmorillonite, and the transformation of a minor fraction of the remaining FeCl + ion pairs to iron(III) hydroxide chloride complexes having low solubility.

Controls on radium transport by adsorption to iron minerals

NASA Astrophysics Data System (ADS)

Chen, M.; Wang, T.; Kocar, B. D.

2015-12-01

Radium is a naturally occurring radioactive metal found in many subsurface environments. Radium isotopes are generated by uranium and thorium decay, and are particularly abundant within groundwaters where minimal porewater flux leads to accumulation. These isotopes are used as natural tracers for estimating submarine groundwater discharge (SGD) [1], allowing for large scale estimation of GW fluxes into and out of the ocean [2]. They also represent a substantial hazard in wastewater produced after hydraulic fracturing for natural gas extraction [3], resulting in a significant risk of environmental release to surface and near-surface waters, and increased cost for water treatment or disposal. Adsorption to mineral surfaces represents a dominant pathway of radium retention in subsurface environments. For SGD studies, adsorption processes impact estimates of GW fluxes, while in hydraulic fracturing, radium adsorption to aquifer solids mediates wastewater radium activities. Analysis of past sorption studies revealed large variability in partition coefficients [4], while examination of radium adsorption kinetics and surface complexation have only recently started [5]. Accordingly, we present the results of sorption and column experiments of radium with a suite of iron minerals representative of those found within deep saline and near-surface (freshwater) aquifers, and evaluate impacts of varying salinity solutions through artificial waters. Further, we explore the impacts of pyrite oxidation and ferrihydrite transformation to other iron-bearing secondary minerals on the transport and retention of radium. These results will provide critical information on the mineralogical controls on radium retention in subsurface environments, and will therefore improve predictions of radium groundwater transport in natural and contaminated systems. [1] Charette, M.A., Buesseler, K.O. & Andrews, J.E., Limnol. Oceanogr. (2001). [2] Moore, W.S., Ann. Rev. Mar. Sci. (2010). [3] Vengosh, A. et al. Environ. Sci. Technol., (2014). [4] Beck, A., Cochran, M., Marine Chem., (2013). [5] Sajih, M. et al. Geochim. Cosmochim. AC. (2014).

Response to Julian et al. (2015) "comment on and reinterpretation of Gabriel et al. (2014) 'fish mercury and surface water sulfate relationships in the everglades protection area'".

PubMed

Gabriel, Mark C; Axelrad, Don; Orem, William; Osborne, Todd Z

2015-06-01

The purpose of this forum is to respond to a rebuttal submitted by Julian et al., Environ Manag 55:1-5, 2015 where they outlined their overall disagreement with the data preparation, methods, and interpretation of results presented in Gabriel et al. (Environ Manag 53:583-593, 2014). Here, we provide background information on the research premise presented in Gabriel et al. (Environ Manag 53:583-593, 2014) and provide a defense for this work using five themes. In spite of what Julian et al. perceive as limitations in the sampling methods and analytical tools used for this work, the relationships found between fish total mercury and surface water sulfate concentrations in Gabriel et al. (Environ Manag 53:583-593, 2014) are comparable to relationships between pore water methylmercury (MeHg) and pore water sulfate found in past studies indicating that sulfate is important to MeHg production and bioaccumulation in the Everglades. Julian et al. state "…there is no way to justify any ecosystem-wide sulfur strategy as a management approach to reduce mercury risk in the (Everglades) as suggested by Gabriel et al. (Environ Manag 53:583-593, 2014), Corrales et al. (Sci Tot Environ 409:2156-2162, 2011) and Orem et al. (Rev Environ Sci Technol 41 (S1):249-288, 2011)." We disagree, and having stated why sulfate input reduction to the Everglades may be the most effective means of reducing mercury in Everglades fish, it is important that research on sulfur and mercury biogeochemistry continues. If further studies support the relationship between sulfate loading reduction and MeHg reduction, sulfur mass balance studies should commence to (1) better quantify agricultural and connate seawater sulfate inputs and (2) define opportunities to reduce sulfate inputs to the Everglades ecosystem.

A review of the liquid metal diffusion data obtained from the space shuttle endeavour mission STS-47 and the space shuttle columbia mission STS-52

NASA Astrophysics Data System (ADS)

Shirkhanzadeh, Morteza

Accurate data of liquid-phase solute diffusion coefficients are required to validate the condensed -matter physics theories. However, the required data accuracy to discriminate between com-peting theoretical models is 1 to 2 percent(1). Smith and Scott (2) have recently used the measured values of diffusion coefficients for Pb-Au in microgravity to validate the theoretical values of the diffusion coefficients derived from molecular dynamics simulations and several Enskog hard sphere models. The microgravity data used was obtained from the liquid diffusion experiments conducted on board the Space Shuttle Endeavour (mission STS-47) and the Space Shuttle Columbia (mission STS-52). Based on the analysis of the results, it was claimed that the measured values of diffusion coefficients were consistent with the theoretical results and that the data fit a linear relationship with a slope slightly greater than predicted by the molecular dynamics simulations. These conclusions, however, contradict the claims made in previous publications (3-5) where it was reported that the microgravity data obtained from the shuttle experiments fit the fluctuation theory (D proportional to T2). A thorough analysis of data will be presented to demonstrate that the widely-reported micro-gravity results obtained from shuttle experiments are not reliable and sufficiantly accurate to discriminate between competing theoretical models. References: 1. J.P. Garandet, G. Mathiak, V. Botton, P. Lehmann and A. Griesche, Int. J. Thermophysics, 25, 249 (2004). 2.P.J. Scott and R.W. Smith, J. Appl. Physics 104, 043706 (2008). 3. R.W. Smith, Microgravity Sci. Technol. XI (2) 78-84 (1998). 4.Smith et al, Ann. N.Y. Acad. Sci. 974:56-67 (2002) (retracted). 5.R.A. Herring et al, J. Jpn. Soc. Microgravity Appl., Vol.16, 234-244 (1999).

Comparison of Experimenal Photooxidation Rates and Patterns in Glass- and Water-Based Oil Slicks with Daily Weathering Observed in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Sharpless, C.; Aeppli, C.; Reddy, C. M.; Swarthout, B.; Stewart, O. C.; Walters, M.; Valentine, D. L.

2016-02-01

Photooxidation is a well-known degradation route for toxic components of oil (e.g., PAHs). However, recent research suggests that it may play a broader role by enhancing oil's dark1 and photo-toxicity2 and producing persistent, oxidized hydrocarbons.3To better understand photooxidation's importance to oil weathering in marine systems, we are combining laboratory studies with field measurements of compositional changes under controlled conditions. Lab experiments have employed a solar simulator to photooxidize slicks of Dorado Well crude oil on water (Instant Ocean) and glass surfaces. Qualitatively similar compositional changes were seen in both systems, such as rapid loss of aromatics and production of oxidized hydrocarbons as assessed by GCMS, GCxGC, TLC-FID, and FTIR. Rates were much faster on water, a finding tentatively ascribed to the film on glass ( 750 um) being much thicker than on water ( 140 um). Further experiments have been conducted with thinner films on glass, and the results are being analyzed to clarify the importance of film thickness versus surface substrate for photoxidation kinetics. Naturally weathered samples were also collected in the Gulf during a cruise in June, 2015. Surface slicks from natural seeps were tracked and sampled daily under very calm seas with full sun, and solar irradiance was simultaneously measured. These samples, currently undergoing GCxGC and TLC-FID analyses, provide a unique reference with which to assess in-situ transformation rates and compositional changes due to photooxidation. Comparison between results from the field samples and lab experiments should help clarify the absolute contribution of photooxidation to marine oil weathering and improve efforts to use lab results to constrain estimates of environmental transformation rates. 1. D. Rial et al. J. Haz. Mat. 2013, 260, 67 2. J.P. Incardona et al. Proc. Natl. Acad. Sci. 2012, 109, E51 3. C. Aeppli et al. Environ. Sci. Technol. 2012, 46, 8799

Advanced Fabrication Processes for Superconducting Very Large Scale Integrated Circuits

DTIC Science & Technology

2015-10-13

transistors. There are several reasons for this gigantic disparity: insufficient funding and lack of profit-driven investments in superconductor ...Inductance of circuit structures for MIT LL superconductor electronics fabrication process with 8 niobium layers,” IEEE Trans. Appl. Supercond., vol...vol. 25, No. 3, 1301704, June 2015. [7] V. Ambegaokar and A. Baratoff, “Tunneling between superconductors ,” Phys. Rev. Lett., vol. 10, no. 11, pp

Dynamic mechanical characterization of aluminum: analysis of strain-rate-dependent behavior

NASA Astrophysics Data System (ADS)

Rahmat, Meysam

2018-05-01

A significant number of materials show different mechanical behavior under dynamic loads compared to quasi-static (Salvado et al. in Prog. Mater. Sci. 88:186-231, 2017). Therefore, a comprehensive study of material dynamic behavior is essential for applications in which dynamic loads are dominant (Li et al. in J. Mater. Process. Technol. 255:373-386, 2018). In this work, aluminum 6061-T6, as an example of ductile alloys with numerous applications including in the aerospace industry, has been studied under quasi-static and dynamic tensile tests with strain rates of up to 156 s^{-1}. Dogbone specimens were designed, instrumented and tested with a high speed servo-hydraulic load frame, and the results were validated with the literature. It was observed that at a strain rate of 156 s^{-1} the yield and ultimate strength increased by 31% and 33% from their quasi-static values, respectively. Moreover, the failure elongation and fracture energy per unit volume also increased by 18% and 52%, respectively. A Johnson-Cook model was used to capture the behavior of the material at different strain rates, and a modified version of this model was presented to enhance the capabilities of the original model, especially in predicting material properties close to the failure point. Finally, the fracture surfaces of specimens tested under quasi-static and dynamic loads were compared and conclusions about the differences were drawn.

Use of Threshold of Toxicological Concern (TTC) with High ...

EPA Pesticide Factsheets

Although progress has been made with HTS (high throughput screening) in profiling biological activity (e.g., EPA’s ToxCast™), challenges arise interpreting HTS results in the context of adversity & converting HTS assay concentrations to equivalent human doses for the broad domain of commodity chemicals. Here, we propose using TTC as a risk screening method to evaluate exposure ranges derived from NHANES for 7968 chemicals. Because the well-established TTC approach uses hazard values derived from in vivo toxicity data, relevance to adverse effects is robust. We compared the conservative TTC (non-cancer) value of 90 μg/day (1.5 μg/kg/day) (Kroes et al., Fd Chem Toxicol, 2004) to quantitative exposure predictions of the upper 95% credible interval (UCI) of median daily exposures for 7968 chemicals in 10 different demographic groups (Wambaugh et al., Environ Sci Technol. 48:12760-7, 2014). Results indicate: (1) none of the median values of credible interval of exposure for any chemical in any demographic group was above the TTC; & (2) fewer than 5% of chemicals had an UCI that exceeded the TTC for any group. However, these median exposure predictions do not cover highly exposed (e.g., occupational) populations. Additionally, we propose an expanded risk-based screening workflow that comprises a TTC decision tree that includes screening compounds for structural alerts for DNA reactivity, OPs & carbamates as well as a comparison with bioactivity-based margins of

Measurement of acoustic velocity components in a turbulent flow using LDV and high-repetition rate PIV

NASA Astrophysics Data System (ADS)

Léon, Olivier; Piot, Estelle; Sebbane, Delphine; Simon, Frank

2017-06-01

The present study provides theoretical details and experimental validation results to the approach proposed by Minotti et al. (Aerosp Sci Technol 12(5):398-407, 2008) for measuring amplitudes and phases of acoustic velocity components (AVC) that are waveform parameters of each component of velocity induced by an acoustic wave, in fully turbulent duct flows carrying multi-tone acoustic waves. Theoretical results support that the turbulence rejection method proposed, based on the estimation of cross power spectra between velocity measurements and a reference signal such as a wall pressure measurement, provides asymptotically efficient estimators with respect to the number of samples. Furthermore, it is shown that the estimator uncertainties can be simply estimated, accounting for the characteristics of the measured flow turbulence spectra. Two laser-based measurement campaigns were conducted in order to validate the acoustic velocity estimation approach and the uncertainty estimates derived. While in previous studies estimates were obtained using laser Doppler velocimetry (LDV), it is demonstrated that high-repetition rate particle image velocimetry (PIV) can also be successfully employed. The two measurement techniques provide very similar acoustic velocity amplitude and phase estimates for the cases investigated, that are of practical interest for acoustic liner studies. In a broader sense, this approach may be beneficial for non-intrusive sound emission studies in wind tunnel testings.

A study on the maximum power transfer condition in an inductively coupled plasma using transformer circuit model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Young-Do; Lee, Hyo-Chang; Chung, Chin-Wook

Correlations between the external discharge parameters (the driving frequency ω and the chamber dimension R) and plasma characteristics (the skin depth δ and the electron-neutral collision frequency ν{sub m}) are studied using the transformer circuit model [R. B. Piejak et al., Plasma Sources Sci. Technol. 1, 179 (1992)] when the absorbed power is maximized in an inductively coupled plasma. From the analysis of the transformer circuit model, the maximum power transfer conditions, which depend on the external discharge parameters and the internal plasma characteristics, were obtained. It was found that a maximum power transfer occurs when δ≈0.38R for the dischargemore » condition at which ν{sub m}/ω≪1, while it occurs when δ≈√(2)√(ω/ν{sub m})R for the discharge condition at which ν{sub m}/ω≫1. The results of this circuit analysis are consistent with the stable last inductive mode region of an inductive-to-capacitive mode transition [Lee and Chung, Phys. Plasmas 13, 063510 (2006)], which was theoretically derived from Maxwell's equations. Our results were also in agreement with the experimental results. From this work, we demonstrate that a simple circuit analysis can be applied to explain complex physical phenomena to a certain extent.« less

Industrial applications using BASF eco-efficiency analysis: perspectives on green engineering principles.

PubMed

Shonnard, David R; Kicherer, Andreas; Saling, Peter

2003-12-01

Life without chemicals would be inconceivable, but the potential risks and impacts to the environment associated with chemical production and chemical products are viewed critically. Eco-efficiency analysis considers the economic and life cycle environmental effects of a product or process, giving these equal weighting. The major elements of the environmental assessment include primary energy use, raw materials utilization, emissions to all media, toxicity, safety risk, and land use. The relevance of each environmental category and also for the economic versus the environmental impacts is evaluated using national emissions and economic data. The eco-efficiency analysis method of BASF is briefly presented, and results from three applications to chemical processes and products are summarized. Through these applications, the eco-efficiency analyses mostly confirm the 12 Principles listed in Anastas and Zimmerman (Environ. Sci. Technol. 2003, 37(5), 94A), with the exception that, in one application, production systems based on bio-based feedstocks were not the most eco-efficient as compared to those based on fossil resources. Over 180 eco-efficiency analyses have been conducted at BASF, and their results have been used to support strategic decision-making, marketing, research and development, and communication with external parties. Eco-efficiency analysis, as one important strategy and success factor in sustainable development, will continue to be a very strong operational tool at BASF.

Metal mobilization by iron- and sulfur-oxidizing bacteria in a multiple extreme mine tailings in the Atacama Desert, Chile.

PubMed

Korehi, H; Blöthe, M; Sitnikova, M A; Dold, B; Schippers, A

2013-03-05

The marine shore sulfidic mine tailings dump at the Chañaral Bay in the Atacama Desert, northern Chile, is characterized by extreme acidity, high salinity, and high heavy metals concentrations. Due to pyrite oxidation, metals (especially copper) are mobilized under acidic conditions and transported toward the tailings surface and precipitate as secondary minerals (Dold, Environ. Sci. Technol. 2006, 40, 752-758.). Depth profiles of total cell counts in this almost organic-carbon free multiple extreme environment showed variable numbers with up to 10(8) cells g(-1) dry weight for 50 samples at four sites. Real-time PCR quantification and bacterial 16S rRNA gene diversity analysis via clone libraries revealed a dominance of Bacteria over Archaea and the frequent occurrence of the acidophilic iron(II)- and sulfur-oxidizing and iron(III)-reducing genera Acidithiobacillus, Alicyclobacillus, and Sulfobacillus. Acidophilic chemolithoautotrophic iron(II)-oxidizing bacteria were also frequently found via most-probable-number (MPN) cultivation. Halotolerant iron(II)-oxidizers in enrichment cultures were active at NaCl concentrations up to 1 M. Maximal microcalorimetrically determined pyrite oxidation rates coincided with maxima of the pyrite content, total cell counts, and MPN of iron(II)-oxidizers. These findings indicate that microbial pyrite oxidation and metal mobilization preferentially occur in distinct tailings layers at high salinity. Microorganisms for biomining with seawater salt concentrations obviously exist in nature.

Creating wealth from groundwater for dollar-a-day farmers: Where the silent revolution and the four revolutions to end rural poverty meet

NASA Astrophysics Data System (ADS)

Polak, Paul; Yoder, Robert

2006-03-01

More than 550 million of the current 1.1 billion people earning less than 1-a-day earn a living from agriculture in developing countries. A revolution in water control is needed to develop and mass-disseminate new, affordable, small-plot irrigation technologies. A revolution in agriculture is required to enable smallholders to produce high-value, marketable, labor-intensive cash crops. A revolution in markets is needed to open access to markets for the crops they produce and the inputs they need to produce them. Finally, a revolution in design, based on the ruthless pursuit of affordability, is needed to harness shallow groundwater. The experiences of suppliers of treadle pumps, low-cost drip irrigation and water storage systems were examined. The wealth these technologies generated, coupled with falling prices for small diesel pumps in countries like India and China, created a suitable environment for the rapid adoption of affordable diesel pump tubewells, which in turn created vigorous water markets and expanded access to affordable irrigation water for smallholders. The combination of smallholder-centered revolutions, along with the ‘silent revolution in groundwater’ described by Llamas and Martinez-Santos (Water Sci Technol 51(8):167-174, 2005) provide new practical options for meeting the UN Millennium Development Goals on poverty and hunger by 2015.

The SOA formation model combined with semiempirical quantum chemistry for predicting UV-Vis absorption of secondary organic aerosols.

PubMed

Zhong, Min; Jang, Myoseon; Oliferenko, Alexander; Pillai, Girinath G; Katritzky, Alan R

2012-07-07

A new model for predicting the UV-visible absorption spectra of secondary organic aerosols (SOA) has been developed. The model consists of two primary parts: a SOA formation model and a semiempirical quantum chemistry method. The mass of SOA is predicted using the PHRCSOA (Partitioning Heterogeneous Reaction Consortium Secondary Organic Aerosol) model developed by Cao and Jang [Environ. Sci. Technol., 2010, 44, 727]. The chemical composition is estimated using a combination of the kinetic model (MCM) and the PHRCSOA model. The absorption spectrum is obtained by taking the sum of the spectrum of each SOA product calculated using a semiempirical NDDO (Neglect of Diatomic Differential Overlap)-based method. SOA was generated from the photochemical reaction of toluene or α-pinene at different NO(x) levels (low NO(x): 24-26 ppm, middle NO(x): 49 ppb, high NO(x): 104-105 ppb) using a 2 m(3) indoor Teflon film chamber. The model simulation reasonably agrees with the measured absorption spectra of α-pinene SOA but underestimates toluene SOA under high and middle NO(x) conditions. The absorption spectrum of toluene SOA is moderately enhanced with increasing NO(x) concentrations, while that of α-pinene SOA is not affected. Both measured and calculated UV-visible spectra show that the light absorption of toluene SOA is much stronger than that of α-pinene SOA.

Bacterial population dynamics during uranium reduction andre-oxidation: Application of a novel high density oligonucleotidemicroarray approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodie, Eoin L.; DeSantis, Todd Z.; Joyner, Dominique C.

2006-01-30

Reduction of soluble uranium U(VI) to less-soluble uraniumU(IV) is a promising approach to minimize migration from contaminatedaquifers. It is generally assumed that, under constant reducingconditions, U(IV) is stable and immobile; however, in a previous study,we documented reoxidation of U(IV) under continuous reducing conditions(Wan et al., Environ. Sci. Technol. 2005, 39:6162 6169). To determine ifchanges in microbial community composition were a factor in U(IV)reoxidation, we employed a high-density phylogenetic DNA microarray (16Smicroarray) containing 500,000 probes to monitor changes in bacterialpopulations during this remediation process. Comparison of the 16Smicroarray with clone libraries demonstrated successful detection andclassification of most clone groups. Analysis ofmore » the most dynamic groupsof 16S rRNA gene amplicons detected by the 16S microarray identified fiveclusters of bacterial subfamilies responding in a similar manner. Thisapproach demonstrated that amplicons of known metal-reducing bacteriasuch as Geothrix fermentans (confirmed by quantitative PCR) and thosewithin the Geobacteraceae were abundant during U(VI) reduction and didnot decline during the U(IV) reoxidation phase. Significantly, it appearsthat the observed reoxidation of uranium under reducing conditionsoccurred despite elevated microbial activity and the consistent presenceof metal-reducing bacteria. High-density phylogenetic microarraysconstitute a powerful tool, enabling the detection and monitoring of asubstantial portion of the microbial population in a routine, accurate,and reproducible manner.« less

Scintillator based detector for fast-ion losses induced by magnetohydrodynamic instabilities in the ASDEX upgrade tokamak.

PubMed

García-Muñoz, M; Fahrbach, H-U; Zohm, H

2009-05-01

A scintillator based detector for fast-ion losses has been designed and installed on the ASDEX upgrade (AUG) tokamak [A. Herrmann and O. Gruber, Fusion Sci. Technol. 44, 569 (2003)]. The detector resolves in time the energy and pitch angle of fast-ion losses induced by magnetohydrodynamics (MHD) fluctuations. The use of a novel scintillator material with a very short decay time and high quantum efficiency allows to identify the MHD fluctuations responsible for the ion losses through Fourier analysis. A Faraday cup (secondary scintillator plate) has been embedded behind the scintillator plate for an absolute calibration of the detector. The detector is mounted on a manipulator to vary its radial position with respect to the plasma. A thermocouple on the inner side of the graphite protection enables the safety search for the most adequate radial position. To align the scintillator light pattern with the light detectors a system composed by a lens and a vacuum-compatible halogen lamp has been allocated within the detector head. In this paper, the design of the scintillator probe, as well as the new technique used to analyze the data through spectrograms will be described. A last section is devoted to discuss the diagnosis prospects of this method for ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)].

Radium Adsorption to Iron Bearing Minerals in Variable Salinity Waters

NASA Astrophysics Data System (ADS)

Chen, M.; Kocar, B. D.

2014-12-01

Radium is a common, naturally occurring radioactive metal found in many subsurface environments. Radium isotopes are a product of natural uranium and thorium decay, and are particularly abundant within groundwaters where minimal flux leads to accumulation within porewaters. Radium has been used as a natural tracer to estimate submarine groundwater discharge (SGD) [1], where the ratios of various radium isotopes are used to estimate total groundwater flux to and from the ocean [2]. Further, it represents a substantial hazard in waste water produced after hydraulic fracturing for natural gas extraction [3], resulting in a significant risk of environmental release and increased cost for water treatment or disposal. Adsorption to mineral surfaces represents a primary pathway of radium retention within subsurface environments. For SGD studies, it is important to understand adsorption processes to correctly estimate GW fluxes, while in hydraulic fracturing, radium adsorption to aquifer solids will mediate the activities of radium within produced water. While some studies of radium adsorption to various minerals have been performed [4], there is a limited understanding of the surface chemistry of radium adsorption, particularly to iron-bearing minerals such as pyrite, goethite and ferrihydrite. Accordingly, we present the results of sorption experiments of radium to a suite of iron-bearing minerals representative of those found within deep saline and near-surface (freshwater) aquifers, and evaluate impacts of varying salinity solutions through the use of artificial groundwater, seawater, and shale formation brine. Further, we explore the impacts of pyrite oxidation and ferrihydrite transformation to other iron-bearing secondary minerals on the retention of radium. This work lays the groundwork for further study of radium use as a tracer for SGD, as well as understanding mechanisms of radium retention and release from deep aquifer materials following hydraulic fracturing operations. [1] Charette, M.A., Buesseler, K.O. & Andrews, J.E., Limnol. Oceanogr. 46, 465-470 (2001). [2] Moore, W.S., Ann. Rev. Mar. Sci. 2, 59-88 (2010). [3] Vengosh, A., Jackson, R.B., Warner, N., Darrah, T.H. & Kondash, Environ. Sci. Technol., (2014). [4] Ames, L.L, McGarrah, J., & Walker, B., Clays Clay Miner. 31, 335-342 (1983).

Normalization and extension of single-collector efficiency correlation equation

NASA Astrophysics Data System (ADS)

Messina, Francesca; Marchisio, Daniele; Sethi, Rajandrea

2015-04-01

The colloidal transport and deposition are important phenomena involved in many engineering problems. In the environmental engineering field the use of micro- and nano-scale zerovalent iron (M-NZVI) is one of the most promising technologies for groundwater remediation. Colloid deposition is normally studied from a micro scale point of view and the results are then implemented in macro scale models that are used to design field-scale applications. The single collector efficiency concept predicts particles deposition onto a single grain of a complex porous medium in terms of probability that an approaching particle would be retained on the solid grain. In literature, many different approaches and equations exist to predict it, but most of them fail under specific conditions (e.g. very small or very big particle size and very low fluid velocity) because they predict efficiency values exceeding unity. By analysing particle fluxes and deposition mechanisms and performing a mass balance on the entire domain, the traditional definition of efficiency was reformulated and a novel total flux normalized correlation equation is proposed for predicting single-collector efficiency under a broad range of parameters. It has been formulated starting from a combination of Eulerian and Lagrangian numerical simulations, performed under Smoluchowski-Levich conditions, in a geometry which consists of a sphere enveloped by a control volume. In order to guarantee the independence of each term, the correlation equation is derived through a rigorous hierarchical parameter estimation process, accounting for single and mutual interacting transport mechanisms. The correlation equation provides efficiency values lower than one over a wide range of parameters and is valid both for point and finite-size particles. A reduced form is also proposed by elimination of the less relevant terms. References 1. Yao, K. M.; Habibian, M. M.; Omelia, C. R., Water and Waste Water Filtration - Concepts and Applications. Environ Sci Technol 1971, 5, (11), 1105-&. 2. Tufenkji, N., and M. Elimelech, Correlation equation for predicting single-collector efficiency in physicochemical filtration in saturated porous media. Environmental Science & Technology 2004 38(2):529-536. 3. Boccardo, G.; Marchisio, D. L.; Sethi, R., Microscale simulation of particle deposition in porous media. J Colloid Interface Sci 2014, 417, 227-37

Announcing the 2013 Measurement Science and Technology Outstanding Paper Awards

NASA Astrophysics Data System (ADS)

Foss, John; Dewhurst, Richard; Yacoot, Andrew; Tadigadapa, Srinivas; Peters, Kara

2014-07-01

Since 1991, Measurement Science and Technology has awarded a Best Paper prize. The Editorial Board of this journal believe that such a prize is an opportunity to thank authors for submitting their work, and serves as an integral part of the on-going quality review of the journal. The current breadth of topical areas that are covered by MST has made it advisable to expand the recognition of excellent publications. Hence, since 2005 the Editorial Board have presented 'Outstanding Paper Awards'. This year awards were presented in the areas of Fluid Mechanics, Measurement Science, Precision Measurement, Sensors and Sensing Systems, and Optical and Laser-based Techniques. Although the categories mirror subject sections in the journal, the Editorial Board consider articles from all categories in the selection process. 2013 Award Winner—Fluid Mechanics Extraction of skin-friction fields from surface flow visualizations Tianshu Liu Department of Mechanical and Aerospace Engineering, Western Michigan University, Kalamazoo, MI 49008, USA The skin friction or wall shear stress, τ w, for a wall bounded turbulent flow is a quantity of fundamental importance. It is the basis for the wall unit, ν/u τ (kinematic viscosity/friction velocity: [τ w/ρ ]1/2), which establishes the intrinsic length scale in the flow. The selected paper [1] provides a comprehensive review of—and builds upon—prior techniques to obtain τ w values over an area of interest for flow past complex geometries. The quantities that can be measured by optical imaging are shown to be related to the skin friction by the optical flow equation, which in turn is solved numerically as an inverse problem via the variational approach. The paper provides a well defined set of guidelines for other investigators. Detailed examples of skin-friction measurements using luminescent oil films as well as temperature- and pressure-sensitive paints are presented. Quantitative uncertainty estimates are included in the paper. Given the importance of the wall shear stress (skin friction) in fluid mechanics and the notorious difficulty of measuring this quantity directly, this paper is expected to be a seminal contribution. The paper was one of four in the special feature on Wall Shear Stress organized by Professor A Naguib in the December 2013 issue. 2013 Award Winner—Measurement Science Analysis of calibration-free wavelength-scanned wavelength modulation spectroscopy for practical gas sensing using tunable diode lasers K Sun, X Chao, R Sur, C S Goldenstein, J B Jeffries and R K Hanson High Temperature Gasdynamics Laboratory, Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA In the previous two years, the Measurement Science Award has gone to important papers in diagnostic fields, namely particle image velocimetry (PIV [2]) and x-ray micro-computed tomographic systems [3]. This year's award [4] goes to another diagnostic field, infrared spectroscopy for practical gas sensing. Infrared spectroscopy is a very important topic for measurement science, concerned with the monitoring of gases in our environment. Over two decades, this form of spectroscopy has been enabled with the development of tunable diode lasers (TDLs). Hence, tunable diode laser absorption spectroscopy (TDLAS) is now an established method for in situ measurements of gas composition, temperature, pressure and velocity. Gases such as ammonia, methane, carbon dioxide and monoxide, hydrogen chloride, hydrogen fluoride and sulfur dioxide can all be monitored by commercially available systems. Some advances have been associated with improvements in infrared detectors or in the properties of some diode lasers. For homogeneous gases, the interpretation using the Beer-Lambert law and direct absorption (DA) is quite straightforward. DA is the preferred method when an absorption line can be found in the infrared region with an isolated transition of sufficient strength, and with a linewidth small enough to allow the laser to be wavelength-scanned on the absorption line, and just off it (as a reference baseline). Otherwise, wavelength modulation spectroscopy (WMS) is used for those cases where the gas offers small absorbance, or high pressure or for absorbers with closely spaced transitions, which are blended in the wings precluding measurement of a non-absorbing baseline. WMS is a powerful technique, but the interpretation is more complex, and the authors explain in their introduction the strategies that are normally adopted for data interpretation. In this new paper, the authors explain a new strategy for wavelength modulation spectroscopy. The strategy is different in two significant ways. Firstly, the measured laser intensity is used to simulate the transmitted laser intensity. Secondly, digital lock-in and low-pass filter software is used to expand both simulated and measured transmitted laser intensities into harmonics of the modulation frequency. In this way, the analysis scheme does not require an isolated transition; instead it recovers the lineshape for absorption from unresolved blended transitions. The paper goes on to describe an example using this novel method. It discusses the analysis of WMS absorption detection using water as an example. The advantages of the new method are explained, and a comparison is made with the more usual Fourier analysis approach. This paper is excellent in its clarity, presentation and scientific description. Issues have been clearly identified, and a new method of analysis has been presented with some evidence of validation. Its conclusions contain an in-depth summary, and the following 42 references are informative and representative of what is a very large field of study. It was voted as the best paper from a shortlist of 12 nominated papers. 2013 Award Winner—Precision Measurement Interferometric diameter determination of a silicon sphere using a traceable single laser frequency synthesizer Xuejian Wu, Yan Li, Haoyun Wei, Honglei Yang, Guoce Yang and Jitao Zhang State Key Lab of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, People's Republic of China This paper [5] describes the determination of the absolute diameter of a silicon sphere for the Avogadro project using a phase shifting interferometer based on a flat etalon. The absolute diameter is attained by combining the fractional and integral measurement results, which are measured with phase shifting interferometry and frequency sweeping interferometry using laser frequency tuning, respectively. An optical frequency comb is used as the frequency ruler to measure and control the frequency of an external cavity diode laser in order to reduce the uncertainty contribution from the laser frequency on the phase steps to an insignificant level. The Carré algorithm with arbitrary but equal phase steps is used to calculate the fractional interference phases according to the characteristic of single laser frequency synthesiser. The paper provides a comprehensive description of the measurement techniques together with an uncertainty budget for the measurement of a silicon sphere. An overall measurement uncertainty of 5 nm is achieved. This paper has been downloaded more than 130 times since its publication. The selection committee members on the Precision Measurement Award, Dr A Yacoot, Dr P Williams, Dr H Bosse, Professor X Chen and Dr T Eom, selected this paper from a strongly competitive list of several candidates. Considering its impact on accurate evaluation of the measurement of silicon spheres, the paper was selected as the winner of the Precision Measurement Award for 2013. 2013 Award Winner—Sensors and Sensing Systems Enhancing the dynamic range of ultrasound imaging velocimetry using interleaved imaging C Poelma1 and K H Fraser 2 1Laboratory for Aero and Hydrodynamics (3ME-P&E), Delft University of Technology, Leeghwaterstraat 21, 2628 CA Delft, The Netherlands 2Department of Bioengineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK This paper [6] presents an innovative interleaved imaging technique to overcome the dynamic velocity range limitation of current ultrasound imaging velocimetry. Due to the nature of the recording of ultrasound images, the conversion from pixel displacement to velocities is less straightforward since the lines of an image are not recorded at the same time, so the inter-frame time needs to be corrected for any displacement. The upper limit of displacement velocities is widely reported in the literature as a major problem with the best measured in-vivo flow rates of ~ 70-80 cm s-1 or by restricting the field of view to as high as 140 cm s-1. In this study, the authors introduce a novel imaging method that enhances the dynamic range of ultrasound imaging velocimetry by an interleaved read-out approach. Using this technique, the inter-frame time is no longer fixed to the imaging rate and allows for the displacement of fast flows to be reduced by choosing an appropriate image offset parameter. The authors show that this technique allows for measurement of flows of up to 140 cm s-1 with the maximum lateral field of view and unrestricted depth. In their winning paper the authors have very clearly articulated the dynamic range limitations of the flow measurement using ultrasound imaging velocimetry and have very elegantly described the theory and experimental implementation of the interleaved imaging technique. The superior performance of the proposed method is clearly demonstrated through experimental results and images analyzed using the necessary mathematical transforms. The improved dynamic flow rate measurements using ultrasound imaging velocimetry made feasible using this technique are likely to have a significant impact on non-invasive blood flow monitoring for clinical screening and post-operative monitoring. 2013 Award Winner—Optical and Laser-based Techniques Detection of excited level population transfer in an MOT through the measurement of trapped atom number. L Moi1, G Batignani1, A Khanbekyan1, K Khanbekyan1, C Marinelli1, E Mariotti1, L Marmugi1, L Corradi2, A Dainelli2, R Calabrese3, G Mazzocca3, L Tomassetti3 and P Minguzzi4 1CNISM, Physics Department, University of Siena, via Roma 56, 53100 Siena, Italy 2INFN—Laboratori Nazionali di Legnaro, viale dell'Università 2, 35020 Legnaro (PD), Italy 3University of Ferrara and INFN, via Saragat 1, 44122 Ferrara, Italy 4CNISM, Physics Department, University of Pisa, largo Pontecorvo 3, 56127 Pisa, Italy The selected paper [7] applies a direct fluorescence detection scheme to monitor the very low number of trapped atoms, simulating the conditions in a francium magneto-optical trap (MOT). Precise atomic parity nonconservation measurements are inherently difficult due to the fact that extremely weak signals must be detected. By scanning a probe beam across a resonance condition and then detecting the MOT fluorescence, the authors were able to monitor the population transfer from the ground level and the first excited level in the MOT. The significance of this work is that it presents a rapid and flexible method to detect the number of trapped atoms in conditions where very low numbers of these atoms are present. Such high precision measurements are essential in nuclear physics and are fundamental to our understanding of nuclear decay processes. We have selected this article for the Best Paper Award because the measurement technique demonstrated is not only innovative, but also flexible to implement as it is wavelength independent and presents a high signal to noise ratio. The experimental configuration was also extremely well documented in the paper, including a detailed estimate of the detection limits. Data were presented for many different excitation mechanisms to show the wide applicability of the measurement technique. It is expected that this innovative measurement strategy will be seen in successful applications of the study of atomic parity nonconservation in different nuclear particles in the near future. The chairmen would like to thank the authors for choosing to publish their work in Measurement Science and Technology , and hope that other researchers enjoy reading these works and feel encouraged to submit their own best work to the journal. References [1] Liu T 2013 Extraction of skin-friction fields from surface flow visualizations as an inverse problem Meas. Sci. Technol 24 124004 [2] Oishi M, Kinoshita H, Fujii T and Oshima M 2011 Simultaneous measurement of internal and surrounding flows of a moving droplet using multicolour confocal micro-particle image velocimetry micro-PIV Meas. Sci. Technol. 22 105401 [3] Hiller J, Maisl M and Reindl L M 2012 Physical characterization and performance evaluation of an x-ray micro-computed tomography system for dimensional metrology applications Meas. Sci. Technol 23 085404 [4] Sun K, Chao X, Sur R, Goldenstein C S, Jeffries J B and Hanson R K 2013 Analysis of calibration-free wavelength-scanned wavelength modulation spectroscopy for practical gas sensing using tunable diode lasers Meas. Sci. Technol 24 125203 [5] Wu X et al 2013 Interferometric diameter determination of a silicon sphere using a traceable single laser frequency synthesizer Meas. Sci. Technol. 24 115202 [6] Poelma C and Fraser K H 2013 Enhancing the dynamic range of ultrasound imaging velocimetry using interleaved imaging Meas. Sci. Technol. 24 115701 [7] Moi L et al 2013 Detection of excited level population transfer in an MOT through the measurement of trapped atom number Meas. Sci. Technol. 24 015201

Daniel J. Schell | NREL

Science.gov Websites

processing High solids biomass conversion Fermentation process development Separation processes Techno ; Bioresour. Technol. (2010) "An economic comparison of different fermentation configurations to convert

The strongest magnetic barrier in the DIII-D tokamak and comparison with the ASDEX UG

NASA Astrophysics Data System (ADS)

Ali, Halima; Punjabi, Alkesh

2013-05-01

Magnetic perturbations in tokamaks lead to the formation of magnetic islands, chaotic field lines, and the destruction of flux surfaces. Controlling or reducing transport along chaotic field lines is a key challenge in magnetically confined fusion plasmas. A local control method was proposed by Chandre et al. [Nucl. Fusion 46, 33-45 (2006)] to build barriers to magnetic field line diffusion by addition of a small second-order control term localized in the phase space to the field line Hamiltonian. Formation and existence of such magnetic barriers in Ohmically heated tokamaks (OHT), ASDEX UG and piecewise analytic DIII-D [Luxon, J.L.; Davis, L.E., Fusion Technol. 8, 441 (1985)] plasma equilibria was predicted by the authors [Ali, H.; Punjabi, A., Plasma Phys. Control. Fusion 49, 1565-1582 (2007)]. Very recently, this prediction for the DIII-D has been corroborated [Volpe, F.A., et al., Nucl. Fusion 52, 054017 (2012)] by field-line tracing calculations, using experimentally constrained Equilibrium Fit (EFIT) [Lao, et al., Nucl. Fusion 25, 1611 (1985)] DIII-D equilibria perturbed to include the vacuum field from the internal coils utilized in the experiments. This second-order approach is applied to the DIII-D tokamak to build noble irrational magnetic barriers inside the chaos created by the locked resonant magnetic perturbations (RMPs) (m, n)=(3, 1)+(4, 1), with m and n the poloidal and toroidal mode numbers of the Fourier expansion of the magnetic perturbation with amplitude δ. A piecewise, analytic, accurate, axisymmetric generating function for the trajectories of magnetic field lines in the DIII-D is constructed in magnetic coordinates from the experimental EFIT Grad-Shafranov solver [Lao, L, et al., Fusion Sci. Technol. 48, 968 (2005)] for the shot 115,467 at 3000 ms in the DIII-D. A symplectic mathematical map is used to integrate field lines in the DIII-D. A numerical algorithm [Ali, H., et al., Radiat. Eff. Def. Solids Inc. Plasma Sc. Plasma Tech. 165, 83 (2010)] based on continued fraction decomposition of the rotational transform labeling the barriers for selecting and identifying the strongest noble irrational barrier is used. The results are compared and contrasted with our previous results on the ASDEX UG. About six times stronger a barrier can be built in the DIII-D than in the ASDEX UG. High magnetic shear near the separatrix in the DIII-D is inferred as the possible cause of this. Implications of this for the DIII-D and the International Thermonuclear Experimental Reactor (ITER) are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metzler, Dominik; Oehrlein, Gottlieb S., E-mail: oehrlein@umd.edu; Li, Chen

The need for atomic layer etching (ALE) is steadily increasing as smaller critical dimensions and pitches are required in device patterning. A flux-control based cyclic Ar/C{sub 4}F{sub 8} ALE based on steady-state Ar plasma in conjunction with periodic, precise C{sub 4}F{sub 8} injection and synchronized plasma-based low energy Ar{sup +} ion bombardment has been established for SiO{sub 2} [Metzler et al., J. Vac. Sci. Technol. A 32, 020603 (2014)]. In this work, the cyclic process is further characterized and extended to ALE of silicon under similar process conditions. The use of CHF{sub 3} as a precursor is examined and comparedmore » to C{sub 4}F{sub 8}. CHF{sub 3} is shown to enable selective SiO{sub 2}/Si etching using a fluorocarbon (FC) film build up. Other critical process parameters investigated are the FC film thickness deposited per cycle, the ion energy, and the etch step length. Etching behavior and mechanisms are studied using in situ real time ellipsometry and x-ray photoelectron spectroscopy. Silicon ALE shows less self-limitation than silicon oxide due to higher physical sputtering rates for the maximum ion energies used in this work, ranged from 20 to 30 eV. The surface chemistry is found to contain fluorinated silicon oxide during the etching of silicon. Plasma parameters during ALE are studied using a Langmuir probe and establish the impact of precursor addition on plasma properties.« less

On a novel low cost high accuracy experimental setup for tomographic particle image velocimetry

NASA Astrophysics Data System (ADS)

Discetti, Stefano; Ianiro, Andrea; Astarita, Tommaso; Cardone, Gennaro

2013-07-01

This work deals with the critical aspects related to cost reduction of a Tomo PIV setup and to the bias errors introduced in the velocity measurements by the coherent motion of the ghost particles. The proposed solution consists of using two independent imaging systems composed of three (or more) low speed single frame cameras, which can be up to ten times cheaper than double shutter cameras with the same image quality. Each imaging system is used to reconstruct a particle distribution in the same measurement region, relative to the first and the second exposure, respectively. The reconstructed volumes are then interrogated by cross-correlation in order to obtain the measured velocity field, as in the standard tomographic PIV implementation. Moreover, differently from tomographic PIV, the ghost particle distributions of the two exposures are uncorrelated, since their spatial distribution is camera orientation dependent. For this reason, the proposed solution promises more accurate results, without the bias effect of the coherent ghost particles motion. Guidelines for the implementation and the application of the present method are proposed. The performances are assessed with a parametric study on synthetic experiments. The proposed low cost system produces a much lower modulation with respect to an equivalent three-camera system. Furthermore, the potential accuracy improvement using the Motion Tracking Enhanced MART (Novara et al 2010 Meas. Sci. Technol. 21 035401) is much higher than in the case of the standard implementation of tomographic PIV.

Comparing simulation of plasma turbulence with experiment

NASA Astrophysics Data System (ADS)

Ross, David W.; Bravenec, Ronald V.; Dorland, William; Beer, Michael A.; Hammett, G. W.; McKee, George R.; Fonck, Raymond J.; Murakami, Masanori; Burrell, Keith H.; Jackson, Gary L.; Staebler, Gary M.

2002-01-01

The direct quantitative correspondence between theoretical predictions and the measured plasma fluctuations and transport is tested by performing nonlinear gyro-Landau-fluid simulations with the GRYFFIN (or ITG) code [W. Dorland and G. W. Hammett, Phys. Fluids B 5, 812 (1993); M. A. Beer and G. W. Hammett, Phys. Plasmas 3, 4046 (1996)]. In an L-mode reference discharge in the DIII-D tokamak [J. L. Luxon and L. G. Davis, Fusion Technol. 8, 441 (1985)], which has relatively large fluctuations and transport, the turbulence is dominated by ion temperature gradient (ITG) modes. Trapped electron modes and impurity drift waves also play a role. Density fluctuations are measured by beam emission spectroscopy [R. J. Fonck, P. A. Duperrex, and S. F. Paul, Rev. Sci. Instrum. 61, 3487 (1990)]. Experimental fluxes and corresponding diffusivities are analyzed by the TRANSP code [R. J. Hawryluk, in Physics of Plasmas Close to Thermonuclear Conditions, edited by B. Coppi, G. G. Leotta, D. Pfirsch, R. Pozzoli, and E. Sindoni (Pergamon, Oxford, 1980), Vol. 1, p. 19]. The shape of the simulated wave number spectrum is close to the measured one. The simulated ion thermal transport, corrected for E×B low shear, exceeds the experimental value by a factor of 1.5 to 2.0. The simulation overestimates the density fluctuation level by an even larger factor. On the other hand, the simulation underestimates the electron thermal transport, which may be accounted for by modes that are not accessible to the simulation or to the BES measurement.

EDITORIAL: Award for Patrick Gill

NASA Astrophysics Data System (ADS)

Hauptmann, Peter

2007-12-01

On behalf of the journal I would like to congratulate Professor Patrick Gill, a long-serving member of the Editorial Board for Measurement Science and Technology, who has been awarded the prestigious Institute of Physics Young medal and prize for world-leading contributions to optical frequency metrology. He is recognized as the UK leader in the quest for very accurate optical clocks. Professor Gill's work is concerned with the development of cold trapped ion systems as optical frequency standards with potential for future redefinition of the SI second, and the frequency metrology needed to relate optical and microwave standards to high accuracy. Interested readers may wish to read a short review of the wider state-of-the-art development of single cold trapped ion frequency standards, coupled with a more detailed account of results achieved at the National Physical Laboratory, written by Professor Gill and co-workers from NPL: ''Trapped ion optical frequency standards'' by P Gill, G P Barwood, H A Klein, G Huang, S A Webster, P J Blythe, K Hosaka, S N Lea and H S Margolis 2003 Meas. Sci. Technol. 14 (8) 1174-86 He was one of the very early developers of the frequency comb idea, and in 2004 he led an experiment where the femtosecond laser frequency comb measured the prototype optical clock frequency, based on a strontium-ion optical transition, with accuracy close to the capability of the best caesium microwave clocks. Once again I congratulate Professor Gill and wish him every success for his future work.

Atmospheric H2O2 measurement: comparison of cold trap method with impinger bubbling method

NASA Technical Reports Server (NTRS)

Sakugawa, H.; Kaplan, I. R.

1987-01-01

Collection of atmospheric H2O2 was performed by a cold trap method using dry ice-acetone as the refrigerant. The air was drawn by a pump into a glass gas trap immersed in the dry ice-acetone slush in a dewar flask at a flow rate of 2.5 l min-1 for approximately 2 h. Collection efficiency was > 99% and negligible interferences by O3, SO2 or organic matter with the collected H2O2 in the trap were observed. This method was compared with the air impinger bubbling method which has been previously described (Kok et al., 1978a, b, Envir. Sci. Technol. 12, 1072-1080). The measured total peroxide (H2O2 + organic peroxide) values in a series of aim samples collected by the impinger bubbling method (0.06-3.7 ppb) were always higher than those obtained by the cold trap method (0.02-1.2 ppb). Laboratory experiments suggest that the difference in values between the two methods probably results from the aqueous phase generation of H2O2 and organic peroxide in the impinger solution by a reaction of atmospheric O3 with olefinic and aromatic compounds. If these O3-organic compound reactions which occur in the impinger also occur in aqueous droplets in the atmosphere, the process could be very important for aqueous phase generation of H2O2 in clouds and rainwater.

Study of dual radio frequency capacitively coupled plasma: an analytical treatment matched to an experiment

NASA Astrophysics Data System (ADS)

Saikia, P.; Bhuyan, H.; Escalona, M.; Favre, M.; Wyndham, E.; Maze, J.; Schulze, J.

2018-01-01

The behavior of a dual frequency capacitively coupled plasma (2f CCP) driven by 2.26 and 13.56 MHz radio frequency (rf) source is investigated using an approach that integrates a theoretical model and experimental data. The basis of the theoretical analysis is a time dependent dual frequency analytical sheath model that casts the relation between the instantaneous sheath potential and plasma parameters. The parameters used in the model are obtained by operating the 2f CCP experiment (2.26 MHz + 13.56 MHz) in argon at a working pressure of 50 mTorr. Experimentally measured plasma parameters such as the electron density, electron temperature, as well as the rf current density ratios are the inputs of the theoretical model. Subsequently, a convenient analytical solution for the output sheath potential and sheath thickness was derived. A comparison of the present numerical results is done with the results obtained in another 2f CCP experiment conducted by Semmler et al (2007 Plasma Sources Sci. Technol. 16 839). A good quantitative correspondence is obtained. The numerical solution shows the variation of sheath potential with the low and high frequency (HF) rf powers. In the low pressure plasma, the sheath potential is a qualitative measure of DC self-bias which in turn determines the ion energy. Thus, using this analytical model, the measured values of the DC self-bias as a function of low and HF rf powers are explained in detail.

Demonstrating the Value of Fine-resolution Optical Data for Minimising Aliasing Impacts on Biogeochemical Models of Surface Waters

NASA Astrophysics Data System (ADS)

Chappell, N. A.; Jones, T.; Young, P.; Krishnaswamy, J.

2015-12-01

There is increasing awareness that under-sampling may have resulted in the omission of important physicochemical information present in water quality signatures of surface waters - thereby affecting interpretation of biogeochemical processes. For dissolved organic carbon (DOC) and nitrogen this under-sampling can now be avoided using UV-visible spectroscopy measured in-situ and continuously at a fine-resolution e.g. 15 minutes ("real time"). Few methods are available to extract biogeochemical process information directly from such high-frequency data. Jones, Chappell & Tych (2014 Environ Sci Technol: 13289-97) developed one such method using optically-derived DOC data based upon a sophisticated time-series modelling tool. Within this presentation we extend the methodology to quantify the minimum sampling interval required to avoid distortion of model structures and parameters that describe fundamental biogeochemical processes. This shifting of parameters which results from under-sampling is called "aliasing". We demonstrate that storm dynamics at a variety of sites dominate over diurnal and seasonal changes and that these must be characterised by sampling that may be sub-hourly to avoid aliasing. This is considerably shorter than that used by other water quality studies examining aliasing (e.g. Kirchner 2005 Phys Rev: 069902). The modelling approach presented is being developed into a generic tool to calculate the minimum sampling for water quality monitoring in systems driven primarily by hydrology. This is illustrated with fine-resolution, optical data from watersheds in temperate Europe through to the humid tropics.

Comparison of surface vacuum ultraviolet emissions with resonance level number densities. II. Rare-gas plasmas and Ar-molecular gas mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boffard, John B., E-mail: jboffard@wisc.edu; Lin, Chun C.; Wang, Shicong

2015-03-15

Vacuum ultraviolet (VUV) emissions from excited plasma species can play a variety of roles in processing plasmas, including damaging the surface properties of materials used in semiconductor processing. Depending on their wavelength, VUV photons can easily transmit thin upper dielectric layers and affect the electrical characteristics of the devices. Despite their importance, measuring VUV fluxes is complicated by the fact that few materials transmit at VUV wavelengths, and both detectors and windows are easily damaged by plasma exposure. The authors have previously reported on measuring VUV fluxes in pure argon plasmas by monitoring the concentrations of Ar(3p{sup 5}4s) resonance atomsmore » that produce the VUV emissions using noninvasive optical emission spectroscopy in the visible/near-infrared wavelength range [Boffard et al., J. Vac. Sci. Technol., A 32, 021304 (2014)]. Here, the authors extend this technique to other rare-gases (Ne, Kr, and Xe) and argon-molecular gas plasmas (Ar/H{sub 2}, Ar/O{sub 2}, and Ar/N{sub 2}). Results of a model for VUV emissions that couples radiation trapping and the measured rare-gas resonance level densities are compared to measurements made with both a calibrated VUV photodiode and a sodium salicylate fluorescence detection scheme. In these more complicated gas mixtures, VUV emissions from a variety of sources beyond the principal resonance levels of the rare gases are found to contribute to the total VUV flux.« less

Simulations of stress evolution and the current density scaling of electromigration-induced failure times in pure and alloyed interconnects

NASA Astrophysics Data System (ADS)

Park, Young-Joon; Andleigh, Vaibhav K.; Thompson, Carl V.

1999-04-01

An electromigration model is developed to simulate the reliability of Al and Al-Cu interconnects. A polynomial expression for the free energy of solution by Murray [Int. Met. Rev. 30, 211 (1985)] was used to calculate the chemical potential for Al and Cu while the diffusivities were defined based on a Cu-trapping model by Rosenberg [J. Vac. Sci. Technol. 9, 263 (1972)]. The effects of Cu on stress evolution and lifetime were investigated in all-bamboo and near-bamboo stud-to-stud structures. In addition, the significance of the effect of mechanical stress on the diffusivity of both Al and Cu was determined in all-bamboo and near-bamboo lines. The void nucleation and growth process was simulated in 200 μm, stud-to-stud lines. Current density scaling behavior for void-nucleation-limited failure and void-growth-limited failure modes was simulated in long, stud-to-stud lines. Current density exponents of both n=2 for void nucleation and n=1 for void growth failure modes were found in both pure Al and Al-Cu lines. Limitations of the most widely used current density scaling law (Black's equation) in the analysis of the reliability of stud-to-stud lines are discussed. By modifying the input materials properties used in this model (when they are known), this model can be adapted to predict the reliability of other interconnect materials such as pure Cu and Cu alloys.

Image simulation and surface reconstruction of undercut features in atomic force microscopy

NASA Astrophysics Data System (ADS)

Qian, Xiaoping; Villarrubia, John; Tian, Fenglei; Dixson, Ronald

2007-03-01

CD-AFMs (critical dimension atomic force microscopes) are instruments with servo-control of the tip in more than one direction. With appropriately "boot-shaped" or flared tips, such instruments can image vertical or even undercut features. As with any AFM, the image is a dilation of the sample shape with the tip shape. Accurate extraction of the CD requires a correction for the tip effect. Analytical methods to correct images for the tip shape have been available for some time for the traditional (vertical feedback only) AFMs, but were until recently unavailable for instruments with multi-dimensional feedback. Dahlen et al. [J. Vac. Sci. Technol. B23, pp. 2297-2303, (2005)] recently introduced a swept-volume approach, implemented for 2-dimensional (2D) feedback. It permits image simulation and sample reconstruction, techniques previously developed for the traditional instruments, to be extended for the newer tools. We have introduced [X. Qian and J. S. Villarrubia, Ultramicroscopy, in press] an alternative dexel-based method, that does the same in either 2D or 3D. This paper describes the application of this method to sample shapes of interest in semiconductor manufacturing. When the tip shape is known (e.g., by prior measurement using a tip characterizer) a 3D sample surface may be reconstructed from its 3D image. Basing the CD measurement upon such a reconstruction is shown here to remove some measurement artifacts that are not removed (or are incompletely removed) by the existing measurement procedures.

Shrinkage strain-rates of dental resin-monomer and composite systems.

PubMed

Atai, Mohammad; Watts, David C; Atai, Zahra

2005-08-01

The purpose of this study was to investigate the shrinkage strain rate of different monomers, which are commonly used in dental composites and the effect of monomer functionality and molecular mass on the rate. Bis-GMA, TEGDMA, UDMA, MMA, HEMA, HPMA and different ratios of Bis-GMA/TEGDMA were mixed with Camphorquinone and Dimethyl aminoethyle methacrylate as initiator system. The shrinkage strain of the samples photopolymerised at Ca. 550 mW/cm2 and 23 degrees C was measured using the bonded-disk technique of Watts and Cash (Meas. Sci. Technol. 2 (1991) 788-794), and initial shrinkage-strain rates were obtained by numerical differentiation. Shrinkage-strain rates rose rapidly to a maximum, and then fell rapidly upon vitrification. Strain and initial strain rate were dependent upon monomer functionality, molecular mass and viscosity. Strain rates were correlated with Bis-GMA in Bis-GMA/TEGDMA mixtures up to 75-80 w/w%, due to the higher molecular mass of Bis-GMA affecting termination reactions, and then decreased due to its higher viscosity affecting propagation reactions. Monofunctional monomers exhibited lower rates. UDMA, a difunctional monomer of medium viscosity, showed the highest shrinkage strain rate (P < 0.05). Shrinkage strain rate, related to polymerization rate, is an important factor affecting the biomechanics and marginal integrity of composites cured in dental cavities. This study shows how this is related to monomer molecular structure and viscosity. The results are significant for the production, optimization and clinical application of dental composite restoratives.

Capture efficiency of cooking-related fine and ultrafine particles by residential exhaust hoods.

PubMed

Lunden, M M; Delp, W W; Singer, B C

2015-02-01

Effective exhaust hoods can mitigate the indoor air quality impacts of pollutant emissions from residential cooking. This study reports capture efficiencies (CE) measured for cooking-generated particles for scripted cooking procedures in a 121-m3 chamber with kitchenette. CEs also were measured for burner produced CO2 during cooking and separately for pots and pans containing water. The study used four exhaust hoods previously tested by Delp and Singer (Environ. Sci. Technol., 2012, 46, 6167-6173). For pan-frying a hamburger over medium heat on the back burner, CEs for particles were similar to those for burner produced CO2 and mostly above 80%. For stir-frying green beans in a wok (high heat, front burner), CEs for burner CO2 during cooking varied by hood and airflow: CEs were 34-38% for low (51-68 l/s) and 54-72% for high (109-138 l/s) settings. CEs for 0.3-2.0 μm particles during front burner stir-frying were 3-11% on low and 16-70% on high settings. Results indicate that CEs measured for burner CO2 are not predictive of CEs of cooking-generated particles under all conditions, but they may be suitable to identify devices with CEs above 80% both for burner combustion products and for cooking-related particles. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Characterisation of the incident beam and current diffraction capabilities on the VESUVIO spectrometer

NASA Astrophysics Data System (ADS)

Romanelli, G.; Krzystyniak, M.; Senesi, R.; Raspino, D.; Boxall, J.; Pooley, D.; Moorby, S.; Schooneveld, E.; Rhodes, N. J.; Andreani, C.; Fernandez-Alonso, F.

2017-09-01

The VESUVIO spectrometer at the ISIS pulsed neutron and muon source is a unique instrument amongst those available at neutron facilities. This is the only inverted-geometry neutron spectrometer accessing values of energy and wavevector transfer above tens of eV and {\\mathringA}-1 , respectively, and where deep inelastic neutron scattering experiments are routinely performed. As such, the procedure at the base of the technique has been previously described in an article published by this journal (Mayers and Reiter 2012 Meas. Sci. Technol. 23 045902). The instrument has recently witnessed an upsurge of interest due to a new trend to accommodate, within a single experiment, neutron diffraction and transmission measurements in addition to deep inelastic neutron scattering. This work presents a broader description of the instrument following these recent developments. In particular, we assess the absolute intensity and two-dimensional profile of the incident neutron beam and the capabilities of the backscattering diffraction banks. All results are discussed in the light of recent changes to the moderator viewed by the instrument. We find that VESUVIO has to be considered a high-resolution diffractometer as much as other diffractometers at ISIS, with a resolution as high as 2× 10-3 in backscattering. Also, we describe the extension of the wavelength range of the instrument to include lower neutron energies for diffraction measurements, an upgrade that could be readily applied to other neutron instruments as well.

Femtosecond pulsed laser deposition of amorphous, ultrahard boride thin films

NASA Astrophysics Data System (ADS)

Stock, Michael; Molian, Pal

2004-05-01

Amorphous thin films (300-500 nm) of ultrahard AlMgB10 with oxygen and carbon impurities were grown on Si (100) substrates at 300 K using a solid target of AlMgB14 containing a spinel phase (MgAl2O4) and using a 120 fs pulsed, 800 nm wavelength Ti:sapphire laser. The films were subsequently annealed in argon gas up to 1373 K for 2 h. Scanning electron microscopy (SEM) was used to examine the particulate formation, atomic force microscopy was employed to characterize the film surface topography, x-ray diffraction and transmission electron microscopy were used to determine the microstructure, x-ray photoelectron spectroscopy was performed to examine the film composition, and nanoindentation was employed to study the hardness of thin films. The as-deposited and postannealed films (up to 1273 K) had a stochiometry of AlMgB10 with a significant amount of oxygen and carbon impurities and exhibited amorphous structures for a maximum hardness of 40+/-3 GPa. However, postannealing at higher temperatures led to crystallization and transformation of the film to SiB6 with a substantial loss in hardness. Results are also compared with our previous study on 23 ns, 248 nm wavelength (KrF excimer) pulsed laser deposition of AlMgB14 reported in this journal [Y. Tian, A. Constant, C. C. H. Lo, J. W. Anderegg, A. M. Russell, J. E. Snyder, and P. A. Molian, J. Vac. Sci. Technol. A 21, 1055 (2003)]. .

