Robust remote-pumping sodium laser for advanced LIDAR and guide star applications

NASA Astrophysics Data System (ADS)

Ernstberger, Bernhard; Enderlein, Martin; Friedenauer, Axel; Schwerdt, Robin; Wei, Daoping; Karpov, Vladimir; Leisching, Patrick; Clements, Wallace R. L.; Kaenders, Wilhelm G.

2015-10-01

The performance of large ground-based optical telescopes is limited due to wavefront distortions induced by atmospheric turbulence. Adaptive optics systems using natural guide stars with sufficient brightness provide a practical way for correcting the wavefront errors by means of deformable mirrors. Unfortunately, the sky coverage of bright stars is poor and therefore the concept of laser guide stars was invented, creating an artificial star by exciting resonance fluorescence from the mesospheric sodium layer about 90 km above the earth's surface. Until now, mainly dye lasers or sumfrequency mixing of solid state lasers were used to generate laser guide stars. However, these kinds of lasers require a stationary laser clean room for operation and are extremely demanding in maintenance. Under a development contract with the European Southern Observatory (ESO) and W. M. Keck Observatory (WMKO), TOPTICA Photonics AG and its partner MPB Communications have finalized the development of a next-generation sodium guide star laser system which is available now as a commercial off-the-shelf product. The laser is based on a narrow-band diode laser, Raman fiber amplifier (RFA) technology and resonant second-harmonic generation (SHG), thus highly reliable and simple to operate and maintain. It emits > 22 W of narrow-linewidth (≈ 5 MHz) continuous-wave radiation at sodium resonance and includes a re-pumping scheme for boosting sodium return flux. Due to the SHG resonator acting as spatial mode filter and polarizer, the output is diffraction-limited with RMS wavefront error < λ/25. Apart from this unique optical design, a major effort has been dedicated to integrating all optical components into a ruggedized system, providing a maximum of convenience and reliability for telescope operators. The new remote-pumping architecture allows for a large spatial separation between the main part of the laser and the compact laser head. Together with a cooling-water flow of less than 5 l/min and an overall power consumption of < 700 W, the system offers a maximum of flexibility with minimal infrastructure demands on site. Each system is built in a modular way, based on the concept of line-replaceable units (LRU). A comprehensive system software, as well as an intuitive service GUI, allow for remote control and error tracking down to at least the LRU level. In case of a failure, any LRU can be easily replaced. With these fiber-based guide star lasers, TOPTICA for the first time offers a fully engineered, off-the-shelf guide star laser system for groundbased optical telescopes providing convenient, turn-key operation in remote and harsh locations. Reliability and flexibility will be beneficial in particular for advanced satellite and space debris tracking as well as LIDAR applications.

Dependence of sodium laser guide star photon return on the geomagnetic field

NASA Astrophysics Data System (ADS)

Moussaoui, N.; Holzlöhner, R.; Hackenberg, W.; Bonaccini Calia, D.

2009-07-01

Aims: The efficiency of optical pumping that increases the backscatter emission of mesospheric sodium atoms in continuous wave (cw) laser guide stars (LGSs) can be significantly reduced and, in the worst case, eliminated by the action of the geomagnetic field. Our goal is to present an estimation of this effect for several telescope sites. Methods: Sodium atoms precess around magnetic field lines that cycle the magnetic quantum number, reducing the effectiveness of optical pumping. Our method is based on calculating the sodium magnetic sublevel populations in the presence of the geomagnetic field and on experimental measurements of radiance return from sodium LGS conducted at the Starfire optical range (SOR). Results: We propose a relatively simple semi-empirical formula for estimating the effect of the geomagnetic field on enhancing the LGSs photon return due to optical pumping with a circularly polarized cw single-frequency laser beam. Starting from the good agreement between our calculations and the experimental measurements for the geomagnetic field effect, and in order to more realistically estimate the sodium LGSs photon return, we introduce the effect of the distance to the mesospheric sodium layer and the atmospheric attenuation. The combined effect of these three factors is calculated for several telescope sites. Conclusions: In calculating the return flux of LGSs, only the best return conditions are often assumed, relying on strong optical pumping with circularly polarized lasers. However, one can only obtain this optimal return along one specific laser orientation on the sky, where the geomagnetic field lines are parallel to the laser beam. For most of the telescopes, the optimum can be obtained at telescope orientations beyond the observation limit. For the telescopes located close to the geomagnetic pole, the benefit of the optical pumping is much more important than for telescopes located close to the geomagnetic equator.

The TMT Adaptive Optics Program

NASA Astrophysics Data System (ADS)

Ellerbroek, Brent

2011-09-01

We provide an overview of the Thirty Meter Telescope (TMT) AO program, with an emphasis upon the progress made since the first AO4ELT conference held in 2009. The first light facility AO system for TMT is the Narrow Field Infra-Red AO System (NFIRAOS), which will provide diffraction-limited performance in the J, H, and K bands over 18-30 arc sec diameter fields with 50% sky coverage at the galactic pole. This is accomplished with order 60x60 wavefront sensing and correction, two deformable mirrors conjugate to ranges of 0 and 11.2 km, 6 sodium laser guide stars in an asterism with a diameter of 70 arc sec, and three low order (tip/tilt or tip/tilt focus), infra-red natural guide star (NGS) wavefront sensors deployable within a 2 arc minute diameter patrol field. The first light LGS asterism is generated by the Laser Guide Star Facility (LGSF), which initially incorporates 6 20-25W class laser systems mounted to the telescope elevation journal, a mirror-based beam transfer optics system, and a 0.4m diameter laser launch telescope located behind the TMT secondary mirror. Future plans for additional AO capabilities include a mid infra-red AO (MIRAO) system to support science instruments in the 4-20 micron range, a ground-layer AO (GLAO) system for wide-field spectroscopy, a multi-object AO (MOAO) system for multi-object integral field unit spectroscopy, and extreme AO (ExAO) for high contrast imaging. Significant progress has been made in developing the first-light AO architecture since 2009. This includes the adoption of a new NFIRAOS opto-mechanical design consisting of two off-axis parabola (OAP) relays in series, which eliminates field distortion and also significantly simplifies the designs of the LGS wavefront sensors, optical source simulators, and turbulence generator subsystem. The design of the LGSF has also been interated, and has been simplfied by the relocation of the (smaller, gravity invarient) laser systems to the telescope elevation journal. Protoyping activities continue for laser systems, wavefront sensing detectors, and deformable mirrors; work on the associated detector and deformable mirror electronics has also been initiated. AO Performance estimates and error budgets have been further detailed. Some of the modeling topics which have received particular attention include turbulence (Cn2) profile estimation from LGS WFS measurements, sodium layer range tracking, PSF reconstruction for multi-conjugate AO, LGS fratricide, astrometry at the galactic center, and further optimizing sky coverage and the peformance of the tip/tilt and low-order NGS mode control loops. Finally, experiments and field tests continue at the University of British Columbia LIDAR facility to measure the spatial and temporal variability of the sodium layer, and to characterize the sodium coupling efficiency of candidate laser systems for TMT.

Delaminated sodium nonatitanate and a method for producing delaminated sodium nonatitanate

DOEpatents

Nyman, May D.

2016-02-02

A hydrothermal synthesis method of making a delaminated titanate is disclosed. The delaminated titanate has a unique structure or morphology. The delaminated titanate is first formed by forming at a low temperature a layered sodium nonatitanate (SNT), which may be referred to as layered sodium titanate. The layered SNT has a unique morphology. The layered SNT is then synthesized into a delaminated titanate having a unique morphology.

Theoretical and experimental studies of the atmospheric sodium layer

NASA Technical Reports Server (NTRS)

Richter, E. S.; Sechrist, C. F., Jr.

1978-01-01

Atmospheric atomic sodium was studied with a laser radar system. Photocount data were processed using a digital filter to obtain continuous estimates of the sodium concentration versus altitude. Wave-like structures in the sodium layer were observed, and there was evidence for the presence of a standing wave in the layer. The bottomside of the layer was observed to undulate with a period of about 2 1/2 hours, and the layer was observed to broaden through the night. A meteor ablation-cluster ion theory of sodium was developed. The theory shows good agreement with existing atmospheric observations as well as laboratory measurements of rate constants.

Development of New Decon Green (registered trademark): A How-To Guide for the Rapid Decontamination of CARC Paint

DTIC Science & Technology

2008-09-01

sodium carbonate, and extracted with 2-mL chloroform. The chloroform layer was analyzed for residual agent by Gas Chromatography /Atomic Emission...agent remaining on the panel. Solutions were analyzed by Gas Chromatography /Flame-Ionization Detector (GC/FID) to determine the amounts of agent...transferred to glass scintillation vials. A 100-µL aliquot of the DEP was diluted with 900-µL chloroform (1:10 dilution) in a Gas Chromatography

Role of the Vascular Wall in Sodium Homeostasis and Salt Sensitivity

PubMed Central

Olde Engberink, Rik H.G.; Rorije, Nienke M.G.; Homan van der Heide, Jaap J.; van den Born, Bert-Jan H.

2015-01-01

Excessive sodium intake is associated with both hypertension and an increased risk of cardiovascular events, presumably because of an increase in extracellular volume. The extent to which sodium intake affects extracellular volume and BP varies considerably among individuals, discriminating subjects who are salt-sensitive from those who are salt-resistant. Recent experiments have shown that, other than regulation by the kidney, sodium homeostasis is also regulated by negatively charged glycosaminoglycans in the skin interstitium, where sodium is bound to glycosaminoglycans without commensurate effects on extracellular volume. The endothelial surface layer is a dynamic layer on the luminal side of the endothelium that is in continuous exchange with flowing blood. Because negatively charged glycosaminoglycans are abundantly present in this layer, it may act as an intravascular buffer compartment that allows sodium to be transiently stored. This review focuses on the putative role of the endothelial surface layer as a contributor to salt sensitivity, the consequences of a perturbed endothelial surface layer on sodium homeostasis, and the endothelial surface layer as a possible target for the treatment of hypertension and an expanded extracellular volume. PMID:25294232

The Effect of Smear Layer Removal on Endodontic Outcomes

DTIC Science & Technology

2012-06-01

Sundqvist G. The antibacterial effect of sodium hypochlorite and EDTA in 60 cases of endodontic therapy. Int Endod J 1985;18:35-40. 11. Conner DA, Caplan...outcomes. KEY WORDS: Smear layer, smear layer removal, smear layer creation, EDTA, Sodium hypochlorite , Periapical index INTRODUCTION: The...identified the most efficient process for removal of the smear layer. Normal saline and sodium hypochlorite (NaOCl) have been shown not to remove

3D-printed membrane for guided tissue regeneration.

PubMed

Tayebi, Lobat; Rasoulianboroujeni, Morteza; Moharamzadeh, Keyvan; Almela, Thafar K D; Cui, Zhanfeng; Ye, Hua

2018-03-01

Three-dimensional (3D) printing is currently being intensely studied for a diverse set of applications, including the development of bioengineered tissues, as well as the production of functional biomedical materials and devices for dental and orthopedic applications. The aim of this study was to develop and characterize a 3D-printed hybrid construct that can be potentially suitable for guided tissue regeneration (GTR). For this purpose, the rheology analyses have been performed on different bioinks and a specific solution comprising 8% gelatin, 2% elastin and 0.5% sodium hyaluronate has been selected as the most suitable composition for printing a structured membrane for GTR application. Each membrane is composed of 6 layers with strand angles from the first layer to the last layer of 45, 135, 0, 90, 0 and 90°. Confirmed by 3D Laser Measuring imaging, the membrane has small pores on one side and large pores on the other to be able to accommodate different cells like osteoblasts, fibroblasts and keratinocytes on different sides. The ultimate cross-linked product is a 150μm thick flexible and bendable membrane with easy surgical handling. Static and dynamic mechanical testing revealed static tensile modules of 1.95±0.55MPa and a dynamic tensile storage modulus of 314±50kPa. Through seeding the membranes with fibroblast and keratinocyte cells, the results of in vitro tests, including histological analysis, tissue viability examinations and DAPI staining, indicated that the membrane has desirable in vitro biocompatibility. The membrane has demonstrated the barrier function of a GTR membrane by thorough separation of the oral epithelial layer from the underlying tissues. In conclusion, we have characterized a biocompatible and bio-resorbable 3D-printed structured gelatin/elastin/sodium hyaluronate membrane with optimal biostability, mechanical strength and surgical handling characteristics in terms of suturability for potential application in GTR procedures. Copyright © 2017 Elsevier B.V. All rights reserved.

Honeycomb-Ordered Na 3Ni 1.5M 0.5BiO 6 (M = Ni, Cu, Mg, Zn) as High-Voltage Layered Cathodes for Sodium-Ion Batteries

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

Wang, Peng -Fei; Guo, Yu -Jie; Duan, Hui

Developing high-voltage layered cathodes for sodium-ion batteries (SIBs) has always been a severe challenge. Herein, a new family of honeycomb-layered Na 3Ni 1.5M 0.5BiO 6 (M = Ni, Cu, Mg, Zn) with a monoclinic superstructure has been shown to combine good Na + (de)intercalation activity with a competitive 3.3 V high voltage. By coupling the electrochemical process with ex situ X-ray absorption spectroscopy as well as in situ X-ray diffraction, the charge compensation mechanism and structural evolution of these new cathodes are clearly investigated. Interestingly, both Ni 2+/Ni 3+ and Cu 2+/Cu 3+ participate in the redox reaction upon cycling,more » and the succession of single-phase, two-phase, or three-phase regions upon Na+ extraction/insertion were identified with rather good accuracy. Furthermore, this research strategy could provide insights into the structure–function–property relationships on a new series of honeycomb-ordered materials with the general formula Na 3Ni 1.5M 0.5BiO 6 and also serve as a bridge to guide future design of high-performance cathodes for SIBs.« less

Honeycomb-Ordered Na 3Ni 1.5M 0.5BiO 6 (M = Ni, Cu, Mg, Zn) as High-Voltage Layered Cathodes for Sodium-Ion Batteries

DOE PAGES

Wang, Peng -Fei; Guo, Yu -Jie; Duan, Hui; ...

2017-11-01

Developing high-voltage layered cathodes for sodium-ion batteries (SIBs) has always been a severe challenge. Herein, a new family of honeycomb-layered Na 3Ni 1.5M 0.5BiO 6 (M = Ni, Cu, Mg, Zn) with a monoclinic superstructure has been shown to combine good Na + (de)intercalation activity with a competitive 3.3 V high voltage. By coupling the electrochemical process with ex situ X-ray absorption spectroscopy as well as in situ X-ray diffraction, the charge compensation mechanism and structural evolution of these new cathodes are clearly investigated. Interestingly, both Ni 2+/Ni 3+ and Cu 2+/Cu 3+ participate in the redox reaction upon cycling,more » and the succession of single-phase, two-phase, or three-phase regions upon Na+ extraction/insertion were identified with rather good accuracy. Furthermore, this research strategy could provide insights into the structure–function–property relationships on a new series of honeycomb-ordered materials with the general formula Na 3Ni 1.5M 0.5BiO 6 and also serve as a bridge to guide future design of high-performance cathodes for SIBs.« less

A high-capacity, low-cost layered sodium manganese oxide material as cathode for sodium-ion batteries.

PubMed

Guo, Shaohua; Yu, Haijun; Jian, Zelang; Liu, Pan; Zhu, Yanbei; Guo, Xianwei; Chen, Mingwei; Ishida, Masayoshi; Zhou, Haoshen

2014-08-01

A layered sodium manganese oxide material (NaMn3 O5 ) is introduced as a novel cathode materials for sodium-ion batteries. Structural characterizations reveal a typical Birnessite structure with lamellar stacking of the synthetic nanosheets. Electrochemical tests reveal a particularly large discharge capacity of 219 mAh g(-1) in the voltage rang of 1.5-4.7 V vs. Na/Na(+) . With an average potential of 2.75 V versus sodium metal, layered NaMn3 O5 exhibits a high energy density of 602 Wh kg(-1) , and also presents good rate capability. Furthermore, the diffusion coefficient of sodium ions in the layered NaMn3 O5 electrode is investigated by using the galvanostatic intermittent titration technique. The results greatly contribute to the development of room-temperature sodium-ion batteries based on earth-abundant elements. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adaptive Optics for the Thirty Meter Telescope

NASA Astrophysics Data System (ADS)

Ellerbroek, Brent

2013-12-01

This paper provides an overview of the progress made since the last AO4ELT conference towards developing the first-light AO architecture for the Thirty Meter Telescope (TMT). The Preliminary Design of the facility AO system NFIRAOS has been concluded by the Herzberg Institute of Astrophysics. Work on the client Infrared Imaging Spectrograph (IRIS) has progressed in parallel, including a successful Conceptual Design Review and prototyping of On-Instrument WFS (OIWFS) hardware. Progress on the design for the Laser Guide Star Facility (LGSF) continues at the Institute of Optics and Electronics in Chengdu, China, including the final acceptance of the Conceptual Design and modest revisions for the updated TMT telescope structure. Design and prototyping activities continue for lasers, wavefront sensing detectors, detector readout electronics, real-time control (RTC) processors, and deformable mirrors (DMs) with their associated drive electronics. Highlights include development of a prototype sum frequency guide star laser at the Technical Institute of Physics and Chemistry (Beijing); fabrication/test of prototype natural- and laser-guide star wavefront sensor CCDs for NFIRAOS by MIT Lincoln Laboratory and W.M. Keck Observatory; a trade study of RTC control algorithms and processors, with prototyping of GPU and FPGA architectures by TMT and the Dominion Radio Astrophysical Observatory; and fabrication/test of a 6x60 actuator DM prototype by CILAS. Work with the University of British Columbia LIDAR is continuing, in collaboration with ESO, to measure the spatial/temporal variability of the sodium layer and characterize the sodium coupling efficiency of several guide star laser systems. AO performance budgets have been further detailed. Modeling topics receiving particular attention include performance vs. computational cost tradeoffs for RTC algorithms; optimizing performance of the tip/tilt, plate scale, and sodium focus tracking loops controlled by the NGS on-instrument wavefront sensors, sky coverage, PSF reconstruction for LGS MCAO, and precision astrometry for the galactic center and other observations.

Testing the pyramid truth wavefront sensor for NFIRAOS in the lab

NASA Astrophysics Data System (ADS)

Mieda, Etsuko; Rosensteiner, Matthias; van Kooten, Maaike; Veran, Jean-Pierre; Lardiere, Olivier; Herriot, Glen

2016-07-01

For today and future adaptive optics observations, sodium laser guide stars (LGSs) are crucial; however, the LGS elongation problem due to the sodium layer has to be compensated, in particular for extremely large telescopes. In this paper, we describe the concept of truth wavefront sensing as a solution and present its design using a pyramid wavefront sensor (PWFS) to improve NFIRAOS (Narrow Field InfraRed Adaptive Optics System), the first light adaptive optics system for Thirty Meter Telescope. We simulate and test the truth wavefront sensor function under a controlled environment using the HeNOS (Herzberg NFIRAOS Optical Simulator) bench, a scaled-down NFIRAOS bench at NRC-Herzberg. We also touch on alternative pyramid component options because despite recent high demands for PWFSs, we suffer from the lack of pyramid supplies due to engineering difficulties.

AMPS data management requirements study. [user manuals (computer programs)/display devices - computerized simulation/experimentation/ionosphere

NASA Technical Reports Server (NTRS)

1975-01-01

A data simulation is presented for instruments and associated control and display functions required to perform controlled active experiments of the atmosphere. A comprehensive user's guide is given for the data requirements and software developed for the following experiments: (1) electromagnetic wave transmission; (2) passive observation of ambient plasmas; (3) ionospheric measurements with a subsatellite; (4) electron accelerator beam measurements; and (5) measurement of acoustic gravity waves in the sodium layer using lasers. A complete description of each experiment is given.

An effective method to screen sodium-based layered materials for sodium ion batteries

NASA Astrophysics Data System (ADS)

Zhang, Xu; Zhang, Zihe; Yao, Sai; Chen, An; Zhao, Xudong; Zhou, Zhen

2018-03-01

Due to the high cost and insufficient resource of lithium, sodium-ion batteries are widely investigated for large-scale applications. Typically, insertion-type materials possess better cyclic stability than alloy-type and conversion-type ones. Therefore, in this work, we proposed a facile and effective method to screen sodium-based layered materials based on Materials Project database as potential candidate insertion-type materials for sodium ion batteries. The obtained Na-based layered materials contains 38 kinds of space group, which reveals that the credibility of our screening approach would not be affected by the space group. Then, some important indexes of the representative materials, including the average voltage, volume change and sodium ion mobility, were further studied by means of density functional theory computations. Some materials with extremely low volume changes and Na diffusion barriers are promising candidates for sodium ion batteries. We believe that our classification algorithm could also be used to search for other alkali and multivalent ion-based layered materials, to accelerate the development of battery materials.

Generation of alkali-free and high-proton concentration layer in a soda lime glass using non-contact corona discharge

NASA Astrophysics Data System (ADS)

Ikeda, Hiroshi; Sakai, Daisuke; Funatsu, Shiro; Yamamoto, Kiyoshi; Suzuki, Toshio; Harada, Kenji; Nishii, Junji

2013-08-01

Formation mechanisms of alkali-free and high-proton concentration surfaces were investigated for a soda lime glass using a corona discharge treatment under an atmospheric pressure. Protons produced by high DC voltage around an anode needle electrode were incorporated into a sodium ion site in the anode side glass. The sodium ion was swept away to the cathode side as a charge carrier. Then it was discharged. The precipitated sodium was transformed to a Na2CO3 powder when the surface contacted with air. The sodium ion in the glass surface layer of the anode side was replaced completely by protons. The concentration of OH groups in the layer was balanced with the amount of excluded sodium ions. The substitution reaction of sodium ions with protons tends to be saturated according to a square root function of time. The alkali depletion layer formation rate was affected by the large difference in mobility between sodium ions and protons in the glass.

Characteristics of convective structures of sodium layer in lower thermosphere (105-120 km) at Haikou (19.99°N, 110.34°E), China

NASA Astrophysics Data System (ADS)

Jiao, Jing; Yang, Guotao; Wang, Jihong; Zhang, Tiemin; Peng, Hongyan; Xun, Yuchang; Liu, Zhengkuan; Wang, Chi

2017-11-01

The atmospheric sodium layer normally occurs in the mesopause (80-105 km) region, but rarely in the lower thermosphere region (>105 km) at low latitude. We observed a kind of peculiar sodium layer in lower thermosphere at Haikou (19.99°N, 110.34°E)-the thermospheric convective sodium layer (TCSL) in a lidargram. The TCSL's sodium density unstably developed over time and appeared as several discontinuous convective shapes vertically. It is the first time convective sodium layer observed in the lower thermosphere region (105-120 km). Based on Haikou lidar data, we obtained 14 TCSL events during 180 nights from March 2010 to August 2012. Most of the apogees of the TCSL events are higher than 108 km. A TCSL event lasts several hours and is composed of several convective structures, with each veitical shape lasting ∼5-30 min. All TCSL events occurred during spring and summer, and generally appear near midnight (22:00-00:00 LT). The TCSL has potential regional feature and appears to be related to the thermospheric sporadic E (Es) layers, winds, and field-aligned ionospheric irregularities (FAI).

Daytime lidar measurements of tidal winds in the mesospheric sodium layer at Urbana, Illinois

NASA Technical Reports Server (NTRS)

Kwon, K. H.; Senft, D. C.; Gardner, C. S.; Voelz, D. G.; Sechrist, C. F., Jr.; Roesler, F. L.

1986-01-01

For more than 15 years lidar systems have been used to study the chemistry and dynamics of the mesospheric sodium layer. Because the layer is an excellent tracer of atmospheric wave motions, sodium lidar has proven to be particularly useful for studying the influence of gravity waves and tides on mesospheric dynamics. These waves, which originate in the troposphere and stratosphere, propagate through the mesosphere and dissipate their energy near the mesopause making important contributions to the momentum and turbulence budget in this region of the atmosphere. Recently, the sodium lidar was modified for daytime operation so that wave phenomena and chemical effects could be monitored throughout the complete diurnal cycle. The results of continuous 24 hour lidar observations of the sodium layer structure are presented alond with measurement of the semidiurnal tidal winds.

Generation of alkali-free and high-proton concentration layer in a soda lime glass using non-contact corona discharge

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

Ikeda, Hiroshi; Sakai, Daisuke; Nishii, Junji

2013-08-14

Formation mechanisms of alkali-free and high-proton concentration surfaces were investigated for a soda lime glass using a corona discharge treatment under an atmospheric pressure. Protons produced by high DC voltage around an anode needle electrode were incorporated into a sodium ion site in the anode side glass. The sodium ion was swept away to the cathode side as a charge carrier. Then it was discharged. The precipitated sodium was transformed to a Na{sub 2}CO{sub 3} powder when the surface contacted with air. The sodium ion in the glass surface layer of the anode side was replaced completely by protons. Themore » concentration of OH groups in the layer was balanced with the amount of excluded sodium ions. The substitution reaction of sodium ions with protons tends to be saturated according to a square root function of time. The alkali depletion layer formation rate was affected by the large difference in mobility between sodium ions and protons in the glass.« less

Polarization switching of sodium guide star laser for brightness enhancement

NASA Astrophysics Data System (ADS)

Fan, Tingwei; Zhou, Tianhua; Feng, Yan

2016-07-01

The efficiency of optical pumping that enhances the brightness of sodium laser guide star with circularly polarized light is reduced substantially due to the precession of sodium atoms in geomagnetic field. Switching the laser between left and right circular polarization at the Larmor frequency is proposed to improve the photon return. With ESO's cw laser guide star system at Paranal as example, numerical simulation for both square-wave and sine-wave polarization modulation is conducted. For the square-wave switching case, the return flux is increased when the angle between geomagnetic field and laser beam is larger than 60°, as much as 40% at 90°. The method can also be applied for remote measurement of magnetic field with available cw guide star laser.

Improved performance of the laser guide star adaptive optics system at Lick Observatory

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

An, J R; Avicola, K; Bauman, B J

1999-07-20

Results of experiments with the laser guide star adaptive optics system on the 3-meter Shane telescope at Lick Observatory have demonstrated a factor of 4 performance improvement over previous results. Stellar images recorded at a wavelength of 2 {micro}m were corrected to over 40% of the theoretical diffraction-limited peak intensity. For the previous two years, this sodium-layer laser guide star system has corrected stellar images at this wavelength to {approx}10% of the theoretical peak intensity limit. After a campaign to improve the beam quality of the laser system, and to improve calibration accuracy and stability of the adaptive optics systemmore » using new techniques for phase retrieval and phase-shifting diffraction interferometry, the system performance has been substantially increased. The next step will be to use the Lick system for astronomical science observations, and to demonstrate this level of performance with the new system being installed on the 10-meter Keck II telescope.« less

Study of guided wave transmission through complex junction in sodium cooled reactor

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

Elie, Q.; Le Bourdais, F.; Jezzine, K.

2015-07-01

Ultrasonic guided wave techniques are seen as suitable candidates for the inspection of welded structures within sodium cooled fast reactors (SFR), as the long range propagation of guided waves without amplitude attenuation can overcome the accessibility problem due to the liquid sodium. In the context of the development of the Advanced Sodium Test Reactor for Industrial Demonstration (ASTRID), the French Atomic Commission (CEA) investigates non-destructive testing techniques based on guided wave propagation. In this work, guided wave NDT methods are applied to control the integrity of welds located in a junction-type structure welded to the main vessel. The method presentedmore » in this paper is based on the analysis of scattering matrices peculiar to each expected defect, and takes advantage of the multi-modal and dispersive characteristics of guided wave generation. In a simulation study, an algorithm developed using the CIVA software is presented. It permits selecting appropriate incident modes to optimize detection and identification of expected flawed configurations. In the second part of this paper, experimental results corresponding to a first validation step of the simulation results are presented. The goal of the experiments is to estimate the effectiveness of the incident mode selection in plates. The results show good agreement between experience and simulation. (authors)« less

Few-Layer MXenes Delaminated via High-Energy Mechanical Milling for Enhanced Sodium-Ion Batteries Performance.

PubMed

Wu, Yuting; Nie, Ping; Wang, Jiang; Dou, Hui; Zhang, Xiaogang

2017-11-15

The global availability of sodium makes the exploration of superior sodium-ion batteries attractive for energy storage application. MXenes, as one of the most promising anodes for sodium-ion batteries, have been reported to have many advantages, such as high electronic conductivity and a hydrophilic surface. However, the compact multilayer structure and deficient delamination significantly inhibits their application, requiring high energy and showing decreased storage capacity and poor rate capabilities. Few-layer MXene has been proved to benefit superior electrochemical properties with a better ionic conductivity and two-dimensional layer structure. Herein, we report scale delamination of few-layer MXene nanosheets as anodes for sodium-ion batteries, which are prepared via an organic solvent assist high-energy mechanical-milling method. This approach efficiently prevents the oxidation of MXene and produces few-layer nanosheets structure, facilitating fast electron transport and Na + diffusion. Electrochemical tests demonstrate that the few-layer MXenes show high specific capacity, excellent cycle stability, and good rate performance. Specifically, few-layer MXene nanosheets deliver a high reversible capacity of 267 mA h g -1 at a current density of 0.1 A g -1 . After cycling 1500 cycles at a high rate of 1 A g -1 , a reversible capacity of 76 mA h g -1 could be maintained.

Stabilized Alkali-Metal Ultraviolet-Band-Pass Filters

NASA Technical Reports Server (NTRS)

Mardesich, Nick; Fraschetti, George A.; Mccann, Timothy; Mayall, Sherwood D.; Dunn, Donald E.; Trauger, John T.

1995-01-01

Layers of bismuth 5 to 10 angstrom thick incorporated into alkali-metal ultraviolet-band-pass optical filters by use of advanced fabrication techniques. In new filters layer of bismuth helps to reduce surface migration of sodium. Sodium layer made more stable and decreased tendency to form pinholes by migration.

Status of the ARGOS project

NASA Astrophysics Data System (ADS)

Rabien, Sebastian; Barl, Lothar; Beckmann, Udo; Bonaglia, Marco; Borelli, José Luis; Brynnel, Joar; Buschkamp, Peter; Busoni, Lorenzo; Christou, Julian; Connot, Claus; Davies, Richard; Deysenroth, Matthias; Esposito, Simone; Gässler, Wolfgang; Gemperlein, Hans; Hart, Michael; Kulas, Martin; Lefebvre, Michael; Lehmitz, Michael; Mazzoni, Tommaso; Nussbaum, Edmund; Orban de Xivry, Gilles; Peter, Diethard; Quirrenbach, Andreas; Raab, Walfried; Rahmer, Gustavo; Storm, Jesper; Ziegleder, Julian

2014-07-01

ARGOS is the Laser Guide Star and Wavefront sensing facility for the Large Binocular Telescope. With first laser light on sky in 2013, the system is currently undergoing commissioning at the telescope. We present the overall status and design, as well as first results on sky. Aiming for a wide field ground layer correction, ARGOS is designed as a multi- Rayleigh beacon adaptive optics system. A total of six powerful pulsed lasers are creating the laser guide stars in constellations above each of the LBTs primary mirrors. With a range gated detection in the wavefront sensors, and the adaptive correction by the deformable secondary's, we expect ARGOS to enhance the image quality over a large range of seeing conditions. With the two wide field imaging and spectroscopic instruments LUCI1 and LUCI2 as receivers, a wide range of scientific programs will benefit from ARGOS. With an increased resolution, higher encircled energy, both imaging and MOS spectroscopy will be boosted in signal to noise by a large amount. Apart from the wide field correction ARGOS delivers in its ground layer mode, we already foresee the implementation of a hybrid Sodium with Rayleigh beacon combination for a diffraction limited AO performance.

Antisite occupation induced single anionic redox chemistry and structural stabilization of layered sodium chromium sulfide

DOE PAGES

Shadike, Zulipiya; Zhou, Yong -Ning; Chen, Lan -Li; ...

2017-08-30

The intercalation compounds with various electrochemically active or inactive elements in the layered structure have been the subject of increasing interest due to their high capacities, good reversibility, simple structures and ease of synthesis. However, their reversible intercalation/deintercalation redox chemistries in all previous compounds involve a single cationic redox reaction or a cumulative cationic and anionic redox reaction. Here we report an anionic redox only chemistry and structural stabilization of layered sodium chromium sulfide. It is discovered that sulfur in sodium chromium sulfide is electrochemical active undergoing oxidation/reduction of sulfur rather than chromium. Significantly, sodium ions can successfully move outmore » and into without changing its lattice parameter c, which is explained in terms of the occurrence of chromium/sodium vacancy antisite during desodiation and sodiation processes. Here, our present work not only enriches the electrochemistry of layered intercalation compounds, but also extends the scope of investigation on high-capacity electrodes.« less

Antisite occupation induced single anionic redox chemistry and structural stabilization of layered sodium chromium sulfide

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

Shadike, Zulipiya; Zhou, Yong -Ning; Chen, Lan -Li

The intercalation compounds with various electrochemically active or inactive elements in the layered structure have been the subject of increasing interest due to their high capacities, good reversibility, simple structures and ease of synthesis. However, their reversible intercalation/deintercalation redox chemistries in all previous compounds involve a single cationic redox reaction or a cumulative cationic and anionic redox reaction. Here we report an anionic redox only chemistry and structural stabilization of layered sodium chromium sulfide. It is discovered that sulfur in sodium chromium sulfide is electrochemical active undergoing oxidation/reduction of sulfur rather than chromium. Significantly, sodium ions can successfully move outmore » and into without changing its lattice parameter c, which is explained in terms of the occurrence of chromium/sodium vacancy antisite during desodiation and sodiation processes. Here, our present work not only enriches the electrochemistry of layered intercalation compounds, but also extends the scope of investigation on high-capacity electrodes.« less

A meteor ablation-cluster ion atmospheric sodium theory

NASA Technical Reports Server (NTRS)

Richter, E. S.; Sechrist, C. F., Jr.

1979-01-01

Neutral and ionic forms of sodium form narrow, well-defined layers which peak in the 90-95 km altitude region at midlatitudes. A new theory for the sodium layer is presented, which is found to be in good agreement with existing atmospheric observations as well as available laboratory measurements of rate constants. The layer is believed to result naturally from a meteor ablation source over a chemical sink with vertical transport of Na(+) playing an important role in the layer shape and variation. While the neutral chemistry is believed to consist of chemical equilibrium between Na and NaO, the ion chemistry departs from earlier studies and considers a cluster ion scheme. It is possible that higher-order cluster ions of sodium play a role in the formation of aerosols, through attachment or ion-induced nucleation processes.

Ultrafast laser control of backward superfluorescence towards standoff sensing

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

Ariunbold, Gombojav O.; National University of Mongolia, Ulaanbaatar 210646; Baylor University, Waco, Texas 76798

2014-01-13

We study infrared backward cooperative emission in a rubidium vapor induced by ultrafast two-photon optical excitations. The laser coherent control of the backward emission is demonstrated by using a pair of 100 fs pulses with a variable time delay. The temporal variation (quantum beat) of the backward beam intensity due to interference of atomic transitions in the rubidium atomic level system 5S-5P-5D is produced and controlled. Based on the obtained experimental results, we discuss possible applications of the developed approach for creation of an effective “guide star” in the sodium atomic layer in the upper atmosphere (mesosphere)

Daylight operation of a sodium laser guide star

NASA Astrophysics Data System (ADS)

Hart, Michael; Jefferies, Stuart; Murphy, Neil

2016-07-01

We report photometric measurements of a sodium resonance guide star against the daylight sky when observed through a tuned magneto-optical filter (MOF). The MOF comprises a sodium vapor cell in a kilogauss-level magnetic field between crossed polarizers and has a very narrow transmission profile at the sodium D2 resonance of approximately 0.008 nm. Our observations were made with the 1.5 m Kuiper telescope on Mt. Bigelow, AZ, which has a separately mounted guide star laser projecting a circularly polarized single-frequency beam of approximately 6.5 W at 589.16 nm. Both the beam projector and the 1.5 m telescope were pointed close to zenith; the baseline between them is approximately 5 m. Measurements of the guide star were made on the morning of 2016 March 24 using an imaging camera focused on the beacon and looking through the full aperture of the telescope. The guide star flux was estimated at 1.20×106 photon/m2/s while at approximately 45 minutes after sunrise, the sky background through the MOF was 1100 photon/m2/s/arcsec2. We interpret our results in terms of thermal infrared observations with adaptive optics on the next generation of extremely large telescopes now being built.

Influences of urea and sodium nitrite on surface coating of plasma electrolytic oxidation

NASA Astrophysics Data System (ADS)

Yeh, Shang-Chun; Tsai, Dah-Shyang; Guan, Sheng-Yong; Chou, Chen-Chia

2015-11-01

Urea and sodium nitrite are generally viewed as nitridation additives in the electrolyte for plasma electrolytic oxidation (PEO) of aluminum alloys. We study the influences of these two convenient chemicals in presence of sodium aluminate and find very different effects on film growth. Urea addition enhances the nitrogen content of PEO layer, diminishes the layer thickness, increases the porosity, interferes with the α-alumina formation, and promotes precipitation in the electrolyte. Hence, the electrolytic urea content ought to be maintained less than 45 g dm-3. On the other hand, sodium nitrite behaves like an oxidation additive, more than a nitridation additive. NaNO2 addition effectively introduces nitrogen in the PEO layer at low concentration, yet the nitrogen content of oxide layer decreases with increasing NaNO2 concentration. The effects of NaNO2, such as increasing layer thickness, reducing porosity, promoting α-alumina formation are attributed to oxidation enhancement, not because of nitridation.

A Guided-Inquiry Approach to the Sodium Borohydride Reduction and Grignard Reaction of Carbonyl Compounds

ERIC Educational Resources Information Center

Rosenberg, Robert E.

2007-01-01

The guided-inquiry approach is applied to the reactions of sodium borohydride and phenyl magnesium bromide with benzaldehyde, benzophenone, benzoic anhydride, and ethyl benzoate. Each team of four students receives four unknowns. Students identify the unknowns and their reaction products by using the physical state of the unknown, an…

Chitosan-Sodium Phytate Films with a Strong Water Barrier and Antimicrobial Properties Produced via One-Step-Consecutive-Stripping and Layer-by-Layer-Casting Technologies.

PubMed

Yang, Jie; Xiong, Liu; Li, Man; Sun, Qingjie

2018-06-20

The pursuit of sustainable functional materials requires the development of materials based on renewable resources and efficient fabrication methods. Here, we first fabricated chitosan-sodium phytate films via one-step-stripping and layer-by-layer-casting technologies. The proposed film-fabrication methods are general, facile, environmentally benign, cost-effective, and easy to scale up. The resultant one-step-stripped film was thin (9 ± 1 μm), soft, transparent, and strong, whereas the thickness of the layer-by-layer-cast film was 70 ± 3 μm. FTIR analysis of the films indicated the formation of interactions between the phosphoric groups in sodium phytate and the amino groups in chitosan. More importantly, the water-vapor-permeability values of the one-step-stripped and cast films were 4-5 orders of magnitude lower than chitosan films reported before. Layer-by-layer-cast films in particular exhibited high tensile strength (49.21 ± 1.12 MPa) and were more than three times stronger than other polyelectrolyte multilayer films. Both types of films remained stable in an acidic environment. Furthermore, the layer-by-layer-assembled films presented greater antimicrobial activity than the stripped films. The developed chitosan-sodium phytate films can enhance several biomedical and environmental applications, such as packaging, drug delivery, diagnostics, microfluidics, and biosensing.

Controllable self-assembly of sodium caseinate with a zwitterionic vitamin-derived bolaamphiphile.

PubMed

Sun, Li-Hui; Sun, Yu-Long; Yang, Li-Jun; Zhang, Jian; Chen, Zhong-Xiu

2013-11-06

The control of self-assembly of sodium caseinate (SC) including the formation of mixed layers, microspheres, or nanoparticles is highly relevant to the microstructure of food and the design of promising drug delivery systems. In this paper, we designed a structure-switchable zwitterionic bolaamphiphile, 1,12-diaminododecanediorotate (DDO), from orotic acid, which has special binding sites and can guide the self-assembly of SC. Complexation between SC and DDO was investigated using dynamic light scattering, transmission electron microscopy, differential scanning calorimetry, and fluorescence spectra measurements. Monomeric DDO was bound to the negatively charged sites on the SC micelle and made the structure of SC more compact with decreased electrostatic repulsion between the head groups. Vesicular DDO led to reassociation of vesicles with enlarged size via preferable hydrophobic interactions. Moreover, the aggregation between SC and DDO was found to be temperature-dependent and reversible. This research provides an effective way to control the reversible self-assembly of SC by the zwitterionic vitamin-derived bolaamphiphile.

Lidar observations of wave-like structure in the atmospheric sodium layer

NASA Technical Reports Server (NTRS)

Rowlett, J. R.; Gardner, C. S.; Richter, E. S.; Sechrist, C. F., Jr.

1978-01-01

The University of Illinois (Urbana) lidar system has been developed to study the atmospheric sodium layer near 90 km altitude through the mechanism of resonance scattering. The photocount data are processed using digital smoothing filters to obtain continuous estimates of the sodium density versus altitude. The filter cutoff frequency is related to the height resolution and accuracy of the estimated profile. Lidar photocount data processed using this filtering technique show wave-like structures in the sodium layer which move downward with time. The waves have typical wavelengths of 3-15 km and phase velocities of less than 1 m/sec. The movement of these structures seems to be independent of the motion of the bottomside of the layer, which also has been observed to move up or down by as much as 2 km over a period of a few hours.

A sodium-ion battery exploiting layered oxide cathode, graphite anode and glyme-based electrolyte

NASA Astrophysics Data System (ADS)

Hasa, Ivana; Dou, Xinwei; Buchholz, Daniel; Shao-Horn, Yang; Hassoun, Jusef; Passerini, Stefano; Scrosati, Bruno

2016-04-01

Room-temperature rechargeable sodium-ion batteries (SIBs), in view of the large availability and low cost of sodium raw materials, represent an important class of electrochemical systems suitable for application in large-scale energy storage. In this work, we report a novel, high power SIB formed by coupling the layered P2-Na0.7CoO2 cathode with the graphite anode in an optimized ether-based electrolyte. The study firstly addresses the electrochemical optimization of the two electrode materials and then the realization and characterization of the novel SIB based on their combination. The cell represents an original sodium rocking chair battery obtained combining the intercalation/de-intercalation processes of sodium within the cathode and anode layers. We show herein that this battery, favored by suitable electrode/electrolyte combination, offers unique performance in terms of cycle life, efficiency and, especially, power capability.

Improving sodium laser guide star brightness by polarization switching

PubMed Central

Fan, Tingwei; Zhou, Tianhua; Feng, Yan

2016-01-01

Optical pumping with circularly polarized light has been used to enhance the brightness of sodium laser guide star. But the benefit is reduced substantially due to the precession of sodium atoms in geomagnetic field. Switching the laser between left and right circular polarization at the Larmor frequency is proposed to improve the return. With ESO’s laser guide star system at Paranal as example, numerical simulation shows that the return flux is increased when the angle between geomagnetic field and laser beam is larger than 60°, as much as 50% at 90°. The proposal is significant since most astronomical observation is at angle between 60° and 90° and it only requires a minor addition to the delivery optics of present laser system. PMID:26797503

Theoretical and lidar studies of the density response of the mesospheric sodium layer to gravity wave perturbations

NASA Technical Reports Server (NTRS)

Shelton, J. D.; Gardner, C. S.

1981-01-01

The density response of atmospheric layers to gravity waves is developed in two forms, an exact solution and a perturbation series solution. The degree of nonlinearity in the layer density response is described by the series solution whereas the exact solution gives insight into the nature of the responses. Density perturbation in an atmospheric layer are shown to be substantially greater than the atmospheric density perturbation associated with the propagation of a gravity wave. Because of the density gradients present in atmospheric layers, interesting effects were observed such as a phase reversal in the linear layer response which occurs near the layer peak. Once the layer response is understood, the sodium layer can be used as a tracer of atmospheric wave motions. A two dimensional digital signal processing technique was developed. Both spatial and temporal filtering are utilized to enhance the resolution by decreasing shot noise by more han 10 dB. Many of the features associated with a layer density response to gravity waves were observed in high resolution density profiles of the mesospheric sodium layer. These include nonlinearities as well as the phase reversal in the linear layer response.

pH-Responsive Layer-by-Layer Nanoshells for Direct Regulation of Cell Activity

DTIC Science & Technology

2012-01-01

PVPON1,300), a monomer of metharcylic acid (MAA), hydrochloric acid, sodium hydroxide, sodium chloride , monobasic sodium phosphate, and 1-ethyl-3...dimethylamino- propyl )carbodiimide hydrochloride (EDC) were purchased from Sigma-Aldrich. Initiator, 2,20-azobis(2-methylpropionitrile) (AIBN), was purchased...butoxycarbonylaminopropyl)methacrylamide (t-BOCAPMA) for synthesis of amine-functionalized PMAA, and 4.0 ( 0.2 μm silica particles as 10% aqueous suspension were

Metallization pattern on solid electrolyte or porous support of sodium battery process

DOEpatents

Kim, Jin Yong; Li, Guosheng; Lu, Xiaochuan; Sprenkle, Vincent L.; Lemmon, John P.

2016-05-31

A new battery configuration and process are detailed. The battery cell includes a solid electrolyte configured with an engineered metallization layer that distributes sodium across the surface of the electrolyte extending the active area of the cathode in contact with the anode during operation. The metallization layer enhances performance, efficiency, and capacity of sodium batteries at intermediate temperatures at or below about 200.degree. C.

Apparatus for detecting leakage of liquid sodium

DOEpatents

Himeno, Yoshiaki

1978-01-01

An apparatus for detecting the leakage of liquid sodium includes a cable-like sensor adapted to be secured to a wall of piping or other equipment having sodium on the opposite side of the wall, and the sensor includes a core wire electrically connected to the wall through a leak current detector and a power source. An accidental leakage of the liquid sodium causes the corrosion of a metallic layer and an insulative layer of the sensor by products resulted from a reaction of sodium with water or oxygen in the atmospheric air so as to decrease the resistance between the core wire and the wall. Thus, the leakage is detected as an increase in the leaking electrical current. The apparatus is especially adapted for use in detecting the leakage of liquid sodium from sodium-conveying pipes or equipment in a fast breeder reactor.

Recent research progress on iron- and manganese-based positive electrode materials for rechargeable sodium batteries

PubMed Central

Yabuuchi, Naoaki; Komaba, Shinichi

2014-01-01

Large-scale high-energy batteries with electrode materials made from the Earth-abundant elements are needed to achieve sustainable energy development. On the basis of material abundance, rechargeable sodium batteries with iron- and manganese-based positive electrode materials are the ideal candidates for large-scale batteries. In this review, iron- and manganese-based electrode materials, oxides, phosphates, fluorides, etc, as positive electrodes for rechargeable sodium batteries are reviewed. Iron and manganese compounds with sodium ions provide high structural flexibility. Two layered polymorphs, O3- and P2-type layered structures, show different electrode performance in Na cells related to the different phase transition and sodium migration processes on sodium extraction/insertion. Similar to layered oxides, iron/manganese phosphates and pyrophosphates also provide the different framework structures, which are used as sodium insertion host materials. Electrode performance and reaction mechanisms of the iron- and manganese-based electrode materials in Na cells are described and the similarities and differences with lithium counterparts are also discussed. Together with these results, the possibility of the high-energy battery system with electrode materials made from only Earth-abundant elements is reviewed. PMID:27877694

Recent research progress on iron- and manganese-based positive electrode materials for rechargeable sodium batteries.

PubMed

Yabuuchi, Naoaki; Komaba, Shinichi

2014-08-01

Large-scale high-energy batteries with electrode materials made from the Earth-abundant elements are needed to achieve sustainable energy development. On the basis of material abundance, rechargeable sodium batteries with iron- and manganese-based positive electrode materials are the ideal candidates for large-scale batteries. In this review, iron- and manganese-based electrode materials, oxides, phosphates, fluorides, etc, as positive electrodes for rechargeable sodium batteries are reviewed. Iron and manganese compounds with sodium ions provide high structural flexibility. Two layered polymorphs, O3- and P2-type layered structures, show different electrode performance in Na cells related to the different phase transition and sodium migration processes on sodium extraction/insertion. Similar to layered oxides, iron/manganese phosphates and pyrophosphates also provide the different framework structures, which are used as sodium insertion host materials. Electrode performance and reaction mechanisms of the iron- and manganese-based electrode materials in Na cells are described and the similarities and differences with lithium counterparts are also discussed. Together with these results, the possibility of the high-energy battery system with electrode materials made from only Earth-abundant elements is reviewed.

COATING METHOD

DOEpatents

Townsend, R.G.

1959-08-25

A method is described for protectively coating beryllium metal by etching the metal in an acid bath, immersing the etched beryllium in a solution of sodium zincate for a brief period of time, immersing the beryllium in concentrated nitric acid, immersing the beryhlium in a second solution of sodium zincate, electroplating a thin layer of copper over the beryllium, and finally electroplating a layer of chromium over the copper layer.

Evaluation of ethylenediaminetetraacetic acid (EDTA) solution and gel for smear layer removal.

PubMed

Dotto, Sidney Ricardo; Travassos, Rosana Maria Coelho; de Oliveira, Elias Pandonor Motcy; Machado, Manoel Eduardo de Lima; Martins, José Luiz

2007-08-01

The purpose of this in vitro study was to compare the efficacy of 24% ethylenediaminetetraacetic acid (EDTA) gel and 17% EDTA solution in cleaning dentine walls after root canal instrumentation. Thirty human canine teeth were divided into three groups of 10 teeth each. In Group 1, 1% sodium hypochlorite was used as the irrigating solution; in Group 2, 1% sodium hypochlorite was used with 17% EDTA solution; and in Group 3, 1% sodium hypochlorite was used with 24% EDTA gel. The presence of a smear layer was analysed after instrumentation using scanning electron microscopy. The Kruskal-Wallis test revealed a statistical difference (P < 0.05) between Groups 1 and 2, and also between Groups 1 and 3. No difference was observed between Groups 2 and 3 (P > 0.05). The results indicate that 1% sodium hypochlorite alone does not remove the smear layer and that there was no statistical difference between EDTA gel and EDTA solution in smear layer removal.

Beneficial effect of boron in layered sodium-ion cathode materials - The example of Na2/3B0.11Mn0.89O2

NASA Astrophysics Data System (ADS)

Vaalma, Christoph; Buchholz, Daniel; Passerini, Stefano

2017-10-01

Sodium-ion batteries are regarded as a complementary drop-in technology to lithium-ion batteries because they promise lower cost and a higher degree of environmental friendliness. Among other reasons, these benefits come from the use of manganese-based materials, whose stabilization via cation substitution is intensively studied to improve the electrochemical performance. Although multiple elements have been considered as substituent, surprisingly, boron has not been reported for layered sodium-ion cathode materials up to date. Our investigation of layered Na2/3B0.11Mn0.89O2 reveals an unexpectedly good electrochemical performance, with charge and discharge capacities of more than 175 mAh g-1 at 10 mA g-1 and 135 mAh g-1 at 500 mA g-1. The measured capacities are among the highest ever reported for sodium-based layered oxides in the potential range of 4.0-2.0 V vs. Na/Na+.

The topside behavior in the mesospheric sodium layer observed by lidar at Yanqing (40.46°N, 115.98°E) and at Haikou (20.01°N, 110.32°E)

NASA Astrophysics Data System (ADS)

Liu, Yingjie; Clemesha, Barclay Robert; Wang, Jihong

2016-04-01

Due to meteoric ablation, large amounts of metal atoms deposit in the mesopause region, forming the metal layers that can be observed by ground-based lidars. It is widely acknowledged that the meteoric metal layers are normally confined to altitudes of 75-115 km. In fact, the observable upper limit of the topside layer depends largely on the performance of the instruments, the integration time and the observation conditions. With the support of the Chinese Meridional project in the eastern hemisphere, two brand new sodium fluorescence lidars with the same configuration were respectively set up at Yanqing (40.46°N, 115.98°E) and at Haikou (20.01°N, 110.32°E) in April, 2010. They displayed powerful detection capabilities which allow us to study the topside behavior of the mesospheric sodium layer. Based on the observations made at Yanqing between April 2010 and June 2012 and those at Haikou between April 2010 and December 2012, seasonal variations of sodium densities were studied. Comparison between these two sites (~2300 km apart) reveals a strong correlation in the topside sodium layer. Independently of their seasonal characteristics at lower altitudes, they both show an extension to 120 km and above, predominantly during summer. 90 nights of simultaneous observations at these two sites shows that the variation trends of sodium densities above 102 km are remarkably similar in contrast to their different seasonal characteristics below 98 km. At 105 km the correlation coefficient reaches up to 0.71, and almost all of the major peaks can be found one by one with their relative strengths reproduced to a large degree. It indicates that the topside extension effect is global in the mesospheric sodium layer, combined with the observations at other latitudes. Comparison with known meteor showers shows that most of these extensions correspond well to one or more meteor showers, although not one by one. Meteor showers with velocities less than 35 km/s appear to have more influence on these extensions.

Pseudocapacitive Sodium Storage by Ferroelectric Sn2 P2 S6 with Layered Nanostructure.

PubMed

Huang, Sheng; Meng, Chao; Xiao, Min; Ren, Shan; Wang, Shuanjin; Han, Dongmei; Li, Yuning; Meng, Yuezhong

2018-04-19

Sodium ion batteries (SIB) are considered promising alternative candidates for lithium ion batteries (LIB) because of the wide availability and low cost of sodium, therefore the development of alternative sodium storage materials with comparable performance to LIB is urgently desired. The sodium ions with larger sizes resist intercalation or alloying because of slow reaction kinetics. Most pseudocapacitive sodium storage materials are based on subtle nanomaterial engineering, which is difficult for large-scale production. Here, ferroelectric Sn 2 P 2 S 6 with layered nanostructure is developed as sodium ion storage material. The ferroelectricity-enhanced pseudocapacitance of sodium ion in the interlayer spacing makes the electrochemical reaction easier and faster, endowing the Sn 2 P 2 S 6 electrode with excellent rate capability and cycle stability. Furthermore, the facile solid state reaction synthesis and common electrode fabrication make the Sn 2 P 2 S 6 that becomes a promising anode material of SIB. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

POST-OPERATIONAL TREATMENT OF RESIDUAL NA COOLLANT IN EBR-2 USING CARBONATION

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

Sherman, S.; Knight, C.

2011-03-08

At the end of 2002, the Experimental Breeder Reactor Two (EBR-II) facility became a U.S. Resource Conservation and Recovery Act (RCRA) permitted site, and the RCRA permit1 compelled further treatment of the residual sodium in order to convert it into a less reactive chemical form and remove the by-products from the facility, so that a state of RCRA 'closure' for the facility may be achieved (42 U.S.C. 6901-6992k, 2002). In response to this regulatory driver, and in recognition of project budgetary and safety constraints, it was decided to treat the residual sodium in the EBR-II primary and secondary sodium systemsmore » using a process known as 'carbonation.' In early EBR-II post-operation documentation, this process is also called 'passivation.' In the carbonation process (Sherman and Henslee, 2005), the system containing residual sodium is flushed with humidified carbon dioxide (CO{sub 2}). The water vapor in the flush gas reacts with residual sodium to form sodium hydroxide (NaOH), and the CO{sub 2} in the flush gas reacts with the newly formed NaOH to make sodium bicarbonate (NaHCO{sub 3}). Hydrogen gas (H{sub 2}) is produced as a by-product. The chemical reactions occur at the exposed surface of the residual sodium. The NaHCO{sub 3} layer that forms is porous, and humidified carbon dioxide can penetrate the NaHCO{sub 3} layer to continue reacting residual sodium underneath. The rate of reaction is controlled by the thickness of the NaHCO{sub 3} surface layer, the moisture input rate, and the residual sodium exposed surface area. At the end of carbonation, approximately 780 liters of residual sodium in the EBR-II primary tank ({approx}70% of original inventory), and just under 190 liters of residual sodium in the EBR-II secondary sodium system ({approx}50% of original inventory), were converted into NaHCO{sub 3}. No bare surfaces of residual sodium remained after treatment, and all remaining residual sodium deposits are covered by a layer of NaHCO{sub 3}. From a safety standpoint, the inventory of residual sodium in these systems was greatly reduced by using the carbonation process. From a regulatory standpoint, the process was not able to achieve deactivation of all residual sodium, and other more aggressive measures will be needed if the remaining residual sodium must also be deactivated to meet the requirements of the existing environmental permit. This chapter provides a project history and technical summary of the carbonation of EBR-II residual sodium. Options for future treatment are also discussed.« less

Modulating the Electrochemical Performances of Layered Cathode Materials for Sodium Ion Batteries through Tuning Coulombic Repulsion between Negatively Charged TMO2 Slabs.

PubMed

Li, Zheng-Yao; Wang, Huibo; Yang, Wenyun; Yang, Jinbo; Zheng, Lirong; Chen, Dongfeng; Sun, Kai; Han, Songbai; Liu, Xiangfeng

2018-01-17

Exploiting advanced layered transition metal oxide cathode materials is of great importance to rechargeable sodium batteries. Layered oxides are composed of negatively charged TMO 2 slabs (TM = transition metal) separated by Na + diffusion layers. Herein, we propose a novel insight, for the first time, to control the electrochemical properties by tuning Coulombic repulsion between negatively charged TMO 2 slabs. Coulombic repulsion can finely tailor the d-spacing of Na ion layers and material structural stability, which can be achieved by employing Na + cations to serve as effective shielding layers between TMO 2 layers. A series of O3-type Na x Mn 1/3 Fe 1/3 Cu 1/6 Mg 1/6 O 2 (x = 1.0, 0.9, 0.8, and 0.7) have been prepared, and Na 0.7 Mn 1/3 Fe 1/3 Cu 1/6 Mg 1/6 O 2 shows the largest Coulombic repulsion between TMO 2 layers, the largest space for Na ion diffusion, the best structural stability, and also the longest Na-O chemical bond with weaker Coulombic attraction, thus leading to the best electrochemical performance. Meanwhile, the thermal stability depends on the Na concentration in pristine materials. Ex situ X-ray absorption (XAS) analysis indicates that Mn, Fe, and Cu ions are all electrochemically active components during insertion and extraction of sodium ion. This study enables some new insights to promote the development of advanced layered Na x TMO 2 materials for rechargeable sodium batteries in the future.

Evaluation of fouling in nanofiltration for desalination using a resistance-in-series model and optical coherence tomography.

PubMed

Park, Jongkwan; Lee, Sungyun; You, Jeongyeop; Park, Sanghun; Ahn, Yujin; Jung, Woonggyu; Cho, Kyung Hwa

2018-06-12

Resistance-in-series models have been applied to investigate fouling behavior. However, it is difficult to model the influence of morphology on fouling behavior because resistance is indirectly calculated from the water flux and transmembrane pressure. In this study, optical coherence tomography (OCT) was applied to evaluate the resistance of the fouling layer based on fouling morphology. Sodium alginate, humic acid, and bovine serum albumin (BSA) with high salts concentrations (conductivity: 23 mS/cm) were used as model foulants. At the same total fouling resistance, BSA showed the highest cake layer thickness (BSA (114.5 μm) > humic acid (53.5 μm) > sodium alginate (20.0 μm)). However, a different order was found for the cake layer resistance (BSA > sodium alginate > humic acid). This indicates that fouling thickness is not correlated with cake layer resistance. According to the Carman-Kozeny equation, fouling layer porosity decreased in the following order: humic acid (0.30) > BSA (0.21) > sodium alginate (0.20). In addition, we provided a specific value that was calculated using the ratio between the fouling thickness and cake layer resistance. The results show that alginic acid induced a stronger cake layer resistance, despite its thin fouling layer, whereas BSA showed a relatively low potential for inducing cake layer resistance. The results obtained in this study could be used for estimating and predicting fouling behavior. Copyright © 2018 Elsevier B.V. All rights reserved.

A Review Over Benefits and Drawbacks of Combining Sodium Hypochlorite with Other Endodontic Materials.

PubMed

Mohammadi, Zahed; Shalavi, Sousan; Moeintaghavi, Amir; Jafarzadeh, Hamid

2017-01-01

As the root canal system considered to be complex and unpredictable, using root canal irrigants and medicaments are essential in order to enhance the disinfection of the canal. Sodium hypochlorite is the most common irrigant in endodontics. Despite its excellent antimicrobial activity and tissue solubility, sodium hypochlorite lacks some important properties such as substantivity and smear layer removing ability. The aim of this review was to address benefits and drawbacks of combining sodium hypochlorite with other root canal irrigants and medicaments. According to the reviewed articles, NaOCl is the most common irrigation solution in endodontics. However, it has some drawbacks such as inability to remove smear layer. One of the drawbacks of NaOCl is its inability to remove the smear layer and lack of substantivity. The adjunctive use of other materials has been suggested to improve NaOCl efficacy. Nevertheless, further studies are required in this field.

Effect of flowing sodium on corrosion and tensile properties of AISI type 316LN stainless steel at 823 K

NASA Astrophysics Data System (ADS)

Sivai Bharasi, N.; Thyagarajan, K.; Shaikh, H.; Balamurugan, A. K.; Bera, Santanu; Kalavathy, S.; Gurumurthy, K.; Tyagi, A. K.; Dayal, R. K.; Rajan, K. K.; Khatak, H. S.

2008-07-01

AISI type 316LN stainless steel was exposed to flowing sodium in mass transfer loop (MTL) at 823 K for 16 000 h and then examined for changes in the tensile properties due to the mass transfer and corrosion effects. Comparisons in microstructural and mechanical properties were made between annealed, thermally aged and sodium exposed materials. Microstructural examination of thermally aged and sodium exposed materials revealed precipitation of carbides at the grain boundaries. The sodium exposed samples contained a degraded layer at the surface up to a depth of around 10 μm and a surface carburized layer of about 30 μm. There was about 15% increase in yield strength and a decrease of about 20% in ductility for the sodium exposed material vis-a-vis thermally aged material and this was attributed to carburization effects and microstructural changes.

Design and construction of a multiple beam laser projector and dynamically refocused wavefront sensor

NASA Astrophysics Data System (ADS)

Stalcup, Thomas Eugene, Jr.

Adaptive optics using natural guide stars can produce images of amazing quality, but is limited to a small fraction of the sky due to the need for a relatively bright guidestar. Adaptive optics systems using a laser generated artificial reference can be used over a majority of the sky, but these systems have some attendant problems. These problems can be reduced by increasing the altitude of the laser return, and indeed a simple, single laser source focused at an altitude of 95 km on a layer of atmospheric sodium performs well for the current generation of 8--10 m telescopes. For future giant telescopes in the 20--30 m class, however, the errors due to incorrect atmospheric sampling and spot elongation will prohibit such a simple system from working. The system presented in this dissertation provides a solution to these problems. Not only does it provide the 6.5m MMT with a relatively inexpensive laser guide star system with unique capabilities, it allows research into solving many of the problems faced by laser guide star systems on future giant telescopes. The MMT laser guidestar system projects a constellation of five doubled Nd:YAG laser beams focused at a mean height of 25 km, with a dynamic refocus system that corrects for spot elongation and allows integrating the return from a 10 km long range gate. It has produced seeing limited spot sizes in ˜1 arcsecond seeing conditions, and has enabled the first on-sky results of Ground Layer Adaptive Optics (GLAO).

Possible forerunners of earthquakes in optical range

NASA Astrophysics Data System (ADS)

Malnev, V. N.; Martysh, E. V.; Koshevya, S.; Kotsarenko, A.; Siqueiros Alatorre, J.

2007-05-01

The monitoring of the electrostatic field on the eve of the strong earthquakes detect its ultra-low-frequency perturbations with a period of a few hours (10-4Hz) and a magnitude of the order of 10 V/cm. Usually this field is on the level of one V/cm. The anomalous electric field as a forerunner of the coming earthquake considerably increases a concentration of the metal ions (sodium) in the E-domain at altitudes ~120 km and the electron concentration, as well. In particular, the latter may enlarge by one order comparing with the initial electron concentration in this domain. The typical dimensions of this layer are ~ 100 km in a length and ~ 10 km in a thickness. The perturbations of this electric field form a layer with higher than usual concentration of sodium ions and atoms in the E- ionosphere and the field will heats-up electrons in this layer. Simple evaluations show the electron temperature in this layer in the presence of the seismogenic electric field is approximately about 1000-1300K at altitudes 100-120 km provided that the electric field is ~ 10-3 V/cm. It is important the cross-section of excitation of the nitrogen low vibration levels by electrons at this energy is anomalous and close to 5x10-15cm2. It happens to be that the eighth vibration level of a nitrogen molecule practically coincides with the first excited state of a sodium atom with energy ENa=2.1eV. Thus, the resonant transfer of the vibration energy of excited nitrogen with excitation of a sodium atom takes place practically in every collision. Our evaluation of the sodium doublet intensity due to the above-discussed mechanism from the ionosphere layer, mentioned above, gives 5x10-3erg/cm2s. A comparison of this quantity with the conventional intensity of the sodium doublet from this layer 7x10-4erg/cm2s shows that the suggested mechanism provides the intensity almost by one order larger than the conventional intensity of the sodium doublet. The considerable increasing in the intensity of the sodium doublet in the spectrum of the night ionosphere can be registered by monitoring the night sky over the seismic dangerous regions.

Atmospheric tomography using a fringe pattern in the sodium layer.

PubMed

Baharav, Y; Ribak, E N; Shamir, J

1994-02-15

We wish to measure and separate the contribution of atmospheric turbulent layers for multiconjugate adaptive optics. To this end, we propose to create a periodic fringe pattern in the sodium layer and image it with a modified Hartmann sensor. Overlapping sections of the fringes are imaged by a lenslet array onto contiguous areas in a large-format camera. Low-layer turbulence causes an overall shift of the fringe pattern in each lenslet, and high-attitude turbulence results in internal deformations in the pattern. Parallel Fourier analysis permits separation of the atmospheric layers. Two mirrors, one conjugate to a ground layer and the other conjugate to a single high-altitude layer, are shown to widen the field of view significantly compared with existing methods.

Laser-sodium interaction for the polychromatic laser guide star project

NASA Astrophysics Data System (ADS)

Bellanger, Veronique; Petit, Alain D.

2002-02-01

We developed a code aimed at determining the laser parameters leading to the maximum return flux of photons at 0.33 micrometers for a polychromatic sodium Laser Guide Star. This software relies upon a full 48-level collisionless and magnetic-field-free density-matrix description of the hyperfine structure of Na and includes Doppler broadening and Zeeman degeneracy. Experimental validation of BEACON was conducted on the SILVA facilities and will also be discussed in this paper.

Synchrotron Radiation Microcomputed Tomography Guided Chromatographic Analysis for Displaying the Material Distribution in Tablets.

PubMed

Zhang, Liu; Wu, Li; Wang, Caifen; Zhang, Guoqing; Yu, Lin; Li, Haiyan; Maharjan, Abi; Tang, Yan; He, Dunwei; York, Peter; Sun, Huimin; Yin, Xianzhen; Zhang, Jiwen; Sun, Lixin

2018-03-06

One unusual and challenging scientific field that has received only cursory attention to date is the three-dimensional (3D) microstructure and spatial distribution of drug(s) and formulation materials in solid dosage forms. This study aims to provide deeper insight into the relationships between the microstructure of multiple-unit pellet system (MUPS) tablets and the spatial distribution of the active pharmaceutical ingredient (API) and excipients to facilitate the design of quantitative models for drug delivery systems. Synchrotron radiation X-ray microcomputed tomography (SR-μCT) was established as a 3D structure elucidation technique, which, in conjunction with liquid chromatography coupled to mass spectrometry (LC-MS) or liquid chromatography with evaporative light-scattering detector (LC-ELSD) enables chemical analysis of tablets. On the basis of the specific interior construction of theophylline MUPS tablets, the spatial distribution of materials was acquired by quantifying microregion samples that had been validated by SR-μCT for their locations in the MUPS tablets. The 3D structure of the MUPS tablets was catalogued as three structural domains: a matrix layer (ML), a protective cushion layer (PCL), and pellets (PL). Compared with the components in the ML, components in the PL had a larger proportion of theophylline, sucrose, and diethyl phthalate and a smaller proportion of lactose and sodium lauryl sulfate, whereas glyceryl monostearate was found to account for a large portion of the PCL. Microstructural characterization-guided zonal chemical determination represents a new approach for quality assessment and the development of drug delivery systems with in-depth insight into their constituent layers on a new scale.

Long-distance transmission of light in a scintillator-based radiation detector

DOEpatents

Dowell, Jonathan L.; Talbott, Dale V.; Hehlen, Markus P.

2017-07-11

Scintillator-based radiation detectors capable of transmitting light indicating the presence of radiation for long distances are disclosed herein. A radiation detector can include a scintillator layer and a light-guide layer. The scintillator layer is configured to produce light upon receiving incident radiation. The light-guide layer is configured to receive light produced by the scintillator layer and either propagate the received light through the radiation detector or absorb the received light and emit light, through fluorescence, that is propagated through the radiation detector. A radiation detector can also include an outer layer partially surrounding the scintillator layer and light-guide layer. The index of refraction of the light-guide layer can be greater than the index of refraction of adjacent layers.

A cluster ion chemistry for the mesospheric sodium layer

NASA Technical Reports Server (NTRS)

Richter, E. S.; Sechrist, C. F., Jr.

1979-01-01

A cluster ion chemistry for sodium is developed which relates the Na(+) profile to the Na profile using reactions involving Na(+).N2, Na(+).CO2, and Na(+).H2O. Removal of sodium from the mesosphere is accomplished by the formation of higher order clusters of the form Na(+).(H2O)n which presumably precipitate to the lower atmosphere. This sink is most effective in the 80-85 km altitude range. The chemical equilibrium model is applied to experimental observations of the Na and Na(+) layers.

Insights into the structural effects of layered cathode materials for high voltage sodium-ion batteries

DOE PAGES

Xu, Gui -Liang; Amine, Rachid; Xu, Yue -Feng; ...

2017-06-08

Cathode materials are critical to the energy density, power density and safety of sodium-ion batteries (SIBs). Herein, we performed a comprehensive study to elucidate and exemplify the interplay mechanism between phase structures, interfacial microstrain and electrochemical properties of layered-structured Na xNi 1/3Co 1/3Mn 1/3O 2 cathode materials for high voltage SIBs. The electrochemical test results showed that Na xNi 1/3Co 1/3Mn 1/3O 2 with an intergrowth P2/O3/O1 structure demonstrates better electrochemical performance and better thermal stability than Na xNi 1/3Co 1/3Mn 1/3O 2 with P2/O3 binary-phase integration and Na xNi 1/3Co 1/3Mn 1/3O 2 where only the P phase ismore » dominant. This result is caused by the distinct interfacial microstrain development during the synthesis and cycling of the P2/O3/O1 phase. In operando high energy X-ray diffraction further revealed that the intergrowth P2/O1/O3 cathode can inhibit the irreversible P2–O2 phase transformation and simultaneously improve the structure stability of the O3 and O1 phases during cycling. Here, we believe that interfacial microstrain can serve as an indispensable bridge to guide future design and synthesis of high performance SIB cathode materials and other high energy battery materials.« less

Investigating Sodium Storage Mechanisms in Tin Anodes: A Combined Pair Distribution Function Analysis, Density Functional Theory, and Solid-State NMR Approach.