Superconductivity and the environment: a Roadmap

NASA Astrophysics Data System (ADS)

Nishijima, Shigehiro; Eckroad, Steven; Marian, Adela; Choi, Kyeongdal; Kim, Woo Seok; Terai, Motoaki; Deng, Zigang; Zheng, Jun; Wang, Jiasu; Umemoto, Katsuya; Du, Jia; Febvre, Pascal; Keenan, Shane; Mukhanov, Oleg; Cooley, Lance D.; Foley, Cathy P.; Hassenzahl, William V.; Izumi, Mitsuru

2013-11-01

There is universal agreement between the United Nations and governments from the richest to the poorest nations that humanity faces unprecedented global challenges relating to sustainable energy, clean water, low-emission transportation, coping with climate change and natural disasters, and reclaiming use of land. We have invited researchers from a range of eclectic research areas to provide a Roadmap of how superconducting technologies could address these major challenges confronting humanity. Superconductivity has, over the century since its discovery by Kamerlingh Onnes in 1911, promised to provide solutions to many challenges. So far, most superconducting technologies are esoteric systems that are used in laboratories and hospitals. Large science projects have long appreciated the ability of superconductivity to efficiently create high magnetic fields that are otherwise very costly to achieve with ordinary materials. The most successful applications outside of large science are high-field magnets for magnetic resonance imaging, laboratory magnetometers for mineral and materials characterization, filters for mobile communications, and magnetoencephalography for understanding the human brain. The stage is now set for superconductivity to make more general contributions. Humanity uses practically unthinkable amounts of energy to drive our modern way of life. Overall, global power usage has been predicted to almost double from 16.5 to 30 TW in the next four decades (2011 Equinox Summit: Energy 2030 http://wgsi.org/publications-resources). The economy with which electrons carry energy compels the continued quest for efficient superconducting power generation, energy storage, and power transmission. The growing global population requires new arable land and treatment of water, especially in remote areas, and superconductivity offers unique solutions to these problems. Exquisite detectors give warning of changes that are otherwise invisible. Prediction of climate and disasters will be helped by future supercomputer technologies that support huge amounts of data and sophisticated modeling, and with the aid of superconductivity these systems might not require the energy of a large city. We present different sections on applications that could address (or are addressing) a range of environmental issues. The Roadmap covers water purification, power distribution and storage, low-environmental impact transport, environmental sensing (particularly for the removal of unexploded munitions), monitoring the Earth’s magnetic fields for earthquakes and major solar activity, and, finally, developing a petaflop supercomputer that only requires 3% of the current supercomputer power provision while being 50 times faster. Access to fresh water. With only 2.5% of the water on Earth being fresh and climate change modeling forecasting that many areas will become drier, the ability to recycle water and achieve compact water recycling systems for sewage or ground water treatment is critical. The first section (by Nishijima) points to the potential of superconducting magnetic separation to enable water recycling and reuse. Energy. The Equinox Summit held in Waterloo Canada 2011 (2011 Equinox Summit: Energy 2030 http://wgsi.org/publications-resources) identified electricity use as humanity’s largest contributor to greenhouse gas emissions. Our appetite for electricity is growing faster than for any other form of energy. The communiqué from the summit said ‘Transforming the ways we generate, distribute and store electricity is among the most pressing challenges facing society today…. If we want to stabilize CO2 levels in our atmosphere at 550 parts per million, all of that growth needs to be met by non-carbon forms of energy’ (2011 Equinox Summit: Energy 2030 http://wgsi.org/publications-resources). Superconducting technologies can provide the energy efficiencies to achieve, in the European Union alone, 33-65% of the required reduction in greenhouse gas emissions according to the Kyoto Protocol (Hartikainen et al 2003 Supercond. Sci. Technol. 16 963). New technologies would include superconducting energy storage systems to effectively store power generation from renewable sources as well as high-temperature superconducting systems used in generators, transformers and synchronous motors in power stations and heavy-industry facilities. However, to be effective, these systems must be superior to conventional systems and, in reality, market penetration will occur as existing electrical machinery is written off. At current write-off rates, to achieve a 50% transfer to superconducting systems will take 20 years (Hartikainen et al 2003 Supercond. Sci. Technol. 16 963). The Roadmap next considers dc transmission of green power with a section by Eckroad and Marian who provide an update on the development of superconducting power transmission lines in view of recent sustainability studies. The potential of magnetic energy storage is then presented by Coi and Kim, who argue that a successful transition to wind and solar power generation must be harmonized with the conventional electrical network, which requires a storage technology with a fast response and long backup times. Transport. Superconducting Maglev trains and motors for international shipping have the potential to considerably reduce the emissions that contribute to greenhouse gases while improving their economic viability by reducing losses and improving efficiencies. International shipping, alone, contributes 3% of the greenhouse gas emissions. Three sections of the Roadmap identify how high-speed rail can be a major solution to providing fast, low energy, environmentally-friendly transport enabling reduction in automobile and aircraft travel by offering an alternative that is very competitive. With maritime international environmental regulations tightening, HTS motors with the characteristics of high torque and compactness will become important devices for high-performance and low-emission electric ship propulsion systems. A section on the development of a megawatt-class superconducting motor for ship propulsion is presented by Umemoto. Monitoring in manufacturing for waste reduction. Environmental impact from the waste created by the manufacturing sector and the need to make manufacturing efficient can be addressed by terahertz imaging. This technology has great potential in non-destructive testing, industrial process monitoring and control to greatly improve the industry process efficiency and reliability by reducing waste materials and toxic by-products. The section by Du shows how terahertz imaging can provide process and property information such as rust levels under paint that can assist with the reduction of waste in manufacturing and maintenance. Monitoring for naturally occurring disturbances. The environmental and social impact of natural disasters is mounting. Febvre provides the Roadmap for the use of ultra-sensitive magnetometry to understand geomagnetic phenomena and Earth-ionosphere couplings through the study of very small variations of the magnetic field. This magnetic monitoring has many implications for understanding our environment and providing new tools for early warning of natural hazards, either on Earth or in space which will enable us to be better prepared for natural disasters. Restoring environments after military use. Throughout the world, there are many areas confirmed or suspected of being contaminated by unexploded munitions known as unexploded ordnance (UXO). Its presence is the result of wars and training of military forces. Areas affected by UXO contamination are hazardous to the public and have a major influence on the nature of land use. UXO has impact in developed as well as developing nations. For example, the USA has UXO dating back to the American Civil War and countries such as Cambodia are living with landmines as a daily issue due to more recent wars. Underwater UXO has caused severe impacts such as the explosion in 1969 in the waters of Kent in the UK that caused a reading of 4.5 on the Richter scale for earthquake monitors. Another example was a land-based detonation of a 500 kg World War II bomb in Germany killing three people in 2010. There is countless UXO from recent conflicts worldwide. Detection and accurate location with 100% reliability is required to return land to safe civilian use. Keenan provides details of a prototype magnetic gradiometer developed for this purpose. Reducing power needs for high-end IT. Supercomputers are so large that they are close to requiring their own small power plant to support the energy needed to run the computer. For example, in 2011 Facebook data centers and operations used 532 million kW hours of energy. Mukhanov explores the potential of reducing the power dissipation for future supercomputers from more than 500 MW for Exascale systems to 0.2 MW by using superconducting-ferromagnetic Josephson junctions for magnetic memory and programmable logic. Clearly superconductivity is an ultimate energy-saving technology, and its practical implementation will contribute to the reduction of CO2 emissions, improved water purification, reduction of waste and timely preparedness for natural disasters or significant events. This Roadmap shows how the application of superconducting technologies will have a significant impact when they are adopted.

DEMONSTRATION BULLETIN: SOLIDIFICATION/STABILIZATION PROCESS, Hazcon, Inc.

EPA Science Inventory

The solidification/stabilization technology mixes hazardous wastes, cement, water and an additive called Chloranan. Chloranan, a nontoxic chemical, encapsulates organic molecules, rendering them ineffective in retarding or inhibiting solidification. This treatment technol...

Predict-first experimental analysis using automated and integrated magnetohydrodynamic modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lyons, B. C.; Paz-Soldan, C.; Meneghini, O.

An integrated-modeling workflow has been developed in this paper for the purpose of performing predict-first analysis of transient-stability experiments. Starting from an existing equilibrium reconstruction from a past experiment, the workflow couples together the EFIT Grad-Shafranov solver [L. Lao et al., Fusion Sci. Technol. 48, 968 (2005)], the EPED model for the pedestal structure [P. B. Snyder et al., Phys. Plasmas 16, 056118 (2009)], and the NEO drift-kinetic-equation solver [E. A. Belli and J. Candy, Plasma Phys. Controlled Fusion 54, 015015 (2012)] (for bootstrap current calculations) in order to generate equilibria with self-consistent pedestal structures as the plasma shape andmore » various scalar parameters (e.g., normalized β, pedestal density, and edge safety factor [q 95]) are changed. These equilibria are then analyzed using automated M3D-C1 extended-magnetohydrodynamic modeling [S. C. Jardin et al., Comput. Sci. Discovery 5, 014002 (2012)] to compute the plasma response to three-dimensional magnetic perturbations. This workflow was created in conjunction with a DIII-D experiment examining the effect of triangularity on the 3D plasma response. Several versions of the workflow were developed, and the initial ones were used to help guide experimental planning (e.g., determining the plasma current necessary to maintain the constant edge safety factor in various shapes). Subsequent validation with the experimental results was then used to revise the workflow, ultimately resulting in the complete model presented here. We show that quantitative agreement was achieved between the M3D-C1 plasma response calculated for equilibria generated by the final workflow and equilibria reconstructed from experimental data. A comparison of results from earlier workflows is used to show the importance of properly matching certain experimental parameters in the generated equilibria, including the normalized β, pedestal density, and q 95. On the other hand, the details of the pedestal current did not significantly impact the plasma response in these equilibria. A comparison to the experimentally measured plasma response shows mixed agreement, indicating that while the equilibria are predicted well, additional analysis tools may be needed. In conclusion, we note the implications that these results have for the success of future predict-first studies, particularly the need for scans of uncertain parameters and for close collaboration between experimentalists and theorists.« less

Predict-first experimental analysis using automated and integrated magnetohydrodynamic modeling

DOE PAGES

Lyons, B. C.; Paz-Soldan, C.; Meneghini, O.; ...

2018-05-07

An integrated-modeling workflow has been developed in this paper for the purpose of performing predict-first analysis of transient-stability experiments. Starting from an existing equilibrium reconstruction from a past experiment, the workflow couples together the EFIT Grad-Shafranov solver [L. Lao et al., Fusion Sci. Technol. 48, 968 (2005)], the EPED model for the pedestal structure [P. B. Snyder et al., Phys. Plasmas 16, 056118 (2009)], and the NEO drift-kinetic-equation solver [E. A. Belli and J. Candy, Plasma Phys. Controlled Fusion 54, 015015 (2012)] (for bootstrap current calculations) in order to generate equilibria with self-consistent pedestal structures as the plasma shape andmore » various scalar parameters (e.g., normalized β, pedestal density, and edge safety factor [q 95]) are changed. These equilibria are then analyzed using automated M3D-C1 extended-magnetohydrodynamic modeling [S. C. Jardin et al., Comput. Sci. Discovery 5, 014002 (2012)] to compute the plasma response to three-dimensional magnetic perturbations. This workflow was created in conjunction with a DIII-D experiment examining the effect of triangularity on the 3D plasma response. Several versions of the workflow were developed, and the initial ones were used to help guide experimental planning (e.g., determining the plasma current necessary to maintain the constant edge safety factor in various shapes). Subsequent validation with the experimental results was then used to revise the workflow, ultimately resulting in the complete model presented here. We show that quantitative agreement was achieved between the M3D-C1 plasma response calculated for equilibria generated by the final workflow and equilibria reconstructed from experimental data. A comparison of results from earlier workflows is used to show the importance of properly matching certain experimental parameters in the generated equilibria, including the normalized β, pedestal density, and q 95. On the other hand, the details of the pedestal current did not significantly impact the plasma response in these equilibria. A comparison to the experimentally measured plasma response shows mixed agreement, indicating that while the equilibria are predicted well, additional analysis tools may be needed. In conclusion, we note the implications that these results have for the success of future predict-first studies, particularly the need for scans of uncertain parameters and for close collaboration between experimentalists and theorists.« less

Predict-first experimental analysis using automated and integrated magnetohydrodynamic modeling

NASA Astrophysics Data System (ADS)

Lyons, B. C.; Paz-Soldan, C.; Meneghini, O.; Lao, L. L.; Weisberg, D. B.; Belli, E. A.; Evans, T. E.; Ferraro, N. M.; Snyder, P. B.

2018-05-01

An integrated-modeling workflow has been developed for the purpose of performing predict-first analysis of transient-stability experiments. Starting from an existing equilibrium reconstruction from a past experiment, the workflow couples together the EFIT Grad-Shafranov solver [L. Lao et al., Fusion Sci. Technol. 48, 968 (2005)], the EPED model for the pedestal structure [P. B. Snyder et al., Phys. Plasmas 16, 056118 (2009)], and the NEO drift-kinetic-equation solver [E. A. Belli and J. Candy, Plasma Phys. Controlled Fusion 54, 015015 (2012)] (for bootstrap current calculations) in order to generate equilibria with self-consistent pedestal structures as the plasma shape and various scalar parameters (e.g., normalized β, pedestal density, and edge safety factor [q95]) are changed. These equilibria are then analyzed using automated M3D-C1 extended-magnetohydrodynamic modeling [S. C. Jardin et al., Comput. Sci. Discovery 5, 014002 (2012)] to compute the plasma response to three-dimensional magnetic perturbations. This workflow was created in conjunction with a DIII-D experiment examining the effect of triangularity on the 3D plasma response. Several versions of the workflow were developed, and the initial ones were used to help guide experimental planning (e.g., determining the plasma current necessary to maintain the constant edge safety factor in various shapes). Subsequent validation with the experimental results was then used to revise the workflow, ultimately resulting in the complete model presented here. We show that quantitative agreement was achieved between the M3D-C1 plasma response calculated for equilibria generated by the final workflow and equilibria reconstructed from experimental data. A comparison of results from earlier workflows is used to show the importance of properly matching certain experimental parameters in the generated equilibria, including the normalized β, pedestal density, and q95. On the other hand, the details of the pedestal current did not significantly impact the plasma response in these equilibria. A comparison to the experimentally measured plasma response shows mixed agreement, indicating that while the equilibria are predicted well, additional analysis tools may be needed. Finally, we note the implications that these results have for the success of future predict-first studies, particularly the need for scans of uncertain parameters and for close collaboration between experimentalists and theorists.

Otolith Asymmetry and kinetotic Behaviour of Fish in Parabolic Flights and under simulated Parabolic Flight "Micro"Gravity - a Drop-Tower Experiment

NASA Astrophysics Data System (ADS)

Knie, M.; Hilbig, R.; Anken, R.

We have shown earlier that some fish of a given batch reveal motion sickness a kinetosis at the transition from earth gravity to diminished gravity The percentual ratios of the various types of behaviour normal swimming and kinetotic swimming kinetotic specimens revealed looping responses LR or spinning movements SM however highly differed depending on the quality of diminished gravity Anken and Hilbig Microgravity Sci Technol 15 52-57 2004 Whereas kinetoses were exhibited by some 90 of the individuals who had experienced flights at high quality microgravity HQM 10-6g ZARM drop-tower only some 15-25 depending on the batch of all animals had shown a kinetotic behaviour during parabolic aircraft flights PFs low quality microgravity LQM 0 03-0 05g Probably LQM is sufficient for most fish to be perceived - in relation to the individual shape or weight of otoliths and thus the performance of the vestibular system - and used as a cue for postural control In striking contrast to the results gained using PF specimens according to which otolith asymmetry differences in the size and calcium incorporation of the inner ear stones between the left and right side of the body was significantly higher in kinetotic specimens as compared to normally swimming fish a comparable asymmetry between the kinetotically and normally swimming drop-tower samples could statistically not be verified Anken et al Adv Space Res submitted The present study was designed to further elucidate the role of otolith asymmetry concerning an individually different

State of the art on granular sludge by using bibliometric analysis.

PubMed

Zheng, Tianlong; Li, Pengyu; Wu, Wenjun; Liu, Jianguo; Shi, Zhining; Guo, Xuesong; Liu, Junxin

2018-04-01

With rapid industrialization and urbanization in the nineteenth century, the activated sludge process (ASP) has experienced significant steps forward in the face of greater awareness of and sensitivity toward water-related environmental problems. Compared with conventional flocculent ASP, the major advantages of granular sludge are characterized by space saving and resource recovery, where the methane and hydrogen recovery in anaerobic granular and 50% more space saving, 30-50% of energy consumption reduction, 75% of footprint cutting, and even alginate recovery in aerobic granular. Numerous engineers and scientists have made great efforts to explore the superiority over the last 40 years. Therefore, a bibliometric analysis was desired to trace the global trends of granular sludge research from 1992 to 2016 indexed in the SCI-EXPANDED. Articles were published in 276 journals across 44 subject categories spanning 1420 institutes across 68 countries. Bioresource Technology (293, 11.9%), Water Research (235, 9.6%), and Applied Microbiology and Biotechnology (127, 5.2%) dominated in top three journals. The Engineering (991, 40.3%), China (906, 36.9%), and Harbin Inst Technol, China (114, 4.6%) were the most productive subject category, country, and institution, respectively. The hotspot is the emerging techniques depended on granular reactors in response to the desired removal requirements and bio-energy production (primarily in anaerobic granular sludge). In view of advanced and novel bio-analytical methods, the characteristics, functions, and mechanisms for microbial granular were further revealed in improving and innovating the granulation techniques. Therefore, a promising technique armed with strengthened treatment efficiency and efficient resource and bio-energy recovery can be achieved.

Quantification of oxide particle composition in model oxide dispersion strengthened steel alloys.

PubMed

London, A J; Lozano-Perez, S; Moody, M P; Amirthapandian, S; Panigrahi, B K; Sundar, C S; Grovenor, C R M

2015-12-01

Oxide dispersion strengthened ferritic steels (ODS) are being considered for structural components of future designs of fission and fusion reactors because of their impressive high-temperature mechanical properties and resistance to radiation damage, both of which arise from the nanoscale oxide particles they contain. Because of the critical importance of these nanoscale phases, significant research activity has been dedicated to analysing their precise size, shape and composition (Odette et al., Annu. Rev. Mater. Res. 38 (2008) 471-503 [1]; Miller et al., Mater. Sci. Technol. 29(10) (2013) 1174-1178 [2]). As part of a project to develop new fuel cladding alloys in India, model ODS alloys have been produced with the compositions, Fe-0.3Y2O3, Fe-0.2Ti-0.3Y2O3 and Fe-14Cr-0.2Ti-0.3Y2O3. The oxide particles in these three model alloys have been studied by APT in their as-received state and following ion irradiation (as a proxy for neutron irradiation) at various temperatures. In order to adequately quantify the composition of the oxide clusters, several difficulties must be managed, including issues relating to the chemical identification (ranging and variable peak-overlaps); trajectory aberrations and chemical structure; and particle sizing. This paper presents how these issues can be addressed by the application of bespoke data analysis tools and correlative microscopy. A discussion follows concerning the achievable precision in these measurements, with reference to the fundamental limiting factors. Copyright © 2015 Elsevier B.V. All rights reserved.

On non-equilibrium atmospheric pressure plasma jets and plasma bullet

NASA Astrophysics Data System (ADS)

Lu, Xinpei

2012-10-01

Because of the enhanced plasma chemistry, atmospheric pressure nonequilibrium plasmas (APNPs) have been widely studied for several emerging applications such as biomedical applications. For the biomedical applications, plasma jet devices, which generate plasma in open space (surrounding air) rather than in confined discharge gaps only, have lots of advantages over the traditional dielectric barrier discharge (DBD) devices. For example, it can be used for root canal disinfection, which can't be realized by the traditional plasma device. On the other hand, currently, the working gases of most of the plasma jet devices are noble gases or the mixtures of the noble gases with small amount of O2, or air. If ambient air is used as the working gas, several serious difficulties are encountered in the plasma generation process. Amongst these are high gas temperatures and disrupting instabilities. In this presentation, firstly, a brief review of the different cold plasma jets developed to date is presented. Secondly, several different plasma jet devices developed in our lab are reported. The effects of various parameters on the plasma jets are discussed. Finally, one of the most interesting phenomena of APNP-Js, the plasma bullet is discussed and its behavior is described. References: [1] X. Lu, M. Laroussi, V. Puech, Plasma Sources Sci. Technol. 21, 034005 (2012); [2] Y. Xian, X. Lu, S. Wu, P. Chu, and Y. Pan, Appl. Phys. Lett. 100, 123702 (2012); [3] X. Pei, X. Lu, J. Liu, D. Liu, Y. Yang, K. Ostrikov, P. Chu, and Y. Pan, J. Phys. D 45, 165205 (2012).

Iodine-frequency-stabilized laser diode and displacement-measuring interferometer based on sinusoidal phase modulation

NASA Astrophysics Data System (ADS)

Duong, Quang Anh; Vu, Thanh Tung; Higuchi, Masato; Wei, Dong; Aketagawa, Masato

2018-06-01

We propose a sinusoidal phase modulation method to achieve both the frequency stabilization of an external-cavity laser diode (ECLD) to an 127I2 saturated absorption transition near 633 nm and displacement measurement using a Mach–Zehnder interferometer. First, the frequency of the ECLD is stabilized to the b 21 hyperfine component of the P(33) 6-3 transition of 127I2 by combining sinusoidal phase modulation by an electro-optic modulator and frequency modulation spectroscopy by chopping the pump beam using an acousto-optic modulator. Even though a small modulation index of m  =  3.768 rad is utilized, a relative frequency stability of 10‑11 order is obtained over a sampling time of 400 s. Secondly, the frequency-stabilized ECLD is applied as a light source to a Mach–Zehnder interferometer. From the two consecutive modulation harmonics (second and third orders) involved in the interferometer signal, the displacement of the moving mirror is determined for four optical path differences (L 0  =  100, 200, 500, and 1000 mm). The measured modulation indexes for the four optical path differences coincide with the designated value (3.768 rad) within 0.5%. Compared with the sinusoidal frequency modulation Michelson interferometer (Vu et al 2016 Meas. Sci. Technol. 27 105201) which was demonstrated by some of the same authors of this paper, the phase modulation Mach–Zhender interferometer could fix the modulation index to a constant value for the four optical path differences. In this report, we discuss the measurement principle, experimental system, and results.

Measuring time of flight of fusion products in an inertial electrostatic confinement fusion device for spatial profiling of fusion reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donovan, D. C.; Boris, D. R.; Kulcinski, G. L.

2013-03-15

A new diagnostic has been developed that uses the time of flight (TOF) of the products from a nuclear fusion reaction to determine the location where the fusion reaction occurred. The TOF diagnostic uses charged particle detectors on opposing sides of the inertial electrostatic confinement (IEC) device that are coupled to high resolution timing electronics to measure the spatial profile of fusion reactions occurring between the two charged particle detectors. This diagnostic was constructed and tested by the University of Wisconsin-Madison Inertial Electrostatic Confinement Fusion Group in the IEC device, HOMER, which accelerates deuterium ions to fusion relevant energies inmore » a high voltage ({approx}100 kV), spherically symmetric, electrostatic potential well [J. F. Santarius, G. L. Kulcinski, R. P. Ashley, D. R. Boris, B. B. Cipiti, S. K. Murali, G. R. Piefer, R. F. Radel, T. E. Radel, and A. L. Wehmeyer, Fusion Sci. Technol. 47, 1238 (2005)]. The TOF diagnostic detects the products of D(d,p)T reactions and determines where along a chord through the device the fusion event occurred. The diagnostic is also capable of using charged particle spectroscopy to determine the Doppler shift imparted to the fusion products by the center of mass energy of the fusion reactants. The TOF diagnostic is thus able to collect spatial profiles of the fusion reaction density along a chord through the device, coupled with the center of mass energy of the reactions occurring at each location. This provides levels of diagnostic detail never before achieved on an IEC device.« less

New Insight into the Local Structure of Hydrous Ferric Arsenate Using Full-Potential Multiple Scattering Analysis, Density Functional Theory Calculations, and Vibrational Spectroscopy.

PubMed

Wang, Shaofeng; Ma, Xu; Zhang, Guoqing; Jia, Yongfeng; Hatada, Keisuke

2016-11-15

Hydrous ferric arsenate (HFA) is an important arsenic-bearing precipitate in the mining-impacted environment and hydrometallurgical tailings. However, there is no agreement on its local atomic structure. The local structure of HFA was reprobed by employing a full-potential multiple scattering (FPMS) analysis, density functional theory (DFT) calculations, and vibrational spectroscopy. The FPMS simulations indicated that the coordination number of the As-Fe, Fe-As, or both in HFA was approximately two. The DFT calculations constructed a structure of HFA with the formula of Fe(HAsO 4 ) x (H 2 AsO 4 ) 1-x (OH) y ·zH 2 O. The presence of protonated arsenate in HFA was also evidenced by vibrational spectroscopy. The As and Fe K-edge X-ray absorption near-edge structure spectra of HFA were accurately reproduced by FPMS simulations using the chain structure, which was also a reasonable model for extended X-Ray absorption fine structure fitting. The FPMS refinements indicated that the interatomic Fe-Fe distance was approximately 5.2 Å, consistent with that obtained by Mikutta et al. (Environ. Sci. Technol. 2013, 47 (7), 3122-3131) using wavelet analysis. All of the results suggested that HFA was more likely to occur as a chain with AsO 4 tetrahedra and FeO 6 octahedra connecting alternately in an isolated bidentate-type fashion. This finding is of significance for understanding the fate of arsenic and the formation of ferric arsenate minerals in an acidic environment.

Model analysis of secondary organic aerosol formation by glyoxal in laboratory studies: the case for photoenhanced chemistry.

PubMed

Sumner, Andrew J; Woo, Joseph L; McNeill, V Faye

2014-10-21

The reactive uptake of glyoxal by atmospheric aerosols is believed to be a significant source of secondary organic aerosol (SOA). Several recent laboratory studies have been performed with the goal of characterizing this process, but questions remain regarding the effects of photochemistry on SOA growth. We applied GAMMA (McNeill et al. Environ. Sci. Technol. 2012, 46, 8075-8081), a photochemical box model with coupled gas-phase and detailed aqueous aerosol-phase chemistry, to simulate aerosol chamber studies of SOA formation by the uptake of glyoxal by wet aerosol under dark and irradiated conditions (Kroll et al. J. Geophys. Res. 2005, 110 (D23), 1-10; Volkamer et al. Atmos. Chem. Phys. 2009, 9, 1907-1928; Galloway et al. Atmos. Chem. Phys. 2009, 9, 3331- 306 3345 and Geophys. Res. Lett. 2011, 38, L17811). We find close agreement between simulated SOA growth and the results of experiments conducted under dark conditions using values of the effective Henry's Law constant of 1.3-5.5 × 10(7) M atm(-1). While irradiated conditions led to the production of some organic acids, organosulfates, and other oxidation products via well-established photochemical mechanisms, these additional product species contribute negligible aerosol mass compared to the dark uptake of glyoxal. Simulated results for irradiated experiments therefore fell short of the reported SOA mass yield by up to 92%. This suggests a significant light-dependent SOA formation mechanism that is not currently accounted for by known bulk photochemistry, consistent with recent laboratory observations of SOA production via photosensitizer chemistry.

Reconstruction of the static magnetic field of a magnetron

NASA Astrophysics Data System (ADS)

Krüger, Dennis; Köhn, Kevin; Gallian, Sara; Brinkmann, Ralf Peter

2018-06-01

The simulation of magnetron discharges requires a quantitatively correct mathematical model of the magnetic field structure. This study presents a method to construct such a model on the basis of a spatially restricted set of experimental data and a plausible a priori assumption on the magnetic field configuration. The example in focus is that of a planar circular magnetron. The experimental data are Hall probe measurements of the magnetic flux density in an accessible region above the magnetron plane [P. D. Machura et al., Plasma Sources Sci. Technol. 23, 065043 (2014)]. The a priori assumption reflects the actual design of the device, and it takes the magnetic field emerging from a center magnet of strength m C and vertical position d C and a ring magnet of strength m R , vertical position d R , and radius R. An analytical representation of the assumed field configuration can be formulated in terms of generalized hypergeometric functions. Fitting the ansatz to the experimental data with a least square method results in a fully specified analytical field model that agrees well with the data inside the accessible region and, moreover, is physically plausible in the regions outside of it. The outcome proves superior to the result of an alternative approach which starts from a multimode solution of the vacuum field problem formulated in terms of polar Bessel functions and vertical exponentials. As a first application of the obtained field model, typical electron and ion Larmor radii and the gradient and curvature drift velocities of the electron guiding center are calculated.

Relativistic R -matrix calculations for the electron-impact excitation of neutral molybdenum

NASA Astrophysics Data System (ADS)

Smyth, R. T.; Johnson, C. A.; Ennis, D. A.; Loch, S. D.; Ramsbottom, C. A.; Ballance, C. P.

2017-10-01

A recent PISCES-B Mod experiment [Nishijima et al., J. Phys. B 43, 225701 (2010), 10.1088/0953-4075/43/22/225701] has revealed up to a factor of 5 discrepancy between measurement and the two existing theoretical models [Badnell et al., J. Phys. B 29, 3683 (1996), 10.1088/0953-4075/29/16/014; Bartschat et al., J. Phys. B 35, 2899 (2002), 10.1088/0953-4075/35/13/305], providing important diagnostics for Mo i. In the following paper we address this issue by employing a relativistic atomic structure and R -matrix scattering calculations to improve upon the available models for future applications and benchmark results against a recent Compact Toroidal Hybrid experiment [Hartwell et al., Fusion Sci. Technol. 72, 76 (2017), 10.1080/15361055.2017.1291046]. We determine the atomic structure of Mo i using grasp0, which implements the multiconfigurational Dirac-Fock method. Fine structure energies and radiative transition rates are presented and compared to existing experimental and theoretical values. The electron-impact excitation of Mo i is investigated using the relativistic R -matrix method and the parallel versions of the Dirac atomic R -matrix codes. Electron-impact excitation cross sections are presented and compared to the few available theoretical cross sections. Throughout, our emphasis is on improving the results for the z 1,2,3o5P →a S52,z 2,3,4o7P → a S73 and y 2,3,4o7P → a S73 electric dipole transitions of particular relevance for diagnostic work.

Measurements and modeling of the impact of weak magnetic fields on the plasma properties of a planar slot antenna driven plasma source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshikawa, Jun, E-mail: jun.yoshikawa@tel.com; Susa, Yoshio; Ventzek, Peter L. G.

The radial line slot antenna plasma source is a type of surface wave plasma source driven by a planar slot antenna. Microwave power is transmitted through a slot antenna structure and dielectric window to a plasma characterized by a generation zone adjacent to the window and a diffusion zone that contacts a substrate. The diffusion zone is characterized by a very low electron temperature. This renders the source useful for soft etch applications and thin film deposition processes requiring low ion energy. Another property of the diffusion zone is that the plasma density tends to decrease from the axis tomore » the walls under the action of ambipolar diffusion at distances far from where the plasma is generated. A previous simulation study [Yoshikawa and. Ventzek, J. Vac. Sci. Technol. A 31, 031306 (2013)] predicted that the anisotropy in transport parameters due to weak static magnetic fields less than 50 G could be leveraged to manipulate the plasma profile in the radial direction. These simulations motivated experimental tests in which weak magnetic fields were applied to a radial line slot antenna source. Plasma absorption probe measurements of electron density and etch rate showed that the magnetic fields remote from the wafer were able to manipulate both parameters. A summary of these results is presented in this paper. Argon plasma simulation trends are compared with experimental plasma and etch rate measurements. A test of the impact of magnetic fields on charge up damage showed no perceptible negative effect.« less

A status report of the multipurpose superconducting electron cyclotron resonance ion source.

PubMed

Ciavola, G; Gammino, S; Barbarino, S; Celona, L; Consoli, F; Gallo, G; Maimone, F; Mascali, D; Passarello, S; Galatà, A; Tinschert, K; Spaedtke, P; Lang, R; Maeder, J; Rossbach, J; Koivisto, H; Savonen, M; Koponen, T; Suominen, P; Ropponen, T; Baruè, C; Lechartier, M; Beijers, J P M; Brandenburg, S; Kremers, H R; Vanrooyen, D; Kuchler, D; Scrivens, R; Schachter, L; Dobrescu, S; Stiebing, K

2008-02-01

Intense heavy ion beam production with electron cyclotron resonance (ECR) ion sources is a common requirement for many of the accelerators under construction in Europe and elsewhere. An average increase of about one order of magnitude per decade in the performance of ECR ion sources was obtained up to now since the time of pioneering experiment of R. Geller at CEA, Grenoble, and this trend is not deemed to get the saturation at least in the next decade, according to the increased availability of powerful magnets and microwave generators. Electron density above 10(13) cm(-3) and very high current of multiply charged ions are expected with the use of 28 GHz microwave heating and of an adequate plasma trap, with a B-minimum shape, according to the high B mode concept [S. Gammino and G. Ciavola, Plasma Sources Sci. Technol. 5, 19 (1996)]. The MS-ECRIS ion source has been designed following this concept and its construction is underway at GSI, Darmstadt. The project is the result of the cooperation of nine European institutions with the partial funding of EU through the sixth Framework Programme. The contribution of different institutions has permitted to build in 2006-2007 each component at high level of expertise. The description of the major components will be given in the following with a view on the planning of the assembly and commissioning phase to be carried out in fall 2007. An outline of the experiments to be done with the MS-ECRIS source in the next two years will be presented.

Production of internal transport barriers via self-generated mean flows in Alcator C-Moda)

NASA Astrophysics Data System (ADS)

Fiore, C. L.; Ernst, D. R.; Podpaly, Y. A.; Mikkelsen, D.; Howard, N. T.; Lee, Jungpyo; Reinke, M. L.; Rice, J. E.; Hughes, J. W.; Ma, Y.; Rowan, W. L.; Bespamyatnov, I.

2012-05-01

New results suggest that changes observed in the intrinsic toroidal rotation influence the internal transport barrier (ITB) formation in the Alcator C-Mod tokamak [E. S. Marmar and Alcator C-Mod group, Fusion Sci. Technol. 51, 261 (2007)]. These arise when the resonance for ion cyclotron range of frequencies (ICRF) minority heating is positioned off-axis at or outside of the plasma half-radius. These ITBs form in a reactor relevant regime, without particle or momentum injection, with Ti ≈ Te, and with monotonic q profiles (qmin < 1). C-Mod H-mode plasmas exhibit strong intrinsic co-current rotation that increases with increasing stored energy without external drive. When the resonance position is moved off-axis, the rotation decreases in the center of the plasma resulting in a radial toroidal rotation profile with a central well which deepens and moves farther off-axis when the ICRF resonance location reaches the plasma half-radius. This profile results in strong E × B shear (>1.5 × 105 rad/s) in the region where the ITB foot is observed. Gyrokinetic analyses indicate that this spontaneous shearing rate is comparable to the linear ion temperature gradient (ITG) growth rate at the ITB location and is sufficient to reduce the turbulent particle and energy transport. New and detailed measurement of the ion temperature demonstrates that the radial profile flattens as the ICRF resonance position moves off axis, decreasing the drive for the ITG the instability as well. These results are the first evidence that intrinsic rotation can affect confinement in ITB plasmas.

Ultra-high-speed 3D astigmatic particle tracking velocimetry: application to particle-laden supersonic impinging jets

NASA Astrophysics Data System (ADS)

Buchmann, N. A.; Cierpka, C.; Kähler, C. J.; Soria, J.

2014-11-01

The paper demonstrates ultra-high-speed three-component, three-dimensional (3C3D) velocity measurements of micron-sized particles suspended in a supersonic impinging jet flow. Understanding the dynamics of individual particles in such flows is important for the design of particle impactors for drug delivery or cold gas dynamic spray processing. The underexpanded jet flow is produced via a converging nozzle, and micron-sized particles ( d p = 110 μm) are introduced into the gas flow. The supersonic jet impinges onto a flat surface, and the particle impact velocity and particle impact angle are studied for a range of flow conditions and impingement distances. The imaging system consists of an ultra-high-speed digital camera (Shimadzu HPV-1) capable of recording rates of up to 1 Mfps. Astigmatism particle tracking velocimetry (APTV) is used to measure the 3D particle position (Cierpka et al., Meas Sci Technol 21(045401):13, 2010) by coding the particle depth location in the 2D images by adding a cylindrical lens to the high-speed imaging system. Based on the reconstructed 3D particle positions, the particle trajectories are obtained via a higher-order tracking scheme that takes advantage of the high temporal resolution to increase robustness and accuracy of the measurement. It is shown that the particle velocity and impingement angle are affected by the gas flow in a manner depending on the nozzle pressure ratio and stand-off distance where higher pressure ratios and stand-off distances lead to higher impact velocities and larger impact angles.

Analytical Solution for Reactive Solute Transport Considering Incomplete Mixing

NASA Astrophysics Data System (ADS)

Bellin, A.; Chiogna, G.

2013-12-01

The laboratory experiments of Gramling et al. (2002) showed that incomplete mixing at the pore scale exerts a significant impact on transport of reactive solutes and that assuming complete mixing leads to overestimation of product concentration in bimolecular reactions. We consider here the family of equilibrium reactions for which the concentration of the reactants and the product can be expressed as a function of the mixing ratio, the concentration of a fictitious non reactive solute. For this type of reactions we propose, in agreement with previous studies, to model the effect of incomplete mixing at scales smaller than the Darcy scale assuming that the mixing ratio is distributed within an REV according to a Beta distribution. We compute the parameters of the Beta model by imposing that the mean concentration is equal to the value that the concentration assumes at the continuum Darcy scale, while the variance decays with time as a power law. We show that our model reproduces the concentration profiles of the reaction product measured in the Gramling et al. (2002) experiments using the transport parameters obtained from conservative experiments and an instantaneous reaction kinetic. The results are obtained applying analytical solutions both for conservative and for reactive solute transport, thereby providing a method to handle the effect of incomplete mixing on multispecies reactive solute transport, which is simpler than other previously developed methods. Gramling, C. M., C. F. Harvey, and L. C. Meigs (2002), Reactive transport in porous media: A comparison of model prediction with laboratory visualization, Environ. Sci. Technol., 36(11), 2508-2514.

New Low-Temperature Magnetic Data Acquired on Synthetic Lepidocrocite

NASA Astrophysics Data System (ADS)

Guyodo, Y.; Bonville, P.; Ona-Nguema, G.; Carvallo, C.; Wang, Y.; Morin, G.

2007-12-01

Lepidocrocite (γ-FeOOH) is an iron oxyhydroxide commonly found in the environment, which is assumed to be antiferromagnetic with a small ferromagnetic-like behavior and a Néel temperature of about 50K (e.g., Hirt et al., 2002, JGR, 107, 10.1029/2001JB000242). It is currently used as starting material in bio- reduction experiments leading to the formation of Fe(II)-bearing minerals such as green rusts, magnetite, and siderite (e.g., Ona-Nguema et al., 2002, Environ. Sci. Technol., 36, 16-20). Both initial and resulting materials are being characterized using various techniques including low-temperature magnetic methods. At this meeting, results obtained on the initial synthetic lepidocrocite samples will be presented, which describe an unusual magnetic behavior. In particular, field cooled and zero field cooled induced magnetization curves (obtained using a 5mT magnetic induction) merge at a temperature around 150K (well above 50K). Below this temperature, the difference between the two curves can be qualified as a remanent magnetization, acquired during cooling of the sample in the presence of a magnetic field. As a consequence, some ferromagnetic-like behavior persists at temperatures above the admitted Néel temperature. The cooling/warming cycle of the room temperature remanent magnetization (acquired using a 2.5T magnetic induction) also indicates that some remanence can be acquired well above that temperature. Other types of measurement have been performed in order to better constrain the low-temperature magnetic behavior of these samples, in particular using a high-field VSM.

An area-preserving mapping in natural canonical coordinates for magnetic field line trajectories in the DIII-D tokamak

NASA Astrophysics Data System (ADS)

Punjabi, Alkesh

2009-11-01

The new approach of integrating magnetic field line trajectories in natural canonical coordinates (Punjabi and Ali 2008 Phys. Plasmas 15 122502) in divertor tokamaks is used for the DIII-D tokamak (Luxon and Davis1985 Fusion Technol. 8 441). The equilibrium EFIT data (Evans et al 2004 Phys. Rev. Lett. 92 235003, Lao et al 2005 Fusion Sci. Technol. 48 968) for the DIII-D tokamak shot 115467 at 3000 ms is used to construct the equilibrium generating function (EGF) for the DIII-D in natural canonical coordinates. The EGF gives quite an accurate representation of the closed and open equilibrium magnetic surfaces near the separatrix, the separatrix, the position of the X-point and the poloidal magnetic flux inside the ideal separatrix in the DIII-D. The equilibrium safety factor q from the EGF is somewhat smaller than the DIII-D EFIT q profile. The equilibrium safety factor is calculated from EGF as described in the previous paper (Punjabi and Ali 2008 Phys. Plasmas 15 122502). Here the safety factor for the open surfaces in the DIII-D is calculated. A canonical transformation is used to construct a symplectic mapping for magnetic field line trajectories in the DIII-D in natural canonical coordinates. The map is explored in more detail in this work, and is used to calculate field line trajectories in the DIII-D tokamak. The continuous analogue of the map does not distort the DIII-D magnetic surfaces in different toroidal planes between successive iterations of the map. The map parameter k can represent effects of magnetic asymmetries in the DIII-D. These effects in the DIII-D are illustrated. The DIII-D map is then used to calculate stochastic broadening of the ideal separatrix from the topological noise and field errors, the low mn, the high mn and peeling-ballooning magnetic perturbations in the DIII-D. The width of the stochastic layer scales as 1/2 power of amplitude with a maximum deviation of 6% from the Boozer-Rechester scaling (Boozer and Rechester 1978 Phys. Fluids 21 682). The loss of poloidal flux scales linearly with the amplitude of perturbation with a maximum deviation of 10% from linearity. Perturbations with higher mode numbers result in higher stochasticity. The higher the complexity and coupling in the equilibrium magnetic geometry, the closer is the scaling to the Boozer-Rechester scaling of width. The comparison of the EGF for the simple map (Punjabi et al 1992 Phys. Rev. Lett. 69 3322) with that of the DIII-D shows that the more complex the magnetic geometry and the more coupling of modes in equilibrium, the more robust or resilient is the system against the chaos-inducing, symmetry-breaking perturbations.

Army Reserve Component Personalized Empowerment Program (ARCPEP)

DTIC Science & Technology

2010-10-01

in U.S. hospitals—2007. Am J Health Syst Pharm 2008; 65:2244-64 2. Hardiker NR, Grant MJ. Barriers and facilitators that affect public engagement with eHealth services. Stud Health Technol Inform 2010; 160:13-7

Transforming NAD 27 and NAD 83 positions : making legacy mapping and surveys GPS compatible.

DOT National Transportation Integrated Search

2015-06-01

The Connecticut Department of Transportation (CTDOT) and the University of Connecticut are creating a real-time network (RTN) to make real-time surveying widely available in Connecticut. This RTN uses global navigation satellite system (GNSS) technol...

Determination of the Threshold of Gravity for the Susceptibility to Kinetosis in Fish - a Centrifuge Experiment in the ZARM Drop-Tower employing gradually reduced Gravity

NASA Astrophysics Data System (ADS)

Anken, R.; Hilbig, R.

In the course of earlier experiments at diminished gravity conditions we have successfully used larval cichlid fish Oreochromis mossambicus as a vertebrate model system in investigating the basic cause of susceptibility to motion sickness kinetosis It was observed that most animals of a given batch reveal kinetoses i e performing looping responses LR or spinning movements SM at high quality microgravity 10-6g ZARM drop-tower whereas comparatively few individuals swim kinetotically at low quality microgravity LQM 0 03-0 05g during parabolic aircraft flights Anken and Hilbig Microgravity Sci Technol 15 52-57 2004 In order to gain further insights into a possible threshold of gravity for inducing motion sickness animals were subjected to drop-tower flights within a centrifuge The levels of gravity applied ranged from 0 009g until 0 3g The lowest level of gravity under which few normally swimming fish were observed ranged around 0 015g Since this is a very low level of gravity the normally swimming fish have to be considered to be either extremely sensitive to any force of gravity in order to use it as a cue for postural control or they use cues other than the residual gravity for maintaining equilibrium Most of the remaining kinetotically swimming animals showed LR whereas few exhibited SM With increasing gravity the ratio of normally swimming and spinning specimens increased accompanied by a decrease in the number of looping larvae Regarding the ratio a shift from LR to SM took place at around 0 02g At 0 3g all animals behaved

Analytical investigation of microwave resonances of a curling probe for low and high-pressure plasma diagnostics

NASA Astrophysics Data System (ADS)

Arshadi, Ali; Brinkmann, Ralf Peter

2017-01-01

The concept of ‘active plasma resonance spectroscopy’ (APRS) has attracted greater interest in recent years as an established plasma diagnostic technique. The APRS describes a class of related methods utilizing the intrinsic ability of plasma to resonate at or near the electron plasma frequency {ω\\text{pe}} . The Curling probe (CP) as a novel realization of the APRS idea, is a miniaturized spiral slot embedded flatly in the chamber wall. Consequently, a plasma diagnostic technique with minimum disturbance and without metal contamination can be developed. To measure the plasma parameters the CP is fed with a weak frequency-swept signal from the exterior of the plasma chamber by a network analyzer which also records the response of the plasma versus the frequency. The resonance behavior is strongly dependent on the electron density and the gas pressure. The CP has also the advantage of resonating at a frequency greater than {ω\\text{pe}} which is dependent on the spiral’s length. The double resonance characteristic gives the CP the ability to be applied in varying plasma regimes. Assuming that the spiralization does not have a considerable effect on the resonances, a ‘straightened’ infinite length CP has recently been investigated (Arshadi and Brinkmann 2016 Plasma Sources Sci. Technol. 25 045014) to obtain the surface wave resonances. This work generalizes the approach and models the CP by a rectangular slot-type resonator located between plasma and quartz. Cold plasma theory and Maxwell’s equations are utilized to compute the electromagnetic fields propagating into the plasma by the diffraction of an incident plane wave at the slot. A mathematical model is employed and both kinds of resonances are derived. The analytical study of this paper shows good agreement with the numerical results of the probe inventors.

A Scheme for the Integrated Assessment of Mitigation Options

NASA Astrophysics Data System (ADS)

Held, H.; Edenhofer, O.

2003-04-01

After some consensus has been achieved that the global mean temperature will have increased by 1.4 to 5.8^oC at the end of this century in case of continued ``business as usual'' greenhouse gas emissions, society has to decide if or which mitigation measures should be taken. A new integrated assessment project on this very issue will be started at PIK in spring 2003. The assessment will cover economic aspects as well as potential side effects of various measures. In the economic module, the effects of investment decisions on technological innovation will be explicitly taken into account. Special emphasize will be put on the issue of uncertainty. Hereby we distinguish the uncertainty related to the Integrated Assessment modules, including the economic module, from the fact that no over-complex system can be fully captured by a model. Therefore, a scheme for the assessment of the ``residual'', the non-modelled part of the system, needs to be worked out. The scheme must be truly interdisciplinary, i.e. must be applicable to at least the natural science and the economic aspects. A scheme based on meta-principles like minimum persistence, ubiquity, or irreversibility of potential measures appears to be a promising candidate. An implementation of ubiquity as at present successfully operated in environmental chemistry may serve as a guideline [1]. Here, the best-known mechanism within a complex impact chain of potentially harmful chemicals, their transport, is captured by a reaction-diffusion mechanism [2]. begin{thebibliography}{0} bibitem{s} M. Scheringer, Persistence and spatial range as endpoints of an exposure-based assessment of organic chemicals. Environ. Sci. Technol. 30: 1652-1659 (1996). bibitem{h} H. Held, Robustness of spatial ranges of environmental chemicals with respect to model dimension, accepted for publication in Stoch. Environ. Res. Risk Assessment.

Fast-ion transport in qmin>2, high- β steady-state scenarios on DIII-D

DOE PAGES

Holcomb, C. T.; Heidbrink, W. W.; Ferron, J. R.; ...

2015-05-22

The results from experiments on DIII-D [J. L. Luxon, Fusion Sci. Technol. 48, 828 (2005)] aimed at developing high β steady-state operating scenarios with high-qminqmin confirm that fast-ion transport is a critical issue for advanced tokamak development using neutral beam injection current drive. In DIII-D, greater than 11 MW of neutral beam heating power is applied with the intent of maximizing β N and the noninductive current drive. However, in scenarios with q min>2 that target the typical range of q 95= 5–7 used in next-step steady-state reactor models, Alfvén eigenmodes cause greater fast-ion transport than classical models predict. Thismore » enhanced transport reduces the absorbed neutral beam heating power and current drive and limits the achievable β N. Conversely similar plasmas except with q min just above 1 have approximately classical fast-ion transport. Experiments that take q min>3 plasmas to higher β P with q 95= 11–12 for testing long pulse operation exhibit regimes of better than expected thermal confinement. Compared to the standard high-q min scenario, the high β P cases have shorter slowing-down time and lower ∇β fast, and this reduces the drive for Alfvénic modes, yielding nearly classical fast-ion transport, high values of normalized confinement, β N, and noninductive current fraction. These results suggest DIII-D might obtain better performance in lower-q 95, high-q min plasmas using broader neutral beam heating profiles and increased direct electron heating power to lower the drive for Alfvén eigenmodes.« less

Detection and kinetics of protein nitration in aerosols by NO2 and O3

NASA Astrophysics Data System (ADS)

Yang, H.; Zhang, Y.; Pöschl, U.

2009-04-01

The effects of air pollution on allergic diseases are not yet well-understood, but recent studies have shown that proteins are efficiently nitrated by polluted air (Franze et al., 2005) and that nitration enhances the allergenic potential of proteins such as the prominent birch pollen allergen Bet v 1 (Gruijthuijsen et al., 2006). Accordingly, the nitration of proteins in bioaerosol particles such as pollen and spores by NO2 and O3 might be a reason why allergies are on the increase in areas with traffic-related air pollution such as mega-cities and city clusters. In this study we have developed a method to determine the nitrotyrosine residue number per molecule in nitrated model proteins (bovine serum albumin, BSA; ovalbumin, OVA) by liquid chromatography coupled to UV-Vis photometry and mass spectrometry detectors (LC-DAD and LC-ESI-MS). Nitration experiments were carried out by exposing proteins to synthetic gas mixtures of nitrogen dioxide, ozone, nitrogen, synthetic air and water vapor. Reaction rates were measured at different concentration levels of NO2 and O3, and rate coefficients for the heterogeneous chemical reaction were determined. The implications for atmospheric aging and chemical transformation of bioaerosol particles and their potential effects on public health will be discussed. References: Franze, T., Weller, M.G., Niessner, R., Pöschl, U., Protein nitration by polluted air, Environ. Sci. Technol. 39, 1673-1678, 2005. Gruijthuijsen, Y.K., Grieshuber, I., Stöcklinger, A., Tischler, U., Fehrenbach, T., Weller, M.G., Vogel, L., Vieths, S., Pöschl, U., Duschl, A., Nitration enhances the allergenic potential of proteins, Int. Arch. Allergy Immunol. 141, 265-275, 2006.

Development of diagnostic and manipulation systems for space-charge dominated electron beams and confined electron plasmas in ELTRAP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rome, M.; Cavaliere, F.; Maero, G.

2013-03-19

Modifications have been implemented in the Penning-Malmberg device ELTRAP aimed at performing studies on the dynamics of space-charge dominated nanosecond electron bunches traveling along the magnetic field. In particular, a Thomson backscattering apparatus has been developed where an infrared (IR) laser pulse collides with the bunched electron beam. The frequency-shifted backscattered radiation, acquired by means of a photomultiplier (PMT), can be exploited to evaluate information on energy, energy spread and density of the bunch. The achievable sensitivity of the diagnostics has been estimated, and valuable information on the main parameters affecting the signal-to-noise (S/N) ratio has been obtained [B. Paroli,more » F. Cavaliere, M. Cavenago, F. De Luca, M. Ikram, G. Maero, C. Marini, R. Pozzoli, and M. Rome, JINST 7, P01008 (2012)]. A series of upgrades are under way, aimed at increasing the S/N ratio through the use of a new laser for the electron source, the insertion of a stray light shield, and the optimization of the detection electronics. Moreover, electromagnetic simulations relevant to the design and implementation of a microwave heating system are presented. The generation of an electron plasma in ELTRAP by means of a low-power radio frequency (RF) drive in the MHz range applied on one of the trap electrodes and under ultra-high vacuum (UHV) conditions has previously been demonstrated [B. Paroli, F. De Luca, G. Maero, F. Pozzoli, and M. Rome, Plasma Sources Sci. Technol. 19, 045013 (2010)]. The new heating system will allow the extension of the RF studies to the GHz range and in particular the production of a more energetic electron plasma via cyclotron resonant excitation.« less

Abundance and antibiotic susceptibility of Vibrio spp. isolated from microplastics

NASA Astrophysics Data System (ADS)

Laverty, A. L.; Darr, K.; Dobbs, F. C.

2016-02-01

In recent years, there has been a growing concern for `microplastics' (particles < 5 mm) in the marine environment. Since plastics degrade very slowly, they remain in the environment on much longer timescales than most natural substrates and can thus provide a novel habitat for colonization by microbial communities (Zettler et al. 2013 Environ. Sci. Technol. 47:7137). The full spectrum of relationships between microplastics and bacteria, however, is little understood. In summer 2015, we examined microplastics collected from a tributary of the lower Chesapeake Bay and determined the presence, abundance, and antibiotic-resistance profiles of Vibrio spp. found on them. We collected 22 microplastic pieces, paired seawater samples, and from them cultured 44 putative Vibrio spp. isolates, 18 of which were PCR-confirmed as V. parahaemolyticus and 3 as V. vulnificus. There were no PCR-confirmed V. cholerae isolates. We used the Kirby-Bauer disk diffusion susceptibility test to examine the isolates' response to six antibiotics: chloramphenicol (30μg), gentamicin (10μg), ampicillin (10μg), streptomycin (10μg), tetracycline (30μg), and rifampin (5μg). Vibrio isolates were susceptible to three or more of the six antibiotics tested and all were susceptible to tetracycline and chloramphenicol. There were no apparent differences between the antibiotic susceptibilities of vibrios isolated from microplastics compared to those from the water column. In every instance tested, vibrios on microplastics were enriched by at least two orders of magnitude compared to those from paired seawater samples. This study demonstrates that microplastic particles serve as a habitat for Vibrio species, in particular V. vulnificus and V. parahaemolyticus, confirming the conjecture of Zettler et al. (2013) that plastics may serve as a vector for these and other potentially pathogenic bacteria.

Dynamics of δ-dopant redistribution during heterostructure growth

NASA Astrophysics Data System (ADS)

Pankratov, E. L.

2007-06-01

It has recently been shown that growth of a multilayer structure with one or more delta-layers at high temperature leads to spreading and asymmetrization of the dopant distribution [see, for example, E.F.J. Schubert, Vac. Sci. Technol. A. 8, 2980 (1990), A.M. Nazmul, S. Sugahara, M. Tanaka, J. Crystal Growth 251, 303 (2003); R.C. Newman, M.J. Ashwin, M.R. Fahy, L. Hart, S.N. Holmes, C. Roberts, X. Zhang, Phys. Rev. B 54, 8769 (1996); E.F. Schubert, J.M. Kuo, R.F. Kopf, H.S. Luftman, L.C. Hopkins, N.J. Sauer, J. Appl. Phys. 67, 1969 (1990); P.M. Zagwijn, J.F. van der Veen, E. Vlieg, A.H. Reader, D.J. Gravesteijn, J. Appl. Phys. 78, 4933 (1995); W.S. Hobson, S.J. Pearton, E.F. Schubert, G. Cabaniss, Appl. Phys. Lett. 55, 1546 (1989); Delta Doping of Semiconductors, edited by E.F. Schubert (Cambridge University Press, Cambridge, 1996); Yu.N. Drozdov, N.B. Baidus', B.N. Zvonkov, M.N. Drozdov, O.I. Khrykin, V.I. Shashkin, Semiconductors 37, 194 (2003); E. Skuras, A.R. Long, B. Vogele, M.C. Holland, C.R. Stanley, E.A. Johnson, M. van der Burgt, H. Yaguchi, J. Singleton, Phys. Rev. B 59, 10712 (1999); G. Li, C. Jagadish, Solid-State Electronics 41, 1207 (1997)]. In this work analytical and numerical analysis of dopant dynamics in a delta-doped area of a multilayer structure has been accomplished using Fick's second law. Some reasons for asymmetrization of a delta-dopant distribution are illustrated. The spreading of a delta-layer has been estimated using example materials of a multilayer structure, a delta-layer and an overlayer.

Multi-channel transport experiments at Alcator C-Mod and comparison with gyrokinetic simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, A. E.; Howard, N. T.; Greenwald, M.

2013-05-15

Multi-channel transport experiments have been conducted in auxiliary heated (Ion Cyclotron Range of Frequencies) L-mode plasmas at Alcator C-Mod [Marmar and Alcator C-Mod Group, Fusion Sci. Technol. 51(3), 3261 (2007)]. These plasmas provide good diagnostic coverage for measurements of kinetic profiles, impurity transport, and turbulence (electron temperature and density fluctuations). In the experiments, a steady sawtoothing L-mode plasma with 1.2 MW of on-axis RF heating is established and density is scanned by 20%. Measured rotation profiles change from peaked to hollow in shape as density is increased, but electron density and impurity profiles remain peaked. Ion or electron heat fluxesmore » from the two plasmas are the same. The experimental results are compared directly to nonlinear gyrokinetic theory using synthetic diagnostics and the code GYRO [Candy and Waltz, J. Comput. Phys. 186, 545 (2003)]. We find good agreement with experimental ion heat flux, impurity particle transport, and trends in the fluctuation level ratio (T(tilde sign){sub e}/T{sub e})/(ñ{sub e}/n{sub e}), but underprediction of electron heat flux. We find that changes in momentum transport (rotation profiles changing from peaked to hollow) do not correlate with changes in particle transport, and also do not correlate with changes in linear mode dominance, e.g., Ion Temperature Gradient versus Trapped Electron Mode. The new C-Mod results suggest that the drives for momentum transport differ from drives for heat and particle transport. The experimental results are inconsistent with present quasilinear models, and the strong sensitivity of core rotation to density remains unexplained.« less

Nanoscale topographic pattern formation on Kr{sup +}-bombarded germanium surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perkinson, Joy C.; Madi, Charbel S.; Aziz, Michael J.

2013-03-15

The nanoscale pattern formation of Ge surfaces uniformly irradiated by Kr{sup +} ions was studied in a low-contamination environment at ion energies of 250 and 500 eV and at angles of 0 Degree-Sign through 80 Degree-Sign . The authors present a phase diagram of domains of pattern formation occurring as these two control parameters are varied. The results are insensitive to ion energy over the range covered by the experiments. Flat surfaces are stable from normal incidence up to an incidence angle of {theta} = 55 Degree-Sign from normal. At higher angles, the surface is linearly unstable to the formationmore » of parallel-mode ripples, in which the wave vector is parallel to the projection of the ion beam on the surface. For {theta} {>=} 75 Degree-Sign the authors observe perpendicular-mode ripples, in which the wave vector is perpendicular to the ion beam. This behavior is qualitatively similar to those of Madi et al. for Ar{sup +}-irradiated Si but is inconsistent with those of Ziberi et al. for Kr{sup +}-irradiated Ge. The existence of a window of stability is qualitatively inconsistent with a theory based on sputter erosion [R. M. Bradley and J. M. Harper, J. Vac. Sci. Technol. A 6, 2390 (1988)] and qualitatively consistent with a model of ion impact-induced mass redistribution [G. Carter and V. Vishnyakov, Phys. Rev. B 54, 17647 (1996)] as well as a crater function theory incorporating both effects [S. A. Norris et al., Nat. Commun. 2, 276 (2011)]. The critical transition angle between stable and rippled surfaces occurs 10 Degree-Sign -15 Degree-Sign above the value of 45 Degree-Sign predicted by the mass redistribution model.« less

Common y-intercept and single compound regressions of gas-particle partitioning data vs 1/T

NASA Astrophysics Data System (ADS)

Pankow, James F.

Confidence intervals are placed around the log Kp vs 1/ T correlation equations obtained using simple linear regressions (SLR) with the gas-particle partitioning data set of Yamasaki et al. [(1982) Env. Sci. Technol.16, 189-194]. The compounds and groups of compounds studied include the polycylic aromatic hydrocarbons phenanthrene + anthracene, me-phenanthrene + me-anthracene, fluoranthene, pyrene, benzo[ a]fluorene + benzo[ b]fluorene, chrysene + benz[ a]anthracene + triphenylene, benzo[ b]fluoranthene + benzo[ k]fluoranthene, and benzo[ a]pyrene + benzo[ e]pyrene (note: me = methyl). For any given compound, at equilibrium, the partition coefficient Kp equals ( F/ TSP)/ A where F is the particulate-matter associated concentration (ng m -3), A is the gas-phase concentration (ng m -3), and TSP is the concentration of particulate matter (μg m -3). At temperatures more than 10°C from the mean sampling temperature of 17°C, the confidence intervals are quite wide. Since theory predicts that similar compounds sorbing on the same particulate matter should possess very similar y-intercepts, the data set was also fitted using a special common y-intercept regression (CYIR). For most of the compounds, the CYIR equations fell inside of the SLR 95% confidence intervals. The CYIR y-intercept value is -18.48, and is reasonably close to the type of value that can be predicted for PAH compounds. The set of CYIR regression equations is probably more reliable than the set of SLR equations. For example, the CYIR-derived desorption enthalpies are much more highly correlated with vaporization enthalpies than are the SLR-derived desorption enthalpies. It is recommended that the CYIR approach be considered whenever analysing temperature-dependent gas-particle partitioning data.

Wave-induced mass transport affects daily Escherichia coli fluctuations in nearshore water.

PubMed

Ge, Zhongfu; Whitman, Richard L; Nevers, Meredith B; Phanikumar, Mantha S

2012-02-21

Characterization of diel variability of fecal indicator bacteria concentration in nearshore waters is of particular importance for development of water sampling standards and protection of public health. Significant nighttime increase in Escherichia coli (E. coli) concentration in beach water, previously observed at marine sites, has also been identified in summer 2000 from fixed locations in waist- and knee-deep waters at Chicago 63rd Street Beach, an embayed, tideless, freshwater beach with low currents at night (approximately 0.015 m s(-1)). A theoretical model using wave-induced mass transport velocity for advection was developed to assess the contribution of surface waves to the observed nighttime E. coli replenishment in the nearshore water. Using average wave conditions for the summer season of year 2000, the model predicted an amount of E. coli transported from water of intermediate depth, where sediment resuspension occurred intermittently, that would be sufficient to have elevated E. coli concentration in the surf and swash zones as observed. The nighttime replenishment of E. coli in the surf and swash zones revealed here is an important phase in the cycle of diel variations of E. coli concentration in nearshore water. According to previous findings in Ge et al. (Environ. Sci. Technol. 2010, 44, 6731-6737), enhanced current circulation in the embayment during the day tends to displace and deposit material offshore, which partially sets up the system by the early evening for a new period of nighttime onshore movement. This wave-induced mass transport effect, although facilitating a significant base supply of material shoreward, can be perturbed or significantly influenced by high currents (orders of magnitude larger than a typical wave-induced mass transport velocity), current-induced turbulence, and tidal forcing.

Two-Dimensional Stable Isotope Fractionation During Aerobic and Anaerobic Alkane Biodegradation and Implications for the Field

NASA Astrophysics Data System (ADS)

El Morris, Brandon; Suflita, Joseph M.; Richnow, Hans-Hermann

2010-05-01

Quantitatively, n-alkanes comprise a major portion of most crude oils. In petroliferous formations, it may be possible to relate the loss of these compounds to the levels of biodegradation occurring in situ [1]. Moreover, it is important to develop indicators of alkane degradation that may be used to monitor bioremediation of hydrocarbon-impacted environments. Desulfoglaeba alkanexedens and Pseudomonas putida GPo1 were used to determine if carbon and hydrogen stable isotope fractionation could differentiate between n-alkane degradation under anaerobic and aerobic conditions, respectively in the context of the Rayleigh equation model [2]. Bacterial cultures were sacrificed by acidification and headspace samples were analyzed for stable isotope composition using gas chromatography-isotope ratio mass spectrometry. Carbon enrichment factors (bulk) for anaerobic and aerobic biodegradation of hexane were -5.52 ± 0.2‰ and -4.34 ± 0.3‰, respectively. Hydrogen enrichment during hexane degradation was -43.14 ± 6.32‰ under sulfate-reducing conditions, and was too low for quantification during aerobiosis. Collectively, this indicates that the correlation between carbon and hydrogen stable isotope fractionation (may be used to help elucidate in situ microbial processes in oil reservoirs, and during intrinsic as well as engineered remediation efforts. References 1. Asif, M.; Grice, K.; Fazeelat, T., Assessment of petroleum biodegradation using stable hydrogen isotopes of individual saturated hydrocarbon and polycyclic aromatic hydrocarbon distributions in oils from the Upper Indus Basin, Pakistan. Organic Geochemistry 2009, 40, (3), 301-311. 2. Fischer, A.; Herklotz, I.; Herrmann, S.; Thullner, M.; Weelink, S. A. B.; Stams, A., J. M.; Schloemann, M.; Richnow, H.-H.; Vogt, C., Combined carbon and hydrogen isotope fractionation investigations for elucidating benzene biodegradation pathways. Environ. Sci. Technol. 2008, 42, 4356-4363.