PubMed

Stratford, Joshua M; Mayo, Martin; Allan, Phoebe K; Pecher, Oliver; Borkiewicz, Olaf J; Wiaderek, Kamila M; Chapman, Karena W; Pickard, Chris J; Morris, Andrew J; Grey, Clare P

2017-05-31

The alloying mechanism of high-capacity tin anodes for sodium-ion batteries is investigated using a combined theoretical and experimental approach. Ab initio random structure searching (AIRSS) and high-throughput screening using a species-swap method provide insights into a range of possible sodium-tin structures. These structures are linked to experiments using both average and local structure probes in the form of operando pair distribution function analysis, X-ray diffraction, and 23 Na solid-state nuclear magnetic resonance (ssNMR), along with ex situ 119 Sn ssNMR. Through this approach, we propose structures for the previously unidentified crystalline and amorphous intermediates. The first electrochemical process of sodium insertion into tin results in the conversion of crystalline tin into a layered structure consisting of mixed Na/Sn occupancy sites intercalated between planar hexagonal layers of Sn atoms (approximate stoichiometry NaSn 3 ). Following this, NaSn 2 , which is predicted to be thermodynamically stable by AIRSS, forms; this contains hexagonal layers closely related to NaSn 3 , but has no tin atoms between the layers. NaSn 2 is broken down into an amorphous phase of approximate composition Na 1.2 Sn. Reverse Monte Carlo refinements of an ab initio molecular dynamics model of this phase show that the predominant tin connectivity is chains. Further reaction with sodium results in the formation of structures containing Sn-Sn dumbbells, which interconvert through a solid-solution mechanism. These structures are based upon Na 5-x Sn 2 , with increasing occupancy of one of its sodium sites commensurate with the amount of sodium added. ssNMR results indicate that the final product, Na 15 Sn 4 , can store additional sodium atoms as an off-stoichiometry compound (Na 15+x Sn 4 ) in a manner similar to Li 15 Si 4 .

Atomistic Molecular Dynamics Simulations of the Electrical Double

NASA Astrophysics Data System (ADS)

Li, Zifeng; Milner, Scott; Fichthorn, Kristen

2015-03-01

The electrical double layer (EDL) near the polymer/water interface plays a key role in the colloidal stability of latex paint. To elucidate the structure of the EDL at the molecular level, we conducted an all-atom molecular dynamics simulations. We studied two representative surface charge groups in latex, the ionic surfactant sodium dodecyl sulfate (SDS) and the grafted short polyelectrolyte charged by dissociated methyl methacrylic acid (MAA) monomers. Our results confirm that the Poisson-Boltzmann theory works well outside the Stern layer. Our calculated electrostatic potential at the Outer Helmholtz Plane (OHP) is close to the zeta potential measured experimentally, which suggests that the potential at the OHP is a good estimate of the zeta potential. We found that the position of the OHP for the MAA polyelectrolyte system extends much further into the aqueous phase than that in the SDS system, resulting in a Stern layer that is twice as thick. This model will allow for future investigations of the interactions of the surface with different surfactants and rheology modifiers, which may serve as a guide to tune the rheology of latex formulations. We thank Dow Chemical Company for financial support.

A Review Over Benefits and Drawbacks of Combining Sodium Hypochlorite with Other Endodontic Materials

PubMed Central

Mohammadi, Zahed; Shalavi, Sousan; Moeintaghavi, Amir

2017-01-01

Introduction: As the root canal system considered to be complex and unpredictable, using root canal irrigants and medicaments are essential in order to enhance the disinfection of the canal. Sodium hypochlorite is the most common irrigant in endodontics. Despite its excellent antimicrobial activity and tissue solubility, sodium hypochlorite lacks some important properties such as substantivity and smear layer removing ability. Objective: The aim of this review was to address benefits and drawbacks of combining sodium hypochlorite with other root canal irrigants and medicaments. Discussion: According to the reviewed articles, NaOCl is the most common irrigation solution in endodontics. However, it has some drawbacks such as inability to remove smear layer. One of the drawbacks of NaOCl is its inability to remove the smear layer and lack of substantivity. Conclusion: The adjunctive use of other materials has been suggested to improve NaOCl efficacy. Nevertheless, further studies are required in this field. PMID:29387282

Buffer layer enhanced stability of sodium-ion storage

NASA Astrophysics Data System (ADS)

Wang, Xusheng; Yang, Zhanhai; Wang, Chao; Chen, Dong; Li, Rui; Zhang, Xinxiang; Chen, Jitao; Xue, Mianqi

2017-11-01

Se-Se buffer layers are introduced into tin sequences as SnSe2 single crystal to enhance the cycling stability for long-term sodium-ion storage by blazing a trail of self-defence strategy to structural pulverization especially at high current density. Specifically, under half-cell test, the SnSe2 electrodes could yield a high discharge capacity of 345 mAh g-1 after 300 cycles at 1 A g-1 and a high discharge capacity of 300 mAh g-1 after 2100 cycles at 5 A g-1 with stable coulombic efficiency and no capacity fading. Even with the ultrafast sodium-ion storage at 10 A g-1, the cycling stability still makes a positive response and a high discharge capacity of 221 mAh g-1 is demonstrated after 2700 cycles without capacity fading. The full-cell test for the SnSe2 electrodes also demonstrates the superior cycling stability. The flexible and tough Se-Se buffer layers are favourable to accommodate the sodium-ion intercalation process, and the autogenous Na2Se layers could confine the structural pulverization of further sodiated tin sequences by the slip along the Na2Se-NaxSn interfaces.

Rapidly Synthesized, Few-Layered Pseudocapacitive SnS2 Anode for High-Power Sodium Ion Batteries.

PubMed

Thangavel, Ranjith; Samuthira Pandian, Amaresh; Ramasamy, Hari Vignesh; Lee, Yun-Sung

2017-11-22

The abundance of sodium resources has recently motivated the investigation of sodium ion batteries (SIBs) as an alternative to commercial lithium ion batteries. However, the low power and low capacity of conventional sodium anodes hinder their practical realization. Although most research has concentrated on the development of high-capacity sodium anodes, anodes with a combination of high power and high capacity have not been widely realized. Herein, we present a simple microwave irradiation technique for obtaining few-layered, ultrathin two-dimensional SnS 2 over graphene sheets in a few minutes. SnS 2 possesses a large number of active surface sites and exhibits high-capacity, rapid sodium ion storage kinetics induced by quick, nondestructive pseudocapacitance. Enhanced sodium ion storage at a high current density (12 A g -1 ), accompanied by high reversibility and high stability, was demonstrated. Additionally, a rationally designed sodium ion full cell coupled with SnS 2 //Na 3 V 2 (PO 4 ) 3 exhibited exceptional performance with high initial Coulombic efficiency (99%), high capacity, high stability, and a retention of ∼53% of the initial capacity even after the current density was increased by a factor of 140. In addition, a high specific energy of ∼140 Wh kg -1 and an ultrahigh specific power of ∼8.3 kW kg -1 (based on the mass of both the anode and cathode) were observed. Because of its outstanding performance and rapid synthesis, few-layered SnS 2 could be a promising candidate for practical realization of high-power SIBs.

Efficacy of Sodium Hypochlorite Activated With Laser in Intracanal Smear Layer Removal: An SEM Study

PubMed Central

Shahriari, Shahriar; Kasraei, Shahin; Roshanaei, Ghodratollah; Karkeabadi, Hamed; Davanloo, Hossein

2017-01-01

Introduction: The purpose of the present study was to evaluate the different concentrations of sodium hypochlorite activated with laser in removing of the smear layer in the apical, middle, and coronal segments of root canal walls by scanning electron microscopy analysis. Methods: Sixty single-rooted human mandibular teeth were decoronated to a standardized length. The samples were prepared by using Race rotary system to size 40, 0.04 taper and divided into 4 equal groups (n = 15). Group 1, irrigated with EDTA 17% and 5.25% NaOCl, groups 2, 3 and 4, 1%, 2.5%, and 5% NaOCl activated with Nd:YAG laser, respectively. Teeth were split longitudinally and subjected to scanning electron microscope (SEM). Data were analyzed by Kruskal-Wallis, Mann-Whitney tests. P value of <0.05 was considered statistically significant. Results: Five percent NaOCl LAI (laser-activated irrigation) showed best smear layer removal in test groups and the difference was statistically significant (P < 0.001). Control group (EDTA 17% and 5.25% NaOCl irrigation) showed significantly better outcomes in comparative with test groups (P < 0.001). In the apical third, compared to coronal and middle third, the canal walls were often contaminated by inorganic debris and smear layer. Conclusion: All different concentrations of sodium hypochlorite activated with laser have a positive effect on removing of smear layer. Sodium hypochlorite activated with laser removed smear layer more effectively at the coronal and middle third compared to the apical third. PMID:28912942

RECONDITIONING FUEL ELEMENTS

DOEpatents

Brandt, H.L.

1962-02-20

A process is given for decanning fuel elements that consist of a uranium core, an intermediate section either of bronze, silicon, Al-Si, and uranium silicide layers or of lead, Al-Si, and uranium silicide layers around said core, and an aluminum can bonded to said intermediate section. The aluminum can is dissolved in a solution of sodium hydroxide (9 to 20 wt%) and sodium nitrate (35 to 12 wt %), and the layers of the intermediate section are dissolved in a boiling sodium hydroxide solution of a minimum concentration of 50 wt%. (AEC) A method of selectively reducing plutonium oxides and the rare earth oxides but not uranium oxides is described which comprises placing the oxides in a molten solvent of zinc or cadmium and then adding metallic uranium as a reducing agent. (AEC)

Investigation on the adsorption characteristics of sodium benzoate and taurine on gold nanoparticle film by ATR-FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Kumar, Naveen; Thomas, S.; Tokas, R. B.; Kshirsagar, R. J.

2014-01-01

Fourier transform infrared (FTIR) spectroscopic studies of sodium benzoate and taurine adsorbed on gold nanoparticle (AuNp) film on silanised glass slides have been studied by attenuated total reflection technique (ATR). The surface morphology of the AuNp films has been measured by Atomic Force Microscopy. The ATR spectra of sodium benzoate and taurine deposited on AuNp film are compared with ATR spectra of their powdered bulk samples. A new red-shifted band appeared along with the symmetric and asymmetric stretches of carboxylate group of sodium benzoate leading to a broadening of the above peaks. Similar behavior is also seen in the case of symmetric and asymmetric stretches of sulphonate group of taurine. The results indicate presence of both chemisorbed and physisorbed layers of both sodium benzoate and taurine on the AuNp film with bottom layer chemically bound to AuNp through carboxylate and sulphonate groups respectively.

A comparative study of layered transition metal oxide cathodes for application in sodium-ion battery.

PubMed

Hasa, Ivana; Buchholz, Daniel; Passerini, Stefano; Hassoun, Jusef

2015-03-11

Herein, we report a study on P-type layered sodium transition metal-based oxides with a general formula of NaxMO2 (M = Ni, Fe, Mn). We synthesize the materials via coprecipitation followed by annealing in air and rinsing with water, and we examine the electrodes as cathodes for sodium-ion batteries using a propylene carbonate-based electrolyte. We fully investigate the effect of the Ni-to-Fe ratio, annealing temperature, and sodium content on the electrochemical performances of the electrodes. The impact of these parameters on the structural and electrochemical properties of the materials is revealed by X-ray diffraction, scanning electron microscopy, and cyclic voltammetry, respectively. The suitability of this class of P-type materials for sodium battery application is finally demonstrated by cycling tests revealing an excellent electrochemical performance in terms of delivered capacity (i.e., about 200 mAh g(-1)) and charge-discharge efficiency (approaching 100%).

Lower thermospheric-enhanced sodium layers observed at low latitude and possible formation: Case studies

NASA Astrophysics Data System (ADS)

Xue, X. H.; Dou, X. K.; Lei, J.; Chen, J. S.; Ding, Z. H.; Li, T.; Gao, Q.; Tang, W. W.; Cheng, X. W.; Wei, K.

2013-05-01

We report two lower thermospheric-enhanced sodium layer (TeSL) cases observed at a low-latitude station, Lijiang, China (26.7°N, 100.0°E), on 10 March and 10 April 2012, respectively. The TeSLs in the two cases were located at altitudes near 122 and 112 km, respectively. In addition, strong sporadic sodium layers (SSLs) near 100 km accompanied the TeSL observed on 10 March 2012. Both the TeSLs and SSLs exhibited tidal-induced downward motion. The adjacent ground-based and space-borne ionospheric radio observations showed strong Es layers before the appearance of the TeSLs, suggesting an " Es- TeSLs (SSLs)" chain formed through the tidal wind shear mechanism. Assuming that the vertical tidal wavelengths remain unchanged, it is found that in different regions caused by the tidal wind shear, different TeSLs evolution processes are expected: (1) in a tidal-convergence region, a TeSL/SSL with a downward propagation phase is enhanced due to a rapid decrease in the Na+lifetime at the lower altitude; (2) in an ion convergence-divergence interface region, a TeSL/SSL will still follow the tidal downward phase progression, but sodium density does not exhibit evident enhancement; and (3) when a TeSL/SSL enters into a tidal wind-divergence zone, the layer density tends to decrease.

Modulation of a pulsatile release drug delivery system using different swellable/rupturable materials.

PubMed

El-Maradny, Hoda A

2007-11-01

Diclofenac sodium tablets consisting of core coated with two layers of swelling and rupturable coatings were prepared and evaluated as a pulsatile drug delivery system. Cores containing the drug were prepared by direct compression using microcrystalline cellulose and Ludipress as hydrophilic excipients with the ratio of 1:1. Cores were then coated sequentially with an inner swelling layer of different swellable materials; either Explotab, Croscarmellose sodium, or Starch RX 1500, and an outer rupturable layer of different levels of ethylcellulose. The effect of the nature of the swelling layer and the level of the rupturable coating on the lag time and the water uptake were investigated. Drug release rate studies were performed using USP paddle method. Results showed the dependence of the lag time and water uptake prior to tablet rupture on the nature of the swelling layer and the coating levels. Explotab showed a significant decrease in the lag time, followed by Croscarmellose sodium and finally by Starch RX 1500. Increasing the level of ethylcellulose coating retarded the diffusion of the release medium to the swelling layer and the rupture of the coat, thus prolonging the lag time.

Case study of simultaneous observations of sporadic sodium layer, E-region field-aligned irregularities and sporadic E layer at low latitude of China

NASA Astrophysics Data System (ADS)

Xie, H. Y.; Ning, B. Q.; Zhao, X. K.; Hu, L. H.

2017-03-01

Using the Na lidar at Haikou (20.0°N, 110.3°E), the VHF coherent radar and the digital ionosonde both at Sanya (18.4°N, 109.6°E), cases of simultaneous observations of sporadic sodium layer (SSL), E-region field-aligned irregularities (FAI) and sporadic E layer (Es) in the mesosphere and lower thermosphere (MLT) region at low latitude of China are studied. It is found that SSL occurs simultaneously or follows the enhancement of Es and FAI. The Es, FAI and SSL descend slowly with time which is mostly controlled by the diurnal tide (DT). Besides, the interaction of gravity wave (GW) with tides can cause oscillations in FAI and SSL. Our observations support the neutralization of ions for SSL formation: when the metallic ions layer descents to the altitudes where models predict, the sodium ions convert rapidly to atomic Na that may form an SSL event. Moreover, the SSL peak density will increase (decrease) in the convergence (divergence) vertical shear region of zonal wind.

Isomolybdate conversion coatings

NASA Technical Reports Server (NTRS)

Minevski, Zoran (Inventor); Maxey, Jason (Inventor); Nelson, Carl (Inventor); Eylem, Cahit (Inventor)

2002-01-01

A conversion coating solution and process forms a stable and corrosion-resistant layer on metal substrates or layers or, more preferably, on a boehmite layer or other base conversion coating. The conversion coating process involves contacting the substrate, layer or coating with an aqueous alkali metal isomolybdate solution in order to convert the surface of the substrate, layer or coating to a stable conversion coating. The aqueous alkali metal molybdates are selected from sodium molybdate (Na.sub.2 MoO.sub.4), lithium molybdate (Li.sub.2 MoO.sub.4), potassium molybdate (K.sub.2 MoO.sub.4), or combinations thereof, with the most preferred alkali metal molybdate being sodium molybdate. The concentration of alkali metal molybdates in the solution is preferably less than 5% by weight. In addition to the alkali metal molybdates, the conversion coating solution may include alkaline metal passivators selected from lithium nitrate (LiNO.sub.3), sodium nitrate (NaNO.sub.3), ammonia nitrate (NH.sub.4 NO.sub.3), and combinations thereof; lithium chloride, potassium hexafluorozirconate (K.sub.2 ZrF.sub.6) or potassium hexafluorotitanate (K.sub.2 TiF.sub.6).

The CSSL (combined sporadic structures and layers) payload: In situ observations of mesospheric sodium and related parameters

NASA Technical Reports Server (NTRS)

Machuga, David W.; Kane, Timothy J.; Wheeler, Timothy F.; Croskey, Charles L.; Mathews, John D.; Mitchell, John D.

1997-01-01

The objectives, design and results of the sensor systems for the combined sporadic structures and layers (CSSL) payload are analyzed. The CSSL main objectives were to: validate current models of mesospheric sodium chemistry; explore the relationship between turbulence and Na fluctuations; and to explore the relationship between high latitude electric fields and the formation of Na anomalies.

Multi-layered fabrication of large area PDMS flexible optical light guide sheets

NASA Astrophysics Data System (ADS)

Green, Robert; Knopf, George K.; Bordatchev, Evgueni V.

2017-02-01

Large area polydimethylsiloxane (PDMS) flexible optical light guide sheets can be used to create a variety of passive light harvesting and illumination systems for wearable technology, advanced indoor lighting, non-planar solar light collectors, customized signature lighting, and enhanced safety illumination for motorized vehicles. These thin optically transparent micro-patterned polymer sheets can be draped over a flat or arbitrarily curved surface. The light guiding behavior of the optical light guides depends on the geometry and spatial distribution of micro-optical structures, thickness and shape of the flexible sheet, refractive indices of the constituent layers, and the wavelength of the incident light. A scalable fabrication method that combines soft-lithography, closed thin cavity molding, partial curing, and centrifugal casting is described in this paper for building thin large area multi-layered PDMS optical light guide sheets. The proposed fabrication methodology enables the of internal micro-optical structures (MOSs) in the monolithic PDMS light guide by building the optical system layer-by-layer. Each PDMS layer in the optical light guide can have the similar, or a slightly different, indices of refraction that permit total internal reflection within the optical sheet. The individual molded layers may also be defect free or micro-patterned with microlens or reflecting micro-features. In addition, the bond between adjacent layers is ensured because each layer is only partially cured before the next functional layer is added. To illustrate the scalable build-by-layers fabrication method a three-layer mechanically flexible illuminator with an embedded LED strip is constructed and demonstrated.

Characterisation of Ceramic-Coated 316LN Stainless Steel Exposed to High-Temperature Thermite Melt and Molten Sodium

NASA Astrophysics Data System (ADS)

Ravi Shankar, A.; Vetrivendan, E.; Shukla, Prabhat Kumar; Das, Sanjay Kumar; Hemanth Rao, E.; Murthy, S. S.; Lydia, G.; Nashine, B. K.; Mallika, C.; Selvaraj, P.; Kamachi Mudali, U.

2017-11-01

Currently, stainless steel grade 316LN is the material of construction widely used for core catcher of sodium-cooled fast reactors. Design philosophy for core catcher demands its capability to withstand corium loading from whole core melt accidents. Towards this, two ceramic coatings were investigated for its application as a layer of sacrificial material on the top of core catcher to enhance its capability. Plasma-sprayed thermal barrier layer of alumina and partially stabilised zirconia (PSZ) with an intermediate bond coat of NiCrAlY are selected as candidate material and deposited over 316LN SS substrates and were tested for their suitability as thermal barrier layer for core catcher. Coated specimens were exposed to high-temperature thermite melt to simulate impingement of molten corium. Sodium compatibility of alumina and PSZ coatings were also investigated by exposing samples to molten sodium at 400 °C for 500 h. The surface morphology of high-temperature thermite melt-exposed samples and sodium-exposed samples was examined using scanning electron microscope. Phase identification of the exposed samples was carried out by x-ray diffraction technique. Observation from sodium exposure tests indicated that alumina coating offers better protection compared to PSZ coating. However, PSZ coating provided better protection against high-temperature melt exposure, as confirmed during thermite melt exposure test.

Preparation and in vitro evaluation of guar gum based triple-layer matrix tablet of diclofenac sodium

PubMed Central

Chavda, H.V.; Patel, M.S.; Patel, C.N.

2012-01-01

The objective of the present study was to design an oral controlled drug delivery system for sparingly soluble diclofenac sodium (DCL) using guar gum as triple-layer matrix tablets. Matrix tablet granules containing 30% (D1), 40% (D2) or 50% (D3) of guar gum were prepared by the conventional wet granulation technique. Matrix tablets of diclofenac sodium were prepared by compressing three layers one by one. Centre layer of sandwich like structure was incorporated with matrix granules containing DCL which was covered on either side by guar gum granule layers containing either 70, 80 or 87% of guar gum as release retardant layers. The tablets were evaluated for hardness, thickness, drug content, and drug release studies. To ascertain the kinetics of drug release, the dissolution profiles were fitted to various mathematical models. The in vitro drug release from proposed system was best explained by the Hopfenberg model indicating that the release of drug from tablets displayed heterogeneous erosion. D3G3, containing 87% of guar gum in guar gum layers and 50% of guar gum in DCL matrix granule layer was found to provide the release rate for prolonged period of time. The results clearly indicate that guar gum could be a potential hydrophilic carrier in the development of oral controlled drug delivery systems. PMID:23181081

A high dietary intake of sodium glutamate as flavoring (ajinomoto) causes gross changes in retinal morphology and function.

PubMed

Ohguro, Hiroshi; Katsushima, Harumi; Maruyama, Ikuyo; Maeda, Tadao; Yanagihashi, Satsuki; Metoki, Tomomi; Nakazawa, Mitsuru

2002-09-01

The purpose of this study was to investigate the effects of glutamate accumulation in vitreous on retinal structure and function, due to a diet high in sodium glutamate. Three different diet groups were created, consisting of rats fed on a regular diet (diet A), a moderate excess of sodium glutamate diet (diet B) and a large excess of sodium glutamate diet (diet C). After 1, 3 and 6 months of the administration of these diets, amino acids concentrations in vitreous were analyzed. In addition, retinal morphology and function by electroretinogram (ERG) of three different diet groups were studied. Significant accumulation of glutamate in vitreous was observed in rats following addition of sodium glutamate to the diet as compared to levels with a regular diet. In the retinal morphology, thickness of retinal neuronal layers was remarkably thinner in rats fed on sodium glutamate diets than in those on a regular diet. TdT-dUTP terminal nick-end labelling (TUNEL) staining revealed significant accumulation of the positive staining cells within the retinal ganglion cell layers in retinas from diets B and C as compared with that from diet A. Similar to this, immunohistochemistry demonstrated increased expression of glial fibrillary acidic protein (GFAP) within the retinal inner layers from diets B and C as compared with diet A. Functionally, ERG responses were reduced in rats fed on a sodium glutamate diets as compared with those on a regular diet. The present study suggests that a diet with excess sodium glutamate over a period of several years may increase glutamate concentrations in vitreous and may cause retinal cell destruction.

Investigating Sodium Storage Mechanisms in Tin Anodes: A Combined Pair Distribution Function Analysis, Density Functional Theory, and Solid-State NMR Approach

DOE PAGES

Stratford, Joshua M.; Mayo, Martin; Allan, Phoebe K.; ...

2017-05-04

Here, the alloying mechanism of high-capacity tin anodes for sodium-ion batteries is investigated using a combined theoretical and experimental approach. Ab initio random structure searching (AIRSS) and high-throughput screening using a species-swap method provide insights into a range of possible sodium–tin structures. These structures are linked to experiments using both average and local structure probes in the form of operando pair distribution function analysis, X-ray diffraction, and 23Na solid-state nuclear magnetic resonance (ssNMR), along with ex situ 119Sn ssNMR. Through this approach, we propose structures for the previously unidentified crystalline and amorphous intermediates. The first electrochemical process of sodium insertionmore » into tin results in the conversion of crystalline tin into a layered structure consisting of mixed Na/Sn occupancy sites intercalated between planar hexagonal layers of Sn atoms (approximate stoichiometry NaSn 3). Following this, NaSn 2, which is predicted to be thermodynamically stable by AIRSS, forms; this contains hexagonal layers closely related to NaSn 3, but has no tin atoms between the layers. NaSn 2 is broken down into an amorphous phase of approximate composition Na 1.2Sn. Reverse Monte Carlo refinements of an ab initio molecular dynamics model of this phase show that the predominant tin connectivity is chains. Further reaction with sodium results in the formation of structures containing Sn–Sn dumbbells, which interconvert through a solid-solution mechanism. These structures are based upon Na 5–xSn 2, with increasing occupancy of one of its sodium sites commensurate with the amount of sodium added. ssNMR results indicate that the final product, Na 15Sn 4, can store additional sodium atoms as an off-stoichiometry compound (Na 15+xSn 4) in a manner similar to Li 15Si 4.« less

Investigating Sodium Storage Mechanisms in Tin Anodes: A Combined Pair Distribution Function Analysis, Density Functional Theory, and Solid-State NMR Approach

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

Stratford, Joshua M.; Mayo, Martin; Allan, Phoebe K.

Here, the alloying mechanism of high-capacity tin anodes for sodium-ion batteries is investigated using a combined theoretical and experimental approach. Ab initio random structure searching (AIRSS) and high-throughput screening using a species-swap method provide insights into a range of possible sodium–tin structures. These structures are linked to experiments using both average and local structure probes in the form of operando pair distribution function analysis, X-ray diffraction, and 23Na solid-state nuclear magnetic resonance (ssNMR), along with ex situ 119Sn ssNMR. Through this approach, we propose structures for the previously unidentified crystalline and amorphous intermediates. The first electrochemical process of sodium insertionmore » into tin results in the conversion of crystalline tin into a layered structure consisting of mixed Na/Sn occupancy sites intercalated between planar hexagonal layers of Sn atoms (approximate stoichiometry NaSn 3). Following this, NaSn 2, which is predicted to be thermodynamically stable by AIRSS, forms; this contains hexagonal layers closely related to NaSn 3, but has no tin atoms between the layers. NaSn 2 is broken down into an amorphous phase of approximate composition Na 1.2Sn. Reverse Monte Carlo refinements of an ab initio molecular dynamics model of this phase show that the predominant tin connectivity is chains. Further reaction with sodium results in the formation of structures containing Sn–Sn dumbbells, which interconvert through a solid-solution mechanism. These structures are based upon Na 5–xSn 2, with increasing occupancy of one of its sodium sites commensurate with the amount of sodium added. ssNMR results indicate that the final product, Na 15Sn 4, can store additional sodium atoms as an off-stoichiometry compound (Na 15+xSn 4) in a manner similar to Li 15Si 4.« less

Blood-Brain Barrier Disruption, Sodium Fluorescein, And Fluorescence-Guided Surgery Of Gliomas.

PubMed

Xiang, Yan; Zhu, Xiao-Peng; Zhao, Jian-Nong; Huang, Guo-Hao; Tang, Jun-Hai; Chen, Huan-Ran; Du, Lei; Zhang, Dong; Tang, Xue-Feng; Yang, Hui; Lv, Sheng-Qing

2018-01-22

Sodium fluorescein (SF) is an ideal dye for intraoperative guided-resection of high-grade gliomas (HGGs). However, it is not well understood whether the SF-guided technique is suitable for different grades of gliomas, and the correlation between fluorescence and pathology is also not yet clear. In this study, we investigated 28 patients, including 23 patients with HGG and 5 patients with low-grade glioma (LGG). All patients were treated using the SF-guided technique on a Pentero 900 microscope (Carl Zeiss, Oberkochen, Germany). Claudin-5 immunohistochemical (IHC) staining for the tumours and peritumour tissues was analyzed. Intraoperative yellow fluorescence was noted in all the HGGs but not in the LGGs. Claudin-5 expression in the blood brain barrier endothelial cells was downregulated and disconnected in the HGGs (p < 0.05), but had no difference or slightly decreased in the LGGs (p > 0.05). The SF-guided technique is suitable for HGG surgery but not for LGG surgery. Downregulation of claudin-5 expression may contribute to the presence of yellow fluorescence in the glioma in SF-guided surgery.

Investigation of Tank 241-AW-104 Composite Floating Layer

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

Meznarich, H. K.; Bolling, S. D.; Lachut, J. S.

Seven grab samples and one field blank were taken from Tank 241-AW-104 (AW-104) on June 2, 2017, and received at 222-S Laboratory on June 5, 2017. A visible layer with brown solids was observed floating on the top of two surface tank waste samples (4AW-17-02 and 4AW 17 02DUP). The floating layer from both samples was collected, composited, and submitted for chemical analyses and solid phase characterization in order to understand the composition of the floating layer. Tributyl phosphate and tridecane were higher in the floating layer than in the aqueous phase. Density in the floating layer was slightly lowermore » than the mean density of all grab samples. Sodium nitrate and sodium carbonate were major components with a trace of gibbsite and very small size agglomerates were present in the solids of the floating layer. The supernate consisted of organics, soluble salt, and particulates.« less

Atmospheric turbulence compensation with laser phase shifting interferometry

NASA Astrophysics Data System (ADS)

Rabien, S.; Eisenhauer, F.; Genzel, R.; Davies, R. I.; Ott, T.

2006-04-01

Laser guide stars with adaptive optics allow astronomical image correction in the absence of a natural guide star. Single guide star systems with a star created in the earth's sodium layer can be used to correct the wavefront in the near infrared spectral regime for 8-m class telescopes. For possible future telescopes of larger sizes, or for correction at shorter wavelengths, the use of a single guide star is ultimately limited by focal anisoplanatism that arises from the finite height of the guide star. To overcome this limitation we propose to overlap coherently pulsed laser beams that are expanded over the full aperture of the telescope, traveling upwards along the same path which light from the astronomical object travels downwards. Imaging the scattered light from the resultant interference pattern with a camera gated to a certain height above the telescope, and using phase shifting interferometry we have found a method to retrieve the local wavefront gradients. By sensing the backscattered light from two different heights, one can fully remove the cone effect, which can otherwise be a serious handicap to the use of laser guide stars at shorter wavelengths or on larger telescopes. Using two laser beams multiconjugate correction is possible, resulting in larger corrected fields. With a proper choice of laser, wavefront correction could be expanded to the visible regime and, due to the lack of a cone effect, the method is applicable to any size of telescope. Finally the position of the laser spot could be imaged from the side of the main telescope against a bright background star to retrieve tip-tilt information, which would greatly improve the sky coverage of the system.

Structure analysis of aqueous ferrofluids at interface with silicon: neutron reflectometry data

NASA Astrophysics Data System (ADS)

Gapon, I. V.; Petrenko, V. I.; Bulavin, L. A.; Balasoiu, M.; Kubovcikova, M.; Zavisova, V.; Koneracka, M.; Kopcansky, P.; Chiriac, H.; Avdeev, M. V.

2017-05-01

Adsorption of nanoparticles from aqueous ferrofluids (FFs) on solid surface (crystalline silicon) was studied by neutron reflectometry (NR). Two kinds of FFs were considered. First kind was heavy water-based ferrofluids with magnetite nanoparticles coated by double layer of sodium oleate. Second one FF was cobalt ferrite nanoparticles stabilized by lauric acid/sodium n-dodecylsulphate layer and dispersed in water. It was obtained only a single adsorption layer for two types of ferrofluids. The impact of the magnetic nanoparticles concentration and geometry was considered in frame of the adsorption characteristic of FFs.

Investigation on the adsorption characteristics of sodium benzoate and taurine on gold nanoparticle film by ATR-FTIR spectroscopy.

PubMed

Kumar, Naveen; Thomas, S; Tokas, R B; Kshirsagar, R J

2014-01-24

Fourier transform infrared (FTIR) spectroscopic studies of sodium benzoate and taurine adsorbed on gold nanoparticle (AuNp) film on silanised glass slides have been studied by attenuated total reflection technique (ATR). The surface morphology of the AuNp films has been measured by Atomic Force Microscopy. The ATR spectra of sodium benzoate and taurine deposited on AuNp film are compared with ATR spectra of their powdered bulk samples. A new red-shifted band appeared along with the symmetric and asymmetric stretches of carboxylate group of sodium benzoate leading to a broadening of the above peaks. Similar behavior is also seen in the case of symmetric and asymmetric stretches of sulphonate group of taurine. The results indicate presence of both chemisorbed and physisorbed layers of both sodium benzoate and taurine on the AuNp film with bottom layer chemically bound to AuNp through carboxylate and sulphonate groups respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Guide star lasers for adaptive optics

NASA Astrophysics Data System (ADS)

Roberts, William Thomas, Jr.

Exploitation of the imaging capabilities of the new generation of ground-based astronomical telescopes relies heavily on Adaptive Optics (AO). Current AO system designs call for sodium guide star lasers capable of producing at least eight Watts of power tuned to the peak of the sodium D2 line, with a high duty cycle to avoid saturation, and with 0.5-1.0 GHz spectral broadening. This work comprises development and testing of six candidate laser systems and materials which may afford a path to achieving these goals. An end-pumped CW dye laser producing 4.0 Watts of tuned output power was developed and used to obtain the first accurate measurement of sodium layer scattering efficiency. Methods of optimizing the laser output through improving pump overlap efficiency and reducing the number of intracavity scattering surfaces are covered. The 1181 nm fluorescence peak of Mn5+ ion in Ba5 (PO4)3Cl could be tuned and doubled to reach 589 nm. While efforts to grow this crystal were under way, the Mn5+ ion in natural apatite (Ca5(PO4)3F) was studied as a potential laser material. Fluorescence saturation measurements and transmission saturation are presented, as well as efforts to obtain CW lasing in natural apatite. A Q-switched laser color-center laser in LiF : F-2 was developed and successfully tuned and doubled to the sodium D 2 line. Broad-band lasing of 80 mW and tuned narrow-band lasing of 35 mW at 1178 nm were obtained with 275 mW of input pump power at 1064 nm. The measured thermal properties of this material indicate its potential for scaling to much higher power. A Q-switched intracavity Raman laser was developed in which CaWO 4 was used to shift a Nd:YAG laser, the frequency-doubled output of which was centered at 589.3 nm. To obtain light at 589.0 nm, a compositionally tuned pump laser of Nd : Y3Ga1.1Al3.9O 12 was produced which generated the desired shift, but was inhomogeneous broadened, limiting the tunable power of the material. Finally, temperature tuning of a Nd:YAG laser was demonstrated in which the laser emitted up to 8.6 Watts at a temperature of -21.5 C, bringing the wavelength into a regime favorable for efficient Raman shifting by CaWO4.

Sodium Fluorescein-Guided Resection under the YELLOW 560 nm Surgical Microscope Filter in Malignant Gliomas: Our First 38 Cases Experience.

PubMed

Zhang, Ningning; Tian, Hailong; Huang, Dezhang; Meng, Xianbing; Guo, Wenqiang; Wang, Chaochao; Yin, Xin; Zhang, Hongying; Jiang, Bin; He, Zheng; Wang, Zhigang

2017-01-01

Sodium fluorescein (FL) had been safely used in fluorescence-guided microsurgery for imaging various brain tumors. Under the YELLOW 560 nm surgical microscope filter, low-dose FL as a fluorescent dye helps in visualization. Our study investigated the safety and efficacy of this innovative technique in malignant glioma (MG) patients. 38 patients suffering from MGs confirmed by pathology underwent FL-guided resection under YELLOW 560 nm surgical microscope filter. We retrospectively analyzed the clinical characters, microsurgery procedure, extent of resection, pathology of MGs, progression-free survival (PFS), and overall survival (OS). Thirty-eight patients had MGs (10 WHO grade III, 28 WHO grade IV). With YELLOW 560 nm surgical microscope filter combined with neuronavigation, sodium fluorescein-guided gross total resection (GTR) was achieved in 35 (92.1%) patients and subtotal resection in 3 (7.69%). The sensitivity and specificity of FL were 94.4% and 88.6% regardless of radiographic localization. Intraoperatively, 10 biopsies (10/28 FL[+]) showed "low" or "high" fluorescence in non-contrast-enhancement region and are also confirmed by pathology. Our data showed 6-month PFS of 92.3% and median survival of 11 months. FL-guided resection of MGs under the YELLOW 560 nm surgical microscope filter combined with neuronavigation was safe and effective, especially in non-contrast-MRI regions. It is feasible for improving the extent of resection in MGs especially during emergency cases.

Elastic guided waves in a layered plate with rectangular cross section.

PubMed

Mukdadi, O M; Desai, Y M; Datta, S K; Shah, A H; Niklasson, A J

2002-11-01

Guided waves in a layered elastic plate of rectangular cross section (finite width and thickness) has been studied in this paper. A semianalytical finite element method in which the deformation of the cross section is modeled by two-dimensional finite elements and analytical representation of propagating waves along the length of the plate has been used. The method is applicable to arbitrary number of layers and general anisotropic material properties of each layer, and is similar to the stiffness method used earlier to study guided waves in a laminated composite plate of infinite width. Numerical results showing the effect of varying the width of the plate on the dispersion of guided waves are presented and are compared with those for an infinite plate. In addition, effect of thin anisotropic coating or interface layers on the guided waves is investigated.

Pervaporation dehydration of ethanol by hyaluronic acid/sodium alginate two-active-layer composite membranes.

PubMed

Gao, Chengyun; Zhang, Minhua; Ding, Jianwu; Pan, Fusheng; Jiang, Zhongyi; Li, Yifan; Zhao, Jing

2014-01-01

The composite membranes with two-active-layer (a capping layer and an inner layer) were prepared by sequential spin-coatings of hyaluronic acid (HA) and sodium alginate (NaAlg) on the polyacrylonitrile (PAN) support layer. The SEM showed a mutilayer structure and a distinct interface between the HA layer and the NaAlg layer. The coating sequence of two-active-layer had an obvious influence on the pervaporation dehydration performance of membranes. When the operation temperature was 80 °C and water concentration in feed was 10 wt.%, the permeate fluxes of HA/Alg/PAN membrane and Alg/HA/PAN membrane were similar, whereas the separation factor were 1130 and 527, respectively. It was found that the capping layer with higher hydrophilicity and water retention capacity, and the inner layer with higher permselectivity could increase the separation performance of the composite membranes. Meanwhile, effects of operation temperature and water concentration in feed on pervaporation performance as well as membrane properties were studied. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bi-layered nanocomposite bandages for controlling microbial infections and overproduction of matrix metalloproteinase activity.

PubMed

Anjana, J; Mohandas, Annapoorna; Seethalakshmy, S; Suresh, Maneesha K; Menon, Riju; Biswas, Raja; Jayakumar, R

2018-04-15

Chronic diabetic wounds is characterised by increased microbial contamination and overproduction of matrix metalloproteases that would degrade the extracellular matrix. A bi-layer bandage was developed, that promotes the inhibition of microbial infections and matrix metalloprotease (MMPs) activity. Bi-layer bandage containing benzalkonium chloride loaded gelatin nanoparticles (BZK GNPs) in chitosan-Hyaluronic acid (HA) as a bottom layer and sodium alendronate containing chitosan as top layer was developed. We hypothesized that the chitosan-gelatin top layer with sodium alendronate could inhibit the MMPs activity, whereas the chitosan-HA bottom layer with BZK GNPs (240±66nm) would enable the elimination of microbes. The porosity, swelling and degradation nature of the prepared Bi-layered bandage was studied. The bottom layer could degrade within 4days whereas the top layer remained upto 7days. The antimicrobial activity of the BZK NPs loaded bandage was determined using normal and clinical strains. Gelatin zymography shows that the proteolytic activity of MMP was inhibited by the bandage. Copyright © 2017 Elsevier B.V. All rights reserved.

Habit plane-driven P2-type manganese-based layered oxide as long cycling cathode for Na-ion batteries

NASA Astrophysics Data System (ADS)

Luo, Rui; Wu, Feng; Xie, Man; Ying, Yao; Zhou, Jiahui; Huang, Yongxin; Ye, Yusheng; Li, Li; Chen, RenJie

2018-04-01

Layered transition metal oxides are considered to be promising candidates as cathode materials for sodium-ion batteries. Herein, a facile solid-state reaction is developed to synthesize hexagons plate-like Na0.67Ni0.25Mn0.75O2+δ (denoted as P2-NNM) material with habit plane formed. The structure of this layered oxide is characterized by XRD, HR-TEM and SAED. The layered material delivers a high reversible capacity of 91.8 mAh g-1 at 0.2 C with a capacity retention of 94.4 % after 280 cycles, superior rate capability and long cycle life (84.2 % capacity retention after 1000 cycle). Ni2+ is an active ion and Ni doping alleviates the Jahn-Teller distortion, and Mn3+/Mn4+ coexist as Mn4+ is desired from the stability perspective. Particularly, CV and XPS results confirm these results. Moreover, the electrode exhibits a quasi-solid-solution reaction during the sodium extraction and insertion. This contribution demonstrates that P2-NNM is a promising cathode electrode for rechargeable long-life sodium-ion batteries.

Synthesis-microstructure-performance relationship of layered transition metal oxides as cathode for rechargeable sodium batteries prepared by high-temperature calcination.

PubMed

Xie, Man; Luo, Rui; Lu, Jun; Chen, Renjie; Wu, Feng; Wang, Xiaoming; Zhan, Chun; Wu, Huiming; Albishri, Hassan M; Al-Bogami, Abdullah S; El-Hady, Deia Abd; Amine, Khalil

2014-10-08

Research on sodium batteries has made a comeback because of concern regarding the limited resources and cost of lithium for Li-ion batteries. From the standpoint of electrochemistry and economics, Mn- or Fe-based layered transition metal oxides should be the most suitable cathode candidates for affordable sodium batteries. Herein, this paper reports a novel cathode material, layered Na1+x(Fey/2Niy/2Mn1-y)1-xO2 (x = 0.1-0.5), synthesized through a facile coprecipitation process combined with subsequent calcination. For such cathode material calcined at 800 °C for 20 h, the Na/Na1+x(Fey/2Niy/2Mn1-y)1-xO2 (x = 0.4) electrode exhibited a good capacity of 99.1 mAh g(-1) (cycled at 1.5-4.0 V) and capacity retention over 87% after 50 cycles. Optimization of this material would make layered transition metal oxides a strong candidate for the Na-ion battery cathode.

Device for measuring oxygen activity in liquid sodium

DOEpatents

Roy, P.; Young, R.S.

1973-12-01

A composite ceramic electrolyte in a configuration (such as a closed end tube or a plate) suitable to separate liquid sodium from a reference electrode with a high impedance voltmeter connected to measure EMF between the sodium and the reference electrode as a measure of oxygen activity in the sodium is described. The composite electrolyte consists of zirconiacalcia with a bonded layer of thoria-yttria. The device is used with a gaseous reference electrode on the zirconia-calcia side and liquid sodium on the thoria-yttria side of the electrolyte. (Official Gazette)

Thiolated alginate-based multiple layer mucoadhesive films of metformin forintra-pocket local delivery: in vitro characterization and clinical assessment.

PubMed

Kassem, Abeer Ahmed; Issa, Doaa Ahmed Elsayed; Kotry, Gehan Sherif; Farid, Ragwa Mohamed

2017-01-01

Periodontal disease broadly defines group of conditions in which the supportive structure of the tooth (periodontium) is destroyed. Recent studies suggested that the anti-diabetic drug metformin hydrochloride (MF) has an osteogenic effect and is beneficial for the management of periodontitis. Development of strong mucoadhesive multiple layer film loading small dose of MF for intra-pocket application. Multiple layer film was developed by double casting followed by compression method. Either 6% carboxy methyl cellulose sodium (CMC) or sodium alginate (ALG) constituted the inner drug (0.6%) loaded layer. Thiolated sodium alginate (TSA; 2 or 4%) constituted the outer drug free layers to enhance mucoadhesion and achieve controlled drug release. Optimized formulation was assessed clinically on 20 subjects. Films were uniform, thin and hard enough for easy insertion into periodontal pockets. Based on water uptake and in vitro drug release, CMC based film with 4% TSA as an outer layer was the optimized formulation with enhanced mucoadhesion and controlled drug release (83.73% over 12 h). SEM showed the effective fabrication of the triple layer film in which connective lines between the layers could be observed. FTIR examination suggests possibility of hydrogen bonding between the -NH groups of metformin and -OH groups of CMC. DSC revealed the presence of MF mainly in the amorphous form. Clinical results indicated improvement of all clinical parameters six months post treatment. The results suggested that local application of the mucoadhesive multiple layer films loaded with metformin hydrochloride was able to manage moderate chronic periodontitis.

Formulation, in vitro evaluation and study of variables on tri-layered gastro-retentive delivery system of diltiazem HCl.

PubMed

Raut Desai, Shilpa; Rohera, Bhagwan D

2014-03-01

Tri-layered floating tablets using only one grade of polyethylene oxide (PEO) would enable easy manufacturing, reproducibility and controlled release for highly soluble drugs. To evaluate the potential of PEO as a sole polymer for the controlled release and to study the effect of formulation variables on release and gastric retention of highly soluble Diltiazem hydrochloride (DTZ). Tablets were compressed with middle layer consisting of drug and polymer while outer layers consisted of polymer with sodium bicarbonate. Design of formulation to obtain 12 h, zero-order release and rapid floatation was done by varying the grades, quantity of PEO and sodium bicarbonate. Dissolution data were fitted in drug release models and swelling/erosion studies were undertaken to verify the drug release mechanism. Effect of formulation variables and tablet surface morphology using scanning electron microscopy were studied. The optimized formula passed the criteria of USP dissolution test I and exhibited floating lag-time of 3-4 min. Drug release was faster from low molecular weight (MW) PEO as compared to high MW. With an increase in the amount of sodium bicarbonate, faster buoyancy was achieved due to the increased CO2 gas formation. Drug release followed zero-order and gave a good fit to the Korsmeyer-Peppas model, which suggested that drug release was due to diffusion through polymer swelling. Zero-order, controlled release profile with the desired buoyancy can be achieved by using optimum formula quantities of sodium bicarbonate and polymer. The tri-layered system shows promising delivery of DTZ, and possibly other water-soluble drugs.

MoTe2, A novel anode material for sodium ion battery

NASA Astrophysics Data System (ADS)

Panda, Manas Ranjan; Anish Raj, K.; Bao, Qiaoliang; Mitra, Sagar

2018-04-01

2D layered transition metal dichalcogenides are considered as a potential anode for sodium-ion batteries due to their high specific capacity, structural stability and its well-developed two-dimensional layers. 2D layered structure Molybdenum ditelluride (MoTe2) provides a superior Na-ion storage properties in sodium ion battery due to its comparative more interlayer spacing (0.699 nm). In the current study MoTe2 polycrystalline powder sample has been prepared by solid state reaction process, the structural and morphological studies have been carried out by XRD, FE-SEM and EDS etc. XRD study revealsthe well crystalline structure of the material having hexagonal structure. FE-SEM and EDS studies depict the uniformflakes like structure of the material. When it is tested as sodium-ion battery anode by applying a potential window 0.1-2.5 V, the material demonstrates a high capacity and high power performances. The as prepared MoTe2 shows an initial discharge capacity of 376 mA h g-1 and a corresponding discharge capacity of 303 mA h g-1 after the 50th cycle at a current density of 500 mA g-1.

Sodium alginate hydrogel-based bioprinting using a novel multinozzle bioprinting system.

PubMed

Song, Seung-Joon; Choi, Jaesoon; Park, Yong-Doo; Hong, Soyoung; Lee, Jung Joo; Ahn, Chi Bum; Choi, Hyuk; Sun, Kyung

2011-11-01

Bioprinting is a technology for constructing bioartificial tissue or organs of complex three-dimensional (3-D) structure with high-precision spatial shape forming ability in larger scale than conventional tissue engineering methods and simultaneous multiple components composition ability. It utilizes computer-controlled 3-D printer mechanism or solid free-form fabrication technologies. In this study, sodium alginate hydrogel that can be utilized for large-dimension tissue fabrication with its fast gelation property was studied regarding material-specific printing technique and printing parameters using a multinozzle bioprinting system developed by the authors. A sodium alginate solution was prepared with a concentration of 1% (wt/vol), and 1% CaCl(2) solution was used as cross-linker for the gelation. The two materials were loaded in each of two nozzles in the multinozzle bioprinting system that has a total of four nozzles of which the injection speed can be independently controlled. A 3-D alginate structure was fabricated through layer-by-layer printing. Each layer was formed through two phases of printing, the first phase with the sodium alginate solution and the second phase with the calcium chloride solution, in identical printing pattern and speed condition. The target patterns were lattice shaped with 2-mm spacing and two different line widths. The nozzle moving speed was 6.67 mm/s, and the injection head speed was 10 µm/s. For the two different line widths, two injection needles with inner diameters of 260 and 410 µm were used. The number of layers accumulated was five in this experiment. By varying the nozzle moving speed and the injection speed, various pattern widths could be achieved. The feasibility of sodium alginate hydrogel free-form formation by alternate printing of alginate solution and sodium chloride solution was confirmed in the developed multinozzle bioprinting system. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Destabilization of yttria-stabilized zirconia induced by molten sodium vanadate-sodium sulfate melts

NASA Technical Reports Server (NTRS)

Nagelberg, A. S.; Hamilton, J. C.

1985-01-01

The extent of surface destabilization of ZrO2 - 8 wt percent Y2O3 ceramic disks was determined after exposure to molten salt mixtures of sodium sulfate containing up to 15 mole percent sodium metavanadate (NaVO3) at 1173 K. The ceramic surface was observed to transform from the cubic/tetragonal to monoclinic phase, concurrent with chemical changes in the molten salt layer in contact with the ceramic. Significant attack rates were observed in both pure sulfate and metavanadate sulfate melts. The rate of attack was found to be quite sensitive to the mole fraction of vanadate in the molten salt solution and the partial pressure of sulfur trioxide in equilibrium with the salt melt. The observed parabolic rate of attack is interpreted to be caused by a reaction controlled by diffusion in the salt that penetrates into the porous layer formed by the destabilization. The parabolic rate constant in mixed sodium metavanadate - sodium sulfate melts was found to be proportional to the SO3 partial pressure and the square of the metavanadate concentration. In-situ Raman spectroscopic measurements allowed simultaneous observations of the ceramic phases and salt chemistry during the attack process.

An ultrastable anode for long-life room-temperature sodium-ion batteries.

PubMed

Yu, Haijun; Ren, Yang; Xiao, Dongdong; Guo, Shaohua; Zhu, Yanbei; Qian, Yumin; Gu, Lin; Zhou, Haoshen

2014-08-18

Sodium-ion batteries are important alternative energy storage devices that have recently come again into focus for the development of large-scale energy storage devices because sodium is an abundant and low-cost material. However, the development of electrode materials with long-term stability has remained a great challenge. A novel negative-electrode material, a P2-type layered oxide with the chemical composition Na(2/3)Co(1/3)Ti(2/3)O2, exhibits outstanding cycle stability (ca. 84.84 % capacity retention for 3000 cycles, very small decrease in the volume (0.046 %) after 500 cycles), good rate capability (ca. 41 % capacity retention at a discharge/charge rate of 10 C), and a usable reversible capacity of about 90 mAh g(-1) with a safe average storage voltage of approximately 0.7 V in the sodium half-cell. This P2-type layered oxide is a promising anode material for sodium-ion batteries with a long cycle life and should greatly promote the development of room-temperature sodium-ion batteries. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Status of ARGOS - The Laser Guide Star System for the LBT

NASA Astrophysics Data System (ADS)

Raab, Walfried; Rabien, Sebastian; Gaessler, Wolfgang; Esposito, Simone; Antichi, Jacopo; Lloyd-Hart, Michael; Barl, Lothar; Beckmann, Udo; Bonaglia, Marco; Borelli, Jose; Brynnel, Joar; Buschkamp, Peter; Busoni, Lorenzo; Carbonaro, Luca; Christou, Julian; Connot, Claus; Davies, Richard; Deysenroth, Matthias; Durney, Olivier; Green, Richard; Gemperlein, Hans; Gasho, Victor; Haug, Marcus; Hubbard, Pete; Ihle, Sebastian; Kulas, Martin; Loose, Christina; Lehmitz, Michael; Noenickx, Jamison; Nussbaum, Edmund; Orban De Xivry, Gilles; Quirrenbach, Andreas; Peter, Diethard; Rahmer, Gustavo; Rademacher, Matt; Storm, Jesper; Schwab, Christian; Vaitheeswaran, Vidhya; Ziegleder, Julian

2013-12-01

ARGOS is an innovative multiple laser guide star adaptive optics system for the Large Binocular Telescope (LBT), designed to perform effective GLAO correction over a very wide field of view. The system is using high powered pulsed green (532 nm) lasers to generate a set of three guide stars above each of the LBT mirrors. The laser beams are launched through a 40 cm telescope and focused at an altitude of 12 km, creating laser beacons by means of Rayleigh scattering. The returning scattered light, primarily sensitive to the turbulences close to the ground, is detected by a gated wavefront sensor system. The derived ground layer correction signals are directly driving the adaptive secondary mirror of the LBT. ARGOS is especially designed for operation with the multiple object spectrograph Luci, which will benefit from both, the improved spatial resolution, as well as the strongly enhanced flux. In addition to the GLAO Rayleigh beacon system, ARGOS was also designed for a possible future upgrade with a hybrid sodium laser - Rayleigh beacon combination, enabling diffraction limited operation. The ARGOS laser system has undergone extensive tests during Summer 2012 and is scheduled for installation at the LBT in Spring 2013. The remaining sub-systems will be installed during the course of 2013. We report on the overall status of the ARGOS system and the results of the sub-system characterizations carried out so far.

Large-area, laterally-grown epitaxial semiconductor layers

DOEpatents

Han, Jung; Song, Jie; Chen, Danti

2017-07-18

Structures and methods for confined lateral-guided growth of a large-area semiconductor layer on an insulating layer are described. The semiconductor layer may be formed by heteroepitaxial growth from a selective growth area in a vertically-confined, lateral-growth guiding structure. Lateral-growth guiding structures may be formed in arrays over a region of a substrate, so as to cover a majority of the substrate region with laterally-grown epitaxial semiconductor tiles. Quality regions of low-defect, stress-free GaN may be grown on silicon.

Sodium Fluorescein-Guided Resection under the YELLOW 560 nm Surgical Microscope Filter in Malignant Gliomas: Our First 38 Cases Experience

PubMed Central

Tian, Hailong; Huang, Dezhang; Meng, Xianbing; Guo, Wenqiang; Wang, Chaochao; Yin, Xin; Zhang, Hongying; Jiang, Bin; He, Zheng

2017-01-01

Objective Sodium fluorescein (FL) had been safely used in fluorescence-guided microsurgery for imaging various brain tumors. Under the YELLOW 560 nm surgical microscope filter, low-dose FL as a fluorescent dye helps in visualization. Our study investigated the safety and efficacy of this innovative technique in malignant glioma (MG) patients. Patients and Method 38 patients suffering from MGs confirmed by pathology underwent FL-guided resection under YELLOW 560 nm surgical microscope filter. We retrospectively analyzed the clinical characters, microsurgery procedure, extent of resection, pathology of MGs, progression-free survival (PFS), and overall survival (OS). Results Thirty-eight patients had MGs (10 WHO grade III, 28 WHO grade IV). With YELLOW 560 nm surgical microscope filter combined with neuronavigation, sodium fluorescein-guided gross total resection (GTR) was achieved in 35 (92.1%) patients and subtotal resection in 3 (7.69%). The sensitivity and specificity of FL were 94.4% and 88.6% regardless of radiographic localization. Intraoperatively, 10 biopsies (10/28 FL[+]) showed “low” or “high” fluorescence in non-contrast-enhancement region and are also confirmed by pathology. Our data showed 6-month PFS of 92.3% and median survival of 11 months. Conclusion FL-guided resection of MGs under the YELLOW 560 nm surgical microscope filter combined with neuronavigation was safe and effective, especially in non-contrast-MRI regions. It is feasible for improving the extent of resection in MGs especially during emergency cases. PMID:29124069

Fabrication of oxide layer on zirconium by micro-arc oxidation: Structural and antimicrobial characteristics.

PubMed

Fidan, S; Muhaffel, F; Riool, M; Cempura, G; de Boer, L; Zaat, S A J; Filemonowicz, A Czyrska-; Cimenoglu, H

2017-02-01

The aim of this study was to cover the surfaces of zirconium (Zr) with an antimicrobial layer for biomedical applications. For this purpose, the micro-arc oxidation (MAO) process was employed in a sodium silicate and sodium hydroxide containing base electrolyte with and without addition of silver acetate (AgC 2 H 3 O 2 ). In general, synthesized MAO layers were composed of zirconium oxide (ZrO 2 ) and zircon (ZrSiO 4 ). Addition of AgC 2 H 3 O 2 into the base electrolyte caused homogenous precipitation of silver-containing particles in the MAO layer, which exhibited excellent antibacterial efficiency against methicillin-resistant Staphylococcus aureus (MRSA) as compared to the untreated and MAO-treated Zr. Copyright © 2016 Elsevier B.V. All rights reserved.

Electrochemical investigation of MoTe2/rGO composite materials for sodium-ion battery application

NASA Astrophysics Data System (ADS)

Panda, Manas Ranjan; Anish Raj, K.; Sarkar, Ananta; Bao, Qiaoliang; Mitra, Sagar

2018-05-01

2D layered materials are found to be promising anode materials for renewable energy storage devices like sodium and Li-ion batteries and have become attractive options due to their high specific capacity, abundance and low cost. In this work, we synthesized 2D MoTe2 layers embedded in reduced graphene oxide (rGO) anode material for sodium-ion battery applications. 2D MoTe2 was prepared by a solid-state reaction in vacuum at a temperature of 800 °C. The prepared composite material MoTe2/rGO showed excellent electrochemical performance against the sodium metal. The discharge capacity of MoTe2/rGO was observed to be 280 mAh g-1 at a current rate of 1.0 A g-1 for 100 cycles. rGO plays an important role in embedding the MoTe2 structure, thus improving the electrical and mechanical properties, leading to a superior cycling stability and excellent electrochemical performances of MoTe2 for sodium-ion battery applications.

Decoupled direct tracking control system based on use of a virtual track for multilayer disk with a separate guide layer

NASA Astrophysics Data System (ADS)

Tanaka, Yukinobu; Ogata, Takeshi; Imagawa, Seiji

2015-09-01

We developed a decoupled direct tracking control system for multilayer optical disk that uses a separate guide layer. Data marks are recorded on a recording layer immediately above the guide layer by using two spatially separated spots with different wavelengths. Accurate data mark recording requires that the relative positions of the corresponding spots on the recording layer and guide layer are maintained. However, a disk tilt can shift their relative positions and cause previously recorded data marks to be overwritten. Additionally, a two-input/two-output control system is susceptible to mutual interference phenomenon between the two outputs, which can destabilize tracking control. A tracking control system based on use of data marks previously recorded as a virtual track has been developed that prevents spot shifting and mutual interference even if the disk tilt reaches 0.7°, thereby preventing overwriting.

Molten salt corrosion of SiC: Pitting mechanism

NASA Technical Reports Server (NTRS)

Jacobson, N. S.; Smialek, J. L.

1985-01-01

Thin films of Na2SO4 and Na2CO3 at 1000 C lead to severe pitting of sintered alpha-SiC. These pits are important as they cause a strength reduction in this material. The growth of product layers is related to pit formation for the Na2CO3 case. The early reaction stages involve repeated oxidation and dissolution to form sodium silicate. This results in severe grain boundary attack. After this a porous silica layer forms between the sodium silicate melt and the SiC. The pores in this layer appear to act as paths for the melt to reach the SiC and create larger pits.

Poly(sodium 4-styrenseulfonate)-modified monolayer graphene for anode applications of organic photovoltaic cells

NASA Astrophysics Data System (ADS)

Zhou, Yongfang; Wang, Min; Wang, Liang; Liu, Shuli; Chen, Shufen; Cao, Kun; Shang, Wenjuan; Mai, Jiangquan; Zhao, Baomin; Feng, Jing; Lu, Xinhui; Huang, Wei

2017-09-01

An insulated poly(sodium 4-styrenseulfonate) (PSS) was used to modify monolayer graphene for anode applications of organic photovoltaics (OPVs). With this PSS interfacial modification layer, the OPVs showed a significant increase of 56.4% in efficiency due to an improved work function and hydrophilic feature of graphene and an enlarged recombination resistance of carriers/excitons. Doping a highly contorted 1,2,5-thiadiazole-fused 12-ring polyaromatic hydrocarbon into the active layer to form ternary blended OPVs further enlarged the recombination resistance of carriers/excitons and improved light absorption of the active layer, with which a high power conversion efficiency of 6.29% was acquired.

Semiconductor laser having a non-absorbing passive region with beam guiding

NASA Technical Reports Server (NTRS)

Botez, Dan (Inventor)

1986-01-01

A laser comprises a semiconductor body having a pair of end faces and including an active region comprising adjacent active and guide layers which is spaced a distance from the end face and a passive region comprising adjacent non-absorbing guide and mode control layers which extends between the active region and the end face. The combination of the guide and mode control layers provides a weak positive index waveguide in the lateral direction thereby providing lateral mode control in the passive region between the active region and the end face.

A Green, Guided-Inquiry Based Electrophilic Aromatic Substitution for the Organic Chemistry Laboratory

ERIC Educational Resources Information Center

Eby, Eric; Deal, S. Todd

2008-01-01

We developed an alternative electrophilic aromatic substitution reaction for the organic chemistry teaching laboratory. The experiment is an electrophilic iodination reaction of salicylamide, a popular analgesic, using environmentally friendly reagents--sodium iodide and household bleach. Further, we designed the lab as a guided-inquiry…

The ARGOS laser system: green light for ground layer adaptive optics at the LBT

NASA Astrophysics Data System (ADS)

Raab, Walfried; Rabien, Sebastian; Gässler, Wolfgang; Esposito, Simone; Barl, Lothar; Borelli, Jose; Daysenroth, Matthias; Gemperlein, Hans; Kulas, Martin; Ziegleder, Julian

2014-07-01

We report on the development of the laser system of ARGOS, the multiple laser guide star adaptive optics system for the Large Binocular Telescope (LBT). The system uses a total of six high powered, pulsed Nd:YAG lasers frequency-doubled to a wavelength of 532 nm to generate a set of three guide stars above each of the LBT telescopes. The position of each of the LGS constellations on sky as well as the relative position of the individual laser guide stars within this constellation is controlled by a set of steerable mirrors and a fast tip-tilt mirror within the laser system. The entire opto-mechanical system is housed in two hermetically sealed and thermally controlled enclosures on the SX and DX side of the LBT telescope. The laser beams are propagated through two refractive launch telescopes which focus the beams at an altitude of 12 km, creating a constellation of laser guide stars around a 4 arcminute diameter circle by means of Rayleigh scattering. In addition to the GLAO Rayleigh beacon system, ARGOS has also been designed for a possible future upgrade with a hybrid sodium laser - Rayleigh beacon combination, enabling diffraction limited operation. The ARGOS laser system was successfully installed at the LBT in April 2013. Extensive functional tests have been carried out and have verified the operation of the systems according to specifications. The alignment of the laser system with respect to the launch telescope was carried out during two more runs in June and October 2013, followed by the first propagation of laser light on sky in November 2013.

Self-Cooling Gradient Shell for Body Armor

DTIC Science & Technology

2012-05-10

Silica gel 2.1 Filter paper pocket (no absorbent) 2.0 2 g Silica gel (150-Å pore size) + 2 g sodium polyacrylate (SPA) in filter paper pocket 2.7...layer of filter paper improved the temperature difference by an additional 0.5 °C. More-absorbent materials, such as sodium polyacrylate (SPA) or... sodium polyacrylate SPM scanning probe microscopy µm micrometer Wm-2 watts per square meter °C degrees Celsius

Electrochemical cell having an alkali-metal-nitrate electrode

DOEpatents

Roche, M.F.; Preto, S.K.

1982-06-04

A power-producing secondary electrochemical cell includes a molten alkali metal as the negative-electrode material and a molten-nitrate salt as the positive-electrode material. The molten material in the respective electrodes are separated by a solid barrier of alkali-metal-ion conducting material. A typical cell includes active materials of molten sodium separated from molten sodium nitrate and other nitrates in mixture by a layer of sodium ..beta..'' alumina.

Nanomechanics and Sodium Permeability of Endothelial Surface Layer Modulated by Hawthorn Extract WS 1442

PubMed Central

Peters, Wladimir; Drueppel, Verena; Kusche-Vihrog, Kristina; Schubert, Carola; Oberleithner, Hans

2012-01-01

The endothelial glycocalyx (eGC) plays a pivotal role in the physiology of the vasculature. By binding plasma proteins, the eGC forms the endothelial surface layer (ESL) which acts as an interface between bloodstream and endothelial cell surface. The functions of the eGC include mechanosensing of blood flow induced shear stress and thus flow dependent vasodilation. There are indications that levels of plasma sodium concentrations in the upper range of normal and beyond impair flow dependent regulation of blood pressure and may therefore increase the risk for hypertension. Substances, therefore, that prevent sodium induced endothelial dysfunction may be attractive for the treatment of cardiovascular disease. By means of combined atomic force - epifluorescence microscopy we studied the impact of the hawthorn (Crataegus spp.) extract WS 1442, a herbal therapeutic with unknown mechanism of action, on the mechanics of the ESL of ex vivo murine aortae. Furthermore, we measured the impact of WS 1442 on the sodium permeability of endothelial EA.hy 926 cell monolayer. The data show that (i) the ESL contributes by about 11% to the total endothelial barrier resistance for sodium and (ii) WS 1442 strengthens the ESL resistance for sodium up to about 45%. This mechanism may explain some of the vasoprotective actions of this herbal therapeutic. PMID:22253842

Nanomechanics and sodium permeability of endothelial surface layer modulated by hawthorn extract WS 1442.

PubMed

Peters, Wladimir; Drüppel, Verena; Drueppel, Verena; Kusche-Vihrog, Kristina; Schubert, Carola; Oberleithner, Hans

2012-01-01

The endothelial glycocalyx (eGC) plays a pivotal role in the physiology of the vasculature. By binding plasma proteins, the eGC forms the endothelial surface layer (ESL) which acts as an interface between bloodstream and endothelial cell surface. The functions of the eGC include mechanosensing of blood flow induced shear stress and thus flow dependent vasodilation. There are indications that levels of plasma sodium concentrations in the upper range of normal and beyond impair flow dependent regulation of blood pressure and may therefore increase the risk for hypertension. Substances, therefore, that prevent sodium induced endothelial dysfunction may be attractive for the treatment of cardiovascular disease. By means of combined atomic force-epifluorescence microscopy we studied the impact of the hawthorn (Crataegus spp.) extract WS 1442, a herbal therapeutic with unknown mechanism of action, on the mechanics of the ESL of ex vivo murine aortae. Furthermore, we measured the impact of WS 1442 on the sodium permeability of endothelial EA.hy 926 cell monolayer. The data show that (i) the ESL contributes by about 11% to the total endothelial barrier resistance for sodium and (ii) WS 1442 strengthens the ESL resistance for sodium up to about 45%. This mechanism may explain some of the vasoprotective actions of this herbal therapeutic.

Nickel container of highly-enriched uranium bodies and sodium

DOEpatents

Zinn, Walter H.

1976-01-01

A fuel element comprises highly a enriched uranium bodies coated with a nonfissionable, corrosion resistant material. A plurality of these bodies are disposed in layers, with sodium filling the interstices therebetween. The entire assembly is enclosed in a fluid-tight container of nickel.

Research in the Optical Sciences

DTIC Science & Technology

1990-03-12

organics for guided wave devices; nonlinear propagation and wave mixing in sodium vapor: gain/feedback approach to optical instabilities; conical... SODIUM VAPOR: GAIN/FEEDBACK APPROACH TO OPTICAL INSTABILITIES; CONICAL EMISSION; KALEIDOSCOPIC SPATIAL INSTABILITY G. Khitrova and H . M . Gibbs...Falco, "Ex situ characterization of MBE-grown molybdenum silicide thin films, The 8th Annual Symposium of the Arizona chapter of The American Vacuum

Influence of Near-Surface Severe Plastic Deformation of Mild Steel on the Inhibition Performance of Sodium Molybdate and 1H-Benzotriazole in Artificial Sea Water

NASA Astrophysics Data System (ADS)

Sabet Bokati, Kazem; Dehghanian, Changiz; Babaei, Mahdi

2018-02-01

The effects of near-surface severe plastic deformation (NS-SPD) on the inhibition performance of sodium molybdate (SM) and 1H-benzotriazole (BTA) for mild steel were investigated using weight loss, polarization and electrochemical impedance spectroscopy measurements. The crystal grain size of NS-SPD-processed surface was analyzed by x-ray diffractometry and field emission scanning electron microscopy. A deformed layer with thickness of 20 ± 5 µm was produced on mild steel surface after NS-SPD process due to accumulated strains. The NS-SPD process caused more effective adsorption of corrosion inhibitors due to the fabrication of a surface with a high density of preferential adsorption sites. However, the stability of protective layer was predominantly influenced by the effect of NS-SPD process on inhibition efficiency. The fairly good persistence of protective layer formed on the surface by SM-containing solution and also positive effect of NS-SPD process on adsorption of molybdate ions caused higher inhibition performance for sodium molybdate. However, NS-SPD process encouraged deterioration of protective layer formed on steel surface in the presence of BTA inhibitor. It was ascribed to partial coverage of surface, low stability of adsorbed layer and thus more adsorption of aggressive ions on unprotected area which was uncovered during immersion time.

User-guided segmentation for volumetric retinal optical coherence tomography images

PubMed Central

Yin, Xin; Chao, Jennifer R.; Wang, Ruikang K.

2014-01-01

Abstract. Despite the existence of automatic segmentation techniques, trained graders still rely on manual segmentation to provide retinal layers and features from clinical optical coherence tomography (OCT) images for accurate measurements. To bridge the gap between this time-consuming need of manual segmentation and currently available automatic segmentation techniques, this paper proposes a user-guided segmentation method to perform the segmentation of retinal layers and features in OCT images. With this method, by interactively navigating three-dimensional (3-D) OCT images, the user first manually defines user-defined (or sketched) lines at regions where the retinal layers appear very irregular for which the automatic segmentation method often fails to provide satisfactory results. The algorithm is then guided by these sketched lines to trace the entire 3-D retinal layer and anatomical features by the use of novel layer and edge detectors that are based on robust likelihood estimation. The layer and edge boundaries are finally obtained to achieve segmentation. Segmentation of retinal layers in mouse and human OCT images demonstrates the reliability and efficiency of the proposed user-guided segmentation method. PMID:25147962

User-guided segmentation for volumetric retinal optical coherence tomography images.

PubMed

Yin, Xin; Chao, Jennifer R; Wang, Ruikang K

2014-08-01

Despite the existence of automatic segmentation techniques, trained graders still rely on manual segmentation to provide retinal layers and features from clinical optical coherence tomography (OCT) images for accurate measurements. To bridge the gap between this time-consuming need of manual segmentation and currently available automatic segmentation techniques, this paper proposes a user-guided segmentation method to perform the segmentation of retinal layers and features in OCT images. With this method, by interactively navigating three-dimensional (3-D) OCT images, the user first manually defines user-defined (or sketched) lines at regions where the retinal layers appear very irregular for which the automatic segmentation method often fails to provide satisfactory results. The algorithm is then guided by these sketched lines to trace the entire 3-D retinal layer and anatomical features by the use of novel layer and edge detectors that are based on robust likelihood estimation. The layer and edge boundaries are finally obtained to achieve segmentation. Segmentation of retinal layers in mouse and human OCT images demonstrates the reliability and efficiency of the proposed user-guided segmentation method.

Two-Fold Anisotropy Governs Morphological Evolution and Stress Generation in Sodiated Black Phosphorus for Sodium Ion Batteries.