Enhanced circular photogalvanic effect in HgTe quantum wells in the heavily inverted regime

NASA Astrophysics Data System (ADS)

Li, Jun; Yang, Wen; Liu, Jiang-Tao; Huang, Wei; Li, Cheng; Chen, Song-Yan

2017-01-01

HgTe-based quantum wells (QWs) possess very strong spin-orbit interaction (SOI) and have become an ideal platform for the study of fundamental SOI-dependent phenomena and the topological insulator phase. Circular photogalvanic effect (CPGE) in HgTe QWs is of great interest because it provides an effective optical access to probe the spin-related information of HgTe systems. However, the complex band structure and large spin splitting of HgTe QWs makes it inadequate to analyze the experimental results of CPGE in HgTe QWs [B. Wittmann et al., Semicond. Sci. Technol. 25, 095005 (2010), 10.1088/0268-1242/25/9/095005] with reduced band models. Here, based on the realistic eight-band k .p Hamiltonian and combined with the density-matrix formalism, we present a detailed theoretical investigation of CPGE in (001)-oriented Hg0.3Cd0.7Te /HgTe /Hg0.3Cd0.7Te QWs. We find the CPGE currents in HgTe QWs in the heavily inverted regime are significantly enhanced due to the strong distortion of band dispersion at a certain range of the energy spectrum. This enhancement effect could offer an experimental certificate that the HgTe QW is in the heavily inverted phase (usually accompanied with the emergence of two-dimensional topological edge states), and could also be utilized in engineering the high efficiency ellipticity detector of infrared and terahertz radiation [S. N. Danilov et al., J. Appl. Phys. 105, 013106 (2009), 10.1063/1.3056393]. Additionally, within the same theoretical framework, we also investigate the interplay effect of structure inversion asymmetry and bulk inversion asymmetry and the pure spin currents driven by linearly polarized light in HgTe QWs.

Wave modeling in a cylindrical non-uniform helicon discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, L.; Hole, M. J.; Caneses, J. F.

2012-08-15

A radio frequency field solver based on Maxwell's equations and a cold plasma dielectric tensor is employed to describe wave phenomena observed in a cylindrical non-uniform helicon discharge. The experiment is carried out on a recently built linear plasma-material interaction machine: The magnetized plasma interaction experiment [Blackwell et al., Plasma Sources Sci. Technol. (submitted)], in which both plasma density and static magnetic field are functions of axial position. The field strength increases by a factor of 15 from source to target plate, and the plasma density and electron temperature are radially non-uniform. With an enhancement factor of 9.5 to themore » electron-ion Coulomb collision frequency, a 12% reduction in the antenna radius, and the same other conditions as employed in the experiment, the solver produces axial and radial profiles of wave amplitude and phase that are consistent with measurements. A numerical study on the effects of axial gradient in plasma density and static magnetic field on wave propagations is performed, revealing that the helicon wave has weaker attenuation away from the antenna in a focused field compared to a uniform field. This may be consistent with observations of increased ionization efficiency and plasma production in a non-uniform field. We find that the relationship between plasma density, static magnetic field strength, and axial wavelength agrees well with a simple theory developed previously. A numerical scan of the enhancement factor to the electron-ion Coulomb collision frequency from 1 to 15 shows that the wave amplitude is lowered and the power deposited into the core plasma decreases as the enhancement factor increases, possibly due to the stronger edge heating for higher collision frequencies.« less

DiAs Web Monitoring: A Real-Time Remote Monitoring System Designed for Artificial Pancreas Outpatient Trials

PubMed Central

Place, Jérôme; Robert, Antoine; Brahim, Najib Ben; Patrick, Keith-Hynes; Farret, Anne; Marie-Josée, Pelletier; Buckingham, Bruce; Breton, Marc; Kovatchev, Boris; Renard, Eric

2013-01-01

Background Developments in an artificial pancreas (AP) for patients with type 1 diabetes have allowed a move toward performing outpatient clinical trials. “Home-like” environment implies specific protocol and system adaptations among which the introduction of remote monitoring is meaningful. We present a novel tool allowing multiple patients to monitor AP use in home-like settings. Methods We investigated existing systems, performed interviews of experienced clinical teams, listed required features, and drew several mockups of the user interface. The resulting application was tested on the bench before it was used in three outpatient studies representing 3480 h of remote monitoring. Results Our tool, called DiAs Web Monitoring (DWM), is a web-based application that ensures reception, storage, and display of data sent by AP systems. Continuous glucose monitoring (CGM) and insulin delivery data are presented in a colored chart to facilitate reading and interpretation. Several subjects can be monitored simultaneously on the same screen, and alerts are triggered to help detect events such as hypoglycemia or CGM failures. In the third trial, DWM received approximately 460 data per subject per hour: 77% for log messages, 5% for CGM data. More than 97% of transmissions were achieved in less than 5 min. Conclusions Transition from a hospital setting to home-like conditions requires specific AP supervision to which remote monitoring systems can contribute valuably. DiAs Web Monitoring worked properly when tested in our outpatient studies. It could facilitate subject monitoring and even accelerate medical and technical assessment of the AP. It should now be adapted for long-term studies with an enhanced notification feature. J Diabetes Sci Technol 2013;7(6):1427–1435 PMID:24351169

Adaptive vector validation in image velocimetry to minimise the influence of outlier clusters

NASA Astrophysics Data System (ADS)

Masullo, Alessandro; Theunissen, Raf

2016-03-01

The universal outlier detection scheme (Westerweel and Scarano in Exp Fluids 39:1096-1100, 2005) and the distance-weighted universal outlier detection scheme for unstructured data (Duncan et al. in Meas Sci Technol 21:057002, 2010) are the most common PIV data validation routines. However, such techniques rely on a spatial comparison of each vector with those in a fixed-size neighbourhood and their performance subsequently suffers in the presence of clusters of outliers. This paper proposes an advancement to render outlier detection more robust while reducing the probability of mistakenly invalidating correct vectors. Velocity fields undergo a preliminary evaluation in terms of local coherency, which parametrises the extent of the neighbourhood with which each vector will be compared subsequently. Such adaptivity is shown to reduce the number of undetected outliers, even when implemented in the afore validation schemes. In addition, the authors present an alternative residual definition considering vector magnitude and angle adopting a modified Gaussian-weighted distance-based averaging median. This procedure is able to adapt the degree of acceptable background fluctuations in velocity to the local displacement magnitude. The traditional, extended and recommended validation methods are numerically assessed on the basis of flow fields from an isolated vortex, a turbulent channel flow and a DNS simulation of forced isotropic turbulence. The resulting validation method is adaptive, requires no user-defined parameters and is demonstrated to yield the best performances in terms of outlier under- and over-detection. Finally, the novel validation routine is applied to the PIV analysis of experimental studies focused on the near wake behind a porous disc and on a supersonic jet, illustrating the potential gains in spatial resolution and accuracy.

Application of the Fokker-Planck molecular mixing model to turbulent scalar mixing using moment methods

NASA Astrophysics Data System (ADS)

Madadi-Kandjani, E.; Fox, R. O.; Passalacqua, A.

2017-06-01

An extended quadrature method of moments using the β kernel density function (β -EQMOM) is used to approximate solutions to the evolution equation for univariate and bivariate composition probability distribution functions (PDFs) of a passive scalar for binary and ternary mixing. The key element of interest is the molecular mixing term, which is described using the Fokker-Planck (FP) molecular mixing model. The direct numerical simulations (DNSs) of Eswaran and Pope ["Direct numerical simulations of the turbulent mixing of a passive scalar," Phys. Fluids 31, 506 (1988)] and the amplitude mapping closure (AMC) of Pope ["Mapping closures for turbulent mixing and reaction," Theor. Comput. Fluid Dyn. 2, 255 (1991)] are taken as reference solutions to establish the accuracy of the FP model in the case of binary mixing. The DNSs of Juneja and Pope ["A DNS study of turbulent mixing of two passive scalars," Phys. Fluids 8, 2161 (1996)] are used to validate the results obtained for ternary mixing. Simulations are performed with both the conditional scalar dissipation rate (CSDR) proposed by Fox [Computational Methods for Turbulent Reacting Flows (Cambridge University Press, 2003)] and the CSDR from AMC, with the scalar dissipation rate provided as input and obtained from the DNS. Using scalar moments up to fourth order, the ability of the FP model to capture the evolution of the shape of the PDF, important in turbulent mixing problems, is demonstrated. Compared to the widely used assumed β -PDF model [S. S. Girimaji, "Assumed β-pdf model for turbulent mixing: Validation and extension to multiple scalar mixing," Combust. Sci. Technol. 78, 177 (1991)], the β -EQMOM solution to the FP model more accurately describes the initial mixing process with a relatively small increase in computational cost.

Wave-induced mass transport affects daily Escherichia coli fluctuations in nearshore water

USGS Publications Warehouse

Ge, Zhongfu; Whitman, Richard L.; Nevers, Meredith B.; Phanikumar, Mantha S.

2012-01-01

Characterization of diel variability of fecal indicator bacteria concentration in nearshore waters is of particular importance for development of water sampling standards and protection of public health. Significant nighttime increase in Escherichia coli (E. coli) concentration in beach water, previously observed at marine sites, has also been identified in summer 2000 from fixed locations in waist- and knee-deep waters at Chicago 63rd Street Beach, an embayed, tideless, freshwater beach with low currents at night (approximately 0.015 m s–1). A theoretical model using wave-induced mass transport velocity for advection was developed to assess the contribution of surface waves to the observed nighttime E. coli replenishment in the nearshore water. Using average wave conditions for the summer season of year 2000, the model predicted an amount of E. coli transported from water of intermediate depth, where sediment resuspension occurred intermittently, that would be sufficient to have elevated E. coli concentration in the surf and swash zones as observed. The nighttime replenishment of E. coli in the surf and swash zones revealed here is an important phase in the cycle of diel variations of E. coli concentration in nearshore water. According to previous findings in Ge et al. (Environ. Sci. Technol. 2010, 44, 6731–6737), enhanced current circulation in the embayment during the day tends to displace and deposit material offshore, which partially sets up the system by the early evening for a new period of nighttime onshore movement. This wave-induced mass transport effect, although facilitating a significant base supply of material shoreward, can be perturbed or significantly influenced by high currents (orders of magnitude larger than a typical wave-induced mass transport velocity), current-induced turbulence, and tidal forcing.

Hazard assessment of exhaust emissions - The next generation of fast and reliable tools for in vitro screening

NASA Astrophysics Data System (ADS)

Rothen-Rutishauser, B.

2017-12-01

Hazard assessment of exhaust emissions - The next generation of fast and reliable tools for in vitro screening Barbara Rothen-Rutishauser Adolphe Merkle Institute, University of Fribourg, Switzerland; barbara.rothen@unifr.ch Pollution by vehicles is a major problem for the environment due to the various components in the exhaust gasses that are emitted into the atmosphere. A large number of epidemiological studies demonstrate the profound impact of vehicle emissions upon human health [1-3]. Such studies however, are unable to attribute a given subset of emissions to a certain adverse effect, which renders decision making difficult. Standardized protocols for exhaust toxicity assessment are lacking and it relies in many aspects on epidemiological and in vivo studies (animals), which are very time and cost-intensive and suffer from considerable ethical issues. An overview about the current state of research and clinical aspects in the field, as well as about the development of sophisticated in vitro approaches mimicking the inhalation of airborne particles / exhaust for the toxicological testing of engine emissions will be provided. Data will be presented that show that the combination of an air-liquid exposure system and 3D lung-cell culture model offers an adequate tool for fast and reliable investigations of complete exhaust toxicity as well as the effects of particulate fraction [4,5]. This approach yields important results for novel and improved emission technologies in the early stages of product development. [1] Donaldson et al. Part Fibre Toxicol 2005, 2: 10. [2] Ghio et al. J Toxicol Environ Health B Crit Rev 2012, 15: 1-21. [3] Peters et al. Res Rep Health Eff Inst 2009, 5-77. [4] Bisig et al. Emiss Control Sci Technol 2015, 1: 237-246. [5] Steiner et al. Atmos Environ 2013, 81: 380-388.

Diclofenac degradation by heterogeneous photocatalysis with Fe3O4/Ti x O y /activated carbon fiber composite synthesized by ultrasound irradiation

NASA Astrophysics Data System (ADS)

Moreno-Valencia, E. I.; Paredes-Carrera, S. P.; Sánchez-Ochoa, J. C.; Flores-Valle, S. O.; Avendaño-Gómez, J. R.

2017-11-01

In this work, a photocatalytic system to degrade diclofenac was developed using a composite Fe3O4/Ti x O y on an activated carbon fiber. Diclofenac is widely used as an anti-inflammatory compound worldwide and it is constantly being added as waste in the environment (Heberer 2002 J. Hydrol. 266 175-89), exceeding the permissible maximum concentration in the wastewater (GEO-3 2002 Programa de las Naciones Unidas para el Medio Ambiente; Golet et al 2003 Environ. Sci. Technol. 37 3243-9 Oviedo et al 2010 Environ. Toxicol. Pharmacol. 29 9-43 Le-Minh et al 2010 Water Res. 44 4295-323 Legrini et al 1993 Chem. Rev. 1093 671-98). The composite was synthesized by sol-gel technique with and without ultrasound irradiation (Singh and Nakate 2014 J. Nanopart. 2014 326747). The solids were deposited by ultrasound irradiation on active carbon fiber in order to optimize the diclofenac degradation. The solids were characterized by x-ray diffraction (XRD), nitrogen physisorption (BET), and scanning electron microscopy with EDS microanalysis (SEM-EDS). The crystal size was calculated with the Debye-Scherrer equation, and the band gap values by the diffuse reflectance method. The evaluation process was studied by UV-vis spectroscopy (Rizzoa et al 2009 Water Res. 43 979-88). It was found that in this synthesis method (ultrasound), textural properties such as porosity, specific surface area and morphology depend on the ultrasound irradiation. The proposed system, Fe3O4/titanium oxide hydrate showed better degradation profile than TiO2 anatase phase; the increase of diclofenac degradation was attributed to the textural properties of the composite, it avoids the filtering process since the separation can be achieved by magnetizing and/or decantation.

Fast-ion transport in q{sub min}>2, high-β steady-state scenarios on DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holcomb, C. T.; Heidbrink, W. W.; Collins, C.

2015-05-15

Results from experiments on DIII-D [J. L. Luxon, Fusion Sci. Technol. 48, 828 (2005)] aimed at developing high β steady-state operating scenarios with high-q{sub min} confirm that fast-ion transport is a critical issue for advanced tokamak development using neutral beam injection current drive. In DIII-D, greater than 11 MW of neutral beam heating power is applied with the intent of maximizing β{sub N} and the noninductive current drive. However, in scenarios with q{sub min}>2 that target the typical range of q{sub 95}= 5–7 used in next-step steady-state reactor models, Alfvén eigenmodes cause greater fast-ion transport than classical models predict. Thismore » enhanced transport reduces the absorbed neutral beam heating power and current drive and limits the achievable β{sub N}. In contrast, similar plasmas except with q{sub min} just above 1 have approximately classical fast-ion transport. Experiments that take q{sub min}>3 plasmas to higher β{sub P} with q{sub 95}= 11–12 for testing long pulse operation exhibit regimes of better than expected thermal confinement. Compared to the standard high-q{sub min} scenario, the high β{sub P} cases have shorter slowing-down time and lower ∇β{sub fast}, and this reduces the drive for Alfvénic modes, yielding nearly classical fast-ion transport, high values of normalized confinement, β{sub N}, and noninductive current fraction. These results suggest DIII-D might obtain better performance in lower-q{sub 95}, high-q{sub min} plasmas using broader neutral beam heating profiles and increased direct electron heating power to lower the drive for Alfvén eigenmodes.« less

SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Fourth Results Report

DOT National Transportation Integrated Search

2013-01-01

SunLine Transit Agency provides public transit services to the Coachella Valley area of California. SunLine has demonstrated hydrogen and fuel cell bus technologies for more than 10 years. In May 2010, SunLine began demonstrating the advanced technol...

Los Angeles congestion reduction demonstration (Metro ExpressLanes) program. National evaluation : surveys, interviews, and workshops test plan.

DOT National Transportation Integrated Search

1997-09-01

Integration of intelligent transportation systems (ITS) within a metropolitan area is crucial for effective deployment. The Early Deployment Planning (EDP) Process is one tool that allows transportation officials to plan for and implement ITS technol...

University Research Initiative Program for Combat Readiness

DTIC Science & Technology

1999-05-01

found in sponge-associated bacteria Micrococcus luteus (Bultel-Ponce et al., 1998). Such compounds have antimicrobial activity. Water contact angles...Guyot, M. 1998. Metabolites from the sponge-associated bacterium Micrococcus luteus. J. Mar. Biotechnol. 6:233-236. 3. Incze, B.I., Sea Technol. 1996, 37

Passive hind-limb cycling improves cardiac function and reduces cardiovascular disease risk in experimental spinal cord injury.

PubMed

West, Christopher R; Crawford, Mark A; Poormasjedi-Meibod, Malihe-Sadat; Currie, Katharine D; Fallavollita, Andre; Yuen, Violet; McNeill, John H; Krassioukov, Andrei V

2014-04-15

Spinal cord injury (SCI) causes altered autonomic control and severe physical deconditioning that converge to drive maladaptive cardiac remodelling. We used a clinically relevant experimental model to investigate the cardio-metabolic responses to SCI and to establish whether passive hind-limb cycling elicits a cardio-protective effect. Initially, 21 male Wistar rats were evenly assigned to three groups: uninjured control (CON), T3 complete SCI (SCI) or T3 complete SCI plus passive hind-limb cycling (SCI-EX; 2 × 30 min day(-1), 5 days week(-1) for 4 weeks beginning 6 days post-SCI). On day 32, cardio-metabolic function was assessed using in vivo echocardiography, ex vivo working heart assessments, cardiac histology/molecular biology and blood lipid profiles. Twelve additional rats (n = 6 SCI and n = 6 SCI-EX) underwent in vivo echocardiography and basal haemodynamic assessments pre-SCI and at days 7, 14 and 32 post-SCI to track temporal cardiovascular changes. Compared with CON, SCI exhibited a rapid and sustained reduction in left ventricular dimensions and function that ultimately manifested as reduced contractility, increased myocardial collagen deposition and an up-regulation of transforming growth factor beta-1 (TGFβ1) and mothers against decapentaplegic homolog 3 (Smad3) mRNA. For SCI-EX, the initial reduction in left ventricular dimensions and function at day 7 post-SCI was completely reversed by day 32 post-SCI, and there were no differences in myocardial contractility between SCI-EX and CON. Collagen deposition was similar between SCI-EX and CON. TGFβ1 and Smad3 were down-regulated in SCI-EX. Blood lipid profiles were improved in SCI-EX versus SCI. We provide compelling novel evidence that passive hind-limb cycling prevents cardiac dysfunction and reduces cardiovascular disease risk in experimental SCI.

Plasma iron levels appraised 15 days after spinal cord injury in a limb movement animal model.

PubMed

Reis, F M; Esteves, A M; Tufik, S; de Mello, M T

2011-03-01

Experimental, controlled trial. The purpose of this study was to evaluate plasma iron and transferrin levels in a limb movement animal model with spinal cord injury (SCI). Universidade Federal de São Paulo, Departamento de Psicobiologia. In all, 72 male Wistar rats aged 90 days were divided into four groups: (1) acute SCI (1 day, SCI1), (2) 3 days post-SCI (SCI3), (3) 7 days post-SCI (SCI7) and (4) 15 days post-SCI (SCI15). Each of these groups had corresponding control (CTRL) and SHAM groups. Plasma iron and transferrin levels of the different groups were analyzed using a one-way analysis of variance (ANOVA) followed by Tukey's test. We found a significant reduction in iron plasma levels after SCI compared with the CTRL group: SCI1 (CTRL: 175±10.58 μg dl(-1); SCI: 108.28±11.7 μg dl(-1)), SCI3 (CTRL: 195.5±11.00 μg dl(-1); SCI: 127.88±12.63 μg dl(-1)), SCI7 (CTRL: 186±2.97 μg dl(-1); SCI: 89.2±15.39 μg dl(-1)) and SCI15 (CTRL: 163±5.48 μg dl(-1); SCI: 124.44±10.30 μg dl(-1)) (P<0.05; ANOVA). The SHAM1 group demonstrated a reduction in iron plasma after acute SCI (CTRL: 175±10.58 μg dl(-1); SHAM: 114.60±7.81 μg dl(-1)) (P<0.05; ANOVA). Reduced iron metabolism after SCI may be one of the mechanisms involved in the pathogenesis of sleep-related movement disorders.

The SDF-1/CXCR4 axis promotes recovery after spinal cord injury by mediating bone marrow-derived from mesenchymal stem cells

PubMed Central

Wang, Xiao; Zhang, Yong-Le; Zhang, Ya-Dong; Xue, Feng

2017-01-01

This study aims to explore the role of the SDF-1/CXCR4 axis in mediating BMSCs and SCI recovery. BMSCs were collected and SCI rat models were established. Wistar rats were assigned into the blank control, sham, SCI, SCI + BMSCs, SCI + BMSCs + SDF-1, SCI + BMSCs + AMD3100 (an inhibitor of SDF-1/CXCR4 axis) and SCI + BMSCs + SDF-1 + AMD3100 groups. Hind limb motor function was measured 7, 14, 21 and 28 days after operation. qRT-PCR, western blotting and ELISA was performed to determine the expressions of SDF-1, CXCR4, NGF, BDNF, GFAP and GAP-43, TNF-α, IL-1β, L-6 and IFN-γ. Hind limb motor function scores 7 days after the operation were reduced in the SCI rats of the blank control and sham groups. Hind limb function was found to be better in the SCI + BMSCs and SCI + BMSCs + SDF-1 groups than in the SCI, SCI + BMSCs + AMD3100 and SCI + BMSCs + SDF-1 + AMD3100 groups 14, 21 and 28 days after operation. Furthermore, the SCI group had lower SDF-1, CXCR4, NGF, BDNF and GAP-43 expressions but higher GFAP, TNF-α, IL-1β, IL-6 and IFN-γ than the blank control and sham groups 28 days after operation. While, the SCI + BMSCs, SCI + BMSCs + SDF-1 and SCI + BMSCs + SDF-1 + AMD3100 groups displayed opposite trends to the SCI and SCI + BMSCs + AMD3100 groups. In conclusion, SDF-1/CXCR4 axis promotes recovery after SCI by mediating BMSCs. PMID:28099928

CAPSTONE SENIOR DESIGN - SUPRAMOLECULAR PROTON EXCHANGE MEMBRANES FOR FUEL CELLS

EPA Science Inventory

In order to assume a leading role in the burgeoning hydrogen economy, new infrastructure will be required for fuel cell manufacturing and R&D capabilities. The objective of this proposal is the development of a new generation of advanced proton exchange membrane (PEM) technol...

Water-Soluble Nanodiamond (Postprint)

DTIC Science & Technology

2012-03-01

Lim, D.-S. Tribological behavior of PTFE film with nanodiamond. Surf. Coat. Technol. 2004, 188−189, 534−538. (9) Williams , O. A.; Nesladek, M.; Daenen...properties and applications. Russ. Chem. Rev. 2001, 70, 607−626. (27) Liang, Y.; Meinhardt, T.; Jarre, G.; Ozawa, M.; Vrodijak, P.; Scholl , A

THE U.S. ENVIRONMENTAL PROTECTION AGENCY'S SITE EMERGING TECHNOLOGY PROGRAM

EPA Science Inventory

Under the SITE Emerging Technology Program, the U.S. Environmental Protection Agency is seeking to foster the further development of technol- ogies that have been successfully tested at bench-scale and are now ready for pilot-scale testing, prior to field- or full-scale demonstra...

BIOREMEDIATION OF HAZARDOUS WASTES - RESEARCH, DEVELOPMENT AND FIELD EVALUATIONS - 1995

EPA Science Inventory

The proceedings of the 1995 Symposium on Bioremediation of Hazardous Wastes, hosted by the Office of Research and Development (ORD) of the EPA in Rye Brook, New York. he symposium was the eighth annual meeting for the presentation of research conducted by EPA's Biosystems Technol...

Passive hind-limb cycling improves cardiac function and reduces cardiovascular disease risk in experimental spinal cord injury

PubMed Central

West, Christopher R; Crawford, Mark A; Poormasjedi-Meibod, Malihe-Sadat; Currie, Katharine D; Fallavollita, Andre; Yuen, Violet; McNeill, John H; Krassioukov, Andrei V

2014-01-01

Spinal cord injury (SCI) causes altered autonomic control and severe physical deconditioning that converge to drive maladaptive cardiac remodelling. We used a clinically relevant experimental model to investigate the cardio-metabolic responses to SCI and to establish whether passive hind-limb cycling elicits a cardio-protective effect. Initially, 21 male Wistar rats were evenly assigned to three groups: uninjured control (CON), T3 complete SCI (SCI) or T3 complete SCI plus passive hind-limb cycling (SCI-EX; 2 × 30 min day−1, 5 days week−1 for 4 weeks beginning 6 days post-SCI). On day 32, cardio-metabolic function was assessed using in vivo echocardiography, ex vivo working heart assessments, cardiac histology/molecular biology and blood lipid profiles. Twelve additional rats (n = 6 SCI and n = 6 SCI-EX) underwent in vivo echocardiography and basal haemodynamic assessments pre-SCI and at days 7, 14 and 32 post-SCI to track temporal cardiovascular changes. Compared with CON, SCI exhibited a rapid and sustained reduction in left ventricular dimensions and function that ultimately manifested as reduced contractility, increased myocardial collagen deposition and an up-regulation of transforming growth factor beta-1 (TGFβ1) and mothers against decapentaplegic homolog 3 (Smad3) mRNA. For SCI-EX, the initial reduction in left ventricular dimensions and function at day 7 post-SCI was completely reversed by day 32 post-SCI, and there were no differences in myocardial contractility between SCI-EX and CON. Collagen deposition was similar between SCI-EX and CON. TGFβ1 and Smad3 were down-regulated in SCI-EX. Blood lipid profiles were improved in SCI-EX versus SCI. We provide compelling novel evidence that passive hind-limb cycling prevents cardiac dysfunction and reduces cardiovascular disease risk in experimental SCI. PMID:24535438

A miniature laser ablation mass spectrometer for quantitative in situ chemical composition investigation of lunar surface

NASA Astrophysics Data System (ADS)

Brigitte Neuland, Maike; Grimaudo, Valentine; Mezger, Klaus; Moreno-García, Pavel; Riedo, Andreas; Tulej, Marek; Wurz, Peter

2016-04-01

The chemical composition of planetary bodies, moons, comets and asteroids is a key to understand their origin and evolution [Wurz,2009]. Measurements of the elemental and isotopic composition of rocks yield information about the formation of the planetary body, its evolution and following processes shaping the planetary surface. From the elemental composition, conclusions about modal mineralogy and petrology can be drawn. Isotope ratios are a sensitive indicator for past events on the planetary body and yield information about origin and transformation of the matter, back to events that occurred in the early solar system. Finally, measurements of radiogenic isotopes make it possible to carry out dating analyses. All these topics, particularly in situ dating analyses, quantitative elemental and highly accurate isotopic composition measurements, are top priority scientific questions for future lunar missions. An instrument for precise measurements of chemical composition will be a key element in scientific payloads of future landers or rovers on lunar surface. We present a miniature laser ablation mass spectrometer (LMS) designed for in situ research in planetary and space science and optimised for measurements of the chemical composition of rocks and soils on a planetary surface. By means of measurements of standard reference materials we demonstrate that LMS is a suitable instrument for in situ measurements of elemental and isotopic composition with high precision and accuracy. Measurements of soil standards are used to confirm known sensitivity coefficients of the instrument and to prove the power of LMS for quantitative elemental analyses [Neuland,2016]. For demonstration of the capability of LMS to measure the chemical composition of extraterrestrial material we use a sample of Allende meteorite [Neuland,2014]. Investigations of layered samples confirm the high spatial resolution in vertical direction of LMS [Grimaudo,2015], which allows in situ studying of past surface processes on a planetary surface. Analyses of Pb isotopes show that the statistical uncertainty for the age determination by LMS is about ±100 Myrs, if abundance of 206Pb and 207Pb is 20ppm and 2ppm respectively [Riedo,2013]. These Pb isotopes have abundances of tens to hundreds of ppm in lunar KREEP [Nemchin,2008]. We demonstrate the measurement capabilities of LMS for petrographic and mineralogical analyses, for isotopic studies and dating analyses, which are key topics for future missions to the Moon. Having the LMS instrument installed on a lunar rover would allow measuring the chemical composition of many rock and soil samples, distributed over a certain area, inside the South Pole Aitken Basin for example. LMS measurements would yield valuable conclusions about age and mineralogy. References: [Wurz,2009]Wurz,P. et al. 2009, AIP Conf.Proc., CP1144:70-75. [Grimaudo,2015]Grimaudo, V. et al. 2015, Anal.Chem. 87: 2037-2041. [Neuland,2014]Neuland, M.B. et al. 2014, Planet.Space Sci.101:196-209. [Neuland,2016]Neuland M.B. et al. 2016, Meas. Sci. Technol.,submitted. [Riedo,2013]Riedo A. et al., 2013 Planet. Space Sci. 87: 1-13. [Nemchin,2008]Nemchin et al., 2008 Geochim. Cosmochim.Acta 72:668-689.

Chemical analysis of solid materials by a LIMS instrument designed for space research: 2D elemental imaging, sub-nm depth profiling and molecular surface analysis

NASA Astrophysics Data System (ADS)

Moreno-García, Pavel; Grimaudo, Valentine; Riedo, Andreas; Neuland, Maike B.; Tulej, Marek; Broekmann, Peter; Wurz, Peter

2016-04-01

Direct quantitative chemical analysis with high lateral and vertical resolution of solid materials is of prime importance for the development of a wide variety of research fields, including e.g., astrobiology, archeology, mineralogy, electronics, among many others. Nowadays, studies carried out by complementary state-of-the-art analytical techniques such as Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), Secondary Ion Mass Spectrometry (SIMS), Glow Discharge Time-of-Flight Mass Spectrometry (GD-TOF-MS) or Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) provide extensive insight into the chemical composition and allow for a deep understanding of processes that might have fashioned the outmost layers of an analyte due to its interaction with the surrounding environment. Nonetheless, these investigations typically employ equipment that is not suitable for implementation on spacecraft, where requirements concerning weight, size and power consumption are very strict. In recent years Laser Ablation/Ionization Mass Spectrometry (LIMS) has re-emerged as a powerful analytical technique suitable not only for laboratory but also for space applications.[1-3] Its improved performance and measurement capabilities result from the use of cutting edge ultra-short femtosecond laser sources, improved vacuum technology and fast electronics. Because of its ultimate compactness, simplicity and robustness it has already proven to be a very suitable analytical tool for elemental and isotope investigations in space research.[4] In this contribution we demonstrate extended capabilities of our LMS instrument by means of three case studies: i) 2D chemical imaging performed on an Allende meteorite sample,[5] ii) depth profiling with unprecedented sub-nm vertical resolution on Cu electrodeposited interconnects[6,7] and iii) preliminary molecular desorption of polymers without assistance of matrix or functionalized substrates.[8] On the whole, these results prove the adequacy of LMS as a powerful analytical tool able to address a great variety of topics in in situ space research. References: [1] U. Rohner, J. A. Whitby, P. Wurz, Meas. Sci. Technol. 2003, 14, 2159. [2] W. B. Brinckerhoff, G. G. Managadze, R. W. McEntire, A. F. Cheng, W. J. Green, Rev. Sci. Instrum. 2000, 71, 536. [3] G. G. Managadze, P. Wurz, R. Z. Sagdeev, A. E. Chumikov, M. Tuley, M. Yakovleva, N. G. Managadze, A. L. Bondarenko, Sol. Syst. Res. 2010, 44, 376. [4] A. Riedo, M. Neuland, S. Meyer, M. Tulej, P. Wurz, J. Anal. At. Spectrom. 2013, 28, 1256. [5] M.B. Neuland, S. Meyer, K. Mezger, A. Riedo, M. Tulej, P. Wurz, Planet. Space Sci. 2014, 101, 196. [6] V. Grimaudo, P. Moreno-García, A. Riedo, M. B. Neuland, M. Tulej, P. Broekmann, P. Wurz, Anal. Chem. 2015, 87, 2037. [7] A. Riedo, V. Grimaudo, P. Moreno-García, M. B. Neuland, M. Tulej, P. Wurz, P. Broekmann, J. Anal. At. Spectrom. 2015, 30, 2371. [8] P. Moreno-García, V. Grimaudo, A. Riedo, M. Tulej, P. Wurz, P. Broekmann, submitted to Rapid. Commun. Mass Spectrom., 2016.

Discrepancies between implicit and explicit self-concepts of intelligence: relations to modesty, narcissism, and achievement motivation

PubMed Central

Gerstenberg, Friederike X. R.; Imhoff, Roland; Banse, Rainer; Schmitt, Manfred

2014-01-01

Previous research has shown that different configurations of the implicit self-concept of intelligence (iSCI) and the explicit self-concept of intelligence (eSCI) are consistently related to individuals’ performance on different intelligence tests (Dislich etal., 2012). The results indicated that any discrepant configuration between the iSCI and the eSCI impairs performance. In the present study, how correspondence between the iSCI and the eSCI is related to intelligence test performance as well as personality traits of modesty (low eSCI, high iSCI), narcissism (high eSCI, low iSCI), and achievement motivation was investigated. Furthermore, a moderated mediation analysis showed that the relation between the iSCI–eSCI configurations and intelligence test performance was mediated by achievement motivation for modest individuals. PMID:24575063

INNOVATIVE TECHNOLOGY EVALUATION REPORT: RADIO FREQUENCY HEATING, KAI TECHNOLOGIES, INC.

EPA Science Inventory

A demonstration of KAI Technologies in-situ radio frequency heating system for soil treatment was conducted from January 1994 to July 1994 at Kelly Air Force Base in San Antonio, Texas. This demonstration was conducted as a joint effort between the USEPA and the USAF. The technol...

Maskless Lithography Using Surface Plasmon Enhanced Illumination

DTIC Science & Technology

2007-04-30

Dale Larson Figure 1. Nanohole array probes exhibiting extraordinary optical transmission of light with a high degree of collimation. Left: a bull’s...Technol. B 22, 3552-3556 (2004). 2. Stark, P., Halleck, A. E. & Larson, D. N. Short order nanohole arrays in metals for highly sensitive probing of local

The Phases Differential Astrometry Data Archive. 5. Candidate Substellar Companions to Binary Systems

DTIC Science & Technology

2010-12-01

Mathematics and Astronomy , 105-24, California Institute of Technology, Pasadena, CA 91125, USA 5 Nicolaus Copernicus Astronomical Center, Polish Academy...Blind Test with support from NASA contract NAS7-03001 (JPL 1336910). PHASES is funded in part by the California Institute of Technol- ogy Astronomy

Development of Microbial and Enzymatic Fuel Cells for Bio-Inspired Power Sources

DTIC Science & Technology

2009-03-01

that of the oxidation of NADH as possible.[30] A variety of organic mediators have been studied for the anode, including phenazines ,[38] dyes,[39,40...glucose-6-phosphate dehydrogenase on the rotating graphite disc electrode modified with phenazine methosulfate. Enzyme Microb. Technol. 1993, 15 (6), 525

Object-Oriented Dynamic Bayesian Network-Templates for Modelling Mechatronic Systems

DTIC Science & Technology

2002-05-04

daimlerchrysler.com Abstract are widespread. For modelling mechanical systems The object-oriented paradigma is a new but proven technol- ADAMS [31 or...hardware (sub-)systems. On the Software side thermal flow or hydraulics, see Figure 1. It also contains a the object-oriented paradigma is by now (at

Length of stay and medical stability for spinal cord-injured patients on admission to an inpatient rehabilitation hospital: a comparison between a model SCI trauma center and non-SCI trauma center.

PubMed

Ploumis, A; Kolli, S; Patrick, M; Owens, M; Beris, A; Marino, R J

2011-03-01

Retrospective database review. To compare lengths of stay (LOS), pressure ulcers and readmissions to the acute care hospital of patients admitted to the inpatient rehabilitation facility (IRF) from a model spinal cord injury (SCI) trauma center or from a non-SCI acute hospital. Only sparse data exist comparing the status of patients admitted to IRF from a model SCI trauma center or from a non-SCI acute hospital. Acute care, IRF and total LOS were compared between patients transferred to IRF from the SCI center (n=78) and from non-SCI centers (n=131). The percentages of pressure ulcers on admission to IRF and transfer back to acute care were also compared. Patients admitted to IRF from the SCI trauma center (SCI TC) had significantly shorter (P=0.01) acute care LOS and total LOS compared with patients admitted from non-SCI TCs. By neurological category, acute-care LOS was less for all groups admitted from the SCI center, but statistically significant only for tetraplegia. There was no significant difference in the incidence of readmissions to acute care from IRF. More patients from non-SCI centers (34%) than SCI centers (12%) had pressure ulcers (P<0.001). Acute care in organized SCI TCs before transfer to IRF can significantly lower acute-care LOS or total LOS and incidence of pressure ulcers compared with non-SCI TCs. Patients admitted to IRF from SCI TCs are no more likely to be sent back to an acute hospital than those from non-SCI TCs.

The Implementation Challenge and the Learning Health System for SCI Initiative.

PubMed

Stucki, Gerold; Bickenbach, Jerome

2017-02-01

The paper introduces the special issue by linking the International Spinal Cord Injury (InSCI) Community Survey study to the Learning Health System for SCI Initiative (LHS-SCI). The LHS-SCI was designed to respond to the implementation challenge of bringing about policy reform in light of the targeted policy recommendations of World Health Organization's International Perspectives on SCI report as well as the call for action of WHO's Global Disability Action Plan. The paper reviews the components of LHS-SCI relevant to internationally comparable information, a theory of change to guide for action, and the tools for evidence-informed policy. The interplay between persons, their health needs, and the societal response to those needs provides the foundation for the organization of the LHS-SCI Initiative. Moreover, as the other articles in this special issue describe in detail, the rationale, conceptualization, and study design of the InSCI study are also informed by the rationale, and mission, of the LHS for SCI Initiative. The LHS-SCI, and the implementation challenge that motivates it, is responsible for the design of the InSCI study and the overall mission of LHS-SCI to continuously improve the lived experience of people living with SCI around the world through an international evidence- and rights-informed research and policy reform effort.

EDITORIAL: Announcing the 2009 Measurement Science and Technology Outstanding Paper Awards Announcing the 2009 Measurement Science and Technology Outstanding Paper Awards

NASA Astrophysics Data System (ADS)

Foss, John; Dewhurst, Richard; Fujii, Kenichi; Regtien, Paul

2010-06-01

Since 1991, Measurement Science and Technology has awarded a Best Paper prize. The Editorial Board of this journal believes that such a prize is an opportunity to thank authors for submitting their work, and serves as an integral part of the on-going quality review of the journal. The current breadth of topical areas that are covered by MST has made it advisable to expand the recognition of excellent publications. Hence, since 2005 the Editorial Board have presented 'Outstanding Paper Awards' in four subject categories: Fluid Mechanics; Measurement Science; Precision Measurements; and Sensors and Sensing Systems. This year also saw the introduction of a new category—Optical and Laser-based Techniques. 2009 Award Winners—Fluid Mechanics Digital particle image velocimetry (DPIV) robust phase correlation Adric Eckstein and Pavlos P Vlachos Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, USA This paper [1] represents a valuable improvement to the phase-only correlation technique (first proposed by Wernet in this journal in 2005 (Wernet M 2005 Symmetric phase-only filtering: a new paradigm for DPIV data processing Meas. Sci. Technol. 16 601-18) for particle-image-velocimetry (PIV) measurements of fluid flow. The authors establish a sound theoretical foundation and clearly describe the working principle of their robust phase correlation method. The methodology for assessing performance is excellent. Detailed results on several internationally recognized PIV test cases are presented. The robust phase correlation method is of general applicability and therefore can be expected to have substantial impact in this very active area of fluid-mechanics measurements. 2009 Award Winner—Precision Measurement A nanonewton force facility and a novel method for measurements of the air and vacuum permittivity at zero frequencies V Nesterov Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, D-38116 Braunschweig, Germany This paper [2] describes a new method for measuring the air and vacuum permittivity by observing a nanonewton force in a disk-pendulum. The frequency dependence of the vacuum permittivity, ɛ0, has been one of the fundamental questions in physics. Although it is confidently believed that there is no frequency dependence in ɛ0, very few experiments have been conducted to verify the properties of ɛ0. Especially in the region near zero frequencies, no experiment has been done in the vacuum. The precise measurement of the vacuum permittivity is therefore of fundamental interest to test the correctness of Maxwell's equations in an electrostatic field. In this paper, the author developed a new principle using a disk-pendulum, where the displacement of the disk-pendulum in the presence of an electrostatic field has been detected by optical interferometry. The nanonewton forces generated by the electrostatic field have been measured to evaluate the air and vacuum permittivity at zero frequencies, achieving a relative standard uncertainty of 10-5 in the measurement of ɛ0. The measurement system developed here also opened a new way for the force standard in the nanonewton region, investigation of the Casimir effect, direct measurement of laser power etc. This paper has been downloaded more than 200 times since its publication. The selection committee members on precision measurement selected this paper from a strongly competitive list of eleven candidates for its sophisticated idea, originality in apparatus, and excellent result with uncertainty evaluation. Considering its impact on fundamental physics and also on precision force measurement in the nanonewton region, the paper was nominated for the MST Precision Measurement Award from the papers published in 2009. 2009 Award Winners—Sensors and Sensing Systems High-resolution and compact refractometer for salinity measurements D Malardé, Z Y Wu, P Grosso, J-L de Bougrenet de la Tocnaye and M Le Menn Optics Department, UMR CNRS 6082 FOTON, TELECOM Bretagne, CS 83818, 29238 Brest Cédex 3, France Laboratoire de Métrologie et de Chimie Océanographique, SHOM 13 rue du Châtelier, BP 30316, 29603 Brest Cedex, France The absolute salinity of seawater is an important component in the determination of the ocean's thermodynamic properties. This paper [3] presents a measurement system for very accurate determination of the salinity. The method is based on measuring the refractive index of seawater, a parameter that is related to the salinity. Although the method is essentially simple: using a prism and a PSD for direct measurement of the angle of refraction, the refraction also depends on many more parameters (temperature, pressure, wavelength). Moreover, for obtaining accurate salinity values, a high resolution of the refractive index is required, of the order of 10-7, under all possible conditions. Starting with a list of notations and symbols, the paper follows with an overview of existing methods for salinity measurements and their performances. Next, the principle based on refractometry is introduced, and a theoretical model is presented, comprising a large number of parameters that influence the properties of the refractometer. From this analysis there follows an optimization of the geometry of the device. The sensitivity for salinity and other water parameters are estimated from theory, and verified experimentally. Salinity measurements are compared with those using standard salinometers, and show an uncertainty less than a few 10-3 psu (practical salinity units). The obtained resolution is about 4 × 10-7, which is limited by that of the readout electronics of the PSD. It is demonstrated that this can be further improved to achieve the required resolution lower than 10-7. The authors make clear that their prototype, the length of which is about 12 cm, is an important step to a fully in situ oceanographic salinometer, but further testing is required to confirm reliability. Indeed, the paper does not report on long term effects of, for instance, contamination of the optical parts. Hopefully this will be investigated and published in the next stage of the research. 2009 Award Winners—Measurement Science Analysis and mitigation of measurement uncertainties in the traceability chain for the calibration of photovoltaic devices Harald Mullejans, Willem Zaaiman and Roberto Galleano European Commission, Joint Research Centre, Institute for Energy, Renewable Energy Unit, European Solar Test Installation, Via E Fermi 2749, I-21027 Ispra (Va), Italy The energy output and efficiency from different types of photovoltaic (PV) devices is an essential characteristic of photovoltaics. They may only be assessed from cell performance under standard test conditions, with traceability back to international standards. As this paper [4] points out in its introduction, the reliability of the measurements and their uncertainty are of crucial importance to manufacturers, operators and investors. Several features in the format of the article help to make this an excellent paper. Following an informative abstract, the paper has a concise introduction followed by a detailed formulation of the problem to be addressed. After a discussion of present-day international codes related to the measurement and performance of PVs, the paper goes on to describe one of the most difficult issues in traceability, that of deriving an irradiance quantity which is normally measured by a reference PV device. This might appear straightforward, but the paper highlights the difficulties of measuring the irradiance of sunlight (either simulated or natural) during the evaluation of the electrical performance of PV devices. The calibration of any PV device essentially consists of the measurement of the IV characteristics, by sweeping the device from its short-circuit condition (SC) to its open-circuit condition (OC) when exposed to (pulsed or continuous) simulated or natural sunlight. In this paper, all measurements were carried out at the European Solar Test Installation at Ispra in Italy. After describing the measurement methods, the authors discuss at length the calculations of measurement uncertainty. This leads to a rigorous discussion of relative uncertainties from measurement parameters. Uncertainties arise from a range of parameters that include small contributions from electrical, temperature and fill factor parameters. But the greatest arises from uncertainties both in the optical source and in the reference cell. As a consequence, the authors make a convincing case both for identifying the sources of uncertainty and for reducing overall uncertainties from +/-2.6% to below +/-2%. The conclusions are concise, and the paper is rounded off with a list of 34 references with several papers cited from 2005 onwards. This paper was rated as excellent by external referees, and has been downloaded several hundred times since its publication. It is one of 30 papers nominated this year in the Measurement Science category, and gained most votes from those short-listed. The discussion on measurement uncertainty sets a fine example to all researchers involved in experimental measurement science. 2009 Award Winners—Optical and Laser-based Techniques Measurement of tiny droplets using a newly developed optical fibre probe micro-fabricated by a femtosecond pulse laser T Saito, K Matsuda, Y Ozawa, S Oishi and S Aoshima Shizuoka University, 3-5-1 Johoku, Naka-ku Hamamatsu, Shizuoka 432-8561, Japan CRL, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku Hamamatsu, Shizuoka 434-8601, Japan This Award goes to a paper [5] describing a fascinating and novel optical fibre probe applied to measurements in gas-liquid two-phase flows. Optical probes have already been widely applied to two-phase flows. These include the use of four-tip optical probes (F-TOP) for millimetre-size bubbles/droplets, and a single-tip optical fibre probe (S-TOP) for sub-millimetre size bubbles/droplets. This new paper describes how micro-machining a groove into the side of the silica fibre using a femtosecond laser system leads to a new optical fibre probe (Fs-TOP). It is capable of measurements of velocity and size of droplets down to about 50 µm in diameter. A useful introduction describes the importance of characterization required in gas-liquid two-phase flows. Measurements are required in a variety of research fields, e.g. sprays, automotive engines, fine chemistry and atomic power plants. Characterization of bubbles/droplets at high density has been desired for both laboratory and industrial use. Addressed towards this goal, this paper describes the use of optical fibre probes that have been modified with a side-wall groove. The authors point out that whereas the S-TOP is made very easily, with the tip of the S-TOP only micro-ground into a wedge shape, the Fs-TOP is very difficult to fabricate. In addition to a wedge tip, fabrication involves a femtosecond laser system with nano-order six-axis automatic optical stages and confocal optics. Hence it is important to intelligently select between these two types of probe depending on the measurement objective. Moreover, like all types of new probe, it is first necessary to validate its performance against other probes with accepted performance characteristics. After describing the experimental arrangement, the authors discuss at length the performance of the new Fs-TOP and that of the S-TOP for comparison. Additionally, results from the Fs-TOP are compared with those from visualization of the droplets by a high-speed video camera. Results show satisfactory agreement. After a lengthy presentation of results and discussion, the authors produce a concise set of inclusions, including a summary of the small perturbation in droplet size arising from the presence of the probe. The paper was one of 22 papers nominated this year for the Best Paper Award in Optical and Laser-based Techniques. It crosses the disciplines of optical measurement science and measurements required for the characterization of two-phase fluid flow. Exploiting new technological facilities in micromachining, the paper is an excellent example of new opportunities that may arise in measurement. References [1] Eckstein A and Vlachos P P 2009 Digital particle image velocimetry (DPIV) robust phase correlation Meas. Sci. Technol. 20 055401 (14pp) [2] Nesterov V 2009 A nanonewton force facility and a novel method for measurements of the air and vacuum permittivity at zero frequencies Meas. Sci. Technol. 20 084012 (6pp) [3] Malardé D, Wu Z Y, Grosso P, de Bougrenet de la Tocnaye J-L and Le Menn M 2009 High-resolution and compact refractometer for salinity measurements Meas. Sci. Technol. 20 015204 (8pp) [4] Müllejans H, Zaaiman W and Galleano R 2009 Analysis and mitigation of measurement uncertainties in the traceability chain for the calibration of photovoltaic devices Meas. Sci. Technol. 20 075101 (12pp) [5] Saito T, Matsuda K, Ozawa Y, Oishi S and Aoshima S 2009 Measurement of tiny droplets using a newly developed optical fibre probe micro-fabricated by a femtosecond pulse laser Meas. Sci. Technol. 20 114002 (12pp)

Exploring Pupils' Beliefs about Designers and Designing

ERIC Educational Resources Information Center

Trebell, Donna

2011-01-01

The purpose of this paper is to report on an investigation into pupil beliefs about designers and designing conducted as part of a research project focusing on Designerly Activity in Secondary Design and Technology which builds upon a pilot study (Barlex and Trebell in "Int J Technol Design Educ," 2007). Four research questions drove this element…

New National Cryo-EM Facility Provides Access to Cutting-Edge Technology for Cancer Research Community | Frederick National Laboratory for Cancer Research

Cancer.gov

Cancer researchers nationwide now have access to the latest technology in the field of cryo-electron microscopy (cryo-EM)—the study of protein structures at atomic resolution—at the Frederick National Lab for Cancer Research. The emerging technol

Effect of Ocean Interannual Variability on Acoustic Propagation in the Philippine Sea and South China Sea

DTIC Science & Technology

2017-06-01

Coronas , 1920). The dominant pattern of interannual variability is the El Nino Southern Oscillation (ENSO), which has two quasi-periodic states...Validation of Wavewatch-III using TOPEX/ Poseidon data. J. Atmos. Oceanic Technol., 21, 1718–1733. Coronas , J., 1920: The climate and weather of the

IEA/Annex II Powder Characterization Cooperative Program

DTIC Science & Technology

1989-06-01

entatie Sampling of Particks with a Spinning Riffler. Stochastic ModeL Powder Technol., v. 19, 1978. p. 227-233 6. CHARLIER, R., and GOOSSENS , P. J. D...12222 St. Paul, Mix 55144 1 ATTN: Prof. W. A. Lanfo d ATTN: R. E. Richards State University of New York at Stony Brook, Department of Technology

Fundamental Properteries and Capabilities of Plasmonic Antennas for Efficient Interaction with Nanoeletronics

DTIC Science & Technology

2015-08-20

the THz region. Microwave Opt. Technol. Lett. 48, 524-529 (2006). 57. Huo, Y., Taylor, G. W. & Bansal , R. Planar log-periodic antennas on extended...Berry, M. R. Hashemi and M. Jarrahi, Appl. Phys. Lett. 14, 081122, 2014. [39] Y. Huo, G. W. Taylor and R. Bansal , J. Infrared, Millimeter and

Increasing specialty care access through use of an innovative home telehealth-based spinal cord injury disease management protocol (SCI DMP)

PubMed Central

Seton, Jacinta M.; Washington, Monique; Tomlinson, Suk C.; Phrasavath, Douangmala; Farrell, Karen R.; Goldstein, Barry

2016-01-01

Background A spinal cord injury disease management protocol (SCI DMP) was developed to address the unique medical, physical, functional, and psychosocial needs of those living with spinal cord injuries and disorders (SCI/D). The SCI DMP was piloted to evaluate DMP clinical content and to identify issues for broader implementation across the Veterans Affairs (VA) SCI System of Care. Methods Thirty-three patients with SCI/D from four VA SCI centers participated in a 6-month pilot. Patients received customized SCI DMP questions through a data messaging device (DMD). Nurse home telehealth care coordinators (HTCC) monitored responses and addressed clinical alerts daily. One site administered the Duke Severity of Illness (DUSOI) Checklist and Short Form-8 (SF-8™) to evaluate the changes in comorbidity severity and health-related quality of life while on the SCI DMP. Results Patients remained enrolled an average of 116 days, with a mean response rate of 56%. The average distance between patient's home and their VA SCI center was 59 miles. Feedback on SCI DMP content and the DMD included requests for additional clinical topics, changes in administration frequency, and adapting the DMD for functional impairments. Improvement in clinical outcomes was seen in a subset of patients enrolled on the SCI DMP. Conclusion SCI HTCCs and patients reported that the program was most beneficial for newly injured patients recently discharged from acute rehabilitation that live far from specialty SCI care facilities. SCI DMP content changes and broader implementation strategies are currently being evaluated based on lessons learned from the pilot. PMID:24617497

Increasing specialty care access through use of an innovative home telehealth-based spinal cord injury disease management protocol (SCI DMP).

PubMed

Woo, Christine; Seton, Jacinta M; Washington, Monique; Tomlinson, Suk C; Phrasavath, Douangmala; Farrell, Karen R; Goldstein, Barry

2016-01-01

A spinal cord injury disease management protocol (SCI DMP) was developed to address the unique medical, physical, functional, and psychosocial needs of those living with spinal cord injuries and disorders (SCI/D). The SCI DMP was piloted to evaluate DMP clinical content and to identify issues for broader implementation across the Veterans Affairs (VA) SCI System of Care. Thirty-three patients with SCI/D from four VA SCI centers participated in a 6-month pilot. Patients received customized SCI DMP questions through a data messaging device (DMD). Nurse home telehealth care coordinators (HTCC) monitored responses and addressed clinical alerts daily. One site administered the Duke Severity of Illness (DUSOI) Checklist and Short Form-8 (SF-8™) to evaluate the changes in comorbidity severity and health-related quality of life while on the SCI DMP. Patients remained enrolled an average of 116 days, with a mean response rate of 56%. The average distance between patient's home and their VA SCI center was 59 miles. Feedback on SCI DMP content and the DMD included requests for additional clinical topics, changes in administration frequency, and adapting the DMD for functional impairments. Improvement in clinical outcomes was seen in a subset of patients enrolled on the SCI DMP. SCI HTCCs and patients reported that the program was most beneficial for newly injured patients recently discharged from acute rehabilitation that live far from specialty SCI care facilities. SCI DMP content changes and broader implementation strategies are currently being evaluated based on lessons learned from the pilot.

Psychometric evaluation of the Spanish version of the MPI-SCI.

PubMed

Soler, M D; Cruz-Almeida, Y; Saurí, J; Widerström-Noga, E G

2013-07-01

Postal surveys. To confirm the factor structure of the Spanish version of the MPI-SCI (MPI-SCI-S, Multidimensional Pain Inventory in the SCI population) and to test its internal consistency and construct validity in a Spanish population. Guttmann Institute, Barcelona, Spain. The MPI-SCI-S along with Spanish measures of pain intensity (Numerical Rating Scale), pain interference (Brief Pain Inventory), functional independence (Functional Independence Measure), depression (Beck Depression Inventory), locus of control (Multidimensional health Locus of Control), support (Functional Social Support Questionnaire (Duke-UNC)), psychological well-being (Psychological Global Well-Being Index) and demographic/injury characteristics were assessed in persons with spinal cord injury (SCI) and chronic pain (n=126). Confirmatory factor analysis suggested an adequate factor structure for the MPI-SCI-S. The internal consistency of the MPI-SCI-S subscales ranged from acceptable (r=0.66, Life Control) to excellent (r=0.94, Life Interference). All MPI-SCI-S subscales showed adequate construct validity, with the exception of the Negative and Solicitous Responses subscales. The Spanish version of the MPI-SCI is adequate for evaluating chronic pain impact following SCI in a Spanish-speaking population. Future studies should include additional measures of pain-related support in the Spanish-speaking SCI population.

Infertility in Men with Spinal Cord Injury: Research and Treatment

PubMed Central

Brackett, Nancy L.

2012-01-01

Spinal cord injury (SCI) occurs most often to young men. Following SCI, most men are infertile due to a combination of erectile dysfunction, ejaculatory dysfunction and semen abnormalities. Erectile dysfunction may be treated by the same therapies that are used in the general population. Similarly, the same treatments that are effective to assist conception in couples with non-SCI male factor patients are effective in assisting conception in SCI male-factor patients. The most apparent differences in male-factor symptoms between SCI and non-SCI patients are the high occurrences of anejaculation and atypical semen profiles in men with SCI. Methods available to assist ejaculation in men with SCI include penile vibratory stimulation and EEJ. Use of surgical sperm retrieval as the first line of treatment for anejaculation in men with SCI is controversial. Most men with SCI have a unique semen profile characterized by normal sperm concentration, but abnormally low sperm motility. Toxic substances in the semen contribute to this problem. Despite impaired sperm parameters, pregnancy outcomes using sperm from men with SCI are similar to pregnancy outcomes using sperm from non-SCI men. Future studies should focus on improving natural ejaculation and improving semen quality in these men. PMID:24278717

Prevalence and Etiology of Hypogonadism in Young Men With Chronic Spinal Cord Injury: A Cross-Sectional Analysis From Two University-Based Rehabilitation Centers.

PubMed

Sullivan, Shannon D; Nash, Mark S; Tefera, Eshetu; Tinsley, Emily; Blackman, Marc R; Groah, Suzanne

2017-08-01

Spinal cord injury (SCI) triggers an "accelerated aging" process that may include development of hypogonadism, even among younger men with SCI; however, few studies have investigated the prevalence or etiology of hypogonadism in men with SCI. Young men with SCI also are at increased risk for developing metabolic dysfunction after injury, which may be exacerbated by concomitant testosterone (T) deficiency, thus identifying the prevalence and risk factors for T deficiency in men with SCI is important for their long-term health. To investigate the prevalence, risk factors, and etiology of T deficiency (hypogonadism) in otherwise-healthy men with chronic, motor complete SCI. Secondary cross-sectional analysis. Rehabilitation research centers in Washington, DC, and Miami, Florida. Men (n = 58) aged 18-45 years with chronic (≥1 year), motor complete SCI without comorbidities or use of testosterone therapy. Plasma concentrations of hormones were measured with standardized assays. Body composition was assessed with dual-energy x-ray absorptiometry scan. Serum total T and calculated free T. T deficiency was more common in men after SCI than in a matched cohort of similarly-aged men without SCI (25%, SCI versus 6.7%, non-SCI, P < .001). The risk of hypogonadism appeared to be increased in men with more extensive injury and with higher percent body fat. The majority of men with SCI with low T had low serum LH levels, suggesting that central suppression of the hypothalamic-pituitary-gonadal axis may be the most common etiology of hypogonadism after SCI. Hypogonadism is more common in young men with SCI than in similarly aged men without SCI, suggesting that SCI should be identified as a risk factor for T deficiency and that routine screening for hypogonadism should be performed in the SCI population. II. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Combined SCI and TBI: Recovery of forelimb function after unilateral cervical spinal cord injury (SCI) is retarded by contralateral traumatic brain injury (TBI), and ipsilateral TBI balances the effects of SCI on paw placement

PubMed Central

Inoue, Tomoo; Lin, Amity; Ma, Xiaokui; McKenna, Stephen L.; Creasey, Graham H.; Manley, Geoffrey T.; Ferguson, Adam R.; Bresnahan, Jacqueline C.; Beattie, Michael S.

2015-01-01

A significant proportion (estimates range from 16–74%) of patients with spinal cord injury (SCI) have concomitant traumatic brain injury (TBI), and the combination often produces difficulties in planning and implementing rehabilitation strategies and drug therapies. For example, many of the drugs used to treat SCI may interfere with cognitive rehabilitation, and conversely drugs that are used to control seizures in TBI patients may undermine locomotor recovery after SCI. The current paper presents an experimental animal model for combined SCI and TBI to help drive mechanistic studies of dual diagnosis. Rats received a unilateral SCI (75 kdyn) at C5 vertebral level, a unilateral TBI (2.0 mm depth, 4.0 m/s velocity impact on the forelimb sensori-motor cortex), or both SCI + TBI. TBI was placed either contralateral or ipsilateral to the SCI. Behavioral recovery was examined using paw placement in a cylinder, grooming, open field locomotion, and the IBB cereal eating test. Over 6 weeks, in the paw placement test, SCI + contralateral TBI produced a profound deficit that failed to recover, but SCI + ipsilateral TBI increased the relative use of the paw on the SCI side. In the grooming test, SCI + contralateral TBI produced worse recovery than either lesion alone even though contralateral TBI alone produced no observable deficit. In the IBB forelimb test, SCI + contralateral TBI revealed a severe deficit that recovered in 3 weeks. For open field locomotion, SCI alone or in combination with TBI resulted in an initial deficit that recovered in 2 weeks. Thus, TBI and SCI affected forelimb function differently depending upon the test, reflecting different neural substrates underlying, for example, exploratory paw placement and stereotyped grooming. Concurrent SCI and TBI had significantly different effects on outcomes and recovery, depending upon laterality of the two lesions. Recovery of function after cervical SCI was retarded by the addition of a moderate TBI in the contralateral hemisphere in all tests, but forepaw placements were relatively increased by an ipsilateral TBI relative to SCI alone, perhaps due to the dual competing injuries influencing the use of both forelimbs. These findings emphasize the complexity of recovery from combined CNS injuries, and the possible role of plasticity and laterality in rehabilitation, and provide a start towards a useful preclinical model for evaluating effective therapies for combine SCI and TBI. PMID:23770071

Combined SCI and TBI: recovery of forelimb function after unilateral cervical spinal cord injury (SCI) is retarded by contralateral traumatic brain injury (TBI), and ipsilateral TBI balances the effects of SCI on paw placement.

PubMed

Inoue, Tomoo; Lin, Amity; Ma, Xiaokui; McKenna, Stephen L; Creasey, Graham H; Manley, Geoffrey T; Ferguson, Adam R; Bresnahan, Jacqueline C; Beattie, Michael S

2013-10-01

A significant proportion (estimates range from 16 to 74%) of patients with spinal cord injury (SCI) have concomitant traumatic brain injury (TBI), and the combination often produces difficulties in planning and implementing rehabilitation strategies and drug therapies. For example, many of the drugs used to treat SCI may interfere with cognitive rehabilitation, and conversely drugs that are used to control seizures in TBI patients may undermine locomotor recovery after SCI. The current paper presents an experimental animal model for combined SCI and TBI to help drive mechanistic studies of dual diagnosis. Rats received a unilateral SCI (75 kdyn) at C5 vertebral level, a unilateral TBI (2.0 mm depth, 4.0 m/s velocity impact on the forelimb sensori-motor cortex), or both SCI+TBI. TBI was placed either contralateral or ipsilateral to the SCI. Behavioral recovery was examined using paw placement in a cylinder, grooming, open field locomotion, and the IBB cereal eating test. Over 6weeks, in the paw placement test, SCI+contralateral TBI produced a profound deficit that failed to recover, but SCI+ipsilateral TBI increased the relative use of the paw on the SCI side. In the grooming test, SCI+contralateral TBI produced worse recovery than either lesion alone even though contralateral TBI alone produced no observable deficit. In the IBB forelimb test, SCI+contralateral TBI revealed a severe deficit that recovered in 3 weeks. For open field locomotion, SCI alone or in combination with TBI resulted in an initial deficit that recovered in 2 weeks. Thus, TBI and SCI affected forelimb function differently depending upon the test, reflecting different neural substrates underlying, for example, exploratory paw placement and stereotyped grooming. Concurrent SCI and TBI had significantly different effects on outcomes and recovery, depending upon laterality of the two lesions. Recovery of function after cervical SCI was retarded by the addition of a moderate TBI in the contralateral hemisphere in all tests, but forepaw placements were relatively increased by an ipsilateral TBI relative to SCI alone, perhaps due to the dual competing injuries influencing the use of both forelimbs. These findings emphasize the complexity of recovery from combined CNS injuries, and the possible role of plasticity and laterality in rehabilitation, and provide a start towards a useful preclinical model for evaluating effective therapies for combine SCI and TBI. Copyright © 2013 Elsevier Inc. All rights reserved.

Neuroprotective effects of lycopene in spinal cord injury in rats via antioxidative and anti-apoptotic pathway.