PubMed

Chen, Tianwu; Zhao, Peng; Guo, Xu; Zhang, Sulin

2017-04-12

Phosphorus represents a promising anode material for sodium ion batteries owing to its extremely high theoretical capacity. Recent in situ transmission electron microscopy studies evidenced anisotropic swelling in sodiated black phosphorus, which may find an origin from the two intrinsic anisotropic properties inherent to the layered structure of black phosphorus: sodium diffusional directionality and insertion strain anisotropy. To understand the morphological evolution and stress generation in sodiated black phosphorus, we develop a chemo-mechanical model by incorporating the intrinsic anisotropic properties into the large elasto-plastic deformation. Our modeling results reveal that the apparent morphological evolution in sodiated black phosphorus is critically controlled by the coupled effect of the two intrinsic anisotropic properties. In particular, sodium diffusional directionality generates sharp interphases along the [010] and [001] directions, which constrain anisotropic development of the insertion strain. The coupled effect renders distinctive stress-generation and fracture mechanisms when sodiation starts from different crystal facets. In addition to providing a powerful modeling framework for sodiation and lithiation of layered structures, our findings shed significant light on the sodiation-induced chemo-mechanical degradation of black phosphorus as a promising anode for the next-generation sodium ion batteries.

Hollow nanoparticle cathode materials for sodium electrochemical cells and batteries

DOEpatents

Shevchenko, Elena; Rajh, Tijana; Johnson, Christopher S.; Koo, Bonil

2016-07-12

A cathode comprises, in its discharged state, a layer of hollow .gamma.-Fe.sub.2O.sub.3 nanoparticles disposed between two layers of carbon nanotubes, and preferably including a metallic current collector in contact with one of the layers of carbon nanotubes. Individual particles of the hollow .gamma.-Fe.sub.2O.sub.3 nanoparticles comprise a crystalline shell of .gamma.-Fe.sub.2O.sub.3 including cation vacancies within the crystal structure of the shell (i.e., iron vacancies of anywhere between 3% to 90%, and preferably 44 to 77% of available octahedral iron sites). Sodium ions are intercalated within at least some of the cation vacancies within the crystalline shell of the hollow .gamma.-Fe.sub.2O.sub.3 nanoparticles.

Optical properties of Na2O-TiO2-SiO2 glass films prepared by the sol-gel method

NASA Astrophysics Data System (ADS)

Barton, Ivo; Matejec, Vlastimil; Mrazek, Jan; Predoana, Luminita; Zaharescu, Maria

2017-12-01

Layers based on TiO2-SiO2 systems fabricated by sol-gel method have been investigated for the preparation of planar waveguides, antireflective coatings, Bragg mirrors, etc. However, at high titania contents such materials exhibit high viscosities and tendency to phase separation. In this paper we present optical properties of films containing TiO2 which are prepared via a novel approach sol-gel on the basis of ternary Na2O-TiO2-SiO2 glasses and which can exhibit lower viscosities. Films of Na2O-TiO2-SiO2 systems were prepared from input sols mixed of silica, titania and sodium oxide sols. The silica sol was prepared from tetraethyl orthosilicate (TEOS), ethanol, hydrochloric acid and water, with a TEOS c= 2 mol/l and water/alkoxide ratio 1.75. The titania sol was mixed from titanium tetraisopropoxide (TiPr), propan-2-ol, nitric acid and water, c= 0.5 mol/l, RW= 0.42. The sodium oxide sols with c= 0.474 mol/l were prepared from sodium ethoxide and ethanol. Input sols were prepared by mixing the silica and titania sols first and then the sodium sol was added. The input sols were aged for one hour. Stable input sols were obtained. The input sols were deposited on glass and silica slides by dip-coating technique at a withdrawing speeds of 200 mm/min. Applied gel layers were thermally treated at temperatures of 450 and 900°C. Layers containing sodium oxide and titania in concentration ranges of 0-20 mol.% and 0-30 mol.% respectively have been fabricated. Optical properties of layers were determined by UV-VIS-NIR transmission and reflection spectrophotometry. Refractive indices of layers were determined by spectral ellipsometry and from transmission spectra. Optical properties were correlated with results of XRD spectroscopy, optical microscopy, and atomic force microscopy. Transparent homogenous films with a maximum refractive index of 1.61 at a wavelength of 600 nm have been obtained.

System and method for ultrafast optical signal detecting via a synchronously coupled anamorphic light pulse encoded laterally

DOEpatents

Heebner, John E [Livermore, CA

2010-08-03

In one general embodiment, a method for ultrafast optical signal detecting is provided. In operation, a first optical input signal is propagated through a first wave guiding layer of a waveguide. Additionally, a second optical input signal is propagated through a second wave guiding layer of the waveguide. Furthermore, an optical control signal is applied to a top of the waveguide, the optical control signal being oriented diagonally relative to the top of the waveguide such that the application is used to influence at least a portion of the first optical input signal propagating through the first wave guiding layer of the waveguide. In addition, the first and the second optical input signals output from the waveguide are combined. Further, the combined optical signals output from the waveguide are detected. In another general embodiment, a system for ultrafast optical signal recording is provided comprising a waveguide including a plurality of wave guiding layers, an optical control source positioned to propagate an optical control signal towards the waveguide in a diagonal orientation relative to a top of the waveguide, at least one optical input source positioned to input an optical input signal into at least a first and a second wave guiding layer of the waveguide, and a detector for detecting at least one interference pattern output from the waveguide, where at least one of the interference patterns results from a combination of the optical input signals input into the first and the second wave guiding layer. Furthermore, propagation of the optical control signal is used to influence at least a portion of the optical input signal propagating through the first wave guiding layer of the waveguide.

Impact of Sodium Bicarbonate-Buffered Lidocaine on Patient Pain During Image-Guided Breast Biopsy.

PubMed

Vasan, Alison; Baker, Jay A; Shelby, Rebecca A; Soo, Mary Scott C

2017-09-01

This randomized, double-blind controlled study evaluated the effectiveness of sodium bicarbonate-buffered lidocaine on reducing pain during imaging-guided breast biopsies. This prospective, HIPAA-compliant study randomly assigned 85 women undergoing ultrasound- or stereotactic-guided core-needle breast biopsies to receive intradermally and intraparenchymally either 1% lidocaine buffered with sodium bicarbonate (9:1 ratio) (bicarbonate study group) or 1% lidocaine alone (control group). Pain was evaluated using a 0-to-10 Likert pain scale during both intradermal and intraparenchymal anesthesia injections and during tissue sampling. Prebiopsy breast pain, anxiety, medical history, demographics, biopsy type, radiologist level of training, breast density, and lesion histology were recorded. Data were analyzed using analysis of variance and analysis of covariance. Unadjusted mean pain scores were 1.47 and 2.07 (study and control groups, respectively; P = .15) during intradermal injections, and 1.84 and 2.98 (study and control groups, respectively; P = .03) during intraparenchymal injections. Tissue sampling mean pain scores were .81 and 1.71 (study and control groups, respectively; P = .07). Moderator analyses found (1) among patients with preprocedural pain, those in the bicarbonate group experienced less intradermal injection pain (0.85 ± 1.23) than patients in the control group (2.50 ± 2.09); (2) among patients with fatty or scattered fibroglandular tissue, those in the bicarbonate group (1.35 ± 1.95) experienced less intraparenchymal injection pain than the control group (3.52 ± 3.13); and (3) during ultrasound-guided biopsies, patients in the bicarbonate group experienced less tissue-sampling pain (0.23 ± 0.63) than the control group (1.79 ± 3.05). Overall, buffering lidocaine with sodium bicarbonate significantly reduced pain during intraparenchymal injections, and additional pain reduction was found in certain patient subgroups during intradermal injections, intraparenchymal injections, and tissue sampling. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Mn-Based Cathode with Synergetic Layered-Tunnel Hybrid Structures and Their Enhanced Electrochemical Performance in Sodium Ion Batteries.

PubMed

Wu, Zhen-Guo; Li, Jun-Tao; Zhong, Yan-Jun; Guo, Xiao-Dong; Huang, Ling; Zhong, Ben-He; Agyeman, Daniel-Adjei; Lim, Jin-Myoung; Kim, Du-Ho; Cho, Maeng-Hyo; Kang, Yong-Mook

2017-06-28

A synergistic approach for advanced cathode materials is proposed. Sodium manganese oxide with a layered-tunnel hybrid structure was designed, synthesized, and subsequently investigated. The layered-tunnel hybrid structure provides fast Na ion diffusivity and high structural stability thanks to the tunnel phase, enabling high rate capability and greatly improved cycling stability compared to that of the pure P2 layered phase while retaining the high specific capacity of the P2 layered phase. The hybrid structure provided a decent discharge capacity of 133.4 mAh g -1 even at 8 C, which exceeds the reported best rate capability for Mn-based cathodes. It also displayed an impressive cycling stability, maintaining 83.3 mAh g -1 after 700 cycles at 10 C. Theoretical calculation and the potentiostatic intermittent titration technique (PITT) demonstrated that this hybrid structure helps enhance Na ion diffusivity during charge and discharge, attaining, as a result, an unprecendented electrochemical performance.

Effect of different irrigation on smear layer removal after post space preparation.

PubMed

Gu, Xin-Hua; Mao, Cai-Yun; Kern, Matthias

2009-04-01

The purpose of this study was to evaluate the effect of different irrigating solutions on smear layer removal and dentinal tubule opening on root canal surfaces after post space preparation and to study whether additional ultrasonic irrigation has any effect on smear layer removal. Forty-eight anterior teeth were treated endodontically. After post space preparation, they were assigned to six groups: group 1, EDTA; group 2, EDTA with ultrasonic activation; group 3, sodium hypochlorite (NaOCl); group 4, NaOCl with ultrasonic activation; group 5, sodium chloride (NaCl); and group 6, NaCl with ultrasonic activation. Specimens were examined under a field-emission scanning electron microscope and scored for debris removal and dentinal tubule opening at the coronal, middle, and apical thirds of the root canal. The results showed that EDTA performed significantly better than NaCl and NaOCl in smear layer removal and dentinal tubule opening. Additional ultrasonic irrigation did not improve smear layer removal significantly.

Effects of sodium polyacrylate on water retention and infiltration capacity of a sandy soil.

PubMed

Zhuang, Wenhua; Li, Longguo; Liu, Chao

2013-01-01

Based on the laboratory study, the effects of sodium polyacrylate (SP) was investigated at 5 rates of 0, 0.08, 0.2, 0.5, and 1%, on water retention, saturated hydraulic conductivity(Ks), infiltration characteristic and water distribution profiles of a sandy soil. The results showed that water retention and available water capacity effectively increased with increasing SP rate. The Ks and the rate of wetting front advance and infiltration under certain pond infiltration was significantly reduced by increasing SP rate, which effectively reduced water in a sandy soil leaking to a deeper layer under the plough layer. The effect of SP on water distribution was obviously to the up layer and very little to the following deeper layers. Considering both the effects on water retention and infiltration capacity, it is suggested that SP be used to the sandy soil at concentrations ranging from 0.2 to 0.5%.

Improving the Performance of Layered Oxide Cathode Materials with Football-Like Hierarchical Structure for Na-Ion Batteries by Incorporating Mg2+ into Vacancies in Na-Ion Layers.

PubMed

Li, Zheng-Yao; Wang, Huibo; Chen, Dongfeng; Sun, Kai; Yang, Wenyun; Yang, Jinbo; Liu, Xiangfeng; Han, Songbai

2018-04-09

The development of advanced cathode materials is still a great interest for sodium-ion batteries. The feasible commercialization of sodium-ion batteries relies on the design and exploitation of suitable electrode materials. This study offers a new insight into material design to exploit high-performance P2-type cathode materials for sodium-ion batteries. The incorporation of Mg 2+ into intrinsic Na + vacancies in Na-ion layers can lead to a high-performance P2-type cathode material for sodium-ion batteries. The materials prepared by the coprecipitation approach show a well-defined morphology of secondary football-like hierarchical structures. Neutron power diffraction and refinement results demonstrate that the incorporation of Mg 2+ into intrinsic vacancies can enlarge the space for Na-ion diffusion, which can increase the d-spacing of the (0 0 2) peak and the size of slabs but reduce the chemical bond length to result in an enhanced rate capability and cycling stability. The incorporation of Mg 2+ into available vacancies and a unique morphology make Na 0.7 Mg 0.05 Mn 0.8 Ni 0.1 Co 0.1 O 2 a promising cathode, which can be charged and discharged at an ultra-high current density of 2000 mA g -1 with an excellent specific capacity of 60 mAh g -1 . This work provides a new insight into the design of electrode materials for sodium-ion batteries. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon-Stabilized Interlayer-Expanded Few-Layer MoSe2 Nanosheets for Sodium Ion Batteries with Enhanced Rate Capability and Cycling Performance.

PubMed

Tang, Yongchao; Zhao, Zongbin; Wang, Yuwei; Dong, Yanfeng; Liu, Yang; Wang, Xuzhen; Qiu, Jieshan

2016-11-30

Sodium ion batteries (SIBs) have been considered as a promising alternative to lithium ion batteries, owing to the abundant reserve and low-cost accessibility of the sodium source. To date, the pursuit of high-performance anode materials remains a great challenge for the SIBs. In this work, carbon-stabilized interlayer-expanded few-layer MoSe 2 nanosheets (MoSe 2 @C) have been fabricated by an oleic acid (OA) functionalized synthesis-polydopamine (PDA) stabilization-carbonization strategy, and their structural, morphological, and electrochemical properties have been carefully characterized and compared with the carbon-free MoSe 2 . When evaluated as anode for sodium ion half batteries, the MoSe 2 @C exhibits a remarkably enhanced rate capability of 367 mA h g -1 at 5 A g -1 , a high reversible discharge capacity of 445 mA h g -1 at 1 A g -1 , and a long-term cycling stability over 100 cycles. To further explore the potential applications, the MoSe 2 @C is assembled into sodium ion full batteries with Na 3 V 2 (PO 4 ) 3 (NVP) as cathode materials, showing an impressively high reversible capacity of 421 mA h g -1 at 0.2 A g -1 after 100 cycles. Such results are primarily attributed to the unique carbon-stabilized interlayer-expanded few-layer MoSe 2 nanosheets structure, which facilitates the permeation of electrolyte into the inner of MoSe 2 nanosheets, promoting charge transfer efficiency among MoSe 2 nanosheets, and accommodating the volume change from discharge-charge cycling.

Surface transformation by a “cocktail” solvent enables stable cathode materials for sodium ion batteries

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

Mu, Linqin; Rahman, Muhammad Mominur; Zhang, Yan

Coating the surfaces of active materials has become an effective and indispensable path towards the stable operation of practical rechargeable batteries. Improving the affordability of coating processes can bring enormous manufacturing advantages to battery applications. Here in this paper, we report a cheap, simple and efficient method to create conformal coating layers on the primary particles of sodium layered oxide materials for improving battery performance. Mimicking the cathode–electrolyte interfacial reaction in practical cells, we create conformal coating layers via the spontaneous reaction between the oxidative cathode surfaces and a cocktail of reductive organic solvents. The conformal coating layers consist ofmore » metal–organic compounds with reduced transition metal cations, i.e., artificial cathode–electrolyte interphases (CEIs). The cells containing these coated cathode materials deliver much improved cycle life while maintaining reasonably high reversible capacity and rate capability. Furthermore, the structural stability and water resistance are enhanced, which can practically help simplify the storage protocol of cathode powders prior to battery manufacturing. The surfaces of most oxide cathode materials (e.g., lithium cathodes and sodium cathodes) are highly oxidative, and thus we expect that the present method, with tailored experimental parameters, can be readily applied to most battery systems.« less

Microporous ceramic coated separators with superior wettability for enhancing the electrochemical performance of sodium-ion batteries

NASA Astrophysics Data System (ADS)

Suharto, Yustian; Lee, Yongho; Yu, Ji-Sang; Choi, Wonchang; Kim, Ki Jae

2018-02-01

Finding an alternative to glass fiber (GF) separators is a crucial factor for the fast commercialization of sodium-ion batteries (SIBs), because GF separators are too thick for use in SIBs, thereby decreasing the volumetric and gravimetric energy density. Here we propose a microporous composite separator prepared by introducing a polymeric coating layer of polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP co-polymer) with ZrO2 nanoparticles to a polyethylene (PE) separator. The coated separator efficiently enhances the cell performance of SIBs. The ZrO2 nanoparticles, finely dispersed on the polymeric coating layer, induce the formation of many micropores on the polymeric coating layer, suggesting that micropore formation on the coating layer renders the composite separator more open in structure. An ethylene carbonate/propylene carbonate liquid electrolyte for SIBs is not absorbed by PE separators even after 1 h of electrolyte droplet testing, while the proposed separator with many micropores is completely wetted by the electrolyte. Sodium ion migration across the composite separator is therefore effectively enhanced by the formation of ion transfer pathways, which improve ionic conductivity. As a result, the microporous composite separator affords stable cycle performances and excellent specific capacity retention (95.8%) after 50 cycles, comparable to those offered by a SIB with a GF separator.

Surface transformation by a “cocktail” solvent enables stable cathode materials for sodium ion batteries

DOE PAGES

Mu, Linqin; Rahman, Muhammad Mominur; Zhang, Yan; ...

2018-01-09

Coating the surfaces of active materials has become an effective and indispensable path towards the stable operation of practical rechargeable batteries. Improving the affordability of coating processes can bring enormous manufacturing advantages to battery applications. Here in this paper, we report a cheap, simple and efficient method to create conformal coating layers on the primary particles of sodium layered oxide materials for improving battery performance. Mimicking the cathode–electrolyte interfacial reaction in practical cells, we create conformal coating layers via the spontaneous reaction between the oxidative cathode surfaces and a cocktail of reductive organic solvents. The conformal coating layers consist ofmore » metal–organic compounds with reduced transition metal cations, i.e., artificial cathode–electrolyte interphases (CEIs). The cells containing these coated cathode materials deliver much improved cycle life while maintaining reasonably high reversible capacity and rate capability. Furthermore, the structural stability and water resistance are enhanced, which can practically help simplify the storage protocol of cathode powders prior to battery manufacturing. The surfaces of most oxide cathode materials (e.g., lithium cathodes and sodium cathodes) are highly oxidative, and thus we expect that the present method, with tailored experimental parameters, can be readily applied to most battery systems.« less

Oxide film on metal substrate reduced to form metal-oxide-metal layer structure

NASA Technical Reports Server (NTRS)

Youngdahl, C. A.

1967-01-01

Electrically conductive layer of zirconium on a zirconium-oxide film residing on a zirconium substrate is formed by reducing the oxide in a sodium-calcium solution. The reduced metal remains on the oxide surface as an adherent layer and seems to form a barrier that inhibits further reaction.

A Guide to Oceanic Sedimentary Layering.

DTIC Science & Technology

1983-07-28

Profiling," J. Geophys. Res. 73, 2597-2614. L3 Lee, H. J., 1980. "Physical Properties of Northeast Pacific Sedi- ments Related to Sedimentary Environment and...7i -AI33 060 A GUIDE TO OCEANIC SEDIMENTARY LAYERING(U) TEXAS UNIV 1/i AT AUSTIN APPLIED RESEARCH LABS C B BENNETT ET AL, 28 JUL 83 RRL-TR-83-25...Copy No. 3 A GUIDE TO OCEANIC SEDIMENTARY LAYERING Christopher B. Bennett J. Mark Daniels APPLIED RESEARCH LABORATORIES THE UNIVERSITY OF TEXAS AT

Sodium Laser Guide Star Technique, Spectroscopy and Imaging with Adaptive Optics

NASA Astrophysics Data System (ADS)

Ge, Jian

A sodium laser guide star (LGS) adaptive optics (AO) system developed at Stewart Observatory is to be used at the 6.5m MMT. Annual measurements at Kitt Peak show that the mean mesospheric sodium column density varies from ~2×109cm-2 (summer) to ~5×109cm-2 (winter). The sodium column density also varies by a factor of two during a one hour period. The first simultaneous measurements of sodium LGS brightness, sodium column density and laser power were obtained. The absolute sodium return for a continuous wave circularly polarized beam is 1.2([/pm]0.3)× 106 photons s-1m-2W-1 for the sodium column density of 3.7×109cm-2. Theoretical studies demonstrate that the 6.5m MMT LGS AO can provide Strehl ratios better than 0.15 and about 50% flux concentration within 0.2'' aperture for 1-5.5μm under median seeing. This correction will be available for the full sky. Better Strehl and higher flux concentration can be achieved with natural guide stars, but limited sky coverage. The AO corrected field-of-view is about 60''. The Arizona IR Imager and Echelle Spectrograph (ARIES) was designed to match the 6.5m MMT AO. Detection limits of more than 2 magnitude fainter can be reached with the AO over without the AO. A pre-ARIES wide field near-IR camera was designed, built and tested. The camera provides 1'' images in the near-IR over an 8.5 × 8.5arcmin2 field. The 10-σ detection limit with one minute exposures is 17.9 mag. in the K band. A prototype very high resolution cross-dispersed optical echelle spectrograph was designed and built to match the Starfire Optical Range 1.5m AO images. Interstellar KI 7698A absorption lines have been detected in the spectra of αCyg and ζPer. The spectral resolution is 250.000. About 300A wavelengths were covered in a single exposure. Total detection efficiency of 1% has been achieved. For the first time, a near-single-mode fiber with 10μm core size was applied to transmit the Mt. Wilson 100inch AO corrected beams to a spectrograph. The coupling efficiency of the fiber reached up to 70%. Spectra of αOri were recorded. The spectral resolution is 200,000. The total wavelength coverage is about 650A per exposure.

A solid state tunable laser for resonance measurements of atmospheric sodium

NASA Technical Reports Server (NTRS)

Philbrick, C. R.; Bufton, J. L.; Gardner, C. S.

1985-01-01

The measurement of wave dynamics in the upper mesosphere using a solid-state laser to excite the resonance fluorescence line of sodium is examined. Two Nd:YAG lasers are employed to produce the sodium resonance line. The method involves mixing the 1064 nm radiation with that from a second Nd:YAG operating at 1319 nm in a nonlinear infrared crystal to directly produce 589 nm radiation by sum frequency generation. The use of the transmitter to measure the sodium layer from the Space Shuttle Platform is proposed. A diagram of the laser transmitter is presented.

Insights into the Effects of Zinc Doping on Structural Phase Transition of P2-Type Sodium Nickel Manganese Oxide Cathodes for High-Energy Sodium Ion Batteries.

PubMed

Wu, Xuehang; Xu, Gui-Liang; Zhong, Guiming; Gong, Zhengliang; McDonald, Matthew J; Zheng, Shiyao; Fu, Riqiang; Chen, Zonghai; Amine, Khalil; Yang, Yong

2016-08-31

P2-type sodium nickel manganese oxide-based cathode materials with higher energy densities are prime candidates for applications in rechargeable sodium ion batteries. A systematic study combining in situ high energy X-ray diffraction (HEXRD), ex situ X-ray absorption fine spectroscopy (XAFS), transmission electron microscopy (TEM), and solid-state nuclear magnetic resonance (SS-NMR) techniques was carried out to gain a deep insight into the structural evolution of P2-Na0.66Ni0.33-xZnxMn0.67O2 (x = 0, 0.07) during cycling. In situ HEXRD and ex situ TEM measurements indicate that an irreversible phase transition occurs upon sodium insertion-extraction of Na0.66Ni0.33Mn0.67O2. Zinc doping of this system results in a high structural reversibility. XAFS measurements indicate that both materials are almost completely dependent on the Ni(4+)/Ni(3+)/Ni(2+) redox couple to provide charge/discharge capacity. SS-NMR measurements indicate that both reversible and irreversible migration of transition metal ions into the sodium layer occurs in the material at the fully charged state. The irreversible migration of transition metal ions triggers a structural distortion, leading to the observed capacity and voltage fading. Our results allow a new understanding of the importance of improving the stability of transition metal layers.

Improved Barrier Properties in Flexible Plastic Substrates

DTIC Science & Technology

2009-01-01

layer 2:1 sandwich is required to balance this charge deficit. The extra charge is provided by a layer of large cations, usually potassium or sodium...ions (K+).32,30 Each of the potassium ions in this interiayer is shared among 12 oxygen atoms and the electrostatic force between the potassium ion...layer. Potassium • Aluminum • Silicon • Oxygen {-* Hydroxyl pair b axfs" This tabulation giving the layer by layer population of elements

Thermal Stability of NaxCrO2 for Rechargeable Sodium Batteries; Studies by High-Temperature Synchrotron X-ray Diffraction.

PubMed

Yabuuchi, Naoaki; Ikeuchi, Issei; Kubota, Kei; Komaba, Shinichi

2016-11-30

Thermal stability and phase transition processes of NaCrO 2 and Na 0.5 CrO 2 are carefully examined by high-temperature synchrotron X-ray diffraction method. O3-type NaCrO 2 shows anisotropic thermal expansion on heating, which is a common character as layered materials, without phase transition in the temperature range of 27-527 °C. In contrast, for the desodiated phase, in-plane distorted P3-type layered oxide (P'3 Na 0.5 CrO 2 ), phase transition occurs in the following order. Monoclinic distortion associated with Na/vacancy ordering is gradually lost on heating, and its symmetry increases and changes to a rhombohedral lattice at 207 °C. On further heating, phase segregation to two P3 layered metastable phases, which have different interlayer distances (17.0 and 13.5 Å, presumably sodium-rich and sodium-free P3 phases, respectively) are observed on heating to 287-477 °C, but oxygen loss is not observed. Oxygen loss is observed at temperatures only above 500 °C, resulting in the formation of corundum-type Cr 2 O 3 and O3 NaCrO 2 as thermodynamically stable phases. From these results, possibility of Na x CrO 2 as a positive electrode material for safe rechargeable sodium batteries is also discussed.

Formulation and evaluation of bilayer tablets of metoclopramide hydrochloride and diclofenac sodium.

PubMed

Gattani, Surendra G; Khabiya, Sohan S; Amrutkar, Jitendra R; Kushare, Sachin S

2012-01-01

The main objective of the present research work was to develop a bilayer tablet of metoclopramide hydrochloride (MTH) and diclofenac sodium (DS) in separate layers to avoid incompatibility and thus to maximize the efficacy of both drugs in combination for the effective treatment of migraine headaches. MTH and DS were formulated as immediate and sustained release layers respectively. In vitro dissolution kinetic studies of an optimized (D10) batch of DS in both sustained release layer and bilayer tablet forms show good linearity of regression coefficient 0.9773 (first order equation). The results reveal that an optimized immediate release layer (M5) of MTH and a sustained release layer (D10) of DS might be suitable for the treatment of migraine by sequential release of the two drugs in a bilayer tablet. Migraine is a type of recurring headache of moderate to severe intensity associated with gastrointestinal, neurological, and autonomic symptoms. In migraine, a combination of pretreatment with antiemetics is required for symptomatic treatment, when nausea and vomiting are severe. In our present research, we have selected the metoclopramide hydrochloride (MTH) active ingredient for study because it has an antiemetic effect and is a prokinetic agent. MTH is more effective to counteract gastric stasis associated with migraine, and it enhances the rate of absorption of non-steroidal anti-inflammatory drugs (NSAIDs). In the present investigation we combine MTH and a second active ingredient, diclofenac sodium, as a formulated bilayer tablet to prevent degradation of MTH.

Long-term stability of sodium caseinate-stabilized nanoemulsions.

PubMed

Yerramilli, Manispuritha; Ghosh, Supratim

2017-01-01

Oil-in-water (5 wt%) nanoemulsions were prepared with different concentration (2.5-10 wt%) of sodium caseinate as a sole emulsifier and their long-term storage stability was investigated for 6 months. Previous studies associated with sodium caseinate looked only into nanoemulsion formation; hence the challenges with long-term stability were not addressed. All nanoemulsions displayed an average droplet size <200 nm, which remained unchanged over 6 months. However, all of them displayed rapid creaming due to unabsorbed protein induced depletion flocculation, whose extent increased with protein concentration, although the cream layer formed was weak and re-dispersible upon gentle mixing. Microstructural analysis of the cream layer showed compaction of flocculated nanodroplet network with time leaving the aqueous phase out. Calculation of depletion interaction energy showed an increase in inter-droplet attraction with protein concentration and decrease with a reduction in droplet size, making the nanoemulsions more resistant to flocculation than conventional emulsions. This work aids in understanding the dependence of protein concentration on long-term stability of sodium caseinate-stabilized nanoemulsions.

Nanoporous hydroxyapatite/sodium titanate bilayer on titanium implants for improved osteointegration.

PubMed

Carradò, A; Perrin-Schmitt, F; Le, Q V; Giraudel, M; Fischer, C; Koenig, G; Jacomine, L; Behr, L; Chalom, A; Fiette, L; Morlet, A; Pourroy, G

2017-03-01

The aim of this study was to improve the strength and quality of the titanium-hydroxyapatite interface in order to prevent long-term failure of the implanted devices originating from coating delamination and to test it in an in-vivo model. Ti disks and dental commercial implants were etched in Kroll solution. Thermochemical treatments of the acid-etched titanium were combined with sol-gel hydroxyapatite (HA) coating processes to obtain a nanoporous hydroxyapatite/sodium titanate bilayer. The sodium titanate layer was created by incorporating sodium ions onto the Ti surface during a NaOH alkaline treatment and stabilized using a heat treatment. HA layer was added by dip-coating in a sol-gel solution. The bioactivity was assessed in vitro with murine MC3T3-E1 and human SaOs-2 cells. Functional and histopathological evaluations of the coated Ti implants were performed at 22, 34 and 60days of implantation in a dog lower mandible model. Nanoporous hydroxyapatite/sodium titanate bilayer on titanium implants was sensitive neither to crack propagation nor to layer delamination. The in vitro results on murine MC3T3-E1 and human SaOs-2 cells confirm the advantage of this coating regarding the capacity of cell growth and differentiation. Signs of progressive bone incorporation, such as cancellous bone formed in contact with the implant over the existing compact bone, were notable as early as day 22. Overall, osteoconduction and osteointegration mean scores were higher for test implants compared to the controls at 22 and 34 days. Nanoporous hydroxyapatite/sodium titanate bilayer improves the in-vivo osteoconduction and osteointegration. It prevents the delamination during the screwing and it could increase HA-coated dental implant stability without adhesive failures. The combination of thermochemical treatments with dip coating is a low-cost strategy. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Fibrillar films obtained from sodium soap fibers and polyelectrolyte multilayers.

PubMed

Zawko, Scott A; Schmidt, Christine E

2011-08-01

An objective of tissue engineering is to create synthetic polymer scaffolds with a fibrillar microstructure similar to the extracellular matrix. Here, we present a novel method for creating polymer fibers using the layer-by-layer method and sacrificial templates composed of sodium soap fibers. Soap fibers were prepared from neutralized fatty acids using a sodium chloride crystal dissolution method. Polyelectrolyte multilayers (PEMs) of polystyrene sulfonate and polyallylamine hydrochloride were deposited onto the soap fibers, crosslinked with glutaraldehyde, and then the soap fibers were leached with warm water and ethanol. The morphology of the resulting PEM structures was a dense network of fibers surrounded by a nonfibrillar matrix. Microscopy revealed that the PEM fibers were solid structures, presumably composed of polyelectrolytes complexed with residual fatty acids. These fibrillar PEM films were found to support the attachment of human dermal fibroblasts. Copyright © 2011 Wiley Periodicals, Inc.

Dependence of astigmatism, far-field pattern, and spectral envelope width on active layer thickness of gain guided lasers with narrow stripe geometry

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

Mamine, T.

1984-06-15

The effects of active layer thickness on the astigmatism, the angle of far-field pattern width parallel to the junction, and the spectral envelope width of a gain guided laser with a narrow stripe geometry have been investigated analytically and experimentally. It is concluded that a large level of astigmatism, a narrow far-field pattern width, and a rapid convergence of the spectral envelope width are inherent to the gain guided lasers with thin active layers.

Investigation on the relationship among sporadic Na, sporadic E, Field aligned irregularities and neutral winds

NASA Astrophysics Data System (ADS)

Sundararajan, Sridharan; Patra, Amit Kumar; Pant, Tarun; Gurubaran, Subramanian; Raghunath, Karnam

In the Mesosphere and Lower Thermosphere region (80-100 km), metallic atoms, namely, sodium, potassium, lithium, Iron etc are formed due to ablation of meteors. The lidars based on resonance fluorescence principle has been used to study the vertical distribution of sodium atoms, because of their large abundance than other metals. The profiles of sodium density sometimes show enhancement by a factor of 2 than the normal layer in a narrow altitude region of 2 km and on these occasions, they are called sporadic sodium layer, or briefly Ns. On the other hand, there are observations on sporadic E and radar observations of Field Aligned Irregularities (FAI) associated with these sporadic E. Some investigations have been made to understand the relationship between sporadic E and FAI. Considering that sporadic E is composed of metallic ions and the time of metallic ions are larger compared to other ions, the sodium observations in the same height region would be of significant importance to understand the process involved. Despite a few past observations, no clear picture has emerged due to lack of simultaneous measurements of these parameters. The simultaneous observations of FAI echoes by the Indian MST radar and sodium concentration by the sodium lidar at Gadanki (13.5o N, 79.2o E) are being used to investigate the above mentioned relationship. The Sporadic E and neutral wind information are obtained from the ionosonde, meteor/MF radar observations from Trivandrum (8.5o N, 77E) and Tirunelveli (8.7o N, 77.8o E). The results obtained will be presented during the meeting.

Monitoring of Soft Deposition Layers in Liquid-Filled Tubes with Guided Acoustic Waves Excited by Clamp-on Transducers.

PubMed

Tietze, Sabrina; Singer, Ferdinand; Lasota, Sandra; Ebert, Sandra; Landskron, Johannes; Schwuchow, Katrin; Drese, Klaus Stefan; Lindner, Gerhard

2018-02-09

The monitoring of liquid-filled tubes with respect to the formation of soft deposition layers such as biofilms on the inner walls calls for non-invasive and long-term stable sensors, which can be attached to existing pipe structures. For this task a method is developed, which uses an ultrasonic clamp-on device. This method is based on the impact of such deposition layers on the propagation of circumferential guided waves on the pipe wall. Such waves are partly converted into longitudinal compressional waves in the liquid, which are back-converted to guided waves in a circular cross section of the pipe. Validating this approach, laboratory experiments with gelatin deposition layers on steel tubes exhibited a distinguishable sensitivity of both wave branches with respect to the thickness of such layers. This allows the monitoring of the layer growth.

Mechanisms for sodium insertion in carbon materials

NASA Astrophysics Data System (ADS)

Stevens, David Andrew

2000-12-01

This thesis details the mechanisms for sodium insertion into different carbons using both electrochemical and vapour techniques. Room temperature electrochemical measurements were completed to examine the insertion and removal of sodium from soft (graphitizable) and nanoporous hard (non-graphitizable) carbons prepared by the heat treatment of organic precursors to a range of temperatures. The mechanisms identified from these studies were further investigated through a series of in situ x-ray scattering studies on operating electrochemical cells. The results obtained were then compared with x-ray scattering measurements on carbons after exposure to sodium vapour at 890C. This work is primarily driven by the aluminium industry's need to understand how sodium insertion causes carbon cathode blocks in aluminium reduction cells to swell. The results obtained are also of relevance to the lithium-ion battery field as they help to verify mechanisms proposed in the literature for lithium insertion into carbon hosts. Some carbons were also identified that could accommodate large amounts of sodium, making them attractive candidates for anodes in rechargeable sodium ion batteries. For soft carbons, the results showed that both sodium and lithium insert between approximately parallel carbon layers along the sloping voltage region of the electrochemical curves, increasing the average interlayer spacing. The sodium and lithium capacities decreased with increasing carbon heat treatment temperature. For the soft carbons studied, the sodium capacity was found to be consistently lower than the lithium capacity, implying that some lithium-accessible sites were unavailable for sodium insertion. The electrochemical profiles for the hard carbons also contained capacity along a sloping voltage region and, as with the soft carbons, this was shown to result from the insertion of sodium and lithium between approximately parallel carbon layers. In contrast to the soft carbons, however, the electrochemical profiles for the hard carbons also exhibited significant capacity along low voltage plateaus at chemical potentials close to the chemical potential of the metal. An in situ small angle x-ray scattering experimental method was therefore developed to examine changes in scattering from the nanopores during sodium and lithium insertion/removal. The results from this technique clearly showed that the low voltage plateau capacity resulted from the insertion of sodium and lithium into nanopores in the carbon.

Submersible sodium pump

DOEpatents

Brynsvold, Glen V.; Lopez, John T.; Olich, Eugene E.; West, Calvin W.

1989-01-01

An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates.

Submersible sodium pump

DOEpatents

Brynsvold, G.V.; Lopez, J.T.; Olich, E.E.; West, C.W.

1989-11-21

An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates. 14 figs.

Sodium sulfur battery seal

DOEpatents

Mikkor, Mati

1981-01-01

This disclosure is directed to an improvement in a sodium sulfur battery construction in which a seal between various battery compartments is made by a structure in which a soft metal seal member is held in a sealing position by holding structure. A pressure applying structure is used to apply pressure on the soft metal seal member when it is being held in sealing relationship to a surface of a container member of the sodium sulfur battery by the holding structure. The improvement comprises including a thin, well-adhered, soft metal layer on the surface of the container member of the sodium sulfur battery to which the soft metal seal member is to be bonded.

The self-adjusting file (SAF). Part 3: removal of debris and smear layer-A scanning electron microscope study.

PubMed

Metzger, Zvi; Teperovich, Ehud; Cohen, Raphaela; Zary, Raviv; Paqué, Frank; Hülsmann, Michael

2010-04-01

The aim of this study was to evaluate the cleaning ability of the Self-Adjusting File (SAF) system in terms of removal of debris and smear layer. Root canal preparations were performed in 20 root canals using an SAF operated with a continuous irrigation device. The glide path was initially established using a size 20 K-file followed by the SAF file that was operated in the root canal via a vibrating motion for a total of 4 minutes. Sodium hypochlorite (3%) and EDTA (17%) were used as continuous irrigants and were alternated every minute during this initial 4-minute period. This was followed by a 30-second rinse using EDTA applied through a nonactivated SAF and a final flush with sodium hypochlorite. The roots were split longitudinally and subjected to scanning electron microscopy (SEM). The presence of debris and a smear layer in the coronal, middle, and apical thirds of the canal were evaluated through the analysis of the SEM images using five-score evaluation systems based on reference photographs. The SAF operation with continuous irrigation, using alternating irrigants, resulted in root canal walls that were free of debris in all thirds of the canal in all (100%) of the samples. In addition, smear layer-free surfaces were observed in 100% and 80% of the coronal and middle thirds of the canal, respectively. In the apical third of the canal, smear layer-free surfaces were found in 65% of the root canals. The operation of the SAF system with continuous irrigation coupled with alternating sodium hypochlorite and EDTA treatment resulted in a clean and mostly smear layer-free dentinal surface in all parts of the root canal. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Sodiation kinetics of metal oxide conversion electrodes: A comparative study with lithiation

DOE PAGES

He, Kai; Lin, Feng; Zhu, Yizhou; ...

2015-08-19

The development of sodium ion batteries (NIBs) can provide an alternative to lithium ion batteries (LIBs) for sustainable, low-cost energy storage. However, due to the larger size and higher m/e ratio of the sodium ion compared to lithium, sodiation reactions of candidate electrodes are expected to differ in significant ways from the corresponding lithium ones. In this work, we investigated the sodiation mechanism of a typical transition metal-oxide, NiO, through a set of correlated techniques, including electrochemical and synchrotron studies, real-time electron microscopy observation, and ab initio molecular dynamics (MD) simulations. We found that a crystalline Na₂O reaction layer thatmore » was formed at the beginning of sodiation plays an important role in blocking the further transport of sodium ions. In addition, sodiation in NiO exhibits a “shrinking-core” mode that results from a layer-by-layer reaction, as identified by ab initio MD simulations. For lithiation, however, the formation of Li anti-site defects significantly distorts the local NiO lattice that facilitates Li insertion, thus enhancing the overall reaction rate. These observations delineate the mechanistic difference between sodiation and lithiation in metal-oxide conversion materials. More importantly, our findings identify the importance of understanding the role of reaction layers on the functioning of electrodes and thus provide critical insights into further optimizing NIB materials through surface engineering.« less

The erythrocyte sodium and potassium in patients treated with digoxin.

PubMed Central

Morgan, D B; Cumberbatch, M; Cohn, S; Scott, D; Gunasuntharam, T; Davidson, C; Chapman, C

1980-01-01

1 Four healthy persons and ten patients with heart failure were studied for 5 to 20 days after they started taking digoxin. The sodium content of their erythrocytes increased and there was an equimolar decrease in potassium content. 2 The increase in erythrocyte sodium for a given increase in plasma digoxin during this acute digitalization was less on average and varied more in the patients than in the healthy persons, that is the patients' erythrocytes were less responsive to digoxin. 3 The average erythrocyte sodium was greater in 183 patients who had been taking digoxin for at least 2 months than in 100 healthy persons not taking digoxin but there was no significant correlation between the plasma digoxin concentrations and erythrocyte sodium concentration in the patients. Indeed, there was no apparent change in the erythrocyte sodium in many of the patients taking digoxin. 4 If the erythrocyte sodium concentration is a reliable guide to the tissue effects of digoxin then the results suggest that there is a wide variation in the response to digoxin between patients both during acute digitalization and during chronic treatment with digoxin. PMID:7426274

Research of centroiding algorithms for extended and elongated spot of sodium laser guide star

NASA Astrophysics Data System (ADS)

Shao, Yayun; Zhang, Yudong; Wei, Kai

2016-10-01

Laser guide stars (LGSs) increase the sky coverage of astronomical adaptive optics systems. But spot array obtained by Shack-Hartmann wave front sensors (WFSs) turns extended and elongated, due to the thickness and size limitation of sodium LGS, which affects the accuracy of the wave front reconstruction algorithm. In this paper, we compared three different centroiding algorithms , the Center-of-Gravity (CoG), weighted CoG (WCoG) and Intensity Weighted Centroid (IWC), as well as those accuracies for various extended and elongated spots. In addition, we compared the reconstructed image data from those three algorithms with theoretical results, and proved that WCoG and IWC are the best wave front reconstruction algorithms for extended and elongated spot among all the algorithms.

Concept for polychromatic laser guide stars: one-photon excitation of the 4P3/2 level of a sodium atom.

PubMed

Pique, Jean-Paul; Moldovan, Ioana Cristina; Fesquet, Vincent

2006-11-01

One challenge for polychromatic laser guide stars is to create a sufficiently intense source in the UV. The flux required for the measurement of differential tip-tilt is the main issue that we address. We describe a model that has been validated using on-sky data. We present a method that excites the 4P3/2 sodium level using a one-photon excitation at 330 nm. It is more efficient than the two-photon excitation previously suggested since its power slope flux is 3 x 10(4) photons/s/m2/W instead of 1.3 x 10(3) photons/s/m2/W. This method is very promising both in terms of flux and system simplicity.

Raising the Corrosion Resistance of Low-Carbon Steels by Electrolytic-Plasma Saturation with Nitrogen and Carbon

NASA Astrophysics Data System (ADS)

Kusmanov, S. A.; Grishina, E. P.; Belkin, P. N.; Kusmanova, Yu. V.; Kudryakova, N. O.

2017-05-01

Structural features of the external oxide layer and internal nitrided, carbonitrided and carburized layers in steels 10, 20 and St3 produced by the method of electrolytic plasma treatment are studied. Specimens of the steels are tested for corrosion in a naturally aerated 1-N solution of sodium chloride. The condition of the metal/sodium chloride solution interface is studied by the method of electrochemical impedance spectroscopy. It is shown that the corrosion resistance of low-carbon steels can be raised by anode electrolytic-plasma saturation with nitrogen and carbon. Recommendations are given on the choice of carbonitriding modes for structural steels.

Insights into the Effects of Zinc Doping on Structural Phase Transition of P2-Type Sodium Nickel Manganese Oxide Cathodes for High-Energy Sodium Ion Batteries

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

Wu, Xuehang; Xu, Gui-Liang; Zhong, Guiming

P2-type sodium nickel manganese oxide-based cathode materials with higher energy densities are prime candidates for applications in rechargeable sodium ion batteries. A systematic study combining in situ high energy X-ray diffraction (HEXRD), ex situ Xray absorption fine spectroscopy (XAFS), transmission electron microscopy (TEM), and solid-state nuclear magnetic resonance (SSNMR) techniques was carried out to gain a deep insight into the structural evolution of P2-Na 0.66Ni 0.33-xZn xMn 0.67O 2 (x = 0, 0.07) during cycling. In situ HEXRD and ex situ TEM measurements indicate that an irreversible phase transition occurs upon sodium insertion-extraction of Na 0.66Ni 0.33Mn 0.67O 2. Zincmore » doping of this system results in a high structural reversibility. XAFS measurements indicate that both materials are almost completely dependent on the Ni 4+/Ni 3+/ Ni 2+ redox couple to provide charge/discharge capacity. SS-NMR measurements indicate that both reversible and irreversible migration of transition metal ions into the sodium layer occurs in the material at the fully charged state. The irreversible migration of transition metal ions triggers a structural distortion, leading to the observed capacity and voltage fading. Our results allow a new understanding of the importance of improving the stability of transition metal layers.« less

Layer-by-Layer Self-Assembly of Plexcitonic Nanoparticles

DTIC Science & Technology

2013-08-12

nitrate , trisodium citrate tribasic dihydrate, sodium poly(styrene sulfonate) (PSS, MW ~70,000), poly(diallyldimethyl ammonium chloride ) (PDADMAC...Abstract: Colloidal suspensions of multilayer nanoparticles composed of a silver core, a polyelectrolyte spacer layer (inner shell), and a J-aggregate...multilayer architecture served as a framework for examining the coupling of the localized surface plasmon resonance exhibited by the silver core with

Fluorescein sodium-guided surgery of a brain abscess: A case report

PubMed Central

Höhne, Julius; Brawanski, Alexander; Schebesch, Karl-Michael

2016-01-01

Background: Up to now, the feasibility and benefit of using fluorescein sodium under a dedicated surgical microscope filter (YE560, YELLOW 560 nm filter, Carl Zeiss Meditec, Germany) has never been clinically evaluated in infectious disorders of the brain. Case Description: Here, we report the case of a male patient with a brain abscess in the right parietal lobe that was removed under fluorescence-guidance (intravenous administration of fluorescein sodium 10%, 5 mg/kg bodyweight). The abscess capsule showed intensive yellow fluorescent staining, while − under white light − the cortex appeared normal. Conclusion: This technique may improve the identification and surgical removal of brain abscesses. PMID:28031990

Insertion compounds and composites made by ball milling for advanced sodium-ion batteries

PubMed Central

Zhang, Biao; Dugas, Romain; Rousse, Gwenaelle; Rozier, Patrick; Abakumov, Artem M.; Tarascon, Jean-Marie

2016-01-01

Sodium-ion batteries have been considered as potential candidates for stationary energy storage because of the low cost and wide availability of Na sources. However, their future commercialization depends critically on control over the solid electrolyte interface formation, as well as the degree of sodiation at the positive electrode. Here we report an easily scalable ball milling approach, which relies on the use of metallic sodium, to prepare a variety of sodium-based alloys, insertion layered oxides and polyanionic compounds having sodium in excess such as the Na4V2(PO4)2F3 phase. The practical benefits of preparing sodium-enriched positive electrodes as reservoirs to compensate for sodium loss during solid electrolyte interphase formation are demonstrated by assembling full C/P′2-Na1[Fe0.5Mn0.5]O2 and C/‘Na3+xV2(PO4)2F3' sodium-ion cells that show substantial increases (>10%) in energy storage density. Our findings may offer electrode design principles for accelerating the development of the sodium-ion technology. PMID:26777573

Gateways to clinical trials.

PubMed

Bayes, M; Rabasseda, X; Prous, J R

2002-05-01

Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables can be retrieved from the Clinical Studies knowledge area of Prous Science Integrity, the drug discovery and development portal, http://integrity.prous.com. This issue focuses on the following selection of drugs: Abacavir sulfate, abarelix, abciximab, acarbose, alefacept, alteplase, amisulpride, amoxicillin trihydrate, apomorphine hydrochloride, aprepitant, argatroban monohydrate, aspirin, atenolol; Betamethasone dipropionate, betamethasone valerate, bicalutamide, bleomycin sulfate; Calcium carbonate, candesartan cilexetil, celecoxib, cetirizine hydrochloride, cisplatin, clarithromycin, clavulanate potassium, clomethiazole edisilate, clopidogrel hydrogensulfate, cyclophosphamide, chorionic gonadotropin (human); Dalteparin sodium, desloratadine, dexamethasone, doxorubicin, DPC-083; Efalizumab, efavirenz, enoxaparin sodium, eprosartan mesilate, etanercept, etoposide, ezetimibe; Faropenem daloxate, fenofibrate, fluocinolone acetonide, flutamide, fluvastatin sodium, follitropin beta, fondaparinux sodium; Gabapentin, glibenclamide, goserelin, granisetron hydrochloride; Haloperidol, hydrochlorothiazide; Imiquimod, interferon beta-1a, irbesartan, iseganan hydrochloride; L-758298, lamivudine, lanoteplase, leflunomide, leuprorelin acetate, loratadine, losartan potassium; Melagatran, metformin hydrochloride, methotrexate, metronidazole, micafungin sodium, mitoxantrone hydrochloride; Nelfinavir mesilate, neutral insulin injection, nizatidine; Olopatadine hydrochloride, omeprazole, ondansetron hydrochloride; Pamidronate sodium, paracetamol, paroxetine hydrochloride, perindopril, pimecrolimus, pioglitazone hydrochloride, piroxicam, pleconaril, pralmorelin, pravastatin sodium, prednisolone, prednisone, propofol; Raloxifene hydrochloride, ranpirnase, remifentanil hydrochloride, risedronate sodium, risperidone, rofecoxib, ropinirole hydrochloride, rosuvastatin calcium; Sevoflurane, sildenafil citrate, simvastatin, somatropin; Tacrolimus, tamoxifen citrate, telmisartan, temozolomide, thiopental sodium, tinzaparin sodium, tirofiban hydrochloride, treosulfan, triamcinolone acetonide; Urokinase; Valsartan, vardenafil, vincristine; Warfarin sodium; Ximelagatran; Zidovudine.

Impact of food choice on sodium intake patterns from multiple NHANES surveys.

PubMed

Dong, Zefeng; Gao, Zhifeng; McFadden, Brandon

2017-02-01

To examine how the food consumption from various food groups would impact American adults' sodium intake and whether this impact structurally changes over time, data were obtained from six-cycle National Health and Nutrition Examination Survey (NHANES) 1999-2010. Foods were categorized by the first two digits of the USDA food code. Regression models were employed to investigate the associations between the consumption of each food group and sodium intake, and whether there were changes in the associations in consecutive six cycles. Results show that the calorie consumption of oils, beverages and water, fruit juices, fruits, lamb, fruit products, and sugars and sweets had no significant impact on individuals' sodium intake, while calorie consumption of tomatoes, fish, dark-green vegetables, and crackers contributes the most to sodium intake. The contribution to sodium intake of most food groups does not change significantly over time, with the exception of salad dressing whose contribution to sodium intake increased in four consecutive years when compared to that of 1999-2000. The sodium amount contributed by one calorie consumption (sodium density) of most food was above the daily recommendation level, 1.2 mg per calorie per day. Lowering individuals' sodium intake involves either guiding individuals to consume more fruit related products or decreasing the amount of sodium in most food groups at the production or food preparation stages. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultrasonic guided wave propagation across waveguide transitions: energy transfer and mode conversion.

PubMed

Puthillath, Padmakumar; Galan, Jose M; Ren, Baiyang; Lissenden, Cliff J; Rose, Joseph L

2013-05-01

Ultrasonic guided wave inspection of structures containing adhesively bonded joints requires an understanding of the interaction of guided waves with geometric and material discontinuities or transitions in the waveguide. Such interactions result in mode conversion with energy being partitioned among the reflected and transmitted modes. The step transition between an aluminum layer and an aluminum-adhesive-aluminum multi-layer waveguide is analyzed as a model structure. Dispersion analysis enables assessment of (i) synchronism through dispersion curve overlap and (ii) wavestructure correlation. Mode-pairs in the multi-layer waveguide are defined relative to a prescribed mode in a single layer as being synchronized and having nearly perfect wavestructure matching. Only a limited number of mode-pairs exist, and each has a unique frequency range. A hybrid model based on semi-analytical finite elements and the normal mode expansion is implemented to assess mode conversion at a step transition in a waveguide. The model results indicate that synchronism and wavestructure matching is associated with energy transfer through the step transition, and that the energy of an incident wave mode in a single layer is transmitted almost entirely to the associated mode-pair, where one exists. This analysis guides the selection of incident modes that convert into transmitted modes and improve adhesive joint inspection with ultrasonic guided waves.

Guided elastic waves in a pre-stressed compressible interlayer

PubMed

Sotiropoulos

2000-03-01

The propagation of guided elastic waves in a pre-stressed elastic compressible layer embedded in a different compressible material is examined. The waves propagate parallel to the planar layer interfaces as a superposed dynamic stress state on the statically pre-stressed layer and host material. The underlying stress condition in the two materials is characterized by equibiaxial in-plane deformations with common principal axes of strain, one of the axes being perpendicular to the layering. Both materials have arbitrary strain energy functions. The dispersion equation is derived in explicit form. Analysis of the dispersion equation reveals the propagation characteristics and their dependence on frequency, material parameters and stress parameters. Combinations of these parameters are also defined for which guided waves cannot propagate.

Femtosecond Amplifiers and Microlasers in the Deep Ultraviolet

DTIC Science & Technology

2013-11-19

Laser guide stars have applications of growing importance to the DOD, astronomy, and environmental monitoring. However, realizing a laser that is...pump wavelength, photoassociation-pumped lasers hold considerable promise as guide star lasers . The most exciting aspect of these results, however...highlights of several experiments that were mentioned briefly in the last section. A. Dual Wavelength Sodium Laser Pumped By Na-Xe Pair Absorption

Filling a Plastic Bag with Carbon Dioxide: A Student-Designed Guided-Inquiry Lab for Advanced Placement and College Chemistry Courses

ERIC Educational Resources Information Center

Lanni, Laura M.

2014-01-01

A guided-inquiry lab, suitable for first-year general chemistry or high school advanced placement chemistry, is presented that uses only inexpensive, store-bought materials. The reaction of sodium bicarbonate (baking soda) with aqueous acetic acid (vinegar), under the constraint of the challenge to completely fill a sealable plastic bag with the…

Metam Sodium and Metam Potassium Fumigant Safe Handling Guide

EPA Pesticide Factsheets

Safety training is required for certified pesticide applicators and handlers to handle soil fumigants. Measures to mitigate exposure include personal protective equipment, air monitoring, respiratory protection, and emergency preparedness.

Layer moduli of Nebraska pavements for the new Mechanistic-Empirical Pavement Design Guide (MEPDG).

DOT National Transportation Integrated Search

2010-12-01

As a step-wise implementation effort of the Mechanistic-Empirical Pavement Design Guide (MEPDG) for the design : and analysis of Nebraska flexible pavement systems, this research developed a database of layer moduli dynamic : modulus, creep compl...

Spectroscopic Study of Neon Z-Pinch Plasma for Sodium-Neon Photopumping Experiments

DTIC Science & Technology

1992-01-06

enhancement of the 11-A radiation from the n=4 level of neon when the sodium pump was present. For the 25-GV pump power, theoretical calculations predict...when the neon plasma is photopumped. Extensive theoretical analysis has been devoted to establishing the appropriate conditions for these plasmas. 5 ,44...producing thermonuclear neutrons. 63-65 Extensive theoretical modeling of the stability of these plasmas has guided this work.66 An imploding-liner Z

A statistical study of sporadic sodium layer observed by Sodium lidar at Hefei (31.8° N, 117.3° E)

NASA Astrophysics Data System (ADS)

Dou, X.-K.; Xue, X.-H.; Chen, T.-D.; Wan, W.-X.; Cheng, X.-W.; Li, T.; Chen, C.; Qiu, S.; Chen, Z.-Y.

2009-06-01

Sodium lidar observations of sporadic sodium layers (SSLs) during the past 3 years at a mid-latitude location (Hefei, China, 31.8° N, 117.3° E) are reported in this paper. From 64 SSL events detected in about 900 h of observation, an SSL occurrence rate of 1 event every 14 h at our location was obtained. This result, combined with previous studies, reveals that the SSL occurrence can be relatively frequent at some mid-latitude locations. Statistical analysis of main parameters for the 64 SSL events was performed. By examining the corresponding data from an ionosonde, a considerable correlation was found with a Pearson coefficient of 0.66 between seasonal variations of SSL and those of sporadic E (Es) during nighttime, which was in line with the research by Nagasawa and Abo (1995). From comparison between observations from the University of Science and Technology of China (USTC) lidar and from Wuhan Institute of Physics and Mathematics (WIPM) lidar (Wuhan, China, 31° N, 114° E), the minimum horizontal range for some events was estimated to be over 500 km.

Alkali metal protective garment and composite material

DOEpatents

Ballif, III, John L.; Yuan, Wei W.

1980-01-01

A protective garment and composite material providing satisfactory heat resistance and physical protection for articles and personnel exposed to hot molten alkali metals, such as sodium. Physical protection is provided by a continuous layer of nickel foil. Heat resistance is provided by an underlying backing layer of thermal insulation. Overlying outer layers of fireproof woven ceramic fibers are used to protect the foil during storage and handling.

Robust, flexible, and bioadhesive free-standing films for the co-delivery of antibiotics and growth factors.

PubMed

Chen, Dongdong; Wu, Mingda; Chen, Jie; Zhang, Chunqiu; Pan, Tiezheng; Zhang, Bing; Tian, Huayu; Chen, Xuesi; Sun, Junqi

2014-11-25

Free-standing polymer films that adhere strongly to tissue and can codeliver multiple therapeutic agents in a controlled manner are useful as medical plasters. In this study, a bilayer polymer film comprising a drug reservoir layer and a supporting layer is fabricated by spin-coating poly(lactic-co-glycolic acid) (PLGA) on top of a layer-by-layer assembled film of poly(β-amino esters) (PAE), alginate sodium (ALG), and recombinant human basic fibroblast growth factor (bFGF). Apart from bFGF, the bilayer film can also load antibiotic drug ceftriaxone sodium (CTX) by a postdiffusion process. The PLGA supporting layer facilitates the direct peeling of the bilayer film from substrate to produce a robust and flexible free-standing film with excellent adhesion onto the human skin and porcine liver. The excellent adhesion of the bilayer film originates from the ALG component in the drug reservoir layer. CTX is quickly released by easily breaking its electrostatic interaction with the drug reservoir layer, whereas the sustained release of bFGF is due to the slow degradation of PAE component in the drug reservoir layer. Wounds can be synergetically treated by fast release of CTX to effectively eradicate invasive bacteria and by sustained release of bFGF to accelerate wound healing. Our results serve as a basis for designing multifunctional free-standing films with combination therapy for biomedical applications.

Mesospheric sodium over Gadanki during Geminid meteor shower 2007

NASA Astrophysics Data System (ADS)

Lokanadham, B.; Rakesh Chandra, N.; Bhaskara Rao, S. Vijaya; Raghunath, K.; Yellaiah, G.

Resonance LIDAR system at Gadanki has been used for observing the mesospheric sodium during the night of 12-13 Dec 2007 when the peak activity of Geminid meteor shower occurred. Geminid meteor shower is observed along with the co-located MST radar in the altitude range 80-110 km. Sodium density profiles have been obtained with a vertical resolution of 300 m and a temporal resolution of 120 s with sodium resonance scattering LIDAR system. The sodium layers were found to exist in the altitude range 90-100 km. The enhanced Geminid meteor rates were recorded with the co-located MST radar in the same altitude range. The sodium concentration in the atmospheric altitude of ~93 km is estimated to be 2000 per cc where the meteoric concentration of Geminid is maximum and reduced to around 800 on the non activity of Geminid. These observations showed that the sodium levels in the E-region are found to be increasing during meteor shower nights at least by a factor of two.

Comparison of reduction products from graphite oxide and graphene oxide for anode applications in lithium-ion batteries and sodium-ion batteries.

PubMed

Sun, Yige; Tang, Jie; Zhang, Kun; Yuan, Jinshi; Li, Jing; Zhu, Da-Ming; Ozawa, Kiyoshi; Qin, Lu-Chang

2017-02-16

Hydrazine-reduced graphite oxide and graphene oxide were synthesized to compare their performances as anode materials in lithium-ion batteries and sodium-ion batteries. Reduced graphite oxide inherits the layer structure of graphite, with an average spacing between neighboring layers (d-spacing) of 0.374 nm; this exceeds the d-spacing of graphite (0.335 nm). The larger d-spacing provides wider channels for transporting lithium ions and sodium ions in the material. We showed that reduced graphite oxide as an anode in lithium-ion batteries can reach a specific capacity of 917 mA h g -1 , which is about three times of 372 mA h g -1 , the value expected for the LiC 6 structures on the electrode. This increase is consistent with the wider d-spacing, which enhances lithium intercalation and de-intercalation on the electrodes. The electrochemical performance of the lithium-ion batteries and sodium-ion batteries with reduced graphite oxide anodes show a noticeable improvement compared to those with reduced graphene oxide anodes. This improvement indicates that reduced graphite oxide, with larger interlayer spacing, has fewer defects and is thus more stable. In summary, we found that reduced graphite oxide may be a more favorable form of graphene for the fabrication of electrodes for lithium-ion and sodium-ion batteries and other energy storage devices.

Layering, interface and edge effects in multi-layered composite medium

NASA Technical Reports Server (NTRS)

Datta, S. K.; Shah, A. H.; Karunesena, W.

1990-01-01

Guided waves in a cross-ply laminated plate are studied. Because of the complexity of the exact dispersion equation that governs the wave propagation in a multi-layered fiber-reinforced plate, a stiffness method that can be applied to any number of layers is presented. It is shown that, for a sufficiently large number of layers, the plate can be modeled as a homogeneous anisotropic plate. Also studied is the reflection of guided waves from the edge of a multilayered plate. These results are quite different than in the case of a single homogeneous plate.

Synthesis and electrochemical sodium-storage of few-layered MoS2/nitrogen, phosphorus-codoped graphene

NASA Astrophysics Data System (ADS)

Xu, Limei; Ma, Lin; Li, Wenyan; Yang, Xinxin; Ling, Yan

2018-07-01

Few-layered molybdenum disulfide/nitrogen, phosphorus co-doped graphene composites are synthesized by a quaternary phosphonium salt-assisted hydrothermal and annealing procedure. The prepared composites are analyzed by x-ray powder diffraction, x-ray photoelectron spectra, scanning electronic microscopy, transmission electronic microscopy, Raman spectra and nitrogen adsorption and desorption. Experimental results indicate that the MoS2 nanosheets are of few-layered and defective structures and are well anchored on flexible conductive nitrogen, phosphorus co-doped graphene to constitute mesoporous composites with increased surface areas. Benefiting from the structural merits as well as surface-dominated pseudocapacitive contribution, the composite electrode presents a high electrochemical sodium storage capacity that arrives at 542 mAh g‑1 at a current density of 100 mA g‑1 with an excellent cyclability. Moreover, a superior high-rate capability can also be achieved.

Alkali metal-refractory metal biphase electrode for AMTEC

NASA Technical Reports Server (NTRS)

Williams, Roger M. (Inventor); Bankston, Clyde P. (Inventor); Cole, Terry (Inventor); Khanna, Satish K. (Inventor); Jeffries-Nakamura, Barbara (Inventor); Wheeler, Bob L. (Inventor)

1989-01-01

An electrode having increased output with slower degradation is formed of a film applied to a beta-alumina solid electrolyte (BASE). The film comprises a refractory first metal M.sup.1 such as a platinum group metal, suitably platinum or rhodium, capable of forming a liquid or a strong surface adsorption phase with sodium at the operating temperature of an alkali metal thermoelectric converter (AMTEC) and a second refractory metal insoluble in sodium or the NaM.sup.1 liquid phase such as a Group IVB, VB or VIB metal, suitably tungsten, molybdenum, tantalum or niobium. The liquid phase or surface film provides fast transport through the electrode while the insoluble refractory metal provides a structural matrix for the electrode during operation. A trilayer structure that is stable and not subject to deadhesion comprises a first, thin layer of tungsten, an intermediate co-deposited layer of tungsten-platinum and a thin surface layer of platinum.

Synthesis and electrochemical sodium-storage of few-layered MoS2/nitrogen, phosphorus-codoped graphene.

PubMed

Xu, Limei; Ma, Lin; Li, Wenyan; Yang, Xinxin; Ling, Yan

2018-07-27

Few-layered molybdenum disulfide/nitrogen, phosphorus co-doped graphene composites are synthesized by a quaternary phosphonium salt-assisted hydrothermal and annealing procedure. The prepared composites are analyzed by x-ray powder diffraction, x-ray photoelectron spectra, scanning electronic microscopy, transmission electronic microscopy, Raman spectra and nitrogen adsorption and desorption. Experimental results indicate that the MoS 2 nanosheets are of few-layered and defective structures and are well anchored on flexible conductive nitrogen, phosphorus co-doped graphene to constitute mesoporous composites with increased surface areas. Benefiting from the structural merits as well as surface-dominated pseudocapacitive contribution, the composite electrode presents a high electrochemical sodium storage capacity that arrives at 542 mAh g -1 at a current density of 100 mA g -1 with an excellent cyclability. Moreover, a superior high-rate capability can also be achieved.

An Experiment to Study Sporadic Sodium Layers in the Earth's Mesosphere and Lower Thermosphere

NASA Technical Reports Server (NTRS)

Swenson, Charles M.

2002-01-01

The Utah State University / Space Dynamics Lab was funded under a NASA Grant. This investigation has been part of Rockwell Universities Sudden Atom Layer Investigation (SAL). USU/SDL provided an electron density measurement instrument, the plasma frequency probe, which was launched on the vehicle 21.117 from Puerto-Rico in February of 1998. The instrument successfully measured electron density as designed and measurement techniques included in this version of the Plasma Frequency probe provided valuable insight into the electron density structures associated with sudden sodium layers in a collisional plasma. Electron density data was furnished to Rockwell University but no science meetings were held by Rockwell Data from the instrument was presented to the scientific community at the URSI General Session in 1999. A paper is in preparation for publication in Geophysical Research Letters. The following document provides a summary of the experiment and data obtained as a final report on this grant.

Multilayer Films and Capsules of Sodium Carboxymethylcellulose and Polyhexamethylenguanidine Hydrochloride

NASA Astrophysics Data System (ADS)

Guzenko, Nataliia; Gabchak, Oleksandra; Pakhlov, Evgenij

The complexation of polyhexamethylenguanidine hydrochloride (PHMG) and sodium carboxymethylcellulose (CMC) was investigated for different conditions. Mixing of equiconcentrated aqueous solutions of the polyelectrolytes was found to result in the formation of an insoluble interpolyelectrolyte complex with an overweight of carboxymethylcellulose. A step-by-step formation of stable, irreversibly adsorbed multilayer film of the polymers was demonstrated using the quartz crystal microbalance method. Unusually thick polymer shells with a large number of loops and tails of the polyanion were formed by the method of layer-by-layer self-assembly of PHMG and CMC on spherical CaCO3 particles. Hollow multilayer capsules stable in neutral media were obtained by dissolution of the inorganic matrix in EDTA solution.

Steam based conversion coating on AA6060 alloy: Effect of sodium silicate chemistry and corrosion performance

NASA Astrophysics Data System (ADS)

Din, Rameez Ud; Bordo, Kirill; Tabrizian, Naja; Jellesen, Morten Stendahl; Ambat, Rajan

2017-11-01

Surface treatment of aluminium alloy AA6060 using an industrially applicable pilot steam jet system with and without silicate chemistry has been investigated. Treatment using steam alone and steam with silicate, resulted in an oxide layer formation with thickness ∼425 nm and ∼160 nm, respectively. Moreover, the use of sodium silicate resulted in the formation of distinct microstructure and incorporation of silicate into the oxide film. These oxide films reduced the anodic activity 4 times, while the corrosion protection by silicate containing oxide was the function of its concentration. Further, in acid salt spray and filiform corrosion tests, oxide layer containing silicate exhibited two times higher corrosion resistance.

Improved compensation of atmospheric turbulence effects by multiple adaptive mirror systems.

PubMed

Shamir, J; Crowe, D G; Beletic, J W

1993-08-20

Optical wave-front propagation in a layered model for the atmosphere is analyzed by the use of diffraction theory, leading to a novel approach for utilizing artificial guide stars. Considering recent observations of layering in the atmospheric turbulence, the results of this paper indicate that, even for very large telescopes, a substantial enlargement of the compensated angular field of view is possible when two adaptive mirrors and four or five artificial guide stars are employed. The required number of guide stars increases as the thickness of the turbulent layers increases, converging to the conventional results at the limit of continuously turbulent atmosphere.

Photosensitive adhesive bonding process of magnetooptic waveguides with Si guiding layer for optical nonreciprocal devices

NASA Astrophysics Data System (ADS)

Choowitsakunlert, Salinee; Takagiwa, Kenji; Kobashigawa, Takuya; Hosoya, Nariaki; Silapunt, Rardchawadee; Yokoi, Hideki

2018-05-01

A photosensitive adhesive bonding process for a magnetooptic waveguide for an optical isolator employing a nonreciprocal guided-radiation mode conversion is investigated at 1.55 µm. The magnetooptic waveguide is a straight rib type, and it is fabricated by bonding the Si guiding layer to a magnetic garnet. In the fabrication process, an adhesive material is diluted to obtain a certain thickness before depositing on a silicon-on-insulator (SOI) substrate. The relationship between the percent dilution ratio and the thickness of the adhesive layer is considered. The smallest gap thickness is found to be 0.66 µm at a dilution ratio of 2%.

Does endodontic post space irrigation affect smear layer removal and bonding effectiveness?

PubMed

Gu, Xin-Hua; Mao, Cai-Yun; Liang, Cong; Wang, Hui-Ming; Kern, Matthias

2009-10-01

The effect of different post space irrigants on smear layer removal and dentin bond strength was evaluated. Sixty-six extracted sound maxillary central incisors were endodontically treated. After post space preparation, the teeth were assigned to three groups of 22 teeth each. The teeth of these three groups were irrigated for 1 min with 17% ethylenediaminetetracetic acid (EDTA) (group 1), 5.25% sodium hypochlorite (NaOCl) (group 2), or 0.9% sodium chloride (NaCl) (group 3). In each group, eight specimens were split longitudinally for smear layer evaluation, and the other fourteen specimens were filled with a self-etching adhesive system (Panavia F). Four of 14 specimens of each group were prepared for evaluation of the resin-dentin interdiffusion zone (RDIZ) and resin tags, and the other 10 specimens were serially sectioned for push-out test analysis. Smear layer removal and bond strength were affected by different post space irrigants. EDTA removed the smear layer extremely effectively and, as a result, improved the bond strength at each region (apical, middle, and coronal) of the roots. Resin tag formation and the RDIZ were also affected by different irrigants and in accordance with bond strength. Therefore, removal of the smear layer use a self-etching luting system plays an important role in bonding effectiveness.

Concentration and time-dependent effect of initial sodium hypochlorite on the ability of QMix and ethylenediaminetetraacetic acid to remove smear layer.

PubMed

Aksel, Hacer; Serper, Ahmet

2017-01-01

The aim of this study was to compare the ability of 17% ethylenediaminetetraacetic acid (EDTA) and QMix with different concentrations and time exposures of initial sodium hypochlorite (NaOCl) to remove the smear layer from the root canals. Eighty maxillary central incisors were used. After instrumentation, the teeth were divided into eight experimental groups according to the initial and final rinse. About 2.5% and 5% NaOCl were used during instrumentation and for 1 or 3 min was used as postinstrumentation initial irrigants, and 17% EDTA and QMix used as final irrigants. The apical and middle parts of the specimens were observed by scanning electron microscope. Data were analyzed using the Kruskal-Wallis, Mann-Whitney, and Friedman's test. Regardless of the type of final irrigant, QMix allowed more smear layer removal than EDTA after using 5% initial NaOCl for 3 min. In the apical part of the root canal walls, the smear layer was not completely removed. QMix and EDTA were similarly effective in smear layer removal at the middle parts of the root canal regardless of the concentration and time exposure of initial NaOCl, while none of the irrigation protocols was able to remove smear layer at the apical parts.

Comparison of mesospheric sodium layers at different latitudes

NASA Astrophysics Data System (ADS)

Liu, Yingjie

With the support of the Chinese Meridional project in the eastern hemisphere, two brand new sodium fluorescence lidars with the same configuration were respectively set up at Yanqing (40.46(°) N, 115.98(°) E) and Haikou (20.04(°) N, 110.34(°) E) in April, 2010. Based on the observations obtained from 2010 to 2012, comparison of the Na layer at these two latitudes was performed. It reveals a strong correlation in the topside layer between these two sites. Independently of their seasonal characteristics at lower altitudes, they both show an extension to 120 km and above, predominantly during summer. Simultaneous observations at these two sites show that the correlation above 102 km is remarkable in contrast to their different seasonal characteristics below 98 km. It indicates that different processes dominate different height ranges in the Na layer. Meanwhile, it indicates that the topside extension effect is global, combined with the observations at other latitudes. Besides, when the topside layer has an extension, the bottom side layer extends slightly downward, too. Comparison with known meteor showers shows that most of these extensions correspond well to one or more meteor showers, although not one by one. Meteor showers with velocities less than 35 km/s appear to have more influence on these extensions.

Sporadic and thermospheric enhanced sodium layers observed by a lidar chain over China

NASA Astrophysics Data System (ADS)

Dou, X. K.; Qiu, S. C.; Xue, X. H.; Chen, T. D.; Ning, B. Q.

2013-10-01

We report the statistical features of sporadic sodium layers (SSLs) and the thermospheric enhanced sodium layers (TeSLs) observed by a lidar chain located at Beijing (40.2°N, 116.2°E), Hefei (31.8°N, 117.3°E), Wuhan (30.5°N, 114.4°E), and Haikou (19.5°N, 109.1°E). The average SSL occurrence rate was approximately 46.0, 12.3, 13.8, and 15.0 h per SSL at Beijing, Hefei, Wuhan, and Haikou, respectively. However, the TeSLs occurred relatively infrequently and were more likely to appear at low and high latitudinal sites. Both the SSLs and TeSLs at four lidar sites showed evident summer enhancements and correlated well with Es (foEs>4 MHz). The coobservations of SSLs at three lidar site pairs, i.e., Hefei-Beijing, Hefei-Wuhan, and Hefei-Beijing, indicated that a large-scale SSL extended horizontally for at least a few hundred kilometers and exhibited a tidal-induced modulation. Moreover, the SSLs were better correlated for the Hefei-Wuhan and Hefei-Haikou pairs than the Hefei-Beijing pair, which suggested a difference in the dynamical/chemical process in mesosphere and lower thermosphere (MLT) between the Beijing site and the other sites.

Sporadic and Thermospheric Enhanced Sodium Layers Observed by a Lidar Chain over China

NASA Astrophysics Data System (ADS)

Xue, X.

2013-12-01

We report the statistical features of sporadic sodium layers (SSLs) and the thermospheric enhanced sodium layers (TeSLs) observed by a lidar chain located at Beijing (40.2N,116.2E), Hefei (31.8N, 117.3E), Wuhan (30.5N, 114.4E), and Haikou (19.5N, 109.1E). The average SSL occurrence rate was approximately 46.0, 12.3, 13.8, and 15.0 hr per SSL at Beijing, Hefei, Wuhan, and Haikou, respectively. However, the TeSLs occurred relatively infrequently and were more likely to appear at low and high latitudinal sites. Both the SSLs and TeSLs at four lidar sites showed evident summer enhancements and correlated well with Es (foEs>4MHz). The co-observations of SSLs at three lidar site pairs, i.e., Hefei -- Beijing, Hefei -- Wuhan and Hefei -- Beijing, indicated that a large-scale SSL extended horizontally for at least a few hundred kilometers and exhibited a tidal-induced modulation. Moreover, the SSLs were better correlated for the Hefei -- Wuhan and Hefei -- Haikou pairs than the Hefei -- Beijing pair, which suggested a difference in the dynamical/chemical process in mesosphere and lower thermosphere (MLT) between the Beijing site and the other sites.

An O3-type Oxide with Low Sodium Content as the Phase-Transition-Free Anode for Sodium-Ion Batteries.

PubMed

Zhao, Chenglong; Avdeev, Maxim; Chen, Liquan; Hu, Yong-Sheng

2018-06-11

Layered transition metal oxides Na x MO 2 (M=transition metal) with P2 or O3 structure have attracted attention in sodium-ion batteries (NIBs). A universal law is found to distinguish structural competition between P2 and O3 types based on the ratio of interlayer distances of the alkali metal layer d (O-Na-O) and transition-metal layer d (O-M-O) . The ratio of about 1.62 can be used as an indicator. O3-type Na 0.66 Mg 0.34 Ti 0.66 O 2 oxide is prepared as a stable anode for NIBs, in which the low Na-content (ca. 0.66) usually undergoes a P2-type structure with respect to Na x MO 2 . This material delivers an available capacity of about 98 mAh g -1 within a voltage range of 0.4-2.0 V and exhibits a better cycling stability (ca. 94.2 % of capacity retention after 128 cycles). In situ X-ray diffraction reveals a single-phase reaction in the discharge-charge process, which is different from the common phase transitions reported in O3-type electrodes, ensuring long-term cycling stability. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tunnel-structured K xTiO 2 nanorods by in situ carbothermal reduction as a long cycle and high rate anode for sodium-ion batteries

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

Zhang, Qing; Wei, Yaqing; Yang, Haotian

Here, the low electronic conductivity and the sluggish sodium-ion diffusion in the compact crystal structure of Ti-based anodes seriously restrict their development in sodium-ion batteries. In this study, a new hollandite K xTiO 2 with large (2 × 2) tunnels is synthesized by a facile carbothermal reduction method, and its sodium storage performance is investigated. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses illustrate the formation mechanism of the hollandite K xTiO 2 upon the carbothermal reduction process. Compared to the traditional layered or small (1 × 1) tunnel-type Ti-based materials, the hollandite K xTiO 2 with large (2more » × 2) tunnels may accommodate more sodium ions and facilitate the Na + diffusion in the structure; thus, it is expected to get a large capacity and realize high rate capability. The synthesized K xTiO 2 with large (2 × 2) tunnels shows a stable reversible capacity of 131 mAh g –1 (nearly 3 times of (1 × 1) tunnel-structured Na 2Ti 6O 13) and superior cycling stability with no obvious capacity decay even after 1000 cycles, which is significantly better than the traditional layered Na 2Ti 3O 7 (only 40% of capacity retention in 20 cycles). Moreover, the carbothermal process can naturally introduce oxygen vacancy and low-valent titanium as well as the surface carbon coating layer to the structure, which would greatly enhance the electronic conductivity of K xTiO 2 and thus endow this material high rate capability. With a good rate capability and long cyclability, this hollandite K xTiO 2 can serve as a new promising anode material for room-temperature long-life sodium-ion batteries for large-scale energy storage systems, and the carbothermal reduction method is believed to be an effective and facile way to develop novel Ti-based anodes with simultaneous carbon coating and Ti(III) self-doping.« less

Tunnel-structured K xTiO 2 nanorods by in situ carbothermal reduction as a long cycle and high rate anode for sodium-ion batteries

DOE PAGES

Zhang, Qing; Wei, Yaqing; Yang, Haotian; ...

2017-02-03

Here, the low electronic conductivity and the sluggish sodium-ion diffusion in the compact crystal structure of Ti-based anodes seriously restrict their development in sodium-ion batteries. In this study, a new hollandite K xTiO 2 with large (2 × 2) tunnels is synthesized by a facile carbothermal reduction method, and its sodium storage performance is investigated. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses illustrate the formation mechanism of the hollandite K xTiO 2 upon the carbothermal reduction process. Compared to the traditional layered or small (1 × 1) tunnel-type Ti-based materials, the hollandite K xTiO 2 with large (2more » × 2) tunnels may accommodate more sodium ions and facilitate the Na + diffusion in the structure; thus, it is expected to get a large capacity and realize high rate capability. The synthesized K xTiO 2 with large (2 × 2) tunnels shows a stable reversible capacity of 131 mAh g –1 (nearly 3 times of (1 × 1) tunnel-structured Na 2Ti 6O 13) and superior cycling stability with no obvious capacity decay even after 1000 cycles, which is significantly better than the traditional layered Na 2Ti 3O 7 (only 40% of capacity retention in 20 cycles). Moreover, the carbothermal process can naturally introduce oxygen vacancy and low-valent titanium as well as the surface carbon coating layer to the structure, which would greatly enhance the electronic conductivity of K xTiO 2 and thus endow this material high rate capability. With a good rate capability and long cyclability, this hollandite K xTiO 2 can serve as a new promising anode material for room-temperature long-life sodium-ion batteries for large-scale energy storage systems, and the carbothermal reduction method is believed to be an effective and facile way to develop novel Ti-based anodes with simultaneous carbon coating and Ti(III) self-doping.« less

Tunnel-Structured KxTiO2 Nanorods by in Situ Carbothermal Reduction as a Long Cycle and High Rate Anode for Sodium-Ion Batteries.

PubMed

Zhang, Qing; Wei, Yaqing; Yang, Haotian; Su, Dong; Ma, Ying; Li, Huiqiao; Zhai, Tianyou

2017-03-01

The low electronic conductivity and the sluggish sodium-ion diffusion in the compact crystal structure of Ti-based anodes seriously restrict their development in sodium-ion batteries. In this study, a new hollandite K x TiO 2 with large (2 × 2) tunnels is synthesized by a facile carbothermal reduction method, and its sodium storage performance is investigated. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses illustrate the formation mechanism of the hollandite K x TiO 2 upon the carbothermal reduction process. Compared to the traditional layered or small (1 × 1) tunnel-type Ti-based materials, the hollandite K x TiO 2 with large (2 × 2) tunnels may accommodate more sodium ions and facilitate the Na + diffusion in the structure; thus, it is expected to get a large capacity and realize high rate capability. The synthesized K x TiO 2 with large (2 × 2) tunnels shows a stable reversible capacity of 131 mAh g -1 (nearly 3 times of (1 × 1) tunnel-structured Na 2 Ti 6 O 13 ) and superior cycling stability with no obvious capacity decay even after 1000 cycles, which is significantly better than the traditional layered Na 2 Ti 3 O 7 (only 40% of capacity retention in 20 cycles). Moreover, the carbothermal process can naturally introduce oxygen vacancy and low-valent titanium as well as the surface carbon coating layer to the structure, which would greatly enhance the electronic conductivity of K x TiO 2 and thus endow this material high rate capability. With a good rate capability and long cyclability, this hollandite K x TiO 2 can serve as a new promising anode material for room-temperature long-life sodium-ion batteries for large-scale energy storage systems, and the carbothermal reduction method is believed to be an effective and facile way to develop novel Ti-based anodes with simultaneous carbon coating and Ti(III) self-doping.

Summary of the Madison Dynamo Experiment

NASA Astrophysics Data System (ADS)

Kendrick, R. D.; Spence, E. J.; Nornberg, M. D.; Forest, C. B.

2001-10-01

A spherical dynamo experiment has been constructed at the University of Wisconsin's liquid sodium facility. The goals of the experiment are to observe and understand magnetic instabilities driven by flow shear in MHD systems, investigate MHD turbulence for magnetic Reynolds numbers of ~100, and understand the role of fluid turbulence in current generation. Magnetic field generation is possible for only specific flow geometries. We have studied and achieved simple roll flow geometries in a full scale water experiment. Results from this experiment have guided the design of the sodium experiment. The experiment consists of a 1 m diameter, spherical stainless steel vessel filled with liquid sodium at 110 Celsius. Two 100 Hp motors with impellers drive flows in the liquid sodium with flow velocities ~ 15 m/s. A gaussian grid of Hall probes on the surface of the sodium vessel measure the generated external magnetic field. Hall probe feed-thru arrays measure the internal field. Preliminary investigations include measurements of the turbulent electromotive force and excitation of magnetic eigenmodes.

Design of the Madison Dynamo Experiment

NASA Astrophysics Data System (ADS)

Kendrick, R. D.; Bayliss, R. A.; Forest, C. B.; Nornberg, M. D.; O'Connell, R.; Spence, E. J.

2003-10-01

A spherical dynamo experiment has been constructed at the University of Wisconsin's liquid sodium facility. The goals of the experiment are to observe and understand magnetic instabilities driven by flow shear in MHD systems, investigate MHD turbulence for magnetic Reynolds numbers of ˜100, and understand the role of fluid turbulence in current generation. Magnetic field generation is possible for only specific flow geometries. We have studied and achieved simple roll flow geometries in a full scale water experiment. Results from this experiment have guided the design of the sodium experiment. The experiment consists of a 1 m diameter, spherical stainless steel vessel filled with liquid sodium at 110 Celsius. Two 100 Hp motors with impellers drive flows in the liquid sodium with flow velocities ˜ 15 m/s. A grid of Hall probes on the surface of the sodium vessel measure the generated external magnetic field. Hall probe feed-thru arrays measure the internal field. Preliminary investigations include measurements of the turbulent electromotive force and excitation of magnetic eigenmodes.

Innovation in Layer-by-Layer Assembly.

PubMed

Richardson, Joseph J; Cui, Jiwei; Björnmalm, Mattias; Braunger, Julia A; Ejima, Hirotaka; Caruso, Frank

2016-12-14

Methods for depositing thin films are important in generating functional materials for diverse applications in a wide variety of fields. Over the last half-century, the layer-by-layer assembly of nanoscale films has received intense and growing interest. This has been fueled by innovation in the available materials and assembly technologies, as well as the film-characterization techniques. In this Review, we explore, discuss, and detail innovation in layer-by-layer assembly in terms of past and present developments, and we highlight how these might guide future advances. A particular focus is on conventional and early developments that have only recently regained interest in the layer-by-layer assembly field. We then review unconventional assemblies and approaches that have been gaining popularity, which include inorganic/organic hybrid materials, cells and tissues, and the use of stereocomplexation, patterning, and dip-pen lithography, to name a few. A relatively recent development is the use of layer-by-layer assembly materials and techniques to assemble films in a single continuous step. We name this "quasi"-layer-by-layer assembly and discuss the impacts and innovations surrounding this approach. Finally, the application of characterization methods to monitor and evaluate layer-by-layer assembly is discussed, as innovation in this area is often overlooked but is essential for development of the field. While we intend for this Review to be easily accessible and act as a guide to researchers new to layer-by-layer assembly, we also believe it will provide insight to current researchers in the field and help guide future developments and innovation.

Utilizing Co 2+/Co 3+ Redox Couple in P2-Layered Na 0.66Co 0.22Mn 0.44Ti 0.34O 2 Cathode for Sodium-Ion Batteries

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

Wang, Qin-Chao; Hu, Enyuan; Pan, Yang

Developing sodium-ion batteries for large-scale energy storage applications is facing big challenges of the lack of high-performance cathode materials. Here, a series of new cathode materials Na 0.66Co xMn 0.66–xTi 0.34O 2 for sodium-ion batteries are designed and synthesized aiming to reduce transition metal-ion ordering, charge ordering, as well as Na+ and vacancy ordering. An interesting structure change of Na 0.66Co xMn 0.66–xTi 0.34O 2 from orthorhombic to hexagonal is revealed when Co content increases from x = 0 to 0.33. In particular, Na 0.66Co 0.22Mn 0.44Ti 0.34O 2 with a P2-type layered structure delivers a reversible capacity of 120more » mAh g -1 at 0.1 C. When the current density increases to 10 C, a reversible capacity of 63.2 mAh g -1 can still be obtained, indicating a promising rate capability. The low valence Co 2+ substitution results in the formation of average Mn 3.7+ valence state in Na 0.66Co 0.22Mn 0.44Ti 0.34O 2, effectively suppressing the Mn3+-induced Jahn–Teller distortion, and in turn stabilizing the layered structure. X-ray absorption spectroscopy results suggest that the charge compensation of Na 0.66Co 0.22Mn 0.44Ti 0.34O 2 during charge/discharge is contributed by Co 2.2+/Co 3+ and Mn 3.3+/Mn 4+ redox couples. This is the first time that the highly reversible Co 2+/Co 3+ redox couple is observed in P2-layered cathodes for sodium-ion batteries. This finding may open new approaches to design advanced intercalation-type cathode materials.« less

Utilizing Co 2+/Co 3+ Redox Couple in P2-Layered Na 0.66Co 0.22Mn 0.44Ti 0.34O 2 Cathode for Sodium-Ion Batteries

DOE PAGES

Wang, Qin-Chao; Hu, Enyuan; Pan, Yang; ...

2017-07-06

Developing sodium-ion batteries for large-scale energy storage applications is facing big challenges of the lack of high-performance cathode materials. Here, a series of new cathode materials Na 0.66Co xMn 0.66–xTi 0.34O 2 for sodium-ion batteries are designed and synthesized aiming to reduce transition metal-ion ordering, charge ordering, as well as Na+ and vacancy ordering. An interesting structure change of Na 0.66Co xMn 0.66–xTi 0.34O 2 from orthorhombic to hexagonal is revealed when Co content increases from x = 0 to 0.33. In particular, Na 0.66Co 0.22Mn 0.44Ti 0.34O 2 with a P2-type layered structure delivers a reversible capacity of 120more » mAh g -1 at 0.1 C. When the current density increases to 10 C, a reversible capacity of 63.2 mAh g -1 can still be obtained, indicating a promising rate capability. The low valence Co 2+ substitution results in the formation of average Mn 3.7+ valence state in Na 0.66Co 0.22Mn 0.44Ti 0.34O 2, effectively suppressing the Mn3+-induced Jahn–Teller distortion, and in turn stabilizing the layered structure. X-ray absorption spectroscopy results suggest that the charge compensation of Na 0.66Co 0.22Mn 0.44Ti 0.34O 2 during charge/discharge is contributed by Co 2.2+/Co 3+ and Mn 3.3+/Mn 4+ redox couples. This is the first time that the highly reversible Co 2+/Co 3+ redox couple is observed in P2-layered cathodes for sodium-ion batteries. This finding may open new approaches to design advanced intercalation-type cathode materials.« less

Utilizing Co2+/Co3+ Redox Couple in P2-Layered Na0.66Co0.22Mn0.44Ti0.34O2 Cathode for Sodium-Ion Batteries.

PubMed

Wang, Qin-Chao; Hu, Enyuan; Pan, Yang; Xiao, Na; Hong, Fan; Fu, Zheng-Wen; Wu, Xiao-Jing; Bak, Seong-Min; Yang, Xiao-Qing; Zhou, Yong-Ning

2017-11-01

Developing sodium-ion batteries for large-scale energy storage applications is facing big challenges of the lack of high-performance cathode materials. Here, a series of new cathode materials Na 0.66 Co x Mn 0.66- x Ti 0.34 O 2 for sodium-ion batteries are designed and synthesized aiming to reduce transition metal-ion ordering, charge ordering, as well as Na + and vacancy ordering. An interesting structure change of Na 0.66 Co x Mn 0.66- x Ti 0.34 O 2 from orthorhombic to hexagonal is revealed when Co content increases from x = 0 to 0.33. In particular, Na 0.66 Co 0.22 Mn 0.44 Ti 0.34 O 2 with a P2-type layered structure delivers a reversible capacity of 120 mAh g -1 at 0.1 C. When the current density increases to 10 C, a reversible capacity of 63.2 mAh g -1 can still be obtained, indicating a promising rate capability. The low valence Co 2+ substitution results in the formation of average Mn 3.7+ valence state in Na 0.66 Co 0.22 Mn 0.44 Ti 0.34 O 2 , effectively suppressing the Mn 3+ -induced Jahn-Teller distortion, and in turn stabilizing the layered structure. X-ray absorption spectroscopy results suggest that the charge compensation of Na 0.66 Co 0.22 Mn 0.44 Ti 0.34 O 2 during charge/discharge is contributed by Co 2.2+ /Co 3+ and Mn 3.3+ /Mn 4+ redox couples. This is the first time that the highly reversible Co 2+ /Co 3+ redox couple is observed in P2-layered cathodes for sodium-ion batteries. This finding may open new approaches to design advanced intercalation-type cathode materials.

A complex guided spectral transform Lanczos method for studying quantum resonance states

DOE PAGES

Yu, Hua-Gen

2014-12-28

A complex guided spectral transform Lanczos (cGSTL) algorithm is proposed to compute both bound and resonance states including energies, widths and wavefunctions. The algorithm comprises of two layers of complex-symmetric Lanczos iterations. A short inner layer iteration produces a set of complex formally orthogonal Lanczos (cFOL) polynomials. They are used to span the guided spectral transform function determined by a retarded Green operator. An outer layer iteration is then carried out with the transform function to compute the eigen-pairs of the system. The guided spectral transform function is designed to have the same wavefunctions as the eigenstates of the originalmore » Hamiltonian in the spectral range of interest. Therefore the energies and/or widths of bound or resonance states can be easily computed with their wavefunctions or by using a root-searching method from the guided spectral transform surface. The new cGSTL algorithm is applied to bound and resonance states of HO₂, and compared to previous calculations.« less

Gateways to Clinical Trials.

PubMed

Bayés, M; Rabasseda, X; Prous, J R

2002-09-01

Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables has been retrieved from the Clinical Studies knowledge area of Prous Science Integrity, the drug discovery and development portal, http://integrity.prous.com. This issue focuses on the following selection of drugs: Adalimumab, aeroDose insulin inhaler, agomelatine, alendronic acid sodium salt, aliskiren fumarate, alteplase, amlodipine, aspirin, atazanavir; Bacillus Calmette-Guérin, basiliximab, BQ-788, bupropion hydrochloride; Cabergoline, caffeine citrate, carbamazepine, carvedilol, celecoxib, cyclosporine, clopidogrel hydrogensulfate, colestyramine; Dexamethasone, diclofenac sodium, digoxin, dipyridamole, docetaxel, dutasteride; Eletriptan, enfuvirtidie, eplerenone, ergotamine tartrate, esomeprazole magnesium, estramustine phosphate sodium; Finasteride, fluticasone propionate, fosinopril sodium; Ganciclovir, GBE-761-ONC, glatiramer acetate, gliclazide, granulocyte-CSF; Heparin sodium, human isophane insulin (pyr), Hydrochlorothiazide; Ibuprofen, inhaled insulin, interferon alfa, interferon beta-1a; Laminvudine, lansoprazole, lisinopril, lonafarnib, losartan potassium, lumiracoxib; MAb G250, meloxicam methotrexate, methylprednisolone aceponate, mitomycin, mycophenolate mofetil; Naproxen sodium, natalizumab, nelfinavir mesilate, nemifitide ditriflutate, nimesulide; Omalizumab, omapatrilat, omeprazole, oxybutynin chloride; Pantoprazole sodium, paracetamol, paroxetine, pentoxifylline, pergolide mesylate, permixon, phVEGF-A165, pramipexole hydrochloride, prasterone, prednisone, probucol, propiverine hydrochloride; Rabeprazole sodium, resiniferatoxin, risedronate sodium, risperidone, rofecoxib rosiglitazone maleate, ruboxistaurin mesilate hydrate; Selegiline transdermal system, sertraline, sildenafil citrate, streptokinase; Tadalafil, tamsulosin hydrochloride, technosphere/Insulin, tegaserod maleate, tenofovir disoproxil fumarate, testosterone heptanoate, testosterone undecanoate, tipifarnib, tolterodine tartrate, topiramate, troglitazone; Ursodeoxycholic acid; Valdecoxib, valsartan, vardenafil, venlafaxine hydrochloride, VX-745.

Dietary sodium, added salt, and serum sodium associations with growth and depression in the U.S. general population.

PubMed

Goldstein, Pavel; Leshem, Micah

2014-08-01

It is not known why salt is so attractive to humans. Here, guided by hypotheses suggesting that the attraction of salt is conditioned by postingestive benefits, we sought to establish whether there are such benefits in a population by analyzing the National Health and Nutrition Examination Survey (NHANES) 2007-2008 database (n = ~ 10,000). We focus on two potential benefits supported by the literature, growth and moderation of depression, and examine their relationship to sodium, dietary, added at table, and serum. We find that during growth (<18 years), there is a specific increase in adjusted dietary sodium intake, independent of caloric or other electrolyte intakes. We find that adding salt and depression are related. In contrast, and in women only, dietary sodium and depression are inversely related. The relationships are correlational, but we speculate that this constellation may reflect self-medication for depression by adding salt, and that men may be protected by their higher dietary sodium intake. Additional findings are that women add more salt than men below age ~30, after which men add more, and below 40 years of age, serum sodium is lower in women than in men. It remains possible that small but beneficial effects of sodium could condition salt preference and thus contribute to population-wide sodium intake. Copyright © 2014 Elsevier Ltd. All rights reserved.

Intumescent all-polymer multilayer nanocoating capable of extinguishing flame on fabric

USDA-ARS?s Scientific Manuscript database

Cotton fabric was treated with flame-retardant coatings composed of poly (sodium phosphate), PSP, which acts as the acid source, and poly (allylamine), PAAm, which is used as the blowing agent, prepared via layer-by-layer (LbL) assembly. By applying these thin coating on fabric, after-glow is elimi...

Optical coupler

DOEpatents

Majewski, Stanislaw; Weisenberger, Andrew G.

2004-06-15

In a camera or similar radiation sensitive device comprising a pixilated scintillation layer, a light guide and an array of position sensitive photomultiplier tubes, wherein there exists so-called dead space between adjacent photomultiplier tubes the improvement comprising a two part light guide comprising a first planar light spreading layer or portion having a first surface that addresses the scintillation layer and optically coupled thereto at a second surface that addresses the photomultiplier tubes, a second layer or portion comprising an array of trapezoidal light collectors defining gaps that span said dead space and are individually optically coupled to individual position sensitive photomultiplier tubes. According to a preferred embodiment, coupling of the trapezoidal light collectors to the position sensitive photomultiplier tubes is accomplished using an optical grease having about the same refractive index as the material of construction of the two part light guide.

Diet and Nutrition

MedlinePlus

... 05-04T19:35:54+00:00 DIET AND NUTRITION Just as diet and nutrition were concerns before your PH diagnosis, pulmonary hypertension ... Guide for a complete overview of diet and nutrition. Controlling Salt and Sodium Consumption Monitoring Your Fluid ...

An adaptive optics package designed for astronomical use with a laser guide star tuned to an absorption line of atomic sodium

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

Salmon, J.T.; Avicola, K.; Brase, J.M.

1994-04-11

We present the design and implementation of a very compact adaptive optic system that senses the return light from a sodium guide-star and controls a deformable mirror and a pointing mirror to compensate atmospheric perturbations in the wavefront. The deformable mirror has 19 electrostrictive actuators and triangular subapertures. The wavefront sensor is a Hartmann sensor with lenslets on triangular centers. The high-bandwidth steering mirror assembly incorporates an analog controller that samples the tilt with an avalanche photodiode quad cell. An {line_integral}/25 imaging leg focuses the light into a science camera that can either obtain long-exposure images or speckle data. Inmore » laboratory tests overall Strehl ratios were improved by a factor of 3 when a mylar sheet was used as an aberrator. The crossover frequency at unity gain is 30 Hz.« less

All-Solid-State Sodium-Selective Electrode with a Solid Contact of Chitosan/Prussian Blue Nanocomposite

PubMed Central

Ghosh, Tanushree; Rieger, Jana

2017-01-01

Conventional ion-selective electrodes with a liquid junction have the disadvantage of potential drift. All-solid-state ion-selective electrodes with solid contact in between the metal electrode and the ion-selective membrane offer high capacitance or conductance to enhance potential stability. Solution-casted chitosan/Prussian blue nanocomposite (ChPBN) was employed as the solid contact layer for an all-solid-state sodium ion-selective electrode in a potentiometric sodium ion sensor. Morphological and chemical analyses confirmed that the ChPBN is a macroporous network of chitosan that contains abundant Prussian blue nanoparticles. Situated between a screen-printed carbon electrode and a sodium-ionophore-filled polyvinylchloride ion-selective membrane, the ChPBN layer exhibited high redox capacitance and fast charge transfer capability, which significantly enhanced the performance of the sodium ion-selective electrode. A good Nernstian response with a slope of 52.4 mV/decade in the linear range from 10−4–1 M of NaCl was observed. The stability of the electrical potential of the new solid contact was tested by chronopotentiometry, and the capacitance of the electrode was 154 ± 4 µF. The response stability in terms of potential drift was excellent (1.3 µV/h) for 20 h of continuous measurement. The ChPBN proved to be an efficient solid contact to enhance the potential stability of the all-solid-state ion-selective electrode. PMID:29099804

[Accidental injection sodium hypochlorite during endodontic therapy. Better understand to better manage].

PubMed

Ben Rejeb, H; Douki, N

2015-09-01

The high frequency of iatrogenic incidents during endodontic treatment is a source of stress for the practitioner. These incidents may occur during the different steps of a root canal treatment. During irrigation, extrusion of sodium hypochlorite beyond the apex is a rare but impressive accident. Sodium hypochlorite, is the most common irrigant used in modern endodontics, but when it comes in contact with the periapical tissue, it can cause complications ranging from mild discomfort to serious tissue damage such as the hematoma and hemato-emphysema. The aims of this article are to discuss through the presentation of two clinical cases: Etiological and predisposing factors; Signs guiding to suspicion of accidental injection of sodium hypochlorite. In this work, we focused on clinical keys that help the practitioner in better understanding this accident in order to prevent it or to manage it well when it occurs.

Biochemical Effects of Cadmium Exposure and the Potential Pharmacologic Significance of Cadmium Mediated Hydrolase Inhibition

DTIC Science & Technology

1997-04-18

DNA polymerase Alcohol dehydrogenase Hexokinase Glucose-6- phosphatase Arginase Pyruvate kinase (also requires Mg2•) Urease Nitrate...cyclohexane. The layers are separated by centrifugation (5 min at 1000 x g), the top organic layer is removed and dried with anhydrous sodium sulfate...An aliquot of the dried organic layer is transferred to a clean tube and evaporated under a gentle stream of nitrogen at room temperature

Barbiturates Block Sodium and Potassium Conductance Increases in Voltage-Clamped Lobster Axons

PubMed Central

Blaustein, M. P.

1968-01-01

Sodium pentobarbital and sodium thiopental decrease both the peak initial (Na) and late steady-state (K) currents and reduce the maximum sodium and potassium conductance increases in voltage-clamped lobster giant axons. These barbiturates also slow the rate at which the sodium conductance turns on, and shift the normalized sodium conductance vs. voltage curves in the direction of depolarization along the voltage axis. Since pentobarbital (pKa = 8.0) blocks the action potential more effectively at pH 8.5 than at pH 6.7, the anionic form of the drug appears to be active. The data suggest that these drugs affect the axon membrane directly, rather than secondarily through effects on intermediary metabolism. It is suggested that penetration of the lipid layer of the membrane by the nonpolar portion of the barbiturate molecules may cause the decrease in membrane conductances, while electrostatic interactions involving the anionic group on the barbiturate, divalent cations, and "fixed charges" in the membrane could account for the slowing of the rate of sodium conductance turn-on and the shift of the normalized conductance curves along the voltage axis. PMID:5648829

Sodium ion transport mechanisms in antiperovskite electrolytes Na 3OBr and Na 4OI 2: An in Situ neutron diffraction study

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

Zhu, Jinlong; Wang, Yonggang; Li, Shuai

Na-rich antiperovskites are recently developed solid electrolytes with enhanced sodium ionic conductivity and show promising functionality as a novel solid electrolyte in an all solid-stat battery. In this work, the sodium ionic transport pathways of the parent compound Na 3OBr, as well as the modified layered antiperovskite Na 4OI 2, were studied and compared through temperature dependent neutron diffraction combined with the maximum entropy method. In the cubic Na 3OBr antiperovskite, the nuclear density distribution maps at 500 K indicate that sodium ions ho within and among oxygen octahedra, and Br - ions are not involved in the tetragonal Namore » 4OI 2 antiperovskite, Na ions, which connect octahedra in the ab plane, have the lowest activation energy barrier. In conclusion, the transport of sodium ions along the c axis is assisted by I - ions.« less

Chemically Bonded Phosphorus/Graphene Hybrid as a High Performance Anode for Sodium-Ion Batteries

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

Song, Jiangxuan; Yu, Zhaoxin; Gordin, Mikhail

2014-11-12

Room temperature sodium-ion batteries are of great interest for high-energy-density energy storage systems because of low-cost, natural abundance of sodium. Here, we report a novel graphene nanosheets-wrapped phosphorus composite as an anode for high performance sodium-ion batteries though a facile ball-milling of red phosphorus and graphene nanosheets. Not only can the graphene nanosheets significantly improve the electrical conductivity, but they also serve as a buffer layer to accommodate the large volume change of phosphorus in the charge-discharge process. As a result, the graphene wrapped phosphorus composite anode delivers a high reversible capacity of 2077 mAh/g with excellent cycling stability (1700more » mAh/g after 60 cycles) and high Coulombic efficiency (>98%). This simple synthesis approach and unique nanostructure can potentially extend to other electrode materials with unstable solid electrolyte interphases in sodium-ion batteries.« less

Cover-gas seal program. Test report - sodium dip-seal wetting study. [at 450/sup 0/F

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

Carnevali, R.

1977-10-20

This report documents the tests conducted to find a reliable surface preparation method of treating the CRBRP dip seal blade (SA508 Class 2 steel) to insure its sodium wettability at 450F or less. Two techniques were established which depressed the sodium wetting temperature of SA 508, Class 2 dip seal blade material to 375F. These techniques were depositing an approx. 60 x 10/sup -6/ inch layer of tin on the blade surface by a brush-on plating process, and, by cleaning the blade surface with ultrasonics while it is immersed in sodium. The tin plating technique is recommended as the initialmore » and primary surface preparation method and ultrasonics as a rewetting and backup technique. This work was conducted in support of the Sodium Dip Seal Feature Test, DRS 32.05.« less

Sodium ion transport mechanisms in antiperovskite electrolytes Na 3OBr and Na 4OI 2: An in Situ neutron diffraction study

DOE PAGES

Zhu, Jinlong; Wang, Yonggang; Li, Shuai; ...

2016-06-02

Na-rich antiperovskites are recently developed solid electrolytes with enhanced sodium ionic conductivity and show promising functionality as a novel solid electrolyte in an all solid-stat battery. In this work, the sodium ionic transport pathways of the parent compound Na 3OBr, as well as the modified layered antiperovskite Na 4OI 2, were studied and compared through temperature dependent neutron diffraction combined with the maximum entropy method. In the cubic Na 3OBr antiperovskite, the nuclear density distribution maps at 500 K indicate that sodium ions ho within and among oxygen octahedra, and Br - ions are not involved in the tetragonal Namore » 4OI 2 antiperovskite, Na ions, which connect octahedra in the ab plane, have the lowest activation energy barrier. In conclusion, the transport of sodium ions along the c axis is assisted by I - ions.« less

The Statitical and Case studies of the Thermospheric Enhanced Sodium Layers (TeSLs)

NASA Astrophysics Data System (ADS)

Xue, X.; Li, G.; She, C. Y.; Dou, X.

2015-12-01

We report the thermospheric enhanced sodium layers (TeSLs) observed at low and middle latitude region. Based on the statistical results of the TeSLs observed at Hainan, China (20.0N), a low latitude region, during the year 2011 - 2012, we found a good correlation between the TeSLs and the ionospheric counterparts in E region. For nine of the total 10 TeSLs, which were observed by a sodium lidar, the adjacent ionospheric observations from the COSMIC radio occultation and ionosondes exhibited abrupt perturbations in the RO SNR profiles and spread Es in the ionograms, respectively, indicating the existence of large-scale complex Es. Further, all the TeSLs, which had the co-observations by a VHF radar located nearby, were accompanied by the E region field-aligned irregularity (FAI) echoes. And seven FAIs (7/10) showed evident upwelling structure covering altitudes of 100 -- 140 km, well correlated with the development of the TeSLs. The occurrence of the large-scale complex Es possibly implies the direct altitude modulation of the horizontal Es layers by the atmospheric waves or the strong eastward polarization electric fields, which contribute the formation the FAI structures. In the course of the altitude modulation of the Es layers, sufficient ions (including sodium ions) and electrons could be accumulated in the upper altitude during the upward motion of the FAI plasma and benefits the formation of TeSLs through the chemical reaction. Two TeSL cases observed at Fort Collins, CO (20.0N), a middle latitude region, during day of year (DOY) 177 - 179 and DOY 191 during the year 2003. The enhanced sodium density in the lower thermospheric region provided the simultaneous observations for the horizontal wind and temperature. The TeSLs observed at Fort Collins had the similar feathers, i.e., they appeared at approximately 110 km and propagated with a downward speed of 1.5 - 2.5 km/hr, meanwhile, the higher temperature with approximately 50K increase and strong horizontal wind shear were accompanied with the TeSLs. Further investigation indicated that the TeSLs might be caused mainly by the ions vertical convergence due to horizontal wind-shear induced by the semi-diurnal tides, and the temperature enhancement at the altitude of 110 km had little contributions to the formation of TeSLs.

Study of Early Transition Metal Carbides for Energy Storage Applications

NASA Astrophysics Data System (ADS)

Dall'Agnese, Yohan

An increase in energy and power density is needed to match the growing energy storage demands linked with the development of renewable energy production, and portable electronics. Several energy storage technologies exist including lithium-ion batteries, sodium-ion batteries, fuel cells and supercapacitors. These systems are mutually complementary. For example, supercapacitors can deliver high power densities whereas batteries can be used for high energy density applications. The first objective of this work was to investigate the electrochemical performances of a new family of 2-D materials called MXenes by cyclic voltammetry and galvanostatic charge-discharge measurements and to propose new solutions to tackle the energy storage concern. To achieve this goal, several directions have been explored. The first part of the research focused on Ti3C 2-based MXenes behavior as electrode materials for supercapacitors in aqueous electrolytes. The charge storage mechanisms in basic and neutral aqueous electrolytes, investigated by X-ray diffraction, were demonstrated to be attributed to cations intercalation between Ti3C2 layers. X-ray photoelectron spectroscopy highlighted the contribution of oxygenated functional groups on surface redox reactions in sulfuric acid. High capacitances were achieved, up to 520 F/cm3 and 325 F/g. Then the electrochemical behaviors of MXenes in sodium-based organic electrolytes were explored. A new hybrid system of sodium-ion capacitor was proposed. It was demonstrated that V2C-based MXene electrodes were suitable to be used as positive electrodes with an operating potential from 1 V to 3.5 V vs. Na+/Na. Continuous intercalation and de-intercalation of sodium ions between the V2C layers during sodiation and desodiation were showed by X-ray diffraction. An asymmetric sodium-ion capacitor full cell was assembled using hard carbon as negative electrode and showed promising results, with a capacity of 50 mAh/g. The last part was focused on the study of MXene electrodes for supercapacitors in an organic electrolyte; 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMITFSI) in acetonitrile. High volumetric capacitances, up to 245 F/cm 3, were achieved by using carbon nanotubes as an additive to improve ion accessibility to Ti3C2 layers. The redox intercalation of large EMI+ cations between Ti3C2 layers at -0.4 V vs. Ag was observed by X-ray diffraction.

The circulation of a baroclinic ocean around planetary scale islands with topography

NASA Astrophysics Data System (ADS)

Pedlosky, J.

2010-12-01

The circulation around planetary-scale islands is considered for an island with a topographic skirt for a stratified ocean. The simplest model of the ocean is a two layer ocean in a circular domain with the island in the center. When the girdling topography is steep, closed geostrophic contours guide the flow in each of the two layers although that guiding occurs at different horizontal locations in each layer. For flows with weak dissipation, modeled as bottom and interfacial friction, explicit formulae are given for the dependence of the streamfunction in each layer on the ambient potential vorticity, f/(layer depth). Numerical model calculations will be presented to supplement the analytical results.

Molecular simulation of structure and diffusion at smectite-water interfaces: Using expanded clay interlayers as model nanopores

DOE PAGES

Greathouse, Jeffery A.; Hart, David; Bowers, Geoffrey M.; ...

2015-07-20

In geologic settings relevant to a number of extraction and potential sequestration processes, nanopores bounded by clay mineral surfaces play a critical role in the transport of aqueous species. Solution structure and dynamics at clay–water interfaces are quite different from their bulk values, and the spatial extent of this disruption remains a topic of current interest. We have used molecular dynamics simulations to investigate the structure and diffusion of aqueous solutions in clay nanopores approximately 6 nm thick, comparing the effect of clay composition with model Na-hectorite and Na-montmorillonite surfaces. In addition to structural properties at the interface, water andmore » ion diffusion coefficients were calculated within each aqueous layer at the interface, as well as in the central bulk-like region of the nanopore. The results show similar solution structure and diffusion properties at each surface, with subtle differences in sodium adsorption complexes and water structure in the first adsorbed layer due to different arrangements of layer hydroxyl groups in the two clay models. Interestingly, the extent of surface disruption on bulk-like solution structure and diffusion extends to only a few water layers. Additionally, a comparison of sodium ion residence times confirms similar behavior of inner-sphere and outer-sphere surface complexes at each clay surface, but ~1% of sodium ions adsorb in ditrigonal cavities on the hectorite surface. Thus, the presence of these anhydrous ions is consistent with highly immobile anhydrous ions seen in previous nuclear magnetic resonance spectroscopic measurements of hectorite pastes.« less

Projected Pupil Plane Pattern: an alternative LGS wavefront sensing technique

NASA Astrophysics Data System (ADS)

Yang, Huizhe; Bharmal, Nazim A.; Myers, Richard M.

2018-07-01

We have analysed and simulated a novel alternative Laser Guide Star (LGS) configuration termed Projected Pupil Plane Pattern (PPPP), including wavefront sensing and the reconstruction method. A key advantage of this method is that a collimated beam is launched through the telescope primary mirror, therefore the wavefront measurements do not suffer from the effects of focal anisoplanatism. A detailed simulation including the upward wave optics propagation, return path imaging, and linearized wavefront reconstruction has been presented. The conclusions that we draw from the simulation include the optimum pixel number across the pupilN = 32, the optimum number of Zernike modes (which is 78), propagation altitudes h1 = 10 km and h2 = 20 km for Rayleigh scattered returns, and the choice for the laser beam modulation (Gaussian beam). We also investigate the effects of turbulence profiles with multiple layers and find that it does not reduce PPPP performance as long as the turbulence layers are below h1. A signal-to-noise ratio analysis has been given when photon and read noise are introduced. Finally, we compare the PPPP performance with a conventional Shack-Hartmann Wavefront Sensor in an open loop, using Rayleigh LGS or sodium LGS, for 4-m and 10-m telescopes, respectively. For this purpose, we use a full Monte Carlo end-to-end AO simulation tool, Soapy. From these results, we confirm that PPPP does not suffer from focus anisoplanatism.

Toddler foods, children's foods: assessing sodium in packaged supermarket foods targeted at children.

PubMed

Elliott, Charlene D; Conlon, Martin J

2011-03-01

To critically examine child-oriented packaged food products sold in Canada for their sodium content, and to assess them light of intake recommendations, the current policy context and suggested targets. Baby/toddler foods (n 186) and child-oriented packaged foods (n 354) were coded for various attributes (including sodium). Summary statistics were created for sodium, then the children's food products were compared with the UK Food Standards Agency (FSA) 'targets' for sodium in packaged foods. Also assessed were the products' per-serving sodium levels were assessed in light of the US Institute of Medicine's dietary reference intakes and Canada's Food Guide. Calgary, Alberta, Canada. None. Twenty per cent of products could be classified as having high sodium levels. Certain sub-categories of food (i.e. toddler entrées, children's packaged lunches, soups and canned pastas) were problematic. Significantly, when scaled in according to Schedule M or viewed in light of the serving sizes on the Nutrition Facts table, the sodium level in various dry goods products generally fell within, and below, the Adequate Intake (AI)/Tolerable Upper Intake Level (UL) band for sodium. When scaled in accordance with the UK FSA targets, however, none of the (same) products met the targets. In light of AI/UL thresholds based on age and per-serving cut-offs, packaged foodstuffs for youngsters fare relatively well, with the exception of some problematic areas. 'Stealth sodium' and 'subtle sodium' are important considerations; so is use of the FSA's scaling method to evaluate sodium content, because it is highly sensitive to the difference between the reference amount and the actual real-world serving size for the product being considered.

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

Zhu, Jinlong; Wang, Yonggang; Li, Shuai

Na-rich antiperovskites are recently developed solid electrolytes with enhanced sodium ionic conductivity and show promising functionality as a novel solid electrolyte in an all solid-state battery. In this work, the sodium ionic transport pathways of the parent compound Na3OBr, as well as the modified layered antiperovskite Na4OI2, were studied and compared through temperature dependent neutron diffraction combined with the maximum entropy method. In the cubic Na3OBr antiperovskite, the nuclear density distribution maps at 500 K indicate that sodium ions hop within and among oxygen octahedra, and Br- ions are not involved. In the tetragonal Na4OI2 antiperovskite, Na ions, which connectmore » octahedra in the ab plane, have the lowest activation energy barrier. The transport of sodium ions along the c axis is assisted by I- ions.« less

Carbon coated anatase TiO2 mesocrystals enabling ultrastable and robust sodium storage

NASA Astrophysics Data System (ADS)

Zhang, Weifeng; Lan, Tongbin; Ding, Tianli; Wu, Nae-Lih; Wei, Mingdeng

2017-08-01

Nanoporous anatase TiO2 mesocrystals with tunable architectures and crystalline phases were successfully fabricated in the presence of the butyl oleate and oleylamine. Especially, the introduced surfactants served as a carbon source, bring a uniform carbon layer (about 2-8 nm) for heightening the electronic conductivity. The carbon coated TiO2 mesocrystals assembled from crystalline tiny subunits have more space sites for sodium-ion storage. When the material was applied as an electrode material in rechargeable sodium-ion batteries, it exhibited a superior capacity of about 90 mA h g-1 at 20 C (1 C = 168 mA g-1) and a highly reversible capacity for 5000 cycles, which is the longest cycle life reported for sodium storage in TiO2 electrodes.

Nanostructured Black Phosphorus/Ketjenblack-Multiwalled Carbon Nanotubes Composite as High Performance Anode Material for Sodium-Ion Batteries.

PubMed

Xu, Gui-Liang; Chen, Zonghai; Zhong, Gui-Ming; Liu, Yuzi; Yang, Yong; Ma, Tianyuan; Ren, Yang; Zuo, Xiaobing; Wu, Xue-Hang; Zhang, Xiaoyi; Amine, Khalil

2016-06-08

Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack-multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (∼1700 mAh g(-1) after 100 cycles at 1.3 A g(-1) based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries.

THE PROCESS OF MASS TRANSFER ON THE SOLID-LIQUID BOUNDARY LAYER DURING THE RELEASE OF DICLOFENAC SODIUM AND PAPAVERINE HYDROCHLORIDE FROM TABLETS IN A PADDLE APPARATUS.

PubMed

Kasperek, Regina; Zimmer, Lukasz; Poleszak, Ewa

2016-01-01

The release study of diclofenac sodium (DIC) and papaverine hydrochloride (PAP) from two formulations of the tablets in the paddle apparatus using different rotation speeds to characterize the process of mass transfer on the solid-liquid boundary layer was carried out. The dissolution process of active substances was described by values of mass transfer coefficients, the diffusion boundary layer thickness and dimensionless numbers (Sh and Re). The values of calculated parameters showed that the release of DIC and PAP from tablets comprising potato starch proceeded faster than from tablets containing HPMC and microcrystalline cellulose. They were obtained by direct dependencies between Sh and Re in the range from 75 rpm to 125 rpm for both substances from all tablets. The description of the dissolution process with the dimensionless numbers make it possible to plan the drug with the required release profile under given in vitro conditions.

3D solid supported inter-polyelectrolyte complexes obtained by the alternate deposition of poly(diallyldimethylammonium chloride) and poly(sodium 4-styrenesulfonate)

PubMed Central

Maestro, Armando; Llamas, Sara; Álvarez-Rodríguez, Jesús; Ortega, Francisco; Maroto-Valiente, Ángel

2016-01-01

Summary This work addresses the formation and the internal morphology of polyelectrolyte layers obtained by the layer-by-layer method. A multimodal characterization showed the absence of stratification of the films formed by the alternate deposition of poly(diallyldimethylammonium chloride) and poly(sodium 4-styrenesulfonate). Indeed the final organization might be regarded as three-dimensional solid-supported inter-polyelectrolyte films. The growth mechanism of the multilayers, followed using a quartz crystal microbalance, evidences two different growth trends, which show a dependency on the ionic strength due to its influence onto the polymer conformation. The hydration state does not modify the multilayer growth, but it contributes to the total adsorbed mass of the film. The water associated with the polyelectrolyte films leads to their swelling and plastification. The use of X-ray photoelectron spectroscopy has allowed for deeper insights on the internal structure and composition of the polyelectrolyte multilayers. PMID:26977377

3D solid supported inter-polyelectrolyte complexes obtained by the alternate deposition of poly(diallyldimethylammonium chloride) and poly(sodium 4-styrenesulfonate).

PubMed

Guzmán, Eduardo; Maestro, Armando; Llamas, Sara; Álvarez-Rodríguez, Jesús; Ortega, Francisco; Maroto-Valiente, Ángel; Rubio, Ramón G

2016-01-01

This work addresses the formation and the internal morphology of polyelectrolyte layers obtained by the layer-by-layer method. A multimodal characterization showed the absence of stratification of the films formed by the alternate deposition of poly(diallyldimethylammonium chloride) and poly(sodium 4-styrenesulfonate). Indeed the final organization might be regarded as three-dimensional solid-supported inter-polyelectrolyte films. The growth mechanism of the multilayers, followed using a quartz crystal microbalance, evidences two different growth trends, which show a dependency on the ionic strength due to its influence onto the polymer conformation. The hydration state does not modify the multilayer growth, but it contributes to the total adsorbed mass of the film. The water associated with the polyelectrolyte films leads to their swelling and plastification. The use of X-ray photoelectron spectroscopy has allowed for deeper insights on the internal structure and composition of the polyelectrolyte multilayers.

Tuning the density profile of surface-grafted hyaluronan and the effect of counter-ions.

PubMed

Berts, Ida; Fragneto, Giovanna; Hilborn, Jöns; Rennie, Adrian R

2013-07-01

The present paper investigates the structure and composition of grafted sodium hyaluronan at a solid-liquid interface using neutron reflection. The solvated polymer at the surface could be described with a density profile that decays exponentially towards the bulk solution. The density profile of the polymer varied depending on the deposition protocol. A single-stage deposition resulted in denser polymer layers, while layers created with a two-stage deposition process were more diffuse and had an overall lower density. Despite the diffuse density profile, two-stage deposition leads to a higher surface excess. Addition of calcium ions causes a strong collapse of the sodium hyaluronan chains, increasing the polymer density near the surface. This effect is more pronounced on the sample prepared by two-stage deposition due to the initial less dense profile. This study provides an understanding at a molecular level of how surface functionalization alters the structure and how surface layers respond to changes in calcium ions in the solvent.

Formulation and in-vitro evaluation of floating bilayer tablet of lisinopril maleate and metoprolol tartrate.

PubMed

Ijaz, Hira; Qureshi, Junaid; Danish, Zeeshan; Zaman, Muhammad; Abdel-Daim, Mohamed; Hanif, Muhammad; Waheed, Imran; Mohammad, Imran Shair

2015-11-01

The purpose of this study was to introduce the technology for the development of rate-controlled oral drug delivery system to overcome various physiological problems. Several approaches are being used for the purpose of increasing the gastric retentive time, including floating drug delivery system. Gastric floating lisinopril maleate and metoprolol tartrate bilayer tablets were formulated by direct compression method using the sodium starch glycolate, crosscarmellose sodium for IR layer. Eudragit L100, pectin, acacia as sustained release polymers in different ratios for SR metoprolol tartrate layer and sodium bicarbonate, citric acid as gas generating agents for the floating extended release layer. The floating bilayer tablets of lisinopril maleate and metoprolol tartrate were designed to overcome the various problems associated with conventional oral dosage form. Floating tablets were evaluated for floating lag time, drug contents and in-vitro dissolution profile and different kinetic release models were applied. It was clear that the different ratios of polymers affected the drug release and floating time. L2 and M4 showed good drug release profile and floating behavior. The linear regression and model fitting showed that all formulation followed Higuchi model of drug release model except M4 that followed zero order kinetic. From the study it is evident that a promising controlled release by floating bilyer tablets of lisinopril maleate and metoprolol tartrate can be developed successfully.

Formulation of Novel Layered Sodium Carboxymethylcellulose Film Wound Dressings with Ibuprofen for Alleviating Wound Pain

PubMed Central

Vinklárková, Lenka; Vetchý, David; Bernatonienė, Jurga

2015-01-01

Effective assessment and management of wound pain can facilitate both improvements in healing rates and overall quality of life. From a pharmacological perspective, topical application of nonsteroidal anti-inflammatory drugs in the form of film wound dressings may be a good choice. Thus, the aim of this work was to develop novel layered film wound dressings containing ibuprofen based on partially substituted fibrous sodium carboxymethylcellulose (nonwoven textile Hcel NaT). To this end, an innovative solvent casting method using a sequential coating technique has been applied. The concentration of ibuprofen which was incorporated as an acetone solution or as a suspension in a sodium carboxymethylcellulose dispersion was 0.5 mg/cm2 and 1.0 mg/cm2 of film. Results showed that developed films had adequate mechanical and swelling properties and an advantageous acidic surface pH for wound application. An in vitro drug release study implied that layered films retained the drug for a longer period of time and thus could minimize the frequency of changing the dressing. Films with suspended ibuprofen demonstrated higher drug content uniformity and superior in vitro drug release characteristics in comparison with ibuprofen incorporation as an acetone solution. Prepared films could be potential wound dressings for the effective treatment of wound pain in low exuding wounds. PMID:26090454

Electropulse treatment of water solution of humic substances in a layer iron granules in process of water treatment

NASA Astrophysics Data System (ADS)

Lobanova, G. L.; Yurmazova, T. A.; Shiyan, L. N.; Machekhina, K. I.

2016-02-01

The present work is a part of a continuations study of the physical and chemical processes complex in natural waters containing humic-type organic substances at the influence of pulsed electrical discharges in a layer of iron pellets. The study of humic substances processing in the iron granules layer by means of pulsed electric discharge for the purpose of water purification from organic compounds humic origin from natural water of the northern regions of Russia is relevant for the water treatment technologies. In case of molar humate sodium - iron ions (II) at the ratio 2:3, reduction of solution colour and chemical oxygen demand occur due to the humate sodium ions and iron (II) participation in oxidation-reduction reactions followed by coagulation insoluble compounds formation at a pH of 6.5. In order to achieve this molar ratio and the time of pulsed electric discharge, equal to 10 seconds is experimentally identified. The role of secondary processes that occur after disconnection of the discharge is shown. The time of contact in active erosion products with sodium humate, equal to 1 hour is established. During this time, the value of permanganate oxidation and iron concentration in solution achieves the value of maximum permissible concentrations and further contact time increase does not lead to the controlled parameters change.

Surface modification of graphene oxide nanosheets by protamine sulfate/sodium alginate for anti-cancer drug delivery application

NASA Astrophysics Data System (ADS)

Xie, Meng; Zhang, Feng; Liu, Lijiao; Zhang, Yanan; Li, Yeping; Li, Huaming; Xie, Jimin

2018-05-01

In order to improve the efficiency of anticancer drug delivery, a graphene oxide (GO) based drug delivery system modificated by natural peptide protamine sulfate (PRM) and sodium alginate (SA) was established via electrostatic attraction at each step of adsorption based on layer-by-layer self-assembly. The nanocomposites were then loaded with anticancer drug doxorubicin hydrochloride (DOX) to estimate the feasibility as drug carriers. The nanocomposites loaded with DOX revealed a remarkable pH-sensitive drug release property. The modification with protamine sulfate and sodium alginate could not only impart the nanocomposites an improved dispersibility and stability under physiological pH, but also suppress the protein adhesion. Due to the high water dispersibility and the small particle size, GO-PRM/SA nanocomposites were able to be uptaken by MCF-7 cells. It was found that GO-PRM/SA nanocomposites exhibited no obvious cytotoxicity towards MCF-7 cells, while GO-PRM/SA-DOX exhibited better cytotoxicity than GO-DOX. Therefore, the GO-PRM/SA nanocomposites were feasible as drug delivery vehicles.

Unravelling the origin of irreversible capacity loss in NaNiO 2 for high voltage sodium ion batteries

DOE PAGES

Wang, Liguang; Wang, Jiajun; Zhang, Xiaoyi; ...

2017-02-24

Layered transition metal compounds have attracted much attention due to their high theoretical capacity and energy density for sodium ion batteries. However, this kind of material suffers from serious irreversible capacity decay during the charge and discharge process. Here, using synchrotron-based operando transmission X-ray microscopy and high-energy X-ray diffraction combined with electrochemical measurements, the visualization of the dissymmetric phase transformation and structure evolution mechanism of layered NaNiO 2 material during initial charge and discharge cycles are clarified. Phase transformation and deformation of NaNiO 2 during the voltage range of below 3.0 V and over 4.0 V are responsible for themore » irreversible capacity loss during the first cycling, which is also confirmed by the evolution of reaction kinetics behavior obtained by the galvanostatic intermittent titration technique. Lastly, these findings reveal the origin of the irreversibility of NaNiO 2 and offer valuable insight into the phase transformation mechanism, which will provide underlying guidance for further development of high-performance sodium ion batteries.« less

Fabrication of porous carbon sphere@SnO2@carbon layer coating composite as high performance anode for sodium-ion batteries

NASA Astrophysics Data System (ADS)

Li, Xin; Sun, Xiaohong; Gao, Zhiwen; Hu, Xudong; Guo, Jingdong; Cai, Shu; Guo, Ruisong; Ji, Huiming; Zheng, Chunming; Hu, Wenbin

2018-03-01

SnO2 has triggered lots of research efforts as anode for sodium-ion batteries. However, the volume expansion and poor conductivity lead to an unsatisfactory electrochemical performance for the practical application of SnO2. In this work, a novel carbon-coated SnO2 supported by porous carbon sphere composite is synthesized by hydrothermal process combining with annealing method. The porous carbon sphere@SnO2@carbon layer coating composite anode delivers a reversible capacity of 326 mAh g-1 over 80 cycles at a current density of 50 mA g-1. Even at 1600 mA g-1, a capacity of 82 mAh g-1 is still maintained after 550 cycles. Such excellent performance can be ascribed to the unique structure, which efficiently accommodates volume expansion, enhances conductivity and offers shortened sodium-ion transport pathway. The charge-storage mechanisms can be comprised of diffusion-controlled reaction and pseudocapacitance effect. At high scan rate of 1.0 mV s-1, the capacity contribution of pseudocapacitance effect could reach as high as 78%.

Unravelling the origin of irreversible capacity loss in NaNiO 2 for high voltage sodium ion batteries

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

Wang, Liguang; Wang, Jiajun; Zhang, Xiaoyi

Layered transition metal compounds have attracted much attention due to their high theoretical capacity and energy density for sodium ion batteries. However, this kind of material suffers from serious irreversible capacity decay during the charge and discharge process. Here, using synchrotron-based operando transmission X-ray microscopy and high-energy X-ray diffraction combined with electrochemical measurements, the visualization of the dissymmetric phase transformation and structure evolution mechanism of layered NaNiO 2 material during initial charge and discharge cycles are clarified. Phase transformation and deformation of NaNiO 2 during the voltage range of below 3.0 V and over 4.0 V are responsible for themore » irreversible capacity loss during the first cycling, which is also confirmed by the evolution of reaction kinetics behavior obtained by the galvanostatic intermittent titration technique. Lastly, these findings reveal the origin of the irreversibility of NaNiO 2 and offer valuable insight into the phase transformation mechanism, which will provide underlying guidance for further development of high-performance sodium ion batteries.« less

Unravelling the origin of irreversible capacity loss in NaNiO 2 for high voltage sodium ion batteries

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

Wang, Liguang; Wang, Jiajun; Zhang, Xiaoyi

Layered transition metal compounds have attracted much attention due to their high theoretical capacity and energy density for sodium ion batteries. However, this kind of material suffers from serious irreversible capacity decay during the charge and discharge process. Here, using synchrotron-based operando transmission X-ray microscopy and high-energy X-ray diffraction combined with electrochemical measurements, the visualization of the dissymmetric phase transformation and structure evolution mechanism of layered NaNiO2 material during initial charge and discharge cycles are clarified. Phase transformation and deformation of NaNiO2 during the voltage range of below 3.0 V and over 4.0 V are responsible for the irreversible capacitymore » loss during the first cycling, which is also confirmed by the evolution of reaction kinetics behavior obtained by the galvanostatic intermittent titration technique. These findings reveal the origin of the irreversibility of NaNiO2 and offer valuable insight into the phase transformation mechanism, which will provide underlying guidance for further development of high-performance sodium ion batteries.« less

Hydrophobic forces in the foam films stabilized by sodium dodecyl sulfate: effect of electrolyte.

PubMed

Wang, Liguang; Yoon, Roe-Hoan

2004-12-21

Further studies of the hydrophobic force in foam films were carried out, including the effect of added inorganic electrolyte. We used a thin film balance of Scheludko-Exerowa type to obtain the disjoining pressure isotherms of the foam films stabilized by 10(-4) M sodium dodecyl sulfate in varying concentrations of sodium chloride. The results were compared with the disjoining pressure isotherms predicted from the extended Derjaguin-Landau-Verwey-Overbeek theory, which considers contributions from hydrophobic force in addition to those from double layer and van der Waals dispersion forces. The double layer forces were calculated from the surface potentials (psi s) obtained using the Gibbs adsorption equation and corrected for the counterion binding effect, while the dispersion forces were calculated using the Hamaker constant (A232) of 3.7 x 10(-20) J. The hydrophobic forces were calculated from the equilibrium film thickness as described previously. The predicted disjoining pressure isotherms were in good agreement with the experimental ones. It was found that the hydrophobic force is dampened substantially by the added electrolyte.

Dispersion Energy Analysis of Rayleigh and Love Waves in the Presence of Low-Velocity Layers in Near-Surface Seismic Surveys

NASA Astrophysics Data System (ADS)

Mi, Binbin; Xia, Jianghai; Shen, Chao; Wang, Limin

2018-03-01

High-frequency surface-wave analysis methods have been effectively and widely used to determine near-surface shear (S) wave velocity. To image the dispersion energy and identify different dispersive modes of surface waves accurately is one of key steps of using surface-wave methods. We analyzed the dispersion energy characteristics of Rayleigh and Love waves in near-surface layered models based on numerical simulations. It has been found that if there is a low-velocity layer (LVL) in the half-space, the dispersion energy of Rayleigh or Love waves is discontinuous and ``jumping'' appears from the fundamental mode to higher modes on dispersive images. We introduce the guided waves generated in an LVL (LVL-guided waves, a trapped wave mode) to clarify the complexity of the dispersion energy. We confirm the LVL-guided waves by analyzing the snapshots of SH and P-SV wavefield and comparing the dispersive energy with theoretical values of phase velocities. Results demonstrate that LVL-guided waves possess energy on dispersive images, which can interfere with the normal dispersion energy of Rayleigh or Love waves. Each mode of LVL-guided waves having lack of energy at the free surface in some high frequency range causes the discontinuity of dispersive energy on dispersive images, which is because shorter wavelengths (generally with lower phase velocities and higher frequencies) of LVL-guided waves cannot penetrate to the free surface. If the S wave velocity of the LVL is higher than that of the surface layer, the energy of LVL-guided waves only contaminates higher mode energy of surface waves and there is no interlacement with the fundamental mode of surface waves, while if the S wave velocity of the LVL is lower than that of the surface layer, the energy of LVL-guided waves may interlace with the fundamental mode of surface waves. Both of the interlacements with the fundamental mode or higher mode energy may cause misidentification for the dispersion curves of surface waves.

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

Xu, Gui-Liang; Chen, Zonghai; Zhong, Gui-Ming

Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack–multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (~1700 mAh g–1 after 100 cycles atmore » 1.3 A g–1 based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries.« less

Propagation of Electromagnetic Waves in Slab Waveguide Structure Consisting of Chiral Nihility Claddings and Negative-Index Material Core Layer

NASA Astrophysics Data System (ADS)

Helal, Alaa N. Abu; Taya, Sofyan A.; Elwasife, Khitam Y.

2018-06-01

The dispersion equation of an asymmetric three-layer slab waveguide, in which all layers are chiral materials is presented. Then, the dispersion equation of a symmetric slab waveguide, in which the claddings are chiral materials and the core layer is negative index material, is derived. Normalized cut-off frequencies, field profile, and energies flow of right-handed and left-handed circularly polarized modes are derived and plotted. We consider both odd and even guided modes. Numerical results of guided low-order modes are provided. Some novel features, such as abnormal dispersion curves, are found.

Organic contaminant removal efficiency of sodium bentonite/clay (BC) mixtures in high permeability regions utilizing reclaimed wastewater: A meso-scale study

NASA Astrophysics Data System (ADS)

Xiao, Yang; Li, Yunkai; Ning, Zigong; Li, Pengxiang; Yang, Peiling; Liu, Chengcheng; Liu, Zhongwei; Xu, Feipeng; Hynds, Paul Dylan

2018-03-01

Wastewater reclamation now represents an effective measure for sustainable water resource management in arid regions, however wastewater components (organic micropollutants) may potentially impact local ecological and/or human health. Previous studies have shown that sodium bentonite/natural clay (BC) mixes may be used to effectively reduce riverbed infiltration in regions characterized by excessively high hydraulic conductivity. Accordingly, the current study sought to investigate the contaminant removal efficiency (Re) of several BC mass ratios in simulated dry riverbeds. Results indicate that the measured Re of NH4+-N, CODcr and BOD5 increased in concurrence with an increasing sodium bentonite ratio, up to a maximum Re of 97.4% (NH4+-N), 55.2% (CODcr), and 51.5% (BOD5). The primary contaminant removal site was shown to be the infiltration-reducing (BC) layer, accounting for approximately 40%, 60%, and 70% of NH4+-N, CODcr and BOD5 removal, respectively. Conversely, the removal efficiency of NO3-N was found to be low (<15%), while total phosphorous (TP) was found to actively leach from the infiltration-reduction layer, resulting in measured TP discharges 2.4-4.8 times those of initial infiltration values. The current study provides a technical baseline for the efficacy of sodium bentonite as an effective bi-functional material in areas utilizing reclaimed water i.e. concurrent reduction of infiltration rates (Function 1) and decontamination of reclaimed wastewater infiltration/recharge (Function 2). Findings indicate that sodium bentonite-clay mixes may represent a feasible alternative for managing recharge of non-potable aquifers with reclaimed wastewater.

Directed Self-Assembly on Photo-Crosslinked Polystyrene Sub-Layers: Nanopattern Uniformity and Orientation

PubMed Central

Koh, Haeng-Deog; Kim, Mi-Jeong

2016-01-01

A photo-crosslinked polystyrene (PS) thin film is investigated as a potential guiding sub-layer for polystyrene-block-poly (methyl methacrylate) block copolymer (BCP) cylindrical nanopattern formation via topographic directed self-assembly (DSA). When compared to a non-crosslinked PS brush sub-layer, the photo-crosslinked PS sub-layer provided longer correlation lengths of the BCP nanostructure, resulting in a highly uniform DSA nanopattern with a low number of BCP dislocation defects. Depending on the thickness of the sub-layer used, parallel or orthogonal orientations of DSA nanopattern arrays were obtained that covered the entire surface of patterned Si substrates, including both trench and mesa regions. The design of DSA sub-layers and guide patterns, such as hardening the sub-layer by photo-crosslinking, nano-structuring on mesas, the relation between trench/mesa width, and BCP equilibrium period, were explored with a view to developing defect-reduced DSA lithography technology. PMID:28773768

Positively charged and bipolar layered poly(ether imide) nanofiltration membranes for water softening applications

NASA Astrophysics Data System (ADS)

Gassara, S.; Abdelkafi, A.; Quémener, D.; Amar, R. Ben; Deratani, A.

2015-07-01

Poly(ether imide) (PEI) ultrafiltration membranes were chemically modified with branched poly(ethyleneimine) to obtain nanofiltration (NF) membrane Cat PEI with a positive charge in the pH range below 9. An oppositely charged polyelectrolyte layer was deposited on the resulting membrane surface by using sodium polystyrene sulfonate (PSSNa) and sodium polyvinyl sulfonate (PVSNa) to prepare a bipolar layered membrane NF Cat PEI_PSS and Cat PEI_PVS having a negatively charged surface and positively charged pores. Cat PEI exhibited good performance to remove multivalent cations (more than 90% of Ca2+) from single salt solutions except in presence of sulfate ions. Adding an anionic polyelectrolyte layer onto the positively charged surface resulted in a significant enhancement of rejection performance even in presence of sulfate anions. Application of the prepared membranes in water softening of natural complex mixtures was successful for the different studied membranes and a large decrease of hardness was obtained. Moreover, Cat PEI_PSS showed a good selectivity for nitrate removal. Fouling experiments were carried out with bovine serum albumin, as model protein foulant. Cat PEI_PSS showed much better fouling resistance than Cat PEI with a quantitative flux recovery ratio.

Cu sbnd Al sbnd Fe layered double hydroxides with CO32- and anionic surfactants with different alkyl chains in the interlayer

NASA Astrophysics Data System (ADS)

Trujillano, Raquel; Holgado, María Jesús; González, José Luis; Rives, Vicente

2005-08-01

Layered double hydroxides (LDHs), with the hydrotalcite-like structure containing Cu(II), Al(III) and Fe(III) in the layers, and different alkyl sulfonates in the interlayer, have been prepared and characterized by powder X-ray diffraction, FT-IR spectroscopy, differential thermal analysis and thermogravimetric analysis. Pure crystalline phases have been obtained in all cases. Upon heating, combustion of the organic chain takes place at lower temperature than the corresponding sodium salts.

Influence of Smear Layer on the Antimicrobial Activity of a Sodium Hypochlorite/Etidronic Acid Irrigating Solution in Infected Dentin.

PubMed

Morago, Ana; Ordinola-Zapata, Ronald; Ferrer-Luque, Carmen María; Baca, Pilar; Ruiz-Linares, Matilde; Arias-Moliz, María Teresa

2016-11-01

The aim of this study was to evaluate the influence of the smear layer on the antimicrobial activity of a 2.5% sodium hypochlorite (NaOCl)/9% etidronic acid (HEBP) irrigating solution against bacteria growing inside dentin tubules. Dentin tubules were infected with Enterococcus faecalis by centrifugation. After 5 days of incubation, the smear layer had formed in half of the samples, which were then treated with 2.5% NaOCl either alone or combined with 9% HEBP for 3 minutes. The percentage of dead cells in infected dentinal tubules was measured using confocal laser scanning microscopy and the live/dead technique. The smear layer on the surface of the root canal wall was also observed by scanning electron microscopy. Results of the percentage of dead cells were compared using parametric tests after subjecting data to the normalized Anscombe transformation. The level of significance was P < .05. In the absence of the smear layer, 2.5% NaOCl alone and combined with 9% HEBP showed high antimicrobial activity without significant differences between the 2. The smear layer reduced the antimicrobial activity of 2.5% NaOCl significantly, whereas the solution with HEBP was not affected. No dentin tubules free of the smear layer were obtained in the 2.5% NaOCl group. In the case of 2.5% NaOCl/9% HEBP, 95.40% ± 3.63% of dentin tubules were cleaned. The presence of the smear layer reduced the antimicrobial activity of 2.5% NaOCl. The combination of 2.5% NaOCl/9% HEBP exerted antimicrobial activity that was not reduced by the smear layer. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Mixed layers of sodium caseinate + dextran sulfate: influence of order of addition to oil-water interface.