PubMed

Hu, Wei; Wang, Hongbo; Liu, Zhenfeng; Liu, Yanlu; Wang, Rong; Luo, Xiao; Huang, Yifei

2017-03-06

Oxidative damage induced-mitochondrial dysfunction and apoptosis has been widely studied in spinal cord injury (SCI). Lycopene, a polyunsaturated hydrocarbon, has the highest antioxidant capacity compared to the other carotenoids. However, the role of lycopene in SCI is unknown. In the present study, we evaluated the antioxidant effects of lycopene on mitochondrial dysfunction and apoptosis following T10 contusion SCI in rats. The rats were randomized into 5 groups: the sham group, the SCI group and the SCI pre-treated with lycopene (5, 10, or 20mg/kg) group. The SCI group showed increased malondialdehyde (MDA) content, decreased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) ability, which indicated that SCI could induce oxidative damage. What's more, the SCI group showed decreased mRNA expression of cytochrome b and mitochondrial transcription factor A (Tfam), and decreased mitochondrial membrane potential (ΔYm), which indicated that SCI could induce mitochondrial dysfunction. Besides, the SCI group showed decreased protein expression of bcl-2 and mitochondrial cytochrome C, increased protein expression of cytosolic cytochrome C, cleaved caspase-9, cleaved caspase-3 and bax, and increased TUNEL-positive cell numbers, which indicated that SCI could induce cell apoptosis. Fortunately, the lycopene treatment significantly ameliorated oxidative damage, mitochondrial dysfunction and cell apoptosis via the reversion of those parameters described above in the dose of lycopene of 10 and 20mg/kg. In addition, lycopene significantly ameliorated the hind limb motor disturbances in the SCI+lyco10 group and the SCI+lyco20 group compared with the SCI group. These results suggested that lycopene administration could improve total antioxidant status and might have neuroprotective effects on SCI. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Spinal Cord Injury in Heart Rate Variability After Acute and Chronic Exercise: A Systematic Review.

PubMed

Buker, Daniel Bueno; Oyarce, Cristóbal Castillo; Plaza, Raúl Smith

2018-01-01

Background: Spinal cord injury (SCI) above T6 is followed by a loss of sympathetic supraspinal control of the heart, disturbing the autonomic balance and increasing cardiovascular risk. Heart rate variability (HRV) is a widely used tool for assessing the cardiac autonomic nervous system and positive adaptations after regular exercise in able-bodied subjects. However, adaptations in SCI subjects are not well known. Objectives: To compare HRV between able-bodied and SCI subjects and analyze the effects of chronic and acute exercise on HRV in the SCI group. Methods: We searched MEDLINE, Embase, Web of Science, SciELO, and Google Scholar databases to July 2016. We selected English and Spanish observational or experimental studies reporting HRV after training or acute exercise in SCI patients. We also included studies comparing HRV in SCI individuals with able-bodied subjects. Animal studies and nontraumatic SCI studies were excluded. We screened 279 articles by title and abstract; of these, we fully reviewed 29 articles. Eighteen articles fulfilled criteria for inclusion in this study. Results: SCI individuals showed lower HRV values in the low frequency band compared to able-bodied subjects. Regular exercise improved HRV in SCI subjects, however time and intensity data were lacking. HRV decreases after an acute bout of exercise on SCI subjects, but recovery kinetics are unknown. Conclusion: HRV is affected following SCI. Able-bodied subjects and SCI individuals have different values of HRV. Acute bouts of exercise change HRV temporarily, and chronic exercise might improve autonomic balance in SCI.

Overview of the Spinal Cord Injury--Quality of Life (SCI-QOL) measurement system.

PubMed

Tulsky, David S; Kisala, Pamela A; Victorson, David; Tate, Denise G; Heinemann, Allen W; Charlifue, Susan; Kirshblum, Steve C; Fyffe, Denise; Gershon, Richard; Spungen, Ann M; Bombardier, Charles H; Dyson-Hudson, Trevor A; Amtmann, Dagmar; Kalpakjian, Claire Z; Choi, Seung W; Jette, Alan M; Forchheimer, Martin; Cella, David

2015-05-01

The Spinal Cord Injury--Quality of Life (SCI-QOL) measurement system was developed to address the shortage of relevant and psychometrically sound patient reported outcome (PRO) measures available for clinical care and research in spinal cord injury (SCI) rehabilitation. Using a computer adaptive testing (CAT) approach, the SCI-QOL builds on the Patient Reported Outcomes Measurement Information System (PROMIS) and the Quality of Life in Neurological Disorders (Neuro-QOL) initiative. This initial manuscript introduces the background and development of the SCI-QOL measurement system. Greater detail is presented in the additional manuscripts of this special issue. Classical and contemporary test development methodologies were employed. Qualitative input was obtained from individuals with SCI and clinicians through interviews, focus groups, and cognitive debriefing. Item pools were field tested in a multi-site sample (n=877) and calibrated using item response theory methods. Initial reliability and validity testing was performed in a new sample of individuals with traumatic SCI (n=245). Five Model SCI System centers and one Department of Veterans Affairs Medical Center across the United States. Adults with traumatic SCI. n/a n/a The SCI-QOL consists of 19 item banks, including the SCI-Functional Index banks, and 3 fixed-length scales measuring physical, emotional, and social aspects of health-related QOL (HRQOL). The SCI-QOL measurement system consists of psychometrically sound measures for individuals with SCI. The manuscripts in this special issue provide evidence of the reliability and initial validity of this measurement system. The SCI-QOL also links to other measures designed for a general medical population.

Bacterial susceptibility patterns in patients with spinal cord injury and disorder (SCI/D): an opportunity for customized stewardship tools.

PubMed

Suda, K J; Patel, U C; Sabzwari, R; Cao, L; Ramanathan, S; Hill, J N; Evans, C T

2016-11-01

Retrospective observational study of bacterial susceptibilities in Veterans with SCI/D as compared to a general patient population. The purpose of this project was to evaluate the prevalence and susceptibility of bacteria isolated from spinal cord injury and disorder (SCI/D) patients as compared with a general patient population and determine whether a SCI/D-specific antibiogram, a report of bacterial susceptibilities used to guide empiric antibiotic selection, would be a useful stewardship tool. Veterans Affairs Medical Center located in Cook county, IL, USA. Microbiology reports from 1 October 2012 to 30 September 2013 were compiled into a SCI/D-specific antibiogram and compared to a non-SCI/D antibiogram. Persons with positive cultures and SCI/D were younger and had a higher Charlson Index as compared to non-SCI/D patients (P<0.0001 for both). Five thousand one hundred and thirty-one unique isolate cultures were evaluated (SCI/D=23.0%). Frequencies of pathogens isolated in SCI/D and non-SCI/D differed. Methicillin-resistant Staphylococcus aureus occurred more frequently in SCI/D (27.8% vs 55.4%; P<0.0001). Gram-negatives had generally lower susceptibilities in SCI/D and a higher frequency of organisms producing extended-spectrum Beta-lactamases (17.6% vs 5.0%; P<0.0001), carbapenem-resistant Enterobacteriaceae (2.4% vs 0.5%; P<0.0001), carbapenem resistance (7.6% vs 2.4%; P<0.0001) and isolates resistant to ⩾3 antibiotic classes (60.7% vs 28.0%; P=0.0001). Different pathogens with poorer susceptibilities are isolated in SCI/D. Thus an SCI/D-specific antibiogram reflective of resistance patterns in these patients may increase the appropriateness of empiric antibiotic selection. The frequency of multi-drug resistant organisms in cultures obtained from patients with SCI/D is worrisome.

Tracking functional status across the spinal cord injury lifespan: linking pediatric and adult patient-reported outcome scores.

PubMed

Tian, Feng; Ni, Pengsheng; Mulcahey, M J; Hambleton, Ronald K; Tulsky, David; Haley, Stephen M; Jette, Alan M

2014-11-01

To use item response theory (IRT) methods to link scores from 2 recently developed contemporary functional outcome measures, the adult Spinal Cord Injury-Functional Index (SCI-FI) and the Pedi SCI (both the parent version and the child version). Secondary data analysis of the physical functioning items of the adult SCI-FI and the Pedi SCI instruments. We used a nonequivalent group design with items common to both instruments and the Stocking-Lord method for the linking. Linking was conducted so that the adult SCI-FI and Pedi SCI scaled scores could be compared. Community. This study included a total sample of 1558 participants. Pedi SCI items were administered to a sample of children (n=381) with SCI aged 8 to 21 years, and of parents/caregivers (n=322) of children with SCI aged 4 to 21 years. Adult SCI-FI items were administered to a sample of adults (n=855) with SCI aged 18 to 92 years. Not applicable. Five scales common to both instruments were included in the analysis: Wheelchair, Daily Routine/Self-care, Daily Routine/Fine Motor, Ambulation, and General Mobility functioning. Confirmatory factor analysis and exploratory factor analysis results indicated that the 5 scales are unidimensional. A graded response model was used to calibrate the items. Misfitting items were identified and removed from the item banks. Items that function differently between the adult and child samples (ie, exhibit differential item functioning) were identified and removed from the common items used for linking. Domain scores from the Pedi SCI instruments were transformed onto the adult SCI-FI metric. This IRT linking allowed estimation of adult SCI-FI scale scores based on Pedi SCI scale scores and vice versa; therefore, it provides clinicians with a means of tracking long-term functional data for children with an SCI across their entire lifespan. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

In-situ single particle composition analysis of free tropospheric ice nuclei and ice residues in mixed-phase clouds during INUIT-JFJ 2013

NASA Astrophysics Data System (ADS)

Schmidt, Susan; Schneider, Johannes; Thomas, Klimach; Stephan, Mertes; Ludwig, Schenk; Udo, Kästner; Frank, Stratmann; Joachim, Curtius; Piotr, Kupiszewski; Ernest, Weingartner; Emanuel, Hammer; Paul, Vochezer; Martin, Schnaiter; Stephan, Borrmann

2014-05-01

In the framework of the DFG (deutsche Forschungsgemeinschaft)-funded research unit INUIT (Ice Nuclei research UnIT) a field campaign at the High Alpine Research Station Jungfraujoch (JFJ, Swiss Alps, Sphinx Laboratory, 3580 m asl; 7°59'2''E, 46°32'53''N) took place in January/February 2013 (INUIT-JFJ 2013). The goal of the measurements was to investigate the chemical composition of ice particle residues (IPR) in ambient air as well as the background aerosol particles. Previous investigations conducted at the JFJ showed that particles consisting of mineral components dominate the ice particle residue number (Kamphus et al., 2008) but also particles consisting of black carbon were found to be enriched in IPR (Mertes et al., 2007; Cozic et al., 2008). Cziczo et al. find out that lead as well is a good ice nucleus and was measured in IPR at previous measurements at the JFJ. During INUIT-JFJ 2013, the IPR were sampled out of mixed-phase clouds by an Ice-CVI (Ice Counterflow Virtual Impactor, Mertes et al., 2007) and an ISI (Ice Selective Inlet, Kupiszewski et al., 2013) and analyzed by the single particle mass spectrometer ALABAMA (Aircraft-based Laser Ablation Aerosol Mass Spectrometer; Brands et al., 2011). Additionally, the ALABAMA was connected to a total aerosol-inlet to investigate the chemical composition of background aerosol particles. During 217 hours of background aerosol measurements we analyzed more than 27000 aerosol particles, which consisted mainly of pure organic components or organics mixed with ammonium, metals or mineral components. During six cloud events with approximately 63 h measurement time we detected 162 IPR sampled by the Ice-CVI. The main part of these IPR were also composed of organic material mixed with other chemical compounds. Additionally, we found particles which consisted of mineral components (approximately 23 %). Sampling mixed-phase cloud through the ISI we measured during four cloud events 34 ice residues in approximately 30 h measurement time. The main part of the chemical compounds of these IPR were also organic material mixed with metals or with mineral compounds. We also found a smaller part of particles which consisted of pure mineral components (about 48 %). Lead was also found in the IPR measured behind Ice-CVI (~14 %) as well as in the background aerosol (~0.04 %). Black carbon particles were only found in the background aerosol. Because of the topography of the JFJ, air masses can reach the station only from the northwestern or southeastern direction (Hammer et al., 2013). Back trajectory calculations show that during our measurements the air masses were dominated mainly by long-distance transport from North America over Great Britain and France. This may explain the lower abundance of mineral dust in the ice residues compared to the previous studies. Brands, M., Kamphus, M., Böttger, T., Schneider, J., Drewnick, F., Roth, A., Curtius, J., Voigt, C., Borbon, A., Beekmann, M., Bourdon, A., Perrin, T. and Borrmann, S. (2011) Aerosol Sci. Technol., 45, 46-64. Cozic, J., Mertes, S., Verheggen, B., Cziczo, D. J., Gallavardin, S. J., Walter, S., Baltensperger, U. and Weingartner, E. (2008) J. Geophys. Res.-Atmos., 113, D15209. Cziczo, D. J., Stetzer. O., Worringen, A., Ebert, M., Weinbruch, S., Kamphus, M., Gallavardin, S. J., Curtius, J., Borrmann, S., Froyd, K. D., Mertes, S., Möhler, O., Lohmann, U. (2009) Nature Geoscience, 2, 333-336 Hammer, E., Bukowiecki, N., Gysel, M., Jurányi, Z., Hoyle, C. R., Vogt, R., Baltensperger, U. and Weingartner, E. (2013) Atmos. Chem. Phys. Discuss., 13, 20419-20462 Kamphus, M., Ettner-Mahl, M., Klimach, T., Drewnick, F, Keller, L., Cziczo, D. J., Mertes, S., Borrmann, S. and Curtius1, J. (2010) Atmos. Chem. Phys., 10, 8077-8095. Kupiszewski, P., Weingartner, E., Färber, R., Gysel, M., Hammer, E., Fuchs, C., Baltensperger, U., Vochezer, P., Schnaiter, M., Linke, C., Toprak, E., Mertes, S., Schneider, J., Schmidt, S. (2013) European Aerosol Conference, Prague. Mertes, S., Verheggen, B., Walter,S., Connolly,P., Ebert, M., Schneider, J., Bower, K. N., Cozic, J., Weinbruch, S., Baltensperger, U. and Weingartner, E. (2007) Aerosol Sci. Technol., 41, 848-864.

Ship-borne measurements of microbial enzymatic activity: A rapid biochemical indicator for microbial water quality monitoring

NASA Astrophysics Data System (ADS)

Stadler, Philipp; Loken, Luke; Crawford, John; Schramm, Paul; Sorsa, Kirsti; Kuhn, Catherine; Savio, Domenico; Striegl, Rob; Butman, David; Stanley, Emily; Farnleitner, Andreas H.; Zessner, Matthias

2017-04-01

Contamination of aquatic ecosystems by human and animal wastes is a global concern for water quality. Disclosing fate and transport processes of fecal indicator organism (FIO) in large water bodies is a big challenge due to material intensive and time consuming methods used in microbiological water quality monitoring. In respect of utilization of large surface water resources there is a dearth of rapid microbiological methods that allow a near-real time health related water quality monitoring to be implemented into early warning systems. The detection of enzymatic activities has been proposed as a rapid surrogate for microbiological pollution monitoring of water and water resources (Cabral, 2010; Farnleitner et al., 2001, 2002). Methods such as the beta-D-Glucuronidase assay (GLUC), targeting FIO such as E. coli, were established. New automated enzymatic assays have been implemented during the last years into on-site monitoring stations, ranging from ground- to surface waters (Ryzinska-Paier et al., 2014; Stadler et al., 2017, 2016). While these automated enzymatic methods cannot completely replace assays for culture-based FIO enumeration, they yielded significant information on pollution events and temporal dynamics on a catchment specific basis, but were restricted to stationary measurements. For the first time we conducted ship-borne and automated measurements of enzymatic GLUC activity on large fresh water bodies, including the Columbia River, the Mississippi River and Lake Mendota. Not only are automated enzymatic assays technically feasible from a mobile vessel, but also can be used to localize point sources of potential microbial fecal contamination, such as tributaries or storm drainages. Spatial and temporal patterns of enzymatic activity were disclosed and the habitat specific correlation with microbiological standard assays for FIO determined due to reference samples. The integration of rapid and automated enzymatic assays into well-established systems for ship-borne measurements of physico-chemical parameters, such as the FLAMe (Crawford et al., 2015), paves new ground for data interpretation and process understanding. Cabral, J.P.S., 2010. Water Microbiology. Bacterial Pathogens and Water. Int. J. Environ. Res. Public. Health 7, 3657-3703. doi:10.3390/ijerph7103657 Crawford, J.T., Loken, L.C., Casson, N.J., Smith, C., Stone, A.G., Winslow, L.A., 2015. High-speed limnology: using advanced sensors to investigate spatial variability in biogeochemistry and hydrology. Environ. Sci. Technol. 49, 442-450. doi:10.1021/es504773x Farnleitner, A. h., Hocke, L., Beiwl, C., Kavka, G. c., Zechmeister, T., Kirschner, A. k. t., Mach, R. l., 2001. Rapid enzymatic detection of Escherichia coli contamination in polluted river water. Lett. Appl. Microbiol. 33, 246-250. doi:10.1046/j.1472-765x.2001.00990.x Farnleitner, A.H., Hocke, L., Beiwl, C., Kavka, G.G., Mach, R.L., 2002. Hydrolysis of 4-methylumbelliferyl-β-d-glucuronide in differing sample fractions of river waters and its implication for the detection of fecal pollution. Water Res. 36, 975-981. doi:10.1016/S0043-1354(01)00288-3 Ryzinska-Paier, G., Lendenfeld, T., Correa, K., Stadler, P., Blaschke, A.P., Mach, R.L., Stadler, H., Kirschner, A.K.T., Farnleitner, A.H., 2014. A sensitive and robust method for automated on-line monitoring of enzymatic activities in water and water resources. Water Sci. Technol. J. Int. Assoc. Water Pollut. Res. 69, 1349-1358. doi:10.2166/wst.2014.032 Stadler, P., Blöschl, G., Vogl, W., Koschelnik, J., Epp, M., Lackner, M., Oismüller, M., Kumpan, M., Nemeth, L., Strauss, P., Sommer, R., Ryzinska-Paier, G., Farnleitner, A.H., Zessner, M., 2016. Real-time monitoring of beta-d-glucuronidase activity in sediment laden streams: A comparison of prototypes. Water Res. 101, 252-261. doi:10.1016/j.watres.2016.05.072 Stadler, P., Farnleitner, A.H., Zessner, M., 2017. Development and evaluation of a self-cleaning custom-built auto sampler controlled by a low-cost RaspberryPi microcomputer for online enzymatic activity measurements. Talanta 162, 390-397. doi:10.1016/j.talanta.2016.10.031

Lipid Peroxidation and Its Role in the Expression of NLRP1a and NLRP3 Genes in Testicular Tissue of Male Rats: a Model of Spinal Cord Injury

PubMed

Bazrafkan, Mahshid; Nikmehr, Banafsheh; Shahverdi, Abdolhossein; Hosseini, Seyed Reza; Hassani, Fatemeh; Poorhassan, Mahnaz; Mokhtari, Tahmineh; Abolhassani, Farid; Choobineh, Hamid; Beyer, Cordian; Hassanzadeh, Gholamreza

2017-10-16

The majority of male patients with spinal cord injury (SCI) suffer from infertility. Nucleotide-binding oligomerization domain-like receptors NOD-like receptors (NLRs) are a kind of receptors that corporate in the inflammasome complex. Recent studies have introduced the inflammasome as the responsible agent for secreting cytokines in semen. Reactive oxygen species (ROS) is one of the elements that trigger inflammasome activation. Genital infections in SCI can lead to ROS generation. We investigated the relation between lipid peroxidation and inflammasome complex activity in testicular tissue of SCI rats. Adult male rats (n=20), weighting 200-250 g, were included and divided into four groups: three experimental groups, including SCI1, SCI3, and SCI7, i.e. the rats were subjected to SCI procedure and sacrificed after one, three, and seven days, respectively and a control group. We performed a moderate, midline spinal contusion injury at thoracic level 10. The animals were anesthetized, and testes were collected for measurement of gene expression by real-time PCR. Caudal parts of epididymis were collected for malondialdehyde (MDA) measurement. No NLRP1a mRNA over expression was seen in the testes of control and SCI groups. After seven days from SCI surgery, NLRP3 mRNA expression was significantly increased in SCI7 animals (P≤0.05). There was a significant difference in MDA level in SCI7 versus control group, as well as SCI1 and SCI3 animals (P≤0.05). NLRP3 overexpression occurs due to the increased ROS production in testicular tissue of SCI rats.

Lipid Peroxidation and Its Role in the Expression of NLRP1a and NLRP3 Genes in Testicular Tissue of Male Rats: A Model of Spinal Cord Injury

PubMed Central

Bazrafkan, Mahshid; Nikmehr, Banafsheh; Shahverdi, Abdolhossein; Hosseini, Seyed Reza; Hassani, Fatemeh; Poorhassan, Mahnaz; Mokhtari, Tahmineh; Abolhassani, Farid; Choobineh, Hamid; Beyer, Cordian; Hassanzadeh, Gholamreza

2018-01-01

Background: The majority of male patients with spinal cord injury (SCI) suffer from infertility. Nucleotide-binding oligomerization domain-like receptors NOD-like receptors (NLRs) are a kind of receptors that corporate in the inflammasome complex. Recent studies have introduced the inflammasome as the responsible agent for secreting cytokines in semen. Reactive oxygen species (ROS) is one of the elements that trigger inflammasome activation. Genital infections in SCI can lead to ROS generation. We investigated the relation between lipid peroxidation and inflammasome complex activity in testicular tissue of SCI rats. Methods: Adult male rats (n=20), weighting 200-250 g, were included and divided into four groups: three experimental groups, including SCI1, SCI3, and SCI7, i.e. the rats were subjected to SCI procedure and sacrificed after one, three, and seven days, respectively and a control group. We performed a moderate, midline spinal contusion injury at thoracic level 10. The animals were anesthetized, and testes were collected for measurement of gene expression by real-time PCR. Caudal parts of epididymis were collected for malondialdehyde (MDA) measurement. Results: No NLRP1a mRNA overexpression was seen in the testes of control and SCI groups. After seven days from SCI surgery, NLRP3 mRNA expression was significantly increased in SCI7 animals (p ≤ 0.05). There was a significant difference in MDA level in SCI7 versus control group, as well as SCI1 and SCI3 animals (p ≤ 0.05). Conclusion: NLRP3 overexpression occurs due to the increased ROS production in testis tissue of SCI rats

Overview of the Spinal Cord Injury – Quality of Life (SCI-QOL) measurement system

PubMed Central

Tulsky, David S.; Kisala, Pamela A.; Victorson, David; Tate, Denise G.; Heinemann, Allen W.; Charlifue, Susan; Kirshblum, Steve C.; Fyffe, Denise; Gershon, Richard; Spungen, Ann M.; Bombardier, Charles H.; Dyson-Hudson, Trevor A.; Amtmann, Dagmar; Z. Kalpakjian, Claire; W. Choi, Seung; Jette, Alan M.; Forchheimer, Martin; Cella, David

2015-01-01

Context/Objective The Spinal Cord Injury – Quality of Life (SCI-QOL) measurement system was developed to address the shortage of relevant and psychometrically sound patient reported outcome (PRO) measures available for clinical care and research in spinal cord injury (SCI) rehabilitation. Using a computer adaptive testing (CAT) approach, the SCI-QOL builds on the Patient Reported Outcomes Measurement Information System (PROMIS) and the Quality of Life in Neurological Disorders (Neuro-QOL) initiative. This initial manuscript introduces the background and development of the SCI-QOL measurement system. Greater detail is presented in the additional manuscripts of this special issue. Design Classical and contemporary test development methodologies were employed. Qualitative input was obtained from individuals with SCI and clinicians through interviews, focus groups, and cognitive debriefing. Item pools were field tested in a multi-site sample (n = 877) and calibrated using item response theory methods. Initial reliability and validity testing was performed in a new sample of individuals with traumatic SCI (n = 245). Setting Five Model SCI System centers and one Department of Veterans Affairs Medical Center across the United States. Participants Adults with traumatic SCI. Interventions n/a Outcome Measures n/a Results The SCI-QOL consists of 19 item banks, including the SCI-Functional Index banks, and 3 fixed-length scales measuring physical, emotional, and social aspects of health-related QOL (HRQOL). Conclusion The SCI-QOL measurement system consists of psychometrically sound measures for individuals with SCI. The manuscripts in this special issue provide evidence of the reliability and initial validity of this measurement system. The SCI-QOL also links to other measures designed for a general medical population. PMID:26010962

Investigating "The Coolest School in America": How Technology Is Used in a Learner-Centered School

ERIC Educational Resources Information Center

Aslan, Sinem; Reigeluth, Charles M.

2016-01-01

Reigeluth et al. ("Educ Technol" 48(6):32-39, 2008) proposed major and secondary functions for educational technology systems for the learner-centered paradigm of education. However, the functions proposed should be formatively evaluated and revised using a variety of cases to develop a better understanding of how technology can support…

Bacterial Degradation of Nitrogenous Energetic Compounds (NEC) in Coastal Waters and Sediments

DTIC Science & Technology

2008-09-10

2006) Enzymatic immobilization of 2,4,6-trinitrotoluene (TNT) biodegradation products onto model humic substances. Enzyme Microbial Technol 39:1197...11 2.3 Heterotrophic bacterial production ...collected May 2006: A) Average (AVG) rates of TNT incorporation and bacterial production (μg C L-1 d-1); and, B) TNT incorporation normalized for

Compact, High Power, Multi-Spectral Mid-Infrared Semiconductor Laser Package

DTIC Science & Technology

2001-10-01

depositions to map out effects due to stress in the films. Stress in the film will result in the substrate curvature. This curvature results in the...Lasers at 4.5 µm”, IEEE Photon. Technol. Lett., vol. 9, pp. 1573-1575, (1997). 58 18. A. N. Baranov, N. Bertru, Y. Cuminal , G. Boissier, C. Alibert, and

Three Dimensionally Interconnected Silicon Nanomembranes for Optical Phased Array (OPA) and Optical True Time Delay (TTD) Applications

DTIC Science & Technology

2012-06-01

Nanophotonic Waveguides," J. Lightwave Technol. 25 (1), 151-156 (2007). [7-4] Yongbo Tang, Zhechao Wang, Lech Wosinski, Urban Westergren, and Sailing...Waveguides," Photonics Journal, IEEE 3 (2), 203-208 (2011). [8-25] Zhechao Wang, Ning Zhu, Yongbo Tang, Lech Wosinski, Daoxin Dai, and Sailing He

Evaluation of Magnetostrictive Shunt Damper Performance Using Iron (Fe)-Gallium (Ga) Alloy

DTIC Science & Technology

2013-09-01

Technol. 2003, 11 (4), 482– 494 3. Manning, K. V.; Watanabe, K.; Drake, A. E.; Wright, A. Eddy Current. in AccessScience , ©McGraw-Hill Education...2012, http://www.accessscience.com. 4. Manning, K. V. Lenz’s Law in AccessScience , ©McGraw-Hill Education, 2012, http://www.accessscience.com 5

High Temperature Bonding Techniques for Solar Cell Array

DTIC Science & Technology

1977-11-01

Kedaya, E. , Kawakami, J. K., Kopf, P. W. , Kwiatkowski, G. T., McNeil, D. W. , and Tulis , R. W., "Union Carbide Rept. " UCRI-735 (30 July 1973...6. Peters, E. N., Kedaya, E., Kawakami, J. K. , Kwiatkowski, G. T. , McNeil, D. W., and Tulis , R. W., Rubber Chem. and Technol. 48 (1), 14-18 (1975

Study of the genetic diversity of the aflatoxin biosynthesis cluster in Aspergillus section Flavi using insertion/deletion markers in peanut seeds from Georgia, USA

USDA-ARS?s Scientific Manuscript database

Aflatoxins are among the most powerful carcinogens in nature. The major aflatoxin-producing fungi are Aspergillus flavus and A. parasiticus. Numerous crops, including peanut, are susceptible to aflatoxin contamination by these fungi. There has been an increased use of RNA interference (RNAi) technol...

Circulating sclerostin is elevated in short-term and reduced in long-term SCI

PubMed Central

Battaglino, Ricardo A.; Sudhakar, Supreetha; Lazzari, Antonio; Garshick, Eric; Zafonte, Ross; Morse, Leslie R.

2012-01-01

Spinal cord injury (SCI) causes profound bone loss due to muscle paralysis resulting in the inability to walk. Sclerostin, a Wnt signaling pathway antagonist produced by osteocytes, is a potent inhibitor of bone formation. Short-term studies in rodent models have demonstrated increased sclerostin in response to mechanical unloading that is reversed with reloading. Although sclerostin inhibition has been proposed as a potential therapy for bone loss, it is not known if sclerostin levels vary with duration of SCI in humans. We analyzed circulating sclerostin in 155 men with varying degrees of SCI who were 1 year or more post-injury. We report that sclerostin levels are greatest in subjects with short-term SCI (≤ 5 years post-injury) and decrease significantly over the first 5 years post-injury. There was no association between sclerostin and injury duration in subjects with long-term SCI (> 5 years post-injury). In subjects with long-term SCI, sclerostin levels were positively associated with lower extremity bone density and bone mineral content. These data suggest that sclerostin levels in SCI are initially increased after SCI in response to mechanical unloading. This response is time-limited and as bone loss progresses, circulating sclerostin is lowest in subjects with severe osteoporosis. These findings support a dual role for sclerostin after SCI: a therapeutic target in acute SCI, and a biomarker of osteoporosis severity in chronic SCI. PMID:22575440

Learning by Creating and Exchanging Objects: The SCY Experience

ERIC Educational Resources Information Center

De Jong, Ton; Van Joolingen, Wouter R.; Giemza, Adam; Girault, Isabelle; Hoppe, Ulrich; Kindermann, Jorg; Kluge, Anders; Lazonder, Ard W.; Vold, Vibeke; Weinberger, Armin; Weinbrenner, Stefan; Wichmann, Astrid; Anjewierden, Anjo; Bodin, Marjolaine; Bollen, Lars; D'Ham, Cedric; Dolonen, Jan; Engler, Jan; Geraedts, Caspar; Grosskreutz, Henrik; Hovardas, Tasos; Julien, Rachel; Lechner, Judith; Ludvigsen, Sten; Matteman, Yuri; Meistadt, Oyvind; Naess, Bjorge; Ney, Muriel; Pedaste, Margus; Perritano, Anthony; Rinket, Marieke; Von Schlanbusch, Henrik; Sarapuu, Tago; Schulz, Florian; Sikken, Jakob; Slotta, Jim; Toussaint, Jeremy; Verkade, Alex; Wajeman, Claire; Wasson, Barbara; Zacharia, Zacharias C.; Van Der Zanden, Martine

2010-01-01

Science Created by You (SCY) is a project on learning in science and technology domains. SCY uses a pedagogical approach that centres around products, called "emerging learning objects" (ELOs) that are created by students. Students work individually and collaboratively in SCY-Lab (the general SCY learning environment) on "missions" that are guided…

75 FR 24747 - SCI, LLC/Zener-Rectifier Operations Division A Wholly Owned Subsidiary of SCI, LLC/ON...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,235] SCI, LLC/Zener-Rectifier... Adjustment Assistance on October 19, 2009, applicable to workers of SCI LLC/Zener-Rectifier, Operations... Technical Resources were employed on-site at the Phoenix Arizona location of SCI LLC/Zener-Rectifier...

Sensitivity of the SCI-FI/AT in Individuals With Traumatic Spinal Cord Injury.

PubMed

Keeney, Tamra; Slavin, Mary; Kisala, Pamela; Ni, Pengsheng; Heinemann, Allen W; Charlifue, Susan; Fyffe, Denise C; Marino, Ralph J; Morse, Leslie R; Worobey, Lynn A; Tate, Denise; Rosenblum, David; Zafonte, Ross; Tulsky, David; Jette, Alan M

2018-03-31

To examine the ability of the Spinal Cord Injury-Functional Index/Assistive Technology (SCI-FI/AT) measure to detect change in persons with spinal cord injury (SCI). Multisite longitudinal (12-mo follow-up) study. Nine SCI Model Systems programs. Adults (N=165) with SCI enrolled in the SCI Model Systems database. Not applicable. SCI-FI/AT computerized adaptive test (CAT) (Basic Mobility, Self-Care, Fine Motor Function, Wheelchair Mobility, and/or Ambulation domains) completed at discharge from rehabilitation and 12 months after SCI. For each domain, effect size estimates and 95% confidence intervals were calculated for subgroups with paraplegia and tetraplegia. The demographic characteristics of the sample were as follows: 46% (n=76) individuals with paraplegia, 76% (n=125) male participants, 57% (n=94) used a manual wheelchair, 38% (n=63) used a power wheelchair, 30% (n=50) were ambulatory. For individuals with paraplegia, the Basic Mobility, Self-Care, and Ambulation domains of the SCI-FI/AT detected a significantly large amount of change; in contrast, the Fine Motor Function and Wheelchair Mobility domains detected only a small amount of change. For those with tetraplegia, the Basic Mobility, Fine Motor Function, and Self-Care domains detected a small amount of change whereas the Ambulation item domain detected a medium amount of change. The Wheelchair Mobility domain for people with tetraplegia was the only SCI-FI/AT domain that did not detect significant change. SCI-FI/AT CAT item banks detected an increase in function from discharge to 12 months after SCI. The effect size estimates for the SCI-FI/AT CAT vary by domain and level of lesion. Findings support the use of the SCI-FI/AT CAT in the population with SCI and highlight the importance of multidimensional functional measures. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Acute and Chronic Deficits in the Urinary Bladder after Spinal Contusion Injury in the Adult Rat

PubMed Central

Herrera, Juan J.; Haywood-Watson, Ricky J.L.

2010-01-01

Abstract Traumatic spinal cord injury (SCI) permanently alters bladder function in humans. Hematuria and cystitis occur in both human SCI as well as in rodent models of SCI. Others have reported early SCI-dependent disruption to bladder uroepithelial integrity that results in increased permeability to urine and urine-borne substances. This can result in cystitis, or inflammation of the bladder, an ongoing pathological condition present throughout the chronic phase of SCI in humans. The goals of our study were twofold: (1) to begin to examine the inflammatory and molecular changes that occur within the bladder uroepithelium using a clinically-relevant spinal contusion model of injury, and (2) to assess whether these alterations continue into the chronic phase of SCI. Rats received either moderate SCI or sham surgery. Urine was collected from SCI and sham subjects over 7 days or at 7 months to assess levels of excreted proteins. Inflammation in the bladder wall was assessed via biochemical and immunohistochemical methods. Bladder tight junction proteins, mediators of uroepithelial integrity, were also measured in both the acute and chronic phases of SCI. Urine protein and hemoglobin levels rapidly increase following SCI. An SCI-dependent elevation in numbers of neutrophils within the bladder wall peaked at 48 h. Bladder tight junction proteins demonstrate a rapid but transient decrease as early as 2 h post-SCI. Surprisingly, elevated levels of urine proteins and significant deficits in bladder tight junction proteins could be detected in chronic SCI, suggesting that early pathological changes to the bladder may continue throughout the chronic phase of injury. PMID:19891526

Linking carbon and iron cycles by investigating transport, fate and mineralogy of iron-bearing colloids from peat-draining rivers - Scotland as model for high-latitude rivers

NASA Astrophysics Data System (ADS)

Wood, Deborah; Crocket, Kirsty; Brand, Tim; Stutter, Marc; Wilson, Clare; Schröder, Christian

2016-04-01

Linking carbon and iron cycles by investigating transport, fate and mineralogy of iron-bearing colloids from peat-draining rivers - Scotland as model for high-latitude rivers Wood, D.A¹, Crocket, K², Brand, T², Stutter, M³, Wilson, C¹ & Schröder, C¹ ¹Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA ²Scottish Association for Marine Science, University of the Highlands and Islands, Dunbeg, Oban, PA37 1QA ³James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH The biogeochemical iron cycle exerts significant control on the carbon cycle¹. Iron is a limiting nutrient in large areas of the world's oceans and its bioavailability controls CO2 uptake by marine photosynthesizing microorganisms. While atmospheric iron inputs to the open ocean have been extensively measured, global river inputs have likely been underestimated because most major world rivers exhibit extensive iron removal by flocculation and sedimentation during seawater mixing. Iron minerals and organic matter mutually stabilise each other², which results in a 'rusty carbon sink' in sediments³ on the one hand but may also enhance transport beyond the salinity gradient on the other. Humic-rich, high latitude rivers have a higher iron-carrying capacity⁴-⁶ but are underrepresented in iron flux calculations. The West Coast sea lochs in Scotland are fed by predominantly peatland drainage catchments, and the rivers entering the sea lochs carry a high load of organic matter. The short distance between many of these catchments and the coastal ocean facilitates source-to-sea research investigating transport, fate and mineralogy of iron-bearing colloids providing a good analogue for similar high latitude fjordic systems. We use SeaFAST+ICP-MS and Mössbauer spectroscopy to survey trace metal concentrations, with emphasis on iron concentrations, speciation and mineralogy, across salinity gradients. In combination with ultra-filtration techniques, this allows determination of the concentrations and chemical composition of different size fractions of iron-organic matter particles and colloids. We are developing new filtering and enrichment protocols to enable the use of Mössbauer spectroscopy in order to close a gap in the understanding of iron mineralogy in sub-micron particles. Here we will present results from a first sampling campaign in Loch Sunart and its tributaries. Acknowledgements: This is a MASTS-funded PhD project (GSS30). Preliminary work was supported by a SAGES PECRE grant to C.S., and a MASTS Visiting Fellowship award (VF41) to K.C. References: 1. Raiswell and Canfield (2012). The Iron Biogeochemical Cycle Past and Present. Geochemical Perspectives 1(1), 1-220. 2. Schröder et al. The biogeochemical iron cycle and astrobiology. Hyperfine Interactions in press. 3. Lalonde et al. (2012). Preservation of organic matter in sediments promoted by iron. Nature 483, 198-200. 4. Batchelli et al. (2010). Evidence for strong but dynamic iron-humic colloidal associations in humic-rich coastal waters. Environ. Sci. Technol., 44, 8485-8490. 5. Krachler et al. (2010). Relevance of peat-draining rivers for the riverine input of dissolved iron into the ocean. Sci. Total Environ., 408, 2402-2408. 6. Pokrovsky et al. (2014). Fate of colloids during estuarine mixing in the Arctic. Ocean Sci., 10, 107-125.

Aerosol volatility in a boreal forest environment

NASA Astrophysics Data System (ADS)

Häkkinen, S. A. K.; ńijälä, M.; Lehtipalo, K.; Junninen, H.; Virkkula, A.; Worsnop, D. R.; Kulmala, M.; Petäjä, T.; Riipinen, I.

2012-04-01

Climate and health effects of atmospheric aerosols are determined by their properties such as their chemical composition. Aerosol chemical composition can be studied indirectly by measuring volatility of aerosol particles. The volatility of submicron aerosol particles (20-500 nm) was studied in a boreal forest site at SMEAR II (Station for Measuring Ecosystem-Atmosphere Relations II) station (Vesala et al., 1998) in Hyytiälä, Finland, during 01/2008-05/2010. The instrument used for the measurements was VDMPS (Volatility Differential Mobility Particle Sizer), which consists of two separate instruments: DMPS (Differential Mobility Particle Sizer, Aalto et al., 2001) and TD (Thermodenuder, Wehner et al., 2002). Aerosol evaporation was examined by heating the aerosol and comparing the total aerosol mass before and after heating. In the VDMPS system ambient aerosol sample was heated up to temperatures ranging from 80 °C to 280 °C. The higher the heating temperature was the more aerosol material was evaporated. There was a non-volatile residual present in aerosol particles when heated up to 280 °C. This residual explained (20±8)% of the total aerosol mass. Aerosol non-volatile mass fraction was highest during winter and smallest during summer months. The role of black carbon in the observed non-volatile residual was determined. Black carbon explained 40 to 90% of the non-volatile mass. Especially during colder seasons noticeable amount of non-volatile material, something else than black carbon, was observed. According to Kalberer et al. (2004) some atmospheric organic species can form polymers that have high evaporation temperatures. Also low-volatile organic salts may contribute to the non-volatile aerosol (Smith et al., 2010). Aerosol mass composition measured directly with AMS (Aerosol Mass Spectrometer, Jayne et al., 2000) was analyzed in order to examine the properties of the non-volatile material (other than black carbon). The AMS measurements were performed during spring and autumn 2008. Results from the aerosol mass spectrometry indicate that the non-volatile residual consists of nitrate and organic compounds, especially during autumn. These compounds may be low-volatile organic nitrates or salts. During winter and spring the non-volatile core (black carbon removed) correlated markedly with carbon monoxide, which is a tracer of anthropogenic emissions. Due to this, the non-volatile residual may also contain other pollutants in addition to black carbon. Thus, it seems that the amount of different compounds in submicron aerosol particles varies with season and as a result the chemical composition of the non-volatile residual changes within a year. This work was supported by University of Helsinki three-year research grant No 490082 and Maj and Tor Nessling Foundation grant No 2010143. Aalto et al., (2001). Physical characterization of aerosol particles during nucleation events. Tellus B, 53, 344-358. Jayne, et al., (2000). Development of an aerosol mass spectrometer for size and composition analysis of submicron particles. Aerosol Sci. Technol., 33(1-2), 49-70. Kalberer et al., (2004). Identification of Polymers as Major Components of Atmospheric Organic Aerosols. Science, 303, 1659-1662. Smith et al., (2010). Observations of aminium salts in atmospheric nanoparticles and possible climatic implications. P. Natl. Acad. Sci., 107(15). Vesala et al., (1998). Long-term field measurements of atmosphere-surface interactions in boreal forest combining forest ecology, micrometeorology, aerosol physics and atmospheric chemistry. Trends Heat, Mass Mom. Trans., 4, 17-35. Wehner et al., (2002). Design and calibration of a thermodenuder with an improved heating unit to measure the size-dependent volatile fraction of aerosol particles. J. Aerosol Sci., 33, 1087-1093.

Targeting Translational Successes through CANSORT-SCI: Using Pet Dogs To Identify Effective Treatments for Spinal Cord Injury.

PubMed

Moore, Sarah A; Granger, Nicolas; Olby, Natasha J; Spitzbarth, Ingo; Jeffery, Nick D; Tipold, Andrea; Nout-Lomas, Yvette S; da Costa, Ronaldo C; Stein, Veronika M; Noble-Haeusslein, Linda J; Blight, Andrew R; Grossman, Robert G; Basso, D Michele; Levine, Jonathan M

2017-06-15

Translation of therapeutic interventions for spinal cord injury (SCI) from laboratory to clinic has been historically challenging, highlighting the need for robust models of injury that more closely mirror the human condition. The high prevalence of acute, naturally occurring SCI in pet dogs provides a unique opportunity to evaluate expeditiously promising interventions in a population of animals that receive diagnoses and treatment clinically in a manner similar to persons with SCI, while adhering to National Institutes of Health guidelines for scientific rigor and transparent reporting. In addition, pet dogs with chronic paralysis are often maintained long-term by their owners, offering a similarly unique population for study of chronic SCI. Despite this, only a small number of studies have used the clinical dog model of SCI. The Canine Spinal Cord Injury Consortium (CANSORT-SCI) was recently established by a group of veterinarians and basic science researchers to promote the value of the canine clinical model of SCI. The CANSORT-SCI group held an inaugural meeting November 20 and 21, 2015 to evaluate opportunities and challenges to the use of pet dogs in SCI research. Key challenges identified included lack of familiarity with the model among nonveterinary scientists and questions about how and where in the translational process the canine clinical model would be most valuable. In light of these, we review the natural history, outcome, and available assessment tools associated with canine clinical SCI with emphasis on their relevance to human SCI and the translational process.

High Prevalence of Stress and Low Prevalence of Alzheimer Disease CSF Biomarkers in a Clinical Sample with Subjective Cognitive Impairment.

PubMed

Eckerström, Marie; Berg, Anne Ingeborg; Nordlund, Arto; Rolstad, Sindre; Sacuiu, Simona; Wallin, Anders

2016-01-01

Subjective cognitive impairment (SCI) is a trigger for seeking health care in a possible preclinical phase of Alzheimer's disease (AD), although the characteristics of SCI need clarification. We investigated the prevalence of psychosocial stress, depressive symptoms and CSF AD biomarkers in SCI and MCI (mild cognitive impairment). Memory clinic patients (SCI: n = 90; age: 59.8 ± 7.6 years; MCI: n = 160; age: 63.7 ± 7.0 years) included in the Gothenburg MCI study were examined at baseline. Variables were analyzed using logistic regression with SCI as dependent variable. Stress was more prevalent in SCI (51.1%) than MCI (23.1%); p < 0.0005. SCI patients had more previous depressive symptoms (p = 0.006), but showed no difference compared to MCI patients considering current depressive symptoms. A positive CSF AD profile was present in 14.4% of SCI patients and 35.0% of MCI patients (p = 0.001). Stress (p = 0.002), previous stress/depressive symptoms (p = 0.006) and a negative CSF AD profile (p = 0.036) predicted allocation to the SCI group. Psychosocial stress is more prevalent in SCI than previously acknowledged. The high prevalence and long-term occurrence of stress/depressive symptoms in SCI in combination with a low prevalence of altered CSF AD biomarkers strengthens the notion that AD is not the most likely etiology of SCI. © 2016 S. Karger AG, Basel.

Use, knowledge, and perception of the scientific contribution of Sci-Hub in medical students: Study in six countries in Latin America.

PubMed

Mejia, Christian R; Valladares-Garrido, Mario J; Miñan-Tapia, Armando; Serrano, Felipe T; Tobler-Gómez, Liz E; Pereda-Castro, William; Mendoza-Flores, Cynthia R; Mundaca-Manay, Maria Y; Valladares-Garrido, Danai

2017-01-01

Sci-Hub is a useful web portal for people working in science as it provides access to millions of free scientific articles. Satisfaction and usage should be explored in the Latino student population. The objective of this study was to evaluate the use, knowledge, and perception of the scientific contribution of Sci-Hub in medical students from Latin America. A multicenter, observational, analytical study was conducted in 6632 medical students from 6 countries in Latin America. We surveyed from a previously validated instrument, delving into knowledge, monthly average usage, satisfaction level, and perception of the scientific contributions provided by Sci-Hub. Frequencies and percentages are described, and generalized linear models were used to establish statistical associations. Only 19.2% of study participants knew of Sci-Hub and its function, while the median use was twice a month. 29.9% of Sci-Hub-aware participants claimed they always find the desired scientific information in their Sci-Hub search; 62.5% of participants affirmed that Sci-Hub contributes to scientific investigation; only 2.2% reported that Sci-Hub does not contribute to science. The majority of Latino students are not aware of Sci-Hub.

Recommendations for the National Institute for Neurologic Disorders and Stroke spinal cord injury common data elements for children and youth with SCI.

PubMed

Mulcahey, M J; Vogel, L C; Sheikh, M; Arango-Lasprilla, J C; Augutis, M; Garner, E; Hagen, E M; Jakeman, L B; Kelly, E; Martin, R; Odenkirchen, J; Scheel-Sailer, A; Schottler, J; Taylor, H; Thielen, C C; Zebracki, K

2017-04-01

In 2014, the adult spinal cord injury (SCI) common data element (CDE) recommendations were made available. This project was a review of the adult SCI CDE for relevance to children and youth with SCI. The objective of this study was to review the National Institute of Neurologic Disorders and Stroke (NINDS) adult SCI CDEs for relevance to children and youth with SCI. International. The pediatric working group consisted of international members with varied fields of expertise related to pediatric SCI. The group convened biweekly meetings for 6 months in 2015. All of the adult SCI CDEs were reviewed, evaluated and modified/created for four age groups: 0-5 years, 6-12 years, 13-15 years and 16-18 years. Whenever possible, results of published research studies were used to guide recommendations. In the absence of empirical support, grey literature and international content expert consensus were garnered. Existing pediatric NINDS CDEs and new CDEs were developed in areas where adult recommendations were not appropriate. After internal working group review of domain recommendations, these pediatric CDEs were vetted during a public review from November through December 2015. Version 1.0 of the pediatric SCI CDEs was posted in February 2016. The pediatric SCI CDEs are incorporated directly into the NINDS SCI CDE sets and can be found at https://commondataelements.ninds.nih.gov.

Spinal cord injury below-level neuropathic pain relief with dorsal root entry zone microcoagulation performed caudal to level of complete spinal cord transection.

PubMed

Falci, Scott; Indeck, Charlotte; Barnkow, Dave

2018-06-01

OBJECTIVE Surgically created lesions of the spinal cord dorsal root entry zone (DREZ) to relieve central pain after spinal cord injury (SCI) have historically been performed at and cephalad to, but not below, the level of SCI. This study was initiated to investigate the validity of 3 proposed concepts regarding the DREZ in SCI central pain: 1) The spinal cord DREZ caudal to the level of SCI can be a primary generator of SCI below-level central pain. 2) Neuronal transmission from a DREZ that generates SCI below-level central pain to brain pain centers can be primarily through sympathetic nervous system (SNS) pathways. 3) Perceived SCI below-level central pain follows a unique somatotopic map of DREZ pain-generators. METHODS Three unique patients with both intractable SCI below-level central pain and complete spinal cord transection at the level of SCI were identified. All 3 patients had previously undergone surgical intervention to their spinal cords-only cephalad to the level of spinal cord transection-with either DREZ microcoagulation or cyst shunting, in failed attempts to relieve their SCI below-level central pain. Subsequent to these surgeries, DREZ lesioning of the spinal cord solely caudal to the level of complete spinal cord transection was performed using electrical intramedullary guidance. The follow-up period ranged from 1 1/2 to 11 years. RESULTS All 3 patients in this study had complete or near-complete relief of all below-level neuropathic pain. The analyzed electrical data confirmed and enhanced a previously proposed somatotopic map of SCI below-level DREZ pain generators. CONCLUSIONS The results of this study support the following hypotheses. 1) The spinal cord DREZ caudal to the level of SCI can be a primary generator of SCI below-level central pain. 2) Neuronal transmission from a DREZ that generates SCI below-level central pain to brain pain centers can be primarily through SNS pathways. 3) Perceived SCI below-level central pain follows a unique somatotopic map of DREZ pain generators.

Not just quantity: gluteus maximus muscle characteristics in able-bodied and SCI individuals--implications for tissue viability.

PubMed

Wu, Gary A; Bogie, Kath M

2013-08-01

Some individuals with spinal cord injury (SCI) remain pressure ulcer (PU) free whilst others experience a recurring cycle of tissue breakdown. Detailed analysis of gluteal muscle characteristics may provide insights to local tissue viability variability. The study hypothesis was that SCI individuals have altered muscle composition compared to able-bodied (AB). Ten AB and ten SCI received a supine pelvic CT scan, with contrast. Cross-sectional area (CSA) and overall muscle volume were derived using image analysis. Gluteal muscle tissue type was classified at the S2/S3 sacral vertebrae midpoint, the superior greater trochanters margin (GT) and the inferior ischial tuberosities margin (IT) using the linear transformation Hounsfield Unit scale. SCI gluteal CSA was less than for AB throughout the muscle, with the greatest relative atrophy at the IT (48%). Average AB gluteal volume was nearly double SCI. Eight SCI had over 20% infiltrative adipose tissue, three with over 50%. SCI gluteal CSA and intramuscular fat infiltration were significantly negatively correlated (p < 0.05). SCI IT axial slices showed less lean muscle and higher intramuscular fat infiltration than more proximally (p < 0.05). SCI gluteal muscle characteristics were indicative of impaired tissue viability. SCI disuse muscle atrophy was anticipated; the analytic approach further indicated that intramuscular atrophy was not uniform. SCI muscle composition showed increased proportions of both low density muscle and adipose tissue. CT scan with contrast is effective for gluteal muscle characterization. This assessment technique may contribute to determination of personalized risk for PU development and other secondary complications. Published by Elsevier Ltd.

Targeting Translational Successes through CANSORT-SCI: Using Pet Dogs To Identify Effective Treatments for Spinal Cord Injury

PubMed Central

Granger, Nicolas; Olby, Natasha J.; Spitzbarth, Ingo; Jeffery, Nick D.; Tipold, Andrea; Nout-Lomas, Yvette S.; da Costa, Ronaldo C.; Stein, Veronika M.; Noble-Haeusslein, Linda J.; Blight, Andrew R.; Grossman, Robert G.; Basso, D. Michele; Levine, Jonathan M.

2017-01-01

Abstract Translation of therapeutic interventions for spinal cord injury (SCI) from laboratory to clinic has been historically challenging, highlighting the need for robust models of injury that more closely mirror the human condition. The high prevalence of acute, naturally occurring SCI in pet dogs provides a unique opportunity to evaluate expeditiously promising interventions in a population of animals that receive diagnoses and treatment clinically in a manner similar to persons with SCI, while adhering to National Institutes of Health guidelines for scientific rigor and transparent reporting. In addition, pet dogs with chronic paralysis are often maintained long-term by their owners, offering a similarly unique population for study of chronic SCI. Despite this, only a small number of studies have used the clinical dog model of SCI. The Canine Spinal Cord Injury Consortium (CANSORT-SCI) was recently established by a group of veterinarians and basic science researchers to promote the value of the canine clinical model of SCI. The CANSORT-SCI group held an inaugural meeting November 20 and 21, 2015 to evaluate opportunities and challenges to the use of pet dogs in SCI research. Key challenges identified included lack of familiarity with the model among nonveterinary scientists and questions about how and where in the translational process the canine clinical model would be most valuable. In light of these, we review the natural history, outcome, and available assessment tools associated with canine clinical SCI with emphasis on their relevance to human SCI and the translational process. PMID:28230415

Microbiology of Fresh Comminuted Turkey Meat

DTIC Science & Technology

1976-04-12

823 Reprinted from J. Milk Food Technol. Vol. 39. No. 12. Pages 823-829 (December. 1976) Cooyright 1976, International Association of Milk , Food, and...most probable number (MPN) method (13). niacin, and riboflavin (29). Canadian officials have proposed microbial standards The literature contains...onto Mueller-Hinton agar plates containing 5% various retail markets in the San Francisco Bay Area. They were defibrinated sheep blood. Representative

JPRS Report China

DTIC Science & Technology

1988-05-23

materials and teach them the technol- ogy. Once armed with the technology, they went into business on their own, borrowing capital from overseas Chinese or...opened this year. 12802 AGRICULTURE Projects Supported by National Natural Science Foundation 40060239 Beijing ZHIWU XUEBAO [ACTA BOTANICA SINICAJ...On Research in Educational Psychology; * 1. Research in the psychology of esthetics; * 2. Study and application of psychology of teaching ; 3

Lethal and Legal The Ethics of Drone Strikes

DTIC Science & Technology

2015-12-01

analysis, evaluation, and refinement of professional expertise in war, strategy, operations, national security, resource management , and responsible...in business studies and holds an M.Phil. in defence and security studies from the Defence College of Management and Technol- ogy, Defence Academy...in unsafe buildings, search and rescue missions in treacherous conditions, police searches for missing or wanted persons, traffic management , public

Software Development for Decision Analysis

DTIC Science & Technology

1975-03-01

to p Pollution Cost/lb Sulfur Emitted ( Flue Gas Desulfurization ) 178 3.11 Sensitivity of Total Societal Cost/KWH to...34 and "FGD ( flue gas desulfurization ) technology" have all been represented. The branching structure shown in Figure 3.7 (and for that matter each... Gas Desulfurization ) technol- ogy" are decision variables representing possible means of sulfur oxide emission control avallabie for the electric

THE EFFECT OF AMOUNT OF CRUDE OIL ON EXTENT OF ITS BIODEGRADATION IN OPEN WATER- AND SANDY BEACH- LABORATORY SIMULATIONS

EPA Science Inventory

Lepo, J.E., C. R. Cripe, J.L. Kavanaugh, S. Zhang and G.P. Norton. 2003. Effect of Amount of Crude Oil on Extent of Its Biodegradation in Open Water- and Sandy Beach-Laboratory Simulations. Environ. Technol. 24(10):1291-1302. (ERL,GB 1109).

We examined the biodegradation ...

Spinal-Cord-Injured Individual's Experiences of Having a Partner: A Phenomenological-Hermeneutic Study.

PubMed

Angel, Sanne

2015-06-01

Having a partner is a strong factor in adaptation to the new life situation with a spinal cord injury (SCI). Still, more knowledge in detail about the partner's influences according to the experiences of individuals with SCI could contribute to the understanding of the situation after an injury. The aim of this phenomenological-hermeneutic article is to achieve a deeper understanding of nine individuals' experiences the first 2 years after SCI. In rehabilitation after SCI, the partner supported the SCI individual's life spirit by not giving up and by still seeing possibilities in the future. The partner reinforced the SCI individual's commitment to life by sharing experiences; providing love, trust, and hope; and giving priority to the best things in life for the SCI individual. This implied cohabitation providing concrete help and an intimacy that helped to cope with problems and anxieties and allowed SCI individuals the ability to self-realize. This promoted feelings of profound gratitude but also dependency. Thus, the SCI individual benefitted from the partner's support mentally and physically, which enabled a life that would not otherwise be possible.

Global meaning in people with spinal cord injury: Content and changes

PubMed Central

Littooij, Elsbeth; Widdershoven, Guy A.M.; Stolwijk-Swüste, Janneke M.; Doodeman, Suzan; Leget, Carlo J.W.; Dekker, Joost

2016-01-01

Background After spinal cord injury (SCI), people are confronted with abrupt discontinuity in almost all areas of life, leading to questions on how to live a meaningful life again. Global meaning refers to basic ideas and goals that guide people in giving meaning to their lives, in specific situations. Little is known about global meaning relating to SCI and whether global meaning changes after SCI. Purpose The purpose of this study was twofold: (i) to explore the content of global meaning of people with SCI, and (ii) to explore whether or not global meaning changes after SCI. Methods In-depth semi-structured interviews were conducted with 16 people with SCI. Interviews were analyzed according to the method of grounded theory. Results (i) Five aspects of global meaning were found: core values, relationships, worldview, identity and inner posture. (ii) Overall, little change in the content of global meaning was found after SCI; specific aspects of global meaning were foregrounded after SCI. Conclusion Five aspects of global meaning were found in people with SCI. Global meaning seems hardly subject to change. PMID:25615571

Evaluation and Management of SCI-Associated Pain.

PubMed

Saulino, Michael; Averna, Justin F

2016-09-01

Traumatic spinal cord injury (SCI) is a devastating neurological condition. Treatment of SCI-related pain is challenging for the treating physician, as normal neural pathways are disrupted. Patients with SCI consistently rate pain as one of the most difficult problems associated with their injury. SCI-related pain can be refractory and complete relief is often not possible. The multidimensional nature of SCI-related pain affects the neural system including autonomic nervous system deregulation and can alter metabolic and biochemical processes throughout the body. Co-morbid psychological illnesses such as depression and adjustment disorder are seen in a significant percentage of patients. Despite a better understanding of the underlying pain mechanisms and advances in procedural, pharmacologic, and non-pharmacologic therapies, treatment of pain after SCI remains elusive. This manuscript reviews the current evidence-based evaluation and management of the SCI patient with the overarching goal of providing appropriate and effective management of their pain. In particular, additional well-designed studies are needed to help elucidate effective treatments for SCI-related neuropathic pain in an effort to help provide these patients with better management of their pain and improve their quality of life.

Resting-state synchrony between the retrosplenial cortex and anterior medial cortical structures relates to memory complaints in subjective cognitive impairment.

PubMed

Yasuno, Fumihiko; Kazui, Hiroaki; Yamamoto, Akihide; Morita, Naomi; Kajimoto, Katsufumi; Ihara, Masafumi; Taguchi, Akihiko; Matsuoka, Kiwamu; Kosaka, Jun; Tanaka, Toshihisa; Kudo, Takashi; Takeda, Masatoshi; Nagatsuka, Kazuyuki; Iida, Hidehiro; Kishimoto, Toshifumi

2015-06-01

Subjective cognitive impairment (SCI) is a clinical state characterized by subjective cognitive deficits without cognitive impairment. To test the hypothesis that this state might involve dysfunction of self-referential processing mediated by cortical midline structures, we investigated abnormalities of functional connectivity in these structures in individuals with SCI using resting-state functional magnetic resonance imaging. We performed functional connectivity analysis for 23 individuals with SCI and 30 individuals without SCI. To reveal the pathophysiological basis of the functional connectivity change, we performed magnetic resonance-diffusion tensor imaging. Positron emission tomography-amyloid imaging was conducted in 13 SCI and 15 nonSCI subjects. Individuals with SCI showed reduced functional connectivity in cortical midline structures. Reduction in white matter connections was related to reduced functional connectivity, but we found no amyloid deposition in individuals with SCI. The results do not necessarily contradict the possibility that SCI indicates initial cognitive decrements, but imply that reduced functional connectivity in cortical midline structures contributes to overestimation of the experience of forgetfulness. Copyright © 2015 Elsevier Inc. All rights reserved.

Stable Fe isotope fractionation during anaerobic microbial dissimilatory iron reduction at low pH

NASA Astrophysics Data System (ADS)

Chanda, P.; Amenabar, M. J.; Boyd, E. S.; Beard, B. L.; Johnson, C.

2017-12-01

In low-temperature anaerobic environments microbial dissimilatory iron reduction (DIR) plays an important role in Fe cycling. At neutral pH, sorption of aqueous Fe(II) (Fe(II)aq, produced by DIR) catalyzes isotopic exchange between Fe(II) and solid Fe(III), producing 56Fe/54Fe fractionations on the order of 3‰ during DIR[1,2,3]. At low pH, however, the absence of sorbed Fe(II) produces only limited abiologic isotopic exchange[4]. Here we investigated the scope of isotopic exchange between Fe(II)aq and ferric (hydr)oxides (ferrihydrite and goethite) and the associated stable Fe isotope fractionation during DIR by Acidianus strain DS80 at pH 3.0 and 80°C[5]. Over 19 days, 13% reduction of both minerals via microbial DIR was observed. The δ56Fe values of the fluid varied from -2.31 to -1.63‰ (ferrihydrite) and -0.45 to 0.02‰ (goethite). Partial leaching of bulk solid from each reactor with dilute HCl showed no sorption of Fe(II), and the surface layers of the solids were composed of Fe(III) with high δ56Fe values (ferrihydrite: 0.20 to 0.48‰ and goethite: 1.20 to 1.30‰). These results contrast with the lack of Fe isotope exchange in abiologic low-pH systems and indicate a key role for biology in catalyzing Fe isotope exchange between Fe(II)aq and Fe(III) solids, despite the absence of sorbed Fe(II). The estimated fractionation factor (ΔFeFe(III) -Fe(II)aq 2.6‰) from leaching of ferrihydrite is similar to the abiologic equilibrium fractionation factor ( 3.0‰)[3]. The fractionation factor (ΔFeFe(III) -Fe(II)aq 2.0‰) for goethite is higher than the abiologic fractionation factor ( 1.05‰)[2], but is consistent with the previously proposed "distorted surface layer" of goethite produced during the exchange with Fe(II)aq at neutral pH[1]. This study indicates that significant variations in Fe isotope compositions may be produced in low-pH environments where biological cycling of Fe occurs, in contrast to the expected lack of isotopic fractionation in low-pH abiologic systems, and such results bear on the search for biosignatures in Mars and Mars-analog settings. [1] Crosby et al., 2007 Geobiol. 5, 169-189 [2] Beard et al., 2010 Earth Planet. Sci. Lett. 295, 241-250 [3] Wu et al., 2011 Environ. Sci. Technol. 45, 1847-1852 [4] Reddy et al., 2015 Chem. Geol. 397, 118-127 [5] Amenabar et al., 2017 Nat. Geosci. In press

32 CFR 154.19 - Reinvestigation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... to Sensitive Compartmented Information (SCI). Each individual having current access to SCI shall be... certain SCI duties may require very special compartmentation and other special security measures. In such... for continued SCI access. (h) Foreign nationals employed by DoD organizations overseas. Foreign...