PubMed

Jourdain, Laureline S; Schmitt, Christophe; Leser, Martin E; Murray, Brent S; Dickinson, Eric

2009-09-01

We report on the interfacial properties of electrostatic complexes of protein (sodium caseinate) with a highly sulfated polysaccharide (dextran sulfate). Two routes were investigated for preparation of adsorbed layers at the n-tetradecane-water interface at pH = 6. Bilayers were made by the layer-by-layer deposition technique whereby polysaccharide was added to a previously established protein-stabilized interface. Mixed layers were made by the conventional one-step method in which soluble protein-polysaccharide complexes were adsorbed directly at the interface. Protein + polysaccharide systems gave a slower decay of interfacial tension and stronger dilatational viscoelastic properties than the protein alone, but there was no significant difference in dilatational properties between mixed layers and bilayers. Conversely, shear rheology experiments exhibited significant differences between the two kinds of interfacial layers, with the mixed system giving much stronger interfacial films than the bilayer system, i.e., shear viscosities and moduli at least an order of magnitude higher. The film shear viscoelasticity was further enhanced by acidification of the biopolymer mixture to pH = 2 prior to interface formation. Taken together, these measurements provide insight into the origin of previously reported differences in stability properties of oil-in-water emulsions made by the bilayer and mixed layer approaches. Addition of a proteolytic enzyme (trypsin) to both types of interfaces led to a significant increase in the elastic modulus of the film, suggesting that the enzyme was adsorbed at the interface via complexation with dextran sulfate. Overall, this study has confirmed the potential of shear rheology as a highly sensitive probe of associative electrostatic interactions and interfacial structure in mixed biopolymer layers.

[Separation and purification of an endogenous inhibitor of sodium pump from chansu by thin-layer chromatography and reversed-phase high performance liquid chromatography].

PubMed

Li, S Q

2001-11-01

An endogenous inhibitor of the sodium pump from the Chinese medication Chansu was purified. The dry substance Chansu was extracted with methanol. The dry residue dissolved in water and filtered subsequently through membrane filters with the exclusion size of 1000 Da, 3000 Da and 10000 Da in a Filtron Pro Vario-3-System and applied to thin-layer chromatographic plate made of Silica gel 60 F254 + 366 developed with a mixture of CHCl3-MeOH-H2O(75:20:5, volume ratio). The fractions with Rf 0.55 inhibiting the sodium pump were purified on an HPLC C18-RP column using a linear H2O-methanol gradient with 220 nm and 300 nm DAD detection. The bioactivity was measured by 86Rb-uptake into human red blood cells. The results showed that a low molecular weight, water soluble compound, which inhibited the sodium pump activity in the red blood cells and had a maximum absorbance at 250 nm was isolated from the Chinese medication Chansu. Several mg of the compound in pure state could be obtained from 1 kg Chansu. It was different from ouabain and proscillaridin A in chemical structure, because ouabain and proscillaridin A show a UV maximum absorption at 220 nm and 300 nm, while the new inhibitor at 250 nm.

O3-type layered transition metal oxide Na(NiCoFeTi) 1/4O 2 as a high rate and long cycle life cathode material for sodium ion batteries

DOE PAGES

Yue, Ji -Li; Yang, Xiao -Qing; Zhou, Yong -Ning; ...

2015-10-09

High rate capability and long cycle life are challenging goals for the development of room temperature sodium-ion batteries. Here we report a new single phase quaternary O3-type layer-structured transition metal oxide Na(NiCoFeTi) 1/4O 2 synthesized by a simple solid-state reaction as a new cathode material for sodium-ion batteries. It can deliver a reversible capacity of 90.6 mA h g –1 at a rate as high as 20C. At 5C, 75.0% of the initial specific capacity can be retained after 400 cycles with a capacity-decay rate of 0.07% per cycle, demonstrating a superior long-term cyclability at high current density. X-ray diffractionmore » and absorption characterization revealed reversible phase transformations and electronic structural changes during the Na + deintercalation/intercalation process. Ni, Co and Fe ions contribute to charge compensation during charge and discharge. Although Ti ions do not contribute to the charge transfer, they play a very important role in stabilizing the structure during charge and discharge by suppressing the Fe migration. Additionally, Ti substitution can also smooth the charge–discharge plateaus effectively, which provides a potential advantage for the commercialization of this material for room temperature sodium-ion batteries.« less

Method for ultrafast optical deflection enabling optical recording via serrated or graded light illumination

DOEpatents

Heebner, John E [Livermore, CA

2009-09-08

In one general embodiment, a method for deflecting an optical signal input into a waveguide is provided. In operation, an optical input signal is propagated through a waveguide. Additionally, an optical control signal is applied to a mask positioned relative to the waveguide such that the application of the optical control signal to the mask is used to influence the optical input signal propagating in the waveguide. Furthermore, the deflected optical input signal output from the waveguide is detected in parallel on an array of detectors. In another general embodiment, a beam deflecting structure is provided for deflecting an optical signal input into a waveguide, the structure comprising at least one wave guiding layer for guiding an optical input signal and at least one masking layer including a pattern configured to influence characteristics of a material of the guiding layer when an optical control signal is passed through the masking layer in a direction of the guiding layer. In another general embodiment, a system is provided including a waveguide, an attenuating mask positioned on the waveguide, and an optical control source positioned to propagate pulsed laser light towards the attenuating mask and the waveguide such that a pattern of the attenuating mask is applied to the waveguide and material properties of at least a portion of the waveguide are influenced.

Effect of Duration of Irrigation with Sodium Hypochlorite in Clinical Protocol of MTAD on Removal of Smear Layer and Creating Dentinal Erosion

PubMed Central

Lotfi, Mehrdad; Moghaddam, Negar; Vosoughhosseini, Sepideh; Zand, Vahid; Saghiri, Mohammad Ali

2012-01-01

Background and aims The aim of the present study was to compare 1.3% sodium hypochlorite (NaOCl) in MTAD (mixture of tetracycline isomer, acid, and detergent) for the removal of the smear layer and induction of canal erosion. Materials and methods 38 maxillary incisors were divided in three experimental groups of 10 and two positive and negative control groups of each 4 teeth, and prepared using rotary files. In test groups, 1.3% NaOCl was used for 5, 10 and 20 minutes during preparation followed by MTAD as the final rinse. In negative control group, 5.25% NaOCl was used for 10 minutes followed by 17% Ethylenediamine Tetra-Acetic Acid (EDTA) as the final rinse. In positive control group, dis-tilled water was used for 10 minutes during preparation and then as the final rinse. The samples were examined under scan-ning electron microscope, and the smear layer and dentinal erosion scores were recorded. Results Five and 10 min groups had significant differences with 20 min group (p < 0.05). In apical third, 5 and 10 min groups had also significant differences with 20 min (p < 0.05). In the coronal thirds, when the time of irrigation with 1.3% NaOCl increased from 5 min to 20 min, erosion also increased significantly. However, 5 and 10 min groups had no signifi-cant differences with negative control group. Conclusion The use of 1.3% sodium hypochlorite for 5 and 10 minutes in the MTAD protocol removes the smear layer in the coronal and middle thirds but does not induce erosion. PMID:22991642

Bovine and Porcine Transscleral Solute Transport: Influence of Lipophilicity and the Choroid–Bruch’s Layer

PubMed Central

Cheruvu, Narayan P. S.; Kompella, Uday B.

2012-01-01

Purpose To determine the influence of the choroid–Bruch’s layer and solute lipophilicity on in vitro transscleral drug permeability in bovine and porcine eyes. Methods The in vitro permeability of two VEGF inhibitory drugs, budesonide and celecoxib, which are lipophilic and neutral at physiologic pH, and of three marker solutes, 3H-mannitol (hydrophilic, neutral), sodium fluorescein (hydrophilic, anionic), and rhodamine 6G (lipophilic, cationic), were determined across freshly excised scleras, with or without the underlying choroid–Bruch’s layer. Select studies were performed using porcine sclera with and without choroid–Bruch’s layer. Neural retina was removed by exposure of the eyecup to isotonic buffer and wherever required, the retinal pigment epithelial (RPE) layer of the preparation was disrupted and removed by exposure to hypertonic buffer. Because of the poor solubility of celecoxib and budesonide, permeability studies were conducted with 5% wt/vol of hydroxypropyl-β-cyclodextrin (HPβCD). For other solutes, permeability studies were conducted, with and without HPβCD. Partitioning of the solutes into bovine sclera and choroid–Bruch’s layer was also determined. Results The calculated log (distribution coefficient) values were −2.89, −0.68, 2.18, 3.12, and 4.02 for mannitol, sodium fluorescein, budesonide, celecoxib, and rhodamine 6G, respectively. Removal of RPE was confirmed by transmission electron microscopy and differences in the transport of mannitol. The order of the permeability coefficients (Papp) across sclera and sclera–choroid–Bruch’s layers in bovine and porcine models was 3H-mannitol > fluorescein > budesonide > celecoxib > rhodamine 6G, with HPβCD, and 3H-mannitol > fluorescein > rhodamine 6G, without HPβCD. The presence of choroid–Bruch’s layer reduced the bovine scleral permeability by 2-, 8-, 16-, 36-, and 50-fold and porcine tissue permeability by 2-, 7-, 15-, 33-, and 40-fold, respectively, for mannitol, sodium fluorescein, budesonide, celecoxib, and rhodamine 6G. The partition coefficients measured in bovine tissues correlated positively with the log (distribution coefficient) and exhibited a trend opposite that of transport. The partition coefficient ratio of bovine choroid–Bruch’s layer to sclera was ~1, 1.5, 1.7, 2, and 3.5, respectively, for the solutes, as listed earlier. Conclusions The choroid–Bruch’s layer is a more significant barrier to drug transport than is sclera. It hinders the transport of lipophilic solutes, especially a cationic solute, more than hydrophilic solutes and in a more dramatic way than does sclera. The reduction in transport across this layer directly correlates with solute binding to the tissue. Understanding the permeability properties of sclera and underlying layers would be beneficial in designing better drugs for transscleral delivery. PMID:17003447

Centrifugal Spinning and Its Energy Storage Applications

NASA Astrophysics Data System (ADS)

Yao, Lu

Lithium-ion batteries (LIBs) and supercapacitors are important electrochemical energy storage systems. LIBs have high specific energy density, long cycle life, good thermal stability, low self-discharge, and no memory effect. However, the low abundance of Li in the Earth's crust and the rising cost of LIBs urge the attempts to develop alternative energy storage systems. Recently, sodium-ion batteries (SIBs) have become an attractive alternative to LIBs due to the high abundance and low cost of Na. Although the specific capacity and energy density of SIBs are not as high as LIBs, SIBs can still be promising power sources for certain applications such as large-scale, stationary grids. Supercapacitors are another important class of energy storage devices. Electric double-layer capacitors (EDLCs) are one important type of supercapacitors and they exhibit high power density, long cycle life, excellent rate capability and environmental friendliness. The potential applications of supercapacitors include memory protection in electronic circuitry, consumer portable electronic devices, and electrical hybrid vehicles. The electrochemical performance of SIBs and EDLCs is largely dependent on the electrode materials. Therefore, development of superior electrodes is the key to achieve highperformance alternative energy storage systems. Recently, one-dimensional nano-/micro-fiber based electrodes have become promising candidates in energy storage because they possess a variety of desirable properties including large specific surface area, well-guided ionic/electronic transport, and good electrode-electrolyte contact, which contribute to enhanced electrochemical performance. Currently, most nano-/micro-fiber based electrodes are prepared via electrospinning method. However, the low production rate of this approach hinders its practical application in the production of fibrous electrodes. Thus, it is significantly important to employ a rapid, low-cost and scalable nano-/micro-fiber production method to substitute electrospinning in industrial production. Recently, centrifugal spinning has gained researchers' attention. The centrifugal spinning method avoids the use of high voltage supply and can work with concentrated solutions, and most importantly, it can increase the production rate of nano-/micro-fibers to at least two orders or magnitude higher than that of electrospinning. This novel fiber fabrication approach is mostly used in tissue engineering field, and it can be potentially applied in preparing electrodes for SIBs and EDLCs. In the present work, we firstly study the influence of solution intrinsic properties and operational parameters using polyacrylonitrile as an example, and establish the processing-structure relationships for this spinning technique. We then use this novel spinning method to prepare porous carbon nanofibers (PCNFs), SnO2 microfibers and lithium-substituted sodium layered transition metal oxide fibers and use them as electrodes for EDLCs and SIBs. The as-prepared PCNFs, SnO2 microfibers and lithiumsubstituted sodium layered transition metal oxide fibers exhibit good electrochemical performance. It is therefore demonstrated that centrifugal spinning can be a promising nano- /micro-fiber preparation approach for mass production of electrode materials used in energy storage applications.

Advanced Na[Ni0.25Fe0.5Mn0.25]O2/C-Fe3O4 sodium-ion batteries using EMS electrolyte for energy storage.

PubMed

Oh, Seung-Min; Myung, Seung-Taek; Yoon, Chong Seung; Lu, Jun; Hassoun, Jusef; Scrosati, Bruno; Amine, Khalil; Sun, Yang-Kook

2014-03-12

While much research effort has been devoted to the development of advanced lithium-ion batteries for renewal energy storage applications, the sodium-ion battery is also of considerable interest because sodium is one of the most abundant elements in the Earth's crust. In this work, we report a sodium-ion battery based on a carbon-coated Fe3O4 anode, Na[Ni0.25Fe0.5Mn0.25]O2 layered cathode, and NaClO4 in fluoroethylene carbonate and ethyl methanesulfonate electrolyte. This unique battery system combines an intercalation cathode and a conversion anode, resulting in high capacity, high rate capability, thermal stability, and much improved cycle life. This performance suggests that our sodium-ion system is potentially promising power sources for promoting the substantial use of low-cost energy storage systems in the near future.

Development of Mesospheric Sodium Laser Beacon for Atmospheric Adaptive Optics

NASA Technical Reports Server (NTRS)

Jeys, T. H.

1992-01-01

A solid-state source of long pulse length, sodium-resonance radiation was developed for the purpose of generating an artificial star in the earth's mesospheric sodium layer. This radiation is generated by sum-frequency mixing the output of a 1.064 micron Nd:YAG laser with the output of a 1.319-micron Nd:YAG laser. By operating these lasers at wavelengths very close to the peak of their tuning curves, it is possible to match the wavelength of the sum-frequency radiation to that of the sodium D2 adsorption wavelength. Two pulsed laser systems were constructed, one producing as much as 0.6 J of sodium resonance radiation at a 10-Hz repetition rate and another producing as much as 24 mJ at a 840-Hz repetition rate. In both laser systems, the 1.06-micron and 1.32-micron Nd:YAG lasers are configured as mode-locked master oscillators followed by power amplifiers. Other aspects of this project are presented.

A Wireless, Passive, Magnetically-soft Harmonic Sensor for Monitoring Sodium Hypochlorite Concentrations in Water

PubMed Central

Ong, Keat G.; Paulose, Maggie; Grimes, Craig A.

2003-01-01

A wireless, passive, remote-query sensor for monitoring sodium hypochlorite (bleach) solutions is reported. The sensor is comprised of a magnetically-soft ferromagnetic ribbon, coated with a layer of polyurethane and alumina, having a large and nonlinear permeability that supports higher-order harmonics in response to a time varying magnetic field. The hypochlorite ions induce swelling in the coating, with the resultant stress altering the harmonic signature of the sensor from which the sodium hypochlorite concentration can be determined. The wireless, passive nature of the sensor platform enables long-term monitoring of bleach concentrations in the environment. The sensor platform can be extended to other chemical analytes of interest as desired.

Investigation of Oral Preparation That Is Expected to Improve Medication Administration: Preparation and Evaluation of Oral Gelling Tablet Using Sodium Alginate.

PubMed

Ito, Ikumi; Ito, Akihiko; Unezaki, Sakae

2017-01-01

We investigated the preparation of a gelling tablet that swells and forms a gel upon absorbing water, and hence would be easy for patients to swallow. We prepared naked tablets and compressed coated tablets by the direct tableting or wet granule-compression methods, using the commonly prescribed drug acetaminophen (AA) and sodium alginate (AG) as a thickening agent. The tablets quickly absorbed water, had favorable gelling properties, low adhesiveness, appropriate drug dissolution profile, and at the same time, were easy to swallow. In the case of naked tablets, water absorption increased upon granulation, but gelling of AG interfere when AA and AG were present together. There was no change in the adhesiveness, and more than 30 min were required to achieve a 25% dissolution ratio. Compressed coated tablets that were made with AA in the inner layer and granulated AG in the outer layer showed improved dissolution behavior, it was about 90% dissolution ratio in 30 min, owing to the water absorption property of AG, and decreased adhesiveness. In this case, there was a difference in the outer layer thickness. As the outer layer amount increased, dissolution slowed, but it did not depend on the compression pressure. Our gelling tablet can be prepared by using AA (main drug) in the inner layer and an appropriate thickness of granulated AG in the outer layer of compressed coated tablets.

Gateways to clinical trials.

PubMed

Bayes, M; Rabasseda, X; Prous, J R

2003-06-01

Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables has been retrieved from the Clinical Studies knowledge area of Prous Science Integrity(R), the drug discovery and development portal, http://integrity.prous.com. This issue focuses on the following selection of drugs: AdGVVEGF121.10, anakinra, andolast, anidulafungin, APC-2059, l-arginine hydrochloride, aripiprazole, arzoxifene hydrochloride, asimadoline; Bexarotene, bimatoprost, bimosiamose, bizelesin, BMS-188667, botulinum toxin type B, bromfenac sodium, bryostatin 1; Cannabidiol, cariporide mesilate, CCI-1004, CDP-571, cerivastatin sodium, clevudine; Dalbavancin, darbepoetin alfa, decitabine, deligoparin sodium, diethylnorspermine, drotrecogin alfa (activated), DTaP-HBV-IPV/Hib-vaccine; E-5564, eculizumab, edodekin alfa, emtricitabine, enfuvirtide, (-)-epigallocatechin gallate, eplerenone, esomeprazole magnesium, etaquine, etoricoxib, ezetimibe; Fesoterodine, fipamezole hydrochloride, fondaparinux sodium, fosamprenavir calcium, frovatriptan, fulvestrant; Gadofosveset sodium, galiximab, ghrelin (human), glufosfamide; Homoharringtonine; Idraparinux sodium, imatinib mesylate, INS-37217; KRN-7000; L-651582, lafutidine, lanthanum carbonate, lenercept, levetiracetam, lusupultide; Magnesium sulfate, melatonin, mepolizumab, midostaurin, morphine hydrochloride, mozavaptan; Natalizumab, nesiritide; OPC-51803, oregovomab, oritavancin; Peginterferon alfa-2(a), pleconaril, plevitrexed, prasterone, pregabalin; Ranibizumab, Ro-31-7453, roxifiban acetate, rubitecan; SCV-07, SHL-749, sho-saiko-to, soblidotin, solifenacin succinate; Tegaserod maleate, telithromycin, tenecteplase, theraCIM, tipifarnib, travoprost; Valdecoxib, vardenafil hydrochloride hydrate, voriconazole; Ximelagatran; Ziprasidone hydrochloride, ZYC-00101. (c) 2003 Prous Science. All rights reserved.

Optical properties of antiferromagnetic/ion-crystal superlattices

NASA Astrophysics Data System (ADS)

Ta, Jin-Xing; Song, Yu-Ling; Wang, Xuan-Zhang

2012-01-01

Transmission, refraction and absorption properties of an antiferromagnetic/ion-crystal superlattice are investigated. The transmission spectra based on FeF2/TlBr superlattices reveal that there exist two intriguing guided modes in a wide stop band. Additionally, FeF2/TlBr superlattices possess either the negative refraction or the quasi left-handedness, or even simultaneously hold them at certain frequencies of two guided modes, which require both negative magnetic permeability of antiferromagnetic layers and negative permittivity of ion-crystal layers. Frequency regimes of the guided modes will be dependent on the magnitude of the external magnetic field. Therefore, handedness and refraction properties of the system can be manipulated by modifying the external magnetic field. Absorption spectra exhibit that absorption corresponding to guided modes is noticeable.

Phase characteristics of rare earth elements in metallic fuel for a sodium-cooled fast reactor by injection casting

NASA Astrophysics Data System (ADS)

Kuk, Seoung Woo; Kim, Ki Hwan; Kim, Jong Hwan; Song, Hoon; Oh, Seok Jin; Park, Jeong-Yong; Lee, Chan Bock; Youn, Young-Sang; Kim, Jong-Yun

2017-04-01

Uranium-zirconium-rare earth (U-Zr-RE) fuel slugs for a sodium-cooled fast reactor were manufactured using a modified injection casting method, and investigated with respect to their uniformity, distribution, composition, and phase behavior according to RE content. Nd, Ce, Pr, and La were chosen as four representative lanthanide elements because they are considered to be major RE components of fuel ingots after pyroprocessing. Immiscible layers were found on the top layers of the melt-residue commensurate with higher fuel slug RE content. Scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) data showed that RE elements in the melt-residue were distributed uniformly throughout the fuel slugs. RE element agglomeration did not contaminate the fuel slugs but strongly affected the RE content of the slugs.

Influence of ablation impurities on blunt body re-entry ionization

NASA Technical Reports Server (NTRS)

Schexnayder, C. J., Jr.; Evans, J. S.

1974-01-01

Electron density profiles which include the effect of an ablated sodium impurity were computed for the boundary layer on a blunt-nosed body re-entering the atmosphere at 7.62 km/sec. Profiles are computed from the nose to a distance of four diameters along the RAM C-payload. A finite-difference, laminar, nonequilibrium chemistry boundary-layer program was used. Comparison of theory with S-band diagnostic antenna results, electron concentration deduced from X- and C-band attenuation data, and Langmuir probe data at several different aft body locations show that agreement is good at high altitude. At the lower altitudes there is disagreement between theory and S-band antenna data where the apparent discrepancy is attributed to the three-body recombination rate constant used for deionization of sodium coupled with the effect of angle of attack.

Yolk–shell Fe 2O 3 ⊙ C composites anchored on MWNTs with enhanced lithium and sodium storage

DOE PAGES

Zhao, Yi; Feng, Zhenxing; Xu, Zhichuan J.

2015-04-24

For this research, a unique architecture with yolk–shell Fe 2O 3 ⊙ C composites attached to the surface of MWNTs is designed. Benefiting from the good electrical conductivity of MWNTs and carbon layers, as well as the large void space to accommodate the volume expansion/extraction of Fe 2O 3 during battery cycling, the obtained MWNT@Fe 2O 3 ⊙ C exhibited outstanding lithium and sodium storage performance.

Chronoamperometric study of mild steel pitting in sodium sulfide aqueous solution

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

Otero, T.F.; Achucarro, C.

1994-08-01

Mild steel samples were studied by chronoamperometry in sodium sulfide (Na[sub 2]S) aqueous solution. Pit nucleation and growth also were monitored by optical microscopy. The influence of variables such as temperature, polarization potential, surface roughness, the presence of electrochemically generated oxide layers, and the simultaneous presence of potassium hydroxide (KOH) was studied. The influence of each parameter on pit shape and growth was reviewed. Different reactions and competitive processes were proposed based on the experimental results.

The role of halide ions on the electrochemical behaviour of iron in alkali solutions

NASA Astrophysics Data System (ADS)

Begum, S. Nathira; Muralidharan, V. S.; Basha, C. Ahmed

2008-02-01

Active dissolution and passivation of transition metals in alkali solutions is of technological importance in batteries. The performance of alkaline batteries is decided by the presence of halides as they influence passivation. Cyclic voltammetric studies were carried out on iron in different sodium hydroxide solutions in presence of halides. In alkali solutions iron formed hydroxo complexes and their polymers in the interfacial diffusion layer. With progress of time they formed a cation selective layer. The diffusion layer turned into bipolar ion selective layer consisted of halides, a selective inner sublayer to the metal side and cation selective outer layer to the solution side. At very high anodic potentials, dehydration and deprotonation led to the conversion of salt layer into an oxide.

An in vitro evaluation of passive ultrasonic agitation of different irrigants on smear layer removal after post space preparation: a scanning electron microscopic study.

PubMed

Srirekha, A; Rashmi, K; Hegde, Jayshree; Lekha, S; Rupali, K; Reshmi, George

2013-09-01

This study evaluated the removal of debris and smear layer after post space preparation using different irrigations and passive ultrasonic agitation. Sixty human premolars were decoronated and post space prepared after endodontic therapy. The samples were then randomly divided into three experimental groups (Groups A, B, C) and one control group (Group D) with fifteen samples in each group. Groups A and B samples were treated with 10 % citric acid and 17 % ethylenediamintetraacetic acid (EDTA), respectively and passive ultrasonic agitation was done, rinsed with sodium hypochlorite and finally flushed with saline. Group C samples were conditioned with 36 % phosphoric acid and then rinsed with saline. The control group was treated with 3 % sodium hypochlorite, passive ultrasonic agitation done and flushed with saline. The samples were sectioned and evaluated for debris and smear layer removal under scanning electron microscope. 10 % citric acid showed the best removal of smear layer when compared with 17 % EDTA and 36 % phosphoric acid, but was not statistically significant (p > 0.05). The difference in scoring for debris and smear layer removal in the coronal, middle and apical third of post space of experimental groups in comparison with control group was statistically significant (p < 0.001).

Novel Swelling-Resistant Sodium Alginate Membrane Branching Modified by Glycogen for Highly Aqueous Ethanol Solution Pervaporation.

PubMed

Ji, Chen-Hao; Xue, Shuang-Mei; Xu, Zhen-Liang

2016-10-12

A novel carbohydrate chain cross-linking method of sodium alginate (SA) is proposed in which glycogen with the branched-chain structure is utilized to cross-link with SA matrix by the bridging of glutaraldehyde (GA). The active layer of SA composite ceramic membrane modified by glycogen and GA for pervaporation (PV) demonstrates great advantages. The branched structure increases the chain density of the active layer, which compresses the free volume between the carbohydrate chains of SA. Large amounts of hydroxyl groups are consumed during the reaction with GA, which reduces the hydrogen bond formation between water molecules and the polysaccharide matrix. The two factors benefit the active layer with great improvement in swelling resistance, promoting the potential of the active layer for the dehydration of an ethanol-water solution containing high water content. Meanwhile, the modified active layer is loaded on the rigid α-Al 2 O 3 ceramic membrane by dip-coating method with the enhancement of anti-deformation and controllable thickness of the active layer. Characterization techniques such as SEM, AFM, XRD, FTIR, XPS, and water contact angle are utilized to observe the composite structure and surface morphology of the composite membrane, to probe the free volume variation, and to determine the chemical composition and hydrophilicity difference of the active layer caused by the different glycogen additive amounts. The membrane containing 3% glycogen in the selective layer demonstrates the flux at 1250 g m -2 h -1 coupled with the separation factor of 187 in the 25 wt % water content feed solution at the operating temperature of 75 °C, reflecting superior pervaporation processing capacity compared with the general organic PV membranes in the same condition.

Facile synthesis of 3D MnNi-layered double hydroxides (LDH)/graphene composites from directly graphites for pseudocapacitor and their electrochemical analysis

NASA Astrophysics Data System (ADS)

Lee, Ilbok; Jeong, Gyoung Hwa; An, Soyeon; Kim, Sang-Wook; Yoon, Songhun

2018-01-01

Herein, MnNi-layered double hydroxides (LDH) were imbibed within the interlayers of graphene nanosheets. The anionic surfactant, sodium dodecyl sulfate played a role of graphite exfoliator adding interaction with metal cations. Using this process, layered MnNi-LDH-graphene nanocomposite was prepared without formation of graphene oxide. When applied into pseudocapacitor electrode, LDH-graphene with optimal ratio between Mn and Ni exhibited very stable cycle with 90% at 1400 cycles and high energy 47.29 Wh kg-1 at the power density of 7473 W kg-1, which was attributed to highly stable layered LDH structure within conductive graphene layers.

Role of adsorbed surfactant in the reaction of aryl diazonium salts with single-walled carbon nanotubes.

PubMed

Hilmer, Andrew J; McNicholas, Thomas P; Lin, Shangchao; Zhang, Jingqing; Wang, Qing Hua; Mendenhall, Jonathan D; Song, Changsik; Heller, Daniel A; Barone, Paul W; Blankschtein, Daniel; Strano, Michael S

2012-01-17

Because covalent chemistry can diminish the optical and electronic properties of single-walled carbon nanotubes (SWCNTs), there is significant interest in developing methods of controllably functionalizing the nanotube sidewall. To date, most attempts at obtaining such control have focused on reaction stoichiometry or strength of oxidative treatment. Here, we examine the role of surfactants in the chemical modification of single-walled carbon nanotubes with aryl diazonium salts. The adsorbed surfactant layer is shown to affect the diazonium derivatization of carbon nanotubes in several ways, including electrostatic attraction or repulsion, steric exclusion, and direct chemical modification of the diazonium reactant. Electrostatic effects are most pronounced in the cases of anionic sodium dodecyl sulfate and cationic cetyltrimethylammonium bromide, where differences in surfactant charge can significantly affect the ability of the diazonium ion to access the SWCNT surface. For bile salt surfactants, with the exception of sodium cholate, we find that the surfactant wraps tightly enough such that exclusion effects are dominant. Here, sodium taurocholate exhibits almost no reactivity under the explored reaction conditions, while for sodium deoxycholate and sodium taurodeoxycholate, we show that the greatest extent of reaction is observed among a small population of nanotube species, with diameters between 0.88 and 0.92 nm. The anomalous reaction of nanotubes in this diameter range seems to imply that the surfactant is less effective at coating these species, resulting in a reduced surface coverage on the nanotube. Contrary to the other bile salts studied, sodium cholate enables high selectivity toward metallic species and small band gap semiconductors, which is attributed to surfactant-diazonium coupling to form highly reactive diazoesters. Further, it is found that the rigidity of anionic surfactants can significantly influence the ability of the surfactant layer to stabilize the diazonium ion near the nanotube surface. Such Coulombic and surfactant packing effects offer promise toward employing surfactants to controllably functionalize carbon nanotubes. © 2011 American Chemical Society

Transbronchial drainage using endobronchial ultrasonography with guide sheath for lung abscess: A case report.

PubMed

Yaguchi, Daizo; Ichikawa, Motoshi; Inoue, Noriko; Kobayashi, Daisuke; Shizu, Masato; Imai, Naoyuki

2018-05-01

Lung abscess was previously treated surgically, but is now mainly treated with antibiotics and ideally with direct drainage, although postural drainage canalso be used. A chest abnormal shadow was detected in an 82-year-old man and he was referred to our department in November 2017. On chest computed tomography (CT), a low-density mass shadow was present in the left S8 segment. Lung abscess and lung cancer were considered as differential diagnoses, and treatment with sulbactam sodium/ampicillin sodium (SBT/ABPC) was first initiated for lung abscess. The etiologic agent could not be identified by sputum examination, and the abscess shadow remained. Lung abscess. Endobronchial ultrasonography with a guide sheath (EBUS-GS)-guided bronchoscopy was performed on hospital day 21 to diagnose the lesion, identify the etiologic agent if the lesion was a lung abscess, and attempt drainage. Vacuum aspiration performed in the guide sheath after the probe was placed within the lesion produced 4-5 ml of gray turbid pus, and the abscess was judged to have been drained. A subsequent pathological examination did not detect malignant cells. Klebsiella pneumoniae, Prevotella spp. was identified as the etiologic agent in bacteriological tests. Antibiotics were changed based on sensitivity test results, and drainage was similarly performed on hospital day 28. The shadow gradually improved and disappeared. Therefore, this procedure and treatment led to identification of the etiologic agent and helped with cure of the disease. Based on the basic principle of treatment for abscess using as much drainage as possible, EBUS-GS-guided transbronchial drainage may be considered to be a "new procedure" for lung abscess.

Transbronchial drainage using endobronchial ultrasonography with guide sheath for lung abscess

PubMed Central

Yaguchi, Daizo; Ichikawa, Motoshi; Inoue, Noriko; Kobayashi, Daisuke; Shizu, Masato; Imai, Naoyuki

2018-01-01

Abstract Rationale: Lung abscess was previously treated surgically, but is now mainly treated with antibiotics and ideally with direct drainage, although postural drainage canalso be used. Patient concerns: A chest abnormal shadow was detected in an 82-year-old man and he was referred to our department in November 2017. On chest computed tomography (CT), a low-density mass shadow was present in the left S8 segment. Lung abscess and lung cancer were considered as differential diagnoses, and treatment with sulbactam sodium/ampicillin sodium (SBT/ABPC) was first initiated for lung abscess. The etiologic agent could not be identified by sputum examination, and the abscess shadow remained. Diagnoses: Lung abscess. Interventions: Endobronchial ultrasonography with a guide sheath (EBUS-GS)-guided bronchoscopy was performed on hospital day 21 to diagnose the lesion, identify the etiologic agent if the lesion was a lung abscess, and attempt drainage. Vacuum aspiration performed in the guide sheath after the probe was placed within the lesion produced 4-5 ml of gray turbid pus, and the abscess was judged to have been drained. Outcomes: A subsequent pathological examination did not detect malignant cells. Klebsiella pneumoniae, Prevotella spp. was identified as the etiologic agent in bacteriological tests. Antibiotics were changed based on sensitivity test results, and drainage was similarly performed on hospital day 28. The shadow gradually improved and disappeared. Therefore, this procedure and treatment led to identification of the etiologic agent and helped with cure of the disease. Lessons: Based on the basic principle of treatment for abscess using as much drainage as possible, EBUS-GS-guided transbronchial drainage may be considered to be a “new procedure” for lung abscess. PMID:29768382

Insights into the dual-electrode characteristics of layered Na 0.5Ni 0.25Mn 0.75O 2 materials for sodium-ion batteries

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

Manikandan, Palanisamy; Kim, Hyunwoo; Heo, Seongwoo

Sodium-ion batteries are now close to replacing lithium-ion batteries because they provide superior alternative energy storage solutions that are in great demand, particularly for large-scale applications. To that end, the present study is focused on the properties of a new type of dual-electrode material, Na 0.5Ni 0.25Mn 0.75O 2, synthesized using a mixed hydroxycarbonate route. Cyclic voltammetry confirms that redox couples, at high and low voltage ranges, are facilitated by the unique features and properties of this dual-electrode, through sodium ion deintercalation/intercalation into the layered Na 0.5Ni 0.25Mn 0.25O 2 material. This material provides superior performance for Na-ion batteries, asmore » evidenced by the fabricated sodium cell that yielded initial charge discharge capacities of 125/218 mAh g -1 in the voltage range of 1.5-4.4 V at 0.5 C. At a low voltage range (1.5-2.6 V), the anode cell delivered discharge charge capacities of 100/99 mAh g -1 with 99% capacity retention, which corresponds to highly reversible redox reaction of the Mn 4+/3+ reduction and the Mn 3+/4+ oxidation observed at 1.85 and 2.06 V, respectively. The symmetric Na-ion cell, fabricated using Na 0.5Ni 0.25Mn 0.25O 2, yielded initial charge discharge capacities of 196/187 μAh at 107 μA. Lastly, these results encourage the further development of new types of futuristic sodium-ion battery-based energy storage systems.« less

Insights into the dual-electrode characteristics of layered Na 0.5Ni 0.25Mn 0.75O 2 materials for sodium-ion batteries

DOE PAGES

Manikandan, Palanisamy; Kim, Hyunwoo; Heo, Seongwoo; ...

2017-03-09

Sodium-ion batteries are now close to replacing lithium-ion batteries because they provide superior alternative energy storage solutions that are in great demand, particularly for large-scale applications. To that end, the present study is focused on the properties of a new type of dual-electrode material, Na 0.5Ni 0.25Mn 0.75O 2, synthesized using a mixed hydroxycarbonate route. Cyclic voltammetry confirms that redox couples, at high and low voltage ranges, are facilitated by the unique features and properties of this dual-electrode, through sodium ion deintercalation/intercalation into the layered Na 0.5Ni 0.25Mn 0.25O 2 material. This material provides superior performance for Na-ion batteries, asmore » evidenced by the fabricated sodium cell that yielded initial charge discharge capacities of 125/218 mAh g -1 in the voltage range of 1.5-4.4 V at 0.5 C. At a low voltage range (1.5-2.6 V), the anode cell delivered discharge charge capacities of 100/99 mAh g -1 with 99% capacity retention, which corresponds to highly reversible redox reaction of the Mn 4+/3+ reduction and the Mn 3+/4+ oxidation observed at 1.85 and 2.06 V, respectively. The symmetric Na-ion cell, fabricated using Na 0.5Ni 0.25Mn 0.25O 2, yielded initial charge discharge capacities of 196/187 μAh at 107 μA. Lastly, these results encourage the further development of new types of futuristic sodium-ion battery-based energy storage systems.« less

Insights into the Dual-Electrode Characteristics of Layered Na0.5Ni0.25Mn0.75O2 Materials for Sodium-Ion Batteries.

PubMed

Palanisamy, Manikandan; Kim, Hyun Woo; Heo, Seongwoo; Lee, Eungje; Kim, Youngsik

2017-03-29

Sodium-ion batteries are now close to replacing lithium-ion batteries because they provide superior alternative energy storage solutions that are in great demand, particularly for large-scale applications. To that end, the present study is focused on the properties of a new type of dual-electrode material, Na 0.5 Ni 0.25 Mn 0.75 O 2 , synthesized using a mixed hydroxy-carbonate route. Cyclic voltammetry confirms that redox couples, at high and low voltage ranges, are facilitated by the unique features and properties of this dual-electrode, through sodium ion deintercalation/intercalation into the layered Na 0.5 Ni 0.25 Mn 0.75 O 2 material. This material provides superior performance for Na-ion batteries, as evidenced by the fabricated sodium cell that yielded initial charge-discharge capacities of 125/218 mAh g -1 in the voltage range of 1.5-4.4 V at 0.5 C. At a low voltage range (1.5-2.6 V), the anode cell delivered discharge-charge capacities of 100/99 mAh g -1 with 99% capacity retention, which corresponds to highly reversible redox reaction of the Mn 4+/3+ reduction and the Mn 3+/4+ oxidation observed at 1.85 and 2.06 V, respectively. The symmetric Na-ion cell, fabricated using Na 0.5 Ni 0.25 Mn 0.75 O 2 , yielded initial charge-discharge capacities of 196/187 μAh at 107 μA. These results encourage the further development of new types of futuristic sodium-ion-battery-based energy storage systems.

Sorbents based on asbestos with a layer of an hydroxyethylcyclam derivative of PVC containing aquacomplexes of sulfuric acid or sodium hydroxide with aza-crown groups

NASA Astrophysics Data System (ADS)

Tsivadze, A. Yu.; Fridman, A. Ya.; Morozova, E. M.; Sokolova, N. P.; Voloshchuk, A. M.; Petukhova, G. A.; Bardyshev, I. I.; Gorbunov, A. M.; Polyakova, I. Ya.; Titova, V. N.; Yavich, A. A.; Novikov, A. K.; Petrova, N. V.

2016-07-01

Aquacomplexes of sulfuric acid and sodium hydroxide with aza-crown groups are synthesized in cavities of a sorbent from the porous layer of a PVC cyclam-derivative grafted onto fibers of asbestos fabric. The structure of sorbents with complexes is studied and their adsorption characteristics are determined. It is shown that the affinity of the developed surface toward ethanol, benzene, and hexane depends on the nature of complexes in the pore walls, and the volume of cavities formed as a result of the pores on the developed asbestos surface being coated with networks of aza-crown groups is larger than that of cavities with walls of aza-crown groups in the layers of a PVC cyclam derivative. Indicators of H+- and OH--conductivity of sorbents with complexes as electrochemical bridges are determined. It is shown that the major part of H+- and OH--ions moves through complexes with aza-crown groups in the region of cavities formed of pores on the surface of asbestos.

Heterojunction solar cell with 6% efficiency based on an n-type aluminum-gallium-oxide thin film and p-type sodium-doped Cu2O sheet

NASA Astrophysics Data System (ADS)

Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

2015-02-01

In this paper, we describe efforts to enhance the efficiency of Cu2O-based heterojunction solar cells fabricated with an aluminum-gallium-oxide (Al-Ga-O) thin film as the n-type layer and a p-type sodium (Na)-doped Cu2O (Cu2O:Na) sheet prepared by thermally oxidizing copper sheets. The optimal Al content [X; Al/(Ga + Al) atomic ratio] of an AlX-Ga1-X-O thin-film n-type layer was found to be approximately 2.5 at. %. The optimized resistivity was approximately 15 Ω cm for n-type AlX-Ga1-X-O/p-type Cu2O:Na heterojunction solar cells. A MgF2/AZO/Al0.025-Ga0.975-O/Cu2O:Na heterojunction solar cell with 6.1% efficiency was fabricated using a 60-nm-thick n-type oxide thin-film layer and a 0.2-mm-thick Cu2O:Na sheet with the optimized resistivity.

Effects of Additives on Electrochemical Growth of Cu Film on Co/SiO2/Si Substrate by Alternating Underpotential Deposition of Pb and Surface-Limited Redox Replacement by Cu

NASA Astrophysics Data System (ADS)

Fang, J. S.; Lin, L. Y.; Wu, C. L.; Cheng, Y. L.; Chen, G. S.

2017-11-01

The effects of additives to an acidic electrolyte for electrochemical deposition of copper film to prevent corrosion of the Co/SiO2/Si substrate have been investigated. A sacrificial Pb layer was formed by underpotential deposition (UPD), then a Cu layer was prepared using surface-limited redox replacement (SLRR) to exchange the UPD-Pb layer in an acidic copper electrolyte with trisodium citrate, sodium perchlorate, and ethylenediamine as additives. The additives significantly affected the replacement of UPD-Pb by Cu and prevented galvanic corrosion of the Co/SiO2/Si substrate in the acidic Cu electrolyte. The results showed that both sodium perchlorate and ethylenediamine reduced the corrosion of the Co substrate and resulted in Cu film with low electrical resistivity. However, residual Pb was present in the Cu film when using trisodium citrate, as the citrate ions slowed copper displacement. The proposed sequential UPD-Pb and SLRR-Cu growth method may enable electrochemical deposition for fabrication of Cu interconnects on Co substrate from acidic Cu electrolyte.

Encapsulation of methotrexate loaded magnetic microcapsules for magnetic drug targeting and controlled drug release

NASA Astrophysics Data System (ADS)

Chakkarapani, Prabu; Subbiah, Latha; Palanisamy, Selvamani; Bibiana, Arputha; Ahrentorp, Fredrik; Jonasson, Christian; Johansson, Christer

2015-04-01

We report on the development and evaluation of methotrexate magnetic microcapsules (MMC) for targeted rheumatoid arthritis therapy. Methotrexate was loaded into CaCO3-PSS (poly (sodium 4-styrenesulfonate)) doped microparticles that were coated successively with poly (allylamine hydrochloride) and poly (sodium 4-styrenesulfonate) by layer-by-layer technique. Ferrofluid was incorporated between the polyelectrolyte layers. CaCO3-PSS core was etched by incubation with EDTA yielding spherical MMC. The MMC were evaluated for various physicochemical, pharmaceutical parameters and magnetic properties. Surface morphology, crystallinity, particle size, zeta potential, encapsulation efficiency, loading capacity, drug release pattern, release kinetics and AC susceptibility studies revealed spherical particles of ~3 μm size were obtained with a net zeta potential of +24.5 mV, 56% encapsulation and 18.6% drug loading capacity, 96% of cumulative drug release obeyed Hixson-Crowell model release kinetics. Drug excipient interaction, surface area, thermal and storage stability studies for the prepared MMC was also evaluated. The developed MMC offer a promising mode of targeted and sustained release drug delivery for rheumatoid arthritis therapy.

Preparation and characterization of coating sodium trisilicate (Na2O.nSiO2) at calcium carbonate (CaCO3) for blowing agent in Mg alloy foam

NASA Astrophysics Data System (ADS)

Erryani, Aprilia; Lestari, Franciska Pramuji; Annur, Dhyah; Kartika, Ika

2018-05-01

The role of blowing agent in the manufacture of porous metal alloys is very important to produce the desired pore. The thermal stability and speed of foam formation have an effect on the resulting pore structure. In porous metal alloys, uniformity of size and pore deployment are the main determinants of the resulting alloys. The coating process of calcium carbonate (CaCO3) has been done using Sodium trisilicate solution by sol-gel method. Foaming agent was pretreated by coating SiO2 passive layer on the surface of CaCO3. This coating aims to produce a more stable blowing agent so that the foaming process can produce a more uniform pore size. The microstructure of the SiO2 passive was observed using Scanning Electron Microscope (SEM) equipped by Energy Dispersive X-Ray Spectrometer (EDS) mapping. The results showed coating CaCO3 using sodium trisilicate was successfully done creating a passive layer of SiO2 on the surface of CaCO3. By the coating process, the thermal stability of coated CaCO3 increased compared to uncoated CaCO3.

A High-Performance Sodium-Ion Full Cell with a Layered Oxide Cathode and a Phosphorous-Based Composite Anode

DOE PAGES

Oh, Seung-Min; Oh, Pilgun; Kim, Sang-Ok; ...

2016-12-29

A low-cost sodium-ion full cell with a O3-type layered Na[Cu 0.2(Fe 1/3Mn2/3) 0.8]O 2 cathode and an alloy-type P-TiP2-C anode is presented. The cathode is synthesized by an oxalate coprecipitation method and optimized cathodes shows a high specific capacity of 135 mAh g -1 at 0.1C rate with a high rate capability of 90 mAh g-1 at 1C rate and 70 mAh g -1 at 2C rate with good cyclability. The full cell exhibits better capacity retention than the half cell with the cathode due to the elimination of the degradation caused by sodium-metal anode. The dramatically enhanced electrochemical performancemore » of the Na[Cu 0.2(Fe 1/3Mn 2/3) 0.8]O 2 / P-TiP 2-C full cell compared to that of the sample with no Cu is attributed to the structural stabilization imparted by Cu by suppressing the phase change from the O3 structure to the P3 structure during cycling.« less

High-Power Arctic Lidar for observations of Sodium layer and Calcium Ion Cyclotron Resonance Heating

NASA Astrophysics Data System (ADS)

Wuerker, R. F.; Foley, J.; Kidd, P.; Wong, A. Y.

1998-11-01

The UCLA HIPAS Observatory is located at 64o 54' 22"N, 146o 50' 33" W. It passes under the auroral oval, has a 2.7 m diameter liquid mirror collector (LMT), and two bistatic laser illuminators; a Doubled YAG pumped dye laser and a Doubled (tunable) Alexandrite laser. The first emits 0.1 J - 10 ns pulses at 590nm (Na) at 20 Hz. The second laser emits 0.15 J -10 ns pulses at 393 nm (Ca+) and 391.4 nm (N2) at 10 Hz. New sporadic sodium layers have been observed during the passage of the electrojet and auroras in periods of 20-30 seconds, indicating that sodium is liberated from micrometeors during auroral precipitations. The Laser Induced Fluorescence techniques will be used to observe the acceleration of the Ca+ ions when they are driven by the 80 MW (ERP) 2.85MHz RF array, modulated at the Ca+ ion Cyclotron Frequency. 1. Ionospheric Modifaction and Enviromental Research in the Auroral Region in Plasma Science and the Environment. Publisher: AIP Press, Woodbury, NY. Editors: W. Manheimer, L. Sugiyama, T. Stix; Chapter 3, pgs. 41-75, 1997. Research supported by ONR N00014-96-C-0040

Dendrite-Free Sodium-Metal Anodes for High-Energy Sodium-Metal Batteries.

PubMed

Sun, Bing; Li, Peng; Zhang, Jinqiang; Wang, Dan; Munroe, Paul; Wang, Chengyin; Notten, Peter H L; Wang, Guoxiu

2018-05-31

Sodium (Na) metal is one of the most promising electrode materials for next-generation low-cost rechargeable batteries. However, the challenges caused by dendrite growth on Na metal anodes restrict practical applications of rechargeable Na metal batteries. Herein, a nitrogen and sulfur co-doped carbon nanotube (NSCNT) paper is used as the interlayer to control Na nucleation behavior and suppress the Na dendrite growth. The N- and S-containing functional groups on the carbon nanotubes induce the NSCNTs to be highly "sodiophilic," which can guide the initial Na nucleation and direct Na to distribute uniformly on the NSCNT paper. As a result, the Na-metal-based anode (Na/NSCNT anode) exhibits a dendrite-free morphology during repeated Na plating and striping and excellent cycling stability. As a proof of concept, it is also demonstrated that the electrochemical performance of sodium-oxygen (Na-O 2 ) batteries using the Na/NSCNT anodes show significantly improved cycling performances compared with Na-O 2 batteries with bare Na metal anodes. This work opens a new avenue for the development of next-generation high-energy-density sodium-metal batteries. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnetic Eigenmodes in the Madison Dynamo Experiment

NASA Astrophysics Data System (ADS)

Nornberg, M. D.; Bayliss, R. A.; Forest, C. B.; Kendrick, R. D.; O'Connell, R.; Spence, E. J.

2002-11-01

A spherical dynamo experiment has been constructed at the University of Wisconsin's liquid sodium facility. The goals of the experiment are to observe and understand magnetic instabilities driven by flow shear in MHD systems, investigate MHD turbulence for magnetic Reynolds numbers of 100, and understand the role of fluid turbulence in current generation. Magnetic field generation is only possible for specific flow geometries. We have studied and achieved simple roll flow geometries in a full scale water experiment. Results from the water experiment have guided the design of the sodium experiment. The experiment consists of a 1 m diameter, spherical stainless steel vessel filled with liquid sodium at 110 Celsius. Two 100 Hp motors with impellers drive flows in the liquid sodium with flow velocities of 15 m/s. A gaussian grid of 66 Hall probes on the surface of the sodium vessel measure the generated external magnetic field. Hall probe feed-thru arrays measure the internal field. A pair of magnetic field coils produce a roughly uniform field inside the sphere with a centerline field strength of 100 gauss. Preliminary investigations include measurements of the turbulent electromotive force and excitation of magnetic eigenmodes.

Influence of Sodium Silicate/Sodium Alginate Additives on Discharge Performance of Mg-Air Battery Based on AZ61 Alloy

NASA Astrophysics Data System (ADS)

Ma, Jingling; Wang, Guangxin; Li, Yaqiong; Li, Wuhui; Ren, Fengzhang

2018-04-01

The application of Mg-air batteries is limited due to passivation and self-corrosion of anode alloys in electrolyte. In effort of solving this problem, the present work studied the influence of sodium silicate (SS)/sodium alginate (SA) on electrochemical behaviors of AZ61 alloy in NaCl solution by circle potentiodynamic polarization and galvanostatic discharge. The corrosion morphology and discharge product were examined by scanning electron microscopy (SEM) and x-ray diffraction (XRD). Results have shown that sodium silicate/sodium alginate inhibitors have an apparent effect on the self-corrosion of AZ61 alloy without affecting its discharge performance. The discharge capacity and the anodic utilization for Mg-air battery in a 0.6 M NaCl + 0.01 M SS +0.04 M SA solution are measured to be 1397 mAhg-1 and 48.2%, respectively. Electrochemical impedance spectroscopy (EIS) and SEM investigation have confirmed that the sodium silicate/sodium alginate inhibitor can obviously decrease the self-corrosion of AZ61 alloy. SEM and XRD diffraction examinations suggest that the inhibiting mechanism is due to the formation of a compact and "cracked mud" layer. AZ61 alloy can be used as the anode for Mg-air battery in a solution of 0.6 M NaCl + 0.01 M SS +0.04 M SA.

Influence of Sodium Silicate/Sodium Alginate Additives on Discharge Performance of Mg-Air Battery Based on AZ61 Alloy

NASA Astrophysics Data System (ADS)

Ma, Jingling; Wang, Guangxin; Li, Yaqiong; Li, Wuhui; Ren, Fengzhang

2018-05-01

The application of Mg-air batteries is limited due to passivation and self-corrosion of anode alloys in electrolyte. In effort of solving this problem, the present work studied the influence of sodium silicate (SS)/sodium alginate (SA) on electrochemical behaviors of AZ61 alloy in NaCl solution by circle potentiodynamic polarization and galvanostatic discharge. The corrosion morphology and discharge product were examined by scanning electron microscopy (SEM) and x-ray diffraction (XRD). Results have shown that sodium silicate/sodium alginate inhibitors have an apparent effect on the self-corrosion of AZ61 alloy without affecting its discharge performance. The discharge capacity and the anodic utilization for Mg-air battery in a 0.6 M NaCl + 0.01 M SS +0.04 M SA solution are measured to be 1397 mAhg-1 and 48.2%, respectively. Electrochemical impedance spectroscopy (EIS) and SEM investigation have confirmed that the sodium silicate/sodium alginate inhibitor can obviously decrease the self-corrosion of AZ61 alloy. SEM and XRD diffraction examinations suggest that the inhibiting mechanism is due to the formation of a compact and "cracked mud" layer. AZ61 alloy can be used as the anode for Mg-air battery in a solution of 0.6 M NaCl + 0.01 M SS +0.04 M SA.

Laser generated guided waves and finite element modeling for the thickness gauging of thin layers.

PubMed

Lefevre, F; Jenot, F; Ouaftouh, M; Duquennoy, M; Ourak, M

2010-03-01

In this paper, nondestructive testing has been performed on a thin gold layer deposited on a 2 in. silicon wafer. Guided waves were generated and studied using a laser ultrasonic setup and a two-dimensional fast Fourier transform technique was employed to obtain the dispersion curves. A gold layer thickness of 1.33 microm has been determined with a +/-5% margin of error using the shape of the two first propagating modes, assuming for the substrate and the layer an uncertainty on the elastic parameters of +/-2.5%. A finite element model has been implemented to validate the data post-treatment and the experimental results. A good agreement between the numerical simulation, the analytical modeling and the experimentations has been observed. This method was considered suitable for thickness layer higher than 0.7 microm.

Inverted Planar Perovskite Solar Cells with a High Fill Factor and Negligible Hysteresis by the Dual Effect of NaCl-Doped PEDOT:PSS.

PubMed

Hu, Lijun; Sun, Kuan; Wang, Ming; Chen, Wei; Yang, Bo; Fu, Jiehao; Xiong, Zhuang; Li, Xinyi; Tang, Xiaosheng; Zang, Zhigang; Zhang, Shupeng; Sun, Lidong; Li, Meng

2017-12-20

The performance of inverted perovskite solar cells is highly dependent on hole extraction and surface properties of hole transport layers. To highlight the important role of hole transport layers, a facile and simple method is developed by adding sodium chloride (NaCl) into poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The average power conversion efficiency of the perovskite solar cells prepared on NaCl-doped PEDOT:PSS is 17.1% with negligible hysteresis, compared favorably to the control devices (15.1%). Particularly, they exhibit markedly improved V oc and fill factor (FF), with the best FF as high as 81.9%. The enhancement of photovoltaic performance is ascribed to two effects. Better conductivity and hole extraction of PEDOT:PSS are observed after NaCl doping. More intriguingly, the perovskite polycrystalline film shows a preferred orientation along the (001) direction on NaCl-doped PEDOT:PSS, leading to a more uniform thin film. The comparison of the crystal structure between NaCl and MAPbCl 3 indicates a lattice constant mismatch less than 2% and a matched chlorine atom arrangement on the (001) surface, which implies that the NaCl crystallites on the top surface of PEDOT:PSS might serve as seeds guiding the growth of perovskite crystals. This simple method is fully compatible with printing technologies to mass-produce perovskite solar cells with high efficiency and tunable crystal orientations.

Penetration of salicylic acid and salicylate into the multilayer membrane system and into the human horny layer.

PubMed

Neubert, R; Partyka, D; Wohlrab, W; Dettlaff, B; Fürst, W; Taube, K M

1990-01-01

Using a multilayer membrane system and human horny layer the difference in the penetration of salicylic acid (SA) and its sodium (Na-S) and choline (Ch-S) salts from topical formulations was studied. It was found Na-S and Ch-S were markedly accumulated in the first membrane of the three layer membrane system used. In contrast, a rapid penetration into all three membranes was observed when SA was used. Similar penetration profiles were obtained in human horny layer. Hence, the use of the salts of SA appears to be more suitable for the application as keratolytic.

Obsidian hydration profiles measured by sputter-induced optical emission.

PubMed

Tsong, I S; Houser, C A; Yusef, N A; Messier, R F; White, W B; Michels, J W

1978-07-28

The variation of concentrations of hydrogen, sodium, potassium, lithium, calcium, magnesium, silicon, and aluminum as a function of depth in the hydration layer of obsidian artifacts has been determined by sputter-induced optical emission. The surface hydration is accompanied by dealkalization, and there is a buildup of alkaline earths, calcium and magnesium in the outermost layers. These results have clarified the phenomena underlying the obsidian hydration dating technique.

Plasma carburizing with surface micro-melting

NASA Astrophysics Data System (ADS)

Balanovsky, A. E.; Grechneva, M. V.; Van Huy, Vu; Ponomarev, B. B.

2018-03-01

This paper presents carburizing the surface of 20 low carbon steel using electric arc and graphite prior. A carbon black solution was prepared with graphite powder and sodium silicate in water. A detailed analysis of the phase structure and the distribution profile of the sample hardness after plasma treatment were given. The hardened layer consists of three different zones: 1 – the cemented layer (thin white zone) on the surface, 2 – heat-affected zone (darkly etching structure), 3 – the base metal. The experimental result shows that the various microstructures and micro-hardness profiles were produced depending on the type of graphite coating (percentage of liquid glass) and processing parameters. The experiment proved that the optimum content of liquid glass in graphite coating is 50–87.5%. If the amount of liquid glass is less than 50%, adhesion to metal is insufficient. If liquid glass content is more than 87.5%, carburization of a metal surface does not occur. A mixture of the eutectic lamellar structure, martensite and austenite was obtained by using graphite prior with 67% sodium silicate and the levels of the hardness layer increased to around 1000 HV. The thickness of the cemented layer formed on the surface was around 200 μm. It is hoped that this plasma surface carburizing treatment could improve the tribological resistance properties.

Stability indicating high performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in combined dosage form

PubMed Central

Bageshwar, Deepak; Khanvilkar, Vineeta; Kadam, Vilasrao

2011-01-01

A specific, precise and stability indicating high-performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in pharmaceutical formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F254 as the stationary phase. The solvent system consisted of methanol:water:ammonium acetate; 4.0:1.0:0.5 (v/v/v). This system was found to give compact and dense spots for both itopride hydrochloride (Rf value of 0.55±0.02) and pantoprazole sodium (Rf value of 0.85±0.04). Densitometric analysis of both drugs was carried out in the reflectance–absorbance mode at 289 nm. The linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9988±0.0012 in the concentration range of 100–400 ng for pantoprazole sodium. Also, the linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9990±0.0008 in the concentration range of 200–1200 ng for itopride hydrochloride. The method was validated for specificity, precision, robustness and recovery. Statistical analysis proves that the method is repeatable and selective for the estimation of both the said drugs. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating method. PMID:29403710

Stability indicating high performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in combined dosage form.

PubMed

Bageshwar, Deepak; Khanvilkar, Vineeta; Kadam, Vilasrao

2011-11-01

A specific, precise and stability indicating high-performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in pharmaceutical formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F 254 as the stationary phase. The solvent system consisted of methanol:water:ammonium acetate; 4.0:1.0:0.5 (v/v/v). This system was found to give compact and dense spots for both itopride hydrochloride ( R f value of 0.55±0.02) and pantoprazole sodium ( R f value of 0.85±0.04). Densitometric analysis of both drugs was carried out in the reflectance-absorbance mode at 289 nm. The linear regression analysis data for the calibration plots showed a good linear relationship with R 2 =0.9988±0.0012 in the concentration range of 100-400 ng for pantoprazole sodium. Also, the linear regression analysis data for the calibration plots showed a good linear relationship with R 2 =0.9990±0.0008 in the concentration range of 200-1200 ng for itopride hydrochloride. The method was validated for specificity, precision, robustness and recovery. Statistical analysis proves that the method is repeatable and selective for the estimation of both the said drugs. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating method.

Sodium citrate functionalized reusable Fe3O4@TiO2 photocatalyst for water purification

NASA Astrophysics Data System (ADS)

Li, Wenyu; Wu, Haoyi

2017-10-01

Easy-recycle photocatalysts are new materials for water treatment technologies. In order to improve the recyclable ability, we employed Fe3O4 particles, which were functionalized by sodium citrate, to serve as a substrate core to attract the deposition of a shell of TiO2 particles. When compared to the calcining process for preparing the composite, the TiO2 distributed homogeneously on the sodium citrate treated Fe3O4, forming a mesoporous shell layer. Due to the mesoporous structure, this Fe3O4@TiO2 exhibited high photocatalytic degradation activity to Rhodamine B, and it was easily recycled using a magnetic field to recover the catalyst from solution.

The behaviour of water and sodium chloride solution confined into asbestos nanotube

NASA Astrophysics Data System (ADS)

Fomin, Yu. D.; Ryzhov, V. N.; Tsiok, E. N.

2016-08-01

We present the molecular simulation study of the behaviour of water and sodium chloride solution confined in lizardite asbestos nanotube which is a typical example of hydrophilic confinement. The local structure and orientational and dynamic properties are studied. It is shown that at low enough temperatures there is a well-defined orientational ordering of the water molecules. At high local densities corresponding to the maxima of the density distribution function, the water molecules are oriented parallel to the axis of the tube. It is also shown that the diffusion coefficient drops about two orders of magnitude comparing to the bulk case. The behaviour of sodium chloride solutions is also considered and the formation of double layer is observed.

Borohydride Reduction of Estrone: Demonstration of Diastereoselectivity in the Undergraduate Organic Chemistry Laboratory

ERIC Educational Resources Information Center

Aditya, Animesh; Nichols, David E.; Loudon, G. Marc

2008-01-01

This experiment presents a guided-inquiry approach to the demonstration of diastereoselectivity in an undergraduate organic chemistry laboratory. Chiral hindered ketones such as estrone, undergo facile reduction with sodium borohydride in a highly diastereoselective manner. The diastereomeric estradiols produced in the reaction can be analyzed and…

Delamination Defect Detection Using Ultrasonic Guided Waves in Advanced Hybrid Structural Elements

NASA Astrophysics Data System (ADS)

Yan, Fei; Qi, Kevin ``Xue''; Rose, Joseph L.; Weiland, Hasso

2010-02-01

Nondestructive testing for multilayered structures is challenging because of increased numbers of layers and plate thicknesses. In this paper, ultrasonic guided waves are applied to detect delamination defects inside a 23-layer Alcoa Advanced Hybrid Structural plate. A semi-analytical finite element (SAFE) method generates dispersion curves and wave structures in order to select appropriate wave structures to detect certain defects. One guided wave mode and frequency is chosen to achieve large in-plane displacements at regions of interest. The interactions of the selected mode with defects are simulated using finite element models. Experiments are conducted and compared with bulk wave measurements. It is shown that guided waves can detect deeply embedded damages inside thick multilayer fiber-metal laminates with suitable mode and frequency selection.

Use of Sodium Dithionite as Part of a More Efficient Groundwater Restoration Method Following In-situ Recovery of Uranium at the Smith-Ranch Highland Site in Wyoming

NASA Astrophysics Data System (ADS)

Harris, R.; Reimus, P. W.; Ware, D.; Williams, K.; Chu, D.; Perkins, G.; Migdissov, A. A.; Bonwell, C.

2017-12-01

Uranium is primarily mined for nuclear power production using an aqueous extraction technique called in-situ recovery (ISR). ISR can pollute groundwater with residual uranium and other heavy metals. Reverse osmosis and groundwater sweep are currently used to restore groundwater after ISR mining, but are not permanent solutions. Sodium dithionite is being tested as part of a method to more permanently restore groundwater after ISR mining at the Smith-Ranch Highland site in Wyoming. Sodium dithionite is a chemical reductant that can reduce sediments that were oxidized during ISR. The reduced sediments can reduce soluble uranium (VI) in the groundwater to insoluble uranium (IV). Laboratory studies that use sodium dithionite to treat sediments and waters from the site may help predict how it will behave during a field deployment. An aqueous batch experiment showed that sodium dithionite reduced uranium in post-mined untreated groundwater from 38 ppm to less than 1 ppm after 1 day. A sediment reduction batch experiment showed that sodium dithionite-treated sediments were capable of reducing uranium in post-mined untreated groundwater from 38 ppm to 2 ppm after 7 days. One column experiment is showing post-mined sodium dithionite-treated sediments are capable of reducing uranium in post-mined groundwater for over 30 pore volumes past the initial injection. While these results are promising for field deployments of sodium dithionite, another column experiment with sodium dithionite-treated sediments containing uranium rich organic matter is showing net production of uranium instead of uranium uptake. Sodium dithionite appears to liberate uranium from the organic matter. Another sediment reduction experiment is being conducted to further investigate this hypothesis. These experiments are helping guide plans for field deployments of sodium dithionite at uranium ISR mining sites.

Three-dimensional bioprinting of rat embryonic neural cells.

PubMed

Lee, Wonhye; Pinckney, Jason; Lee, Vivian; Lee, Jong-Hwan; Fischer, Krisztina; Polio, Samuel; Park, Je-Kyun; Yoo, Seung-Schik

2009-05-27

We present a direct cell printing technique to pattern neural cells in a three-dimensional (3D) multilayered collagen gel. A layer of collagen precursor was printed to provide a scaffold for the cells, and the rat embryonic neurons and astrocytes were subsequently printed on the layer. A solution of sodium bicarbonate was applied to the cell containing collagen layer as nebulized aerosols, which allowed the gelation of the collagen. This process was repeated layer-by-layer to construct the 3D cell-hydrogel composites. Upon characterizing the relationship between printing resolutions and the growth of printed neural cells, single/multiple layers of neural cell-hydrogel composites were constructed and cultured. The on-demand capability to print neural cells in a multilayered hydrogel scaffold offers flexibility in generating artificial 3D neural tissue composites.

In situ optical diagnostic for monitoring or control of sodium diffusion in photovoltaics manufacturing

DOEpatents

Li, Jian; Levi, Dean; Contreras, Miguel; Glynn, Stephen

2015-09-15

A method of fabricating a photovoltaic device 100, includes the steps of providing a glass substrate 102, depositing a molybdenum layer 104 on a surface of the glass substrate, directing light through the glass substrate to the near-substrate region of the molybdenum layer 206, detecting an optical property of the near-substrate region of the molybdenum layer after interaction with the incident light 208 and determining a density of the near-substrate region of the molybdenum layer from the detected optical property 210. A molybdenum deposition parameter may be controlled based upon the determined density of the near-substrate region of the molybdenum layer 218. A non-contact method measures a density of the near-substrate region of a molybdenum layer and a deposition chamber 300.

Influence of the foundation layer on the layer-by-layer assembly of poly-L-lysine and poly(styrenesulfonate) and its usage in the fabrication of 3D microscale features.

PubMed

Zhou, Dejian; Bruckbauer, Andreas; Batchelor, Matthew; Kang, Dae-Joon; Abell, Chris; Klenerman, David

2004-10-12

The layer-by-layer (LBL) assembly of a polypeptide, poly-L-lysine (PLL), with poly(styrenesulfonate) sodium salt (PSS) on flat template-stripped gold (TSG) surfaces precoated with a self-assembled monolayer of alkanethiols terminated with positive (pyridinium), negative (carboxylic acid), and neutral [hexa(ethylene glycol)] groups is investigated. Both the topography and the rate of film thickness growth are found to be strongly dependent on the initial surface foundation layer. LBL assembly of PLL and PSS on patterned TSG surfaces produced by micro contact printing leads to structurally distinct microscale features, including pillars, ridges, and wells, whose height can be controlled with nanometer precision. Copyright 2004 American Chemical Society

Layered double hydroxide using hydrothermal treatment: morphology evolution, intercalation and release kinetics of diclofenac sodium

NASA Astrophysics Data System (ADS)

Joy, Mathew; Iyengar, Srividhya J.; Chakraborty, Jui; Ghosh, Swapankumar

2017-12-01

The present work demonstrates the possibilities of hydrothermal transformation of Zn-Al layered double hydroxide (LDH) nanostructure by varying the synthetic conditions. The manipulation in washing step before hydrothermal treatment allows control over crystal morphologies, size and stability of their aqueous solutions. We examined the crystal growth process in the presence and the absence of extra ions during hydrothermal treatment and its dependence on the drug (diclofenac sodium (Dic-Na)) loading and release processes. Hexagonal plate-like crystals show sustained release with ˜90% of the drug from the matrix in a week, suggesting the applicability of LDH nanohybrids in sustained drug delivery systems. The fits to the release kinetics data indicated the drug release as a diffusion-controlled release process. LDH with rod-like morphology shows excellent colloidal stability in aqueous suspension, as studied by photon correlation spectroscopy.

Boundary layers in turbulent convection for air, liquid gallium and liquid sodium

NASA Astrophysics Data System (ADS)

Scheel, Janet; Schumacher, Joerg

2017-11-01

The scaling of physical quantities that characterize the shape and dynamics of the viscous and thermal boundary layers with respect to the Rayleigh number will be presented for three series of three-dimensional high-resolution direct numerical simulations of Rayleigh-Benard convection (RBC) in a closed cylindrical cell of aspect ratio one. The simulations have been conducted for convection in air at a Prandtl number Pr = 0.7, in liquid gallium at Pr = 0.021 and in liquid sodium at Pr = 0.005. Then we discuss three statistical analysis methods which have been developed to predict the transition of turbulent RBC into the ultimate regime. The methods are based on the large-scale properties of the velocity profile. All three methods indicate that the range of critical Rayleigh numbers is shifted to smaller magnitudes as the Prandtl number becomes smaller. This work is supported by the Priority Programme SPP 1881 of the Deutsche Forschungsgemeinschaft.

Computational NMR, IR/RAMAN calculations in sodium pravastatin: Investigation of the Self-Assembled Nanostructure of Pravastatin-LDH (Layered Double Hydroxides) Systems

NASA Astrophysics Data System (ADS)

Petersen, Philippe; Cunha, Vanessa; Gonçalves, Marcos; Petrilli, Helena; Constantino, Vera; Instituto de Física, Departamento de Física de Materiais e Mecânica Team; Instituto de Química, Departamento de Química Fundamental Team

2013-03-01

Layered double hydroxides (LDH) can be used as nanocontainers for immobilization of Pravastatin, in order to obtain suitable drug carriers. The material's structure and spectroscopic properties were analyzed by NMR, IR/RAMAN and supported by theoretical calculations. Density Functional Theory (DFT) calculations were performed using the Gaussian03 package. The geometry optimizations were performed considering the single crystal X-ray diffraction data of tert-octylamonium salt of Pravastatin. Tetramethylsilane (TMS), obtained with the same basis set, was used as reference for calculating the chemical shift of 13C. A scaling factor was used to compare theoretical and experimental harmonic vibrational frequencies. Through the NMR and IR/RAMAN spectra, we were able to make precise assignments of the NMR and IR/RAMAN of Sodium Pravastatin. We acknowledge support from CAPES, INEO and CNPQ.

Impact of sodium caseinate concentration and location on magnesium release from multiple W/O/W emulsions.

PubMed

Bonnet, Marie; Cansell, Maud; Placin, Frédéric; Anton, Marc; Leal-Calderon, Fernando

2010-06-15

Water-in-oil-in-water (W/O/W) double emulsions were prepared and the rate of release of magnesium ions from the internal to the external aqueous phase was followed. Sodium caseinate was used not only as a hydrophilic surface-active species but also as a chelating agent able to bind magnesium ions. The release occurred without film rupturing (no coalescence). The kinetics of the release process depended on the location (in only one or in both aqueous compartments) and on the concentration of sodium caseinate. The rate of release increased with the concentration of sodium caseinate in the external phase and decreased when sodium caseinate was present in the inner droplets. The experiments were interpreted within the frame of a mean-field model based on diffusion, integrating the effect of ion binding. The data could be adequately fitted by considering a time-dependent permeation coefficient of the magnesium ions across the oil phase. Our results suggested that ion permeability was influenced by the state of the protein interfacial layers which itself depended on the extent of magnesium binding.

Comparison of magnesium sulfate and sodium sulfate for removal of water from pesticide extracts of foods.

PubMed

Schenck, Frank J; Callery, Patrick; Gannett, Peter M; Daft, Jonathan R; Lehotay, Steven J

2002-01-01

Water-miscible solvents, such as acetone and acetonitrile, effectively extract both polar and nonpolar pesticide residues from nonfatty foods. The addition of sodium chloride to the resulting acetonitrile-water or acetone-water extract (salting out) results in the separation of the water from the organic solvent. However, the organic solvent layer (pesticide extract) still contains some residual water, which can adversely affect separation procedures that follow, such as solid-phase extraction and/or gas chromatography. Drying agents, such as sodium sulfate or magnesium sulfate, are used to remove the water from the organic extracts. In the present study, we used nuclear magnetic resonance spectroscopy to study the composition of the phases resulting from salting out and to compare the effectiveness of sodium sulfate and magnesium sulfate as drying agents. The study showed that considerable amounts of water remained in the organic phase after phase separation. Sodium sulfate was a relatively ineffective drying agent, removing little or no residual water from the organic solvent. Magnesium sulfate proved to be a much more effective drying agent.

Painful Na-channelopathies: an expanding universe.

PubMed

Waxman, Stephen G

2013-07-01

The universe of painful Na-channelopathies--human disorders caused by mutations in voltage-gated sodium channels--has recently expanded in three dimensions. We now know that mutations of sodium channels cause not only rare genetic 'model disorders' such as inherited erythromelalgia and channelopathy-associated insensitivity to pain but also common painful neuropathies. We have learned that mutations of NaV1.8, as well as mutations of NaV1.7, can cause painful Na-channelopathies. Moreover, recent studies combining atomic level structural models and pharmacogenomics suggest that the goal of genomically guided pain therapy may not be unrealistic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Gateways to clinical trials.

PubMed

Bayés, M; Rabasseda, X; Prous, J R

2005-12-01

Gateways to Clinical Trials are a guide to the most recent clinical trials in current literature and congresses. The data in the following tables have been retrieved from the Clinical Trials Knowledge Area of Prous Science Integrity, the drug discovery and development portal, http://integrity. prous.com. This issue focuses on the following selection of drugs: 131I-chTNT; Abatacept, adalimumab, alemtuzumab, APC-8015, aprepitant, atazanavir sulfate, atomoxetine hydrochloride, azimilide hydrochloride; Bevacizumab, bortezomib, bosentan, buserelin; Caspofungin acetate, CC-4047, ChAGCD3, ciclesonide, clopidogrel, curcumin, Cypher; Dabigatran etexilate, dapoxetine hydrochloride, darbepoetin alfa, darusentan, denosumab, DMXB-Anabaseine, drospirenone, drospirenone/estradiol, duloxetine hydrochloride, dutasteride; Edodekin alfa, efaproxiral sodium, elaidic acid-cytarabine, erlotinib hydrochloride, ertapenem sodium, escitalopram oxalate, eszopiclone, etonogestrel/testosterone decanoate, exenatide; Fulvestrant; Gefitinib, glycine, GVS-111; Homoharringtonine; ICC-1132, imatinib mesylate, iodine (I131) tositumomab, i.v. gamma-globulin; Levetiracetam, levocetirizine, lintuzumab, liposomal nystatin, lumiracoxib, lurtotecan; Manitimus, mapatumumab, melatonin, micafungin sodium, mycophenolic acid sodium salt; Oblimersen sodium, OGX-011, olmesartan medoxomil, omalizumab, omapatrilat, oral insulin; Parathyroid hormone (human recombinant), pasireotide, peginterferon alfa-2a, peginterferon alfa-2b, peginterferon alfa-2b/ribavirin, phVEGF-A165, pimecrolimus, pitavastatin calcium, plerixafor hydrochloride, posaconazole, pramlintide acetate, prasterone, pregabalin, PT-141; Quercetin; Ranolazine, rosuvastatin calcium, rubitecan, rupatadine fumarate; Sardomozide, sunitinib malate; Tadalafil, talactoferrin alfa, tegaserod maleate, telithromycin, testosterone transdermal patch, TH-9507, tigecycline, tiotropium bromide, tipifarnib, tocilizumab, treprostinil sodium; Valdecoxib, vandetanib, vardenafil hydrochloride hydrate, voriconazole. Copyright 2005 Prous Science. All rights reserved.

Multiple-channel guided mode resonance Brewster filter with controllable spectral separation.

PubMed

Ma, Jianyong; Cao, Hongchao; Zhou, Changhe

2014-05-01

In this work, a single-layer, multiple-channel guided mode resonance (GMR) Brewster filter with controllable spectral separation is proposed using the plane waveguide method and rigorous coupled-wave analysis. Based on the normalized eigenvalue equation, the controllability of the spectral separation is analyzed when the fill ratio of the grating layer is changed while its effective index is identical to that of the substrate. The location and the separation between resonances can be specifically controlled by modifying the fill ratio of the grating layer. In contrast to the ordinary GMR filter, where the location of the resonances is material dependent, it is demonstrated that the spectral separation for the first and second resonances can be linearly controlled by altering the fill ratio of the grating layer. In addition, the maximal shift of the second resonance is up to 5% of the first resonant wavelength using the single-layer Brewster filter.

Neural field model of memory-guided search.

PubMed

Kilpatrick, Zachary P; Poll, Daniel B

2017-12-01

Many organisms can remember locations they have previously visited during a search. Visual search experiments have shown exploration is guided away from these locations, reducing redundancies in the search path before finding a hidden target. We develop and analyze a two-layer neural field model that encodes positional information during a search task. A position-encoding layer sustains a bump attractor corresponding to the searching agent's current location, and search is modeled by velocity input that propagates the bump. A memory layer sustains persistent activity bounded by a wave front, whose edges expand in response to excitatory input from the position layer. Search can then be biased in response to remembered locations, influencing velocity inputs to the position layer. Asymptotic techniques are used to reduce the dynamics of our model to a low-dimensional system of equations that track the bump position and front boundary. Performance is compared for different target-finding tasks.

Neural field model of memory-guided search

NASA Astrophysics Data System (ADS)

Kilpatrick, Zachary P.; Poll, Daniel B.

2017-12-01

Many organisms can remember locations they have previously visited during a search. Visual search experiments have shown exploration is guided away from these locations, reducing redundancies in the search path before finding a hidden target. We develop and analyze a two-layer neural field model that encodes positional information during a search task. A position-encoding layer sustains a bump attractor corresponding to the searching agent's current location, and search is modeled by velocity input that propagates the bump. A memory layer sustains persistent activity bounded by a wave front, whose edges expand in response to excitatory input from the position layer. Search can then be biased in response to remembered locations, influencing velocity inputs to the position layer. Asymptotic techniques are used to reduce the dynamics of our model to a low-dimensional system of equations that track the bump position and front boundary. Performance is compared for different target-finding tasks.

Mathematical Modeling and Optimization Studies on Development of Fuel Cells for Multifarious Applications

DTIC Science & Technology

2010-05-12

multicomponent steady-state model for liquid -feed solid polymer electrolyte DBFCs. These fuel cells use sodium borohydride (NaBH4) in alkaline media...layers, diffusion layers and the polymer electrolyte membrane for a liquid feed DBFC. Diffusion of reactants within and between the pores is accounted...projected for futuristic portable applications. In this project we developed a three- dimensional, multicomponent steady-state model for liquid -feed solid

The effect of Ca/P concentration and temperature of simulated body fluid on the growth of hydroxyapatite coating on alkali-treated 316L stainless steel.

PubMed

Lin, Feng-Huei; Hsu, Yao-Shan; Lin, Shih-Hsun; Sun, Jui-Sheng

2002-10-01

316L-SS is one of the important materials both in orthopaedics and dentistry for bone screw/plate, intra-medullary rod, fixation wire, HIP joint, and knee joint. However, the biocompatibility and bone-bonding ability troubled researches for years. In the study, a simple chemical method was tried so as to establish and induce a bioactive HA layer on the surface of 316L stainless steel. When the metallic substrates treated with 10 M NaOH aqueous solution and subsequently heated at 600 degrees C, a thin sodium chromium oxide layer was formed on the surfaces as the linking layer for HA and 316L-SS. After 316L-SS treated with alkali solution, it would soak into a simulated body fluid with higher concentration of calcium and phosphorous ions to increase the possibility of nucleation of HA. However, the iron oxide and iron chromium oxides were formed on the surface when calcium and phosphorous ions increased. This resulted in loosening the HA layer. When the alkali-treated 316L-SS was soaked into SBF at a temperature of 80 degrees C, it could form a dense and uniform bone-like hydroxyapatite layer on the surface. In the research, the mechanism of the formation of sodium chromium oxide and HA would also be described by the analysis of X-ray diffractometer, scanning electron microscope, energy-dispersion spectrophotometer, and Fourier transformation infrared.

Analysis of signals propagating in a phononic crystal PZT layer deposited on a silicon substrate.

PubMed

Hladky-Hennion, Anne-Christine; Vasseur, Jérôme; Dubus, Bertrand; Morvan, Bruno; Wilkie-Chancellier, Nicolas; Martinez, Loïc

2013-12-01

The design of a stop-band filter constituted by a periodically patterned lead zirconate titanate (PZT) layer, polarized along its thickness, deposited on a silicon substrate and sandwiched between interdigitated electrodes for emission/reception of guided elastic waves, is investigated. The filter characteristics are theoretically evaluated by using finite element simulations: dispersion curves of a patterned PZT layer with a specific pattern geometry deposited on a silicon substrate present an absolute stop band. The whole structure is modeled with realistic conditions, including appropriate interdigitated electrodes to propagate a guided mode in the piezoelectric layer. A robust method for signal analysis based on the Gabor transform is applied to treat transmitted signals; extract attenuation, group delays, and wave number variations versus frequency; and identify stop-band filter characteristics.

TE and TM guided modes in an air waveguide with negative-index-material cladding.

PubMed

D'Aguanno, G; Mattiucci, N; Scalora, M; Bloemer, M J

2005-04-01

We numerically demonstrate that a planar waveguide in which the inner layer is a gas with refractive index n0 = 1, sandwiched between two identical semi-infinite layers of a negative index material, can support both transverse electric and transverse magnetic guided modes with low losses. Recent developments in the design of metamaterials with an effective negative index suggest that this waveguide could operate in the infrared region of the spectrum.

Determination of Components in Beverages by Thin-Layer Chromatography.

ERIC Educational Resources Information Center

Ma, Yinfa; Yeung, Edward S.

1990-01-01

Described is a simple and interesting chromatography experiment using three different fluorescence detection principles for the determination of caffeine, saccharin and sodium benzoate in beverages. Experimental procedures and an analysis and discussion of the results are included. (CW)

In Situ Formation of Polysulfonamide Supported Poly(ethylene glycol) Divinyl Ether Based Polymer Electrolyte toward Monolithic Sodium Ion Batteries.

PubMed

Zhang, Jianjun; Wen, Huijie; Yue, Liping; Chai, Jingchao; Ma, Jun; Hu, Pu; Ding, Guoliang; Wang, Qingfu; Liu, Zhihong; Cui, Guanglei; Chen, Liquan

2017-01-01

Sodium ion battery is one of the promising rechargeable batteries due to the low-cost and abundant sodium sources. In this work, a monolithic sodium ion battery based on a Na 3 V 2 (PO 4 ) 3 cathode, MoS 2 layered anode, and polyether-based polymer electrolyte is reported. In addition, a new kind of polysulfonamide-supported poly(ethylene glycol) divinyl ether based polymer electrolyte is also demonstrated for monolithic sodium ion battery via in situ preparation. The resultant polymer electrolyte exhibits relatively high ionic conductivity (1.2 mS cm -1 ) at ambient temperature, wide electrochemical window (4.7 V), and favorable mechanical strength (25 MPa). Moreover, such a monolithic Na 3 V 2 (PO 4 ) 3 /MoS 2 sodium ion battery using this polymer electrolyte delivers outstanding rate capability (up to 10 C) and superior cyclic stability (84%) after 1000 cycles at 0.5 C. What is more essential, such a polymer electrolyte based soft-package monolithic sodium ion cell can still power a red light emitting diode lamp and run finite times without suffering from any internal short-circuit failures, even in the case of a bended and wrinkled state. Considering these aspects, this work no doubt provides a new approach for the design of a high-performance polymer electrolyte toward monolithic sodium ion battery with exceptional rate capability and high safety. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Depth profiling of marker layers using x-ray waveguide structures

NASA Astrophysics Data System (ADS)

Gupta, Ajay; Rajput, Parasmani; Saraiya, Amit; Reddy, V. R.; Gupta, Mukul; Bernstorff, Sigrid; Amenitsch, H.

2005-08-01

It is demonstrated that x-ray waveguide structures can be used for depth profiling of a marker layer inside the guiding layer with an accuracy of better than 0.2 nm. A combination of x-ray fluorescence and x-ray reflectivity measurements can provide detailed information about the structure of the guiding layer. The position and thickness of the marker layer affect different aspects of the angle-dependent x-ray fluorescence pattern, thus making it possible to determine the structure of the marker layer in an unambiguous manner. As an example, effects of swift heavy ion irradiation on a Si/M/Si trilayer ( M=Fe , W), forming the cavity of the waveguide structure, have been studied. It is found that in accordance with the prediction of thermal spike model, Fe is much more sensitive to swift heavy ion induced modifications as compared to W, even in thin film form. However, a clear evidence of movement of the Fe marker layer towards the surface is observed after irradiation, which cannot be understood in terms of the thermal spike model alone.

Growth and characterization of organic layers deposited on porous-patterned Si surface

NASA Astrophysics Data System (ADS)

Gorbach, Tamara Ya.; Smertenko, Petro S.; Olkhovik, G. P.; Wisz, Grzegorz

2017-01-01

The organic layers with the thickness from a few nanometers up to few micrometers have been deposited from the chemical solution at room temperature on porous patterned Si surfaces using two medical solutions: thiamine diphosphide (pH=1÷2) and metamizole sodium (pH=6÷7). Based on evolution of morphology, structural and compositional features obtained by scanning electron microscopy, X-ray analysis, reflectance high energy electron diffraction the grown mechanisms in thin organic layers are discussed in the terms of terrace-step-kink model whereas self-organized assemblies evaluated more thick layers. Transport mechanism features and possible photovoltaic properties are discussed on the base of differential current-voltage characteristics.

Inversion layer solar cell fabrication and evaluation. [etching on silicon films

NASA Technical Reports Server (NTRS)

Call, R. L.

1974-01-01

Inversion layer solar cells were fabricated by etching through the diffused layer on p-type silicon wafers in a comb-like contact pattern. The charge separation comes from an induced p-n junction at the surface. The inverted surface is caused by a layer of transparent material applied to the surface that either contains free positive ions or that creates donor states at the interface. Cells are increased from 3 ma I sub sc to 100 ma by application of sodium silicate. The action is unstable, however, and decays. Non-mesa contaminated oxide cells were fabricated with short circuit currents of over 100 ma measured in the sun. Cells of this type have demonstrated stability.

Resonant scattering of light from a glass/Ag/MgF2/air system with rough interfaces and supporting guided modes in attenuated total reflection.

PubMed

Ramírez-Duverger, Aldo S; Gaspar-Armenta, Jorge A; García-Llamas, Raúl

2003-08-01

We report experimental results of the resonant scattering of light from a prism-glass/Ag/MgF2/air system with use of the attenuated total reflection technique for p and s polarized light. Two MgF2 film thicknesses were used. The system with the thinner dielectric layer supports two transverse magnetic (TM) and two transverse electric (TE) guided modes at a wavelength of 632.8 nm, and the system with the thicker dielectric layer supports three TM and three TE guided modes. In both cases we found dips in the specular reflection as a function of incident angle that is due to excitation of guided modes in the MgF2 film. The scattered light shows peaks at angles corresponding to the measured excitation of the guided modes. These peaks are due to single-order scattering and occur for any angle of the incident light. All features in the scattering response are enhanced in resonance conditions, and the efficiency of injecting light into the guide is reduced.

A Global Model of Meteoric Sodium

NASA Technical Reports Server (NTRS)

Marsh, Daniel R.; Janches, Diego; Feng, Wuhu; Plane, John M. C.

2013-01-01

A global model of sodium in the mesosphere and lower thermosphere has been developed within the framework of the National Center for Atmospheric Research's Whole Atmosphere Community Climate Model (WACCM). The standard fully interactive WACCM chemistry module has been augmented with a chemistry scheme that includes nine neutral and ionized sodium species. Meteoric ablation provides the source of sodium in the model and is represented as a combination of a meteoroid input function (MIF) and a parameterized ablation model. The MIF provides the seasonally and latitudinally varying meteoric flux which is modeled taking into consideration the astronomical origins of sporadic meteors and considers variations in particle entry angle, velocity, mass, and the differential ablation of the chemical constituents. WACCM simulations show large variations in the sodium constituents over time scales from days to months. Seasonality of sodium constituents is strongly affected by variations in the MIF and transport via the mean meridional wind. In particular, the summer to winter hemisphere flow leads to the highest sodium species concentrations and loss rates occurring over the winter pole. In the Northern Hemisphere, this winter maximum can be dramatically affected by stratospheric sudden warmings. Simulations of the January 2009 major warming event show that it caused a short-term decrease in the sodium column over the polar cap that was followed by a factor of 3 increase in the following weeks. Overall, the modeled distribution of atomic sodium in WACCM agrees well with both ground-based and satellite observations. Given the strong sensitivity of the sodium layer to dynamical motions, reproducing its variability provides a stringent test of global models and should help to constrain key atmospheric variables in this poorly sampled region of the atmosphere.

Prototype of a laser guide star wavefront sensor for the Extremely Large Telescope

NASA Astrophysics Data System (ADS)

Patti, M.; Lombini, M.; Schreiber, L.; Bregoli, G.; Arcidiacono, C.; Cosentino, G.; Diolaiti, E.; Foppiani, I.

2018-06-01

The new class of large telescopes, like the future Extremely Large Telescope (ELT), are designed to work with a laser guide star (LGS) tuned to a resonance of atmospheric sodium atoms. This wavefront sensing technique presents complex issues when applied to big telescopes for many reasons, mainly linked to the finite distance of the LGS, the launching angle, tip-tilt indetermination and focus anisoplanatism. The implementation of a laboratory prototype for the LGS wavefront sensor (WFS) at the beginning of the phase study of MAORY (Multi-conjugate Adaptive Optics Relay) for ELT first light has been indispensable in investigating specific mitigation strategies for the LGS WFS issues. This paper presents the test results of the LGS WFS prototype under different working conditions. The accuracy within which the LGS images are generated on the Shack-Hartmann WFS has been cross-checked with the MAORY simulation code. The experiments show the effect of noise on centroiding precision, the impact of LGS image truncation on wavefront sensing accuracy as well as the temporal evolution of the sodium density profile and LGS image under-sampling.

End State Condition Report for Materials and Fuels Complex Facilities MFC-799, 799A, and 770C

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

Gary Mecham

2010-10-01

The Materials and Fuels Complex (MFC) facilities MFC-799, “Sodium Processing Facility” (a single building consisting of two areas: the Sodium Process Area and the Carbonate Process Area); MFC-799A, “Caustic Storage Area;” and MFC-770C, “Nuclear Calibration Laboratory,” have been declared excess to future Department of Energy (DOE) Office of Nuclear Energy(NE) mission requirements. Transfer of these facilities from NE to the DOE Office of Environmental Management (EM), and an associated schedule for doing so, have been agreed upon by the two offices. This report documents the completion of pre-transfer stabilization actions, as identified in DOE Guide 430.1-5, “Transition Implementation Guide,” formore » buildings MFC-799/799A and 770C, and indicates that these facilities are ready for transfer from NE to EM. The facilities are in a known, safe condition and information is provided to support efficient decommissioning and demolition (D&D) planning while minimizing the possibility of encountering unforeseen circumstances during the D&D activities.« less

MELCOR/CONTAIN LMR Implementation Report. FY14 Progress

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

Humphries, Larry L; Louie, David L.Y.

2014-10-01

This report describes the preliminary implementation of the sodium thermophysical properties and the design documentation for the sodium models of CONTAIN-LMR to be implemented into MELCOR 2.1. In the past year, the implementation included two separate sodium properties from two different sources. The first source is based on the previous work done by Idaho National Laboratory by modifying MELCOR to include liquid lithium equation of state as a working fluid to model the nuclear fusion safety research. To minimize the impact to MELCOR, the implementation of the fusion safety database (FSD) was done by utilizing the detection of the datamore » input file as a way to invoking the FSD. The FSD methodology has been adapted currently for this work, but it may subject modification as the project continues. The second source uses properties generated for the SIMMER code. Preliminary testing and results from this implementation of sodium properties are given. In this year, the design document for the CONTAIN-LMR sodium models, such as the two condensable option, sodium spray fire, and sodium pool fire is being developed. This design document is intended to serve as a guide for the MELCOR implementation. In addition, CONTAIN-LMR code used was based on the earlier version of CONTAIN code. Many physical models that were developed since this early version of CONTAIN may not be captured by the code. Although CONTAIN 2, which represents the latest development of CONTAIN, contains some sodium specific models, which are not complete, the utilizing CONTAIN 2 with all sodium models implemented from CONTAIN-LMR as a comparison code for MELCOR should be done. This implementation should be completed in early next year, while sodium models from CONTAIN-LMR are being integrated into MELCOR. For testing, CONTAIN decks have been developed for verification and validation use.« less

Impact of Sodium Contamination in Tin Sulfide Thin-Film Solar Cells

DOE PAGES

Steinmann, Vera; Brandt, Riley E.; Chakraborty, Rupak; ...

2016-02-12

Empirical observations show that sodium(Na) is a benign contaminant in some thin-filmsolar cells. Here, we intentionally contaminate thermally evaporated tin sulfide (SnS)thin-films with sodium and measure the SnS absorber properties and solar cellcharacteristics. The carrier concentration increases from 2 × 10 16 cm -3 to 4.3 × 10 17 cm -3 in Na-doped SnSthin-films, when using a 13 nm NaCl seed layer, which is detrimental for SnS photovoltaic applications but could make Na-doped SnS an attractive candidate in thermoelectrics. We observed trends in carrier concentration and found that it is in good agreement with density functional theory calculations, which predictmore » an acceptor-type NaSn defect with low formation energy.« less

Laser transmitter for space-based sodium lidar instrument

NASA Astrophysics Data System (ADS)

Yu, Anthony W.; Krainak, Michael A.; Janches, Diego; Konoplev, Oleg

2016-05-01

We are currently developing a laser transmitter to remotely measure Sodium (Na) by adapting existing lidar technology with space flight heritage. The developed instrumentation will serve as the core for the planning of a Heliophysics mission targeted to study the composition and dynamics of Earth's mesosphere based on a spaceborne lidar that will measure the mesospheric Na layer. We present performance results from our laser transmitter development effort with emphasis on wavelength tuning and power scaling of a diode-pumped Q-switched self-Raman c-cut Nd:YVO4 laser with intra-cavity frequency doubling that could produce multi-watt 589 nm wavelength output. We will review technologies that provide strong leverage for the sodium lidar laser system with strong heritage from past and current space flight missions.

Natural guide-star processing for wide-field laser-assisted AO systems

NASA Astrophysics Data System (ADS)

Correia, Carlos M.; Neichel, Benoit; Conan, Jean-Marc; Petit, Cyril; Sauvage, Jean-Francois; Fusco, Thierry; Vernet, Joel D. R.; Thatte, Niranjan

2016-07-01

Sky-coverage in laser-assisted AO observations largely depends on the system's capability to guide on the faintest natural guide-stars possible. Here we give an up-to-date status of our natural guide-star processing tailored to the European-ELT's visible and near-infrared (0.47 to 2.45 μm) integral field spectrograph - Harmoni. We tour the processing of both the isoplanatic and anisoplanatic tilt modes using the spatio-angular approach whereby the wavefront is estimated directly in the pupil plane avoiding a cumbersome explicit layered estimation on the 35-layer profiles we're currently using. Taking the case of Harmoni, we cover the choice of wave-front sensors, the number and field location of guide-stars, the optimised algorithms to beat down angular anisoplanatism and the performance obtained with different temporal controllers under split high-order/low-order tomography or joint tomography. We consider both atmospheric and far greater telescope wind buffeting disturbances. In addition we provide the sky-coverage estimates thus obtained.

Super Gas Barrier Thin Films via Layer-by-Layer Assembly of Polyelectrolytes and Clay

NASA Astrophysics Data System (ADS)

Priolo, Morgan; Gamboa, Daniel; Grunlan, Jaime

2010-03-01

Thin composite films of branched polyethylenimine (PEI), polyacrylic acid (PAA) and sodium montmorillonite clay (MMT) platelets were prepared using layer-by-layer assembly. Film thickness, mass deposited per layer, and barrier were shown to increase exponentially with the number of deposition cycles. After 32 layers (i.e., eight PEI/PAA/PEI/MMT quadlayers) are deposited, the resulting transparent film exhibits an oxygen transmission rate below the detection limit of commercial instrumentation (< 0.005 cm^3/m^2 . day). This level of oxygen barrier is believed to be due to a nano-brick wall microstructure comprised of exfoliated clay bricks in polymeric mortar, where the enhanced spacing between MMT layers, provided by PEI and PAA, creates channels perpendicular concentration gradient that delay the permeating molecule. These films are good candidates for flexible electronics, food, and pharmaceutical packaging due to their transparency, super gas barrier (that rivals SiOx) and lack of metal.

Aluminum manganese oxides with mixed crystal structure: high-energy-density cathodes for rechargeable sodium batteries.

PubMed

Han, Dong-Wook; Ku, Jun-Hwan; Kim, Ryoung-Hee; Yun, Dong-Jin; Lee, Seok-Soo; Doo, Seok-Gwang

2014-07-01

We report a new discovery for enhancing the energy density of manganese oxide (Nax MnO2 ) cathode materials for sodium rechargeable batteries by incorporation of aluminum. The Al incorporation results in NaAl(0.1) Mn(0.9) O2 with a mixture of tunnel and layered crystal structures. NaAl(0.1) Mn(0.9) O2 shows a much higher initial discharge capacity and superior cycling performance compared to pristine Na(0.65) MnO2 . We ascribe this enhancement in performance to the formation of a new orthorhombic layered NaMnO2 phase merged with a small amount of tunnel Na(0.44) MnO2 phase in NaAl(0.1) Mn(0.9) O2 , and to improvements in the surface stability of the NaAl(0.1) Mn(0.9) O2 particles caused by the formation of Al-O bonds on their surfaces. Our findings regarding the phase transformation and structure stabilization induced by incorporation of aluminum, closely related to the structural analogy between orthorhombic Na(0.44) MnO2 and NaAl(0.1) Mn(0.9) O2 , suggest a strategy for achieving sodium rechargeable batteries with high energy density and stability. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In vitro bioactivity investigation of alkali treated Ti6Al7Nb alloy foams

NASA Astrophysics Data System (ADS)

Butev, Ezgi; Esen, Ziya; Bor, Sakir

2015-02-01

Biocompatible Ti6Al7Nb alloy foams with 70% porosity manufactured by space holder method were activated via alkali treatment using 5 M NaOH solution at 60 °C. The interconnected pore structures enabled formation of homogenous sodium rich coating on the foam surfaces by allowing penetration of alkali solution throughout the pores which had average size of 200 μm. The resulted coating layer having 500 nm thickness exhibited porous network morphology with 100 nm pore size. On the other hand, heat treatment conducted subsequent to alkali treatment at 600 °C in air transformed sodium rich coating into crystalline bioactive sodium titanate phases. Although the coatings obtained by additional heat treatment were mechanically stable and preserved their morphology, oxidation of the samples deteriorated the compressive strength significantly without affecting the elastic modulus. However, heat treated samples revealed better hydroxyapatite formation when soaked in simulated body fluid (SBF) compared to alkali treated foams. On the other hand, untreated surfaces containing bioactive TiO2 layer were observed to comprise of Ca and P rich precipitates only rather than hydroxyapatite within 15 days. The apatite formed on the treated porous surfaces was observed to have flower-like structure with Ca/P ratio around 1.5 close to that of natural bone.

PTX-loaded three-layer PLGA/CS/ALG nanoparticle based on layer-by-layer method for cancer therapy.

PubMed

Wang, Fang; Yuan, Jian; Zhang, Qian; Yang, Siqian; Jiang, Shaohua; Huang, Chaobo

2018-05-17

Poly (lactic-co-glycolic acid) (PLGA) nanoparticles are an ideal paclitaxel (PTX)-carrying system due to its biocompatibility and biodegradability. But it possessed disadvantage of drug burst release. In this research, a layer-by-layer deposition of chitosan (CS) and sodium alginate (ALG) was applied to modify the PLGA nanoparticles. The surface charges and morphology of the PLGA, PLGA/CS and PLGA/CS/ALG particles was measured by capillary electrophoresis and SEM and TEM, respectively. The drug encapsulation and loading efficiency were confirmed by ultraviolet spectrophotometer. The nanoparticles were stable and exhibited controlled drug release performance, with good cytotoxicity to human lung carcinoma cells (HepG 2). Cumulatively, our research suggests that this kind of three-layer nanoparticle with LbL-coated shield has great properties to act as a novel drug-loaded system.

3D printed glass: surface finish and bulk properties as a function of the printing process

NASA Astrophysics Data System (ADS)

Klein, Susanne; Avery, Michael P.; Richardson, Robert; Bartlett, Paul; Frei, Regina; Simske, Steven

2015-03-01

It is impossible to print glass directly from a melt, layer by layer. Glass is not only very sensitive to temperature gradients between different layers but also to the cooling process. To achieve a glass state the melt, has to be cooled rapidly to avoid crystallization of the material and then annealed to remove cooling induced stress. In 3D-printing of glass the objects are shaped at room temperature and then fired. The material properties of the final objects are crucially dependent on the frit size of the glass powder used during shaping, the chemical formula of the binder and the firing procedure. For frit sizes below 250 μm, we seem to find a constant volume of pores of less than 5%. Decreasing frit size leads to an increase in the number of pores which then leads to an increase of opacity. The two different binders, 2- hydroxyethyl cellulose and carboxymethylcellulose sodium salt, generate very different porosities. The porosity of samples with 2-hydroxyethyl cellulose is similar to frit-only samples, whereas carboxymethylcellulose sodium salt creates a glass foam. The surface finish is determined by the material the glass comes into contact with during firing.

Electroless Cu Plating on Anodized Al Substrate for High Power LED.

PubMed

Rha, Sa-Kyun; Lee, Youn-Seoung

2015-03-01

Area-selective copper deposition on screen printed Ag pattern/anodized Al/Al substrate was attempted using a neutral electroless plating processes for printed circuit boards (PCBs), according to a range of variation of pH 6.5-pH 8 at 70 °C. The utilized basic electroless solution consisted of copper(II) sulfate pentahydrate, sodium phosphinate monohydrate, sodium citrate tribasic dihydrate, ammonium chloride, and nickel(II) sulfate hexahydrate. The pH of the copper plating solutions was adjusted from pH 6.5 to pH 8 using NH4OH. Using electroless plating in pH 6.5 and pH 7 baths, surface damage to the anodized Al layer hardly occurred; the structure of the plated Cu-rich films was a typical fcc-Cu, but a small Ni component was co-deposited. In electroless plating at pH 8, the surface of the anodized Al layer was damaged and the Cu film was composed of a lot of Ni and P which were co-deposited with Cu. Finally, in a pH 7 bath, we can make a selectively electroless plated Cu film on a PCB without any lithography and without surface damage to the anodized Al layer.

Root canal obturation: experimental study on the thermafil system related to different irrigation protocols

PubMed Central

Migliau, Guido; Sofan, Afrah Ali Abdullah; Sofan, Eshrak Ali Abdullah; Cosma, Salvatore; Eramo, Stefano; Gallottini, Livio

2014-01-01

Summary Aim The aim of this study was to stress the ability of a specific obturation technique (thermafil technique) to seal root canal system in presence or absence of smear layer. Methodology Sixteen monoradicular teeth, extracted for periodontal reasons, were collected for this study. All specimens were prepared with nickel-titanium rotary files, and then divided into two groups: for each group was applied a different kind of irrigation method, verifying the effectiveness in removing the smear layer, thus rendering the dentinal tubules more permeable for penetration of softened gutta-percha. Thermafil system was used to fill the root canals, and then all the specimens were observed under scanning electron microscope (SEM). Results The results showed that the Group which followed irrigation only with sodium hypochlorite exhibited significantly less gutta-percha tags when compared to the second Group, which was irrigated with sodium hypochlorite and EDTA. Conclusion The thermafil systems have a very good quality of compression and fluency that permit to gain a good seal of endodontic space; furthermore it allows the penetration of gutta-percha with the formation of numerous of gutta-percha tags inside the dentinal tubules above all when smear layer is reduced or eliminated. PMID:25506413

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

Liu Shengwei; Yu Jiaguo

Bi{sub 2}WO{sub 6} hierarchical multilayered flower-like assemblies are fabricated on a large scale by a simple hydrothermal method in the presence of polymeric poly(sodium 4-styrenesulfonate). Such 3D Bi{sub 2}WO{sub 6} assemblies are constructed from orderly arranged 2D layers, which are further composed of a large number of interconnected nanoplates with a mean side length of ca. 50 nm. The bimodal mesopores associated with such hierarchical assembly exhibit peak mesopore size of ca. 4 nm for the voids within a layer, and peak mesopore size of ca. 40 nm corresponding to the interspaces between stacked layers, respectively. The formation process ismore » discussed on the basis of the results of time-dependent experiments, which support a novel 'coupled cooperative assembly and localized ripening' formation mechanism. More interestingly, we have noticed that the collective effect related to such hierarchical assembly induces a significantly enhanced optical absorbance in the UV-visible region. This work may shed some light on the design of complex architectures and exploitation of their potential applications. - Graphical abstract: Bi{sub 2}WO{sub 6} hierarchical multilayered flower-like assemblies are fabricated on a large scale by a simple hydrothermal method in the presence of polymeric poly(sodium 4-styrenesulfonate)« less

Transglutaminase catalyzed cross-linking of sodium caseinate improves oxidative stability of flaxseed oil emulsion.

PubMed

Ma, Hairan; Forssell, Pirkko; Kylli, Petri; Lampi, Anna-Maija; Buchert, Johanna; Boer, Harry; Partanen, Riitta

2012-06-20

Sodium caseinate was modified by transglutaminase catalyzed cross-linking reaction prior to the emulsification process in order to study the effect of cross-linking on the oxidative stability of protein stabilized emulsions. The extent of the cross-linking catalyzed by different dosages of transglutaminase was investigated by following the ammonia production during the reaction and using SDS-PAGE gel. O/W emulsions prepared with the cross-linked and non-cross-linked sodium caseinates were stored for 30 days under the same conditions. Peroxide value measurement, oxygen consumption measurement, and headspace gas chromatography analysis were used to study the oxidative stability of the emulsions. The emulsion made of the cross-linked sodium caseinate showed an improved oxidative stability with reduced formation of fatty acid hydroperoxides and volatiles and a longer period of low rate oxygen consumption. The improving effect of transglutaminase catalyzed cross-linking could be most likely attributed to the enhanced physical stability of the interfacial protein layer against competitive adsorption by oil oxidation products.

Ultrafast and Highly Reversible Sodium Storage in Zinc-Antimony Intermetallic Nanomaterials

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

Nie, Anmin; Gan, Li-yong; Cheng, Yingchun

2015-12-17

The progress on sodium-ion battery technology faces many grand challenges, one of which is the considerably lower rate of sodium insertion/deinsertion in electrode materials due to the larger size of sodium (Na) ions and complicated redox reactions compared to the lithium-ion systems. Here, it is demonstrated that sodium ions can be reversibly stored in Zn-Sb intermetallic nanowires at speeds that can exceed 295 nm s -1. Remarkably, these values are one to three orders of magnitude higher than the sodiation rate of other nanowires electrochemically tested with in situ transmission electron micro­scopy. It is found that the nanowires display aboutmore » 161% volume expansion after the first sodiation and then cycle with an 83% reversible volume expansion. Despite their massive expansion, the nanowires can be cycled without any cracking or facture during the ultrafast sodiation/desodiation process. Additionally, most of the phases involved in the sodiation/desodiation process possess high electrical conductivity. More specifically, the NaZnSb exhibits a layered structure, which provides channels for fast Na + diffusion. This observation indicates that Zn-Sb intermetallic nanomaterials offer great promise as high rate and good cycling stability anodic materials for the next generation of sodium-ion batteries.« less

Living with a leaky skin: upregulation of ion transport proteins during sloughing.

PubMed

Wu, Nicholas C; Cramp, Rebecca L; Franklin, Craig E

2017-06-01

Amphibian skin is a multifunctional organ providing protection from the external environment and facilitating the physiological exchange of gases, water and salts with the environment. In order to maintain these functions, the outer layer of skin is regularly replaced in a process called sloughing. During sloughing, the outermost layer of the skin is removed in its entirety, which has the potential to interfere with skin permeability and ion transport, disrupting homeostasis. In this study, we measured, in vivo , the effects of sloughing on the cutaneous efflux of ions in toads Rhinella marina kept in freshwater conditions. We also measured transepithelial potential, cutaneous resistance, active ion transport and the distribution, abundance and gene expression of the key ion transport proteins sodium-potassium ATPase (NKA) and epithelial sodium channel (ENaC) during sloughing. We hypothesised that the increase in transepithelial efflux of ions during sloughing is a consequence of increased permeability and/or a reduction in the abundance or expression of cutaneous ion transport proteins, resulting in disruption of internal ion homeostasis. There was a significant increase in sodium and chloride efflux during sloughing in R. marina However, although in vitro skin resistance decreased after sloughing, active sodium transport increased commensurate with an increase in NKA and ENaC protein abundance in the skin. These changes in skin function associated with sloughing did not affect the maintenance of internal electrolyte homeostasis. These results suggest that during sloughing, amphibians actively maintain internal homeostasis by increasing cutaneous rates of ion uptake. © 2017. Published by The Company of Biologists Ltd.

Effect of topical 3% diquafosol sodium on eyes with dry eye disease and meibomian gland dysfunction.

PubMed

Amano, Shiro; Inoue, Kenji

2017-01-01

To prospectively evaluate the effect of topical diquafosol sodium on eyes with dry eye disease (DED) and meibomian gland dysfunction (MGD). The subjects were consecutive patients diagnosed with both DED and MGD at Inouye Eye Hospital between March and September of 2016. The subjects were administered topical 3% diquafosol sodium ophthalmic solution six times a day for 3 months. At each study visit, subjects underwent slit-lamp examination and completed MGD symptoms and dry eye-related quality of life score (DEQS) questionnaires. Meibum quality (meibum score) and meibomian gland loss (meiboscore) were evaluated. Tear lipid layer thickness was measured in both eyes with an ocular surface interferometer immediately after clinic arrival and 20 minutes after instillation of one drop of topical diquafosol. Thirteen patients (3 men, 10 women) with a mean age of 69.5±8.3 years completed the 3-month study. The number of telangiectasia and plugged meibomian gland orifices significantly decreased from baseline after 1 month of diquafosol use. The meibum score and the meiboscore significantly decreased from baseline at 3 months. Also, the lipid layer thickness was greater after diquafosol administration than before administration at baseline and 1, 2, and 3 months by 12.2, 11.5, 9.5, and 17.0 nm, respectively, but this difference was only significant at 3 months ( p =0.039). The DEQS ocular symptom ( p =0.065) and MGD questionnaire ( p =0.081) scores tended to be lower than baseline at 3 months. Diquafosol sodium ophthalmic solution improves DED- and MGD-related signs in eyes with MGD.

Desmopressin to Prevent Rapid Sodium Correction in Severe Hyponatremia: A Systematic Review.

PubMed

MacMillan, Thomas E; Tang, Terence; Cavalcanti, Rodrigo B

2015-12-01

Hyponatremia is common among inpatients and is associated with severe adverse outcomes such as osmotic demyelination syndrome. Current guidelines recommend serum sodium concentration correction targets of no more than 8 mEq/L per day in patients at high risk of osmotic demyelination syndrome. Desmopressin is recommended to control high rates of serum sodium concentration correction in severe hyponatremia. However, recommendations are based on limited data. The objective of this study is to review current strategies for DDAVP use in severe hyponatremia. Systematic literature search of 4 databases of peer-reviewed studies was performed and study quality was appraised. The literature search identified 17 observational studies with 80 patients. We found 3 strategies for desmopressin administration in hyponatremia: 1) proactive, where desmopressin is administered early based on initial serum sodium concentration; 2) reactive, where desmopressin is administered based on changes in serum sodium concentration or urine output; 3) rescue, where desmopressin is administered after serum sodium correction targets are exceeded or when osmotic demyelination appears imminent. A proactive strategy of desmopressin administration with hypertonic saline was associated with lower incidence of exceeding serum sodium concentration correction targets, although this evidence is derived from a small case series. Three distinct strategies for desmopressin administration are described in the literature. Limitations in study design and sample size prevent definitive conclusions about the optimal strategy for desmopressin administration to correct hyponatremia. There is a pressing need for better quality research to guide clinicians in managing severe hyponatremia. Copyright © 2015 Elsevier Inc. All rights reserved.

A 25% tannic acid solution as a root canal irrigant cleanser: a scanning electron microscope study.

PubMed

Bitter, N C

1989-03-01

A scanning electron microscope was used to evaluate the cleansing properties of a 25% tannic acid solution on the dentinal surface in the pulp chamber of endodontically prepared teeth. This was compared with the amorphous smear layer of the canal with the use of hydrogen peroxide and sodium hypochlorite solution as an irrigant. The tannic acid solution removed the smear layer more effectively than the regular cleansing agent.

Three-layered radio frequency coil arrangement for sodium MRI of the human brain at 9.4 Tesla.

PubMed

Shajan, G; Mirkes, Christian; Buckenmaier, Kai; Hoffmann, Jens; Pohmann, Rolf; Scheffler, Klaus

2016-02-01

A multinuclei imaging setup with the capability to acquire both sodium ((23) Na) and proton ((1) H) signals at 9.4 Tesla is presented. The main objective was to optimize coil performance at the (23) Na frequency while still having the ability to acquire satisfactory (1) H images. The setup consisted of a combination of three radio frequency (RF) coils arranged in three layers: the innermost layer was a 27-channel (23) Na receive helmet which was surrounded by a four-channel (23) Na transceiver array. The outer layer consisted of a four-channel (1) H dipole array for B0 shimming and anatomical localization. Transmit and receive performance of the (23) Na arrays was compared to a single-tuned (23) Na birdcage resonator. While the transmit efficiency of the (23) Na transceiver array was comparable to the birdcage, the (23) Na receive array provided substantial signal-to-noise ratio (SNR) gain near the surface and comparable SNR in the center. The utility of this customized setup was demonstrated by (23) Na images of excellent quality. High SNR, efficient transmit excitation and B0 shimming capability can be achieved for (23) Na MRI at 9.4T using novel coil combination. This RF configuration is easily adaptable to other multinuclei applications at ultra high field (≥ 7T). © 2015 Wiley Periodicals, Inc.

Formation of protein/surfactant adsorption layer at the air/water interface as studied by dilational surface rheology.

PubMed

Mikhailovskaya, A A; Noskov, B A; Lin, S-Y; Loglio, G; Miller, R

2011-08-25

The dynamic dilatational surface elasticity of mixed solutions of globular proteins (β-lactoglobulin (BLG) and bovine serum albumin (BSA)) with cationic (dodecyltrimethylammonium bromide (DTAB)) and anionic (sodium dodecyl sulfate (SDS)) surfactants was measured as a function of the surfactant concentration and surface age. If the cationic surfactant concentration exceeds a certain critical value, the kinetic dependencies of the dynamic surface elasticity of BLG/DTAB and BSA/DTAB solutions become nonmonotonous and resemble those of mixed solutions of proteins with guanidine hydrochloride. This result indicates not only the destruction of the protein tertiary structure in the surface layer of mixed solution but also a strong perturbation of the secondary structure. The corresponding kinetic dependencies for protein solutions with added anionic surfactants are always monotonous, thereby revealing a different mechanism of the adsorption layer formation. One can assume that the secondary structure is destroyed to a lesser extent in the latter case and hinders the formation of loops and tails at the interface. The increase of the solution's ionic strength by the addition of sodium chloride results in stronger changes of the protein conformations in the surface layer and the appearance of a local maximum in the kinetic dependencies of the dynamic surface elasticity in a relatively narrow range of SDS concentration. © 2011 American Chemical Society

Performance analysis and experimental study on rainfall water purification with an extensive green roof matrix layer in Shanghai, China.

PubMed

Guo, Jiankang; Zhang, Yanting; Che, Shengquan

2018-02-01

Current research has validated the purification of rainwater by a substrate layer of green roofs to some extent, though the effects of the substrate layer on rainwater purification have not been adequately quantified. The present study set up nine extensive green roof experiment combinations based on the current conditions of precipitation characteristics observed in Shanghai, China. Different rain with pollutants were simulated, and the orthogonal design L9 (33) test was conducted to measure purification performance. The purification influences of the extensive green roof substrate layer were quantitatively analyzed in Shanghai to optimize the thickness, proportion of substrate, and sodium polyacrylate content. The experimental outcomes resulted in ammonium nitrogen (NH 4 + -N), lead (Pb), and zinc (Zn) removal of up to 93.87%, 98.81%, and 94.55% in the artificial rainfall, respectively, and NH 4 + -N, Pb, and Zn event mean concentration (EMC) was depressed to 0.263 mg/L, 0.002 mg/L and 0.018 mg/L, respectively, which were all well below the pollutant concentrations of artificial rainfall. With reference to the rainfall chemical characteristics of Shanghai, a combination of a 200 mm thickness, proportions of 1:1:2 of Loam: Perlite: Cocopeat and 2 g/L sodium polyacrylate content was suggested for the design of an extensive green roof substrate to purify NH 4 + -N, Pb and Zn.

Stabilization of Ag nanostructures by tuning their Fermi levels

NASA Astrophysics Data System (ADS)

Tani, Tadaaki; Kan, Ryota; Yamano, Yuka; Uchida, Takayuki

2018-05-01

The oxidation of Ag nanostructures has been studied as a key step for their degradation under the guiding principle in the previous paper that they are stable when their Fermi level is lower than those of their surroundings. The drop of the Fermi level of a thin Ag layer was caused by the formation of self-assembled monolayers (SAMs) of certain organic compounds including those of photographic interest and a monolayer of AgI, and attributed to the formation of dielectric layers, whose positive charges were closer to the Ag layer than negative charges. A consideration is given on further examinations needed to realize the above guiding principle in individual devices.

Unraveling the storage mechanism in organic carbonyl electrodes for sodium-ion batteries

PubMed Central

Wu, Xiaoyan; Jin, Shifeng; Zhang, Zhizhen; Jiang, Liwei; Mu, Linqin; Hu, Yong-Sheng; Li, Hong; Chen, Xiaolong; Armand, Michel; Chen, Liquan; Huang, Xuejie

2015-01-01

Organic carbonyl compounds represent a promising class of electrode materials for secondary batteries; however, the storage mechanism still remains unclear. We take Na2C6H2O4 as an example to unravel the mechanism. It consists of alternating Na-O octahedral inorganic layer and π-stacked benzene organic layer in spatial separation, delivering a high reversible capacity and first coulombic efficiency. The experiment and calculation results reveal that the Na-O inorganic layer provides both Na+ ion transport pathway and storage site, whereas the benzene organic layer provides electron transport pathway and redox center. Our contribution provides a brand-new insight in understanding the storage mechanism in inorganic-organic layered host and opens up a new exciting direction for designing new materials for secondary batteries. PMID:26601260

A reversible phase transition for sodium insertion in anatase TiO 2

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

Li, Wei; Fukunishi, Mika; Morgan, Benjamin J.

Anatase TiO 2 is a potential negative electrode for sodium-ion batteries. The sodium storage mechanism is, however, still under debate, yet its comprehension is required to optimize the electrochemical properties. To clarify the sodium storage mechanism occurring in anatase, we have used both electrochemical and chemical routes from which we obtained similar trends. During the first discharge, an irreversible plateau region is observed which corresponds to the insertion of Na+ within the interstitial sites of anatase and is accompanied by a drastic loss of the long-range order as revealed by X-ray diffraction, high resolution of high angle annular dark-field scanningmore » transmission electron microscope (HAADF-STEM), and pair distribution function (PDF) analysis. Further structural analysis of the total scattering data indicates that the sodiated phase displays a layered-like rhombohedral R3m structure built from the stacking of Ti and Na slabs. Because of the initial 3D network of anatase, the reduced phase shows strong disorder due to cationic intermixing between the Ti and Na slabs and the refined chemical formula is (Na 0.43Ti 0.57) 3a 0.22Na 0.39Ti 0.39) 3bO 2, where refers to vacancy. The presence of high valence Ti ions in the Na layers induces a contraction of the c-parameter as compared to the ordered phase. Upon desodiation, the structure further amorphized and the local structure probed by PDF is shown to be similar to the anatase TiO 2, suggesting that the 3D network is recovered. The reversible sodium insertion/deinsertion is thus attributed to the rhombohedral active phase formed during the first discharge, and an oxidized phase featuring the local structure of anatase. Due to the amorphous nature of the two phases, the potential-composition curves are characterized by a sloping curve. Lastly, a comparison between the intercalation of lithium and sodium into anatase TiO 2 performed by DFT calculations confirmed that, for the sodiated phase, the rhombohedral structure is more stable than the tetragonal phase observed during the lithiation of nanoparticles.« less

A reversible phase transition for sodium insertion in anatase TiO 2

DOE PAGES

Li, Wei; Fukunishi, Mika; Morgan, Benjamin J.; ...

2017-02-07

Anatase TiO 2 is a potential negative electrode for sodium-ion batteries. The sodium storage mechanism is, however, still under debate, yet its comprehension is required to optimize the electrochemical properties. To clarify the sodium storage mechanism occurring in anatase, we have used both electrochemical and chemical routes from which we obtained similar trends. During the first discharge, an irreversible plateau region is observed which corresponds to the insertion of Na+ within the interstitial sites of anatase and is accompanied by a drastic loss of the long-range order as revealed by X-ray diffraction, high resolution of high angle annular dark-field scanningmore » transmission electron microscope (HAADF-STEM), and pair distribution function (PDF) analysis. Further structural analysis of the total scattering data indicates that the sodiated phase displays a layered-like rhombohedral R3m structure built from the stacking of Ti and Na slabs. Because of the initial 3D network of anatase, the reduced phase shows strong disorder due to cationic intermixing between the Ti and Na slabs and the refined chemical formula is (Na 0.43Ti 0.57) 3a 0.22Na 0.39Ti 0.39) 3bO 2, where refers to vacancy. The presence of high valence Ti ions in the Na layers induces a contraction of the c-parameter as compared to the ordered phase. Upon desodiation, the structure further amorphized and the local structure probed by PDF is shown to be similar to the anatase TiO 2, suggesting that the 3D network is recovered. The reversible sodium insertion/deinsertion is thus attributed to the rhombohedral active phase formed during the first discharge, and an oxidized phase featuring the local structure of anatase. Due to the amorphous nature of the two phases, the potential-composition curves are characterized by a sloping curve. Lastly, a comparison between the intercalation of lithium and sodium into anatase TiO 2 performed by DFT calculations confirmed that, for the sodiated phase, the rhombohedral structure is more stable than the tetragonal phase observed during the lithiation of nanoparticles.« less

A comparative scanning electron microscopy evaluation of smear layer removal with apple vinegar and sodium hypochlorite associated with EDTA

PubMed Central

CANDEIRO, George Táccio de Miranda; de MATOS, Isabela Barbosa; da COSTA, Clarice Fernandes Eloy; FONTELES, Cristiane Sá Roriz; do VALE, Mônica Sampaio

2011-01-01

Objective The purpose of this study was to evaluate by scanning electron microscopy (SEM) the removal of smear layer from the middle and apical root thirds after use of different irrigating solutions. Material and Methods Forty roots of permanent human teeth had their canals instrumented and were randomly assigned to 4 groups (n=10), according to the irrigating solution: apple vinegar (group A), apple vinegar finished with 17% ethylenediaminetetraacetic acid (EDTA) (group B), 1% sodium hypochlorite (NaOCl) finished with 17% EDTA (group C) and saline (group D - control). After chemomechanical preparation, the roots were cleaved longitudinally and their middle and apical thirds were examined by SEM at ×1,000 magnification. Two calibrated examiners (kappa=0.92) analyzed the SEM micrographs qualitatively attributing scores that indicated the efficacy of the solutions in removing the smear layer from the surface of the dentin tubules (1 - poor, 2 - good and 3 - excellent). Data from the control and experimental groups were analyzed by the Kruskal-Wallis and Dunn's test, while the Wilcoxon test was used to compare the middle and apical thirds of the canals within the same group (α=0.05). Results The middle third presented less amount of smear layer than the apical third, regardless of the irrigant. There was statistically significant difference (p=0.0402) among the groups in the middle third. In the apical third, the apple vinegar/EDTA group showed the greatest removal of smear layer (p=0.0373). Conclusion Apple vinegar associated or not with EDTA was effective in removing smear layer when used as an endodontic irrigant. PMID:22231000

Structural characterization of layered Na0.5Co0.5Mn0.5O2 material as a promising cathode for sodium-ion batteries

NASA Astrophysics Data System (ADS)

Manikandan, Palanisamy; Heo, Seongwoo; Kim, Hyun Woo; Jeong, Hu Young; Lee, Eungje; Kim, Youngsik

2017-09-01

Layered Na0.5Co0.5Mn0.5O2 material is synthesized through a facile mixed hydroxy-carbonate route using (Co0.5Mn0.5)2(OH)2CO3 precursor and well characterized as a hexagonal layered structure under P63/mmc space group. The lattice parameters and unit cell volume (a = 2.8363 Å, c = 11.3152 Å and V = 78.83 Å3) are calculated by Rietveld refinement analysis. A flaky-bundle morphology is obtained to the layered Na0.5Co0.5Mn0.5O2 material with the hexagonal flake size ∼30 nm. Advanced transmission electron microscopic images are revealed the local structure of the layered Na0.5Co0.5Mn0.5O2 material with contrasting bright dots and faint dark dots corresponding to the Co/Mn and Na atoms. Two oxidation and reduction peaks are occurred in a cyclic voltammetric analysis corresponding to Co3+/Co4+ and Mn3+/Mn4+ redox processes. These reversible processes are attributed to the intercalation/de-intercalation of Na+ ions into the host structure of layered Na0.5Co0.5Mn0.5O2 material. Accordingly, the sodium cell is delivered the initial charge-discharge capacity 53/144 mAh g-1 at 0.5 C, which cycling studies are extended to rate capability test at 1 C, 3 C and 5C. Eventually, the Na-ion full-cell is yielded cathode charge-discharge capacity 55/52 mAh g-1 at 0.212 mA and exhibited as a high voltage cathode for Na-ion batteries.

Sodium Iodate Produces a Strain-Dependent Retinal Oxidative Stress Response Measured In Vivo Using QUEST MRI.

PubMed

Berkowitz, Bruce A; Podolsky, Robert H; Lenning, Jacob; Khetarpal, Nikita; Tran, Catherine; Wu, Johnny Y; Berri, Ali M; Dernay, Kristin; Shafie-Khorassani, Fatema; Roberts, Robin

2017-06-01

We identify noninvasive biomarkers that measure the severity of oxidative stress within retina layers in sodium iodate (SI)-atrophy vulnerable (C57BL/6 [B6]) and SI-atrophy resistant (129S6/SvEvTac [S6]) mice. At 24 hours after administering systemic SI to B6 and S6 mice we measured: (1) superoxide production in whole retina ex vivo, (2) excessive free radical production in vivo based on layer-specific 1/T1 values before and after α-lipoic acid (ALA) administration while the animal was inside the magnet (QUEnch-assiSTed MRI [QUEST MRI]), and (3) visual performance (optokinetic tracking) ± antioxidants; control mice were similarly assessed. Retinal layer spacing and thickness in vivo also were evaluated (optical coherence tomography, MRI). SI-treated B6 mice retina had a significantly higher superoxide production than SI-treated S6 mice. ALA-injected SI-treated B6 mice had reduced 1/T1 in more retinal layers in vivo than in SI-treated S6 mice. Uninjected and saline-injected SI-treated B6 mice had similar transretinal 1/T1 profiles. Notably, the inner segment layer 1/T1 of SI-treated B6 mice was responsive to ALA but was unresponsive in SI-treated S6 mice. In both SI-treated strains, antioxidants improved contrast sensitivity to similar extents; antioxidants did not change acuity in either group. Retinal thicknesses were normal in both SI-treated strains at 24 hours after treatment. QUEST MRI uniquely measured severity of excessive free radical production within retinal layers of the same subject. Identifying the mechanisms underlying genetic vulnerabilities to oxidative stress is expected to help in understanding the pathogenesis of retinal degeneration.

Final Technical Report for GO15056 Millennium Cell: Development of an Advanced Chemical Hydrogen Storage and Generation System

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

Moreno, Oscar

The objectives of this project are to increase system storage capacity by improving hydrogen generation from concentrated sodium borohydride, with emphasis on reactor and system engineering; to complete a conceptual system design based on sodium borohydride that will include key technology improvements to enable a hydrogen fuel system that will meet the systembased storage capacity of 1.2 kWh/L (36 g H2/L) and 1.5 kWh/kg (45 g H2/kg), by the end of FY 2007; and to utilize engineering expertise to guide Center research in both off-board chemical hydride regeneration and on-board hydrogen generation systems.

Leaching of silicon from ferronickel (FeNi) smelting slag with sodium hydroxide solution at atmospheric pressure

NASA Astrophysics Data System (ADS)

Mufakhir, F. R.; Mubarok, M. Z.; Ichlas, Z. T.

2018-01-01

The present paper reports the leaching behavior of silicon from ferronickel slag under atmospheric pressure using sodium hydroxide solution. The effect of several experimental variables, namely concentration of leaching agent, operating temperature, stirring speed, and slurry density was investigated. The leaching kinetic was also investigated by using shrinking core model. It was determined that leaching of silicon from the slag was controlled by diffusion through product layer, although the activation energy was found to be 85.84 kJ/mol, which was unusually high for such a diffusion-controlled process.

Magnetite solubility and phase stability in alkaline media at elevated temperatures

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

Ziemniak, S.E.; Jones, M.E.; Combs, K.E.S.

Magnetite, Fe{sub 3}O{sub 4}, is the dominant oxide constituent of the indigenous corrosion layers that form on iron base alloys in high purity, high temperature water. The apparent simultaneous stability of two distinct oxidation states of iron in this metal oxide is responsible for its unique solubility behavior. The present work was undertaken to extend the experimental and theoretical bases for estimating solubilities of an iron corrosion product (Fe{sub 3}O{sub 4}/Fe(OH){sub 2}) over a broader temperature range and in the presence of complexing, pH-controlling reagents. These results indicate that a surface layer of ferrous hydroxide controls magnetite solubility behavior atmore » low temperatures in much the same manner as a surface layer of nickel(II) hydroxide was previously reported to control the low temperature solubility behavior of NiO. The importance of Fe(III) ion complexes implies not only that most previously-derived thermodynamic properties of the Fe(OH){sub 3}{sup {minus}} ion are incorrect, but that magnetite phase stability probably shifts to favor a sodium ferric hydroxyphosphate compound in alkaline sodium phosphate solutions at elevated temperatures. The test methodology involved pumping alkaline solutions of known composition through a bed of Fe{sub 3}O{sub 4} granules and analyzing the emerging solution for Fe. Two pH-controlling reagents were tested: sodium phosphate and ammonia. Equilibria for the following reactions were described in thermodynamic terms: (a) Fe(OH){sub 2}/Fe{sub 3}O{sub 4} dissolution and transformation, (b) Fe(II) and Fe(III) ion hydroxocomplex formation (hydrolysis), (c) Fe(II) ion amminocomplex formation, and (d) Fe(II) and Fe(III) ion phosphatocomplex formation. 36 refs.« less

The Mesospheric Sodium Layer as a Remotely, Optically Pumped Magnetometer for Investigation of Birkeland Currents

NASA Astrophysics Data System (ADS)

Matzka, J.; Johnsen, M. G.; Hoppe, U. P.; Serrano, A.

2016-12-01

By means of optical pumping, it is possible to use the naturally occurring sodium layer in the mesosphere to measure Earth's scalar magnetic field at 90 km above ground. This is an altitude not accessible by other means than rockets, which only will provide point measurements of very short time scales. We are planning to modify the sodium lidar at ALOMAR in Northern Norway to be able, for the first time, to measure and monitor the magnetic field in situ in the high latitude mesosphere over longer time scales. The planned modifications to the lidar instrument will allow alternating between the new magnetometer mode and its present mode for atmospheric temperatures and winds. The technique, which has been proposed earlier for measurements at low or mid-latitudes for studies of Earth's internal magnetic field, will in our project be applied to high latitudes in the auroral zone. This opens for a completely new domain of measurements of externally generated geomagnetic variations related to currents in the magnetosphere-ionosphere system. In particular, we aim to measure the magnetic field variations in close vicinity to Birkeland currents associated with particle precipitation events penetrating to altitudes below 90 km and small-scale, discrete auroral arcs. It is, furthermore, anticipated that it will be possible to detect horizontal current structures in the E-layer on much smaller length scales than it is presently possible from ground observations alone. During the project we plan take advantage of the rich space science infrastructure located in northern Norway, including ALOMAR, EISCAT and the Tromsø Geophysical Observatory magnetometer network. If possible, we also aim to make measurements in conjunction with overpasses of the SWARM satellites.

Synthesis and characterization of sodium vanadium oxide gels: the effects of water (n) and sodium (x) content on the electrochemistry of Na(x)V2O5·nH2O.

PubMed

Lee, Chia-Ying; Marschilok, Amy C; Subramanian, Aditya; Takeuchi, Kenneth J; Takeuchi, Esther S

2011-10-28

Sodium vanadium oxide gels, Na(x)V(2)O(5)·nH(2)O, of varying sodium content (0.12 < x < 0.32) were prepared by careful control of an ion exchange process. The water content (0.23 > n > 0.01) and interlayer spacing were found to be inversely proportional to the sodium level (x), thus control of sodium (x) content provided a direct, chimie douce approach for control of hydration level (n) and interlayer spacing, without the need for high temperature treatment to affect dehydration. Notably, the use of high temperatures to modify hydration levels can result in crystallization and collapse of the interlayer structure, highlighting the distinct advantage of our novel chimie douce synthesis strategy. Subsequent to synthesis and characterization, results from an electrochemical study of a series of Na(x)V(2)O(5)·nH(2)O samples highlight the significant impact of interlayer water on delivered capacity of the layered materials. Specifically, the sodium vanadium oxide gels with higher sodium content and lower water content provided higher capacities in lithium based cells, where capacity delivered to 2.0 V under C/20 discharge ranged from 170 mAh/g for Na(0.12)V(2)O(5)·0.23H(2)O to 300 mAh/g for Na(0.32)V(2)O(5)·0.01H(2)O. The capacity differences were maintained as the cells were cycled. This journal is © the Owner Societies 2011

Preparation of bilayer-core osmotic pump tablet by coating the indented core tablet.

PubMed

Liu, Longxiao; Xu, Xiangning

2008-03-20

In this paper, a bilayer-core osmotic pump tablet (OPT) which does not require laser drilling to form the drug delivery orifice is described. The bilayer-core consisted of two layers: (a) push layer and (b) drug layer, and was made with a modified upper tablet punch, which produced an indentation at the center of the drug layer surface. The indented tablets were coated by using a conventional pan-coating process. Although the bottom of the indentation could be coated, the side face of the indentation was scarcely sprayed by the coating solution and this part of the tablet remained at least partly uncoated leaving an aperture from which drug release could occur. Nifedipine was selected as the model drug. Sodium chloride was used as osmotic agent, polyvinylpyrrolidone as suspending agent and croscarmellose sodium as expanding agent. The indented core tablet was coated by ethyl cellulose as semipermeable membrane containing polyethylene glycol 400 for controlling the membrane permeability. The formulation of core tablet was optimized by orthogonal design and the release profiles of various formulations were evaluated by similarity factor (f(2)). It was found that the optimal OPT was able to deliver nifedipine at an approximate zero-order up to 24 h, independent on both release media and agitation rates. The preparation of bilayer-core OPT was simplified by coating the indented core tablet, by which sophisticated technology of the drug layer identification and laser drilling could be eliminated. It might be promising in the field of preparation of bilayer-core OPT.

Preparation and characterization of highly water-soluble magnetic Fe3O4 nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

NASA Astrophysics Data System (ADS)

Li, Honghong; Qin, Li; Feng, Ying; Hu, Lihua; Zhou, Chunhua

2015-06-01

A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe3O4 magnetic nanoparticles (Fe3O4-AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe3O4-AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe3O4-AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe3O4. Transmission electron microscopy (TEM) analysis confirmed that the Fe3O4-AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe3O4-AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe3O4-MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe3O4-AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature TB of Fe3O4-AOS-MN capped with double-layered AOS is 170 K.

Large-area few-layer hexagonal boron nitride prepared by quadrupole field aided exfoliation

NASA Astrophysics Data System (ADS)

Lun Lu, Han; Zhi Rong, Min; Qiu Zhang, Ming

2018-03-01

A quadrupole electric field-mediated exfoliation method is proposed to convert micron-sized hexagonal boron nitride (h-BN) powder into few-layer hexagonal boron nitride nanosheets (h-BNNS). Under optimum conditions (400 Hz, 40 V, 32 μg ml-1, sodium deoxycholate, TAE medium), the h-BN powders (thickness >200 nm, horizontal scale ˜10 μm) are successfully exfoliated into 0.5-4 nm (1-10 layers) thick h-BNNS with the same horizontal scale. Dynamic laser scattering and atomic force microscope data show that the yield is 47.6% (for the portion with the thickness of 0.5-6 nm), and all of the vertical sizes are reduced to smaller than 18 nm (45 layers).

Pulsed laser deposition of functionalized Mg-Al layered double hydroxide thin films

NASA Astrophysics Data System (ADS)

Vlad, A.; Birjega, R.; Tirca, I.; Matei, A.; Mardare, C. C.; Hassel, A. W.; Nedelcea, A.; Dinescu, M.; Zavoianu, R.

2018-02-01

In this paper, magnesium-aluminium layered double hydroxide (LDH) has been functionalized with sodium dodecyl sulfate (DS) and deposited as thin film by pulsed laser deposition (PLD). Mg, Al-LDH powders were prepared by co-precipitation and used as reference material. Intercalation of DS as an anionic surfactant into the LDHs host layers has been prepared in two ways: co-precipitation (P) and reconstruction (R). DS intercalation occurred in LDH powder via both preparation methods. The films deposited via PLD, in particular at 532 and 1064 nm, preserve the organic intercalated layered structure of the targets prepared from these powders. The results reveal the ability of proposed deposition technique to produce functional composite organo-modified LDHs thin films.

Inorganic-Organic Coating via Molecular Layer Deposition Enables Long Life Sodium Metal Anode.

PubMed

Zhao, Yang; Goncharova, Lyudmila V; Zhang, Qian; Kaghazchi, Payam; Sun, Qian; Lushington, Andrew; Wang, Biqiong; Li, Ruying; Sun, Xueliang

2017-09-13

Metallic Na anode is considered as a promising alternative candidate for Na ion batteries (NIBs) and Na metal batteries (NMBs) due to its high specific capacity, and low potential. However, the unstable solid electrolyte interphase layer caused by serious corrosion and reaction in electrolyte will lead to big challenges, including dendrite growth, low Coulombic efficiency and even safety issues. In this paper, we first demonstrate the inorganic-organic coating via advanced molecular layer deposition (alucone) as a protective layer for metallic Na anode. By protecting Na anode with controllable alucone layer, the dendrites and mossy Na formation have been effectively suppressed and the lifetime has been significantly improved. Moreover, the molecular layer deposition alucone coating shows better performances than the atomic layer deposition Al 2 O 3 coating. The novel design of molecular layer deposition protected Na metal anode may bring in new opportunities to the realization of the next-generation high energy-density NIBs and NMBs.

Crystal structure of centrosymmetric 12-layer sodium-rich eudialyte

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

Rozenberg, K. A.; Rastsvetaeva, R. K., E-mail: rast@ns.crys.ras.ru; Verin, I. A.

2009-05-15

The structure of a new representative of the eudialyte group with the formula (Na,Sr,K){sub 18}Ca{sub 6}Zr{sub 3}Fe[Si{sub 25}O{sub 72}](OH){sub 2}Cl . H{sub 2}O from the Lovozero massif (Kola Peninsula) was studied by X-ray diffraction. The trigonal unit-cell parameters are a = 14.226 A, c = 30.339 A, sp. gr. R3-barm; the R factor is 0.045 based on 990 reflections. This sample is of interest as a sodium-rich and iron-poor mineral having a rare centrosymmetric structure, in which the M(2) site is occupied predominantly by sodium atoms. The dependence of the formation of centrosymmetric and non-centrosymmetric structures on the composition ofmore » eudialyte-group minerals was analyzed.« less

Microwave absorption in substances that form hydration layers with water

NASA Astrophysics Data System (ADS)

Garner, H. R.; Ohkawa, T.; Tuason, O.; Lee, R. L.

1990-12-01

The microwave absorption of certain water soluble polymers (polyethylene glycol, polyvinyl pyrrolidone, proteins, and DNA) in solution is composed of three parts: absorption in the free water, absorption in the substance, and absorption in the hydration layer. Ethanol, sucrose, glycerol, and sodium acetate, which form weak hydrogen bonds or have an ionic nature in aqueous solutions, also have microwave absorption signatures similar to polymers that form hydration layers. The frequency-dependent absorption of the free water and of the hydration layer water is described by a simple Debye relaxation model. The absorption per unit sample volume attributable to the hydration layer is solute concentration dependent, and a simple model is used to describe the dependence. The hydration-layer relaxation time was found to vary from substance to substance and with solute concentration. The relaxation time was also found to be independent of solute length.

Ultrasound-guided near-infrared spectroscopy for brain functional study: feasibility analysis and preliminary work

NASA Astrophysics Data System (ADS)

Xu, Ronald; Qiang, Bo; Liu, Jun

2005-04-01

Recent advances in diffuse optical imaging and spectroscopy (DOIS) allow the noninvasive measurement of local changes in cerebral oxygenation and hemodynamics. Available DOIS devices fall into three categories: time domain (TD), frequency domain (FD) and continuous wave (CW). The TD and FD devices have potential for high spatial resolution, high temporal resolution and high accuracy measurement, but the instrument cost and the hardware size prevent their wide clinical application. Furthermore, the presence of the low scattering cerebrospinal fluid layer (CSF) and its thickness variation during motion challenges quantitative, continuous monitoring of the cortex layer oxygenation and blood content. MRI has been used to provide a priori knowledge of the head anatomy that helps the NIR image reconstruction. However, the technology is expensive and lacks portability. This paper proposes a method that combines the accuracy of a TD/FD system and the portability of a CW device. With the optical baseline measured by a TD or FD device and the layer thickness characterized by an ultrasound transducer, a conventional CW system may be able to quantify the cortex layer optical absorption with high accuracy. In this paper, the feasibility of using ultrasound guided CW spectroscopy to monitor brain activities was studied on a multi layer head model using Monte Carlo simulation and order of magnitude analysis. A forward algorithm based on diffuse approximation and 2D Fourier Transform was used to optimize the source detector separation. Both analytical and neuron network approaches were developed for inverse calculation of the cortex layer absorption in real time. An ultrasound transducer was used to monitor the thickness of different layers surrounding the cerebral cortex. The concept of ultrasound guided CW spectroscopy was demonstrated by numerical simulation on a 2 layer head model and the use of the ultrasound transducer for layer thickness characterization was verified by animal and bench top results.

Confined Transformation Derived Ultrathin Titanate Nanosheets/ Graphene Films for Excellent Na/K Ion Storage.