Measuring stigma after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Stigma item bank and short form.

PubMed

Kisala, Pamela A; Tulsky, David S; Pace, Natalie; Victorson, David; Choi, Seung W; Heinemann, Allen W

2015-05-01

To develop a calibrated item bank and computer adaptive test (CAT) to assess the effects of stigma on health-related quality of life in individuals with spinal cord injury (SCI). Grounded-theory based qualitative item development methods, large-scale item calibration field testing, confirmatory factor analysis, and item response theory (IRT)-based psychometric analyses. Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. SCI-QOL Stigma Item Bank A sample of 611 individuals with traumatic SCI completed 30 items assessing SCI-related stigma. After 7 items were iteratively removed, factor analyses confirmed a unidimensional pool of items. Graded Response Model IRT analyses were used to estimate slopes and thresholds for the final 23 items. The SCI-QOL Stigma item bank is unique not only in the assessment of SCI-related stigma but also in the inclusion of individuals with SCI in all phases of its development. Use of confirmatory factor analytic and IRT methods provide flexibility and precision of measurement. The item bank may be administered as a CAT or as a 10-item fixed-length short form and can be used for research and clinical applications.

Development and psychometric characteristics of the SCI-QOL Pressure Ulcers scale and short form.

PubMed

Kisala, Pamela A; Tulsky, David S; Choi, Seung W; Kirshblum, Steven C

2015-05-01

To develop a self-reported measure of the subjective impact of pressure ulcers on health-related quality of life (HRQOL) in individuals with spinal cord injury (SCI) as part of the SCI quality of life (SCI-QOL) measurement system. Grounded-theory based qualitative item development methods, large-scale item calibration testing, confirmatory factor analysis (CFA), and item response theory-based psychometric analysis. Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. SCI-QOL Pressure Ulcers scale. 189 individuals with traumatic SCI who experienced a pressure ulcer within the past 7 days completed 30 items related to pressure ulcers. CFA confirmed a unidimensional pool of items. IRT analyses were conducted. A constrained Graded Response Model with a constant slope parameter was used to estimate item thresholds for the 12 retained items. The 12-item SCI-QOL Pressure Ulcers scale is unique in that it is specifically targeted to individuals with spinal cord injury and at every stage of development has included input from individuals with SCI. Furthermore, use of CFA and IRT methods provide flexibility and precision of measurement. The scale may be administered in its entirety or as a 7-item "short form" and is available for both research and clinical practice.

Measuring stigma after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Stigma item bank and short form

PubMed Central

Kisala, Pamela A.; Tulsky, David S.; Pace, Natalie; Victorson, David; Choi, Seung W.; Heinemann, Allen W.

2015-01-01

Objective To develop a calibrated item bank and computer adaptive test (CAT) to assess the effects of stigma on health-related quality of life in individuals with spinal cord injury (SCI). Design Grounded-theory based qualitative item development methods, large-scale item calibration field testing, confirmatory factor analysis, and item response theory (IRT)-based psychometric analyses. Setting Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Participants Adults with traumatic SCI. Main Outcome Measures SCI-QOL Stigma Item Bank Results A sample of 611 individuals with traumatic SCI completed 30 items assessing SCI-related stigma. After 7 items were iteratively removed, factor analyses confirmed a unidimensional pool of items. Graded Response Model IRT analyses were used to estimate slopes and thresholds for the final 23 items. Conclusions The SCI-QOL Stigma item bank is unique not only in the assessment of SCI-related stigma but also in the inclusion of individuals with SCI in all phases of its development. Use of confirmatory factor analytic and IRT methods provide flexibility and precision of measurement. The item bank may be administered as a CAT or as a 10-item fixed-length short form and can be used for research and clinical applications. PMID:26010973

Use, knowledge, and perception of the scientific contribution of Sci-Hub in medical students: Study in six countries in Latin America

PubMed Central

Mejia, Christian R.; Valladares-Garrido, Mario J.; Miñan-Tapia, Armando; Serrano, Felipe T.; Tobler-Gómez, Liz E.; Pereda-Castro, William; Mendoza-Flores, Cynthia R.; Mundaca-Manay, Maria Y.; Valladares-Garrido, Danai

2017-01-01

Introduction Sci-Hub is a useful web portal for people working in science as it provides access to millions of free scientific articles. Satisfaction and usage should be explored in the Latino student population. The objective of this study was to evaluate the use, knowledge, and perception of the scientific contribution of Sci-Hub in medical students from Latin America. Methodology A multicenter, observational, analytical study was conducted in 6632 medical students from 6 countries in Latin America. We surveyed from a previously validated instrument, delving into knowledge, monthly average usage, satisfaction level, and perception of the scientific contributions provided by Sci-Hub. Frequencies and percentages are described, and generalized linear models were used to establish statistical associations. Results Only 19.2% of study participants knew of Sci-Hub and its function, while the median use was twice a month. 29.9% of Sci-Hub-aware participants claimed they always find the desired scientific information in their Sci-Hub search; 62.5% of participants affirmed that Sci-Hub contributes to scientific investigation; only 2.2% reported that Sci-Hub does not contribute to science. Conclusion The majority of Latino students are not aware of Sci-Hub. PMID:28982181

Sleep disordered breathing in chronic spinal cord injury.

PubMed

Sankari, Abdulghani; Bascom, Amy; Oomman, Sowmini; Badr, M Safwan

2014-01-15

Spinal cord injury (SCI) is associated with 2-5 times greater prevalence of sleep disordered breathing (SDB) than the general population. The contribution of SCI on sleep and breathing at different levels of injury using two scoring methods has not been assessed. The objectives of this study were to characterize the sleep disturbances in the SCI population and the associated physiological abnormalities using quantitative polysomnography and to determine the contribution of SCI level on the SDB mechanism. We studied 26 consecutive patients with SCI (8 females; age 42.5 ± 15.5 years; BMI 25.9 ± 4.9 kg/m2; 15 cervical and 11 thoracic levels) by spirometry, a battery of questionnaires and by attended polysomnography with flow and pharyngeal pressure measurements. Inclusion criteria for SCI: chronic SCI (> 6 months post injury), level T6 and above and not on mechanical ventilation. Ventilation, end-tidal CO2 (PETCO2), variability in minute ventilation (VI-CV) and upper airway resistance (RUA) were monitored during wakefulness and NREM sleep in all subjects. Each subject completed brief history and exam, Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), Berlin questionnaire (BQ) and fatigue severity scale (FSS). Sleep studies were scored twice, first using standard 2007 American Academy of Sleep Medicine (AASM) criteria and second using new 2012 recommended AASM criteria. Mean PSQI was increased to 10.3 ± 3.7 in SCI patients and 92% had poor sleep quality. Mean ESS was increased 10.4 ± 4.4 in SCI patients and excessive daytime sleepiness (ESS ≥ 10) was present in 59% of the patients. Daytime fatigue (FSS > 20) was reported in 96% of SCI, while only 46% had high-risk score of SDB on BQ. Forced vital capacity (FVC) in SCI was reduced to 70.5% predicted in supine compared to 78.5% predicted in upright positions (p < 0.05). Likewise forced expiratory volume in first second (FEV1) was 64.9% predicted in supine compared to 74.7% predicted in upright positions (p < 0.05). Mean AHI in SCI patients was 29.3 ± 25.0 vs. 20.0 ± 22.8 events/h using the new and conventional AASM scoring criteria, respectively (p < 0.001). SCI patients had SDB (AHI > 5 events/h) in 77% of the cases using the new AASM scoring criteria compared to 65% using standard conventional criteria (p < 0.05). In cervical SCI, VI decreased from 7.2 ± 1.6 to 5.5 ± 1.3 L/min, whereas PETCO2 and VI-CV, increased during sleep compared to thoracic SCI. The majority of SCI survivors have symptomatic SDB and poor sleep that may be missed if not carefully assessed. Decreased VI and increased PETCO2 during sleep in patients with cervical SCI relative to thoracic SCI suggests that sleep related hypoventilation may contribute to the pathogenesis SDB in patients with chronic cervical SCI.

Potential of personal health record portals in the care of individuals with spinal cord injuries and disorders: Provider perspectives.

PubMed

Hill, Jennifer N; Smith, Bridget M; Weaver, Frances M; Nazi, Kim M; Thomas, Florian P; Goldstein, Barry; Hogan, Timothy P

2018-05-01

Although personal health record (PHR) portals are designed for patients, healthcare providers are a key influence in how patients use their features and realize benefits from them. A few studies have examined provider attitudes toward PHR portals, but none have focused on those who care for individuals with spinal cord injuries and disorders (SCI/D). We characterize SCI/D provider perspectives of PHR portals, including perceived advantages and disadvantages of PHR portal use in SCI/D care. Cross-sectional; semi-structured interviews. Spinal Cord Injury (SCI) Centers in the Veterans Health Administration. Twenty-six SCI/D healthcare providers. None. Perceived advantages and disadvantages of PHR portals. The complex situations of individuals with SCI/D shaped provider perspectives of PHR portals and their potential role in practice. Perceived advantages of PHR portal use in SCI/D care included the ability to coordinate information and care, monitor and respond to outpatient requests, support patient self-management activities, and provide reliable health information to patients. Perceived disadvantages of PHR portal use in SCI/D care included concerns about the quality of patient-generated health data, other potential liabilities for providers and workload burden, and the ability of individuals with SCI/D to understand clinical information accessed through a portal. Our study highlights advantages and disadvantages that should be considered when promoting engagement of SCI/D healthcare providers in use of PHR portals, and portal features that may have the most utility in SCI/D care.

Circulating sclerostin is elevated in short-term and reduced in long-term SCI.

PubMed

Battaglino, Ricardo A; Sudhakar, Supreetha; Lazzari, Antonio A; Garshick, Eric; Zafonte, Ross; Morse, Leslie R

2012-09-01

Spinal cord injury (SCI) causes profound bone loss due to muscle paralysis resulting in the inability to walk. Sclerostin, a Wnt signaling pathway antagonist produced by osteocytes, is a potent inhibitor of bone formation. Short-term studies in rodent models have demonstrated increased sclerostin in response to mechanical unloading that is reversed with reloading. Although sclerostin inhibition has been proposed as a potential therapy for bone loss, it is not known if sclerostin levels vary with duration of SCI in humans. We analyzed circulating sclerostin in 155 men with varying degrees of SCI who were 1 year or more post-injury. We report that sclerostin levels are greatest in subjects with short-term SCI (≤5 years post-injury) and decrease significantly over the first 5 years post-injury. There was no association between sclerostin and injury duration in subjects with long-term SCI (>5 years post-injury). In subjects with long-term SCI, sclerostin levels were positively associated with lower extremity bone density and bone mineral content. These data suggest that sclerostin levels are initially increased after SCI in response to mechanical unloading. This response is time-limited and as bone loss progresses, circulating sclerostin is lowest in subjects with severe osteoporosis. These findings support a dual role for sclerostin after SCI: a therapeutic target in acute SCI, and a biomarker of osteoporosis severity in chronic SCI. Copyright © 2012 Elsevier Inc. All rights reserved.

Curcumin Increase the Expression of Neural Stem/Progenitor Cells and Improves Functional Recovery after Spinal Cord Injury

PubMed Central

Bang, Woo-Seok; Kim, Kyoung-Tae; Seo, Ye Jin; Cho, Dae-Chul; Sung, Joo-Kyung; Kim, Chi Heon

2018-01-01

Objective To investigates the effect of curcumin on proliferation of spinal cord neural stem/progenitor cells (SC-NSPCs) and functional outcome in a rat spinal cord injury (SCI) model. Methods Sixty adult male Sprague-Dawley rats were randomly and blindly allocated into three groups (sham control group; curcumin treated group after SCI; vehicle treated group after SCI). Functional recovery was evaluated by the Basso, Beattie, and Bresnahan (BBB) scale during 6 weeks after SCI. The expression of SC-NSPC proliferation and astrogliosis were analyzed by nestin/Bromodeoxyuridine (BrdU) and Glial fibrillary acidic protein (GFAP) staining. The injured spinal cord was then examined histologically, including quantification of cavitation. Results The BBB score of the SCI-curcumin group was better than that of SCI-vehicle group up to 14 days (p<0.05). The co-immunoreactivity of nestin/BrdU in the SCI-curcumin group was much higher than that of the SCI-vehicle group 1 week after surgery (p<0.05). The GFAP immunoreactivity of the SCI-curcumin group was remarkably lower than that of the SCI-vehicle group 4 weeks after surgery (p<0.05). The lesion cavity was significantly reduced in the curcumin group as compared to the control group (p<0.05). Conclusion These results indicate that curcumin could increase the expression of SC-NSPCs, and reduce the activity of reactive astrogliosis and lesion cavity. Consequently curcumin could improve the functional recovery after SCI via SC-NSPC properties. PMID:29354231

Spinal Cord Injury Impairs Cardiovascular Capacity in Elite Wheelchair Rugby Athletes.

PubMed

Gee, Cameron M; Currie, Katharine D; Phillips, Aaron A; Squair, Jordan W; Krassioukov, Andrei V

2017-12-19

To examine differences in heart rate (HR) responses during international wheelchair rugby competition between athletes with and without a cervical spinal cord injury (SCI) and across standardized sport classifications. Observational study. The 2015 Parapan American Games wheelchair rugby competition. Forty-three male athletes (31 ± 8 years) with a cervical SCI (n = 32) or tetraequivalent impairment (non-SCI, n = 11). Average and peak HR (HRavg and HRpeak, respectively). To characterize HR responses in accordance with an athletes' International Wheelchair Rugby Federation (IWRF) classification, we separated athletes into 3 groups: group I (IWRF classification 0.5-1.5, n = 15); group II (IWRF classification 2.0, n = 15); and group III (IWRF classification 2.5-3.5, n = 13). Athletes with SCI had lower HRavg (111 ± 14 bpm vs 155 ± 13 bpm) and HRpeak (133 ± 12 bpm vs 178 ± 13 bpm) compared with non-SCI (both P < 0.001). Average HR was higher in group III than in I (136 ± 25 bpm vs 115 ± 20 bpm, P = 0.045); however, SCI athletes showed no difference in HRavg or HRpeak between groups. Within group III, SCI athletes had lower HRavg (115 ± 6 bpm vs 160 ± 8 bpm) and HRpeak (135 ± 11 bpm vs 183 ± 11 bpm) than non-SCI athletes (both P < 0.001). This study is the first to demonstrate attenuated HR responses during competition in SCI compared with non-SCI athletes, likely due to injury to spinal autonomic pathways. Among athletes with SCI, IWRF classification was not related to differences in HR. Specific assessment of autonomic function after SCI may be able to predict HR during competition and consideration of autonomic impairments may improve the classification process.

Understanding Quality of Life in Adults with Spinal Cord Injury Via SCI-Related Needs and Secondary Complications.

PubMed

Sweet, Shane N; Noreau, Luc; Leblond, Jean; Dumont, Frédéric S

2014-01-01

Understanding the factors that can predict greater quality of life (QoL) is important for adults with spinal cord injury (SCI), given that they report lower levels of QoL than the general population. To build a conceptual model linking SCI-related needs, secondary complications, and QoL in adults with SCI. Prior to testing the conceptual model, we aimed to develop and evaluate the factor structure for both SCI-related needs and secondary complications. Individuals with a traumatic SCI (N = 1,137) responded to an online survey measuring 13 SCI-related needs, 13 secondary complications, and the Life Satisfaction Questionnaire to assess QoL. The SCI-related needs and secondary complications were conceptualized into factors, tested with a confirmatory factor analysis, and subsequently evaluated in a structural equation model to predict QoL. The confirmatory factor analysis supported a 2-factor model for SCI related needs, χ(2)(61, N = 1,137) = 250.40, P <.001, comparative fit index (CFI) = .93, root mean square error of approximation (RMSEA) = .05, standardized root mean square residual (SRMR) = .04, and for 11 of the 13 secondary complications, χ(2)(44, N = 1,137) = 305.67, P < .001, CFI = .91, RMSEA = .060, SRMR = .033. The final 2 secondary complications were kept as observed constructs. In the structural model, both vital and personal development unmet SCI-related needs (β = -.22 and -.20, P < .05, respectively) and the neuro-physiological systems factor (β = -.45, P < .05) were negatively related with QoL. Identifying unmet SCI-related needs of individuals with SCI and preventing or managing secondary complications are essential to their QoL.

Methodology for the development and calibration of the SCI-QOL item banks

PubMed Central

Tulsky, David S.; Kisala, Pamela A.; Victorson, David; Choi, Seung W.; Gershon, Richard; Heinemann, Allen W.; Cella, David

2015-01-01

Objective To develop a comprehensive, psychometrically sound, and conceptually grounded patient reported outcomes (PRO) measurement system for individuals with spinal cord injury (SCI). Methods Individual interviews (n = 44) and focus groups (n = 65 individuals with SCI and n = 42 SCI clinicians) were used to select key domains for inclusion and to develop PRO items. Verbatim items from other cutting-edge measurement systems (i.e. PROMIS, Neuro-QOL) were included to facilitate linkage and cross-population comparison. Items were field tested in a large sample of individuals with traumatic SCI (n = 877). Dimensionality was assessed with confirmatory factor analysis. Local item dependence and differential item functioning were assessed, and items were calibrated using the item response theory (IRT) graded response model. Finally, computer adaptive tests (CATs) and short forms were administered in a new sample (n = 245) to assess test-retest reliability and stability. Participants and Procedures A calibration sample of 877 individuals with traumatic SCI across five SCI Model Systems sites and one Department of Veterans Affairs medical center completed SCI-QOL items in interview format. Results We developed 14 unidimensional calibrated item banks and 3 calibrated scales across physical, emotional, and social health domains. When combined with the five Spinal Cord Injury – Functional Index physical function banks, the final SCI-QOL system consists of 22 IRT-calibrated item banks/scales. Item banks may be administered as CATs or short forms. Scales may be administered in a fixed-length format only. Conclusions The SCI-QOL measurement system provides SCI researchers and clinicians with a comprehensive, relevant and psychometrically robust system for measurement of physical-medical, physical-functional, emotional, and social outcomes. All SCI-QOL instruments are freely available on Assessment CenterSM. PMID:26010963

Methodology for the development and calibration of the SCI-QOL item banks.

PubMed

Tulsky, David S; Kisala, Pamela A; Victorson, David; Choi, Seung W; Gershon, Richard; Heinemann, Allen W; Cella, David

2015-05-01

To develop a comprehensive, psychometrically sound, and conceptually grounded patient reported outcomes (PRO) measurement system for individuals with spinal cord injury (SCI). Individual interviews (n=44) and focus groups (n=65 individuals with SCI and n=42 SCI clinicians) were used to select key domains for inclusion and to develop PRO items. Verbatim items from other cutting-edge measurement systems (i.e. PROMIS, Neuro-QOL) were included to facilitate linkage and cross-population comparison. Items were field tested in a large sample of individuals with traumatic SCI (n=877). Dimensionality was assessed with confirmatory factor analysis. Local item dependence and differential item functioning were assessed, and items were calibrated using the item response theory (IRT) graded response model. Finally, computer adaptive tests (CATs) and short forms were administered in a new sample (n=245) to assess test-retest reliability and stability. A calibration sample of 877 individuals with traumatic SCI across five SCI Model Systems sites and one Department of Veterans Affairs medical center completed SCI-QOL items in interview format. We developed 14 unidimensional calibrated item banks and 3 calibrated scales across physical, emotional, and social health domains. When combined with the five Spinal Cord Injury--Functional Index physical function banks, the final SCI-QOL system consists of 22 IRT-calibrated item banks/scales. Item banks may be administered as CATs or short forms. Scales may be administered in a fixed-length format only. The SCI-QOL measurement system provides SCI researchers and clinicians with a comprehensive, relevant and psychometrically robust system for measurement of physical-medical, physical-functional, emotional, and social outcomes. All SCI-QOL instruments are freely available on Assessment CenterSM.

The role of capsaicin-sensitive C-fiber afferent pathways in the control of micturition in spinal-intact and spinal cord-injured mice.

PubMed

Kadekawa, Katsumi; Majima, Tsuyoshi; Shimizu, Takahiro; Wada, Naoki; de Groat, William C; Kanai, Anthony J; Goto, Momokazu; Yoshiyama, Mitsuharu; Sugaya, Kimio; Yoshimura, Naoki

2017-09-01

We examined bladder and urethral sphincter activity in mice with or without spinal cord injury (SCI) after C-fiber afferent desensitization induced by capsaicin pretreatment and changes in electrophysiological properties of mouse bladder afferent neurons 4 wk after SCI. Female C57BL/6N mice were divided into four groups: 1 ) spinal intact (SI)-control, 2 ) SI-capsaicin pretreatment (Cap), 3 ) SCI-control, and 4 ) SCI-Cap groups. Continuous cystometry and external urethral sphincter (EUS)-electromyogram (EMG) were conducted under an awake condition. In the Cap groups, capsaicin (25, 50, or 100 mg/kg) was injected subcutaneously 4 days before the experiments. In the SI-Cap group, 100 mg/kg capsaicin pretreatment significantly increased bladder capacity and decreased the silent period duration of EUS/EMG compared with the SI-control group. In the SCI-Cap group, 50 and 100 mg/kg capsaicin pretreatment decreased the number of nonvoiding contractions (NVCs) and the duration of reduced EUS activity during voiding, respectively, compared with the SCI-control group. In SCI mice, hexamethonium, a ganglionic blocker, almost completely blocked NVCs, suggesting that they are of neurogenic origin. Patch-clamp recordings in capsaicin-sensitive bladder afferent neurons from SCI mice showed hyperexcitability, which was evidenced by decreased spike thresholds and increased firing rate compared with SI mice. These results indicate that capsaicin-sensitive C-fiber afferent pathways, which become hyperexcitable after SCI, can modulate bladder and urethral sphincter activity in awake SI and SCI mice. Detrusor overactivity as shown by NVCs in SCI mice is significantly but partially dependent on capsaicin-sensitive C-fiber afferents, whereas the EUS relaxation during voiding is enhanced by capsaicin-sensitive C-fiber bladder afferents in SI and SCI mice. Copyright © 2017 the American Physiological Society.

Investigation of Microbiota Alterations and Intestinal Inflammation Post-Spinal Cord Injury in Rat Model.

PubMed

O'Connor, Gregory; Jeffrey, Elisabeth; Madorma, Derik; Marcillo, Alexander; Abreu, Maria T; Deo, Sapna K; Dietrich, W Dalton; Daunert, Sylvia

2018-06-07

Although there has been a significant amount of research focused on the pathophysiology of spinal cord injury (SCI), there is limited information on the consequences of SCI on remote organs. SCI can produce significant effects on a variety of organ systems, including the gastrointestinal tract. Patients with SCI often suffer from severe, debilitating bowel dysfunction in addition to their physical disabilities, which is of major concern for these individuals because of the adverse impact on their quality of life. Herein, we report on our investigation into the effects of SCI and subsequent antibiotic treatment on the intestinal tissue and microbiota. For that, we used a thoracic SCI rat model and investigated changes to the microbiota, proinflammatory cytokine levels, and bacterial communication molecule levels post-injury and gentamicin treatment for 7 days. We discovered significant changes, the most interesting being the differences in the gut microbiota beta diversity of 8-week SCI animals compared to control animals at the family, genus, and species level. Specifically, 35 operational taxonomic units were enriched in the SCI animal group and three were identified at species level; Lactobacillus intestinalis, Clostridium disporicum, and Bifidobacterium choerinum. In contrast, Clostridium saccharogumia was identified as depleted in the SCI animal group. Proinflammatory cytokines interleukin (IL)-12, macrophage inflammatory protein-2 (MIP-2), and tumor necrosis factor alpha were found to be significantly elevated in intestinal tissue homogenate 4 weeks post-SCI compared to 8-weeks post-injury. Further, levels of IL-1β, IL-12, and MIP-2 significantly correlated with changes in beta diversity 8-weeks post-SCI. Our data provide a greater understanding of the early effects of SCI on the microbiota and gastrointestinal tract, highlighting the need for further investigation to elucidate the mechanism underlying these effects.

The Role of Scientific Communication Skills in Trainees' Intention to Pursue Biomedical Research Careers: A Social Cognitive Analysis.

PubMed

Cameron, Carrie; Lee, Hwa Young; Anderson, Cheryl; Byars-Winston, Angela; Baldwin, Constance D; Chang, Shine

2015-01-01

Scientific communication (SciComm) skills are indispensable for success in biomedical research, but many trainees may not have fully considered the necessity of regular writing and speaking for research career progression. Our purpose was to investigate the relationship between SciComm skill acquisition and research trainees' intentions to remain in research careers. We used social cognitive career theory (SCCT) to test a model of the relationship of SciComm skills to SciComm-related cognitive variables in explaining career intentions. A sample of 510 graduate students and postdoctoral fellows at major academic health science centers in the Texas Medical Center, Houston, Texas, were surveyed online. Results suggested that interest in performing SciComm tasks, SciComm outcome expectations (SCOEs), and SciComm productivity predicted intention to remain in a research career, while SciComm self-efficacy did not directly predict career intention. SCOEs also predicted interest in performing SciComm tasks. As in other SCCT studies, SciComm self-efficacy predicted SCOEs. We conclude that social cognitive factors of SciComm skill acquisition and SciComm productivity significantly predict biomedical trainees' intentions to pursue research careers whether within or outside academia. While further studies are needed, these findings may lead to evidence-based interventions to help trainees remain in their chosen career paths. © 2015 C. Cameron et al. CBE—Life Sciences Education © 2015 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

An efficient and accurate approach to MTE-MART for time-resolved tomographic PIV

NASA Astrophysics Data System (ADS)

Lynch, K. P.; Scarano, F.

2015-03-01

The motion-tracking-enhanced MART (MTE-MART; Novara et al. in Meas Sci Technol 21:035401, 2010) has demonstrated the potential to increase the accuracy of tomographic PIV by the combined use of a short sequence of non-simultaneous recordings. A clear bottleneck of the MTE-MART technique has been its computational cost. For large datasets comprising time-resolved sequences, MTE-MART becomes unaffordable and has been barely applied even for the analysis of densely seeded tomographic PIV datasets. A novel implementation is proposed for tomographic PIV image sequences, which strongly reduces the computational burden of MTE-MART, possibly below that of regular MART. The method is a sequential algorithm that produces a time-marching estimation of the object intensity field based on an enhanced guess, which is built upon the object reconstructed at the previous time instant. As the method becomes effective after a number of snapshots (typically 5-10), the sequential MTE-MART (SMTE) is most suited for time-resolved sequences. The computational cost reduction due to SMTE simply stems from the fewer MART iterations required for each time instant. Moreover, the method yields superior reconstruction quality and higher velocity field measurement precision when compared with both MART and MTE-MART. The working principle is assessed in terms of computational effort, reconstruction quality and velocity field accuracy with both synthetic time-resolved tomographic images of a turbulent boundary layer and two experimental databases documented in the literature. The first is the time-resolved data of flow past an airfoil trailing edge used in the study of Novara and Scarano (Exp Fluids 52:1027-1041, 2012); the second is a swirling jet in a water flow. In both cases, the effective elimination of ghost particles is demonstrated in number and intensity within a short temporal transient of 5-10 frames, depending on the seeding density. The increased value of the velocity space-time correlation coefficient demonstrates the increased velocity field accuracy of SMTE compared with MART.

Turbulent motion of mass flows. Mathematical modeling

NASA Astrophysics Data System (ADS)

Eglit, Margarita; Yakubenko, Alexander; Yakubenko, Tatiana

2016-04-01

New mathematical models for unsteady turbulent mass flows, e.g., dense snow avalanches and landslides, are presented. Such models are important since most of large scale flows are turbulent. In addition to turbulence, the two other important points are taken into account: the entrainment of the underlying material by the flow and the nonlinear rheology of moving material. The majority of existing models are based on the depth-averaged equations and the turbulent character of the flow is accounted by inclusion of drag proportional to the velocity squared. In this paper full (not depth-averaged) equations are used. It is assumed that basal entrainment takes place if the bed friction equals the shear strength of the underlying layer (Issler D, M. Pastor Peréz. 2011). The turbulent characteristics of the flow are calculated using a three-parameter differential model (Lushchik et al., 1978). The rheological properties of moving material are modeled by one of the three types of equations: 1) Newtonian fluid with high viscosity, 2) power-law fluid and 3) Bingham fluid. Unsteady turbulent flows down long homogeneous slope are considered. The flow dynamical parameters and entrainment rate behavior in time as well as their dependence on properties of moving and underlying materials are studied numerically. REFERENCES M.E. Eglit and A.E. Yakubenko, 2014. Numerical modeling of slope flows entraining bottom material. Cold Reg. Sci. Technol., 108, 139-148 Margarita E. Eglit and Alexander E. Yakubenko, 2016. The effect of bed material entrainment and non-Newtonian rheology on dynamics of turbulent slope flows. Fluid Dynamics, 51(3) Issler D, M. Pastor Peréz. 2011. Interplay of entrainment and rheology in snow avalanches; a numerical study. Annals of Glaciology, 52(58), 143-147 Lushchik, V.G., Paveliev, A.A. , and Yakubenko, A.E., 1978. Three-parameter model of shear turbulence. Fluid Dynamics, 13, (3), 350-362

Hydrophilic PEO-PDMS for microfluidic applications

NASA Astrophysics Data System (ADS)

Yao, Mingjin; Fang, Ji

2012-02-01

Polydimethylsiloxane (PDMS) is a popularly used nontoxic and biocompatible material in microfluidic systems, which is relatively cheap and does not break easily like glass. The simple fabrication, optical transparency and elastomeric property make PDMS a handy material to work with. In order to develop different applications of PDMS in microfluidics and bioengineering, it is necessary to modify the PDMS surface nature to improve wetting characteristics, and to have a better control in nonspecific binding of proteins and cells, as well as to increase adhesion. At the moment, the hydrophilic surface modification performance of PDMS is known to recover its hydrophobicity shortly after oxidation modification, which is not stable in the long term (Owen and Smith 1994 J. Adhes. Sci. Technol. 8 1063-75). This paper presents a long-term stable hydrophilic surface modification processing of PDMS. The poly(dimethylsiloxane-ethylene oxide polymeric) (PDMS-b-PEO) is used in this project as a surfactant additive to be added into the PDMS base and the curing agent mixture during polymerization and to create hydrophilic PEO-PDMS. The contact angle can be controlled at 21.5-80.9° with the different mixing ratios and the hydrophilicity will remain stable for two months and then slightly varied later. We also investigate the bonding conditions of the modified PDMS to a silicon wafer and a glass wafer. To demonstrate its applications, we designed a device which consists of microchannels on a silicon wafer, and PEO-PDMS is utilized as a cover sheet. The capillary function was investigated under the different contact angles of PED-PDMS and with different aspect ratios of microchannels. All of the processes and testing data are presented in detail. This easy and cost-effective modified PDMS with a good bonding property can be widely used in the capillary device and systems, and microfluidic devices for fluid flow control of the microchannels in biological, chemical, medical applications.

The electrical resistivity of rough thin films: A model based on electron reflection at discrete step edges

NASA Astrophysics Data System (ADS)

Zhou, Tianji; Zheng, Pengyuan; Pandey, Sumeet C.; Sundararaman, Ravishankar; Gall, Daniel

2018-04-01

The effect of the surface roughness on the electrical resistivity of metallic thin films is described by electron reflection at discrete step edges. A Landauer formalism for incoherent scattering leads to a parameter-free expression for the resistivity contribution from surface mound-valley undulations that is additive to the resistivity associated with bulk and surface scattering. In the classical limit where the electron reflection probability matches the ratio of the step height h divided by the film thickness d, the additional resistivity Δρ = √{3 /2 } /(g0d) × ω/ξ, where g0 is the specific ballistic conductance and ω/ξ is the ratio of the root-mean-square surface roughness divided by the lateral correlation length of the surface morphology. First-principles non-equilibrium Green's function density functional theory transport simulations on 1-nm-thick Cu(001) layers validate the model, confirming that the electron reflection probability is equal to h/d and that the incoherent formalism matches the coherent scattering simulations for surface step separations ≥2 nm. Experimental confirmation is done using 4.5-52 nm thick epitaxial W(001) layers, where ω = 0.25-1.07 nm and ξ = 10.5-21.9 nm are varied by in situ annealing. Electron transport measurements at 77 and 295 K indicate a linear relationship between Δρ and ω/(ξd), confirming the model predictions. The model suggests a stronger resistivity size effect than predictions of existing models by Fuchs [Math. Proc. Cambridge Philos. Soc. 34, 100 (1938)], Sondheimer [Adv. Phys. 1, 1 (1952)], Rossnagel and Kuan [J. Vac. Sci. Technol., B 22, 240 (2004)], or Namba [Jpn. J. Appl. Phys., Part 1 9, 1326 (1970)]. It provides a quantitative explanation for the empirical parameters in these models and may explain the recently reported deviations of experimental resistivity values from these models.

Lead isotopes and trace metal ratios of aerosols as tracers of Pb pollution sources in Kanpur, India

NASA Astrophysics Data System (ADS)

Sen, Indra; Bizimis, Michael; Tripathi, Sachchida; Paul, Debajyoti; Tyagi, Swati; Sengupta, Deep

2015-04-01

The anthropogenic flux of Pb in the Earth's surface is almost an order of magnitude higher than its corresponding natural flux [1]. Identifying the sources and pathways of anthropogenic Pb in environment is important because Pb toxicity is known to have adverse effects on human health. Pb pollution sources for America, Europe, and China are well documented. However, sources of atmospheric Pb are unknown in India, particularly after leaded gasoline was phased out in 2000. India has a developing economy with a rapidly emerging automobile and high temperature industry, and anthropogenic Pb emission is expected to rise in the next decade. In this study, we report on the Pb- isotope compositions and trace metal ratios of airborne particulates collected in Kanpur, an industrial city in northern India. The Pb concentration in the airborne particulate matter varies between 14-216 ng/m3, while the other heavy metals vary by factor of 10 or less, e.g. Cd=0.3-3 ng/m3, As=0.4-3.5 ng/m3, Zn=36-161 ng/m3, and Cu=3-22 ng/m3. The 206Pb/207Pb, 208Pb/206Pb, and 208Pb/207Pb vary between 1.112 - 1.129, 2.123-2.141, and 2.409-2.424 respectively, and are highly correlated with each other (R2>0.9). Pb isotopes and trace metal data reveals that coal combustion is the major source of anthropogenic Pb in the atmosphere, with limited contribution from mining and smelting processes. We further conclude that combination of Pb isotope ratios and V/Pb ratios are powerful tracers for Pb source apportionment studies, which is otherwise difficult to differentiate based only on Pb systematics [1] Sen and Peucker-Ehrenbrink (2012), Environ. Sci. Technol.(46), 8601-8609

Particulate matter in new technology diesel exhaust (NTDE) is quantitatively and qualitatively very different from that found in traditional diesel exhaust (TDE).

PubMed

Hesterberg, Thomas W; Long, Christopher M; Sax, Sonja N; Lapin, Charles A; McClellan, Roger O; Bunn, William B; Valberg, Peter A

2011-09-01

Diesel exhaust (DE) characteristic of pre-1988 engines is classified as a "probable" human carcinogen (Group 2A) by the International Agency for Research on Cancer (IARC), and the U.S. Environmental Protection Agency has classified DE as "likely to be carcinogenic to humans." These classifications were based on the large body of health effect studies conducted on DE over the past 30 or so years. However, increasingly stringent U.S. emissions standards (1988-2010) for particulate matter (PM) and nitrogen oxides (NOx) in diesel exhaust have helped stimulate major technological advances in diesel engine technology and diesel fuel/lubricant composition, resulting in the emergence of what has been termed New Technology Diesel Exhaust, or NTDE. NTDE is defined as DE from post-2006 and older retrofit diesel engines that incorporate a variety of technological advancements, including electronic controls, ultra-low-sulfur diesel fuel, oxidation catalysts, and wall-flow diesel particulate filters (DPFs). As discussed in a prior review (T. W. Hesterberg et al.; Environ. Sci. Technol. 2008, 42, 6437-6445), numerous emissions characterization studies have demonstrated marked differences in regulated and unregulated emissions between NTDE and "traditional diesel exhaust" (TDE) from pre-1988 diesel engines. Now there exist even more data demonstrating significant chemical and physical distinctions between the diesel exhaust particulate (DEP) in NTDE versus DEP from pre-2007 diesel technology, and its greater resemblance to particulate emissions from compressed natural gas (CNG) or gasoline engines. Furthermore, preliminary toxicological data suggest that the changes to the physical and chemical composition of NTDE lead to differences in biological responses between NTDE versus TDE exposure. Ongoing studies are expected to address some of the remaining data gaps in the understanding of possible NTDE health effects, but there is now sufficient evidence to conclude that health effects studies of pre-2007 DE likely have little relevance in assessing the potential health risks of NTDE exposures.

Revisiting the cape cod bacteria injection experiment using a stochastic modeling approach

USGS Publications Warehouse

Maxwell, R.M.; Welty, C.; Harvey, R.W.

2007-01-01

Bromide and resting-cell bacteria tracer tests conducted in a sandy aquifer at the U.S. Geological Survey Cape Cod site in 1987 were reinterpreted using a three-dimensional stochastic approach. Bacteria transport was coupled to colloid filtration theory through functional dependence of local-scale colloid transport parameters upon hydraulic conductivity and seepage velocity in a stochastic advection - dispersion/attachment - detachment model. Geostatistical information on the hydraulic conductivity (K) field that was unavailable at the time of the original test was utilized as input. Using geostatistical parameters, a groundwater flow and particle-tracking model of conservative solute transport was calibrated to the bromide-tracer breakthrough data. An optimization routine was employed over 100 realizations to adjust the mean and variance ofthe natural-logarithm of hydraulic conductivity (InK) field to achieve best fit of a simulated, average bromide breakthrough curve. A stochastic particle-tracking model for the bacteria was run without adjustments to the local-scale colloid transport parameters. Good predictions of mean bacteria breakthrough were achieved using several approaches for modeling components of the system. Simulations incorporating the recent Tufenkji and Elimelech (Environ. Sci. Technol. 2004, 38, 529-536) correlation equation for estimating single collector efficiency were compared to those using the older Rajagopalan and Tien (AIChE J. 1976, 22, 523-533) model. Both appeared to work equally well at predicting mean bacteria breakthrough using a constant mean bacteria diameter for this set of field conditions. Simulations using a distribution of bacterial cell diameters available from original field notes yielded a slight improvement in the model and data agreement compared to simulations using an average bacterial diameter. The stochastic approach based on estimates of local-scale parameters for the bacteria-transport process reasonably captured the mean bacteria transport behavior and calculated an envelope of uncertainty that bracketed the observations in most simulation cases. ?? 2007 American Chemical Society.

Repeated helicopter-based surveys of fugitive hydrocarbon emissions from tight oil operations: Persistence and driving factors

NASA Astrophysics Data System (ADS)

Englander, J. G.; Brandt, A. R.; Jackson, R. B.; Alvarez, R.; Lyon, D. R.

2016-12-01

A recent study used helicopters and optical gas imaging (infrared-based) to study hydrocarbon leaks [1] across numerous oil and gas producing basins. The appearance of leaks appeared to have small statistical correlations with factors such as age of wells, production rate, or water production. However, there have not been few if any attempts to observe the presence of leaks over time. In this work, we used the same helicopter-based optical gas imaging techniques to revisit wells in the Bakken formation that had previously been measured in 2014 [1] In this study, we visited 353 of the total 683 well pads in Bakken from the original study, and we also visited 50 randomly selected well pads that were newly developed between studies. We first examine the presence of leaks as a function of different factors, including: operator, number of wells, tanks, and treaters on a well pad; and numerous other possible emissions drivers. In addition, using the previous years observations as our prior, we conducted a Bayesian analysis to determine the likelihood of finding a leaking or non-leaking well pad and compared the observations to a Monte Carlo simulation of randomly distributed leaks. We find that the overall prevalence of observed emissions was similar for each year (11% for 2014 observations and 10% for 2015 observations). We also find whether a pad was found to be leaking in the first observation year had a statistically significant influence (4.9σ) on the presence of a leak in the following observation year. Similar levels of persistence are also apparent for non-leaking well pads. [1] D. R. Lyon, R. A. Alvarez, D. Zavala-Araiza, A. R. Brandt, R. B. Jackson, and S. P. Hamburg, "Aerial surveys of elevated hydrocarbon emissions from oil and gas production sites," Environ. Sci. Technol., p. acs.est.6b00705, Apr. 2016.

Structures of dynamic particle accumulation in Marangoni convection in half-zone liquid bridge

NASA Astrophysics Data System (ADS)

Tanaka, S.; Ueno, I.; Kawamura, H.

Thermocapillary convection is induced by the temperature difference T between two cylindrical rods sustaining liquid bridge. It is well known that the induced flow exhibits a transition from 2-D steady to 3-D time-dependent oscillatory flows with the increasing T. These convections can be visualized by using fine particles as tracers. In a certain flow condition, the particles were found to get accumulated. This is called PAS, particle accumulation structure, after Schwabe et al. (Microgravity, sci. technol. 1996). The authors group (Ueno et al, Proc. TSFP-2, 2001) categorized the induced flow fields into several regimes by the particle motion, structures and the surface temperature variation. Two sets of pulsating and rotating flows appeared. It was observed clearly that the particle gathered along a closed single path. This kind of structure was named as TL-PAS, Twisted-loop particle accumulation structure, (Tanaka et al, J. Japan Soc. Microgravity Appl, 2000). Special attention was paid for this kind of PAS in this study. The TL-PAS exhibited several types of closed path lines. Its detailed structure changed even in the same regime with a slight change of T and aspect ratio. The experimental setup consisted of the transparent crystal top and aluminum bottom rods. Flow fields were observed from top and side through two CCD cameras. A laser-light-sheet was employed in order to grasp the 3-D structures of TL-PAS. The liquid bridge of Silicone oil of 2 cSt was formed between rods of 5mm in diameter. Several kinds of particles were tested as tracer. The surface temperature variation was measured simultaneously by use of a 25μm thermocouple up to 50Hz, or 2.5μm CCT probe (constant current thermometry) up to 100Hz. By use of this apparatus, 3-D structure of TL-PAS and motions of individual particles were captured.

Seasonal Influences on Ground-Surface Water Interactions in an Arsenic-Affected Aquifer in Cambodia

NASA Astrophysics Data System (ADS)

Richards, L. A.; Magnone, D.; Van Dongen, B.; Bryant, C.; Boyce, A.; Ballentine, C. J.; Polya, D. A.

2015-12-01

Millions of people in South and Southeast Asia consume drinking water daily which contains dangerous levels of arsenic exceeding health-based recommendations [1]. A key control on arsenic mobilization in aquifers in these areas has been controversially identified as the interaction of 'labile' organic matter contained in surface waters with groundwaters and sediments at depth [2-4], which may trigger the release of arsenic from the solid- to aqueous-phase via reductive dissolution of iron-(hyr)oxide minerals [5]. In a field site in Kandal Province, Cambodia, which is an arsenic-affected area typical to others in the region, there are strong seasonal patterns in groundwater flow direction, which are closely related to monsoonal rains [6] and may contribute to arsenic release in this aquifer. The aim of this study is to explore the implications of the high susceptibility of this aquifer system to seasonal changes on potential ground-surface water interactions. The main objectives are to (i) identify key zones where there are likely ground-surface water interactions, (ii) assess the seasonal impact of such interactions and (iii) quantify the influence of interactions using geochemical parameters (such as As, Fe, NO3, NH4, 14C, 3T/3He, δ18O, δ2H). Identifying the zones, magnitude and seasonal influence of ground-surface water interactions elucidates new information regarding potential locations/pathways of arsenic mobilization and/or transport in affected aquifers and may be important for water management strategies in affected areas. This research is supported by NERC (NE/J023833/1) to DP, BvD and CJB and a NERC PhD studentship (NE/L501591/1) to DM. References: [1] World Health Organization, 2008. [2] Charlet & Polya (2006), Elements, 2, 91-96. [3] Harvey et al. (2002), Science, 298, 1602-1606. [4] Lawson et al. (2013), Env. Sci. Technol. 47, 7085 - 7094. [5] Islam et al. (2004), Nature, 430, 68-71. [6] Benner et al. (2008) Appl. Geochem. 23(11), 3072 - 3087.

Charging and performance of the CubeSTAR satellite studied by numerical simulations

NASA Astrophysics Data System (ADS)

Miloch, Wojciech; Bekkeng, Tore André; Lindem, Torfinn

2012-07-01

A good understanding of spacecraft-plasma interaction is important for all space missions and experiments. The spacecraft potential is determined by the plasma, photoemission and other currents [1]. A charged object can significantly disturb the surrounding plasma, and lead to wake formation. The wake features, such as ion focusing, can influence the measurements of the plasma by the instruments onboard. A study of this problem using analytical models is difficult and can not account for all phenomena. This has encouraged use of numerical models for self-consistent studies of the plasma-object interactions on a detailed kinetic level [2][3]. With three-dimensional particle-in-cell (PIC) simulations [3][4], we address the spacecraft-plasma interaction in various plasma environments, and account for the self-consistent charging of the spacecraft by plasma and photoemission currents. As a specific case, we consider the interactions between plasma and a CubeSTAR satellite. CubeSTAR is a nano-satellite for the space weather studies being constructed in Norway, with the launch scheduled for year 2013. With a novel Langmuir probe system [5], it will measure the absolute electron densities with a high spatial resolution, allowing for studies of small scale plasma irregularities. We perform a systematic study of the role of the wakefield on the measurements with the Langmuir probes onboard the CubeSTAR for the plasma conditions relevant for the planned polar orbit. The simulation results are of relevance also for other spacecraft missions. [1] Whipple E C, Rep. Prog. Phys. 44, 1197 (1981). [2] Roussel J F and Berthelier J J, J. Geophys. Res. 109, A01104 (2004). [3] Yaroshenko V V et al., J. Geophys. Res. 116, A12218 (2011). [4] Miloch W J Kroll M and Block D 2010 Phys. Plasmas 17, 103703 (2010). [5] Bekkeng T A et al. Meas. Sci. Technol. 21, 085903 (2010).

Application of the integrating sphere method to separate the contributions of brown and black carbon in atmospheric aerosols.

PubMed

Wonaschütz, Anna; Hitzenberger, Regina; Bauer, Heidi; Pouresmaeil, Parissa; Klatzer, Barbara; Caseiro, Alexandre; Puxbaum, Hans

2009-02-15

Until about a decade ago, black carbon (BC) was thought to be the only light absorbing substance in the atmospheric aerosol except for soil or desert dust In more recent years, light absorbing polymeric carbonaceous material was found in atmospheric aerosols. Absorption increases appreciably toward short wavelengths, so this fraction was called brown carbon. Because brown carbon is thermally rather refractory, it influences the split between organic carbon (OC) and elemental carbon (EC) in thermal methods and, through its light absorption characteristics, leads to overestimations of BC concentrations. The goal of the present study was to extend the integrating sphere method to correct the BC signal for the contribution of brown carbon and to obtain an estimate of brown carbon concentrations. Humic acid sodium salt was used as proxy for brown carbon. The extended method is first tested on mixtures of test substances and then applied to atmospheric samples collected during biomass smoke episodes (Easter bonfires) in Austria. The resulting concentrations of black and brown carbon are compared to EC obtained with a widely used thermal method, the Cachier method (Cachier et al. Tellus 1989, 41B, 379-390) and a thermal-optical method (Schmid et al. Atmos. Environ. 2001, 35, 2111-2121), as well as to concentrations of humic like substances (HULIS) and to biomass smoke POM (particulate organic matter). Both the thermal methods were found to overestimate BC on days with large contributions of woodsmoke, which agrees with the findings of the method intercomparison study by Reisinger et at. (Environ. Sci. Technol. 2008, 42, 884-889). During the days of the bonfires, the Cachier method gave EC concentrations that were higher by a factor of 3.8 than the BC concentrations, while the concentrations obtained with the thermal-optical method were higher by a factor of 2.6.

Planar laser imaging of differential molecular diffusion in gas-phase turbulent jets

NASA Astrophysics Data System (ADS)

Brownell, C. J.; Su, L. K.

2008-03-01

Planar laser Rayleigh scattering yields quantitative, two-dimensional measurements of differential diffusion in a turbulent propane-helium jet issuing into air. The jet exit Reynolds number ranges from 1000 to 3000, corresponding to estimated outer-scale Reynolds numbers from 4300 to 13 000. Using a technique originally proposed by Bilger and Dibble [Combust. Sci. Technol. 28, 161 (1982)], the imaging measurements allow direct determination of a normalized scalar difference quantity ξ. For the lower Re, significant differential diffusion develops in the pretransitional portion of the flow. Downstream of the turbulent transition, radial profiles of mean ξ take on a characteristic form, with an excess of the less-diffusive propane on the jet boundary. This characteristic form is independent of Reynolds number, and is thus apparently independent of the degree of differential diffusion in the pretransition range. Evolution of the ξ fields in the turbulent part of the flow is surprisingly consistent with the mixing of conventional scalar quantities. Fluctuation profiles of ξ have a self-similar, bimodal shape for each Re, and power spectra of ξ are monotonically decreasing, with a distinct k-5/3 inertial range. This spectral form is at odds with prior analytical and computational results in isotropic turbulence, which predicted that the spectrum would show a peak intermediate between the diffusive cutoffs of the individual scalars. The discrepancy appears to be due to the forcing applied in the simulations; the differential diffusion in the experiments preferentially develops in the jet near field, so the resulting evolution is more akin to a decay process. This is further emphasized by the observation that the thickness of ξ structures in the jet decreases with downstream distance. The present results indicate that consideration of differential diffusion must account for the details of the flow configuration, particularly the uniformity of turbulence levels. This has important implications for reacting flows, where local laminarization by heat release can be significant.

Reactive oxygen species from secondary organic aerosols decomposition in water and surrogate lung lining fluid

NASA Astrophysics Data System (ADS)

Tong, H.; Shen, F.; Lakey, P. S. J.; Arangio, A. M.; Socorro, J.; Brune, W. H.; Lucas, K.; Poeschl, U.; Shiraiwa, M.

2016-12-01

Reactive oxygen species (ROS) play a significant role in climate and adverse health effects of air pollutants (Anglada, J. M. et al., 2015; Pöschl and Shiraiwa, 2015). Secondary organic aerosols (SOA) account for a major fraction of fine particles (Jimenez et al., 2009; Huang et al., 2014). Thus, studies on ROS production ability of SOA are important for comprehensive evaluation of the impacts of air particulate matter on climate change and public health. In this study, we have investigated ROS formation by laboratory-generated SOA particles using a variety of different experimental techniques including electron paramagnetic resonance spectrometry, dithiothreitol and fluorometric hydrogen peroxide assays, and LC-MS/MS spectrometry, we found substantial amounts of ROS species such as •OH, O2•-, RO•, R• and H2O2 were generated by isoprene, β-pinene, and naphthalene SOA upon interaction with water and surrogate lung lining fluid. Antioxidants contained in surrogate lung lining fluid scavenge •OH and O2•-efficiently, but not organic radicals. LC-MS/MS analysis and kinetic modeling suggest that organic hydroperoxides, which account for a major fraction of SOA particles (Docherty et al., 2005; Ehn et al., 2014) play a critical role in ROS formation (Tong et al., 2016). We also found the cellular responses of human alveolar basal epithelial (A549) and macrophage cells (THP-1) to SOA could be explained by the ROS yields, indicating a key role of ROS on the cytotoxicity of SOA. Anglada, J. M. et al., Acc. Chem. Res. 48, 575-583, 2015. Docherty, K. S. eta al. Environ. Sci. Technol. 39, 4049-4059, 2005. Ehn, M. et al., Nature 506, 476-479, 2014. Huang, R.-J. et al., Nature 514, 218-222, 2014. Jimenez, J. L. et al., Science 326, 1525-1529, 2009. Pöschl, U., and Shiraiwa, M. Chem. Rev., 115, 4440-4475, 2015. Tong, H. et al., Atmos. Chem. Phys. 16, 1761-1771, 2016.

Dose Accuracy and Injection Force of Different Insulin Glargine Pens

PubMed Central

Friedrichs, Arnd; Bohnet, Janine; Korger, Volker; Adler, Steffen; Schubert-Zsilavecz, Manfred; Abdel-Tawab, Mona

2013-01-01

Background Dose accuracy and injection force, representing key parameters of insulin pens, were determined for three pens delivering insulin glargine-based copies, Pen Royale (WR) and DispoPen (WD) for Glaritus® (Wockhardt) and GanLee Pen (GL) for Basalin® (Gan & Lee), compared with pens of the originator, ClikSTAR® (CS) and S o l o S TA R® (SS) for Lantus® (Sanofi) . Methods Using the weighing procedure recommended by DIN EN ISO 11608–1:2000, dose accuracy was evaluated based on nonrandomized delivery of low (5 U), mid (30 U), and high (60 U) dosage levels. Injection force was measured by dispensing the maximum dose of insulin (60 U for the GL, WR, and WD; 80 U for the SS and CS) at dose speeds of 6 and 10 U/s. Results All tested pens delivered comparable average doses within the DIN EN ISO 11608–1:2000 limits at all dosage levels. The GL revealed a higher coefficient of variation (CV) at 5 U, and the WR and WD had higher CVs at all dosage levels compared with the CS and SS. Injection force was higher for the WR, WD, and GL compared with the CS and SS at both dose speeds. In contrast to the CS and SS with an end-of-content feature, doses exceeding the remaining insulin could be dialed with the WR, GL, and WD and, apparently, dispensed with the WD. Conclusions All pens fulfilled the dose accuracy requirements defined by DIN EN ISO 11608–1:2000 standards at all three dosage levels, with the WR, WD, and GL showing higher dosage variability and injection force compared with the SS and CS. Thus, the devices that deliver insulin glargine copies show different performance characteristics compared with the originator. J Diabetes Sci Technol 2013;7(5):1346–1353 PMID:24124963

Upscaling mixing in porous media from an experimental quantification of pore scale Lagrangian deformation statistics

NASA Astrophysics Data System (ADS)

Turuban, R.; Jimenez-Martinez, J.; De Anna, P.; Tabuteau, H.; Meheust, Y.; Le Borgne, T.

2014-12-01

As dissolved chemical elements are transported in the subsurface, their mixing with other compounds and potential reactivity depends on the creation of local scale chemical gradients, which ultimately drive diffusive mass transfer and reaction. The distribution of concentration gradients is in turn shaped by the spatial gradients of flow velocity arising from the random distribution of solid grains. We present an experimental investigation of the relationship between the microscale flow stretching properties and the effective large scale mixing dynamics in porous media. We use a flow cell that models a horizontal quasi two-dimensional (2D) porous medium, the grains of which are cylinders randomly positioned between two glass plates [de Anna et al. 2013]. In this setup, we perform both non diffusive and diffusive transport tests, by injecting respectively microsphere solid tracers and a fluorescent dye. While the dye front propagates through the medium, it undergoes in time a kinematic stretching that is controlled by the flow heterogeneity, as it encounters stagnation zones and high velocity channels between the grains. The spatial distribution of the dye can then be described as a set of stretched lamellae whose rate of diffusive smoothing is locally enhanced by kinematic stretching [Le Borgne et al., 2013]. We show that this representation allows predicting the temporal evolution of the mixing rate and the probability distribution of concentration gradients for a range of Peclet numbers. This upscaling framework hence provides a quantification of the dynamics of effective mixing from the microscale Lagrangian velocity statistics. References:[1] P. de Anna, J. Jimenez-Martinez, H. Tabuteau, R. Turuban, T. Le Borgne, M. Derrien,and Yves Méheust, Mixing and reaction kinetics in porous media : an experimental pore scale quantification, Environ. Sci. Technol. 48, 508-516, 2014. [2] Le Borgne, T., M. Dentz, E. Villermaux, Stretching, coalescence and mixing in porous media, Phys. Rev. Lett., 110, 204501 (2013)

Towards improved photovoltaic conversion using dilute magnetic semiconductors (abstract only)

NASA Astrophysics Data System (ADS)

Olsson, Pär; Guillemoles, J.-F.; Domain, C.

2008-02-01

Present photovoltaic devices, based on p/n junctions, are limited from first principles to maximal efficiencies of 31% (40% under full solar concentration; Shockley and Queisser 1961 J. Appl. Phys. 32 510). However, more innovative schemes may overcome the Shockley-Queisser limit since the theoretical maximal efficiency of solar energy conversion is higher than 85% (Harder and Würfel 2003 Semicond. Sci. Technol. 18 S151). To date, the only practical realization of such an innovative scheme has been multi-junction devices, which at present hold the world record for efficiency at nearly 41% at significant solar concentration (US DOE news site: http://www.energy.gov/news/4503.htm). It has been proposed that one could make use of the solar spectrum in much the same way as the multi-junction devices do but in a single cell, using impurity induced intermediate levels to create gaps of different sizes. This intermediate level semiconductor (ILSC) concept (Green and Wenham 1994 Appl. Phys. Lett. 65 2907; Luque and Martí1997 Phys. Rev. Lett. 78 5014) has a maximal efficiency similar to that of multi-junction devices but suffers from prohibitively large non-radiative recombination rates. We here propose to use a ferromagnetic impurity scheme in order to reduce the non-radiative recombination rates while maintaining the high theoretical maximum efficiency of the ILSC scheme, that is about 46%. Using density functional theory calculations, the electronic and energetic properties of transition metal impurities for a wide range of semiconductors have been analysed. Of the several hundred compounds studied, only a few fulfil the design criteria that we present here. As an example, wide gap AlP is one of the most promising compounds. It was found that inclusion of significant amounts of Mn in AlP induces band structures providing conversion efficiencies potentially close to the theoretical maximum, with an estimated Curie temperature reaching above 100 K.

Kinetics of Deliquescence

NASA Astrophysics Data System (ADS)

McGraw, R. L.; Lewis, E.

2009-12-01

We examine deliquescence phase transformation for inorganic salt particles ranging from bulk down to several nanometers in size. Thermodynamic properties of the particles, coated with aqueous solution layers of varying thickness and surrounded by vapor, are analyzed. A thin layer criterion is introduced to define a limiting deliquescence relative humidity (DRH). Nano-size particles are predicted to deliquesce at relative humidity just below the DRH on crossing a nucleation barrier, located at a critical solution layer thickness. This barrier vanishes precisely at the DRH defined by the criterion. For a population of particles, the inherent random nature of the nucleation process is predicted to result in a distribution of RH values over which deliquescence will be seen to occur. Measurement of this (apparent) non-abrupt deliquescence of the population should provide both a validation of the nucleation mechanism and a quantitative determination of nucleation rate. This paper presents calculations of crossing (i.e. deliquescence) rate using the theory of mean first passage times (MFPT). MFPT theory is shown to provide a generalization of Becker-Döring nucleation kinetics especially useful for barrier heights much lower than those typically encountered in vapor-liquid nucleation. Barrier heights for deliquescence depend on the concentration of pre-deliquesced particles and observation time, but are typically in the 5-15kT range. Calculations use the tandem nano-differential mobility analyzer setup of Biskos et al. [1] as a model framework. In their experiment, a concentration of dry salt particles is subject to a higher RH for some observation time, after which is measured the (well-separated) populations of un-deliquesced particles and those that have deliquesced. Theoretical estimates for the conversion kinetics are presented as a function of dry particle size, DRH, and salt properties. [1] G. Biskos, A. Malinowski, L. M. Russell, P. R. Buseck, and S. T. Martin, Aerosol Sci. and Technol. 40, 97 (2006).

Current practice of methylprednisolone administration for acute spinal cord injury in Germany: a national survey.

PubMed

Druschel, Claudia; Schaser, Klaus-Dieter; Schwab, Jan M

2013-05-15

Written mail-out survey. To determine current practice in high-dose methylprednisolone succinate (MPSS) administration for treatment of acute spinal cord injury (SCI) in Germany. Reanalysis of the National Acute Spinal Cord Injury Studies (NASCIS) resulted in criticism of the use of high-dose MPSS for treatment of acute SCI. Subsequently, SCI treatment guidelines were revised leading to a reduction in MPSS use across North America. The impact of these revisions on SCI treatment in Germany is not known. A questionnaire was sent to all trauma, orthopedic and neurosurgical departments of German university centers, affiliated teaching hospitals, and specialized SCI care centers. Survey included 6 questions about the administration of MPSS after acute SCI. Three hundred seventy-two respondents completed the survey (response rate: 51% overall, 76% university hospitals, 85% specialized SCI care centers). Overall, 55% of departments that treat SCI prescribe MPSS. Among them, 73% are "frequent" users administering MPSS to more than 50% of their patients. Ten percent prescribe according to NASCIS I, 43% NASCIS II, 33% NASCIS III, and 13% "generic protocols." As justification for MPSS treatment, "effectiveness" ranked before "common practice" and "medicolegal reasons." "Specialized" SCI care centers differ in that (1) MPSS is administered less frequently, (2) NASCIS I doses are not used, and (3) during the past several years, practice patterns are more likely to have shifted away from the treatment of SCI with MPSS. About one-half of the institutions continue to prescribe MPSS in the setting of acute SCI. A need for further education in almost one-fourth of German departments treating acute SCI is demonstrated through responses indicating use of the outdated NASCIS I protocol, a "legal need" or "unchanged MPSS application during the last years." "Specialized" SCI centers are more likely to change their practice in accordance with evolving literature. 3.

Persistent Polyuria in a Rat Spinal Contusion Model

PubMed Central

Ward, Patricia J.

2012-01-01

Abstract Polyuria contributes to bladder overdistention, which confounds both lower and upper urinary tract management in individuals having a spinal cord injury (SCI). Bladder overdistention post-SCI is one of the most common triggers for autonomic dysreflexia, a potentially life-threatening condition. Post-SCI polyuria is thought to result from loss of vascular tone in the lower extremities, leading to edema and subsequent excess fluid, resulting in polyuria. Mild SCIs that have near complete recovery would therefore be expected to have little to no polyuria, while severe injuries resulting in flaccid limbs and lower extremity edema would be expected to exhibit severe polyuria. Since interventions that may decrease lower extremity edema are recommended to lessen the severity of polyuria, step training (which promotes vascular circulation) was evaluated as a therapy to reduce post-SCI polyuria. In the present study, polyuria was evaluated in mild, moderate, and severe contusive SCI in adult male rats. The animals were housed in metabolic cages for 24-hour periods pre- and post-SCI (to 6 weeks). Urine, feces, food, water, and body weights were collected. Other assessments included residual expressed urine volumes, locomotor scoring, in-cage activity, and lesion histology. SCI produced an immediate increase in 24-hour urine collection, as early as 3 days post-SCI. Approximately 2.6-fold increases in urine collection occurred from weeks 1–6 post-SCI for all injury severities. Even with substantial gains in locomotor and bladder function following a mild SCI, polyuria remained severe. Step training (30 min/day, 6 days/week) did not alleviate polyuria in the moderate SCI contusion group. These results indicate that (1) mild injuries retaining weight-bearing locomotion that should have mild, if any, edema/loss of vascular tone still exhibit severe polyuria, and (2) step training was unable to reduce post-SCI polyuria. Taken together, these results indicate that the current mechanistic hypothesis of post-SCI polyuria may be incomplete. PMID:22708983

Persistent polyuria in a rat spinal contusion model.

PubMed

Ward, Patricia J; Hubscher, Charles H

2012-10-10

Polyuria contributes to bladder overdistention, which confounds both lower and upper urinary tract management in individuals having a spinal cord injury (SCI). Bladder overdistention post-SCI is one of the most common triggers for autonomic dysreflexia, a potentially life-threatening condition. Post-SCI polyuria is thought to result from loss of vascular tone in the lower extremities, leading to edema and subsequent excess fluid, resulting in polyuria. Mild SCIs that have near complete recovery would therefore be expected to have little to no polyuria, while severe injuries resulting in flaccid limbs and lower extremity edema would be expected to exhibit severe polyuria. Since interventions that may decrease lower extremity edema are recommended to lessen the severity of polyuria, step training (which promotes vascular circulation) was evaluated as a therapy to reduce post-SCI polyuria. In the present study, polyuria was evaluated in mild, moderate, and severe contusive SCI in adult male rats. The animals were housed in metabolic cages for 24-hour periods pre- and post-SCI (to 6 weeks). Urine, feces, food, water, and body weights were collected. Other assessments included residual expressed urine volumes, locomotor scoring, in-cage activity, and lesion histology. SCI produced an immediate increase in 24-hour urine collection, as early as 3 days post-SCI. Approximately 2.6-fold increases in urine collection occurred from weeks 1-6 post-SCI for all injury severities. Even with substantial gains in locomotor and bladder function following a mild SCI, polyuria remained severe. Step training (30 min/day, 6 days/week) did not alleviate polyuria in the moderate SCI contusion group. These results indicate that (1) mild injuries retaining weight-bearing locomotion that should have mild, if any, edema/loss of vascular tone still exhibit severe polyuria, and (2) step training was unable to reduce post-SCI polyuria. Taken together, these results indicate that the current mechanistic hypothesis of post-SCI polyuria may be incomplete.

E2F4 Promotes Neuronal Regeneration and Functional Recovery after Spinal Cord Injury in Zebrafish

PubMed Central

Sasagawa, Shota; Nishimura, Yuhei; Hayakawa, Yuka; Murakami, Soichiro; Ashikawa, Yoshifumi; Yuge, Mizuki; Okabe, Shiko; Kawaguchi, Koki; Kawase, Reiko; Tanaka, Toshio

2016-01-01

Mammals exhibit poor recovery after spinal cord injury (SCI), whereas non-mammalian vertebrates exhibit significant spontaneous recovery after SCI. The mechanisms underlying this difference have not been fully elucidated; therefore, the purpose of this study was to investigate these mechanisms. Using comparative transcriptome analysis, we demonstrated that genes related to cell cycle were significantly enriched in the genes specifically dysregulated in zebrafish SCI. Most of the cell cycle-related genes dysregulated in zebrafish SCI were down-regulated, possibly through activation of e2f4. Using a larval zebrafish model of SCI, we demonstrated that the recovery of locomotive function and neuronal regeneration after SCI were significantly inhibited in zebrafish treated with an E2F4 inhibitor. These results suggest that activation of e2f4 after SCI may be responsible, at least in part, for the significant recovery in zebrafish. This provides novel insight into the lack of recovery after SCI in mammals and informs potential therapeutic strategies. PMID:27242526

Spinal cord injury rehabilitation in Riyadh, Saudi Arabia: Time to rehabilitation admission, length of stay and functional independence

PubMed Central

Mahmoud, Husam; Qannam, Hazem; Mortenson, Ben

2017-01-01

Objectives 1) To describe functional status, length of stay (LOS), and time to rehabilitation admission trends. 2) To identify independent predictors of motor function following rehabilitation for traumatic and nontraumatic spinal cord injury (SCI). Participants Adult patients with SCI discharged from inpatient rehabilitation between 2009–2014. Design Retrospective cohort study. Setting Spinal injury rehabilitation unit at the King Fahad Medical City, Riyadh, Saudi Arabia. Methods From retrospective chart reviews of 312 traumatic and 106 nontraumatic SCI, we extracted information on time from injury to rehabilitation admission, rehabilitation LOS, and Functional Independence Measure (FIM) score (admission and discharge). Additionally we collected information on SCI patients’ demographics and injury characteristics. Hierarchical regression was employed to investigate variables associated with FIM motor score at discharge for traumatic SCI and nontraumatic SCI. Outcome measures FIM motor score measured at discharge. Results Mean and median days from injury to rehabilitation admission were not significantly different for traumatic SCI (377±855, 150) and nontraumatic SCI (288±403, 176). Mean and median days for rehabilitation LOS were significantly longer for traumatic SCI (85±60, 70) compared to nontraumatic SCI (64±59, 49) (p=…..). FIM scores improved significantly from admission to discharge in both groups. For individuals with traumatic SCI, after accounting for admission FIM motor score, tetraplegia and time from injury to rehabilitation, admission had a significant but small negative association with discharge FIM motor score. For individuals with nontraumatic SCI, increasing age and AIS score of A or B had a significant negative association with discharge FIM motor score. LOS in rehabilitation was not a significant contributor for either model. Conclusions Decreasing the time from injury to rehabilitation admission may improve outcomes for those with traumatic SCI. Since time spent in rehabilitation was shorter than most other countries, a change in practice in this area may be warranted. Developing new strategies to improve outcomes for older patients with nontraumatic SCI would also be beneficial. PMID:28139661

Health Information Seeking and Technology Use Among Veterans With Spinal Cord Injuries and Disorders.

PubMed

Hogan, Timothy P; Hill, Jennifer N; Locatelli, Sara M; Weaver, Frances M; Thomas, Florian P; Nazi, Kim M; Goldstein, Barry; Smith, Bridget M

2016-02-01

Access to health information is crucial to persons living with a spinal cord injury or disorder (SCI/D). Although previous research has provided insights on computer and Internet use among persons with SCI/D, as well as how and where persons with SCI/D gather health information, few studies have focused on U.S. veterans with SCI/D. To characterize health information seeking among veterans with SCI/D and to examine the association between technology use and the characteristics of veterans with SCI/D. Cross-sectional. Veterans Health Administration (VHA). Sample of 290 veterans with SCI/D who utilize services at 2 VHA SCI/D Centers. Postal mail survey. Extent of computer, Internet, and text messaging use, information source use, and e-Health literacy rates. The survey response rate was 38%. The majority of respondents were male (97.2%), younger than 65 years (71.0%), and white (71.7%). Of the respondents, 64.8% indicated that they use a computer, 62.9% reported use of the Internet, and 26.2% reported use of text messaging. The mean overall e-Health Literacy Scale score was 27.3 (standard deviation = 7.2). Similar to findings reported in studies focused outside the veteran population, the most frequent source that veterans turned to for information about SCI/D was a health professional (85.1%); this was also the most frequent source that veterans indicated they would turn to first to get information about SCI/D (75.9%). Other frequently reported sources of information included other persons with SCI/D (41.0%), Internet resources (31.0%), and family and friends (27.9%). Fairly high levels of computer and Internet use exist among veterans with SCI/D. Veterans with SCI/D also have a strong preference for people-particularly health professionals, and to a lesser extent peers and family and friends-as sources of information about SCI/D. These findings highlight the importance of combining technology and human interaction to meet the information needs of this population. Published by Elsevier Inc.

76 FR 10395 - BreconRidge Manufacturing Solutions, Now Known as Sanmina-SCI Corporation, Division...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-24

... Solutions, Now Known as Sanmina-SCI Corporation, Division Optoelectronic and Microelectronic Design and Manufacturing, a Subsidiary of Sanmina-SCI Corporation, Including On- Site Leased Workers From Kelly Services... Manufacturing Solutions, now known as Sanmina-SCI Corporation, Division Optoelectronic and Microelectronic...

A pilot study to evaluate the role of the Spinal Cord Impairment Pressure Ulcer Monitoring Tool (SCI-PUMT) in clinical decisions for pressure ulcer treatment.

PubMed

Thomason, Susan S; Graves, Barbara Ann; Madaris, Linda

2014-12-01

The Spinal Cord Impairment Pressure Ulcer Monitoring Tool (SCI-PUMT) was designed to assess pressure ulcer (PrU) healing in the spinal cord impaired (SCI) population. The tool contains 7 variables: wound surface area, depth, edges, tunneling, undermining, exudate type, and necrotic tissue amount. A 2-phased, quantitative pilot study based on the Theory of Reasoned Action and Theory of Planned Behavior was conducted at a large SCI/Disorders Center in the Department of Veterans Affairs (VA). In the first phase of the study, a convenience sample of 5 physicians, 3 advanced practice registered nurses, and 3 certified wound care nurses (CWCN) was surveyed using a 2-part questionnaire to assess use of the SCI-PUMT instrument, its anticipated improvement in PrU assessment, and intent to use the SCI-PUMT in clinical practice. Attitudes, subjective norms, perceived behavioral controls, and barriers related to the intent to use the SCI-PUMT were evaluated using a 5-point Likert scale (range: 1= extremely likely, 5 = extremely unlikely). In the second phase of the study, the electronic health records (EHR) of 24 veterans (with 30 PrUs) who had at least 2 completed SCI-PUMT scores during a 4-week period were used to evaluate whether an association existed between magnitudes of change of total SCI-PUMT scores and ordered changes in PrU treatment. The overall mean score for intent to use SCI-PUMT was 1.80 (SD 0.75). The least favorable scores were for convenience and motivation to use the SCI-PUMT. Analysis of EHR data showed no significant difference in magnitudes of change in the SCI-PUMT score and changes in PrU treatment recommendations made by the CWCNs. The significance was not affected regardless of an increase or no change in the score (χ2 with 1 degree of freedom = 1.158, P = 0.282) or for a decrease in the score (χ2 with 1 degree of freedom = 0.5, P = 0.478). In this pilot study, the expressed intent to use the SCI-PUMT in making clinical decisions was generally positive but reservations remain. Additional research is being conducted to determine the barriers and facilitators to SCI-PUMT implementation. The SCI-PUMT was the first tool found to be valid, reliable, and sensitive to assess PrU healing in persons with SCI, and studies to examine the prospective validity of using this instrument on ulcer treatment decisions and outcomes are warranted.

Oligomerization reactions for precursors to secondary organic aerosol: Comparison between two formation mechanisms for the oligomeric hydroxyalkyl hydroperoxides

NASA Astrophysics Data System (ADS)

Zhao, Qiangli; Wang, Weina; Liu, Fengyi; Lü, Jian; Wang, Wenliang

2017-10-01

To better understand the formation mechanism of oligomeric hydroxyalkyl hydroperoxides HOROO(SCI)nH composed of stabilized Criegee intermediate (SCI) as a chain unit, the reactions of SCI with hydroxyalkyl hydroperoxides (HOROOH) and hydroxyalkylperoxy radical (HORO2) as well as HO2 radical were investigated. For the reactions of HORO2 + SCI, two preferred pathways involving a SCI insertion in HOROOH hydroperoxide bond can be found, and the formation of HOROO(SCI)H is the dominant pathway in the reaction of HOCH2(CH3)2COOH + (CH3)2COO. The structures of the HORO2, HOROOH as well as the SCIs play a crucial role in determining the reactivity of the oligomerization. Both the reactions of HORO2 + SCI + HO2 and HOROOH + SCI could be the source of the processors to the formation of secondary organic aerosol (SOA). But from the point of free energy barriers, the formation of HOROO(SCI)H prefers to follow the mechanism involving initiation by the reaction of a HORO2 and a SCI, sequential addition of SCIs, and termination by reaction with the HO2 radical. The rate coefficients show negative temperature dependence and vary in different systems depending on the reactants. The reaction process and constituents of the products can be regulated by temperature and reactants.

Abdominal Manual Therapy Repairs Interstitial Cells of Cajal and Increases Colonic c-Kit Expression When Treating Bowel Dysfunction after Spinal Cord Injury

PubMed Central

Zhang, Wenyi; Zhu, Zhaojin; Xie, Bin; Yu, Jun

2017-01-01

Background This study aimed to evaluate the therapeutic effects of abdominal manual therapy (AMT) on bowel dysfunction after spinal cord injury (SCI), investigating interstitial cells of Cajal (ICCs) and related c-kit expression. Methods Model rats were divided as SCI and SCI with drug treatment (intragastric mosapride), low-intensity (SCI + LMT; 50 g, 50 times/min), and high-intensity AMT (SCI + HMT; 100 g, 150 times/min). After 14 days of treatment, weight, improved Basso-Beattie-Bresnahan (BBB) locomotor score, and intestinal movement were evaluated. Morphological structure of spinal cord and colon tissues were examined. Immunostaining, RT-PCR, and western blot were used to assess c-kit expression. Results In SCI rats, AMT could not restore BBB, but it significantly increased weight, shortened time to defecation, increased feces amounts, and improved fecal pellet traits and colon histology. AMT improved the number, distribution, and ultrastructure of colonic ICCs, increasing colonic c-kit mRNA and protein levels. Compared with the SCI + Drug and SCI + LMT groups, the SCI + HMT group showed better therapeutic effect in improving intestinal transmission function and promoting c-kit expression. Conclusions AMT is an effective therapy for recovery of intestinal transmission function. It could repair ICCs and increase c-kit expression in colon tissues after SCI, in a frequency-dependent and pressure-dependent manner. PMID:29349063

Indoxacarb, Metaflumizone, and Other Sodium Channel Inhibitor Insecticides: Mechanism and Site of Action on Mammalian Voltage-Gated Sodium Channels

PubMed Central

von Stein, Richard T.; Silver, Kristopher S.; Soderlund, David M.

2013-01-01

Sodium channel inhibitor (SCI) insecticides were discovered almost four decades ago but have only recently yielded important commercial products (eg., indoxacarb and metaflumizone). SCI insecticides inhibit sodium channel function by binding selectively to slow-inactivated (non-conducting) sodium channel states. Characterization of the action of SCI insecticides on mammalian sodium channels using both biochemical and electrophysiological approaches demonstrates that they bind at or near a drug receptor site, the "local anesthetic (LA) receptor." This mechanism and site of action on sodium channels differentiates SCI insecticides from other insecticidal agents that act on sodium channels. However, SCI insecticides share a common mode of action with drugs currently under investigation as anticonvulsants and treatments for neuropathic pain. In this paper we summarize the development of the SCI insecticide class and the evidence that this structurally diverse group of compounds have a common mode of action on sodium channels. We then review research that has used site-directed mutagenesis and heterologous expression of cloned mammalian sodium channels in Xenopus laevis oocytes to further elucidate the site and mechanism of action of SCI insecticides. The results of these studies provide new insight into the mechanism of action of SCI insecticides on voltage-gated sodium channels, the location of the SCI insecticide receptor, and its relationship to the LA receptor that binds therapeutic SCI agents. PMID:24072940

Development and psychometric characteristics of the SCI-QOL Pressure Ulcers scale and short form

PubMed Central

Kisala, Pamela A.; Tulsky, David S.; Choi, Seung W.; Kirshblum, Steven C.

2015-01-01

Objective To develop a self-reported measure of the subjective impact of pressure ulcers on health-related quality of life (HRQOL) in individuals with spinal cord injury (SCI) as part of the SCI quality of life (SCI-QOL) measurement system. Design Grounded-theory based qualitative item development methods, large-scale item calibration testing, confirmatory factor analysis (CFA), and item response theory-based psychometric analysis. Setting Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Participants Adults with traumatic SCI. Main Outcome Measures SCI-QOL Pressure Ulcers scale. Results 189 individuals with traumatic SCI who experienced a pressure ulcer within the past 7 days completed 30 items related to pressure ulcers. CFA confirmed a unidimensional pool of items. IRT analyses were conducted. A constrained Graded Response Model with a constant slope parameter was used to estimate item thresholds for the 12 retained items. Conclusions The 12-item SCI-QOL Pressure Ulcers scale is unique in that it is specifically targeted to individuals with spinal cord injury and at every stage of development has included input from individuals with SCI. Furthermore, use of CFA and IRT methods provide flexibility and precision of measurement. The scale may be administered in its entirety or as a 7-item “short form” and is available for both research and clinical practice. PMID:26010965

Performance of the SciBar cosmic ray telescope (SciCRT) toward the detection of high-energy solar neutrons in solar cycle 24

NASA Astrophysics Data System (ADS)

Sasai, Yoshinori; Nagai, Yuya; Itow, Yoshitaka; Matsubara, Yutaka; Sako, Takashi; Lopez, Diego; Itow, Tsukasa; Munakata, Kazuoki; Kato, Chihiro; Kozai, Masayoshi; Miyazaki, Takahiro; Shibata, Shoichi; Oshima, Akitoshi; Kojima, Hiroshi; Tsuchiya, Harufumi; Watanabe, Kyoko; Koi, Tatsumi; Valdés-Galicia, Jose Francisco; González, Luis Xavier; Ortiz, Ernesto; Musalem, Octavio; Hurtado, Alejandro; Garcia, Rocio; Anzorena, Marcos

2014-12-01

We plan to observe solar neutrons at Mt. Sierra Negra (4,600 m above sea level) in Mexico using the SciBar detector. This project is named the SciBar Cosmic Ray Telescope (SciCRT). The main aims of the SciCRT project are to observe solar neutrons to study the mechanism of ion acceleration on the surface of the sun and to monitor the anisotropy of galactic cosmic-ray muons. The SciBar detector, a fully active tracker, is composed of 14,848 scintillator bars, whose dimension is 300 cm × 2.5 cm × 1.3 cm. The structure of the detector enables us to obtain the particle trajectory and its total deposited energy. This information is useful for the energy reconstruction of primary neutrons and particle identification. The total volume of the detector is 3.0 m × 3.0 m × 1.7 m. Since this volume is much larger than the solar neutron telescope (SNT) in Mexico, the detection efficiency of the SciCRT for neutrons is highly enhanced. We performed the calibration of the SciCRT at Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) located at 2,150 m above sea level in Mexico in 2012. We installed the SciCRT at Mt. Sierra Negra in April 2013 and calibrated this detector in May and August 2013. We started continuous observation in March 2014. In this paper, we report the detector performance as a solar neutron telescope and the current status of the SciCRT.

Spinal Cord Injury Causes Chronic Liver Pathology in Rats

PubMed Central

Sauerbeck, Andrew D.; Laws, J. Lukas; Bandaru, Veera V.R.; Popovich, Phillip G.; Haughey, Norman J.

2015-01-01

Abstract Traumatic spinal cord injury (SCI) causes major disruption to peripheral organ innervation and regulation. Relatively little work has investigated these post-SCI systemic changes, however, despite considerable evidence that multiple organ system dysfunction contributes to chronic impairments in health. Because metabolic dysfunction is common after SCI and the liver is a pivotal site for metabolic homeostasis, we sought to determine if liver pathology occurs as a result of SCI in a rat spinal contusion model. Histologic evidence showed excess lipid accumulation in the liver for at least 21 days post-injury after cervical or midthoracic SCI. Lipidomic analysis revealed an acute increase in hepatic ceramides as well as chronically elevated lactosylceramide. Post-SCI hepatic changes also included increased proinflammatory gene expression, including interleukin (IL)-1α, IL-1β, chemokine ligand-2, and tumor necrosis factor-α mRNA. These were coincident with increased CD68+ macrophages in the liver through 21 days post-injury. Serum alanine transaminase, used clinically to detect liver damage, was significantly increased at 21 days post-injury, suggesting that early metabolic and inflammatory damage preceded overt liver pathology. Surprisingly, liver inflammation was even detected after lumbar SCI. Collectively, these results suggest that SCI produces chronic liver injury with symptoms strikingly similar to those of nonalcoholic steatohepatitis (fatty liver disease). These clinically significant hepatic changes after SCI are known to contribute to systemic inflammation, cardiovascular disease, and metabolic syndrome, all of which are more prevalent in persons with SCI. Targeting acute and prolonged hepatic pathology may improve recovery and reduce long-term complications after SCI. PMID:25036371

Valproic Acid Increases Expression of Neuronal Stem/Progenitor Cell in Spinal Cord Injury

PubMed Central

Bang, Woo-Seok; Cho, Dae-Chul; Kim, Hye-Jeong; Sung, Joo-Kyung

2013-01-01

Objective This study investigates the effect of valproic acid (VPA) on expression of neural stem/progenitor cells (NSPCs) in a rat spinal cord injury (SCI) model. Methods Adult male rats (n=24) were randomly and blindly allocated into three groups. Laminectomy at T9 was performed in all three groups. In group 1 (sham), only laminectomy was performed. In group 2 (SCI-VPA), the animals received a dose of 200 mg/kg of VPA. In group 3 (SCI-saline), animals received 1.0 mL of the saline vehicle solution. A modified aneurysm clip with a closing force of 30 grams was applied extradurally around the spinal cord at T9, and then rapidly released with cord compression persisting for 2 minutes. The rats were sacrificed and the spinal cord were collected one week after SCI. Immunohistochemistry (IHC) and western blotting sample were obtained from 5 mm rostral region to the lesion and prepared. We analyzed the nestin immunoreactivity from the white matter of ventral cord and the ependyma of central canal. Nestin and SOX2 were used for markers for NSPCs and analyzed by IHC and western blotting, respectively. Results Nestin and SOX2 were expressed significantly in the SCI groups but not in the sham group. Comparing SCI groups, nestin and SOX2 expression were much stronger in SCI-VPA group than in SCI-saline group. Conclusion Nestin and SOX2 as markers for NSPCs showed increased expression in SCI-VPA group in comparison with SCI-saline group. This result suggests VPA increases expression of spinal NSPCs in SCI. PMID:24044073

Effect of lycopene on the blood-spinal cord barrier after spinal cord injury in mice.

PubMed

Zhang, Qian; Wang, Jianbo; Gu, Zhengsong; Zhang, Qing; Zheng, Hong

2016-09-05

The current study aimed to investigate the effect of lycopene on the blood-spinal cord barrier (BSCB) after spinal cord injury (SCI) in a mouse model. Lycopene inhibited lipid peroxidation and oxidative DNA damage as a highly efficient antioxidant and free radical scavenger. Lycopene (4 mg/kg/d) was administrated immediately following SCI. The permeability of the BSCB and water content in the spinal cord tissue were evaluated. Additionally, levels of expression of tight junction proteins and heme oxygenase-1 (HO-1) were determined with Western blotting. An enzyme-linked immunosorbent assay analysis of spinal cord tissue homogenates was performed 48 h after SCI to evaluate the expression of inflammation-related cytokines. In addition, recovery of motor function was assessed 1 d, 2 d, 5 d, 10 d, and 15 d after SCI using the Basso Mouse Scale to score locomotion. Compared to the group with an untreated SCI, mice with an SCI treated with lycopene had significantly reduced spinal cord tissue water content and BSCB permeability. Furthermore, motor function of mice with an SCI was also greatly improved by lycopene administration. The expression of the proinflammatory factors TNF-α and NF-kB increased markedly 48 h after SCI, and their upregulation was significantly attenuated by lycopene treatment. The expression of molecules that protect tight junctions, zonula occluden-1 and claudin-5, was upregulated by lycopene treatment after SCI. Taken together, these results clearly indicate that lycopene attenuated SCI by promoting repair of the damaged BSCB, so lycopene is a novel and promising treatment for SCI in humans.

GeoSciML v3.0 - a significant upgrade of the CGI-IUGS geoscience data model

NASA Astrophysics Data System (ADS)

Raymond, O.; Duclaux, G.; Boisvert, E.; Cipolloni, C.; Cox, S.; Laxton, J.; Letourneau, F.; Richard, S.; Ritchie, A.; Sen, M.; Serrano, J.-J.; Simons, B.; Vuollo, J.

2012-04-01

GeoSciML version 3.0 (http://www.geosciml.org), released in late 2011, is the latest version of the CGI-IUGS* Interoperability Working Group geoscience data interchange standard. The new version is a significant upgrade and refactoring of GeoSciML v2 which was released in 2008. GeoSciML v3 has already been adopted by several major international interoperability initiatives, including OneGeology, the EU INSPIRE program, and the US Geoscience Information Network, as their standard data exchange format for geoscience data. GeoSciML v3 makes use of recently upgraded versions of several Open Geospatial Consortium (OGC) and ISO data transfer standards, including GML v3.2, SWE Common v2.0, and Observations and Measurements v2 (ISO 19156). The GeoSciML v3 data model has been refactored from a single large application schema with many packages, into a number of smaller, but related, application schema modules with individual namespaces. This refactoring allows the use and future development of modules of GeoSciML (eg; GeologicUnit, GeologicStructure, GeologicAge, Borehole) in smaller, more manageable units. As a result of this refactoring and the integration with new OGC and ISO standards, GeoSciML v3 is not backwardly compatible with previous GeoSciML versions. The scope of GeoSciML has been extended in version 3.0 to include new models for geomorphological data (a Geomorphology application schema), and for geological specimens, geochronological interpretations, and metadata for geochemical and geochronological analyses (a LaboratoryAnalysis-Specimen application schema). In addition, there is better support for borehole data, and the PhysicalProperties model now supports a wider range of petrophysical measurements. The previously used CGI_Value data type has been superseded in favour of externally governed data types provided by OGC's SWE Common v2 and GML v3.2 data standards. The GeoSciML v3 release includes worked examples of best practice in delivering geochemical analytical data using the Observations and Measurements (ISO19156) and SWE Common v2 models. The GeoSciML v3 data model does not include vocabularies to support the data model. However, it does provide a standard pattern to reference controlled vocabulary concepts using HTTP-URIs. The international GeoSciML community has developed distributed RDF-based geoscience vocabularies that can be accessed by GeoSciML web services using the standard pattern recommended in GeoSciML v3. GeoSciML v3 is the first version of GeoSciML that will be accompanied by web service validation tools using Schematron rules. For example, these validation tools may check for compliance of a web service to a particular profile of GeoSciML, or for logical consistency of data content that cannot be enforced by the application schemas. This validation process will support accreditation of GeoSciML services and a higher degree of semantic interoperability. * International Union of Geological Sciences Commission for Management and Application of Geoscience Information (CGI-IUGS)

Measuring Meaningful Outcomes in Consequential Contexts: Searching for a Happy Medium in Educational Technology Research (Phase II)

ERIC Educational Resources Information Center

Ross, Steven M.; Morrison, Jennifer R.

2014-01-01

In a paper published 25 years ago, Ross and Morrison ("Educ Technol Res Dev" 37(1):19-33, 1989) called for a "happy medium" in educational technology research, to be achieved by balancing high rigor of studies (internal validity) with relevance to real-world applications (external validity). In this paper, we argue that,…

AGARD Index of Publications, 1977 - 1979.

DTIC Science & Technology

1980-08-01

therefore, experimental verification of calculation Walter Schutz In AGARD Fracture Mach Design Methodology methods, hypotheses etc. is very time...2-. 3-. or 4-D navigation initial stages of preliminary design analysis The state of the art systems and allows experimental or theoretical...Technol. on Weapons Systems Design Dot. 1978 1ES WITH WINGS NON -LEVEL 23 01 AERONAUTICS (GENERAL) J Stanley Ausman In AGARD The Impact of Integrated

Thromboelastography to Direct the Administration of Recombinant Activated Factor VII in a Child with Traumatic Injury Requiring Massive Transfusion

DTIC Science & Technology

2009-01-01

in a child with hemophilia and high titer inhibitors to factor VIII: A case report and brief review. J Extra Cor- por Technol 2006; 38:254–259 16...J Trauma 1969; 9:939–965 20. Sorensen B, Ingerslev J: Thromboelastogra- phy and recombinant factor VIIa- hemophilia and beyond. Semin Hematol 2004; 41

LLCySA: Making Sense of Cyberspace

DTIC Science & Technology

2014-01-01

data center. His other activities include the development of immersive 3D environments leveraging video- game technology to provide a multiplayer ...exploring data-driven approaches to network protection. Imagine a cyber analyst navigating a three-dimen- sional (3D) game , walking down virtual office...because of information overload. One approach to this challenge leverages technol- ogy utilized in the 3D gaming industry. The video- game medium

Research in Technology Education: Looking Back to Move Forward … Again

ERIC Educational Resources Information Center

Williams, P. John

2016-01-01

In 2013 I published, in this Journal, a review of journals and conference publications in Technology Education from 2006 to 2010 as one measure of the nature of research that was being conducted in the area (Williams in "Int J Technol Des Educ" 23(1):1-9, 2013). An element of that review was a prediction of trends, from the findings, to…

2012 NRL Review: Building a Workforce and Assembling Scientific Tools for the Future

DTIC Science & Technology

2012-01-01

fiber optics, electro-optics, microelectronics, fracture mechan ics, vacuum science, laser phys ics and joining technol ogy, and radio frequen cy...ics, elastic/plastic fracture mechanics , materials, finite-element methods, nondestruc tive evalua tion, characterization of fracture resistance of...NRL Review chapter entitled “Programs for Professional Development.” For additional information about NRL, the NRL Fact Book lists the organizations

JPRS Report, Science & Technology, Europe

DTIC Science & Technology

1992-02-18

could penetrate the ceramic layer. At the time, the Essen researchers were unable to present any proof of the obvious assumption that microfine pores...carbon fiber tubes and titanium frame joints that are very light and strong. The manufacturing system and experiments are installed as modules on...study also view the manufacturing technol- ogies and jointing techniques for active cooling with an integrated cooling tube system as unavailable—pure

Health behavior in persons with spinal cord injury: development and initial validation of an outcome measure.

PubMed

Pruitt, S D; Wahlgren, D R; Epping-Jordan, J E; Rossi, A L

1998-10-01

To describe the development and initial psychometric properties of a new outcome measure for health behaviors that delay or prevent secondary impairments associated with spinal cord injury (SCI). Persons with SCI were surveyed during routine annual physical evaluations. Veterans Affairs Medical Center Spinal Cord Injury Unit, which specializes in primary care for persons with SCI. Forty-nine persons with SCI, aged 19-73 years, 1-50 years post-SCI. The newly developed Spinal Cord Injury Lifestyle Scale (SCILS). Internal consistency is high (alpha = 0.81). Correlations between clinicians' ratings of participants' health behavior and the new SCILS provide preliminary support for construct validity. The SCILS is a brief, self-report measure of health-related behavior in persons with SCI. It is a promising new outcome measure to evaluate the effectiveness of clinical and educational efforts for health maintenance and prevention of secondary impairments associated with SCI.

Clinical interpretation of the Spinal Cord Injury Functional Index (SCI-FI).

PubMed

Fyffe, Denise; Kalpakjian, Claire Z; Slavin, Mary; Kisala, Pamela; Ni, Pengsheng; Kirshblum, Steven C; Tulsky, David S; Jette, Alan M

2016-09-01

To provide validation of functional ability levels for the Spinal Cord Injury - Functional Index (SCI-FI). Cross-sectional. Inpatient rehabilitation hospital and community settings. A sample of 855 individuals with traumatic spinal cord injury enrolled in 6 rehabilitation centers participating in the National Spinal Cord Injury Model Systems Network. Not Applicable. Spinal Cord Injury-Functional Index (SCI-FI). Cluster analyses identified three distinct groups that represent low, mid-range and high SCI-FI functional ability levels. Comparison of clusters on personal and other injury characteristics suggested some significant differences between groups. These results strongly support the use of SCI-FI functional ability levels to document the perceived functional abilities of persons with SCI. Results of the cluster analysis suggest that the SCI-FI functional ability levels capture function by injury characteristics. Clinical implications regarding tracking functional activity trajectories during follow-up visits are discussed.

Measurement of Bone: Diagnosis of SCI-Induced Osteoporosis and Fracture Risk Prediction

PubMed Central

Morse, Leslie R.

2015-01-01

Background: Spinal cord injury (SCI) is associated with a rapid loss of bone mass, resulting in severe osteoporosis and a 5- to 23-fold increase in fracture risk. Despite the seriousness of fractures in SCI, there are multiple barriers to osteoporosis diagnosis and wide variations in treatment practices for SCI-induced osteoporosis. Methods: We review the biological and structural changes that are known to occur in bone after SCI in the context of promoting future research to prevent or reduce risk of fracture in this population. We also review the most commonly used methods for assessing bone after SCI and discuss the strengths, limitations, and clinical applications of each method. Conclusions: Although dual-energy x-ray absorptiometry assessments of bone mineral density may be used clinically to detect changes in bone after SCI, 3-dimensional methods such as quantitative CT analysis are recommended for research applications and are explained in detail. PMID:26689691

The CanPain SCI Clinical Practice Guidelines for Rehabilitation Management of Neuropathic Pain after Spinal Cord: screening and diagnosis recommendations.

PubMed

Mehta, S; Guy, S D; Bryce, T N; Craven, B C; Finnerup, N B; Hitzig, S L; Orenczuk, S; Siddall, P J; Widerström-Noga, E; Casalino, A; Côté, I; Harvey, D; Kras-Dupuis, A; Lau, B; Middleton, J W; Moulin, D E; O'Connell, C; Parrent, A G; Potter, P; Short, C; Teasell, R; Townson, A; Truchon, C; Wolfe, D; Bradbury, C L; Loh, E

2016-08-01

Clinical practice guidelines. To develop the first Canadian clinical practice guidelines for screening and diagnosis of neuropathic pain in people with spinal cord injury (SCI). The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. The CanPainSCI Working Group reviewed evidence to address clinical questions regarding screening and diagnosis of neuropathic pain after SCI. A consensus process was followed to achieve agreement on recommendations and clinical considerations. Twelve recommendations, based on expert consensus, were developed for the screening and diagnosis of neuropathic pain after SCI. The recommendations address methods for assessment, documentation tools, team member accountability, frequency of screening and considerations for diagnostic investigation. Important clinical considerations accompany each recommendation. The expert Working Group developed recommendations for the screening and diagnosis of neuropathic pain after SCI that should be used to inform practice.

Measurement of Bone: Diagnosis of SCI-Induced Osteoporosis and Fracture Risk Prediction.

PubMed

Troy, Karen L; Morse, Leslie R

2015-01-01

Spinal cord injury (SCI) is associated with a rapid loss of bone mass, resulting in severe osteoporosis and a 5- to 23-fold increase in fracture risk. Despite the seriousness of fractures in SCI, there are multiple barriers to osteoporosis diagnosis and wide variations in treatment practices for SCI-induced osteoporosis. We review the biological and structural changes that are known to occur in bone after SCI in the context of promoting future research to prevent or reduce risk of fracture in this population. We also review the most commonly used methods for assessing bone after SCI and discuss the strengths, limitations, and clinical applications of each method. Although dual-energy x-ray absorptiometry assessments of bone mineral density may be used clinically to detect changes in bone after SCI, 3-dimensional methods such as quantitative CT analysis are recommended for research applications and are explained in detail.

SciLinks

Science.gov Websites

SciLinks Forgot your login? Sign up for FREE access Log In I'm a ... Teacher Student User Name questions and satisfy their curiosity Learn More Sign up for Free Access Sites in the SciLinks program . SciLinks-Targeted, Grade-Specific Web Content for your Books Free web content to extend and expand student

DoD-Wide Intelligence Career Development Program. General Intelligence Personnel

DTIC Science & Technology

1988-07-01

Science ASTRONMY /SPACE SCI Ballistics BALLISTCS Cartography CARTOGRY Cartographic Technician CARTOGR TECH Chemistry/Biochemistry CHEMSTRY/BIOCHEMSTRY...ARCHVST ....................... 4-63 E&E ............................ 4-60 ASTRONMY /SPACE SCI ........... 4-69 ECONMCS ....................... 4-75 AUTO...SPACE SCI-see ASTRONMY / OB-NAV ......................... 4-54 SPACE SCI OCEANOGY ..................... 4-70 SPACE SYS-ENGR ................ 4-48 OFC

The Structured Clinical Interview for DSM-5 Internet Gaming Disorder: Development and Validation for Diagnosing IGD in Adolescents

PubMed Central

Koo, Hoon Jung; Han, Doug Hyun; Park, Sung-Yong

2017-01-01

Objective This study aimed to develop and validate a Structured Clinical Interview for Internet Gaming Disorder (SCI-IGD) in adolescents. Methods First, we generated preliminary items of the SCI-IGD based on the information from the DSM-5 literature reviews and expert consultations. Next, a total of 236 adolescents, from both community and clinical settings, were recruited to evaluate the psychometric properties of the SCI-IGD. Results First, the SCI-IGD was found to be consistent over the time period of about one month. Second, diagnostic concordances between the SCI-IGD and clinician's diagnostic impression were good to excellent. The Likelihood Ratio Positive and the Likelihood Ratio Negative estimates for the diagnosis of SCI-IGD were 10.93 and 0.35, respectively, indicating that SCI-IGD was ‘very useful test’ for identifying the presence of IGD and ‘useful test’ for identifying the absence of IGD. Third, SCI-IGD could identify disordered gamers from non-disordered gamers. Conclusion The implications and limitations of the study are also discussed. PMID:28096871

Physical Activity Inventory for Patients with Spinal Cord Injury

PubMed Central

Butler, Jolene A.; Miller, Terrya; O’Connell, Susan; Jelinek, Christine; Collins, Eileen G.

2010-01-01

Objectives To test the reliability and validity of a physical activity instrument adapted for individuals with spinal cord injuries (SCI), the Physical Activity Instrument-SCI (PAI-SCI). Methods Eligible participants completed the adapted PAI-SCI questionnaire at baseline and 1 week later. At baseline, they were also given an Actical accelerometer to wear on their wrist for 1 week. Results Forty-three male subjects completed the study. There was a moderate relationship between total score on the PAI-SCI and total activity count determined by accelerometry (r = 0.42, P = 0.036). The PAI-SCI was able to differentiate between people with upper and lower level injuries (P = 0.05). Test-retest reliability was supported for the exercise and the general activity/self care subscales and not supported for the light household or the outdoor/gardening subscales. Conclusion The PAI-SCI was able to distinguish between physical activity amongst those with upper level and lower level injuries. More research is needed before the PAI-SCI can be recommended for use in clinical trials. PMID:25190905

The Correlation of Gene Expression of Inflammasome Indicators and Impaired Fertility in Rat Model of Spinal Cord Injury: A Time Course Study.

PubMed

Nikmehr, Banafsheh; Bazrafkan, Mahshid; Hassanzadeh, Gholamreza; Shahverdi, Abdolhossein; Sadighi Gilani, Mohammad Ali; Kiani, Sahar; Mokhtari, Tahmineh; Abolhassani, Farid

2017-11-04

Expression assessment of the inflammasome genes in the acute and the chronic phases of Spinal cord injury (SCI) on adult rat testis and examination of associations between inflammasome complex expression and sperm parameters. In this study, 25 adult male rats were randomly divided into 5 groups. SCI surgery was performed at T10-T11 level of rats' spinal cord in four groups (SCI1, SCI3, SCI7, and SCI56). They were sacrificed after 1day, 3days, 7days and 56 days post SCI, respectively. One group remained intact as control (Co).CASA analysis of sperm parameters and qRT-PCR (ASC and Caspase-1) were made in all cases. Our data showed a severe reduction in sperm count and motility, especially on day 3 and 7. ASC gene expression had a non-significant increase on day 1 and 56 after surgery compared to control group. Caspase-1 expression increased significantly on day 3 post injury versus the control group (P = .009). Moreover, Caspase-1 overexpression, had significant correlations with sperm count (r = -0.555, P = .01) and sperm progressive motility (r = -0.524, P = .02). Inflammasome complex expression increase following SCI induction. This overexpression correlates to low sperm parameters in SCI rats.

Development and initial evaluation of the SCI-FI/AT

PubMed Central

Jette, Alan M.; Slavin, Mary D.; Ni, Pengsheng; Kisala, Pamela A.; Tulsky, David S.; Heinemann, Allen W.; Charlifue, Susie; Tate, Denise G.; Fyffe, Denise; Morse, Leslie; Marino, Ralph; Smith, Ian; Williams, Steve

2015-01-01

Objectives To describe the domain structure and calibration of the Spinal Cord Injury Functional Index for samples using Assistive Technology (SCI-FI/AT) and report the initial psychometric properties of each domain. Design Cross sectional survey followed by computerized adaptive test (CAT) simulations. Setting Inpatient and community settings. Participants A sample of 460 adults with traumatic spinal cord injury (SCI) stratified by level of injury, completeness of injury, and time since injury. Interventions None Main outcome measure SCI-FI/AT Results Confirmatory factor analysis (CFA) and Item response theory (IRT) analyses identified 4 unidimensional SCI-FI/AT domains: Basic Mobility (41 items) Self-care (71 items), Fine Motor Function (35 items), and Ambulation (29 items). High correlations of full item banks with 10-item simulated CATs indicated high accuracy of each CAT in estimating a person's function, and there was high measurement reliability for the simulated CAT scales compared with the full item bank. SCI-FI/AT item difficulties in the domains of Self-care, Fine Motor Function, and Ambulation were less difficult than the same items in the original SCI-FI item banks. Conclusion With the development of the SCI-FI/AT, clinicians and investigators have available multidimensional assessment scales that evaluate function for users of AT to complement the scales available in the original SCI-FI. PMID:26010975

Walking in water and on land after an incomplete spinal cord injury.

PubMed

Tamburella, Federica; Scivoletto, Giorgio; Cosentino, Elena; Molinari, Marco

2013-10-01

Although no data are available on the effects of water environment on the gait of subjects with spinal cord injury (SCI), hydrotherapy is used in the rehabilitation protocols of SCI patients. The aim of this study was to characterize gait features of subjects with incomplete SCI walking in water and on land in comparison with healthy controls (CTRLs) to identify the specificity of water environment on influencing gait in SCI subjects. This is a matched case-control study. Kinematic gait parameters and range of motion of joint angles of 15 SCI subjects and 15 CTRLs were analyzed. Compared with gait on land, gait in water of the SCI patients was characterized by speed and stance phase reduction, gait cycle time increment, and invariance of stride length and range of motion values. Comparison with CTRL data remarked that walking in water reduces gait differences between the groups. Furthermore, in water, the SCI subjects presented a reduction in variability of the hip and knee joint angles, whereas in the CTRLs, a larger variability was observed. Gait in water of the SCI subjects is associated with kinematic parameters more similar to those of the CTRLs, particularly regarding speed, stride length, and stance phase, supporting the idea that walking in a water environment may be of rehabilitative significance for SCI subjects.

SCY-635, a Novel Nonimmunosuppressive Analog of Cyclosporine That Exhibits Potent Inhibition of Hepatitis C Virus RNA Replication In Vitro ▿ †

PubMed Central

Hopkins, Sam; Scorneaux, Bernard; Huang, Zhuhui; Murray, Michael G.; Wring, Stephen; Smitley, Craig; Harris, Richard; Erdmann, Frank; Fischer, Gunter; Ribeill, Yves

2010-01-01

SCY-635 is a novel nonimmunosuppressive cyclosporine-based analog that exhibits potent suppression of hepatitis C virus (HCV) replication in vitro. SCY-635 inhibited the peptidyl prolyl isomerase activity of cyclophilin A at nanomolar concentrations but showed no detectable inhibition of calcineurin phosphatase activity at concentrations up to 2 μM. Metabolic studies indicated that SCY-635 did not induce the major cytochrome P450 enzymes 1A2, 2B6, and 3A4. SCY-635 was a weak inhibitor and a poor substrate for P-glycoprotein. Functional assays with stimulated Jurkat cells and stimulated human peripheral blood mononuclear cells indicated that SCY-635 is a weaker inhibitor of interleukin-2 secretion than cyclosporine. A series of two-drug combination studies was performed in vitro. SCY-635 exhibited synergistic antiviral activity with alpha interferon 2b and additive antiviral activity with ribavirin. SCY-635 was shown to be orally bioavailable in multiple animal species and produced blood and liver concentrations of parent drug that exceeded the 50% effective dose determined in the bicistronic con1b-derived replicon assay. These results suggest that SCY-635 warrants further investigation as a novel therapeutic agent for the treatment of individuals who are chronically infected with HCV. PMID:19933795

Development and initial evaluation of the SCI-FI/AT.

PubMed

Jette, Alan M; Slavin, Mary D; Ni, Pengsheng; Kisala, Pamela A; Tulsky, David S; Heinemann, Allen W; Charlifue, Susie; Tate, Denise G; Fyffe, Denise; Morse, Leslie; Marino, Ralph; Smith, Ian; Williams, Steve

2015-05-01

To describe the domain structure and calibration of the Spinal Cord Injury Functional Index for samples using Assistive Technology (SCI-FI/AT) and report the initial psychometric properties of each domain. Cross sectional survey followed by computerized adaptive test (CAT) simulations. Inpatient and community settings. A sample of 460 adults with traumatic spinal cord injury (SCI) stratified by level of injury, completeness of injury, and time since injury. None SCI-FI/AT RESULTS: Confirmatory factor analysis (CFA) and Item response theory (IRT) analyses identified 4 unidimensional SCI-FI/AT domains: Basic Mobility (41 items) Self-care (71 items), Fine Motor Function (35 items), and Ambulation (29 items). High correlations of full item banks with 10-item simulated CATs indicated high accuracy of each CAT in estimating a person's function, and there was high measurement reliability for the simulated CAT scales compared with the full item bank. SCI-FI/AT item difficulties in the domains of Self-care, Fine Motor Function, and Ambulation were less difficult than the same items in the original SCI-FI item banks. With the development of the SCI-FI/AT, clinicians and investigators have available multidimensional assessment scales that evaluate function for users of AT to complement the scales available in the original SCI-FI.

The Cross-Cultural Societal Response to SCI: Health and Related Systems.

PubMed

Pacheco, Diana; Gross-Hemmi, Mirja H

2017-02-01

The Learning Health System for Spinal Cord Injury (LHS-SCI) is an initiative aligned with the World Health Organization's (WHO) Global Disability Action Plan. Based on the outcomes of this initiative, countries will be able to shape their health systems to better respond to the needs of persons with SCI. This paper describes and compares the macroeconomic situation and societal response to SCI across 27 countries from all 6 WHO regions that will participate in the LHS-SCI initiative. A concurrent mixed-methods study was conducted to identify key indicators that describe the situation of persons with SCI, the general societal response, the health and rehabilitation system, and the experience for a SCI person after discharge from inpatient rehabilitation. A strong correlation was found between the efficiency of a healthcare system and the amount a country invests in health. Higher availability of resources does not necessarily imply that unrestricted access to the healthcare system is warranted. Variations in the health systems were found for various domains of the health and rehabilitation systems. The evaluation and comparative analysis of the societal response to SCI raise the awareness of the need of more standardized data to identify current needs and gaps in the quality and access to SCI-specific health system.

Effect of oxidative stress induced by intracranial iron overload on central pain after spinal cord injury.

PubMed

Meng, Fan Xing; Hou, Jing Ming; Sun, Tian Sheng

2017-02-08

Central pain (CP) is a common clinical problem in patients with spinal cord injury (SCI). Recent studies found the pathogenesis of CP was related to the remodeling of the brain. We investigate the roles of iron overload and subsequent oxidative stress in the remodeling of the brain after SCI. We established a rat model of central pain after SCI. Rats were divided randomly into four groups: SCI, sham operation, SCI plus deferoxamine (DFX) intervention, and SCI plus nitric oxide synthase (NOS) inhibitor treatment. Pain behavior was observed and thermal pain threshold was measured regularly, and brain levels of iron, transferrin receptor 1 (TfR1), ferritin (Fn), and lactoferrin (Lf), were detected in the different groups 12 weeks after establishment of the model. Rats demonstrated self-biting behavior after SCI. Furthermore, the latent period of thermal pain was reduced and iron levels in the hind limb sensory area, hippocampus, and thalamus increased after SCI. Iron-regulatory protein (IRP) 1 levels increased in the hind limb sensory area, while Fn levels decreased. TfR1 mRNA levels were also increased and oxidative stress was activated. Oxidative stress could be inhibited by ferric iron chelators and NOS inhibitors. SCI may cause intracranial iron overload through the NOS-iron-responsive element/IRP pathway, resulting in central pain mediated by the oxidative stress response. Iron chelators and oxidative stress inhibitors can effectively relieve SCI-associated central pain.

Spinal Cord Injury and Migraine Headache: A Population-Based Study

PubMed Central

Warner, Freda M.; Cragg, Jacquelyn J.; Weisskopf, Marc G.; Kramer, John K.

2015-01-01

Migraine headaches are a common neurological condition, negatively impacting health and quality of life. Among potential risk factors for migraine headache, risk of migraine headaches was elevated in individuals with spinal cord injury (SCI). The association between migraines and SCI is intriguing to consider from the perspective that migraine headaches may be acquired in response to damage in the spinal cord. The primary objective of this study was to further examine the association between SCI and migraine headache, controlling for potential confounding variables. A secondary objective was to determine the impact of migraine headaches on self-perceived health. Data from a sample of 61,047 participants were obtained from the cross-sectional Canadian Community Health Survey. Multivariable logistic regression was used to explore the association between SCI and migraine headache using probability weights and adjusting for confounders. The multivariable age- and sex-adjusted model revealed a strong association between SCI and migraine headache, with an adjusted odds ratio for migraine of 4.82 (95% confidence interval [3.02, 7.67]) among those with SCI compared to those without SCI. Further, individuals who experienced both SCI and migraine tended to report poorer perceived general health compared with the other groups (i.e., SCI and no migraine). In conclusion, this study established a strong association between SCI and migraine headache. Further research is needed to explore the possible mechanisms underlying this relationship. Improvements in clinical practice to minimize this issue could result in significant improvements in quality of life. PMID:26308549

Comparison of in vitro fertilization/intracytoplasmic sperm injection outcomes in male factor infertility patients with and without spinal cord injuries.

PubMed

Kathiresan, Anupama S Q; Ibrahim, Emad; Aballa, Teodoro C; Attia, George R; Ory, Steven J; Hoffman, David I; Maxson, Wayne S; Barrionuevo, Marcelo J; Lynne, Charles M; Brackett, Nancy L

2011-09-01

To determine if outcomes after in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) using sperm from men with spinal cord injury (SCI group) differ from those of other etiologies of male factor infertility (non-SCI group). In men with SCI, to determine if IVF/ICSI outcomes differ with sperm obtained by penile vibratory stimulation (PVS group) versus electroejaculation (EEJ group). Retrospective analysis. University medical center and major infertility center. Couples with male factor infertility due to SCI versus other etiologies. PVS, EEJ, surgical sperm retrieval, and IVF/ICSI. Rates of fertilization, pregnancy, and live birth. A total of 31 couples in the SCI group underwent 48 cycles of IVF/ICSI, and a total of 297 couples in the non-SCI group underwent 443 cycles of IVF/ICSI. The SCI group had lower fertilization rates but similar pregnancy and live birth rates compared with the non-SCI group. These rates, however, did not differ significantly when the PVS group was compared with the EEJ group. IVF/ICSI of sperm from men with SCI yield lower fertilization rates but similar pregnancy and live birth outcomes as IVF/ICSI of sperm from men with other etiologies of male factor infertility. Sperm collected by PVS versus EEJ in men with SCI appear to result in similar IVF/ICSI success rates. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Cognitive performance of people with traumatic spinal cord injury: a cross-sectional study comparing people with subacute and chronic injuries.

PubMed

Molina, B; Segura, A; Serrano, J P; Alonso, F J; Molina, L; Pérez-Borrego, Y A; Ugarte, M I; Oliviero, A

2018-02-22

Cross-sectional study. To assess the impact of spinal cord injury (SCI) on cognitive function in individuals with subacute and chronic SCI. National Hospital for SCI patients (Spain). The present investigation was designed to determine the nature, pattern, and extent of cognitive deficits in a group of participants with subacute (n = 32) and chronic (n = 34) SCI, using a comprehensive battery of reliable and validated neuropsychological assessments to study a broad range of cognitive functions. Twenty-seven able-bodied subjects matched to the groups with SCI for age and educational level formed the control group. The neuropsychological assessment showed alterations in the domain of attention, processing speed, memory and learning, executive functions, and in recognition in participants with SCI. The prevalence of cognitive dysfunction in the chronic stage was also confirmed at the individual level. The comparison of the neuropsychological assessment between the groups with subacute and chronic SCI showed a worsening of cognitive functions in those with chronic SCI compared to the group with subacute SCI. In participants with SCI, cognitive dysfunctions are present in the subacute stage and worsen over time. From a clinical point of view, we confirmed the presence of cognitive dysfunction that may interfere with the first stage of rehabilitation which is the most intense and important. Moreover, cognitive dysfunction may be important beyond the end of the first stage of rehabilitation as it can affect an individual's quality of life and possible integration to society.

Secretory expression and surface display of a new and biologically active single-chain insulin (SCI-59) analog by lactic acid bacteria.

PubMed

Mao, Ruifeng; Wu, Dongli; Hu, Shimeng; Zhou, Kangping; Wang, Man; Wang, Yefu

2017-04-01

Insulin plays an important role in drug therapies for diabetes mellitus and as the main route of insulin delivery, subcutaneous injection may cause local discomfort, hypoglycemia, hyperinsulinemia, and patient non-compliance. Therefore, oral delivery of insulin is more preferred. However, there is a low bioavailability due to insulin degradation by proteolytic enzymes and severe pH conditions along the gastrointestinal tract. In order to use the food-grade bacteria lactic acid bacteria (LAB) as oral delivery vehicles, a new and bioactive single-chain insulin (SCI-59) analog, containing the insulin B- and A-chains connected by an eight-residue linker (RSRGLPFR), was secretory expressed in Lactococcus lactis NZ3900 without using an antibiotic resistance gene and displayed onto the surface of various non-viable bacteria (NVBs) without genetic modification. Both the free SCI-59 and SCI-59 displayed on the surface of NVBs are biologically active as assayed by their ability to stimulate Akt signaling in differentiated 3T3-L1 adipocytes. Modification of the pH of the medium by NaOH addition at early time during induction can enhance the bioactivity of SCI-59. The C-terminal fused anchoring domain, three LysM repeats, does not affect the formation of disulfide bonds and/or the folding of SCI-59, and SCI-59 could be exposed properly and fully when SCI-59-3LysM bound to the surface of NVBs. Compared to the free form SCI-59, SCI-59 displayed on the surface of NVBs is more stable in simulate gastric juice. It may open new prospects for possible oral treatments of diabetes using live LAB secreting or NVBs carrying bioactive SCI analogs.

Natural Killer (NK) Cell Functionality after human Spinal Cord Injury (SCI): protocol of a prospective, longitudinal study.

PubMed

Laginha, Inês; Kopp, Marcel A; Druschel, Claudia; Schaser, Klaus-Dieter; Brommer, Benedikt; Hellmann, Rick C; Watzlawick, Ralf; Ossami-Saidi, Ramin-Raul; Prüss, Harald; Failli, Vieri; Meisel, Christian; Liebscher, Thomas; Prilipp, Erik; Niedeggen, Andreas; Ekkernkamp, Axel; Grittner, Ulrike; Piper, Sophie K; Dirnagl, Ulrich; Killig, Monica; Romagnani, Chiara; Schwab, Jan M

2016-09-13

Natural killer (NK) cells comprise the main components of lymphocyte-mediated nonspecific immunity. Through their effector function they play a crucial role combating bacterial and viral challenges. They are also thought to be key contributors to the systemic spinal cord injury-induced immune-deficiency syndrome (SCI-IDS). SCI-IDS increases susceptibility to infection and extends to the post-acute and chronic phases after SCI. The prospective study of NK cell function after traumatic SCI was carried out in two centers in Berlin, Germany. SCI patients and control patients with neurologically silent vertebral fracture also undergoing surgical stabilization were enrolled. Furthermore healthy controls were included to provide reference data. The NK cell function was assessed at 7 (5-9) days, 14 days (11-28) days, and 10 (8-12) weeks post-trauma. Clinical documentation included the American Spinal Injury Association (ASIA) impairment scale (AIS), neurological level of injury, infection status, concomitant injury, and medications. The primary endpoint of the study is CD107a expression by NK cells (cytotoxicity marker) 8-12 weeks following SCI. Secondary endpoints are the NK cell's TNF-α and IFN-γ production by the NK cells 8-12 weeks following SCI. The protocol of this study was developed to investigate the hypotheses whether i) SCI impairs NK cell function throughout the post-acute and sub-acute phases after SCI and ii) the degree of impairment relates to lesion height and severity. A deeper understanding of the SCI-IDS is crucial to enable strategies for prevention of infections, which are associated with poor neurological outcome and elevated mortality. DRKS00009855 .

Measuring depression after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Depression item bank and linkage with PHQ-9.

PubMed

Tulsky, David S; Kisala, Pamela A; Kalpakjian, Claire Z; Bombardier, Charles H; Pohlig, Ryan T; Heinemann, Allen W; Carle, Adam; Choi, Seung W

2015-05-01

To develop a calibrated spinal cord injury-quality of life (SCI-QOL) item bank, computer adaptive test (CAT), and short form to assess depressive symptoms experienced by individuals with SCI, transform scores to the Patient Reported Outcomes Measurement Information System (PROMIS) metric, and create a crosswalk to the Patient Health Questionnaire (PHQ)-9. We used grounded-theory based qualitative item development methods, large-scale item calibration field testing, confirmatory factor analysis, item response theory (IRT) analyses, and statistical linking techniques to transform scores to a PROMIS metric and to provide a crosswalk with the PHQ-9. Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. Spinal Cord Injury--Quality of Life (SCI-QOL) Depression Item Bank Individuals with SCI were involved in all phases of SCI-QOL development. A sample of 716 individuals with traumatic SCI completed 35 items assessing depression, 18 of which were PROMIS items. After removing 7 non-PROMIS items, factor analyses confirmed a unidimensional pool of items. We used a graded response IRT model to estimate slopes and thresholds for the 28 retained items. The SCI-QOL Depression measure correlated 0.76 with the PHQ-9. The SCI-QOL Depression item bank provides a reliable and sensitive measure of depressive symptoms with scores reported in terms of general population norms. We provide a crosswalk to the PHQ-9 to facilitate comparisons between measures. The item bank may be administered as a CAT or as a short form and is suitable for research and clinical applications.

B-Cell Maturation Antigen, A Proliferation-Inducing Ligand, and B-Cell Activating Factor Are Candidate Mediators of Spinal Cord Injury-Induced Autoimmunity

PubMed Central

Saltzman, Jonah W.; Battaglino, Ricardo A.; Salles, Loise; Jha, Prateek; Sudhakar, Supreetha; Garshick, Eric; Stott, Helen L.; Zafonte, Ross

2013-01-01

Abstract Autoimmunity is thought to contribute to poor neurological outcomes after spinal cord injury (SCI). There are few mechanism-based therapies, however, designed to reduce tissue damage and neurotoxicity after SCI because the molecular and cellular bases for SCI-induced autoimmunity are not completely understood. Recent groundbreaking studies in rodents indicate that B cells are responsible for SCI-induced autoimmunity. This novel paradigm, if confirmed in humans, could aid in the design of neuroprotective immunotherapies. The aim of this study was to investigate the molecular signaling pathways and mechanisms by which autoimmunity is induced after SCI, with the goal of identifying potential targets in therapies designed to reduce tissue damage and inflammation in the chronic phase of SCI. To that end, we performed an exploratory microarray analysis of peripheral blood mononuclear cells to identify differentially expressed genes in chronic SCI. We identified a gene network associated with lymphoid tissue structure and development that was composed of 29 distinct molecules and five protein complexes, including two cytokines, a proliferation-inducing ligand (APRIL) and B-cell–activating factor (BAFF), and one receptor, B-cell maturation antigen (BMCA) involved in B cell development, proliferation, activation, and survival. Real-time polymerase chain reaction analysis from ribonucleic acid samples confirmed upregulation of these three genes in SCI. To our knowledge, this is the first report that peripheral blood mononuclear cells produce increased levels of BAFF and APRIL in chronic SCI. This finding provides evidence of systemic regulation of SCI-autoimmunity via APRIL and BAFF mediated activation of B cells through BMCA and points toward these molecules as potential targets of therapies designed to reduce neuroinflammation after SCI. PMID:23088438

Characterization of the Antibody Response after Cervical Spinal Cord Injury

PubMed Central

Ulndreaj, Antigona; Tzekou, Apostolia; Mothe, Andrea J.; Siddiqui, Ahad M.; Dragas, Rachel; Tator, Charles H.; Torlakovic, Emina E.

2017-01-01

Abstract The immune system plays a critical and complex role in the pathobiology of spinal cord injury (SCI), exerting both beneficial and detrimental effects. Increasing evidence suggests that there are injury level–dependent differences in the immune response to SCI. Patients with traumatic SCI have elevated levels of circulating autoantibodies against components of the central nervous system, but the role of these antibodies in SCI outcomes remains unknown. In rodent models of mid-thoracic SCI, antibody-mediated autoimmunity appears to be detrimental to recovery. However, whether autoantibodies against the spinal cord are generated following cervical SCI (cSCI), the most common level of injury in humans, remains undetermined. To address this knowledge gap, we investigated the antibody responses following cSCI in a rat model of injury. We found increased immunoglobulin G (IgG) and IgM antibodies in the spinal cord in the subacute phase of injury (2 weeks), but not in more chronic phases (10 and 20 weeks). At 2 weeks post-cSCI, antibodies were detected at the injury epicenter and co-localized with the astroglial scar and neurons of the ventral horn. These increased levels of antibodies corresponded with enhanced activation of immune responses in the spleen. Higher counts of antibody-secreting cells were observed in the spleen of injured rats. Further, increased levels of secreted IgG antibodies and enhanced proliferation of T-cells in splenocyte cultures from injured rats were found. These findings suggest the potential development of autoantibody responses following cSCI in the rat. The impact of the post-traumatic antibody responses on functional outcomes of cSCI is a critical topic that requires further investigation. PMID:27775474

Exercise modulates chloride homeostasis after spinal cord injury.

PubMed

Côté, Marie-Pascale; Gandhi, Sapan; Zambrotta, Marina; Houlé, John D

2014-07-02

Activity-based therapies are routinely integrated in spinal cord injury (SCI) rehabilitation programs because they result in a reduction of hyperreflexia and spasticity. However, the mechanisms by which exercise regulates activity in spinal pathways to reduce spasticity and improve functional recovery are poorly understood. Persisting alterations in the action of GABA on postsynaptic targets is a signature of CNS injuries, including SCI. The action of GABA depends on the intracellular chloride concentration, which is determined largely by the expression of two cation-chloride cotransporters (CCCs), KCC2 and NKCC1, which serve as chloride exporters and importers, respectively. We hypothesized that the reduction in hyperreflexia with exercise after SCI relies on a return to chloride homeostasis. Sprague Dawley rats received a spinal cord transection at T12 and were assigned to SCI-7d, SCI-14d, SCI-14d+exercise, SCI-28d, SCI-28d+exercise, or SCI-56d groups. During a terminal experiment, H-reflexes were recorded from interosseus muscles after stimulation of the tibial nerve and the low-frequency-dependent depression (FDD) was assessed. We provide evidence that exercise returns spinal excitability and levels of KCC2 and NKCC1 toward normal levels in the lumbar spinal cord. Acutely altering chloride extrusion using the KCC2 blocker DIOA masked the effect of exercise on FDD, whereas blocking NKCC1 with bumetanide returned FDD toward intact levels after SCI. Our results indicate that exercise contributes to reflex recovery and restoration of endogenous inhibition through a return to chloride homeostasis after SCI. This lends support for CCCs as part of a pathway that could be manipulated to improve functional recovery when combined with rehabilitation programs. Copyright © 2014 the authors 0270-6474/14/348976-12$15.00/0.

(-)-Epigallocatechin-3-gallate (EGCG) modulates neurological function when intravenously infused in acute and, chronically injured spinal cord of adult rats.