PubMed

Zeng, Cheng; Xie, Fangxi; Yang, Xianfeng; Jaroniec, Mietek; Zhang, Lei; Qiao, Shizhang

2018-05-02

Confined transformation of assembled two-dimensional MXene (titanium carbide) and reduced graphene oxide (rGO) nanosheets was employed to prepare the free-standing films of the integrated ultrathin sodium titanate (NTO)/potassium titanate (KTO) nanosheets sandwiched between graphene layers. The ultrathin Ti-based nanosheets reduce the diffusion distance while rGO layers enhance conductivity. Incorporation of graphene into the titanate films produced efficient binder-free anodes for ion storage. The resulting NTO/rGO electrode for sodium ion batteries exhibited an excellent rate performance and long cycling stability characterized by reversible capacity of 72 mA h g-1 at 5 A g-1 after 10000 cycles. Moreover, flexible KTO/rGO electrode for potassium ion batteries maintained a reversible capacity of 75 mA h g-1 after 700 cycles at 2 A g-1. These results demonstrate the superiority of the unique sandwich-type electrodes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of Different Concentration of Sodium Hydroxide [NaOH] on Kenaf Sandwich Structures

NASA Astrophysics Data System (ADS)

Aziz, M.; Halim, Z.; Othman, M.

2018-01-01

Sandwich panels are structures that made of three layers, low-density core inserted in between thin skin layers. This structures allow the achievement of excellent mechanical performance with low weight, thus this characteristic fulfil requirement to be use in aircraft application. In recent time, sandwich structures have been studied due to it has multifunction properties and lightweight. The aim of this study is to fabricate a composite sandwich structures with biodegradable material for face sheet [skin] where the fibre being treat with different concentration of sodium hydroxide [NaOH] with 10 and 20 hours of soaking time. Kenaf fibre [treated] reinforced epoxy will be used as skins and Nomex honeycomb is chosen to perform as core for this sandwich composite structure. The mechanical properties that are evaluated such as flexural strength and impact energy of kenaf fibre-reinforced epoxy sandwich structures. For flexural test, the optimum flexural strength is 13.4 MPa and impact strength is 18.3 J.

A novel Ag catalyzation process using swelling impregnation method for electroless Ni deposition on Kevlar® fiber

NASA Astrophysics Data System (ADS)

Pang, Hongwei; Bai, Ruicheng; Shao, Qinsi; Gao, Yufang; Li, Aijun; Tang, Zhiyong

2015-12-01

A novel Ag catalyzation process using swelling impregnation pretreatment method was developed for electroless nickel (EN) deposition on Kevlar fiber. Firstly, the fiber was immersed into an aqueous dimethylsulfoxide (DMSO) solution of silver nitrate to impart silver nitrate into the inner part of the fiber near the surface. Subsequently silver nitrate was reduced to metal silver nanoparticles on the fiber surface by treatment with aqueous solution of sodium borohydride. After electroless plating, a dense and homogeneous nickel coating was obtained on the fiber surface. The silver nanoparticles formed at the fiber surface functioned as a catalyst for electroless deposition as well as an anchor for the plated layer. The study also revealed that the incorporation of surfactant sodium dodecyl sulfate (SDS) in electroless nickel plating bath can enhance the adhesion strength of EN layer with the fiber surface and minimize the surface roughness of the EN coating. The Ni plated Kevlar fiber possessed excellent corrosion resistance and high tensile strength.

Composite of K-doped (NH4)2V3O8/graphene as an anode material for sodium-ion batteries.

PubMed

Liu, Xin; Li, Zhiwei; Fei, Hailong; Wei, Mingdeng

2015-11-21

A layer structured K-doped (NH4)2V3O8/graphene (K-NVG) was prepared via a hydrothermal route and then used as an anode material for sodium-ion batteries for the first time. The K-NVG nanosheets have a diameter in the range of 200-500 nm. The K-NVG electrode exhibited stable cycling and a good rate performance with a reversible capacity of 235.4 mA h g(-1), which is much higher than the 90.5 mA h g(-1) value of the (NH4)2V3O8/graphene electrode after 100 cycles at a current density of 100 mA g(-1). Simultaneously, the retention rate was maintained at 82% even after 250 cycles at the current density of 300 mA g(-1). Such good electrochemical properties may be attributed to the K-NVG's stable layered structure.

A fusion algorithm for infrared and visible based on guided filtering and phase congruency in NSST domain

NASA Astrophysics Data System (ADS)

Liu, Zhanwen; Feng, Yan; Chen, Hang; Jiao, Licheng

2017-10-01

A novel and effective image fusion method is proposed for creating a highly informative and smooth surface of fused image through merging visible and infrared images. Firstly, a two-scale non-subsampled shearlet transform (NSST) is employed to decompose the visible and infrared images into detail layers and one base layer. Then, phase congruency is adopted to extract the saliency maps from the detail layers and a guided filtering is proposed to compute the filtering output of base layer and saliency maps. Next, a novel weighted average technique is used to make full use of scene consistency for fusion and obtaining coefficients map. Finally the fusion image was acquired by taking inverse NSST of the fused coefficients map. Experiments show that the proposed approach can achieve better performance than other methods in terms of subjective visual effect and objective assessment.

Monolithically Integrated Dual-Wavelength Self-Sustained Pulsating Laser Diodes with Real Refractive Index Guided Self-Aligned Structure

NASA Astrophysics Data System (ADS)

Onishi, Toshikazu; Imafuji, Osamu; Fukuhisa, Toshiya; Mochida, Atsunori; Kobayashi, Yasuhiro; Yuri, Masaaki; Itoh, Kunio; Shimizu, Hirokazu

2001-11-01

Monolithically integrated 780-nm-band and 650-nm-band self-sustained pulsating (SSP) lasers, which are desirable for simplified optical pickups in digital versatile disk (DVD) systems, have been developed for the first time. The real refractive index guided self-aligned (RISA) waveguide structure is adapted to reduce absorption loss in the current blocking layers. In order to obtain stable SSP, a saturable absorber formed in the active layer outside the current stripe, and a saturable absorbing layer above the active layer are utilized for the 780-nm-band and 650-nm-band laser diodes (LDs), respectively. Relative intensity noise less than -130 dB/Hz is maintained at temperatures of up to 80°C at an output power of 7 mW for the 650 nm band and 10 mW for the 780 nm band, which suggests that stable SSP operations have been realized.

Local anesthetic and antiepileptic drug access and binding to a bacterial voltage-gated sodium channel

PubMed Central

Boiteux, Céline; Vorobyov, Igor; French, Robert J.; French, Christopher; Yarov-Yarovoy, Vladimir; Allen, Toby W.

2014-01-01

Voltage-gated sodium (Nav) channels are important targets in the treatment of a range of pathologies. Bacterial channels, for which crystal structures have been solved, exhibit modulation by local anesthetic and anti-epileptic agents, allowing molecular-level investigations into sodium channel-drug interactions. These structures reveal no basis for the “hinged lid”-based fast inactivation, seen in eukaryotic Nav channels. Thus, they enable examination of potential mechanisms of use- or state-dependent drug action based on activation gating, or slower pore-based inactivation processes. Multimicrosecond simulations of NavAb reveal high-affinity binding of benzocaine to F203 that is a surrogate for FS6, conserved in helix S6 of Domain IV of mammalian sodium channels, as well as low-affinity sites suggested to stabilize different states of the channel. Phenytoin exhibits a different binding distribution owing to preferential interactions at the membrane and water–protein interfaces. Two drug-access pathways into the pore are observed: via lateral fenestrations connecting to the membrane lipid phase, as well as via an aqueous pathway through the intracellular activation gate, despite being closed. These observations provide insight into drug modulation that will guide further developments of Nav inhibitors. PMID:25136136

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

Zohar, S.; Choi, Y.; Love, D. M.

We use X-ray Excited Luminescence Microscopy to investigate the elemental and layer resolved magnetic reversal in an interlayer exchange coupled (IEC) epitaxial Fe/Cr wedge/Co heterostructure. The transition from strongly coupled parallel Co-Fe reversal for Cr thickness t(Cr) < 0.34 nm to weakly coupled layer independent reversal for t(Cr) > 1.5 nm is punctuated at 0.34 < t(Cr) < 1.5 nm by a combination of IEC guided domain wall motion and stationary zig zag domain walls. Domain walls nucleated at switching field minima are guided by IEC spatial gradients and collapse at switching field maxima.

High-frequency guided ultrasonic waves for hidden defect detection in multi-layered aircraft structures.

PubMed

Masserey, Bernard; Raemy, Christian; Fromme, Paul

2014-09-01

Aerospace structures often contain multi-layered metallic components where hidden defects such as fatigue cracks and localized disbonds can develop, necessitating non-destructive testing. Employing standard wedge transducers, high frequency guided ultrasonic waves that penetrate through the complete thickness were generated in a model structure consisting of two adhesively bonded aluminium plates. Interference occurs between the wave modes during propagation along the structure, resulting in a frequency dependent variation of the energy through the thickness with distance. The wave propagation along the specimen was measured experimentally using a laser interferometer. Good agreement with theoretical predictions and two-dimensional finite element simulations was found. Significant propagation distance with a strong, non-dispersive main wave pulse was achieved. The interaction of the high frequency guided ultrasonic waves with small notches in the aluminium layer facing the sealant and on the bottom surface of the multilayer structure was investigated. Standard pulse-echo measurements were conducted to verify the detection sensitivity and the influence of the stand-off distance predicted from the finite element simulations. The results demonstrated the potential of high frequency guided waves for hidden defect detection at critical and difficult to access locations in aerospace structures from a stand-off distance. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Guided wave propagation in single and double layer hollow cylinders embedded in infinite media.

PubMed

Jia, Hua; Jing, Mu; Joseph, L Rose

2011-02-01

Millions of miles of pipes are being used for the transportation, distribution, and local use of petroleum products, gas, water, and chemicals. Most of the pipes are buried in soil, leading to the significance of the study on the subject of guided wave propagation in pipes with soil influence. Previous investigations of ultrasonic guided wave propagation in an elastic hollow cylinder and in an elastic hollow cylinder coated with a viscoelastic material have led to the development of inspection techniques for bare and coated pipes. However, the lack of investigation on guided wave propagation in hollow cylinders embedded in infinite media like soil has hindered the development of pipe inspection methods. Therefore the influence of infinite media on wave propagation is explored in this paper. Dispersion curves and wave structures of both axisymmetric and nonaxisymmetric wave modes are developed. Due to the importance of the convergence of numerical calculations, the requirements of thickness and element number of the finite soil layer between hollow cylinder and infinite element layer are discussed, and an optimal combination is obtained in this paper. Wave structures are used for the mode identification in the non-monotonic region caused by the viscoelastic properties of coating and infinite media.

Hazardous Materials Verification and Limited Characterization Report on Sodium and Caustic Residuals in Materials and Fuel Complex Facilities MFC-799/799A

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

Gary Mecham

2010-08-01

This report is a companion to the Facilities Condition and Hazard Assessment for Materials and Fuel Complex Sodium Processing Facilities MFC-799/799A and Nuclear Calibration Laboratory MFC-770C (referred to as the Facilities Condition and Hazards Assessment). This report specifically responds to the requirement of Section 9.2, Item 6, of the Facilities Condition and Hazards Assessment to provide an updated assessment and verification of the residual hazardous materials remaining in the Sodium Processing Facilities processing system. The hazardous materials of concern are sodium and sodium hydroxide (caustic). The information supplied in this report supports the end-point objectives identified in the Transition Planmore » for Multiple Facilities at the Materials and Fuels Complex, Advanced Test Reactor, Central Facilities Area, and Power Burst Facility, as well as the deactivation and decommissioning critical decision milestone 1, as specified in U.S. Department of Energy Guide 413.3-8, “Environmental Management Cleanup Projects.” Using a tailored approach and based on information obtained through a combination of process knowledge, emergency management hazardous assessment documentation, and visual inspection, this report provides sufficient detail regarding the quantity of hazardous materials for the purposes of facility transfer; it also provides that further characterization/verification of these materials is unnecessary.« less

Modeling Sodium Abundance Variations in the Lunar Crust: A Likely Proxy of Past Solar System History and a Potential Guide to Close-In Rocky Exoplanets

NASA Astrophysics Data System (ADS)

Saxena, P.; Killen, R. M.; Petro, N. E.; Airapetian, V.; Mandell, A.

2017-12-01

While the Moon and Earth are generally similar in terms of composition, there exist variations in the abundance of certain elements among the two bodies. These differences are a likely consequence of differing physical evolution of the two bodies over the solar system's history. We describe how our past and current modeling efforts indicate that a significant fraction of the initial sodium budget of the Moon may have been depleted and transported from the lunar surface since the Moon's formation. Using profiles of sodium abundances from lunar crustal samples may thus serve as a powerful tool towards exploring conditions on the Moon's surface throughout solar system history. Additionally, conditions on the Moon immediately after formation may still be recorded in the lunar crust and may provide a window towards interpreting observations from some of the first rocky exoplanets that will be most amenable to characterization.

Layered P2-Na 2/3 Co 1/2 Ti 1/2 O 2 as a high-performance cathode material for sodium-ion batteries

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

Sabi, Noha; Doubaji, Siham; Hashimoto, Kazuki

Layered oxides are regarded as promising cathode materials for sodium-ion batteries. We present Na2/3Co1/2Ti1/2O2 as a potential new cathode material for sodium-ion batteries. The crystal features and morphology of the pristine powder were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The cathode material is evaluated in galvanostatic charge-discharge and galvanostatic intermittent titration tests, as well as ex-situ X-ray diffraction analysis. Synthesized by a high-temperature solid state reaction, Na2/3Co1/2Ti1/2O2 crystallizes in P2-type structure with P6(3)/mmc space group. The material presents reversible electrochemical behavior and delivers a specific discharge capacity of 100 mAh g(-1) when tested in Na halfmore » cells between 2.0 and 4.2 V (vs. Na+/Na), with capacity retention of 98% after 50 cycles. Furthermore, the electrochemical cycling of this titanium-containing material evidenced a reduction of the potential jumps recorded in the NaxCoO2 parent phase, revealing a positive impact of Ti substitution for Co. The ex-situ XRD measurements confirmed the reversibility and stability of the material. No structural changes were observed in the XRD patterns, and the P2-type structure was stable during the charge/discharge process between 2.0 and 4.2 V vs. Na+/Na. These outcomes will contribute to the progress of developing low cost electrode materials for sodium-ion batteries. (C) 2017 Elsevier B.V. All rights reserved.« less

Electrodeposition Process and Performance of CuIn(Se x S1- x )2 Film for Absorption Layer of Thin-Film Solar Cells

NASA Astrophysics Data System (ADS)

Li, Libo; Yang, Xueying; Gao, Guanxiong; Wang, Wentao; You, Jun

2017-11-01

CuIn(Se x S1- x )2 thin film is prepared by the electrodeposition method for the absorption layer of the solar cell. The CuIn(Se x S1- x )2 films are characterized by cyclic voltammetry measurement for the reduction of copper, indium, selenium and sulfur in selenium and sulfur in aqueous solutions with sodium citrate and without sodium citrate. In the four cases, the defined reduction process for every single element is obtained and it is observed that sodium citrate changes the reduction potentials. A linear relationship between the current density of the reduction peak and (scan rate v)1/2 for copper and indium is achieved, indicating that the process is diffusion controlled. The diffusion coefficients of copper and indium ions are calculated. The diffusional coefficient D value of copper is higher than that of indium, and this is the reason why the deposition rate of copper is higher. When four elements are co-deposited in the aqueous solution with sodium citrate, the quaternary compound of CuIn(Se x S1- x )2 is deposited together with Cu3Se2 impure phases after annealing, as found by XRD spectra. Morphology is observed by SEM and AFM. The chemical state of the films components is analyzed by XPS. The UV-Visible spectrophotometer and electrochemistry workstation are employed to measure the photoelectric properties. The results show that the smooth, uniform and compact CuIn(Se x S1- x )2 film is a semiconductor with a band gap of 1.49 eV and a photovoltaic conversion efficiency of 0.45%.

Nanostructured lipid carriers to enhance transdermal delivery and efficacy of diclofenac.

PubMed

Nguyen, Chien Ngoc; Nguyen, Thi Thuy Trang; Nguyen, Hanh Thuy; Tran, Tuan Hiep

2017-10-01

Lipid carrier-mediated transdermal drug delivery offers several advantages because it is non-irritating and non-toxic, provides effective control of drug release, and forms an adhesive film that hydrates the outer skin layers. However, to penetrate the deeper skin layers, these formulations need to overcome several barriers in the stratum corneum. This study evaluates factors influencing particle size and drug-loading capacity, which play a key role in drug permeation and efficacy. Diclofenac sodium was chosen as the model drug. The fabrication of diclofenac sodium-loaded lipid nanoparticles was optimized by modulating several parameters, including the lipids and surfactants employed, the drug/lipid ratio, and the pH of the aqueous phase. The physical properties and loading efficiencies of the nanoparticles were characterized. The optimized formulation was then dispersed into a polymer solution to form a gel, which demonstrated a sustained ex vivo permeation of diclofenac sodium over 24 h through excised rat skin and a higher drug penetrating capacity than that of a commercially available gel. In vivo anti-inflammatory activity was assessed in a rat carrageenan-induced paw edema model; the anti-edema effects of the prepared gel and commercially available gel over 24 h were comparable. The present findings indicate the effects of particle size and drug loading on the ability of nanostructured lipid carrier preparations to provide transdermal drug delivery.

A highly stable (SnOx-Sn)@few layered graphene composite anode of sodium-ion batteries synthesized by oxygen plasma assisted milling

NASA Astrophysics Data System (ADS)

Cheng, Deliang; Liu, Jiangwen; Li, Xiang; Hu, Renzong; Zeng, Meiqing; Yang, Lichun; Zhu, Min

2017-05-01

The (SnOx-Sn)@few layered graphene ((SnOx-Sn)@FLG) composite has been synthesized by oxygen plasma-assisted milling. Owing to the synergistic effect of rapid plasma heating and ball mill grinding, SnOx (1 ≤ x ≤ 2) nanoparticles generated from the reaction of Sn with oxygen are tightly wrapped by FLG nanosheets which are simultaneously exfoliated from expanded graphite, forming secondary micro granules. Inside the granules, the small size of the SnOx nanoparticles enables the fast kinetics for Na+ transfer. The in-situ formed FLG and residual Sn nanoparticles improve the electrical conductivity of the composite, meanwhile alleviate the aggregation of SnOx nanoparticles and relieve the volume change during the cycling, which is beneficial for the cyclic stability for the Na+ storage. As an anode material for sodium-ion batteries, the (SnOx-Sn)@FLG composite exhibits a high reversible capacity of 448 mAh g-1 at a current density of 100 mA g-1 in the first cycle, with 82.6% capacity retention after 250 cycles. Even when the current density increases to 1000 mA g-1, this composite retains 316.5 mAh g-1 after 250 cycles. With superior Na+ storage stability, the (SnOx-Sn)@FLG composite can be a promising anode material for high performance sodium-ion batteries.

Matrix polyelectrolyte capsules based on polysaccharide/MnCO₃ hybrid microparticle templates.

PubMed

Wei, Qingrong; Ai, Hua; Gu, Zhongwei

2011-06-15

An efficient strategy for biomacromolecule encapsulation based on spontaneous deposition into polysaccharide matrix-containing capsules is introduced in this study. First, hybrid microparticles composed of manganese carbonate and ionic polysaccharides including sodium hyaluronate (HA), sodium alginate (SA) and dextran sulfate sodium (DS) with narrow size distribution were synthesized to provide monodisperse templates. Incorporation of polysaccharide into the hybrid templates was successful as verified by thermogravimetric analysis (TGA) and confocal laser scanning microscopy (CLSM). Matrix polyelectrolyte microcapsules were fabricated through layer-by-layer (LbL) self-assembly of oppositely charged polyelectrolytes (PEs) onto the hybrid particles, followed by removal of the inorganic part of the cores, leaving polysaccharide matrix inside the capsules. The loading and release properties of the matrix microcapsules were investigated using myoglobin as a model biomacromolecule. Compared to matrix-free capsules, the matrix capsules had a much higher loading capacity up to four times; the driving force is mostly due to electrostatic interactions between myoglobin and the polysaccharide matrix. From our observations, for the same kind of polysaccharide, a higher amount of polysaccharide inside the capsules usually led to better loading capacity. The release behavior of the loaded myoglobin could be readily controlled by altering the environmental pH. These matrix microcapsules may be used as efficient delivery systems for various charged water-soluble macromolecules with applications in biomedical fields. Copyright © 2010 Elsevier B.V. All rights reserved.

HIGH RESISTIVITY BEHAVIOR OF HOT-SIDE ELECTROSTATIC PRECIPITATORS

EPA Science Inventory

The report gives results of experiments to explain the high resistivity behavior of hot-side electrostatic precipitators (ESPs) collecting fly ash. The working hypothesis is that the behavior is the result of the buildup of a thin layer of sodium-ion-depleted fly ash which has a ...

Raman spectroscopic studies of the interaction of oxalic acid and sodium oxalate used as corrosion inhibitors with copper

NASA Astrophysics Data System (ADS)

Jeziorowski, H.; Moser, B.

1985-09-01

The Raman spectra of the liquid-solid interface recorded in situ show the formation of a salt complex of the inhibitor molecules and the copper ions. This suggests that this chemisorbed surface species produces the protective layer.

HORIZONTAL CONFIGURATION OF THE LASAGNA (TM) TREATMENT TECHNOLOGY USER GUIDE

EPA Science Inventory

This report is a user's guide that discusses the technology and operations unique to the installation and operation of the horizontal configuration of the Lasagna? integrated soil remediation technology. This technology, called Lasagna? because of the layers of electrodes and tr...

Bilayer Poly(Lactic-co-glycolic acid)/Nano-Hydroxyapatite Membrane with Barrier Function and Osteogenesis Promotion for Guided Bone Regeneration

PubMed Central

Fu, Li; Wang, Zhanfeng; Dong, Shujun; Cai, Yan; Ni, Yuxin; Zhang, Tianshou; Wang, Lin; Zhou, Yanmin

2017-01-01

Guided bone regeneration (GBR) is one such treatment that reconstructs neo-bone tissue by using a barrier membrane to prevent the invasion of soft tissue and to create a space for guiding new bone growth into the bone defect. Herein, we report a novel functionally graded bilayer membrane (FGBM) for GBR application. To fabricate the novel membrane, the composites of poly(lactic-co-glycolic acid) and nano-hydroxyapatite were prepared by phase inversion for the dense layer and by electrospinning for another porous layer, and their corresponding properties were evaluated including surface morphology, mechanics, degradability, cell barrier function, and in vitro osteogenic bioactivity. The results showed that PLGA with 5% nHA in dense layer could meet the requirement of mechanical strength and have excellent barrier function even on condition of post-degradation. Furthermore, PLGA with 30% nHA in porous layer could achieve the good physical and chemical properties. In addition, 30% nHA incorporation would enhance the in vitro mineralization, and have superior capabilities of cell adhesion, proliferation and differentiation compared to other groups. Therefore, the designed FGBM could potentially serve as a barrier for preferential tissue ingrowth and achieve a desirable therapeutic result for bone tissue regeneration. PMID:28772618

Microbial communities associated with the anthropogenic, highly alkaline environment of a saline soda lime, Poland.

PubMed

Kalwasińska, Agnieszka; Felföldi, Tamás; Szabó, Attila; Deja-Sikora, Edyta; Kosobucki, Przemysław; Walczak, Maciej

2017-07-01

Soda lime is a by-product of the Solvay soda process for the production of sodium carbonate from limestone and sodium chloride. Due to a high salt concentration and alkaline pH, the lime is considered as a potential habitat of haloalkaliphilic and haloalkalitolerant microbial communities. This artificial and unique environment is nutrient-poor and devoid of vegetation, due in part to semi-arid, saline and alkaline conditions. Samples taken from the surface layer of the lime and from the depth of 2 m (both having pH ~11 and EC e up to 423 dS m -1 ) were investigated using culture-based (culturing on alkaline medium) and culture-independent microbiological approaches (microscopic analyses and pyrosequencing). A surprisingly diverse bacterial community was discovered in this highly saline, alkaline and nutrient-poor environment, with the bacterial phyla Proteobacteria (representing 52.8% of the total bacterial community) and Firmicutes (16.6%) showing dominance. Compared to the surface layer, higher bacterial abundance and diversity values were detected in the deep zone, where more stable environmental conditions may occur. The surface layer was dominated by members of the genera Phenylobacterium, Chelativorans and Skermanella, while in the interior layer the genus Fictibacillus was dominant. The culturable aerobic, haloalkaliphilic bacteria strains isolated in this study belonged mostly to the genus Bacillus and were closely related to the species Bacillus pseudofirmus, B. cereus, B. plakortidis, B. thuringensis and B. pumilus.

The molecular origin of a loading-induced black layer in the deep region of articular cartilage at the magic angle

PubMed Central

Wang, Nian; Kahn, David; Badar, Farid; Xia, Yang

2014-01-01

Purpose To investigate the molecular origin of an unusual low-intensity layer in the deep region of articular cartilage as seen in MRI when the tissue is imaged under compression and oriented at the magic angle. Materials and Methods Microscopic MRI (μMRI) T2 and T1ρ experiments were carried out for both native and degraded (treated with trypsin) 18 specimens. The glycosaminoglycan (GAG) concentrations in the specimens were quantified by both sodium ICP-OES and μMRI Gd(DTPA)2--contrast methods. The mechanical modulus of the specimens was also measured. Results Native tissue shows no load-induced layer, while the trypsin-degraded tissue shows clearly the low-intensity line at the deep part of tissue. The GAG reductions are confirmed by the sodium ICP-OES (from 81.7 ± 5.4 mg/ml to 9.2 ± 3.4 mg/ml), MRI GAG quantification (from 72.4 ± 6.7 mg/ml to 11.2 ± 2.9 mg/ml). The modulus reduction is confirmed by biomechanics (from 4.3 ± 0.7 MPa to 0.3 ± 0.1 MPa). Conclusion Both T2 and T1ρ profiles in native and degraded cartilage show strongly strain-, depth-, and angle-dependent using high resolution MRI. The GAG reduction is responsible for the visualization of a low-intensity layer in deep cartilage when it is loaded and orientated at 55°. PMID:24833266

The critical role of sodium content on structure, morphology and electrochemical performance of layered P2-type NaxNi0.167Co0.167Mn0.67O2 for sodium ion batteries

NASA Astrophysics Data System (ADS)

Bao, Shuo; Luo, Shaohua; Wang, Zhiyuan; Wang, Qing; Hao, Aimin; Zhang, Yahui; Wang, Yingling

2017-09-01

P2-type manganese-based ternary transition metal oxides have triggered extensive researches as potential cathode materials for sodium ion batteries. However, these kinds of materials display the large difference in electrochemical performance with sodium content varying from 0.45 to 0.8, the relevant investigations on effects of sodium content are insufficient. In this work, we synthesize a series of spherical P2-type cathode materials NaxNi0.167Co0.167Mn0.67O2 with different sodium content (x = 0.45, 0.55, 0.67, 0.8, 0.9, 1) and investigate the effects of sodium content on structure and electrochemical performance. The results reveal that NaxNi0.167Co0.167Mn0.67O2 (x = 0.45, 0.55) consist of P2-phase and P3-phase, while NaxNi0.167Co0.167Mn0.67O2 (x = 0.67, 0.8, 0.9, 1) exhibit pure P2-phase. Na0.45Ni0.167Co0.167Mn0.67O2 delivers an initial discharge capacity of 143 mAh g-1, while a fast capacity decay is observed after 50 cycles. In comparison, Na0.67Ni0.167Co0.167Mn0.67O2 shows excellent cycling stability and rate performance. The significant difference in electrochemical performance is attributed to the initial sodium content, which leads to the existence of P3-phase. Moreover, higher sodium content promotes primary particles to grow larger and thicker, which is not favorable for the diffusion of Na+. Generally, Na0.67Ni0.167Co0.167Mn0.67O2 is favored by suitable sodium content, offers excellent electrochemical performance in terms of capacity, rate performance and cycling stability.

High Resolution Imaging Testbed Utilizing Sodium Laser Guide Star Adaptive Optics: The Real Time Wavefront Reconstructor Computer

DTIC Science & Technology

2008-07-31

Unlike the Lyrtech, each DSP on a Bittware board offers 3 MB of on-chip memory and 3 GFLOPs of 32-bit peak processing power. Based on the performance...Each NVIDIA 8800 Ultra features 576 GFLOPS on 128 612-MHz single-precision floating-point SIMD processors, arranged in 16 clusters of eight. Each

Factors Influencing Pre-Service Science Teachers' Imagination at the Microscopic Level in Chemistry

ERIC Educational Resources Information Center

Al-Balushi, Sulaiman M.

2009-01-01

This study explores the mental images at the microscopic level of matter created by 22 preservice science teachers in Oman. Participants were encouraged during a guided imagery session to construct mental images for a scenario written about the explanation of the reaction of sodium in water. They were then asked to describe what they envisioned in…

Current status of the laser guide star adaptive optics system for Subaru Telescope

NASA Astrophysics Data System (ADS)

Hayano, Yutaka; Takami, Hideki; Guyon, Olivier; Oya, Shin; Hattori, Masayuki; Saito, Yoshihiko; Watanabe, Makoto; Murakami, Naoshi; Minowa, Yosuke; Ito, Meguru; Colley, Stephen; Eldred, Michael; Golota, Taras; Dinkins, Matthew; Kashikawa, Nobunari; Iye, Masanori

2008-07-01

The current status and recent results, since last SPIE conference at Orlando in 2006, for the laser guide star adaptive optics system for Subaru Telescope is presented. We had a first light using natural guide star and succeed to launch the sodium laser beam in October 2006. The achieved Strehl ratio on the 10th magnitude star was around 0.5 at K band. We confirmed that the full-width-half-maximum of the stellar point spread function is smaller than 0.1 arcsec even at the 0.9 micrometer wavelehgth. The size of the artificial guide star by the laser beam tuned at the wavelength of 589 nm was estimated to be 10 arcsec. The obtained blurred artificial guide star is caused by the wavefront error on the laser launching telescope. After the first light and first launch, we found that we need to modify and to fix the components, which are temporarily finished. Also components, which were postponed to fabricate after the first light, are required to build newly. All components used by the natural guide star adaptive optics system are finalized recently and we are ready to go on the sky. Next engineering observation is scheduled in August, 2008.

Thermodynamics of manganese oxides: Sodium, potassium, and calcium birnessite and cryptomelane

PubMed Central

Birkner, Nancy; Navrotsky, Alexandra

2017-01-01

Manganese oxides with layer and tunnel structures occur widely in nature and inspire technological applications. Having variable compositions, these structures often are found as small particles (nanophases). This study explores, using experimental thermochemistry, the role of composition, oxidation state, structure, and surface energy in the their thermodynamic stability. The measured surface energies of cryptomelane, sodium birnessite, potassium birnessite and calcium birnessite are all significantly lower than those of binary manganese oxides (Mn3O4, Mn2O3, and MnO2), consistent with added stabilization of the layer and tunnel structures at the nanoscale. Surface energies generally decrease with decreasing average manganese oxidation state. A stabilizing enthalpy contribution arises from increasing counter-cation content. The formation of cryptomelane from birnessite in contact with aqueous solution is favored by the removal of ions from the layered phase. At large surface area, surface-energy differences make cryptomelane formation thermodynamically less favorable than birnessite formation. In contrast, at small to moderate surface areas, bulk thermodynamics and the energetics of the aqueous phase drive cryptomelane formation from birnessite, perhaps aided by oxidation-state differences. Transformation among birnessite phases of increasing surface area favors compositions with lower surface energy. These quantitative thermodynamic findings explain and support qualitative observations of phase-transformation patterns gathered from natural and synthetic manganese oxides. PMID:28130549

Electron beam-induced radiation damage: the bubbling response in amorphous dried sodium phosphate buffer.

PubMed

Massover, William H

2010-06-01

Irradiation of an amorphous layer of dried sodium phosphate buffer (pH = 7.0) by transmission electron microscopy (100-120 kV) causes rapid formation of numerous small spherical bubbles [10-100 A (= 1-10 nm)] containing an unknown gas. Bubbling is detected even with the first low-dose exposure. In a thin layer (ca. 100-150 A), bubbling typically goes through nucleation, growth, possible fusion, and end-state, after which further changes are not apparent; co-irradiated adjacent areas having a slightly smaller thickness never develop bubbles. In moderately thicker regions (ca. over 200 A), there is no end-state. Instead, a complex sequence of microstructural changes is elicited during continued intermittent high-dose irradiation: nucleation, growth, early simple fusions, a second round of extensive multiple fusions, general reduction of matrix thickness (producing flattening and expansion of larger bubbles, occasional bubble fission, and formation of very large irregularly-shaped bubbles by a third round of compound fusion events), and slow shrinkage of all bubbles. The ongoing lighter appearance of bubble lumens, maintenance of their rounded shape, and extensive changes in size and form indicate that gas content continues throughout their surprisingly long lifetime; the thin dense boundary layer surrounding all bubbles is proposed to be the main mechanism for their long lifetime.

Bilayered Films Based on Novel Polymer Derivative for Improved Ocular Therapy of Gatifloxacin

PubMed Central

Aher, Naval Dinesh; Nair, Hema Ajit

2014-01-01

Context. Thiomers could prove to be suitable mucoadhesives for fabrication of ocular inserts. Objective. The study intends to explore the application of thiolated sodium alginate (TSA) to the preparation of bilayered ocular inserts of gatifloxacin. Methods. Cysteine moieties were grafted onto sodium alginate (SA) and the resultant thiomer was characterized for relevant physicochemical properties. Bilayered inserts were fabricated with a mucoadhesive immediate release layer composed of either SA or TSA and a sustained release layer composed of acrylates. Films were prepared by solvent evaporation and evaluated for mechanical properties, drug content, and in vitro release. Results and Discussion. The synthesized TSA possessed 248.80 ± 49.7 μmol thiol groups/gm and its solutions thickened on standing due to disulphide bridging. Its films showed improved mucoadhesion and also a strikingly beneficial property of resisting erosion and remaining as a hydrated adhesive layer for the duration of drug release. The bilayered films were found to be flexible, with good folding endurance, uniform thickness, and appropriate drug content, and showed a release of about 80% of loaded gatifloxacin in 12 h. Conclusion. The study demonstrates promise in employing thiolated polymer in conjunction with acrylates for the design of ocular inserts for twice a day therapy with gatifloxacin. PMID:24516362

The Effect of Eu Doping on Microstructure, Morphology and Methanal-Sensing Performance of Highly Ordered SnO2 Nanorods Array

PubMed Central

Zhao, Yanping; Li, Yuehua; Ren, Xingping; Gao, Fan; Zhao, Heyun

2017-01-01

Layered Eu-doped SnO2 ordered nanoarrays constructed by nanorods with 10 nm diameters and several hundred nanometers length were synthesized by a substrate-free hydrothermal route using alcohol and water mixed solvent of sodium stannate and sodium hydroxide at 200 °C. The Eu dopant acted as a crystal growth inhibitor to prevent the SnO2 nanorods growth up, resulting in tenuous SnO2 nanorods ordered arrays. The X-ray diffraction (XRD) revealed the tetragonal rutile-type structure with a systematic average size reduction and unit cell volume tumescence, while enhancing the residual strain as the Eu-doped content increases. The surface defects that were caused by the incorporation of Eu ions within the surface oxide matrix were observed by high-resolution transmission electron microscope (HRTEM). The results of the response properties of sensors based on the different levels of Eu-doped SnO2 layered nanoarrays demonstrated that the 0.5 at % Eu-doped SnO2 layered nanorods arrays exhibited an excellent sensing response to methanal at 278 °C. The reasons of the enhanced sensing performance were discussed from the complicated defect surface structure, the large specific surface area, and the excellent catalytic properties of Eu dopant. PMID:29168796

A Biopolymer Heparin Sodium Interlayer Anchoring TiO2 and MAPbI3 Enhances Trap Passivation and Device Stability in Perovskite Solar Cells.

PubMed

You, Shuai; Wang, Hui; Bi, Shiqing; Zhou, Jiyu; Qin, Liang; Qiu, Xiaohui; Zhao, Zhiqiang; Xu, Yun; Zhang, Yuan; Shi, Xinghua; Zhou, Huiqiong; Tang, Zhiyong

2018-04-18

Traps in the photoactive layer or interface can critically influence photovoltaic device characteristics and stabilities. Here, traps passivation and retardation on device degradation for methylammonium lead trihalide (MAPbI 3 ) perovskite solar cells enabled by a biopolymer heparin sodium (HS) interfacial layer is investigated. The incorporated HS boosts the power conversion efficiency from 17.2 to 20.1% with suppressed hysteresis and Shockley-Read-Hall recombination, which originates primarily from the passivation of traps near the interface between the perovskites and the TiO 2 cathode. The incorporation of an HS interfacial layer also leads to a considerable retardation of device degradation, by which 85% of the initial performance is maintained after 70 d storage in ambient environment. Aided by density functional theory calculations, it is found that the passivation of MAPbI 3 and TiO 2 surfaces by HS occurs through the interactions of the functional groups (COO - , SO 3 - , or Na + ) in HS with undersaturated Pb and I ions in MAPbI 3 and Ti 4+ in TiO 2 . This work demonstrates a highly viable and facile interface strategy using biomaterials to afford high-performance and stable perovskite solar cells. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Disinfection of Contaminated Canals by Different Laser Wavelengths, while Performing Root Canal Therapy

PubMed Central

Asnaashari, Mohammad; Safavi, Nassimeh

2013-01-01

Removal of smear layer and disinfection of canals are important objectives of teeth root canal cleaning. In order to achieve this purpose, rinsing substances, intra canal drugs as well as ultrasound are used. Today, use of laser to remove smear layer and to disinfect root canals has increasingly attracted the attentions. Till now different lasers such as CO2, Nd:YAG, Er:YAG, Er,Cr:YSGG have been used for debris and smear removal from the canals. Numerous studies have shown that Er:YAG is the most appropriate laser for intra canal debris and smear removal. In addition different laser wavelengths have been used directly or as an adjunctive to disinfect canals. Laser light can penetrate areas of canals where irrigating and disinfecting solutions cannot reach, like secondary canals and deep dentinal tubules and also can eliminate microorganisms. Different studies have confirmed the penetration of Nd:YAG laser in deep dentin and reduction of microorganisms penetration. But studies on comparison of antibacterial effects of Nd:YAG laser with sodium hypochlorite showed effectiveness of both, with a better effect for sodium hypochlorite. Studies performed in relation with anti-microbial effects of Diode laser with various parameters show that this laser can be effective in reducing intra canal bacterial count and penetration in the depth of 500 microns in dentin. In studies performed on Diode laser in combination with canal irrigating solutions such as sodium hypochlorite and oxygenated water better results were obtained. Although studies on disinfection by the Erbium laser family show that use of this laser alone can be effective in disinfecting canals, studies evaluating the disinfecting effects of this laser and different concentrations of sodium hypochlorite show that the latter alone is more effective in disinfecting canals. And better results were obtained when Erbium laser was used in combination with sodium hypochlorite irrigating solution in canals. Results of the aforementioned articles indicate that this laser is effective in combination with a rinsing solution such as sodium hypochlorite. Results from studies including several types of the different Er:YAG, Ho:YAG, Nd:YAG, Er,Cr:YSGG lasers in disinfecting canals showed that all wavelengths used in disinfection for different thicknesses of dentin were efficacious without damaging thermal effect. Considering that use of different lasers in canals can be accompanied with temperature increase which can sometimes lead to damages to teeth and surrounding tissues, thus the use of photochemical phenomenon for elimination of microorganisms have attracted attention of many researchers. Studies in this field imply the efficacy of this method in reducing canal bacterial count and recommend its use as an adjunctive after biomechanical preparation of canals. Results from performed studies show removal of intra canal debris and smear layer by different lasers and particularly the Erbium laser family. Furthermore various laser wavelengths, particularly of Diode and Nd:YAG lasers can be effective in reducing intra canal microbial count. Maximum effect is obtained when laser light is used in canals in combination with sodium hypochlorite irrigating substance in appropriate concentration. Therefore use of laser energy can improve success rate of root canal treatments. PMID:25606301

Cleanliness in the Root Canal System: An Scanning Electron Microscopic Evaluation of Manual and Automated Instrumentation using 4% Sodium Hypochlorite and EDTA (Glyde File Prep)―An in vitro Study

PubMed Central

Meshram, GK

2010-01-01

ABSTRACT Aim : To assess the cleaning efficacy of manual and automated instrumentation using 4% sodium hypochlorite singly and in combination with Glyde file Prep as root canal irrigant. Methodology : The study utilized 40 extracted human permanent premolars with single, straight and fully formed root. The teeth were then divided into four groups of ten each, Group I and II were prepared by manual instruments with 4% sodium hypochlorite used as irrigant singly [Group I] or in combination with Glyde file prep. Group III and IV were prepared by automated instruments at 250 rpm with 4% sodium hypochlorite as irrigant singly [Group III] and in combination with glyde file prep [Group IV] automated instrumentation. After completion of the root canal preparation the canal, teeth were prepared for SEM examination. These photomicrographs were qualitatively evaluated using criteria. Overall cleanliness, presence or absence of the smear layer, presence or absence of the debris, patency of the opening of dentinal tubules. Results : When comparing the cleansing efficacy of manual and automated instrumentation using 4% sodium hypochlorite better cleansing was there with manual instrumentation. When comparing the cleansing efficacy of manual and automated instrumentation using combination regime cleansing is better with automated instrumentation. When comparing the cleansing efficacy of manual instrumentation using 4% sodium hypochlorite singly and in combination with EDTA, the combination regime led to better cleansing. When comparing the cleansing efficacy of automated instrumentation using 4% sodium hypochlorite singly and in combination regime lead to better cleansing. Conclusion : Neither of instrumentation technique, nor irrigating regimes were capable of providing a completely clean canal. Automated instrumentation with a combination of sodium hypochlorite & EDTA resulted the best cleansing efficacy. PMID:27616839

Effective Interlayer Engineering of Two-Dimensional VOPO4 Nanosheets via Controlled Organic Intercalation for Improving Alkali Ion Storage.

PubMed

Peng, Lele; Zhu, Yue; Peng, Xu; Fang, Zhiwei; Chu, Wangsheng; Wang, Yu; Xie, Yujun; Li, Yafei; Cha, Judy J; Yu, Guihua

2017-10-11

Two-dimensional (2D) energy materials have shown the promising electrochemical characteristics for lithium ion storage. However, the decreased active surfaces and the sluggish charge/mass transport for beyond-lithium ion storage that has potential for large-scale energy storage systems, such as sodium or potassium ion storage, caused by the irreversible restacking of 2D materials during electrode processing remain a major challenge. Here we develop a general interlayer engineering strategy to address the above-mentioned challenges by using 2D ultrathin vanadyl phosphate (VOPO 4 ) nanosheets as a model material for challenging sodium ion storage. Via controlled intercalation of organic molecules, such as triethylene glycol and tetrahydrofuran, the sodium ion transport in VOPO 4 nanosheets has been significantly improved. In addition to advanced characterization including X-ray diffraction, high-resolution transmission electron microscopy, and X-ray absorption fine structure to characterize the interlayer and the chemical bonding/configuration between the organic intercalants and the VOPO 4 host layers, density functional theory calculations are also performed to understand the diffusion behavior of sodium ions in the pure and TEG intercalated VOPO 4 nanosheets. Because of the expanded interlayer spacing in combination with the decreased energy barriers for sodium ion diffusion, intercalated VOPO 4 nanosheets show much improved sodium ion transport kinetics and greatly enhanced rate capability and cycling stability for sodium ion storage. Our results afford deeper understanding of the interlayer-engineering strategy to improve the sodium ion storage performance of the VOPO 4 nanosheets. Our results may also shed light on possible multivalent-ion based energy storage such as Mg 2+ and Al 3+ .

Avoidance of Overt Precipitation and Patient Harm Following Errant Y-Site Administration of Calcium Chloride and Parenteral Nutrition Compounded With Sodium Glycerophosphate.

PubMed

Anderson, Collin; Stidham, Chanelle; Boehme, Sabrina; Cash, Jared

2017-12-14

Calcium phosphate precipitates present 1 of many challenges associated with parenteral nutrition (PN) compounding. Extensive research has led to the establishment of solubility curves to guide practitioners in the prescription and preparation of stable PN. Concurrent dosing of intravenous products via y-site administration with PN can alter the chemical balance of the solution and modify solubility. Medications containing calcium or phosphate should not be administered in the same line as PN, due to the high potential for precipitation. Herein a case is reported from a pediatric cardiac intensive care unit where a physician ordered the administration of calcium chloride. The bedside nurse added the calcium chloride intermittent infusion as a y-site administration with the patient's PN. The patient's PN had been compounded with sodium glycerophosphate, temporarily available in the United States during a sodium phosphate shortage. The patient did not experience any observable adverse effects from the y-site administration with PN. Following this event, the scenario was replicated to investigate any precipitation risk associated with the y-site administration. Additionally, a separate PN solution containing sodium phosphate rather than glycerophosphate was compounded and used in a laboratory setting to demonstrate the potential for harm had the patient's PN been compounded with an inorganic phosphate source. This replication of the error demonstrates the additional safety gained in relation to precipitation risk when PN solutions are compounded with sodium glycerophosphate in place of sodium phosphate. © 2017 American Society for Parenteral and Enteral Nutrition.

Molecular dynamics simulations of the surface tension and structure of salt solutions and clusters.

PubMed

Sun, Lu; Li, Xin; Hede, Thomas; Tu, Yaoquan; Leck, Caroline; Ågren, Hans

2012-03-15

Sodium halides, which are abundant in sea salt aerosols, affect the optical properties of aerosols and are active in heterogeneous reactions that cause ozone depletion and acid rain problems. Interfacial properties, including surface tension and halide anion distributions, are crucial issues in the study of the aerosols. We present results from molecular dynamics simulations of water solutions and clusters containing sodium halides with the interatomic interactions described by a conventional force field. The simulations reproduce experimental observations that sodium halides increase the surface tension with respect to pure water and that iodide anions reach the outermost layer of water clusters or solutions. It is found that the van der Waals interactions have an impact on the distribution of the halide anions and that a conventional force field with optimized parameters can model the surface tension of the salt solutions with reasonable accuracy. © 2012 American Chemical Society

Large Area Few Layers Hexagonal Boron Nitride Prepared by Quadrupole Field Aided Exfoliation.

PubMed

Hanlun, Lu; Rong, Min Zhi; Zhang, Ming Qiu

2018-01-16

A quadrupole electric field mediated exfoliation method is proposed to convert micron sized hexagonal boron nitride (hBN) powders into few layers hexagonal boron nitride nano-sheets (h-BNNS). Under the optimum conditions (400 Hz, 40 V, 32μg/mL, sodium deoxycholate, TAE medium), the hBN powders (thickness > 200 nm, horizontal scale ~ 10 μm) are successfully exfoliated into 0.5-4 nm (1-10 layers) thick h-BNNS with the same horizontal scale. Dynamic laser scattering (DLS) and atomic force microscope (AFM) statistics show that the yield is 47.6 % (for the portion with the thickness of 0.5-6 nm), and all of the vertical sizes are reduced to smaller than 18 nm (45 layers). © 2018 IOP Publishing Ltd.

Disintegration-controllable stimuli-responsive polyelectrolyte multilayer microcapsules via covalent layer-by-layer assembly.

PubMed

Mu, Bin; Lu, Chunyin; Liu, Peng

2011-02-01

The disintegration-controllable stimuli-responsive polyelectrolyte multilayer microcapsules have been fabricated via the covalent layer-by-layer assembly between the amino groups of chitosan (CS) and the aldehyde groups of the oxidized sodium alginate (OSA) onto the sacrificial templates (polystyrene sulfonate, PSS) which was removed by dialysis subsequently. The covalent crosslinking bonds of the multilayer microcapsules were confirmed by FTIR analysis. The TEM analysis showed that the diameter of the multilayer microcapsules was <200nm. The diameter of the multilayer microcapsules decreased with the increasing of the pH values or the ionic strength. The pH and ionic strength dual-responsive multilayer microcapsules were stable in acidic and neutral media while they could disintegrate only at strong basic media. Copyright © 2010 Elsevier B.V. All rights reserved.

Graphene-Rich Wrapped Petal-Like Rutile TiO2 tuned by Carbon Dots for High-Performance Sodium Storage.

PubMed

Zhang, Yan; Foster, Christopher W; Banks, Craig E; Shao, Lidong; Hou, Hongshuai; Zou, Guoqiang; Chen, Jun; Huang, Zhaodong; Ji, Xiaobo

2016-11-01

Carbon dots inducing petal-like rutile TiO 2 wrapped by ultrathin graphene-rich layers are proposed to fabricate superior anodes for sodium-ion batteries, featuring high-rate capabilities and long-term cyclelife, benefiting from promoted electron transport and a shortened Na + diffusion length. High capacities of 144.4 mA h g -1 (at 837.5 mA g -1 ) after 1100 cycles and 74.6 mA h g -1 (at 3350 mA g -1 ) after 4000 cycles are delivered outstandingly. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Small-scale modelling of cementation by descending silica-bearing fluids: Explanation of the origin of arenitic caves in South American tepuis

NASA Astrophysics Data System (ADS)

Aubrecht, R.; Lánczos, T.; Schlögl, J.; Audy, M.

2017-12-01

Geoscientific research was performed on South American table mountains (tepuis) and in their sandstone cave systems. To explain speleogenesis in these poorly soluble rocks, two theories were introduced: a) arenization theory implying selective weathering of quartz along grain boundaries and releasing of sand grains, b) selective lithification theory implying cementation by descending silica-bearing fluid flow. The latter theory presumes that the descending fluid flow becomes unstable on the interface between two layers with different porosity and splits to separate flow channels (so-called ;finger flow;). The arenites outside these channels remain uncemented. To verify the latter theory, small-scale modelling was performed, using layered sands and sodium-silicate solution. Fine to medium sand was used (0.08-0.5 mm), along with a coarse sand fraction (0.5-1.5 mm). The sands were layered and compacted in a transparent plastic boxes. Three liters of sodium-silicate solution (so-called water glass) were left to drip for several hours to the top of the sediment. The fine-grained layers were perfectly laterally impregnated, whereas the descending fluid flows split to ;fingers; in the coarse-grained layers due their higher hydraulic conductivity. This small-scale laboratory simulation mimics the real diagenesis by descending silica-bearing fluids and matches the real phenomena observed on the tepuis. The resulting cemented constructions closely mimic many geomorphological features observed on tepuis and inside their caves, e.g. ;finger-flow; pillars, overhangs, imperfectly formed (aborted) pillars in forms of hummocks hanging from ceilings, locally also thicker central pillars that originated by merging of smaller fluid-flow channels. The modelling showed that selective lithification theory can explain most of the geomorphological aspects related to the speleogenesis in tepuis.

Effectiveness of chamomile (Matricaria recutita L.), MTAD and sodium hypochlorite irrigants on smear layer.

PubMed

Venkataram, V; Gokhale, S T; Kenchappa, M; Nagarajappa, R

2013-08-01

Endodontic success depends heavily on effective chemo-mechanical debridement of root canals through the use of instruments and irrigating solutions. To compare the effectiveness of chamomile hydroalcoholic extract, Biopure™ mixture of tetracycline isomer, acid and detergent (MTAD) and 2.5 % sodium hypochlorite (NaOCl) on removal of the smear layer. Randomised controlled trial. Thirty extracted single-rooted, primary human teeth were allocated at random into three experimental groups of 10 teeth each. For each tooth, the canal was prepared using the step-back technique. During instrumentation, 2 ml of the irrigant was used for at least 10 s after each file and 10 ml as a final flush for 2 min for chamomile and NaOCL irrigants. Whereas for MTAD, an initial rinse with 1.3 % NaOCl for a cumulated period of 20 min, and use of MTAD as the final rinse for a period of 5 min was followed. Longitudinal grooves were made on root segments, then split into two halves with a chisel, stored in 2.5 % glutaraldehyde solution and fixed in ethanol series. Specimens were examined for the smear layer according to Hulsmann et al. (Int Endod J 35:668-679, 2002) criteria using a scanning electron microscope. Kruskal-Wallis and Mann-Whitney U tests were used. The most effective result in removal of smear layer occurred with the use of MTAD, followed by chamomile extract. The chamomile extract was found to be significantly more effective than 2.5 % NaOCl solution which had only minor effects. The efficacy of chamomile to remove the smear layer was superior to 2.5 % NaOCl alone, but less effective than MTAD mixture.

Reorientation of the ‘free OH’ group in the top-most layer of air/water interface of sodium fluoride aqueous solution probed with sum-frequency generation vibrational spectroscopy

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

Feng, Ran-Ran; Guo, Yuan; Wang, Hongfei

2014-09-17

Many experimental and theoretical studies have established the specific anion, as well as cation effects on the hydrogen-bond structures at the air/water interface of electrolyte solutions. However, the ion effects on the top-most layer of the air/water interface, which is signified by the non-hydrogen-bonded so-called ‘free O-H’ group, has not been discussed or studied. In this report, we present the measurement of changes of the orientational angle of the ‘free O-H’ group at the air/water interface of the sodium fluoride (NaF) solutions at different concentrations using the interface selective sum-frequency generation vibrational spectroscopy (SFG-VS) in the ssp and ppp polarizations.more » The polarization dependent SFG-VS results show that the average tilt angle of the ‘free O-H’ changes from about 35.3 degrees ± 0.5 degrees to 43.4 degrees ± 2.1degrees as the NaF concentration increase from 0 to 0.94M (nearly saturated). Such tilt angle change is around the axis of the other O-H group of the same water molecule at the top-most layer at the air/water interface that is hydrogen-bonded to the water molecules below the top-most layer. These results provide quantitative molecular details of the ion effects of the NaF salt on the structure of the water molecules at the top-most layer of the air/water interfacial, even though both the Na+ cation and the F- anion are believed to be among the most excluded ions from the air/water interface.« less

Role of diclofenac sodium and paracetamol on colonic anastomosis: An experimental rodent model.

PubMed

Gulcicek, Osman Bilgin; Solmaz, Ali; Yigitbas, Hakan; Ercetin, Candas; Yavuz, Erkan; Ozdogan, Kamil; Biricik, Aytac; Akkalp, Asli Kahraman; Uzun, Hafize; Kutnu, Muge; Celebi, Fatih; Celik, Atilla

2018-05-01

Despite many advances in surgery and technology, colonic anastomosis remains a challenge after colonic resection. The purpose of this study is to compare the safety of using diclofenac sodium and paracetamol for analgesia in colonic anastomosis on rats. Wistar-Hannover rats were randomly allocated to four groups: Group 1, sham-operated group; Group 2, control group; Group 3, diclofenac sodium group; Group 4, paracetamol group. After laparotomy, the left colon was transected and a single-layer anastomosis was made with 5/0 vicryl in Groups 2, 3, and 4. Only laparotomy was performed in Group 1. After anastomosis, we administered saline to Group 2, diclofenac sodium to Group 3, and paracetamol to Group 4 for 7 days. Then, all animals were decapitated. The anastomotic region was resected, and bursting pressure was measured. Then, the specimen was sent to the laboratory for histological examination and hydroxyproline analysis. Bursting pressure and hydroxyproline level were significantly higher in the paracetamol group (p<0.05). When we looked at the fibrosis levels of these groups, it was also higher in paracetamol group. Bursting pressure, hydroxyproline levels, and fibrosis levels indicate that the perioperative use of paracetamol for analgesia when undergoing colonic anastomosis is safer than diclofenac sodium. Copyright © 2017. Published by Elsevier Taiwan.

Study of corrosion behavior on the addition of sodium citrate in nickel electroplating on SPCC steel using EIS

NASA Astrophysics Data System (ADS)

Riastuti, R.; Ramadini, C.; Siallagan, S. T.; Rifki, A.; Herdino, F.

2018-04-01

The addition of sodium citrate to nickel electroplating process as additive is useful for refining the grain size of nickel deposit. The refining of grain size in nickel deposit as coating layer can improve surface performance, one of which corrosion resistance. This paper aims to investigate the effect of sodium citrate addition as grain refiner to promote corrosion resistance on SPCC steel. This experiment used Watt’s Bath solution of NiSO4 300 g/L, NiCl4 45 g/L, H3BO3 60 g/L, wetting agent 0.2 cc/L. Sodium citrate was added in composition of 45g/L and 60g/L. Nickel were deposited by direct current using current density on 6 A/dm2 at the acidity level of 5 for 30 minutes by keeping the operating temperature stable at 50°C. The grain size of nickel deposit was observed through Optical Microscope and Atomic Force Microscope (AFM). The corrosion behavior of SPCC was observed by linear polarization and Electrochemical Impedance Spectroscopy (EIS) methods using 3% NaCl solution. Based on the research, the addition of sodium citrate as grain refiner will increasing corrosion resistance on SPCC steel from 0.35 to 0.05 mm/year.

Strong guided mode resonant local field enhanced visible harmonic generation in an azo-polymer resonant waveguide grating.

PubMed

Lin, Jian Hung; Tseng, Chun-Yen; Lee, Ching-Ting; Young, Jeff F; Kan, Hung-Chih; Hsu, Chia Chen

2014-02-10

Guided mode resonance (GMR) enhanced second- and third-harmonic generation (SHG and THG) is demonstrated in an azo-polymer resonant waveguide grating (RWG), comprised of a poled azo-polymer layer on top of a textured SU8 substrate with a thin intervening layer of TiO2. Strong SHG and THG outputs are observed by matching either in-coming fundamental- or out-going harmonic-wavelength to the GMR wavelengths of the azo-polymer RWG. Without the azo-polymer coating, pure TiO2 RWGs, do not generate any detectable SHG using a fundamental beam peak intensity of 2 MW/cm(2). Without the textured TiO2 layer, a planar poled azo-polymer layer results in 3650 times less SHG than the full nonlinear RWG structure under identical excitation conditions. Rigorous coupled-wave analysis calculations confirm that this enhancement of the nonlinear conversion is due to strong local electric fields that are generated at the interfaces of the TiO2 and azo-polymer layers when the RWG is excited at resonant wavelengths associated with both SHG and THG conversion processes.

Microslab - Waveguide medium for the future

NASA Astrophysics Data System (ADS)

Sequeira, H. B.

1986-09-01

'Microslab' technology, which has the transmission properties of both microstrip and dielectric slab waveguides, and which is aimed for use in MIMIC devices, is described. The Microslab configuration consists of a guiding layer bonded to a metallized dielectric substrate (slab) and a metallized dielectric rod, with the dielectric material and thicknesses chosen for minimal loss and dispersion and for optimum control of the propagating energy. The propagating energy is confined mainly to the guiding layer. The new technology has been used to couple a GaAs Gunn oscillator directly to a GaAs Microslab network to produce 0.25 mW at 141 GHz.

Establishing layer coefficients for CTB, PMBB, and RAP.

DOT National Transportation Integrated Search

1991-09-01

In 1988, the Oregon State Highway Division adopted the 1986 AASHTO guide for pavement thickness design. Currently the OSHD uses a layer coefficient of .22 to .24 for cement treated base (CTB), and .32 for plant mix bituminous base (PMBB). Recycled as...

Ozone Layer Educator's Guide.

ERIC Educational Resources Information Center

Environmental Protection Agency, Washington, DC.

This guide has been developed through a collaborative effort involving the U.S. Environmental Protection Agency (EPA), the National Oceanic and Atmospheric Administration (NOAA), and the National Aeronautics and Space Administration (NASA). It is part of an ongoing commitment to ensure that the results of scientific research on ozone depletion are…

Reserving Interior Void Space for Volume Change Accommodation: An Example of Cable-Like MWNTs@SnO2@C Composite for Superior Lithium and Sodium Storage.

PubMed

Zhao, Yi; Wei, Chao; Sun, Shengnan; Wang, Luyuan Paul; Xu, Zhichuan J

2015-06-01

Reserving interior void space in the cable-like structure of multiwalled carbon nanotubes-in-SnO 2 -in-carbon layer (MWNTs@SnO 2 @C) is reported for the first time. Such a design enables the structure performing excellent for Li and Na storage, which benefit from the good electrical conductivity of MWNTs and carbon layer as well as the reserved void space to accommodate the volume changes of SnO 2 .

PLUTONIUM RECOVERY FROM NEUTRON-BOMBARDED URANIUM FUEL

DOEpatents

Moore, R.H.

1962-04-10

A process of recovering plutonium from neutronbombarded uranium fuel by dissolving the fuel in equimolar aluminum chloride-potassium chloride; heating the mass to above 700 deg C for decomposition of plutonium tetrachloride to the trichloride; extracting the plutonium trichloride into a molten salt containing from 40 to 60 mole % of lithium chloride, from 15 to 40 mole % of sodium chloride, and from 0 to 40 mole % of potassium chloride or calcium chloride; and separating the layer of equimolar chlorides containing the uranium from the layer formed of the plutonium-containing salt is described. (AEC)

Structure and thermal decomposition of sulfated β-cyclodextrin intercalated in a layered double hydroxide

NASA Astrophysics Data System (ADS)

Wang, Ji; Wei, Min; Rao, Guoying; Evans, David G.; Duan, Xue

2004-01-01

The sodium salt of hexasulfated β-cyclodextrin has been synthesized and intercalated into a magnesium-aluminum layered double hydroxide by ion exchange. The structure, composition and thermal decomposition behavior of the intercalated material have been studied by variable temperature X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma emission spectroscopy (ICP), and thermal analysis (TG-DTA) and a model for the structure has been proposed. The thermal stability of the intercalated sulfated β-cyclodextrin is significantly enhanced compared with the pure form before intercalation.

Copper Oxide Thin Films through Solution Based Methods for Electrical Energy Conversion and Storage

NASA Astrophysics Data System (ADS)

Zhu, Changqiong

Copper oxides (Cu2O and CuO), composed of non-toxic and earth abundant elements, are promising materials for electrical energy generation and storage devices. Solution based techniques for creating thin films of these materials, such as electrodeposition, are important to understand and develop because of their potential for realizing substantial energy savings compared to traditional fabrication methods. Cuprous oxide (Cu2O), with its direct band gap, is a p-type semiconductor that is well suited for creating solution-processed photovoltaic devices (solar cells); several key advancements made toward this application are the primary focus of this thesis. Electrodeposition of single-phase, crystalline Cu2O thin films is demonstrated using previously unexplored, acidic lactate/Cu2+ solutions, which has provided additional understanding of the impacts of growth solution chemistry on film formation. The influence of pH on the resulting Cu2O thin film properties is revealed by using the same ligand (sodium lactate) at various solution pH values. Cu2O films grown from acidic lactate solutions can exhibit a distinctive flowerlike, dendritic morphology, in contrast to the faceted, dense films obtained using alkaline lactate solutions. Relative speciation distributions of the various metal complex ions present under different growth conditions are calculated using reported equilibrium association constants and experimentally supported by UV-Visible absorption spectroscopy. Dependence of thin film morphology on the lactate/Cu2+ molar ratio and applied potential is described. Cu2O/eutectic gallium-indium Schottky junction devices are formed and devices are tested under monochromatic green LED illumination. Further surface examination of the Cu2O films using X-ray photoelectron spectroscopy (XPS) reveals the fact that films grown from acidic lactate solution with a small lactate/Cu2+ molar ratio, which exhibit improved photovoltaic performance compared to films grown from basic lactate solution with a large lactate/Cu2+ molar ratio, are sodium-free. This finding stands in contrast to the observation that films grown in basic solution contain a significant amount of sodium impurity at their top surfaces. Therefore, it is concluded that the sodium impurities present in films grown from basic lactate solutions are detrimental to overall photovoltaic device performance by introducing interface traps and recombination centers for charge carriers, which suggests that removing these impurities may be a promising strategy for improving Cu2O based solar cells. It has been found that impurities at the surface of electrodeposited p-Cu2O films can be efficiently removed through the use of concentrated aqueous ammonia solution as a wet etching agent. The performance of Cu 2O homojunction photovoltaic devices incorporating etched p-Cu 2O as the bottom layer is higher compared to devices with as-deposited p-Cu2O layers due to an improvement of the homojunction interface quality. Reducing the density of defect states that act as carrier recombination centers is found to lead to larger open circuit voltages. Zinc-doped cuprous oxide (Zn:Cu2O) thin films have also been prepared via single step electrodeposition from an aqueous solution containing sodium perchlorate. The Zn/Cu molar ratio in the Cu2O films can be tuned by adjusting the magnitude of the applied potential and the sodium perchlorate concentration. Electrical characterization reveals that zinc dopants increase the Fermi level in Zn:Cu2O films, enabling a three-fold improvement in the power conversion efficiency of a fully electrodeposited Cu2O homojunction photovoltaic device. Complementary to the development of Cu2O based photovoltaic devices, the use of solution deposited cupric oxide (CuO) thin films for capacitive energy storage has also been investigated. A seed layer-assisted chemical bath deposition (SCBD) method has been developed to create high quality CuO thin films on transparent conductive electrode (ITO)/glass substrates. A CuO seed layer is formed by the electrodeposition of Cu2O on ITO electrode for 10 s, followed by a brief (15 min) heating step to convert the Cu 2O to CuO. The seed layer is found to be essential for the growth of micrometer-thick, adherent CuO thin films on ITO-coated glass, as no films were observed to form on substrates without a seed layer. The addition of sodium lactate to the SCBD solution can be used to tune the morphology and relative crystallinity of the CuO films. A highly crystalline CuO film has been deposited from a solution without sodium lactate, while a largely amorphous CuO film was realized using lactate/Cu2+ molar ratio equal to 1.0. The CuO film with greater amorphous character exhibited a significantly larger specific capacitance as a redox active electrode compared to the crystalline film (2700 mF/g vs. 96 mF/g).

Bonding-Compatible Corrosion Inhibitor for Rinsing Metals

NASA Technical Reports Server (NTRS)

Saunders, C. R.; Wurth, L. A.; Radar, A.

2005-01-01

A corrosion-inhibiting mixture of compounds has been developed for addition to the water used to rinse metal parts that have been cleaned with aqueous solutions in preparation for adhesive bonding of the metals to rubber and rubber-like materials. Prior to the development of this corrosion inhibitor, the parts (made, variously, of D6AC steel and 7075-T73 aluminum) were rinsed by deionized water, which caused corrosion in some places on the steel parts especially in such occluded places as sealing surfaces and threaded blind holes. An integral part of the particular cleaning process is the deposition of a thin layer of silicates and silane primers that increase the strength of the adhesive bond. The corrosion inhibitor is formulated, not only to inhibit corrosion of both D6AC steel and 7075- T73 aluminum, but also to either increase or at least not reduce the strength of the adhesive bond to be formed subsequently. The corrosion inhibitor is a mixture of sodium silicate and sodium tetraborate. The sodium silicate functions as both a corrosion inhibitor and a bond-strength promoter in association with the silane primers. The sodium tetraborate buffers the rinse solution at the optimum pH and functions as a secondary corrosion inhibitor for the steel. For a given application, the concentrations of sodium silicate and sodium tetraborate must be chosen in a compromise among the needs to inhibit corrosion of steel, inhibit corrosion of aluminum, and minimize cosmetic staining of both steel and aluminum. Concentrations of sodium silicate in excess of 150 parts of silicon per million parts of solution (ppm Si) have been determined to enhance inhibition of corrosion; unfortunately, because of the alkalinity of sodium silicate, even a small concentration can raise the pH of the rinse solution to such a level that aluminum becomes corroded despite the inhibiting effect. The pH of a solution that contains a high concentration of sodium silicate can be decreased by adding sodium tetraborate. On the other hand, the addition of sodium tetraborate increases the concentration of dissolved solids to such a high level that cosmetic staining becomes an issue.

The Installation Restoration Program Toxicology Guide. Volume 1

DTIC Science & Technology

1989-07-01

affinity for adipose tissue , which is more prevalent in women and would result in less unchanged chloroform and more carbon dioxide exhaled. This...magnesium, potassium, sodium, tin, zinc , and their alloys. ADI Acceptable daily intake ADL Arthur D. Little, Inc. Adenocarcinoma A malignant tumor...originating in glandular or ductal epithelium. Adenoma A benign growth of glandular tissue . ae Acid equivalent Aerosol A suspension or dispersion of small

Determination of the in-place hot-mix asphalt layer modulus for rehabilitation projects using a mechanistic-empirical procedure.

DOT National Transportation Integrated Search

2006-01-01

This project evaluated the procedures proposed by the Mechanistic-Empirical Pavement Design Guide (MEPDG) to characterize existing hot-mix asphalt (HMA) layers for rehabilitation purposes. Thirty-three cores were extracted from nine sites in Virginia...

Preparation of 3D Architecture Graphdiyne Nanosheets for High-Performance Sodium-Ion Batteries and Capacitors.

PubMed

Wang, Kun; Wang, Ning; He, Jianjiang; Yang, Ze; Shen, Xiangyan; Huang, Changshui

2017-11-22

Here, we apply three-dimensional (3D) architecture graphdiyne nanosheet (GDY-NS) as anode materials for sodium-ion storage devices achieving high energy and power performance along with excellent cyclic ability. The contribution of 3D architecture nanostructure and intramolecular pores of the GDY-NS can substantially optimize the sodium storage behavior through the accommodated intramolecular pore, 3D interconnective porous structure, and increased activity sites to facilitate a fast sodium-ion-diffusion channel. The contribution of butadiyne linkages and the formation of a stable solid electrolyte interface layer are directly confirmed through the in situ Raman measurement. The GDY-NS-based sodium-ion batteries exhibit a stable reversible capacity of approximately 812 mAh g -1 at a current density of 0.05 A g -1 ; they maintain more than 405 mAh g -1 over 1000 cycles at a current density of 1 A g -1 . Furthermore, the sodium-ion capacitors could deliver a capacitance more than 200 F g -1 over 3000 cycles at 1 A g -1 and display an initial specific energy as high as 182.3 Wh kg -1 at a power density of 300 W kg -1 and maintain specific energy of 166 Wh kg -1 even at a power density of 15 000 W kg -1 . The high energy and power density along with excellent cyclic performance based on the GDY-NS anode offers a great potential toward application on next-generation energy storage devices.

Shelterwood Teacher's Guide: Discovering the Forest.

ERIC Educational Resources Information Center

Markowsky, Judy Kellogg

This teacher's guide explores forest diversity, from learning about different kind of trees to understanding how the layers in a forest provide habitat for all kinds of animals and insects. Each chapter offers useful introductory material and clear objectives, followed by fun activities that encourage exploration while teaching important skills.…

Drinking water salinity and risk of hypertension: A systematic review and meta-analysis.

PubMed

Talukder, Mohammad Radwanur Rahman; Rutherford, Shannon; Huang, Cunrui; Phung, Dung; Islam, Mohammad Zahirul; Chu, Cordia

2017-05-04

We summarized epidemiological studies assessing sodium in drinking water and changes in blood pressure or hypertension published in English from 1960 to 2015 from PubMed, Scopus, and Web of Science. We extracted data on blood pressure level or prevalence of hypertension and calculated pooled estimates using an inverse variance weighted random-effects model. The pooled standardized mean difference (SMD) in 7 studies (12 data sets) comparing the low and high water sodium exposure groups for systolic blood pressure (SBP) was 0.08 (95% CI, -0.17 to 0.34) and for diastolic blood pressure (DBP) was 0.23 (95% CI, 0.09-0.36). Of the 3 studies that assessed the association between high water sodium and odds of hypertension, 2 recent studies showed consistent findings of higher risk of hypertension. Our systematic review suggests an association between water sodium and human blood pressure (more consistently for DBP) but remain inconclusive because of the small number of studies (largely in young populations) and the cross-sectional design and methodological drawbacks. In the context of climate-change-related sea level rise and increasing saltwater intrusion into drinking water sources, further research is urgently warranted to investigate and guide intervention in this increasingly widespread problem.

Investigation of return photons from sodium laser beacon excited by a 40-watt facility-class pulsed laser for adaptive optical telescope applications.

PubMed

Bian, Qi; Bo, Yong; Zuo, Junwei; Li, Min; Dong, Ruoxi; Deng, Keran; Zhang, Dingwen; He, Liping; Zong, Qingshuang; Cui, Dafu; Peng, Qinjun; Chen, Hongbin; Xu, Zuyan

2018-06-15

The brightness of the artificial beacon is one critical performance parameter for adaptive optics. Here, a 40-watt level narrow-linewidth microsecond pulsed yellow laser is produced at 589 nm with a high repetition frequency of 600 Hz and a pulse duration of 120 μs. An experiment to project the pulse beam up to the sky and measure the fluorescence photon returns of the Na atoms has been held on the 1.8-meter telescope in Lijiang observatory. During the sky test, a laser guide star (LGS) spot is firstly observed with Rayleigh scattering elimination by means of a gateable pulse format. And, the central wavelength of the laser could be accurately locked to be 589.1584 nm with a linewidth of ~0.34 GHz to match that of sodium-D 2a line. Optical pumping with circularly polarized light has also been used to increase the brightness of sodium LGS. In order to maximize the return flux, sodium D 2b repumping option is done by an electro-optic modulator with the optimum D 2a -D 2b frequency offset. As a result, a bright sodium LGS with the return flux of 1610 photons/cm 2 /s is achieved, corresponding to ~47 photons/cm 2 /s/W of emitted laser power, which represents a significant improvement in terms of brightness reported ever.

Sodium channel slow inactivation as a therapeutic target for myotonia congenita

PubMed Central

Novak, Kevin R; Norman, Jennifer; Mitchell, Jacob R; Pinter, Martin J; Rich, Mark M

2014-01-01

Objective Patients with myotonia congenita have muscle hyperexcitability due to loss-of-function mutations in the chloride channel in skeletal muscle, which causes spontaneous firing of muscle action potentials (myotonia), producing muscle stiffness. In patients, muscle stiffness lessens with exercise, a change known as the warm-up phenomenon. Our goal was to identify the mechanism underlying warm up and to use this information to guide development of novel therapy. Methods To determine the mechanism underlying warm-up, we used a recently discovered drug to eliminate muscle contraction, thus allowing prolonged intracellular recording from individual muscle fibers during induction of warm-up in a mouse model of myotonia congenita. Results Changes in action potentials suggested slow inactivation of sodium channels as an important contributor to warm-up. These data suggested enhancing slow inactivation of sodium channels might offer effective therapy for myotonia. Lacosamide and ranolazine enhance slow inactivation of sodium channels and are FDA-approved for other uses in patients. We compared the efficacy of both drugs to mexiletine, a sodium channel blocker currently used to treat myotonia. In vitro studies suggested both lacosamide and ranolazine were superior to mexiletine. However, in vivo studies in a mouse model of myotonia congenita suggested side effects could limit the efficacy of lacosamide. Ranolazine produced fewer side effects and was as effective as mexiletine at a dose that produced none of mexiletine’s hypoexcitability side effects. Interpretation We conclude ranolazine has excellent therapeutic potential for treatment of patients with myotonia congenita. PMID:25515836

Time series geophysical monitoring of permanganate injections and in situ chemical oxidation of PCE, OU1 area, Savage Superfund Site, Milford, NH, USA

NASA Astrophysics Data System (ADS)

Harte, Philip T.; Smith, Thor E.; Williams, John H.; Degnan, James R.

2012-05-01

In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated aquifer. Therefore, monitoring tools that provide enhanced tracking capability of the injectate offer considerable benefit to guide subsequent ISCO injections. Time-series geophysical surveys were performed at a superfund site in New Hampshire, USA over a one-year period to identify temporal changes in the bulk electrical conductivity of a tetrachloroethylene (PCE; also called tetrachloroethene) contaminated, glacially deposited aquifer due to the injection of sodium permanganate. The ISCO treatment involved a series of pulse injections of sodium permanganate from multiple injection wells within a contained area of the aquifer. After the initial injection, the permanganate was allowed to disperse under ambient groundwater velocities. Time series geophysical surveys identified the downward sinking and pooling of the sodium permanganate atop of the underlying till or bedrock surface caused by density-driven flow, and the limited horizontal spread of the sodium permanganate in the shallow parts of the aquifer during this injection period. When coupled with conventional monitoring, the surveys allowed for an assessment of ISCO treatment effectiveness in targeting the PCE plume and helped target areas for subsequent treatment.

Time series geophysical monitoring of permanganate injections and in situ chemical oxidation of PCE, OU1 area, Savage Superfund Site, Milford, NH, USA

USGS Publications Warehouse

Harte, Philip T.; Smith, Thor E.; Williams, John H.; Degnan, James R.

2012-01-01

In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated aquifer. Therefore, monitoring tools that provide enhanced tracking capability of the injectate offer considerable benefit to guide subsequent ISCO injections. Time-series geophysical surveys were performed at a superfund site in New Hampshire, USA over a one-year period to identify temporal changes in the bulk electrical conductivity of a tetrachloroethylene (PCE; also called tetrachloroethene) contaminated, glacially deposited aquifer due to the injection of sodium permanganate. The ISCO treatment involved a series of pulse injections of sodium permanganate from multiple injection wells within a contained area of the aquifer. After the initial injection, the permanganate was allowed to disperse under ambient groundwater velocities. Time series geophysical surveys identified the downward sinking and pooling of the sodium permanganate atop of the underlying till or bedrock surface caused by density-driven flow, and the limited horizontal spread of the sodium permanganate in the shallow parts of the aquifer during this injection period. When coupled with conventional monitoring, the surveys allowed for an assessment of ISCO treatment effectiveness in targeting the PCE plume and helped target areas for subsequent treatment.

Time series geophysical monitoring of permanganate injections and in situ chemical oxidation of PCE, OU1 area, Savage Superfund Site, Milford, NH, USA.

PubMed

Harte, Philip T; Smith, Thor E; Williams, John H; Degnan, James R

2012-05-01

In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated aquifer. Therefore, monitoring tools that provide enhanced tracking capability of the injectate offer considerable benefit to guide subsequent ISCO injections. Time-series geophysical surveys were performed at a superfund site in New Hampshire, USA over a one-year period to identify temporal changes in the bulk electrical conductivity of a tetrachloroethylene (PCE; also called tetrachloroethene) contaminated, glacially deposited aquifer due to the injection of sodium permanganate. The ISCO treatment involved a series of pulse injections of sodium permanganate from multiple injection wells within a contained area of the aquifer. After the initial injection, the permanganate was allowed to disperse under ambient groundwater velocities. Time series geophysical surveys identified the downward sinking and pooling of the sodium permanganate atop of the underlying till or bedrock surface caused by density-driven flow, and the limited horizontal spread of the sodium permanganate in the shallow parts of the aquifer during this injection period. When coupled with conventional monitoring, the surveys allowed for an assessment of ISCO treatment effectiveness in targeting the PCE plume and helped target areas for subsequent treatment. Published by Elsevier B.V.

Analysis of liquid-phase chemical detection using guided shear horizontal-surface acoustic wave sensors.

PubMed

Li, Zhonghui; Jones, Yolanda; Hossenlopp, Jeanne; Cernosek, Richard; Josse, Fabien

2005-07-15

Direct chemical sensing in liquid environments using polymer-guided shear horizontal surface acoustic wave sensor platforms on 36 degrees rotated Y-cut LiTaO3 is investigated. Design considerations for optimizing these devices for liquid-phase detection are systematically explored. Two different sensor geometries are experimentally and theoretically analyzed. Dual delay line devices are used with a reference line coated with poly (methyl methacrylate) (PMMA) and a sensing line coated with a chemically sensitive polymer, which acts as both a guiding layer and a sensing layer or with a PMMA waveguide and a chemically sensitive polymer. Results show the three-layer model provides higher sensitivity than the four-layer model. Contributions from mass loading and coating viscoelasticity changes to the sensor response are evaluated, taking into account the added mass, swelling, and plasticization. Chemically sensitive polymers are investigated in the detection of low concentrations (1-60 ppm) of toluene, ethylbenzene, and xylenes in water. A low-ppb level detection limit is estimated from the present experimental measurements. Sensor properties are investigated by varying the sensor geometries, coating thickness combinations, coating properties, and curing temperature for operation in liquid environments. Partition coefficients for polymer-aqueous analyte pairs are used to explain the observed trend in sensitivity for the polymers PMMA, poly(isobutylene), poly(epichlorohydrin), and poly(ethyl acrylate) used in this work.

Multiple Concentric Cylinder Model (MCCM) user's guide

NASA Technical Reports Server (NTRS)

Williams, Todd O.; Pindera, Marek-Jerzy

1994-01-01

A user's guide for the computer program mccm.f is presented. The program is based on a recently developed solution methodology for the inelastic response of an arbitrarily layered, concentric cylinder assemblage under thermomechanical loading which is used to model the axisymmetric behavior of unidirectional metal matrix composites in the presence of various microstructural details. These details include the layered morphology of certain types of ceramic fibers, as well as multiple fiber/matrix interfacial layers recently proposed as a means of reducing fabrication-induced, and in-service, residual stress. The computer code allows efficient characterization and evaluation of new fibers and/or new coating systems on existing fibers with a minimum of effort, taking into account inelastic and temperature-dependent properties and different morphologies of the fiber and the interfacial region. It also facilitates efficient design of engineered interfaces for unidirectional metal matrix composites.

Sodium chloride crystallization from thin liquid sheets, thick layers, and sessile drops in microgravity

NASA Astrophysics Data System (ADS)

Fontana, Pietro; Pettit, Donald; Cristoforetti, Samantha

2015-10-01

Crystallization from aqueous sodium chloride solutions as thin liquid sheets, 0.2-0.7 mm thick, with two free surfaces supported by a wire frame, thick liquid layers, 4-6 mm thick, with two free surfaces supported by metal frame, and hemispherical sessile drops, 20-32 mm diameter, supported by a flat polycarbonate surface or an initially flat gelatin film, were carried out under microgravity on the International Space Station (ISS). Different crystal morphologies resulted based on the fluid geometry: tabular hoppers, hopper cubes, circular [111]-oriented crystals, and dendrites. The addition of polyethylene glycol (PEG-3350) inhibited the hopper growth resulting in flat-faced surfaces. In sessile drops, 1-4 mm tabular hopper crystals formed on the free surface and moved to the fixed contact line at the support (polycarbonate or gelatin) self-assembling into a shell. Ring formation created by sessile drop evaporation to dryness was observed but with crystals 100 times larger than particles in terrestrially formed coffee rings. No hopper pyramids formed. By choosing solution geometries offered by microgravity, we found it was possible to selectively grow crystals of preferred morphologies.

In situ catalytic growth of large-area multilayered graphene/MoS2 heterostructures.

PubMed

Fu, Wei; Du, Fei-Hu; Su, Juan; Li, Xin-Hao; Wei, Xiao; Ye, Tian-Nan; Wang, Kai-Xue; Chen, Jie-Sheng

2014-04-14

Stacking various two-dimensional atomic crystals on top of each other is a feasible approach to create unique multilayered heterostructures with desired properties. Herein for the first time, we present a controlled preparation of large-area graphene/MoS2 heterostructures via a simple heating procedure on Mo-oleate complex coated sodium sulfate under N2 atmosphere. Through a direct in situ catalytic reaction, graphene layer has been uniformly grown on the MoS2 film formed by the reaction of Mo species with Species, which is from the carbothermal reduction of sodium sulfate. Due to the excellent graphene "painting" on MoS2 atomic layers, the significantly shortened lithium ion diffusion distance and the markedly enhanced electronic conductivity, these multilayered graphene/MoS2 heterostructures exhibit high specific capacity, unprecedented rate performance and outstanding cycling stability, especially at a high current density, when used as an anode material for lithium batteries. This work provides a simple but efficient route for the controlled fabrication of large-area multilayered graphene/metal sulfide heterostructures with promising applications in battery manufacture, electronics or catalysis.

In situ catalytic growth of large-area multilayered graphene/MoS2 heterostructures

PubMed Central

Fu, Wei; Du, Fei-Hu; Su, Juan; Li, Xin-Hao; Wei, Xiao; Ye, Tian-Nan; Wang, Kai-Xue; Chen, Jie-Sheng

2014-01-01

Stacking various two-dimensional atomic crystals on top of each other is a feasible approach to create unique multilayered heterostructures with desired properties. Herein for the first time, we present a controlled preparation of large-area graphene/MoS2 heterostructures via a simple heating procedure on Mo-oleate complex coated sodium sulfate under N2 atmosphere. Through a direct in situ catalytic reaction, graphene layer has been uniformly grown on the MoS2 film formed by the reaction of Mo species with S pecies, which is from the carbothermal reduction of sodium sulfate. Due to the excellent graphene “painting” on MoS2 atomic layers, the significantly shortened lithium ion diffusion distance and the markedly enhanced electronic conductivity, these multilayered graphene/MoS2 heterostructures exhibit high specific capacity, unprecedented rate performance and outstanding cycling stability, especially at a high current density, when used as an anode material for lithium batteries. This work provides a simple but efficient route for the controlled fabrication of large-area multilayered graphene/metal sulfide heterostructures with promising applications in battery manufacture, electronics or catalysis. PMID:24728289

In situ catalytic growth of large-area multilayered graphene/MoS2 heterostructures

NASA Astrophysics Data System (ADS)

Fu, Wei; Du, Fei-Hu; Su, Juan; Li, Xin-Hao; Wei, Xiao; Ye, Tian-Nan; Wang, Kai-Xue; Chen, Jie-Sheng

2014-04-01

Stacking various two-dimensional atomic crystals on top of each other is a feasible approach to create unique multilayered heterostructures with desired properties. Herein for the first time, we present a controlled preparation of large-area graphene/MoS2 heterostructures via a simple heating procedure on Mo-oleate complex coated sodium sulfate under N2 atmosphere. Through a direct in situ catalytic reaction, graphene layer has been uniformly grown on the MoS2 film formed by the reaction of Mo species with S pecies, which is from the carbothermal reduction of sodium sulfate. Due to the excellent graphene ``painting'' on MoS2 atomic layers, the significantly shortened lithium ion diffusion distance and the markedly enhanced electronic conductivity, these multilayered graphene/MoS2 heterostructures exhibit high specific capacity, unprecedented rate performance and outstanding cycling stability, especially at a high current density, when used as an anode material for lithium batteries. This work provides a simple but efficient route for the controlled fabrication of large-area multilayered graphene/metal sulfide heterostructures with promising applications in battery manufacture, electronics or catalysis.

Double layer drainage performance of porous asphalt pavement

NASA Astrophysics Data System (ADS)

Ji, Yangyang; Xie, Jianguang; Liu, Mingxi

2018-06-01

In order to improve the design reliability of the double layer porous asphalt pavement, the 3D seepage finite element method was used to study the drainage capacity of double layer PAC pavements with different geometric parameters. It revealed that the effect of pavement drainage length, slope, permeability coefficient and structure design on the drainage capacity. The research of this paper can provide reference for the design of double layer porous asphalt pavement in different rainfall intensity areas, and provide guides for the related engineering design.

Effects of topical corticosteroid and tacrolimus on ceramides and irritancy to sodium lauryl sulphate in healthy skin.

PubMed

Jungersted, Jakob Mutanu; Høgh, Julie K; Hellegren, Lars I; Jemec, Gregor B E; Agner, Tove

2011-05-01

The skin barrier, located in the stratum corneum, is influenced mainly by the lipid and protein composition of this layer. In eczematous diseases impairment of the skin barrier is thought to be of prime importance. Topical anti-inflammatory drugs and emollients are the most widely used eczema treatments. The aim of this study was to examine the effects of topically applied corticosteroid, tacrolimus and emollient on stratum corneum lipids and barrier parameters. Nineteen healthy volunteers participated in the study. Both forearms of the subjects were divided into four areas, which were treated twice daily for one week with betamethasone, tacrolimus, emollient, or left untreated, respectively. After one week each area was challenged with a 24 h sodium lauryl sulphate patch test. The lipids were collected using the cyanoacrylate method and evaluated by high performance thin layer chromatography. For evaluation of the skin barrier, transepidermal water loss, erythema and electrical capacitance were measured. The ceramide/cholesterol ratio was increased in betamethasone- (p = 0.008) and tacrolimus-treated (p = 0.025) skin compared with emollient-treated skin. No differences in ceramide subgroups were found between treatment regimes. Pretreatment with betamethasone (p = 0.01) or with tacrolimus (p = 0.001) causes a decreased inflammatory response to sodium lauryl sulphate compared with emollient. In conclusion, treatment with betamethasone and tacrolimus has a positive effect on the ceramide/cholesterol ratio and susceptibility to irritant reaction compared with an emollient.

Solid-Solution Sulfides Derived from Tunable Layered Double Hydroxide Precursors/Graphene Aerogel for Pseudocapacitors and Sodium-Ion Batteries.

PubMed

Song, Yajie; Li, Hui; Yang, Lan; Bai, Daxun; Zhang, Fazhi; Xu, Sailong

2017-12-13

Transition-metal sulfides (TMSs) are suggested as promising electrode materials for electrochemical pseudocapacitors and lithium- and sodium-ion batteries; however, they typically involve mixed composites or conventionally stoichiometric TMSs (such as NiCo 2 S 4 and Ni 2 CoS 4 ). Herein we demonstrate a preparation of solid-solution sulfide (Ni 0.7 Co 0.3 )S 2 supported on three-dimensional graphene aerogel (3DGA) via a sulfuration of NiCo-layered double hydroxide (NiCo-LDH) precursor/3DGA. The electrochemical tests show that the (Ni 0.7 Co 0.3 )S 2 /3DGA electrode exhibits a capacitance of 2165 F g -1 at 1 A g -1 , 2055 F g -1 at 2 A g -1 , and 1478 F g -1 at 10 A g -1 ; preserves 78.5% capacitance retention upon 1000 cycles for pseudocapacitors; and in particular, possesses a relatively high charge capacity of 388.7 mA h g -1 after 50 cycles at 100 mA g -1 as anode nanomaterials for sodium-ion batteries. Furthermore, the electrochemical performances are readily tuned by varying the cationic type of the tunable LDH precursors to prepare different solid-solution sulfides, such as (Ni 0.7 Fe 0.3 )S 2 /3DGA and (Co 0.7 Fe 0.3 )S 2 /3DGA. Our results show that engineering LDH precursors can offer an alternative for preparing diverse transition-metal sulfides for energy storage.

Water-dissolvable sodium sulfate nanowires as a versatile template for the fabrication of polyelectrolyte- and metal-based nanotubes.

PubMed

Pu, Ying-Chih; Hwu, Jih Ru; Su, Wu-Chou; Shieh, Dar-Bin; Tzeng, Yonhua; Yeh, Chen-Sheng

2006-09-06

This study presents the synthesis of water-dissolvable sodium sulfate nanowires, where Na(2)SO(4) nanowires were produced by an easy reflux process in an organic solvent, N,N-dimethylformamide (DMF) and formed from the coexistence of AgNO(3), SnCl(2), dodecylsodium sulfate (SDS), and cetyltrimethylammonium bromide (CTAB). Na(2)SO(4) nanowires were derived from SDS, and the morphology control of the Na(2)SO(4) nanowires was established by the cooperative effects of Sn and NO(3)(-), while CTAB served as the template and led to homogeneous nanowires with a smooth surface. Since the as-synthesized sodium sulfate nanowires are readily dissolved in water, these nanowires can be treated as soft templates for the fabrication of nanotubes by removing the Na(2)SO(4) core. This process is therefore significantly better than other reported methodologies to remove the templates under harsh condition. We have demonstrated the preparation of biocompatible polyelectrolyte (PE) nanotubes using a layer-by-layer (LbL) method on the Na(2)SO(4) nanowires and the formation of Au nanotubes by the self-assembly of Au nanoparticles. In both nanotube synthesis processes, PEI (polyethylenimine), PAA (poly(acrylic acid)), and Au nanoparticles served as the building blocks on the Na(2)SO(4) templates, which were then rinsed with water to remove the core templates. This unique water-dissolvable template is anticipated to bring about versatile and flexible downstream applications.

A Spinel-integrated P2-type Layered Composite: High-rate Cathode for Sodium-ion Batteries

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

Zheng, Jianming; Yan, Pengfei; Kan, Wang Hay

2016-01-14

Sodium-ion batteries (SIB) are being intensively investigated, owing to the natural abundance and low cost of Na resources. However, the SIBs still suffer from poor rate capability due to the large ionic radius of Na+ ion and the significant kinetic barrier to Na+-ion transport. Here, we present an Fd-3m spinel-integrated P2-type layered composite (P2 + Fd-3m) material as a high-rate cathode for SIBs. The P2 + Fd-3m composite material Na0.50Ni1/6Co1/6Mn2/3O2 shows significantly enhanced discharge capacity, energy density, and rate capability as compared to the pure P2-type counterpart. The composite delivers a high capacity of 85 mA h g-1 when dischargingmore » at a very high current density of 1500 mA g-1 (10C rate) between 2.0 and 4.5 V, validating it as a promising cathode candidate for high-power SIBs. The superior performance is ascribed to the improved kinetics in the presence of the integrated-spinel phase, which facilitates fast electron transport to coordinate with the timely Na+-ion insertion/extraction. The findings of this work also shed light on the importance of developing lattice doping, surface coating, and electrolyte additives to further improve the structural and interfacial stability of P2-type cathode materials and fully realize their practical applications in sodium-ion batteries.« less

The impact of N,N-dimethyldodecylamine N-oxide (DDAO) concentration on the crystallisation of sodium dodecyl sulfate (SDS) systems and the resulting changes to crystal structure, shape and the kinetics of crystal growth.

PubMed

Summerton, Emily; Hollamby, Martin J; Zimbitas, Georgina; Snow, Tim; Smith, Andrew J; Sommertune, Jens; Bettiol, Jeanluc; Jones, Christopher; Britton, Melanie M; Bakalis, Serafim

2018-05-19

At low temperatures stability issues arise in commercial detergent products when surfactant crystallisation occurs, a process which is not currently well-understood. An understanding of the phase transition can be obtained using a simple binary SDS (sodium dodecyl sulfate) + DDAO (N,N-dimethyldodecylamine N-oxide) aqueous system. It expected that the crystallisation temperature of an SDS system can be lowered with addition of DDAO, thus providing a route to improve detergent stability. Detergent systems are typically comprised of anionic surfactants, non-ionic surfactants and water. This study explores the crystallisation of a three component system consisting of sodium dodecyl sulfate (SDS), N,N-dimethyldodecylamine N-oxide (DDAO), and water using wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC) and confocal Raman microscopy. The presence of DDAO lowered the crystallisation temperature of a 20 wt% SDS system. For all aqueous mixtures of SDS + DDAO at low temperatures, SDS hydrated crystals, SDS.1/2H 2 O or SDS·H 2 O, formed. SDS hydrates comprising of layers of SDS separated by water layers. DDAO tended to reside in the vicinity of these SDS crystals. In the absence of DDAO an additional intermediary hydrate structure, SDS.1/8H 2 O, formed whereas for mixed SDS + DDAO systems no such structure was detected during crystallisation. Copyright © 2018. Published by Elsevier Inc.

Cu2+ Dual-Doped Layer-Tunnel Hybrid Na0.6Mn1- xCu xO2 as a Cathode of Sodium-Ion Battery with Enhanced Structure Stability, Electrochemical Property, and Air Stability.

PubMed

Chen, Ting-Ru; Sheng, Tian; Wu, Zhen-Guo; Li, Jun-Tao; Wang, En-Hui; Wu, Chun-Jin; Li, Hong-Tai; Guo, Xiao-Dong; Zhong, Ben-He; Huang, Ling; Sun, Shi-Gang

2018-03-28

Sodium-ion batteries (SIBs) have been regarded as a promising candidate for large-scale renewable energy storage system. Layered manganese oxide cathode possesses the advantages of high energy density, low cost and natural abundance while suffering from limited cycling life and poor rate capacity. To overcome these weaknesses, layer-tunnel hybrid material was developed and served as the cathode of SIB, which integrated high capacity, superior cycle ability, and rate performance. In the current work, the doping of copper was adopted to suppress the Jahn-Teller effect of Mn 3+ and to affect relevant structural parameters. Multifunctions of the Cu 2+ doping were carefully investigated. It was found that the structure component ratio is varied with the Cu 2+ doping amount. Results demonstrated that Na + /vacancy rearrangement and phase transitions were suppressed during cycling without sacrificing the reversible capacity and enhanced electrochemical performances evidenced with 96 mA h g -1 retained after 250 cycles at 4 C and 85 mA h g -1 at 8 C. Furthermore, ex situ X-ray diffraction has demonstrated high reversibility of the Na 0.6 Mn 0.9 Cu 0.1 O 2 cathode during Na + extraction/insertion processes and superior air stability that results in better storage properties. This study reveals that the Cu 2+ doping could be an effective strategy to tune the properties and related performances of Mn-based layer-tunnel hybrid cathode.

Thermal treatment to improve the hydrophobicity of ground CaCO3 particles modified with sodium stearate

NASA Astrophysics Data System (ADS)

Liang, Yong; Yu, Keyi; Zheng, Qinzhong; Xie, Jiuren; Wang, Ting-Jie

2018-04-01

The surface modification of calcium carbonate (CaCO3) particles, which is used as a filler, significantly affects the properties of the composed materials. The effects of thermal treatment on ground calcium carbonate (GCC) particles subjected to hydrophobic modification using sodium stearate (RCOONa) were studied. The contact angle of the modified GCC particles increased from 24.7° to 118.9° when the amount of RCOONa added was increased from 0% to 5% and then decreased to 97.5° when the RCOONa content was further increased to 10%. When a large amount of RCOONa was added, RCOO- reacts with Ca2+ and generates (RCOO)2Ca nuclei, which are adsorbed on the surface of the GCC particles, forming a discontinuous (RCOO)2Ca modified layer. After thermal treatment under sealed conditions, the contact angle of the GCC particles modified using 1.5% RCOONa/GCC increased from 112.8° to 139.6°. The thermal stability of the (RCOO)2Ca modified layer was increased, with the temperature increase of the mass-loss peak from 358.0 to 463.0 °C. It is confirmed that the spreading of melted (RCOO)2Ca nuclei on the surface of the GCC particles during the thermal treatment increased the continuity of the modified layer, converting the physical adsorption of the (RCOO)2Ca nuclei into chemisorption. The grafting density of RCOO- on the GCC particle surface after thermal treatment approximates to 5.00/nm2, which is close to the single-molecular-layer grafting density of RCOO-, indicating that excellent modification was achieved.

Delayed release film coating applications on oral solid dosage forms of proton pump inhibitors: case studies.

PubMed

Missaghi, Shahrzad; Young, Cara; Fegely, Kurt; Rajabi-Siahboomi, Ali R

2010-02-01

Formulation of proton pump inhibitors (PPIs) into oral solid dosage forms is challenging because the drug molecules are acid-labile. The aim of this study is to evaluate different formulation strategies (monolithic and multiparticulates) for three PPI drugs, that is, rabeprazole sodium, lansoprazole, and esomeprazole magnesium, using delayed release film coating applications. The core tablets of rabeprazole sodium were prepared using organic wet granulation method. Multiparticulates of lansoprazole and esomeprazole magnesium were prepared through drug layering of sugar spheres, using powder layering and suspension layering methods, respectively. Tablets and drug-layered multiparticulates were seal-coated, followed by delayed release film coating application, using Acryl-EZE(R), aqueous acrylic enteric system. Multiparticulates were then filled into capsules. The final dosage forms were evaluated for physical properties, as well as in vitro dissolution testing in both compendial acid phase, 0.1N HCl (pH 1.2), and intermediate pH, acetate buffer (pH 4.5), followed by phosphate buffer, pH 6.8. The stability of the delayed release dosage forms was evaluated upon storage in accelerated conditions [40 degrees C/75% relative humidity] for 3 months. All dosage forms demonstrated excellent enteric protection in the acid phase, followed by rapid release in their respective buffer media. Moreover, the delayed release dosage forms remained stable under accelerated stability conditions for 3 months. Results showed that Acryl-EZE enteric coating systems provide excellent performance in both media (0.1N HCl and acetate buffer pH 4.5) for monolithic and multiparticulate dosage forms.

Development of all-solid-state coherent 589 nm light source: toward the realization of sodium lidar and laser guide star adaptive optics

NASA Astrophysics Data System (ADS)

Saito, Norihito; Akagawa, Kazuyuki; Kato, Mayumi; Takazawa, Akira; Hayano, Yutaka; Saito, Yoshihiko; Ito, Meguru; Takami, Hideki; Iye, Masanori; Wada, Satoshi

2006-12-01

We report an all-solid-state coherent 589 nm light source in single-pass sum-frequency generation (SFG) with actively mode-locked Nd:YAG lasers for the realization of sodium lidar and laser guide star adaptive optics. The Nd:YAG lasers are constructed as a LD-side-pumped configuration and are operated at 1064 and 1319 nm for 589 nm light generation in SFG. Output powers of 16.5 and 5.3 W at 1064 and 1319 nm are obtained with two pumping chambers. Each chamber consisted of three 80-W-LD arrays. Single transverse mode TEM 00; M2 ~1.1 is achieved with adjustment of cavity length considering thermal lens effect with increase of input LD power. The cavity length is set to approximately 1 m. Accordingly the mode-locked lasers are operated at a repetition rate of approximately 150 MHz. Synchronization of two pulse trains at 1064 and 1319 nm is accomplished by control of phase difference between two radio frequencies input in acousto-optic mode-lockers. Then temporal delay is controlled with a resolution of 37 ps/degree. Pump beams are mixed in periodically poled stoichiometric lithium tantalate (PPSLT) without an antireflection coating. The effective aperture and length of the crystal are 0.5 × 2 mm2 and 15 mm. When input intensity is set at 5.6 MW/cm , an average output power of 4.6 W is obtained at 589.159 nm. Precise tuning to the sodium D II line is accomplished by thermal control of etalons set in the Nd:YAG lasers. The output power at 589.159 nm is stably maintained within +/-1.2% for 8 hours.

Validation of a patch clamp screening protocol that simultaneously measures compound activity in multiple states of the voltage-gated sodium channel Nav1.2.

PubMed

Liu, Yi; Beck, Edward J; Flores, Christopher M

2011-12-01

Hyperactivity of voltage-gated sodium channels underlies, at least in part, a range of pathological states, including pain and epilepsy. Selective blockers of these channels may offer effective treatment of such disorders. Currently employed methods to screen for sodium channel blockers, however, are inadequate to rationally identify mechanistically diverse blockers, limiting the potential range of indications that may be treated by such agents. Here, we describe an improved patch clamp screening assay that increases the mechanistic diversity of sodium channel blockers being identified. Using QPatch HT, a medium-throughput, automated patch clamp system, we tested three common sodium channel blockers (phenytoin, lidocaine, and tetrodotoxin) with distinct mechanistic profiles at Nav1.2. The single-voltage protocol employed in this assay simultaneously measured the compound activity in multiple states, including the slow inactivated state, of the channel. A long compound incubation period (10 s) was introduced during channel inactivation to increase the probability of identifying "slow binders." As such, phenytoin, which preferentially binds with slow kinetics to the fast inactivated state, exhibited significantly higher potency than that obtained from a brief exposure (100 ms) used in typical assays. This assay also successfully detected the use-dependent block of tetrodotoxin, a well-documented property of this molecule yet unobserved in typical patch clamp protocols. These results indicate that the assay described here can increase the likelihood of identification and mechanistic diversity of sodium channel blockers from a primary screen. It can also be used to efficiently guide the in vitro optimization of leads that retain the desired mechanistic properties. © MARY ANN LIEBERT, INC.

Investigation of Corrosion Protection in Oil Mineral Reservoirs by Nanocomposites Used as Coating Layers

NASA Astrophysics Data System (ADS)

Al-Sarraf, Abdulhameed R.; Al-Saaidi, Samer A.

2018-05-01

In this study, a number of nanocomposites were prepared by adding magnesium oxide (MgO) with weight percentages (1, 2 & 3)% to cellulose nitrate and sodium silicate as an intermediate layer and other nanocomposites by adding MgO, coal coke and hybrid (MgO & coal coke with ratio 1:1) with weight percentages (1, 2 & 3)% to epoxy resin as final layer. The identity of the used metal is determined by spectrometer OE thermo. The nature and topography of the surface layers were examined by optical microscope and atomic force microscope (AFM). Mechanical properties are indicated by hardness, wear rate, impact strength and adhesion strength. The efficiency of the layers prepared to inhibit corrosion in the oil mineral reservoirs of the oil products distribution company was studied by electrochemical corrosion test in addition to the chemical corrosion test. The used metal is (St-37) according to (ASTM). It was found that the best intermediate layer (cellulose nitrate+3%MgO) and the final layer is the epoxy resin reinforced by 2% hybrid.

Anti-corrosion activities of apen-class inhibitive drug on aluminium alloy in simulated chloride environment

NASA Astrophysics Data System (ADS)

Fayomi, O. S. I.; Anawe, PAL; Ayoola, A. A.; Joseph, O. O.

2018-05-01

In this study, aluminium material normally used in the underlie ship was immersed in simulated sodium chloride environment and its degradation properties was evaluated. Investigation of corrosion rate and mass weight loss through gravimetric tests measurements showed that less mass loss was recorded for tests in sodium chloride with 3-(2'-chloro-6' fluorophenyl) and lowest corrosion rate values were found at 10%. On the other hand, the mass loss deteriorated in all 3-(2'-chloro-6' fluorophenyl) with less uniform corrosion. The existence of chloride dissolved the interfacial surface layer resulting into pit initiation and growth. It is found that corrosion degradation of aluminum is dependent on chloride and inhibitive concentration.

Selective mucosal ablation using CO2 laser for the development of novel endoscopic submucosal dissection: comparison of continuous wave and nanosecond pulsed wave

NASA Astrophysics Data System (ADS)

Ishii, K.; Watanabe, S.; Obata, D.; Hazama, H.; Morita, Y.; Matsuoka, Y.; Kutsumi, H.; Azuma, T.; Awazu, K.

2010-02-01

Endoscopic submucosal dissection (ESD) is accepted as a minimally invasive treatment technique for small early gastric cancers. Procedures are carried out using some specialized electrosurgical knifes with a submucosal injection solution. However it is not widely used because its procedure is difficult. The objective of this study is to develop a novel ESD method which is safe in principle and widely used by using laser techniques. In this study, we used CO2 lasers with a wavelength of 10.6 μm for mucosal ablation. Two types of pulse, continuous wave and pulsed wave with a pulse width of 110 ns, were studied to compare their values. Porcine stomach tissues were used as a sample. Aqueous solution of sodium hyaluronate (MucoUpR) with 50 mg/ml sodium dihydrogenphosphate is injected to a submucosal layer. As a result, ablation effect by CO2 laser irradiation was stopped because submucosal injection solution completely absorbed CO2 laser energy in the invasive energy condition which perforates a muscle layer without submucosal injection solution. Mucosal ablation by the combination of CO2 Laser and a submucosal injection solution is a feasible technique for treating early gastric cancers safely because it provides a selective mucosal resection and less-invasive interaction to muscle layer.

Multiband guided-mode resonance filter in bilayer asymmetric metallic gratings

NASA Astrophysics Data System (ADS)

Wang, Yanhui; Li, Xiangjun; Lang, Tingting; Jing, Xufeng; Hong, Zhi

2018-07-01

In this paper, a guided-mode resonances (GMRs) based multiband filter in bilayer asymmetric metallic gratings is presented. Four sharp dips are generated in the frequency range of 1.4-2.0 THz, which are induced by the split of two GMR modes (TE0 and TM0) due to the break of the structure's symmetry. This symmetry of the structure depends on the relative position between the upper layer and lower layer gratings. Therefore, by choosing proper lateral displacement, the split of TE0 or/and TM0 modes can be eliminated. Two-, three-, and four- GMRs based polarization insensitive or sensitive filters are demonstrated numerically.

Guided-mode resonance nanophotonics in materially sparse architectures

NASA Astrophysics Data System (ADS)

Magnusson, Robert; Niraula, Manoj; Yoon, Jae W.; Ko, Yeong H.; Lee, Kyu J.

2016-03-01

The guided-mode resonance (GMR) concept refers to lateral quasi-guided waveguide modes induced in periodic layers. Whereas these effects have been known for a long time, new attributes and innovations continue to appear. Here, we review some recent progress in this field with emphasis on sparse, or minimal, device embodiments. We discuss properties of wideband resonant reflectors designed with gratings in which the grating ridges are matched to an identical material to eliminate local reflections and phase changes. This critical interface therefore possesses zero refractive-index contrast; hence we call them "zero-contrast gratings." Applying this architecture, we present single-layer, wideband reflectors that are robust under experimentally realistic parametric variations. We introduce a new class of reflectors and polarizers fashioned with dielectric nanowire grids that are mostly empty space. Computed results predict high reflection and attendant polarization extinction for these sparse lattices. Experimental verification with Si nanowire grids yields ~200-nm-wide band of high reflection for one polarization state and free transmission of the orthogonal state. Finally, we present bandpass filters using all-dielectric resonant gratings. We design, fabricate, and test nanostructured single layer filters exhibiting high efficiency and sub-nanometer-wide passbands surrounded by 100-nm-wide stopbands.

Insight into Ca-Substitution Effects on O3-Type NaNi1/3 Fe1/3 Mn1/3 O2 Cathode Materials for Sodium-Ion Batteries Application.

PubMed

Sun, Liqi; Xie, Yingying; Liao, Xiao-Zhen; Wang, Hong; Tan, Guoqiang; Chen, Zonghai; Ren, Yang; Gim, Jihyeon; Tang, Wan; He, Yu-Shi; Amine, Khalil; Ma, Zi-Feng

2018-04-18

O3-type NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NaNFM) is well investigated as a promising cathode material for sodium-ion batteries (SIBs), but the cycling stability of NaNFM still needs to be improved by using novel electrolytes or optimizing their structure with the substitution of different elements sites. To enlarge the alkali-layer distance inside the layer structure of NaNFM may benefit Na + diffusion. Herein, the effect of Ca-substitution is reported in Na sites on the structural and electrochemical properties of Na 1- x Ca x /2 NFM (x = 0, 0.05, 0.1). X-ray diffraction (XRD) patterns of the prepared Na 1- x Ca x /2 NFM samples show single α-NaFeO 2 type phase with slightly increased alkali-layer distance as Ca content increases. The cycling stabilities of Ca-substituted samples are remarkably improved. The Na 0.9 Ca 0.05 Ni 1/3 Fe 1/3 Mn 1/3 O 2 (Na 0.9 Ca 0.05 NFM) cathode delivers a capacity of 116.3 mAh g -1 with capacity retention of 92% after 200 cycles at 1C rate. In operando XRD indicates a reversible structural evolution through an O3-P3-P3-O3 sequence of Na 0.9 Ca 0.05 NFM cathode during cycling. Compared to NaNMF, the Na 0.9 Ca 0.05 NFM cathode shows a wider voltage range in pure P3 phase state during the charge/discharge process and exhibits better structure recoverability after cycling. The superior cycling stability of Na 0.9 Ca 0.05 NFM makes it a promising material for practical applications in sodium-ion batteries. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design of light guide sleeve on hyperspectral imaging system for skin diagnosis

NASA Astrophysics Data System (ADS)

Yan, Yung-Jhe; Chang, Chao-Hsin; Huang, Ting-Wei; Chiang, Hou-Chi; Wu, Jeng-Fu; Ou-Yang, Mang

2017-08-01

A hyperspectral imaging system is proposed for early study of skin diagnosis. A stable and high hyperspectral image quality is important for analysis. Therefore, a light guide sleeve (LGS) was designed for the embedded on a hyperspectral imaging system. It provides a uniform light source on the object plane with the determined distance. Furthermore, it can shield the ambient light from entering the system and increasing noise. For the purpose of producing a uniform light source, the LGS device was designed in the symmetrical double-layered structure. It has light cut structures to adjust distribution of rays between two layers and has the Lambertian surface in the front-end to promote output uniformity. In the simulation of the design, the uniformity of illuminance was about 91.7%. In the measurement of the actual light guide sleeve, the uniformity of illuminance was about 92.5%.

Optimal reconstruction for closed-loop ground-layer adaptive optics with elongated spots.

PubMed

Béchet, Clémentine; Tallon, Michel; Tallon-Bosc, Isabelle; Thiébaut, Éric; Le Louarn, Miska; Clare, Richard M

2010-11-01

The design of the laser-guide-star-based adaptive optics (AO) systems for the Extremely Large Telescopes requires careful study of the issue of elongated spots produced on Shack-Hartmann wavefront sensors. The importance of a correct modeling of the nonuniformity and correlations of the noise induced by this elongation has already been demonstrated for wavefront reconstruction. We report here on the first (to our knowledge) end-to-end simulations of closed-loop ground-layer AO with laser guide stars with such an improved noise model. The results are compared with the level of performance predicted by a classical noise model for the reconstruction. The performance is studied in terms of ensquared energy and confirms that, thanks to the improved noise model, central or side launching of the lasers does not affect the performance with respect to the laser guide stars' flux. These two launching schemes also perform similarly whatever the atmospheric turbulence strength.

Layered metal sulfides: Exceptionally selective agents for radioactive strontium removal

PubMed Central

Manos, Manolis J.; Ding, Nan; Kanatzidis, Mercouri G.

2008-01-01

In this article, we report the family of robust layered sulfides K2xMnxSn3-xS6 (x = 0.5–0.95) (KMS-1). These materials feature hexagonal [MnxSn3-xS6]2x− slabs of the CdI2 type and contain highly mobile K+ ions in their interlayer space that are easily exchangeable with other cations and particularly strontium. KMS-1 display outstanding preference for strontium ions in highly alkaline solutions containing extremely large excess of sodium cations as well as in acidic environment where most alternative adsorbents with oxygen ligands are nearly inactive. The implication of these results is that simple layered sulfides should be considered for the efficient remediation of certain nuclear wastes. PMID:18316731

Emerging Prototype Sodium-Ion Full Cells with Nanostructured Electrode Materials.

PubMed

Ren, Wenhao; Zhu, Zixuan; An, Qinyou; Mai, Liqiang

2017-06-01

Due to steadily increasing energy consumption, the demand of renewable energy sources is more urgent than ever. Sodium-ion batteries (SIBs) have emerged as a cost-effective alternative because of the earth abundance of Na resources and their competitive electrochemical behaviors. Before practical application, it is essential to establish a bridge between the sodium half-cell and the commercial battery from a full cell perspective. An overview of the major challenges, most recent advances, and outlooks of non-aqueous and aqueous sodium-ion full cells (SIFCs) is presented. Considering the intimate relationship between SIFCs and electrode materials, including structure, composition and mutual matching principle, both the advance of various prototype SIFCs and the electrochemistry development of nanostructured electrode materials are reviewed. It is noted that a series of SIFCs combined with layered oxides and hard carbon are capable of providing a high specific gravimetric energy above 200 Wh kg -1 , and an NaCrO 2 //hard carbon full cell is able to deliver a high rate capability over 100 C. To achieve industrialization of SIBs, more systematic work should focus on electrode construction, component compatibility, and battery technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel reverse osmosis membrane by ferrous sulfate assisted controlled oxidation of polyamide layer

NASA Astrophysics Data System (ADS)

Raval, Hiren D.; Raviya, Mayur R.; Gauswami, Maulik V.

2017-11-01

With growing desalination capacity, it is very important to evaluate the performance of thin film composite reverse osmosis (TFC RO) membrane in terms of energy consumption for desalination. There is a trade-off between salt rejection and water-flux of TFC RO membrane. This article presents a novel approach of analyzing the effect of mixture of an oxidizing agent sodium hypochlorite and a reducing agent ferrous sulfate on virgin TFC RO membrane. Experiments were carried out by varying the concentrations of both sodium hypochlorite and ferrous sulfate. The negative charge was induced on the membrane due to the treatment of combination of sodium hypochlorite and ferrous sulfate, thereby resulting in higher rejection of negative ions due to repulsive force. Membrane treated with 1000 mg l-1 sodium hypochlorite and 2000 mg l-1 ferrous sulfate showed the best salt rejection i.e. 96.23%. The characterization was carried out to understand the charge on the membrane surface by Zeta potential, morphology of membrane surface by scanning electron microscope (SEM), surface roughness features by atomic force microscope (AFM) and chemical structural changes by nuclear magnetic resonance (NMR) analysis.

Design and Comparative Study of O3/P2 Hybrid Structures for Room Temperature Sodium-Ion Batteries.

PubMed

Qi, Xingguo; Liu, Lilu; Song, Ningning; Gao, Fei; Yang, Kai; Lu, Yaxiang; Yang, Haitao; Hu, Yong-Sheng; Cheng, Zhao-Hua; Chen, Liquan

2017-11-22

Rechargeable sodium-ion batteries have drawn increasing attention as candidates for the post lithium-ion batteries in large-scale energy storage systems. Layered oxides are the most promising cathode materials and their pure phases (e.g., P2, O3) have been widely investigated. Here we report a series of cathode materials with O3/P2 hybrid phase for sodium-ion batteries, which possesses advantages of both P2 and O3 structures. The designed material, Na 0.78 Ni 0.2 Fe 0.38 Mn 0.42 O 2 , can deliver a capacity of 86 mAh g -1 with great rate capability and cycling performance. 66% capacity is still maintained when the current rate reaches as high as 10C, and the capacity retention is 90% after 1500 cycles. Moreover, in situ XRD was performed to examine the structure change during electrochemical testing in different voltage ranges, and the results demonstrate 4 V as the optimized upper voltage limit, with which smaller polarization, better structural stability, and better cycling performance are achieved. The results obtained here provide new insights in designing cathode materials with optimal structure and improved performance for sodium-ion batteries.

Biophysical analysis of water filtration phenomenon in the roots of halophytes

NASA Astrophysics Data System (ADS)

Kim, Kiwoong; Lee, Sang Joon

2015-11-01

The water management systems of plants, such as water collection and water filtration have been optimized through a long history. In this point of view, new bio-inspired technologies can be developed by mimicking the nature's strategies for the survival of the fittest. In this study, the biophysical characteristics of water filtration process in the roots of halophytes are experimentally investigated in the plant hydrodynamic point of view. To understand the functional features of the halophytes 3D morphological structure of their roots are analyzed using advanced bioimaging techniques. The surface properties of the roots of halophytes are also examined Based on the quantitatively analyzed information, water filtration phenomenon in the roots is examined. Sodium treated mangroves are soaked in sodium acting fluorescent dye solution to trace sodium ions in the roots. In addition, in vitroexperiment is carried out by using the roots. As a result, the outermost layer of the roots filters out continuously most of sodium ions. This study on developing halophytes would be helpful for understanding the water filtration mechanism of the roots of halophytes and developing a new bio inspired desalination system. This research was financially supported by the National Research Foundation (NRF) of Korea (Contract grant number: 2008-0061991).

Flexible, liquid core light guide with focusing and light shaping attachments

DOEpatents

Wojcik, Randolph Frank; Majewski, Stanislaw; Zorn, Carl John; Kross, Brian

1999-01-01

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. The end closures include a metal crimping arrangement that utilizes two layers of deformable materials to prevent cracking of endplugs.

Wildland resource information system: user's guide

Treesearch

Robert M. Russell; David A. Sharpnack; Elliot L. Amidon

1975-01-01

This user's guide provides detailed information about how to use the computer programs of WRIS, a computer system for storing and manipulating data about land areas. Instructions explain how to prepare maps, digitize by automatic scanners or by hand, produce polygon maps, and combine map layers. Support programs plot maps, store them on tapes, produce summaries,...

Metal fires and their implications for advanced reactors.

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

Nowlen, Steven Patrick; Figueroa, Victor G.; Olivier, Tara Jean

This report details the primary results of the Laboratory Directed Research and Development project (LDRD 08-0857) Metal Fires and Their Implications for Advance Reactors. Advanced reactors may employ liquid metal coolants, typically sodium, because of their many desirable qualities. This project addressed some of the significant challenges associated with the use of liquid metal coolants, primary among these being the extremely rapid oxidation (combustion) that occurs at the high operating temperatures in reactors. The project has identified a number of areas for which gaps existed in knowledge pertinent to reactor safety analyses. Experimental and analysis capabilities were developed in thesemore » areas to varying degrees. In conjunction with team participation in a DOE gap analysis panel, focus was on the oxidation of spilled sodium on thermally massive surfaces. These are spills onto surfaces that substantially cool the sodium during the oxidation process, and they are relevant because standard risk mitigation procedures seek to move spill environments into this regime through rapid draining of spilled sodium. While the spilled sodium is not quenched, the burning mode is different in that there is a transition to a smoldering mode that has not been comprehensively described previously. Prior work has described spilled sodium as a pool fire, but there is a crucial, experimentally-observed transition to a smoldering mode of oxidation. A series of experimental measurements have comprehensively described the thermal evolution of this type of sodium fire for the first time. A new physics-based model has been developed that also predicts the thermal evolution of this type of sodium fire for the first time. The model introduces smoldering oxidation through porous oxide layers to go beyond traditional pool fire analyses that have been carried out previously in order to predict experimentally observed trends. Combined, these developments add significantly to the safety analysis capabilities of the advanced-reactor community for directly relevant scenarios. Beyond the focus on the thermally-interacting and smoldering sodium pool fires, experimental and analysis capabilities for sodium spray fires have also been developed in this project.« less

A Procedural Guide on Sick Building Syndrome.

DTIC Science & Technology

1987-03-01

membrane irrition. Sodium dodecyl sulfate , an ingredient in many carpet shampoos has also been associated with mucous membrane irritation in certain offices...American Industrial Hygiene Conference, 20 May 1986 13. Kreiss, K, and M.G. Gonzales, et al, "Respiratory Irritation Due to Carpet Shampoo ," Chronic...Carpet Shampoo ," Proc. Fifth Inter. Symp. Medichem, San Francisco, p. 347 (1977) 12 15. Threshold Limit Values and Biological Exposure Indices for 1985

Environmental Restoration - Expedient Methods and Technologies: A User Guide with Case Studies

DTIC Science & Technology

1998-03-01

benzene, high fructose corn syrup , raw molasses, butane gas, sodium benzoate, or acetate. Enhanced anaerobic biodegradation of jet fuels in ground water...appendix discusses technology applications that are deemed impractical because of high cost, difficulty of use, or other factors. Also included is a...conversations with knowledgeable 1 Technologically sophisticated processes are not addressed in this study because of high cost, which includes the engineering

[Diet in Chronic Kidney Disease - A Practical Guide].

PubMed

Bischoff, Stephan C; Basrai, Maryam

2018-06-01

Chronic kidney disease is associated with metabolic disorders. The nutrient requirement varies considerably and often it is not covered. This is why many patients experience severe deficiencies ("kidney disease wasting"), which limits their quality of life and prognosis. On the other hand sodium, potassium and phosphate must be limited. Nutritional therapy is a relevant part of the therapy. © Georg Thieme Verlag KG Stuttgart · New York.

A confined "microreactor" synthesis strategy to three dimensional nitrogen-doped graphene for high-performance sodium ion battery anodes

NASA Astrophysics Data System (ADS)

Li, Jiajie; Zhang, Yumin; Gao, Tangling; Han, Jiecai; Wang, Xianjie; Hultman, Benjamin; Xu, Ping; Zhang, Zhihua; Wu, Gang; Song, Bo

2018-02-01

In virtue of abundant sodium resources, sodium ion batteries (SIBs) have been regarded as one of the most promising alternatives for large-scale energy storage applications. However, the absence of a suitable anode material makes it difficult to realize these applications. Here, we demonstrate an effective synthesis strategy of using a "microreactor" consisting of melamine fiber (inside) and graphene oxide (GO, outside) to fabricate three dimensional (3D) nitrogen doped (N-doped) graphene as high-performance anode materials for sodium ion batteries. Through a controlled pyrolysis, the inside melamine fiber and the outside GO layer has been converted into N-doped graphene and reduced graphene oxide (r-GO) respectively, and thus the "microreactor" is transformed into interconnected 3D N-doped graphene structures. Such highly desired 3D graphene structures show reversible sodium storage capacities up to ∼305 mA h g-1 after 500 cycles at a current density of 0.2 A g-1 and promising long cycling stability with a stable capacity of ∼198 mA h g-1 at 5 A g-1 after 5000 cycles. The high capacity and superior durability in combination with the facile synthesis procedure of the 3D graphene structure make it a promising anode material for SIBs and other energy storage applications.

Powder X-ray diffraction, infrared and 13C NMR spectroscopic studies of the homologous series of some solid-state zinc(II) and sodium(I) n-alkanoates

NASA Astrophysics Data System (ADS)

Nelson, Peter N.; Taylor, Richard A.

2015-03-01

A comparative study of the room temperature molecular packing and lattice structures for the homologous series of zinc(II) and sodium(I) n-alkanoates adduced from Fourier transform infrared and solid-state 13C NMR spectroscopic data in conjunction with X-ray powder diffraction measurements is carried out. For zinc carboxylates, metal-carboxyl bonding is via asymmetric bridging bidentate coordination whilst for the sodium adducts, coordination is via asymmetric chelating bidentate bonding. All compounds are packed in a monoclinic crystal system. Furthermore, the fully extended all-trans hydrocarbon chains are arranged as lamellar bilayers. For zinc compounds, there is bilayer overlap, for long chain adducts (nc > 8) but not for sodium compounds where methyl groups from opposing layers in the lamellar are only closely packed. Additionally, the hydrocarbon chains are extended along the a-axis of the unit cell for zinc compounds whilst for sodium carboxylates they are extended along the c-axis. These packing differences are responsible for different levels of Van der Waals effects in the lattices of these two series of compounds, hence, observed odd-even alternation is different. The significant difference in lattice packing observed for these two series of compounds is proposed to be due to the difference in metal-carboxyl coordination mode, arising from the different electronic structure of the central metal ions.

Simultaneous lidar observation of peculiar sporadic K and Na layers at São José dos Campos (23.1°S, 45.9°W), Brazil

NASA Astrophysics Data System (ADS)

Jiao, Jing; Yang, Guotao; Cheng, Xuewu; Liu, Zhengkuan; Wang, Jihong; Yan, Zhenzhong; Wang, Chi; Batista, Paulo; Pimenta, Alexandre; Andrioli, Vânia; Denardini, C. M.

2018-04-01

We present the first simultaneous observation of mesopause sodium (Na) and potassium (K) layer by a lidar which has Na and K channel simultaneously at the South Hemisphere site, São José dos Campos (23.1°S, 45.9°W). Measurements reported here were conducted on two nights with 3.5 and 8 h of observations in November 2016. On 20 November 2016, sporadic layers in both Na and K layer occurred above 100 km, and the higher layers corresponded well with sporadic E (Es) layer. And the density of Na at 100-105 km is higher than that at main layer around 90 km, but K density around 100 km is at least 3 times smaller compared with the K density around 90 km for the similar period. On 21 November 2016, both sporadic layers occurred in main layer height with obvious descending variations with time, which seems like tidal induced. Notably, the peak K/Na ratio slowly increased with time. And Na layer and K layer showed different processes along with time with K density reaching its maximum 1 h later than that of Na. Correlations of Na/K density, Es, and winds were also discussed.

Gateways to clinical trials.

PubMed

Bayes, M; Rabasseda, X; Prous, J R

2005-10-01

Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables have been retrieved from the Clinical Trials Knowledge Area of Prous Science Integrity, the drug discovery and development portal, http://integrity.prous.com. This issue focuses on the following selection of drugs: (-)-Epigallocatechin gallate, (Z)-4-hydroxytamoxifen; Ad.muIFN-beta AD-237, adalimumab, adefovir dipivoxil, agalsidase alfa, alemtuzumab, almotriptan, ALVAC vCP1452, alvimopan hydrate, ambrisentan, anakinra, anti-IFN-gamma MAb; Bimatoprost, BMS-188797, BMS-214662, bortezomib, bosentan, bovine lactoferrin; Caffeine, canertinib dihydrochloride, canfosfamide hydrochloride, cannabidiol, caspofungin acetate, cetuximab, cH36, ChimeriVax-JE, ciclesonide, cilansetron, cinacalcet hydrochloride, clopidogrel, CpG-7909, Cypher; Daptomycin, darbepoetin alfa, darifenacin hydrobromide, decitabine, denufosol tetrasodium, Dexamet, diindolemethane, drotrecogin alfa (activated), duloxetine hydrochloride, DX-9065a; E-7010, edaravone, efalizumab, eicosapentaenoic acid/docosahexaenoic acid, elacridar, eletriptan, emtricitabine, epratuzumab, erlotinib hydrochloride, ertapenem sodium, eszopiclone, everolimus, ezetimibe; Fludarabine, fondaparinux sodium; gamma-Hydroxybutyrate sodium, gavestinel sodium, gefitinib, granisetron-Biochronomer; Human Albumin, human insulin; Imatinib mesylate, indiplon, interleukin-2 XL, isatoribine, ISS-1018, i.v. gamma-globulin, ivabradine hydrochloride, ixabepilone; Lanthanum carbonate, L-arginine hydrochloride, liposomal doxorubicin, LY-450139; Magnesium sulfate, melatonin, motexafin gadolinium, mycophenolic acid sodium salt; Natalizumab, nesiritide, niacin/lovastatin; OGX-011, olmesartan medoxomil, omalizumab, ospemifene; PACAP38, panitumumab, parathyroid hormone (human recombinant), parecoxib sodium, patupilone, pegfilgrastim, peginterferon alfa-2a, peginterferon alfa-2b, peginterferon alfa-2b/ribavirin, pemetrexed disodium, pimecrolimus, pirfenidone, posaconazole, prasterone, pregabalin; R-112, ramelteon, ranolazine, rasagiline mesilate, rebimastat, roflumilast, rosuvastatin calcium, rotigotine hydrochloride, rupatadine fumarate; S-3013, S-3304, semustine, sitaxsentan sodium, St. John's Wort extract; Tadalafil, tamoxifen, Taxus, Tc-99m-EDDA-HYNIC-TOC, TH-9507, tiotropium bromide, tipifarnib, tocilizumab, tolvaptan, torcetrapib, TR-14035, tramadol hydrochloride/acetaminophen, treprostinil diethanolamine, troglitazone, troxacitabine; Valdecoxib, valganciclovir hydrochloride, vandetanib, vardenafil hydrochloride hydrate, VAS-991, veglin, vinflunine, voriconazole; White sweet potato extract; Ximelagatran. (c) 2005 Prous Science. All rights reserved.

Discussion of boundary-layer characteristics near the casing of an axial-flow compressor

NASA Technical Reports Server (NTRS)

Mager, Artur; Mahoney, John J; Budinger, Ray E

1951-01-01

Boundary-layer velocity profiles on the casing of an axial-flow compressor behind the guide vanes and rotor were measured and resolved into two components: along the streamline of the flow and perpendicular to it. Boundary-layer thickness and the deflection of the boundary layer at the wall were the generalizing parameters. By use of these results and the momentum-integral equations, the characteristics of boundary on the walls of axial-flow compressor are qualitatively discussed. Important parameters concerning secondary flow in the boundary layer appear to be turning of the flow and the product of boundary-layer thickness and streamline curvature outside the boundary layer. Two types of separation are shown to be possible in three dimensional boundary layer.

Application of dynamic slip wall modeling to a turbine nozzle guide vane

NASA Astrophysics Data System (ADS)

Bose, Sanjeeb; Talnikar, Chaitanya; Blonigan, Patrick; Wang, Qiqi

2015-11-01

Resolution of near-wall turbulent structures is computational prohibitive necessitating the need for wall-modeled large-eddy simulation approaches. Standard wall models are often based on assumptions of equilibrium boundary layers, which do not necessarily account for the dissimilarity of the momentum and thermal boundary layers. We investigate the use of the dynamic slip wall boundary condition (Bose and Moin, 2014) for the prediction of surface heat transfer on a turbine nozzle guide vane (Arts and de Rouvroit, 1992). The heat transfer coefficient is well predicted by the slip wall model, including capturing the transition to turbulence. The sensitivity of the heat transfer coefficient to the incident turbulence intensity will additionally be discussed. Lastly, the behavior of the thermal and momentum slip lengths will be contrasted between regions where the strong Reynolds analogy is invalid (near transition on the suction side) and an isothermal, zero pressure gradient flat plate boundary layer (Wu and Moin, 2010).

Fast detection of humidity with a subwavelength-diameter fiber taper coated with gelatin film.

PubMed

Zhang, Lei; Gu, Fuxing; Lou, Jingyi; Yin, Xuefeng; Tong, Limin

2008-08-18

A subwavelength-diameter tapered optical fiber coated with gelatin layer for fast relative humidity (RH) sensing is reported. The sensing element is composed of a 680-nm-diameter fiber taper coated with a 80-nm-thickness 8-mm-length gelatin layer, and is operated at a wavelength of 1550 nm. When exposed to moisture, the change in refractive index of the gelatin layer changes the mode field of the guided mode of the coated fiber, and converts a portion of power from guided mode to radiation mode, resulting in RH-dependent loss for optical sensing. The sensor is operated within a wide humidity range (9-94% RH) with high sensitivity and good reversibility. Measured response time is about 70 ms, which is one or two orders of magnitude faster than other types of RH sensors relying on conventional optical fibers or films.

Interaction of Fe-Al-Cr-C with the melt of an alkali metal carbonate

NASA Astrophysics Data System (ADS)

Nikitina, E. V.

2015-08-01

The interaction of an Fe-Al-Cr-C (29.5 wt % Fe, 29.35 wt % Cr, 2.56 wt % C, 38.59 wt % Al) alloy with the melt of a lithium, sodium, or potassium carbonate containing 1-5 wt % addition to a salt phase is studied by gravimetry and measuring the corrosion potential and anode polarization curves in the temperature range 500-600°C. As passivators, the substances that decrease the corrosion losses due to hardening and thickening of an oxide film (lithium, sodium, potassium hydroxides) are used. As corrosion stimulators (activators), sodium chloride, fluoride, and sulfate are used. The coalloying of iron with chromium and aluminum results in high corrosion resistance against both frontal (continuous) and local (pitting, intercrystalline) corrosion as a result of formation of chemically resistant and high-adhesion oxide layers with their participation. X-ray diffraction analysis reveals gamma aluminum oxide, spinel (alumochromite) traces, and lithium aluminate at the surface.

Preliminary Design of Critical Function Monitoring System of PGSFR

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

NONE

2015-07-01

A PGSFR (Prototype Gen-IV Sodium-cooled Fast Reactor) is under development at Korea Atomic Energy Research Institute. A critical function monitoring system of the PGSFR is preliminarily studied. The functions of CFMS are to display critical plant variables related to the safety of the plant during normal and accident conditions and guide the operators corrective actions to keep the plant in a safe condition and mitigate the consequences of accidents. The minimal critical functions of the PGSFR are composed of reactivity control, reactor core cooling, reactor coolant system integrity, primary heat transfer system(PHTS) heat removal, sodium water reaction mitigation, radiation controlmore » and containment conditions. The variables and alarm legs of each critical function of the PGSFR are as follows; - Reactivity control: The variables of reactivity control function are power range neutron flux instrumentation, intermediate range neutron flux instrumentation, source range neutron flux instrumentation, and control rod bottom contacts. The alarm leg to display the reactivity controls consists of status of control drop malfunction, high post trip power and thermal reactivity addition. - Reactor core cooling: The variables are PHTS sodium level, hot pool temperature of PHTS, subassembly exit temperature, cold pool temperature of the PHTS, PHTS pump current, and PHTS pump breaker status. The alarm leg consists of high core delta temperature, low sodium level of the PHTS, high subassembly exit temperature, and low PHTS pump load. - Reactor coolant system integrity: The variables are PHTS sodium level, cover gas pressure, and safeguard vessel sodium level. The alarm leg is composed of low sodium level of PHTS, high cover gas pressure and high sodium level of the safety guard vessel. - PHTS heat removal: The variables are PHTS sodium level, hot pool temperature of PHTS, core exit temperature, cold pool temperature of the PHTS, flow rate of passive residual heat removal system, flow rate of active residual heat removal system, and temperatures of air heat exchanger temperature of residual heat removal systems. The alarm legs are composed of two legs of a 'passive residual heat removal system not cooling' and 'active residual heat removal system not cooling'. - Sodium water reaction mitigation: The variables are intermediate heat transfer system(IHTS) pressure, pressure and temperature and level of sodium dump tank, the status of rupture disk, hydrogen concentration in IHTS and direct variable of sodium-water-reaction measure. The alarm leg consists of high IHTS pressure, the status of sodium water reaction mitigation system and the indication of direct measure. - Radiation control: The variables are radiation of PHTS, radiation of IHTS, and radiation of containment purge. The alarm leg is composed of high radiation of PHTS and IHTS, and containment purge system. - Containment condition: The variables are containment pressure, containment isolation status, and sodium fire. The alarm leg consists of high containment pressure, status of containment isolation and status of sodium fire. (authors)« less

Modelling aqueous corrosion of nuclear waste phosphate glass

NASA Astrophysics Data System (ADS)

Poluektov, Pavel P.; Schmidt, Olga V.; Kascheev, Vladimir A.; Ojovan, Michael I.

2017-02-01

A model is presented on nuclear sodium alumina phosphate (NAP) glass aqueous corrosion accounting for dissolution of radioactive glass and formation of corrosion products surface layer on the glass contacting ground water of a disposal environment. Modelling is used to process available experimental data demonstrating the generic inhibiting role of corrosion products on the NAP glass surface.

Preparation and Characterization of Single Crystals and Epitaxial Layers of Silicon Carbide by Molten Salt Electrolysis.

DTIC Science & Technology

1980-10-01

requires the simultaneous cathodic deposi- tion of silicon and carbon under conditions where reaction to form SiC will occur. In this study sodium or...reactivity with the melt. Nickel suffers from the disadvantage that it reacts with silicon to form nickel silicides , but the concentration of silicides in

Understanding Ionic Bonding--A Scan across the Croatian Education System

ERIC Educational Resources Information Center

Vladušic, R.; Bucat, R. B.; Ožic, M.

2016-01-01

A study was conducted on the understandings of the accepted model of ionic substances that are held by participants at all levels of the chemical education system in Croatia, including secondary school students, university students, and chemistry teachers. We follow the research of Taber who found that a diagram of a layer of a sodium chloride…

Undergraduate Organic Experiment: Tetrazole Formation by Microwave Heated (3 + 2) Cycloaddition in Aqueous Solution

ERIC Educational Resources Information Center

DeFrancesco, Heather; Dudley, Joshua; Coca, Adiel

2018-01-01

An undergraduate experiment for the organic laboratory is described that utilizes microwave heating to prepare 5- substituted 1H-tetrazole derivatives through a (3 + 2) cycloaddition between aryl nitriles and sodium azide. The reaction mixture is analyzed by thin layer chromatography. The products are purified through an acid-base extraction and…

Multicolor Layer-by-Layer films using weak polyelectrolyte assisted synthesis of silver nanoparticles

NASA Astrophysics Data System (ADS)

Rivero, Pedro Jose; Goicoechea, Javier; Urrutia, Aitor; Matias, Ignacio Raul; Arregui, Francisco Javier

2013-10-01

In the present study, we show that silver nanoparticles (AgNPs) with different shape, aggregation state and color (violet, green, orange) have been successfully incorporated into polyelectrolyte multilayer thin films using the layer-by-layer (LbL) assembly. In order to obtain colored thin films based on AgNPs is necessary to maintain the aggregation state of the nanoparticles, a non-trivial aspect in which this work is focused on. The use of Poly(acrylic acid, sodium salt) (PAA) as a protective agent of the AgNPs is the key element to preserve the aggregation state and makes possible the presence of similar aggregates (shape and size) within the LbLcolored films. This approach based on electrostatic interactions of the polymeric chains and the immobilization of AgNPs with different shape and size into the thin films opens up a new interesting perspective to fabricate multicolornanocomposites based on AgNPs.

Designed drug-release systems having various breathable polyurethane film-backed hydrocolloid acrylated adhesive layers for moisture healing.

PubMed

Chang, Ching-Hsien; Liu, Hsia-Wei; Huang, Ching-Cheng

2014-01-01

A series of designed drug-release systems were prepared and established for clear moisture healing. These systems were designed to have an interpenetrating polymer network (IPN) structure, which contained a breathable polyurethane film, hydrocolloidlayer, and polyacrylate adhesive layer. Breathable polyurethane film (2000 g/m(2)/24 hr) with high moisture permeability was employed as a base for new drug-release systems or wound dressings. All drug-release systems having a polyurethane film-backed hydrocolloid acrylated adhesive layer showed an increase of water uptakes with increasing time. After 114 hours, high water uptakes of drug-release systems with 20% hydrocolloid components were observed in the values of 160, 1100, and 1870% for different additional hydrocolloid components of carboxymethylcellulose, sodium alginate, and carbomer U10, respectively. New drug-release systems of polyurethane film-backed hydrocolloid/adhesive layers could be designed and established for wound care managements.

Multicolor Layer-by-Layer films using weak polyelectrolyte assisted synthesis of silver nanoparticles

PubMed Central

2013-01-01

In the present study, we show that silver nanoparticles (AgNPs) with different shape, aggregation state and color (violet, green, orange) have been successfully incorporated into polyelectrolyte multilayer thin films using the layer-by-layer (LbL) assembly. In order to obtain colored thin films based on AgNPs is necessary to maintain the aggregation state of the nanoparticles, a non-trivial aspect in which this work is focused on. The use of Poly(acrylic acid, sodium salt) (PAA) as a protective agent of the AgNPs is the key element to preserve the aggregation state and makes possible the presence of similar aggregates (shape and size) within the LbLcolored films. This approach based on electrostatic interactions of the polymeric chains and the immobilization of AgNPs with different shape and size into the thin films opens up a new interesting perspective to fabricate multicolornanocomposites based on AgNPs. PMID:24148227

Electrical properties of multilayers from low- and high-molecular-weight polyelectrolytes.

PubMed

Radeva, Tsetska; Milkova, Viktoria; Petkanchin, Ivana

2004-11-15

The formation of stable multilayer films by using as constituents sodium poly(4-styrene sulfonate) (PSS) and poly(4-vinyl pyridine) (PVP) was studied by electrooptics. A strong increase in basicity of the pyridine rings in the electrical field of the oppositely charged PSS chains was suggested to be the driving force for multilayer film formation. A linear increase in the film thickness was registered after deposition of the first three layers, with no dependence on the polyelectrolyte molecular weight. The electrooptical effect was found to increase with increasing area of each next layer, but depended on the molecular weights of both polymers. Polarization of "condensed" counterions along the chains of the last-adsorbed layer was suggested to explain this dependence. Following the counterion dynamics, we come to the conclusion that the electrical properties of the top layer govern the electrooptical behavior of the PSS/PVP film.

Complexation of lysozyme with adsorbed PtBS-b-SCPI block polyelectrolyte micelles on silver surface.

PubMed

Papagiannopoulos, Aristeidis; Christoulaki, Anastasia; Spiliopoulos, Nikolaos; Vradis, Alexandros; Toprakcioglu, Chris; Pispas, Stergios

2015-01-20

We present a study of the interaction of the positively charged model protein lysozyme with the negatively charged amphiphilic diblock polyelectrolyte micelles of poly(tert-butylstyrene-b-sodium (sulfamate/carboxylate)isoprene) (PtBS-b-SCPI) on the silver/water interface. The adsorption kinetics are monitored by surface plasmon resonance, and the surface morphology is probed by atomic force microscopy. The micellar adsorption is described by stretched-exponential kinetics, and the micellar layer morphology shows that the micelles do not lose their integrity upon adsorption. The complexation of lysozyme with the adsorbed micellar layers depends on the micelles arrangement and density in the underlying layer, and lysozyme follows the local morphology of the underlying roughness. When the micellar adsorbed amount is small, the layers show low capacity in protein complexation and low resistance in loading. When the micellar adsorbed amount is high, the situation is reversed. The adsorbed layers both with or without added protein are found to be irreversibly adsorbed on the Ag surface.