PubMed

Renno, Waleed M; Al-Khaledi, Ghanim; Mousa, Alyaa; Karam, Shaima M; Abul, Habib; Asfar, Sami

2014-02-01

Spinal cord injury (SCI) causes severe and long lasting motor and sensory deficits, chronic pain, and autonomic dysreflexia. (-)-epigallocatechin-3-gallate (EGCG) has shown to produce neuroprotective effect in a broad range of neurodegenerative disease animal models. This study designed to test the efficacy of intravenous infusion of EGCG for 36 h, in acutely injured rats' spinal cord: within first 4 h post-injury and, in chronically SC injured rats: after one year of injury. Functional outcomes measured using standard BBB scale, The Louisville Swim Scale (LSS) and, pain behavior assessment tests. 72 Female adult rats subjected to moderate thoracic SCI using MASCIS Impactor, blindly randomized as the following: (I) Acute SCI + EGCG (II) Acute SCI + saline. (III) Chronic SCI + EGCG. (IV) Chronic SCI + saline and, sham SCI animals. EGCG i.v. treatment of acute and, chronic SCI animals resulted in significantly better recovery of motor and sensory functions, BBB and LSS (P < 0.005) and (P < 0.05) respectively. Tactile allodynia, mechanical nociception (P < 0.05) significantly improved. Paw withdrawal and, tail flick latencies increase significantly (P < 0.05). Moreover, in the EGCG treated acute SCI animals the percentage of lesion size area significantly reduced (P < 0.0001) and, the number of neurons in the spinal cord increased (P < 0.001). Percent areas of GAP-43 and GFAP immunohistochemistry showed significant (P < 0.05) increase. We conclude that the therapeutic window of opportunity for EGCG to depict neurological recovery in SCI animals, is viable up to one year post SCI when intravenously infused for 36 h. Copyright © 2013 Elsevier Ltd. All rights reserved.

Health Care Costs for Patients With Chronic Spinal Cord Injury in the Veterans Health Administration

PubMed Central

French, Dustin D; Campbell, Robert R; Sabharwal, Sunil; Nelson, Audrey L; Palacios, Polly A; Gavin-Dreschnack, Deborah

2007-01-01

Background/Objective: Recurring annual costs of caring for patients with chronic spinal cord injury (SCI) is a large economic burden on health care systems, but information on costs of SCI care beyond the acute and initial postacute phase is sparse. The objective of this study was to establish a frame of reference and estimate of the annual direct medical costs associated with health care for a sample of patients with chronic SCI (ie, >2 years after injury). Methods: Patients were recruited from 3 Veterans Health Administration (VHA) SCI facilities; baseline patient information was cross-referenced to the Decision Support System (DSS) National Data Extracts (NDE) to obtain patient-specific health care costs in VHA. Descriptive statistical analysis of annual DSS-NDE cost of patients with SCI (N = 675) for fiscal year (FY) 2005 by level and completeness of injury was conducted. Results: Total (inpatient and outpatient) annual (FY 2005) direct medical costs for 675 patients with SCI exceeded $14.47 million or $21,450 per patient. Average annual total costs varied from $28,334 for cervical complete SCI to $16,792 for thoracic incomplete SCI. Two hundred thirty-three of the 675 patients with SCI who were hospitalized over the study period accounted for a total of 378 hospital discharges, costing in excess of $7.19 million. This approximated a cost of outpatient care received of $7.28 million for our entire sample. Conclusions: The comprehensive nature of health care delivery and related cost capture for people with chronic SCI in the VHA provided us the opportunity to accurately determine health care costs for this population. Future SCI postacute care cost analyses should consider case-mix adjusting patients at high risk for rehospitalization. PMID:18092564

Prognostic Factors Associated with Recovery of Ambulation and Urinary Continence in Dogs with Acute Lumbosacral Spinal Cord Injury.

PubMed

Shaw, T A; De Risio, L; Laws, E J; Rose, J H; Harcourt-Brown, T R; Granger, N

2017-05-01

Limited information is available about prognostic factors for recovery after spinal cord injury (SCI) to the L4-S3 segments. Previous research suggests that L4-S3 SCI does not have a worse prognosis than T3-L3 SCI. To elucidate prognostic factors for regaining urinary continence and ambulation in dogs with L4-S3 SCI and compare prognosis to T3-L3 SCI. A retrospective study on 61 nonambulatory dogs with L4-S3 SCI, matched to dogs with T3-L3 SCI, compared 3 weeks after onset. Prognostic factors explored using logistic regression and used for matching: nonchondrodystrophic dogs >15 kg versus dogs that were chondrodystrophic or <15 kg; compressive versus noncompressive lesions; presence versus absence of conscious pain perception (CPP); and lower vs upper motor neuron (LMN/UMN) incontinence. Fewer L4-S3 dogs regained continence compared to T3-L3 dogs (64 vs 85%, P = .0033), but no difference existed for regaining ambulation (66 vs 75%, P = .1306). In L4-S3 SCI dogs, fewer dogs regained continence with loss of CPP (P < .001), LMN incontinence (P = .004), and noncompressive lesions (P = .006). Negative prognostic factors for regaining ambulation included absent CPP (P < .001) and large nonchondrodystrophic breed (P = .022). Dogs with L4-S3 SCI have a poorer short-term prognosis than do dogs with T3-L3 SCI. Dogs with L4-S3 SCI had a poor prognosis with loss of CPP, or noncompressive lesions combined with LMN incontinence. Small-breed or chondrodystrophic dogs with retained CPP, compressive lesions, and UMN incontinence had an excellent prognosis. These findings may help guide decision-making in L4-S3 SCI. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Aquaporins in Spinal Cord Injury: The Janus Face of AQP4

PubMed Central

Nesic, Olivera; Guest, James D.; Zivadinovic, Dragoslava; Narayana, Ponnada A.; Herrera, Juan J.; Grill, Raymond J.; Mokkapati, Venkata U.L.; Gelman, Benjamin B.; Lee, Julieann

2010-01-01

Although malfunction of spinal cord water channels (aquaporins, AQP) likely contributes to severe disturbances in ion/water homeostasis after spinal cord injury (SCI), their roles are still poorly understood. Here we report and discuss the potential significance of changes in the AQP4 expression in human SCI that generates GFAP-labeled astrocytes devoid of AQP4, and GFAP-labeled astroglia that overexpress AQP4. We used a rat model of contusion SCI to study observed changes in human SCI. AQP4-negative astrocytes are likely generated during the process of SCI-induced replacement of lost astrocytes, but their origin and role in SCI remains to be investigated. We found that AQP4-overexpression is likely triggered by hypoxia. Our transcriptional profiling of injured rat cords suggests that elevated AQP4-mediated water influx accompanies increased uptake of chloride and potassium ions which represents a protective astrocytic reaction to hypoxia. However, unbalanced water intake also results in astrocytic swelling that can contribute to motor impairment, but likely only in milder injuries. In severe rat SCI, a low abundance of AQP4-overexpressing astrocytes was found during the motor recovery phase. Our results suggest that severe rat contusion SCI is a better model to analyze AQP4 functions after SCI. We found that AQP4 increases in the chronic post-injury phase are associated with the development of pain-like behavior in SCI rats, while possible mechanisms underlying pain development may involve astrocytic swelling-induced glutamate release. In contrast, the formation and size of fluid-filled cavities occurring later after SCI does not appear to be affected by the extent of increased AQP4 levels. Therefore, the effect of therapeutic interventions targeting AQP4 will depend not only on the time interval after SCI or animal models, but also on the balance between protective role of increased AQP4 in hypoxia and deleterious effects of ongoing astrocytic swelling. PMID:20109536

Low-energy extracorporeal shock wave therapy promotes vascular endothelial growth factor expression and improves locomotor recovery after spinal cord injury.

PubMed

Yamaya, Seiji; Ozawa, Hiroshi; Kanno, Haruo; Kishimoto, Koshi N; Sekiguchi, Akira; Tateda, Satoshi; Yahata, Kenichiro; Ito, Kenta; Shimokawa, Hiroaki; Itoi, Eiji

2014-12-01

Extracorporeal shock wave therapy (ESWT) is widely used for the clinical treatment of various human diseases. Recent studies have demonstrated that low-energy ESWT upregulates the expression of vascular endothelial growth factor (VEGF) and promotes angiogenesis and functional recovery in myocardial infarction and peripheral artery disease. Many previous reports suggested that VEGF produces a neuroprotective effect to reduce secondary neural tissue damage after spinal cord injury (SCI). The purpose of the present study was to investigate whether low-energy ESWT promotes VEGF expression and neuroprotection and improves locomotor recovery after SCI. Sixty adult female Sprague-Dawley rats were randomly divided into 4 groups: sham group (laminectomy only), sham-SW group (low-energy ESWT applied after laminectomy), SCI group (SCI only), and SCI-SW group (low-energy ESWT applied after SCI). Thoracic spinal cord contusion injury was inflicted using an impactor. Low-energy ESWT was applied to the injured spinal cord 3 times a week for 3 weeks. Locomotor function was evaluated using the Basso, Beattie, and Bresnahan (BBB) Scale (open field locomotor score) at different time points over 42 days after SCI. Hematoxylin and eosin staining was performed to assess neural tissue damage in the spinal cord. Neuronal loss was investigated by immunostaining for NeuN. The mRNA expressions of VEGF and its receptor, Flt-1, in the spinal cord were assessed using real-time polymerase chain reaction. Immunostaining for VEGF was performed to evaluate VEGF protein expression in the spinal cord. In both the sham and sham-SW groups, no animals showed locomotor impairment on BBB scoring. Histological analysis of H & E and NeuN stainings in the sham-SW group confirmed that no neural tissue damage was induced by the low-energy ESWT. Importantly, animals in the SCI-SW group demonstrated significantly better locomotor improvement than those in the SCI group at 7, 35, and 42 days after injury (p < 0.05). The number of NeuN-positive cells in the SCI-SW group was significantly higher than that in the SCI group at 42 days after injury (p < 0.05). In addition, mRNA expressions of VEGF and Flt-1 were significantly increased in the SCI-SW group compared with the SCI group at 7 days after injury (p < 0.05). The expression of VEGF protein in the SCI-SW group was significantly higher than that in the SCI group at 7 days (p < 0.01). The present study showed that low-energy ESWT significantly increased expressions of VEGF and Flt-1 in the spinal cord without any detrimental effect. Furthermore, it significantly reduced neuronal loss in damaged neural tissue and improved locomotor function after SCI. These results suggested that low-energy ESWT enhances the neuroprotective effect of VEGF in reducing secondary injury and leads to better locomotor recovery following SCI. This study provides the first evidence that low-energy ESWT can be a safe and promising therapeutic strategy for SCI.

MadSciNet: The 24-hour exploding laboratory.

Science.gov Websites

Page New! Help Improve The Madsci Network Help Support MadSci MAD Head MAD egg Welcome to the laboratory that never sleeps! MadSci Network represents a collective cranium of scientists providing answers Sunday May 27, 2018. Lynn MadSci Network is a non-profit organization operating in partnership with Third

32 CFR 171.6 - Reutilization and transfer procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., it shall send a written notice of dispute to the owning Military Service and ADUSD(L&MR/SCI) within thirty (30) days of its notice from the Military Service. ADUSD(L&MR/SCI) shall then resolve the dispute... and ADUSD(L&MR/SCI) within thirty (30) days of its notice from the Military Service. ADUSD(L&MR/SCI...

32 CFR 171.6 - Reutilization and transfer procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., it shall send a written notice of dispute to the owning Military Service and ADUSD(L&MR/SCI) within thirty (30) days of its notice from the Military Service. ADUSD(L&MR/SCI) shall then resolve the dispute... and ADUSD(L&MR/SCI) within thirty (30) days of its notice from the Military Service. ADUSD(L&MR/SCI...

Spinal Cord Injury Clinical Registries: Improving Care across the SCI Care Continuum by Identifying Knowledge Gaps.

PubMed

Dvorak, Marcel F; Cheng, Christiana L; Fallah, Nader; Santos, Argelio; Atkins, Derek; Humphreys, Suzanne; Rivers, Carly S; White, Barry A B; Ho, Chester; Ahn, Henry; Kwon, Brian K; Christie, Sean; Noonan, Vanessa K

2017-10-15

Timely access and ongoing delivery of care and therapeutic interventions is needed to maximize recovery and function after traumatic spinal cord injury (tSCI). To ensure these decisions are evidence-based, access to consistent, reliable, and valid sources of clinical data is required. The Access to Care and Timing Model used data from the Rick Hansen SCI Registry (RHSCIR) to generate a simulation of healthcare delivery for persons after tSCI and to test scenarios aimed at improving outcomes and reducing the economic burden of SCI. Through model development, we identified knowledge gaps and challenges in the literature and current health outcomes data collection throughout the continuum of SCI care. The objectives of this article were to describe these gaps and to provide recommendations for bridging them. Accurate information on injury severity after tSCI was hindered by difficulties in conducting neurological assessments and classifications of SCI (e.g., timing), variations in reporting, and the lack of a validated SCI-specific measure of associated injuries. There was also limited availability of reliable data on patient factors such as multi-morbidity and patient-reported measures. Knowledge gaps related to structures (e.g., protocols) and processes (e.g., costs) at each phase of care have prevented comprehensive evaluation of system performance. Addressing these knowledge gaps will enhance comparative and cost-effectiveness evaluations to inform decision-making and standards of care. Recommendations to do so were: standardize data element collection and facilitate database linkages, validate and adopt more outcome measures for SCI, and increase opportunities for collaborations with stakeholders from diverse backgrounds.

Measuring pain phenomena after spinal cord injury: Development and psychometric properties of the SCI-QOL Pain Interference and Pain Behavior assessment tools.

PubMed

Cohen, Matthew L; Kisala, Pamela A; Dyson-Hudson, Trevor A; Tulsky, David S

2018-05-01

To develop modern patient-reported outcome measures that assess pain interference and pain behavior after spinal cord injury (SCI). Grounded-theory based qualitative item development; large-scale item calibration field-testing; confirmatory factor analyses; graded response model item response theory analyses; statistical linking techniques to transform scores to the Patient Reported Outcome Measurement Information System (PROMIS) metric. Five SCI Model Systems centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. N/A. Spinal Cord Injury - Quality of Life (SCI-QOL) Pain Interference item bank, SCI-QOL Pain Interference short form, and SCI-QOL Pain Behavior scale. Seven hundred fifty-seven individuals with traumatic SCI completed 58 items addressing various aspects of pain. Items were then separated by whether they assessed pain interference or pain behavior, and poorly functioning items were removed. Confirmatory factor analyses confirmed that each set of items was unidimensional, and item response theory analyses were used to estimate slopes and thresholds for the items. Ultimately, 7 items (4 from PROMIS) comprised the Pain Behavior scale and 25 items (18 from PROMIS) comprised the Pain Interference item bank. Ten of these 25 items were selected to form the Pain Interference short form. The SCI-QOL Pain Interference item bank and the SCI-QOL Pain Behavior scale demonstrated robust psychometric properties. The Pain Interference item bank is available as a computer adaptive test or short form for research and clinical applications, and scores are transformed to the PROMIS metric.

Measuring anxiety after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Anxiety item bank and linkage with GAD-7.

PubMed

Kisala, Pamela A; Tulsky, David S; Kalpakjian, Claire Z; Heinemann, Allen W; Pohlig, Ryan T; Carle, Adam; Choi, Seung W

2015-05-01

To develop a calibrated item bank and computer adaptive test to assess anxiety symptoms in individuals with spinal cord injury (SCI), transform scores to the Patient Reported Outcomes Measurement Information System (PROMIS) metric, and create a statistical linkage with the Generalized Anxiety Disorder (GAD)-7, a widely used anxiety measure. Grounded-theory based qualitative item development methods; large-scale item calibration field testing; confirmatory factor analysis; graded response model item response theory analyses; statistical linking techniques to transform scores to a PROMIS metric; and linkage with the GAD-7. Setting Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Participants Adults with traumatic SCI. Spinal Cord Injury-Quality of Life (SCI-QOL) Anxiety Item Bank Seven hundred sixteen individuals with traumatic SCI completed 38 items assessing anxiety, 17 of which were PROMIS items. After 13 items (including 2 PROMIS items) were removed, factor analyses confirmed unidimensionality. Item response theory analyses were used to estimate slopes and thresholds for the final 25 items (15 from PROMIS). The observed Pearson correlation between the SCI-QOL Anxiety and GAD-7 scores was 0.67. The SCI-QOL Anxiety item bank demonstrates excellent psychometric properties and is available as a computer adaptive test or short form for research and clinical applications. SCI-QOL Anxiety scores have been transformed to the PROMIS metric and we provide a method to link SCI-QOL Anxiety scores with those of the GAD-7.

Differences in the use of everyday technology among persons with MCI, SCI and older adults without known cognitive impairment.

PubMed

Malinowsky, Camilla; Kottorp, Anders; Wallin, Anders; Nordlund, Arto; Björklund, Eva; Melin, Ilse; Pernevik, Anette; Rosenberg, Lena; Nygård, Louise

2017-07-01

To use valid subjective reports sensible to cognitive decline is vital to identify very early signs of dementia development. Use of everyday technology (ET) has been shown to be sensitive to differentiate adults with mild cognitive impairment (MCI) from controls, but the group with subjective cognitive impairment (SCI) has not yet been examined. This study aims to investigate and compare self-perceived ability in ET use and number of ETs reported as actually used in a sample of older adults with SCI, MCI, and older adults with no known cognitive impairment, i.e. Older adults with MCI (n = 29), SCI ( n = 26), and controls (n = 30) were interviewed with the short version of the Everyday Technology Use Questionnaire (S-ETUQ) to capture self-perceived ability in ET use and number of ETs used. To generate individual measures of ability to use ET, Rasch analysis was used. The measures were then compared group-wise using ANCOVA. The numbers of ETs used were compared group-wise with ANOVA. Controls versus SCI and MCI differed significantly regarding ETs reported as used, but not SCI versus MCI. Similarly, in ability to use ET, controls versus SCI and MCI differed significantly but not SCI versus MCI. The significantly lower numbers of ETs reported as actually used and the lower ability in SCI and MCI groups compared to controls suggest that ET use is affected already in very minor cognitive decline. This indicates that self-reported ET use based on the S-ETUQ is sensitive to detect changes already in SCI.

Incidence of acute spinal cord injury in the Czech Republic: a prospective epidemiological study 2006-2015.

PubMed

Kriz, J; Kulakovska, M; Davidova, H; Silova, M; Kobesova, A

2017-09-01

A prospective study. Analysis of epidemiological data about acute spinal cord injury (SCI) in the Czech Republic over a period of 10 years (2006-2015). A data collection system was implemented in the rehabilitation centres which provides care to patients with acute SCI in the Czech Republic. The recorded variables are as follows: age at time of SCI; gender; cause of injury; neurological level of injury (NLI); and its severity (ASIA Impairment Scale (AIS)). Data from 2006 to 2015 were analysed and trends were determined. The overall number of acute SCI ranges between 250 and 300 cases annually. Two-third of the affected population are males. The average age at time of SCI is 49.1 years. The average incidence of traumatic SCI is 15.5 cases per year and is gradually decreasing. The leading cause of SCI are falls (44.5%), followed by traffic accidents (28.2%) and sports injuries including diving into water (19.7%). The incidence of non-traumatic SCI is 8.6 cases per year on average and has an upward trend. Inflammatory lesions account for 26.7% of cases, tumours account for 20.9%, and vascular related injuries make up 17.7%. The NLI occurs most often in the cervical segments (45.3%). The most frequently occurring lesions are motor incomplete: AIS D (33.3%). This study shows a stable occurrence of SCI in the Czech Republic, with cervical and motor incomplete cases being the leading ones. Epidemiological data are needed to improve the care of SCI patients and to promote an active life following it.

Spinal Cord Injury Clinical Registries: Improving Care across the SCI Care Continuum by Identifying Knowledge Gaps

PubMed Central

Cheng, Christiana L.; Fallah, Nader; Santos, Argelio; Atkins, Derek; Humphreys, Suzanne; Rivers, Carly S.; White, Barry A.B.; Ho, Chester; Ahn, Henry; Kwon, Brian K.; Christie, Sean; Noonan, Vanessa K.

2017-01-01

Abstract Timely access and ongoing delivery of care and therapeutic interventions is needed to maximize recovery and function after traumatic spinal cord injury (tSCI). To ensure these decisions are evidence-based, access to consistent, reliable, and valid sources of clinical data is required. The Access to Care and Timing Model used data from the Rick Hansen SCI Registry (RHSCIR) to generate a simulation of healthcare delivery for persons after tSCI and to test scenarios aimed at improving outcomes and reducing the economic burden of SCI. Through model development, we identified knowledge gaps and challenges in the literature and current health outcomes data collection throughout the continuum of SCI care. The objectives of this article were to describe these gaps and to provide recommendations for bridging them. Accurate information on injury severity after tSCI was hindered by difficulties in conducting neurological assessments and classifications of SCI (e.g., timing), variations in reporting, and the lack of a validated SCI-specific measure of associated injuries. There was also limited availability of reliable data on patient factors such as multi-morbidity and patient-reported measures. Knowledge gaps related to structures (e.g., protocols) and processes (e.g., costs) at each phase of care have prevented comprehensive evaluation of system performance. Addressing these knowledge gaps will enhance comparative and cost-effectiveness evaluations to inform decision-making and standards of care. Recommendations to do so were: standardize data element collection and facilitate database linkages, validate and adopt more outcome measures for SCI, and increase opportunities for collaborations with stakeholders from diverse backgrounds. PMID:28745934

Return to work following spinal cord injury: a review.

PubMed

Lidal, Ingeborg Beate; Huynh, Tuan Khai; Biering-Sørensen, Fin

2007-09-15

To review literature on return to work (RTW) and employment in persons with spinal cord injury (SCI), and present employment rates, factors influencing employment, and interventions aimed at helping people with SCI to obtain and sustain productive work. A systematic review for 2000 - 2006 was carried out in PubMed/Medline, AMED, (ISI) Web of Science, EMBASE, CINAHL, PsycInfo and Sociological abstracts database. The keywords 'spinal cord injuries', 'spinal cord disorder', 'spinal cord lesion' or 'spinal cord disease' were cross-indexed with 'employment', 'return to work', 'occupation' or 'vocational'. Out of approximately 270 hits, 110 references were used, plus 13 more found elsewhere. Among individuals with SCI working at the time of injury 21 - 67% returned to work after injury. RTW was higher in persons injured at a younger age, had less severe injuries and higher functional independence. Employment rate improved with time after SCI. Persons with SCI employed ranged from 11.5% to 74%. Individuals who sustained SCI during childhood or adolescence had higher adult employment rates. Most common reported barriers to employment were problems with transportation, health and physical limitations, lack of work experience, education or training, physical or architectural barriers, discrimination by employers, and loss of benefits. Individuals with SCI discontinue working at younger age. This review confirmed low employment rates after SCI. Future research should explore interventions aimed at helping people with SCI to obtain and sustain productive work.

32 CFR 154.77 - Reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Secret, Secret, and Confidential clearances revoked; (4) Number of SCI access determinations issued; (5) Number of SCI access determinations denied; (6) Number of SCI access determinations revoked; and (7...

Weapons Systems, United States Army 1997.

DTIC Science & Technology

1997-01-01

fewer grenades, a new warhead section fuze and a modified center core burster. The XM85 grenade is equipped with a new self -destruct fuze designed to...Liquid Propellant Gun and an automated loading system. Crusader also requires 3 fewer crewmen than previous self -propelled artillery systems. The new ...market, creating new market opportunities for commercial rotocraft and ensuring the continued supremacy of this technol- ogy that is so critical to

Surface Grafting of Thermoresponsive Microgel Nanoparticles (Postprint)

DTIC Science & Technology

2011-01-01

and cell immobilization, as biosensors, and for in vivo drug delivery .33,34,36,49–53 PNIPAM-containing microgels have been synthesized and...2007, 25, 577–583. 51 J. Jagur-Grodzinski, Polym. Adv. Technol., 2010, 21, 27–47.Soft Matter52 M. Hamidi, A. Azadi and P. Rafiei,Adv. Drug Delivery ...prospective applications in micro- and nanofluidics, biocompatible materials, controlled drug release, nano- and biotribology, controlled cell growth

JPRS Report, Nuclear Developments

DTIC Science & Technology

1989-08-29

Korea is developing nuclear weapons Yi and Bartholomew agreed that the two governments capability. should reestablish a bilateral science and...early this year. Taking advantage of such a mood of The government should develop state-of-the-art technol- detente. even our country is now actively...counter to such a mood of detente. and why can they not The report recommended that the government establish abandon nuclear weapons at a time when

Pathfinder. Volume 8, Number 6, November/December 2010

DTIC Science & Technology

2010-12-01

transferring information between multiple systems . Nevertheless, without an end-to-end TCPED process and the associated standards, policies and equipment in...products with partners whose information technology systems vary and are not compatible with those of the NSG, NGA and the U.S. Depart- ment of...Pacific. ARF DReaMS is based on Web service technol- ogy, where traditional maps, data and any relevant geospatial information are made available

Design Insights for MapReduce from Diverse Production Workloads

DTIC Science & Technology

2012-01-25

different industries [5]. Consequently, there is a need to develop systematic knowledge of MapRe- duce behavior at both established users within technol...relevant to MapReduce-like systems that combine data movements and computation. 5.2 Task granularity Many MapReduce workload management mechanisms make...ex- ecutes the jobs given, versus what the jobs actually are. MapReduce workload managers currently optimize exe- cution scheduling and placement

Diagnostic accuracy of evoked potentials for functional impairment after contusive spinal cord injury in adult rats.

PubMed

Thirumala, Parthasarathy; Zhou, James; Krishnan, Rohan; Manem, Nihita; Umredkar, Shreya; Hamilton, D K; Balzer, Jeffrey R; Oudega, Martin

2016-03-01

Iatrogenic spinal cord injury (SCI) is a cause of potentially debilitating post-operative neurologic complications. Currently, intra-operative neurophysiological monitoring (IONM) via somatosensory evoked potentials and motor-evoked potentials is used to detect and prevent impending SCI. However, no empirically validated interventions exist to halt the progression of iatrogenic SCI once it is detected. This is in part due to the lack of a suitable translational model that mimics the circumstances surrounding iatrogenic SCI detected via IONM. Here, we evaluate a model of simulated contusive iatrogenic SCI detected via IONM in adult female Sprague-Dawley rats. We show that transient losses of somatosensory evoked potentials responses are 88.24% sensitive (95% confidence interval [CI] 63.53-98.20) and 80% specific (95% CI 51.91-95.43) for significant functional impairment following simulated iatrogenic SCI. Similarly, we show that transient losses in motor-evoked potentials responses are 70.83% sensitive (95% CI 48.91-87.33) and 100% specific (95% CI 62.91-100.00) for significant functional impairment following simulated iatrogenic SCI. These results indicate that our model is a suitable replica of the circumstances surrounding clinical iatrogenic SCI. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of melatonin on spinal cord injury-induced oxidative damage in mice testis.

PubMed

Yuan, X-C; Wang, P; Li, H-W; Wu, Q-B; Zhang, X-Y; Li, B-W; Xiu, R-J

2017-09-01

This study evaluated the effects of melatonin on spinal cord injury (SCI)-induced oxidative damage in testes. Adult male C57BL/6 mice were randomly divided into sham-, SCI- or melatonin (10 mg/kg, i.p.)-treated SCI groups. To induce SCI, a standard weight-drop method that induced a contusion injury at T10 was used. After 1 week, testicular blood flow velocity was measured using the Laser Doppler Line Scanner. Malondialdehyde (MDA), glutathione (GSH), oxidised glutathione (GSSG) and myeloperoxidase (MPO) were measured in testis homogenates. Microvascular permeability of the testes to Evan's Blue was examined by spectrophotometric and fluorescence microscopic quantitation. The tight junction protein zonula occludens-1 (ZO-1) and occludin in testes were assessed by immunoblot analysis. Melatonin increased the reduced blood flow and decreased SCI-induced permeability of capillaries. MDA levels and MPO activity were elevated in the SCI group compared with shams, which was reversed by melatonin. In contrast, SCI-induced reductions in GSH/GSSG ratio were restored by melatonin. Decreased expression of ZO-1 and occludin was observed, which was attenuated by melatonin. Overall, melatonin treatment protects the testes against oxidative stress damage caused by SCI. © 2016 Blackwell Verlag GmbH.

Geraniol promotes functional recovery and attenuates neuropathic pain in rats with spinal cord injury.

PubMed

Lv, Yan; Zhang, Liang; Li, Na; Mai, Naiken; Zhang, Yu; Pan, Shuyi

2017-12-01

Geraniol, a plant-derived monoterpene, has been extensively studied and showed a wide variety of beneficial effects. The aim of this study was to investigate the therapeutic effect of geraniol on functional recovery and neuropathic pain in rats with spinal cord injury (SCI). Rats received a clip-compression SCI and were treated with geraniol 6 h following SCI. Treatment of SCI rats with geraniol markedly improved locomotor function, and reduced sensitivity to the mechanical allodynia and thermal hyperalgesia. Treatment of SCI rats with geraniol increased NeuN-positive cells, suppressed expression of glial fibrillary acidic protein, and reduced activity of caspase-3 in the injured region. Treatment of SCI rats with geraniol reduced levels of malondialdehyde and 3-nitrotyrosine, upregulated protein expression of nuclear factor-erythroid 2-related factor 2 and heme oxygenase 1, and suppressed expression of inducible nitric oxide synthase in the injured region. In addition, treatment of SCI rats with geraniol downregulated protein expression of N-methyl-d-aspartate receptor 1 and reduced the number of CD68-positive cells and protein levels of TNF-α in the injured region. In conclusion, geraniol significantly promoted the recovery of neuronal function and attenuated neuropathic pain after SCI.

Clinical interpretation of the Spinal Cord Injury Functional Index (SCI-FI)

PubMed Central

Fyffe, Denise; Kalpakjian, Claire Z.; Slavin, Mary; Kisala, Pamela; Ni, Pengsheng; Kirshblum, Steven C.; Tulsky, David S.; Jette, Alan M.

2016-01-01

Objective: To provide validation of functional ability levels for the Spinal Cord Injury – Functional Index (SCI-FI). Design: Cross-sectional. Setting: Inpatient rehabilitation hospital and community settings. Participants: A sample of 855 individuals with traumatic spinal cord injury enrolled in 6 rehabilitation centers participating in the National Spinal Cord Injury Model Systems Network. Interventions: Not Applicable. Main Outcome Measures: Spinal Cord Injury-Functional Index (SCI-FI). Results: Cluster analyses identified three distinct groups that represent low, mid-range and high SCI-FI functional ability levels. Comparison of clusters on personal and other injury characteristics suggested some significant differences between groups. Conclusions: These results strongly support the use of SCI-FI functional ability levels to document the perceived functional abilities of persons with SCI. Results of the cluster analysis suggest that the SCI-FI functional ability levels capture function by injury characteristics. Clinical implications regarding tracking functional activity trajectories during follow-up visits are discussed. PMID:26781769

Spinal cord injury-induced immunodeficiency is mediated by a sympathetic-neuroendocrine adrenal reflex.

PubMed

Prüss, Harald; Tedeschi, Andrea; Thiriot, Aude; Lynch, Lydia; Loughhead, Scott M; Stutte, Susanne; Mazo, Irina B; Kopp, Marcel A; Brommer, Benedikt; Blex, Christian; Geurtz, Laura-Christin; Liebscher, Thomas; Niedeggen, Andreas; Dirnagl, Ulrich; Bradke, Frank; Volz, Magdalena S; DeVivo, Michael J; Chen, Yuying; von Andrian, Ulrich H; Schwab, Jan M

2017-11-01

Acute spinal cord injury (SCI) causes systemic immunosuppression and life-threatening infections, thought to result from noradrenergic overactivation and excess glucocorticoid release via hypothalamus-pituitary-adrenal axis stimulation. Instead of consecutive hypothalamus-pituitary-adrenal axis activation, we report that acute SCI in mice induced suppression of serum norepinephrine and concomitant increase in cortisol, despite suppressed adrenocorticotropic hormone, indicating primary (adrenal) hypercortisolism. This neurogenic effect was more pronounced after high-thoracic level (Th1) SCI disconnecting adrenal gland innervation, compared with low-thoracic level (Th9) SCI. Prophylactic adrenalectomy completely prevented SCI-induced glucocorticoid excess and lymphocyte depletion but did not prevent pneumonia. When adrenalectomized mice were transplanted with denervated adrenal glands to restore physiologic glucocorticoid levels, the animals were completely protected from pneumonia. These findings identify a maladaptive sympathetic-neuroendocrine adrenal reflex mediating immunosuppression after SCI, implying that therapeutic normalization of the glucocorticoid and catecholamine imbalance in SCI patients could be a strategy to prevent detrimental infections.

Online support for individuals with spinal cord injuries: An ethnographic investigation

PubMed Central

O'Riley, Alisa A.; Rose, Jon; Dalal, Brinda

2014-01-01

Background Although social support is an important protective factor for individuals with spinal cord injuries (SCIs), individuals often encounter significant barriers to obtaining support after experiencing a SCI. It has been suggested that the Internet may serve to help individuals with disabilities overcome common barriers in obtaining support, yet research examining the efficacy of Internet-based support for individuals with SCI has been mixed. Objective To develop a more nuanced understanding of how individuals with SCI can or might use the Internet for support. Design Using an ethnographic approach, we conducted semi-structured interviews with nine individuals with SCI to explore perceived needs and barriers to information-seeking and online support. Setting Participants were recruited from Veterans Administration medical center outpatient and inpatient units providing specialty care to individuals with SCIs and from a community SCI Center of Excellence. Results Individuals with SCI gain emotional, problem-focused, and reciprocal support from online sources. Conclusions Online resources can provide important opportunities for social support for individuals with SCI. PMID:24090378

Against the odds: what to expect in rehabilitation of chronic spinal cord injury with a neurologically controlled Hybrid Assistive Limb exoskeleton. A subgroup analysis of 55 patients according to age and lesion level.

PubMed

Grasmücke, Dennis; Zieriacks, Amrei; Jansen, Oliver; Fisahn, Christian; Sczesny-Kaiser, Matthias; Wessling, Martin; Meindl, Renate C; Schildhauer, Thomas A; Aach, Mirko

2017-05-01

Objective Age and lesion level are believed to represent outcome predictors in rehabilitation of patients with chronic spinal cord injury (SCI). The Hybrid Assistive Limb (HAL) exoskeleton enables patients to perform a voluntary controlled gait pattern via an electromyography-triggered neuromuscular feedback system, and has been introduced as a temporary gait training tool in patients with SCI. The aim of this prospective pre- and postintervention study was to examine functional outcomes as a function of age and lesion level in patients with chronic incomplete SCI (iSCI) or chronic complete SCI (cSCI) with zones of partial preservation (ZPP) by using the HAL as a temporary training tool. Methods Fifty-five participants with chronic iSCI or cSCI (mean time since injury 6.85 ± 5.12 years) were classified according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS) and divided by age (< 50 or ≥ 50 years), independent of lesion level, and also into 4 homogeneous groups according to lesion level. The subgroups were as follows: Subgroup 1, tetraplegic iSCI (n = 13) (C2-8, AIS C [n = 8] and AIS D [n = 5]); Subgroup 2, paraplegic iSCI with spastic motor behavior (n = 15) (T2-12, AIS C [n = 8] and AIS D [n = 7]); Subgroup 3, paraplegic cSCI with complete motor paraplegia and absence of spastic motor behavior (n = 18) (T11-L4 [AIS A], and ZPP from L-3 to S-1); and Subgroup 4, paraplegic iSCI with absence of spastic motor behavior (n = 9) (T12-L3, AIS C [n = 8] and AIS D [n = 1]). The training paradigm consisted of 12 weeks of HAL-assisted treadmill training (5 times/week). Baseline status was documented prior to intervention by using the AIS grade, Walking Index for SCI II (WISCI II) score, the 10-meter walk test (10MWT), and the 6-minute walk test (6MinWT). Training effects were assessed after 6 and 12 weeks of therapy, without HAL assistance. Results Overall, a time reduction of 47% in the 10MWT, self-selected speed (10MWTsss) (< 50 years = 56% vs ≥ 50 years = 37%) and an increase of 50% in the 6MinWT were documented. The WISCI II scores showed a mean gain of 1.69 levels. At the end of the study, 24 of 55 patients (43.6%) were less dependent on walking aids. Age had a nonsignificant negative influence on the 10MWTsss. Despite a few nonsignificant subgroup differences, participants improved across all tests. Namely, patients with iSCI who had spastic motor behavior improved to a nonsignificant, lesser extent in the 6MinWT. Conclusions The HAL-assisted treadmill training leads to functional improvements in chronic iSCI or cSCI, both in and out of the exoskeleton. An improvement of approximately 50% in the 10MWTsss and in gait endurance (6MinWT) can be expected from such training. The influences of SCI lesion level and age on functional outcome were nonsignificant in the present study. Older age (≥ 50 years) may be associated with smaller improvements in the 10MWTsss. An iSCI in paraplegic patients with spastic motor behavior may be a nonsignificant negative predictor in gait endurance improvements. Clinical trial registration no.: DRKS00010250 ( https://drks-neu.uniklinik-freiburg.de/drks_web/setLocale_DE.do ).

Low-energy extracorporeal shock wave therapy for promotion of vascular endothelial growth factor expression and angiogenesis and improvement of locomotor and sensory functions after spinal cord injury.

PubMed

Yahata, Kenichiro; Kanno, Haruo; Ozawa, Hiroshi; Yamaya, Seiji; Tateda, Satoshi; Ito, Kenta; Shimokawa, Hiroaki; Itoi, Eiji

2016-12-01

OBJECTIVE Extracorporeal shock wave therapy (ESWT) is widely used to treat various human diseases. Low-energy ESWT increases expression of vascular endothelial growth factor (VEGF) in cultured endothelial cells. The VEGF stimulates not only endothelial cells to promote angiogenesis but also neural cells to induce neuroprotective effects. A previous study by these authors demonstrated that low-energy ESWT promoted expression of VEGF in damaged neural tissue and improved locomotor function after spinal cord injury (SCI). However, the neuroprotective mechanisms in the injured spinal cord produced by low-energy ESWT are still unknown. In the present study, the authors investigated the cell specificity of VEGF expression in injured spinal cords and angiogenesis induced by low-energy ESWT. They also examined the neuroprotective effects of low-energy ESWT on cell death, axonal damage, and white matter sparing as well as the therapeutic effect for improvement of sensory function following SCI. METHODS Adult female Sprague-Dawley rats were divided into the SCI group (SCI only) and SCI-SW group (low-energy ESWT applied after SCI). Thoracic SCI was produced using a New York University Impactor. Low-energy ESWT was applied to the injured spinal cord 3 times a week for 3 weeks after SCI. Locomotor function was evaluated using the Basso, Beattie, and Bresnahan open-field locomotor score for 42 days after SCI. Mechanical and thermal allodynia in the hindpaw were evaluated for 42 days. Double staining for VEGF and various cell-type markers (NeuN, GFAP, and Olig2) was performed at Day 7; TUNEL staining was also performed at Day 7. Immunohistochemical staining for CD31, α-SMA, and 5-HT was performed on spinal cord sections taken 42 days after SCI. Luxol fast blue staining was performed at Day 42. RESULTS Low-energy ESWT significantly improved not only locomotion but also mechanical and thermal allodynia following SCI. In the double staining, expression of VEGF was observed in NeuN-, GFAP-, and Olig2-labeled cells. Low-energy ESWT significantly promoted CD31 and α-SMA expressions in the injured spinal cords. In addition, low-energy ESWT significantly reduced the TUNEL-positive cells in the injured spinal cords. Furthermore, the immunodensity of 5-HT-positive axons was significantly higher in the animals treated by low-energy ESWT. The areas of spared white matter were obviously larger in the SCI-SW group than in the SCI group, as indicated by Luxol fast blue staining. CONCLUSIONS The results of this study suggested that low-energy ESWT promotes VEGF expression in various neural cells and enhances angiogenesis in damaged neural tissue after SCI. Furthermore, the neuroprotective effect of VEGF induced by low-energy ESWT can suppress cell death and axonal damage and consequently improve locomotor and sensory functions after SCI. Thus, low-energy ESWT can be a novel therapeutic strategy for treatment of SCI.

ScienceDirect through SciVerse: a new way to approach Elsevier.

PubMed

Bengtson, Jason

2011-01-01

SciVerse is the new combined portal from Elsevier that services their ScienceDirect collection, SciTopics, and their Scopus database. Using SciVerse to access ScienceDirect is the specific focus of this review. Along with advanced keyword searching and citation searching options, SciVerse also incorporates a very useful image search feature. The aim seems to be not only to create an interface that provides broad functionality on par with other database search tools that many searchers use regularly but also to create an open platform that could be changed to respond effectively to the needs of customers.

Evaluating implementation of methicillin-resistant Staphylococcus aureus (MRSA) prevention guidelines in spinal cord injury centers using the PARIHS framework: a mixed methods study.

PubMed

Balbale, Salva N; Hill, Jennifer N; Guihan, Marylou; Hogan, Timothy P; Cameron, Kenzie A; Goldstein, Barry; Evans, Charlesnika T

2015-09-09

To prevent methicillin-resistant Staphylococcus aureus (MRSA) in Spinal Cord Injury and Disorder (SCI/D) Centers, the "Guidelines for Implementation of MRSA Prevention Initiative in the Spinal Cord Injury Centers" were released in July 2008 in the Veterans Affairs (VA) Health Care System. The purpose of this study was to use the Promoting Action on Research Implementation in Health Systems (PARiHS) framework to evaluate the experiences of implementation of SCI/D MRSA prevention guidelines in VA SCI/D Centers approximately 2-3 years after the guidelines were released. Mixed methods were used across two phases in this study. The first phase included an anonymous, web-based cross-sectional survey administered to providers at all 24 VA SCI/D Centers. The second phase included semi-structured telephone interviews with providers at 9 SCI/D Centers. The PARiHS framework was used as the foundation of both the survey questions and semi-structured interview guide. The survey was completed by 295 SCI/D providers (43.8 % response rate) from 22 of the 24 SCI/D Centers (91.7 % participation rate). Respondents included nurses (57.3 %), therapists (24.4 %), physicians (11.1 %), physician assistants (3.4 %), and other health care professionals (3.8 %). Approximately 36 % of the SCI/D providers surveyed had not seen, did not remember seeing, or had never heard of the MRSA SCI/D guidelines, whereas 42.3 % of providers reported that the MRSA SCI/D guidelines were fully implemented in their SCI/D Center. Data revealed numerous barriers and facilitators to guideline implementation. Facilitators included enhanced leadership support and provider education, focused guideline dissemination to reach SCI/D providers, and strong perceived evidence supporting the guidelines. Barriers included lack of awareness of the guidelines among physical therapists and physician assistants and challenges in cohorting/isolating MRSA-positive patients and following contact precautions. Successful implementation of MRSA infection prevention guidelines in SCI/D settings requires (1) guideline dissemination that reaches the full range of SCI/D providers working in inpatient, outpatient, and other care settings, (2) provider education that is frequent and systematic, (3) strong leadership support, and (4) that barriers unique to the recommendations are addressed. These findings may be used to inform selection of implementation strategies and optimize infection prevention beyond MRSA as well as in other specialty care populations.

Costs and Length of Stay for the Acute Care of Patients with Motor-Complete Spinal Cord Injury Following Cervical Trauma: The Impact of Early Transfer to Specialized Acute SCI Center.

PubMed

Richard-Denis, Andréane; Ehrmann Feldman, Debbie; Thompson, Cynthia; Bourassa-Moreau, Étienne; Mac-Thiong, Jean-Marc

2017-07-01

Acute spinal cord injury (SCI) centers aim to optimize outcome following SCI. However, there is no timeframe to transfer patients from regional to SCI centers in order to promote cost-efficiency of acute care. Our objective was to compare costs and length of stay (LOS) following early and late transfer to the SCI center. A retrospective cohort study involving 116 individuals was conducted. Group 1 (n = 87) was managed in an SCI center promptly after the trauma, whereas group 2 (n = 29) was transferred to the SCI center only after surgery. Direct comparison and multivariate linear regression analyses were used to assess the relationship between costs, LOS, and timing to transfer to the SCI center. Length of stay was significantly longer for group 2 (median, 93.0 days) as compared with group 1 (median, 40.0 days; P < 10), and average costs were also higher (median, Canadian $17,920.0 vs. $10,521.6; P = 0.004) for group 2, despite similar characteristics. Late transfer to the SCI center was the main predictive factor of longer LOS and increased costs. Early admission to the SCI center was associated with shorter LOS and lower costs for patients sustaining tetraplegia. Early referral to an SCI center before surgery could lower the financial burden for the health care system. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Determine the optimal timing for transfer of individuals with cervical traumatic spinal cord injury (SCI) in order to decrease acute care resource utilization; (2) Determine benefits of a complete perioperative management in a specialized SCI center; and (3) Identify factors that may influence resource utilization for acute care following motor-complete tetraplegia. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Assessment of Neuroprotective Properties of Melissa officinalis in Combination With Human Umbilical Cord Blood Stem Cells After Spinal Cord Injury

PubMed Central

Hosseini, Seyed Ruhollah; Joghataei, Mohammad Taghi; Hooshmandi, Mehdi; Sadraie, Seyed Homayoon; Yaghoobi, Kayvan; Mohammadi, Alireza

2016-01-01

Introduction The pathophysiology of spinal cord injury (SCI) has a classically bad prognosis. It has been demonstrated that human umbilical cord blood stem cells (hUCBSCs) and Melissa officinalis (MO) are useful for the prevention of neurological disease. Methods Thirty-six adult male rats were randomly divided into intact, sham, control (SCI), MO, hUCBSC, and MO-hUCBSC groups. Intraperitoneal injection of MO (150 mg/kg) was commenced 24 hr post-SCI and continued once a day for 14 days. Intraspinal grafting of hUCBSCs was commenced immediately in the next day. The motor and sensory functions of all animals were evaluated once a week after the commencement of SCI. Electromyography (EMG) was performed in the last day in order to measure the recruitment index. Immunohistochemistry, reverse transcription-polymerase chain reaction, and transmission electron microscopy evaluations were performed to determine the level of astrogliosis and myelination. Results The results revealed that motor function (MO-hUCBSC: 15 ± 0.3, SCI: 8.2 ± 0.37, p < .001), sensory function (MO-hUCBSC: 3.57 ± 0.19, SCI: 6.38 ± 0.23, p < .001), and EMG recruitment index (MO-hUCBSC: 3.71 ± 0.18, SCI: 1.6 ± 0.1, p < .001) were significantly improved in the MO-hUCBSC group compared with SCI group. Mean cavity area (MO-hUCBSC: 0.03 ± 0.03, SCI: 0.07 ± 0.004, p < .001) was reduced and loss of lower motor neurons (MO-hUCBSC: 7.6 ± 0.43, SCI: 3 ± 0.12, p < .001) and astrogliosis density (MO-hUCBSC: 3.1 ± 0.15, SCI: 6.25 ± 1.42, p < 0.001) in the ventral horn of spinal cord were prevented in MO-hUCBSC group compared with SCI group. Conclusion The results revealed that the combination of MO and hUCBSCs in comparison with the control group has neuroprotective effects in SCI. PMID:27815336

Lack of Impact by SCY-078, a First-in-Class Oral Fungicidal Glucan Synthase Inhibitor, on the Pharmacokinetics of Rosiglitazone, a Substrate for CYP450 2C8, Supports the Low Risk for Clinically Relevant Metabolic Drug-Drug Interactions.

PubMed

Wring, Stephen; Murphy, Gail; Atiee, George; Corr, Christy; Hyman, Michele; Willett, Michael; Angulo, David

2018-05-10

SCY-078, the first in a new class of β 1,3-glucan synthesis inhibitors, is being developed as an oral and intravenous antifungal treatment for Candida and Aspergillus species fungal infections. In vitro, studies indicated SCY-078 is an inhibitor of cytochrome P450 (CYP) 2C8 with markedly lower effect over other CYP isozymes. To examine clinically relevant effects of the potential interaction with SCY-078, this phase 1, open-label, 2-period crossover study evaluated the pharmacokinetic parameters of rosiglitazone, a sensitive substrate of CYP2C8 metabolism, in the absence and presence of SCY-078 dosed to therapeutically relevant SCY-078 concentration exposure after repeat dosing. Healthy adult subjects were randomized to 2 treatment sequences: a single oral 4-mg rosiglitazone dose alone on day 1 or a 1250-mg SCY-078 loading dose on day 1 followed by a once-daily 750-mg SCY-078 dose for an additional 7 days (reflecting the clinical regimen evaluated during phase 2 studies for infections by Candida species) and concurrent administration of a single oral 4-mg rosiglitazone dose on day 3, before alternating following a ≥10-day washout. The exposure to SCY-078 observed in this study was in line with the intended exposure for treatment of invasive fungal infections. The 90% confidence intervals for rosiglitazone exposure geometric mean ratios were within the prespecified no effect interval of 0.70-1.43. Additionally, maximum concentration values for rosiglitazone and its metabolite, N-desmethylrosiglitazone, were not significantly affected by co-administration with SCY-078. Overall, rosiglitazone exposure was not impacted to a clinically meaningful extent with co-administration of therapeutically relevant SCY-078 concentration exposure after repeat dosing. The results are indicative of low risk for interaction of SCY-078 with drugs metabolized via the CYP family of enzymes. © 2018, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.

Mechanical ventilation weaning and extubation after spinal cord injury: a Western Trauma Association multicenter study.

PubMed

Kornblith, Lucy Z; Kutcher, Matthew E; Callcut, Rachael A; Redick, Brittney J; Hu, Charles K; Cogbill, Thomas H; Baker, Christopher C; Shapiro, Mark L; Burlew, Clay C; Kaups, Krista L; DeMoya, Marc A; Haan, James M; Koontz, Christopher H; Zolin, Samuel J; Gordy, Stephanie D; Shatz, David V; Paul, Doug B; Cohen, Mitchell J

2013-12-01

Respiratory failure after acute spinal cord injury (SCI) is well recognized, but data defining which patients need long-term ventilator support and criteria for weaning and extubation are lacking. We hypothesized that many patients with SCI, even those with cervical SCI, can be successfully managed without long-term mechanical ventilation and its associated morbidity. Under the auspices of the Western Trauma Association Multi-Center Trials Group, a retrospective study of patients with SCI at 14 major trauma centers was conducted. Comprehensive injury, demographic, and outcome data on patients with acute SCI were compiled. The primary outcome variable was the need for mechanical ventilation at discharge. Secondary outcomes included the use of tracheostomy and development of acute lung injury and ventilator-associated pneumonia. A total of 360 patients had SCI requiring mechanical ventilation. Sixteen patients were excluded for death within the first 2 days of hospitalization. Of the 344 patients included, 222 (64.5%) had cervical SCI. Notably, 62.6% of the patients with cervical SCI were ventilator free by discharge. One hundred forty-nine patients (43.3%) underwent tracheostomy, and 53.7% of them were successfully weaned from the ventilator, compared with an 85.6% success rate among those with no tracheostomy (p < 0.05). Patients who underwent tracheostomy had significantly higher rates of ventilator-associated pneumonia (61.1% vs. 20.5%, p < 0.05) and acute lung injury (12.8% vs. 3.6%, p < 0.05) and fewer ventilator-free days (1 vs. 24 p < 0.05). When controlled for injury severity, thoracic injury, and respiratory comorbidities, tracheostomy after cervical SCI was an independent predictor of ventilator dependence with an associated 14-fold higher likelihood of prolonged mechanical ventilation (odds ratio, 14.1; 95% confidence interval, 2.78-71.67; p < 0.05). While many patients with SCI require short-term mechanical ventilation, the majority can be successfully weaned before discharge. In patients with SCI, tracheostomy is associated with major morbidity, and its use, especially among patients with cervical SCI, deserves further study. Prognostic study, level III.

SciServer Compute brings Analysis to Big Data in the Cloud

NASA Astrophysics Data System (ADS)

Raddick, Jordan; Medvedev, Dmitry; Lemson, Gerard; Souter, Barbara

2016-06-01

SciServer Compute uses Jupyter Notebooks running within server-side Docker containers attached to big data collections to bring advanced analysis to big data "in the cloud." SciServer Compute is a component in the SciServer Big-Data ecosystem under development at JHU, which will provide a stable, reproducible, sharable virtual research environment.SciServer builds on the popular CasJobs and SkyServer systems that made the Sloan Digital Sky Survey (SDSS) archive one of the most-used astronomical instruments. SciServer extends those systems with server-side computational capabilities and very large scratch storage space, and further extends their functions to a range of other scientific disciplines.Although big datasets like SDSS have revolutionized astronomy research, for further analysis, users are still restricted to downloading the selected data sets locally - but increasing data sizes make this local approach impractical. Instead, researchers need online tools that are co-located with data in a virtual research environment, enabling them to bring their analysis to the data.SciServer supports this using the popular Jupyter notebooks, which allow users to write their own Python and R scripts and execute them on the server with the data (extensions to Matlab and other languages are planned). We have written special-purpose libraries that enable querying the databases and other persistent datasets. Intermediate results can be stored in large scratch space (hundreds of TBs) and analyzed directly from within Python or R with state-of-the-art visualization and machine learning libraries. Users can store science-ready results in their permanent allocation on SciDrive, a Dropbox-like system for sharing and publishing files. Communication between the various components of the SciServer system is managed through SciServer‘s new Single Sign-on Portal.We have created a number of demos to illustrate the capabilities of SciServer Compute, including Python and R scripts accessing a range of datasets and showing the data flow between storage and compute components.Demos, documentation, and more information can be found at www.sciserver.org.SciServer is funded by the National Science Foundation Award ACI-1261715.

Impact of Blood Pressure Dysregulation on Health-Related Quality of Life in Persons With Spinal Cord Injury: Development of a Conceptual Model

PubMed Central

Carlozzi, Noelle E.; Fyffe, Denise; Morin, Kel G.; Byrne, Rachel; Tulsky, David S.; Victorson, David; Lai, Jin-Shei; Wecht, Jill M.

2015-01-01

Objectives To identify medically relevant aspects of blood pressure dysregulation (BPD) related to quality of life in individuals with spinal cord injury (SCI), and to propose an integrated conceptual framework based on input from both individuals with SCI and their clinical providers. This framework will serve as a guide for the development of a patient-reported outcome (PRO) measure specifically related to BPD. Design Three focus groups with individuals with SCI and 3 groups with SCI providers were analyzed using grounded-theory based qualitative analysis to ascertain how blood pressure impacts health-related quality of life (HRQOL) in individuals with SCI. Setting Focus groups were conducted at 2 Veterans Affairs medical centers and a research center. Participants Individuals with SCI (n=27) in 3 focus groups and clinical providers (n=25) in 3 focus groups. Interventions Not applicable. Main Outcome Measures Not applicable. Results Qualitative analysis indicated that all focus groups spent the highest percentage of time discussing symptoms of BPD (39%), followed by precipitators/causes of BPD (16%), preventative actions (15%), corrective actions (12%), and the impact that BPD has on social or emotional functioning (8%). While patient/consumer focus groups and provider focus groups raised similar issues, providers spent more time discussing precipitators/causes of BPD and preventative actions (38%) than patient/consumer groups (24%). Conclusions These results suggest that BPD uniquely and adversely impacts HRQOL in persons with SCI. While both individuals with SCI and their providers highlighted the relevant symptoms of BPD, the SCI providers offered additional detailed information regarding the precipitators/causes and what can be done to prevent/treat BPD. Further, the results suggest that persons with SCI are aware of how BPD impacts their HRQOL and are able to distinguish between subtle signs and symptoms. These findings exemplify the need for a validated and sensitive clinical measurement tool that can assess the extent to which BPD impacts HRQOL in patients with SCI. PMID:23499779

Epidemiology of pediatric spinal cord injury in the United States: years 1997 and 2000.

PubMed

Vitale, Michael G; Goss, Jordan M; Matsumoto, Hiroko; Roye, David P

2006-01-01

The purpose of this study is to report the current incidence rates of pediatric spinal cord injury (SCI) in the United States and identify specific high-risk populations as a knowledge basis for improving the prevention and treatment of this traumatic injury. The Kids' Inpatient Database (KID) and the National Trauma Data Bank (NTDB) were used to investigate the etiology of pediatric SCI. Significant differences in the annual incidence rate of pediatric SCI were found to exist between patient populations stratified by race and sex. African Americans (1.53 cases/100,000 children) exhibit a significantly higher rate of pediatric SCI than native Americans (1.00), Hispanics (0.87), and Asians (0.36), whereas Asians show a significantly lower incidence than all other races. Also, boys (2.79) are more than twice as likely to experience SCI as girls (1.15). The overall incidence of pediatric SCI in the United States is 1.99 cases per 100,000 children. From these data, it is estimated that 1455 children are admitted to US hospitals each year for treatment of SCI. The etiology of pediatric SCI was also investigated, and the major causative factors were identified: motor vehicle accident (56%), accidental fall (14%), firearm injury (9%), and sports injury (7%). Of those children injured in a motor vehicle accident, 67.7% (n = 107) were reported as not wearing a seatbelt. The role of alcohol and drugs was also investigated and found to be involved in 30% (n = 82) of all pediatric SCI cases. Using discharge records from a public database, it is possible to identify high-risk demographic groups and activities that predispose a child to SCI. With a more thorough understanding of the etiology of pediatric SCI, clinicians and parents are better equipped to devise measures for prevention and treatment of this injury.

Simulating the Atmospheric Impact of Criegee Intermediates: Implementation of new understanding in atmospheric chemical mechanisms

NASA Astrophysics Data System (ADS)

Bloss, William; Newland, Mike; Rickard, Andrew; Vereecken, Luc; Evans, Mathew; Munoz, Amalia; Rodenas, Mila

2016-04-01

Unsaturated hydrocarbons - alkenes - account for about 90% of global VOC. Stabilized Criegee Intermediates (SCI) are thought to be formed in the atmosphere mainly from reactions of unsaturated hydrocarbons with ozone. SCI have been shown in laboratory and chamber experiments to rapidly oxidise SO2 and NO2, providing a potentially important gas phase oxidation route for these species in the atmosphere. They have also been implicated in the formation of aerosol and organic acids. However, the importance of SCI reactions with traces gases is critically dependent on the relative ratio of the rate constants for the reactions of the SCI with these and other trace gases, with H2O, and for unimolecular decomposition, which vary between SCIs, and between geometric isomers. The selection of reactions and rate constants is critically important in determining the calculated impact of SCI processes upon atmospheric composition and chemistry. Since the recent resurgence in interest in this chemistry, a number of model studies have been performed, with SCI mechanisms of varying comprehensiveness and accuracy, as the understanding of the community has evolved from new laboratory, theoretical and chamber studies, and field observations. Here we present an assessment of the dependence of modelled SCI abundance, behaviour and impacts upon the Criegee mechanism adopted, in the context of (a) the accepted status quo prior to the laboratory and field studies of Welz et al. and Mauldin et al., (b) changes to the SCI mechanism reflecting new kinetics for key bimolecular reactions, e.g. with SO2 and NO2; (c) emerging understanding of the interactions of SCI with water vapour and their unimolecular decomposition and (d) reactions with other atmospheric trace gases. The modelled SCI behaviour is compared with the results from recent chamber studies, and the resulting calculated SCI abundance and impacts evaluated for urban and forested atmospheric boundary layer scenarios.

The role of cation-dependent chloride transporters in neuropathic pain following spinal cord injury

PubMed Central

Cramer, Samuel W; Baggott, Christopher; Cain, John; Tilghman, Jessica; Allcock, Bradley; Miranpuri, Gurwattan; Rajpal, Sharad; Sun, Dandan; Resnick, Daniel

2008-01-01

Background Altered Cl- homeostasis and GABAergic function are associated with nociceptive input hypersensitivity. This study investigated the role of two major intracellular Cl- regulatory proteins, Na+-K+-Cl- cotransporter 1 (NKCC1) and K+-Cl- cotransporter 2 (KCC2), in neuropathic pain following spinal cord injury (SCI). Results Sprague-Dawley rats underwent a contusive SCI at T9 using the MASCIS impactor. The rats developed hyperalgesia between days 21 and 42 post-SCI. Thermal hyperalgesia (TH) was determined by a decrease in hindpaw thermal withdrawal latency time (WLT) between days 21 and 42 post-SCI. Rats with TH were then treated with either vehicle (saline containing 0.25% NaOH) or NKCC1 inhibitor bumetanide (BU, 30 mg/kg, i.p.) in vehicle. TH was then re-measured at 1 h post-injection. Administration of BU significantly increased the mean WLT in rats (p < 0.05). The group administered with the vehicle alone showed no anti-hyperalgesic effects. Moreover, an increase in NKCC1 protein expression occurred in the lesion epicenter of the spinal cord during day 2–14 post-SCI and peaked on day 14 post-SCI (p < 0.05). Concurrently, a down-regulation of KCC2 protein was detected during day 2–14 post-SCI. The rats with TH exhibited a sustained loss of KCC2 protein during post-SCI days 21–42. No significant changes of these proteins were detected in the rostral region of the spinal cord. Conclusion Taken together, expression of NKCC1 and KCC2 proteins was differentially altered following SCI. The anti-hyperalgesic effect of NKCC1 inhibition suggests that normal or elevated NKCC1 function and loss of KCC2 function play a role in the development and maintenance of SCI-induced neuropathic pain. PMID:18799000

Can FES-rowing mediate bone mineral density in SCI: a pilot study.

PubMed

Gibbons, R S; McCarthy, I D; Gall, A; Stock, C G; Shippen, J; Andrews, B J

2014-11-01

A single case study. To compare proximal tibia trabecular bone mineral density (BMD) of a participant with complete spinal cord injury (SCI), long-termed functional electrical stimulation-rowing (FES-R) trained, with previously reported SCI and non-SCI group norms. To estimate lower limb joint contact forces (JCFs) in the FES-R trained participant. UK University and orthopaedic hospital research centre. Bilateral proximal tibial trabecular BMD of the FES-R trained participant was measured using peripheral quantitative computerised tomography, and the data were compared with SCI and non-SCI groups. An instrumented four-channel FES-R system was used to measure the lower limb JCFs in the FES-R trained participant. Structurally, proximal tibial trabecular BMD was higher in the FES-R trained participant compared with the SCI group, but was less than the non-SCI group. Furthermore, left (184.7 mg cm(-3)) and right (160.7 mg cm(-3)) BMD were well above the threshold associated with non-traumatic fracture. The knee JCFs were above the threshold known to mediate BMD in SCI, but below threshold at the hip and ankle. As pathological fractures predominate in the distal femur and proximal tibia in chronic SCI patients, the fact that the FES-R trained participant's knee JCFs were above those known to partially prevent bone loss, suggests that FES-R training may provide therapeutic benefit. Although the elevated bilateral proximal tibial BMD of the FES-R participant provides circumstantial evidence of osteogenesis, this single case precludes any statement on the clinical significance. Further investigations are required involving larger numbers and additional channels of FES to increase loading at the hip and ankle.

A randomized controlled trial to test the efficacy of the SCI Get Fit Toolkit on leisure-time physical activity behaviour and social-cognitive processes in adults with spinal cord injury.

PubMed

Arbour-Nicitopoulos, Kelly P; Sweet, Shane N; Lamontagne, Marie-Eve; Ginis, Kathleen A Martin; Jeske, Samantha; Routhier, François; Latimer-Cheung, Amy E

2017-01-01

Single blind, two-group randomized controlled trial. To evaluate the efficacy of the SCI Get Fit Toolkit delivered online on theoretical constructs and moderate-to-vigorous physical activity (MVPA) among adults with SCI. Ontario and Quebec, Canada. Inactive, English- and French-speaking Canadian adults with traumatic SCI with Internet access, and no self-reported cognitive or memory impairments. Participants ( N =90 M age =48.12±11.29 years; 79% male) were randomized to view the SCI Get Fit Toolkit or the Physical Activity Guidelines for adults with SCI (PAG-SCI) online. Primary (intentions) and secondary (outcome expectancies, self-efficacy, planning and MVPA behaviour) outcomes were assessed over a 1-month period. Of the 90 participants randomized, 77 were included in the analyses. Participants viewed the experimental stimuli only briefly, reading the 4-page toolkit for approximately 2.5 min longer than the 1-page guideline document. No condition effects were found for intentions, outcome expectancies, self-efficacy, and planning (ΔR 2 ⩽0.03). Individuals in the toolkit condition were more likely to participate in at least one bout of 20 min of MVPA behaviour at 1-week post-intervention compared to individuals in the guidelines condition (OR=3.54, 95% CI=0.95, 13.17). However, no differences were found when examining change in weekly minutes of MVPA or comparing whether participants met the PAG-SCI. No firm conclusions can be made regarding the impact of the SCI Get Fit Toolkit in comparison to the PAG-SCI on social cognitions and MVPA behaviour. The limited online access to this resource may partially explain these null findings.

Activation of KCNQ Channels Suppresses Spontaneous Activity in Dorsal Root Ganglion Neurons and Reduces Chronic Pain after Spinal Cord Injury

PubMed Central

Wu, Zizhen; Li, Lin; Xie, Fuhua; Du, Junhui; Zuo, Yan; Frost, Jeffrey A.; Carlton, Susan M.; Walters, Edgar T.

2017-01-01

Abstract A majority of people who have sustained spinal cord injury (SCI) experience chronic pain after injury, and this pain is highly resistant to available treatments. Contusive SCI in rats at T10 results in hyperexcitability of primary sensory neurons, which contributes to chronic pain. KCNQ channels are widely expressed in nociceptive dorsal root ganglion (DRG) neurons, are important for controlling their excitability, and their activation has proven effective in reducing pain in peripheral nerve injury and inflammation models. The possibility that activators of KCNQ channels could be useful for treating SCI-induced chronic pain is strongly supported by the following findings. First, SCI, unlike peripheral nerve injury, failed to decrease the functional or biochemical expression of KCNQ channels in DRG as revealed by electrophysiology, real-time quantitative polymerase chain reaction, and Western blot; therefore, these channels remain available for pharmacological targeting of SCI pain. Second, treatment with retigabine, a specific KCNQ channel opener, profoundly decreased spontaneous activity in primary sensory neurons of SCI animals both in vitro and in vivo without changing the peripheral mechanical threshold. Third, retigabine reversed SCI-induced reflex hypersensitivity, adding to our previous demonstration that retigabine supports the conditioning of place preference after SCI (an operant measure of spontaneous pain). In contrast to SCI animals, naïve animals showed no effects of retigabine on reflex sensitivity or conditioned place preference by pairing with retigabine, indicating that a dose that blocks chronic pain-related behavior has no effect on normal pain sensitivity or motivational state. These results encourage the further exploration of U.S. Food and Drug Administration–approved KCNQ activators for treating SCI pain, as well as efforts to develop a new generation of KCNQ activators that lack central side effects. PMID:28073317

Activation of KCNQ Channels Suppresses Spontaneous Activity in Dorsal Root Ganglion Neurons and Reduces Chronic Pain after Spinal Cord Injury.

PubMed

Wu, Zizhen; Li, Lin; Xie, Fuhua; Du, Junhui; Zuo, Yan; Frost, Jeffrey A; Carlton, Susan M; Walters, Edgar T; Yang, Qing

2017-03-15

A majority of people who have sustained spinal cord injury (SCI) experience chronic pain after injury, and this pain is highly resistant to available treatments. Contusive SCI in rats at T10 results in hyperexcitability of primary sensory neurons, which contributes to chronic pain. KCNQ channels are widely expressed in nociceptive dorsal root ganglion (DRG) neurons, are important for controlling their excitability, and their activation has proven effective in reducing pain in peripheral nerve injury and inflammation models. The possibility that activators of KCNQ channels could be useful for treating SCI-induced chronic pain is strongly supported by the following findings. First, SCI, unlike peripheral nerve injury, failed to decrease the functional or biochemical expression of KCNQ channels in DRG as revealed by electrophysiology, real-time quantitative polymerase chain reaction, and Western blot; therefore, these channels remain available for pharmacological targeting of SCI pain. Second, treatment with retigabine, a specific KCNQ channel opener, profoundly decreased spontaneous activity in primary sensory neurons of SCI animals both in vitro and in vivo without changing the peripheral mechanical threshold. Third, retigabine reversed SCI-induced reflex hypersensitivity, adding to our previous demonstration that retigabine supports the conditioning of place preference after SCI (an operant measure of spontaneous pain). In contrast to SCI animals, naïve animals showed no effects of retigabine on reflex sensitivity or conditioned place preference by pairing with retigabine, indicating that a dose that blocks chronic pain-related behavior has no effect on normal pain sensitivity or motivational state. These results encourage the further exploration of U.S. Food and Drug Administration-approved KCNQ activators for treating SCI pain, as well as efforts to develop a new generation of KCNQ activators that lack central side effects.

Patients with Spinal Cord Injuries Favor Administration of Methylprednisolone

PubMed Central

Bowers, Christian A.; Kundu, Bornali; Rosenbluth, Jeffrey; Hawryluk, Gregory W. J.

2016-01-01

Methylprednisolone sodium succinate (MPSS) for treatment of acute spinal cord injury (SCI) has been associated with both benefits and adverse events. MPSS administration was the standard of care for acute SCI until recently when its use has become controversial. Patients with SCI have had little input in the debate, thus we sought to learn their opinions regarding administration of MPSS. A summary of the published literature to date on MPSS use for acute SCI was created and adjudicated by 28 SCI experts. This summary was then emailed to 384 chronic SCI patients along with a survey that interrogated the patients’ neurological deficits, communication with physicians and their views on MPSS administration. 77 out of 384 patients completed the survey. 28 respondents indicated being able to speak early after injury and of these 24 reported arriving at the hospital within 8 hours of injury. One recalled a physician speaking to them about MPSS and one patient reported choosing whether or not to receive MPSS. 59.4% felt that the small neurological benefits associated with MPSS were ‘very important’ to them (p<0.0001). Patients had ‘little concern’ for potential side-effects of MPSS (p = 0.001). Only 1.4% felt that MPSS should not be given to SCI patients regardless of degree of injury (p<0.0001). This is the first study to report SCI patients’ preferences regarding MPSS treatment for acute SCI. Patients favor the administration of MPSS for acute SCI, however few had input into whether or not it was administered. Conscious patients should be given greater opportunity to decide their treatment. These results also provide some guidance regarding MPSS administration in patients unable to communicate. PMID:26789007

The Economic Burden of Urinary Tract Infection and Pressure Ulceration in Acute Traumatic Spinal Cord Injury Admissions: Evidence for Comparative Economics and Decision Analytics from a Matched Case-Control Study.

PubMed

White, Barry A B; Dea, Nicolas; Street, John T; Cheng, Christiana L; Rivers, Carly S; Attabib, Najmedden; Kwon, Brian K; Fisher, Charles G; Dvorak, Marcel F

2017-10-15

Secondary complications of spinal cord injury (SCI) are a burden to affected individuals and the rest of society. There is limited evidence of the economic burden or cost of complications in SCI populations in Canada, however, which is necessary for comparative economic analyses and decision analytic modeling of possible solutions to these common health problems. Comparative economic analyses can inform resource allocation decisions, but the outputs are only as good as the inputs. In this article, new evidence of the excess or incremental costs of urinary tract infection (UTI) and pressure ulceration (PU) in acute traumatic SCI from an exploratory case series analysis of admissions to a Level I specialized Canadian spine facility (2008-2013) is presented. Participants in a national SCI registry were case-control matched (1:1) on the predicted probability of experiencing UTI or PU during initial acute SCI admission. The excess costs of UTI and PU are estimated as the mean of the differences in total direct acute SCI admission costs (length of stay, accommodation, nursing, pharmacy) from the perspective of the admitting facility between participants matched or paired on demographic and SCI characteristics. Even relatively minor UTI and PU, respectively, added an average of $7,790 (standard deviation [SD] $6,267) and $18,758 (SD $27,574) to the direct cost of acute SCI admission in 2013 Canadian dollars (CAD). This case series analysis established evidence of the excess costs of UTI and PU in acute SCI admissions, which will support decision-informing analyses in SCI.

Cardiac dysfunctions following spinal cord injury

PubMed Central

Sandu, AM; Popescu, M; Iacobini, MA; Stoian, R; Neascu, C; Popa, F

2009-01-01

The aim of this article is to analyze cardiac dysfunctions occurring after spinal cord injury (SCI). Cardiac dysfunctions are common complications following SCI. Cardiovascular disturbances are the leading causes of morbidity and mortality in both acute and chronic stages of SCI. We reviewed epidemiology of cardiac disturbances after SCI, and neuroanatomy and pathophysiology of autonomic nervous system, sympathetic and parasympathetic. SCI causes disruption of descendent pathways from central control centers to spinal sympathetic neurons, originating into intermediolateral nuclei of T1–L2 spinal cord segments. Loss of supraspinal control over sympathetic nervous system results in reduced overall sympathetic activity below the level of injury and unopposed parasympathetic outflow through intact vagal nerve. SCI associates significant cardiac dysfunction. Impairment of autonomic nervous control system, mostly in patients with cervical or high thoracic SCI, causes cardiac dysrrhythmias, especially bradycardia and, rarely, cardiac arrest, or tachyarrhytmias and hypotension. Specific complication dependent on the period of time after trauma like spinal shock and autonomic dysreflexia are also reviewed. Spinal shock occurs during the acute phase following SCI and is a transitory suspension of function and reflexes below the level of the injury. Neurogenic shock, part of spinal shock, consists of severe bradycardia and hypotension. Autonomic dysreflexia appears during the chronic phase, after spinal shock resolution, and it is a life–threatening syndrome of massive imbalanced reflex sympathetic discharge occurring in patients with SCI above the splanchnic sympathetic outflow (T5–T6). Besides all this, additional cardiac complications, such as cardiac deconditioning and coronary heart disease may also occur. Proper prophylaxis, including nonpharmacologic and pharmacological strategies and cardiac rehabilitation diminish occurrence of the cardiac dysfunction following SCI. Each type of cardiac disturbance requires specific treatment. PMID:20108532

Anabolic steroids reduce spinal cord injury-related bone loss in rats associated with increased Wnt signaling

PubMed Central

Sun, Li; Pan, Jiangping; Peng, Yuanzhen; Wu, Yong; Li, Jianghua; Liu, Xuan; Qin, Yiwen; Bauman, William A.; Cardozo, Christopher; Zaidi, Mone; Qin, Weiping

2013-01-01

Background Spinal cord injury (SCI) causes severe bone loss. At present, there is no practical treatment to delay or prevent bone loss in individuals with motor-complete SCI. Hypogonadism is common in men after SCI and may exacerbate bone loss. The anabolic steroid nandrolone reduces bone loss due to microgravity or nerve transection. Objective To determine whether nandrolone reduced bone loss after SCI and, if so, to explore the mechanisms of nandrolone action. Methods Male rats with complete transection of the spinal cord were administered nandrolone combined with a physiological replacement dose of testosterone, or vehicle, beginning on day 29 after SCI and continued for 28 days. Results SCI reduced distal femoral and proximal tibial bone mineral density (BMD) by 25 and 16%, respectively, at 56 days. This bone loss was attenuated by nandrolone. In ex vivo osteoclasts cultures, SCI increased mRNA levels for tartrate-resistant acid phosphatase (TRAP) and calcitonin receptor; nandrolone-normalized expression levels of these transcripts. In ex vivo osteoblast cultures, SCI increased receptor activator of NF-kB ligand (RANKL) mRNA levels but did not alter osteoprotegerin (OPG) mRNA expression; nandrolone-increased expression of OPG and OPG/RANKL ratio. SCI reduced mRNA levels of Wnt signaling-related genes Wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5), Fzd5, Tcf7, and ectodermal-neural cortex 1 (ENC1) in osteoblasts, whereas nandrolone increased expression of each of these genes. Conclusions The results demonstrate that nandrolone reduces bone loss after SCI. A potential mechanism is suggested by our findings wherein nandrolone modulates genes for differentiation and activity of osteoclasts and osteoblasts, at least in part, through the activation of Wnt signaling. PMID:24090150

Semen quality in ejaculates produced by masturbation in men with spinal cord injury.

PubMed

Kathiresan, A S Q; Ibrahim, E; Modh, R; Aballa, T C; Lynne, C M; Brackett, N L

2012-12-01

Retrospective study. Most men with spinal cord injury are anejaculatory. Much has been reported about their semen quality collected by penile vibratory stimulation and electroejaculation (EEJ). What is not well-described is the nature of semen quality in SCI patients who can ejaculate by masturbation. This study was performed to understand the degree to which their semen quality differed from that of anejaculatory SCI patients versus that of healthy non-SCI control subjects. University of Miami. Retrospective chart review of Male Fertility Research Program participants from 1991 to 2011. Of 528 SCI subjects, 444 met inclusion criteria of completing an algorithm in which ejaculation occurred by masturbation (n=43), PVS (n=243), or EEJ (n=158). Sperm motility was higher in the SCI-masturbation group (36.9%) than the PVS group (25.9%, P<0.001) or EEJ group (15.0%, P<0.001), but lower compared with a control group of 61 non-SCI healthy men who collected their semen by masturbation (58.0%, P<0.001). The SCI-masturbation group had similar antegrade sperm concentration (83.3×10(6) cc(-1)) as the PVS group (77.4×10(6) cc(-1)) and control group (82.0×10(6) cc(-1)), but higher than the EEJ group (49.8×10(6) cc(-1), P<0.001). The SCI-masturbation group had significantly more men with incomplete injuries (84%) than the PVS group (54%, P<0.01) or EEJ group (41%, P<0.001). This is the first report focusing on semen quality obtained by masturbation in men with SCI. Sperm motility was higher in men with SCI who could, versus could not, ejaculate by masturbation. Completeness of injury may contribute to this difference.

The effects of using the Internet on the health-related quality of life in people with spinal cord injury: a controlled study.

PubMed

Celik, B; Ones, K; Celik, E C; Bugdayci, D S; Paker, N; Avci, C; Ince, N

2014-05-01

Prospective cohort study. To compare the health-related quality of life (HRQoL) in people with spinal cord injury (SCI) who use the Internet versus those who don't and with a control group of able-bodied individuals. To investigate the frequency of Internet usage before and after injury. To evaluate the differences in terms of demographic features of both groups, analyze the variation in the Internet usage pattern of people with SCI before and after the injury. Istanbul, Turkey. A total of 60 people with SCI (38 Internet users, 22 nonusers) were included in the study. The control group consisted of 33 healthy persons of similar age and sex. The HRQoL was evaluated with the SF-36 Health Survey. The scores of all the subscales of the SF-36, except vitality, were significantly lower in people with SCI than those of the controls'. The bodily pain subscale and physical component scores were found to be significantly higher in people with SCI using the Internet than the nonuser group with SCI (P<0.05). The Internet usage frequency increased significantly in people with SCI after injury (P<0.05). A significant correlation was found between time since injury and Internet use (r=0.365, P=0.007). Although HRQoL scores were lower in people with an SCI, the physical status component score was better in the Internet user SCI group. As there is a significant increase in the time spent online after injury, the Internet could be an effective modality to contact and educate people with an SCI.

RNA-Seq Analysis of Microglia Reveals Time-Dependent Activation of Specific Genetic Programs following Spinal Cord Injury

PubMed Central

Noristani, Harun N.; Gerber, Yannick N.; Sabourin, Jean-Charles; Le Corre, Marine; Lonjon, Nicolas; Mestre-Frances, Nadine; Hirbec, Hélène E.; Perrin, Florence E.

2017-01-01

Neurons have inherent competence to regrow following injury, although not spontaneously. Spinal cord injury (SCI) induces a pronounced neuroinflammation driven by resident microglia and infiltrating peripheral macrophages. Microglia are the first reactive glial population after SCI and participate in recruitment of monocyte-derived macrophages to the lesion site. Both positive and negative influence of microglia and macrophages on axonal regeneration had been reported after SCI, raising the issue whether their response depends on time post-lesion or different lesion severity. We analyzed molecular alterations in microglia at several time-points after different SCI severities using RNA-sequencing. We demonstrate that activation of microglia is time-dependent post-injury but is independent of lesion severity. Early transcriptomic response of microglia after SCI involves proliferation and neuroprotection, which is then switched to neuroinflammation at later stages. Moreover, SCI induces an autologous microglial expression of astrocytic markers with over 6% of microglia expressing glial fibrillary acidic protein and vimentin from as early as 72 h post-lesion and up to 6 weeks after injury. We also identified the potential involvement of DNA damage and in particular tumor suppressor gene breast cancer susceptibility gene 1 (Brca1) in microglia after SCI. Finally, we established that BRCA1 protein is specifically expressed in non-human primate spinal microglia and is upregulated after SCI. Our data provide the first transcriptomic analysis of microglia at multiple stages after different SCI severities. Injury-induced microglia expression of astrocytic markers at RNA and protein levels demonstrates novel insights into microglia plasticity. Finally, increased microglia expression of BRCA1 in rodents and non-human primate model of SCI, suggests the involvement of oncogenic proteins after CNS lesion. PMID:28420963

Delayed Influence of Spinal Cord Injury on the Amino Acids of NO• Metabolism in Rat Cerebral Cortex Is Attenuated by Thiamine

PubMed Central

Boyko, Alexandra; Ksenofontov, Alexander; Ryabov, Sergey; Baratova, Lyudmila; Graf, Anastasia; Bunik, Victoria

2018-01-01

Severe spinal cord injuries (SCIs) result in chronic neuroinflammation in the brain, associated with the development of cognitive and behavioral impairments. Nitric oxide (NO•) is a gaseous messenger involved in neuronal signaling and inflammation, contributing to nitrosative stress under dysregulated production of reactive nitrogen species. In this work, biochemical changes induced in the cerebral cortex of rats 8 weeks after SCI are assessed by quantification of the levels of amino acids participating in the NO• and glutathione metabolism. The contribution of the injury-induced neurodegeneration is revealed by comparison of the SCI- and laminectomy (LE)-subjected animals. Effects of the operative interventions are assessed by comparison of the operated (LE/SCI) and non-operated animals. Lower ratios of citrulline (Cit) to arginine (Arg) or Cit to ornithine and a more profound decrease in the ratio of lysine to glycine distinguish SCI animals from those after LE. The data suggest decreased NO• production from both Arg and homoarginine in the cortex 8 weeks after SCI. Both LE and SCI groups show a strong decrease in the level of cortex glutathione. The neurotropic, anti-inflammatory, and antioxidant actions of thiamine (vitamin B1) prompted us to study the thiamine effects on the SCI-induced changes in the NO• and glutathione metabolism. A thiamine injection (400 mg/kg intraperitoneally) within 24 h after SCI abrogates the changes in the cerebral cortex amino acids related to NO•. Thiamine-induced normalization of the brain glutathione levels after LE and SCI may involve increased supply of glutamate for glutathione biosynthesis. Thus, thiamine protects from sequelae of SCI on NO•-related amino acids and glutathione in cerebral cortex. PMID:29379782

Neuro magnetic resonance spectroscopy using wavelet decomposition and statistical testing identifies biochemical changes in people with spinal cord injury and pain.

PubMed

Stanwell, Peter; Siddall, Philip; Keshava, Nirmal; Cocuzzo, Daniel; Ramadan, Saadallah; Lin, Alexander; Herbert, David; Craig, Ashley; Tran, Yvonne; Middleton, James; Gautam, Shiva; Cousins, Michael; Mountford, Carolyn

2010-11-01

Spinal cord injury (SCI) can be accompanied by chronic pain, the mechanisms for which are poorly understood. Here we report that magnetic resonance spectroscopy measurements from the brain, collected at 3T, and processed using wavelet-based feature extraction and classification algorithms, can identify biochemical changes that distinguish control subjects from subjects with SCI as well as subdividing the SCI group into those with and without chronic pain. The results from control subjects (n=10) were compared to those with SCI (n=10). The SCI cohort was made up of subjects with chronic neuropathic pain (n=5) and those without chronic pain (n=5). The wavelet-based decomposition of frequency domain MRS signals employs statistical significance testing to identify features best suited to discriminate different classes. Moreover, the features benefit from careful attention to the post-processing of the spectroscopy data prior to the comparison of the three cohorts. The spectroscopy data, from the thalamus, best distinguished control subjects without SCI from those with SCI with a sensitivity and specificity of 0.9 (Percentage of Correct Classification). The spectroscopy data obtained from the prefrontal cortex and anterior cingulate cortex both distinguished between SCI subjects with chronic neuropathic pain and those without pain with a sensitivity and specificity of 1.0. In this study, where two underlying mechanisms co-exist (i.e. SCI and pain), the thalamic changes appear to be linked more strongly to SCI, while the anterior cingulate cortex and prefrontal cortex changes appear to be specifically linked to the presence of pain. Copyright 2010 Elsevier Inc. All rights reserved.

Mental health and life satisfaction of individuals with spinal cord injury and their partners 5 years after discharge from first inpatient rehabilitation.

PubMed

Scholten, Eline W M; Tromp, Maria E H; Hillebregt, Chantal F; de Groot, Sonja; Ketelaar, Marjolijn; Visser-Meily, Johanna M A; Post, Marcel W M

2018-06-01

Cross-sectional study. To describe and compare mental health and life satisfaction between individuals with spinal cord injury (SCI) and their partners 5 years after discharge from first inpatient rehabilitation; and to examine if injury severity moderates the association between individuals' with SCI and their partners' mental health and life satisfaction. Dutch community. Sixty-five individuals with SCI and their partners completed a self-report questionnaire. Main outcome measures were the mental health subscale of the Short-Form Health Survey and the Life Satisfaction Questionnaire. Levels of mental health and life satisfaction of individuals with SCI and partners were similar, with median scores of 76 and 4.8 versus 76 and 4.6, respectively. Moderate to strong correlations between individuals with SCI and their partners were found for the mental health (r S  = 0.35) and life satisfaction scores (r S  = 0.51). These associations were generally stronger in the subgroup of individuals with less severe SCI. Associations between scores on separate life domains ranged from negligible (0.05) to moderate (0.53). Individuals with SCI and their partners were least satisfied with their 'sexual life'. Compared with their partners, individuals with SCI were significantly more satisfied in the domains 'leisure situation', 'partnership relation' and 'family life', and less satisfied in 'self-care ability'. This study showed similarities but also differences in mental health and life satisfaction between individuals with SCI and their partners. In clinical practice, attention on mental health and life satisfaction should, therefore, focus on different domains for individuals with SCI and partners.

How Do Iranian People with Spinal Cord Injury Understand Marriage?

PubMed Central

Merghati-Khoei, Effat; Maasoumi, Raziyeh; Zarei, Fatemeh; Laleh, Leila; Pasha, Yousofreza Yousofnia; Korte, Jeffrey E.

2017-01-01

Background: Spinal cord injury (SCI) is a life-altering experience. There is little information about the perspectives of people with SCI toward marriage. Purpose: To explore the understandings of Iranian adults with SCI about marriage. Methods: In this qualitative inquiry, using a semi-structured interview guide, we collected data from 53 single adults with SCI (41 men and 12 women) who were referred to the Brain and Spinal Cord Injury Research Center, Tehran University of Medical Sciences in Tehran. Barun and Clarke's thematic analysis approach was applied for data analysis. Results: “Marriage” was thematized in outer and inner scenarios. The outer scenario was explored in terms of physical disability identified as a seminal determinant in successful marriage. “Attractiveness,” “able body for breadwinning,” “sexually active,” and “reproduction” were dominant concepts extracted from the participants' narratives. The participants' inner scenarios revealed that marriage would be welcomed if a potential partner accepted them as a “whole person” regardless of their SCI condition. Conclusion: The findings suggest that adults with SCI do not ignore or reject marriage, however it was not their life priority due to major concerns that they had internalized. Considering the quality of care, people with SCI must be reassured about their potential to get married. SCI-based sexuality education and premarital counseling support the patients in their postmarital lives. Our findings will provide decision makers and health providers with significant insight for utilizing culturally appropriate services for people with SCI. PMID:29339879

Effects of melatonin on severe crush spinal cord injury-induced reactive astrocyte and scar formation.

PubMed

Krityakiarana, Warin; Sompup, Kamonrapat; Jongkamonwiwat, Nopporn; Mukda, Sujira; Pinilla, Fernando Gomez; Govitrapong, Piyarat; Phansuwan-Pujito, Pansiri

2016-12-01

The present work aimed at analyzing the effects of melatonin on scar formation after spinal cord injury (SCI). Upregulation of reactive astrocyte under SCI pathological conditions has been presented in several studies. It has been proved that the crucial factor in triggering this upregulation is proinflammatory cytokines. Moreover, scar formation is an important barrier to axonal regeneration through the lesion area. Melatonin plays an important role in reducing inflammation, but its effects on scar formation in the injured spinal cord remain unknown. Hence, we used the model of severe crush injury in mice to investigate the effects of melatonin on scar formation. Mice were randomly separated into four groups; SCI, SCI+Melatonin 1 (single dose), SCI+Melatonin 14 (14 daily doses), and control. Melatonin was administered by intraperitoneal injection (10 mg/kg) after injury. Immunohistochemical analysis, Western blot, and behavioral evaluation were used to explore the effects of melatonin after SCI for 14 days. The melatonin-treated mice presented higher expression of neuronal markers (P < 0.001). Remarkably, the inflammatory response appeared to be greatly reduced in the SCI+Melatonin 14 group (P < 0.001), which also displayed less scar formation (P < 0.05). These findings suggest that melatonin inhibits scar formation by acting on inflammatory cytokines after SCI. Overall, our results suggest that melatonin is a promising treatment strategy after SCI that deserves further investigation. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Pathological activity in mediodorsal thalamus of rats with spinal cord injury pain.

PubMed

Whitt, Jessica L; Masri, Radi; Pulimood, Nisha S; Keller, Asaf

2013-02-27

Spinal cord injury (SCI) results not only in motor deficits, but produces, in many patients, excruciating chronic pain (SCI pain). We have previously shown, in a rodent model, that SCI causes suppression of activity in the GABAergic nucleus, the zona incerta (ZI), and concomitant increased activity in one of its main targets, the posterior nucleus of the thalamus (PO); the increased PO activity is correlated with the maintenance and expression of hyperalgesia after SCI. Here, we test the hypothesis that SCI causes a similar pathological increase in other thalamic nuclei regulated by the ZI, specifically the mediodorsal thalamus (MD), which is involved in the emotional-affective aspects of pain. We recorded single and multiunit activity from MD of either anesthetized or awake rats, and compared data from rats with SCI with data from sham-operated controls (anesthetized experiments) or with data from the same animals prelesion (awake experiments). Consistent with our hypothesis, MD neurons from rats with SCI show significant increases in spontaneous firing rates and in the magnitude and duration of responses to noxious stimuli. In a subset of anesthetized animals, similar changes in activity of MD neurons were produced by pharmacologically inactivating ZI in naive rats, suggesting that the changes in the MD after SCI are related to suppressed inhibition from the ZI. These data support our hypothesis that SCI pain results, at least in part, from a loss of inhibition to thalamic nuclei associated with both the sensory-discriminative and emotional-affective components of pain.

Earnings among people with spinal cord injury.

PubMed

Ramakrishnan, K; Loh, S Y; Omar, Z

2011-09-01

Secondary analysis of cross-sectional data. To identify differences in earnings among participants with spinal cord injury (SCI) and their relation to demographic, injury, educational and employment-related factors. People living with SCI in the community who were members of a disability support organization. A total of 76 members who have had traumatic SCI for at least 2 years, between 15 and 64 years of age at time of study and were working before SCI were interviewed over the phone. The earnings were categorized as more, same or less than before SCI or no income for those unemployed. Of the 76 participants (who averaged about 15.1 years post SCI), only 13 participants (17.1%) were earning more than before injury, whereas majority were in the category of having no income, being unemployed at time of study, n=36 (47.4%). Factors positively related to earnings were having more years in education, both at time of injury and at time of survey. As anticipated, those currently in full time and paid employments were earning more while receipt of financial compensation was negatively related to earnings. Despite a lengthy period of time post SCI, only a minority were earning more, reflecting poorly on the quality of post SCI employment experience. The rehabilitation team should therefore focus on improving both educational and vocational opportunities for persons with SCI and aim for full time, paid employments. The current workers' compensation scheme renders the recipient at a static income and may need to be revised.

Physical activity is related to lower levels of pain, fatigue and depression in individuals with spinal-cord injury: a correlational study.

PubMed

Tawashy, A E; Eng, J J; Lin, K H; Tang, P F; Hung, C

2009-04-01

This was a prospective cross-sectional study for people with chronic spinal cord injury (SCI). To (1) evaluate the intensity level and nature of physical activity in community-dwelling individuals living with SCI, and (2) explore the relation between descriptive individual variables (for example, lesion level), secondary complications and participation in physical activity. Urban community setting. A total of 49 subjects with SCI who used a manual wheelchair for primary mode of mobility (mean years since injury, 11.8; mean age, 43.7 years; 67% paraplegia) completed the physical activity recall assessment for people with SCI (PARA-SCI). Approximately 50% of reported physical activity among individuals with SCI is due to activities of daily living. The amount of physical activity was not related to lesion level, age, body mass index or waistline size. Greater heavy-intensity activity was related to lower levels of pain and fatigue and higher levels of self-efficacy, whereas higher amounts of mild-intensity activity and total activity were related to less depressive symptoms. Activities of daily living are a large component for physical activity among individuals with SCI. It appears that greater physical activity is associated with less secondary complications (pain, fatigue and depression) in individuals with SCI.

[Subjective cognitive impairment and Alzheimer's disease: a two year follow up of 51 subjects during two years].

PubMed

Sambuchi, Nathalie; Muraccioli, Isabelle; Alescio-Lautier, Béatrice; Paban, Véronique; Sambuc, Roland; Jouve, Élisabeth; Geda, Yonas Endale; Petersen, Ronald Karl; Michel, Bernard François

2015-12-01

Subjective cognitive impairment (SCI) is defined by a state of subjective complaint, without objective cognitive deterioration. Amnestic mild cognitive impairment (A-MCI), which characterizes a syndrome between normal cognitive aging and early Alzheimer's disease (E-AD), is preceded by A-MCI from many years. SCI expresses a metacognitive impairment. A cohort of 51 subjects [7 normal controls (NC), 28 SCI, 12 A-MCI and 5 E-AD] was followed up during 24 months, with a neuropsychological evaluation each 6 months during 1 year (V1, V2, V3), then 1 year later (V4). Among the 28 SCI, 6 converted to A-MCI at V4 (21.42%), 1 to A-MCI-A at V3, then to E-AD at V4. These results suggest a continuum from SCI to A-MCI, and E-AD. Progressive SCI differed from non-progressive SCI on verbal episodic memory and executive functions tests at the initial examination. MRI showed anterior cingular atrophy in all SCI patients but hippocampal atrophy was only observed in 20 patients. Our results suggest that metacognition impairment is the expression of a dysfunction in the anterior pre-frontal cortex, in correlation with a syndrome of hyper-attention.

From basics to clinical: a comprehensive review on spinal cord injury.

PubMed

Silva, Nuno A; Sousa, Nuno; Reis, Rui L; Salgado, António J

2014-03-01

Spinal cord injury (SCI) is a devastating neurological disorder that affects thousands of individuals each year. Over the past decades an enormous progress has been made in our understanding of the molecular and cellular events generated by SCI, providing insights into crucial mechanisms that contribute to tissue damage and regenerative failure of injured neurons. Current treatment options for SCI include the use of high dose methylprednisolone, surgical interventions to stabilize and decompress the spinal cord, and rehabilitative care. Nonetheless, SCI is still a harmful condition for which there is yet no cure. Cellular, molecular, rehabilitative training and combinatorial therapies have shown promising results in animal models. Nevertheless, work remains to be done to ascertain whether any of these therapies can safely improve patient's condition after human SCI. This review provides an extensive overview of SCI research, as well as its clinical component. It starts covering areas from physiology and anatomy of the spinal cord, neuropathology of the SCI, current clinical options, neuronal plasticity after SCI, animal models and techniques to assess recovery, focusing the subsequent discussion on a variety of promising neuroprotective, cell-based and combinatorial therapeutic approaches that have recently moved, or are close, to clinical testing. Copyright © 2013 Elsevier Ltd. All rights reserved.

ComSciCon: The Communicating Science Workshop for Graduate Students

NASA Astrophysics Data System (ADS)

Sanders, Nathan; Drout, Maria; Kohler, Susanna; Cook, Ben; ComSciCon Leadership Team

2018-01-01

ComSciCon (comscicon.com) is a national workshop series organized by graduate students, for graduate students, focused on leadership and training in science communication. Our goal is to empower young scientists to become leaders in their field, propagating appreciation and understanding of research results to broad and diverse audiences. ComSciCon attendees meet and interact with professional communicators, build lasting networks with graduate students in all fields of science and engineering from around the country, and write and publish original works. ComSciCon consists of both a flagship national conference series run annually for future leaders in science communication, and a series of regional and specialized workshops organized by ComSciCon alumni nationwide. We routinely receive over 1000 applications for 50 spots in our national workshop. Since its founding in 2012, over 300 STEM graduate students have participated in the national workshop, and 23 local spin-off workshops have been organized in 10 different locations throughout the country. This year, ComSciCon is working to grow as a self-sustaining organization by launching as an independent 501(c)(3) non-profit. In this poster we will discuss the ComSciCon program and methods, our results to date, potential future collaborations between ComSciCon and AAS, and how you can become involved.

Melatonin Inhibits Neural Cell Apoptosis and Promotes Locomotor Recovery via Activation of the Wnt/β-Catenin Signaling Pathway After Spinal Cord Injury.

PubMed

Shen, Zhaoliang; Zhou, Zipeng; Gao, Shuang; Guo, Yue; Gao, Kai; Wang, Haoyu; Dang, Xiaoqian

2017-08-01

The spinal cord is highly sensitive to spinal cord injury (SCI) by external mechanical damage, resulting in irreversible neurological damage. Activation of the Wnt/β-catenin signaling pathway can effectively reduce apoptosis and protect against SCI. Melatonin, an indoleamine originally isolated from bovine pineal tissue, exerts neuroprotective effects after SCI through activation of the Wnt/β-catenin signaling pathway. In this study, we demonstrated that melatonin exhibited neuroprotective effects on neuronal apoptosis and supported functional recovery in a rat SCI model by activating the Wnt/β-catenin signaling pathway. We found that melatonin administration after SCI significantly upregulated the expression of low-density lipoprotein receptor related protein 6 phosphorylation (p-LRP-6), lymphoid enhancer factor-1 (LEF-1) and β-catenin protein in the spinal cord. Melatonin enhanced motor neuronal survival in the spinal cord ventral horn and improved the locomotor functions of rats after SCI. Melatonin administration after SCI also reduced the expression levels of Bax and cleaved caspase-3 in the spinal cord and the proportion of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) positive cells, but increased the expression level of Bcl-2. These results suggest that melatonin attenuated SCI by activating the Wnt/β-catenin signaling pathway.

Developing a spinal cord injury research strategy using a structured process of evidence review and stakeholder dialogue. Part III: outcomes.

PubMed

Middleton, J W; Piccenna, L; Lindsay Gruen, R; Williams, S; Creasey, G; Dunlop, S; Brown, D; Batchelor, P E; Berlowitz, D J; Coates, S; Dunn, J A; Furness, J B; Galea, M P; Geraghty, T; Kwon, B K; Urquhart, S; Yates, D; Bragge, P

2015-10-01

Focus Group. To develop a unified, regional spinal cord injury (SCI) research strategy for Australia and New Zealand. Australia. A 1-day structured stakeholder dialogue was convened in 2013 in Melbourne, Australia, by the National Trauma Research Institute in collaboration with the SCI Network of Australia and New Zealand. Twenty-three experts participated, representing local and international research, clinical, consumer, advocacy, government policy and funding perspectives. Preparatory work synthesised evidence and articulated draft principles and options as a starting point for discussion. A regional SCI research strategy was proposed, whose objectives can be summarised under four themes. (1) Collaborative networks and strategic partnerships to increase efficiency, reduce duplication, build capacity and optimise research funding. (2) Research priority setting and coordination to manage competing studies. (3) Mechanisms for greater consumer engagement in research. (4) Resources and infrastructure to further develop SCI data registries, evaluate research translation and assess alignment of research strategy with stakeholder interests. These are consistent with contemporary international SCI research strategy development activities. This first step in a regional SCI research strategy has articulated objectives for further development by the wider SCI research community. The initiative has also reinforced the importance of coordinated, collective action in optimising outcomes following SCI.

[Analysis of the citation of the articles published in National Journal of Andrology by SCI periodicals from 2002 to 2008].

PubMed

Huang, Hai

2009-03-01

Science Citation Index (SCI) is one of the world's most important and influential information retrieval systems. Today Web of Science covers over 9000 international and regional journals and book series in every field of natural sciences, social sciences, and arts and humanities. More and more Chinese periodicals have been cited by SCI. This paper briefly introduces the SCI database and its selection process and analyzes the citation of the articles published in National Journal of Andrology (NJA) by SCI journals from 2002 to 2008, aiming to provide some information for the internationalization of NJA.

Institutional profile: the national Swedish academic drug discovery & development platform at SciLifeLab

PubMed Central

Arvidsson, Per I; Sandberg, Kristian; Sakariassen, Kjell S

2017-01-01

The Science for Life Laboratory Drug Discovery and Development Platform (SciLifeLab DDD) was established in Stockholm and Uppsala, Sweden, in 2014. It is one of ten platforms of the Swedish national SciLifeLab which support projects run by Swedish academic researchers with large-scale technologies for molecular biosciences with a focus on health and environment. SciLifeLab was created by the coordinated effort of four universities in Stockholm and Uppsala: Stockholm University, Karolinska Institutet, KTH Royal Institute of Technology and Uppsala University, and has recently expanded to other Swedish university locations. The primary goal of the SciLifeLab DDD is to support selected academic discovery and development research projects with tools and resources to discover novel lead therapeutics, either molecules or human antibodies. Intellectual property developed with the help of SciLifeLab DDD is wholly owned by the academic research group. The bulk of SciLifeLab DDD's research and service activities are funded from the Swedish state, with only consumables paid by the academic research group through individual grants. PMID:28670468

Chronic Spinal Injury Repair by Olfactory Bulb Ensheathing Glia and Feasibility for Autologous Therapy

PubMed Central

Muñoz-Quiles, Cintia; Santos-Benito, Fernando F.; Llamusí, M. Beatriz; Ramón-Cueto, Almudena

2009-01-01

Olfactory bulb ensheathing glia (OB-OEG) promote repair of spinal cord injury (SCI) in rats after transplantation at acute or subacute (up to 45 days) stages. The most relevant clinical scenario in humans, however, is chronic SCI, in which no more major cellular or molecular changes occur at the injury site; this occurs after the third month in rodents. Whether adult OB-OEG grafts promote repair of severe chronic SCI has not been previously addressed. Rats with complete SCI that were transplanted with OB-OEG 4 months after injury exhibited progressive improvement in motor function and axonal regeneration from different brainstem nuclei across and beyond the SCI site. A positive correlation between motor outcome and axonal regeneration suggested a role for brainstem neurons in the recovery. Functional and histological outcomes did not differ at subacute or chronic stages. Thus, autologous transplantation is a feasible approach as there is time for patient stabilization and OEG preparation in human chronic SCI; the healing effects of OB-OEG on established injuries may offer new therapeutic opportunities for chronic SCI patients. PMID:19915486

Subjective cognitive impairment: functional MRI during a divided attention task.

PubMed

Rodda, J; Dannhauser, T; Cutinha, D J; Shergill, S S; Walker, Z

2011-10-01

Individuals with subjective cognitive impairment (SCI) have persistent memory complaints but normal neurocognitive performance. For some, this may represent a pre-mild cognitive impairment (MCI) stage of Alzheimer's disease (AD). Given that attentional deficits and associated brain activation changes are present early in the course of AD, we aimed to determine whether SCI is associated with brain activation changes during attentional processing. Eleven SCI subjects and 10 controls completed a divided attention task during functional magnetic resonance imaging. SCI and control groups did not differ in sociodemographic, neurocognitive or behavioural measures. When group activation during the divided attention task was compared, the SCI group demonstrated increased activation in left medial temporal lobe, bilateral thalamus, posterior cingulate and caudate. This pattern of increased activation is similar to the pattern of decreased activation reported during divided attention in AD and may indicate compensatory changes. These findings suggest the presence of early functional changes in SCI; longitudinal studies will help to further elucidate the relationship between SCI and AD. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Combined polymer-curcumin conjugate and ependymal progenitor/stem cell treatment enhances spinal cord injury functional recovery.

PubMed

Requejo-Aguilar, Raquel; Alastrue-Agudo, Ana; Cases-Villar, Marta; Lopez-Mocholi, Eric; England, Richard; Vicent, María J; Moreno-Manzano, Victoria

2017-01-01

Spinal cord injury (SCI) suffers from a lack of effective therapeutic strategies. Animal models of acute SCI have provided evidence that transplantation of ependymal stem/progenitor cells of the spinal cord (epSPCs) induces functional recovery, while systemic administration of the anti-inflammatory curcumin provides neuroprotection. However, functional recovery from chronic stage SCI requires additional enhancements in available therapeutic strategies. Herein, we report on a combination treatment for SCI using epSPCs and a pH-responsive polymer-curcumin conjugate. The incorporation of curcumin in a pH-responsive polymeric carrier mainchain, a polyacetal (PA), enhances blood bioavailability, stability, and provides a means for highly localized delivery. We find that PA-curcumin enhances neuroprotection, increases axonal growth, and can improve functional recovery in acute SCI. However, when combined with epSPCs, PA-curcumin also enhances functional recovery in a rodent model of chronic SCI. This suggests that combination therapy may be an exciting new therapeutic option for the treatment of chronic SCI in humans. Copyright © 2016 Elsevier Ltd. All rights reserved.

Institutional profile: the national Swedish academic drug discovery & development platform at SciLifeLab.

PubMed

Arvidsson, Per I; Sandberg, Kristian; Sakariassen, Kjell S

2017-06-01

The Science for Life Laboratory Drug Discovery and Development Platform (SciLifeLab DDD) was established in Stockholm and Uppsala, Sweden, in 2014. It is one of ten platforms of the Swedish national SciLifeLab which support projects run by Swedish academic researchers with large-scale technologies for molecular biosciences with a focus on health and environment. SciLifeLab was created by the coordinated effort of four universities in Stockholm and Uppsala: Stockholm University, Karolinska Institutet, KTH Royal Institute of Technology and Uppsala University, and has recently expanded to other Swedish university locations. The primary goal of the SciLifeLab DDD is to support selected academic discovery and development research projects with tools and resources to discover novel lead therapeutics, either molecules or human antibodies. Intellectual property developed with the help of SciLifeLab DDD is wholly owned by the academic research group. The bulk of SciLifeLab DDD's research and service activities are funded from the Swedish state, with only consumables paid by the academic research group through individual grants.

Fate of patients with spinal cord ischemia complicating thoracic endovascular aortic repair.

PubMed

DeSart, Kenneth; Scali, Salvatore T; Feezor, Robert J; Hong, Michael; Hess, Philip J; Beaver, Thomas M; Huber, Thomas S; Beck, Adam W

2013-09-01

Spinal cord ischemia (SCI) is a potentially devastating complication of thoracic endovascular aortic repair (TEVAR) that can result in varying degrees of short-term and permanent disability. This study was undertaken to describe the clinical outcomes, long-term functional impact, and influence on survival of SCI after TEVAR. A retrospective review of all TEVAR patients at the University of Florida from 2000 to 2011 was performed to identify individuals experiencing SCI, defined by any new lower extremity neurologic deficit not attributable to another cause. SCI was dichotomized into immediate or delayed onset, with immediate onset defined as SCI noted upon awakening from anesthesia, and delayed characterized as a period of normal function, followed by development of neurologic injury. Ambulatory status was determined using database query, record review, and phone interviews with patients and/or family. Mortality was estimated using life-table analysis. A total of 607 TEVARs were performed for various indications, with 57 patients (9.4%) noted to have postoperative SCI (4.3% permanent). SCI patients were more likely to be older (63.9 ± 15.6 vs 70.5 ± 11.2 years; P = .002) and have a number of comorbidities, including chronic obstructive pulmonary disease, hypertension, dyslipidemia, and cerebrovascular disease (P < .0001). At some point in their care, a cerebrospinal fluid drain was placed in 54 patients (95%), with 54% placed postoperatively. In-hospital mortality was 8.8% for the entire cohort (SCI vs no SCI; P = .45). SCI developed immediately in 12 patients, delayed onset in 40, and indeterminate in five patients due to indiscriminate timing from postoperative sedation. Three patients (25%) with immediate SCI had measurable functional improvement (FI), whereas 28 (70%) of the delayed-onset patients experienced some degree of neurologic recovery (P = .04). Of the 34 patients with complete data available, 26 (76%) reported quantifiable FI, but only 13 (38%) experienced return to their preoperative baseline. Estimated mean (± standard error) survival for patients with and without SCI was 37.2 ± 4.5 and 71.6 ± 3.9 months (P < .0006), respectively. Patients with FI had a mean survival of 53.9 ± 5.9 months compared with 9.6 ± 3.6 months for those without improvement (P < .0001). Survival and return of neurologic function were not significantly different when patients with preoperative and postoperative cerebrospinal fluid drains were compared. The minority of patients experience complete return to baseline function after SCI with TEVAR, and outcomes in patients without early functional recovery are particularly dismal. Patients experiencing delayed SCI are more likely to have FI and may anticipate similar life-expectancy with neurologic recovery compared with patients without SCI. Timing of drain placement does not appear to have an impact on postdischarge FI or long-term mortality. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Folic Acid Modulates Matrix Metalloproteinase-2 Expression, Alleviates Neuropathic Pain, and Improves Functional Recovery in Spinal Cord-Injured Rats

PubMed Central

Miranpuri, Gurwattan S.; Meethal, Sivan Vadakkadath; Sampene, Emmanuel; Chopra, Abhishek; Buttar, Seah; Nacht, Carrie; Moreno, Neydis; Patel, Kush; Liu, Lisa; Singh, Anupama; Singh, Chandra K.; Hariharan, Nithya; Iskandar, Bermans; Resnick, Daniel K.

2017-01-01

Background The molecular underpinnings of spinal cord injury (SCI) associated with neuropathic pain (NP) are unknown. Recent studies have demonstrated that matrix metalloproteinases (MMPs) such as MMP2 play a critical role in inducing NP following SCI. Promoter methylation of MMPs is known to suppress their transcription and reduce NP. In this context, it has been shown in rodents that folic acid (FA), an FDA approved dietary supplement and key methyl donor in the central nervous system (CNS), increases axonal regeneration and repair of injured CNS in part via methylation. Purpose Based on above observations, in this study, we test whether FA could decrease MMP2 expression and thereby decrease SCI-induced NP. Methods Sprague-Dawley male rats weighing 250–270 g received contusion spinal cord injuries (cSCIs) with a custom spinal cord impactor device that drops a 10 g weight from a height of 12.5 mm. The injured rats received either i.p. injections of FA (80 µg/kg) or water (control) 3 days prior and 17 days post-cSCI (mid phase) or for 3 days pre-cSCI and 14 days post-cSCI ending on the 42nd day of cSCI (late phase). The functional neurological deficits due to cSCI were then assessed by Basso, Beattie, and Bresnahan (BBB) scores either on post-impaction days 0 through 18 post-cSCI (mid phase) or on days 0, 2, 7, 14, 21, 28, 35, and 42 (late phase). Baseline measurements were taken the day before starting treatments. Thermal hyperalgesia (TH) testing for pain was performed on 4 days pre-cSCI (baseline data) and on days 18, 21, 28, 35, and 42 post-cSCI. Following TH testing, animals were euthanized and spinal cords harvested for MMP-2 expression analysis. Result The FA-treated groups showed higher BBB scores during mid phase (day 18) and in late phase (day 42) of injury compared to controls, suggesting enhanced functional recovery. There is a transient decline in TH in animals from the FA-treated group compared to controls when tested on days 18, 21, 28, and 35, indicative of a decrease in NP. However, when tested 25 days after stopping FA administration on day 42 of cSCI, no significant difference in TH was observed between FA-treated and control animals. Western blot analysis of the injured spinal cord from FA-treated animals showed significant decline in MMP2 expression compared to spinal cord samples from water-treated controls. Conclusion Together, these data suggest that FA could alleviate NP and improve functional recovery post-SCI, possibly by reducing the expression of MMP2. Further studies will open up a novel and easy natural therapy, ideal for clinical translation with minimal side effects, for managing SCI-induced NP. Such studies might also throw light on a possible epigenetic mechanism in FA-induced recovery after SCI. PMID:28588362

Real-Time Telemetric Monitoring in Whole-Body 60Co Gamma-Photon Irradiated Rhesus Macaques (Macaca mulatta)

DTIC Science & Technology

2010-01-01

clinically healthy adult male rhesus maca - ques (M. mulatta), 7–13 kg and 5–14 years of age, were obtained from the non-naı̈ve pool of NHPs of the US...11/9/2009. 15 Reinhardt V: Space utilization by captive rhesus maca - ques. Anim Technol 1992; 43:11–7. 16 Rosoff CB: Role of intestinal bacteria in the

2017 Emerging Technology Domains Risk Survey

DTIC Science & Technology

2017-10-01

REV-03.18.2016.0 2017 Emerging Technology Domains Risk Survey Daniel Klinedinst Joel Land Kyle O’Meara October 2017 TECHNICAL REPORT CMU/SEI...to the CERT/CC 2016 Emerging Technol- ogy Domains Risk Survey [King 2016]. This list does not supersede previous reports. Many of the previously... Survey [King 2016]. Table 1: New and Emerging Technologies Gartner’s 2015 List of New Technology CERT’s List of Emerging Domains Trust Boundary

Recent Naval Postgraduate School Publications

DTIC Science & Technology

1988-08-30

kind. Part 1: Regular kernals Applied Mathematics and Computation, vol. 21, p. 171-184, (1987). Neta B- Williams, R T Stability and phase speed for...Cong., Oslo Norway Aug. 5-9, 1985. IN Proc., IMAC, p. 209-213, (198). Neta Bi Williams, R T Stability and phase speed for various finite element...development phases DoD Software Technol. for Adaptable, Reliable Systems (STARS) Business Practices Area Manage. Workshop, Los Angeles, CA, Nov. 18-22, (1985

Interpolation of the Radial Velocity Data from Coastal HF Radars

DTIC Science & Technology

2013-01-01

practical applications and may help to solve many environmental problems caused by human activity. References [1] Alvera -Azcarate A., A. Barth, M. Rixen...surface temperature, Ocean Modelling, 9,325-346. [2] Alvera -Azcarate, A., A. Barth,. J.-M. Beckers, and R. H. Weisber, 2007: Multivari- ate...predictions from the global Navy Coastal Ocean Model (NCOM) dur- ing 1998-2001,7. Atmos. Oceanic TechnoL, 21(12), 1876-1894. [4] Barth, A., Alvera

Development and Evaluation of Stereographic Display for Lung Cancer Screening

DTIC Science & Technology

2006-12-01

and also by grant CA80836 from the National Cancer Institute, National Institutes of Health . The content of the contained information does not...Evers H, Henn C, Glombitza G, Meinzer HP. Interactive real- time Doppler-ultrasound visualization of the heart. Stud Health Technol Inform. 2000;70:119...nodule, the scoring form with questionnaire related to the detected nodule would pop up for nodule assessment. We have also implemented mouse cursor as

Terrorist and Insurgent Unmanned Aerial Vehicles: Use, Potentials, and Military Implications

DTIC Science & Technology

2015-08-01

Strategic. While the drone swarms of normal and micro - sized UAVs projected in this threat scenario may still be a few decades out and possibly...craft for reconnaissance and pro- paganda video purposes. Such groups are still very much in an experimental phase of using these craft and possess...technol- ogy trends influencing their potential uses, three red teaming threat scenarios have been created for early warning purposes: 1) Single UAV

Self-Replenishing Vascularized Fouling-Release Surfaces

DTIC Science & Technology

2014-01-01

similar results. Surfaces submerged for 12 days in static cultures of B. braunii, a green microalga known for its potential in the algae biofuels...Technol. 2004, 32, 219−222. (12) Kirschner, C. M.; Brennan, A. B. Bio -Inspired Antifouling Strategies. Annu. Rev. Mater. Res. 2012, 42, 211−229. (13...Release from Fouling Release Coatings. Biofouling 2000, 15, 73−81. (25) Liu, K.; Jiang, L. Bio -Inspired Self-Cleaning Surfaces. Annu. Rev. Mater. Res

Bibliography of Technical Publications and Papers, July 1975 - June 1976

DTIC Science & Technology

1976-07-01

MASUOKA, Y., K. R. JOHNSON, and A. R. RAHIMA. Packaged dry imitation vinegar product. US Patent No. 3,898,344, 5 August 1975. 199. RAHIDAN, A. R., and G...242. , and D. STERWBERG. Recent advances in cellulase technology. J. Ferment . Technol., 54(4): 267-286 (1976). 243. , J. NYSTROM, and D. BOLGER. Waste...Enzymatic Utilization of Cellulosic Resources, Annual Meeting, Society of Fermentation Technology, Osaka, Japan, 30 October 1975. 329. Recent advances in

PROJECT SQUID. Field Survey Report. Volume 1, Part 4. Fluid Mechanics

DTIC Science & Technology

1947-06-30

title of TechnolOgyl) .. .1 Figure 4. Sketch showing position of compresion shocks in conical ditfitsers. (Aflcr Osiruaitscw) . 12 Figure 5. Maximnum...degree. However, experimen- sary to secure separation of the boundary layer. A tal investigations are being conducted on this problem blister was added at...MECHANIC v Since temperature is a transferable properky in the general nature of the mathematical background and to same sense as momentumt and vorticity

Recent Naval Postgraduate School Publications.

DTIC Science & Technology

1981-05-01

Technol., vol. 16, no. 2, p. 629-634, (Har./Apr., 1979). Winograd, NGa rlso ,B J; garrison, D B.Angular distrlbutlo f ejected articles from ion bombarded...AD-A119 757 NAVAL POSTGRADUATE SCHOOL MONTEREY CA F /O 5/1 RECENT NAVAL POSTGRADUATE SCHOOL PUBLZCATIONS.(U) MAY 81 W M TOLLES UNCLASSIFIED NPS-012...SCIENCE PUBLISHED PAPERS (contsd) Burkhead F Parallel roces inq of recursive functions Ann. Cnf. o te Assoc _1or Computing Machine.,Detroit, Hic

Pressure Relief Behaviors and Weight-Shifting Activities to Prevent Pressure Ulcers in Persons with SCI

DTIC Science & Technology

2014-10-01

Prevent Pressure Ulcers in Persons with SCI PRINCIPAL INVESTIGATOR: Stephen Sprigle, PhD CONTRACTING ORGANIZATION: Georgia Tech Research...Pressure Ulcers in Persons with SCI 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-13-1-0387 5c. PROGRAM ELEMENT NUMBER...SUPPLEMENTARY NOTES 14. ABSTRACT Pressure ulcers (PU) are the most costly secondary complication following an SCI. In addition to the medical costs

a Study on the Document Information Service of the National Agricultural Library for Agricultural Sci-Tech Innovation in China

NASA Astrophysics Data System (ADS)

Xu, Qian; Meng, Xianxue

This paper presents the significant function of the Chinese National Agricultural Library (CNAL) in the agricultural sci-tech innovation system in China, analyses the development of collection and service in the CNAL, explores the challenge towards sustain and develop information services for the agricultural sci-tech research and innovation, at last proposes the strategy for sci-tech document information service development.

Experience of sleep in individuals with spinal cord injury

PubMed Central

Fogelberg, Donald J.; Leland, Natalie E.; Blanchard, Jeanine; Rich, Timothy J.; Clark, Florence A.

2017-01-01

Background Poor sleep contributes to adverse health outcomes making it important to understand sleep in medically vulnerable populations, including those with spinal cord injury (SCI). However, little attention has been paid to circumstances specific to SCI that may negatively impact sleep, or to consequences of poor sleep in this population. Objectives To examine the experience of sleep among individuals with SCI. Methodology Secondary analysis using thematic coding of qualitative data from an ethnographic study of community-dwelling adults with SCI. Results Sleep-related data were found in transcripts for 90% of the sample. Participants described diminished sleep duration and irregular sleep patterns. Several factors contributing to poor sleep were identified, including SCI-related circumstances and sleep environment. Participants also discussed how poor sleep affected occupational engagement. Conclusion This study highlights the extent of sleep disturbance experienced after SCI, the subsequent impact on occupational performance, and provides direction for clinical practice. PMID:28196449

Functional Electrical Stimulation and Spinal Cord Injury

PubMed Central

Ho, Chester H.; Triolo, Ronald J.; Elias, Anastasia L.; Kilgore, Kevin L.; DiMarco, Anthony F.; Bogie, Kath; Vette, Albert H.; Audu, Musa; Kobetic, Rudi; Chang, Sarah R.; Chan, K. Ming; Dukelow, Sean; Bourbeau, Dennis J.; Brose, Steven W.; Gustafson, Kenneth J.; Kiss, Zelma; Mushahwar, Vivian K.

2015-01-01

Synopsis Spinal cord injuries (SCI) can disrupt communications between the brain and the body, leading to a loss of control over otherwise intact neuromuscular systems. The use of electrical stimulation (ES) of the central and peripheral nervous system can take advantage of these intact neuromuscular systems to provide therapeutic exercise options, to allow functional restoration, and even to manage or prevent many medical complications following SCI. The use of ES for the restoration of upper extremity, lower extremity and truncal functions can make many activities of daily living a potential reality for individuals with SCI. Restoring bladder and respiratory functions and preventing pressure ulcers may significantly decrease the morbidity and mortality following SCI. Many of the ES devices are already commercially available and should be considered by all SCI clinicians routinely as part of the lifelong rehabilitation care plan for all eligible individuals with SCI. PMID:25064792

“Don’t Think Paralysis Takes Away Your Womanhood”: Sexual Intimacy After Spinal Cord Injury

PubMed Central

Dillaway, Heather; Lysack, Cathy L.

2015-01-01

Sexuality and intimacy are important components of health and well-being. Issues surrounding sexuality and intimacy are equally important for men and women living with physical disabilities, including spinal cord injury (SCI). Yet, women’s sexuality after SCI remains largely unexamined. This article presents the findings from an in-depth qualitative investigation of the sexual and reproductive health experiences of 20 women with SCI in or around Detroit, MI. Findings echo existing literature documenting the sexual consequences of life after SCI and suggest new areas of inquiry important for better addressing sexual concerns across the lifespan. Specifically, findings suggest a need to consider the variable effects of SCI on sexual intimacy in relation to a person’s developmental trajectory, the appropriate timing of sexual education, the need to expand conceptualizations of sexual intimacy, and the ways SCI may affect sexuality in later life. PMID:26122683

Comparison of two psycho-educational family group interventions for improving psycho-social outcomes in persons with spinal cord injury and their caregivers: a randomized-controlled trial of multi-family group intervention versus an active education control condition.

PubMed

Dyck, Dennis G; Weeks, Douglas L; Gross, Sarah; Lederhos Smith, Crystal; Lott, Hilary A; Wallace, Aimee J; Wood, Sonya M

2016-07-26

Over 12,000 individuals suffer a spinal cord injury (SCI) annually in the United States, necessitating long-term, complex adjustments and responsibilities for patients and their caregivers. Despite growing evidence that family education and support improves the management of chronic conditions for care recipients as well as caregiver outcomes, few systematic efforts have been made to involve caregivers in psycho-educational interventions for SCI. As a result, a serious gap exists in accumulated knowledge regarding effective, family-based treatment strategies for improving outcomes for individuals with SCI and their caregivers. The proposed research aims to fill this gap by evaluating the efficacy of a structured adaptation of an evidence-based psychosocial group treatment called Multi-Family Group (MFG) intervention. The objective of this study is to test, in a randomized-controlled design, an MFG intervention for the treatment of individuals with SCI and their primary caregivers. Our central hypothesis is that by providing support in an MFG format, we will improve coping skills of persons with SCI and their caregivers as well as supportive strategies employed by caregivers. We will recruit 32 individuals with SCI who have been discharged from inpatient rehabilitation within the previous 3 years and their primary caregivers. Patient/caregiver pairs will be randomized to the MFG intervention or an active SCI education control (SCIEC) condition in a two-armed randomized trial design. Participants will be assessed pre- and post-program and 6 months post-program. Intent to treat analyses will test two a priori hypotheses: (1) MFG-SCI will be superior to SCIEC for SCI patient activation, health status, and emotion regulation, caregiver burden and health status, and relationship functioning, and (2) MFG will be more effective for individuals with SCI and their caregivers when the person with SCI is within 18 months of discharge from inpatient rehabilitation compared to when the person is between 19 and 36 months post discharge. Support for our hypotheses will indicate that MFG-SCI is superior to specific education for assisting patients and their caregivers in the management of difficult, long-term, life adjustments in the months and years after SCI, with increased efficacy closer in time to the injury. ClinicalTrials.gov NCT02161913 . Registered 10 June 2014.

Development of an International Canine Spinal Cord Injury observational registry: a collaborative data-sharing network to optimize translational studies of SCI.

PubMed

Moore, Sarah A; Zidan, Natalia; Spitzbarth, Ingo; Nout-Lomas, Yvette S; Granger, Nicolas; da Costa, Ronaldo C; Levine, Jonathan M; Jeffery, Nick D; Stein, Veronika M; Tipold, Andrea; Olby, Natasha J

2018-05-23

Prospective cross-sectional cohort study. The canine spontaneous model of spinal cord injury (SCI) is as an important pre-clinical platform as it recapitulates key facets of human injury in a naturally occurring context. The establishment of an observational canine SCI registry constitutes a key step in performing epidemiologic studies and assessing the impact of therapeutic strategies to enhance translational research. Further, accumulating information on dogs with SCI may contribute to current "big data" approaches to enhance understanding of the disease using heterogeneous multi-institutional, multi-species datasets from both pre-clinical and human studies. Multiple veterinary academic institutions across the United States and Europe. Common data elements recommended for experimental and human SCI studies were reviewed and adapted for use in a web-based registry, to which all dogs presenting to member veterinary tertiary care facilities were prospectively entered over ~1 year. Analysis of data accumulated during the first year of the registry suggests that 16% of dogs with SCI present with severe, sensorimotor-complete injury and that 15% of cases are seen by a tertiary care facility within 8 h of injury. Similar to the human SCI population, 34% were either overweight or obese. Severity of injury and timing of presentation suggests that neuroprotective studies using the canine clinical model could be conducted efficiently using a multi-institutional approach. Additionally, pet dogs with SCI experience similar comorbidities to people with SCI, in particular obesity, and could serve as an important model to evaluate the effects of this condition.

Role of Caspase-8 and Fas in Cell Death After Spinal Cord Injury

PubMed Central

Sobrido-Cameán, Daniel; Barreiro-Iglesias, Antón

2018-01-01

Spinal cord injury (SCI) causes the death of neurons and glial cells due to the initial mechanical forces (i.e., primary injury) and through a cascade of secondary molecular events (e.g., inflammation or excitotoxicity) that exacerbate cell death. The loss of neurons and glial cells that are not replaced after the injury is one of the main causes of disability after SCI. Evidence accumulated in last decades has shown that the activation of apoptotic mechanisms is one of the factors causing the death of intrinsic spinal cord (SC) cells following SCI. Although this is not as clear for brain descending neurons, some studies have also shown that apoptosis can be activated in the brain following SCI. There are two main apoptotic pathways, the extrinsic and the intrinsic pathways. Activation of caspase-8 is an important step in the initiation of the extrinsic pathway. Studies in rodents have shown that caspase-8 is activated in SC glial cells and neurons and that the Fas receptor plays a key role in its activation following a traumatic SCI. Recent work in the lamprey model of SCI has also shown the retrograde activation of caspase-8 in brain descending neurons following SCI. Here, we review our current knowledge on the role of caspase-8 and the Fas pathway in cell death following SCI. We also provide a perspective for future work on this process, like the importance of studying the possible contribution of Fas/caspase-8 signaling in the degeneration of brain neurons after SCI in mammals. PMID:29666570